2 * @brief Lightning memory-mapped database library
4 * A Btree-based database management library modeled loosely on the
5 * BerkeleyDB API, but much simplified.
8 * Copyright 2011-2015 Howard Chu, Symas Corp.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted only as authorized by the OpenLDAP
15 * A copy of this license is available in the file LICENSE in the
16 * top-level directory of the distribution or, alternatively, at
17 * <http://www.OpenLDAP.org/license.html>.
19 * This code is derived from btree.c written by Martin Hedenfalk.
21 * Copyright (c) 2009, 2010 Martin Hedenfalk <martin@bzero.se>
23 * Permission to use, copy, modify, and distribute this software for any
24 * purpose with or without fee is hereby granted, provided that the above
25 * copyright notice and this permission notice appear in all copies.
27 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
28 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
29 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
30 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
31 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
32 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
33 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
42 /* We use native NT APIs to setup the memory map, so that we can
43 * let the DB file grow incrementally instead of always preallocating
44 * the full size. These APIs are defined in <wdm.h> and <ntifs.h>
45 * but those headers are meant for driver-level development and
46 * conflict with the regular user-level headers, so we explicitly
47 * declare them here. Using these APIs also means we must link to
48 * ntdll.dll, which is not linked by default in user code.
51 NtCreateSection(OUT PHANDLE sh, IN ACCESS_MASK acc,
52 IN void * oa OPTIONAL,
53 IN PLARGE_INTEGER ms OPTIONAL,
54 IN ULONG pp, IN ULONG aa, IN HANDLE fh OPTIONAL);
56 typedef enum _SECTION_INHERIT {
62 NtMapViewOfSection(IN PHANDLE sh, IN HANDLE ph,
63 IN OUT PVOID *addr, IN ULONG_PTR zbits,
64 IN SIZE_T cs, IN OUT PLARGE_INTEGER off OPTIONAL,
65 IN OUT PSIZE_T vs, IN SECTION_INHERIT ih,
66 IN ULONG at, IN ULONG pp);
71 /** getpid() returns int; MinGW defines pid_t but MinGW64 typedefs it
72 * as int64 which is wrong. MSVC doesn't define it at all, so just
76 #define MDB_THR_T DWORD
77 #include <sys/types.h>
80 # include <sys/param.h>
82 # define LITTLE_ENDIAN 1234
83 # define BIG_ENDIAN 4321
84 # define BYTE_ORDER LITTLE_ENDIAN
86 # define SSIZE_MAX INT_MAX
90 #include <sys/types.h>
92 #define MDB_PID_T pid_t
93 #define MDB_THR_T pthread_t
94 #include <sys/param.h>
97 #ifdef HAVE_SYS_FILE_H
103 #if defined(__mips) && defined(__linux)
104 /* MIPS has cache coherency issues, requires explicit cache control */
105 #include <asm/cachectl.h>
106 extern int cacheflush(char *addr, int nbytes, int cache);
107 #define CACHEFLUSH(addr, bytes, cache) cacheflush(addr, bytes, cache)
109 #define CACHEFLUSH(addr, bytes, cache)
112 #if defined(__linux) && !defined(MDB_FDATASYNC_WORKS)
113 /** fdatasync is broken on ext3/ext4fs on older kernels, see
114 * description in #mdb_env_open2 comments. You can safely
115 * define MDB_FDATASYNC_WORKS if this code will only be run
116 * on kernels 3.6 and newer.
118 #define BROKEN_FDATASYNC
124 #include <inttypes.h>
132 typedef SSIZE_T ssize_t;
137 #if defined(__sun) || defined(ANDROID)
138 /* Most platforms have posix_memalign, older may only have memalign */
139 #define HAVE_MEMALIGN 1
143 #if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER))
144 #include <netinet/in.h>
145 #include <resolv.h> /* defines BYTE_ORDER on HPUX and Solaris */
148 #if defined(__APPLE__) || defined (BSD)
149 # if !(defined(MDB_USE_POSIX_MUTEX) || defined(MDB_USE_POSIX_SEM))
150 # define MDB_USE_SYSV_SEM 1
152 # define MDB_FDATASYNC fsync
153 #elif defined(ANDROID)
154 # define MDB_FDATASYNC fsync
159 #ifdef MDB_USE_POSIX_SEM
160 # define MDB_USE_HASH 1
161 #include <semaphore.h>
162 #elif defined(MDB_USE_SYSV_SEM)
165 #ifdef _SEM_SEMUN_UNDEFINED
168 struct semid_ds *buf;
169 unsigned short *array;
171 #endif /* _SEM_SEMUN_UNDEFINED */
173 #define MDB_USE_POSIX_MUTEX 1
174 #endif /* MDB_USE_POSIX_SEM */
177 #if defined(_WIN32) + defined(MDB_USE_POSIX_SEM) + defined(MDB_USE_SYSV_SEM) \
178 + defined(MDB_USE_POSIX_MUTEX) != 1
179 # error "Ambiguous shared-lock implementation"
183 #include <valgrind/memcheck.h>
184 #define VGMEMP_CREATE(h,r,z) VALGRIND_CREATE_MEMPOOL(h,r,z)
185 #define VGMEMP_ALLOC(h,a,s) VALGRIND_MEMPOOL_ALLOC(h,a,s)
186 #define VGMEMP_FREE(h,a) VALGRIND_MEMPOOL_FREE(h,a)
187 #define VGMEMP_DESTROY(h) VALGRIND_DESTROY_MEMPOOL(h)
188 #define VGMEMP_DEFINED(a,s) VALGRIND_MAKE_MEM_DEFINED(a,s)
190 #define VGMEMP_CREATE(h,r,z)
191 #define VGMEMP_ALLOC(h,a,s)
192 #define VGMEMP_FREE(h,a)
193 #define VGMEMP_DESTROY(h)
194 #define VGMEMP_DEFINED(a,s)
198 # if (defined(_LITTLE_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN))
199 /* Solaris just defines one or the other */
200 # define LITTLE_ENDIAN 1234
201 # define BIG_ENDIAN 4321
202 # ifdef _LITTLE_ENDIAN
203 # define BYTE_ORDER LITTLE_ENDIAN
205 # define BYTE_ORDER BIG_ENDIAN
208 # define BYTE_ORDER __BYTE_ORDER
212 #ifndef LITTLE_ENDIAN
213 #define LITTLE_ENDIAN __LITTLE_ENDIAN
216 #define BIG_ENDIAN __BIG_ENDIAN
219 #if defined(__i386) || defined(__x86_64) || defined(_M_IX86)
220 #define MISALIGNED_OK 1
226 #if (BYTE_ORDER == LITTLE_ENDIAN) == (BYTE_ORDER == BIG_ENDIAN)
227 # error "Unknown or unsupported endianness (BYTE_ORDER)"
228 #elif (-6 & 5) || CHAR_BIT != 8 || UINT_MAX < 0xffffffff || ULONG_MAX % 0xFFFF
229 # error "Two's complement, reasonably sized integer types, please"
233 /** Put infrequently used env functions in separate section */
235 # define ESECT __attribute__ ((section("__TEXT,text_env")))
237 # define ESECT __attribute__ ((section("text_env")))
244 #define CALL_CONV WINAPI
249 /** @defgroup internal LMDB Internals
252 /** @defgroup compat Compatibility Macros
253 * A bunch of macros to minimize the amount of platform-specific ifdefs
254 * needed throughout the rest of the code. When the features this library
255 * needs are similar enough to POSIX to be hidden in a one-or-two line
256 * replacement, this macro approach is used.
260 /** Features under development */
265 /** Wrapper around __func__, which is a C99 feature */
266 #if __STDC_VERSION__ >= 199901L
267 # define mdb_func_ __func__
268 #elif __GNUC__ >= 2 || _MSC_VER >= 1300
269 # define mdb_func_ __FUNCTION__
271 /* If a debug message says <mdb_unknown>(), update the #if statements above */
272 # define mdb_func_ "<mdb_unknown>"
275 /* Internal error codes, not exposed outside liblmdb */
276 #define MDB_NO_ROOT (MDB_LAST_ERRCODE + 10)
278 #define MDB_OWNERDEAD ((int) WAIT_ABANDONED)
279 #elif defined MDB_USE_SYSV_SEM
280 #define MDB_OWNERDEAD (MDB_LAST_ERRCODE + 11)
281 #elif defined(MDB_USE_POSIX_MUTEX) && defined(EOWNERDEAD)
282 #define MDB_OWNERDEAD EOWNERDEAD /**< #LOCK_MUTEX0() result if dead owner */
286 #define GLIBC_VER ((__GLIBC__ << 16 )| __GLIBC_MINOR__)
288 /** Some platforms define the EOWNERDEAD error code
289 * even though they don't support Robust Mutexes.
290 * Compile with -DMDB_USE_ROBUST=0, or use some other
291 * mechanism like -DMDB_USE_SYSV_SEM instead of
292 * -DMDB_USE_POSIX_MUTEX. (SysV semaphores are
293 * also Robust, but some systems don't support them
296 #ifndef MDB_USE_ROBUST
297 /* Android currently lacks Robust Mutex support. So does glibc < 2.4. */
298 # if defined(MDB_USE_POSIX_MUTEX) && (defined(ANDROID) || \
299 (defined(__GLIBC__) && GLIBC_VER < 0x020004))
300 # define MDB_USE_ROBUST 0
302 # define MDB_USE_ROBUST 1
303 /* glibc < 2.12 only provided _np API */
304 # if defined(__GLIBC__) && GLIBC_VER < 0x02000c
305 # define PTHREAD_MUTEX_ROBUST PTHREAD_MUTEX_ROBUST_NP
306 # define pthread_mutexattr_setrobust(attr, flag) pthread_mutexattr_setrobust_np(attr, flag)
307 # define pthread_mutex_consistent(mutex) pthread_mutex_consistent_np(mutex)
310 #endif /* MDB_USE_ROBUST */
312 #if defined(MDB_OWNERDEAD) && MDB_USE_ROBUST
313 #define MDB_ROBUST_SUPPORTED 1
317 #define MDB_USE_HASH 1
318 #define MDB_PIDLOCK 0
319 #define THREAD_RET DWORD
320 #define pthread_t HANDLE
321 #define pthread_mutex_t HANDLE
322 #define pthread_cond_t HANDLE
323 typedef HANDLE mdb_mutex_t, mdb_mutexref_t;
324 #define pthread_key_t DWORD
325 #define pthread_self() GetCurrentThreadId()
326 #define pthread_key_create(x,y) \
327 ((*(x) = TlsAlloc()) == TLS_OUT_OF_INDEXES ? ErrCode() : 0)
328 #define pthread_key_delete(x) TlsFree(x)
329 #define pthread_getspecific(x) TlsGetValue(x)
330 #define pthread_setspecific(x,y) (TlsSetValue(x,y) ? 0 : ErrCode())
331 #define pthread_mutex_unlock(x) ReleaseMutex(*x)
332 #define pthread_mutex_lock(x) WaitForSingleObject(*x, INFINITE)
333 #define pthread_cond_signal(x) SetEvent(*x)
334 #define pthread_cond_wait(cond,mutex) do{SignalObjectAndWait(*mutex, *cond, INFINITE, FALSE); WaitForSingleObject(*mutex, INFINITE);}while(0)
335 #define THREAD_CREATE(thr,start,arg) thr=CreateThread(NULL,0,start,arg,0,NULL)
336 #define THREAD_FINISH(thr) WaitForSingleObject(thr, INFINITE)
337 #define LOCK_MUTEX0(mutex) WaitForSingleObject(mutex, INFINITE)
338 #define UNLOCK_MUTEX(mutex) ReleaseMutex(mutex)
339 #define mdb_mutex_consistent(mutex) 0
340 #define getpid() GetCurrentProcessId()
341 #define MDB_FDATASYNC(fd) (!FlushFileBuffers(fd))
342 #define MDB_MSYNC(addr,len,flags) (!FlushViewOfFile(addr,len))
343 #define ErrCode() GetLastError()
344 #define GET_PAGESIZE(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;}
345 #define close(fd) (CloseHandle(fd) ? 0 : -1)
346 #define munmap(ptr,len) UnmapViewOfFile(ptr)
347 #ifdef PROCESS_QUERY_LIMITED_INFORMATION
348 #define MDB_PROCESS_QUERY_LIMITED_INFORMATION PROCESS_QUERY_LIMITED_INFORMATION
350 #define MDB_PROCESS_QUERY_LIMITED_INFORMATION 0x1000
354 #define THREAD_RET void *
355 #define THREAD_CREATE(thr,start,arg) pthread_create(&thr,NULL,start,arg)
356 #define THREAD_FINISH(thr) pthread_join(thr,NULL)
357 #define Z "z" /**< printf format modifier for size_t */
359 /** For MDB_LOCK_FORMAT: True if readers take a pid lock in the lockfile */
360 #define MDB_PIDLOCK 1
362 #ifdef MDB_USE_POSIX_SEM
364 typedef sem_t *mdb_mutex_t, *mdb_mutexref_t;
365 #define LOCK_MUTEX0(mutex) mdb_sem_wait(mutex)
366 #define UNLOCK_MUTEX(mutex) sem_post(mutex)
369 mdb_sem_wait(sem_t *sem)
372 while ((rc = sem_wait(sem)) && (rc = errno) == EINTR) ;
376 #elif defined MDB_USE_SYSV_SEM
378 typedef struct mdb_mutex {
382 } mdb_mutex_t[1], *mdb_mutexref_t;
384 #define LOCK_MUTEX0(mutex) mdb_sem_wait(mutex)
385 #define UNLOCK_MUTEX(mutex) do { \
386 struct sembuf sb = { 0, 1, SEM_UNDO }; \
387 sb.sem_num = (mutex)->semnum; \
388 *(mutex)->locked = 0; \
389 semop((mutex)->semid, &sb, 1); \
393 mdb_sem_wait(mdb_mutexref_t sem)
395 int rc, *locked = sem->locked;
396 struct sembuf sb = { 0, -1, SEM_UNDO };
397 sb.sem_num = sem->semnum;
399 if (!semop(sem->semid, &sb, 1)) {
400 rc = *locked ? MDB_OWNERDEAD : MDB_SUCCESS;
404 } while ((rc = errno) == EINTR);
408 #define mdb_mutex_consistent(mutex) 0
410 #else /* MDB_USE_POSIX_MUTEX: */
411 /** Shared mutex/semaphore as it is stored (mdb_mutex_t), and as
412 * local variables keep it (mdb_mutexref_t).
414 * An mdb_mutex_t can be assigned to an mdb_mutexref_t. They can
415 * be the same, or an array[size 1] and a pointer.
418 typedef pthread_mutex_t mdb_mutex_t[1], *mdb_mutexref_t;
420 /** Lock the reader or writer mutex.
421 * Returns 0 or a code to give #mdb_mutex_failed(), as in #LOCK_MUTEX().
423 #define LOCK_MUTEX0(mutex) pthread_mutex_lock(mutex)
424 /** Unlock the reader or writer mutex.
426 #define UNLOCK_MUTEX(mutex) pthread_mutex_unlock(mutex)
427 /** Mark mutex-protected data as repaired, after death of previous owner.
429 #define mdb_mutex_consistent(mutex) pthread_mutex_consistent(mutex)
430 #endif /* MDB_USE_POSIX_SEM || MDB_USE_SYSV_SEM */
432 /** Get the error code for the last failed system function.
434 #define ErrCode() errno
436 /** An abstraction for a file handle.
437 * On POSIX systems file handles are small integers. On Windows
438 * they're opaque pointers.
442 /** A value for an invalid file handle.
443 * Mainly used to initialize file variables and signify that they are
446 #define INVALID_HANDLE_VALUE (-1)
448 /** Get the size of a memory page for the system.
449 * This is the basic size that the platform's memory manager uses, and is
450 * fundamental to the use of memory-mapped files.
452 #define GET_PAGESIZE(x) ((x) = sysconf(_SC_PAGE_SIZE))
455 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
457 #elif defined(MDB_USE_SYSV_SEM)
458 #define MNAME_LEN (sizeof(int))
460 #define MNAME_LEN (sizeof(pthread_mutex_t))
463 #ifdef MDB_USE_SYSV_SEM
464 #define SYSV_SEM_FLAG 1 /**< SysV sems in lockfile format */
466 #define SYSV_SEM_FLAG 0
471 #ifdef MDB_ROBUST_SUPPORTED
472 /** Lock mutex, handle any error, set rc = result.
473 * Return 0 on success, nonzero (not rc) on error.
475 #define LOCK_MUTEX(rc, env, mutex) \
476 (((rc) = LOCK_MUTEX0(mutex)) && \
477 ((rc) = mdb_mutex_failed(env, mutex, rc)))
478 static int mdb_mutex_failed(MDB_env *env, mdb_mutexref_t mutex, int rc);
480 #define LOCK_MUTEX(rc, env, mutex) ((rc) = LOCK_MUTEX0(mutex))
481 #define mdb_mutex_failed(env, mutex, rc) (rc)
485 /** A flag for opening a file and requesting synchronous data writes.
486 * This is only used when writing a meta page. It's not strictly needed;
487 * we could just do a normal write and then immediately perform a flush.
488 * But if this flag is available it saves us an extra system call.
490 * @note If O_DSYNC is undefined but exists in /usr/include,
491 * preferably set some compiler flag to get the definition.
495 # define MDB_DSYNC O_DSYNC
497 # define MDB_DSYNC O_SYNC
502 /** Function for flushing the data of a file. Define this to fsync
503 * if fdatasync() is not supported.
505 #ifndef MDB_FDATASYNC
506 # define MDB_FDATASYNC fdatasync
510 # define MDB_MSYNC(addr,len,flags) msync(addr,len,flags)
521 /** A page number in the database.
522 * Note that 64 bit page numbers are overkill, since pages themselves
523 * already represent 12-13 bits of addressable memory, and the OS will
524 * always limit applications to a maximum of 63 bits of address space.
526 * @note In the #MDB_node structure, we only store 48 bits of this value,
527 * which thus limits us to only 60 bits of addressable data.
529 typedef MDB_ID pgno_t;
531 /** A transaction ID.
532 * See struct MDB_txn.mt_txnid for details.
534 typedef MDB_ID txnid_t;
536 /** @defgroup debug Debug Macros
540 /** Enable debug output. Needs variable argument macros (a C99 feature).
541 * Set this to 1 for copious tracing. Set to 2 to add dumps of all IDLs
542 * read from and written to the database (used for free space management).
548 static int mdb_debug;
549 static txnid_t mdb_debug_start;
551 /** Print a debug message with printf formatting.
552 * Requires double parenthesis around 2 or more args.
554 # define DPRINTF(args) ((void) ((mdb_debug) && DPRINTF0 args))
555 # define DPRINTF0(fmt, ...) \
556 fprintf(stderr, "%s:%d " fmt "\n", mdb_func_, __LINE__, __VA_ARGS__)
558 # define DPRINTF(args) ((void) 0)
560 /** Print a debug string.
561 * The string is printed literally, with no format processing.
563 #define DPUTS(arg) DPRINTF(("%s", arg))
564 /** Debuging output value of a cursor DBI: Negative in a sub-cursor. */
566 (((mc)->mc_flags & C_SUB) ? -(int)(mc)->mc_dbi : (int)(mc)->mc_dbi)
569 /** @brief The maximum size of a database page.
571 * It is 32k or 64k, since value-PAGEBASE must fit in
572 * #MDB_page.%mp_upper.
574 * LMDB will use database pages < OS pages if needed.
575 * That causes more I/O in write transactions: The OS must
576 * know (read) the whole page before writing a partial page.
578 * Note that we don't currently support Huge pages. On Linux,
579 * regular data files cannot use Huge pages, and in general
580 * Huge pages aren't actually pageable. We rely on the OS
581 * demand-pager to read our data and page it out when memory
582 * pressure from other processes is high. So until OSs have
583 * actual paging support for Huge pages, they're not viable.
585 #define MAX_PAGESIZE (PAGEBASE ? 0x10000 : 0x8000)
587 /** The minimum number of keys required in a database page.
588 * Setting this to a larger value will place a smaller bound on the
589 * maximum size of a data item. Data items larger than this size will
590 * be pushed into overflow pages instead of being stored directly in
591 * the B-tree node. This value used to default to 4. With a page size
592 * of 4096 bytes that meant that any item larger than 1024 bytes would
593 * go into an overflow page. That also meant that on average 2-3KB of
594 * each overflow page was wasted space. The value cannot be lower than
595 * 2 because then there would no longer be a tree structure. With this
596 * value, items larger than 2KB will go into overflow pages, and on
597 * average only 1KB will be wasted.
599 #define MDB_MINKEYS 2
601 /** A stamp that identifies a file as an LMDB file.
602 * There's nothing special about this value other than that it is easily
603 * recognizable, and it will reflect any byte order mismatches.
605 #define MDB_MAGIC 0xBEEFC0DE
607 /** The version number for a database's datafile format. */
608 #define MDB_DATA_VERSION ((MDB_DEVEL) ? 999 : 1)
609 /** The version number for a database's lockfile format. */
610 #define MDB_LOCK_VERSION ((MDB_DEVEL) ? 999 : 1)
612 /** @brief The max size of a key we can write, or 0 for computed max.
614 * This macro should normally be left alone or set to 0.
615 * Note that a database with big keys or dupsort data cannot be
616 * reliably modified by a liblmdb which uses a smaller max.
617 * The default is 511 for backwards compat, or 0 when #MDB_DEVEL.
619 * Other values are allowed, for backwards compat. However:
620 * A value bigger than the computed max can break if you do not
621 * know what you are doing, and liblmdb <= 0.9.10 can break when
622 * modifying a DB with keys/dupsort data bigger than its max.
624 * Data items in an #MDB_DUPSORT database are also limited to
625 * this size, since they're actually keys of a sub-DB. Keys and
626 * #MDB_DUPSORT data items must fit on a node in a regular page.
628 #ifndef MDB_MAXKEYSIZE
629 #define MDB_MAXKEYSIZE ((MDB_DEVEL) ? 0 : 511)
632 /** The maximum size of a key we can write to the environment. */
634 #define ENV_MAXKEY(env) (MDB_MAXKEYSIZE)
636 #define ENV_MAXKEY(env) ((env)->me_maxkey)
639 /** @brief The maximum size of a data item.
641 * We only store a 32 bit value for node sizes.
643 #define MAXDATASIZE 0xffffffffUL
646 /** Key size which fits in a #DKBUF.
649 #define DKBUF_MAXKEYSIZE ((MDB_MAXKEYSIZE) > 0 ? (MDB_MAXKEYSIZE) : 511)
652 * This is used for printing a hex dump of a key's contents.
654 #define DKBUF char kbuf[DKBUF_MAXKEYSIZE*2+1]
655 /** Display a key in hex.
657 * Invoke a function to display a key in hex.
659 #define DKEY(x) mdb_dkey(x, kbuf)
665 /** An invalid page number.
666 * Mainly used to denote an empty tree.
668 #define P_INVALID (~(pgno_t)0)
670 /** Test if the flags \b f are set in a flag word \b w. */
671 #define F_ISSET(w, f) (((w) & (f)) == (f))
673 /** Round \b n up to an even number. */
674 #define EVEN(n) (((n) + 1U) & -2) /* sign-extending -2 to match n+1U */
676 /** Used for offsets within a single page.
677 * Since memory pages are typically 4 or 8KB in size, 12-13 bits,
680 typedef uint16_t indx_t;
682 /** Default size of memory map.
683 * This is certainly too small for any actual applications. Apps should always set
684 * the size explicitly using #mdb_env_set_mapsize().
686 #define DEFAULT_MAPSIZE 1048576
688 /** @defgroup readers Reader Lock Table
689 * Readers don't acquire any locks for their data access. Instead, they
690 * simply record their transaction ID in the reader table. The reader
691 * mutex is needed just to find an empty slot in the reader table. The
692 * slot's address is saved in thread-specific data so that subsequent read
693 * transactions started by the same thread need no further locking to proceed.
695 * If #MDB_NOTLS is set, the slot address is not saved in thread-specific data.
697 * No reader table is used if the database is on a read-only filesystem, or
698 * if #MDB_NOLOCK is set.
700 * Since the database uses multi-version concurrency control, readers don't
701 * actually need any locking. This table is used to keep track of which
702 * readers are using data from which old transactions, so that we'll know
703 * when a particular old transaction is no longer in use. Old transactions
704 * that have discarded any data pages can then have those pages reclaimed
705 * for use by a later write transaction.
707 * The lock table is constructed such that reader slots are aligned with the
708 * processor's cache line size. Any slot is only ever used by one thread.
709 * This alignment guarantees that there will be no contention or cache
710 * thrashing as threads update their own slot info, and also eliminates
711 * any need for locking when accessing a slot.
713 * A writer thread will scan every slot in the table to determine the oldest
714 * outstanding reader transaction. Any freed pages older than this will be
715 * reclaimed by the writer. The writer doesn't use any locks when scanning
716 * this table. This means that there's no guarantee that the writer will
717 * see the most up-to-date reader info, but that's not required for correct
718 * operation - all we need is to know the upper bound on the oldest reader,
719 * we don't care at all about the newest reader. So the only consequence of
720 * reading stale information here is that old pages might hang around a
721 * while longer before being reclaimed. That's actually good anyway, because
722 * the longer we delay reclaiming old pages, the more likely it is that a
723 * string of contiguous pages can be found after coalescing old pages from
724 * many old transactions together.
727 /** Number of slots in the reader table.
728 * This value was chosen somewhat arbitrarily. 126 readers plus a
729 * couple mutexes fit exactly into 8KB on my development machine.
730 * Applications should set the table size using #mdb_env_set_maxreaders().
732 #define DEFAULT_READERS 126
734 /** The size of a CPU cache line in bytes. We want our lock structures
735 * aligned to this size to avoid false cache line sharing in the
737 * This value works for most CPUs. For Itanium this should be 128.
743 /** The information we store in a single slot of the reader table.
744 * In addition to a transaction ID, we also record the process and
745 * thread ID that owns a slot, so that we can detect stale information,
746 * e.g. threads or processes that went away without cleaning up.
747 * @note We currently don't check for stale records. We simply re-init
748 * the table when we know that we're the only process opening the
751 typedef struct MDB_rxbody {
752 /** Current Transaction ID when this transaction began, or (txnid_t)-1.
753 * Multiple readers that start at the same time will probably have the
754 * same ID here. Again, it's not important to exclude them from
755 * anything; all we need to know is which version of the DB they
756 * started from so we can avoid overwriting any data used in that
757 * particular version.
759 volatile txnid_t mrb_txnid;
760 /** The process ID of the process owning this reader txn. */
761 volatile MDB_PID_T mrb_pid;
762 /** The thread ID of the thread owning this txn. */
763 volatile MDB_THR_T mrb_tid;
766 /** The actual reader record, with cacheline padding. */
767 typedef struct MDB_reader {
770 /** shorthand for mrb_txnid */
771 #define mr_txnid mru.mrx.mrb_txnid
772 #define mr_pid mru.mrx.mrb_pid
773 #define mr_tid mru.mrx.mrb_tid
774 /** cache line alignment */
775 char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)];
779 /** The header for the reader table.
780 * The table resides in a memory-mapped file. (This is a different file
781 * than is used for the main database.)
783 * For POSIX the actual mutexes reside in the shared memory of this
784 * mapped file. On Windows, mutexes are named objects allocated by the
785 * kernel; we store the mutex names in this mapped file so that other
786 * processes can grab them. This same approach is also used on
787 * MacOSX/Darwin (using named semaphores) since MacOSX doesn't support
788 * process-shared POSIX mutexes. For these cases where a named object
789 * is used, the object name is derived from a 64 bit FNV hash of the
790 * environment pathname. As such, naming collisions are extremely
791 * unlikely. If a collision occurs, the results are unpredictable.
793 typedef struct MDB_txbody {
794 /** Stamp identifying this as an LMDB file. It must be set
797 /** Format of this lock file. Must be set to #MDB_LOCK_FORMAT. */
799 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
800 char mtb_rmname[MNAME_LEN];
801 #elif defined(MDB_USE_SYSV_SEM)
805 /** Mutex protecting access to this table.
806 * This is the reader table lock used with LOCK_MUTEX().
808 mdb_mutex_t mtb_rmutex;
810 /** The ID of the last transaction committed to the database.
811 * This is recorded here only for convenience; the value can always
812 * be determined by reading the main database meta pages.
814 volatile txnid_t mtb_txnid;
815 /** The number of slots that have been used in the reader table.
816 * This always records the maximum count, it is not decremented
817 * when readers release their slots.
819 volatile unsigned mtb_numreaders;
822 /** The actual reader table definition. */
823 typedef struct MDB_txninfo {
826 #define mti_magic mt1.mtb.mtb_magic
827 #define mti_format mt1.mtb.mtb_format
828 #define mti_rmutex mt1.mtb.mtb_rmutex
829 #define mti_rmname mt1.mtb.mtb_rmname
830 #define mti_txnid mt1.mtb.mtb_txnid
831 #define mti_numreaders mt1.mtb.mtb_numreaders
832 #ifdef MDB_USE_SYSV_SEM
833 #define mti_semid mt1.mtb.mtb_semid
834 #define mti_rlocked mt1.mtb.mtb_rlocked
836 char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];
839 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
840 char mt2_wmname[MNAME_LEN];
841 #define mti_wmname mt2.mt2_wmname
842 #elif defined MDB_USE_SYSV_SEM
844 #define mti_wlocked mt2.mt2_wlocked
846 mdb_mutex_t mt2_wmutex;
847 #define mti_wmutex mt2.mt2_wmutex
849 char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)];
851 MDB_reader mti_readers[1];
854 /** Lockfile format signature: version, features and field layout */
855 #define MDB_LOCK_FORMAT \
857 ((MDB_LOCK_VERSION) \
858 /* Flags which describe functionality */ \
859 + (SYSV_SEM_FLAG << 18) \
860 + (((MDB_PIDLOCK) != 0) << 16)))
863 /** Common header for all page types.
864 * Overflow records occupy a number of contiguous pages with no
865 * headers on any page after the first.
867 typedef struct MDB_page {
868 #define mp_pgno mp_p.p_pgno
869 #define mp_next mp_p.p_next
871 pgno_t p_pgno; /**< page number */
872 struct MDB_page *p_next; /**< for in-memory list of freed pages */
875 /** @defgroup mdb_page Page Flags
877 * Flags for the page headers.
880 #define P_BRANCH 0x01 /**< branch page */
881 #define P_LEAF 0x02 /**< leaf page */
882 #define P_OVERFLOW 0x04 /**< overflow page */
883 #define P_META 0x08 /**< meta page */
884 #define P_DIRTY 0x10 /**< dirty page, also set for #P_SUBP pages */
885 #define P_LEAF2 0x20 /**< for #MDB_DUPFIXED records */
886 #define P_SUBP 0x40 /**< for #MDB_DUPSORT sub-pages */
887 #define P_LOOSE 0x4000 /**< page was dirtied then freed, can be reused */
888 #define P_KEEP 0x8000 /**< leave this page alone during spill */
890 uint16_t mp_flags; /**< @ref mdb_page */
891 #define mp_lower mp_pb.pb.pb_lower
892 #define mp_upper mp_pb.pb.pb_upper
893 #define mp_pages mp_pb.pb_pages
896 indx_t pb_lower; /**< lower bound of free space */
897 indx_t pb_upper; /**< upper bound of free space */
899 uint32_t pb_pages; /**< number of overflow pages */
901 indx_t mp_ptrs[1]; /**< dynamic size */
904 /** Size of the page header, excluding dynamic data at the end */
905 #define PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs))
907 /** Address of first usable data byte in a page, after the header */
908 #define METADATA(p) ((void *)((char *)(p) + PAGEHDRSZ))
910 /** ITS#7713, change PAGEBASE to handle 65536 byte pages */
911 #define PAGEBASE ((MDB_DEVEL) ? PAGEHDRSZ : 0)
913 /** Number of nodes on a page */
914 #define NUMKEYS(p) (((p)->mp_lower - (PAGEHDRSZ-PAGEBASE)) >> 1)
916 /** The amount of space remaining in the page */
917 #define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower)
919 /** The percentage of space used in the page, in tenths of a percent. */
920 #define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \
921 ((env)->me_psize - PAGEHDRSZ))
922 /** The minimum page fill factor, in tenths of a percent.
923 * Pages emptier than this are candidates for merging.
925 #define FILL_THRESHOLD 250
927 /** Test if a page is a leaf page */
928 #define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF)
929 /** Test if a page is a LEAF2 page */
930 #define IS_LEAF2(p) F_ISSET((p)->mp_flags, P_LEAF2)
931 /** Test if a page is a branch page */
932 #define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH)
933 /** Test if a page is an overflow page */
934 #define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW)
935 /** Test if a page is a sub page */
936 #define IS_SUBP(p) F_ISSET((p)->mp_flags, P_SUBP)
938 /** The number of overflow pages needed to store the given size. */
939 #define OVPAGES(size, psize) ((PAGEHDRSZ-1 + (size)) / (psize) + 1)
941 /** Link in #MDB_txn.%mt_loose_pgs list */
942 #define NEXT_LOOSE_PAGE(p) (*(MDB_page **)((p) + 2))
944 /** Header for a single key/data pair within a page.
945 * Used in pages of type #P_BRANCH and #P_LEAF without #P_LEAF2.
946 * We guarantee 2-byte alignment for 'MDB_node's.
948 typedef struct MDB_node {
949 /** lo and hi are used for data size on leaf nodes and for
950 * child pgno on branch nodes. On 64 bit platforms, flags
951 * is also used for pgno. (Branch nodes have no flags).
952 * They are in host byte order in case that lets some
953 * accesses be optimized into a 32-bit word access.
955 #if BYTE_ORDER == LITTLE_ENDIAN
956 unsigned short mn_lo, mn_hi; /**< part of data size or pgno */
958 unsigned short mn_hi, mn_lo;
960 /** @defgroup mdb_node Node Flags
962 * Flags for node headers.
965 #define F_BIGDATA 0x01 /**< data put on overflow page */
966 #define F_SUBDATA 0x02 /**< data is a sub-database */
967 #define F_DUPDATA 0x04 /**< data has duplicates */
969 /** valid flags for #mdb_node_add() */
970 #define NODE_ADD_FLAGS (F_DUPDATA|F_SUBDATA|MDB_RESERVE|MDB_APPEND)
973 unsigned short mn_flags; /**< @ref mdb_node */
974 unsigned short mn_ksize; /**< key size */
975 char mn_data[1]; /**< key and data are appended here */
978 /** Size of the node header, excluding dynamic data at the end */
979 #define NODESIZE offsetof(MDB_node, mn_data)
981 /** Bit position of top word in page number, for shifting mn_flags */
982 #define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0)
984 /** Size of a node in a branch page with a given key.
985 * This is just the node header plus the key, there is no data.
987 #define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))
989 /** Size of a node in a leaf page with a given key and data.
990 * This is node header plus key plus data size.
992 #define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size)
994 /** Address of node \b i in page \b p */
995 #define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i] + PAGEBASE))
997 /** Address of the key for the node */
998 #define NODEKEY(node) (void *)((node)->mn_data)
1000 /** Address of the data for a node */
1001 #define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize)
1003 /** Get the page number pointed to by a branch node */
1004 #define NODEPGNO(node) \
1005 ((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | \
1006 (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0))
1007 /** Set the page number in a branch node */
1008 #define SETPGNO(node,pgno) do { \
1009 (node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \
1010 if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0)
1012 /** Get the size of the data in a leaf node */
1013 #define NODEDSZ(node) ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16))
1014 /** Set the size of the data for a leaf node */
1015 #define SETDSZ(node,size) do { \
1016 (node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)
1017 /** The size of a key in a node */
1018 #define NODEKSZ(node) ((node)->mn_ksize)
1020 /** Copy a page number from src to dst */
1021 #ifdef MISALIGNED_OK
1022 #define COPY_PGNO(dst,src) dst = src
1024 #if SIZE_MAX > 4294967295UL
1025 #define COPY_PGNO(dst,src) do { \
1026 unsigned short *s, *d; \
1027 s = (unsigned short *)&(src); \
1028 d = (unsigned short *)&(dst); \
1035 #define COPY_PGNO(dst,src) do { \
1036 unsigned short *s, *d; \
1037 s = (unsigned short *)&(src); \
1038 d = (unsigned short *)&(dst); \
1044 /** The address of a key in a LEAF2 page.
1045 * LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate sub-DBs.
1046 * There are no node headers, keys are stored contiguously.
1048 #define LEAF2KEY(p, i, ks) ((char *)(p) + PAGEHDRSZ + ((i)*(ks)))
1050 /** Set the \b node's key into \b keyptr, if requested. */
1051 #define MDB_GET_KEY(node, keyptr) { if ((keyptr) != NULL) { \
1052 (keyptr)->mv_size = NODEKSZ(node); (keyptr)->mv_data = NODEKEY(node); } }
1054 /** Set the \b node's key into \b key. */
1055 #define MDB_GET_KEY2(node, key) { key.mv_size = NODEKSZ(node); key.mv_data = NODEKEY(node); }
1057 /** Information about a single database in the environment. */
1058 typedef struct MDB_db {
1059 uint32_t md_pad; /**< also ksize for LEAF2 pages */
1060 uint16_t md_flags; /**< @ref mdb_dbi_open */
1061 uint16_t md_depth; /**< depth of this tree */
1062 pgno_t md_branch_pages; /**< number of internal pages */
1063 pgno_t md_leaf_pages; /**< number of leaf pages */
1064 pgno_t md_overflow_pages; /**< number of overflow pages */
1065 size_t md_entries; /**< number of data items */
1066 pgno_t md_root; /**< the root page of this tree */
1069 /** mdb_dbi_open flags */
1070 #define MDB_VALID 0x8000 /**< DB handle is valid, for me_dbflags */
1071 #define PERSISTENT_FLAGS (0xffff & ~(MDB_VALID))
1072 #define VALID_FLAGS (MDB_REVERSEKEY|MDB_DUPSORT|MDB_INTEGERKEY|MDB_DUPFIXED|\
1073 MDB_INTEGERDUP|MDB_REVERSEDUP|MDB_CREATE)
1075 /** Handle for the DB used to track free pages. */
1077 /** Handle for the default DB. */
1079 /** Number of DBs in metapage (free and main) - also hardcoded elsewhere */
1082 /** Number of meta pages - also hardcoded elsewhere */
1085 /** Meta page content.
1086 * A meta page is the start point for accessing a database snapshot.
1087 * Pages 0-1 are meta pages. Transaction N writes meta page #(N % 2).
1089 typedef struct MDB_meta {
1090 /** Stamp identifying this as an LMDB file. It must be set
1093 /** Version number of this file. Must be set to #MDB_DATA_VERSION. */
1094 uint32_t mm_version;
1095 void *mm_address; /**< address for fixed mapping */
1096 size_t mm_mapsize; /**< size of mmap region */
1097 MDB_db mm_dbs[CORE_DBS]; /**< first is free space, 2nd is main db */
1098 /** The size of pages used in this DB */
1099 #define mm_psize mm_dbs[FREE_DBI].md_pad
1100 /** Any persistent environment flags. @ref mdb_env */
1101 #define mm_flags mm_dbs[FREE_DBI].md_flags
1102 pgno_t mm_last_pg; /**< last used page in file */
1103 volatile txnid_t mm_txnid; /**< txnid that committed this page */
1106 /** Buffer for a stack-allocated meta page.
1107 * The members define size and alignment, and silence type
1108 * aliasing warnings. They are not used directly; that could
1109 * mean incorrectly using several union members in parallel.
1111 typedef union MDB_metabuf {
1114 char mm_pad[PAGEHDRSZ];
1119 /** Auxiliary DB info.
1120 * The information here is mostly static/read-only. There is
1121 * only a single copy of this record in the environment.
1123 typedef struct MDB_dbx {
1124 MDB_val md_name; /**< name of the database */
1125 MDB_cmp_func *md_cmp; /**< function for comparing keys */
1126 MDB_cmp_func *md_dcmp; /**< function for comparing data items */
1127 MDB_rel_func *md_rel; /**< user relocate function */
1128 void *md_relctx; /**< user-provided context for md_rel */
1131 /** A database transaction.
1132 * Every operation requires a transaction handle.
1135 MDB_txn *mt_parent; /**< parent of a nested txn */
1136 /** Nested txn under this txn, set together with flag #MDB_TXN_HAS_CHILD */
1138 pgno_t mt_next_pgno; /**< next unallocated page */
1139 /** The ID of this transaction. IDs are integers incrementing from 1.
1140 * Only committed write transactions increment the ID. If a transaction
1141 * aborts, the ID may be re-used by the next writer.
1144 MDB_env *mt_env; /**< the DB environment */
1145 /** The list of pages that became unused during this transaction.
1147 MDB_IDL mt_free_pgs;
1148 /** The list of loose pages that became unused and may be reused
1149 * in this transaction, linked through #NEXT_LOOSE_PAGE(page).
1151 MDB_page *mt_loose_pgs;
1152 /* #Number of loose pages (#mt_loose_pgs) */
1154 /** The sorted list of dirty pages we temporarily wrote to disk
1155 * because the dirty list was full. page numbers in here are
1156 * shifted left by 1, deleted slots have the LSB set.
1158 MDB_IDL mt_spill_pgs;
1160 /** For write txns: Modified pages. Sorted when not MDB_WRITEMAP. */
1161 MDB_ID2L dirty_list;
1162 /** For read txns: This thread/txn's reader table slot, or NULL. */
1165 /** Array of records for each DB known in the environment. */
1167 /** Array of MDB_db records for each known DB */
1169 /** Array of sequence numbers for each DB handle */
1170 unsigned int *mt_dbiseqs;
1171 /** @defgroup mt_dbflag Transaction DB Flags
1175 #define DB_DIRTY 0x01 /**< DB was modified or is DUPSORT data */
1176 #define DB_STALE 0x02 /**< Named-DB record is older than txnID */
1177 #define DB_NEW 0x04 /**< Named-DB handle opened in this txn */
1178 #define DB_VALID 0x08 /**< DB handle is valid, see also #MDB_VALID */
1179 #define DB_USRVALID 0x10 /**< As #DB_VALID, but not set for #FREE_DBI */
1181 /** In write txns, array of cursors for each DB */
1182 MDB_cursor **mt_cursors;
1183 /** Array of flags for each DB */
1184 unsigned char *mt_dbflags;
1185 /** Number of DB records in use, or 0 when the txn is finished.
1186 * This number only ever increments until the txn finishes; we
1187 * don't decrement it when individual DB handles are closed.
1191 /** @defgroup mdb_txn Transaction Flags
1195 /** #mdb_txn_begin() flags */
1196 #define MDB_TXN_BEGIN_FLAGS (MDB_NOMETASYNC|MDB_NOSYNC|MDB_RDONLY)
1197 #define MDB_TXN_NOMETASYNC MDB_NOMETASYNC /**< don't sync meta for this txn on commit */
1198 #define MDB_TXN_NOSYNC MDB_NOSYNC /**< don't sync this txn on commit */
1199 #define MDB_TXN_RDONLY MDB_RDONLY /**< read-only transaction */
1200 /* internal txn flags */
1201 #define MDB_TXN_WRITEMAP MDB_WRITEMAP /**< copy of #MDB_env flag in writers */
1202 #define MDB_TXN_FINISHED 0x01 /**< txn is finished or never began */
1203 #define MDB_TXN_ERROR 0x02 /**< txn is unusable after an error */
1204 #define MDB_TXN_DIRTY 0x04 /**< must write, even if dirty list is empty */
1205 #define MDB_TXN_SPILLS 0x08 /**< txn or a parent has spilled pages */
1206 #define MDB_TXN_HAS_CHILD 0x10 /**< txn has an #MDB_txn.%mt_child */
1207 /** most operations on the txn are currently illegal */
1208 #define MDB_TXN_BLOCKED (MDB_TXN_FINISHED|MDB_TXN_ERROR|MDB_TXN_HAS_CHILD)
1210 unsigned int mt_flags; /**< @ref mdb_txn */
1211 /** #dirty_list room: Array size - \#dirty pages visible to this txn.
1212 * Includes ancestor txns' dirty pages not hidden by other txns'
1213 * dirty/spilled pages. Thus commit(nested txn) has room to merge
1214 * dirty_list into mt_parent after freeing hidden mt_parent pages.
1216 unsigned int mt_dirty_room;
1219 /** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty.
1220 * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to
1221 * raise this on a 64 bit machine.
1223 #define CURSOR_STACK 32
1227 /** Cursors are used for all DB operations.
1228 * A cursor holds a path of (page pointer, key index) from the DB
1229 * root to a position in the DB, plus other state. #MDB_DUPSORT
1230 * cursors include an xcursor to the current data item. Write txns
1231 * track their cursors and keep them up to date when data moves.
1232 * Exception: An xcursor's pointer to a #P_SUBP page can be stale.
1233 * (A node with #F_DUPDATA but no #F_SUBDATA contains a subpage).
1236 /** Next cursor on this DB in this txn */
1237 MDB_cursor *mc_next;
1238 /** Backup of the original cursor if this cursor is a shadow */
1239 MDB_cursor *mc_backup;
1240 /** Context used for databases with #MDB_DUPSORT, otherwise NULL */
1241 struct MDB_xcursor *mc_xcursor;
1242 /** The transaction that owns this cursor */
1244 /** The database handle this cursor operates on */
1246 /** The database record for this cursor */
1248 /** The database auxiliary record for this cursor */
1250 /** The @ref mt_dbflag for this database */
1251 unsigned char *mc_dbflag;
1252 unsigned short mc_snum; /**< number of pushed pages */
1253 unsigned short mc_top; /**< index of top page, normally mc_snum-1 */
1254 /** @defgroup mdb_cursor Cursor Flags
1256 * Cursor state flags.
1259 #define C_INITIALIZED 0x01 /**< cursor has been initialized and is valid */
1260 #define C_EOF 0x02 /**< No more data */
1261 #define C_SUB 0x04 /**< Cursor is a sub-cursor */
1262 #define C_DEL 0x08 /**< last op was a cursor_del */
1263 #define C_UNTRACK 0x40 /**< Un-track cursor when closing */
1265 unsigned int mc_flags; /**< @ref mdb_cursor */
1266 MDB_page *mc_pg[CURSOR_STACK]; /**< stack of pushed pages */
1267 indx_t mc_ki[CURSOR_STACK]; /**< stack of page indices */
1270 /** Context for sorted-dup records.
1271 * We could have gone to a fully recursive design, with arbitrarily
1272 * deep nesting of sub-databases. But for now we only handle these
1273 * levels - main DB, optional sub-DB, sorted-duplicate DB.
1275 typedef struct MDB_xcursor {
1276 /** A sub-cursor for traversing the Dup DB */
1277 MDB_cursor mx_cursor;
1278 /** The database record for this Dup DB */
1280 /** The auxiliary DB record for this Dup DB */
1282 /** The @ref mt_dbflag for this Dup DB */
1283 unsigned char mx_dbflag;
1286 /** State of FreeDB old pages, stored in the MDB_env */
1287 typedef struct MDB_pgstate {
1288 pgno_t *mf_pghead; /**< Reclaimed freeDB pages, or NULL before use */
1289 txnid_t mf_pglast; /**< ID of last used record, or 0 if !mf_pghead */
1292 /** The database environment. */
1294 HANDLE me_fd; /**< The main data file */
1295 HANDLE me_lfd; /**< The lock file */
1296 HANDLE me_mfd; /**< just for writing the meta pages */
1297 /** Failed to update the meta page. Probably an I/O error. */
1298 #define MDB_FATAL_ERROR 0x80000000U
1299 /** Some fields are initialized. */
1300 #define MDB_ENV_ACTIVE 0x20000000U
1301 /** me_txkey is set */
1302 #define MDB_ENV_TXKEY 0x10000000U
1303 /** fdatasync is unreliable */
1304 #define MDB_FSYNCONLY 0x08000000U
1305 uint32_t me_flags; /**< @ref mdb_env */
1306 unsigned int me_psize; /**< DB page size, inited from me_os_psize */
1307 unsigned int me_os_psize; /**< OS page size, from #GET_PAGESIZE */
1308 unsigned int me_maxreaders; /**< size of the reader table */
1309 /** Max #MDB_txninfo.%mti_numreaders of interest to #mdb_env_close() */
1310 volatile int me_close_readers;
1311 MDB_dbi me_numdbs; /**< number of DBs opened */
1312 MDB_dbi me_maxdbs; /**< size of the DB table */
1313 MDB_PID_T me_pid; /**< process ID of this env */
1314 char *me_path; /**< path to the DB files */
1315 char *me_map; /**< the memory map of the data file */
1316 MDB_txninfo *me_txns; /**< the memory map of the lock file or NULL */
1317 MDB_meta *me_metas[NUM_METAS]; /**< pointers to the two meta pages */
1318 void *me_pbuf; /**< scratch area for DUPSORT put() */
1319 MDB_txn *me_txn; /**< current write transaction */
1320 MDB_txn *me_txn0; /**< prealloc'd write transaction */
1321 size_t me_mapsize; /**< size of the data memory map */
1322 off_t me_size; /**< current file size */
1323 pgno_t me_maxpg; /**< me_mapsize / me_psize */
1324 MDB_dbx *me_dbxs; /**< array of static DB info */
1325 uint16_t *me_dbflags; /**< array of flags from MDB_db.md_flags */
1326 unsigned int *me_dbiseqs; /**< array of dbi sequence numbers */
1327 pthread_key_t me_txkey; /**< thread-key for readers */
1328 txnid_t me_pgoldest; /**< ID of oldest reader last time we looked */
1329 MDB_pgstate me_pgstate; /**< state of old pages from freeDB */
1330 # define me_pglast me_pgstate.mf_pglast
1331 # define me_pghead me_pgstate.mf_pghead
1332 MDB_page *me_dpages; /**< list of malloc'd blocks for re-use */
1333 /** IDL of pages that became unused in a write txn */
1334 MDB_IDL me_free_pgs;
1335 /** ID2L of pages written during a write txn. Length MDB_IDL_UM_SIZE. */
1336 MDB_ID2L me_dirty_list;
1337 /** Max number of freelist items that can fit in a single overflow page */
1339 /** Max size of a node on a page */
1340 unsigned int me_nodemax;
1341 #if !(MDB_MAXKEYSIZE)
1342 unsigned int me_maxkey; /**< max size of a key */
1344 int me_live_reader; /**< have liveness lock in reader table */
1346 int me_pidquery; /**< Used in OpenProcess */
1348 #ifdef MDB_USE_POSIX_MUTEX /* Posix mutexes reside in shared mem */
1349 # define me_rmutex me_txns->mti_rmutex /**< Shared reader lock */
1350 # define me_wmutex me_txns->mti_wmutex /**< Shared writer lock */
1352 mdb_mutex_t me_rmutex;
1353 mdb_mutex_t me_wmutex;
1355 void *me_userctx; /**< User-settable context */
1356 MDB_assert_func *me_assert_func; /**< Callback for assertion failures */
1359 /** Nested transaction */
1360 typedef struct MDB_ntxn {
1361 MDB_txn mnt_txn; /**< the transaction */
1362 MDB_pgstate mnt_pgstate; /**< parent transaction's saved freestate */
1365 /** max number of pages to commit in one writev() call */
1366 #define MDB_COMMIT_PAGES 64
1367 #if defined(IOV_MAX) && IOV_MAX < MDB_COMMIT_PAGES
1368 #undef MDB_COMMIT_PAGES
1369 #define MDB_COMMIT_PAGES IOV_MAX
1372 /** max bytes to write in one call */
1373 #define MAX_WRITE (0x80000000U >> (sizeof(ssize_t) == 4))
1375 /** Check \b txn and \b dbi arguments to a function */
1376 #define TXN_DBI_EXIST(txn, dbi, validity) \
1377 ((txn) && (dbi)<(txn)->mt_numdbs && ((txn)->mt_dbflags[dbi] & (validity)))
1379 /** Check for misused \b dbi handles */
1380 #define TXN_DBI_CHANGED(txn, dbi) \
1381 ((txn)->mt_dbiseqs[dbi] != (txn)->mt_env->me_dbiseqs[dbi])
1383 static int mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp);
1384 static int mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp);
1385 static int mdb_page_touch(MDB_cursor *mc);
1387 #define MDB_END_NAMES {"committed", "empty-commit", "abort", "reset", \
1388 "reset-tmp", "fail-begin", "fail-beginchild"}
1390 /* mdb_txn_end operation number, for logging */
1391 MDB_END_COMMITTED, MDB_END_EMPTY_COMMIT, MDB_END_ABORT, MDB_END_RESET,
1392 MDB_END_RESET_TMP, MDB_END_FAIL_BEGIN, MDB_END_FAIL_BEGINCHILD
1394 #define MDB_END_OPMASK 0x0F /**< mask for #mdb_txn_end() operation number */
1395 #define MDB_END_UPDATE 0x10 /**< update env state (DBIs) */
1396 #define MDB_END_FREE 0x20 /**< free txn unless it is #MDB_env.%me_txn0 */
1397 #define MDB_END_SLOT MDB_NOTLS /**< release any reader slot if #MDB_NOTLS */
1398 static void mdb_txn_end(MDB_txn *txn, unsigned mode);
1400 static int mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **mp, int *lvl);
1401 static int mdb_page_search_root(MDB_cursor *mc,
1402 MDB_val *key, int modify);
1403 #define MDB_PS_MODIFY 1
1404 #define MDB_PS_ROOTONLY 2
1405 #define MDB_PS_FIRST 4
1406 #define MDB_PS_LAST 8
1407 static int mdb_page_search(MDB_cursor *mc,
1408 MDB_val *key, int flags);
1409 static int mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst);
1411 #define MDB_SPLIT_REPLACE MDB_APPENDDUP /**< newkey is not new */
1412 static int mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,
1413 pgno_t newpgno, unsigned int nflags);
1415 static int mdb_env_read_header(MDB_env *env, MDB_meta *meta);
1416 static MDB_meta *mdb_env_pick_meta(const MDB_env *env);
1417 static int mdb_env_write_meta(MDB_txn *txn);
1418 #ifdef MDB_USE_POSIX_MUTEX /* Drop unused excl arg */
1419 # define mdb_env_close0(env, excl) mdb_env_close1(env)
1421 static void mdb_env_close0(MDB_env *env, int excl);
1423 static MDB_node *mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp);
1424 static int mdb_node_add(MDB_cursor *mc, indx_t indx,
1425 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags);
1426 static void mdb_node_del(MDB_cursor *mc, int ksize);
1427 static void mdb_node_shrink(MDB_page *mp, indx_t indx);
1428 static int mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft);
1429 static int mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data);
1430 static size_t mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data);
1431 static size_t mdb_branch_size(MDB_env *env, MDB_val *key);
1433 static int mdb_rebalance(MDB_cursor *mc);
1434 static int mdb_update_key(MDB_cursor *mc, MDB_val *key);
1436 static void mdb_cursor_pop(MDB_cursor *mc);
1437 static int mdb_cursor_push(MDB_cursor *mc, MDB_page *mp);
1439 static int mdb_cursor_del0(MDB_cursor *mc);
1440 static int mdb_del0(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned flags);
1441 static int mdb_cursor_sibling(MDB_cursor *mc, int move_right);
1442 static int mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1443 static int mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1444 static int mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op,
1446 static int mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1447 static int mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1449 static void mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);
1450 static void mdb_xcursor_init0(MDB_cursor *mc);
1451 static void mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node);
1452 static void mdb_xcursor_init2(MDB_cursor *mc, MDB_xcursor *src_mx, int force);
1454 static int mdb_drop0(MDB_cursor *mc, int subs);
1455 static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi);
1456 static int mdb_reader_check0(MDB_env *env, int rlocked, int *dead);
1459 static MDB_cmp_func mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long;
1462 /** Compare two items pointing at size_t's of unknown alignment. */
1463 #ifdef MISALIGNED_OK
1464 # define mdb_cmp_clong mdb_cmp_long
1466 # define mdb_cmp_clong mdb_cmp_cint
1470 static SECURITY_DESCRIPTOR mdb_null_sd;
1471 static SECURITY_ATTRIBUTES mdb_all_sa;
1472 static int mdb_sec_inited;
1474 static int utf8_to_utf16(const char *src, int srcsize, wchar_t **dst, int *dstsize);
1477 /** Return the library version info. */
1479 mdb_version(int *major, int *minor, int *patch)
1481 if (major) *major = MDB_VERSION_MAJOR;
1482 if (minor) *minor = MDB_VERSION_MINOR;
1483 if (patch) *patch = MDB_VERSION_PATCH;
1484 return MDB_VERSION_STRING;
1487 /** Table of descriptions for LMDB @ref errors */
1488 static char *const mdb_errstr[] = {
1489 "MDB_KEYEXIST: Key/data pair already exists",
1490 "MDB_NOTFOUND: No matching key/data pair found",
1491 "MDB_PAGE_NOTFOUND: Requested page not found",
1492 "MDB_CORRUPTED: Located page was wrong type",
1493 "MDB_PANIC: Update of meta page failed or environment had fatal error",
1494 "MDB_VERSION_MISMATCH: Database environment version mismatch",
1495 "MDB_INVALID: File is not an LMDB file",
1496 "MDB_MAP_FULL: Environment mapsize limit reached",
1497 "MDB_DBS_FULL: Environment maxdbs limit reached",
1498 "MDB_READERS_FULL: Environment maxreaders limit reached",
1499 "MDB_TLS_FULL: Thread-local storage keys full - too many environments open",
1500 "MDB_TXN_FULL: Transaction has too many dirty pages - transaction too big",
1501 "MDB_CURSOR_FULL: Internal error - cursor stack limit reached",
1502 "MDB_PAGE_FULL: Internal error - page has no more space",
1503 "MDB_MAP_RESIZED: Database contents grew beyond environment mapsize",
1504 "MDB_INCOMPATIBLE: Operation and DB incompatible, or DB flags changed",
1505 "MDB_BAD_RSLOT: Invalid reuse of reader locktable slot",
1506 "MDB_BAD_TXN: Transaction must abort, has a child, or is invalid",
1507 "MDB_BAD_VALSIZE: Unsupported size of key/DB name/data, or wrong DUPFIXED size",
1508 "MDB_BAD_DBI: The specified DBI handle was closed/changed unexpectedly",
1512 mdb_strerror(int err)
1515 /** HACK: pad 4KB on stack over the buf. Return system msgs in buf.
1516 * This works as long as no function between the call to mdb_strerror
1517 * and the actual use of the message uses more than 4K of stack.
1520 char buf[1024], *ptr = buf;
1524 return ("Successful return: 0");
1526 if (err >= MDB_KEYEXIST && err <= MDB_LAST_ERRCODE) {
1527 i = err - MDB_KEYEXIST;
1528 return mdb_errstr[i];
1532 /* These are the C-runtime error codes we use. The comment indicates
1533 * their numeric value, and the Win32 error they would correspond to
1534 * if the error actually came from a Win32 API. A major mess, we should
1535 * have used LMDB-specific error codes for everything.
1538 case ENOENT: /* 2, FILE_NOT_FOUND */
1539 case EIO: /* 5, ACCESS_DENIED */
1540 case ENOMEM: /* 12, INVALID_ACCESS */
1541 case EACCES: /* 13, INVALID_DATA */
1542 case EBUSY: /* 16, CURRENT_DIRECTORY */
1543 case EINVAL: /* 22, BAD_COMMAND */
1544 case ENOSPC: /* 28, OUT_OF_PAPER */
1545 return strerror(err);
1550 FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM |
1551 FORMAT_MESSAGE_IGNORE_INSERTS,
1552 NULL, err, 0, ptr, sizeof(buf), (va_list *)pad);
1555 return strerror(err);
1559 /** assert(3) variant in cursor context */
1560 #define mdb_cassert(mc, expr) mdb_assert0((mc)->mc_txn->mt_env, expr, #expr)
1561 /** assert(3) variant in transaction context */
1562 #define mdb_tassert(txn, expr) mdb_assert0((txn)->mt_env, expr, #expr)
1563 /** assert(3) variant in environment context */
1564 #define mdb_eassert(env, expr) mdb_assert0(env, expr, #expr)
1567 # define mdb_assert0(env, expr, expr_txt) ((expr) ? (void)0 : \
1568 mdb_assert_fail(env, expr_txt, mdb_func_, __FILE__, __LINE__))
1571 mdb_assert_fail(MDB_env *env, const char *expr_txt,
1572 const char *func, const char *file, int line)
1575 sprintf(buf, "%.100s:%d: Assertion '%.200s' failed in %.40s()",
1576 file, line, expr_txt, func);
1577 if (env->me_assert_func)
1578 env->me_assert_func(env, buf);
1579 fprintf(stderr, "%s\n", buf);
1583 # define mdb_assert0(env, expr, expr_txt) ((void) 0)
1587 /** Return the page number of \b mp which may be sub-page, for debug output */
1589 mdb_dbg_pgno(MDB_page *mp)
1592 COPY_PGNO(ret, mp->mp_pgno);
1596 /** Display a key in hexadecimal and return the address of the result.
1597 * @param[in] key the key to display
1598 * @param[in] buf the buffer to write into. Should always be #DKBUF.
1599 * @return The key in hexadecimal form.
1602 mdb_dkey(MDB_val *key, char *buf)
1605 unsigned char *c = key->mv_data;
1611 if (key->mv_size > DKBUF_MAXKEYSIZE)
1612 return "MDB_MAXKEYSIZE";
1613 /* may want to make this a dynamic check: if the key is mostly
1614 * printable characters, print it as-is instead of converting to hex.
1618 for (i=0; i<key->mv_size; i++)
1619 ptr += sprintf(ptr, "%02x", *c++);
1621 sprintf(buf, "%.*s", key->mv_size, key->mv_data);
1627 mdb_leafnode_type(MDB_node *n)
1629 static char *const tp[2][2] = {{"", ": DB"}, {": sub-page", ": sub-DB"}};
1630 return F_ISSET(n->mn_flags, F_BIGDATA) ? ": overflow page" :
1631 tp[F_ISSET(n->mn_flags, F_DUPDATA)][F_ISSET(n->mn_flags, F_SUBDATA)];
1634 /** Display all the keys in the page. */
1636 mdb_page_list(MDB_page *mp)
1638 pgno_t pgno = mdb_dbg_pgno(mp);
1639 const char *type, *state = (mp->mp_flags & P_DIRTY) ? ", dirty" : "";
1641 unsigned int i, nkeys, nsize, total = 0;
1645 switch (mp->mp_flags & (P_BRANCH|P_LEAF|P_LEAF2|P_META|P_OVERFLOW|P_SUBP)) {
1646 case P_BRANCH: type = "Branch page"; break;
1647 case P_LEAF: type = "Leaf page"; break;
1648 case P_LEAF|P_SUBP: type = "Sub-page"; break;
1649 case P_LEAF|P_LEAF2: type = "LEAF2 page"; break;
1650 case P_LEAF|P_LEAF2|P_SUBP: type = "LEAF2 sub-page"; break;
1652 fprintf(stderr, "Overflow page %"Z"u pages %u%s\n",
1653 pgno, mp->mp_pages, state);
1656 fprintf(stderr, "Meta-page %"Z"u txnid %"Z"u\n",
1657 pgno, ((MDB_meta *)METADATA(mp))->mm_txnid);
1660 fprintf(stderr, "Bad page %"Z"u flags 0x%u\n", pgno, mp->mp_flags);
1664 nkeys = NUMKEYS(mp);
1665 fprintf(stderr, "%s %"Z"u numkeys %d%s\n", type, pgno, nkeys, state);
1667 for (i=0; i<nkeys; i++) {
1668 if (IS_LEAF2(mp)) { /* LEAF2 pages have no mp_ptrs[] or node headers */
1669 key.mv_size = nsize = mp->mp_pad;
1670 key.mv_data = LEAF2KEY(mp, i, nsize);
1672 fprintf(stderr, "key %d: nsize %d, %s\n", i, nsize, DKEY(&key));
1675 node = NODEPTR(mp, i);
1676 key.mv_size = node->mn_ksize;
1677 key.mv_data = node->mn_data;
1678 nsize = NODESIZE + key.mv_size;
1679 if (IS_BRANCH(mp)) {
1680 fprintf(stderr, "key %d: page %"Z"u, %s\n", i, NODEPGNO(node),
1684 if (F_ISSET(node->mn_flags, F_BIGDATA))
1685 nsize += sizeof(pgno_t);
1687 nsize += NODEDSZ(node);
1689 nsize += sizeof(indx_t);
1690 fprintf(stderr, "key %d: nsize %d, %s%s\n",
1691 i, nsize, DKEY(&key), mdb_leafnode_type(node));
1693 total = EVEN(total);
1695 fprintf(stderr, "Total: header %d + contents %d + unused %d\n",
1696 IS_LEAF2(mp) ? PAGEHDRSZ : PAGEBASE + mp->mp_lower, total, SIZELEFT(mp));
1700 mdb_cursor_chk(MDB_cursor *mc)
1706 if (!mc->mc_snum || !(mc->mc_flags & C_INITIALIZED)) return;
1707 for (i=0; i<mc->mc_top; i++) {
1709 node = NODEPTR(mp, mc->mc_ki[i]);
1710 if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno)
1713 if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i]))
1715 if (mc->mc_xcursor && (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
1716 node = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
1717 if (((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA) &&
1718 mc->mc_xcursor->mx_cursor.mc_pg[0] != NODEDATA(node)) {
1726 /** Count all the pages in each DB and in the freelist
1727 * and make sure it matches the actual number of pages
1729 * All named DBs must be open for a correct count.
1731 static void mdb_audit(MDB_txn *txn)
1735 MDB_ID freecount, count;
1740 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
1741 while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
1742 freecount += *(MDB_ID *)data.mv_data;
1743 mdb_tassert(txn, rc == MDB_NOTFOUND);
1746 for (i = 0; i<txn->mt_numdbs; i++) {
1748 if (!(txn->mt_dbflags[i] & DB_VALID))
1750 mdb_cursor_init(&mc, txn, i, &mx);
1751 if (txn->mt_dbs[i].md_root == P_INVALID)
1753 count += txn->mt_dbs[i].md_branch_pages +
1754 txn->mt_dbs[i].md_leaf_pages +
1755 txn->mt_dbs[i].md_overflow_pages;
1756 if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) {
1757 rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST);
1758 for (; rc == MDB_SUCCESS; rc = mdb_cursor_sibling(&mc, 1)) {
1761 mp = mc.mc_pg[mc.mc_top];
1762 for (j=0; j<NUMKEYS(mp); j++) {
1763 MDB_node *leaf = NODEPTR(mp, j);
1764 if (leaf->mn_flags & F_SUBDATA) {
1766 memcpy(&db, NODEDATA(leaf), sizeof(db));
1767 count += db.md_branch_pages + db.md_leaf_pages +
1768 db.md_overflow_pages;
1772 mdb_tassert(txn, rc == MDB_NOTFOUND);
1775 if (freecount + count + NUM_METAS != txn->mt_next_pgno) {
1776 fprintf(stderr, "audit: %lu freecount: %lu count: %lu total: %lu next_pgno: %lu\n",
1777 txn->mt_txnid, freecount, count+NUM_METAS,
1778 freecount+count+NUM_METAS, txn->mt_next_pgno);
1784 mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1786 return txn->mt_dbxs[dbi].md_cmp(a, b);
1790 mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1792 MDB_cmp_func *dcmp = txn->mt_dbxs[dbi].md_dcmp;
1793 #if UINT_MAX < SIZE_MAX
1794 if (dcmp == mdb_cmp_int && a->mv_size == sizeof(size_t))
1795 dcmp = mdb_cmp_clong;
1800 /** Allocate memory for a page.
1801 * Re-use old malloc'd pages first for singletons, otherwise just malloc.
1804 mdb_page_malloc(MDB_txn *txn, unsigned num)
1806 MDB_env *env = txn->mt_env;
1807 MDB_page *ret = env->me_dpages;
1808 size_t psize = env->me_psize, sz = psize, off;
1809 /* For ! #MDB_NOMEMINIT, psize counts how much to init.
1810 * For a single page alloc, we init everything after the page header.
1811 * For multi-page, we init the final page; if the caller needed that
1812 * many pages they will be filling in at least up to the last page.
1816 VGMEMP_ALLOC(env, ret, sz);
1817 VGMEMP_DEFINED(ret, sizeof(ret->mp_next));
1818 env->me_dpages = ret->mp_next;
1821 psize -= off = PAGEHDRSZ;
1826 if ((ret = malloc(sz)) != NULL) {
1827 VGMEMP_ALLOC(env, ret, sz);
1828 if (!(env->me_flags & MDB_NOMEMINIT)) {
1829 memset((char *)ret + off, 0, psize);
1833 txn->mt_flags |= MDB_TXN_ERROR;
1837 /** Free a single page.
1838 * Saves single pages to a list, for future reuse.
1839 * (This is not used for multi-page overflow pages.)
1842 mdb_page_free(MDB_env *env, MDB_page *mp)
1844 mp->mp_next = env->me_dpages;
1845 VGMEMP_FREE(env, mp);
1846 env->me_dpages = mp;
1849 /** Free a dirty page */
1851 mdb_dpage_free(MDB_env *env, MDB_page *dp)
1853 if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
1854 mdb_page_free(env, dp);
1856 /* large pages just get freed directly */
1857 VGMEMP_FREE(env, dp);
1862 /** Return all dirty pages to dpage list */
1864 mdb_dlist_free(MDB_txn *txn)
1866 MDB_env *env = txn->mt_env;
1867 MDB_ID2L dl = txn->mt_u.dirty_list;
1868 unsigned i, n = dl[0].mid;
1870 for (i = 1; i <= n; i++) {
1871 mdb_dpage_free(env, dl[i].mptr);
1876 /** Loosen or free a single page.
1877 * Saves single pages to a list for future reuse
1878 * in this same txn. It has been pulled from the freeDB
1879 * and already resides on the dirty list, but has been
1880 * deleted. Use these pages first before pulling again
1883 * If the page wasn't dirtied in this txn, just add it
1884 * to this txn's free list.
1887 mdb_page_loose(MDB_cursor *mc, MDB_page *mp)
1890 pgno_t pgno = mp->mp_pgno;
1891 MDB_txn *txn = mc->mc_txn;
1893 if ((mp->mp_flags & P_DIRTY) && mc->mc_dbi != FREE_DBI) {
1894 if (txn->mt_parent) {
1895 MDB_ID2 *dl = txn->mt_u.dirty_list;
1896 /* If txn has a parent, make sure the page is in our
1900 unsigned x = mdb_mid2l_search(dl, pgno);
1901 if (x <= dl[0].mid && dl[x].mid == pgno) {
1902 if (mp != dl[x].mptr) { /* bad cursor? */
1903 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
1904 txn->mt_flags |= MDB_TXN_ERROR;
1905 return MDB_CORRUPTED;
1912 /* no parent txn, so it's just ours */
1917 DPRINTF(("loosen db %d page %"Z"u", DDBI(mc),
1919 NEXT_LOOSE_PAGE(mp) = txn->mt_loose_pgs;
1920 txn->mt_loose_pgs = mp;
1921 txn->mt_loose_count++;
1922 mp->mp_flags |= P_LOOSE;
1924 int rc = mdb_midl_append(&txn->mt_free_pgs, pgno);
1932 /** Set or clear P_KEEP in dirty, non-overflow, non-sub pages watched by txn.
1933 * @param[in] mc A cursor handle for the current operation.
1934 * @param[in] pflags Flags of the pages to update:
1935 * P_DIRTY to set P_KEEP, P_DIRTY|P_KEEP to clear it.
1936 * @param[in] all No shortcuts. Needed except after a full #mdb_page_flush().
1937 * @return 0 on success, non-zero on failure.
1940 mdb_pages_xkeep(MDB_cursor *mc, unsigned pflags, int all)
1942 enum { Mask = P_SUBP|P_DIRTY|P_LOOSE|P_KEEP };
1943 MDB_txn *txn = mc->mc_txn;
1949 int rc = MDB_SUCCESS, level;
1951 /* Mark pages seen by cursors */
1952 if (mc->mc_flags & C_UNTRACK)
1953 mc = NULL; /* will find mc in mt_cursors */
1954 for (i = txn->mt_numdbs;; mc = txn->mt_cursors[--i]) {
1955 for (; mc; mc=mc->mc_next) {
1956 if (!(mc->mc_flags & C_INITIALIZED))
1958 for (m3 = mc;; m3 = &mx->mx_cursor) {
1960 for (j=0; j<m3->mc_snum; j++) {
1962 if ((mp->mp_flags & Mask) == pflags)
1963 mp->mp_flags ^= P_KEEP;
1965 mx = m3->mc_xcursor;
1966 /* Proceed to mx if it is at a sub-database */
1967 if (! (mx && (mx->mx_cursor.mc_flags & C_INITIALIZED)))
1969 if (! (mp && (mp->mp_flags & P_LEAF)))
1971 leaf = NODEPTR(mp, m3->mc_ki[j-1]);
1972 if (!(leaf->mn_flags & F_SUBDATA))
1981 /* Mark dirty root pages */
1982 for (i=0; i<txn->mt_numdbs; i++) {
1983 if (txn->mt_dbflags[i] & DB_DIRTY) {
1984 pgno_t pgno = txn->mt_dbs[i].md_root;
1985 if (pgno == P_INVALID)
1987 if ((rc = mdb_page_get(txn, pgno, &dp, &level)) != MDB_SUCCESS)
1989 if ((dp->mp_flags & Mask) == pflags && level <= 1)
1990 dp->mp_flags ^= P_KEEP;
1998 static int mdb_page_flush(MDB_txn *txn, int keep);
2000 /** Spill pages from the dirty list back to disk.
2001 * This is intended to prevent running into #MDB_TXN_FULL situations,
2002 * but note that they may still occur in a few cases:
2003 * 1) our estimate of the txn size could be too small. Currently this
2004 * seems unlikely, except with a large number of #MDB_MULTIPLE items.
2005 * 2) child txns may run out of space if their parents dirtied a
2006 * lot of pages and never spilled them. TODO: we probably should do
2007 * a preemptive spill during #mdb_txn_begin() of a child txn, if
2008 * the parent's dirty_room is below a given threshold.
2010 * Otherwise, if not using nested txns, it is expected that apps will
2011 * not run into #MDB_TXN_FULL any more. The pages are flushed to disk
2012 * the same way as for a txn commit, e.g. their P_DIRTY flag is cleared.
2013 * If the txn never references them again, they can be left alone.
2014 * If the txn only reads them, they can be used without any fuss.
2015 * If the txn writes them again, they can be dirtied immediately without
2016 * going thru all of the work of #mdb_page_touch(). Such references are
2017 * handled by #mdb_page_unspill().
2019 * Also note, we never spill DB root pages, nor pages of active cursors,
2020 * because we'll need these back again soon anyway. And in nested txns,
2021 * we can't spill a page in a child txn if it was already spilled in a
2022 * parent txn. That would alter the parent txns' data even though
2023 * the child hasn't committed yet, and we'd have no way to undo it if
2024 * the child aborted.
2026 * @param[in] m0 cursor A cursor handle identifying the transaction and
2027 * database for which we are checking space.
2028 * @param[in] key For a put operation, the key being stored.
2029 * @param[in] data For a put operation, the data being stored.
2030 * @return 0 on success, non-zero on failure.
2033 mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
2035 MDB_txn *txn = m0->mc_txn;
2037 MDB_ID2L dl = txn->mt_u.dirty_list;
2038 unsigned int i, j, need;
2041 if (m0->mc_flags & C_SUB)
2044 /* Estimate how much space this op will take */
2045 i = m0->mc_db->md_depth;
2046 /* Named DBs also dirty the main DB */
2047 if (m0->mc_dbi >= CORE_DBS)
2048 i += txn->mt_dbs[MAIN_DBI].md_depth;
2049 /* For puts, roughly factor in the key+data size */
2051 i += (LEAFSIZE(key, data) + txn->mt_env->me_psize) / txn->mt_env->me_psize;
2052 i += i; /* double it for good measure */
2055 if (txn->mt_dirty_room > i)
2058 if (!txn->mt_spill_pgs) {
2059 txn->mt_spill_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX);
2060 if (!txn->mt_spill_pgs)
2063 /* purge deleted slots */
2064 MDB_IDL sl = txn->mt_spill_pgs;
2065 unsigned int num = sl[0];
2067 for (i=1; i<=num; i++) {
2074 /* Preserve pages which may soon be dirtied again */
2075 if ((rc = mdb_pages_xkeep(m0, P_DIRTY, 1)) != MDB_SUCCESS)
2078 /* Less aggressive spill - we originally spilled the entire dirty list,
2079 * with a few exceptions for cursor pages and DB root pages. But this
2080 * turns out to be a lot of wasted effort because in a large txn many
2081 * of those pages will need to be used again. So now we spill only 1/8th
2082 * of the dirty pages. Testing revealed this to be a good tradeoff,
2083 * better than 1/2, 1/4, or 1/10.
2085 if (need < MDB_IDL_UM_MAX / 8)
2086 need = MDB_IDL_UM_MAX / 8;
2088 /* Save the page IDs of all the pages we're flushing */
2089 /* flush from the tail forward, this saves a lot of shifting later on. */
2090 for (i=dl[0].mid; i && need; i--) {
2091 MDB_ID pn = dl[i].mid << 1;
2093 if (dp->mp_flags & (P_LOOSE|P_KEEP))
2095 /* Can't spill twice, make sure it's not already in a parent's
2098 if (txn->mt_parent) {
2100 for (tx2 = txn->mt_parent; tx2; tx2 = tx2->mt_parent) {
2101 if (tx2->mt_spill_pgs) {
2102 j = mdb_midl_search(tx2->mt_spill_pgs, pn);
2103 if (j <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[j] == pn) {
2104 dp->mp_flags |= P_KEEP;
2112 if ((rc = mdb_midl_append(&txn->mt_spill_pgs, pn)))
2116 mdb_midl_sort(txn->mt_spill_pgs);
2118 /* Flush the spilled part of dirty list */
2119 if ((rc = mdb_page_flush(txn, i)) != MDB_SUCCESS)
2122 /* Reset any dirty pages we kept that page_flush didn't see */
2123 rc = mdb_pages_xkeep(m0, P_DIRTY|P_KEEP, i);
2126 txn->mt_flags |= rc ? MDB_TXN_ERROR : MDB_TXN_SPILLS;
2130 /** Find oldest txnid still referenced. Expects txn->mt_txnid > 0. */
2132 mdb_find_oldest(MDB_txn *txn)
2135 txnid_t mr, oldest = txn->mt_txnid - 1;
2136 if (txn->mt_env->me_txns) {
2137 MDB_reader *r = txn->mt_env->me_txns->mti_readers;
2138 for (i = txn->mt_env->me_txns->mti_numreaders; --i >= 0; ) {
2149 /** Add a page to the txn's dirty list */
2151 mdb_page_dirty(MDB_txn *txn, MDB_page *mp)
2154 int rc, (*insert)(MDB_ID2L, MDB_ID2 *);
2156 if (txn->mt_flags & MDB_TXN_WRITEMAP) {
2157 insert = mdb_mid2l_append;
2159 insert = mdb_mid2l_insert;
2161 mid.mid = mp->mp_pgno;
2163 rc = insert(txn->mt_u.dirty_list, &mid);
2164 mdb_tassert(txn, rc == 0);
2165 txn->mt_dirty_room--;
2168 /** Allocate page numbers and memory for writing. Maintain me_pglast,
2169 * me_pghead and mt_next_pgno.
2171 * If there are free pages available from older transactions, they
2172 * are re-used first. Otherwise allocate a new page at mt_next_pgno.
2173 * Do not modify the freedB, just merge freeDB records into me_pghead[]
2174 * and move me_pglast to say which records were consumed. Only this
2175 * function can create me_pghead and move me_pglast/mt_next_pgno.
2176 * @param[in] mc cursor A cursor handle identifying the transaction and
2177 * database for which we are allocating.
2178 * @param[in] num the number of pages to allocate.
2179 * @param[out] mp Address of the allocated page(s). Requests for multiple pages
2180 * will always be satisfied by a single contiguous chunk of memory.
2181 * @return 0 on success, non-zero on failure.
2184 mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
2186 #ifdef MDB_PARANOID /* Seems like we can ignore this now */
2187 /* Get at most <Max_retries> more freeDB records once me_pghead
2188 * has enough pages. If not enough, use new pages from the map.
2189 * If <Paranoid> and mc is updating the freeDB, only get new
2190 * records if me_pghead is empty. Then the freelist cannot play
2191 * catch-up with itself by growing while trying to save it.
2193 enum { Paranoid = 1, Max_retries = 500 };
2195 enum { Paranoid = 0, Max_retries = INT_MAX /*infinite*/ };
2197 int rc, retry = num * 60;
2198 MDB_txn *txn = mc->mc_txn;
2199 MDB_env *env = txn->mt_env;
2200 pgno_t pgno, *mop = env->me_pghead;
2201 unsigned i, j, mop_len = mop ? mop[0] : 0, n2 = num-1;
2203 txnid_t oldest = 0, last;
2208 /* If there are any loose pages, just use them */
2209 if (num == 1 && txn->mt_loose_pgs) {
2210 np = txn->mt_loose_pgs;
2211 txn->mt_loose_pgs = NEXT_LOOSE_PAGE(np);
2212 txn->mt_loose_count--;
2213 DPRINTF(("db %d use loose page %"Z"u", DDBI(mc),
2221 /* If our dirty list is already full, we can't do anything */
2222 if (txn->mt_dirty_room == 0) {
2227 for (op = MDB_FIRST;; op = MDB_NEXT) {
2232 /* Seek a big enough contiguous page range. Prefer
2233 * pages at the tail, just truncating the list.
2239 if (mop[i-n2] == pgno+n2)
2246 if (op == MDB_FIRST) { /* 1st iteration */
2247 /* Prepare to fetch more and coalesce */
2248 last = env->me_pglast;
2249 oldest = env->me_pgoldest;
2250 mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
2253 key.mv_data = &last; /* will look up last+1 */
2254 key.mv_size = sizeof(last);
2256 if (Paranoid && mc->mc_dbi == FREE_DBI)
2259 if (Paranoid && retry < 0 && mop_len)
2263 /* Do not fetch more if the record will be too recent */
2264 if (oldest <= last) {
2266 oldest = mdb_find_oldest(txn);
2267 env->me_pgoldest = oldest;
2273 rc = mdb_cursor_get(&m2, &key, NULL, op);
2275 if (rc == MDB_NOTFOUND)
2279 last = *(txnid_t*)key.mv_data;
2280 if (oldest <= last) {
2282 oldest = mdb_find_oldest(txn);
2283 env->me_pgoldest = oldest;
2289 np = m2.mc_pg[m2.mc_top];
2290 leaf = NODEPTR(np, m2.mc_ki[m2.mc_top]);
2291 if ((rc = mdb_node_read(txn, leaf, &data)) != MDB_SUCCESS)
2294 idl = (MDB_ID *) data.mv_data;
2297 if (!(env->me_pghead = mop = mdb_midl_alloc(i))) {
2302 if ((rc = mdb_midl_need(&env->me_pghead, i)) != 0)
2304 mop = env->me_pghead;
2306 env->me_pglast = last;
2308 DPRINTF(("IDL read txn %"Z"u root %"Z"u num %u",
2309 last, txn->mt_dbs[FREE_DBI].md_root, i));
2311 DPRINTF(("IDL %"Z"u", idl[j]));
2313 /* Merge in descending sorted order */
2314 mdb_midl_xmerge(mop, idl);
2318 /* Use new pages from the map when nothing suitable in the freeDB */
2320 pgno = txn->mt_next_pgno;
2321 if (pgno + num >= env->me_maxpg) {
2322 DPUTS("DB size maxed out");
2327 if (env->me_flags & MDB_WRITEMAP) {
2329 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
2330 p = VirtualAlloc(p, env->me_psize * num, MEM_COMMIT,
2331 (env->me_flags & MDB_WRITEMAP) ? PAGE_READWRITE:
2334 DPUTS("VirtualAlloc failed");
2342 if (env->me_flags & MDB_WRITEMAP) {
2343 np = (MDB_page *)(env->me_map + env->me_psize * pgno);
2345 if (!(np = mdb_page_malloc(txn, num))) {
2351 mop[0] = mop_len -= num;
2352 /* Move any stragglers down */
2353 for (j = i-num; j < mop_len; )
2354 mop[++j] = mop[++i];
2356 txn->mt_next_pgno = pgno + num;
2359 mdb_page_dirty(txn, np);
2365 txn->mt_flags |= MDB_TXN_ERROR;
2369 /** Copy the used portions of a non-overflow page.
2370 * @param[in] dst page to copy into
2371 * @param[in] src page to copy from
2372 * @param[in] psize size of a page
2375 mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize)
2377 enum { Align = sizeof(pgno_t) };
2378 indx_t upper = src->mp_upper, lower = src->mp_lower, unused = upper-lower;
2380 /* If page isn't full, just copy the used portion. Adjust
2381 * alignment so memcpy may copy words instead of bytes.
2383 if ((unused &= -Align) && !IS_LEAF2(src)) {
2384 upper = (upper + PAGEBASE) & -Align;
2385 memcpy(dst, src, (lower + PAGEBASE + (Align-1)) & -Align);
2386 memcpy((pgno_t *)((char *)dst+upper), (pgno_t *)((char *)src+upper),
2389 memcpy(dst, src, psize - unused);
2393 /** Pull a page off the txn's spill list, if present.
2394 * If a page being referenced was spilled to disk in this txn, bring
2395 * it back and make it dirty/writable again.
2396 * @param[in] txn the transaction handle.
2397 * @param[in] mp the page being referenced. It must not be dirty.
2398 * @param[out] ret the writable page, if any. ret is unchanged if
2399 * mp wasn't spilled.
2402 mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret)
2404 MDB_env *env = txn->mt_env;
2407 pgno_t pgno = mp->mp_pgno, pn = pgno << 1;
2409 for (tx2 = txn; tx2; tx2=tx2->mt_parent) {
2410 if (!tx2->mt_spill_pgs)
2412 x = mdb_midl_search(tx2->mt_spill_pgs, pn);
2413 if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
2416 if (txn->mt_dirty_room == 0)
2417 return MDB_TXN_FULL;
2418 if (IS_OVERFLOW(mp))
2422 if (env->me_flags & MDB_WRITEMAP) {
2425 np = mdb_page_malloc(txn, num);
2429 memcpy(np, mp, num * env->me_psize);
2431 mdb_page_copy(np, mp, env->me_psize);
2434 /* If in current txn, this page is no longer spilled.
2435 * If it happens to be the last page, truncate the spill list.
2436 * Otherwise mark it as deleted by setting the LSB.
2438 if (x == txn->mt_spill_pgs[0])
2439 txn->mt_spill_pgs[0]--;
2441 txn->mt_spill_pgs[x] |= 1;
2442 } /* otherwise, if belonging to a parent txn, the
2443 * page remains spilled until child commits
2446 mdb_page_dirty(txn, np);
2447 np->mp_flags |= P_DIRTY;
2455 /** Touch a page: make it dirty and re-insert into tree with updated pgno.
2456 * @param[in] mc cursor pointing to the page to be touched
2457 * @return 0 on success, non-zero on failure.
2460 mdb_page_touch(MDB_cursor *mc)
2462 MDB_page *mp = mc->mc_pg[mc->mc_top], *np;
2463 MDB_txn *txn = mc->mc_txn;
2464 MDB_cursor *m2, *m3;
2468 if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
2469 if (txn->mt_flags & MDB_TXN_SPILLS) {
2471 rc = mdb_page_unspill(txn, mp, &np);
2477 if ((rc = mdb_midl_need(&txn->mt_free_pgs, 1)) ||
2478 (rc = mdb_page_alloc(mc, 1, &np)))
2481 DPRINTF(("touched db %d page %"Z"u -> %"Z"u", DDBI(mc),
2482 mp->mp_pgno, pgno));
2483 mdb_cassert(mc, mp->mp_pgno != pgno);
2484 mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
2485 /* Update the parent page, if any, to point to the new page */
2487 MDB_page *parent = mc->mc_pg[mc->mc_top-1];
2488 MDB_node *node = NODEPTR(parent, mc->mc_ki[mc->mc_top-1]);
2489 SETPGNO(node, pgno);
2491 mc->mc_db->md_root = pgno;
2493 } else if (txn->mt_parent && !IS_SUBP(mp)) {
2494 MDB_ID2 mid, *dl = txn->mt_u.dirty_list;
2496 /* If txn has a parent, make sure the page is in our
2500 unsigned x = mdb_mid2l_search(dl, pgno);
2501 if (x <= dl[0].mid && dl[x].mid == pgno) {
2502 if (mp != dl[x].mptr) { /* bad cursor? */
2503 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
2504 txn->mt_flags |= MDB_TXN_ERROR;
2505 return MDB_CORRUPTED;
2510 mdb_cassert(mc, dl[0].mid < MDB_IDL_UM_MAX);
2512 np = mdb_page_malloc(txn, 1);
2517 rc = mdb_mid2l_insert(dl, &mid);
2518 mdb_cassert(mc, rc == 0);
2523 mdb_page_copy(np, mp, txn->mt_env->me_psize);
2525 np->mp_flags |= P_DIRTY;
2528 /* Adjust cursors pointing to mp */
2529 mc->mc_pg[mc->mc_top] = np;
2530 m2 = txn->mt_cursors[mc->mc_dbi];
2531 if (mc->mc_flags & C_SUB) {
2532 for (; m2; m2=m2->mc_next) {
2533 m3 = &m2->mc_xcursor->mx_cursor;
2534 if (m3->mc_snum < mc->mc_snum) continue;
2535 if (m3->mc_pg[mc->mc_top] == mp)
2536 m3->mc_pg[mc->mc_top] = np;
2539 for (; m2; m2=m2->mc_next) {
2540 if (m2->mc_snum < mc->mc_snum) continue;
2541 if (m2 == mc) continue;
2542 if (m2->mc_pg[mc->mc_top] == mp) {
2543 m2->mc_pg[mc->mc_top] = np;
2544 if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
2546 (m2->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
2548 MDB_node *leaf = NODEPTR(np, m2->mc_ki[mc->mc_top]);
2549 if ((leaf->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
2550 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
2558 txn->mt_flags |= MDB_TXN_ERROR;
2563 mdb_env_sync(MDB_env *env, int force)
2566 if (env->me_flags & MDB_RDONLY)
2568 if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) {
2569 if (env->me_flags & MDB_WRITEMAP) {
2570 int flags = ((env->me_flags & MDB_MAPASYNC) && !force)
2571 ? MS_ASYNC : MS_SYNC;
2572 if (MDB_MSYNC(env->me_map, env->me_mapsize, flags))
2575 else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd))
2579 #ifdef BROKEN_FDATASYNC
2580 if (env->me_flags & MDB_FSYNCONLY) {
2581 if (fsync(env->me_fd))
2585 if (MDB_FDATASYNC(env->me_fd))
2592 /** Back up parent txn's cursors, then grab the originals for tracking */
2594 mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst)
2596 MDB_cursor *mc, *bk;
2601 for (i = src->mt_numdbs; --i >= 0; ) {
2602 if ((mc = src->mt_cursors[i]) != NULL) {
2603 size = sizeof(MDB_cursor);
2605 size += sizeof(MDB_xcursor);
2606 for (; mc; mc = bk->mc_next) {
2612 mc->mc_db = &dst->mt_dbs[i];
2613 /* Kill pointers into src to reduce abuse: The
2614 * user may not use mc until dst ends. But we need a valid
2615 * txn pointer here for cursor fixups to keep working.
2618 mc->mc_dbflag = &dst->mt_dbflags[i];
2619 if ((mx = mc->mc_xcursor) != NULL) {
2620 *(MDB_xcursor *)(bk+1) = *mx;
2621 mx->mx_cursor.mc_txn = dst;
2623 mc->mc_next = dst->mt_cursors[i];
2624 dst->mt_cursors[i] = mc;
2631 /** Close this write txn's cursors, give parent txn's cursors back to parent.
2632 * @param[in] txn the transaction handle.
2633 * @param[in] merge true to keep changes to parent cursors, false to revert.
2634 * @return 0 on success, non-zero on failure.
2637 mdb_cursors_close(MDB_txn *txn, unsigned merge)
2639 MDB_cursor **cursors = txn->mt_cursors, *mc, *next, *bk;
2643 for (i = txn->mt_numdbs; --i >= 0; ) {
2644 for (mc = cursors[i]; mc; mc = next) {
2646 if ((bk = mc->mc_backup) != NULL) {
2648 /* Commit changes to parent txn */
2649 mc->mc_next = bk->mc_next;
2650 mc->mc_backup = bk->mc_backup;
2651 mc->mc_txn = bk->mc_txn;
2652 mc->mc_db = bk->mc_db;
2653 mc->mc_dbflag = bk->mc_dbflag;
2654 if ((mx = mc->mc_xcursor) != NULL)
2655 mx->mx_cursor.mc_txn = bk->mc_txn;
2657 /* Abort nested txn */
2659 if ((mx = mc->mc_xcursor) != NULL)
2660 *mx = *(MDB_xcursor *)(bk+1);
2664 /* Only malloced cursors are permanently tracked. */
2671 #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
2677 Pidset = F_SETLK, Pidcheck = F_GETLK
2681 /** Set or check a pid lock. Set returns 0 on success.
2682 * Check returns 0 if the process is certainly dead, nonzero if it may
2683 * be alive (the lock exists or an error happened so we do not know).
2685 * On Windows Pidset is a no-op, we merely check for the existence
2686 * of the process with the given pid. On POSIX we use a single byte
2687 * lock on the lockfile, set at an offset equal to the pid.
2690 mdb_reader_pid(MDB_env *env, enum Pidlock_op op, MDB_PID_T pid)
2692 #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
2695 if (op == Pidcheck) {
2696 h = OpenProcess(env->me_pidquery, FALSE, pid);
2697 /* No documented "no such process" code, but other program use this: */
2699 return ErrCode() != ERROR_INVALID_PARAMETER;
2700 /* A process exists until all handles to it close. Has it exited? */
2701 ret = WaitForSingleObject(h, 0) != 0;
2708 struct flock lock_info;
2709 memset(&lock_info, 0, sizeof(lock_info));
2710 lock_info.l_type = F_WRLCK;
2711 lock_info.l_whence = SEEK_SET;
2712 lock_info.l_start = pid;
2713 lock_info.l_len = 1;
2714 if ((rc = fcntl(env->me_lfd, op, &lock_info)) == 0) {
2715 if (op == F_GETLK && lock_info.l_type != F_UNLCK)
2717 } else if ((rc = ErrCode()) == EINTR) {
2725 /** Common code for #mdb_txn_begin() and #mdb_txn_renew().
2726 * @param[in] txn the transaction handle to initialize
2727 * @return 0 on success, non-zero on failure.
2730 mdb_txn_renew0(MDB_txn *txn)
2732 MDB_env *env = txn->mt_env;
2733 MDB_txninfo *ti = env->me_txns;
2735 unsigned int i, nr, flags = txn->mt_flags;
2737 int rc, new_notls = 0;
2739 if ((flags &= MDB_TXN_RDONLY) != 0) {
2741 meta = mdb_env_pick_meta(env);
2742 txn->mt_txnid = meta->mm_txnid;
2743 txn->mt_u.reader = NULL;
2745 MDB_reader *r = (env->me_flags & MDB_NOTLS) ? txn->mt_u.reader :
2746 pthread_getspecific(env->me_txkey);
2748 if (r->mr_pid != env->me_pid || r->mr_txnid != (txnid_t)-1)
2749 return MDB_BAD_RSLOT;
2751 MDB_PID_T pid = env->me_pid;
2752 MDB_THR_T tid = pthread_self();
2753 mdb_mutexref_t rmutex = env->me_rmutex;
2755 if (!env->me_live_reader) {
2756 rc = mdb_reader_pid(env, Pidset, pid);
2759 env->me_live_reader = 1;
2762 if (LOCK_MUTEX(rc, env, rmutex))
2764 nr = ti->mti_numreaders;
2765 for (i=0; i<nr; i++)
2766 if (ti->mti_readers[i].mr_pid == 0)
2768 if (i == env->me_maxreaders) {
2769 UNLOCK_MUTEX(rmutex);
2770 return MDB_READERS_FULL;
2772 r = &ti->mti_readers[i];
2773 /* Claim the reader slot, carefully since other code
2774 * uses the reader table un-mutexed: First reset the
2775 * slot, next publish it in mti_numreaders. After
2776 * that, it is safe for mdb_env_close() to touch it.
2777 * When it will be closed, we can finally claim it.
2780 r->mr_txnid = (txnid_t)-1;
2783 ti->mti_numreaders = ++nr;
2784 env->me_close_readers = nr;
2786 UNLOCK_MUTEX(rmutex);
2788 new_notls = (env->me_flags & MDB_NOTLS);
2789 if (!new_notls && (rc=pthread_setspecific(env->me_txkey, r))) {
2794 do /* LY: Retry on a race, ITS#7970. */
2795 r->mr_txnid = ti->mti_txnid;
2796 while(r->mr_txnid != ti->mti_txnid);
2797 txn->mt_txnid = r->mr_txnid;
2798 txn->mt_u.reader = r;
2799 meta = env->me_metas[txn->mt_txnid & 1];
2803 /* Not yet touching txn == env->me_txn0, it may be active */
2805 if (LOCK_MUTEX(rc, env, env->me_wmutex))
2807 txn->mt_txnid = ti->mti_txnid;
2808 meta = env->me_metas[txn->mt_txnid & 1];
2810 meta = mdb_env_pick_meta(env);
2811 txn->mt_txnid = meta->mm_txnid;
2815 if (txn->mt_txnid == mdb_debug_start)
2818 txn->mt_child = NULL;
2819 txn->mt_loose_pgs = NULL;
2820 txn->mt_loose_count = 0;
2821 txn->mt_dirty_room = MDB_IDL_UM_MAX;
2822 txn->mt_u.dirty_list = env->me_dirty_list;
2823 txn->mt_u.dirty_list[0].mid = 0;
2824 txn->mt_free_pgs = env->me_free_pgs;
2825 txn->mt_free_pgs[0] = 0;
2826 txn->mt_spill_pgs = NULL;
2828 memcpy(txn->mt_dbiseqs, env->me_dbiseqs, env->me_maxdbs * sizeof(unsigned int));
2831 /* Copy the DB info and flags */
2832 memcpy(txn->mt_dbs, meta->mm_dbs, CORE_DBS * sizeof(MDB_db));
2834 /* Moved to here to avoid a data race in read TXNs */
2835 txn->mt_next_pgno = meta->mm_last_pg+1;
2837 txn->mt_flags = flags;
2840 txn->mt_numdbs = env->me_numdbs;
2841 for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
2842 x = env->me_dbflags[i];
2843 txn->mt_dbs[i].md_flags = x & PERSISTENT_FLAGS;
2844 txn->mt_dbflags[i] = (x & MDB_VALID) ? DB_VALID|DB_USRVALID|DB_STALE : 0;
2846 txn->mt_dbflags[MAIN_DBI] = DB_VALID|DB_USRVALID;
2847 txn->mt_dbflags[FREE_DBI] = DB_VALID;
2849 if (env->me_flags & MDB_FATAL_ERROR) {
2850 DPUTS("environment had fatal error, must shutdown!");
2852 } else if (env->me_maxpg < txn->mt_next_pgno) {
2853 rc = MDB_MAP_RESIZED;
2857 mdb_txn_end(txn, new_notls /*0 or MDB_END_SLOT*/ | MDB_END_FAIL_BEGIN);
2862 mdb_txn_renew(MDB_txn *txn)
2866 if (!txn || !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY|MDB_TXN_FINISHED))
2869 rc = mdb_txn_renew0(txn);
2870 if (rc == MDB_SUCCESS) {
2871 DPRINTF(("renew txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2872 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2873 (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root));
2879 mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
2883 int rc, size, tsize;
2885 flags &= MDB_TXN_BEGIN_FLAGS;
2886 flags |= env->me_flags & MDB_WRITEMAP;
2888 if (env->me_flags & MDB_RDONLY & ~flags) /* write txn in RDONLY env */
2892 /* Nested transactions: Max 1 child, write txns only, no writemap */
2893 flags |= parent->mt_flags;
2894 if (flags & (MDB_RDONLY|MDB_WRITEMAP|MDB_TXN_BLOCKED)) {
2895 return (parent->mt_flags & MDB_TXN_RDONLY) ? EINVAL : MDB_BAD_TXN;
2897 /* Child txns save MDB_pgstate and use own copy of cursors */
2898 size = env->me_maxdbs * (sizeof(MDB_db)+sizeof(MDB_cursor *)+1);
2899 size += tsize = sizeof(MDB_ntxn);
2900 } else if (flags & MDB_RDONLY) {
2901 size = env->me_maxdbs * (sizeof(MDB_db)+1);
2902 size += tsize = sizeof(MDB_txn);
2904 /* Reuse preallocated write txn. However, do not touch it until
2905 * mdb_txn_renew0() succeeds, since it currently may be active.
2910 if ((txn = calloc(1, size)) == NULL) {
2911 DPRINTF(("calloc: %s", strerror(errno)));
2914 txn->mt_dbxs = env->me_dbxs; /* static */
2915 txn->mt_dbs = (MDB_db *) ((char *)txn + tsize);
2916 txn->mt_dbflags = (unsigned char *)txn + size - env->me_maxdbs;
2917 txn->mt_flags = flags;
2922 txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
2923 txn->mt_dbiseqs = parent->mt_dbiseqs;
2924 txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE);
2925 if (!txn->mt_u.dirty_list ||
2926 !(txn->mt_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)))
2928 free(txn->mt_u.dirty_list);
2932 txn->mt_txnid = parent->mt_txnid;
2933 txn->mt_dirty_room = parent->mt_dirty_room;
2934 txn->mt_u.dirty_list[0].mid = 0;
2935 txn->mt_spill_pgs = NULL;
2936 txn->mt_next_pgno = parent->mt_next_pgno;
2937 parent->mt_flags |= MDB_TXN_HAS_CHILD;
2938 parent->mt_child = txn;
2939 txn->mt_parent = parent;
2940 txn->mt_numdbs = parent->mt_numdbs;
2941 memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
2942 /* Copy parent's mt_dbflags, but clear DB_NEW */
2943 for (i=0; i<txn->mt_numdbs; i++)
2944 txn->mt_dbflags[i] = parent->mt_dbflags[i] & ~DB_NEW;
2946 ntxn = (MDB_ntxn *)txn;
2947 ntxn->mnt_pgstate = env->me_pgstate; /* save parent me_pghead & co */
2948 if (env->me_pghead) {
2949 size = MDB_IDL_SIZEOF(env->me_pghead);
2950 env->me_pghead = mdb_midl_alloc(env->me_pghead[0]);
2952 memcpy(env->me_pghead, ntxn->mnt_pgstate.mf_pghead, size);
2957 rc = mdb_cursor_shadow(parent, txn);
2959 mdb_txn_end(txn, MDB_END_FAIL_BEGINCHILD);
2960 } else { /* MDB_RDONLY */
2961 txn->mt_dbiseqs = env->me_dbiseqs;
2963 rc = mdb_txn_renew0(txn);
2966 if (txn != env->me_txn0)
2969 txn->mt_flags |= flags; /* could not change txn=me_txn0 earlier */
2971 DPRINTF(("begin txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2972 txn->mt_txnid, (flags & MDB_RDONLY) ? 'r' : 'w',
2973 (void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root));
2980 mdb_txn_env(MDB_txn *txn)
2982 if(!txn) return NULL;
2987 mdb_txn_id(MDB_txn *txn)
2990 return txn->mt_txnid;
2993 /** Export or close DBI handles opened in this txn. */
2995 mdb_dbis_update(MDB_txn *txn, int keep)
2998 MDB_dbi n = txn->mt_numdbs;
2999 MDB_env *env = txn->mt_env;
3000 unsigned char *tdbflags = txn->mt_dbflags;
3002 for (i = n; --i >= CORE_DBS;) {
3003 if (tdbflags[i] & DB_NEW) {
3005 env->me_dbflags[i] = txn->mt_dbs[i].md_flags | MDB_VALID;
3007 char *ptr = env->me_dbxs[i].md_name.mv_data;
3009 env->me_dbxs[i].md_name.mv_data = NULL;
3010 env->me_dbxs[i].md_name.mv_size = 0;
3011 env->me_dbflags[i] = 0;
3012 env->me_dbiseqs[i]++;
3018 if (keep && env->me_numdbs < n)
3022 /** End a transaction, except successful commit of a nested transaction.
3023 * May be called twice for readonly txns: First reset it, then abort.
3024 * @param[in] txn the transaction handle to end
3025 * @param[in] mode why and how to end the transaction
3028 mdb_txn_end(MDB_txn *txn, unsigned mode)
3030 MDB_env *env = txn->mt_env;
3032 static const char *const names[] = MDB_END_NAMES;
3035 /* Export or close DBI handles opened in this txn */
3036 mdb_dbis_update(txn, mode & MDB_END_UPDATE);
3038 DPRINTF(("%s txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
3039 names[mode & MDB_END_OPMASK],
3040 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
3041 (void *) txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root));
3043 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
3044 if (txn->mt_u.reader) {
3045 txn->mt_u.reader->mr_txnid = (txnid_t)-1;
3046 if (!(env->me_flags & MDB_NOTLS)) {
3047 txn->mt_u.reader = NULL; /* txn does not own reader */
3048 } else if (mode & MDB_END_SLOT) {
3049 txn->mt_u.reader->mr_pid = 0;
3050 txn->mt_u.reader = NULL;
3051 } /* else txn owns the slot until it does MDB_END_SLOT */
3053 txn->mt_numdbs = 0; /* prevent further DBI activity */
3054 txn->mt_flags |= MDB_TXN_FINISHED;
3056 } else if (!F_ISSET(txn->mt_flags, MDB_TXN_FINISHED)) {
3057 pgno_t *pghead = env->me_pghead;
3059 if (!(mode & MDB_END_UPDATE)) /* !(already closed cursors) */
3060 mdb_cursors_close(txn, 0);
3061 if (!(env->me_flags & MDB_WRITEMAP)) {
3062 mdb_dlist_free(txn);
3066 txn->mt_flags = MDB_TXN_FINISHED;
3068 if (!txn->mt_parent) {
3069 mdb_midl_shrink(&txn->mt_free_pgs);
3070 env->me_free_pgs = txn->mt_free_pgs;
3072 env->me_pghead = NULL;
3076 mode = 0; /* txn == env->me_txn0, do not free() it */
3078 /* The writer mutex was locked in mdb_txn_begin. */
3080 UNLOCK_MUTEX(env->me_wmutex);
3082 txn->mt_parent->mt_child = NULL;
3083 txn->mt_parent->mt_flags &= ~MDB_TXN_HAS_CHILD;
3084 env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate;
3085 mdb_midl_free(txn->mt_free_pgs);
3086 mdb_midl_free(txn->mt_spill_pgs);
3087 free(txn->mt_u.dirty_list);
3090 mdb_midl_free(pghead);
3093 if (mode & MDB_END_FREE)
3098 mdb_txn_reset(MDB_txn *txn)
3103 /* This call is only valid for read-only txns */
3104 if (!(txn->mt_flags & MDB_TXN_RDONLY))
3107 mdb_txn_end(txn, MDB_END_RESET);
3111 mdb_txn_abort(MDB_txn *txn)
3117 mdb_txn_abort(txn->mt_child);
3119 mdb_txn_end(txn, MDB_END_ABORT|MDB_END_SLOT|MDB_END_FREE);
3122 /** Save the freelist as of this transaction to the freeDB.
3123 * This changes the freelist. Keep trying until it stabilizes.
3126 mdb_freelist_save(MDB_txn *txn)
3128 /* env->me_pghead[] can grow and shrink during this call.
3129 * env->me_pglast and txn->mt_free_pgs[] can only grow.
3130 * Page numbers cannot disappear from txn->mt_free_pgs[].
3133 MDB_env *env = txn->mt_env;
3134 int rc, maxfree_1pg = env->me_maxfree_1pg, more = 1;
3135 txnid_t pglast = 0, head_id = 0;
3136 pgno_t freecnt = 0, *free_pgs, *mop;
3137 ssize_t head_room = 0, total_room = 0, mop_len, clean_limit;
3139 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
3141 if (env->me_pghead) {
3142 /* Make sure first page of freeDB is touched and on freelist */
3143 rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST|MDB_PS_MODIFY);
3144 if (rc && rc != MDB_NOTFOUND)
3148 if (!env->me_pghead && txn->mt_loose_pgs) {
3149 /* Put loose page numbers in mt_free_pgs, since
3150 * we may be unable to return them to me_pghead.
3152 MDB_page *mp = txn->mt_loose_pgs;
3153 if ((rc = mdb_midl_need(&txn->mt_free_pgs, txn->mt_loose_count)) != 0)
3155 for (; mp; mp = NEXT_LOOSE_PAGE(mp))
3156 mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
3157 txn->mt_loose_pgs = NULL;
3158 txn->mt_loose_count = 0;
3161 /* MDB_RESERVE cancels meminit in ovpage malloc (when no WRITEMAP) */
3162 clean_limit = (env->me_flags & (MDB_NOMEMINIT|MDB_WRITEMAP))
3163 ? SSIZE_MAX : maxfree_1pg;
3166 /* Come back here after each Put() in case freelist changed */
3171 /* If using records from freeDB which we have not yet
3172 * deleted, delete them and any we reserved for me_pghead.
3174 while (pglast < env->me_pglast) {
3175 rc = mdb_cursor_first(&mc, &key, NULL);
3178 pglast = head_id = *(txnid_t *)key.mv_data;
3179 total_room = head_room = 0;
3180 mdb_tassert(txn, pglast <= env->me_pglast);
3181 rc = mdb_cursor_del(&mc, 0);
3186 /* Save the IDL of pages freed by this txn, to a single record */
3187 if (freecnt < txn->mt_free_pgs[0]) {
3189 /* Make sure last page of freeDB is touched and on freelist */
3190 rc = mdb_page_search(&mc, NULL, MDB_PS_LAST|MDB_PS_MODIFY);
3191 if (rc && rc != MDB_NOTFOUND)
3194 free_pgs = txn->mt_free_pgs;
3195 /* Write to last page of freeDB */
3196 key.mv_size = sizeof(txn->mt_txnid);
3197 key.mv_data = &txn->mt_txnid;
3199 freecnt = free_pgs[0];
3200 data.mv_size = MDB_IDL_SIZEOF(free_pgs);
3201 rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
3204 /* Retry if mt_free_pgs[] grew during the Put() */
3205 free_pgs = txn->mt_free_pgs;
3206 } while (freecnt < free_pgs[0]);
3207 mdb_midl_sort(free_pgs);
3208 memcpy(data.mv_data, free_pgs, data.mv_size);
3211 unsigned int i = free_pgs[0];
3212 DPRINTF(("IDL write txn %"Z"u root %"Z"u num %u",
3213 txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, i));
3215 DPRINTF(("IDL %"Z"u", free_pgs[i]));
3221 mop = env->me_pghead;
3222 mop_len = (mop ? mop[0] : 0) + txn->mt_loose_count;
3224 /* Reserve records for me_pghead[]. Split it if multi-page,
3225 * to avoid searching freeDB for a page range. Use keys in
3226 * range [1,me_pglast]: Smaller than txnid of oldest reader.
3228 if (total_room >= mop_len) {
3229 if (total_room == mop_len || --more < 0)
3231 } else if (head_room >= maxfree_1pg && head_id > 1) {
3232 /* Keep current record (overflow page), add a new one */
3236 /* (Re)write {key = head_id, IDL length = head_room} */
3237 total_room -= head_room;
3238 head_room = mop_len - total_room;
3239 if (head_room > maxfree_1pg && head_id > 1) {
3240 /* Overflow multi-page for part of me_pghead */
3241 head_room /= head_id; /* amortize page sizes */
3242 head_room += maxfree_1pg - head_room % (maxfree_1pg + 1);
3243 } else if (head_room < 0) {
3244 /* Rare case, not bothering to delete this record */
3247 key.mv_size = sizeof(head_id);
3248 key.mv_data = &head_id;
3249 data.mv_size = (head_room + 1) * sizeof(pgno_t);
3250 rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
3253 /* IDL is initially empty, zero out at least the length */
3254 pgs = (pgno_t *)data.mv_data;
3255 j = head_room > clean_limit ? head_room : 0;
3259 total_room += head_room;
3262 /* Return loose page numbers to me_pghead, though usually none are
3263 * left at this point. The pages themselves remain in dirty_list.
3265 if (txn->mt_loose_pgs) {
3266 MDB_page *mp = txn->mt_loose_pgs;
3267 unsigned count = txn->mt_loose_count;
3269 /* Room for loose pages + temp IDL with same */
3270 if ((rc = mdb_midl_need(&env->me_pghead, 2*count+1)) != 0)
3272 mop = env->me_pghead;
3273 loose = mop + MDB_IDL_ALLOCLEN(mop) - count;
3274 for (count = 0; mp; mp = NEXT_LOOSE_PAGE(mp))
3275 loose[ ++count ] = mp->mp_pgno;
3277 mdb_midl_sort(loose);
3278 mdb_midl_xmerge(mop, loose);
3279 txn->mt_loose_pgs = NULL;
3280 txn->mt_loose_count = 0;
3284 /* Fill in the reserved me_pghead records */
3290 rc = mdb_cursor_first(&mc, &key, &data);
3291 for (; !rc; rc = mdb_cursor_next(&mc, &key, &data, MDB_NEXT)) {
3292 txnid_t id = *(txnid_t *)key.mv_data;
3293 ssize_t len = (ssize_t)(data.mv_size / sizeof(MDB_ID)) - 1;
3296 mdb_tassert(txn, len >= 0 && id <= env->me_pglast);
3298 if (len > mop_len) {
3300 data.mv_size = (len + 1) * sizeof(MDB_ID);
3302 data.mv_data = mop -= len;
3305 rc = mdb_cursor_put(&mc, &key, &data, MDB_CURRENT);
3307 if (rc || !(mop_len -= len))
3314 /** Flush (some) dirty pages to the map, after clearing their dirty flag.
3315 * @param[in] txn the transaction that's being committed
3316 * @param[in] keep number of initial pages in dirty_list to keep dirty.
3317 * @return 0 on success, non-zero on failure.
3320 mdb_page_flush(MDB_txn *txn, int keep)
3322 MDB_env *env = txn->mt_env;
3323 MDB_ID2L dl = txn->mt_u.dirty_list;
3324 unsigned psize = env->me_psize, j;
3325 int i, pagecount = dl[0].mid, rc;
3326 size_t size = 0, pos = 0;
3328 MDB_page *dp = NULL;
3332 struct iovec iov[MDB_COMMIT_PAGES];
3333 ssize_t wpos = 0, wsize = 0, wres;
3334 size_t next_pos = 1; /* impossible pos, so pos != next_pos */
3340 if (env->me_flags & MDB_WRITEMAP) {
3341 /* Clear dirty flags */
3342 while (++i <= pagecount) {
3344 /* Don't flush this page yet */
3345 if (dp->mp_flags & (P_LOOSE|P_KEEP)) {
3346 dp->mp_flags &= ~P_KEEP;
3350 dp->mp_flags &= ~P_DIRTY;
3355 /* Write the pages */
3357 if (++i <= pagecount) {
3359 /* Don't flush this page yet */
3360 if (dp->mp_flags & (P_LOOSE|P_KEEP)) {
3361 dp->mp_flags &= ~P_KEEP;
3366 /* clear dirty flag */
3367 dp->mp_flags &= ~P_DIRTY;
3370 if (IS_OVERFLOW(dp)) size *= dp->mp_pages;
3375 /* Windows actually supports scatter/gather I/O, but only on
3376 * unbuffered file handles. Since we're relying on the OS page
3377 * cache for all our data, that's self-defeating. So we just
3378 * write pages one at a time. We use the ov structure to set
3379 * the write offset, to at least save the overhead of a Seek
3382 DPRINTF(("committing page %"Z"u", pgno));
3383 memset(&ov, 0, sizeof(ov));
3384 ov.Offset = pos & 0xffffffff;
3385 ov.OffsetHigh = pos >> 16 >> 16;
3386 if (!WriteFile(env->me_fd, dp, size, NULL, &ov)) {
3388 DPRINTF(("WriteFile: %d", rc));
3392 /* Write up to MDB_COMMIT_PAGES dirty pages at a time. */
3393 if (pos!=next_pos || n==MDB_COMMIT_PAGES || wsize+size>MAX_WRITE) {
3396 /* Write previous page(s) */
3397 #ifdef MDB_USE_PWRITEV
3398 wres = pwritev(env->me_fd, iov, n, wpos);
3401 wres = pwrite(env->me_fd, iov[0].iov_base, wsize, wpos);
3404 if (lseek(env->me_fd, wpos, SEEK_SET) == -1) {
3408 DPRINTF(("lseek: %s", strerror(rc)));
3411 wres = writev(env->me_fd, iov, n);
3414 if (wres != wsize) {
3419 DPRINTF(("Write error: %s", strerror(rc)));
3421 rc = EIO; /* TODO: Use which error code? */
3422 DPUTS("short write, filesystem full?");
3433 DPRINTF(("committing page %"Z"u", pgno));
3434 next_pos = pos + size;
3435 iov[n].iov_len = size;
3436 iov[n].iov_base = (char *)dp;
3442 /* MIPS has cache coherency issues, this is a no-op everywhere else
3443 * Note: for any size >= on-chip cache size, entire on-chip cache is
3446 CACHEFLUSH(env->me_map, txn->mt_next_pgno * env->me_psize, DCACHE);
3448 for (i = keep; ++i <= pagecount; ) {
3450 /* This is a page we skipped above */
3453 dl[j].mid = dp->mp_pgno;
3456 mdb_dpage_free(env, dp);
3461 txn->mt_dirty_room += i - j;
3467 mdb_txn_commit(MDB_txn *txn)
3470 unsigned int i, end_mode;
3476 /* mdb_txn_end() mode for a commit which writes nothing */
3477 end_mode = MDB_END_EMPTY_COMMIT|MDB_END_UPDATE|MDB_END_SLOT|MDB_END_FREE;
3479 if (txn->mt_child) {
3480 rc = mdb_txn_commit(txn->mt_child);
3487 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
3491 if (txn->mt_flags & (MDB_TXN_FINISHED|MDB_TXN_ERROR)) {
3492 DPUTS("txn has failed/finished, can't commit");
3494 txn->mt_parent->mt_flags |= MDB_TXN_ERROR;
3499 if (txn->mt_parent) {
3500 MDB_txn *parent = txn->mt_parent;
3504 unsigned x, y, len, ps_len;
3506 /* Append our free list to parent's */
3507 rc = mdb_midl_append_list(&parent->mt_free_pgs, txn->mt_free_pgs);
3510 mdb_midl_free(txn->mt_free_pgs);
3511 /* Failures after this must either undo the changes
3512 * to the parent or set MDB_TXN_ERROR in the parent.
3515 parent->mt_next_pgno = txn->mt_next_pgno;
3516 parent->mt_flags = txn->mt_flags;
3518 /* Merge our cursors into parent's and close them */
3519 mdb_cursors_close(txn, 1);
3521 /* Update parent's DB table. */
3522 memcpy(parent->mt_dbs, txn->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
3523 parent->mt_numdbs = txn->mt_numdbs;
3524 parent->mt_dbflags[FREE_DBI] = txn->mt_dbflags[FREE_DBI];
3525 parent->mt_dbflags[MAIN_DBI] = txn->mt_dbflags[MAIN_DBI];
3526 for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
3527 /* preserve parent's DB_NEW status */
3528 x = parent->mt_dbflags[i] & DB_NEW;
3529 parent->mt_dbflags[i] = txn->mt_dbflags[i] | x;
3532 dst = parent->mt_u.dirty_list;
3533 src = txn->mt_u.dirty_list;
3534 /* Remove anything in our dirty list from parent's spill list */
3535 if ((pspill = parent->mt_spill_pgs) && (ps_len = pspill[0])) {
3537 pspill[0] = (pgno_t)-1;
3538 /* Mark our dirty pages as deleted in parent spill list */
3539 for (i=0, len=src[0].mid; ++i <= len; ) {
3540 MDB_ID pn = src[i].mid << 1;
3541 while (pn > pspill[x])
3543 if (pn == pspill[x]) {
3548 /* Squash deleted pagenums if we deleted any */
3549 for (x=y; ++x <= ps_len; )
3550 if (!(pspill[x] & 1))
3551 pspill[++y] = pspill[x];
3555 /* Remove anything in our spill list from parent's dirty list */
3556 if (txn->mt_spill_pgs && txn->mt_spill_pgs[0]) {
3557 for (i=1; i<=txn->mt_spill_pgs[0]; i++) {
3558 MDB_ID pn = txn->mt_spill_pgs[i];
3560 continue; /* deleted spillpg */
3562 y = mdb_mid2l_search(dst, pn);
3563 if (y <= dst[0].mid && dst[y].mid == pn) {
3565 while (y < dst[0].mid) {
3574 /* Find len = length of merging our dirty list with parent's */
3576 dst[0].mid = 0; /* simplify loops */
3577 if (parent->mt_parent) {
3578 len = x + src[0].mid;
3579 y = mdb_mid2l_search(src, dst[x].mid + 1) - 1;
3580 for (i = x; y && i; y--) {
3581 pgno_t yp = src[y].mid;
3582 while (yp < dst[i].mid)
3584 if (yp == dst[i].mid) {
3589 } else { /* Simplify the above for single-ancestor case */
3590 len = MDB_IDL_UM_MAX - txn->mt_dirty_room;
3592 /* Merge our dirty list with parent's */
3594 for (i = len; y; dst[i--] = src[y--]) {
3595 pgno_t yp = src[y].mid;
3596 while (yp < dst[x].mid)
3597 dst[i--] = dst[x--];
3598 if (yp == dst[x].mid)
3599 free(dst[x--].mptr);
3601 mdb_tassert(txn, i == x);
3603 free(txn->mt_u.dirty_list);
3604 parent->mt_dirty_room = txn->mt_dirty_room;
3605 if (txn->mt_spill_pgs) {
3606 if (parent->mt_spill_pgs) {
3607 /* TODO: Prevent failure here, so parent does not fail */
3608 rc = mdb_midl_append_list(&parent->mt_spill_pgs, txn->mt_spill_pgs);
3610 parent->mt_flags |= MDB_TXN_ERROR;
3611 mdb_midl_free(txn->mt_spill_pgs);
3612 mdb_midl_sort(parent->mt_spill_pgs);
3614 parent->mt_spill_pgs = txn->mt_spill_pgs;
3618 /* Append our loose page list to parent's */
3619 for (lp = &parent->mt_loose_pgs; *lp; lp = &NEXT_LOOSE_PAGE(*lp))
3621 *lp = txn->mt_loose_pgs;
3622 parent->mt_loose_count += txn->mt_loose_count;
3624 parent->mt_child = NULL;
3625 mdb_midl_free(((MDB_ntxn *)txn)->mnt_pgstate.mf_pghead);
3630 if (txn != env->me_txn) {
3631 DPUTS("attempt to commit unknown transaction");
3636 mdb_cursors_close(txn, 0);
3638 if (!txn->mt_u.dirty_list[0].mid &&
3639 !(txn->mt_flags & (MDB_TXN_DIRTY|MDB_TXN_SPILLS)))
3642 DPRINTF(("committing txn %"Z"u %p on mdbenv %p, root page %"Z"u",
3643 txn->mt_txnid, (void*)txn, (void*)env, txn->mt_dbs[MAIN_DBI].md_root));
3645 /* Update DB root pointers */
3646 if (txn->mt_numdbs > CORE_DBS) {
3650 data.mv_size = sizeof(MDB_db);
3652 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
3653 for (i = CORE_DBS; i < txn->mt_numdbs; i++) {
3654 if (txn->mt_dbflags[i] & DB_DIRTY) {
3655 if (TXN_DBI_CHANGED(txn, i)) {
3659 data.mv_data = &txn->mt_dbs[i];
3660 rc = mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data,
3668 rc = mdb_freelist_save(txn);
3672 mdb_midl_free(env->me_pghead);
3673 env->me_pghead = NULL;
3674 mdb_midl_shrink(&txn->mt_free_pgs);
3680 if ((rc = mdb_page_flush(txn, 0)))
3682 if (!F_ISSET(txn->mt_flags, MDB_TXN_NOSYNC) &&
3683 (rc = mdb_env_sync(env, 0)))
3685 if ((rc = mdb_env_write_meta(txn)))
3687 end_mode = MDB_END_COMMITTED|MDB_END_UPDATE;
3690 mdb_txn_end(txn, end_mode);
3698 /** Read the environment parameters of a DB environment before
3699 * mapping it into memory.
3700 * @param[in] env the environment handle
3701 * @param[out] meta address of where to store the meta information
3702 * @return 0 on success, non-zero on failure.
3705 mdb_env_read_header(MDB_env *env, MDB_meta *meta)
3711 enum { Size = sizeof(pbuf) };
3713 /* We don't know the page size yet, so use a minimum value.
3714 * Read both meta pages so we can use the latest one.
3717 for (i=off=0; i<NUM_METAS; i++, off += meta->mm_psize) {
3721 memset(&ov, 0, sizeof(ov));
3723 rc = ReadFile(env->me_fd, &pbuf, Size, &len, &ov) ? (int)len : -1;
3724 if (rc == -1 && ErrCode() == ERROR_HANDLE_EOF)
3727 rc = pread(env->me_fd, &pbuf, Size, off);
3730 if (rc == 0 && off == 0)
3732 rc = rc < 0 ? (int) ErrCode() : MDB_INVALID;
3733 DPRINTF(("read: %s", mdb_strerror(rc)));
3737 p = (MDB_page *)&pbuf;
3739 if (!F_ISSET(p->mp_flags, P_META)) {
3740 DPRINTF(("page %"Z"u not a meta page", p->mp_pgno));
3745 if (m->mm_magic != MDB_MAGIC) {
3746 DPUTS("meta has invalid magic");
3750 if (m->mm_version != MDB_DATA_VERSION) {
3751 DPRINTF(("database is version %u, expected version %u",
3752 m->mm_version, MDB_DATA_VERSION));
3753 return MDB_VERSION_MISMATCH;
3756 if (off == 0 || m->mm_txnid > meta->mm_txnid)
3762 /** Fill in most of the zeroed #MDB_meta for an empty database environment */
3764 mdb_env_init_meta0(MDB_env *env, MDB_meta *meta)
3766 meta->mm_magic = MDB_MAGIC;
3767 meta->mm_version = MDB_DATA_VERSION;
3768 meta->mm_mapsize = env->me_mapsize;
3769 meta->mm_psize = env->me_psize;
3770 meta->mm_last_pg = NUM_METAS-1;
3771 meta->mm_flags = env->me_flags & 0xffff;
3772 meta->mm_flags |= MDB_INTEGERKEY; /* this is mm_dbs[FREE_DBI].md_flags */
3773 meta->mm_dbs[FREE_DBI].md_root = P_INVALID;
3774 meta->mm_dbs[MAIN_DBI].md_root = P_INVALID;
3777 /** Write the environment parameters of a freshly created DB environment.
3778 * @param[in] env the environment handle
3779 * @param[in] meta the #MDB_meta to write
3780 * @return 0 on success, non-zero on failure.
3783 mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
3791 memset(&ov, 0, sizeof(ov));
3792 #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
3794 rc = WriteFile(fd, ptr, size, &len, &ov); } while(0)
3797 #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
3798 len = pwrite(fd, ptr, size, pos); \
3799 if (len == -1 && ErrCode() == EINTR) continue; \
3800 rc = (len >= 0); break; } while(1)
3803 DPUTS("writing new meta page");
3805 psize = env->me_psize;
3807 p = calloc(NUM_METAS, psize);
3811 p->mp_flags = P_META;
3812 *(MDB_meta *)METADATA(p) = *meta;
3814 q = (MDB_page *)((char *)p + psize);
3816 q->mp_flags = P_META;
3817 *(MDB_meta *)METADATA(q) = *meta;
3819 DO_PWRITE(rc, env->me_fd, p, psize * NUM_METAS, len, 0);
3822 else if ((unsigned) len == psize * NUM_METAS)
3830 /** Update the environment info to commit a transaction.
3831 * @param[in] txn the transaction that's being committed
3832 * @return 0 on success, non-zero on failure.
3835 mdb_env_write_meta(MDB_txn *txn)
3838 MDB_meta meta, metab, *mp;
3842 int rc, len, toggle;
3851 toggle = txn->mt_txnid & 1;
3852 DPRINTF(("writing meta page %d for root page %"Z"u",
3853 toggle, txn->mt_dbs[MAIN_DBI].md_root));
3856 flags = txn->mt_flags | env->me_flags;
3857 mp = env->me_metas[toggle];
3858 mapsize = env->me_metas[toggle ^ 1]->mm_mapsize;
3859 /* Persist any increases of mapsize config */
3860 if (mapsize < env->me_mapsize)
3861 mapsize = env->me_mapsize;
3863 if (flags & MDB_WRITEMAP) {
3864 mp->mm_mapsize = mapsize;
3865 mp->mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI];
3866 mp->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
3867 mp->mm_last_pg = txn->mt_next_pgno - 1;
3868 #if (__GNUC__ * 100 + __GNUC_MINOR__ >= 404) && /* TODO: portability */ \
3869 !(defined(__i386__) || defined(__x86_64__))
3870 /* LY: issue a memory barrier, if not x86. ITS#7969 */
3871 __sync_synchronize();
3873 mp->mm_txnid = txn->mt_txnid;
3874 if (!(flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {
3875 unsigned meta_size = env->me_psize;
3876 rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;
3877 ptr = (char *)mp - PAGEHDRSZ;
3878 #ifndef _WIN32 /* POSIX msync() requires ptr = start of OS page */
3879 r2 = (ptr - env->me_map) & (env->me_os_psize - 1);
3883 if (MDB_MSYNC(ptr, meta_size, rc)) {
3890 metab.mm_txnid = mp->mm_txnid;
3891 metab.mm_last_pg = mp->mm_last_pg;
3893 meta.mm_mapsize = mapsize;
3894 meta.mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI];
3895 meta.mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
3896 meta.mm_last_pg = txn->mt_next_pgno - 1;
3897 meta.mm_txnid = txn->mt_txnid;
3899 off = offsetof(MDB_meta, mm_mapsize);
3900 ptr = (char *)&meta + off;
3901 len = sizeof(MDB_meta) - off;
3902 off += (char *)mp - env->me_map;
3904 /* Write to the SYNC fd */
3905 mfd = (flags & (MDB_NOSYNC|MDB_NOMETASYNC)) ? env->me_fd : env->me_mfd;
3908 memset(&ov, 0, sizeof(ov));
3910 if (!WriteFile(mfd, ptr, len, (DWORD *)&rc, &ov))
3915 rc = pwrite(mfd, ptr, len, off);
3918 rc = rc < 0 ? ErrCode() : EIO;
3923 DPUTS("write failed, disk error?");
3924 /* On a failure, the pagecache still contains the new data.
3925 * Write some old data back, to prevent it from being used.
3926 * Use the non-SYNC fd; we know it will fail anyway.
3928 meta.mm_last_pg = metab.mm_last_pg;
3929 meta.mm_txnid = metab.mm_txnid;
3931 memset(&ov, 0, sizeof(ov));
3933 WriteFile(env->me_fd, ptr, len, NULL, &ov);
3935 r2 = pwrite(env->me_fd, ptr, len, off);
3936 (void)r2; /* Silence warnings. We don't care about pwrite's return value */
3939 env->me_flags |= MDB_FATAL_ERROR;
3942 /* MIPS has cache coherency issues, this is a no-op everywhere else */
3943 CACHEFLUSH(env->me_map + off, len, DCACHE);
3945 /* Memory ordering issues are irrelevant; since the entire writer
3946 * is wrapped by wmutex, all of these changes will become visible
3947 * after the wmutex is unlocked. Since the DB is multi-version,
3948 * readers will get consistent data regardless of how fresh or
3949 * how stale their view of these values is.
3952 env->me_txns->mti_txnid = txn->mt_txnid;
3957 /** Check both meta pages to see which one is newer.
3958 * @param[in] env the environment handle
3959 * @return newest #MDB_meta.
3962 mdb_env_pick_meta(const MDB_env *env)
3964 MDB_meta *const *metas = env->me_metas;
3965 return metas[ metas[0]->mm_txnid < metas[1]->mm_txnid ];
3969 mdb_env_create(MDB_env **env)
3973 e = calloc(1, sizeof(MDB_env));
3977 e->me_maxreaders = DEFAULT_READERS;
3978 e->me_maxdbs = e->me_numdbs = CORE_DBS;
3979 e->me_fd = INVALID_HANDLE_VALUE;
3980 e->me_lfd = INVALID_HANDLE_VALUE;
3981 e->me_mfd = INVALID_HANDLE_VALUE;
3982 #ifdef MDB_USE_POSIX_SEM
3983 e->me_rmutex = SEM_FAILED;
3984 e->me_wmutex = SEM_FAILED;
3985 #elif defined MDB_USE_SYSV_SEM
3986 e->me_rmutex->semid = -1;
3987 e->me_wmutex->semid = -1;
3989 e->me_pid = getpid();
3990 GET_PAGESIZE(e->me_os_psize);
3991 VGMEMP_CREATE(e,0,0);
3997 mdb_env_map(MDB_env *env, void *addr)
4000 unsigned int flags = env->me_flags;
4003 int access = SECTION_MAP_READ;
4007 ULONG pageprot = PAGE_READONLY;
4008 if (flags & MDB_WRITEMAP) {
4009 access |= SECTION_MAP_WRITE;
4010 pageprot = PAGE_READWRITE;
4013 rc = NtCreateSection(&mh, access, NULL, NULL, PAGE_READWRITE, SEC_RESERVE, env->me_fd);
4017 msize = env->me_mapsize;
4018 rc = NtMapViewOfSection(mh, GetCurrentProcess(), &map, 0, 0, NULL, &msize, ViewUnmap, MEM_RESERVE, pageprot);
4024 int prot = PROT_READ;
4025 if (flags & MDB_WRITEMAP) {
4027 if (ftruncate(env->me_fd, env->me_mapsize) < 0)
4030 env->me_map = mmap(addr, env->me_mapsize, prot, MAP_SHARED,
4032 if (env->me_map == MAP_FAILED) {
4037 if (flags & MDB_NORDAHEAD) {
4038 /* Turn off readahead. It's harmful when the DB is larger than RAM. */
4040 madvise(env->me_map, env->me_mapsize, MADV_RANDOM);
4042 #ifdef POSIX_MADV_RANDOM
4043 posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM);
4044 #endif /* POSIX_MADV_RANDOM */
4045 #endif /* MADV_RANDOM */
4049 /* Can happen because the address argument to mmap() is just a
4050 * hint. mmap() can pick another, e.g. if the range is in use.
4051 * The MAP_FIXED flag would prevent that, but then mmap could
4052 * instead unmap existing pages to make room for the new map.
4054 if (addr && env->me_map != addr)
4055 return EBUSY; /* TODO: Make a new MDB_* error code? */
4057 p = (MDB_page *)env->me_map;
4058 env->me_metas[0] = METADATA(p);
4059 env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + env->me_psize);
4065 mdb_env_set_mapsize(MDB_env *env, size_t size)
4067 /* If env is already open, caller is responsible for making
4068 * sure there are no active txns.
4076 meta = mdb_env_pick_meta(env);
4078 size = meta->mm_mapsize;
4080 /* Silently round up to minimum if the size is too small */
4081 size_t minsize = (meta->mm_last_pg + 1) * env->me_psize;
4085 munmap(env->me_map, env->me_mapsize);
4086 env->me_mapsize = size;
4087 old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL;
4088 rc = mdb_env_map(env, old);
4092 env->me_mapsize = size;
4094 env->me_maxpg = env->me_mapsize / env->me_psize;
4099 mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs)
4103 env->me_maxdbs = dbs + CORE_DBS;
4108 mdb_env_set_maxreaders(MDB_env *env, unsigned int readers)
4110 if (env->me_map || readers < 1)
4112 env->me_maxreaders = readers;
4117 mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)
4119 if (!env || !readers)
4121 *readers = env->me_maxreaders;
4126 mdb_fsize(HANDLE fd, size_t *size)
4129 LARGE_INTEGER fsize;
4131 if (!GetFileSizeEx(fd, &fsize))
4134 *size = fsize.QuadPart;
4146 #ifdef BROKEN_FDATASYNC
4147 #include <sys/utsname.h>
4148 #include <sys/vfs.h>
4151 /** Further setup required for opening an LMDB environment
4154 mdb_env_open2(MDB_env *env)
4156 unsigned int flags = env->me_flags;
4157 int i, newenv = 0, rc;
4161 /* See if we should use QueryLimited */
4163 if ((rc & 0xff) > 5)
4164 env->me_pidquery = MDB_PROCESS_QUERY_LIMITED_INFORMATION;
4166 env->me_pidquery = PROCESS_QUERY_INFORMATION;
4169 #ifdef BROKEN_FDATASYNC
4170 /* ext3/ext4 fdatasync is broken on some older Linux kernels.
4171 * https://lkml.org/lkml/2012/9/3/83
4172 * Kernels after 3.6-rc6 are known good.
4173 * https://lkml.org/lkml/2012/9/10/556
4174 * See if the DB is on ext3/ext4, then check for new enough kernel
4175 * Kernels 2.6.32.60, 2.6.34.15, 3.2.30, and 3.5.4 are also known
4180 fstatfs(env->me_fd, &st);
4181 while (st.f_type == 0xEF53) {
4185 if (uts.release[0] < '3') {
4186 if (!strncmp(uts.release, "2.6.32.", 7)) {
4187 i = atoi(uts.release+7);
4189 break; /* 2.6.32.60 and newer is OK */
4190 } else if (!strncmp(uts.release, "2.6.34.", 7)) {
4191 i = atoi(uts.release+7);
4193 break; /* 2.6.34.15 and newer is OK */
4195 } else if (uts.release[0] == '3') {
4196 i = atoi(uts.release+2);
4198 break; /* 3.6 and newer is OK */
4200 i = atoi(uts.release+4);
4202 break; /* 3.5.4 and newer is OK */
4203 } else if (i == 2) {
4204 i = atoi(uts.release+4);
4206 break; /* 3.2.30 and newer is OK */
4208 } else { /* 4.x and newer is OK */
4211 env->me_flags |= MDB_FSYNCONLY;
4217 if ((i = mdb_env_read_header(env, &meta)) != 0) {
4220 DPUTS("new mdbenv");
4222 env->me_psize = env->me_os_psize;
4223 if (env->me_psize > MAX_PAGESIZE)
4224 env->me_psize = MAX_PAGESIZE;
4225 memset(&meta, 0, sizeof(meta));
4226 mdb_env_init_meta0(env, &meta);
4227 meta.mm_mapsize = DEFAULT_MAPSIZE;
4229 env->me_psize = meta.mm_psize;
4232 /* Was a mapsize configured? */
4233 if (!env->me_mapsize) {
4234 env->me_mapsize = meta.mm_mapsize;
4237 /* Make sure mapsize >= committed data size. Even when using
4238 * mm_mapsize, which could be broken in old files (ITS#7789).
4240 size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize;
4241 if (env->me_mapsize < minsize)
4242 env->me_mapsize = minsize;
4244 meta.mm_mapsize = env->me_mapsize;
4246 if (newenv && !(flags & MDB_FIXEDMAP)) {
4247 /* mdb_env_map() may grow the datafile. Write the metapages
4248 * first, so the file will be valid if initialization fails.
4249 * Except with FIXEDMAP, since we do not yet know mm_address.
4250 * We could fill in mm_address later, but then a different
4251 * program might end up doing that - one with a memory layout
4252 * and map address which does not suit the main program.
4254 rc = mdb_env_init_meta(env, &meta);
4260 /* For FIXEDMAP, make sure the file is non-empty before we attempt to map it */
4264 rc = WriteFile(env->me_fd, &dummy, 1, &len, NULL);
4272 rc = mdb_env_map(env, (flags & MDB_FIXEDMAP) ? meta.mm_address : NULL);
4277 if (flags & MDB_FIXEDMAP)
4278 meta.mm_address = env->me_map;
4279 i = mdb_env_init_meta(env, &meta);
4280 if (i != MDB_SUCCESS) {
4285 env->me_maxfree_1pg = (env->me_psize - PAGEHDRSZ) / sizeof(pgno_t) - 1;
4286 env->me_nodemax = (((env->me_psize - PAGEHDRSZ) / MDB_MINKEYS) & -2)
4288 #if !(MDB_MAXKEYSIZE)
4289 env->me_maxkey = env->me_nodemax - (NODESIZE + sizeof(MDB_db));
4291 env->me_maxpg = env->me_mapsize / env->me_psize;
4295 MDB_meta *meta = mdb_env_pick_meta(env);
4296 MDB_db *db = &meta->mm_dbs[MAIN_DBI];
4298 DPRINTF(("opened database version %u, pagesize %u",
4299 meta->mm_version, env->me_psize));
4300 DPRINTF(("using meta page %d", (int) (meta->mm_txnid & 1)));
4301 DPRINTF(("depth: %u", db->md_depth));
4302 DPRINTF(("entries: %"Z"u", db->md_entries));
4303 DPRINTF(("branch pages: %"Z"u", db->md_branch_pages));
4304 DPRINTF(("leaf pages: %"Z"u", db->md_leaf_pages));
4305 DPRINTF(("overflow pages: %"Z"u", db->md_overflow_pages));
4306 DPRINTF(("root: %"Z"u", db->md_root));
4314 /** Release a reader thread's slot in the reader lock table.
4315 * This function is called automatically when a thread exits.
4316 * @param[in] ptr This points to the slot in the reader lock table.
4319 mdb_env_reader_dest(void *ptr)
4321 MDB_reader *reader = ptr;
4327 /** Junk for arranging thread-specific callbacks on Windows. This is
4328 * necessarily platform and compiler-specific. Windows supports up
4329 * to 1088 keys. Let's assume nobody opens more than 64 environments
4330 * in a single process, for now. They can override this if needed.
4332 #ifndef MAX_TLS_KEYS
4333 #define MAX_TLS_KEYS 64
4335 static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS];
4336 static int mdb_tls_nkeys;
4338 static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr)
4342 case DLL_PROCESS_ATTACH: break;
4343 case DLL_THREAD_ATTACH: break;
4344 case DLL_THREAD_DETACH:
4345 for (i=0; i<mdb_tls_nkeys; i++) {
4346 MDB_reader *r = pthread_getspecific(mdb_tls_keys[i]);
4348 mdb_env_reader_dest(r);
4352 case DLL_PROCESS_DETACH: break;
4357 const PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
4359 PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
4363 /* Force some symbol references.
4364 * _tls_used forces the linker to create the TLS directory if not already done
4365 * mdb_tls_cbp prevents whole-program-optimizer from dropping the symbol.
4367 #pragma comment(linker, "/INCLUDE:_tls_used")
4368 #pragma comment(linker, "/INCLUDE:mdb_tls_cbp")
4369 #pragma const_seg(".CRT$XLB")
4370 extern const PIMAGE_TLS_CALLBACK mdb_tls_cbp;
4371 const PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
4374 #pragma comment(linker, "/INCLUDE:__tls_used")
4375 #pragma comment(linker, "/INCLUDE:_mdb_tls_cbp")
4376 #pragma data_seg(".CRT$XLB")
4377 PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
4379 #endif /* WIN 32/64 */
4380 #endif /* !__GNUC__ */
4383 /** Downgrade the exclusive lock on the region back to shared */
4385 mdb_env_share_locks(MDB_env *env, int *excl)
4388 MDB_meta *meta = mdb_env_pick_meta(env);
4390 env->me_txns->mti_txnid = meta->mm_txnid;
4395 /* First acquire a shared lock. The Unlock will
4396 * then release the existing exclusive lock.
4398 memset(&ov, 0, sizeof(ov));
4399 if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
4402 UnlockFile(env->me_lfd, 0, 0, 1, 0);
4408 struct flock lock_info;
4409 /* The shared lock replaces the existing lock */
4410 memset((void *)&lock_info, 0, sizeof(lock_info));
4411 lock_info.l_type = F_RDLCK;
4412 lock_info.l_whence = SEEK_SET;
4413 lock_info.l_start = 0;
4414 lock_info.l_len = 1;
4415 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
4416 (rc = ErrCode()) == EINTR) ;
4417 *excl = rc ? -1 : 0; /* error may mean we lost the lock */
4424 /** Try to get exclusive lock, otherwise shared.
4425 * Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive.
4428 mdb_env_excl_lock(MDB_env *env, int *excl)
4432 if (LockFile(env->me_lfd, 0, 0, 1, 0)) {
4436 memset(&ov, 0, sizeof(ov));
4437 if (LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
4444 struct flock lock_info;
4445 memset((void *)&lock_info, 0, sizeof(lock_info));
4446 lock_info.l_type = F_WRLCK;
4447 lock_info.l_whence = SEEK_SET;
4448 lock_info.l_start = 0;
4449 lock_info.l_len = 1;
4450 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
4451 (rc = ErrCode()) == EINTR) ;
4455 # ifndef MDB_USE_POSIX_MUTEX
4456 if (*excl < 0) /* always true when MDB_USE_POSIX_MUTEX */
4459 lock_info.l_type = F_RDLCK;
4460 while ((rc = fcntl(env->me_lfd, F_SETLKW, &lock_info)) &&
4461 (rc = ErrCode()) == EINTR) ;
4471 * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code
4473 * @(#) $Revision: 5.1 $
4474 * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $
4475 * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $
4477 * http://www.isthe.com/chongo/tech/comp/fnv/index.html
4481 * Please do not copyright this code. This code is in the public domain.
4483 * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
4484 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
4485 * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
4486 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
4487 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
4488 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
4489 * PERFORMANCE OF THIS SOFTWARE.
4492 * chongo <Landon Curt Noll> /\oo/\
4493 * http://www.isthe.com/chongo/
4495 * Share and Enjoy! :-)
4498 typedef unsigned long long mdb_hash_t;
4499 #define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL)
4501 /** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer
4502 * @param[in] val value to hash
4503 * @param[in] hval initial value for hash
4504 * @return 64 bit hash
4506 * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the
4507 * hval arg on the first call.
4510 mdb_hash_val(MDB_val *val, mdb_hash_t hval)
4512 unsigned char *s = (unsigned char *)val->mv_data; /* unsigned string */
4513 unsigned char *end = s + val->mv_size;
4515 * FNV-1a hash each octet of the string
4518 /* xor the bottom with the current octet */
4519 hval ^= (mdb_hash_t)*s++;
4521 /* multiply by the 64 bit FNV magic prime mod 2^64 */
4522 hval += (hval << 1) + (hval << 4) + (hval << 5) +
4523 (hval << 7) + (hval << 8) + (hval << 40);
4525 /* return our new hash value */
4529 /** Hash the string and output the encoded hash.
4530 * This uses modified RFC1924 Ascii85 encoding to accommodate systems with
4531 * very short name limits. We don't care about the encoding being reversible,
4532 * we just want to preserve as many bits of the input as possible in a
4533 * small printable string.
4534 * @param[in] str string to hash
4535 * @param[out] encbuf an array of 11 chars to hold the hash
4537 static const char mdb_a85[]= "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";
4540 mdb_pack85(unsigned long l, char *out)
4544 for (i=0; i<5; i++) {
4545 *out++ = mdb_a85[l % 85];
4551 mdb_hash_enc(MDB_val *val, char *encbuf)
4553 mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT);
4555 mdb_pack85(h, encbuf);
4556 mdb_pack85(h>>32, encbuf+5);
4561 /** Open and/or initialize the lock region for the environment.
4562 * @param[in] env The LMDB environment.
4563 * @param[in] lpath The pathname of the file used for the lock region.
4564 * @param[in] mode The Unix permissions for the file, if we create it.
4565 * @param[in,out] excl In -1, out lock type: -1 none, 0 shared, 1 exclusive
4566 * @return 0 on success, non-zero on failure.
4569 mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
4572 # define MDB_ERRCODE_ROFS ERROR_WRITE_PROTECT
4574 # define MDB_ERRCODE_ROFS EROFS
4575 #ifdef O_CLOEXEC /* Linux: Open file and set FD_CLOEXEC atomically */
4576 # define MDB_CLOEXEC O_CLOEXEC
4579 # define MDB_CLOEXEC 0
4582 #ifdef MDB_USE_SYSV_SEM
4591 utf8_to_utf16(lpath, -1, &wlpath, NULL);
4592 env->me_lfd = CreateFileW(wlpath, GENERIC_READ|GENERIC_WRITE,
4593 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
4594 FILE_ATTRIBUTE_NORMAL, NULL);
4597 env->me_lfd = open(lpath, O_RDWR|O_CREAT|MDB_CLOEXEC, mode);
4599 if (env->me_lfd == INVALID_HANDLE_VALUE) {
4601 if (rc == MDB_ERRCODE_ROFS && (env->me_flags & MDB_RDONLY)) {
4606 #if ! ((MDB_CLOEXEC) || defined(_WIN32))
4607 /* Lose record locks when exec*() */
4608 if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0)
4609 fcntl(env->me_lfd, F_SETFD, fdflags);
4612 if (!(env->me_flags & MDB_NOTLS)) {
4613 rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
4616 env->me_flags |= MDB_ENV_TXKEY;
4618 /* Windows TLS callbacks need help finding their TLS info. */
4619 if (mdb_tls_nkeys >= MAX_TLS_KEYS) {
4623 mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey;
4627 /* Try to get exclusive lock. If we succeed, then
4628 * nobody is using the lock region and we should initialize it.
4630 if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
4633 size = GetFileSize(env->me_lfd, NULL);
4635 size = lseek(env->me_lfd, 0, SEEK_END);
4636 if (size == -1) goto fail_errno;
4638 rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
4639 if (size < rsize && *excl > 0) {
4641 if (SetFilePointer(env->me_lfd, rsize, NULL, FILE_BEGIN) != (DWORD)rsize
4642 || !SetEndOfFile(env->me_lfd))
4645 if (ftruncate(env->me_lfd, rsize) != 0) goto fail_errno;
4649 size = rsize - sizeof(MDB_txninfo);
4650 env->me_maxreaders = size/sizeof(MDB_reader) + 1;
4655 mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,
4657 if (!mh) goto fail_errno;
4658 env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL);
4660 if (!env->me_txns) goto fail_errno;
4662 void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
4664 if (m == MAP_FAILED) goto fail_errno;
4670 BY_HANDLE_FILE_INFORMATION stbuf;
4679 if (!mdb_sec_inited) {
4680 InitializeSecurityDescriptor(&mdb_null_sd,
4681 SECURITY_DESCRIPTOR_REVISION);
4682 SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE);
4683 mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);
4684 mdb_all_sa.bInheritHandle = FALSE;
4685 mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;
4688 if (!GetFileInformationByHandle(env->me_lfd, &stbuf)) goto fail_errno;
4689 idbuf.volume = stbuf.dwVolumeSerialNumber;
4690 idbuf.nhigh = stbuf.nFileIndexHigh;
4691 idbuf.nlow = stbuf.nFileIndexLow;
4692 val.mv_data = &idbuf;
4693 val.mv_size = sizeof(idbuf);
4694 mdb_hash_enc(&val, encbuf);
4695 sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", encbuf);
4696 sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", encbuf);
4697 env->me_rmutex = CreateMutexA(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
4698 if (!env->me_rmutex) goto fail_errno;
4699 env->me_wmutex = CreateMutexA(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);
4700 if (!env->me_wmutex) goto fail_errno;
4701 #elif defined(MDB_USE_POSIX_SEM)
4710 #if defined(__NetBSD__)
4711 #define MDB_SHORT_SEMNAMES 1 /* limited to 14 chars */
4713 if (fstat(env->me_lfd, &stbuf)) goto fail_errno;
4714 idbuf.dev = stbuf.st_dev;
4715 idbuf.ino = stbuf.st_ino;
4716 val.mv_data = &idbuf;
4717 val.mv_size = sizeof(idbuf);
4718 mdb_hash_enc(&val, encbuf);
4719 #ifdef MDB_SHORT_SEMNAMES
4720 encbuf[9] = '\0'; /* drop name from 15 chars to 14 chars */
4722 sprintf(env->me_txns->mti_rmname, "/MDBr%s", encbuf);
4723 sprintf(env->me_txns->mti_wmname, "/MDBw%s", encbuf);
4724 /* Clean up after a previous run, if needed: Try to
4725 * remove both semaphores before doing anything else.
4727 sem_unlink(env->me_txns->mti_rmname);
4728 sem_unlink(env->me_txns->mti_wmname);
4729 env->me_rmutex = sem_open(env->me_txns->mti_rmname,
4730 O_CREAT|O_EXCL, mode, 1);
4731 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
4732 env->me_wmutex = sem_open(env->me_txns->mti_wmname,
4733 O_CREAT|O_EXCL, mode, 1);
4734 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
4735 #elif defined(MDB_USE_SYSV_SEM)
4736 unsigned short vals[2] = {1, 1};
4737 key_t key = ftok(lpath, 'M');
4740 semid = semget(key, 2, (mode & 0777) | IPC_CREAT);
4744 if (semctl(semid, 0, SETALL, semu) < 0)
4746 env->me_txns->mti_semid = semid;
4747 #else /* MDB_USE_POSIX_MUTEX: */
4748 pthread_mutexattr_t mattr;
4750 if ((rc = pthread_mutexattr_init(&mattr))
4751 || (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED))
4752 #ifdef MDB_ROBUST_SUPPORTED
4753 || (rc = pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST))
4755 || (rc = pthread_mutex_init(env->me_txns->mti_rmutex, &mattr))
4756 || (rc = pthread_mutex_init(env->me_txns->mti_wmutex, &mattr)))
4758 pthread_mutexattr_destroy(&mattr);
4759 #endif /* _WIN32 || ... */
4761 env->me_txns->mti_magic = MDB_MAGIC;
4762 env->me_txns->mti_format = MDB_LOCK_FORMAT;
4763 env->me_txns->mti_txnid = 0;
4764 env->me_txns->mti_numreaders = 0;
4767 #ifdef MDB_USE_SYSV_SEM
4768 struct semid_ds buf;
4770 if (env->me_txns->mti_magic != MDB_MAGIC) {
4771 DPUTS("lock region has invalid magic");
4775 if (env->me_txns->mti_format != MDB_LOCK_FORMAT) {
4776 DPRINTF(("lock region has format+version 0x%x, expected 0x%x",
4777 env->me_txns->mti_format, MDB_LOCK_FORMAT));
4778 rc = MDB_VERSION_MISMATCH;
4782 if (rc && rc != EACCES && rc != EAGAIN) {
4786 env->me_rmutex = OpenMutexA(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);
4787 if (!env->me_rmutex) goto fail_errno;
4788 env->me_wmutex = OpenMutexA(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
4789 if (!env->me_wmutex) goto fail_errno;
4790 #elif defined(MDB_USE_POSIX_SEM)
4791 env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0);
4792 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
4793 env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0);
4794 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
4795 #elif defined(MDB_USE_SYSV_SEM)
4796 semid = env->me_txns->mti_semid;
4798 /* check for read access */
4799 if (semctl(semid, 0, IPC_STAT, semu) < 0)
4801 /* check for write access */
4802 if (semctl(semid, 0, IPC_SET, semu) < 0)
4806 #ifdef MDB_USE_SYSV_SEM
4807 env->me_rmutex->semid = semid;
4808 env->me_wmutex->semid = semid;
4809 env->me_rmutex->semnum = 0;
4810 env->me_wmutex->semnum = 1;
4811 env->me_rmutex->locked = &env->me_txns->mti_rlocked;
4812 env->me_wmutex->locked = &env->me_txns->mti_wlocked;
4823 /** The name of the lock file in the DB environment */
4824 #define LOCKNAME "/lock.mdb"
4825 /** The name of the data file in the DB environment */
4826 #define DATANAME "/data.mdb"
4827 /** The suffix of the lock file when no subdir is used */
4828 #define LOCKSUFF "-lock"
4829 /** Only a subset of the @ref mdb_env flags can be changed
4830 * at runtime. Changing other flags requires closing the
4831 * environment and re-opening it with the new flags.
4833 #define CHANGEABLE (MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC|MDB_NOMEMINIT)
4834 #define CHANGELESS (MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY| \
4835 MDB_WRITEMAP|MDB_NOTLS|MDB_NOLOCK|MDB_NORDAHEAD)
4837 #if VALID_FLAGS & PERSISTENT_FLAGS & (CHANGEABLE|CHANGELESS)
4838 # error "Persistent DB flags & env flags overlap, but both go in mm_flags"
4842 mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode)
4844 int oflags, rc, len, excl = -1;
4845 char *lpath, *dpath;
4850 if (env->me_fd!=INVALID_HANDLE_VALUE || (flags & ~(CHANGEABLE|CHANGELESS)))
4854 if (flags & MDB_NOSUBDIR) {
4855 rc = len + sizeof(LOCKSUFF) + len + 1;
4857 rc = len + sizeof(LOCKNAME) + len + sizeof(DATANAME);
4862 if (flags & MDB_NOSUBDIR) {
4863 dpath = lpath + len + sizeof(LOCKSUFF);
4864 sprintf(lpath, "%s" LOCKSUFF, path);
4865 strcpy(dpath, path);
4867 dpath = lpath + len + sizeof(LOCKNAME);
4868 sprintf(lpath, "%s" LOCKNAME, path);
4869 sprintf(dpath, "%s" DATANAME, path);
4873 flags |= env->me_flags;
4874 if (flags & MDB_RDONLY) {
4875 /* silently ignore WRITEMAP when we're only getting read access */
4876 flags &= ~MDB_WRITEMAP;
4878 if (!((env->me_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)) &&
4879 (env->me_dirty_list = calloc(MDB_IDL_UM_SIZE, sizeof(MDB_ID2)))))
4882 env->me_flags = flags |= MDB_ENV_ACTIVE;
4886 env->me_path = strdup(path);
4887 env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx));
4888 env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t));
4889 env->me_dbiseqs = calloc(env->me_maxdbs, sizeof(unsigned int));
4890 if (!(env->me_dbxs && env->me_path && env->me_dbflags && env->me_dbiseqs)) {
4894 env->me_dbxs[FREE_DBI].md_cmp = mdb_cmp_long; /* aligned MDB_INTEGERKEY */
4896 /* For RDONLY, get lockfile after we know datafile exists */
4897 if (!(flags & (MDB_RDONLY|MDB_NOLOCK))) {
4898 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
4904 if (F_ISSET(flags, MDB_RDONLY)) {
4905 oflags = GENERIC_READ;
4906 len = OPEN_EXISTING;
4908 oflags = GENERIC_READ|GENERIC_WRITE;
4911 mode = FILE_ATTRIBUTE_NORMAL;
4912 utf8_to_utf16(dpath, -1, &wpath, NULL);
4913 env->me_fd = CreateFileW(wpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
4914 NULL, len, mode, NULL);
4917 if (F_ISSET(flags, MDB_RDONLY))
4920 oflags = O_RDWR | O_CREAT;
4922 env->me_fd = open(dpath, oflags, mode);
4924 if (env->me_fd == INVALID_HANDLE_VALUE) {
4929 if ((flags & (MDB_RDONLY|MDB_NOLOCK)) == MDB_RDONLY) {
4930 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
4935 if ((rc = mdb_env_open2(env)) == MDB_SUCCESS) {
4936 if (flags & (MDB_RDONLY|MDB_WRITEMAP)) {
4937 env->me_mfd = env->me_fd;
4939 /* Synchronous fd for meta writes. Needed even with
4940 * MDB_NOSYNC/MDB_NOMETASYNC, in case these get reset.
4943 len = OPEN_EXISTING;
4944 utf8_to_utf16(dpath, -1, &wpath, NULL);
4945 env->me_mfd = CreateFileW(wpath, oflags,
4946 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len,
4947 mode | FILE_FLAG_WRITE_THROUGH, NULL);
4951 env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode);
4953 if (env->me_mfd == INVALID_HANDLE_VALUE) {
4958 DPRINTF(("opened dbenv %p", (void *) env));
4960 rc = mdb_env_share_locks(env, &excl);
4964 if (!(flags & MDB_RDONLY)) {
4966 int tsize = sizeof(MDB_txn), size = tsize + env->me_maxdbs *
4967 (sizeof(MDB_db)+sizeof(MDB_cursor *)+sizeof(unsigned int)+1);
4968 if ((env->me_pbuf = calloc(1, env->me_psize)) &&
4969 (txn = calloc(1, size)))
4971 txn->mt_dbs = (MDB_db *)((char *)txn + tsize);
4972 txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
4973 txn->mt_dbiseqs = (unsigned int *)(txn->mt_cursors + env->me_maxdbs);
4974 txn->mt_dbflags = (unsigned char *)(txn->mt_dbiseqs + env->me_maxdbs);
4976 txn->mt_dbxs = env->me_dbxs;
4977 txn->mt_flags = MDB_TXN_FINISHED;
4987 mdb_env_close0(env, excl);
4993 /** Destroy resources from mdb_env_open(), clear our readers & DBIs */
4995 mdb_env_close0(MDB_env *env, int excl)
4999 if (!(env->me_flags & MDB_ENV_ACTIVE))
5002 /* Doing this here since me_dbxs may not exist during mdb_env_close */
5004 for (i = env->me_maxdbs; --i >= CORE_DBS; )
5005 free(env->me_dbxs[i].md_name.mv_data);
5010 free(env->me_dbiseqs);
5011 free(env->me_dbflags);
5013 free(env->me_dirty_list);
5015 mdb_midl_free(env->me_free_pgs);
5017 if (env->me_flags & MDB_ENV_TXKEY) {
5018 pthread_key_delete(env->me_txkey);
5020 /* Delete our key from the global list */
5021 for (i=0; i<mdb_tls_nkeys; i++)
5022 if (mdb_tls_keys[i] == env->me_txkey) {
5023 mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1];
5031 munmap(env->me_map, env->me_mapsize);
5033 if (env->me_mfd != env->me_fd && env->me_mfd != INVALID_HANDLE_VALUE)
5034 (void) close(env->me_mfd);
5035 if (env->me_fd != INVALID_HANDLE_VALUE)
5036 (void) close(env->me_fd);
5038 MDB_PID_T pid = env->me_pid;
5039 /* Clearing readers is done in this function because
5040 * me_txkey with its destructor must be disabled first.
5042 * We skip the the reader mutex, so we touch only
5043 * data owned by this process (me_close_readers and
5044 * our readers), and clear each reader atomically.
5046 for (i = env->me_close_readers; --i >= 0; )
5047 if (env->me_txns->mti_readers[i].mr_pid == pid)
5048 env->me_txns->mti_readers[i].mr_pid = 0;
5050 if (env->me_rmutex) {
5051 CloseHandle(env->me_rmutex);
5052 if (env->me_wmutex) CloseHandle(env->me_wmutex);
5054 /* Windows automatically destroys the mutexes when
5055 * the last handle closes.
5057 #elif defined(MDB_USE_POSIX_SEM)
5058 if (env->me_rmutex != SEM_FAILED) {
5059 sem_close(env->me_rmutex);
5060 if (env->me_wmutex != SEM_FAILED)
5061 sem_close(env->me_wmutex);
5062 /* If we have the filelock: If we are the
5063 * only remaining user, clean up semaphores.
5066 mdb_env_excl_lock(env, &excl);
5068 sem_unlink(env->me_txns->mti_rmname);
5069 sem_unlink(env->me_txns->mti_wmname);
5072 #elif defined(MDB_USE_SYSV_SEM)
5073 if (env->me_rmutex->semid != -1) {
5074 /* If we have the filelock: If we are the
5075 * only remaining user, clean up semaphores.
5078 mdb_env_excl_lock(env, &excl);
5080 semctl(env->me_rmutex->semid, 0, IPC_RMID);
5083 munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
5085 if (env->me_lfd != INVALID_HANDLE_VALUE) {
5088 /* Unlock the lockfile. Windows would have unlocked it
5089 * after closing anyway, but not necessarily at once.
5091 UnlockFile(env->me_lfd, 0, 0, 1, 0);
5094 (void) close(env->me_lfd);
5097 env->me_flags &= ~(MDB_ENV_ACTIVE|MDB_ENV_TXKEY);
5101 mdb_env_close(MDB_env *env)
5108 VGMEMP_DESTROY(env);
5109 while ((dp = env->me_dpages) != NULL) {
5110 VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next));
5111 env->me_dpages = dp->mp_next;
5115 mdb_env_close0(env, 0);
5119 /** Compare two items pointing at aligned size_t's */
5121 mdb_cmp_long(const MDB_val *a, const MDB_val *b)
5123 return (*(size_t *)a->mv_data < *(size_t *)b->mv_data) ? -1 :
5124 *(size_t *)a->mv_data > *(size_t *)b->mv_data;
5127 /** Compare two items pointing at aligned unsigned int's.
5129 * This is also set as #MDB_INTEGERDUP|#MDB_DUPFIXED's #MDB_dbx.%md_dcmp,
5130 * but #mdb_cmp_clong() is called instead if the data type is size_t.
5133 mdb_cmp_int(const MDB_val *a, const MDB_val *b)
5135 return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 :
5136 *(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data;
5139 /** Compare two items pointing at unsigned ints of unknown alignment.
5140 * Nodes and keys are guaranteed to be 2-byte aligned.
5143 mdb_cmp_cint(const MDB_val *a, const MDB_val *b)
5145 #if BYTE_ORDER == LITTLE_ENDIAN
5146 unsigned short *u, *c;
5149 u = (unsigned short *) ((char *) a->mv_data + a->mv_size);
5150 c = (unsigned short *) ((char *) b->mv_data + a->mv_size);
5153 } while(!x && u > (unsigned short *)a->mv_data);
5156 unsigned short *u, *c, *end;
5159 end = (unsigned short *) ((char *) a->mv_data + a->mv_size);
5160 u = (unsigned short *)a->mv_data;
5161 c = (unsigned short *)b->mv_data;
5164 } while(!x && u < end);
5169 /** Compare two items lexically */
5171 mdb_cmp_memn(const MDB_val *a, const MDB_val *b)
5178 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
5184 diff = memcmp(a->mv_data, b->mv_data, len);
5185 return diff ? diff : len_diff<0 ? -1 : len_diff;
5188 /** Compare two items in reverse byte order */
5190 mdb_cmp_memnr(const MDB_val *a, const MDB_val *b)
5192 const unsigned char *p1, *p2, *p1_lim;
5196 p1_lim = (const unsigned char *)a->mv_data;
5197 p1 = (const unsigned char *)a->mv_data + a->mv_size;
5198 p2 = (const unsigned char *)b->mv_data + b->mv_size;
5200 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
5206 while (p1 > p1_lim) {
5207 diff = *--p1 - *--p2;
5211 return len_diff<0 ? -1 : len_diff;
5214 /** Search for key within a page, using binary search.
5215 * Returns the smallest entry larger or equal to the key.
5216 * If exactp is non-null, stores whether the found entry was an exact match
5217 * in *exactp (1 or 0).
5218 * Updates the cursor index with the index of the found entry.
5219 * If no entry larger or equal to the key is found, returns NULL.
5222 mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)
5224 unsigned int i = 0, nkeys;
5227 MDB_page *mp = mc->mc_pg[mc->mc_top];
5228 MDB_node *node = NULL;
5233 nkeys = NUMKEYS(mp);
5235 DPRINTF(("searching %u keys in %s %spage %"Z"u",
5236 nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "",
5239 low = IS_LEAF(mp) ? 0 : 1;
5241 cmp = mc->mc_dbx->md_cmp;
5243 /* Branch pages have no data, so if using integer keys,
5244 * alignment is guaranteed. Use faster mdb_cmp_int.
5246 if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) {
5247 if (NODEPTR(mp, 1)->mn_ksize == sizeof(size_t))
5254 nodekey.mv_size = mc->mc_db->md_pad;
5255 node = NODEPTR(mp, 0); /* fake */
5256 while (low <= high) {
5257 i = (low + high) >> 1;
5258 nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size);
5259 rc = cmp(key, &nodekey);
5260 DPRINTF(("found leaf index %u [%s], rc = %i",
5261 i, DKEY(&nodekey), rc));
5270 while (low <= high) {
5271 i = (low + high) >> 1;
5273 node = NODEPTR(mp, i);
5274 nodekey.mv_size = NODEKSZ(node);
5275 nodekey.mv_data = NODEKEY(node);
5277 rc = cmp(key, &nodekey);
5280 DPRINTF(("found leaf index %u [%s], rc = %i",
5281 i, DKEY(&nodekey), rc));
5283 DPRINTF(("found branch index %u [%s -> %"Z"u], rc = %i",
5284 i, DKEY(&nodekey), NODEPGNO(node), rc));
5295 if (rc > 0) { /* Found entry is less than the key. */
5296 i++; /* Skip to get the smallest entry larger than key. */
5298 node = NODEPTR(mp, i);
5301 *exactp = (rc == 0 && nkeys > 0);
5302 /* store the key index */
5303 mc->mc_ki[mc->mc_top] = i;
5305 /* There is no entry larger or equal to the key. */
5308 /* nodeptr is fake for LEAF2 */
5314 mdb_cursor_adjust(MDB_cursor *mc, func)
5318 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
5319 if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) {
5326 /** Pop a page off the top of the cursor's stack. */
5328 mdb_cursor_pop(MDB_cursor *mc)
5331 DPRINTF(("popping page %"Z"u off db %d cursor %p",
5332 mc->mc_pg[mc->mc_top]->mp_pgno, DDBI(mc), (void *) mc));
5338 mc->mc_flags &= ~C_INITIALIZED;
5343 /** Push a page onto the top of the cursor's stack. */
5345 mdb_cursor_push(MDB_cursor *mc, MDB_page *mp)
5347 DPRINTF(("pushing page %"Z"u on db %d cursor %p", mp->mp_pgno,
5348 DDBI(mc), (void *) mc));
5350 if (mc->mc_snum >= CURSOR_STACK) {
5351 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
5352 return MDB_CURSOR_FULL;
5355 mc->mc_top = mc->mc_snum++;
5356 mc->mc_pg[mc->mc_top] = mp;
5357 mc->mc_ki[mc->mc_top] = 0;
5362 /** Find the address of the page corresponding to a given page number.
5363 * @param[in] txn the transaction for this access.
5364 * @param[in] pgno the page number for the page to retrieve.
5365 * @param[out] ret address of a pointer where the page's address will be stored.
5366 * @param[out] lvl dirty_list inheritance level of found page. 1=current txn, 0=mapped page.
5367 * @return 0 on success, non-zero on failure.
5370 mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret, int *lvl)
5372 MDB_env *env = txn->mt_env;
5376 if (! (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_WRITEMAP))) {
5380 MDB_ID2L dl = tx2->mt_u.dirty_list;
5382 /* Spilled pages were dirtied in this txn and flushed
5383 * because the dirty list got full. Bring this page
5384 * back in from the map (but don't unspill it here,
5385 * leave that unless page_touch happens again).
5387 if (tx2->mt_spill_pgs) {
5388 MDB_ID pn = pgno << 1;
5389 x = mdb_midl_search(tx2->mt_spill_pgs, pn);
5390 if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
5391 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
5396 unsigned x = mdb_mid2l_search(dl, pgno);
5397 if (x <= dl[0].mid && dl[x].mid == pgno) {
5403 } while ((tx2 = tx2->mt_parent) != NULL);
5406 if (pgno < txn->mt_next_pgno) {
5408 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
5410 DPRINTF(("page %"Z"u not found", pgno));
5411 txn->mt_flags |= MDB_TXN_ERROR;
5412 return MDB_PAGE_NOTFOUND;
5422 /** Finish #mdb_page_search() / #mdb_page_search_lowest().
5423 * The cursor is at the root page, set up the rest of it.
5426 mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags)
5428 MDB_page *mp = mc->mc_pg[mc->mc_top];
5432 while (IS_BRANCH(mp)) {
5436 DPRINTF(("branch page %"Z"u has %u keys", mp->mp_pgno, NUMKEYS(mp)));
5437 /* Don't assert on branch pages in the FreeDB. We can get here
5438 * while in the process of rebalancing a FreeDB branch page; we must
5439 * let that proceed. ITS#8336
5441 mdb_cassert(mc, !mc->mc_dbi || NUMKEYS(mp) > 1);
5442 DPRINTF(("found index 0 to page %"Z"u", NODEPGNO(NODEPTR(mp, 0))));
5444 if (flags & (MDB_PS_FIRST|MDB_PS_LAST)) {
5446 if (flags & MDB_PS_LAST)
5447 i = NUMKEYS(mp) - 1;
5450 node = mdb_node_search(mc, key, &exact);
5452 i = NUMKEYS(mp) - 1;
5454 i = mc->mc_ki[mc->mc_top];
5456 mdb_cassert(mc, i > 0);
5460 DPRINTF(("following index %u for key [%s]", i, DKEY(key)));
5463 mdb_cassert(mc, i < NUMKEYS(mp));
5464 node = NODEPTR(mp, i);
5466 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
5469 mc->mc_ki[mc->mc_top] = i;
5470 if ((rc = mdb_cursor_push(mc, mp)))
5473 if (flags & MDB_PS_MODIFY) {
5474 if ((rc = mdb_page_touch(mc)) != 0)
5476 mp = mc->mc_pg[mc->mc_top];
5481 DPRINTF(("internal error, index points to a %02X page!?",
5483 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
5484 return MDB_CORRUPTED;
5487 DPRINTF(("found leaf page %"Z"u for key [%s]", mp->mp_pgno,
5488 key ? DKEY(key) : "null"));
5489 mc->mc_flags |= C_INITIALIZED;
5490 mc->mc_flags &= ~C_EOF;
5495 /** Search for the lowest key under the current branch page.
5496 * This just bypasses a NUMKEYS check in the current page
5497 * before calling mdb_page_search_root(), because the callers
5498 * are all in situations where the current page is known to
5502 mdb_page_search_lowest(MDB_cursor *mc)
5504 MDB_page *mp = mc->mc_pg[mc->mc_top];
5505 MDB_node *node = NODEPTR(mp, 0);
5508 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
5511 mc->mc_ki[mc->mc_top] = 0;
5512 if ((rc = mdb_cursor_push(mc, mp)))
5514 return mdb_page_search_root(mc, NULL, MDB_PS_FIRST);
5517 /** Search for the page a given key should be in.
5518 * Push it and its parent pages on the cursor stack.
5519 * @param[in,out] mc the cursor for this operation.
5520 * @param[in] key the key to search for, or NULL for first/last page.
5521 * @param[in] flags If MDB_PS_MODIFY is set, visited pages in the DB
5522 * are touched (updated with new page numbers).
5523 * If MDB_PS_FIRST or MDB_PS_LAST is set, find first or last leaf.
5524 * This is used by #mdb_cursor_first() and #mdb_cursor_last().
5525 * If MDB_PS_ROOTONLY set, just fetch root node, no further lookups.
5526 * @return 0 on success, non-zero on failure.
5529 mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)
5534 /* Make sure the txn is still viable, then find the root from
5535 * the txn's db table and set it as the root of the cursor's stack.
5537 if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED) {
5538 DPUTS("transaction may not be used now");
5541 /* Make sure we're using an up-to-date root */
5542 if (*mc->mc_dbflag & DB_STALE) {
5544 if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))
5546 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);
5547 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, 0);
5554 MDB_node *leaf = mdb_node_search(&mc2,
5555 &mc->mc_dbx->md_name, &exact);
5557 return MDB_NOTFOUND;
5558 if ((leaf->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)
5559 return MDB_INCOMPATIBLE; /* not a named DB */
5560 rc = mdb_node_read(mc->mc_txn, leaf, &data);
5563 memcpy(&flags, ((char *) data.mv_data + offsetof(MDB_db, md_flags)),
5565 /* The txn may not know this DBI, or another process may
5566 * have dropped and recreated the DB with other flags.
5568 if ((mc->mc_db->md_flags & PERSISTENT_FLAGS) != flags)
5569 return MDB_INCOMPATIBLE;
5570 memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db));
5572 *mc->mc_dbflag &= ~DB_STALE;
5574 root = mc->mc_db->md_root;
5576 if (root == P_INVALID) { /* Tree is empty. */
5577 DPUTS("tree is empty");
5578 return MDB_NOTFOUND;
5582 mdb_cassert(mc, root > 1);
5583 if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root)
5584 if ((rc = mdb_page_get(mc->mc_txn, root, &mc->mc_pg[0], NULL)) != 0)
5590 DPRINTF(("db %d root page %"Z"u has flags 0x%X",
5591 DDBI(mc), root, mc->mc_pg[0]->mp_flags));
5593 if (flags & MDB_PS_MODIFY) {
5594 if ((rc = mdb_page_touch(mc)))
5598 if (flags & MDB_PS_ROOTONLY)
5601 return mdb_page_search_root(mc, key, flags);
5605 mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
5607 MDB_txn *txn = mc->mc_txn;
5608 pgno_t pg = mp->mp_pgno;
5609 unsigned x = 0, ovpages = mp->mp_pages;
5610 MDB_env *env = txn->mt_env;
5611 MDB_IDL sl = txn->mt_spill_pgs;
5612 MDB_ID pn = pg << 1;
5615 DPRINTF(("free ov page %"Z"u (%d)", pg, ovpages));
5616 /* If the page is dirty or on the spill list we just acquired it,
5617 * so we should give it back to our current free list, if any.
5618 * Otherwise put it onto the list of pages we freed in this txn.
5620 * Won't create me_pghead: me_pglast must be inited along with it.
5621 * Unsupported in nested txns: They would need to hide the page
5622 * range in ancestor txns' dirty and spilled lists.
5624 if (env->me_pghead &&
5626 ((mp->mp_flags & P_DIRTY) ||
5627 (sl && (x = mdb_midl_search(sl, pn)) <= sl[0] && sl[x] == pn)))
5631 MDB_ID2 *dl, ix, iy;
5632 rc = mdb_midl_need(&env->me_pghead, ovpages);
5635 if (!(mp->mp_flags & P_DIRTY)) {
5636 /* This page is no longer spilled */
5643 /* Remove from dirty list */
5644 dl = txn->mt_u.dirty_list;
5646 for (ix = dl[x]; ix.mptr != mp; ix = iy) {
5652 mdb_cassert(mc, x > 1);
5654 dl[j] = ix; /* Unsorted. OK when MDB_TXN_ERROR. */
5655 txn->mt_flags |= MDB_TXN_ERROR;
5656 return MDB_CORRUPTED;
5659 txn->mt_dirty_room++;
5660 if (!(env->me_flags & MDB_WRITEMAP))
5661 mdb_dpage_free(env, mp);
5663 /* Insert in me_pghead */
5664 mop = env->me_pghead;
5665 j = mop[0] + ovpages;
5666 for (i = mop[0]; i && mop[i] < pg; i--)
5672 rc = mdb_midl_append_range(&txn->mt_free_pgs, pg, ovpages);
5676 mc->mc_db->md_overflow_pages -= ovpages;
5680 /** Return the data associated with a given node.
5681 * @param[in] txn The transaction for this operation.
5682 * @param[in] leaf The node being read.
5683 * @param[out] data Updated to point to the node's data.
5684 * @return 0 on success, non-zero on failure.
5687 mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data)
5689 MDB_page *omp; /* overflow page */
5693 if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
5694 data->mv_size = NODEDSZ(leaf);
5695 data->mv_data = NODEDATA(leaf);
5699 /* Read overflow data.
5701 data->mv_size = NODEDSZ(leaf);
5702 memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
5703 if ((rc = mdb_page_get(txn, pgno, &omp, NULL)) != 0) {
5704 DPRINTF(("read overflow page %"Z"u failed", pgno));
5707 data->mv_data = METADATA(omp);
5713 mdb_get(MDB_txn *txn, MDB_dbi dbi,
5714 MDB_val *key, MDB_val *data)
5721 DPRINTF(("===> get db %u key [%s]", dbi, DKEY(key)));
5723 if (!key || !data || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
5726 if (txn->mt_flags & MDB_TXN_BLOCKED)
5729 mdb_cursor_init(&mc, txn, dbi, &mx);
5730 return mdb_cursor_set(&mc, key, data, MDB_SET, &exact);
5733 /** Find a sibling for a page.
5734 * Replaces the page at the top of the cursor's stack with the
5735 * specified sibling, if one exists.
5736 * @param[in] mc The cursor for this operation.
5737 * @param[in] move_right Non-zero if the right sibling is requested,
5738 * otherwise the left sibling.
5739 * @return 0 on success, non-zero on failure.
5742 mdb_cursor_sibling(MDB_cursor *mc, int move_right)
5748 if (mc->mc_snum < 2) {
5749 return MDB_NOTFOUND; /* root has no siblings */
5753 DPRINTF(("parent page is page %"Z"u, index %u",
5754 mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]));
5756 if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top]))
5757 : (mc->mc_ki[mc->mc_top] == 0)) {
5758 DPRINTF(("no more keys left, moving to %s sibling",
5759 move_right ? "right" : "left"));
5760 if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) {
5761 /* undo cursor_pop before returning */
5768 mc->mc_ki[mc->mc_top]++;
5770 mc->mc_ki[mc->mc_top]--;
5771 DPRINTF(("just moving to %s index key %u",
5772 move_right ? "right" : "left", mc->mc_ki[mc->mc_top]));
5774 mdb_cassert(mc, IS_BRANCH(mc->mc_pg[mc->mc_top]));
5776 indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5777 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(indx), &mp, NULL)) != 0) {
5778 /* mc will be inconsistent if caller does mc_snum++ as above */
5779 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
5783 mdb_cursor_push(mc, mp);
5785 mc->mc_ki[mc->mc_top] = NUMKEYS(mp)-1;
5790 /** Move the cursor to the next data item. */
5792 mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
5798 if (mc->mc_flags & C_EOF) {
5799 return MDB_NOTFOUND;
5802 mdb_cassert(mc, mc->mc_flags & C_INITIALIZED);
5804 mp = mc->mc_pg[mc->mc_top];
5806 if (mc->mc_db->md_flags & MDB_DUPSORT) {
5807 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5808 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5809 if (op == MDB_NEXT || op == MDB_NEXT_DUP) {
5810 rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);
5811 if (op != MDB_NEXT || rc != MDB_NOTFOUND) {
5812 if (rc == MDB_SUCCESS)
5813 MDB_GET_KEY(leaf, key);
5818 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5819 if (op == MDB_NEXT_DUP)
5820 return MDB_NOTFOUND;
5824 DPRINTF(("cursor_next: top page is %"Z"u in cursor %p",
5825 mdb_dbg_pgno(mp), (void *) mc));
5826 if (mc->mc_flags & C_DEL)
5829 if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) {
5830 DPUTS("=====> move to next sibling page");
5831 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
5832 mc->mc_flags |= C_EOF;
5835 mp = mc->mc_pg[mc->mc_top];
5836 DPRINTF(("next page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
5838 mc->mc_ki[mc->mc_top]++;
5841 DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
5842 mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
5845 key->mv_size = mc->mc_db->md_pad;
5846 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5850 mdb_cassert(mc, IS_LEAF(mp));
5851 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5853 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5854 mdb_xcursor_init1(mc, leaf);
5857 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5860 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5861 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
5862 if (rc != MDB_SUCCESS)
5867 MDB_GET_KEY(leaf, key);
5871 /** Move the cursor to the previous data item. */
5873 mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
5879 mdb_cassert(mc, mc->mc_flags & C_INITIALIZED);
5881 mp = mc->mc_pg[mc->mc_top];
5883 if (mc->mc_db->md_flags & MDB_DUPSORT) {
5884 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5885 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5886 if (op == MDB_PREV || op == MDB_PREV_DUP) {
5887 rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
5888 if (op != MDB_PREV || rc != MDB_NOTFOUND) {
5889 if (rc == MDB_SUCCESS) {
5890 MDB_GET_KEY(leaf, key);
5891 mc->mc_flags &= ~C_EOF;
5897 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5898 if (op == MDB_PREV_DUP)
5899 return MDB_NOTFOUND;
5903 DPRINTF(("cursor_prev: top page is %"Z"u in cursor %p",
5904 mdb_dbg_pgno(mp), (void *) mc));
5906 if (mc->mc_ki[mc->mc_top] == 0) {
5907 DPUTS("=====> move to prev sibling page");
5908 if ((rc = mdb_cursor_sibling(mc, 0)) != MDB_SUCCESS) {
5911 mp = mc->mc_pg[mc->mc_top];
5912 mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;
5913 DPRINTF(("prev page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
5915 mc->mc_ki[mc->mc_top]--;
5917 mc->mc_flags &= ~C_EOF;
5919 DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
5920 mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
5923 key->mv_size = mc->mc_db->md_pad;
5924 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5928 mdb_cassert(mc, IS_LEAF(mp));
5929 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5931 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5932 mdb_xcursor_init1(mc, leaf);
5935 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5938 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5939 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
5940 if (rc != MDB_SUCCESS)
5945 MDB_GET_KEY(leaf, key);
5949 /** Set the cursor on a specific data item. */
5951 mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data,
5952 MDB_cursor_op op, int *exactp)
5956 MDB_node *leaf = NULL;
5959 if (key->mv_size == 0)
5960 return MDB_BAD_VALSIZE;
5963 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5965 /* See if we're already on the right page */
5966 if (mc->mc_flags & C_INITIALIZED) {
5969 mp = mc->mc_pg[mc->mc_top];
5971 mc->mc_ki[mc->mc_top] = 0;
5972 return MDB_NOTFOUND;
5974 if (mp->mp_flags & P_LEAF2) {
5975 nodekey.mv_size = mc->mc_db->md_pad;
5976 nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size);
5978 leaf = NODEPTR(mp, 0);
5979 MDB_GET_KEY2(leaf, nodekey);
5981 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5983 /* Probably happens rarely, but first node on the page
5984 * was the one we wanted.
5986 mc->mc_ki[mc->mc_top] = 0;
5993 unsigned int nkeys = NUMKEYS(mp);
5995 if (mp->mp_flags & P_LEAF2) {
5996 nodekey.mv_data = LEAF2KEY(mp,
5997 nkeys-1, nodekey.mv_size);
5999 leaf = NODEPTR(mp, nkeys-1);
6000 MDB_GET_KEY2(leaf, nodekey);
6002 rc = mc->mc_dbx->md_cmp(key, &nodekey);
6004 /* last node was the one we wanted */
6005 mc->mc_ki[mc->mc_top] = nkeys-1;
6011 if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) {
6012 /* This is definitely the right page, skip search_page */
6013 if (mp->mp_flags & P_LEAF2) {
6014 nodekey.mv_data = LEAF2KEY(mp,
6015 mc->mc_ki[mc->mc_top], nodekey.mv_size);
6017 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6018 MDB_GET_KEY2(leaf, nodekey);
6020 rc = mc->mc_dbx->md_cmp(key, &nodekey);
6022 /* current node was the one we wanted */
6032 /* If any parents have right-sibs, search.
6033 * Otherwise, there's nothing further.
6035 for (i=0; i<mc->mc_top; i++)
6037 NUMKEYS(mc->mc_pg[i])-1)
6039 if (i == mc->mc_top) {
6040 /* There are no other pages */
6041 mc->mc_ki[mc->mc_top] = nkeys;
6042 return MDB_NOTFOUND;
6046 /* There are no other pages */
6047 mc->mc_ki[mc->mc_top] = 0;
6048 if (op == MDB_SET_RANGE && !exactp) {
6052 return MDB_NOTFOUND;
6058 rc = mdb_page_search(mc, key, 0);
6059 if (rc != MDB_SUCCESS)
6062 mp = mc->mc_pg[mc->mc_top];
6063 mdb_cassert(mc, IS_LEAF(mp));
6066 leaf = mdb_node_search(mc, key, exactp);
6067 if (exactp != NULL && !*exactp) {
6068 /* MDB_SET specified and not an exact match. */
6069 return MDB_NOTFOUND;
6073 DPUTS("===> inexact leaf not found, goto sibling");
6074 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
6075 mc->mc_flags |= C_EOF;
6076 return rc; /* no entries matched */
6078 mp = mc->mc_pg[mc->mc_top];
6079 mdb_cassert(mc, IS_LEAF(mp));
6080 leaf = NODEPTR(mp, 0);
6084 mc->mc_flags |= C_INITIALIZED;
6085 mc->mc_flags &= ~C_EOF;
6088 if (op == MDB_SET_RANGE || op == MDB_SET_KEY) {
6089 key->mv_size = mc->mc_db->md_pad;
6090 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
6095 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6096 mdb_xcursor_init1(mc, leaf);
6099 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6100 if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) {
6101 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
6104 if (op == MDB_GET_BOTH) {
6110 rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p);
6111 if (rc != MDB_SUCCESS)
6114 } else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {
6117 if ((rc = mdb_node_read(mc->mc_txn, leaf, &olddata)) != MDB_SUCCESS)
6119 dcmp = mc->mc_dbx->md_dcmp;
6120 #if UINT_MAX < SIZE_MAX
6121 if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
6122 dcmp = mdb_cmp_clong;
6124 rc = dcmp(data, &olddata);
6126 if (op == MDB_GET_BOTH || rc > 0)
6127 return MDB_NOTFOUND;
6134 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
6135 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
6140 /* The key already matches in all other cases */
6141 if (op == MDB_SET_RANGE || op == MDB_SET_KEY)
6142 MDB_GET_KEY(leaf, key);
6143 DPRINTF(("==> cursor placed on key [%s]", DKEY(key)));
6148 /** Move the cursor to the first item in the database. */
6150 mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data)
6156 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
6158 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
6159 rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
6160 if (rc != MDB_SUCCESS)
6163 mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
6165 leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0);
6166 mc->mc_flags |= C_INITIALIZED;
6167 mc->mc_flags &= ~C_EOF;
6169 mc->mc_ki[mc->mc_top] = 0;
6171 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
6172 key->mv_size = mc->mc_db->md_pad;
6173 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size);
6178 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6179 mdb_xcursor_init1(mc, leaf);
6180 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
6184 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
6188 MDB_GET_KEY(leaf, key);
6192 /** Move the cursor to the last item in the database. */
6194 mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)
6200 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
6202 if (!(mc->mc_flags & C_EOF)) {
6204 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
6205 rc = mdb_page_search(mc, NULL, MDB_PS_LAST);
6206 if (rc != MDB_SUCCESS)
6209 mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
6212 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;
6213 mc->mc_flags |= C_INITIALIZED|C_EOF;
6214 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6216 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
6217 key->mv_size = mc->mc_db->md_pad;
6218 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size);
6223 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6224 mdb_xcursor_init1(mc, leaf);
6225 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
6229 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
6234 MDB_GET_KEY(leaf, key);
6239 mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,
6244 int (*mfunc)(MDB_cursor *mc, MDB_val *key, MDB_val *data);
6249 if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)
6253 case MDB_GET_CURRENT:
6254 if (!(mc->mc_flags & C_INITIALIZED)) {
6257 MDB_page *mp = mc->mc_pg[mc->mc_top];
6258 int nkeys = NUMKEYS(mp);
6259 if (!nkeys || mc->mc_ki[mc->mc_top] >= nkeys) {
6260 mc->mc_ki[mc->mc_top] = nkeys;
6266 key->mv_size = mc->mc_db->md_pad;
6267 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
6269 MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6270 MDB_GET_KEY(leaf, key);
6272 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6273 rc = mdb_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT);
6275 rc = mdb_node_read(mc->mc_txn, leaf, data);
6282 case MDB_GET_BOTH_RANGE:
6287 if (mc->mc_xcursor == NULL) {
6288 rc = MDB_INCOMPATIBLE;
6298 rc = mdb_cursor_set(mc, key, data, op,
6299 op == MDB_SET_RANGE ? NULL : &exact);
6302 case MDB_GET_MULTIPLE:
6303 if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
6307 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
6308 rc = MDB_INCOMPATIBLE;
6312 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) ||
6313 (mc->mc_xcursor->mx_cursor.mc_flags & C_EOF))
6316 case MDB_NEXT_MULTIPLE:
6321 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
6322 rc = MDB_INCOMPATIBLE;
6325 if (!(mc->mc_flags & C_INITIALIZED))
6326 rc = mdb_cursor_first(mc, key, data);
6328 rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP);
6329 if (rc == MDB_SUCCESS) {
6330 if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
6333 mx = &mc->mc_xcursor->mx_cursor;
6334 data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) *
6336 data->mv_data = METADATA(mx->mc_pg[mx->mc_top]);
6337 mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1;
6345 case MDB_NEXT_NODUP:
6346 if (!(mc->mc_flags & C_INITIALIZED))
6347 rc = mdb_cursor_first(mc, key, data);
6349 rc = mdb_cursor_next(mc, key, data, op);
6353 case MDB_PREV_NODUP:
6354 if (!(mc->mc_flags & C_INITIALIZED)) {
6355 rc = mdb_cursor_last(mc, key, data);
6358 mc->mc_flags |= C_INITIALIZED;
6359 mc->mc_ki[mc->mc_top]++;
6361 rc = mdb_cursor_prev(mc, key, data, op);
6364 rc = mdb_cursor_first(mc, key, data);
6367 mfunc = mdb_cursor_first;
6369 if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
6373 if (mc->mc_xcursor == NULL) {
6374 rc = MDB_INCOMPATIBLE;
6378 MDB_node *leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6379 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6380 MDB_GET_KEY(leaf, key);
6381 rc = mdb_node_read(mc->mc_txn, leaf, data);
6385 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
6389 rc = mfunc(&mc->mc_xcursor->mx_cursor, data, NULL);
6392 rc = mdb_cursor_last(mc, key, data);
6395 mfunc = mdb_cursor_last;
6398 DPRINTF(("unhandled/unimplemented cursor operation %u", op));
6403 if (mc->mc_flags & C_DEL)
6404 mc->mc_flags ^= C_DEL;
6409 /** Touch all the pages in the cursor stack. Set mc_top.
6410 * Makes sure all the pages are writable, before attempting a write operation.
6411 * @param[in] mc The cursor to operate on.
6414 mdb_cursor_touch(MDB_cursor *mc)
6416 int rc = MDB_SUCCESS;
6418 if (mc->mc_dbi >= CORE_DBS && !(*mc->mc_dbflag & DB_DIRTY)) {
6421 if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))
6423 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, &mcx);
6424 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY);
6427 *mc->mc_dbflag |= DB_DIRTY;
6432 rc = mdb_page_touch(mc);
6433 } while (!rc && ++(mc->mc_top) < mc->mc_snum);
6434 mc->mc_top = mc->mc_snum-1;
6439 /** Do not spill pages to disk if txn is getting full, may fail instead */
6440 #define MDB_NOSPILL 0x8000
6443 mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
6447 MDB_node *leaf = NULL;
6448 MDB_page *fp, *mp, *sub_root = NULL;
6450 MDB_val xdata, *rdata, dkey, olddata;
6452 int do_sub = 0, insert_key, insert_data;
6453 unsigned int mcount = 0, dcount = 0, nospill;
6456 unsigned int nflags;
6459 if (mc == NULL || key == NULL)
6462 env = mc->mc_txn->mt_env;
6464 /* Check this first so counter will always be zero on any
6467 if (flags & MDB_MULTIPLE) {
6468 dcount = data[1].mv_size;
6469 data[1].mv_size = 0;
6470 if (!F_ISSET(mc->mc_db->md_flags, MDB_DUPFIXED))
6471 return MDB_INCOMPATIBLE;
6474 nospill = flags & MDB_NOSPILL;
6475 flags &= ~MDB_NOSPILL;
6477 if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
6478 return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
6480 if (key->mv_size-1 >= ENV_MAXKEY(env))
6481 return MDB_BAD_VALSIZE;
6483 #if SIZE_MAX > MAXDATASIZE
6484 if (data->mv_size > ((mc->mc_db->md_flags & MDB_DUPSORT) ? ENV_MAXKEY(env) : MAXDATASIZE))
6485 return MDB_BAD_VALSIZE;
6487 if ((mc->mc_db->md_flags & MDB_DUPSORT) && data->mv_size > ENV_MAXKEY(env))
6488 return MDB_BAD_VALSIZE;
6491 DPRINTF(("==> put db %d key [%s], size %"Z"u, data size %"Z"u",
6492 DDBI(mc), DKEY(key), key ? key->mv_size : 0, data->mv_size));
6496 if (flags == MDB_CURRENT) {
6497 if (!(mc->mc_flags & C_INITIALIZED))
6500 } else if (mc->mc_db->md_root == P_INVALID) {
6501 /* new database, cursor has nothing to point to */
6504 mc->mc_flags &= ~C_INITIALIZED;
6509 if (flags & MDB_APPEND) {
6511 rc = mdb_cursor_last(mc, &k2, &d2);
6513 rc = mc->mc_dbx->md_cmp(key, &k2);
6516 mc->mc_ki[mc->mc_top]++;
6518 /* new key is <= last key */
6523 rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact);
6525 if ((flags & MDB_NOOVERWRITE) && rc == 0) {
6526 DPRINTF(("duplicate key [%s]", DKEY(key)));
6528 return MDB_KEYEXIST;
6530 if (rc && rc != MDB_NOTFOUND)
6534 if (mc->mc_flags & C_DEL)
6535 mc->mc_flags ^= C_DEL;
6537 /* Cursor is positioned, check for room in the dirty list */
6539 if (flags & MDB_MULTIPLE) {
6541 xdata.mv_size = data->mv_size * dcount;
6545 if ((rc2 = mdb_page_spill(mc, key, rdata)))
6549 if (rc == MDB_NO_ROOT) {
6551 /* new database, write a root leaf page */
6552 DPUTS("allocating new root leaf page");
6553 if ((rc2 = mdb_page_new(mc, P_LEAF, 1, &np))) {
6556 mdb_cursor_push(mc, np);
6557 mc->mc_db->md_root = np->mp_pgno;
6558 mc->mc_db->md_depth++;
6559 *mc->mc_dbflag |= DB_DIRTY;
6560 if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED))
6562 np->mp_flags |= P_LEAF2;
6563 mc->mc_flags |= C_INITIALIZED;
6565 /* make sure all cursor pages are writable */
6566 rc2 = mdb_cursor_touch(mc);
6571 insert_key = insert_data = rc;
6573 /* The key does not exist */
6574 DPRINTF(("inserting key at index %i", mc->mc_ki[mc->mc_top]));
6575 if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
6576 LEAFSIZE(key, data) > env->me_nodemax)
6578 /* Too big for a node, insert in sub-DB. Set up an empty
6579 * "old sub-page" for prep_subDB to expand to a full page.
6581 fp_flags = P_LEAF|P_DIRTY;
6583 fp->mp_pad = data->mv_size; /* used if MDB_DUPFIXED */
6584 fp->mp_lower = fp->mp_upper = (PAGEHDRSZ-PAGEBASE);
6585 olddata.mv_size = PAGEHDRSZ;
6589 /* there's only a key anyway, so this is a no-op */
6590 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
6592 unsigned int ksize = mc->mc_db->md_pad;
6593 if (key->mv_size != ksize)
6594 return MDB_BAD_VALSIZE;
6595 ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize);
6596 memcpy(ptr, key->mv_data, ksize);
6598 /* if overwriting slot 0 of leaf, need to
6599 * update branch key if there is a parent page
6601 if (mc->mc_top && !mc->mc_ki[mc->mc_top]) {
6602 unsigned short dtop = 1;
6604 /* slot 0 is always an empty key, find real slot */
6605 while (mc->mc_top && !mc->mc_ki[mc->mc_top]) {
6609 if (mc->mc_ki[mc->mc_top])
6610 rc2 = mdb_update_key(mc, key);
6621 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6622 olddata.mv_size = NODEDSZ(leaf);
6623 olddata.mv_data = NODEDATA(leaf);
6626 if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) {
6627 /* Prepare (sub-)page/sub-DB to accept the new item,
6628 * if needed. fp: old sub-page or a header faking
6629 * it. mp: new (sub-)page. offset: growth in page
6630 * size. xdata: node data with new page or DB.
6632 unsigned i, offset = 0;
6633 mp = fp = xdata.mv_data = env->me_pbuf;
6634 mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
6636 /* Was a single item before, must convert now */
6637 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6639 /* Just overwrite the current item */
6640 if (flags == MDB_CURRENT)
6642 dcmp = mc->mc_dbx->md_dcmp;
6643 #if UINT_MAX < SIZE_MAX
6644 if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
6645 dcmp = mdb_cmp_clong;
6647 /* does data match? */
6648 if (!dcmp(data, &olddata)) {
6649 if (flags & (MDB_NODUPDATA|MDB_APPENDDUP))
6650 return MDB_KEYEXIST;
6655 /* Back up original data item */
6656 dkey.mv_size = olddata.mv_size;
6657 dkey.mv_data = memcpy(fp+1, olddata.mv_data, olddata.mv_size);
6659 /* Make sub-page header for the dup items, with dummy body */
6660 fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP;
6661 fp->mp_lower = (PAGEHDRSZ-PAGEBASE);
6662 xdata.mv_size = PAGEHDRSZ + dkey.mv_size + data->mv_size;
6663 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
6664 fp->mp_flags |= P_LEAF2;
6665 fp->mp_pad = data->mv_size;
6666 xdata.mv_size += 2 * data->mv_size; /* leave space for 2 more */
6668 xdata.mv_size += 2 * (sizeof(indx_t) + NODESIZE) +
6669 (dkey.mv_size & 1) + (data->mv_size & 1);
6671 fp->mp_upper = xdata.mv_size - PAGEBASE;
6672 olddata.mv_size = xdata.mv_size; /* pretend olddata is fp */
6673 } else if (leaf->mn_flags & F_SUBDATA) {
6674 /* Data is on sub-DB, just store it */
6675 flags |= F_DUPDATA|F_SUBDATA;
6678 /* Data is on sub-page */
6679 fp = olddata.mv_data;
6682 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
6683 offset = EVEN(NODESIZE + sizeof(indx_t) +
6687 offset = fp->mp_pad;
6688 if (SIZELEFT(fp) < offset) {
6689 offset *= 4; /* space for 4 more */
6692 /* FALLTHRU: Big enough MDB_DUPFIXED sub-page */
6694 fp->mp_flags |= P_DIRTY;
6695 COPY_PGNO(fp->mp_pgno, mp->mp_pgno);
6696 mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;
6700 xdata.mv_size = olddata.mv_size + offset;
6703 fp_flags = fp->mp_flags;
6704 if (NODESIZE + NODEKSZ(leaf) + xdata.mv_size > env->me_nodemax) {
6705 /* Too big for a sub-page, convert to sub-DB */
6706 fp_flags &= ~P_SUBP;
6708 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
6709 fp_flags |= P_LEAF2;
6710 dummy.md_pad = fp->mp_pad;
6711 dummy.md_flags = MDB_DUPFIXED;
6712 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
6713 dummy.md_flags |= MDB_INTEGERKEY;
6719 dummy.md_branch_pages = 0;
6720 dummy.md_leaf_pages = 1;
6721 dummy.md_overflow_pages = 0;
6722 dummy.md_entries = NUMKEYS(fp);
6723 xdata.mv_size = sizeof(MDB_db);
6724 xdata.mv_data = &dummy;
6725 if ((rc = mdb_page_alloc(mc, 1, &mp)))
6727 offset = env->me_psize - olddata.mv_size;
6728 flags |= F_DUPDATA|F_SUBDATA;
6729 dummy.md_root = mp->mp_pgno;
6733 mp->mp_flags = fp_flags | P_DIRTY;
6734 mp->mp_pad = fp->mp_pad;
6735 mp->mp_lower = fp->mp_lower;
6736 mp->mp_upper = fp->mp_upper + offset;
6737 if (fp_flags & P_LEAF2) {
6738 memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad);
6740 memcpy((char *)mp + mp->mp_upper + PAGEBASE, (char *)fp + fp->mp_upper + PAGEBASE,
6741 olddata.mv_size - fp->mp_upper - PAGEBASE);
6742 for (i=0; i<NUMKEYS(fp); i++)
6743 mp->mp_ptrs[i] = fp->mp_ptrs[i] + offset;
6751 mdb_node_del(mc, 0);
6755 /* LMDB passes F_SUBDATA in 'flags' to write a DB record */
6756 if ((leaf->mn_flags ^ flags) & F_SUBDATA)
6757 return MDB_INCOMPATIBLE;
6758 /* overflow page overwrites need special handling */
6759 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
6762 int level, ovpages, dpages = OVPAGES(data->mv_size, env->me_psize);
6764 memcpy(&pg, olddata.mv_data, sizeof(pg));
6765 if ((rc2 = mdb_page_get(mc->mc_txn, pg, &omp, &level)) != 0)
6767 ovpages = omp->mp_pages;
6769 /* Is the ov page large enough? */
6770 if (ovpages >= dpages) {
6771 if (!(omp->mp_flags & P_DIRTY) &&
6772 (level || (env->me_flags & MDB_WRITEMAP)))
6774 rc = mdb_page_unspill(mc->mc_txn, omp, &omp);
6777 level = 0; /* dirty in this txn or clean */
6780 if (omp->mp_flags & P_DIRTY) {
6781 /* yes, overwrite it. Note in this case we don't
6782 * bother to try shrinking the page if the new data
6783 * is smaller than the overflow threshold.
6786 /* It is writable only in a parent txn */
6787 size_t sz = (size_t) env->me_psize * ovpages, off;
6788 MDB_page *np = mdb_page_malloc(mc->mc_txn, ovpages);
6794 /* Note - this page is already counted in parent's dirty_room */
6795 rc2 = mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);
6796 mdb_cassert(mc, rc2 == 0);
6797 if (!(flags & MDB_RESERVE)) {
6798 /* Copy end of page, adjusting alignment so
6799 * compiler may copy words instead of bytes.
6801 off = (PAGEHDRSZ + data->mv_size) & -sizeof(size_t);
6802 memcpy((size_t *)((char *)np + off),
6803 (size_t *)((char *)omp + off), sz - off);
6806 memcpy(np, omp, sz); /* Copy beginning of page */
6809 SETDSZ(leaf, data->mv_size);
6810 if (F_ISSET(flags, MDB_RESERVE))
6811 data->mv_data = METADATA(omp);
6813 memcpy(METADATA(omp), data->mv_data, data->mv_size);
6817 if ((rc2 = mdb_ovpage_free(mc, omp)) != MDB_SUCCESS)
6819 } else if (data->mv_size == olddata.mv_size) {
6820 /* same size, just replace it. Note that we could
6821 * also reuse this node if the new data is smaller,
6822 * but instead we opt to shrink the node in that case.
6824 if (F_ISSET(flags, MDB_RESERVE))
6825 data->mv_data = olddata.mv_data;
6826 else if (!(mc->mc_flags & C_SUB))
6827 memcpy(olddata.mv_data, data->mv_data, data->mv_size);
6829 memcpy(NODEKEY(leaf), key->mv_data, key->mv_size);
6834 mdb_node_del(mc, 0);
6840 nflags = flags & NODE_ADD_FLAGS;
6841 nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(env, key, rdata);
6842 if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) {
6843 if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA )
6844 nflags &= ~MDB_APPEND; /* sub-page may need room to grow */
6846 nflags |= MDB_SPLIT_REPLACE;
6847 rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags);
6849 /* There is room already in this leaf page. */
6850 rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);
6852 /* Adjust other cursors pointing to mp */
6853 MDB_cursor *m2, *m3;
6854 MDB_dbi dbi = mc->mc_dbi;
6855 unsigned i = mc->mc_top;
6856 MDB_page *mp = mc->mc_pg[i];
6858 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
6859 if (mc->mc_flags & C_SUB)
6860 m3 = &m2->mc_xcursor->mx_cursor;
6863 if (m3 == mc || m3->mc_snum < mc->mc_snum || m3->mc_pg[i] != mp) continue;
6864 if (m3->mc_ki[i] >= mc->mc_ki[i] && insert_key) {
6867 if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
6868 MDB_node *n2 = NODEPTR(mp, m3->mc_ki[i]);
6869 if ((n2->mn_flags & (F_SUBDATA|F_DUPDATA)) == F_DUPDATA)
6870 m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
6876 if (rc == MDB_SUCCESS) {
6877 /* Now store the actual data in the child DB. Note that we're
6878 * storing the user data in the keys field, so there are strict
6879 * size limits on dupdata. The actual data fields of the child
6880 * DB are all zero size.
6883 int xflags, new_dupdata;
6888 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6889 if (flags & MDB_CURRENT) {
6890 xflags = MDB_CURRENT|MDB_NOSPILL;
6892 mdb_xcursor_init1(mc, leaf);
6893 xflags = (flags & MDB_NODUPDATA) ?
6894 MDB_NOOVERWRITE|MDB_NOSPILL : MDB_NOSPILL;
6897 mc->mc_xcursor->mx_cursor.mc_pg[0] = sub_root;
6898 new_dupdata = (int)dkey.mv_size;
6899 /* converted, write the original data first */
6901 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);
6904 /* we've done our job */
6907 if (!(leaf->mn_flags & F_SUBDATA) || sub_root) {
6908 /* Adjust other cursors pointing to mp */
6910 MDB_xcursor *mx = mc->mc_xcursor;
6911 unsigned i = mc->mc_top;
6912 MDB_page *mp = mc->mc_pg[i];
6913 int nkeys = NUMKEYS(mp);
6915 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
6916 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
6917 if (!(m2->mc_flags & C_INITIALIZED)) continue;
6918 if (m2->mc_pg[i] == mp) {
6919 if (m2->mc_ki[i] == mc->mc_ki[i]) {
6920 mdb_xcursor_init2(m2, mx, new_dupdata);
6921 } else if (!insert_key && m2->mc_ki[i] < nkeys) {
6922 MDB_node *n2 = NODEPTR(mp, m2->mc_ki[i]);
6923 if ((n2->mn_flags & (F_SUBDATA|F_DUPDATA)) == F_DUPDATA)
6924 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
6929 ecount = mc->mc_xcursor->mx_db.md_entries;
6930 if (flags & MDB_APPENDDUP)
6931 xflags |= MDB_APPEND;
6932 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);
6933 if (flags & F_SUBDATA) {
6934 void *db = NODEDATA(leaf);
6935 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
6937 insert_data = mc->mc_xcursor->mx_db.md_entries - ecount;
6939 /* Increment count unless we just replaced an existing item. */
6941 mc->mc_db->md_entries++;
6943 /* Invalidate txn if we created an empty sub-DB */
6946 /* If we succeeded and the key didn't exist before,
6947 * make sure the cursor is marked valid.
6949 mc->mc_flags |= C_INITIALIZED;
6951 if (flags & MDB_MULTIPLE) {
6954 /* let caller know how many succeeded, if any */
6955 data[1].mv_size = mcount;
6956 if (mcount < dcount) {
6957 data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size;
6958 insert_key = insert_data = 0;
6965 if (rc == MDB_KEYEXIST) /* should not happen, we deleted that item */
6968 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
6973 mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
6979 if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
6980 return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
6982 if (!(mc->mc_flags & C_INITIALIZED))
6985 if (mc->mc_ki[mc->mc_top] >= NUMKEYS(mc->mc_pg[mc->mc_top]))
6986 return MDB_NOTFOUND;
6988 if (!(flags & MDB_NOSPILL) && (rc = mdb_page_spill(mc, NULL, NULL)))
6991 rc = mdb_cursor_touch(mc);
6995 mp = mc->mc_pg[mc->mc_top];
6998 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
7000 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
7001 if (flags & MDB_NODUPDATA) {
7002 /* mdb_cursor_del0() will subtract the final entry */
7003 mc->mc_db->md_entries -= mc->mc_xcursor->mx_db.md_entries - 1;
7004 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
7006 if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
7007 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
7009 rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, MDB_NOSPILL);
7012 /* If sub-DB still has entries, we're done */
7013 if (mc->mc_xcursor->mx_db.md_entries) {
7014 if (leaf->mn_flags & F_SUBDATA) {
7015 /* update subDB info */
7016 void *db = NODEDATA(leaf);
7017 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
7020 /* shrink fake page */
7021 mdb_node_shrink(mp, mc->mc_ki[mc->mc_top]);
7022 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
7023 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
7024 /* fix other sub-DB cursors pointed at fake pages on this page */
7025 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
7026 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
7027 if (!(m2->mc_flags & C_INITIALIZED)) continue;
7028 if (m2->mc_pg[mc->mc_top] == mp) {
7029 if (m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top]) {
7030 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
7032 MDB_node *n2 = NODEPTR(mp, m2->mc_ki[mc->mc_top]);
7033 if (!(n2->mn_flags & F_SUBDATA))
7034 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
7039 mc->mc_db->md_entries--;
7042 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
7044 /* otherwise fall thru and delete the sub-DB */
7047 if (leaf->mn_flags & F_SUBDATA) {
7048 /* add all the child DB's pages to the free list */
7049 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
7054 /* LMDB passes F_SUBDATA in 'flags' to delete a DB record */
7055 else if ((leaf->mn_flags ^ flags) & F_SUBDATA) {
7056 rc = MDB_INCOMPATIBLE;
7060 /* add overflow pages to free list */
7061 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
7065 memcpy(&pg, NODEDATA(leaf), sizeof(pg));
7066 if ((rc = mdb_page_get(mc->mc_txn, pg, &omp, NULL)) ||
7067 (rc = mdb_ovpage_free(mc, omp)))
7072 return mdb_cursor_del0(mc);
7075 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
7079 /** Allocate and initialize new pages for a database.
7080 * @param[in] mc a cursor on the database being added to.
7081 * @param[in] flags flags defining what type of page is being allocated.
7082 * @param[in] num the number of pages to allocate. This is usually 1,
7083 * unless allocating overflow pages for a large record.
7084 * @param[out] mp Address of a page, or NULL on failure.
7085 * @return 0 on success, non-zero on failure.
7088 mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp)
7093 if ((rc = mdb_page_alloc(mc, num, &np)))
7095 DPRINTF(("allocated new mpage %"Z"u, page size %u",
7096 np->mp_pgno, mc->mc_txn->mt_env->me_psize));
7097 np->mp_flags = flags | P_DIRTY;
7098 np->mp_lower = (PAGEHDRSZ-PAGEBASE);
7099 np->mp_upper = mc->mc_txn->mt_env->me_psize - PAGEBASE;
7102 mc->mc_db->md_branch_pages++;
7103 else if (IS_LEAF(np))
7104 mc->mc_db->md_leaf_pages++;
7105 else if (IS_OVERFLOW(np)) {
7106 mc->mc_db->md_overflow_pages += num;
7114 /** Calculate the size of a leaf node.
7115 * The size depends on the environment's page size; if a data item
7116 * is too large it will be put onto an overflow page and the node
7117 * size will only include the key and not the data. Sizes are always
7118 * rounded up to an even number of bytes, to guarantee 2-byte alignment
7119 * of the #MDB_node headers.
7120 * @param[in] env The environment handle.
7121 * @param[in] key The key for the node.
7122 * @param[in] data The data for the node.
7123 * @return The number of bytes needed to store the node.
7126 mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data)
7130 sz = LEAFSIZE(key, data);
7131 if (sz > env->me_nodemax) {
7132 /* put on overflow page */
7133 sz -= data->mv_size - sizeof(pgno_t);
7136 return EVEN(sz + sizeof(indx_t));
7139 /** Calculate the size of a branch node.
7140 * The size should depend on the environment's page size but since
7141 * we currently don't support spilling large keys onto overflow
7142 * pages, it's simply the size of the #MDB_node header plus the
7143 * size of the key. Sizes are always rounded up to an even number
7144 * of bytes, to guarantee 2-byte alignment of the #MDB_node headers.
7145 * @param[in] env The environment handle.
7146 * @param[in] key The key for the node.
7147 * @return The number of bytes needed to store the node.
7150 mdb_branch_size(MDB_env *env, MDB_val *key)
7155 if (sz > env->me_nodemax) {
7156 /* put on overflow page */
7157 /* not implemented */
7158 /* sz -= key->size - sizeof(pgno_t); */
7161 return sz + sizeof(indx_t);
7164 /** Add a node to the page pointed to by the cursor.
7165 * @param[in] mc The cursor for this operation.
7166 * @param[in] indx The index on the page where the new node should be added.
7167 * @param[in] key The key for the new node.
7168 * @param[in] data The data for the new node, if any.
7169 * @param[in] pgno The page number, if adding a branch node.
7170 * @param[in] flags Flags for the node.
7171 * @return 0 on success, non-zero on failure. Possible errors are:
7173 * <li>ENOMEM - failed to allocate overflow pages for the node.
7174 * <li>MDB_PAGE_FULL - there is insufficient room in the page. This error
7175 * should never happen since all callers already calculate the
7176 * page's free space before calling this function.
7180 mdb_node_add(MDB_cursor *mc, indx_t indx,
7181 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags)
7184 size_t node_size = NODESIZE;
7188 MDB_page *mp = mc->mc_pg[mc->mc_top];
7189 MDB_page *ofp = NULL; /* overflow page */
7193 mdb_cassert(mc, mp->mp_upper >= mp->mp_lower);
7195 DPRINTF(("add to %s %spage %"Z"u index %i, data size %"Z"u key size %"Z"u [%s]",
7196 IS_LEAF(mp) ? "leaf" : "branch",
7197 IS_SUBP(mp) ? "sub-" : "",
7198 mdb_dbg_pgno(mp), indx, data ? data->mv_size : 0,
7199 key ? key->mv_size : 0, key ? DKEY(key) : "null"));
7202 /* Move higher keys up one slot. */
7203 int ksize = mc->mc_db->md_pad, dif;
7204 char *ptr = LEAF2KEY(mp, indx, ksize);
7205 dif = NUMKEYS(mp) - indx;
7207 memmove(ptr+ksize, ptr, dif*ksize);
7208 /* insert new key */
7209 memcpy(ptr, key->mv_data, ksize);
7211 /* Just using these for counting */
7212 mp->mp_lower += sizeof(indx_t);
7213 mp->mp_upper -= ksize - sizeof(indx_t);
7217 room = (ssize_t)SIZELEFT(mp) - (ssize_t)sizeof(indx_t);
7219 node_size += key->mv_size;
7221 mdb_cassert(mc, key && data);
7222 if (F_ISSET(flags, F_BIGDATA)) {
7223 /* Data already on overflow page. */
7224 node_size += sizeof(pgno_t);
7225 } else if (node_size + data->mv_size > mc->mc_txn->mt_env->me_nodemax) {
7226 int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
7228 /* Put data on overflow page. */
7229 DPRINTF(("data size is %"Z"u, node would be %"Z"u, put data on overflow page",
7230 data->mv_size, node_size+data->mv_size));
7231 node_size = EVEN(node_size + sizeof(pgno_t));
7232 if ((ssize_t)node_size > room)
7234 if ((rc = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp)))
7236 DPRINTF(("allocated overflow page %"Z"u", ofp->mp_pgno));
7240 node_size += data->mv_size;
7243 node_size = EVEN(node_size);
7244 if ((ssize_t)node_size > room)
7248 /* Move higher pointers up one slot. */
7249 for (i = NUMKEYS(mp); i > indx; i--)
7250 mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];
7252 /* Adjust free space offsets. */
7253 ofs = mp->mp_upper - node_size;
7254 mdb_cassert(mc, ofs >= mp->mp_lower + sizeof(indx_t));
7255 mp->mp_ptrs[indx] = ofs;
7257 mp->mp_lower += sizeof(indx_t);
7259 /* Write the node data. */
7260 node = NODEPTR(mp, indx);
7261 node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
7262 node->mn_flags = flags;
7264 SETDSZ(node,data->mv_size);
7269 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
7272 ndata = NODEDATA(node);
7274 if (F_ISSET(flags, F_BIGDATA))
7275 memcpy(ndata, data->mv_data, sizeof(pgno_t));
7276 else if (F_ISSET(flags, MDB_RESERVE))
7277 data->mv_data = ndata;
7279 memcpy(ndata, data->mv_data, data->mv_size);
7281 memcpy(ndata, &ofp->mp_pgno, sizeof(pgno_t));
7282 ndata = METADATA(ofp);
7283 if (F_ISSET(flags, MDB_RESERVE))
7284 data->mv_data = ndata;
7286 memcpy(ndata, data->mv_data, data->mv_size);
7293 DPRINTF(("not enough room in page %"Z"u, got %u ptrs",
7294 mdb_dbg_pgno(mp), NUMKEYS(mp)));
7295 DPRINTF(("upper-lower = %u - %u = %"Z"d", mp->mp_upper,mp->mp_lower,room));
7296 DPRINTF(("node size = %"Z"u", node_size));
7297 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
7298 return MDB_PAGE_FULL;
7301 /** Delete the specified node from a page.
7302 * @param[in] mc Cursor pointing to the node to delete.
7303 * @param[in] ksize The size of a node. Only used if the page is
7304 * part of a #MDB_DUPFIXED database.
7307 mdb_node_del(MDB_cursor *mc, int ksize)
7309 MDB_page *mp = mc->mc_pg[mc->mc_top];
7310 indx_t indx = mc->mc_ki[mc->mc_top];
7312 indx_t i, j, numkeys, ptr;
7316 DPRINTF(("delete node %u on %s page %"Z"u", indx,
7317 IS_LEAF(mp) ? "leaf" : "branch", mdb_dbg_pgno(mp)));
7318 numkeys = NUMKEYS(mp);
7319 mdb_cassert(mc, indx < numkeys);
7322 int x = numkeys - 1 - indx;
7323 base = LEAF2KEY(mp, indx, ksize);
7325 memmove(base, base + ksize, x * ksize);
7326 mp->mp_lower -= sizeof(indx_t);
7327 mp->mp_upper += ksize - sizeof(indx_t);
7331 node = NODEPTR(mp, indx);
7332 sz = NODESIZE + node->mn_ksize;
7334 if (F_ISSET(node->mn_flags, F_BIGDATA))
7335 sz += sizeof(pgno_t);
7337 sz += NODEDSZ(node);
7341 ptr = mp->mp_ptrs[indx];
7342 for (i = j = 0; i < numkeys; i++) {
7344 mp->mp_ptrs[j] = mp->mp_ptrs[i];
7345 if (mp->mp_ptrs[i] < ptr)
7346 mp->mp_ptrs[j] += sz;
7351 base = (char *)mp + mp->mp_upper + PAGEBASE;
7352 memmove(base + sz, base, ptr - mp->mp_upper);
7354 mp->mp_lower -= sizeof(indx_t);
7358 /** Compact the main page after deleting a node on a subpage.
7359 * @param[in] mp The main page to operate on.
7360 * @param[in] indx The index of the subpage on the main page.
7363 mdb_node_shrink(MDB_page *mp, indx_t indx)
7368 indx_t delta, nsize, len, ptr;
7371 node = NODEPTR(mp, indx);
7372 sp = (MDB_page *)NODEDATA(node);
7373 delta = SIZELEFT(sp);
7374 nsize = NODEDSZ(node) - delta;
7376 /* Prepare to shift upward, set len = length(subpage part to shift) */
7380 return; /* do not make the node uneven-sized */
7382 xp = (MDB_page *)((char *)sp + delta); /* destination subpage */
7383 for (i = NUMKEYS(sp); --i >= 0; )
7384 xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta;
7387 sp->mp_upper = sp->mp_lower;
7388 COPY_PGNO(sp->mp_pgno, mp->mp_pgno);
7389 SETDSZ(node, nsize);
7391 /* Shift <lower nodes...initial part of subpage> upward */
7392 base = (char *)mp + mp->mp_upper + PAGEBASE;
7393 memmove(base + delta, base, (char *)sp + len - base);
7395 ptr = mp->mp_ptrs[indx];
7396 for (i = NUMKEYS(mp); --i >= 0; ) {
7397 if (mp->mp_ptrs[i] <= ptr)
7398 mp->mp_ptrs[i] += delta;
7400 mp->mp_upper += delta;
7403 /** Initial setup of a sorted-dups cursor.
7404 * Sorted duplicates are implemented as a sub-database for the given key.
7405 * The duplicate data items are actually keys of the sub-database.
7406 * Operations on the duplicate data items are performed using a sub-cursor
7407 * initialized when the sub-database is first accessed. This function does
7408 * the preliminary setup of the sub-cursor, filling in the fields that
7409 * depend only on the parent DB.
7410 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
7413 mdb_xcursor_init0(MDB_cursor *mc)
7415 MDB_xcursor *mx = mc->mc_xcursor;
7417 mx->mx_cursor.mc_xcursor = NULL;
7418 mx->mx_cursor.mc_txn = mc->mc_txn;
7419 mx->mx_cursor.mc_db = &mx->mx_db;
7420 mx->mx_cursor.mc_dbx = &mx->mx_dbx;
7421 mx->mx_cursor.mc_dbi = mc->mc_dbi;
7422 mx->mx_cursor.mc_dbflag = &mx->mx_dbflag;
7423 mx->mx_cursor.mc_snum = 0;
7424 mx->mx_cursor.mc_top = 0;
7425 mx->mx_cursor.mc_flags = C_SUB;
7426 mx->mx_dbx.md_name.mv_size = 0;
7427 mx->mx_dbx.md_name.mv_data = NULL;
7428 mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp;
7429 mx->mx_dbx.md_dcmp = NULL;
7430 mx->mx_dbx.md_rel = mc->mc_dbx->md_rel;
7433 /** Final setup of a sorted-dups cursor.
7434 * Sets up the fields that depend on the data from the main cursor.
7435 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
7436 * @param[in] node The data containing the #MDB_db record for the
7437 * sorted-dup database.
7440 mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)
7442 MDB_xcursor *mx = mc->mc_xcursor;
7444 if (node->mn_flags & F_SUBDATA) {
7445 memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db));
7446 mx->mx_cursor.mc_pg[0] = 0;
7447 mx->mx_cursor.mc_snum = 0;
7448 mx->mx_cursor.mc_top = 0;
7449 mx->mx_cursor.mc_flags = C_SUB;
7451 MDB_page *fp = NODEDATA(node);
7452 mx->mx_db.md_pad = 0;
7453 mx->mx_db.md_flags = 0;
7454 mx->mx_db.md_depth = 1;
7455 mx->mx_db.md_branch_pages = 0;
7456 mx->mx_db.md_leaf_pages = 1;
7457 mx->mx_db.md_overflow_pages = 0;
7458 mx->mx_db.md_entries = NUMKEYS(fp);
7459 COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno);
7460 mx->mx_cursor.mc_snum = 1;
7461 mx->mx_cursor.mc_top = 0;
7462 mx->mx_cursor.mc_flags = C_INITIALIZED|C_SUB;
7463 mx->mx_cursor.mc_pg[0] = fp;
7464 mx->mx_cursor.mc_ki[0] = 0;
7465 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
7466 mx->mx_db.md_flags = MDB_DUPFIXED;
7467 mx->mx_db.md_pad = fp->mp_pad;
7468 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
7469 mx->mx_db.md_flags |= MDB_INTEGERKEY;
7472 DPRINTF(("Sub-db -%u root page %"Z"u", mx->mx_cursor.mc_dbi,
7473 mx->mx_db.md_root));
7474 mx->mx_dbflag = DB_VALID|DB_USRVALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
7475 #if UINT_MAX < SIZE_MAX
7476 if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(size_t))
7477 mx->mx_dbx.md_cmp = mdb_cmp_clong;
7482 /** Fixup a sorted-dups cursor due to underlying update.
7483 * Sets up some fields that depend on the data from the main cursor.
7484 * Almost the same as init1, but skips initialization steps if the
7485 * xcursor had already been used.
7486 * @param[in] mc The main cursor whose sorted-dups cursor is to be fixed up.
7487 * @param[in] src_mx The xcursor of an up-to-date cursor.
7488 * @param[in] new_dupdata True if converting from a non-#F_DUPDATA item.
7491 mdb_xcursor_init2(MDB_cursor *mc, MDB_xcursor *src_mx, int new_dupdata)
7493 MDB_xcursor *mx = mc->mc_xcursor;
7496 mx->mx_cursor.mc_snum = 1;
7497 mx->mx_cursor.mc_top = 0;
7498 mx->mx_cursor.mc_flags |= C_INITIALIZED;
7499 mx->mx_cursor.mc_ki[0] = 0;
7500 mx->mx_dbflag = DB_VALID|DB_USRVALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
7501 #if UINT_MAX < SIZE_MAX
7502 mx->mx_dbx.md_cmp = src_mx->mx_dbx.md_cmp;
7504 } else if (!(mx->mx_cursor.mc_flags & C_INITIALIZED)) {
7507 mx->mx_db = src_mx->mx_db;
7508 mx->mx_cursor.mc_pg[0] = src_mx->mx_cursor.mc_pg[0];
7509 DPRINTF(("Sub-db -%u root page %"Z"u", mx->mx_cursor.mc_dbi,
7510 mx->mx_db.md_root));
7513 /** Initialize a cursor for a given transaction and database. */
7515 mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
7518 mc->mc_backup = NULL;
7521 mc->mc_db = &txn->mt_dbs[dbi];
7522 mc->mc_dbx = &txn->mt_dbxs[dbi];
7523 mc->mc_dbflag = &txn->mt_dbflags[dbi];
7529 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
7530 mdb_tassert(txn, mx != NULL);
7531 mc->mc_xcursor = mx;
7532 mdb_xcursor_init0(mc);
7534 mc->mc_xcursor = NULL;
7536 if (*mc->mc_dbflag & DB_STALE) {
7537 mdb_page_search(mc, NULL, MDB_PS_ROOTONLY);
7542 mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
7545 size_t size = sizeof(MDB_cursor);
7547 if (!ret || !TXN_DBI_EXIST(txn, dbi, DB_VALID))
7550 if (txn->mt_flags & MDB_TXN_BLOCKED)
7553 if (dbi == FREE_DBI && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
7556 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)
7557 size += sizeof(MDB_xcursor);
7559 if ((mc = malloc(size)) != NULL) {
7560 mdb_cursor_init(mc, txn, dbi, (MDB_xcursor *)(mc + 1));
7561 if (txn->mt_cursors) {
7562 mc->mc_next = txn->mt_cursors[dbi];
7563 txn->mt_cursors[dbi] = mc;
7564 mc->mc_flags |= C_UNTRACK;
7576 mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)
7578 if (!mc || !TXN_DBI_EXIST(txn, mc->mc_dbi, DB_VALID))
7581 if ((mc->mc_flags & C_UNTRACK) || txn->mt_cursors)
7584 if (txn->mt_flags & MDB_TXN_BLOCKED)
7587 mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor);
7591 /* Return the count of duplicate data items for the current key */
7593 mdb_cursor_count(MDB_cursor *mc, size_t *countp)
7597 if (mc == NULL || countp == NULL)
7600 if (mc->mc_xcursor == NULL)
7601 return MDB_INCOMPATIBLE;
7603 if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)
7606 if (!(mc->mc_flags & C_INITIALIZED))
7609 if (!mc->mc_snum || (mc->mc_flags & C_EOF))
7610 return MDB_NOTFOUND;
7612 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
7613 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
7616 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
7619 *countp = mc->mc_xcursor->mx_db.md_entries;
7625 mdb_cursor_close(MDB_cursor *mc)
7627 if (mc && !mc->mc_backup) {
7628 /* remove from txn, if tracked */
7629 if ((mc->mc_flags & C_UNTRACK) && mc->mc_txn->mt_cursors) {
7630 MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi];
7631 while (*prev && *prev != mc) prev = &(*prev)->mc_next;
7633 *prev = mc->mc_next;
7640 mdb_cursor_txn(MDB_cursor *mc)
7642 if (!mc) return NULL;
7647 mdb_cursor_dbi(MDB_cursor *mc)
7652 /** Replace the key for a branch node with a new key.
7653 * @param[in] mc Cursor pointing to the node to operate on.
7654 * @param[in] key The new key to use.
7655 * @return 0 on success, non-zero on failure.
7658 mdb_update_key(MDB_cursor *mc, MDB_val *key)
7664 int delta, ksize, oksize;
7665 indx_t ptr, i, numkeys, indx;
7668 indx = mc->mc_ki[mc->mc_top];
7669 mp = mc->mc_pg[mc->mc_top];
7670 node = NODEPTR(mp, indx);
7671 ptr = mp->mp_ptrs[indx];
7675 char kbuf2[DKBUF_MAXKEYSIZE*2+1];
7676 k2.mv_data = NODEKEY(node);
7677 k2.mv_size = node->mn_ksize;
7678 DPRINTF(("update key %u (ofs %u) [%s] to [%s] on page %"Z"u",
7680 mdb_dkey(&k2, kbuf2),
7686 /* Sizes must be 2-byte aligned. */
7687 ksize = EVEN(key->mv_size);
7688 oksize = EVEN(node->mn_ksize);
7689 delta = ksize - oksize;
7691 /* Shift node contents if EVEN(key length) changed. */
7693 if (delta > 0 && SIZELEFT(mp) < delta) {
7695 /* not enough space left, do a delete and split */
7696 DPRINTF(("Not enough room, delta = %d, splitting...", delta));
7697 pgno = NODEPGNO(node);
7698 mdb_node_del(mc, 0);
7699 return mdb_page_split(mc, key, NULL, pgno, MDB_SPLIT_REPLACE);
7702 numkeys = NUMKEYS(mp);
7703 for (i = 0; i < numkeys; i++) {
7704 if (mp->mp_ptrs[i] <= ptr)
7705 mp->mp_ptrs[i] -= delta;
7708 base = (char *)mp + mp->mp_upper + PAGEBASE;
7709 len = ptr - mp->mp_upper + NODESIZE;
7710 memmove(base - delta, base, len);
7711 mp->mp_upper -= delta;
7713 node = NODEPTR(mp, indx);
7716 /* But even if no shift was needed, update ksize */
7717 if (node->mn_ksize != key->mv_size)
7718 node->mn_ksize = key->mv_size;
7721 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
7727 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst);
7729 /** Perform \b act while tracking temporary cursor \b mn */
7730 #define WITH_CURSOR_TRACKING(mn, act) do { \
7731 MDB_cursor dummy, *tracked, **tp = &(mn).mc_txn->mt_cursors[mn.mc_dbi]; \
7732 if ((mn).mc_flags & C_SUB) { \
7733 dummy.mc_flags = C_INITIALIZED; \
7734 dummy.mc_xcursor = (MDB_xcursor *)&(mn); \
7739 tracked->mc_next = *tp; \
7742 *tp = tracked->mc_next; \
7745 /** Move a node from csrc to cdst.
7748 mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft)
7755 unsigned short flags;
7759 /* Mark src and dst as dirty. */
7760 if ((rc = mdb_page_touch(csrc)) ||
7761 (rc = mdb_page_touch(cdst)))
7764 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7765 key.mv_size = csrc->mc_db->md_pad;
7766 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
7768 data.mv_data = NULL;
7772 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]);
7773 mdb_cassert(csrc, !((size_t)srcnode & 1));
7774 srcpg = NODEPGNO(srcnode);
7775 flags = srcnode->mn_flags;
7776 if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
7777 unsigned int snum = csrc->mc_snum;
7779 /* must find the lowest key below src */
7780 rc = mdb_page_search_lowest(csrc);
7783 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7784 key.mv_size = csrc->mc_db->md_pad;
7785 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
7787 s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
7788 key.mv_size = NODEKSZ(s2);
7789 key.mv_data = NODEKEY(s2);
7791 csrc->mc_snum = snum--;
7792 csrc->mc_top = snum;
7794 key.mv_size = NODEKSZ(srcnode);
7795 key.mv_data = NODEKEY(srcnode);
7797 data.mv_size = NODEDSZ(srcnode);
7798 data.mv_data = NODEDATA(srcnode);
7800 mn.mc_xcursor = NULL;
7801 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) {
7802 unsigned int snum = cdst->mc_snum;
7805 /* must find the lowest key below dst */
7806 mdb_cursor_copy(cdst, &mn);
7807 rc = mdb_page_search_lowest(&mn);
7810 if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {
7811 bkey.mv_size = mn.mc_db->md_pad;
7812 bkey.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, bkey.mv_size);
7814 s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);
7815 bkey.mv_size = NODEKSZ(s2);
7816 bkey.mv_data = NODEKEY(s2);
7818 mn.mc_snum = snum--;
7821 rc = mdb_update_key(&mn, &bkey);
7826 DPRINTF(("moving %s node %u [%s] on page %"Z"u to node %u on page %"Z"u",
7827 IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch",
7828 csrc->mc_ki[csrc->mc_top],
7830 csrc->mc_pg[csrc->mc_top]->mp_pgno,
7831 cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno));
7833 /* Add the node to the destination page.
7835 rc = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags);
7836 if (rc != MDB_SUCCESS)
7839 /* Delete the node from the source page.
7841 mdb_node_del(csrc, key.mv_size);
7844 /* Adjust other cursors pointing to mp */
7845 MDB_cursor *m2, *m3;
7846 MDB_dbi dbi = csrc->mc_dbi;
7847 MDB_page *mpd, *mps;
7849 mps = csrc->mc_pg[csrc->mc_top];
7850 /* If we're adding on the left, bump others up */
7852 mpd = cdst->mc_pg[csrc->mc_top];
7853 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7854 if (csrc->mc_flags & C_SUB)
7855 m3 = &m2->mc_xcursor->mx_cursor;
7858 if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)
7861 m3->mc_pg[csrc->mc_top] == mpd &&
7862 m3->mc_ki[csrc->mc_top] >= cdst->mc_ki[csrc->mc_top]) {
7863 m3->mc_ki[csrc->mc_top]++;
7866 m3->mc_pg[csrc->mc_top] == mps &&
7867 m3->mc_ki[csrc->mc_top] == csrc->mc_ki[csrc->mc_top]) {
7868 m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
7869 m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
7870 m3->mc_ki[csrc->mc_top-1]++;
7872 if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
7874 MDB_node *node = NODEPTR(m3->mc_pg[csrc->mc_top], m3->mc_ki[csrc->mc_top]);
7875 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
7876 m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
7880 /* Adding on the right, bump others down */
7882 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7883 if (csrc->mc_flags & C_SUB)
7884 m3 = &m2->mc_xcursor->mx_cursor;
7887 if (m3 == csrc) continue;
7888 if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)
7890 if (m3->mc_pg[csrc->mc_top] == mps) {
7891 if (!m3->mc_ki[csrc->mc_top]) {
7892 m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
7893 m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
7894 m3->mc_ki[csrc->mc_top-1]--;
7896 m3->mc_ki[csrc->mc_top]--;
7898 if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
7900 MDB_node *node = NODEPTR(m3->mc_pg[csrc->mc_top], m3->mc_ki[csrc->mc_top]);
7901 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
7902 m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
7909 /* Update the parent separators.
7911 if (csrc->mc_ki[csrc->mc_top] == 0) {
7912 if (csrc->mc_ki[csrc->mc_top-1] != 0) {
7913 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7914 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
7916 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
7917 key.mv_size = NODEKSZ(srcnode);
7918 key.mv_data = NODEKEY(srcnode);
7920 DPRINTF(("update separator for source page %"Z"u to [%s]",
7921 csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key)));
7922 mdb_cursor_copy(csrc, &mn);
7925 /* We want mdb_rebalance to find mn when doing fixups */
7926 WITH_CURSOR_TRACKING(mn,
7927 rc = mdb_update_key(&mn, &key));
7931 if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
7933 indx_t ix = csrc->mc_ki[csrc->mc_top];
7934 nullkey.mv_size = 0;
7935 csrc->mc_ki[csrc->mc_top] = 0;
7936 rc = mdb_update_key(csrc, &nullkey);
7937 csrc->mc_ki[csrc->mc_top] = ix;
7938 mdb_cassert(csrc, rc == MDB_SUCCESS);
7942 if (cdst->mc_ki[cdst->mc_top] == 0) {
7943 if (cdst->mc_ki[cdst->mc_top-1] != 0) {
7944 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7945 key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size);
7947 srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
7948 key.mv_size = NODEKSZ(srcnode);
7949 key.mv_data = NODEKEY(srcnode);
7951 DPRINTF(("update separator for destination page %"Z"u to [%s]",
7952 cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key)));
7953 mdb_cursor_copy(cdst, &mn);
7956 /* We want mdb_rebalance to find mn when doing fixups */
7957 WITH_CURSOR_TRACKING(mn,
7958 rc = mdb_update_key(&mn, &key));
7962 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) {
7964 indx_t ix = cdst->mc_ki[cdst->mc_top];
7965 nullkey.mv_size = 0;
7966 cdst->mc_ki[cdst->mc_top] = 0;
7967 rc = mdb_update_key(cdst, &nullkey);
7968 cdst->mc_ki[cdst->mc_top] = ix;
7969 mdb_cassert(cdst, rc == MDB_SUCCESS);
7976 /** Merge one page into another.
7977 * The nodes from the page pointed to by \b csrc will
7978 * be copied to the page pointed to by \b cdst and then
7979 * the \b csrc page will be freed.
7980 * @param[in] csrc Cursor pointing to the source page.
7981 * @param[in] cdst Cursor pointing to the destination page.
7982 * @return 0 on success, non-zero on failure.
7985 mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
7987 MDB_page *psrc, *pdst;
7994 psrc = csrc->mc_pg[csrc->mc_top];
7995 pdst = cdst->mc_pg[cdst->mc_top];
7997 DPRINTF(("merging page %"Z"u into %"Z"u", psrc->mp_pgno, pdst->mp_pgno));
7999 mdb_cassert(csrc, csrc->mc_snum > 1); /* can't merge root page */
8000 mdb_cassert(csrc, cdst->mc_snum > 1);
8002 /* Mark dst as dirty. */
8003 if ((rc = mdb_page_touch(cdst)))
8006 /* get dst page again now that we've touched it. */
8007 pdst = cdst->mc_pg[cdst->mc_top];
8009 /* Move all nodes from src to dst.
8011 j = nkeys = NUMKEYS(pdst);
8012 if (IS_LEAF2(psrc)) {
8013 key.mv_size = csrc->mc_db->md_pad;
8014 key.mv_data = METADATA(psrc);
8015 for (i = 0; i < NUMKEYS(psrc); i++, j++) {
8016 rc = mdb_node_add(cdst, j, &key, NULL, 0, 0);
8017 if (rc != MDB_SUCCESS)
8019 key.mv_data = (char *)key.mv_data + key.mv_size;
8022 for (i = 0; i < NUMKEYS(psrc); i++, j++) {
8023 srcnode = NODEPTR(psrc, i);
8024 if (i == 0 && IS_BRANCH(psrc)) {
8027 mdb_cursor_copy(csrc, &mn);
8028 mn.mc_xcursor = NULL;
8029 /* must find the lowest key below src */
8030 rc = mdb_page_search_lowest(&mn);
8033 if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {
8034 key.mv_size = mn.mc_db->md_pad;
8035 key.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, key.mv_size);
8037 s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);
8038 key.mv_size = NODEKSZ(s2);
8039 key.mv_data = NODEKEY(s2);
8042 key.mv_size = srcnode->mn_ksize;
8043 key.mv_data = NODEKEY(srcnode);
8046 data.mv_size = NODEDSZ(srcnode);
8047 data.mv_data = NODEDATA(srcnode);
8048 rc = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags);
8049 if (rc != MDB_SUCCESS)
8054 DPRINTF(("dst page %"Z"u now has %u keys (%.1f%% filled)",
8055 pdst->mp_pgno, NUMKEYS(pdst),
8056 (float)PAGEFILL(cdst->mc_txn->mt_env, pdst) / 10));
8058 /* Unlink the src page from parent and add to free list.
8061 mdb_node_del(csrc, 0);
8062 if (csrc->mc_ki[csrc->mc_top] == 0) {
8064 rc = mdb_update_key(csrc, &key);
8072 psrc = csrc->mc_pg[csrc->mc_top];
8073 /* If not operating on FreeDB, allow this page to be reused
8074 * in this txn. Otherwise just add to free list.
8076 rc = mdb_page_loose(csrc, psrc);
8080 csrc->mc_db->md_leaf_pages--;
8082 csrc->mc_db->md_branch_pages--;
8084 /* Adjust other cursors pointing to mp */
8085 MDB_cursor *m2, *m3;
8086 MDB_dbi dbi = csrc->mc_dbi;
8087 unsigned int top = csrc->mc_top;
8089 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8090 if (csrc->mc_flags & C_SUB)
8091 m3 = &m2->mc_xcursor->mx_cursor;
8094 if (m3 == csrc) continue;
8095 if (m3->mc_snum < csrc->mc_snum) continue;
8096 if (m3->mc_pg[top] == psrc) {
8097 m3->mc_pg[top] = pdst;
8098 m3->mc_ki[top] += nkeys;
8099 m3->mc_ki[top-1] = cdst->mc_ki[top-1];
8100 } else if (m3->mc_pg[top-1] == csrc->mc_pg[top-1] &&
8101 m3->mc_ki[top-1] > csrc->mc_ki[top-1]) {
8104 if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
8106 MDB_node *node = NODEPTR(m3->mc_pg[top], m3->mc_ki[top]);
8107 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
8108 m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
8113 unsigned int snum = cdst->mc_snum;
8114 uint16_t depth = cdst->mc_db->md_depth;
8115 mdb_cursor_pop(cdst);
8116 rc = mdb_rebalance(cdst);
8117 /* Did the tree height change? */
8118 if (depth != cdst->mc_db->md_depth)
8119 snum += cdst->mc_db->md_depth - depth;
8120 cdst->mc_snum = snum;
8121 cdst->mc_top = snum-1;
8126 /** Copy the contents of a cursor.
8127 * @param[in] csrc The cursor to copy from.
8128 * @param[out] cdst The cursor to copy to.
8131 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst)
8135 cdst->mc_txn = csrc->mc_txn;
8136 cdst->mc_dbi = csrc->mc_dbi;
8137 cdst->mc_db = csrc->mc_db;
8138 cdst->mc_dbx = csrc->mc_dbx;
8139 cdst->mc_snum = csrc->mc_snum;
8140 cdst->mc_top = csrc->mc_top;
8141 cdst->mc_flags = csrc->mc_flags;
8143 for (i=0; i<csrc->mc_snum; i++) {
8144 cdst->mc_pg[i] = csrc->mc_pg[i];
8145 cdst->mc_ki[i] = csrc->mc_ki[i];
8149 /** Rebalance the tree after a delete operation.
8150 * @param[in] mc Cursor pointing to the page where rebalancing
8152 * @return 0 on success, non-zero on failure.
8155 mdb_rebalance(MDB_cursor *mc)
8159 unsigned int ptop, minkeys, thresh;
8163 if (IS_BRANCH(mc->mc_pg[mc->mc_top])) {
8168 thresh = FILL_THRESHOLD;
8170 DPRINTF(("rebalancing %s page %"Z"u (has %u keys, %.1f%% full)",
8171 IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",
8172 mdb_dbg_pgno(mc->mc_pg[mc->mc_top]), NUMKEYS(mc->mc_pg[mc->mc_top]),
8173 (float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10));
8175 if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= thresh &&
8176 NUMKEYS(mc->mc_pg[mc->mc_top]) >= minkeys) {
8177 DPRINTF(("no need to rebalance page %"Z"u, above fill threshold",
8178 mdb_dbg_pgno(mc->mc_pg[mc->mc_top])));
8182 if (mc->mc_snum < 2) {
8183 MDB_page *mp = mc->mc_pg[0];
8185 DPUTS("Can't rebalance a subpage, ignoring");
8188 if (NUMKEYS(mp) == 0) {
8189 DPUTS("tree is completely empty");
8190 mc->mc_db->md_root = P_INVALID;
8191 mc->mc_db->md_depth = 0;
8192 mc->mc_db->md_leaf_pages = 0;
8193 rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
8196 /* Adjust cursors pointing to mp */
8199 mc->mc_flags &= ~C_INITIALIZED;
8201 MDB_cursor *m2, *m3;
8202 MDB_dbi dbi = mc->mc_dbi;
8204 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8205 if (mc->mc_flags & C_SUB)
8206 m3 = &m2->mc_xcursor->mx_cursor;
8209 if (!(m3->mc_flags & C_INITIALIZED) || (m3->mc_snum < mc->mc_snum))
8211 if (m3->mc_pg[0] == mp) {
8214 m3->mc_flags &= ~C_INITIALIZED;
8218 } else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) {
8220 DPUTS("collapsing root page!");
8221 rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
8224 mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0));
8225 rc = mdb_page_get(mc->mc_txn,mc->mc_db->md_root,&mc->mc_pg[0],NULL);
8228 mc->mc_db->md_depth--;
8229 mc->mc_db->md_branch_pages--;
8230 mc->mc_ki[0] = mc->mc_ki[1];
8231 for (i = 1; i<mc->mc_db->md_depth; i++) {
8232 mc->mc_pg[i] = mc->mc_pg[i+1];
8233 mc->mc_ki[i] = mc->mc_ki[i+1];
8236 /* Adjust other cursors pointing to mp */
8237 MDB_cursor *m2, *m3;
8238 MDB_dbi dbi = mc->mc_dbi;
8240 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8241 if (mc->mc_flags & C_SUB)
8242 m3 = &m2->mc_xcursor->mx_cursor;
8245 if (m3 == mc) continue;
8246 if (!(m3->mc_flags & C_INITIALIZED))
8248 if (m3->mc_pg[0] == mp) {
8249 for (i=0; i<mc->mc_db->md_depth; i++) {
8250 m3->mc_pg[i] = m3->mc_pg[i+1];
8251 m3->mc_ki[i] = m3->mc_ki[i+1];
8259 DPUTS("root page doesn't need rebalancing");
8263 /* The parent (branch page) must have at least 2 pointers,
8264 * otherwise the tree is invalid.
8266 ptop = mc->mc_top-1;
8267 mdb_cassert(mc, NUMKEYS(mc->mc_pg[ptop]) > 1);
8269 /* Leaf page fill factor is below the threshold.
8270 * Try to move keys from left or right neighbor, or
8271 * merge with a neighbor page.
8276 mdb_cursor_copy(mc, &mn);
8277 mn.mc_xcursor = NULL;
8279 oldki = mc->mc_ki[mc->mc_top];
8280 if (mc->mc_ki[ptop] == 0) {
8281 /* We're the leftmost leaf in our parent.
8283 DPUTS("reading right neighbor");
8285 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
8286 rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
8289 mn.mc_ki[mn.mc_top] = 0;
8290 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);
8293 /* There is at least one neighbor to the left.
8295 DPUTS("reading left neighbor");
8297 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
8298 rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
8301 mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;
8302 mc->mc_ki[mc->mc_top] = 0;
8306 DPRINTF(("found neighbor page %"Z"u (%u keys, %.1f%% full)",
8307 mn.mc_pg[mn.mc_top]->mp_pgno, NUMKEYS(mn.mc_pg[mn.mc_top]),
8308 (float)PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) / 10));
8310 /* If the neighbor page is above threshold and has enough keys,
8311 * move one key from it. Otherwise we should try to merge them.
8312 * (A branch page must never have less than 2 keys.)
8314 if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= thresh && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) {
8315 rc = mdb_node_move(&mn, mc, fromleft);
8317 /* if we inserted on left, bump position up */
8322 rc = mdb_page_merge(&mn, mc);
8324 oldki += NUMKEYS(mn.mc_pg[mn.mc_top]);
8325 mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1;
8326 /* We want mdb_rebalance to find mn when doing fixups */
8327 WITH_CURSOR_TRACKING(mn,
8328 rc = mdb_page_merge(mc, &mn));
8329 mdb_cursor_copy(&mn, mc);
8331 mc->mc_flags &= ~C_EOF;
8333 mc->mc_ki[mc->mc_top] = oldki;
8337 /** Complete a delete operation started by #mdb_cursor_del(). */
8339 mdb_cursor_del0(MDB_cursor *mc)
8345 MDB_cursor *m2, *m3;
8346 MDB_dbi dbi = mc->mc_dbi;
8348 ki = mc->mc_ki[mc->mc_top];
8349 mp = mc->mc_pg[mc->mc_top];
8350 mdb_node_del(mc, mc->mc_db->md_pad);
8351 mc->mc_db->md_entries--;
8353 /* Adjust other cursors pointing to mp */
8354 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8355 m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;
8356 if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))
8358 if (m3 == mc || m3->mc_snum < mc->mc_snum)
8360 if (m3->mc_pg[mc->mc_top] == mp) {
8361 if (m3->mc_ki[mc->mc_top] == ki) {
8362 m3->mc_flags |= C_DEL;
8363 if (mc->mc_db->md_flags & MDB_DUPSORT)
8364 m3->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
8365 } else if (m3->mc_ki[mc->mc_top] > ki) {
8366 m3->mc_ki[mc->mc_top]--;
8368 if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
8369 MDB_node *node = NODEPTR(m3->mc_pg[mc->mc_top], m3->mc_ki[mc->mc_top]);
8370 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
8371 m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
8376 rc = mdb_rebalance(mc);
8378 if (rc == MDB_SUCCESS) {
8379 /* DB is totally empty now, just bail out.
8380 * Other cursors adjustments were already done
8381 * by mdb_rebalance and aren't needed here.
8386 mp = mc->mc_pg[mc->mc_top];
8387 nkeys = NUMKEYS(mp);
8389 /* Adjust other cursors pointing to mp */
8390 for (m2 = mc->mc_txn->mt_cursors[dbi]; !rc && m2; m2=m2->mc_next) {
8391 m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;
8392 if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))
8394 if (m3->mc_snum < mc->mc_snum)
8396 if (m3->mc_pg[mc->mc_top] == mp) {
8397 /* if m3 points past last node in page, find next sibling */
8398 if (m3->mc_ki[mc->mc_top] >= nkeys) {
8399 rc = mdb_cursor_sibling(m3, 1);
8400 if (rc == MDB_NOTFOUND) {
8401 m3->mc_flags |= C_EOF;
8407 mc->mc_flags |= C_DEL;
8411 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
8416 mdb_del(MDB_txn *txn, MDB_dbi dbi,
8417 MDB_val *key, MDB_val *data)
8419 if (!key || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
8422 if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
8423 return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
8425 if (!F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
8426 /* must ignore any data */
8430 return mdb_del0(txn, dbi, key, data, 0);
8434 mdb_del0(MDB_txn *txn, MDB_dbi dbi,
8435 MDB_val *key, MDB_val *data, unsigned flags)
8440 MDB_val rdata, *xdata;
8444 DPRINTF(("====> delete db %u key [%s]", dbi, DKEY(key)));
8446 mdb_cursor_init(&mc, txn, dbi, &mx);
8455 flags |= MDB_NODUPDATA;
8457 rc = mdb_cursor_set(&mc, key, xdata, op, &exact);
8459 /* let mdb_page_split know about this cursor if needed:
8460 * delete will trigger a rebalance; if it needs to move
8461 * a node from one page to another, it will have to
8462 * update the parent's separator key(s). If the new sepkey
8463 * is larger than the current one, the parent page may
8464 * run out of space, triggering a split. We need this
8465 * cursor to be consistent until the end of the rebalance.
8467 mc.mc_flags |= C_UNTRACK;
8468 mc.mc_next = txn->mt_cursors[dbi];
8469 txn->mt_cursors[dbi] = &mc;
8470 rc = mdb_cursor_del(&mc, flags);
8471 txn->mt_cursors[dbi] = mc.mc_next;
8476 /** Split a page and insert a new node.
8477 * @param[in,out] mc Cursor pointing to the page and desired insertion index.
8478 * The cursor will be updated to point to the actual page and index where
8479 * the node got inserted after the split.
8480 * @param[in] newkey The key for the newly inserted node.
8481 * @param[in] newdata The data for the newly inserted node.
8482 * @param[in] newpgno The page number, if the new node is a branch node.
8483 * @param[in] nflags The #NODE_ADD_FLAGS for the new node.
8484 * @return 0 on success, non-zero on failure.
8487 mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno,
8488 unsigned int nflags)
8491 int rc = MDB_SUCCESS, new_root = 0, did_split = 0;
8494 int i, j, split_indx, nkeys, pmax;
8495 MDB_env *env = mc->mc_txn->mt_env;
8497 MDB_val sepkey, rkey, xdata, *rdata = &xdata;
8498 MDB_page *copy = NULL;
8499 MDB_page *mp, *rp, *pp;
8504 mp = mc->mc_pg[mc->mc_top];
8505 newindx = mc->mc_ki[mc->mc_top];
8506 nkeys = NUMKEYS(mp);
8508 DPRINTF(("-----> splitting %s page %"Z"u and adding [%s] at index %i/%i",
8509 IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno,
8510 DKEY(newkey), mc->mc_ki[mc->mc_top], nkeys));
8512 /* Create a right sibling. */
8513 if ((rc = mdb_page_new(mc, mp->mp_flags, 1, &rp)))
8515 rp->mp_pad = mp->mp_pad;
8516 DPRINTF(("new right sibling: page %"Z"u", rp->mp_pgno));
8518 /* Usually when splitting the root page, the cursor
8519 * height is 1. But when called from mdb_update_key,
8520 * the cursor height may be greater because it walks
8521 * up the stack while finding the branch slot to update.
8523 if (mc->mc_top < 1) {
8524 if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp)))
8526 /* shift current top to make room for new parent */
8527 for (i=mc->mc_snum; i>0; i--) {
8528 mc->mc_pg[i] = mc->mc_pg[i-1];
8529 mc->mc_ki[i] = mc->mc_ki[i-1];
8533 mc->mc_db->md_root = pp->mp_pgno;
8534 DPRINTF(("root split! new root = %"Z"u", pp->mp_pgno));
8535 new_root = mc->mc_db->md_depth++;
8537 /* Add left (implicit) pointer. */
8538 if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) {
8539 /* undo the pre-push */
8540 mc->mc_pg[0] = mc->mc_pg[1];
8541 mc->mc_ki[0] = mc->mc_ki[1];
8542 mc->mc_db->md_root = mp->mp_pgno;
8543 mc->mc_db->md_depth--;
8550 ptop = mc->mc_top-1;
8551 DPRINTF(("parent branch page is %"Z"u", mc->mc_pg[ptop]->mp_pgno));
8554 mdb_cursor_copy(mc, &mn);
8555 mn.mc_xcursor = NULL;
8556 mn.mc_pg[mn.mc_top] = rp;
8557 mn.mc_ki[ptop] = mc->mc_ki[ptop]+1;
8559 if (nflags & MDB_APPEND) {
8560 mn.mc_ki[mn.mc_top] = 0;
8562 split_indx = newindx;
8566 split_indx = (nkeys+1) / 2;
8571 unsigned int lsize, rsize, ksize;
8572 /* Move half of the keys to the right sibling */
8573 x = mc->mc_ki[mc->mc_top] - split_indx;
8574 ksize = mc->mc_db->md_pad;
8575 split = LEAF2KEY(mp, split_indx, ksize);
8576 rsize = (nkeys - split_indx) * ksize;
8577 lsize = (nkeys - split_indx) * sizeof(indx_t);
8578 mp->mp_lower -= lsize;
8579 rp->mp_lower += lsize;
8580 mp->mp_upper += rsize - lsize;
8581 rp->mp_upper -= rsize - lsize;
8582 sepkey.mv_size = ksize;
8583 if (newindx == split_indx) {
8584 sepkey.mv_data = newkey->mv_data;
8586 sepkey.mv_data = split;
8589 ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize);
8590 memcpy(rp->mp_ptrs, split, rsize);
8591 sepkey.mv_data = rp->mp_ptrs;
8592 memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize);
8593 memcpy(ins, newkey->mv_data, ksize);
8594 mp->mp_lower += sizeof(indx_t);
8595 mp->mp_upper -= ksize - sizeof(indx_t);
8598 memcpy(rp->mp_ptrs, split, x * ksize);
8599 ins = LEAF2KEY(rp, x, ksize);
8600 memcpy(ins, newkey->mv_data, ksize);
8601 memcpy(ins+ksize, split + x * ksize, rsize - x * ksize);
8602 rp->mp_lower += sizeof(indx_t);
8603 rp->mp_upper -= ksize - sizeof(indx_t);
8604 mc->mc_ki[mc->mc_top] = x;
8607 int psize, nsize, k;
8608 /* Maximum free space in an empty page */
8609 pmax = env->me_psize - PAGEHDRSZ;
8611 nsize = mdb_leaf_size(env, newkey, newdata);
8613 nsize = mdb_branch_size(env, newkey);
8614 nsize = EVEN(nsize);
8616 /* grab a page to hold a temporary copy */
8617 copy = mdb_page_malloc(mc->mc_txn, 1);
8622 copy->mp_pgno = mp->mp_pgno;
8623 copy->mp_flags = mp->mp_flags;
8624 copy->mp_lower = (PAGEHDRSZ-PAGEBASE);
8625 copy->mp_upper = env->me_psize - PAGEBASE;
8627 /* prepare to insert */
8628 for (i=0, j=0; i<nkeys; i++) {
8630 copy->mp_ptrs[j++] = 0;
8632 copy->mp_ptrs[j++] = mp->mp_ptrs[i];
8635 /* When items are relatively large the split point needs
8636 * to be checked, because being off-by-one will make the
8637 * difference between success or failure in mdb_node_add.
8639 * It's also relevant if a page happens to be laid out
8640 * such that one half of its nodes are all "small" and
8641 * the other half of its nodes are "large." If the new
8642 * item is also "large" and falls on the half with
8643 * "large" nodes, it also may not fit.
8645 * As a final tweak, if the new item goes on the last
8646 * spot on the page (and thus, onto the new page), bias
8647 * the split so the new page is emptier than the old page.
8648 * This yields better packing during sequential inserts.
8650 if (nkeys < 20 || nsize > pmax/16 || newindx >= nkeys) {
8651 /* Find split point */
8653 if (newindx <= split_indx || newindx >= nkeys) {
8655 k = newindx >= nkeys ? nkeys : split_indx+1+IS_LEAF(mp);
8660 for (; i!=k; i+=j) {
8665 node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);
8666 psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
8668 if (F_ISSET(node->mn_flags, F_BIGDATA))
8669 psize += sizeof(pgno_t);
8671 psize += NODEDSZ(node);
8673 psize = EVEN(psize);
8675 if (psize > pmax || i == k-j) {
8676 split_indx = i + (j<0);
8681 if (split_indx == newindx) {
8682 sepkey.mv_size = newkey->mv_size;
8683 sepkey.mv_data = newkey->mv_data;
8685 node = (MDB_node *)((char *)mp + copy->mp_ptrs[split_indx] + PAGEBASE);
8686 sepkey.mv_size = node->mn_ksize;
8687 sepkey.mv_data = NODEKEY(node);
8692 DPRINTF(("separator is %d [%s]", split_indx, DKEY(&sepkey)));
8694 /* Copy separator key to the parent.
8696 if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(env, &sepkey)) {
8697 int snum = mc->mc_snum;
8701 /* We want other splits to find mn when doing fixups */
8702 WITH_CURSOR_TRACKING(mn,
8703 rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0));
8708 if (mc->mc_snum > snum) {
8711 /* Right page might now have changed parent.
8712 * Check if left page also changed parent.
8714 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
8715 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
8716 for (i=0; i<ptop; i++) {
8717 mc->mc_pg[i] = mn.mc_pg[i];
8718 mc->mc_ki[i] = mn.mc_ki[i];
8720 mc->mc_pg[ptop] = mn.mc_pg[ptop];
8721 if (mn.mc_ki[ptop]) {
8722 mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;
8724 /* find right page's left sibling */
8725 mc->mc_ki[ptop] = mn.mc_ki[ptop];
8726 mdb_cursor_sibling(mc, 0);
8731 rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);
8734 if (rc != MDB_SUCCESS) {
8737 if (nflags & MDB_APPEND) {
8738 mc->mc_pg[mc->mc_top] = rp;
8739 mc->mc_ki[mc->mc_top] = 0;
8740 rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags);
8743 for (i=0; i<mc->mc_top; i++)
8744 mc->mc_ki[i] = mn.mc_ki[i];
8745 } else if (!IS_LEAF2(mp)) {
8747 mc->mc_pg[mc->mc_top] = rp;
8752 rkey.mv_data = newkey->mv_data;
8753 rkey.mv_size = newkey->mv_size;
8759 /* Update index for the new key. */
8760 mc->mc_ki[mc->mc_top] = j;
8762 node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);
8763 rkey.mv_data = NODEKEY(node);
8764 rkey.mv_size = node->mn_ksize;
8766 xdata.mv_data = NODEDATA(node);
8767 xdata.mv_size = NODEDSZ(node);
8770 pgno = NODEPGNO(node);
8771 flags = node->mn_flags;
8774 if (!IS_LEAF(mp) && j == 0) {
8775 /* First branch index doesn't need key data. */
8779 rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags);
8785 mc->mc_pg[mc->mc_top] = copy;
8790 } while (i != split_indx);
8792 nkeys = NUMKEYS(copy);
8793 for (i=0; i<nkeys; i++)
8794 mp->mp_ptrs[i] = copy->mp_ptrs[i];
8795 mp->mp_lower = copy->mp_lower;
8796 mp->mp_upper = copy->mp_upper;
8797 memcpy(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1),
8798 env->me_psize - copy->mp_upper - PAGEBASE);
8800 /* reset back to original page */
8801 if (newindx < split_indx) {
8802 mc->mc_pg[mc->mc_top] = mp;
8804 mc->mc_pg[mc->mc_top] = rp;
8806 /* Make sure mc_ki is still valid.
8808 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
8809 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
8810 for (i=0; i<=ptop; i++) {
8811 mc->mc_pg[i] = mn.mc_pg[i];
8812 mc->mc_ki[i] = mn.mc_ki[i];
8816 if (nflags & MDB_RESERVE) {
8817 node = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
8818 if (!(node->mn_flags & F_BIGDATA))
8819 newdata->mv_data = NODEDATA(node);
8822 if (newindx >= split_indx) {
8823 mc->mc_pg[mc->mc_top] = rp;
8825 /* Make sure mc_ki is still valid.
8827 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
8828 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
8829 for (i=0; i<=ptop; i++) {
8830 mc->mc_pg[i] = mn.mc_pg[i];
8831 mc->mc_ki[i] = mn.mc_ki[i];
8838 /* Adjust other cursors pointing to mp */
8839 MDB_cursor *m2, *m3;
8840 MDB_dbi dbi = mc->mc_dbi;
8841 nkeys = NUMKEYS(mp);
8843 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8844 if (mc->mc_flags & C_SUB)
8845 m3 = &m2->mc_xcursor->mx_cursor;
8850 if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED))
8854 /* sub cursors may be on different DB */
8855 if (m3->mc_pg[0] != mp)
8858 for (k=new_root; k>=0; k--) {
8859 m3->mc_ki[k+1] = m3->mc_ki[k];
8860 m3->mc_pg[k+1] = m3->mc_pg[k];
8862 if (m3->mc_ki[0] >= nkeys) {
8867 m3->mc_pg[0] = mc->mc_pg[0];
8871 if (m3->mc_top >= mc->mc_top && m3->mc_pg[mc->mc_top] == mp) {
8872 if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE))
8873 m3->mc_ki[mc->mc_top]++;
8874 if (m3->mc_ki[mc->mc_top] >= nkeys) {
8875 m3->mc_pg[mc->mc_top] = rp;
8876 m3->mc_ki[mc->mc_top] -= nkeys;
8877 for (i=0; i<mc->mc_top; i++) {
8878 m3->mc_ki[i] = mn.mc_ki[i];
8879 m3->mc_pg[i] = mn.mc_pg[i];
8882 } else if (!did_split && m3->mc_top >= ptop && m3->mc_pg[ptop] == mc->mc_pg[ptop] &&
8883 m3->mc_ki[ptop] >= mc->mc_ki[ptop]) {
8886 if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
8888 MDB_node *node = NODEPTR(m3->mc_pg[mc->mc_top], m3->mc_ki[mc->mc_top]);
8889 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
8890 m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
8894 DPRINTF(("mp left: %d, rp left: %d", SIZELEFT(mp), SIZELEFT(rp)));
8897 if (copy) /* tmp page */
8898 mdb_page_free(env, copy);
8900 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
8905 mdb_put(MDB_txn *txn, MDB_dbi dbi,
8906 MDB_val *key, MDB_val *data, unsigned int flags)
8912 if (!key || !data || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
8915 if (flags & ~(MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND|MDB_APPENDDUP))
8918 if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
8919 return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
8921 mdb_cursor_init(&mc, txn, dbi, &mx);
8922 mc.mc_next = txn->mt_cursors[dbi];
8923 txn->mt_cursors[dbi] = &mc;
8924 rc = mdb_cursor_put(&mc, key, data, flags);
8925 txn->mt_cursors[dbi] = mc.mc_next;
8930 #define MDB_WBUF (1024*1024)
8933 /** State needed for a compacting copy. */
8934 typedef struct mdb_copy {
8935 pthread_mutex_t mc_mutex;
8936 pthread_cond_t mc_cond;
8943 pgno_t mc_next_pgno;
8946 volatile int mc_new;
8951 /** Dedicated writer thread for compacting copy. */
8952 static THREAD_RET ESECT CALL_CONV
8953 mdb_env_copythr(void *arg)
8957 int toggle = 0, wsize, rc;
8960 #define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL)
8963 #define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0)
8966 pthread_mutex_lock(&my->mc_mutex);
8968 pthread_cond_signal(&my->mc_cond);
8971 pthread_cond_wait(&my->mc_cond, &my->mc_mutex);
8972 if (my->mc_new < 0) {
8977 wsize = my->mc_wlen[toggle];
8978 ptr = my->mc_wbuf[toggle];
8981 DO_WRITE(rc, my->mc_fd, ptr, wsize, len);
8985 } else if (len > 0) {
8999 /* If there's an overflow page tail, write it too */
9000 if (my->mc_olen[toggle]) {
9001 wsize = my->mc_olen[toggle];
9002 ptr = my->mc_over[toggle];
9003 my->mc_olen[toggle] = 0;
9006 my->mc_wlen[toggle] = 0;
9008 pthread_cond_signal(&my->mc_cond);
9010 pthread_cond_signal(&my->mc_cond);
9011 pthread_mutex_unlock(&my->mc_mutex);
9012 return (THREAD_RET)0;
9016 /** Tell the writer thread there's a buffer ready to write */
9018 mdb_env_cthr_toggle(mdb_copy *my, int st)
9020 int toggle = my->mc_toggle ^ 1;
9021 pthread_mutex_lock(&my->mc_mutex);
9022 if (my->mc_status) {
9023 pthread_mutex_unlock(&my->mc_mutex);
9024 return my->mc_status;
9026 while (my->mc_new == 1)
9027 pthread_cond_wait(&my->mc_cond, &my->mc_mutex);
9029 my->mc_toggle = toggle;
9030 pthread_cond_signal(&my->mc_cond);
9031 pthread_mutex_unlock(&my->mc_mutex);
9035 /** Depth-first tree traversal for compacting copy. */
9037 mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)
9040 MDB_txn *txn = my->mc_txn;
9042 MDB_page *mo, *mp, *leaf;
9047 /* Empty DB, nothing to do */
9048 if (*pg == P_INVALID)
9055 rc = mdb_page_get(my->mc_txn, *pg, &mc.mc_pg[0], NULL);
9058 rc = mdb_page_search_root(&mc, NULL, MDB_PS_FIRST);
9062 /* Make cursor pages writable */
9063 buf = ptr = malloc(my->mc_env->me_psize * mc.mc_snum);
9067 for (i=0; i<mc.mc_top; i++) {
9068 mdb_page_copy((MDB_page *)ptr, mc.mc_pg[i], my->mc_env->me_psize);
9069 mc.mc_pg[i] = (MDB_page *)ptr;
9070 ptr += my->mc_env->me_psize;
9073 /* This is writable space for a leaf page. Usually not needed. */
9074 leaf = (MDB_page *)ptr;
9076 toggle = my->mc_toggle;
9077 while (mc.mc_snum > 0) {
9079 mp = mc.mc_pg[mc.mc_top];
9083 if (!IS_LEAF2(mp) && !(flags & F_DUPDATA)) {
9084 for (i=0; i<n; i++) {
9085 ni = NODEPTR(mp, i);
9086 if (ni->mn_flags & F_BIGDATA) {
9090 /* Need writable leaf */
9092 mc.mc_pg[mc.mc_top] = leaf;
9093 mdb_page_copy(leaf, mp, my->mc_env->me_psize);
9095 ni = NODEPTR(mp, i);
9098 memcpy(&pg, NODEDATA(ni), sizeof(pg));
9099 rc = mdb_page_get(txn, pg, &omp, NULL);
9102 if (my->mc_wlen[toggle] >= MDB_WBUF) {
9103 rc = mdb_env_cthr_toggle(my, 1);
9106 toggle = my->mc_toggle;
9108 mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);
9109 memcpy(mo, omp, my->mc_env->me_psize);
9110 mo->mp_pgno = my->mc_next_pgno;
9111 my->mc_next_pgno += omp->mp_pages;
9112 my->mc_wlen[toggle] += my->mc_env->me_psize;
9113 if (omp->mp_pages > 1) {
9114 my->mc_olen[toggle] = my->mc_env->me_psize * (omp->mp_pages - 1);
9115 my->mc_over[toggle] = (char *)omp + my->mc_env->me_psize;
9116 rc = mdb_env_cthr_toggle(my, 1);
9119 toggle = my->mc_toggle;
9121 memcpy(NODEDATA(ni), &mo->mp_pgno, sizeof(pgno_t));
9122 } else if (ni->mn_flags & F_SUBDATA) {
9125 /* Need writable leaf */
9127 mc.mc_pg[mc.mc_top] = leaf;
9128 mdb_page_copy(leaf, mp, my->mc_env->me_psize);
9130 ni = NODEPTR(mp, i);
9133 memcpy(&db, NODEDATA(ni), sizeof(db));
9134 my->mc_toggle = toggle;
9135 rc = mdb_env_cwalk(my, &db.md_root, ni->mn_flags & F_DUPDATA);
9138 toggle = my->mc_toggle;
9139 memcpy(NODEDATA(ni), &db, sizeof(db));
9144 mc.mc_ki[mc.mc_top]++;
9145 if (mc.mc_ki[mc.mc_top] < n) {
9148 ni = NODEPTR(mp, mc.mc_ki[mc.mc_top]);
9150 rc = mdb_page_get(txn, pg, &mp, NULL);
9155 mc.mc_ki[mc.mc_top] = 0;
9156 if (IS_BRANCH(mp)) {
9157 /* Whenever we advance to a sibling branch page,
9158 * we must proceed all the way down to its first leaf.
9160 mdb_page_copy(mc.mc_pg[mc.mc_top], mp, my->mc_env->me_psize);
9163 mc.mc_pg[mc.mc_top] = mp;
9167 if (my->mc_wlen[toggle] >= MDB_WBUF) {
9168 rc = mdb_env_cthr_toggle(my, 1);
9171 toggle = my->mc_toggle;
9173 mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);
9174 mdb_page_copy(mo, mp, my->mc_env->me_psize);
9175 mo->mp_pgno = my->mc_next_pgno++;
9176 my->mc_wlen[toggle] += my->mc_env->me_psize;
9178 /* Update parent if there is one */
9179 ni = NODEPTR(mc.mc_pg[mc.mc_top-1], mc.mc_ki[mc.mc_top-1]);
9180 SETPGNO(ni, mo->mp_pgno);
9181 mdb_cursor_pop(&mc);
9183 /* Otherwise we're done */
9193 /** Copy environment with compaction. */
9195 mdb_env_copyfd1(MDB_env *env, HANDLE fd)
9200 MDB_txn *txn = NULL;
9205 my.mc_mutex = CreateMutex(NULL, FALSE, NULL);
9206 my.mc_cond = CreateEvent(NULL, FALSE, FALSE, NULL);
9207 my.mc_wbuf[0] = _aligned_malloc(MDB_WBUF*2, env->me_os_psize);
9208 if (my.mc_wbuf[0] == NULL)
9211 pthread_mutex_init(&my.mc_mutex, NULL);
9212 pthread_cond_init(&my.mc_cond, NULL);
9213 #ifdef HAVE_MEMALIGN
9214 my.mc_wbuf[0] = memalign(env->me_os_psize, MDB_WBUF*2);
9215 if (my.mc_wbuf[0] == NULL)
9218 rc = posix_memalign((void **)&my.mc_wbuf[0], env->me_os_psize, MDB_WBUF*2);
9223 memset(my.mc_wbuf[0], 0, MDB_WBUF*2);
9224 my.mc_wbuf[1] = my.mc_wbuf[0] + MDB_WBUF;
9229 my.mc_next_pgno = NUM_METAS;
9235 THREAD_CREATE(thr, mdb_env_copythr, &my);
9237 rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
9241 mp = (MDB_page *)my.mc_wbuf[0];
9242 memset(mp, 0, NUM_METAS * env->me_psize);
9244 mp->mp_flags = P_META;
9245 mm = (MDB_meta *)METADATA(mp);
9246 mdb_env_init_meta0(env, mm);
9247 mm->mm_address = env->me_metas[0]->mm_address;
9249 mp = (MDB_page *)(my.mc_wbuf[0] + env->me_psize);
9251 mp->mp_flags = P_META;
9252 *(MDB_meta *)METADATA(mp) = *mm;
9253 mm = (MDB_meta *)METADATA(mp);
9255 /* Count the number of free pages, subtract from lastpg to find
9256 * number of active pages
9259 MDB_ID freecount = 0;
9262 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
9263 while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
9264 freecount += *(MDB_ID *)data.mv_data;
9265 freecount += txn->mt_dbs[FREE_DBI].md_branch_pages +
9266 txn->mt_dbs[FREE_DBI].md_leaf_pages +
9267 txn->mt_dbs[FREE_DBI].md_overflow_pages;
9269 /* Set metapage 1 */
9270 mm->mm_last_pg = txn->mt_next_pgno - freecount - 1;
9271 mm->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
9272 if (mm->mm_last_pg > NUM_METAS-1) {
9273 mm->mm_dbs[MAIN_DBI].md_root = mm->mm_last_pg;
9276 mm->mm_dbs[MAIN_DBI].md_root = P_INVALID;
9279 my.mc_wlen[0] = env->me_psize * NUM_METAS;
9281 pthread_mutex_lock(&my.mc_mutex);
9283 pthread_cond_wait(&my.mc_cond, &my.mc_mutex);
9284 pthread_mutex_unlock(&my.mc_mutex);
9285 rc = mdb_env_cwalk(&my, &txn->mt_dbs[MAIN_DBI].md_root, 0);
9286 if (rc == MDB_SUCCESS && my.mc_wlen[my.mc_toggle])
9287 rc = mdb_env_cthr_toggle(&my, 1);
9288 mdb_env_cthr_toggle(&my, -1);
9289 pthread_mutex_lock(&my.mc_mutex);
9291 pthread_cond_wait(&my.mc_cond, &my.mc_mutex);
9292 pthread_mutex_unlock(&my.mc_mutex);
9297 CloseHandle(my.mc_cond);
9298 CloseHandle(my.mc_mutex);
9299 _aligned_free(my.mc_wbuf[0]);
9301 pthread_cond_destroy(&my.mc_cond);
9302 pthread_mutex_destroy(&my.mc_mutex);
9303 free(my.mc_wbuf[0]);
9308 /** Copy environment as-is. */
9310 mdb_env_copyfd0(MDB_env *env, HANDLE fd)
9312 MDB_txn *txn = NULL;
9313 mdb_mutexref_t wmutex = NULL;
9319 #define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL)
9323 #define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0)
9326 /* Do the lock/unlock of the reader mutex before starting the
9327 * write txn. Otherwise other read txns could block writers.
9329 rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
9334 /* We must start the actual read txn after blocking writers */
9335 mdb_txn_end(txn, MDB_END_RESET_TMP);
9337 /* Temporarily block writers until we snapshot the meta pages */
9338 wmutex = env->me_wmutex;
9339 if (LOCK_MUTEX(rc, env, wmutex))
9342 rc = mdb_txn_renew0(txn);
9344 UNLOCK_MUTEX(wmutex);
9349 wsize = env->me_psize * NUM_METAS;
9353 DO_WRITE(rc, fd, ptr, w2, len);
9357 } else if (len > 0) {
9363 /* Non-blocking or async handles are not supported */
9369 UNLOCK_MUTEX(wmutex);
9374 w2 = txn->mt_next_pgno * env->me_psize;
9377 if ((rc = mdb_fsize(env->me_fd, &fsize)))
9384 if (wsize > MAX_WRITE)
9388 DO_WRITE(rc, fd, ptr, w2, len);
9392 } else if (len > 0) {
9409 mdb_env_copyfd2(MDB_env *env, HANDLE fd, unsigned int flags)
9411 if (flags & MDB_CP_COMPACT)
9412 return mdb_env_copyfd1(env, fd);
9414 return mdb_env_copyfd0(env, fd);
9418 mdb_env_copyfd(MDB_env *env, HANDLE fd)
9420 return mdb_env_copyfd2(env, fd, 0);
9424 mdb_env_copy2(MDB_env *env, const char *path, unsigned int flags)
9428 HANDLE newfd = INVALID_HANDLE_VALUE;
9433 if (env->me_flags & MDB_NOSUBDIR) {
9434 lpath = (char *)path;
9437 len += sizeof(DATANAME);
9438 lpath = malloc(len);
9441 sprintf(lpath, "%s" DATANAME, path);
9444 /* The destination path must exist, but the destination file must not.
9445 * We don't want the OS to cache the writes, since the source data is
9446 * already in the OS cache.
9449 utf8_to_utf16(lpath, -1, &wpath, NULL);
9450 newfd = CreateFileW(wpath, GENERIC_WRITE, 0, NULL, CREATE_NEW,
9451 FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL);
9454 newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL, 0666);
9456 if (newfd == INVALID_HANDLE_VALUE) {
9461 if (env->me_psize >= env->me_os_psize) {
9463 /* Set O_DIRECT if the file system supports it */
9464 if ((rc = fcntl(newfd, F_GETFL)) != -1)
9465 (void) fcntl(newfd, F_SETFL, rc | O_DIRECT);
9467 #ifdef F_NOCACHE /* __APPLE__ */
9468 rc = fcntl(newfd, F_NOCACHE, 1);
9476 rc = mdb_env_copyfd2(env, newfd, flags);
9479 if (!(env->me_flags & MDB_NOSUBDIR))
9481 if (newfd != INVALID_HANDLE_VALUE)
9482 if (close(newfd) < 0 && rc == MDB_SUCCESS)
9489 mdb_env_copy(MDB_env *env, const char *path)
9491 return mdb_env_copy2(env, path, 0);
9495 mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)
9497 if (flag & ~CHANGEABLE)
9500 env->me_flags |= flag;
9502 env->me_flags &= ~flag;
9507 mdb_env_get_flags(MDB_env *env, unsigned int *arg)
9512 *arg = env->me_flags & (CHANGEABLE|CHANGELESS);
9517 mdb_env_set_userctx(MDB_env *env, void *ctx)
9521 env->me_userctx = ctx;
9526 mdb_env_get_userctx(MDB_env *env)
9528 return env ? env->me_userctx : NULL;
9532 mdb_env_set_assert(MDB_env *env, MDB_assert_func *func)
9537 env->me_assert_func = func;
9543 mdb_env_get_path(MDB_env *env, const char **arg)
9548 *arg = env->me_path;
9553 mdb_env_get_fd(MDB_env *env, mdb_filehandle_t *arg)
9562 /** Common code for #mdb_stat() and #mdb_env_stat().
9563 * @param[in] env the environment to operate in.
9564 * @param[in] db the #MDB_db record containing the stats to return.
9565 * @param[out] arg the address of an #MDB_stat structure to receive the stats.
9566 * @return 0, this function always succeeds.
9569 mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)
9571 arg->ms_psize = env->me_psize;
9572 arg->ms_depth = db->md_depth;
9573 arg->ms_branch_pages = db->md_branch_pages;
9574 arg->ms_leaf_pages = db->md_leaf_pages;
9575 arg->ms_overflow_pages = db->md_overflow_pages;
9576 arg->ms_entries = db->md_entries;
9582 mdb_env_stat(MDB_env *env, MDB_stat *arg)
9586 if (env == NULL || arg == NULL)
9589 meta = mdb_env_pick_meta(env);
9591 return mdb_stat0(env, &meta->mm_dbs[MAIN_DBI], arg);
9595 mdb_env_info(MDB_env *env, MDB_envinfo *arg)
9599 if (env == NULL || arg == NULL)
9602 meta = mdb_env_pick_meta(env);
9603 arg->me_mapaddr = meta->mm_address;
9604 arg->me_last_pgno = meta->mm_last_pg;
9605 arg->me_last_txnid = meta->mm_txnid;
9607 arg->me_mapsize = env->me_mapsize;
9608 arg->me_maxreaders = env->me_maxreaders;
9609 arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : 0;
9613 /** Set the default comparison functions for a database.
9614 * Called immediately after a database is opened to set the defaults.
9615 * The user can then override them with #mdb_set_compare() or
9616 * #mdb_set_dupsort().
9617 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
9618 * @param[in] dbi A database handle returned by #mdb_dbi_open()
9621 mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi)
9623 uint16_t f = txn->mt_dbs[dbi].md_flags;
9625 txn->mt_dbxs[dbi].md_cmp =
9626 (f & MDB_REVERSEKEY) ? mdb_cmp_memnr :
9627 (f & MDB_INTEGERKEY) ? mdb_cmp_cint : mdb_cmp_memn;
9629 txn->mt_dbxs[dbi].md_dcmp =
9630 !(f & MDB_DUPSORT) ? 0 :
9631 ((f & MDB_INTEGERDUP)
9632 ? ((f & MDB_DUPFIXED) ? mdb_cmp_int : mdb_cmp_cint)
9633 : ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn));
9636 int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
9642 int rc, dbflag, exact;
9643 unsigned int unused = 0, seq;
9646 if (flags & ~VALID_FLAGS)
9648 if (txn->mt_flags & MDB_TXN_BLOCKED)
9654 if (flags & PERSISTENT_FLAGS) {
9655 uint16_t f2 = flags & PERSISTENT_FLAGS;
9656 /* make sure flag changes get committed */
9657 if ((txn->mt_dbs[MAIN_DBI].md_flags | f2) != txn->mt_dbs[MAIN_DBI].md_flags) {
9658 txn->mt_dbs[MAIN_DBI].md_flags |= f2;
9659 txn->mt_flags |= MDB_TXN_DIRTY;
9662 mdb_default_cmp(txn, MAIN_DBI);
9666 if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {
9667 mdb_default_cmp(txn, MAIN_DBI);
9670 /* Is the DB already open? */
9672 for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
9673 if (!txn->mt_dbxs[i].md_name.mv_size) {
9674 /* Remember this free slot */
9675 if (!unused) unused = i;
9678 if (len == txn->mt_dbxs[i].md_name.mv_size &&
9679 !strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) {
9685 /* If no free slot and max hit, fail */
9686 if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs)
9687 return MDB_DBS_FULL;
9689 /* Cannot mix named databases with some mainDB flags */
9690 if (txn->mt_dbs[MAIN_DBI].md_flags & (MDB_DUPSORT|MDB_INTEGERKEY))
9691 return (flags & MDB_CREATE) ? MDB_INCOMPATIBLE : MDB_NOTFOUND;
9693 /* Find the DB info */
9694 dbflag = DB_NEW|DB_VALID|DB_USRVALID;
9697 key.mv_data = (void *)name;
9698 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
9699 rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact);
9700 if (rc == MDB_SUCCESS) {
9701 /* make sure this is actually a DB */
9702 MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]);
9703 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)
9704 return MDB_INCOMPATIBLE;
9705 } else if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) {
9706 /* Create if requested */
9707 data.mv_size = sizeof(MDB_db);
9708 data.mv_data = &dummy;
9709 memset(&dummy, 0, sizeof(dummy));
9710 dummy.md_root = P_INVALID;
9711 dummy.md_flags = flags & PERSISTENT_FLAGS;
9712 rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA);
9716 /* OK, got info, add to table */
9717 if (rc == MDB_SUCCESS) {
9718 unsigned int slot = unused ? unused : txn->mt_numdbs;
9719 txn->mt_dbxs[slot].md_name.mv_data = strdup(name);
9720 txn->mt_dbxs[slot].md_name.mv_size = len;
9721 txn->mt_dbxs[slot].md_rel = NULL;
9722 txn->mt_dbflags[slot] = dbflag;
9723 /* txn-> and env-> are the same in read txns, use
9724 * tmp variable to avoid undefined assignment
9726 seq = ++txn->mt_env->me_dbiseqs[slot];
9727 txn->mt_dbiseqs[slot] = seq;
9729 memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db));
9731 mdb_default_cmp(txn, slot);
9741 mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
9743 if (!arg || !TXN_DBI_EXIST(txn, dbi, DB_VALID))
9746 if (txn->mt_flags & MDB_TXN_BLOCKED)
9749 if (txn->mt_dbflags[dbi] & DB_STALE) {
9752 /* Stale, must read the DB's root. cursor_init does it for us. */
9753 mdb_cursor_init(&mc, txn, dbi, &mx);
9755 return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg);
9758 void mdb_dbi_close(MDB_env *env, MDB_dbi dbi)
9761 if (dbi < CORE_DBS || dbi >= env->me_maxdbs)
9763 ptr = env->me_dbxs[dbi].md_name.mv_data;
9764 /* If there was no name, this was already closed */
9766 env->me_dbxs[dbi].md_name.mv_data = NULL;
9767 env->me_dbxs[dbi].md_name.mv_size = 0;
9768 env->me_dbflags[dbi] = 0;
9769 env->me_dbiseqs[dbi]++;
9774 int mdb_dbi_flags(MDB_txn *txn, MDB_dbi dbi, unsigned int *flags)
9776 /* We could return the flags for the FREE_DBI too but what's the point? */
9777 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9779 *flags = txn->mt_dbs[dbi].md_flags & PERSISTENT_FLAGS;
9783 /** Add all the DB's pages to the free list.
9784 * @param[in] mc Cursor on the DB to free.
9785 * @param[in] subs non-Zero to check for sub-DBs in this DB.
9786 * @return 0 on success, non-zero on failure.
9789 mdb_drop0(MDB_cursor *mc, int subs)
9793 rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
9794 if (rc == MDB_SUCCESS) {
9795 MDB_txn *txn = mc->mc_txn;
9800 /* DUPSORT sub-DBs have no ovpages/DBs. Omit scanning leaves.
9801 * This also avoids any P_LEAF2 pages, which have no nodes.
9803 if (mc->mc_flags & C_SUB)
9806 mdb_cursor_copy(mc, &mx);
9807 while (mc->mc_snum > 0) {
9808 MDB_page *mp = mc->mc_pg[mc->mc_top];
9809 unsigned n = NUMKEYS(mp);
9811 for (i=0; i<n; i++) {
9812 ni = NODEPTR(mp, i);
9813 if (ni->mn_flags & F_BIGDATA) {
9816 memcpy(&pg, NODEDATA(ni), sizeof(pg));
9817 rc = mdb_page_get(txn, pg, &omp, NULL);
9820 mdb_cassert(mc, IS_OVERFLOW(omp));
9821 rc = mdb_midl_append_range(&txn->mt_free_pgs,
9825 } else if (subs && (ni->mn_flags & F_SUBDATA)) {
9826 mdb_xcursor_init1(mc, ni);
9827 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
9833 if ((rc = mdb_midl_need(&txn->mt_free_pgs, n)) != 0)
9835 for (i=0; i<n; i++) {
9837 ni = NODEPTR(mp, i);
9840 mdb_midl_xappend(txn->mt_free_pgs, pg);
9845 mc->mc_ki[mc->mc_top] = i;
9846 rc = mdb_cursor_sibling(mc, 1);
9848 if (rc != MDB_NOTFOUND)
9850 /* no more siblings, go back to beginning
9851 * of previous level.
9855 for (i=1; i<mc->mc_snum; i++) {
9857 mc->mc_pg[i] = mx.mc_pg[i];
9862 rc = mdb_midl_append(&txn->mt_free_pgs, mc->mc_db->md_root);
9865 txn->mt_flags |= MDB_TXN_ERROR;
9866 } else if (rc == MDB_NOTFOUND) {
9869 mc->mc_flags &= ~C_INITIALIZED;
9873 int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)
9875 MDB_cursor *mc, *m2;
9878 if ((unsigned)del > 1 || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9881 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
9884 if (TXN_DBI_CHANGED(txn, dbi))
9887 rc = mdb_cursor_open(txn, dbi, &mc);
9891 rc = mdb_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT);
9892 /* Invalidate the dropped DB's cursors */
9893 for (m2 = txn->mt_cursors[dbi]; m2; m2 = m2->mc_next)
9894 m2->mc_flags &= ~(C_INITIALIZED|C_EOF);
9898 /* Can't delete the main DB */
9899 if (del && dbi >= CORE_DBS) {
9900 rc = mdb_del0(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL, F_SUBDATA);
9902 txn->mt_dbflags[dbi] = DB_STALE;
9903 mdb_dbi_close(txn->mt_env, dbi);
9905 txn->mt_flags |= MDB_TXN_ERROR;
9908 /* reset the DB record, mark it dirty */
9909 txn->mt_dbflags[dbi] |= DB_DIRTY;
9910 txn->mt_dbs[dbi].md_depth = 0;
9911 txn->mt_dbs[dbi].md_branch_pages = 0;
9912 txn->mt_dbs[dbi].md_leaf_pages = 0;
9913 txn->mt_dbs[dbi].md_overflow_pages = 0;
9914 txn->mt_dbs[dbi].md_entries = 0;
9915 txn->mt_dbs[dbi].md_root = P_INVALID;
9917 txn->mt_flags |= MDB_TXN_DIRTY;
9920 mdb_cursor_close(mc);
9924 int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
9926 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9929 txn->mt_dbxs[dbi].md_cmp = cmp;
9933 int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
9935 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9938 txn->mt_dbxs[dbi].md_dcmp = cmp;
9942 int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
9944 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9947 txn->mt_dbxs[dbi].md_rel = rel;
9951 int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx)
9953 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9956 txn->mt_dbxs[dbi].md_relctx = ctx;
9961 mdb_env_get_maxkeysize(MDB_env *env)
9963 return ENV_MAXKEY(env);
9967 mdb_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx)
9969 unsigned int i, rdrs;
9972 int rc = 0, first = 1;
9976 if (!env->me_txns) {
9977 return func("(no reader locks)\n", ctx);
9979 rdrs = env->me_txns->mti_numreaders;
9980 mr = env->me_txns->mti_readers;
9981 for (i=0; i<rdrs; i++) {
9983 txnid_t txnid = mr[i].mr_txnid;
9984 sprintf(buf, txnid == (txnid_t)-1 ?
9985 "%10d %"Z"x -\n" : "%10d %"Z"x %"Z"u\n",
9986 (int)mr[i].mr_pid, (size_t)mr[i].mr_tid, txnid);
9989 rc = func(" pid thread txnid\n", ctx);
9993 rc = func(buf, ctx);
9999 rc = func("(no active readers)\n", ctx);
10004 /** Insert pid into list if not already present.
10005 * return -1 if already present.
10008 mdb_pid_insert(MDB_PID_T *ids, MDB_PID_T pid)
10010 /* binary search of pid in list */
10012 unsigned cursor = 1;
10014 unsigned n = ids[0];
10017 unsigned pivot = n >> 1;
10018 cursor = base + pivot + 1;
10019 val = pid - ids[cursor];
10024 } else if ( val > 0 ) {
10029 /* found, so it's a duplicate */
10038 for (n = ids[0]; n > cursor; n--)
10045 mdb_reader_check(MDB_env *env, int *dead)
10051 return env->me_txns ? mdb_reader_check0(env, 0, dead) : MDB_SUCCESS;
10054 /** As #mdb_reader_check(). rlocked = <caller locked the reader mutex>. */
10056 mdb_reader_check0(MDB_env *env, int rlocked, int *dead)
10058 mdb_mutexref_t rmutex = rlocked ? NULL : env->me_rmutex;
10059 unsigned int i, j, rdrs;
10061 MDB_PID_T *pids, pid;
10062 int rc = MDB_SUCCESS, count = 0;
10064 rdrs = env->me_txns->mti_numreaders;
10065 pids = malloc((rdrs+1) * sizeof(MDB_PID_T));
10069 mr = env->me_txns->mti_readers;
10070 for (i=0; i<rdrs; i++) {
10071 pid = mr[i].mr_pid;
10072 if (pid && pid != env->me_pid) {
10073 if (mdb_pid_insert(pids, pid) == 0) {
10074 if (!mdb_reader_pid(env, Pidcheck, pid)) {
10075 /* Stale reader found */
10078 if ((rc = LOCK_MUTEX0(rmutex)) != 0) {
10079 if ((rc = mdb_mutex_failed(env, rmutex, rc)))
10081 rdrs = 0; /* the above checked all readers */
10083 /* Recheck, a new process may have reused pid */
10084 if (mdb_reader_pid(env, Pidcheck, pid))
10088 for (; j<rdrs; j++)
10089 if (mr[j].mr_pid == pid) {
10090 DPRINTF(("clear stale reader pid %u txn %"Z"d",
10091 (unsigned) pid, mr[j].mr_txnid));
10096 UNLOCK_MUTEX(rmutex);
10107 #ifdef MDB_ROBUST_SUPPORTED
10108 /** Handle #LOCK_MUTEX0() failure.
10109 * Try to repair the lock file if the mutex owner died.
10110 * @param[in] env the environment handle
10111 * @param[in] mutex LOCK_MUTEX0() mutex
10112 * @param[in] rc LOCK_MUTEX0() error (nonzero)
10113 * @return 0 on success with the mutex locked, or an error code on failure.
10116 mdb_mutex_failed(MDB_env *env, mdb_mutexref_t mutex, int rc)
10121 if (rc == MDB_OWNERDEAD) {
10122 /* We own the mutex. Clean up after dead previous owner. */
10124 rlocked = (mutex == env->me_rmutex);
10126 /* Keep mti_txnid updated, otherwise next writer can
10127 * overwrite data which latest meta page refers to.
10129 meta = mdb_env_pick_meta(env);
10130 env->me_txns->mti_txnid = meta->mm_txnid;
10131 /* env is hosed if the dead thread was ours */
10133 env->me_flags |= MDB_FATAL_ERROR;
10134 env->me_txn = NULL;
10138 DPRINTF(("%cmutex owner died, %s", (rlocked ? 'r' : 'w'),
10139 (rc ? "this process' env is hosed" : "recovering")));
10140 rc2 = mdb_reader_check0(env, rlocked, NULL);
10142 rc2 = mdb_mutex_consistent(mutex);
10143 if (rc || (rc = rc2)) {
10144 DPRINTF(("LOCK_MUTEX recovery failed, %s", mdb_strerror(rc)));
10145 UNLOCK_MUTEX(mutex);
10151 DPRINTF(("LOCK_MUTEX failed, %s", mdb_strerror(rc)));
10156 #endif /* MDB_ROBUST_SUPPORTED */
10159 #if defined(_WIN32)
10160 static int utf8_to_utf16(const char *src, int srcsize, wchar_t **dst, int *dstsize)
10164 need = MultiByteToWideChar(CP_UTF8, 0, src, srcsize, NULL, 0);
10165 if (need == 0xFFFD)
10169 result = malloc(sizeof(wchar_t) * need);
10170 MultiByteToWideChar(CP_UTF8, 0, src, srcsize, result, need);
10176 #endif /* defined(_WIN32) */
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