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.
41 /** getpid() returns int; MinGW defines pid_t but MinGW64 typedefs it
42 * as int64 which is wrong. MSVC doesn't define it at all, so just
46 #define MDB_THR_T DWORD
47 #include <sys/types.h>
50 # include <sys/param.h>
52 # define LITTLE_ENDIAN 1234
53 # define BIG_ENDIAN 4321
54 # define BYTE_ORDER LITTLE_ENDIAN
56 # define SSIZE_MAX INT_MAX
60 #include <sys/types.h>
62 #define MDB_PID_T pid_t
63 #define MDB_THR_T pthread_t
64 #include <sys/param.h>
67 #ifdef HAVE_SYS_FILE_H
73 #if defined(__mips) && defined(__linux)
74 /* MIPS has cache coherency issues, requires explicit cache control */
75 #include <asm/cachectl.h>
76 extern int cacheflush(char *addr, int nbytes, int cache);
77 #define CACHEFLUSH(addr, bytes, cache) cacheflush(addr, bytes, cache)
79 #define CACHEFLUSH(addr, bytes, cache)
82 #if defined(__linux) && !defined(MDB_FDATASYNC_WORKS)
83 /** fdatasync is broken on ext3/ext4fs on older kernels, see
84 * description in #mdb_env_open2 comments. You can safely
85 * define MDB_FDATASYNC_WORKS if this code will only be run
86 * on kernels 3.6 and newer.
88 #define BROKEN_FDATASYNC
102 typedef SSIZE_T ssize_t;
107 #if defined(__sun) || defined(ANDROID)
108 /* Most platforms have posix_memalign, older may only have memalign */
109 #define HAVE_MEMALIGN 1
113 #if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER))
114 #include <netinet/in.h>
115 #include <resolv.h> /* defines BYTE_ORDER on HPUX and Solaris */
118 #if defined(__APPLE__) || defined (BSD)
119 # define MDB_USE_POSIX_SEM 1
120 # define MDB_FDATASYNC fsync
121 #elif defined(ANDROID)
122 # define MDB_FDATASYNC fsync
127 #ifdef MDB_USE_POSIX_SEM
128 # define MDB_USE_HASH 1
129 #include <semaphore.h>
131 #define MDB_USE_POSIX_MUTEX 1
135 #if defined(_WIN32) + defined(MDB_USE_POSIX_SEM) \
136 + defined(MDB_USE_POSIX_MUTEX) != 1
137 # error "Ambiguous shared-lock implementation"
141 #include <valgrind/memcheck.h>
142 #define VGMEMP_CREATE(h,r,z) VALGRIND_CREATE_MEMPOOL(h,r,z)
143 #define VGMEMP_ALLOC(h,a,s) VALGRIND_MEMPOOL_ALLOC(h,a,s)
144 #define VGMEMP_FREE(h,a) VALGRIND_MEMPOOL_FREE(h,a)
145 #define VGMEMP_DESTROY(h) VALGRIND_DESTROY_MEMPOOL(h)
146 #define VGMEMP_DEFINED(a,s) VALGRIND_MAKE_MEM_DEFINED(a,s)
148 #define VGMEMP_CREATE(h,r,z)
149 #define VGMEMP_ALLOC(h,a,s)
150 #define VGMEMP_FREE(h,a)
151 #define VGMEMP_DESTROY(h)
152 #define VGMEMP_DEFINED(a,s)
156 # if (defined(_LITTLE_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN))
157 /* Solaris just defines one or the other */
158 # define LITTLE_ENDIAN 1234
159 # define BIG_ENDIAN 4321
160 # ifdef _LITTLE_ENDIAN
161 # define BYTE_ORDER LITTLE_ENDIAN
163 # define BYTE_ORDER BIG_ENDIAN
166 # define BYTE_ORDER __BYTE_ORDER
170 #ifndef LITTLE_ENDIAN
171 #define LITTLE_ENDIAN __LITTLE_ENDIAN
174 #define BIG_ENDIAN __BIG_ENDIAN
177 #if defined(__i386) || defined(__x86_64) || defined(_M_IX86)
178 #define MISALIGNED_OK 1
184 #if (BYTE_ORDER == LITTLE_ENDIAN) == (BYTE_ORDER == BIG_ENDIAN)
185 # error "Unknown or unsupported endianness (BYTE_ORDER)"
186 #elif (-6 & 5) || CHAR_BIT != 8 || UINT_MAX < 0xffffffff || ULONG_MAX % 0xFFFF
187 # error "Two's complement, reasonably sized integer types, please"
191 /** Put infrequently used env functions in separate section */
193 # define ESECT __attribute__ ((section("__TEXT,text_env")))
195 # define ESECT __attribute__ ((section("text_env")))
202 #define CALL_CONV WINAPI
207 /** @defgroup internal LMDB Internals
210 /** @defgroup compat Compatibility Macros
211 * A bunch of macros to minimize the amount of platform-specific ifdefs
212 * needed throughout the rest of the code. When the features this library
213 * needs are similar enough to POSIX to be hidden in a one-or-two line
214 * replacement, this macro approach is used.
218 /** Features under development */
223 /** Wrapper around __func__, which is a C99 feature */
224 #if __STDC_VERSION__ >= 199901L
225 # define mdb_func_ __func__
226 #elif __GNUC__ >= 2 || _MSC_VER >= 1300
227 # define mdb_func_ __FUNCTION__
229 /* If a debug message says <mdb_unknown>(), update the #if statements above */
230 # define mdb_func_ "<mdb_unknown>"
233 /* Internal error codes, not exposed outside liblmdb */
234 #define MDB_NO_ROOT (MDB_LAST_ERRCODE + 10)
236 #define MDB_OWNERDEAD ((int) WAIT_ABANDONED)
237 #elif defined(MDB_USE_POSIX_MUTEX) && defined(EOWNERDEAD)
238 #define MDB_OWNERDEAD EOWNERDEAD /**< #LOCK_MUTEX0() result if dead owner */
242 #define GLIBC_VER ((__GLIBC__ << 16 )| __GLIBC_MINOR__)
244 /** Some platforms define the EOWNERDEAD error code
245 * even though they don't support Robust Mutexes.
246 * Compile with -DMDB_USE_ROBUST=0, or use some other
247 * mechanism like -DMDB_USE_SYSV_SEM instead of
248 * -DMDB_USE_POSIX_MUTEX. (SysV semaphores are
249 * also Robust, but some systems don't support them
252 #ifndef MDB_USE_ROBUST
253 /* Android currently lacks Robust Mutex support. So does glibc < 2.4. */
254 # if defined(MDB_USE_POSIX_MUTEX) && (defined(ANDROID) || \
255 (defined(__GLIBC__) && GLIBC_VER < 0x020004))
256 # define MDB_USE_ROBUST 0
258 # define MDB_USE_ROBUST 1
259 /* glibc < 2.10 only provided _np API */
260 # if defined(__GLIBC__) && GLIBC_VER < 0x02000a
261 # define PTHREAD_MUTEX_ROBUST PTHREAD_MUTEX_ROBUST_NP
262 # define pthread_mutexattr_setrobust(attr, flag) pthread_mutexattr_setrobust_np(attr, flag)
263 # define pthread_mutex_consistent(mutex) pthread_mutex_consistent_np(mutex)
266 #endif /* MDB_USE_ROBUST */
268 #if defined(MDB_OWNERDEAD) && MDB_USE_ROBUST
269 #define MDB_ROBUST_SUPPORTED 1
273 #define MDB_USE_HASH 1
274 #define MDB_PIDLOCK 0
275 #define THREAD_RET DWORD
276 #define pthread_t HANDLE
277 #define pthread_mutex_t HANDLE
278 #define pthread_cond_t HANDLE
279 typedef HANDLE mdb_mutex_t, mdb_mutexref_t;
280 #define pthread_key_t DWORD
281 #define pthread_self() GetCurrentThreadId()
282 #define pthread_key_create(x,y) \
283 ((*(x) = TlsAlloc()) == TLS_OUT_OF_INDEXES ? ErrCode() : 0)
284 #define pthread_key_delete(x) TlsFree(x)
285 #define pthread_getspecific(x) TlsGetValue(x)
286 #define pthread_setspecific(x,y) (TlsSetValue(x,y) ? 0 : ErrCode())
287 #define pthread_mutex_unlock(x) ReleaseMutex(*x)
288 #define pthread_mutex_lock(x) WaitForSingleObject(*x, INFINITE)
289 #define pthread_cond_signal(x) SetEvent(*x)
290 #define pthread_cond_wait(cond,mutex) do{SignalObjectAndWait(*mutex, *cond, INFINITE, FALSE); WaitForSingleObject(*mutex, INFINITE);}while(0)
291 #define THREAD_CREATE(thr,start,arg) thr=CreateThread(NULL,0,start,arg,0,NULL)
292 #define THREAD_FINISH(thr) WaitForSingleObject(thr, INFINITE)
293 #define LOCK_MUTEX0(mutex) WaitForSingleObject(mutex, INFINITE)
294 #define UNLOCK_MUTEX(mutex) ReleaseMutex(mutex)
295 #define mdb_mutex_consistent(mutex) 0
296 #define getpid() GetCurrentProcessId()
297 #define MDB_FDATASYNC(fd) (!FlushFileBuffers(fd))
298 #define MDB_MSYNC(addr,len,flags) (!FlushViewOfFile(addr,len))
299 #define ErrCode() GetLastError()
300 #define GET_PAGESIZE(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;}
301 #define close(fd) (CloseHandle(fd) ? 0 : -1)
302 #define munmap(ptr,len) UnmapViewOfFile(ptr)
303 #ifdef PROCESS_QUERY_LIMITED_INFORMATION
304 #define MDB_PROCESS_QUERY_LIMITED_INFORMATION PROCESS_QUERY_LIMITED_INFORMATION
306 #define MDB_PROCESS_QUERY_LIMITED_INFORMATION 0x1000
310 #define THREAD_RET void *
311 #define THREAD_CREATE(thr,start,arg) pthread_create(&thr,NULL,start,arg)
312 #define THREAD_FINISH(thr) pthread_join(thr,NULL)
313 #define Z "z" /**< printf format modifier for size_t */
315 /** For MDB_LOCK_FORMAT: True if readers take a pid lock in the lockfile */
316 #define MDB_PIDLOCK 1
318 #ifdef MDB_USE_POSIX_SEM
320 typedef sem_t *mdb_mutex_t, *mdb_mutexref_t;
321 #define LOCK_MUTEX0(mutex) mdb_sem_wait(mutex)
322 #define UNLOCK_MUTEX(mutex) sem_post(mutex)
325 mdb_sem_wait(sem_t *sem)
328 while ((rc = sem_wait(sem)) && (rc = errno) == EINTR) ;
332 #else /* MDB_USE_POSIX_MUTEX: */
333 /** Shared mutex/semaphore as it is stored (mdb_mutex_t), and as
334 * local variables keep it (mdb_mutexref_t).
336 * When #mdb_mutexref_t is a pointer declaration and #mdb_mutex_t is
337 * not, then it is array[size 1] so it can be assigned to a pointer.
340 typedef pthread_mutex_t mdb_mutex_t[1], *mdb_mutexref_t;
342 /** Lock the reader or writer mutex.
343 * Returns 0 or a code to give #mdb_mutex_failed(), as in #LOCK_MUTEX().
345 #define LOCK_MUTEX0(mutex) pthread_mutex_lock(mutex)
346 /** Unlock the reader or writer mutex.
348 #define UNLOCK_MUTEX(mutex) pthread_mutex_unlock(mutex)
349 /** Mark mutex-protected data as repaired, after death of previous owner.
351 #define mdb_mutex_consistent(mutex) pthread_mutex_consistent(mutex)
352 #endif /* MDB_USE_POSIX_SEM */
354 /** Get the error code for the last failed system function.
356 #define ErrCode() errno
358 /** An abstraction for a file handle.
359 * On POSIX systems file handles are small integers. On Windows
360 * they're opaque pointers.
364 /** A value for an invalid file handle.
365 * Mainly used to initialize file variables and signify that they are
368 #define INVALID_HANDLE_VALUE (-1)
370 /** Get the size of a memory page for the system.
371 * This is the basic size that the platform's memory manager uses, and is
372 * fundamental to the use of memory-mapped files.
374 #define GET_PAGESIZE(x) ((x) = sysconf(_SC_PAGE_SIZE))
377 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
380 #define MNAME_LEN (sizeof(pthread_mutex_t))
385 #ifdef MDB_ROBUST_SUPPORTED
386 /** Lock mutex, handle any error, set rc = result.
387 * Return 0 on success, nonzero (not rc) on error.
389 #define LOCK_MUTEX(rc, env, mutex) \
390 (((rc) = LOCK_MUTEX0(mutex)) && \
391 ((rc) = mdb_mutex_failed(env, mutex, rc)))
392 static int mdb_mutex_failed(MDB_env *env, mdb_mutexref_t mutex, int rc);
394 #define LOCK_MUTEX(rc, env, mutex) ((rc) = LOCK_MUTEX0(mutex))
395 #define mdb_mutex_failed(env, mutex, rc) (rc)
399 /** A flag for opening a file and requesting synchronous data writes.
400 * This is only used when writing a meta page. It's not strictly needed;
401 * we could just do a normal write and then immediately perform a flush.
402 * But if this flag is available it saves us an extra system call.
404 * @note If O_DSYNC is undefined but exists in /usr/include,
405 * preferably set some compiler flag to get the definition.
409 # define MDB_DSYNC O_DSYNC
411 # define MDB_DSYNC O_SYNC
416 /** Function for flushing the data of a file. Define this to fsync
417 * if fdatasync() is not supported.
419 #ifndef MDB_FDATASYNC
420 # define MDB_FDATASYNC fdatasync
424 # define MDB_MSYNC(addr,len,flags) msync(addr,len,flags)
435 /** A page number in the database.
436 * Note that 64 bit page numbers are overkill, since pages themselves
437 * already represent 12-13 bits of addressable memory, and the OS will
438 * always limit applications to a maximum of 63 bits of address space.
440 * @note In the #MDB_node structure, we only store 48 bits of this value,
441 * which thus limits us to only 60 bits of addressable data.
443 typedef MDB_ID pgno_t;
445 /** A transaction ID.
446 * See struct MDB_txn.mt_txnid for details.
448 typedef MDB_ID txnid_t;
450 /** @defgroup debug Debug Macros
454 /** Enable debug output. Needs variable argument macros (a C99 feature).
455 * Set this to 1 for copious tracing. Set to 2 to add dumps of all IDLs
456 * read from and written to the database (used for free space management).
462 static int mdb_debug;
463 static txnid_t mdb_debug_start;
465 /** Print a debug message with printf formatting.
466 * Requires double parenthesis around 2 or more args.
468 # define DPRINTF(args) ((void) ((mdb_debug) && DPRINTF0 args))
469 # define DPRINTF0(fmt, ...) \
470 fprintf(stderr, "%s:%d " fmt "\n", mdb_func_, __LINE__, __VA_ARGS__)
472 # define DPRINTF(args) ((void) 0)
474 /** Print a debug string.
475 * The string is printed literally, with no format processing.
477 #define DPUTS(arg) DPRINTF(("%s", arg))
478 /** Debuging output value of a cursor DBI: Negative in a sub-cursor. */
480 (((mc)->mc_flags & C_SUB) ? -(int)(mc)->mc_dbi : (int)(mc)->mc_dbi)
483 /** @brief The maximum size of a database page.
485 * It is 32k or 64k, since value-PAGEBASE must fit in
486 * #MDB_page.%mp_upper.
488 * LMDB will use database pages < OS pages if needed.
489 * That causes more I/O in write transactions: The OS must
490 * know (read) the whole page before writing a partial page.
492 * Note that we don't currently support Huge pages. On Linux,
493 * regular data files cannot use Huge pages, and in general
494 * Huge pages aren't actually pageable. We rely on the OS
495 * demand-pager to read our data and page it out when memory
496 * pressure from other processes is high. So until OSs have
497 * actual paging support for Huge pages, they're not viable.
499 #define MAX_PAGESIZE (PAGEBASE ? 0x10000 : 0x8000)
501 /** The minimum number of keys required in a database page.
502 * Setting this to a larger value will place a smaller bound on the
503 * maximum size of a data item. Data items larger than this size will
504 * be pushed into overflow pages instead of being stored directly in
505 * the B-tree node. This value used to default to 4. With a page size
506 * of 4096 bytes that meant that any item larger than 1024 bytes would
507 * go into an overflow page. That also meant that on average 2-3KB of
508 * each overflow page was wasted space. The value cannot be lower than
509 * 2 because then there would no longer be a tree structure. With this
510 * value, items larger than 2KB will go into overflow pages, and on
511 * average only 1KB will be wasted.
513 #define MDB_MINKEYS 2
515 /** A stamp that identifies a file as an LMDB file.
516 * There's nothing special about this value other than that it is easily
517 * recognizable, and it will reflect any byte order mismatches.
519 #define MDB_MAGIC 0xBEEFC0DE
521 /** The version number for a database's datafile format. */
522 #define MDB_DATA_VERSION ((MDB_DEVEL) ? 999 : 1)
523 /** The version number for a database's lockfile format. */
524 #define MDB_LOCK_VERSION 1
526 /** @brief The max size of a key we can write, or 0 for computed max.
528 * This macro should normally be left alone or set to 0.
529 * Note that a database with big keys or dupsort data cannot be
530 * reliably modified by a liblmdb which uses a smaller max.
531 * The default is 511 for backwards compat, or 0 when #MDB_DEVEL.
533 * Other values are allowed, for backwards compat. However:
534 * A value bigger than the computed max can break if you do not
535 * know what you are doing, and liblmdb <= 0.9.10 can break when
536 * modifying a DB with keys/dupsort data bigger than its max.
538 * Data items in an #MDB_DUPSORT database are also limited to
539 * this size, since they're actually keys of a sub-DB. Keys and
540 * #MDB_DUPSORT data items must fit on a node in a regular page.
542 #ifndef MDB_MAXKEYSIZE
543 #define MDB_MAXKEYSIZE ((MDB_DEVEL) ? 0 : 511)
546 /** The maximum size of a key we can write to the environment. */
548 #define ENV_MAXKEY(env) (MDB_MAXKEYSIZE)
550 #define ENV_MAXKEY(env) ((env)->me_maxkey)
553 /** @brief The maximum size of a data item.
555 * We only store a 32 bit value for node sizes.
557 #define MAXDATASIZE 0xffffffffUL
560 /** Key size which fits in a #DKBUF.
563 #define DKBUF_MAXKEYSIZE ((MDB_MAXKEYSIZE) > 0 ? (MDB_MAXKEYSIZE) : 511)
566 * This is used for printing a hex dump of a key's contents.
568 #define DKBUF char kbuf[DKBUF_MAXKEYSIZE*2+1]
569 /** Display a key in hex.
571 * Invoke a function to display a key in hex.
573 #define DKEY(x) mdb_dkey(x, kbuf)
579 /** An invalid page number.
580 * Mainly used to denote an empty tree.
582 #define P_INVALID (~(pgno_t)0)
584 /** Test if the flags \b f are set in a flag word \b w. */
585 #define F_ISSET(w, f) (((w) & (f)) == (f))
587 /** Round \b n up to an even number. */
588 #define EVEN(n) (((n) + 1U) & -2) /* sign-extending -2 to match n+1U */
590 /** Used for offsets within a single page.
591 * Since memory pages are typically 4 or 8KB in size, 12-13 bits,
594 typedef uint16_t indx_t;
596 /** Default size of memory map.
597 * This is certainly too small for any actual applications. Apps should always set
598 * the size explicitly using #mdb_env_set_mapsize().
600 #define DEFAULT_MAPSIZE 1048576
602 /** @defgroup readers Reader Lock Table
603 * Readers don't acquire any locks for their data access. Instead, they
604 * simply record their transaction ID in the reader table. The reader
605 * mutex is needed just to find an empty slot in the reader table. The
606 * slot's address is saved in thread-specific data so that subsequent read
607 * transactions started by the same thread need no further locking to proceed.
609 * If #MDB_NOTLS is set, the slot address is not saved in thread-specific data.
611 * No reader table is used if the database is on a read-only filesystem, or
612 * if #MDB_NOLOCK is set.
614 * Since the database uses multi-version concurrency control, readers don't
615 * actually need any locking. This table is used to keep track of which
616 * readers are using data from which old transactions, so that we'll know
617 * when a particular old transaction is no longer in use. Old transactions
618 * that have discarded any data pages can then have those pages reclaimed
619 * for use by a later write transaction.
621 * The lock table is constructed such that reader slots are aligned with the
622 * processor's cache line size. Any slot is only ever used by one thread.
623 * This alignment guarantees that there will be no contention or cache
624 * thrashing as threads update their own slot info, and also eliminates
625 * any need for locking when accessing a slot.
627 * A writer thread will scan every slot in the table to determine the oldest
628 * outstanding reader transaction. Any freed pages older than this will be
629 * reclaimed by the writer. The writer doesn't use any locks when scanning
630 * this table. This means that there's no guarantee that the writer will
631 * see the most up-to-date reader info, but that's not required for correct
632 * operation - all we need is to know the upper bound on the oldest reader,
633 * we don't care at all about the newest reader. So the only consequence of
634 * reading stale information here is that old pages might hang around a
635 * while longer before being reclaimed. That's actually good anyway, because
636 * the longer we delay reclaiming old pages, the more likely it is that a
637 * string of contiguous pages can be found after coalescing old pages from
638 * many old transactions together.
641 /** Number of slots in the reader table.
642 * This value was chosen somewhat arbitrarily. 126 readers plus a
643 * couple mutexes fit exactly into 8KB on my development machine.
644 * Applications should set the table size using #mdb_env_set_maxreaders().
646 #define DEFAULT_READERS 126
648 /** The size of a CPU cache line in bytes. We want our lock structures
649 * aligned to this size to avoid false cache line sharing in the
651 * This value works for most CPUs. For Itanium this should be 128.
657 /** The information we store in a single slot of the reader table.
658 * In addition to a transaction ID, we also record the process and
659 * thread ID that owns a slot, so that we can detect stale information,
660 * e.g. threads or processes that went away without cleaning up.
661 * @note We currently don't check for stale records. We simply re-init
662 * the table when we know that we're the only process opening the
665 typedef struct MDB_rxbody {
666 /** Current Transaction ID when this transaction began, or (txnid_t)-1.
667 * Multiple readers that start at the same time will probably have the
668 * same ID here. Again, it's not important to exclude them from
669 * anything; all we need to know is which version of the DB they
670 * started from so we can avoid overwriting any data used in that
671 * particular version.
673 volatile txnid_t mrb_txnid;
674 /** The process ID of the process owning this reader txn. */
675 volatile MDB_PID_T mrb_pid;
676 /** The thread ID of the thread owning this txn. */
677 volatile MDB_THR_T mrb_tid;
680 /** The actual reader record, with cacheline padding. */
681 typedef struct MDB_reader {
684 /** shorthand for mrb_txnid */
685 #define mr_txnid mru.mrx.mrb_txnid
686 #define mr_pid mru.mrx.mrb_pid
687 #define mr_tid mru.mrx.mrb_tid
688 /** cache line alignment */
689 char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)];
693 /** The header for the reader table.
694 * The table resides in a memory-mapped file. (This is a different file
695 * than is used for the main database.)
697 * For POSIX the actual mutexes reside in the shared memory of this
698 * mapped file. On Windows, mutexes are named objects allocated by the
699 * kernel; we store the mutex names in this mapped file so that other
700 * processes can grab them. This same approach is also used on
701 * MacOSX/Darwin (using named semaphores) since MacOSX doesn't support
702 * process-shared POSIX mutexes. For these cases where a named object
703 * is used, the object name is derived from a 64 bit FNV hash of the
704 * environment pathname. As such, naming collisions are extremely
705 * unlikely. If a collision occurs, the results are unpredictable.
707 typedef struct MDB_txbody {
708 /** Stamp identifying this as an LMDB file. It must be set
711 /** Format of this lock file. Must be set to #MDB_LOCK_FORMAT. */
713 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
714 char mtb_rmname[MNAME_LEN];
716 /** Mutex protecting access to this table.
717 * This is the reader table lock used with LOCK_MUTEX().
719 mdb_mutex_t mtb_rmutex;
721 /** The ID of the last transaction committed to the database.
722 * This is recorded here only for convenience; the value can always
723 * be determined by reading the main database meta pages.
725 volatile txnid_t mtb_txnid;
726 /** The number of slots that have been used in the reader table.
727 * This always records the maximum count, it is not decremented
728 * when readers release their slots.
730 volatile unsigned mtb_numreaders;
733 /** The actual reader table definition. */
734 typedef struct MDB_txninfo {
737 #define mti_magic mt1.mtb.mtb_magic
738 #define mti_format mt1.mtb.mtb_format
739 #define mti_rmutex mt1.mtb.mtb_rmutex
740 #define mti_rmname mt1.mtb.mtb_rmname
741 #define mti_txnid mt1.mtb.mtb_txnid
742 #define mti_numreaders mt1.mtb.mtb_numreaders
743 char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];
746 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
747 char mt2_wmname[MNAME_LEN];
748 #define mti_wmname mt2.mt2_wmname
750 mdb_mutex_t mt2_wmutex;
751 #define mti_wmutex mt2.mt2_wmutex
753 char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)];
755 MDB_reader mti_readers[1];
758 /** Lockfile format signature: version, features and field layout */
759 #define MDB_LOCK_FORMAT \
761 ((MDB_LOCK_VERSION) \
762 /* Flags which describe functionality */ \
763 + (((MDB_PIDLOCK) != 0) << 16)))
766 /** Common header for all page types.
767 * Overflow records occupy a number of contiguous pages with no
768 * headers on any page after the first.
770 typedef struct MDB_page {
771 #define mp_pgno mp_p.p_pgno
772 #define mp_next mp_p.p_next
774 pgno_t p_pgno; /**< page number */
775 struct MDB_page *p_next; /**< for in-memory list of freed pages */
778 /** @defgroup mdb_page Page Flags
780 * Flags for the page headers.
783 #define P_BRANCH 0x01 /**< branch page */
784 #define P_LEAF 0x02 /**< leaf page */
785 #define P_OVERFLOW 0x04 /**< overflow page */
786 #define P_META 0x08 /**< meta page */
787 #define P_DIRTY 0x10 /**< dirty page, also set for #P_SUBP pages */
788 #define P_LEAF2 0x20 /**< for #MDB_DUPFIXED records */
789 #define P_SUBP 0x40 /**< for #MDB_DUPSORT sub-pages */
790 #define P_LOOSE 0x4000 /**< page was dirtied then freed, can be reused */
791 #define P_KEEP 0x8000 /**< leave this page alone during spill */
793 uint16_t mp_flags; /**< @ref mdb_page */
794 #define mp_lower mp_pb.pb.pb_lower
795 #define mp_upper mp_pb.pb.pb_upper
796 #define mp_pages mp_pb.pb_pages
799 indx_t pb_lower; /**< lower bound of free space */
800 indx_t pb_upper; /**< upper bound of free space */
802 uint32_t pb_pages; /**< number of overflow pages */
804 indx_t mp_ptrs[1]; /**< dynamic size */
807 /** Size of the page header, excluding dynamic data at the end */
808 #define PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs))
810 /** Address of first usable data byte in a page, after the header */
811 #define METADATA(p) ((void *)((char *)(p) + PAGEHDRSZ))
813 /** ITS#7713, change PAGEBASE to handle 65536 byte pages */
814 #define PAGEBASE ((MDB_DEVEL) ? PAGEHDRSZ : 0)
816 /** Number of nodes on a page */
817 #define NUMKEYS(p) (((p)->mp_lower - (PAGEHDRSZ-PAGEBASE)) >> 1)
819 /** The amount of space remaining in the page */
820 #define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower)
822 /** The percentage of space used in the page, in tenths of a percent. */
823 #define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \
824 ((env)->me_psize - PAGEHDRSZ))
825 /** The minimum page fill factor, in tenths of a percent.
826 * Pages emptier than this are candidates for merging.
828 #define FILL_THRESHOLD 250
830 /** Test if a page is a leaf page */
831 #define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF)
832 /** Test if a page is a LEAF2 page */
833 #define IS_LEAF2(p) F_ISSET((p)->mp_flags, P_LEAF2)
834 /** Test if a page is a branch page */
835 #define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH)
836 /** Test if a page is an overflow page */
837 #define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW)
838 /** Test if a page is a sub page */
839 #define IS_SUBP(p) F_ISSET((p)->mp_flags, P_SUBP)
841 /** The number of overflow pages needed to store the given size. */
842 #define OVPAGES(size, psize) ((PAGEHDRSZ-1 + (size)) / (psize) + 1)
844 /** Link in #MDB_txn.%mt_loose_pgs list */
845 #define NEXT_LOOSE_PAGE(p) (*(MDB_page **)((p) + 2))
847 /** Header for a single key/data pair within a page.
848 * Used in pages of type #P_BRANCH and #P_LEAF without #P_LEAF2.
849 * We guarantee 2-byte alignment for 'MDB_node's.
851 typedef struct MDB_node {
852 /** lo and hi are used for data size on leaf nodes and for
853 * child pgno on branch nodes. On 64 bit platforms, flags
854 * is also used for pgno. (Branch nodes have no flags).
855 * They are in host byte order in case that lets some
856 * accesses be optimized into a 32-bit word access.
858 #if BYTE_ORDER == LITTLE_ENDIAN
859 unsigned short mn_lo, mn_hi; /**< part of data size or pgno */
861 unsigned short mn_hi, mn_lo;
863 /** @defgroup mdb_node Node Flags
865 * Flags for node headers.
868 #define F_BIGDATA 0x01 /**< data put on overflow page */
869 #define F_SUBDATA 0x02 /**< data is a sub-database */
870 #define F_DUPDATA 0x04 /**< data has duplicates */
872 /** valid flags for #mdb_node_add() */
873 #define NODE_ADD_FLAGS (F_DUPDATA|F_SUBDATA|MDB_RESERVE|MDB_APPEND)
876 unsigned short mn_flags; /**< @ref mdb_node */
877 unsigned short mn_ksize; /**< key size */
878 char mn_data[1]; /**< key and data are appended here */
881 /** Size of the node header, excluding dynamic data at the end */
882 #define NODESIZE offsetof(MDB_node, mn_data)
884 /** Bit position of top word in page number, for shifting mn_flags */
885 #define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0)
887 /** Size of a node in a branch page with a given key.
888 * This is just the node header plus the key, there is no data.
890 #define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))
892 /** Size of a node in a leaf page with a given key and data.
893 * This is node header plus key plus data size.
895 #define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size)
897 /** Address of node \b i in page \b p */
898 #define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i] + PAGEBASE))
900 /** Address of the key for the node */
901 #define NODEKEY(node) (void *)((node)->mn_data)
903 /** Address of the data for a node */
904 #define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize)
906 /** Get the page number pointed to by a branch node */
907 #define NODEPGNO(node) \
908 ((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | \
909 (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0))
910 /** Set the page number in a branch node */
911 #define SETPGNO(node,pgno) do { \
912 (node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \
913 if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0)
915 /** Get the size of the data in a leaf node */
916 #define NODEDSZ(node) ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16))
917 /** Set the size of the data for a leaf node */
918 #define SETDSZ(node,size) do { \
919 (node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)
920 /** The size of a key in a node */
921 #define NODEKSZ(node) ((node)->mn_ksize)
923 /** Copy a page number from src to dst */
925 #define COPY_PGNO(dst,src) dst = src
927 #if SIZE_MAX > 4294967295UL
928 #define COPY_PGNO(dst,src) do { \
929 unsigned short *s, *d; \
930 s = (unsigned short *)&(src); \
931 d = (unsigned short *)&(dst); \
938 #define COPY_PGNO(dst,src) do { \
939 unsigned short *s, *d; \
940 s = (unsigned short *)&(src); \
941 d = (unsigned short *)&(dst); \
947 /** The address of a key in a LEAF2 page.
948 * LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate sub-DBs.
949 * There are no node headers, keys are stored contiguously.
951 #define LEAF2KEY(p, i, ks) ((char *)(p) + PAGEHDRSZ + ((i)*(ks)))
953 /** Set the \b node's key into \b keyptr, if requested. */
954 #define MDB_GET_KEY(node, keyptr) { if ((keyptr) != NULL) { \
955 (keyptr)->mv_size = NODEKSZ(node); (keyptr)->mv_data = NODEKEY(node); } }
957 /** Set the \b node's key into \b key. */
958 #define MDB_GET_KEY2(node, key) { key.mv_size = NODEKSZ(node); key.mv_data = NODEKEY(node); }
960 /** Information about a single database in the environment. */
961 typedef struct MDB_db {
962 uint32_t md_pad; /**< also ksize for LEAF2 pages */
963 uint16_t md_flags; /**< @ref mdb_dbi_open */
964 uint16_t md_depth; /**< depth of this tree */
965 pgno_t md_branch_pages; /**< number of internal pages */
966 pgno_t md_leaf_pages; /**< number of leaf pages */
967 pgno_t md_overflow_pages; /**< number of overflow pages */
968 size_t md_entries; /**< number of data items */
969 pgno_t md_root; /**< the root page of this tree */
972 /** mdb_dbi_open flags */
973 #define MDB_VALID 0x8000 /**< DB handle is valid, for me_dbflags */
974 #define PERSISTENT_FLAGS (0xffff & ~(MDB_VALID))
975 #define VALID_FLAGS (MDB_REVERSEKEY|MDB_DUPSORT|MDB_INTEGERKEY|MDB_DUPFIXED|\
976 MDB_INTEGERDUP|MDB_REVERSEDUP|MDB_CREATE)
978 /** Handle for the DB used to track free pages. */
980 /** Handle for the default DB. */
982 /** Number of DBs in metapage (free and main) - also hardcoded elsewhere */
985 /** Number of meta pages - also hardcoded elsewhere */
988 /** Meta page content.
989 * A meta page is the start point for accessing a database snapshot.
990 * Pages 0-1 are meta pages. Transaction N writes meta page #(N % 2).
992 typedef struct MDB_meta {
993 /** Stamp identifying this as an LMDB file. It must be set
996 /** Version number of this file. Must be set to #MDB_DATA_VERSION. */
998 void *mm_address; /**< address for fixed mapping */
999 size_t mm_mapsize; /**< size of mmap region */
1000 MDB_db mm_dbs[CORE_DBS]; /**< first is free space, 2nd is main db */
1001 /** The size of pages used in this DB */
1002 #define mm_psize mm_dbs[FREE_DBI].md_pad
1003 /** Any persistent environment flags. @ref mdb_env */
1004 #define mm_flags mm_dbs[FREE_DBI].md_flags
1005 pgno_t mm_last_pg; /**< last used page in file */
1006 volatile txnid_t mm_txnid; /**< txnid that committed this page */
1009 /** Buffer for a stack-allocated meta page.
1010 * The members define size and alignment, and silence type
1011 * aliasing warnings. They are not used directly; that could
1012 * mean incorrectly using several union members in parallel.
1014 typedef union MDB_metabuf {
1017 char mm_pad[PAGEHDRSZ];
1022 /** Auxiliary DB info.
1023 * The information here is mostly static/read-only. There is
1024 * only a single copy of this record in the environment.
1026 typedef struct MDB_dbx {
1027 MDB_val md_name; /**< name of the database */
1028 MDB_cmp_func *md_cmp; /**< function for comparing keys */
1029 MDB_cmp_func *md_dcmp; /**< function for comparing data items */
1030 MDB_rel_func *md_rel; /**< user relocate function */
1031 void *md_relctx; /**< user-provided context for md_rel */
1034 /** A database transaction.
1035 * Every operation requires a transaction handle.
1038 MDB_txn *mt_parent; /**< parent of a nested txn */
1039 /** Nested txn under this txn, set together with flag #MDB_TXN_HAS_CHILD */
1041 pgno_t mt_next_pgno; /**< next unallocated page */
1042 /** The ID of this transaction. IDs are integers incrementing from 1.
1043 * Only committed write transactions increment the ID. If a transaction
1044 * aborts, the ID may be re-used by the next writer.
1047 MDB_env *mt_env; /**< the DB environment */
1048 /** The list of pages that became unused during this transaction.
1050 MDB_IDL mt_free_pgs;
1051 /** The list of loose pages that became unused and may be reused
1052 * in this transaction, linked through #NEXT_LOOSE_PAGE(page).
1054 MDB_page *mt_loose_pgs;
1055 /* #Number of loose pages (#mt_loose_pgs) */
1057 /** The sorted list of dirty pages we temporarily wrote to disk
1058 * because the dirty list was full. page numbers in here are
1059 * shifted left by 1, deleted slots have the LSB set.
1061 MDB_IDL mt_spill_pgs;
1063 /** For write txns: Modified pages. Sorted when not MDB_WRITEMAP. */
1064 MDB_ID2L dirty_list;
1065 /** For read txns: This thread/txn's reader table slot, or NULL. */
1068 /** Array of records for each DB known in the environment. */
1070 /** Array of MDB_db records for each known DB */
1072 /** Array of sequence numbers for each DB handle */
1073 unsigned int *mt_dbiseqs;
1074 /** @defgroup mt_dbflag Transaction DB Flags
1078 #define DB_DIRTY 0x01 /**< DB was modified or is DUPSORT data */
1079 #define DB_STALE 0x02 /**< Named-DB record is older than txnID */
1080 #define DB_NEW 0x04 /**< Named-DB handle opened in this txn */
1081 #define DB_VALID 0x08 /**< DB handle is valid, see also #MDB_VALID */
1082 #define DB_USRVALID 0x10 /**< As #DB_VALID, but not set for #FREE_DBI */
1084 /** In write txns, array of cursors for each DB */
1085 MDB_cursor **mt_cursors;
1086 /** Array of flags for each DB */
1087 unsigned char *mt_dbflags;
1088 /** Number of DB records in use, or 0 when the txn is finished.
1089 * This number only ever increments until the txn finishes; we
1090 * don't decrement it when individual DB handles are closed.
1094 /** @defgroup mdb_txn Transaction Flags
1098 /** #mdb_txn_begin() flags */
1099 #define MDB_TXN_BEGIN_FLAGS MDB_RDONLY
1100 #define MDB_TXN_RDONLY MDB_RDONLY /**< read-only transaction */
1101 /* internal txn flags */
1102 #define MDB_TXN_WRITEMAP MDB_WRITEMAP /**< copy of #MDB_env flag in writers */
1103 #define MDB_TXN_FINISHED 0x01 /**< txn is finished or never began */
1104 #define MDB_TXN_ERROR 0x02 /**< txn is unusable after an error */
1105 #define MDB_TXN_DIRTY 0x04 /**< must write, even if dirty list is empty */
1106 #define MDB_TXN_SPILLS 0x08 /**< txn or a parent has spilled pages */
1107 #define MDB_TXN_HAS_CHILD 0x10 /**< txn has an #MDB_txn.%mt_child */
1108 /** most operations on the txn are currently illegal */
1109 #define MDB_TXN_BLOCKED (MDB_TXN_FINISHED|MDB_TXN_ERROR|MDB_TXN_HAS_CHILD)
1111 unsigned int mt_flags; /**< @ref mdb_txn */
1112 /** #dirty_list room: Array size - \#dirty pages visible to this txn.
1113 * Includes ancestor txns' dirty pages not hidden by other txns'
1114 * dirty/spilled pages. Thus commit(nested txn) has room to merge
1115 * dirty_list into mt_parent after freeing hidden mt_parent pages.
1117 unsigned int mt_dirty_room;
1120 /** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty.
1121 * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to
1122 * raise this on a 64 bit machine.
1124 #define CURSOR_STACK 32
1128 /** Cursors are used for all DB operations.
1129 * A cursor holds a path of (page pointer, key index) from the DB
1130 * root to a position in the DB, plus other state. #MDB_DUPSORT
1131 * cursors include an xcursor to the current data item. Write txns
1132 * track their cursors and keep them up to date when data moves.
1133 * Exception: An xcursor's pointer to a #P_SUBP page can be stale.
1134 * (A node with #F_DUPDATA but no #F_SUBDATA contains a subpage).
1137 /** Next cursor on this DB in this txn */
1138 MDB_cursor *mc_next;
1139 /** Backup of the original cursor if this cursor is a shadow */
1140 MDB_cursor *mc_backup;
1141 /** Context used for databases with #MDB_DUPSORT, otherwise NULL */
1142 struct MDB_xcursor *mc_xcursor;
1143 /** The transaction that owns this cursor */
1145 /** The database handle this cursor operates on */
1147 /** The database record for this cursor */
1149 /** The database auxiliary record for this cursor */
1151 /** The @ref mt_dbflag for this database */
1152 unsigned char *mc_dbflag;
1153 unsigned short mc_snum; /**< number of pushed pages */
1154 unsigned short mc_top; /**< index of top page, normally mc_snum-1 */
1155 /** @defgroup mdb_cursor Cursor Flags
1157 * Cursor state flags.
1160 #define C_INITIALIZED 0x01 /**< cursor has been initialized and is valid */
1161 #define C_EOF 0x02 /**< No more data */
1162 #define C_SUB 0x04 /**< Cursor is a sub-cursor */
1163 #define C_DEL 0x08 /**< last op was a cursor_del */
1164 #define C_UNTRACK 0x40 /**< Un-track cursor when closing */
1166 unsigned int mc_flags; /**< @ref mdb_cursor */
1167 MDB_page *mc_pg[CURSOR_STACK]; /**< stack of pushed pages */
1168 indx_t mc_ki[CURSOR_STACK]; /**< stack of page indices */
1171 /** Context for sorted-dup records.
1172 * We could have gone to a fully recursive design, with arbitrarily
1173 * deep nesting of sub-databases. But for now we only handle these
1174 * levels - main DB, optional sub-DB, sorted-duplicate DB.
1176 typedef struct MDB_xcursor {
1177 /** A sub-cursor for traversing the Dup DB */
1178 MDB_cursor mx_cursor;
1179 /** The database record for this Dup DB */
1181 /** The auxiliary DB record for this Dup DB */
1183 /** The @ref mt_dbflag for this Dup DB */
1184 unsigned char mx_dbflag;
1187 /** State of FreeDB old pages, stored in the MDB_env */
1188 typedef struct MDB_pgstate {
1189 pgno_t *mf_pghead; /**< Reclaimed freeDB pages, or NULL before use */
1190 txnid_t mf_pglast; /**< ID of last used record, or 0 if !mf_pghead */
1193 /** The database environment. */
1195 HANDLE me_fd; /**< The main data file */
1196 HANDLE me_lfd; /**< The lock file */
1197 HANDLE me_mfd; /**< just for writing the meta pages */
1198 /** Failed to update the meta page. Probably an I/O error. */
1199 #define MDB_FATAL_ERROR 0x80000000U
1200 /** Some fields are initialized. */
1201 #define MDB_ENV_ACTIVE 0x20000000U
1202 /** me_txkey is set */
1203 #define MDB_ENV_TXKEY 0x10000000U
1204 /** fdatasync is unreliable */
1205 #define MDB_FSYNCONLY 0x08000000U
1206 uint32_t me_flags; /**< @ref mdb_env */
1207 unsigned int me_psize; /**< DB page size, inited from me_os_psize */
1208 unsigned int me_os_psize; /**< OS page size, from #GET_PAGESIZE */
1209 unsigned int me_maxreaders; /**< size of the reader table */
1210 /** Max #MDB_txninfo.%mti_numreaders of interest to #mdb_env_close() */
1211 volatile int me_close_readers;
1212 MDB_dbi me_numdbs; /**< number of DBs opened */
1213 MDB_dbi me_maxdbs; /**< size of the DB table */
1214 MDB_PID_T me_pid; /**< process ID of this env */
1215 char *me_path; /**< path to the DB files */
1216 char *me_map; /**< the memory map of the data file */
1217 MDB_txninfo *me_txns; /**< the memory map of the lock file or NULL */
1218 MDB_meta *me_metas[NUM_METAS]; /**< pointers to the two meta pages */
1219 void *me_pbuf; /**< scratch area for DUPSORT put() */
1220 MDB_txn *me_txn; /**< current write transaction */
1221 MDB_txn *me_txn0; /**< prealloc'd write transaction */
1222 size_t me_mapsize; /**< size of the data memory map */
1223 off_t me_size; /**< current file size */
1224 pgno_t me_maxpg; /**< me_mapsize / me_psize */
1225 MDB_dbx *me_dbxs; /**< array of static DB info */
1226 uint16_t *me_dbflags; /**< array of flags from MDB_db.md_flags */
1227 unsigned int *me_dbiseqs; /**< array of dbi sequence numbers */
1228 pthread_key_t me_txkey; /**< thread-key for readers */
1229 txnid_t me_pgoldest; /**< ID of oldest reader last time we looked */
1230 MDB_pgstate me_pgstate; /**< state of old pages from freeDB */
1231 # define me_pglast me_pgstate.mf_pglast
1232 # define me_pghead me_pgstate.mf_pghead
1233 MDB_page *me_dpages; /**< list of malloc'd blocks for re-use */
1234 /** IDL of pages that became unused in a write txn */
1235 MDB_IDL me_free_pgs;
1236 /** ID2L of pages written during a write txn. Length MDB_IDL_UM_SIZE. */
1237 MDB_ID2L me_dirty_list;
1238 /** Max number of freelist items that can fit in a single overflow page */
1240 /** Max size of a node on a page */
1241 unsigned int me_nodemax;
1242 #if !(MDB_MAXKEYSIZE)
1243 unsigned int me_maxkey; /**< max size of a key */
1245 int me_live_reader; /**< have liveness lock in reader table */
1247 int me_pidquery; /**< Used in OpenProcess */
1249 #ifdef MDB_USE_POSIX_MUTEX /* Posix mutexes reside in shared mem */
1250 # define me_rmutex me_txns->mti_rmutex /**< Shared reader lock */
1251 # define me_wmutex me_txns->mti_wmutex /**< Shared writer lock */
1253 mdb_mutex_t me_rmutex;
1254 mdb_mutex_t me_wmutex;
1256 void *me_userctx; /**< User-settable context */
1257 MDB_assert_func *me_assert_func; /**< Callback for assertion failures */
1260 /** Nested transaction */
1261 typedef struct MDB_ntxn {
1262 MDB_txn mnt_txn; /**< the transaction */
1263 MDB_pgstate mnt_pgstate; /**< parent transaction's saved freestate */
1266 /** max number of pages to commit in one writev() call */
1267 #define MDB_COMMIT_PAGES 64
1268 #if defined(IOV_MAX) && IOV_MAX < MDB_COMMIT_PAGES
1269 #undef MDB_COMMIT_PAGES
1270 #define MDB_COMMIT_PAGES IOV_MAX
1273 /** max bytes to write in one call */
1274 #define MAX_WRITE (0x80000000U >> (sizeof(ssize_t) == 4))
1276 /** Check \b txn and \b dbi arguments to a function */
1277 #define TXN_DBI_EXIST(txn, dbi, validity) \
1278 ((txn) && (dbi)<(txn)->mt_numdbs && ((txn)->mt_dbflags[dbi] & (validity)))
1280 /** Check for misused \b dbi handles */
1281 #define TXN_DBI_CHANGED(txn, dbi) \
1282 ((txn)->mt_dbiseqs[dbi] != (txn)->mt_env->me_dbiseqs[dbi])
1284 static int mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp);
1285 static int mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp);
1286 static int mdb_page_touch(MDB_cursor *mc);
1288 #define MDB_END_NAMES {"committed", "empty-commit", "abort", "reset", \
1289 "reset-tmp", "fail-begin", "fail-beginchild"}
1291 /* mdb_txn_end operation number, for logging */
1292 MDB_END_COMMITTED, MDB_END_EMPTY_COMMIT, MDB_END_ABORT, MDB_END_RESET,
1293 MDB_END_RESET_TMP, MDB_END_FAIL_BEGIN, MDB_END_FAIL_BEGINCHILD
1295 #define MDB_END_OPMASK 0x0F /**< mask for #mdb_txn_end() operation number */
1296 #define MDB_END_UPDATE 0x10 /**< update env state (DBIs) */
1297 #define MDB_END_FREE 0x20 /**< free txn unless it is #MDB_env.%me_txn0 */
1298 #define MDB_END_SLOT MDB_NOTLS /**< release any reader slot if #MDB_NOTLS */
1299 static void mdb_txn_end(MDB_txn *txn, unsigned mode);
1301 static int mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **mp, int *lvl);
1302 static int mdb_page_search_root(MDB_cursor *mc,
1303 MDB_val *key, int modify);
1304 #define MDB_PS_MODIFY 1
1305 #define MDB_PS_ROOTONLY 2
1306 #define MDB_PS_FIRST 4
1307 #define MDB_PS_LAST 8
1308 static int mdb_page_search(MDB_cursor *mc,
1309 MDB_val *key, int flags);
1310 static int mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst);
1312 #define MDB_SPLIT_REPLACE MDB_APPENDDUP /**< newkey is not new */
1313 static int mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,
1314 pgno_t newpgno, unsigned int nflags);
1316 static int mdb_env_read_header(MDB_env *env, MDB_meta *meta);
1317 static MDB_meta *mdb_env_pick_meta(const MDB_env *env);
1318 static int mdb_env_write_meta(MDB_txn *txn);
1319 #ifdef MDB_USE_POSIX_MUTEX /* Drop unused excl arg */
1320 # define mdb_env_close0(env, excl) mdb_env_close1(env)
1322 static void mdb_env_close0(MDB_env *env, int excl);
1324 static MDB_node *mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp);
1325 static int mdb_node_add(MDB_cursor *mc, indx_t indx,
1326 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags);
1327 static void mdb_node_del(MDB_cursor *mc, int ksize);
1328 static void mdb_node_shrink(MDB_page *mp, indx_t indx);
1329 static int mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft);
1330 static int mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data);
1331 static size_t mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data);
1332 static size_t mdb_branch_size(MDB_env *env, MDB_val *key);
1334 static int mdb_rebalance(MDB_cursor *mc);
1335 static int mdb_update_key(MDB_cursor *mc, MDB_val *key);
1337 static void mdb_cursor_pop(MDB_cursor *mc);
1338 static int mdb_cursor_push(MDB_cursor *mc, MDB_page *mp);
1340 static int mdb_cursor_del0(MDB_cursor *mc);
1341 static int mdb_del0(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned flags);
1342 static int mdb_cursor_sibling(MDB_cursor *mc, int move_right);
1343 static int mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1344 static int mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1345 static int mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op,
1347 static int mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1348 static int mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1350 static void mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);
1351 static void mdb_xcursor_init0(MDB_cursor *mc);
1352 static void mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node);
1353 static void mdb_xcursor_init2(MDB_cursor *mc, MDB_xcursor *src_mx, int force);
1355 static int mdb_drop0(MDB_cursor *mc, int subs);
1356 static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi);
1357 static int mdb_reader_check0(MDB_env *env, int rlocked, int *dead);
1360 static MDB_cmp_func mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long;
1363 /** Compare two items pointing at size_t's of unknown alignment. */
1364 #ifdef MISALIGNED_OK
1365 # define mdb_cmp_clong mdb_cmp_long
1367 # define mdb_cmp_clong mdb_cmp_cint
1371 static SECURITY_DESCRIPTOR mdb_null_sd;
1372 static SECURITY_ATTRIBUTES mdb_all_sa;
1373 static int mdb_sec_inited;
1375 static int utf8_to_utf16(const char *src, int srcsize, wchar_t **dst, int *dstsize);
1378 /** Return the library version info. */
1380 mdb_version(int *major, int *minor, int *patch)
1382 if (major) *major = MDB_VERSION_MAJOR;
1383 if (minor) *minor = MDB_VERSION_MINOR;
1384 if (patch) *patch = MDB_VERSION_PATCH;
1385 return MDB_VERSION_STRING;
1388 /** Table of descriptions for LMDB @ref errors */
1389 static char *const mdb_errstr[] = {
1390 "MDB_KEYEXIST: Key/data pair already exists",
1391 "MDB_NOTFOUND: No matching key/data pair found",
1392 "MDB_PAGE_NOTFOUND: Requested page not found",
1393 "MDB_CORRUPTED: Located page was wrong type",
1394 "MDB_PANIC: Update of meta page failed or environment had fatal error",
1395 "MDB_VERSION_MISMATCH: Database environment version mismatch",
1396 "MDB_INVALID: File is not an LMDB file",
1397 "MDB_MAP_FULL: Environment mapsize limit reached",
1398 "MDB_DBS_FULL: Environment maxdbs limit reached",
1399 "MDB_READERS_FULL: Environment maxreaders limit reached",
1400 "MDB_TLS_FULL: Thread-local storage keys full - too many environments open",
1401 "MDB_TXN_FULL: Transaction has too many dirty pages - transaction too big",
1402 "MDB_CURSOR_FULL: Internal error - cursor stack limit reached",
1403 "MDB_PAGE_FULL: Internal error - page has no more space",
1404 "MDB_MAP_RESIZED: Database contents grew beyond environment mapsize",
1405 "MDB_INCOMPATIBLE: Operation and DB incompatible, or DB flags changed",
1406 "MDB_BAD_RSLOT: Invalid reuse of reader locktable slot",
1407 "MDB_BAD_TXN: Transaction must abort, has a child, or is invalid",
1408 "MDB_BAD_VALSIZE: Unsupported size of key/DB name/data, or wrong DUPFIXED size",
1409 "MDB_BAD_DBI: The specified DBI handle was closed/changed unexpectedly",
1413 mdb_strerror(int err)
1416 /** HACK: pad 4KB on stack over the buf. Return system msgs in buf.
1417 * This works as long as no function between the call to mdb_strerror
1418 * and the actual use of the message uses more than 4K of stack.
1421 char buf[1024], *ptr = buf;
1425 return ("Successful return: 0");
1427 if (err >= MDB_KEYEXIST && err <= MDB_LAST_ERRCODE) {
1428 i = err - MDB_KEYEXIST;
1429 return mdb_errstr[i];
1433 /* These are the C-runtime error codes we use. The comment indicates
1434 * their numeric value, and the Win32 error they would correspond to
1435 * if the error actually came from a Win32 API. A major mess, we should
1436 * have used LMDB-specific error codes for everything.
1439 case ENOENT: /* 2, FILE_NOT_FOUND */
1440 case EIO: /* 5, ACCESS_DENIED */
1441 case ENOMEM: /* 12, INVALID_ACCESS */
1442 case EACCES: /* 13, INVALID_DATA */
1443 case EBUSY: /* 16, CURRENT_DIRECTORY */
1444 case EINVAL: /* 22, BAD_COMMAND */
1445 case ENOSPC: /* 28, OUT_OF_PAPER */
1446 return strerror(err);
1451 FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM |
1452 FORMAT_MESSAGE_IGNORE_INSERTS,
1453 NULL, err, 0, ptr, sizeof(buf), (va_list *)pad);
1456 return strerror(err);
1460 /** assert(3) variant in cursor context */
1461 #define mdb_cassert(mc, expr) mdb_assert0((mc)->mc_txn->mt_env, expr, #expr)
1462 /** assert(3) variant in transaction context */
1463 #define mdb_tassert(txn, expr) mdb_assert0((txn)->mt_env, expr, #expr)
1464 /** assert(3) variant in environment context */
1465 #define mdb_eassert(env, expr) mdb_assert0(env, expr, #expr)
1468 # define mdb_assert0(env, expr, expr_txt) ((expr) ? (void)0 : \
1469 mdb_assert_fail(env, expr_txt, mdb_func_, __FILE__, __LINE__))
1472 mdb_assert_fail(MDB_env *env, const char *expr_txt,
1473 const char *func, const char *file, int line)
1476 sprintf(buf, "%.100s:%d: Assertion '%.200s' failed in %.40s()",
1477 file, line, expr_txt, func);
1478 if (env->me_assert_func)
1479 env->me_assert_func(env, buf);
1480 fprintf(stderr, "%s\n", buf);
1484 # define mdb_assert0(env, expr, expr_txt) ((void) 0)
1488 /** Return the page number of \b mp which may be sub-page, for debug output */
1490 mdb_dbg_pgno(MDB_page *mp)
1493 COPY_PGNO(ret, mp->mp_pgno);
1497 /** Display a key in hexadecimal and return the address of the result.
1498 * @param[in] key the key to display
1499 * @param[in] buf the buffer to write into. Should always be #DKBUF.
1500 * @return The key in hexadecimal form.
1503 mdb_dkey(MDB_val *key, char *buf)
1506 unsigned char *c = key->mv_data;
1512 if (key->mv_size > DKBUF_MAXKEYSIZE)
1513 return "MDB_MAXKEYSIZE";
1514 /* may want to make this a dynamic check: if the key is mostly
1515 * printable characters, print it as-is instead of converting to hex.
1519 for (i=0; i<key->mv_size; i++)
1520 ptr += sprintf(ptr, "%02x", *c++);
1522 sprintf(buf, "%.*s", key->mv_size, key->mv_data);
1528 mdb_leafnode_type(MDB_node *n)
1530 static char *const tp[2][2] = {{"", ": DB"}, {": sub-page", ": sub-DB"}};
1531 return F_ISSET(n->mn_flags, F_BIGDATA) ? ": overflow page" :
1532 tp[F_ISSET(n->mn_flags, F_DUPDATA)][F_ISSET(n->mn_flags, F_SUBDATA)];
1535 /** Display all the keys in the page. */
1537 mdb_page_list(MDB_page *mp)
1539 pgno_t pgno = mdb_dbg_pgno(mp);
1540 const char *type, *state = (mp->mp_flags & P_DIRTY) ? ", dirty" : "";
1542 unsigned int i, nkeys, nsize, total = 0;
1546 switch (mp->mp_flags & (P_BRANCH|P_LEAF|P_LEAF2|P_META|P_OVERFLOW|P_SUBP)) {
1547 case P_BRANCH: type = "Branch page"; break;
1548 case P_LEAF: type = "Leaf page"; break;
1549 case P_LEAF|P_SUBP: type = "Sub-page"; break;
1550 case P_LEAF|P_LEAF2: type = "LEAF2 page"; break;
1551 case P_LEAF|P_LEAF2|P_SUBP: type = "LEAF2 sub-page"; break;
1553 fprintf(stderr, "Overflow page %"Z"u pages %u%s\n",
1554 pgno, mp->mp_pages, state);
1557 fprintf(stderr, "Meta-page %"Z"u txnid %"Z"u\n",
1558 pgno, ((MDB_meta *)METADATA(mp))->mm_txnid);
1561 fprintf(stderr, "Bad page %"Z"u flags 0x%u\n", pgno, mp->mp_flags);
1565 nkeys = NUMKEYS(mp);
1566 fprintf(stderr, "%s %"Z"u numkeys %d%s\n", type, pgno, nkeys, state);
1568 for (i=0; i<nkeys; i++) {
1569 if (IS_LEAF2(mp)) { /* LEAF2 pages have no mp_ptrs[] or node headers */
1570 key.mv_size = nsize = mp->mp_pad;
1571 key.mv_data = LEAF2KEY(mp, i, nsize);
1573 fprintf(stderr, "key %d: nsize %d, %s\n", i, nsize, DKEY(&key));
1576 node = NODEPTR(mp, i);
1577 key.mv_size = node->mn_ksize;
1578 key.mv_data = node->mn_data;
1579 nsize = NODESIZE + key.mv_size;
1580 if (IS_BRANCH(mp)) {
1581 fprintf(stderr, "key %d: page %"Z"u, %s\n", i, NODEPGNO(node),
1585 if (F_ISSET(node->mn_flags, F_BIGDATA))
1586 nsize += sizeof(pgno_t);
1588 nsize += NODEDSZ(node);
1590 nsize += sizeof(indx_t);
1591 fprintf(stderr, "key %d: nsize %d, %s%s\n",
1592 i, nsize, DKEY(&key), mdb_leafnode_type(node));
1594 total = EVEN(total);
1596 fprintf(stderr, "Total: header %d + contents %d + unused %d\n",
1597 IS_LEAF2(mp) ? PAGEHDRSZ : PAGEBASE + mp->mp_lower, total, SIZELEFT(mp));
1601 mdb_cursor_chk(MDB_cursor *mc)
1607 if (!mc->mc_snum || !(mc->mc_flags & C_INITIALIZED)) return;
1608 for (i=0; i<mc->mc_top; i++) {
1610 node = NODEPTR(mp, mc->mc_ki[i]);
1611 if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno)
1614 if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i]))
1620 /** Count all the pages in each DB and in the freelist
1621 * and make sure it matches the actual number of pages
1623 * All named DBs must be open for a correct count.
1625 static void mdb_audit(MDB_txn *txn)
1629 MDB_ID freecount, count;
1634 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
1635 while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
1636 freecount += *(MDB_ID *)data.mv_data;
1637 mdb_tassert(txn, rc == MDB_NOTFOUND);
1640 for (i = 0; i<txn->mt_numdbs; i++) {
1642 if (!(txn->mt_dbflags[i] & DB_VALID))
1644 mdb_cursor_init(&mc, txn, i, &mx);
1645 if (txn->mt_dbs[i].md_root == P_INVALID)
1647 count += txn->mt_dbs[i].md_branch_pages +
1648 txn->mt_dbs[i].md_leaf_pages +
1649 txn->mt_dbs[i].md_overflow_pages;
1650 if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) {
1651 rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST);
1652 for (; rc == MDB_SUCCESS; rc = mdb_cursor_sibling(&mc, 1)) {
1655 mp = mc.mc_pg[mc.mc_top];
1656 for (j=0; j<NUMKEYS(mp); j++) {
1657 MDB_node *leaf = NODEPTR(mp, j);
1658 if (leaf->mn_flags & F_SUBDATA) {
1660 memcpy(&db, NODEDATA(leaf), sizeof(db));
1661 count += db.md_branch_pages + db.md_leaf_pages +
1662 db.md_overflow_pages;
1666 mdb_tassert(txn, rc == MDB_NOTFOUND);
1669 if (freecount + count + NUM_METAS != txn->mt_next_pgno) {
1670 fprintf(stderr, "audit: %lu freecount: %lu count: %lu total: %lu next_pgno: %lu\n",
1671 txn->mt_txnid, freecount, count+NUM_METAS,
1672 freecount+count+NUM_METAS, txn->mt_next_pgno);
1678 mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1680 return txn->mt_dbxs[dbi].md_cmp(a, b);
1684 mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1686 MDB_cmp_func *dcmp = txn->mt_dbxs[dbi].md_dcmp;
1687 #if UINT_MAX < SIZE_MAX
1688 if (dcmp == mdb_cmp_int && a->mv_size == sizeof(size_t))
1689 dcmp = mdb_cmp_clong;
1694 /** Allocate memory for a page.
1695 * Re-use old malloc'd pages first for singletons, otherwise just malloc.
1698 mdb_page_malloc(MDB_txn *txn, unsigned num)
1700 MDB_env *env = txn->mt_env;
1701 MDB_page *ret = env->me_dpages;
1702 size_t psize = env->me_psize, sz = psize, off;
1703 /* For ! #MDB_NOMEMINIT, psize counts how much to init.
1704 * For a single page alloc, we init everything after the page header.
1705 * For multi-page, we init the final page; if the caller needed that
1706 * many pages they will be filling in at least up to the last page.
1710 VGMEMP_ALLOC(env, ret, sz);
1711 VGMEMP_DEFINED(ret, sizeof(ret->mp_next));
1712 env->me_dpages = ret->mp_next;
1715 psize -= off = PAGEHDRSZ;
1720 if ((ret = malloc(sz)) != NULL) {
1721 VGMEMP_ALLOC(env, ret, sz);
1722 if (!(env->me_flags & MDB_NOMEMINIT)) {
1723 memset((char *)ret + off, 0, psize);
1727 txn->mt_flags |= MDB_TXN_ERROR;
1731 /** Free a single page.
1732 * Saves single pages to a list, for future reuse.
1733 * (This is not used for multi-page overflow pages.)
1736 mdb_page_free(MDB_env *env, MDB_page *mp)
1738 mp->mp_next = env->me_dpages;
1739 VGMEMP_FREE(env, mp);
1740 env->me_dpages = mp;
1743 /** Free a dirty page */
1745 mdb_dpage_free(MDB_env *env, MDB_page *dp)
1747 if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
1748 mdb_page_free(env, dp);
1750 /* large pages just get freed directly */
1751 VGMEMP_FREE(env, dp);
1756 /** Return all dirty pages to dpage list */
1758 mdb_dlist_free(MDB_txn *txn)
1760 MDB_env *env = txn->mt_env;
1761 MDB_ID2L dl = txn->mt_u.dirty_list;
1762 unsigned i, n = dl[0].mid;
1764 for (i = 1; i <= n; i++) {
1765 mdb_dpage_free(env, dl[i].mptr);
1770 /** Loosen or free a single page.
1771 * Saves single pages to a list for future reuse
1772 * in this same txn. It has been pulled from the freeDB
1773 * and already resides on the dirty list, but has been
1774 * deleted. Use these pages first before pulling again
1777 * If the page wasn't dirtied in this txn, just add it
1778 * to this txn's free list.
1781 mdb_page_loose(MDB_cursor *mc, MDB_page *mp)
1784 pgno_t pgno = mp->mp_pgno;
1785 MDB_txn *txn = mc->mc_txn;
1787 if ((mp->mp_flags & P_DIRTY) && mc->mc_dbi != FREE_DBI) {
1788 if (txn->mt_parent) {
1789 MDB_ID2 *dl = txn->mt_u.dirty_list;
1790 /* If txn has a parent, make sure the page is in our
1794 unsigned x = mdb_mid2l_search(dl, pgno);
1795 if (x <= dl[0].mid && dl[x].mid == pgno) {
1796 if (mp != dl[x].mptr) { /* bad cursor? */
1797 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
1798 txn->mt_flags |= MDB_TXN_ERROR;
1799 return MDB_CORRUPTED;
1806 /* no parent txn, so it's just ours */
1811 DPRINTF(("loosen db %d page %"Z"u", DDBI(mc),
1813 NEXT_LOOSE_PAGE(mp) = txn->mt_loose_pgs;
1814 txn->mt_loose_pgs = mp;
1815 txn->mt_loose_count++;
1816 mp->mp_flags |= P_LOOSE;
1818 int rc = mdb_midl_append(&txn->mt_free_pgs, pgno);
1826 /** Set or clear P_KEEP in dirty, non-overflow, non-sub pages watched by txn.
1827 * @param[in] mc A cursor handle for the current operation.
1828 * @param[in] pflags Flags of the pages to update:
1829 * P_DIRTY to set P_KEEP, P_DIRTY|P_KEEP to clear it.
1830 * @param[in] all No shortcuts. Needed except after a full #mdb_page_flush().
1831 * @return 0 on success, non-zero on failure.
1834 mdb_pages_xkeep(MDB_cursor *mc, unsigned pflags, int all)
1836 enum { Mask = P_SUBP|P_DIRTY|P_LOOSE|P_KEEP };
1837 MDB_txn *txn = mc->mc_txn;
1843 int rc = MDB_SUCCESS, level;
1845 /* Mark pages seen by cursors */
1846 if (mc->mc_flags & C_UNTRACK)
1847 mc = NULL; /* will find mc in mt_cursors */
1848 for (i = txn->mt_numdbs;; mc = txn->mt_cursors[--i]) {
1849 for (; mc; mc=mc->mc_next) {
1850 if (!(mc->mc_flags & C_INITIALIZED))
1852 for (m3 = mc;; m3 = &mx->mx_cursor) {
1854 for (j=0; j<m3->mc_snum; j++) {
1856 if ((mp->mp_flags & Mask) == pflags)
1857 mp->mp_flags ^= P_KEEP;
1859 mx = m3->mc_xcursor;
1860 /* Proceed to mx if it is at a sub-database */
1861 if (! (mx && (mx->mx_cursor.mc_flags & C_INITIALIZED)))
1863 if (! (mp && (mp->mp_flags & P_LEAF)))
1865 leaf = NODEPTR(mp, m3->mc_ki[j-1]);
1866 if (!(leaf->mn_flags & F_SUBDATA))
1875 /* Mark dirty root pages */
1876 for (i=0; i<txn->mt_numdbs; i++) {
1877 if (txn->mt_dbflags[i] & DB_DIRTY) {
1878 pgno_t pgno = txn->mt_dbs[i].md_root;
1879 if (pgno == P_INVALID)
1881 if ((rc = mdb_page_get(txn, pgno, &dp, &level)) != MDB_SUCCESS)
1883 if ((dp->mp_flags & Mask) == pflags && level <= 1)
1884 dp->mp_flags ^= P_KEEP;
1892 static int mdb_page_flush(MDB_txn *txn, int keep);
1894 /** Spill pages from the dirty list back to disk.
1895 * This is intended to prevent running into #MDB_TXN_FULL situations,
1896 * but note that they may still occur in a few cases:
1897 * 1) our estimate of the txn size could be too small. Currently this
1898 * seems unlikely, except with a large number of #MDB_MULTIPLE items.
1899 * 2) child txns may run out of space if their parents dirtied a
1900 * lot of pages and never spilled them. TODO: we probably should do
1901 * a preemptive spill during #mdb_txn_begin() of a child txn, if
1902 * the parent's dirty_room is below a given threshold.
1904 * Otherwise, if not using nested txns, it is expected that apps will
1905 * not run into #MDB_TXN_FULL any more. The pages are flushed to disk
1906 * the same way as for a txn commit, e.g. their P_DIRTY flag is cleared.
1907 * If the txn never references them again, they can be left alone.
1908 * If the txn only reads them, they can be used without any fuss.
1909 * If the txn writes them again, they can be dirtied immediately without
1910 * going thru all of the work of #mdb_page_touch(). Such references are
1911 * handled by #mdb_page_unspill().
1913 * Also note, we never spill DB root pages, nor pages of active cursors,
1914 * because we'll need these back again soon anyway. And in nested txns,
1915 * we can't spill a page in a child txn if it was already spilled in a
1916 * parent txn. That would alter the parent txns' data even though
1917 * the child hasn't committed yet, and we'd have no way to undo it if
1918 * the child aborted.
1920 * @param[in] m0 cursor A cursor handle identifying the transaction and
1921 * database for which we are checking space.
1922 * @param[in] key For a put operation, the key being stored.
1923 * @param[in] data For a put operation, the data being stored.
1924 * @return 0 on success, non-zero on failure.
1927 mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
1929 MDB_txn *txn = m0->mc_txn;
1931 MDB_ID2L dl = txn->mt_u.dirty_list;
1932 unsigned int i, j, need;
1935 if (m0->mc_flags & C_SUB)
1938 /* Estimate how much space this op will take */
1939 i = m0->mc_db->md_depth;
1940 /* Named DBs also dirty the main DB */
1941 if (m0->mc_dbi >= CORE_DBS)
1942 i += txn->mt_dbs[MAIN_DBI].md_depth;
1943 /* For puts, roughly factor in the key+data size */
1945 i += (LEAFSIZE(key, data) + txn->mt_env->me_psize) / txn->mt_env->me_psize;
1946 i += i; /* double it for good measure */
1949 if (txn->mt_dirty_room > i)
1952 if (!txn->mt_spill_pgs) {
1953 txn->mt_spill_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX);
1954 if (!txn->mt_spill_pgs)
1957 /* purge deleted slots */
1958 MDB_IDL sl = txn->mt_spill_pgs;
1959 unsigned int num = sl[0];
1961 for (i=1; i<=num; i++) {
1968 /* Preserve pages which may soon be dirtied again */
1969 if ((rc = mdb_pages_xkeep(m0, P_DIRTY, 1)) != MDB_SUCCESS)
1972 /* Less aggressive spill - we originally spilled the entire dirty list,
1973 * with a few exceptions for cursor pages and DB root pages. But this
1974 * turns out to be a lot of wasted effort because in a large txn many
1975 * of those pages will need to be used again. So now we spill only 1/8th
1976 * of the dirty pages. Testing revealed this to be a good tradeoff,
1977 * better than 1/2, 1/4, or 1/10.
1979 if (need < MDB_IDL_UM_MAX / 8)
1980 need = MDB_IDL_UM_MAX / 8;
1982 /* Save the page IDs of all the pages we're flushing */
1983 /* flush from the tail forward, this saves a lot of shifting later on. */
1984 for (i=dl[0].mid; i && need; i--) {
1985 MDB_ID pn = dl[i].mid << 1;
1987 if (dp->mp_flags & (P_LOOSE|P_KEEP))
1989 /* Can't spill twice, make sure it's not already in a parent's
1992 if (txn->mt_parent) {
1994 for (tx2 = txn->mt_parent; tx2; tx2 = tx2->mt_parent) {
1995 if (tx2->mt_spill_pgs) {
1996 j = mdb_midl_search(tx2->mt_spill_pgs, pn);
1997 if (j <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[j] == pn) {
1998 dp->mp_flags |= P_KEEP;
2006 if ((rc = mdb_midl_append(&txn->mt_spill_pgs, pn)))
2010 mdb_midl_sort(txn->mt_spill_pgs);
2012 /* Flush the spilled part of dirty list */
2013 if ((rc = mdb_page_flush(txn, i)) != MDB_SUCCESS)
2016 /* Reset any dirty pages we kept that page_flush didn't see */
2017 rc = mdb_pages_xkeep(m0, P_DIRTY|P_KEEP, i);
2020 txn->mt_flags |= rc ? MDB_TXN_ERROR : MDB_TXN_SPILLS;
2024 /** Find oldest txnid still referenced. Expects txn->mt_txnid > 0. */
2026 mdb_find_oldest(MDB_txn *txn)
2029 txnid_t mr, oldest = txn->mt_txnid - 1;
2030 if (txn->mt_env->me_txns) {
2031 MDB_reader *r = txn->mt_env->me_txns->mti_readers;
2032 for (i = txn->mt_env->me_txns->mti_numreaders; --i >= 0; ) {
2043 /** Add a page to the txn's dirty list */
2045 mdb_page_dirty(MDB_txn *txn, MDB_page *mp)
2048 int rc, (*insert)(MDB_ID2L, MDB_ID2 *);
2050 if (txn->mt_flags & MDB_TXN_WRITEMAP) {
2051 insert = mdb_mid2l_append;
2053 insert = mdb_mid2l_insert;
2055 mid.mid = mp->mp_pgno;
2057 rc = insert(txn->mt_u.dirty_list, &mid);
2058 mdb_tassert(txn, rc == 0);
2059 txn->mt_dirty_room--;
2062 /** Allocate page numbers and memory for writing. Maintain me_pglast,
2063 * me_pghead and mt_next_pgno.
2065 * If there are free pages available from older transactions, they
2066 * are re-used first. Otherwise allocate a new page at mt_next_pgno.
2067 * Do not modify the freedB, just merge freeDB records into me_pghead[]
2068 * and move me_pglast to say which records were consumed. Only this
2069 * function can create me_pghead and move me_pglast/mt_next_pgno.
2070 * @param[in] mc cursor A cursor handle identifying the transaction and
2071 * database for which we are allocating.
2072 * @param[in] num the number of pages to allocate.
2073 * @param[out] mp Address of the allocated page(s). Requests for multiple pages
2074 * will always be satisfied by a single contiguous chunk of memory.
2075 * @return 0 on success, non-zero on failure.
2078 mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
2080 #ifdef MDB_PARANOID /* Seems like we can ignore this now */
2081 /* Get at most <Max_retries> more freeDB records once me_pghead
2082 * has enough pages. If not enough, use new pages from the map.
2083 * If <Paranoid> and mc is updating the freeDB, only get new
2084 * records if me_pghead is empty. Then the freelist cannot play
2085 * catch-up with itself by growing while trying to save it.
2087 enum { Paranoid = 1, Max_retries = 500 };
2089 enum { Paranoid = 0, Max_retries = INT_MAX /*infinite*/ };
2091 int rc, retry = num * 60;
2092 MDB_txn *txn = mc->mc_txn;
2093 MDB_env *env = txn->mt_env;
2094 pgno_t pgno, *mop = env->me_pghead;
2095 unsigned i, j, mop_len = mop ? mop[0] : 0, n2 = num-1;
2097 txnid_t oldest = 0, last;
2102 /* If there are any loose pages, just use them */
2103 if (num == 1 && txn->mt_loose_pgs) {
2104 np = txn->mt_loose_pgs;
2105 txn->mt_loose_pgs = NEXT_LOOSE_PAGE(np);
2106 txn->mt_loose_count--;
2107 DPRINTF(("db %d use loose page %"Z"u", DDBI(mc),
2115 /* If our dirty list is already full, we can't do anything */
2116 if (txn->mt_dirty_room == 0) {
2121 for (op = MDB_FIRST;; op = MDB_NEXT) {
2126 /* Seek a big enough contiguous page range. Prefer
2127 * pages at the tail, just truncating the list.
2133 if (mop[i-n2] == pgno+n2)
2140 if (op == MDB_FIRST) { /* 1st iteration */
2141 /* Prepare to fetch more and coalesce */
2142 last = env->me_pglast;
2143 oldest = env->me_pgoldest;
2144 mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
2147 key.mv_data = &last; /* will look up last+1 */
2148 key.mv_size = sizeof(last);
2150 if (Paranoid && mc->mc_dbi == FREE_DBI)
2153 if (Paranoid && retry < 0 && mop_len)
2157 /* Do not fetch more if the record will be too recent */
2158 if (oldest <= last) {
2160 oldest = mdb_find_oldest(txn);
2161 env->me_pgoldest = oldest;
2167 rc = mdb_cursor_get(&m2, &key, NULL, op);
2169 if (rc == MDB_NOTFOUND)
2173 last = *(txnid_t*)key.mv_data;
2174 if (oldest <= last) {
2176 oldest = mdb_find_oldest(txn);
2177 env->me_pgoldest = oldest;
2183 np = m2.mc_pg[m2.mc_top];
2184 leaf = NODEPTR(np, m2.mc_ki[m2.mc_top]);
2185 if ((rc = mdb_node_read(txn, leaf, &data)) != MDB_SUCCESS)
2188 idl = (MDB_ID *) data.mv_data;
2191 if (!(env->me_pghead = mop = mdb_midl_alloc(i))) {
2196 if ((rc = mdb_midl_need(&env->me_pghead, i)) != 0)
2198 mop = env->me_pghead;
2200 env->me_pglast = last;
2202 DPRINTF(("IDL read txn %"Z"u root %"Z"u num %u",
2203 last, txn->mt_dbs[FREE_DBI].md_root, i));
2205 DPRINTF(("IDL %"Z"u", idl[j]));
2207 /* Merge in descending sorted order */
2208 mdb_midl_xmerge(mop, idl);
2212 /* Use new pages from the map when nothing suitable in the freeDB */
2214 pgno = txn->mt_next_pgno;
2215 if (pgno + num >= env->me_maxpg) {
2216 DPUTS("DB size maxed out");
2222 if (env->me_flags & MDB_WRITEMAP) {
2223 np = (MDB_page *)(env->me_map + env->me_psize * pgno);
2225 if (!(np = mdb_page_malloc(txn, num))) {
2231 mop[0] = mop_len -= num;
2232 /* Move any stragglers down */
2233 for (j = i-num; j < mop_len; )
2234 mop[++j] = mop[++i];
2236 txn->mt_next_pgno = pgno + num;
2239 mdb_page_dirty(txn, np);
2245 txn->mt_flags |= MDB_TXN_ERROR;
2249 /** Copy the used portions of a non-overflow page.
2250 * @param[in] dst page to copy into
2251 * @param[in] src page to copy from
2252 * @param[in] psize size of a page
2255 mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize)
2257 enum { Align = sizeof(pgno_t) };
2258 indx_t upper = src->mp_upper, lower = src->mp_lower, unused = upper-lower;
2260 /* If page isn't full, just copy the used portion. Adjust
2261 * alignment so memcpy may copy words instead of bytes.
2263 if ((unused &= -Align) && !IS_LEAF2(src)) {
2264 upper = (upper + PAGEBASE) & -Align;
2265 memcpy(dst, src, (lower + PAGEBASE + (Align-1)) & -Align);
2266 memcpy((pgno_t *)((char *)dst+upper), (pgno_t *)((char *)src+upper),
2269 memcpy(dst, src, psize - unused);
2273 /** Pull a page off the txn's spill list, if present.
2274 * If a page being referenced was spilled to disk in this txn, bring
2275 * it back and make it dirty/writable again.
2276 * @param[in] txn the transaction handle.
2277 * @param[in] mp the page being referenced. It must not be dirty.
2278 * @param[out] ret the writable page, if any. ret is unchanged if
2279 * mp wasn't spilled.
2282 mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret)
2284 MDB_env *env = txn->mt_env;
2287 pgno_t pgno = mp->mp_pgno, pn = pgno << 1;
2289 for (tx2 = txn; tx2; tx2=tx2->mt_parent) {
2290 if (!tx2->mt_spill_pgs)
2292 x = mdb_midl_search(tx2->mt_spill_pgs, pn);
2293 if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
2296 if (txn->mt_dirty_room == 0)
2297 return MDB_TXN_FULL;
2298 if (IS_OVERFLOW(mp))
2302 if (env->me_flags & MDB_WRITEMAP) {
2305 np = mdb_page_malloc(txn, num);
2309 memcpy(np, mp, num * env->me_psize);
2311 mdb_page_copy(np, mp, env->me_psize);
2314 /* If in current txn, this page is no longer spilled.
2315 * If it happens to be the last page, truncate the spill list.
2316 * Otherwise mark it as deleted by setting the LSB.
2318 if (x == txn->mt_spill_pgs[0])
2319 txn->mt_spill_pgs[0]--;
2321 txn->mt_spill_pgs[x] |= 1;
2322 } /* otherwise, if belonging to a parent txn, the
2323 * page remains spilled until child commits
2326 mdb_page_dirty(txn, np);
2327 np->mp_flags |= P_DIRTY;
2335 /** Touch a page: make it dirty and re-insert into tree with updated pgno.
2336 * @param[in] mc cursor pointing to the page to be touched
2337 * @return 0 on success, non-zero on failure.
2340 mdb_page_touch(MDB_cursor *mc)
2342 MDB_page *mp = mc->mc_pg[mc->mc_top], *np;
2343 MDB_txn *txn = mc->mc_txn;
2344 MDB_cursor *m2, *m3;
2348 if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
2349 if (txn->mt_flags & MDB_TXN_SPILLS) {
2351 rc = mdb_page_unspill(txn, mp, &np);
2357 if ((rc = mdb_midl_need(&txn->mt_free_pgs, 1)) ||
2358 (rc = mdb_page_alloc(mc, 1, &np)))
2361 DPRINTF(("touched db %d page %"Z"u -> %"Z"u", DDBI(mc),
2362 mp->mp_pgno, pgno));
2363 mdb_cassert(mc, mp->mp_pgno != pgno);
2364 mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
2365 /* Update the parent page, if any, to point to the new page */
2367 MDB_page *parent = mc->mc_pg[mc->mc_top-1];
2368 MDB_node *node = NODEPTR(parent, mc->mc_ki[mc->mc_top-1]);
2369 SETPGNO(node, pgno);
2371 mc->mc_db->md_root = pgno;
2373 } else if (txn->mt_parent && !IS_SUBP(mp)) {
2374 MDB_ID2 mid, *dl = txn->mt_u.dirty_list;
2376 /* If txn has a parent, make sure the page is in our
2380 unsigned x = mdb_mid2l_search(dl, pgno);
2381 if (x <= dl[0].mid && dl[x].mid == pgno) {
2382 if (mp != dl[x].mptr) { /* bad cursor? */
2383 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
2384 txn->mt_flags |= MDB_TXN_ERROR;
2385 return MDB_CORRUPTED;
2390 mdb_cassert(mc, dl[0].mid < MDB_IDL_UM_MAX);
2392 np = mdb_page_malloc(txn, 1);
2397 rc = mdb_mid2l_insert(dl, &mid);
2398 mdb_cassert(mc, rc == 0);
2403 mdb_page_copy(np, mp, txn->mt_env->me_psize);
2405 np->mp_flags |= P_DIRTY;
2408 /* Adjust cursors pointing to mp */
2409 mc->mc_pg[mc->mc_top] = np;
2410 m2 = txn->mt_cursors[mc->mc_dbi];
2411 if (mc->mc_flags & C_SUB) {
2412 for (; m2; m2=m2->mc_next) {
2413 m3 = &m2->mc_xcursor->mx_cursor;
2414 if (m3->mc_snum < mc->mc_snum) continue;
2415 if (m3->mc_pg[mc->mc_top] == mp)
2416 m3->mc_pg[mc->mc_top] = np;
2419 for (; m2; m2=m2->mc_next) {
2420 if (m2->mc_snum < mc->mc_snum) continue;
2421 if (m2->mc_pg[mc->mc_top] == mp) {
2422 m2->mc_pg[mc->mc_top] = np;
2423 if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
2425 m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top])
2427 MDB_node *leaf = NODEPTR(np, mc->mc_ki[mc->mc_top]);
2428 if (!(leaf->mn_flags & F_SUBDATA))
2429 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
2437 txn->mt_flags |= MDB_TXN_ERROR;
2442 mdb_env_sync(MDB_env *env, int force)
2445 if (env->me_flags & MDB_RDONLY)
2447 if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) {
2448 if (env->me_flags & MDB_WRITEMAP) {
2449 int flags = ((env->me_flags & MDB_MAPASYNC) && !force)
2450 ? MS_ASYNC : MS_SYNC;
2451 if (MDB_MSYNC(env->me_map, env->me_mapsize, flags))
2454 else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd))
2458 #ifdef BROKEN_FDATASYNC
2459 if (env->me_flags & MDB_FSYNCONLY) {
2460 if (fsync(env->me_fd))
2464 if (MDB_FDATASYNC(env->me_fd))
2471 /** Back up parent txn's cursors, then grab the originals for tracking */
2473 mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst)
2475 MDB_cursor *mc, *bk;
2480 for (i = src->mt_numdbs; --i >= 0; ) {
2481 if ((mc = src->mt_cursors[i]) != NULL) {
2482 size = sizeof(MDB_cursor);
2484 size += sizeof(MDB_xcursor);
2485 for (; mc; mc = bk->mc_next) {
2491 mc->mc_db = &dst->mt_dbs[i];
2492 /* Kill pointers into src to reduce abuse: The
2493 * user may not use mc until dst ends. But we need a valid
2494 * txn pointer here for cursor fixups to keep working.
2497 mc->mc_dbflag = &dst->mt_dbflags[i];
2498 if ((mx = mc->mc_xcursor) != NULL) {
2499 *(MDB_xcursor *)(bk+1) = *mx;
2500 mx->mx_cursor.mc_txn = dst;
2502 mc->mc_next = dst->mt_cursors[i];
2503 dst->mt_cursors[i] = mc;
2510 /** Close this write txn's cursors, give parent txn's cursors back to parent.
2511 * @param[in] txn the transaction handle.
2512 * @param[in] merge true to keep changes to parent cursors, false to revert.
2513 * @return 0 on success, non-zero on failure.
2516 mdb_cursors_close(MDB_txn *txn, unsigned merge)
2518 MDB_cursor **cursors = txn->mt_cursors, *mc, *next, *bk;
2522 for (i = txn->mt_numdbs; --i >= 0; ) {
2523 for (mc = cursors[i]; mc; mc = next) {
2525 if ((bk = mc->mc_backup) != NULL) {
2527 /* Commit changes to parent txn */
2528 mc->mc_next = bk->mc_next;
2529 mc->mc_backup = bk->mc_backup;
2530 mc->mc_txn = bk->mc_txn;
2531 mc->mc_db = bk->mc_db;
2532 mc->mc_dbflag = bk->mc_dbflag;
2533 if ((mx = mc->mc_xcursor) != NULL)
2534 mx->mx_cursor.mc_txn = bk->mc_txn;
2536 /* Abort nested txn */
2538 if ((mx = mc->mc_xcursor) != NULL)
2539 *mx = *(MDB_xcursor *)(bk+1);
2543 /* Only malloced cursors are permanently tracked. */
2550 #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
2556 Pidset = F_SETLK, Pidcheck = F_GETLK
2560 /** Set or check a pid lock. Set returns 0 on success.
2561 * Check returns 0 if the process is certainly dead, nonzero if it may
2562 * be alive (the lock exists or an error happened so we do not know).
2564 * On Windows Pidset is a no-op, we merely check for the existence
2565 * of the process with the given pid. On POSIX we use a single byte
2566 * lock on the lockfile, set at an offset equal to the pid.
2569 mdb_reader_pid(MDB_env *env, enum Pidlock_op op, MDB_PID_T pid)
2571 #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
2574 if (op == Pidcheck) {
2575 h = OpenProcess(env->me_pidquery, FALSE, pid);
2576 /* No documented "no such process" code, but other program use this: */
2578 return ErrCode() != ERROR_INVALID_PARAMETER;
2579 /* A process exists until all handles to it close. Has it exited? */
2580 ret = WaitForSingleObject(h, 0) != 0;
2587 struct flock lock_info;
2588 memset(&lock_info, 0, sizeof(lock_info));
2589 lock_info.l_type = F_WRLCK;
2590 lock_info.l_whence = SEEK_SET;
2591 lock_info.l_start = pid;
2592 lock_info.l_len = 1;
2593 if ((rc = fcntl(env->me_lfd, op, &lock_info)) == 0) {
2594 if (op == F_GETLK && lock_info.l_type != F_UNLCK)
2596 } else if ((rc = ErrCode()) == EINTR) {
2604 /** Common code for #mdb_txn_begin() and #mdb_txn_renew().
2605 * @param[in] txn the transaction handle to initialize
2606 * @return 0 on success, non-zero on failure.
2609 mdb_txn_renew0(MDB_txn *txn)
2611 MDB_env *env = txn->mt_env;
2612 MDB_txninfo *ti = env->me_txns;
2614 unsigned int i, nr, flags = txn->mt_flags;
2616 int rc, new_notls = 0;
2618 if ((flags &= MDB_TXN_RDONLY) != 0) {
2620 meta = mdb_env_pick_meta(env);
2621 txn->mt_txnid = meta->mm_txnid;
2622 txn->mt_u.reader = NULL;
2624 MDB_reader *r = (env->me_flags & MDB_NOTLS) ? txn->mt_u.reader :
2625 pthread_getspecific(env->me_txkey);
2627 if (r->mr_pid != env->me_pid || r->mr_txnid != (txnid_t)-1)
2628 return MDB_BAD_RSLOT;
2630 MDB_PID_T pid = env->me_pid;
2631 MDB_THR_T tid = pthread_self();
2632 mdb_mutexref_t rmutex = env->me_rmutex;
2634 if (!env->me_live_reader) {
2635 rc = mdb_reader_pid(env, Pidset, pid);
2638 env->me_live_reader = 1;
2641 if (LOCK_MUTEX(rc, env, rmutex))
2643 nr = ti->mti_numreaders;
2644 for (i=0; i<nr; i++)
2645 if (ti->mti_readers[i].mr_pid == 0)
2647 if (i == env->me_maxreaders) {
2648 UNLOCK_MUTEX(rmutex);
2649 return MDB_READERS_FULL;
2651 r = &ti->mti_readers[i];
2652 /* Claim the reader slot, carefully since other code
2653 * uses the reader table un-mutexed: First reset the
2654 * slot, next publish it in mti_numreaders. After
2655 * that, it is safe for mdb_env_close() to touch it.
2656 * When it will be closed, we can finally claim it.
2659 r->mr_txnid = (txnid_t)-1;
2662 ti->mti_numreaders = ++nr;
2663 env->me_close_readers = nr;
2665 UNLOCK_MUTEX(rmutex);
2667 new_notls = (env->me_flags & MDB_NOTLS);
2668 if (!new_notls && (rc=pthread_setspecific(env->me_txkey, r))) {
2673 do /* LY: Retry on a race, ITS#7970. */
2674 r->mr_txnid = ti->mti_txnid;
2675 while(r->mr_txnid != ti->mti_txnid);
2676 txn->mt_txnid = r->mr_txnid;
2677 txn->mt_u.reader = r;
2678 meta = env->me_metas[txn->mt_txnid & 1];
2682 /* Not yet touching txn == env->me_txn0, it may be active */
2684 if (LOCK_MUTEX(rc, env, env->me_wmutex))
2686 txn->mt_txnid = ti->mti_txnid;
2687 meta = env->me_metas[txn->mt_txnid & 1];
2689 meta = mdb_env_pick_meta(env);
2690 txn->mt_txnid = meta->mm_txnid;
2694 if (txn->mt_txnid == mdb_debug_start)
2697 txn->mt_child = NULL;
2698 txn->mt_loose_pgs = NULL;
2699 txn->mt_loose_count = 0;
2700 txn->mt_dirty_room = MDB_IDL_UM_MAX;
2701 txn->mt_u.dirty_list = env->me_dirty_list;
2702 txn->mt_u.dirty_list[0].mid = 0;
2703 txn->mt_free_pgs = env->me_free_pgs;
2704 txn->mt_free_pgs[0] = 0;
2705 txn->mt_spill_pgs = NULL;
2707 memcpy(txn->mt_dbiseqs, env->me_dbiseqs, env->me_maxdbs * sizeof(unsigned int));
2710 /* Copy the DB info and flags */
2711 memcpy(txn->mt_dbs, meta->mm_dbs, CORE_DBS * sizeof(MDB_db));
2713 /* Moved to here to avoid a data race in read TXNs */
2714 txn->mt_next_pgno = meta->mm_last_pg+1;
2716 txn->mt_flags = flags;
2719 txn->mt_numdbs = env->me_numdbs;
2720 for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
2721 x = env->me_dbflags[i];
2722 txn->mt_dbs[i].md_flags = x & PERSISTENT_FLAGS;
2723 txn->mt_dbflags[i] = (x & MDB_VALID) ? DB_VALID|DB_USRVALID|DB_STALE : 0;
2725 txn->mt_dbflags[MAIN_DBI] = DB_VALID|DB_USRVALID;
2726 txn->mt_dbflags[FREE_DBI] = DB_VALID;
2728 if (env->me_flags & MDB_FATAL_ERROR) {
2729 DPUTS("environment had fatal error, must shutdown!");
2731 } else if (env->me_maxpg < txn->mt_next_pgno) {
2732 rc = MDB_MAP_RESIZED;
2736 mdb_txn_end(txn, new_notls /*0 or MDB_END_SLOT*/ | MDB_END_FAIL_BEGIN);
2741 mdb_txn_renew(MDB_txn *txn)
2745 if (!txn || !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY|MDB_TXN_FINISHED))
2748 rc = mdb_txn_renew0(txn);
2749 if (rc == MDB_SUCCESS) {
2750 DPRINTF(("renew txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2751 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2752 (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root));
2758 mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
2762 int rc, size, tsize;
2764 flags &= MDB_TXN_BEGIN_FLAGS;
2765 flags |= env->me_flags & MDB_WRITEMAP;
2767 if (env->me_flags & MDB_RDONLY & ~flags) /* write txn in RDONLY env */
2771 /* Nested transactions: Max 1 child, write txns only, no writemap */
2772 flags |= parent->mt_flags;
2773 if (flags & (MDB_RDONLY|MDB_WRITEMAP|MDB_TXN_BLOCKED)) {
2774 return (parent->mt_flags & MDB_TXN_RDONLY) ? EINVAL : MDB_BAD_TXN;
2776 /* Child txns save MDB_pgstate and use own copy of cursors */
2777 size = env->me_maxdbs * (sizeof(MDB_db)+sizeof(MDB_cursor *)+1);
2778 size += tsize = sizeof(MDB_ntxn);
2779 } else if (flags & MDB_RDONLY) {
2780 size = env->me_maxdbs * (sizeof(MDB_db)+1);
2781 size += tsize = sizeof(MDB_txn);
2783 /* Reuse preallocated write txn. However, do not touch it until
2784 * mdb_txn_renew0() succeeds, since it currently may be active.
2789 if ((txn = calloc(1, size)) == NULL) {
2790 DPRINTF(("calloc: %s", strerror(errno)));
2793 txn->mt_dbxs = env->me_dbxs; /* static */
2794 txn->mt_dbs = (MDB_db *) ((char *)txn + tsize);
2795 txn->mt_dbflags = (unsigned char *)txn + size - env->me_maxdbs;
2796 txn->mt_flags = flags;
2801 txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
2802 txn->mt_dbiseqs = parent->mt_dbiseqs;
2803 txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE);
2804 if (!txn->mt_u.dirty_list ||
2805 !(txn->mt_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)))
2807 free(txn->mt_u.dirty_list);
2811 txn->mt_txnid = parent->mt_txnid;
2812 txn->mt_dirty_room = parent->mt_dirty_room;
2813 txn->mt_u.dirty_list[0].mid = 0;
2814 txn->mt_spill_pgs = NULL;
2815 txn->mt_next_pgno = parent->mt_next_pgno;
2816 parent->mt_flags |= MDB_TXN_HAS_CHILD;
2817 parent->mt_child = txn;
2818 txn->mt_parent = parent;
2819 txn->mt_numdbs = parent->mt_numdbs;
2820 memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
2821 /* Copy parent's mt_dbflags, but clear DB_NEW */
2822 for (i=0; i<txn->mt_numdbs; i++)
2823 txn->mt_dbflags[i] = parent->mt_dbflags[i] & ~DB_NEW;
2825 ntxn = (MDB_ntxn *)txn;
2826 ntxn->mnt_pgstate = env->me_pgstate; /* save parent me_pghead & co */
2827 if (env->me_pghead) {
2828 size = MDB_IDL_SIZEOF(env->me_pghead);
2829 env->me_pghead = mdb_midl_alloc(env->me_pghead[0]);
2831 memcpy(env->me_pghead, ntxn->mnt_pgstate.mf_pghead, size);
2836 rc = mdb_cursor_shadow(parent, txn);
2838 mdb_txn_end(txn, MDB_END_FAIL_BEGINCHILD);
2839 } else { /* MDB_RDONLY */
2840 txn->mt_dbiseqs = env->me_dbiseqs;
2842 rc = mdb_txn_renew0(txn);
2845 if (txn != env->me_txn0)
2848 txn->mt_flags |= flags; /* could not change txn=me_txn0 earlier */
2850 DPRINTF(("begin txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2851 txn->mt_txnid, (flags & MDB_RDONLY) ? 'r' : 'w',
2852 (void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root));
2859 mdb_txn_env(MDB_txn *txn)
2861 if(!txn) return NULL;
2866 mdb_txn_id(MDB_txn *txn)
2869 return txn->mt_txnid;
2872 /** Export or close DBI handles opened in this txn. */
2874 mdb_dbis_update(MDB_txn *txn, int keep)
2877 MDB_dbi n = txn->mt_numdbs;
2878 MDB_env *env = txn->mt_env;
2879 unsigned char *tdbflags = txn->mt_dbflags;
2881 for (i = n; --i >= CORE_DBS;) {
2882 if (tdbflags[i] & DB_NEW) {
2884 env->me_dbflags[i] = txn->mt_dbs[i].md_flags | MDB_VALID;
2886 char *ptr = env->me_dbxs[i].md_name.mv_data;
2888 env->me_dbxs[i].md_name.mv_data = NULL;
2889 env->me_dbxs[i].md_name.mv_size = 0;
2890 env->me_dbflags[i] = 0;
2891 env->me_dbiseqs[i]++;
2897 if (keep && env->me_numdbs < n)
2901 /** End a transaction, except successful commit of a nested transaction.
2902 * May be called twice for readonly txns: First reset it, then abort.
2903 * @param[in] txn the transaction handle to end
2904 * @param[in] mode why and how to end the transaction
2907 mdb_txn_end(MDB_txn *txn, unsigned mode)
2909 MDB_env *env = txn->mt_env;
2911 static const char *const names[] = MDB_END_NAMES;
2914 /* Export or close DBI handles opened in this txn */
2915 mdb_dbis_update(txn, mode & MDB_END_UPDATE);
2917 DPRINTF(("%s txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2918 names[mode & MDB_END_OPMASK],
2919 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2920 (void *) txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root));
2922 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
2923 if (txn->mt_u.reader) {
2924 txn->mt_u.reader->mr_txnid = (txnid_t)-1;
2925 if (!(env->me_flags & MDB_NOTLS)) {
2926 txn->mt_u.reader = NULL; /* txn does not own reader */
2927 } else if (mode & MDB_END_SLOT) {
2928 txn->mt_u.reader->mr_pid = 0;
2929 txn->mt_u.reader = NULL;
2930 } /* else txn owns the slot until it does MDB_END_SLOT */
2932 txn->mt_numdbs = 0; /* prevent further DBI activity */
2933 txn->mt_flags |= MDB_TXN_FINISHED;
2935 } else if (!F_ISSET(txn->mt_flags, MDB_TXN_FINISHED)) {
2936 pgno_t *pghead = env->me_pghead;
2938 if (!(mode & MDB_END_UPDATE)) /* !(already closed cursors) */
2939 mdb_cursors_close(txn, 0);
2940 if (!(env->me_flags & MDB_WRITEMAP)) {
2941 mdb_dlist_free(txn);
2945 txn->mt_flags = MDB_TXN_FINISHED;
2947 if (!txn->mt_parent) {
2948 mdb_midl_shrink(&txn->mt_free_pgs);
2949 env->me_free_pgs = txn->mt_free_pgs;
2951 env->me_pghead = NULL;
2955 mode = 0; /* txn == env->me_txn0, do not free() it */
2957 /* The writer mutex was locked in mdb_txn_begin. */
2959 UNLOCK_MUTEX(env->me_wmutex);
2961 txn->mt_parent->mt_child = NULL;
2962 txn->mt_parent->mt_flags &= ~MDB_TXN_HAS_CHILD;
2963 env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate;
2964 mdb_midl_free(txn->mt_free_pgs);
2965 mdb_midl_free(txn->mt_spill_pgs);
2966 free(txn->mt_u.dirty_list);
2969 mdb_midl_free(pghead);
2972 if (mode & MDB_END_FREE)
2977 mdb_txn_reset(MDB_txn *txn)
2982 /* This call is only valid for read-only txns */
2983 if (!(txn->mt_flags & MDB_TXN_RDONLY))
2986 mdb_txn_end(txn, MDB_END_RESET);
2990 mdb_txn_abort(MDB_txn *txn)
2996 mdb_txn_abort(txn->mt_child);
2998 mdb_txn_end(txn, MDB_END_ABORT|MDB_END_SLOT|MDB_END_FREE);
3001 /** Save the freelist as of this transaction to the freeDB.
3002 * This changes the freelist. Keep trying until it stabilizes.
3005 mdb_freelist_save(MDB_txn *txn)
3007 /* env->me_pghead[] can grow and shrink during this call.
3008 * env->me_pglast and txn->mt_free_pgs[] can only grow.
3009 * Page numbers cannot disappear from txn->mt_free_pgs[].
3012 MDB_env *env = txn->mt_env;
3013 int rc, maxfree_1pg = env->me_maxfree_1pg, more = 1;
3014 txnid_t pglast = 0, head_id = 0;
3015 pgno_t freecnt = 0, *free_pgs, *mop;
3016 ssize_t head_room = 0, total_room = 0, mop_len, clean_limit;
3018 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
3020 if (env->me_pghead) {
3021 /* Make sure first page of freeDB is touched and on freelist */
3022 rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST|MDB_PS_MODIFY);
3023 if (rc && rc != MDB_NOTFOUND)
3027 if (!env->me_pghead && txn->mt_loose_pgs) {
3028 /* Put loose page numbers in mt_free_pgs, since
3029 * we may be unable to return them to me_pghead.
3031 MDB_page *mp = txn->mt_loose_pgs;
3032 if ((rc = mdb_midl_need(&txn->mt_free_pgs, txn->mt_loose_count)) != 0)
3034 for (; mp; mp = NEXT_LOOSE_PAGE(mp))
3035 mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
3036 txn->mt_loose_pgs = NULL;
3037 txn->mt_loose_count = 0;
3040 /* MDB_RESERVE cancels meminit in ovpage malloc (when no WRITEMAP) */
3041 clean_limit = (env->me_flags & (MDB_NOMEMINIT|MDB_WRITEMAP))
3042 ? SSIZE_MAX : maxfree_1pg;
3045 /* Come back here after each Put() in case freelist changed */
3050 /* If using records from freeDB which we have not yet
3051 * deleted, delete them and any we reserved for me_pghead.
3053 while (pglast < env->me_pglast) {
3054 rc = mdb_cursor_first(&mc, &key, NULL);
3057 pglast = head_id = *(txnid_t *)key.mv_data;
3058 total_room = head_room = 0;
3059 mdb_tassert(txn, pglast <= env->me_pglast);
3060 rc = mdb_cursor_del(&mc, 0);
3065 /* Save the IDL of pages freed by this txn, to a single record */
3066 if (freecnt < txn->mt_free_pgs[0]) {
3068 /* Make sure last page of freeDB is touched and on freelist */
3069 rc = mdb_page_search(&mc, NULL, MDB_PS_LAST|MDB_PS_MODIFY);
3070 if (rc && rc != MDB_NOTFOUND)
3073 free_pgs = txn->mt_free_pgs;
3074 /* Write to last page of freeDB */
3075 key.mv_size = sizeof(txn->mt_txnid);
3076 key.mv_data = &txn->mt_txnid;
3078 freecnt = free_pgs[0];
3079 data.mv_size = MDB_IDL_SIZEOF(free_pgs);
3080 rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
3083 /* Retry if mt_free_pgs[] grew during the Put() */
3084 free_pgs = txn->mt_free_pgs;
3085 } while (freecnt < free_pgs[0]);
3086 mdb_midl_sort(free_pgs);
3087 memcpy(data.mv_data, free_pgs, data.mv_size);
3090 unsigned int i = free_pgs[0];
3091 DPRINTF(("IDL write txn %"Z"u root %"Z"u num %u",
3092 txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, i));
3094 DPRINTF(("IDL %"Z"u", free_pgs[i]));
3100 mop = env->me_pghead;
3101 mop_len = (mop ? mop[0] : 0) + txn->mt_loose_count;
3103 /* Reserve records for me_pghead[]. Split it if multi-page,
3104 * to avoid searching freeDB for a page range. Use keys in
3105 * range [1,me_pglast]: Smaller than txnid of oldest reader.
3107 if (total_room >= mop_len) {
3108 if (total_room == mop_len || --more < 0)
3110 } else if (head_room >= maxfree_1pg && head_id > 1) {
3111 /* Keep current record (overflow page), add a new one */
3115 /* (Re)write {key = head_id, IDL length = head_room} */
3116 total_room -= head_room;
3117 head_room = mop_len - total_room;
3118 if (head_room > maxfree_1pg && head_id > 1) {
3119 /* Overflow multi-page for part of me_pghead */
3120 head_room /= head_id; /* amortize page sizes */
3121 head_room += maxfree_1pg - head_room % (maxfree_1pg + 1);
3122 } else if (head_room < 0) {
3123 /* Rare case, not bothering to delete this record */
3126 key.mv_size = sizeof(head_id);
3127 key.mv_data = &head_id;
3128 data.mv_size = (head_room + 1) * sizeof(pgno_t);
3129 rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
3132 /* IDL is initially empty, zero out at least the length */
3133 pgs = (pgno_t *)data.mv_data;
3134 j = head_room > clean_limit ? head_room : 0;
3138 total_room += head_room;
3141 /* Return loose page numbers to me_pghead, though usually none are
3142 * left at this point. The pages themselves remain in dirty_list.
3144 if (txn->mt_loose_pgs) {
3145 MDB_page *mp = txn->mt_loose_pgs;
3146 unsigned count = txn->mt_loose_count;
3148 /* Room for loose pages + temp IDL with same */
3149 if ((rc = mdb_midl_need(&env->me_pghead, 2*count+1)) != 0)
3151 mop = env->me_pghead;
3152 loose = mop + MDB_IDL_ALLOCLEN(mop) - count;
3153 for (count = 0; mp; mp = NEXT_LOOSE_PAGE(mp))
3154 loose[ ++count ] = mp->mp_pgno;
3156 mdb_midl_sort(loose);
3157 mdb_midl_xmerge(mop, loose);
3158 txn->mt_loose_pgs = NULL;
3159 txn->mt_loose_count = 0;
3163 /* Fill in the reserved me_pghead records */
3169 rc = mdb_cursor_first(&mc, &key, &data);
3170 for (; !rc; rc = mdb_cursor_next(&mc, &key, &data, MDB_NEXT)) {
3171 txnid_t id = *(txnid_t *)key.mv_data;
3172 ssize_t len = (ssize_t)(data.mv_size / sizeof(MDB_ID)) - 1;
3175 mdb_tassert(txn, len >= 0 && id <= env->me_pglast);
3177 if (len > mop_len) {
3179 data.mv_size = (len + 1) * sizeof(MDB_ID);
3181 data.mv_data = mop -= len;
3184 rc = mdb_cursor_put(&mc, &key, &data, MDB_CURRENT);
3186 if (rc || !(mop_len -= len))
3193 /** Flush (some) dirty pages to the map, after clearing their dirty flag.
3194 * @param[in] txn the transaction that's being committed
3195 * @param[in] keep number of initial pages in dirty_list to keep dirty.
3196 * @return 0 on success, non-zero on failure.
3199 mdb_page_flush(MDB_txn *txn, int keep)
3201 MDB_env *env = txn->mt_env;
3202 MDB_ID2L dl = txn->mt_u.dirty_list;
3203 unsigned psize = env->me_psize, j;
3204 int i, pagecount = dl[0].mid, rc;
3205 size_t size = 0, pos = 0;
3207 MDB_page *dp = NULL;
3211 struct iovec iov[MDB_COMMIT_PAGES];
3212 ssize_t wpos = 0, wsize = 0, wres;
3213 size_t next_pos = 1; /* impossible pos, so pos != next_pos */
3219 if (env->me_flags & MDB_WRITEMAP) {
3220 /* Clear dirty flags */
3221 while (++i <= pagecount) {
3223 /* Don't flush this page yet */
3224 if (dp->mp_flags & (P_LOOSE|P_KEEP)) {
3225 dp->mp_flags &= ~P_KEEP;
3229 dp->mp_flags &= ~P_DIRTY;
3234 /* Write the pages */
3236 if (++i <= pagecount) {
3238 /* Don't flush this page yet */
3239 if (dp->mp_flags & (P_LOOSE|P_KEEP)) {
3240 dp->mp_flags &= ~P_KEEP;
3245 /* clear dirty flag */
3246 dp->mp_flags &= ~P_DIRTY;
3249 if (IS_OVERFLOW(dp)) size *= dp->mp_pages;
3254 /* Windows actually supports scatter/gather I/O, but only on
3255 * unbuffered file handles. Since we're relying on the OS page
3256 * cache for all our data, that's self-defeating. So we just
3257 * write pages one at a time. We use the ov structure to set
3258 * the write offset, to at least save the overhead of a Seek
3261 DPRINTF(("committing page %"Z"u", pgno));
3262 memset(&ov, 0, sizeof(ov));
3263 ov.Offset = pos & 0xffffffff;
3264 ov.OffsetHigh = pos >> 16 >> 16;
3265 if (!WriteFile(env->me_fd, dp, size, NULL, &ov)) {
3267 DPRINTF(("WriteFile: %d", rc));
3271 /* Write up to MDB_COMMIT_PAGES dirty pages at a time. */
3272 if (pos!=next_pos || n==MDB_COMMIT_PAGES || wsize+size>MAX_WRITE) {
3275 /* Write previous page(s) */
3276 #ifdef MDB_USE_PWRITEV
3277 wres = pwritev(env->me_fd, iov, n, wpos);
3280 wres = pwrite(env->me_fd, iov[0].iov_base, wsize, wpos);
3283 if (lseek(env->me_fd, wpos, SEEK_SET) == -1) {
3287 DPRINTF(("lseek: %s", strerror(rc)));
3290 wres = writev(env->me_fd, iov, n);
3293 if (wres != wsize) {
3298 DPRINTF(("Write error: %s", strerror(rc)));
3300 rc = EIO; /* TODO: Use which error code? */
3301 DPUTS("short write, filesystem full?");
3312 DPRINTF(("committing page %"Z"u", pgno));
3313 next_pos = pos + size;
3314 iov[n].iov_len = size;
3315 iov[n].iov_base = (char *)dp;
3321 /* MIPS has cache coherency issues, this is a no-op everywhere else
3322 * Note: for any size >= on-chip cache size, entire on-chip cache is
3325 CACHEFLUSH(env->me_map, txn->mt_next_pgno * env->me_psize, DCACHE);
3327 for (i = keep; ++i <= pagecount; ) {
3329 /* This is a page we skipped above */
3332 dl[j].mid = dp->mp_pgno;
3335 mdb_dpage_free(env, dp);
3340 txn->mt_dirty_room += i - j;
3346 mdb_txn_commit(MDB_txn *txn)
3349 unsigned int i, end_mode;
3355 /* mdb_txn_end() mode for a commit which writes nothing */
3356 end_mode = MDB_END_EMPTY_COMMIT|MDB_END_UPDATE|MDB_END_SLOT|MDB_END_FREE;
3358 if (txn->mt_child) {
3359 rc = mdb_txn_commit(txn->mt_child);
3366 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
3370 if (txn->mt_flags & (MDB_TXN_FINISHED|MDB_TXN_ERROR)) {
3371 DPUTS("txn has failed/finished, can't commit");
3373 txn->mt_parent->mt_flags |= MDB_TXN_ERROR;
3378 if (txn->mt_parent) {
3379 MDB_txn *parent = txn->mt_parent;
3383 unsigned x, y, len, ps_len;
3385 /* Append our free list to parent's */
3386 rc = mdb_midl_append_list(&parent->mt_free_pgs, txn->mt_free_pgs);
3389 mdb_midl_free(txn->mt_free_pgs);
3390 /* Failures after this must either undo the changes
3391 * to the parent or set MDB_TXN_ERROR in the parent.
3394 parent->mt_next_pgno = txn->mt_next_pgno;
3395 parent->mt_flags = txn->mt_flags;
3397 /* Merge our cursors into parent's and close them */
3398 mdb_cursors_close(txn, 1);
3400 /* Update parent's DB table. */
3401 memcpy(parent->mt_dbs, txn->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
3402 parent->mt_numdbs = txn->mt_numdbs;
3403 parent->mt_dbflags[FREE_DBI] = txn->mt_dbflags[FREE_DBI];
3404 parent->mt_dbflags[MAIN_DBI] = txn->mt_dbflags[MAIN_DBI];
3405 for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
3406 /* preserve parent's DB_NEW status */
3407 x = parent->mt_dbflags[i] & DB_NEW;
3408 parent->mt_dbflags[i] = txn->mt_dbflags[i] | x;
3411 dst = parent->mt_u.dirty_list;
3412 src = txn->mt_u.dirty_list;
3413 /* Remove anything in our dirty list from parent's spill list */
3414 if ((pspill = parent->mt_spill_pgs) && (ps_len = pspill[0])) {
3416 pspill[0] = (pgno_t)-1;
3417 /* Mark our dirty pages as deleted in parent spill list */
3418 for (i=0, len=src[0].mid; ++i <= len; ) {
3419 MDB_ID pn = src[i].mid << 1;
3420 while (pn > pspill[x])
3422 if (pn == pspill[x]) {
3427 /* Squash deleted pagenums if we deleted any */
3428 for (x=y; ++x <= ps_len; )
3429 if (!(pspill[x] & 1))
3430 pspill[++y] = pspill[x];
3434 /* Remove anything in our spill list from parent's dirty list */
3435 if (txn->mt_spill_pgs && txn->mt_spill_pgs[0]) {
3436 for (i=1; i<=txn->mt_spill_pgs[0]; i++) {
3437 MDB_ID pn = txn->mt_spill_pgs[i];
3439 continue; /* deleted spillpg */
3441 y = mdb_mid2l_search(dst, pn);
3442 if (y <= dst[0].mid && dst[y].mid == pn) {
3444 while (y < dst[0].mid) {
3453 /* Find len = length of merging our dirty list with parent's */
3455 dst[0].mid = 0; /* simplify loops */
3456 if (parent->mt_parent) {
3457 len = x + src[0].mid;
3458 y = mdb_mid2l_search(src, dst[x].mid + 1) - 1;
3459 for (i = x; y && i; y--) {
3460 pgno_t yp = src[y].mid;
3461 while (yp < dst[i].mid)
3463 if (yp == dst[i].mid) {
3468 } else { /* Simplify the above for single-ancestor case */
3469 len = MDB_IDL_UM_MAX - txn->mt_dirty_room;
3471 /* Merge our dirty list with parent's */
3473 for (i = len; y; dst[i--] = src[y--]) {
3474 pgno_t yp = src[y].mid;
3475 while (yp < dst[x].mid)
3476 dst[i--] = dst[x--];
3477 if (yp == dst[x].mid)
3478 free(dst[x--].mptr);
3480 mdb_tassert(txn, i == x);
3482 free(txn->mt_u.dirty_list);
3483 parent->mt_dirty_room = txn->mt_dirty_room;
3484 if (txn->mt_spill_pgs) {
3485 if (parent->mt_spill_pgs) {
3486 /* TODO: Prevent failure here, so parent does not fail */
3487 rc = mdb_midl_append_list(&parent->mt_spill_pgs, txn->mt_spill_pgs);
3489 parent->mt_flags |= MDB_TXN_ERROR;
3490 mdb_midl_free(txn->mt_spill_pgs);
3491 mdb_midl_sort(parent->mt_spill_pgs);
3493 parent->mt_spill_pgs = txn->mt_spill_pgs;
3497 /* Append our loose page list to parent's */
3498 for (lp = &parent->mt_loose_pgs; *lp; lp = &NEXT_LOOSE_PAGE(*lp))
3500 *lp = txn->mt_loose_pgs;
3501 parent->mt_loose_count += txn->mt_loose_count;
3503 parent->mt_child = NULL;
3504 mdb_midl_free(((MDB_ntxn *)txn)->mnt_pgstate.mf_pghead);
3509 if (txn != env->me_txn) {
3510 DPUTS("attempt to commit unknown transaction");
3515 mdb_cursors_close(txn, 0);
3517 if (!txn->mt_u.dirty_list[0].mid &&
3518 !(txn->mt_flags & (MDB_TXN_DIRTY|MDB_TXN_SPILLS)))
3521 DPRINTF(("committing txn %"Z"u %p on mdbenv %p, root page %"Z"u",
3522 txn->mt_txnid, (void*)txn, (void*)env, txn->mt_dbs[MAIN_DBI].md_root));
3524 /* Update DB root pointers */
3525 if (txn->mt_numdbs > CORE_DBS) {
3529 data.mv_size = sizeof(MDB_db);
3531 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
3532 for (i = CORE_DBS; i < txn->mt_numdbs; i++) {
3533 if (txn->mt_dbflags[i] & DB_DIRTY) {
3534 if (TXN_DBI_CHANGED(txn, i)) {
3538 data.mv_data = &txn->mt_dbs[i];
3539 rc = mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data,
3547 rc = mdb_freelist_save(txn);
3551 mdb_midl_free(env->me_pghead);
3552 env->me_pghead = NULL;
3553 mdb_midl_shrink(&txn->mt_free_pgs);
3559 if ((rc = mdb_page_flush(txn, 0)) ||
3560 (rc = mdb_env_sync(env, 0)) ||
3561 (rc = mdb_env_write_meta(txn)))
3563 end_mode = MDB_END_COMMITTED|MDB_END_UPDATE;
3566 mdb_txn_end(txn, end_mode);
3574 /** Read the environment parameters of a DB environment before
3575 * mapping it into memory.
3576 * @param[in] env the environment handle
3577 * @param[out] meta address of where to store the meta information
3578 * @return 0 on success, non-zero on failure.
3581 mdb_env_read_header(MDB_env *env, MDB_meta *meta)
3587 enum { Size = sizeof(pbuf) };
3589 /* We don't know the page size yet, so use a minimum value.
3590 * Read both meta pages so we can use the latest one.
3593 for (i=off=0; i<NUM_METAS; i++, off += meta->mm_psize) {
3597 memset(&ov, 0, sizeof(ov));
3599 rc = ReadFile(env->me_fd, &pbuf, Size, &len, &ov) ? (int)len : -1;
3600 if (rc == -1 && ErrCode() == ERROR_HANDLE_EOF)
3603 rc = pread(env->me_fd, &pbuf, Size, off);
3606 if (rc == 0 && off == 0)
3608 rc = rc < 0 ? (int) ErrCode() : MDB_INVALID;
3609 DPRINTF(("read: %s", mdb_strerror(rc)));
3613 p = (MDB_page *)&pbuf;
3615 if (!F_ISSET(p->mp_flags, P_META)) {
3616 DPRINTF(("page %"Z"u not a meta page", p->mp_pgno));
3621 if (m->mm_magic != MDB_MAGIC) {
3622 DPUTS("meta has invalid magic");
3626 if (m->mm_version != MDB_DATA_VERSION) {
3627 DPRINTF(("database is version %u, expected version %u",
3628 m->mm_version, MDB_DATA_VERSION));
3629 return MDB_VERSION_MISMATCH;
3632 if (off == 0 || m->mm_txnid > meta->mm_txnid)
3638 /** Fill in most of the zeroed #MDB_meta for an empty database environment */
3640 mdb_env_init_meta0(MDB_env *env, MDB_meta *meta)
3642 meta->mm_magic = MDB_MAGIC;
3643 meta->mm_version = MDB_DATA_VERSION;
3644 meta->mm_mapsize = env->me_mapsize;
3645 meta->mm_psize = env->me_psize;
3646 meta->mm_last_pg = NUM_METAS-1;
3647 meta->mm_flags = env->me_flags & 0xffff;
3648 meta->mm_flags |= MDB_INTEGERKEY; /* this is mm_dbs[FREE_DBI].md_flags */
3649 meta->mm_dbs[FREE_DBI].md_root = P_INVALID;
3650 meta->mm_dbs[MAIN_DBI].md_root = P_INVALID;
3653 /** Write the environment parameters of a freshly created DB environment.
3654 * @param[in] env the environment handle
3655 * @param[in] meta the #MDB_meta to write
3656 * @return 0 on success, non-zero on failure.
3659 mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
3667 memset(&ov, 0, sizeof(ov));
3668 #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
3670 rc = WriteFile(fd, ptr, size, &len, &ov); } while(0)
3673 #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
3674 len = pwrite(fd, ptr, size, pos); \
3675 if (len == -1 && ErrCode() == EINTR) continue; \
3676 rc = (len >= 0); break; } while(1)
3679 DPUTS("writing new meta page");
3681 psize = env->me_psize;
3683 p = calloc(NUM_METAS, psize);
3688 p->mp_flags = P_META;
3689 *(MDB_meta *)METADATA(p) = *meta;
3691 q = (MDB_page *)((char *)p + psize);
3693 q->mp_flags = P_META;
3694 *(MDB_meta *)METADATA(q) = *meta;
3696 DO_PWRITE(rc, env->me_fd, p, psize * NUM_METAS, len, 0);
3699 else if ((unsigned) len == psize * NUM_METAS)
3707 /** Update the environment info to commit a transaction.
3708 * @param[in] txn the transaction that's being committed
3709 * @return 0 on success, non-zero on failure.
3712 mdb_env_write_meta(MDB_txn *txn)
3715 MDB_meta meta, metab, *mp;
3719 int rc, len, toggle;
3728 toggle = txn->mt_txnid & 1;
3729 DPRINTF(("writing meta page %d for root page %"Z"u",
3730 toggle, txn->mt_dbs[MAIN_DBI].md_root));
3733 flags = env->me_flags;
3734 mp = env->me_metas[toggle];
3735 mapsize = env->me_metas[toggle ^ 1]->mm_mapsize;
3736 /* Persist any increases of mapsize config */
3737 if (mapsize < env->me_mapsize)
3738 mapsize = env->me_mapsize;
3740 if (flags & MDB_WRITEMAP) {
3741 mp->mm_mapsize = mapsize;
3742 mp->mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI];
3743 mp->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
3744 mp->mm_last_pg = txn->mt_next_pgno - 1;
3745 #if (__GNUC__ * 100 + __GNUC_MINOR__ >= 404) && /* TODO: portability */ \
3746 !(defined(__i386__) || defined(__x86_64__))
3747 /* LY: issue a memory barrier, if not x86. ITS#7969 */
3748 __sync_synchronize();
3750 mp->mm_txnid = txn->mt_txnid;
3751 if (!(flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {
3752 unsigned meta_size = env->me_psize;
3753 rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;
3754 ptr = (char *)mp - PAGEHDRSZ;
3755 #ifndef _WIN32 /* POSIX msync() requires ptr = start of OS page */
3756 r2 = (ptr - env->me_map) & (env->me_os_psize - 1);
3760 if (MDB_MSYNC(ptr, meta_size, rc)) {
3767 metab.mm_txnid = mp->mm_txnid;
3768 metab.mm_last_pg = mp->mm_last_pg;
3770 meta.mm_mapsize = mapsize;
3771 meta.mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI];
3772 meta.mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
3773 meta.mm_last_pg = txn->mt_next_pgno - 1;
3774 meta.mm_txnid = txn->mt_txnid;
3776 off = offsetof(MDB_meta, mm_mapsize);
3777 ptr = (char *)&meta + off;
3778 len = sizeof(MDB_meta) - off;
3779 off += (char *)mp - env->me_map;
3781 /* Write to the SYNC fd */
3782 mfd = (flags & (MDB_NOSYNC|MDB_NOMETASYNC)) ? env->me_fd : env->me_mfd;
3785 memset(&ov, 0, sizeof(ov));
3787 if (!WriteFile(mfd, ptr, len, (DWORD *)&rc, &ov))
3792 rc = pwrite(mfd, ptr, len, off);
3795 rc = rc < 0 ? ErrCode() : EIO;
3800 DPUTS("write failed, disk error?");
3801 /* On a failure, the pagecache still contains the new data.
3802 * Write some old data back, to prevent it from being used.
3803 * Use the non-SYNC fd; we know it will fail anyway.
3805 meta.mm_last_pg = metab.mm_last_pg;
3806 meta.mm_txnid = metab.mm_txnid;
3808 memset(&ov, 0, sizeof(ov));
3810 WriteFile(env->me_fd, ptr, len, NULL, &ov);
3812 r2 = pwrite(env->me_fd, ptr, len, off);
3813 (void)r2; /* Silence warnings. We don't care about pwrite's return value */
3816 env->me_flags |= MDB_FATAL_ERROR;
3819 /* MIPS has cache coherency issues, this is a no-op everywhere else */
3820 CACHEFLUSH(env->me_map + off, len, DCACHE);
3822 /* Memory ordering issues are irrelevant; since the entire writer
3823 * is wrapped by wmutex, all of these changes will become visible
3824 * after the wmutex is unlocked. Since the DB is multi-version,
3825 * readers will get consistent data regardless of how fresh or
3826 * how stale their view of these values is.
3829 env->me_txns->mti_txnid = txn->mt_txnid;
3834 /** Check both meta pages to see which one is newer.
3835 * @param[in] env the environment handle
3836 * @return newest #MDB_meta.
3839 mdb_env_pick_meta(const MDB_env *env)
3841 MDB_meta *const *metas = env->me_metas;
3842 return metas[ metas[0]->mm_txnid < metas[1]->mm_txnid ];
3846 mdb_env_create(MDB_env **env)
3850 e = calloc(1, sizeof(MDB_env));
3854 e->me_maxreaders = DEFAULT_READERS;
3855 e->me_maxdbs = e->me_numdbs = CORE_DBS;
3856 e->me_fd = INVALID_HANDLE_VALUE;
3857 e->me_lfd = INVALID_HANDLE_VALUE;
3858 e->me_mfd = INVALID_HANDLE_VALUE;
3859 #ifdef MDB_USE_POSIX_SEM
3860 e->me_rmutex = SEM_FAILED;
3861 e->me_wmutex = SEM_FAILED;
3863 e->me_pid = getpid();
3864 GET_PAGESIZE(e->me_os_psize);
3865 VGMEMP_CREATE(e,0,0);
3871 mdb_env_map(MDB_env *env, void *addr)
3874 unsigned int flags = env->me_flags;
3878 LONG sizelo, sizehi;
3881 if (flags & MDB_RDONLY) {
3882 /* Don't set explicit map size, use whatever exists */
3887 msize = env->me_mapsize;
3888 sizelo = msize & 0xffffffff;
3889 sizehi = msize >> 16 >> 16; /* only needed on Win64 */
3891 /* Windows won't create mappings for zero length files.
3892 * and won't map more than the file size.
3893 * Just set the maxsize right now.
3895 if (SetFilePointer(env->me_fd, sizelo, &sizehi, 0) != (DWORD)sizelo
3896 || !SetEndOfFile(env->me_fd)
3897 || SetFilePointer(env->me_fd, 0, NULL, 0) != 0)
3901 mh = CreateFileMapping(env->me_fd, NULL, flags & MDB_WRITEMAP ?
3902 PAGE_READWRITE : PAGE_READONLY,
3903 sizehi, sizelo, NULL);
3906 env->me_map = MapViewOfFileEx(mh, flags & MDB_WRITEMAP ?
3907 FILE_MAP_WRITE : FILE_MAP_READ,
3909 rc = env->me_map ? 0 : ErrCode();
3914 int prot = PROT_READ;
3915 if (flags & MDB_WRITEMAP) {
3917 if (ftruncate(env->me_fd, env->me_mapsize) < 0)
3920 env->me_map = mmap(addr, env->me_mapsize, prot, MAP_SHARED,
3922 if (env->me_map == MAP_FAILED) {
3927 if (flags & MDB_NORDAHEAD) {
3928 /* Turn off readahead. It's harmful when the DB is larger than RAM. */
3930 madvise(env->me_map, env->me_mapsize, MADV_RANDOM);
3932 #ifdef POSIX_MADV_RANDOM
3933 posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM);
3934 #endif /* POSIX_MADV_RANDOM */
3935 #endif /* MADV_RANDOM */
3939 /* Can happen because the address argument to mmap() is just a
3940 * hint. mmap() can pick another, e.g. if the range is in use.
3941 * The MAP_FIXED flag would prevent that, but then mmap could
3942 * instead unmap existing pages to make room for the new map.
3944 if (addr && env->me_map != addr)
3945 return EBUSY; /* TODO: Make a new MDB_* error code? */
3947 p = (MDB_page *)env->me_map;
3948 env->me_metas[0] = METADATA(p);
3949 env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + env->me_psize);
3955 mdb_env_set_mapsize(MDB_env *env, size_t size)
3957 /* If env is already open, caller is responsible for making
3958 * sure there are no active txns.
3966 meta = mdb_env_pick_meta(env);
3968 size = meta->mm_mapsize;
3970 /* Silently round up to minimum if the size is too small */
3971 size_t minsize = (meta->mm_last_pg + 1) * env->me_psize;
3975 munmap(env->me_map, env->me_mapsize);
3976 env->me_mapsize = size;
3977 old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL;
3978 rc = mdb_env_map(env, old);
3982 env->me_mapsize = size;
3984 env->me_maxpg = env->me_mapsize / env->me_psize;
3989 mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs)
3993 env->me_maxdbs = dbs + CORE_DBS;
3998 mdb_env_set_maxreaders(MDB_env *env, unsigned int readers)
4000 if (env->me_map || readers < 1)
4002 env->me_maxreaders = readers;
4007 mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)
4009 if (!env || !readers)
4011 *readers = env->me_maxreaders;
4016 mdb_fsize(HANDLE fd, size_t *size)
4019 LARGE_INTEGER fsize;
4021 if (!GetFileSizeEx(fd, &fsize))
4024 *size = fsize.QuadPart;
4036 #ifdef BROKEN_FDATASYNC
4037 #include <sys/utsname.h>
4038 #include <sys/vfs.h>
4041 /** Further setup required for opening an LMDB environment
4044 mdb_env_open2(MDB_env *env)
4046 unsigned int flags = env->me_flags;
4047 int i, newenv = 0, rc;
4051 /* See if we should use QueryLimited */
4053 if ((rc & 0xff) > 5)
4054 env->me_pidquery = MDB_PROCESS_QUERY_LIMITED_INFORMATION;
4056 env->me_pidquery = PROCESS_QUERY_INFORMATION;
4059 #ifdef BROKEN_FDATASYNC
4060 /* ext3/ext4 fdatasync is broken on some older Linux kernels.
4061 * https://lkml.org/lkml/2012/9/3/83
4062 * Kernels after 3.6-rc6 are known good.
4063 * https://lkml.org/lkml/2012/9/10/556
4064 * See if the DB is on ext3/ext4, then check for new enough kernel
4065 * Kernels 2.6.32.60, 2.6.34.15, 3.2.30, and 3.5.4 are also known
4070 fstatfs(env->me_fd, &st);
4071 while (st.f_type == 0xEF53) {
4075 if (uts.release[0] < '3') {
4076 if (!strncmp(uts.release, "2.6.32.", 7)) {
4077 i = atoi(uts.release+7);
4079 break; /* 2.6.32.60 and newer is OK */
4080 } else if (!strncmp(uts.release, "2.6.34.", 7)) {
4081 i = atoi(uts.release+7);
4083 break; /* 2.6.34.15 and newer is OK */
4085 } else if (uts.release[0] == '3') {
4086 i = atoi(uts.release+2);
4088 break; /* 3.6 and newer is OK */
4090 i = atoi(uts.release+4);
4092 break; /* 3.5.4 and newer is OK */
4093 } else if (i == 2) {
4094 i = atoi(uts.release+4);
4096 break; /* 3.2.30 and newer is OK */
4098 } else { /* 4.x and newer is OK */
4101 env->me_flags |= MDB_FSYNCONLY;
4107 if ((i = mdb_env_read_header(env, &meta)) != 0) {
4110 DPUTS("new mdbenv");
4112 env->me_psize = env->me_os_psize;
4113 if (env->me_psize > MAX_PAGESIZE)
4114 env->me_psize = MAX_PAGESIZE;
4115 memset(&meta, 0, sizeof(meta));
4116 mdb_env_init_meta0(env, &meta);
4117 meta.mm_mapsize = DEFAULT_MAPSIZE;
4119 env->me_psize = meta.mm_psize;
4122 /* Was a mapsize configured? */
4123 if (!env->me_mapsize) {
4124 env->me_mapsize = meta.mm_mapsize;
4127 /* Make sure mapsize >= committed data size. Even when using
4128 * mm_mapsize, which could be broken in old files (ITS#7789).
4130 size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize;
4131 if (env->me_mapsize < minsize)
4132 env->me_mapsize = minsize;
4134 meta.mm_mapsize = env->me_mapsize;
4136 if (newenv && !(flags & MDB_FIXEDMAP)) {
4137 /* mdb_env_map() may grow the datafile. Write the metapages
4138 * first, so the file will be valid if initialization fails.
4139 * Except with FIXEDMAP, since we do not yet know mm_address.
4140 * We could fill in mm_address later, but then a different
4141 * program might end up doing that - one with a memory layout
4142 * and map address which does not suit the main program.
4144 rc = mdb_env_init_meta(env, &meta);
4150 rc = mdb_env_map(env, (flags & MDB_FIXEDMAP) ? meta.mm_address : NULL);
4155 if (flags & MDB_FIXEDMAP)
4156 meta.mm_address = env->me_map;
4157 i = mdb_env_init_meta(env, &meta);
4158 if (i != MDB_SUCCESS) {
4163 env->me_maxfree_1pg = (env->me_psize - PAGEHDRSZ) / sizeof(pgno_t) - 1;
4164 env->me_nodemax = (((env->me_psize - PAGEHDRSZ) / MDB_MINKEYS) & -2)
4166 #if !(MDB_MAXKEYSIZE)
4167 env->me_maxkey = env->me_nodemax - (NODESIZE + sizeof(MDB_db));
4169 env->me_maxpg = env->me_mapsize / env->me_psize;
4173 MDB_meta *meta = mdb_env_pick_meta(env);
4174 MDB_db *db = &meta->mm_dbs[MAIN_DBI];
4176 DPRINTF(("opened database version %u, pagesize %u",
4177 meta->mm_version, env->me_psize));
4178 DPRINTF(("using meta page %d", (int) (meta->mm_txnid & 1)));
4179 DPRINTF(("depth: %u", db->md_depth));
4180 DPRINTF(("entries: %"Z"u", db->md_entries));
4181 DPRINTF(("branch pages: %"Z"u", db->md_branch_pages));
4182 DPRINTF(("leaf pages: %"Z"u", db->md_leaf_pages));
4183 DPRINTF(("overflow pages: %"Z"u", db->md_overflow_pages));
4184 DPRINTF(("root: %"Z"u", db->md_root));
4192 /** Release a reader thread's slot in the reader lock table.
4193 * This function is called automatically when a thread exits.
4194 * @param[in] ptr This points to the slot in the reader lock table.
4197 mdb_env_reader_dest(void *ptr)
4199 MDB_reader *reader = ptr;
4205 /** Junk for arranging thread-specific callbacks on Windows. This is
4206 * necessarily platform and compiler-specific. Windows supports up
4207 * to 1088 keys. Let's assume nobody opens more than 64 environments
4208 * in a single process, for now. They can override this if needed.
4210 #ifndef MAX_TLS_KEYS
4211 #define MAX_TLS_KEYS 64
4213 static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS];
4214 static int mdb_tls_nkeys;
4216 static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr)
4220 case DLL_PROCESS_ATTACH: break;
4221 case DLL_THREAD_ATTACH: break;
4222 case DLL_THREAD_DETACH:
4223 for (i=0; i<mdb_tls_nkeys; i++) {
4224 MDB_reader *r = pthread_getspecific(mdb_tls_keys[i]);
4226 mdb_env_reader_dest(r);
4230 case DLL_PROCESS_DETACH: break;
4235 const PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
4237 PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
4241 /* Force some symbol references.
4242 * _tls_used forces the linker to create the TLS directory if not already done
4243 * mdb_tls_cbp prevents whole-program-optimizer from dropping the symbol.
4245 #pragma comment(linker, "/INCLUDE:_tls_used")
4246 #pragma comment(linker, "/INCLUDE:mdb_tls_cbp")
4247 #pragma const_seg(".CRT$XLB")
4248 extern const PIMAGE_TLS_CALLBACK mdb_tls_cbp;
4249 const PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
4252 #pragma comment(linker, "/INCLUDE:__tls_used")
4253 #pragma comment(linker, "/INCLUDE:_mdb_tls_cbp")
4254 #pragma data_seg(".CRT$XLB")
4255 PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
4257 #endif /* WIN 32/64 */
4258 #endif /* !__GNUC__ */
4261 /** Downgrade the exclusive lock on the region back to shared */
4263 mdb_env_share_locks(MDB_env *env, int *excl)
4266 MDB_meta *meta = mdb_env_pick_meta(env);
4268 env->me_txns->mti_txnid = meta->mm_txnid;
4273 /* First acquire a shared lock. The Unlock will
4274 * then release the existing exclusive lock.
4276 memset(&ov, 0, sizeof(ov));
4277 if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
4280 UnlockFile(env->me_lfd, 0, 0, 1, 0);
4286 struct flock lock_info;
4287 /* The shared lock replaces the existing lock */
4288 memset((void *)&lock_info, 0, sizeof(lock_info));
4289 lock_info.l_type = F_RDLCK;
4290 lock_info.l_whence = SEEK_SET;
4291 lock_info.l_start = 0;
4292 lock_info.l_len = 1;
4293 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
4294 (rc = ErrCode()) == EINTR) ;
4295 *excl = rc ? -1 : 0; /* error may mean we lost the lock */
4302 /** Try to get exclusive lock, otherwise shared.
4303 * Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive.
4306 mdb_env_excl_lock(MDB_env *env, int *excl)
4310 if (LockFile(env->me_lfd, 0, 0, 1, 0)) {
4314 memset(&ov, 0, sizeof(ov));
4315 if (LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
4322 struct flock lock_info;
4323 memset((void *)&lock_info, 0, sizeof(lock_info));
4324 lock_info.l_type = F_WRLCK;
4325 lock_info.l_whence = SEEK_SET;
4326 lock_info.l_start = 0;
4327 lock_info.l_len = 1;
4328 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
4329 (rc = ErrCode()) == EINTR) ;
4333 # ifndef MDB_USE_POSIX_MUTEX
4334 if (*excl < 0) /* always true when MDB_USE_POSIX_MUTEX */
4337 lock_info.l_type = F_RDLCK;
4338 while ((rc = fcntl(env->me_lfd, F_SETLKW, &lock_info)) &&
4339 (rc = ErrCode()) == EINTR) ;
4349 * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code
4351 * @(#) $Revision: 5.1 $
4352 * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $
4353 * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $
4355 * http://www.isthe.com/chongo/tech/comp/fnv/index.html
4359 * Please do not copyright this code. This code is in the public domain.
4361 * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
4362 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
4363 * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
4364 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
4365 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
4366 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
4367 * PERFORMANCE OF THIS SOFTWARE.
4370 * chongo <Landon Curt Noll> /\oo/\
4371 * http://www.isthe.com/chongo/
4373 * Share and Enjoy! :-)
4376 typedef unsigned long long mdb_hash_t;
4377 #define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL)
4379 /** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer
4380 * @param[in] val value to hash
4381 * @param[in] hval initial value for hash
4382 * @return 64 bit hash
4384 * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the
4385 * hval arg on the first call.
4388 mdb_hash_val(MDB_val *val, mdb_hash_t hval)
4390 unsigned char *s = (unsigned char *)val->mv_data; /* unsigned string */
4391 unsigned char *end = s + val->mv_size;
4393 * FNV-1a hash each octet of the string
4396 /* xor the bottom with the current octet */
4397 hval ^= (mdb_hash_t)*s++;
4399 /* multiply by the 64 bit FNV magic prime mod 2^64 */
4400 hval += (hval << 1) + (hval << 4) + (hval << 5) +
4401 (hval << 7) + (hval << 8) + (hval << 40);
4403 /* return our new hash value */
4407 /** Hash the string and output the encoded hash.
4408 * This uses modified RFC1924 Ascii85 encoding to accommodate systems with
4409 * very short name limits. We don't care about the encoding being reversible,
4410 * we just want to preserve as many bits of the input as possible in a
4411 * small printable string.
4412 * @param[in] str string to hash
4413 * @param[out] encbuf an array of 11 chars to hold the hash
4415 static const char mdb_a85[]= "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";
4418 mdb_pack85(unsigned long l, char *out)
4422 for (i=0; i<5; i++) {
4423 *out++ = mdb_a85[l % 85];
4429 mdb_hash_enc(MDB_val *val, char *encbuf)
4431 mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT);
4433 mdb_pack85(h, encbuf);
4434 mdb_pack85(h>>32, encbuf+5);
4439 /** Open and/or initialize the lock region for the environment.
4440 * @param[in] env The LMDB environment.
4441 * @param[in] lpath The pathname of the file used for the lock region.
4442 * @param[in] mode The Unix permissions for the file, if we create it.
4443 * @param[in,out] excl In -1, out lock type: -1 none, 0 shared, 1 exclusive
4444 * @return 0 on success, non-zero on failure.
4447 mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
4450 # define MDB_ERRCODE_ROFS ERROR_WRITE_PROTECT
4452 # define MDB_ERRCODE_ROFS EROFS
4453 #ifdef O_CLOEXEC /* Linux: Open file and set FD_CLOEXEC atomically */
4454 # define MDB_CLOEXEC O_CLOEXEC
4457 # define MDB_CLOEXEC 0
4465 utf8_to_utf16(lpath, -1, &wlpath, NULL);
4466 env->me_lfd = CreateFileW(wlpath, GENERIC_READ|GENERIC_WRITE,
4467 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
4468 FILE_ATTRIBUTE_NORMAL, NULL);
4471 env->me_lfd = open(lpath, O_RDWR|O_CREAT|MDB_CLOEXEC, mode);
4473 if (env->me_lfd == INVALID_HANDLE_VALUE) {
4475 if (rc == MDB_ERRCODE_ROFS && (env->me_flags & MDB_RDONLY)) {
4480 #if ! ((MDB_CLOEXEC) || defined(_WIN32))
4481 /* Lose record locks when exec*() */
4482 if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0)
4483 fcntl(env->me_lfd, F_SETFD, fdflags);
4486 if (!(env->me_flags & MDB_NOTLS)) {
4487 rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
4490 env->me_flags |= MDB_ENV_TXKEY;
4492 /* Windows TLS callbacks need help finding their TLS info. */
4493 if (mdb_tls_nkeys >= MAX_TLS_KEYS) {
4497 mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey;
4501 /* Try to get exclusive lock. If we succeed, then
4502 * nobody is using the lock region and we should initialize it.
4504 if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
4507 size = GetFileSize(env->me_lfd, NULL);
4509 size = lseek(env->me_lfd, 0, SEEK_END);
4510 if (size == -1) goto fail_errno;
4512 rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
4513 if (size < rsize && *excl > 0) {
4515 if (SetFilePointer(env->me_lfd, rsize, NULL, FILE_BEGIN) != (DWORD)rsize
4516 || !SetEndOfFile(env->me_lfd))
4519 if (ftruncate(env->me_lfd, rsize) != 0) goto fail_errno;
4523 size = rsize - sizeof(MDB_txninfo);
4524 env->me_maxreaders = size/sizeof(MDB_reader) + 1;
4529 mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,
4531 if (!mh) goto fail_errno;
4532 env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL);
4534 if (!env->me_txns) goto fail_errno;
4536 void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
4538 if (m == MAP_FAILED) goto fail_errno;
4544 BY_HANDLE_FILE_INFORMATION stbuf;
4553 if (!mdb_sec_inited) {
4554 InitializeSecurityDescriptor(&mdb_null_sd,
4555 SECURITY_DESCRIPTOR_REVISION);
4556 SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE);
4557 mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);
4558 mdb_all_sa.bInheritHandle = FALSE;
4559 mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;
4562 if (!GetFileInformationByHandle(env->me_lfd, &stbuf)) goto fail_errno;
4563 idbuf.volume = stbuf.dwVolumeSerialNumber;
4564 idbuf.nhigh = stbuf.nFileIndexHigh;
4565 idbuf.nlow = stbuf.nFileIndexLow;
4566 val.mv_data = &idbuf;
4567 val.mv_size = sizeof(idbuf);
4568 mdb_hash_enc(&val, encbuf);
4569 sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", encbuf);
4570 sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", encbuf);
4571 env->me_rmutex = CreateMutexA(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
4572 if (!env->me_rmutex) goto fail_errno;
4573 env->me_wmutex = CreateMutexA(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);
4574 if (!env->me_wmutex) goto fail_errno;
4575 #elif defined(MDB_USE_POSIX_SEM)
4584 #if defined(__NetBSD__)
4585 #define MDB_SHORT_SEMNAMES 1 /* limited to 14 chars */
4587 if (fstat(env->me_lfd, &stbuf)) goto fail_errno;
4588 idbuf.dev = stbuf.st_dev;
4589 idbuf.ino = stbuf.st_ino;
4590 val.mv_data = &idbuf;
4591 val.mv_size = sizeof(idbuf);
4592 mdb_hash_enc(&val, encbuf);
4593 #ifdef MDB_SHORT_SEMNAMES
4594 encbuf[9] = '\0'; /* drop name from 15 chars to 14 chars */
4596 sprintf(env->me_txns->mti_rmname, "/MDBr%s", encbuf);
4597 sprintf(env->me_txns->mti_wmname, "/MDBw%s", encbuf);
4598 /* Clean up after a previous run, if needed: Try to
4599 * remove both semaphores before doing anything else.
4601 sem_unlink(env->me_txns->mti_rmname);
4602 sem_unlink(env->me_txns->mti_wmname);
4603 env->me_rmutex = sem_open(env->me_txns->mti_rmname,
4604 O_CREAT|O_EXCL, mode, 1);
4605 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
4606 env->me_wmutex = sem_open(env->me_txns->mti_wmname,
4607 O_CREAT|O_EXCL, mode, 1);
4608 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
4609 #else /* MDB_USE_POSIX_MUTEX: */
4610 pthread_mutexattr_t mattr;
4612 if ((rc = pthread_mutexattr_init(&mattr))
4613 || (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED))
4614 #ifdef MDB_ROBUST_SUPPORTED
4615 || (rc = pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST))
4617 || (rc = pthread_mutex_init(env->me_txns->mti_rmutex, &mattr))
4618 || (rc = pthread_mutex_init(env->me_txns->mti_wmutex, &mattr)))
4620 pthread_mutexattr_destroy(&mattr);
4621 #endif /* _WIN32 || MDB_USE_POSIX_SEM */
4623 env->me_txns->mti_magic = MDB_MAGIC;
4624 env->me_txns->mti_format = MDB_LOCK_FORMAT;
4625 env->me_txns->mti_txnid = 0;
4626 env->me_txns->mti_numreaders = 0;
4629 if (env->me_txns->mti_magic != MDB_MAGIC) {
4630 DPUTS("lock region has invalid magic");
4634 if (env->me_txns->mti_format != MDB_LOCK_FORMAT) {
4635 DPRINTF(("lock region has format+version 0x%x, expected 0x%x",
4636 env->me_txns->mti_format, MDB_LOCK_FORMAT));
4637 rc = MDB_VERSION_MISMATCH;
4641 if (rc && rc != EACCES && rc != EAGAIN) {
4645 env->me_rmutex = OpenMutexA(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);
4646 if (!env->me_rmutex) goto fail_errno;
4647 env->me_wmutex = OpenMutexA(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
4648 if (!env->me_wmutex) goto fail_errno;
4649 #elif defined(MDB_USE_POSIX_SEM)
4650 env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0);
4651 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
4652 env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0);
4653 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
4664 /** The name of the lock file in the DB environment */
4665 #define LOCKNAME "/lock.mdb"
4666 /** The name of the data file in the DB environment */
4667 #define DATANAME "/data.mdb"
4668 /** The suffix of the lock file when no subdir is used */
4669 #define LOCKSUFF "-lock"
4670 /** Only a subset of the @ref mdb_env flags can be changed
4671 * at runtime. Changing other flags requires closing the
4672 * environment and re-opening it with the new flags.
4674 #define CHANGEABLE (MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC|MDB_NOMEMINIT)
4675 #define CHANGELESS (MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY| \
4676 MDB_WRITEMAP|MDB_NOTLS|MDB_NOLOCK|MDB_NORDAHEAD)
4678 #if VALID_FLAGS & PERSISTENT_FLAGS & (CHANGEABLE|CHANGELESS)
4679 # error "Persistent DB flags & env flags overlap, but both go in mm_flags"
4683 mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode)
4685 int oflags, rc, len, excl = -1;
4686 char *lpath, *dpath;
4691 if (env->me_fd!=INVALID_HANDLE_VALUE || (flags & ~(CHANGEABLE|CHANGELESS)))
4695 if (flags & MDB_NOSUBDIR) {
4696 rc = len + sizeof(LOCKSUFF) + len + 1;
4698 rc = len + sizeof(LOCKNAME) + len + sizeof(DATANAME);
4703 if (flags & MDB_NOSUBDIR) {
4704 dpath = lpath + len + sizeof(LOCKSUFF);
4705 sprintf(lpath, "%s" LOCKSUFF, path);
4706 strcpy(dpath, path);
4708 dpath = lpath + len + sizeof(LOCKNAME);
4709 sprintf(lpath, "%s" LOCKNAME, path);
4710 sprintf(dpath, "%s" DATANAME, path);
4714 flags |= env->me_flags;
4715 if (flags & MDB_RDONLY) {
4716 /* silently ignore WRITEMAP when we're only getting read access */
4717 flags &= ~MDB_WRITEMAP;
4719 if (!((env->me_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)) &&
4720 (env->me_dirty_list = calloc(MDB_IDL_UM_SIZE, sizeof(MDB_ID2)))))
4723 env->me_flags = flags |= MDB_ENV_ACTIVE;
4727 env->me_path = strdup(path);
4728 env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx));
4729 env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t));
4730 env->me_dbiseqs = calloc(env->me_maxdbs, sizeof(unsigned int));
4731 if (!(env->me_dbxs && env->me_path && env->me_dbflags && env->me_dbiseqs)) {
4735 env->me_dbxs[FREE_DBI].md_cmp = mdb_cmp_long; /* aligned MDB_INTEGERKEY */
4737 /* For RDONLY, get lockfile after we know datafile exists */
4738 if (!(flags & (MDB_RDONLY|MDB_NOLOCK))) {
4739 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
4745 if (F_ISSET(flags, MDB_RDONLY)) {
4746 oflags = GENERIC_READ;
4747 len = OPEN_EXISTING;
4749 oflags = GENERIC_READ|GENERIC_WRITE;
4752 mode = FILE_ATTRIBUTE_NORMAL;
4753 utf8_to_utf16(dpath, -1, &wpath, NULL);
4754 env->me_fd = CreateFileW(wpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
4755 NULL, len, mode, NULL);
4758 if (F_ISSET(flags, MDB_RDONLY))
4761 oflags = O_RDWR | O_CREAT;
4763 env->me_fd = open(dpath, oflags, mode);
4765 if (env->me_fd == INVALID_HANDLE_VALUE) {
4770 if ((flags & (MDB_RDONLY|MDB_NOLOCK)) == MDB_RDONLY) {
4771 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
4776 if ((rc = mdb_env_open2(env)) == MDB_SUCCESS) {
4777 if (flags & (MDB_RDONLY|MDB_WRITEMAP)) {
4778 env->me_mfd = env->me_fd;
4780 /* Synchronous fd for meta writes. Needed even with
4781 * MDB_NOSYNC/MDB_NOMETASYNC, in case these get reset.
4784 len = OPEN_EXISTING;
4785 utf8_to_utf16(dpath, -1, &wpath, NULL);
4786 env->me_mfd = CreateFileW(wpath, oflags,
4787 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len,
4788 mode | FILE_FLAG_WRITE_THROUGH, NULL);
4792 env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode);
4794 if (env->me_mfd == INVALID_HANDLE_VALUE) {
4799 DPRINTF(("opened dbenv %p", (void *) env));
4801 rc = mdb_env_share_locks(env, &excl);
4805 if (!(flags & MDB_RDONLY)) {
4807 int tsize = sizeof(MDB_txn), size = tsize + env->me_maxdbs *
4808 (sizeof(MDB_db)+sizeof(MDB_cursor *)+sizeof(unsigned int)+1);
4809 if ((env->me_pbuf = calloc(1, env->me_psize)) &&
4810 (txn = calloc(1, size)))
4812 txn->mt_dbs = (MDB_db *)((char *)txn + tsize);
4813 txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
4814 txn->mt_dbiseqs = (unsigned int *)(txn->mt_cursors + env->me_maxdbs);
4815 txn->mt_dbflags = (unsigned char *)(txn->mt_dbiseqs + env->me_maxdbs);
4817 txn->mt_dbxs = env->me_dbxs;
4818 txn->mt_flags = MDB_TXN_FINISHED;
4828 mdb_env_close0(env, excl);
4834 /** Destroy resources from mdb_env_open(), clear our readers & DBIs */
4836 mdb_env_close0(MDB_env *env, int excl)
4840 if (!(env->me_flags & MDB_ENV_ACTIVE))
4843 /* Doing this here since me_dbxs may not exist during mdb_env_close */
4845 for (i = env->me_maxdbs; --i >= CORE_DBS; )
4846 free(env->me_dbxs[i].md_name.mv_data);
4851 free(env->me_dbiseqs);
4852 free(env->me_dbflags);
4854 free(env->me_dirty_list);
4856 mdb_midl_free(env->me_free_pgs);
4858 if (env->me_flags & MDB_ENV_TXKEY) {
4859 pthread_key_delete(env->me_txkey);
4861 /* Delete our key from the global list */
4862 for (i=0; i<mdb_tls_nkeys; i++)
4863 if (mdb_tls_keys[i] == env->me_txkey) {
4864 mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1];
4872 munmap(env->me_map, env->me_mapsize);
4874 if (env->me_mfd != env->me_fd && env->me_mfd != INVALID_HANDLE_VALUE)
4875 (void) close(env->me_mfd);
4876 if (env->me_fd != INVALID_HANDLE_VALUE)
4877 (void) close(env->me_fd);
4879 MDB_PID_T pid = env->me_pid;
4880 /* Clearing readers is done in this function because
4881 * me_txkey with its destructor must be disabled first.
4883 * We skip the the reader mutex, so we touch only
4884 * data owned by this process (me_close_readers and
4885 * our readers), and clear each reader atomically.
4887 for (i = env->me_close_readers; --i >= 0; )
4888 if (env->me_txns->mti_readers[i].mr_pid == pid)
4889 env->me_txns->mti_readers[i].mr_pid = 0;
4891 if (env->me_rmutex) {
4892 CloseHandle(env->me_rmutex);
4893 if (env->me_wmutex) CloseHandle(env->me_wmutex);
4895 /* Windows automatically destroys the mutexes when
4896 * the last handle closes.
4898 #elif defined(MDB_USE_POSIX_SEM)
4899 if (env->me_rmutex != SEM_FAILED) {
4900 sem_close(env->me_rmutex);
4901 if (env->me_wmutex != SEM_FAILED)
4902 sem_close(env->me_wmutex);
4903 /* If we have the filelock: If we are the
4904 * only remaining user, clean up semaphores.
4907 mdb_env_excl_lock(env, &excl);
4909 sem_unlink(env->me_txns->mti_rmname);
4910 sem_unlink(env->me_txns->mti_wmname);
4914 munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
4916 if (env->me_lfd != INVALID_HANDLE_VALUE) {
4919 /* Unlock the lockfile. Windows would have unlocked it
4920 * after closing anyway, but not necessarily at once.
4922 UnlockFile(env->me_lfd, 0, 0, 1, 0);
4925 (void) close(env->me_lfd);
4928 env->me_flags &= ~(MDB_ENV_ACTIVE|MDB_ENV_TXKEY);
4932 mdb_env_close(MDB_env *env)
4939 VGMEMP_DESTROY(env);
4940 while ((dp = env->me_dpages) != NULL) {
4941 VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next));
4942 env->me_dpages = dp->mp_next;
4946 mdb_env_close0(env, 0);
4950 /** Compare two items pointing at aligned size_t's */
4952 mdb_cmp_long(const MDB_val *a, const MDB_val *b)
4954 return (*(size_t *)a->mv_data < *(size_t *)b->mv_data) ? -1 :
4955 *(size_t *)a->mv_data > *(size_t *)b->mv_data;
4958 /** Compare two items pointing at aligned unsigned int's.
4960 * This is also set as #MDB_INTEGERDUP|#MDB_DUPFIXED's #MDB_dbx.%md_dcmp,
4961 * but #mdb_cmp_clong() is called instead if the data type is size_t.
4964 mdb_cmp_int(const MDB_val *a, const MDB_val *b)
4966 return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 :
4967 *(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data;
4970 /** Compare two items pointing at unsigned ints of unknown alignment.
4971 * Nodes and keys are guaranteed to be 2-byte aligned.
4974 mdb_cmp_cint(const MDB_val *a, const MDB_val *b)
4976 #if BYTE_ORDER == LITTLE_ENDIAN
4977 unsigned short *u, *c;
4980 u = (unsigned short *) ((char *) a->mv_data + a->mv_size);
4981 c = (unsigned short *) ((char *) b->mv_data + a->mv_size);
4984 } while(!x && u > (unsigned short *)a->mv_data);
4987 unsigned short *u, *c, *end;
4990 end = (unsigned short *) ((char *) a->mv_data + a->mv_size);
4991 u = (unsigned short *)a->mv_data;
4992 c = (unsigned short *)b->mv_data;
4995 } while(!x && u < end);
5000 /** Compare two items lexically */
5002 mdb_cmp_memn(const MDB_val *a, const MDB_val *b)
5009 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
5015 diff = memcmp(a->mv_data, b->mv_data, len);
5016 return diff ? diff : len_diff<0 ? -1 : len_diff;
5019 /** Compare two items in reverse byte order */
5021 mdb_cmp_memnr(const MDB_val *a, const MDB_val *b)
5023 const unsigned char *p1, *p2, *p1_lim;
5027 p1_lim = (const unsigned char *)a->mv_data;
5028 p1 = (const unsigned char *)a->mv_data + a->mv_size;
5029 p2 = (const unsigned char *)b->mv_data + b->mv_size;
5031 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
5037 while (p1 > p1_lim) {
5038 diff = *--p1 - *--p2;
5042 return len_diff<0 ? -1 : len_diff;
5045 /** Search for key within a page, using binary search.
5046 * Returns the smallest entry larger or equal to the key.
5047 * If exactp is non-null, stores whether the found entry was an exact match
5048 * in *exactp (1 or 0).
5049 * Updates the cursor index with the index of the found entry.
5050 * If no entry larger or equal to the key is found, returns NULL.
5053 mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)
5055 unsigned int i = 0, nkeys;
5058 MDB_page *mp = mc->mc_pg[mc->mc_top];
5059 MDB_node *node = NULL;
5064 nkeys = NUMKEYS(mp);
5066 DPRINTF(("searching %u keys in %s %spage %"Z"u",
5067 nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "",
5070 low = IS_LEAF(mp) ? 0 : 1;
5072 cmp = mc->mc_dbx->md_cmp;
5074 /* Branch pages have no data, so if using integer keys,
5075 * alignment is guaranteed. Use faster mdb_cmp_int.
5077 if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) {
5078 if (NODEPTR(mp, 1)->mn_ksize == sizeof(size_t))
5085 nodekey.mv_size = mc->mc_db->md_pad;
5086 node = NODEPTR(mp, 0); /* fake */
5087 while (low <= high) {
5088 i = (low + high) >> 1;
5089 nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size);
5090 rc = cmp(key, &nodekey);
5091 DPRINTF(("found leaf index %u [%s], rc = %i",
5092 i, DKEY(&nodekey), rc));
5101 while (low <= high) {
5102 i = (low + high) >> 1;
5104 node = NODEPTR(mp, i);
5105 nodekey.mv_size = NODEKSZ(node);
5106 nodekey.mv_data = NODEKEY(node);
5108 rc = cmp(key, &nodekey);
5111 DPRINTF(("found leaf index %u [%s], rc = %i",
5112 i, DKEY(&nodekey), rc));
5114 DPRINTF(("found branch index %u [%s -> %"Z"u], rc = %i",
5115 i, DKEY(&nodekey), NODEPGNO(node), rc));
5126 if (rc > 0) { /* Found entry is less than the key. */
5127 i++; /* Skip to get the smallest entry larger than key. */
5129 node = NODEPTR(mp, i);
5132 *exactp = (rc == 0 && nkeys > 0);
5133 /* store the key index */
5134 mc->mc_ki[mc->mc_top] = i;
5136 /* There is no entry larger or equal to the key. */
5139 /* nodeptr is fake for LEAF2 */
5145 mdb_cursor_adjust(MDB_cursor *mc, func)
5149 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
5150 if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) {
5157 /** Pop a page off the top of the cursor's stack. */
5159 mdb_cursor_pop(MDB_cursor *mc)
5162 DPRINTF(("popping page %"Z"u off db %d cursor %p",
5163 mc->mc_pg[mc->mc_top]->mp_pgno, DDBI(mc), (void *) mc));
5169 mc->mc_flags &= ~C_INITIALIZED;
5174 /** Push a page onto the top of the cursor's stack. */
5176 mdb_cursor_push(MDB_cursor *mc, MDB_page *mp)
5178 DPRINTF(("pushing page %"Z"u on db %d cursor %p", mp->mp_pgno,
5179 DDBI(mc), (void *) mc));
5181 if (mc->mc_snum >= CURSOR_STACK) {
5182 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
5183 return MDB_CURSOR_FULL;
5186 mc->mc_top = mc->mc_snum++;
5187 mc->mc_pg[mc->mc_top] = mp;
5188 mc->mc_ki[mc->mc_top] = 0;
5193 /** Find the address of the page corresponding to a given page number.
5194 * @param[in] txn the transaction for this access.
5195 * @param[in] pgno the page number for the page to retrieve.
5196 * @param[out] ret address of a pointer where the page's address will be stored.
5197 * @param[out] lvl dirty_list inheritance level of found page. 1=current txn, 0=mapped page.
5198 * @return 0 on success, non-zero on failure.
5201 mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret, int *lvl)
5203 MDB_env *env = txn->mt_env;
5207 if (! (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_WRITEMAP))) {
5211 MDB_ID2L dl = tx2->mt_u.dirty_list;
5213 /* Spilled pages were dirtied in this txn and flushed
5214 * because the dirty list got full. Bring this page
5215 * back in from the map (but don't unspill it here,
5216 * leave that unless page_touch happens again).
5218 if (tx2->mt_spill_pgs) {
5219 MDB_ID pn = pgno << 1;
5220 x = mdb_midl_search(tx2->mt_spill_pgs, pn);
5221 if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
5222 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
5227 unsigned x = mdb_mid2l_search(dl, pgno);
5228 if (x <= dl[0].mid && dl[x].mid == pgno) {
5234 } while ((tx2 = tx2->mt_parent) != NULL);
5237 if (pgno < txn->mt_next_pgno) {
5239 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
5241 DPRINTF(("page %"Z"u not found", pgno));
5242 txn->mt_flags |= MDB_TXN_ERROR;
5243 return MDB_PAGE_NOTFOUND;
5253 /** Finish #mdb_page_search() / #mdb_page_search_lowest().
5254 * The cursor is at the root page, set up the rest of it.
5257 mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags)
5259 MDB_page *mp = mc->mc_pg[mc->mc_top];
5263 while (IS_BRANCH(mp)) {
5267 DPRINTF(("branch page %"Z"u has %u keys", mp->mp_pgno, NUMKEYS(mp)));
5268 mdb_cassert(mc, NUMKEYS(mp) > 1);
5269 DPRINTF(("found index 0 to page %"Z"u", NODEPGNO(NODEPTR(mp, 0))));
5271 if (flags & (MDB_PS_FIRST|MDB_PS_LAST)) {
5273 if (flags & MDB_PS_LAST)
5274 i = NUMKEYS(mp) - 1;
5277 node = mdb_node_search(mc, key, &exact);
5279 i = NUMKEYS(mp) - 1;
5281 i = mc->mc_ki[mc->mc_top];
5283 mdb_cassert(mc, i > 0);
5287 DPRINTF(("following index %u for key [%s]", i, DKEY(key)));
5290 mdb_cassert(mc, i < NUMKEYS(mp));
5291 node = NODEPTR(mp, i);
5293 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
5296 mc->mc_ki[mc->mc_top] = i;
5297 if ((rc = mdb_cursor_push(mc, mp)))
5300 if (flags & MDB_PS_MODIFY) {
5301 if ((rc = mdb_page_touch(mc)) != 0)
5303 mp = mc->mc_pg[mc->mc_top];
5308 DPRINTF(("internal error, index points to a %02X page!?",
5310 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
5311 return MDB_CORRUPTED;
5314 DPRINTF(("found leaf page %"Z"u for key [%s]", mp->mp_pgno,
5315 key ? DKEY(key) : "null"));
5316 mc->mc_flags |= C_INITIALIZED;
5317 mc->mc_flags &= ~C_EOF;
5322 /** Search for the lowest key under the current branch page.
5323 * This just bypasses a NUMKEYS check in the current page
5324 * before calling mdb_page_search_root(), because the callers
5325 * are all in situations where the current page is known to
5329 mdb_page_search_lowest(MDB_cursor *mc)
5331 MDB_page *mp = mc->mc_pg[mc->mc_top];
5332 MDB_node *node = NODEPTR(mp, 0);
5335 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
5338 mc->mc_ki[mc->mc_top] = 0;
5339 if ((rc = mdb_cursor_push(mc, mp)))
5341 return mdb_page_search_root(mc, NULL, MDB_PS_FIRST);
5344 /** Search for the page a given key should be in.
5345 * Push it and its parent pages on the cursor stack.
5346 * @param[in,out] mc the cursor for this operation.
5347 * @param[in] key the key to search for, or NULL for first/last page.
5348 * @param[in] flags If MDB_PS_MODIFY is set, visited pages in the DB
5349 * are touched (updated with new page numbers).
5350 * If MDB_PS_FIRST or MDB_PS_LAST is set, find first or last leaf.
5351 * This is used by #mdb_cursor_first() and #mdb_cursor_last().
5352 * If MDB_PS_ROOTONLY set, just fetch root node, no further lookups.
5353 * @return 0 on success, non-zero on failure.
5356 mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)
5361 /* Make sure the txn is still viable, then find the root from
5362 * the txn's db table and set it as the root of the cursor's stack.
5364 if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED) {
5365 DPUTS("transaction may not be used now");
5368 /* Make sure we're using an up-to-date root */
5369 if (*mc->mc_dbflag & DB_STALE) {
5371 if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))
5373 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);
5374 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, 0);
5381 MDB_node *leaf = mdb_node_search(&mc2,
5382 &mc->mc_dbx->md_name, &exact);
5384 return MDB_NOTFOUND;
5385 if ((leaf->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)
5386 return MDB_INCOMPATIBLE; /* not a named DB */
5387 rc = mdb_node_read(mc->mc_txn, leaf, &data);
5390 memcpy(&flags, ((char *) data.mv_data + offsetof(MDB_db, md_flags)),
5392 /* The txn may not know this DBI, or another process may
5393 * have dropped and recreated the DB with other flags.
5395 if ((mc->mc_db->md_flags & PERSISTENT_FLAGS) != flags)
5396 return MDB_INCOMPATIBLE;
5397 memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db));
5399 *mc->mc_dbflag &= ~DB_STALE;
5401 root = mc->mc_db->md_root;
5403 if (root == P_INVALID) { /* Tree is empty. */
5404 DPUTS("tree is empty");
5405 return MDB_NOTFOUND;
5409 mdb_cassert(mc, root > 1);
5410 if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root)
5411 if ((rc = mdb_page_get(mc->mc_txn, root, &mc->mc_pg[0], NULL)) != 0)
5417 DPRINTF(("db %d root page %"Z"u has flags 0x%X",
5418 DDBI(mc), root, mc->mc_pg[0]->mp_flags));
5420 if (flags & MDB_PS_MODIFY) {
5421 if ((rc = mdb_page_touch(mc)))
5425 if (flags & MDB_PS_ROOTONLY)
5428 return mdb_page_search_root(mc, key, flags);
5432 mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
5434 MDB_txn *txn = mc->mc_txn;
5435 pgno_t pg = mp->mp_pgno;
5436 unsigned x = 0, ovpages = mp->mp_pages;
5437 MDB_env *env = txn->mt_env;
5438 MDB_IDL sl = txn->mt_spill_pgs;
5439 MDB_ID pn = pg << 1;
5442 DPRINTF(("free ov page %"Z"u (%d)", pg, ovpages));
5443 /* If the page is dirty or on the spill list we just acquired it,
5444 * so we should give it back to our current free list, if any.
5445 * Otherwise put it onto the list of pages we freed in this txn.
5447 * Won't create me_pghead: me_pglast must be inited along with it.
5448 * Unsupported in nested txns: They would need to hide the page
5449 * range in ancestor txns' dirty and spilled lists.
5451 if (env->me_pghead &&
5453 ((mp->mp_flags & P_DIRTY) ||
5454 (sl && (x = mdb_midl_search(sl, pn)) <= sl[0] && sl[x] == pn)))
5458 MDB_ID2 *dl, ix, iy;
5459 rc = mdb_midl_need(&env->me_pghead, ovpages);
5462 if (!(mp->mp_flags & P_DIRTY)) {
5463 /* This page is no longer spilled */
5470 /* Remove from dirty list */
5471 dl = txn->mt_u.dirty_list;
5473 for (ix = dl[x]; ix.mptr != mp; ix = iy) {
5479 mdb_cassert(mc, x > 1);
5481 dl[j] = ix; /* Unsorted. OK when MDB_TXN_ERROR. */
5482 txn->mt_flags |= MDB_TXN_ERROR;
5483 return MDB_CORRUPTED;
5486 txn->mt_dirty_room++;
5487 if (!(env->me_flags & MDB_WRITEMAP))
5488 mdb_dpage_free(env, mp);
5490 /* Insert in me_pghead */
5491 mop = env->me_pghead;
5492 j = mop[0] + ovpages;
5493 for (i = mop[0]; i && mop[i] < pg; i--)
5499 rc = mdb_midl_append_range(&txn->mt_free_pgs, pg, ovpages);
5503 mc->mc_db->md_overflow_pages -= ovpages;
5507 /** Return the data associated with a given node.
5508 * @param[in] txn The transaction for this operation.
5509 * @param[in] leaf The node being read.
5510 * @param[out] data Updated to point to the node's data.
5511 * @return 0 on success, non-zero on failure.
5514 mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data)
5516 MDB_page *omp; /* overflow page */
5520 if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
5521 data->mv_size = NODEDSZ(leaf);
5522 data->mv_data = NODEDATA(leaf);
5526 /* Read overflow data.
5528 data->mv_size = NODEDSZ(leaf);
5529 memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
5530 if ((rc = mdb_page_get(txn, pgno, &omp, NULL)) != 0) {
5531 DPRINTF(("read overflow page %"Z"u failed", pgno));
5534 data->mv_data = METADATA(omp);
5540 mdb_get(MDB_txn *txn, MDB_dbi dbi,
5541 MDB_val *key, MDB_val *data)
5548 DPRINTF(("===> get db %u key [%s]", dbi, DKEY(key)));
5550 if (!key || !data || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
5553 if (txn->mt_flags & MDB_TXN_BLOCKED)
5556 mdb_cursor_init(&mc, txn, dbi, &mx);
5557 return mdb_cursor_set(&mc, key, data, MDB_SET, &exact);
5560 /** Find a sibling for a page.
5561 * Replaces the page at the top of the cursor's stack with the
5562 * specified sibling, if one exists.
5563 * @param[in] mc The cursor for this operation.
5564 * @param[in] move_right Non-zero if the right sibling is requested,
5565 * otherwise the left sibling.
5566 * @return 0 on success, non-zero on failure.
5569 mdb_cursor_sibling(MDB_cursor *mc, int move_right)
5575 if (mc->mc_snum < 2) {
5576 return MDB_NOTFOUND; /* root has no siblings */
5580 DPRINTF(("parent page is page %"Z"u, index %u",
5581 mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]));
5583 if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top]))
5584 : (mc->mc_ki[mc->mc_top] == 0)) {
5585 DPRINTF(("no more keys left, moving to %s sibling",
5586 move_right ? "right" : "left"));
5587 if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) {
5588 /* undo cursor_pop before returning */
5595 mc->mc_ki[mc->mc_top]++;
5597 mc->mc_ki[mc->mc_top]--;
5598 DPRINTF(("just moving to %s index key %u",
5599 move_right ? "right" : "left", mc->mc_ki[mc->mc_top]));
5601 mdb_cassert(mc, IS_BRANCH(mc->mc_pg[mc->mc_top]));
5603 indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5604 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(indx), &mp, NULL)) != 0) {
5605 /* mc will be inconsistent if caller does mc_snum++ as above */
5606 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
5610 mdb_cursor_push(mc, mp);
5612 mc->mc_ki[mc->mc_top] = NUMKEYS(mp)-1;
5617 /** Move the cursor to the next data item. */
5619 mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
5625 if (mc->mc_flags & C_EOF) {
5626 return MDB_NOTFOUND;
5629 mdb_cassert(mc, mc->mc_flags & C_INITIALIZED);
5631 mp = mc->mc_pg[mc->mc_top];
5633 if (mc->mc_db->md_flags & MDB_DUPSORT) {
5634 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5635 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5636 if (op == MDB_NEXT || op == MDB_NEXT_DUP) {
5637 rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);
5638 if (op != MDB_NEXT || rc != MDB_NOTFOUND) {
5639 if (rc == MDB_SUCCESS)
5640 MDB_GET_KEY(leaf, key);
5645 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5646 if (op == MDB_NEXT_DUP)
5647 return MDB_NOTFOUND;
5651 DPRINTF(("cursor_next: top page is %"Z"u in cursor %p",
5652 mdb_dbg_pgno(mp), (void *) mc));
5653 if (mc->mc_flags & C_DEL)
5656 if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) {
5657 DPUTS("=====> move to next sibling page");
5658 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
5659 mc->mc_flags |= C_EOF;
5662 mp = mc->mc_pg[mc->mc_top];
5663 DPRINTF(("next page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
5665 mc->mc_ki[mc->mc_top]++;
5668 DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
5669 mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
5672 key->mv_size = mc->mc_db->md_pad;
5673 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5677 mdb_cassert(mc, IS_LEAF(mp));
5678 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5680 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5681 mdb_xcursor_init1(mc, leaf);
5684 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5687 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5688 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
5689 if (rc != MDB_SUCCESS)
5694 MDB_GET_KEY(leaf, key);
5698 /** Move the cursor to the previous data item. */
5700 mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
5706 mdb_cassert(mc, mc->mc_flags & C_INITIALIZED);
5708 mp = mc->mc_pg[mc->mc_top];
5710 if (mc->mc_db->md_flags & MDB_DUPSORT) {
5711 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5712 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5713 if (op == MDB_PREV || op == MDB_PREV_DUP) {
5714 rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
5715 if (op != MDB_PREV || rc != MDB_NOTFOUND) {
5716 if (rc == MDB_SUCCESS) {
5717 MDB_GET_KEY(leaf, key);
5718 mc->mc_flags &= ~C_EOF;
5724 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5725 if (op == MDB_PREV_DUP)
5726 return MDB_NOTFOUND;
5730 DPRINTF(("cursor_prev: top page is %"Z"u in cursor %p",
5731 mdb_dbg_pgno(mp), (void *) mc));
5733 if (mc->mc_ki[mc->mc_top] == 0) {
5734 DPUTS("=====> move to prev sibling page");
5735 if ((rc = mdb_cursor_sibling(mc, 0)) != MDB_SUCCESS) {
5738 mp = mc->mc_pg[mc->mc_top];
5739 mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;
5740 DPRINTF(("prev page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
5742 mc->mc_ki[mc->mc_top]--;
5744 mc->mc_flags &= ~C_EOF;
5746 DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
5747 mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
5750 key->mv_size = mc->mc_db->md_pad;
5751 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5755 mdb_cassert(mc, IS_LEAF(mp));
5756 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5758 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5759 mdb_xcursor_init1(mc, leaf);
5762 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5765 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5766 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
5767 if (rc != MDB_SUCCESS)
5772 MDB_GET_KEY(leaf, key);
5776 /** Set the cursor on a specific data item. */
5778 mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data,
5779 MDB_cursor_op op, int *exactp)
5783 MDB_node *leaf = NULL;
5786 if (key->mv_size == 0)
5787 return MDB_BAD_VALSIZE;
5790 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5792 /* See if we're already on the right page */
5793 if (mc->mc_flags & C_INITIALIZED) {
5796 mp = mc->mc_pg[mc->mc_top];
5798 mc->mc_ki[mc->mc_top] = 0;
5799 return MDB_NOTFOUND;
5801 if (mp->mp_flags & P_LEAF2) {
5802 nodekey.mv_size = mc->mc_db->md_pad;
5803 nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size);
5805 leaf = NODEPTR(mp, 0);
5806 MDB_GET_KEY2(leaf, nodekey);
5808 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5810 /* Probably happens rarely, but first node on the page
5811 * was the one we wanted.
5813 mc->mc_ki[mc->mc_top] = 0;
5820 unsigned int nkeys = NUMKEYS(mp);
5822 if (mp->mp_flags & P_LEAF2) {
5823 nodekey.mv_data = LEAF2KEY(mp,
5824 nkeys-1, nodekey.mv_size);
5826 leaf = NODEPTR(mp, nkeys-1);
5827 MDB_GET_KEY2(leaf, nodekey);
5829 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5831 /* last node was the one we wanted */
5832 mc->mc_ki[mc->mc_top] = nkeys-1;
5838 if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) {
5839 /* This is definitely the right page, skip search_page */
5840 if (mp->mp_flags & P_LEAF2) {
5841 nodekey.mv_data = LEAF2KEY(mp,
5842 mc->mc_ki[mc->mc_top], nodekey.mv_size);
5844 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5845 MDB_GET_KEY2(leaf, nodekey);
5847 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5849 /* current node was the one we wanted */
5859 /* If any parents have right-sibs, search.
5860 * Otherwise, there's nothing further.
5862 for (i=0; i<mc->mc_top; i++)
5864 NUMKEYS(mc->mc_pg[i])-1)
5866 if (i == mc->mc_top) {
5867 /* There are no other pages */
5868 mc->mc_ki[mc->mc_top] = nkeys;
5869 return MDB_NOTFOUND;
5873 /* There are no other pages */
5874 mc->mc_ki[mc->mc_top] = 0;
5875 if (op == MDB_SET_RANGE && !exactp) {
5879 return MDB_NOTFOUND;
5883 rc = mdb_page_search(mc, key, 0);
5884 if (rc != MDB_SUCCESS)
5887 mp = mc->mc_pg[mc->mc_top];
5888 mdb_cassert(mc, IS_LEAF(mp));
5891 leaf = mdb_node_search(mc, key, exactp);
5892 if (exactp != NULL && !*exactp) {
5893 /* MDB_SET specified and not an exact match. */
5894 return MDB_NOTFOUND;
5898 DPUTS("===> inexact leaf not found, goto sibling");
5899 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
5900 mc->mc_flags |= C_EOF;
5901 return rc; /* no entries matched */
5903 mp = mc->mc_pg[mc->mc_top];
5904 mdb_cassert(mc, IS_LEAF(mp));
5905 leaf = NODEPTR(mp, 0);
5909 mc->mc_flags |= C_INITIALIZED;
5910 mc->mc_flags &= ~C_EOF;
5913 if (op == MDB_SET_RANGE || op == MDB_SET_KEY) {
5914 key->mv_size = mc->mc_db->md_pad;
5915 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5920 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5921 mdb_xcursor_init1(mc, leaf);
5924 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5925 if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) {
5926 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
5929 if (op == MDB_GET_BOTH) {
5935 rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p);
5936 if (rc != MDB_SUCCESS)
5939 } else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {
5942 if ((rc = mdb_node_read(mc->mc_txn, leaf, &olddata)) != MDB_SUCCESS)
5944 dcmp = mc->mc_dbx->md_dcmp;
5945 #if UINT_MAX < SIZE_MAX
5946 if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
5947 dcmp = mdb_cmp_clong;
5949 rc = dcmp(data, &olddata);
5951 if (op == MDB_GET_BOTH || rc > 0)
5952 return MDB_NOTFOUND;
5959 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5960 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5965 /* The key already matches in all other cases */
5966 if (op == MDB_SET_RANGE || op == MDB_SET_KEY)
5967 MDB_GET_KEY(leaf, key);
5968 DPRINTF(("==> cursor placed on key [%s]", DKEY(key)));
5973 /** Move the cursor to the first item in the database. */
5975 mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data)
5981 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5983 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
5984 rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
5985 if (rc != MDB_SUCCESS)
5988 mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
5990 leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0);
5991 mc->mc_flags |= C_INITIALIZED;
5992 mc->mc_flags &= ~C_EOF;
5994 mc->mc_ki[mc->mc_top] = 0;
5996 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
5997 key->mv_size = mc->mc_db->md_pad;
5998 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size);
6003 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6004 mdb_xcursor_init1(mc, leaf);
6005 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
6009 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
6013 MDB_GET_KEY(leaf, key);
6017 /** Move the cursor to the last item in the database. */
6019 mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)
6025 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
6027 if (!(mc->mc_flags & C_EOF)) {
6029 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
6030 rc = mdb_page_search(mc, NULL, MDB_PS_LAST);
6031 if (rc != MDB_SUCCESS)
6034 mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
6037 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;
6038 mc->mc_flags |= C_INITIALIZED|C_EOF;
6039 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6041 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
6042 key->mv_size = mc->mc_db->md_pad;
6043 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size);
6048 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6049 mdb_xcursor_init1(mc, leaf);
6050 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
6054 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
6059 MDB_GET_KEY(leaf, key);
6064 mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,
6069 int (*mfunc)(MDB_cursor *mc, MDB_val *key, MDB_val *data);
6074 if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)
6078 case MDB_GET_CURRENT:
6079 if (!(mc->mc_flags & C_INITIALIZED)) {
6082 MDB_page *mp = mc->mc_pg[mc->mc_top];
6083 int nkeys = NUMKEYS(mp);
6084 if (!nkeys || mc->mc_ki[mc->mc_top] >= nkeys) {
6085 mc->mc_ki[mc->mc_top] = nkeys;
6091 key->mv_size = mc->mc_db->md_pad;
6092 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
6094 MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6095 MDB_GET_KEY(leaf, key);
6097 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6098 if (mc->mc_flags & C_DEL)
6099 mdb_xcursor_init1(mc, leaf);
6100 rc = mdb_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT);
6102 rc = mdb_node_read(mc->mc_txn, leaf, data);
6109 case MDB_GET_BOTH_RANGE:
6114 if (mc->mc_xcursor == NULL) {
6115 rc = MDB_INCOMPATIBLE;
6125 rc = mdb_cursor_set(mc, key, data, op,
6126 op == MDB_SET_RANGE ? NULL : &exact);
6129 case MDB_GET_MULTIPLE:
6130 if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
6134 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
6135 rc = MDB_INCOMPATIBLE;
6139 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) ||
6140 (mc->mc_xcursor->mx_cursor.mc_flags & C_EOF))
6143 case MDB_NEXT_MULTIPLE:
6148 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
6149 rc = MDB_INCOMPATIBLE;
6152 if (!(mc->mc_flags & C_INITIALIZED))
6153 rc = mdb_cursor_first(mc, key, data);
6155 rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP);
6156 if (rc == MDB_SUCCESS) {
6157 if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
6160 mx = &mc->mc_xcursor->mx_cursor;
6161 data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) *
6163 data->mv_data = METADATA(mx->mc_pg[mx->mc_top]);
6164 mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1;
6172 case MDB_NEXT_NODUP:
6173 if (!(mc->mc_flags & C_INITIALIZED))
6174 rc = mdb_cursor_first(mc, key, data);
6176 rc = mdb_cursor_next(mc, key, data, op);
6180 case MDB_PREV_NODUP:
6181 if (!(mc->mc_flags & C_INITIALIZED)) {
6182 rc = mdb_cursor_last(mc, key, data);
6185 mc->mc_flags |= C_INITIALIZED;
6186 mc->mc_ki[mc->mc_top]++;
6188 rc = mdb_cursor_prev(mc, key, data, op);
6191 rc = mdb_cursor_first(mc, key, data);
6194 mfunc = mdb_cursor_first;
6196 if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
6200 if (mc->mc_xcursor == NULL) {
6201 rc = MDB_INCOMPATIBLE;
6205 MDB_node *leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6206 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6207 MDB_GET_KEY(leaf, key);
6208 rc = mdb_node_read(mc->mc_txn, leaf, data);
6212 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
6216 rc = mfunc(&mc->mc_xcursor->mx_cursor, data, NULL);
6219 rc = mdb_cursor_last(mc, key, data);
6222 mfunc = mdb_cursor_last;
6225 DPRINTF(("unhandled/unimplemented cursor operation %u", op));
6230 if (mc->mc_flags & C_DEL)
6231 mc->mc_flags ^= C_DEL;
6236 /** Touch all the pages in the cursor stack. Set mc_top.
6237 * Makes sure all the pages are writable, before attempting a write operation.
6238 * @param[in] mc The cursor to operate on.
6241 mdb_cursor_touch(MDB_cursor *mc)
6243 int rc = MDB_SUCCESS;
6245 if (mc->mc_dbi >= CORE_DBS && !(*mc->mc_dbflag & DB_DIRTY)) {
6248 if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))
6250 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, &mcx);
6251 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY);
6254 *mc->mc_dbflag |= DB_DIRTY;
6259 rc = mdb_page_touch(mc);
6260 } while (!rc && ++(mc->mc_top) < mc->mc_snum);
6261 mc->mc_top = mc->mc_snum-1;
6266 /** Do not spill pages to disk if txn is getting full, may fail instead */
6267 #define MDB_NOSPILL 0x8000
6270 mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
6274 MDB_node *leaf = NULL;
6275 MDB_page *fp, *mp, *sub_root = NULL;
6277 MDB_val xdata, *rdata, dkey, olddata;
6279 int do_sub = 0, insert_key, insert_data;
6280 unsigned int mcount = 0, dcount = 0, nospill;
6283 unsigned int nflags;
6286 if (mc == NULL || key == NULL)
6289 env = mc->mc_txn->mt_env;
6291 /* Check this first so counter will always be zero on any
6294 if (flags & MDB_MULTIPLE) {
6295 dcount = data[1].mv_size;
6296 data[1].mv_size = 0;
6297 if (!F_ISSET(mc->mc_db->md_flags, MDB_DUPFIXED))
6298 return MDB_INCOMPATIBLE;
6301 nospill = flags & MDB_NOSPILL;
6302 flags &= ~MDB_NOSPILL;
6304 if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
6305 return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
6307 if (key->mv_size-1 >= ENV_MAXKEY(env))
6308 return MDB_BAD_VALSIZE;
6310 #if SIZE_MAX > MAXDATASIZE
6311 if (data->mv_size > ((mc->mc_db->md_flags & MDB_DUPSORT) ? ENV_MAXKEY(env) : MAXDATASIZE))
6312 return MDB_BAD_VALSIZE;
6314 if ((mc->mc_db->md_flags & MDB_DUPSORT) && data->mv_size > ENV_MAXKEY(env))
6315 return MDB_BAD_VALSIZE;
6318 DPRINTF(("==> put db %d key [%s], size %"Z"u, data size %"Z"u",
6319 DDBI(mc), DKEY(key), key ? key->mv_size : 0, data->mv_size));
6323 if (flags == MDB_CURRENT) {
6324 if (!(mc->mc_flags & C_INITIALIZED))
6327 } else if (mc->mc_db->md_root == P_INVALID) {
6328 /* new database, cursor has nothing to point to */
6331 mc->mc_flags &= ~C_INITIALIZED;
6336 if (flags & MDB_APPEND) {
6338 rc = mdb_cursor_last(mc, &k2, &d2);
6340 rc = mc->mc_dbx->md_cmp(key, &k2);
6343 mc->mc_ki[mc->mc_top]++;
6345 /* new key is <= last key */
6350 rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact);
6352 if ((flags & MDB_NOOVERWRITE) && rc == 0) {
6353 DPRINTF(("duplicate key [%s]", DKEY(key)));
6355 return MDB_KEYEXIST;
6357 if (rc && rc != MDB_NOTFOUND)
6361 if (mc->mc_flags & C_DEL)
6362 mc->mc_flags ^= C_DEL;
6364 /* Cursor is positioned, check for room in the dirty list */
6366 if (flags & MDB_MULTIPLE) {
6368 xdata.mv_size = data->mv_size * dcount;
6372 if ((rc2 = mdb_page_spill(mc, key, rdata)))
6376 if (rc == MDB_NO_ROOT) {
6378 /* new database, write a root leaf page */
6379 DPUTS("allocating new root leaf page");
6380 if ((rc2 = mdb_page_new(mc, P_LEAF, 1, &np))) {
6383 mdb_cursor_push(mc, np);
6384 mc->mc_db->md_root = np->mp_pgno;
6385 mc->mc_db->md_depth++;
6386 *mc->mc_dbflag |= DB_DIRTY;
6387 if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED))
6389 np->mp_flags |= P_LEAF2;
6390 mc->mc_flags |= C_INITIALIZED;
6392 /* make sure all cursor pages are writable */
6393 rc2 = mdb_cursor_touch(mc);
6398 insert_key = insert_data = rc;
6400 /* The key does not exist */
6401 DPRINTF(("inserting key at index %i", mc->mc_ki[mc->mc_top]));
6402 if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
6403 LEAFSIZE(key, data) > env->me_nodemax)
6405 /* Too big for a node, insert in sub-DB. Set up an empty
6406 * "old sub-page" for prep_subDB to expand to a full page.
6408 fp_flags = P_LEAF|P_DIRTY;
6410 fp->mp_pad = data->mv_size; /* used if MDB_DUPFIXED */
6411 fp->mp_lower = fp->mp_upper = (PAGEHDRSZ-PAGEBASE);
6412 olddata.mv_size = PAGEHDRSZ;
6416 /* there's only a key anyway, so this is a no-op */
6417 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
6419 unsigned int ksize = mc->mc_db->md_pad;
6420 if (key->mv_size != ksize)
6421 return MDB_BAD_VALSIZE;
6422 ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize);
6423 memcpy(ptr, key->mv_data, ksize);
6425 /* if overwriting slot 0 of leaf, need to
6426 * update branch key if there is a parent page
6428 if (mc->mc_top && !mc->mc_ki[mc->mc_top]) {
6429 unsigned short dtop = 1;
6431 /* slot 0 is always an empty key, find real slot */
6432 while (mc->mc_top && !mc->mc_ki[mc->mc_top]) {
6436 if (mc->mc_ki[mc->mc_top])
6437 rc2 = mdb_update_key(mc, key);
6448 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6449 olddata.mv_size = NODEDSZ(leaf);
6450 olddata.mv_data = NODEDATA(leaf);
6453 if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) {
6454 /* Prepare (sub-)page/sub-DB to accept the new item,
6455 * if needed. fp: old sub-page or a header faking
6456 * it. mp: new (sub-)page. offset: growth in page
6457 * size. xdata: node data with new page or DB.
6459 unsigned i, offset = 0;
6460 mp = fp = xdata.mv_data = env->me_pbuf;
6461 mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
6463 /* Was a single item before, must convert now */
6464 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6466 /* Just overwrite the current item */
6467 if (flags == MDB_CURRENT)
6469 dcmp = mc->mc_dbx->md_dcmp;
6470 #if UINT_MAX < SIZE_MAX
6471 if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
6472 dcmp = mdb_cmp_clong;
6474 /* does data match? */
6475 if (!dcmp(data, &olddata)) {
6476 if (flags & MDB_NODUPDATA)
6477 return MDB_KEYEXIST;
6482 /* Back up original data item */
6483 dkey.mv_size = olddata.mv_size;
6484 dkey.mv_data = memcpy(fp+1, olddata.mv_data, olddata.mv_size);
6486 /* Make sub-page header for the dup items, with dummy body */
6487 fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP;
6488 fp->mp_lower = (PAGEHDRSZ-PAGEBASE);
6489 xdata.mv_size = PAGEHDRSZ + dkey.mv_size + data->mv_size;
6490 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
6491 fp->mp_flags |= P_LEAF2;
6492 fp->mp_pad = data->mv_size;
6493 xdata.mv_size += 2 * data->mv_size; /* leave space for 2 more */
6495 xdata.mv_size += 2 * (sizeof(indx_t) + NODESIZE) +
6496 (dkey.mv_size & 1) + (data->mv_size & 1);
6498 fp->mp_upper = xdata.mv_size - PAGEBASE;
6499 olddata.mv_size = xdata.mv_size; /* pretend olddata is fp */
6500 } else if (leaf->mn_flags & F_SUBDATA) {
6501 /* Data is on sub-DB, just store it */
6502 flags |= F_DUPDATA|F_SUBDATA;
6505 /* Data is on sub-page */
6506 fp = olddata.mv_data;
6509 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
6510 offset = EVEN(NODESIZE + sizeof(indx_t) +
6514 offset = fp->mp_pad;
6515 if (SIZELEFT(fp) < offset) {
6516 offset *= 4; /* space for 4 more */
6519 /* FALLTHRU: Big enough MDB_DUPFIXED sub-page */
6521 fp->mp_flags |= P_DIRTY;
6522 COPY_PGNO(fp->mp_pgno, mp->mp_pgno);
6523 mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;
6527 xdata.mv_size = olddata.mv_size + offset;
6530 fp_flags = fp->mp_flags;
6531 if (NODESIZE + NODEKSZ(leaf) + xdata.mv_size > env->me_nodemax) {
6532 /* Too big for a sub-page, convert to sub-DB */
6533 fp_flags &= ~P_SUBP;
6535 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
6536 fp_flags |= P_LEAF2;
6537 dummy.md_pad = fp->mp_pad;
6538 dummy.md_flags = MDB_DUPFIXED;
6539 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
6540 dummy.md_flags |= MDB_INTEGERKEY;
6546 dummy.md_branch_pages = 0;
6547 dummy.md_leaf_pages = 1;
6548 dummy.md_overflow_pages = 0;
6549 dummy.md_entries = NUMKEYS(fp);
6550 xdata.mv_size = sizeof(MDB_db);
6551 xdata.mv_data = &dummy;
6552 if ((rc = mdb_page_alloc(mc, 1, &mp)))
6554 offset = env->me_psize - olddata.mv_size;
6555 flags |= F_DUPDATA|F_SUBDATA;
6556 dummy.md_root = mp->mp_pgno;
6560 mp->mp_flags = fp_flags | P_DIRTY;
6561 mp->mp_pad = fp->mp_pad;
6562 mp->mp_lower = fp->mp_lower;
6563 mp->mp_upper = fp->mp_upper + offset;
6564 if (fp_flags & P_LEAF2) {
6565 memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad);
6567 memcpy((char *)mp + mp->mp_upper + PAGEBASE, (char *)fp + fp->mp_upper + PAGEBASE,
6568 olddata.mv_size - fp->mp_upper - PAGEBASE);
6569 for (i=0; i<NUMKEYS(fp); i++)
6570 mp->mp_ptrs[i] = fp->mp_ptrs[i] + offset;
6578 mdb_node_del(mc, 0);
6582 /* LMDB passes F_SUBDATA in 'flags' to write a DB record */
6583 if ((leaf->mn_flags ^ flags) & F_SUBDATA)
6584 return MDB_INCOMPATIBLE;
6585 /* overflow page overwrites need special handling */
6586 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
6589 int level, ovpages, dpages = OVPAGES(data->mv_size, env->me_psize);
6591 memcpy(&pg, olddata.mv_data, sizeof(pg));
6592 if ((rc2 = mdb_page_get(mc->mc_txn, pg, &omp, &level)) != 0)
6594 ovpages = omp->mp_pages;
6596 /* Is the ov page large enough? */
6597 if (ovpages >= dpages) {
6598 if (!(omp->mp_flags & P_DIRTY) &&
6599 (level || (env->me_flags & MDB_WRITEMAP)))
6601 rc = mdb_page_unspill(mc->mc_txn, omp, &omp);
6604 level = 0; /* dirty in this txn or clean */
6607 if (omp->mp_flags & P_DIRTY) {
6608 /* yes, overwrite it. Note in this case we don't
6609 * bother to try shrinking the page if the new data
6610 * is smaller than the overflow threshold.
6613 /* It is writable only in a parent txn */
6614 size_t sz = (size_t) env->me_psize * ovpages, off;
6615 MDB_page *np = mdb_page_malloc(mc->mc_txn, ovpages);
6621 /* Note - this page is already counted in parent's dirty_room */
6622 rc2 = mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);
6623 mdb_cassert(mc, rc2 == 0);
6624 if (!(flags & MDB_RESERVE)) {
6625 /* Copy end of page, adjusting alignment so
6626 * compiler may copy words instead of bytes.
6628 off = (PAGEHDRSZ + data->mv_size) & -sizeof(size_t);
6629 memcpy((size_t *)((char *)np + off),
6630 (size_t *)((char *)omp + off), sz - off);
6633 memcpy(np, omp, sz); /* Copy beginning of page */
6636 SETDSZ(leaf, data->mv_size);
6637 if (F_ISSET(flags, MDB_RESERVE))
6638 data->mv_data = METADATA(omp);
6640 memcpy(METADATA(omp), data->mv_data, data->mv_size);
6644 if ((rc2 = mdb_ovpage_free(mc, omp)) != MDB_SUCCESS)
6646 } else if (data->mv_size == olddata.mv_size) {
6647 /* same size, just replace it. Note that we could
6648 * also reuse this node if the new data is smaller,
6649 * but instead we opt to shrink the node in that case.
6651 if (F_ISSET(flags, MDB_RESERVE))
6652 data->mv_data = olddata.mv_data;
6653 else if (!(mc->mc_flags & C_SUB))
6654 memcpy(olddata.mv_data, data->mv_data, data->mv_size);
6656 memcpy(NODEKEY(leaf), key->mv_data, key->mv_size);
6661 mdb_node_del(mc, 0);
6667 nflags = flags & NODE_ADD_FLAGS;
6668 nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(env, key, rdata);
6669 if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) {
6670 if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA )
6671 nflags &= ~MDB_APPEND; /* sub-page may need room to grow */
6673 nflags |= MDB_SPLIT_REPLACE;
6674 rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags);
6676 /* There is room already in this leaf page. */
6677 rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);
6678 if (rc == 0 && insert_key) {
6679 /* Adjust other cursors pointing to mp */
6680 MDB_cursor *m2, *m3;
6681 MDB_dbi dbi = mc->mc_dbi;
6682 unsigned i = mc->mc_top;
6683 MDB_page *mp = mc->mc_pg[i];
6685 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
6686 if (mc->mc_flags & C_SUB)
6687 m3 = &m2->mc_xcursor->mx_cursor;
6690 if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
6691 if (m3->mc_pg[i] == mp && m3->mc_ki[i] >= mc->mc_ki[i]) {
6698 if (rc == MDB_SUCCESS) {
6699 /* Now store the actual data in the child DB. Note that we're
6700 * storing the user data in the keys field, so there are strict
6701 * size limits on dupdata. The actual data fields of the child
6702 * DB are all zero size.
6705 int xflags, new_dupdata;
6710 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6711 if (flags & MDB_CURRENT) {
6712 xflags = MDB_CURRENT|MDB_NOSPILL;
6714 mdb_xcursor_init1(mc, leaf);
6715 xflags = (flags & MDB_NODUPDATA) ?
6716 MDB_NOOVERWRITE|MDB_NOSPILL : MDB_NOSPILL;
6719 mc->mc_xcursor->mx_cursor.mc_pg[0] = sub_root;
6720 new_dupdata = (int)dkey.mv_size;
6721 /* converted, write the original data first */
6723 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);
6726 /* we've done our job */
6729 if (!(leaf->mn_flags & F_SUBDATA) || sub_root) {
6730 /* Adjust other cursors pointing to mp */
6732 MDB_xcursor *mx = mc->mc_xcursor;
6733 unsigned i = mc->mc_top;
6734 MDB_page *mp = mc->mc_pg[i];
6735 int nkeys = NUMKEYS(mp);
6737 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
6738 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
6739 if (!(m2->mc_flags & C_INITIALIZED)) continue;
6740 if (m2->mc_pg[i] == mp) {
6741 if (m2->mc_ki[i] == mc->mc_ki[i]) {
6742 mdb_xcursor_init2(m2, mx, new_dupdata);
6743 } else if (!insert_key && m2->mc_ki[i] < nkeys) {
6744 MDB_node *n2 = NODEPTR(mp, m2->mc_ki[i]);
6745 if ((n2->mn_flags & (F_SUBDATA|F_DUPDATA)) == F_DUPDATA)
6746 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
6751 ecount = mc->mc_xcursor->mx_db.md_entries;
6752 if (flags & MDB_APPENDDUP)
6753 xflags |= MDB_APPEND;
6754 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);
6755 if (flags & F_SUBDATA) {
6756 void *db = NODEDATA(leaf);
6757 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
6759 insert_data = mc->mc_xcursor->mx_db.md_entries - ecount;
6761 /* Increment count unless we just replaced an existing item. */
6763 mc->mc_db->md_entries++;
6765 /* Invalidate txn if we created an empty sub-DB */
6768 /* If we succeeded and the key didn't exist before,
6769 * make sure the cursor is marked valid.
6771 mc->mc_flags |= C_INITIALIZED;
6773 if (flags & MDB_MULTIPLE) {
6776 /* let caller know how many succeeded, if any */
6777 data[1].mv_size = mcount;
6778 if (mcount < dcount) {
6779 data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size;
6780 insert_key = insert_data = 0;
6787 if (rc == MDB_KEYEXIST) /* should not happen, we deleted that item */
6790 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
6795 mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
6801 if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
6802 return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
6804 if (!(mc->mc_flags & C_INITIALIZED))
6807 if (mc->mc_ki[mc->mc_top] >= NUMKEYS(mc->mc_pg[mc->mc_top]))
6808 return MDB_NOTFOUND;
6810 if (!(flags & MDB_NOSPILL) && (rc = mdb_page_spill(mc, NULL, NULL)))
6813 rc = mdb_cursor_touch(mc);
6817 mp = mc->mc_pg[mc->mc_top];
6820 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6822 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6823 if (flags & MDB_NODUPDATA) {
6824 /* mdb_cursor_del0() will subtract the final entry */
6825 mc->mc_db->md_entries -= mc->mc_xcursor->mx_db.md_entries - 1;
6826 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
6828 if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
6829 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6831 rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, MDB_NOSPILL);
6834 /* If sub-DB still has entries, we're done */
6835 if (mc->mc_xcursor->mx_db.md_entries) {
6836 if (leaf->mn_flags & F_SUBDATA) {
6837 /* update subDB info */
6838 void *db = NODEDATA(leaf);
6839 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
6842 /* shrink fake page */
6843 mdb_node_shrink(mp, mc->mc_ki[mc->mc_top]);
6844 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6845 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6846 /* fix other sub-DB cursors pointed at fake pages on this page */
6847 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
6848 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
6849 if (!(m2->mc_flags & C_INITIALIZED)) continue;
6850 if (m2->mc_pg[mc->mc_top] == mp) {
6851 if (m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top]) {
6852 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6854 MDB_node *n2 = NODEPTR(mp, m2->mc_ki[mc->mc_top]);
6855 if (!(n2->mn_flags & F_SUBDATA))
6856 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
6861 mc->mc_db->md_entries--;
6862 mc->mc_flags |= C_DEL;
6865 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
6867 /* otherwise fall thru and delete the sub-DB */
6870 if (leaf->mn_flags & F_SUBDATA) {
6871 /* add all the child DB's pages to the free list */
6872 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
6877 /* LMDB passes F_SUBDATA in 'flags' to delete a DB record */
6878 else if ((leaf->mn_flags ^ flags) & F_SUBDATA) {
6879 rc = MDB_INCOMPATIBLE;
6883 /* add overflow pages to free list */
6884 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
6888 memcpy(&pg, NODEDATA(leaf), sizeof(pg));
6889 if ((rc = mdb_page_get(mc->mc_txn, pg, &omp, NULL)) ||
6890 (rc = mdb_ovpage_free(mc, omp)))
6895 return mdb_cursor_del0(mc);
6898 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
6902 /** Allocate and initialize new pages for a database.
6903 * @param[in] mc a cursor on the database being added to.
6904 * @param[in] flags flags defining what type of page is being allocated.
6905 * @param[in] num the number of pages to allocate. This is usually 1,
6906 * unless allocating overflow pages for a large record.
6907 * @param[out] mp Address of a page, or NULL on failure.
6908 * @return 0 on success, non-zero on failure.
6911 mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp)
6916 if ((rc = mdb_page_alloc(mc, num, &np)))
6918 DPRINTF(("allocated new mpage %"Z"u, page size %u",
6919 np->mp_pgno, mc->mc_txn->mt_env->me_psize));
6920 np->mp_flags = flags | P_DIRTY;
6921 np->mp_lower = (PAGEHDRSZ-PAGEBASE);
6922 np->mp_upper = mc->mc_txn->mt_env->me_psize - PAGEBASE;
6925 mc->mc_db->md_branch_pages++;
6926 else if (IS_LEAF(np))
6927 mc->mc_db->md_leaf_pages++;
6928 else if (IS_OVERFLOW(np)) {
6929 mc->mc_db->md_overflow_pages += num;
6937 /** Calculate the size of a leaf node.
6938 * The size depends on the environment's page size; if a data item
6939 * is too large it will be put onto an overflow page and the node
6940 * size will only include the key and not the data. Sizes are always
6941 * rounded up to an even number of bytes, to guarantee 2-byte alignment
6942 * of the #MDB_node headers.
6943 * @param[in] env The environment handle.
6944 * @param[in] key The key for the node.
6945 * @param[in] data The data for the node.
6946 * @return The number of bytes needed to store the node.
6949 mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data)
6953 sz = LEAFSIZE(key, data);
6954 if (sz > env->me_nodemax) {
6955 /* put on overflow page */
6956 sz -= data->mv_size - sizeof(pgno_t);
6959 return EVEN(sz + sizeof(indx_t));
6962 /** Calculate the size of a branch node.
6963 * The size should depend on the environment's page size but since
6964 * we currently don't support spilling large keys onto overflow
6965 * pages, it's simply the size of the #MDB_node header plus the
6966 * size of the key. Sizes are always rounded up to an even number
6967 * of bytes, to guarantee 2-byte alignment of the #MDB_node headers.
6968 * @param[in] env The environment handle.
6969 * @param[in] key The key for the node.
6970 * @return The number of bytes needed to store the node.
6973 mdb_branch_size(MDB_env *env, MDB_val *key)
6978 if (sz > env->me_nodemax) {
6979 /* put on overflow page */
6980 /* not implemented */
6981 /* sz -= key->size - sizeof(pgno_t); */
6984 return sz + sizeof(indx_t);
6987 /** Add a node to the page pointed to by the cursor.
6988 * @param[in] mc The cursor for this operation.
6989 * @param[in] indx The index on the page where the new node should be added.
6990 * @param[in] key The key for the new node.
6991 * @param[in] data The data for the new node, if any.
6992 * @param[in] pgno The page number, if adding a branch node.
6993 * @param[in] flags Flags for the node.
6994 * @return 0 on success, non-zero on failure. Possible errors are:
6996 * <li>ENOMEM - failed to allocate overflow pages for the node.
6997 * <li>MDB_PAGE_FULL - there is insufficient room in the page. This error
6998 * should never happen since all callers already calculate the
6999 * page's free space before calling this function.
7003 mdb_node_add(MDB_cursor *mc, indx_t indx,
7004 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags)
7007 size_t node_size = NODESIZE;
7011 MDB_page *mp = mc->mc_pg[mc->mc_top];
7012 MDB_page *ofp = NULL; /* overflow page */
7016 mdb_cassert(mc, mp->mp_upper >= mp->mp_lower);
7018 DPRINTF(("add to %s %spage %"Z"u index %i, data size %"Z"u key size %"Z"u [%s]",
7019 IS_LEAF(mp) ? "leaf" : "branch",
7020 IS_SUBP(mp) ? "sub-" : "",
7021 mdb_dbg_pgno(mp), indx, data ? data->mv_size : 0,
7022 key ? key->mv_size : 0, key ? DKEY(key) : "null"));
7025 /* Move higher keys up one slot. */
7026 int ksize = mc->mc_db->md_pad, dif;
7027 char *ptr = LEAF2KEY(mp, indx, ksize);
7028 dif = NUMKEYS(mp) - indx;
7030 memmove(ptr+ksize, ptr, dif*ksize);
7031 /* insert new key */
7032 memcpy(ptr, key->mv_data, ksize);
7034 /* Just using these for counting */
7035 mp->mp_lower += sizeof(indx_t);
7036 mp->mp_upper -= ksize - sizeof(indx_t);
7040 room = (ssize_t)SIZELEFT(mp) - (ssize_t)sizeof(indx_t);
7042 node_size += key->mv_size;
7044 mdb_cassert(mc, key && data);
7045 if (F_ISSET(flags, F_BIGDATA)) {
7046 /* Data already on overflow page. */
7047 node_size += sizeof(pgno_t);
7048 } else if (node_size + data->mv_size > mc->mc_txn->mt_env->me_nodemax) {
7049 int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
7051 /* Put data on overflow page. */
7052 DPRINTF(("data size is %"Z"u, node would be %"Z"u, put data on overflow page",
7053 data->mv_size, node_size+data->mv_size));
7054 node_size = EVEN(node_size + sizeof(pgno_t));
7055 if ((ssize_t)node_size > room)
7057 if ((rc = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp)))
7059 DPRINTF(("allocated overflow page %"Z"u", ofp->mp_pgno));
7063 node_size += data->mv_size;
7066 node_size = EVEN(node_size);
7067 if ((ssize_t)node_size > room)
7071 /* Move higher pointers up one slot. */
7072 for (i = NUMKEYS(mp); i > indx; i--)
7073 mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];
7075 /* Adjust free space offsets. */
7076 ofs = mp->mp_upper - node_size;
7077 mdb_cassert(mc, ofs >= mp->mp_lower + sizeof(indx_t));
7078 mp->mp_ptrs[indx] = ofs;
7080 mp->mp_lower += sizeof(indx_t);
7082 /* Write the node data. */
7083 node = NODEPTR(mp, indx);
7084 node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
7085 node->mn_flags = flags;
7087 SETDSZ(node,data->mv_size);
7092 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
7095 ndata = NODEDATA(node);
7097 if (F_ISSET(flags, F_BIGDATA))
7098 memcpy(ndata, data->mv_data, sizeof(pgno_t));
7099 else if (F_ISSET(flags, MDB_RESERVE))
7100 data->mv_data = ndata;
7102 memcpy(ndata, data->mv_data, data->mv_size);
7104 memcpy(ndata, &ofp->mp_pgno, sizeof(pgno_t));
7105 ndata = METADATA(ofp);
7106 if (F_ISSET(flags, MDB_RESERVE))
7107 data->mv_data = ndata;
7109 memcpy(ndata, data->mv_data, data->mv_size);
7116 DPRINTF(("not enough room in page %"Z"u, got %u ptrs",
7117 mdb_dbg_pgno(mp), NUMKEYS(mp)));
7118 DPRINTF(("upper-lower = %u - %u = %"Z"d", mp->mp_upper,mp->mp_lower,room));
7119 DPRINTF(("node size = %"Z"u", node_size));
7120 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
7121 return MDB_PAGE_FULL;
7124 /** Delete the specified node from a page.
7125 * @param[in] mc Cursor pointing to the node to delete.
7126 * @param[in] ksize The size of a node. Only used if the page is
7127 * part of a #MDB_DUPFIXED database.
7130 mdb_node_del(MDB_cursor *mc, int ksize)
7132 MDB_page *mp = mc->mc_pg[mc->mc_top];
7133 indx_t indx = mc->mc_ki[mc->mc_top];
7135 indx_t i, j, numkeys, ptr;
7139 DPRINTF(("delete node %u on %s page %"Z"u", indx,
7140 IS_LEAF(mp) ? "leaf" : "branch", mdb_dbg_pgno(mp)));
7141 numkeys = NUMKEYS(mp);
7142 mdb_cassert(mc, indx < numkeys);
7145 int x = numkeys - 1 - indx;
7146 base = LEAF2KEY(mp, indx, ksize);
7148 memmove(base, base + ksize, x * ksize);
7149 mp->mp_lower -= sizeof(indx_t);
7150 mp->mp_upper += ksize - sizeof(indx_t);
7154 node = NODEPTR(mp, indx);
7155 sz = NODESIZE + node->mn_ksize;
7157 if (F_ISSET(node->mn_flags, F_BIGDATA))
7158 sz += sizeof(pgno_t);
7160 sz += NODEDSZ(node);
7164 ptr = mp->mp_ptrs[indx];
7165 for (i = j = 0; i < numkeys; i++) {
7167 mp->mp_ptrs[j] = mp->mp_ptrs[i];
7168 if (mp->mp_ptrs[i] < ptr)
7169 mp->mp_ptrs[j] += sz;
7174 base = (char *)mp + mp->mp_upper + PAGEBASE;
7175 memmove(base + sz, base, ptr - mp->mp_upper);
7177 mp->mp_lower -= sizeof(indx_t);
7181 /** Compact the main page after deleting a node on a subpage.
7182 * @param[in] mp The main page to operate on.
7183 * @param[in] indx The index of the subpage on the main page.
7186 mdb_node_shrink(MDB_page *mp, indx_t indx)
7191 indx_t delta, nsize, len, ptr;
7194 node = NODEPTR(mp, indx);
7195 sp = (MDB_page *)NODEDATA(node);
7196 delta = SIZELEFT(sp);
7197 nsize = NODEDSZ(node) - delta;
7199 /* Prepare to shift upward, set len = length(subpage part to shift) */
7203 return; /* do not make the node uneven-sized */
7205 xp = (MDB_page *)((char *)sp + delta); /* destination subpage */
7206 for (i = NUMKEYS(sp); --i >= 0; )
7207 xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta;
7210 sp->mp_upper = sp->mp_lower;
7211 COPY_PGNO(sp->mp_pgno, mp->mp_pgno);
7212 SETDSZ(node, nsize);
7214 /* Shift <lower nodes...initial part of subpage> upward */
7215 base = (char *)mp + mp->mp_upper + PAGEBASE;
7216 memmove(base + delta, base, (char *)sp + len - base);
7218 ptr = mp->mp_ptrs[indx];
7219 for (i = NUMKEYS(mp); --i >= 0; ) {
7220 if (mp->mp_ptrs[i] <= ptr)
7221 mp->mp_ptrs[i] += delta;
7223 mp->mp_upper += delta;
7226 /** Initial setup of a sorted-dups cursor.
7227 * Sorted duplicates are implemented as a sub-database for the given key.
7228 * The duplicate data items are actually keys of the sub-database.
7229 * Operations on the duplicate data items are performed using a sub-cursor
7230 * initialized when the sub-database is first accessed. This function does
7231 * the preliminary setup of the sub-cursor, filling in the fields that
7232 * depend only on the parent DB.
7233 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
7236 mdb_xcursor_init0(MDB_cursor *mc)
7238 MDB_xcursor *mx = mc->mc_xcursor;
7240 mx->mx_cursor.mc_xcursor = NULL;
7241 mx->mx_cursor.mc_txn = mc->mc_txn;
7242 mx->mx_cursor.mc_db = &mx->mx_db;
7243 mx->mx_cursor.mc_dbx = &mx->mx_dbx;
7244 mx->mx_cursor.mc_dbi = mc->mc_dbi;
7245 mx->mx_cursor.mc_dbflag = &mx->mx_dbflag;
7246 mx->mx_cursor.mc_snum = 0;
7247 mx->mx_cursor.mc_top = 0;
7248 mx->mx_cursor.mc_flags = C_SUB;
7249 mx->mx_dbx.md_name.mv_size = 0;
7250 mx->mx_dbx.md_name.mv_data = NULL;
7251 mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp;
7252 mx->mx_dbx.md_dcmp = NULL;
7253 mx->mx_dbx.md_rel = mc->mc_dbx->md_rel;
7256 /** Final setup of a sorted-dups cursor.
7257 * Sets up the fields that depend on the data from the main cursor.
7258 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
7259 * @param[in] node The data containing the #MDB_db record for the
7260 * sorted-dup database.
7263 mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)
7265 MDB_xcursor *mx = mc->mc_xcursor;
7267 if (node->mn_flags & F_SUBDATA) {
7268 memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db));
7269 mx->mx_cursor.mc_pg[0] = 0;
7270 mx->mx_cursor.mc_snum = 0;
7271 mx->mx_cursor.mc_top = 0;
7272 mx->mx_cursor.mc_flags = C_SUB;
7274 MDB_page *fp = NODEDATA(node);
7275 mx->mx_db.md_pad = 0;
7276 mx->mx_db.md_flags = 0;
7277 mx->mx_db.md_depth = 1;
7278 mx->mx_db.md_branch_pages = 0;
7279 mx->mx_db.md_leaf_pages = 1;
7280 mx->mx_db.md_overflow_pages = 0;
7281 mx->mx_db.md_entries = NUMKEYS(fp);
7282 COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno);
7283 mx->mx_cursor.mc_snum = 1;
7284 mx->mx_cursor.mc_top = 0;
7285 mx->mx_cursor.mc_flags = C_INITIALIZED|C_SUB;
7286 mx->mx_cursor.mc_pg[0] = fp;
7287 mx->mx_cursor.mc_ki[0] = 0;
7288 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
7289 mx->mx_db.md_flags = MDB_DUPFIXED;
7290 mx->mx_db.md_pad = fp->mp_pad;
7291 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
7292 mx->mx_db.md_flags |= MDB_INTEGERKEY;
7295 DPRINTF(("Sub-db -%u root page %"Z"u", mx->mx_cursor.mc_dbi,
7296 mx->mx_db.md_root));
7297 mx->mx_dbflag = DB_VALID|DB_USRVALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
7298 #if UINT_MAX < SIZE_MAX
7299 if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(size_t))
7300 mx->mx_dbx.md_cmp = mdb_cmp_clong;
7305 /** Fixup a sorted-dups cursor due to underlying update.
7306 * Sets up some fields that depend on the data from the main cursor.
7307 * Almost the same as init1, but skips initialization steps if the
7308 * xcursor had already been used.
7309 * @param[in] mc The main cursor whose sorted-dups cursor is to be fixed up.
7310 * @param[in] src_mx The xcursor of an up-to-date cursor.
7311 * @param[in] new_dupdata True if converting from a non-#F_DUPDATA item.
7314 mdb_xcursor_init2(MDB_cursor *mc, MDB_xcursor *src_mx, int new_dupdata)
7316 MDB_xcursor *mx = mc->mc_xcursor;
7319 mx->mx_cursor.mc_snum = 1;
7320 mx->mx_cursor.mc_top = 0;
7321 mx->mx_cursor.mc_flags |= C_INITIALIZED;
7322 mx->mx_cursor.mc_ki[0] = 0;
7323 mx->mx_dbflag = DB_VALID|DB_USRVALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
7324 #if UINT_MAX < SIZE_MAX
7325 mx->mx_dbx.md_cmp = src_mx->mx_dbx.md_cmp;
7327 } else if (!(mx->mx_cursor.mc_flags & C_INITIALIZED)) {
7330 mx->mx_db = src_mx->mx_db;
7331 mx->mx_cursor.mc_pg[0] = src_mx->mx_cursor.mc_pg[0];
7332 DPRINTF(("Sub-db -%u root page %"Z"u", mx->mx_cursor.mc_dbi,
7333 mx->mx_db.md_root));
7336 /** Initialize a cursor for a given transaction and database. */
7338 mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
7341 mc->mc_backup = NULL;
7344 mc->mc_db = &txn->mt_dbs[dbi];
7345 mc->mc_dbx = &txn->mt_dbxs[dbi];
7346 mc->mc_dbflag = &txn->mt_dbflags[dbi];
7352 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
7353 mdb_tassert(txn, mx != NULL);
7354 mc->mc_xcursor = mx;
7355 mdb_xcursor_init0(mc);
7357 mc->mc_xcursor = NULL;
7359 if (*mc->mc_dbflag & DB_STALE) {
7360 mdb_page_search(mc, NULL, MDB_PS_ROOTONLY);
7365 mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
7368 size_t size = sizeof(MDB_cursor);
7370 if (!ret || !TXN_DBI_EXIST(txn, dbi, DB_VALID))
7373 if (txn->mt_flags & MDB_TXN_BLOCKED)
7376 if (dbi == FREE_DBI && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
7379 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)
7380 size += sizeof(MDB_xcursor);
7382 if ((mc = malloc(size)) != NULL) {
7383 mdb_cursor_init(mc, txn, dbi, (MDB_xcursor *)(mc + 1));
7384 if (txn->mt_cursors) {
7385 mc->mc_next = txn->mt_cursors[dbi];
7386 txn->mt_cursors[dbi] = mc;
7387 mc->mc_flags |= C_UNTRACK;
7399 mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)
7401 if (!mc || !TXN_DBI_EXIST(txn, mc->mc_dbi, DB_VALID))
7404 if ((mc->mc_flags & C_UNTRACK) || txn->mt_cursors)
7407 if (txn->mt_flags & MDB_TXN_BLOCKED)
7410 mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor);
7414 /* Return the count of duplicate data items for the current key */
7416 mdb_cursor_count(MDB_cursor *mc, size_t *countp)
7420 if (mc == NULL || countp == NULL)
7423 if (mc->mc_xcursor == NULL)
7424 return MDB_INCOMPATIBLE;
7426 if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)
7429 if (!(mc->mc_flags & C_INITIALIZED))
7432 if (!mc->mc_snum || (mc->mc_flags & C_EOF))
7433 return MDB_NOTFOUND;
7435 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
7436 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
7439 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
7442 *countp = mc->mc_xcursor->mx_db.md_entries;
7448 mdb_cursor_close(MDB_cursor *mc)
7450 if (mc && !mc->mc_backup) {
7451 /* remove from txn, if tracked */
7452 if ((mc->mc_flags & C_UNTRACK) && mc->mc_txn->mt_cursors) {
7453 MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi];
7454 while (*prev && *prev != mc) prev = &(*prev)->mc_next;
7456 *prev = mc->mc_next;
7463 mdb_cursor_txn(MDB_cursor *mc)
7465 if (!mc) return NULL;
7470 mdb_cursor_dbi(MDB_cursor *mc)
7475 /** Replace the key for a branch node with a new key.
7476 * @param[in] mc Cursor pointing to the node to operate on.
7477 * @param[in] key The new key to use.
7478 * @return 0 on success, non-zero on failure.
7481 mdb_update_key(MDB_cursor *mc, MDB_val *key)
7487 int delta, ksize, oksize;
7488 indx_t ptr, i, numkeys, indx;
7491 indx = mc->mc_ki[mc->mc_top];
7492 mp = mc->mc_pg[mc->mc_top];
7493 node = NODEPTR(mp, indx);
7494 ptr = mp->mp_ptrs[indx];
7498 char kbuf2[DKBUF_MAXKEYSIZE*2+1];
7499 k2.mv_data = NODEKEY(node);
7500 k2.mv_size = node->mn_ksize;
7501 DPRINTF(("update key %u (ofs %u) [%s] to [%s] on page %"Z"u",
7503 mdb_dkey(&k2, kbuf2),
7509 /* Sizes must be 2-byte aligned. */
7510 ksize = EVEN(key->mv_size);
7511 oksize = EVEN(node->mn_ksize);
7512 delta = ksize - oksize;
7514 /* Shift node contents if EVEN(key length) changed. */
7516 if (delta > 0 && SIZELEFT(mp) < delta) {
7518 /* not enough space left, do a delete and split */
7519 DPRINTF(("Not enough room, delta = %d, splitting...", delta));
7520 pgno = NODEPGNO(node);
7521 mdb_node_del(mc, 0);
7522 return mdb_page_split(mc, key, NULL, pgno, MDB_SPLIT_REPLACE);
7525 numkeys = NUMKEYS(mp);
7526 for (i = 0; i < numkeys; i++) {
7527 if (mp->mp_ptrs[i] <= ptr)
7528 mp->mp_ptrs[i] -= delta;
7531 base = (char *)mp + mp->mp_upper + PAGEBASE;
7532 len = ptr - mp->mp_upper + NODESIZE;
7533 memmove(base - delta, base, len);
7534 mp->mp_upper -= delta;
7536 node = NODEPTR(mp, indx);
7539 /* But even if no shift was needed, update ksize */
7540 if (node->mn_ksize != key->mv_size)
7541 node->mn_ksize = key->mv_size;
7544 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
7550 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst);
7552 /** Perform \b act while tracking temporary cursor \b mn */
7553 #define WITH_CURSOR_TRACKING(mn, act) do { \
7554 MDB_cursor dummy, *tracked, **tp = &(mn).mc_txn->mt_cursors[mn.mc_dbi]; \
7555 if ((mn).mc_flags & C_SUB) { \
7556 dummy.mc_flags = C_INITIALIZED; \
7557 dummy.mc_xcursor = (MDB_xcursor *)&(mn); \
7562 tracked->mc_next = *tp; \
7565 *tp = tracked->mc_next; \
7568 /** Move a node from csrc to cdst.
7571 mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft)
7578 unsigned short flags;
7582 /* Mark src and dst as dirty. */
7583 if ((rc = mdb_page_touch(csrc)) ||
7584 (rc = mdb_page_touch(cdst)))
7587 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7588 key.mv_size = csrc->mc_db->md_pad;
7589 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
7591 data.mv_data = NULL;
7595 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]);
7596 mdb_cassert(csrc, !((size_t)srcnode & 1));
7597 srcpg = NODEPGNO(srcnode);
7598 flags = srcnode->mn_flags;
7599 if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
7600 unsigned int snum = csrc->mc_snum;
7602 /* must find the lowest key below src */
7603 rc = mdb_page_search_lowest(csrc);
7606 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7607 key.mv_size = csrc->mc_db->md_pad;
7608 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
7610 s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
7611 key.mv_size = NODEKSZ(s2);
7612 key.mv_data = NODEKEY(s2);
7614 csrc->mc_snum = snum--;
7615 csrc->mc_top = snum;
7617 key.mv_size = NODEKSZ(srcnode);
7618 key.mv_data = NODEKEY(srcnode);
7620 data.mv_size = NODEDSZ(srcnode);
7621 data.mv_data = NODEDATA(srcnode);
7623 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) {
7624 unsigned int snum = cdst->mc_snum;
7627 /* must find the lowest key below dst */
7628 mdb_cursor_copy(cdst, &mn);
7629 rc = mdb_page_search_lowest(&mn);
7632 if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {
7633 bkey.mv_size = mn.mc_db->md_pad;
7634 bkey.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, bkey.mv_size);
7636 s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);
7637 bkey.mv_size = NODEKSZ(s2);
7638 bkey.mv_data = NODEKEY(s2);
7640 mn.mc_snum = snum--;
7643 rc = mdb_update_key(&mn, &bkey);
7648 DPRINTF(("moving %s node %u [%s] on page %"Z"u to node %u on page %"Z"u",
7649 IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch",
7650 csrc->mc_ki[csrc->mc_top],
7652 csrc->mc_pg[csrc->mc_top]->mp_pgno,
7653 cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno));
7655 /* Add the node to the destination page.
7657 rc = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags);
7658 if (rc != MDB_SUCCESS)
7661 /* Delete the node from the source page.
7663 mdb_node_del(csrc, key.mv_size);
7666 /* Adjust other cursors pointing to mp */
7667 MDB_cursor *m2, *m3;
7668 MDB_dbi dbi = csrc->mc_dbi;
7669 MDB_page *mpd, *mps;
7671 mps = csrc->mc_pg[csrc->mc_top];
7672 /* If we're adding on the left, bump others up */
7674 mpd = cdst->mc_pg[csrc->mc_top];
7675 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7676 if (csrc->mc_flags & C_SUB)
7677 m3 = &m2->mc_xcursor->mx_cursor;
7680 if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)
7683 m3->mc_pg[csrc->mc_top] == mpd &&
7684 m3->mc_ki[csrc->mc_top] >= cdst->mc_ki[csrc->mc_top]) {
7685 m3->mc_ki[csrc->mc_top]++;
7688 m3->mc_pg[csrc->mc_top] == mps &&
7689 m3->mc_ki[csrc->mc_top] == csrc->mc_ki[csrc->mc_top]) {
7690 m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
7691 m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
7692 m3->mc_ki[csrc->mc_top-1]++;
7696 /* Adding on the right, bump others down */
7698 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7699 if (csrc->mc_flags & C_SUB)
7700 m3 = &m2->mc_xcursor->mx_cursor;
7703 if (m3 == csrc) continue;
7704 if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)
7706 if (m3->mc_pg[csrc->mc_top] == mps) {
7707 if (!m3->mc_ki[csrc->mc_top]) {
7708 m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
7709 m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
7710 m3->mc_ki[csrc->mc_top-1]--;
7712 m3->mc_ki[csrc->mc_top]--;
7719 /* Update the parent separators.
7721 if (csrc->mc_ki[csrc->mc_top] == 0) {
7722 if (csrc->mc_ki[csrc->mc_top-1] != 0) {
7723 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7724 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
7726 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
7727 key.mv_size = NODEKSZ(srcnode);
7728 key.mv_data = NODEKEY(srcnode);
7730 DPRINTF(("update separator for source page %"Z"u to [%s]",
7731 csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key)));
7732 mdb_cursor_copy(csrc, &mn);
7735 /* We want mdb_rebalance to find mn when doing fixups */
7736 WITH_CURSOR_TRACKING(mn,
7737 rc = mdb_update_key(&mn, &key));
7741 if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
7743 indx_t ix = csrc->mc_ki[csrc->mc_top];
7744 nullkey.mv_size = 0;
7745 csrc->mc_ki[csrc->mc_top] = 0;
7746 rc = mdb_update_key(csrc, &nullkey);
7747 csrc->mc_ki[csrc->mc_top] = ix;
7748 mdb_cassert(csrc, rc == MDB_SUCCESS);
7752 if (cdst->mc_ki[cdst->mc_top] == 0) {
7753 if (cdst->mc_ki[cdst->mc_top-1] != 0) {
7754 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7755 key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size);
7757 srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
7758 key.mv_size = NODEKSZ(srcnode);
7759 key.mv_data = NODEKEY(srcnode);
7761 DPRINTF(("update separator for destination page %"Z"u to [%s]",
7762 cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key)));
7763 mdb_cursor_copy(cdst, &mn);
7766 /* We want mdb_rebalance to find mn when doing fixups */
7767 WITH_CURSOR_TRACKING(mn,
7768 rc = mdb_update_key(&mn, &key));
7772 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) {
7774 indx_t ix = cdst->mc_ki[cdst->mc_top];
7775 nullkey.mv_size = 0;
7776 cdst->mc_ki[cdst->mc_top] = 0;
7777 rc = mdb_update_key(cdst, &nullkey);
7778 cdst->mc_ki[cdst->mc_top] = ix;
7779 mdb_cassert(cdst, rc == MDB_SUCCESS);
7786 /** Merge one page into another.
7787 * The nodes from the page pointed to by \b csrc will
7788 * be copied to the page pointed to by \b cdst and then
7789 * the \b csrc page will be freed.
7790 * @param[in] csrc Cursor pointing to the source page.
7791 * @param[in] cdst Cursor pointing to the destination page.
7792 * @return 0 on success, non-zero on failure.
7795 mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
7797 MDB_page *psrc, *pdst;
7804 psrc = csrc->mc_pg[csrc->mc_top];
7805 pdst = cdst->mc_pg[cdst->mc_top];
7807 DPRINTF(("merging page %"Z"u into %"Z"u", psrc->mp_pgno, pdst->mp_pgno));
7809 mdb_cassert(csrc, csrc->mc_snum > 1); /* can't merge root page */
7810 mdb_cassert(csrc, cdst->mc_snum > 1);
7812 /* Mark dst as dirty. */
7813 if ((rc = mdb_page_touch(cdst)))
7816 /* get dst page again now that we've touched it. */
7817 pdst = cdst->mc_pg[cdst->mc_top];
7819 /* Move all nodes from src to dst.
7821 j = nkeys = NUMKEYS(pdst);
7822 if (IS_LEAF2(psrc)) {
7823 key.mv_size = csrc->mc_db->md_pad;
7824 key.mv_data = METADATA(psrc);
7825 for (i = 0; i < NUMKEYS(psrc); i++, j++) {
7826 rc = mdb_node_add(cdst, j, &key, NULL, 0, 0);
7827 if (rc != MDB_SUCCESS)
7829 key.mv_data = (char *)key.mv_data + key.mv_size;
7832 for (i = 0; i < NUMKEYS(psrc); i++, j++) {
7833 srcnode = NODEPTR(psrc, i);
7834 if (i == 0 && IS_BRANCH(psrc)) {
7837 mdb_cursor_copy(csrc, &mn);
7838 /* must find the lowest key below src */
7839 rc = mdb_page_search_lowest(&mn);
7842 if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {
7843 key.mv_size = mn.mc_db->md_pad;
7844 key.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, key.mv_size);
7846 s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);
7847 key.mv_size = NODEKSZ(s2);
7848 key.mv_data = NODEKEY(s2);
7851 key.mv_size = srcnode->mn_ksize;
7852 key.mv_data = NODEKEY(srcnode);
7855 data.mv_size = NODEDSZ(srcnode);
7856 data.mv_data = NODEDATA(srcnode);
7857 rc = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags);
7858 if (rc != MDB_SUCCESS)
7863 DPRINTF(("dst page %"Z"u now has %u keys (%.1f%% filled)",
7864 pdst->mp_pgno, NUMKEYS(pdst),
7865 (float)PAGEFILL(cdst->mc_txn->mt_env, pdst) / 10));
7867 /* Unlink the src page from parent and add to free list.
7870 mdb_node_del(csrc, 0);
7871 if (csrc->mc_ki[csrc->mc_top] == 0) {
7873 rc = mdb_update_key(csrc, &key);
7881 psrc = csrc->mc_pg[csrc->mc_top];
7882 /* If not operating on FreeDB, allow this page to be reused
7883 * in this txn. Otherwise just add to free list.
7885 rc = mdb_page_loose(csrc, psrc);
7889 csrc->mc_db->md_leaf_pages--;
7891 csrc->mc_db->md_branch_pages--;
7893 /* Adjust other cursors pointing to mp */
7894 MDB_cursor *m2, *m3;
7895 MDB_dbi dbi = csrc->mc_dbi;
7896 unsigned int top = csrc->mc_top;
7898 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7899 if (csrc->mc_flags & C_SUB)
7900 m3 = &m2->mc_xcursor->mx_cursor;
7903 if (m3 == csrc) continue;
7904 if (m3->mc_snum < csrc->mc_snum) continue;
7905 if (m3->mc_pg[top] == psrc) {
7906 m3->mc_pg[top] = pdst;
7907 m3->mc_ki[top] += nkeys;
7908 m3->mc_ki[top-1] = cdst->mc_ki[top-1];
7909 } else if (m3->mc_pg[top-1] == csrc->mc_pg[top-1] &&
7910 m3->mc_ki[top-1] > csrc->mc_ki[top-1]) {
7916 unsigned int snum = cdst->mc_snum;
7917 uint16_t depth = cdst->mc_db->md_depth;
7918 mdb_cursor_pop(cdst);
7919 rc = mdb_rebalance(cdst);
7920 /* Did the tree height change? */
7921 if (depth != cdst->mc_db->md_depth)
7922 snum += cdst->mc_db->md_depth - depth;
7923 cdst->mc_snum = snum;
7924 cdst->mc_top = snum-1;
7929 /** Copy the contents of a cursor.
7930 * @param[in] csrc The cursor to copy from.
7931 * @param[out] cdst The cursor to copy to.
7934 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst)
7938 cdst->mc_txn = csrc->mc_txn;
7939 cdst->mc_dbi = csrc->mc_dbi;
7940 cdst->mc_db = csrc->mc_db;
7941 cdst->mc_dbx = csrc->mc_dbx;
7942 cdst->mc_snum = csrc->mc_snum;
7943 cdst->mc_top = csrc->mc_top;
7944 cdst->mc_flags = csrc->mc_flags;
7946 for (i=0; i<csrc->mc_snum; i++) {
7947 cdst->mc_pg[i] = csrc->mc_pg[i];
7948 cdst->mc_ki[i] = csrc->mc_ki[i];
7952 /** Rebalance the tree after a delete operation.
7953 * @param[in] mc Cursor pointing to the page where rebalancing
7955 * @return 0 on success, non-zero on failure.
7958 mdb_rebalance(MDB_cursor *mc)
7962 unsigned int ptop, minkeys, thresh;
7966 if (IS_BRANCH(mc->mc_pg[mc->mc_top])) {
7971 thresh = FILL_THRESHOLD;
7973 DPRINTF(("rebalancing %s page %"Z"u (has %u keys, %.1f%% full)",
7974 IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",
7975 mdb_dbg_pgno(mc->mc_pg[mc->mc_top]), NUMKEYS(mc->mc_pg[mc->mc_top]),
7976 (float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10));
7978 if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= thresh &&
7979 NUMKEYS(mc->mc_pg[mc->mc_top]) >= minkeys) {
7980 DPRINTF(("no need to rebalance page %"Z"u, above fill threshold",
7981 mdb_dbg_pgno(mc->mc_pg[mc->mc_top])));
7985 if (mc->mc_snum < 2) {
7986 MDB_page *mp = mc->mc_pg[0];
7988 DPUTS("Can't rebalance a subpage, ignoring");
7991 if (NUMKEYS(mp) == 0) {
7992 DPUTS("tree is completely empty");
7993 mc->mc_db->md_root = P_INVALID;
7994 mc->mc_db->md_depth = 0;
7995 mc->mc_db->md_leaf_pages = 0;
7996 rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
7999 /* Adjust cursors pointing to mp */
8002 mc->mc_flags &= ~C_INITIALIZED;
8004 MDB_cursor *m2, *m3;
8005 MDB_dbi dbi = mc->mc_dbi;
8007 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8008 if (mc->mc_flags & C_SUB)
8009 m3 = &m2->mc_xcursor->mx_cursor;
8012 if (!(m3->mc_flags & C_INITIALIZED) || (m3->mc_snum < mc->mc_snum))
8014 if (m3->mc_pg[0] == mp) {
8017 m3->mc_flags &= ~C_INITIALIZED;
8021 } else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) {
8023 DPUTS("collapsing root page!");
8024 rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
8027 mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0));
8028 rc = mdb_page_get(mc->mc_txn,mc->mc_db->md_root,&mc->mc_pg[0],NULL);
8031 mc->mc_db->md_depth--;
8032 mc->mc_db->md_branch_pages--;
8033 mc->mc_ki[0] = mc->mc_ki[1];
8034 for (i = 1; i<mc->mc_db->md_depth; i++) {
8035 mc->mc_pg[i] = mc->mc_pg[i+1];
8036 mc->mc_ki[i] = mc->mc_ki[i+1];
8039 /* Adjust other cursors pointing to mp */
8040 MDB_cursor *m2, *m3;
8041 MDB_dbi dbi = mc->mc_dbi;
8043 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8044 if (mc->mc_flags & C_SUB)
8045 m3 = &m2->mc_xcursor->mx_cursor;
8048 if (m3 == mc) continue;
8049 if (!(m3->mc_flags & C_INITIALIZED))
8051 if (m3->mc_pg[0] == mp) {
8052 for (i=0; i<mc->mc_db->md_depth; i++) {
8053 m3->mc_pg[i] = m3->mc_pg[i+1];
8054 m3->mc_ki[i] = m3->mc_ki[i+1];
8062 DPUTS("root page doesn't need rebalancing");
8066 /* The parent (branch page) must have at least 2 pointers,
8067 * otherwise the tree is invalid.
8069 ptop = mc->mc_top-1;
8070 mdb_cassert(mc, NUMKEYS(mc->mc_pg[ptop]) > 1);
8072 /* Leaf page fill factor is below the threshold.
8073 * Try to move keys from left or right neighbor, or
8074 * merge with a neighbor page.
8079 mdb_cursor_copy(mc, &mn);
8080 mn.mc_xcursor = NULL;
8082 oldki = mc->mc_ki[mc->mc_top];
8083 if (mc->mc_ki[ptop] == 0) {
8084 /* We're the leftmost leaf in our parent.
8086 DPUTS("reading right neighbor");
8088 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
8089 rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
8092 mn.mc_ki[mn.mc_top] = 0;
8093 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);
8096 /* There is at least one neighbor to the left.
8098 DPUTS("reading left neighbor");
8100 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
8101 rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
8104 mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;
8105 mc->mc_ki[mc->mc_top] = 0;
8109 DPRINTF(("found neighbor page %"Z"u (%u keys, %.1f%% full)",
8110 mn.mc_pg[mn.mc_top]->mp_pgno, NUMKEYS(mn.mc_pg[mn.mc_top]),
8111 (float)PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) / 10));
8113 /* If the neighbor page is above threshold and has enough keys,
8114 * move one key from it. Otherwise we should try to merge them.
8115 * (A branch page must never have less than 2 keys.)
8117 if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= thresh && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) {
8118 rc = mdb_node_move(&mn, mc, fromleft);
8120 /* if we inserted on left, bump position up */
8125 rc = mdb_page_merge(&mn, mc);
8127 oldki += NUMKEYS(mn.mc_pg[mn.mc_top]);
8128 mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1;
8129 /* We want mdb_rebalance to find mn when doing fixups */
8130 WITH_CURSOR_TRACKING(mn,
8131 rc = mdb_page_merge(mc, &mn));
8132 mdb_cursor_copy(&mn, mc);
8134 mc->mc_flags &= ~C_EOF;
8136 mc->mc_ki[mc->mc_top] = oldki;
8140 /** Complete a delete operation started by #mdb_cursor_del(). */
8142 mdb_cursor_del0(MDB_cursor *mc)
8148 MDB_cursor *m2, *m3;
8149 MDB_dbi dbi = mc->mc_dbi;
8151 ki = mc->mc_ki[mc->mc_top];
8152 mp = mc->mc_pg[mc->mc_top];
8153 mdb_node_del(mc, mc->mc_db->md_pad);
8154 mc->mc_db->md_entries--;
8156 /* Adjust other cursors pointing to mp */
8157 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8158 m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;
8159 if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))
8161 if (m3 == mc || m3->mc_snum < mc->mc_snum)
8163 if (m3->mc_pg[mc->mc_top] == mp) {
8164 if (m3->mc_ki[mc->mc_top] >= ki) {
8165 m3->mc_flags |= C_DEL;
8166 if (m3->mc_ki[mc->mc_top] > ki)
8167 m3->mc_ki[mc->mc_top]--;
8168 else if (mc->mc_db->md_flags & MDB_DUPSORT)
8169 m3->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
8174 rc = mdb_rebalance(mc);
8176 if (rc == MDB_SUCCESS) {
8177 /* DB is totally empty now, just bail out.
8178 * Other cursors adjustments were already done
8179 * by mdb_rebalance and aren't needed here.
8184 mp = mc->mc_pg[mc->mc_top];
8185 nkeys = NUMKEYS(mp);
8187 /* Adjust other cursors pointing to mp */
8188 for (m2 = mc->mc_txn->mt_cursors[dbi]; !rc && m2; m2=m2->mc_next) {
8189 m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;
8190 if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))
8192 if (m3->mc_snum < mc->mc_snum)
8194 if (m3->mc_pg[mc->mc_top] == mp) {
8195 /* if m3 points past last node in page, find next sibling */
8196 if (m3->mc_ki[mc->mc_top] >= nkeys) {
8197 rc = mdb_cursor_sibling(m3, 1);
8198 if (rc == MDB_NOTFOUND) {
8199 m3->mc_flags |= C_EOF;
8205 mc->mc_flags |= C_DEL;
8209 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
8214 mdb_del(MDB_txn *txn, MDB_dbi dbi,
8215 MDB_val *key, MDB_val *data)
8217 if (!key || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
8220 if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
8221 return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
8223 if (!F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
8224 /* must ignore any data */
8228 return mdb_del0(txn, dbi, key, data, 0);
8232 mdb_del0(MDB_txn *txn, MDB_dbi dbi,
8233 MDB_val *key, MDB_val *data, unsigned flags)
8238 MDB_val rdata, *xdata;
8242 DPRINTF(("====> delete db %u key [%s]", dbi, DKEY(key)));
8244 mdb_cursor_init(&mc, txn, dbi, &mx);
8253 flags |= MDB_NODUPDATA;
8255 rc = mdb_cursor_set(&mc, key, xdata, op, &exact);
8257 /* let mdb_page_split know about this cursor if needed:
8258 * delete will trigger a rebalance; if it needs to move
8259 * a node from one page to another, it will have to
8260 * update the parent's separator key(s). If the new sepkey
8261 * is larger than the current one, the parent page may
8262 * run out of space, triggering a split. We need this
8263 * cursor to be consistent until the end of the rebalance.
8265 mc.mc_flags |= C_UNTRACK;
8266 mc.mc_next = txn->mt_cursors[dbi];
8267 txn->mt_cursors[dbi] = &mc;
8268 rc = mdb_cursor_del(&mc, flags);
8269 txn->mt_cursors[dbi] = mc.mc_next;
8274 /** Split a page and insert a new node.
8275 * @param[in,out] mc Cursor pointing to the page and desired insertion index.
8276 * The cursor will be updated to point to the actual page and index where
8277 * the node got inserted after the split.
8278 * @param[in] newkey The key for the newly inserted node.
8279 * @param[in] newdata The data for the newly inserted node.
8280 * @param[in] newpgno The page number, if the new node is a branch node.
8281 * @param[in] nflags The #NODE_ADD_FLAGS for the new node.
8282 * @return 0 on success, non-zero on failure.
8285 mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno,
8286 unsigned int nflags)
8289 int rc = MDB_SUCCESS, new_root = 0, did_split = 0;
8292 int i, j, split_indx, nkeys, pmax;
8293 MDB_env *env = mc->mc_txn->mt_env;
8295 MDB_val sepkey, rkey, xdata, *rdata = &xdata;
8296 MDB_page *copy = NULL;
8297 MDB_page *mp, *rp, *pp;
8302 mp = mc->mc_pg[mc->mc_top];
8303 newindx = mc->mc_ki[mc->mc_top];
8304 nkeys = NUMKEYS(mp);
8306 DPRINTF(("-----> splitting %s page %"Z"u and adding [%s] at index %i/%i",
8307 IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno,
8308 DKEY(newkey), mc->mc_ki[mc->mc_top], nkeys));
8310 /* Create a right sibling. */
8311 if ((rc = mdb_page_new(mc, mp->mp_flags, 1, &rp)))
8313 rp->mp_pad = mp->mp_pad;
8314 DPRINTF(("new right sibling: page %"Z"u", rp->mp_pgno));
8316 /* Usually when splitting the root page, the cursor
8317 * height is 1. But when called from mdb_update_key,
8318 * the cursor height may be greater because it walks
8319 * up the stack while finding the branch slot to update.
8321 if (mc->mc_top < 1) {
8322 if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp)))
8324 /* shift current top to make room for new parent */
8325 for (i=mc->mc_snum; i>0; i--) {
8326 mc->mc_pg[i] = mc->mc_pg[i-1];
8327 mc->mc_ki[i] = mc->mc_ki[i-1];
8331 mc->mc_db->md_root = pp->mp_pgno;
8332 DPRINTF(("root split! new root = %"Z"u", pp->mp_pgno));
8333 new_root = mc->mc_db->md_depth++;
8335 /* Add left (implicit) pointer. */
8336 if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) {
8337 /* undo the pre-push */
8338 mc->mc_pg[0] = mc->mc_pg[1];
8339 mc->mc_ki[0] = mc->mc_ki[1];
8340 mc->mc_db->md_root = mp->mp_pgno;
8341 mc->mc_db->md_depth--;
8348 ptop = mc->mc_top-1;
8349 DPRINTF(("parent branch page is %"Z"u", mc->mc_pg[ptop]->mp_pgno));
8352 mdb_cursor_copy(mc, &mn);
8353 mn.mc_pg[mn.mc_top] = rp;
8354 mn.mc_ki[ptop] = mc->mc_ki[ptop]+1;
8356 if (nflags & MDB_APPEND) {
8357 mn.mc_ki[mn.mc_top] = 0;
8359 split_indx = newindx;
8363 split_indx = (nkeys+1) / 2;
8368 unsigned int lsize, rsize, ksize;
8369 /* Move half of the keys to the right sibling */
8370 x = mc->mc_ki[mc->mc_top] - split_indx;
8371 ksize = mc->mc_db->md_pad;
8372 split = LEAF2KEY(mp, split_indx, ksize);
8373 rsize = (nkeys - split_indx) * ksize;
8374 lsize = (nkeys - split_indx) * sizeof(indx_t);
8375 mp->mp_lower -= lsize;
8376 rp->mp_lower += lsize;
8377 mp->mp_upper += rsize - lsize;
8378 rp->mp_upper -= rsize - lsize;
8379 sepkey.mv_size = ksize;
8380 if (newindx == split_indx) {
8381 sepkey.mv_data = newkey->mv_data;
8383 sepkey.mv_data = split;
8386 ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize);
8387 memcpy(rp->mp_ptrs, split, rsize);
8388 sepkey.mv_data = rp->mp_ptrs;
8389 memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize);
8390 memcpy(ins, newkey->mv_data, ksize);
8391 mp->mp_lower += sizeof(indx_t);
8392 mp->mp_upper -= ksize - sizeof(indx_t);
8395 memcpy(rp->mp_ptrs, split, x * ksize);
8396 ins = LEAF2KEY(rp, x, ksize);
8397 memcpy(ins, newkey->mv_data, ksize);
8398 memcpy(ins+ksize, split + x * ksize, rsize - x * ksize);
8399 rp->mp_lower += sizeof(indx_t);
8400 rp->mp_upper -= ksize - sizeof(indx_t);
8401 mc->mc_ki[mc->mc_top] = x;
8404 int psize, nsize, k;
8405 /* Maximum free space in an empty page */
8406 pmax = env->me_psize - PAGEHDRSZ;
8408 nsize = mdb_leaf_size(env, newkey, newdata);
8410 nsize = mdb_branch_size(env, newkey);
8411 nsize = EVEN(nsize);
8413 /* grab a page to hold a temporary copy */
8414 copy = mdb_page_malloc(mc->mc_txn, 1);
8419 copy->mp_pgno = mp->mp_pgno;
8420 copy->mp_flags = mp->mp_flags;
8421 copy->mp_lower = (PAGEHDRSZ-PAGEBASE);
8422 copy->mp_upper = env->me_psize - PAGEBASE;
8424 /* prepare to insert */
8425 for (i=0, j=0; i<nkeys; i++) {
8427 copy->mp_ptrs[j++] = 0;
8429 copy->mp_ptrs[j++] = mp->mp_ptrs[i];
8432 /* When items are relatively large the split point needs
8433 * to be checked, because being off-by-one will make the
8434 * difference between success or failure in mdb_node_add.
8436 * It's also relevant if a page happens to be laid out
8437 * such that one half of its nodes are all "small" and
8438 * the other half of its nodes are "large." If the new
8439 * item is also "large" and falls on the half with
8440 * "large" nodes, it also may not fit.
8442 * As a final tweak, if the new item goes on the last
8443 * spot on the page (and thus, onto the new page), bias
8444 * the split so the new page is emptier than the old page.
8445 * This yields better packing during sequential inserts.
8447 if (nkeys < 20 || nsize > pmax/16 || newindx >= nkeys) {
8448 /* Find split point */
8450 if (newindx <= split_indx || newindx >= nkeys) {
8452 k = newindx >= nkeys ? nkeys : split_indx+1+IS_LEAF(mp);
8457 for (; i!=k; i+=j) {
8462 node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);
8463 psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
8465 if (F_ISSET(node->mn_flags, F_BIGDATA))
8466 psize += sizeof(pgno_t);
8468 psize += NODEDSZ(node);
8470 psize = EVEN(psize);
8472 if (psize > pmax || i == k-j) {
8473 split_indx = i + (j<0);
8478 if (split_indx == newindx) {
8479 sepkey.mv_size = newkey->mv_size;
8480 sepkey.mv_data = newkey->mv_data;
8482 node = (MDB_node *)((char *)mp + copy->mp_ptrs[split_indx] + PAGEBASE);
8483 sepkey.mv_size = node->mn_ksize;
8484 sepkey.mv_data = NODEKEY(node);
8489 DPRINTF(("separator is %d [%s]", split_indx, DKEY(&sepkey)));
8491 /* Copy separator key to the parent.
8493 if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(env, &sepkey)) {
8494 int snum = mc->mc_snum;
8498 /* We want other splits to find mn when doing fixups */
8499 WITH_CURSOR_TRACKING(mn,
8500 rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0));
8505 if (mc->mc_snum > snum) {
8508 /* Right page might now have changed parent.
8509 * Check if left page also changed parent.
8511 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
8512 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
8513 for (i=0; i<ptop; i++) {
8514 mc->mc_pg[i] = mn.mc_pg[i];
8515 mc->mc_ki[i] = mn.mc_ki[i];
8517 mc->mc_pg[ptop] = mn.mc_pg[ptop];
8518 if (mn.mc_ki[ptop]) {
8519 mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;
8521 /* find right page's left sibling */
8522 mc->mc_ki[ptop] = mn.mc_ki[ptop];
8523 mdb_cursor_sibling(mc, 0);
8528 rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);
8531 if (rc != MDB_SUCCESS) {
8534 if (nflags & MDB_APPEND) {
8535 mc->mc_pg[mc->mc_top] = rp;
8536 mc->mc_ki[mc->mc_top] = 0;
8537 rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags);
8540 for (i=0; i<mc->mc_top; i++)
8541 mc->mc_ki[i] = mn.mc_ki[i];
8542 } else if (!IS_LEAF2(mp)) {
8544 mc->mc_pg[mc->mc_top] = rp;
8549 rkey.mv_data = newkey->mv_data;
8550 rkey.mv_size = newkey->mv_size;
8556 /* Update index for the new key. */
8557 mc->mc_ki[mc->mc_top] = j;
8559 node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);
8560 rkey.mv_data = NODEKEY(node);
8561 rkey.mv_size = node->mn_ksize;
8563 xdata.mv_data = NODEDATA(node);
8564 xdata.mv_size = NODEDSZ(node);
8567 pgno = NODEPGNO(node);
8568 flags = node->mn_flags;
8571 if (!IS_LEAF(mp) && j == 0) {
8572 /* First branch index doesn't need key data. */
8576 rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags);
8582 mc->mc_pg[mc->mc_top] = copy;
8587 } while (i != split_indx);
8589 nkeys = NUMKEYS(copy);
8590 for (i=0; i<nkeys; i++)
8591 mp->mp_ptrs[i] = copy->mp_ptrs[i];
8592 mp->mp_lower = copy->mp_lower;
8593 mp->mp_upper = copy->mp_upper;
8594 memcpy(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1),
8595 env->me_psize - copy->mp_upper - PAGEBASE);
8597 /* reset back to original page */
8598 if (newindx < split_indx) {
8599 mc->mc_pg[mc->mc_top] = mp;
8601 mc->mc_pg[mc->mc_top] = rp;
8603 /* Make sure mc_ki is still valid.
8605 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
8606 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
8607 for (i=0; i<=ptop; i++) {
8608 mc->mc_pg[i] = mn.mc_pg[i];
8609 mc->mc_ki[i] = mn.mc_ki[i];
8613 if (nflags & MDB_RESERVE) {
8614 node = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
8615 if (!(node->mn_flags & F_BIGDATA))
8616 newdata->mv_data = NODEDATA(node);
8619 if (newindx >= split_indx) {
8620 mc->mc_pg[mc->mc_top] = rp;
8622 /* Make sure mc_ki is still valid.
8624 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
8625 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
8626 for (i=0; i<=ptop; i++) {
8627 mc->mc_pg[i] = mn.mc_pg[i];
8628 mc->mc_ki[i] = mn.mc_ki[i];
8635 /* Adjust other cursors pointing to mp */
8636 MDB_cursor *m2, *m3;
8637 MDB_dbi dbi = mc->mc_dbi;
8638 nkeys = NUMKEYS(mp);
8640 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8641 if (mc->mc_flags & C_SUB)
8642 m3 = &m2->mc_xcursor->mx_cursor;
8647 if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED))
8651 /* sub cursors may be on different DB */
8652 if (m3->mc_pg[0] != mp)
8655 for (k=new_root; k>=0; k--) {
8656 m3->mc_ki[k+1] = m3->mc_ki[k];
8657 m3->mc_pg[k+1] = m3->mc_pg[k];
8659 if (m3->mc_ki[0] > nkeys) {
8664 m3->mc_pg[0] = mc->mc_pg[0];
8668 if (m3->mc_top >= mc->mc_top && m3->mc_pg[mc->mc_top] == mp) {
8669 if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE))
8670 m3->mc_ki[mc->mc_top]++;
8671 if (m3->mc_ki[mc->mc_top] >= nkeys) {
8672 m3->mc_pg[mc->mc_top] = rp;
8673 m3->mc_ki[mc->mc_top] -= nkeys;
8674 for (i=0; i<mc->mc_top; i++) {
8675 m3->mc_ki[i] = mn.mc_ki[i];
8676 m3->mc_pg[i] = mn.mc_pg[i];
8679 } else if (!did_split && m3->mc_top >= ptop && m3->mc_pg[ptop] == mc->mc_pg[ptop] &&
8680 m3->mc_ki[ptop] >= mc->mc_ki[ptop]) {
8685 DPRINTF(("mp left: %d, rp left: %d", SIZELEFT(mp), SIZELEFT(rp)));
8688 if (copy) /* tmp page */
8689 mdb_page_free(env, copy);
8691 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
8696 mdb_put(MDB_txn *txn, MDB_dbi dbi,
8697 MDB_val *key, MDB_val *data, unsigned int flags)
8702 if (!key || !data || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
8705 if (flags & ~(MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND|MDB_APPENDDUP))
8708 if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
8709 return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
8711 mdb_cursor_init(&mc, txn, dbi, &mx);
8712 return mdb_cursor_put(&mc, key, data, flags);
8716 #define MDB_WBUF (1024*1024)
8719 /** State needed for a compacting copy. */
8720 typedef struct mdb_copy {
8721 pthread_mutex_t mc_mutex;
8722 pthread_cond_t mc_cond;
8729 pgno_t mc_next_pgno;
8732 volatile int mc_new;
8737 /** Dedicated writer thread for compacting copy. */
8738 static THREAD_RET ESECT CALL_CONV
8739 mdb_env_copythr(void *arg)
8743 int toggle = 0, wsize, rc;
8746 #define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL)
8749 #define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0)
8752 pthread_mutex_lock(&my->mc_mutex);
8754 pthread_cond_signal(&my->mc_cond);
8757 pthread_cond_wait(&my->mc_cond, &my->mc_mutex);
8758 if (my->mc_new < 0) {
8763 wsize = my->mc_wlen[toggle];
8764 ptr = my->mc_wbuf[toggle];
8767 DO_WRITE(rc, my->mc_fd, ptr, wsize, len);
8771 } else if (len > 0) {
8785 /* If there's an overflow page tail, write it too */
8786 if (my->mc_olen[toggle]) {
8787 wsize = my->mc_olen[toggle];
8788 ptr = my->mc_over[toggle];
8789 my->mc_olen[toggle] = 0;
8792 my->mc_wlen[toggle] = 0;
8794 pthread_cond_signal(&my->mc_cond);
8796 pthread_cond_signal(&my->mc_cond);
8797 pthread_mutex_unlock(&my->mc_mutex);
8798 return (THREAD_RET)0;
8802 /** Tell the writer thread there's a buffer ready to write */
8804 mdb_env_cthr_toggle(mdb_copy *my, int st)
8806 int toggle = my->mc_toggle ^ 1;
8807 pthread_mutex_lock(&my->mc_mutex);
8808 if (my->mc_status) {
8809 pthread_mutex_unlock(&my->mc_mutex);
8810 return my->mc_status;
8812 while (my->mc_new == 1)
8813 pthread_cond_wait(&my->mc_cond, &my->mc_mutex);
8815 my->mc_toggle = toggle;
8816 pthread_cond_signal(&my->mc_cond);
8817 pthread_mutex_unlock(&my->mc_mutex);
8821 /** Depth-first tree traversal for compacting copy. */
8823 mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)
8826 MDB_txn *txn = my->mc_txn;
8828 MDB_page *mo, *mp, *leaf;
8833 /* Empty DB, nothing to do */
8834 if (*pg == P_INVALID)
8841 rc = mdb_page_get(my->mc_txn, *pg, &mc.mc_pg[0], NULL);
8844 rc = mdb_page_search_root(&mc, NULL, MDB_PS_FIRST);
8848 /* Make cursor pages writable */
8849 buf = ptr = malloc(my->mc_env->me_psize * mc.mc_snum);
8853 for (i=0; i<mc.mc_top; i++) {
8854 mdb_page_copy((MDB_page *)ptr, mc.mc_pg[i], my->mc_env->me_psize);
8855 mc.mc_pg[i] = (MDB_page *)ptr;
8856 ptr += my->mc_env->me_psize;
8859 /* This is writable space for a leaf page. Usually not needed. */
8860 leaf = (MDB_page *)ptr;
8862 toggle = my->mc_toggle;
8863 while (mc.mc_snum > 0) {
8865 mp = mc.mc_pg[mc.mc_top];
8869 if (!IS_LEAF2(mp) && !(flags & F_DUPDATA)) {
8870 for (i=0; i<n; i++) {
8871 ni = NODEPTR(mp, i);
8872 if (ni->mn_flags & F_BIGDATA) {
8876 /* Need writable leaf */
8878 mc.mc_pg[mc.mc_top] = leaf;
8879 mdb_page_copy(leaf, mp, my->mc_env->me_psize);
8881 ni = NODEPTR(mp, i);
8884 memcpy(&pg, NODEDATA(ni), sizeof(pg));
8885 rc = mdb_page_get(txn, pg, &omp, NULL);
8888 if (my->mc_wlen[toggle] >= MDB_WBUF) {
8889 rc = mdb_env_cthr_toggle(my, 1);
8892 toggle = my->mc_toggle;
8894 mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);
8895 memcpy(mo, omp, my->mc_env->me_psize);
8896 mo->mp_pgno = my->mc_next_pgno;
8897 my->mc_next_pgno += omp->mp_pages;
8898 my->mc_wlen[toggle] += my->mc_env->me_psize;
8899 if (omp->mp_pages > 1) {
8900 my->mc_olen[toggle] = my->mc_env->me_psize * (omp->mp_pages - 1);
8901 my->mc_over[toggle] = (char *)omp + my->mc_env->me_psize;
8902 rc = mdb_env_cthr_toggle(my, 1);
8905 toggle = my->mc_toggle;
8907 memcpy(NODEDATA(ni), &mo->mp_pgno, sizeof(pgno_t));
8908 } else if (ni->mn_flags & F_SUBDATA) {
8911 /* Need writable leaf */
8913 mc.mc_pg[mc.mc_top] = leaf;
8914 mdb_page_copy(leaf, mp, my->mc_env->me_psize);
8916 ni = NODEPTR(mp, i);
8919 memcpy(&db, NODEDATA(ni), sizeof(db));
8920 my->mc_toggle = toggle;
8921 rc = mdb_env_cwalk(my, &db.md_root, ni->mn_flags & F_DUPDATA);
8924 toggle = my->mc_toggle;
8925 memcpy(NODEDATA(ni), &db, sizeof(db));
8930 mc.mc_ki[mc.mc_top]++;
8931 if (mc.mc_ki[mc.mc_top] < n) {
8934 ni = NODEPTR(mp, mc.mc_ki[mc.mc_top]);
8936 rc = mdb_page_get(txn, pg, &mp, NULL);
8941 mc.mc_ki[mc.mc_top] = 0;
8942 if (IS_BRANCH(mp)) {
8943 /* Whenever we advance to a sibling branch page,
8944 * we must proceed all the way down to its first leaf.
8946 mdb_page_copy(mc.mc_pg[mc.mc_top], mp, my->mc_env->me_psize);
8949 mc.mc_pg[mc.mc_top] = mp;
8953 if (my->mc_wlen[toggle] >= MDB_WBUF) {
8954 rc = mdb_env_cthr_toggle(my, 1);
8957 toggle = my->mc_toggle;
8959 mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);
8960 mdb_page_copy(mo, mp, my->mc_env->me_psize);
8961 mo->mp_pgno = my->mc_next_pgno++;
8962 my->mc_wlen[toggle] += my->mc_env->me_psize;
8964 /* Update parent if there is one */
8965 ni = NODEPTR(mc.mc_pg[mc.mc_top-1], mc.mc_ki[mc.mc_top-1]);
8966 SETPGNO(ni, mo->mp_pgno);
8967 mdb_cursor_pop(&mc);
8969 /* Otherwise we're done */
8979 /** Copy environment with compaction. */
8981 mdb_env_copyfd1(MDB_env *env, HANDLE fd)
8986 MDB_txn *txn = NULL;
8991 my.mc_mutex = CreateMutex(NULL, FALSE, NULL);
8992 my.mc_cond = CreateEvent(NULL, FALSE, FALSE, NULL);
8993 my.mc_wbuf[0] = _aligned_malloc(MDB_WBUF*2, env->me_os_psize);
8994 if (my.mc_wbuf[0] == NULL)
8997 pthread_mutex_init(&my.mc_mutex, NULL);
8998 pthread_cond_init(&my.mc_cond, NULL);
8999 #ifdef HAVE_MEMALIGN
9000 my.mc_wbuf[0] = memalign(env->me_os_psize, MDB_WBUF*2);
9001 if (my.mc_wbuf[0] == NULL)
9004 rc = posix_memalign((void **)&my.mc_wbuf[0], env->me_os_psize, MDB_WBUF*2);
9009 memset(my.mc_wbuf[0], 0, MDB_WBUF*2);
9010 my.mc_wbuf[1] = my.mc_wbuf[0] + MDB_WBUF;
9015 my.mc_next_pgno = NUM_METAS;
9021 THREAD_CREATE(thr, mdb_env_copythr, &my);
9023 rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
9027 mp = (MDB_page *)my.mc_wbuf[0];
9028 memset(mp, 0, NUM_METAS * env->me_psize);
9030 mp->mp_flags = P_META;
9031 mm = (MDB_meta *)METADATA(mp);
9032 mdb_env_init_meta0(env, mm);
9033 mm->mm_address = env->me_metas[0]->mm_address;
9035 mp = (MDB_page *)(my.mc_wbuf[0] + env->me_psize);
9037 mp->mp_flags = P_META;
9038 *(MDB_meta *)METADATA(mp) = *mm;
9039 mm = (MDB_meta *)METADATA(mp);
9041 /* Count the number of free pages, subtract from lastpg to find
9042 * number of active pages
9045 MDB_ID freecount = 0;
9048 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
9049 while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
9050 freecount += *(MDB_ID *)data.mv_data;
9051 freecount += txn->mt_dbs[FREE_DBI].md_branch_pages +
9052 txn->mt_dbs[FREE_DBI].md_leaf_pages +
9053 txn->mt_dbs[FREE_DBI].md_overflow_pages;
9055 /* Set metapage 1 */
9056 mm->mm_last_pg = txn->mt_next_pgno - freecount - 1;
9057 mm->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
9058 if (mm->mm_last_pg > NUM_METAS-1) {
9059 mm->mm_dbs[MAIN_DBI].md_root = mm->mm_last_pg;
9062 mm->mm_dbs[MAIN_DBI].md_root = P_INVALID;
9065 my.mc_wlen[0] = env->me_psize * NUM_METAS;
9067 pthread_mutex_lock(&my.mc_mutex);
9069 pthread_cond_wait(&my.mc_cond, &my.mc_mutex);
9070 pthread_mutex_unlock(&my.mc_mutex);
9071 rc = mdb_env_cwalk(&my, &txn->mt_dbs[MAIN_DBI].md_root, 0);
9072 if (rc == MDB_SUCCESS && my.mc_wlen[my.mc_toggle])
9073 rc = mdb_env_cthr_toggle(&my, 1);
9074 mdb_env_cthr_toggle(&my, -1);
9075 pthread_mutex_lock(&my.mc_mutex);
9077 pthread_cond_wait(&my.mc_cond, &my.mc_mutex);
9078 pthread_mutex_unlock(&my.mc_mutex);
9083 CloseHandle(my.mc_cond);
9084 CloseHandle(my.mc_mutex);
9085 _aligned_free(my.mc_wbuf[0]);
9087 pthread_cond_destroy(&my.mc_cond);
9088 pthread_mutex_destroy(&my.mc_mutex);
9089 free(my.mc_wbuf[0]);
9094 /** Copy environment as-is. */
9096 mdb_env_copyfd0(MDB_env *env, HANDLE fd)
9098 MDB_txn *txn = NULL;
9099 mdb_mutexref_t wmutex = NULL;
9105 #define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL)
9109 #define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0)
9112 /* Do the lock/unlock of the reader mutex before starting the
9113 * write txn. Otherwise other read txns could block writers.
9115 rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
9120 /* We must start the actual read txn after blocking writers */
9121 mdb_txn_end(txn, MDB_END_RESET_TMP);
9123 /* Temporarily block writers until we snapshot the meta pages */
9124 wmutex = env->me_wmutex;
9125 if (LOCK_MUTEX(rc, env, wmutex))
9128 rc = mdb_txn_renew0(txn);
9130 UNLOCK_MUTEX(wmutex);
9135 wsize = env->me_psize * NUM_METAS;
9139 DO_WRITE(rc, fd, ptr, w2, len);
9143 } else if (len > 0) {
9149 /* Non-blocking or async handles are not supported */
9155 UNLOCK_MUTEX(wmutex);
9160 w2 = txn->mt_next_pgno * env->me_psize;
9163 if ((rc = mdb_fsize(env->me_fd, &fsize)))
9170 if (wsize > MAX_WRITE)
9174 DO_WRITE(rc, fd, ptr, w2, len);
9178 } else if (len > 0) {
9195 mdb_env_copyfd2(MDB_env *env, HANDLE fd, unsigned int flags)
9197 if (flags & MDB_CP_COMPACT)
9198 return mdb_env_copyfd1(env, fd);
9200 return mdb_env_copyfd0(env, fd);
9204 mdb_env_copyfd(MDB_env *env, HANDLE fd)
9206 return mdb_env_copyfd2(env, fd, 0);
9210 mdb_env_copy2(MDB_env *env, const char *path, unsigned int flags)
9214 HANDLE newfd = INVALID_HANDLE_VALUE;
9219 if (env->me_flags & MDB_NOSUBDIR) {
9220 lpath = (char *)path;
9223 len += sizeof(DATANAME);
9224 lpath = malloc(len);
9227 sprintf(lpath, "%s" DATANAME, path);
9230 /* The destination path must exist, but the destination file must not.
9231 * We don't want the OS to cache the writes, since the source data is
9232 * already in the OS cache.
9235 utf8_to_utf16(lpath, -1, &wpath, NULL);
9236 newfd = CreateFileW(wpath, GENERIC_WRITE, 0, NULL, CREATE_NEW,
9237 FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL);
9240 newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL, 0666);
9242 if (newfd == INVALID_HANDLE_VALUE) {
9247 if (env->me_psize >= env->me_os_psize) {
9249 /* Set O_DIRECT if the file system supports it */
9250 if ((rc = fcntl(newfd, F_GETFL)) != -1)
9251 (void) fcntl(newfd, F_SETFL, rc | O_DIRECT);
9253 #ifdef F_NOCACHE /* __APPLE__ */
9254 rc = fcntl(newfd, F_NOCACHE, 1);
9262 rc = mdb_env_copyfd2(env, newfd, flags);
9265 if (!(env->me_flags & MDB_NOSUBDIR))
9267 if (newfd != INVALID_HANDLE_VALUE)
9268 if (close(newfd) < 0 && rc == MDB_SUCCESS)
9275 mdb_env_copy(MDB_env *env, const char *path)
9277 return mdb_env_copy2(env, path, 0);
9281 mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)
9283 if (flag & ~CHANGEABLE)
9286 env->me_flags |= flag;
9288 env->me_flags &= ~flag;
9293 mdb_env_get_flags(MDB_env *env, unsigned int *arg)
9298 *arg = env->me_flags & (CHANGEABLE|CHANGELESS);
9303 mdb_env_set_userctx(MDB_env *env, void *ctx)
9307 env->me_userctx = ctx;
9312 mdb_env_get_userctx(MDB_env *env)
9314 return env ? env->me_userctx : NULL;
9318 mdb_env_set_assert(MDB_env *env, MDB_assert_func *func)
9323 env->me_assert_func = func;
9329 mdb_env_get_path(MDB_env *env, const char **arg)
9334 *arg = env->me_path;
9339 mdb_env_get_fd(MDB_env *env, mdb_filehandle_t *arg)
9348 /** Common code for #mdb_stat() and #mdb_env_stat().
9349 * @param[in] env the environment to operate in.
9350 * @param[in] db the #MDB_db record containing the stats to return.
9351 * @param[out] arg the address of an #MDB_stat structure to receive the stats.
9352 * @return 0, this function always succeeds.
9355 mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)
9357 arg->ms_psize = env->me_psize;
9358 arg->ms_depth = db->md_depth;
9359 arg->ms_branch_pages = db->md_branch_pages;
9360 arg->ms_leaf_pages = db->md_leaf_pages;
9361 arg->ms_overflow_pages = db->md_overflow_pages;
9362 arg->ms_entries = db->md_entries;
9368 mdb_env_stat(MDB_env *env, MDB_stat *arg)
9372 if (env == NULL || arg == NULL)
9375 meta = mdb_env_pick_meta(env);
9377 return mdb_stat0(env, &meta->mm_dbs[MAIN_DBI], arg);
9381 mdb_env_info(MDB_env *env, MDB_envinfo *arg)
9385 if (env == NULL || arg == NULL)
9388 meta = mdb_env_pick_meta(env);
9389 arg->me_mapaddr = meta->mm_address;
9390 arg->me_last_pgno = meta->mm_last_pg;
9391 arg->me_last_txnid = meta->mm_txnid;
9393 arg->me_mapsize = env->me_mapsize;
9394 arg->me_maxreaders = env->me_maxreaders;
9395 arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : 0;
9399 /** Set the default comparison functions for a database.
9400 * Called immediately after a database is opened to set the defaults.
9401 * The user can then override them with #mdb_set_compare() or
9402 * #mdb_set_dupsort().
9403 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
9404 * @param[in] dbi A database handle returned by #mdb_dbi_open()
9407 mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi)
9409 uint16_t f = txn->mt_dbs[dbi].md_flags;
9411 txn->mt_dbxs[dbi].md_cmp =
9412 (f & MDB_REVERSEKEY) ? mdb_cmp_memnr :
9413 (f & MDB_INTEGERKEY) ? mdb_cmp_cint : mdb_cmp_memn;
9415 txn->mt_dbxs[dbi].md_dcmp =
9416 !(f & MDB_DUPSORT) ? 0 :
9417 ((f & MDB_INTEGERDUP)
9418 ? ((f & MDB_DUPFIXED) ? mdb_cmp_int : mdb_cmp_cint)
9419 : ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn));
9422 int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
9428 int rc, dbflag, exact;
9429 unsigned int unused = 0, seq;
9432 if (flags & ~VALID_FLAGS)
9434 if (txn->mt_flags & MDB_TXN_BLOCKED)
9440 if (flags & PERSISTENT_FLAGS) {
9441 uint16_t f2 = flags & PERSISTENT_FLAGS;
9442 /* make sure flag changes get committed */
9443 if ((txn->mt_dbs[MAIN_DBI].md_flags | f2) != txn->mt_dbs[MAIN_DBI].md_flags) {
9444 txn->mt_dbs[MAIN_DBI].md_flags |= f2;
9445 txn->mt_flags |= MDB_TXN_DIRTY;
9448 mdb_default_cmp(txn, MAIN_DBI);
9452 if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {
9453 mdb_default_cmp(txn, MAIN_DBI);
9456 /* Is the DB already open? */
9458 for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
9459 if (!txn->mt_dbxs[i].md_name.mv_size) {
9460 /* Remember this free slot */
9461 if (!unused) unused = i;
9464 if (len == txn->mt_dbxs[i].md_name.mv_size &&
9465 !strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) {
9471 /* If no free slot and max hit, fail */
9472 if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs)
9473 return MDB_DBS_FULL;
9475 /* Cannot mix named databases with some mainDB flags */
9476 if (txn->mt_dbs[MAIN_DBI].md_flags & (MDB_DUPSORT|MDB_INTEGERKEY))
9477 return (flags & MDB_CREATE) ? MDB_INCOMPATIBLE : MDB_NOTFOUND;
9479 /* Find the DB info */
9480 dbflag = DB_NEW|DB_VALID|DB_USRVALID;
9483 key.mv_data = (void *)name;
9484 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
9485 rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact);
9486 if (rc == MDB_SUCCESS) {
9487 /* make sure this is actually a DB */
9488 MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]);
9489 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)
9490 return MDB_INCOMPATIBLE;
9491 } else if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) {
9492 /* Create if requested */
9493 data.mv_size = sizeof(MDB_db);
9494 data.mv_data = &dummy;
9495 memset(&dummy, 0, sizeof(dummy));
9496 dummy.md_root = P_INVALID;
9497 dummy.md_flags = flags & PERSISTENT_FLAGS;
9498 rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA);
9502 /* OK, got info, add to table */
9503 if (rc == MDB_SUCCESS) {
9504 unsigned int slot = unused ? unused : txn->mt_numdbs;
9505 txn->mt_dbxs[slot].md_name.mv_data = strdup(name);
9506 txn->mt_dbxs[slot].md_name.mv_size = len;
9507 txn->mt_dbxs[slot].md_rel = NULL;
9508 txn->mt_dbflags[slot] = dbflag;
9509 /* txn-> and env-> are the same in read txns, use
9510 * tmp variable to avoid undefined assignment
9512 seq = ++txn->mt_env->me_dbiseqs[slot];
9513 txn->mt_dbiseqs[slot] = seq;
9515 memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db));
9517 mdb_default_cmp(txn, slot);
9527 mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
9529 if (!arg || !TXN_DBI_EXIST(txn, dbi, DB_VALID))
9532 if (txn->mt_flags & MDB_TXN_BLOCKED)
9535 if (txn->mt_dbflags[dbi] & DB_STALE) {
9538 /* Stale, must read the DB's root. cursor_init does it for us. */
9539 mdb_cursor_init(&mc, txn, dbi, &mx);
9541 return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg);
9544 void mdb_dbi_close(MDB_env *env, MDB_dbi dbi)
9547 if (dbi < CORE_DBS || dbi >= env->me_maxdbs)
9549 ptr = env->me_dbxs[dbi].md_name.mv_data;
9550 /* If there was no name, this was already closed */
9552 env->me_dbxs[dbi].md_name.mv_data = NULL;
9553 env->me_dbxs[dbi].md_name.mv_size = 0;
9554 env->me_dbflags[dbi] = 0;
9555 env->me_dbiseqs[dbi]++;
9560 int mdb_dbi_flags(MDB_txn *txn, MDB_dbi dbi, unsigned int *flags)
9562 /* We could return the flags for the FREE_DBI too but what's the point? */
9563 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9565 *flags = txn->mt_dbs[dbi].md_flags & PERSISTENT_FLAGS;
9569 /** Add all the DB's pages to the free list.
9570 * @param[in] mc Cursor on the DB to free.
9571 * @param[in] subs non-Zero to check for sub-DBs in this DB.
9572 * @return 0 on success, non-zero on failure.
9575 mdb_drop0(MDB_cursor *mc, int subs)
9579 rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
9580 if (rc == MDB_SUCCESS) {
9581 MDB_txn *txn = mc->mc_txn;
9586 /* DUPSORT sub-DBs have no ovpages/DBs. Omit scanning leaves.
9587 * This also avoids any P_LEAF2 pages, which have no nodes.
9589 if (mc->mc_flags & C_SUB)
9592 mdb_cursor_copy(mc, &mx);
9593 while (mc->mc_snum > 0) {
9594 MDB_page *mp = mc->mc_pg[mc->mc_top];
9595 unsigned n = NUMKEYS(mp);
9597 for (i=0; i<n; i++) {
9598 ni = NODEPTR(mp, i);
9599 if (ni->mn_flags & F_BIGDATA) {
9602 memcpy(&pg, NODEDATA(ni), sizeof(pg));
9603 rc = mdb_page_get(txn, pg, &omp, NULL);
9606 mdb_cassert(mc, IS_OVERFLOW(omp));
9607 rc = mdb_midl_append_range(&txn->mt_free_pgs,
9611 } else if (subs && (ni->mn_flags & F_SUBDATA)) {
9612 mdb_xcursor_init1(mc, ni);
9613 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
9619 if ((rc = mdb_midl_need(&txn->mt_free_pgs, n)) != 0)
9621 for (i=0; i<n; i++) {
9623 ni = NODEPTR(mp, i);
9626 mdb_midl_xappend(txn->mt_free_pgs, pg);
9631 mc->mc_ki[mc->mc_top] = i;
9632 rc = mdb_cursor_sibling(mc, 1);
9634 if (rc != MDB_NOTFOUND)
9636 /* no more siblings, go back to beginning
9637 * of previous level.
9641 for (i=1; i<mc->mc_snum; i++) {
9643 mc->mc_pg[i] = mx.mc_pg[i];
9648 rc = mdb_midl_append(&txn->mt_free_pgs, mc->mc_db->md_root);
9651 txn->mt_flags |= MDB_TXN_ERROR;
9652 } else if (rc == MDB_NOTFOUND) {
9655 mc->mc_flags &= ~C_INITIALIZED;
9659 int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)
9661 MDB_cursor *mc, *m2;
9664 if ((unsigned)del > 1 || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9667 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
9670 if (TXN_DBI_CHANGED(txn, dbi))
9673 rc = mdb_cursor_open(txn, dbi, &mc);
9677 rc = mdb_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT);
9678 /* Invalidate the dropped DB's cursors */
9679 for (m2 = txn->mt_cursors[dbi]; m2; m2 = m2->mc_next)
9680 m2->mc_flags &= ~(C_INITIALIZED|C_EOF);
9684 /* Can't delete the main DB */
9685 if (del && dbi >= CORE_DBS) {
9686 rc = mdb_del0(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL, F_SUBDATA);
9688 txn->mt_dbflags[dbi] = DB_STALE;
9689 mdb_dbi_close(txn->mt_env, dbi);
9691 txn->mt_flags |= MDB_TXN_ERROR;
9694 /* reset the DB record, mark it dirty */
9695 txn->mt_dbflags[dbi] |= DB_DIRTY;
9696 txn->mt_dbs[dbi].md_depth = 0;
9697 txn->mt_dbs[dbi].md_branch_pages = 0;
9698 txn->mt_dbs[dbi].md_leaf_pages = 0;
9699 txn->mt_dbs[dbi].md_overflow_pages = 0;
9700 txn->mt_dbs[dbi].md_entries = 0;
9701 txn->mt_dbs[dbi].md_root = P_INVALID;
9703 txn->mt_flags |= MDB_TXN_DIRTY;
9706 mdb_cursor_close(mc);
9710 int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
9712 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9715 txn->mt_dbxs[dbi].md_cmp = cmp;
9719 int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
9721 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9724 txn->mt_dbxs[dbi].md_dcmp = cmp;
9728 int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
9730 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9733 txn->mt_dbxs[dbi].md_rel = rel;
9737 int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx)
9739 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9742 txn->mt_dbxs[dbi].md_relctx = ctx;
9747 mdb_env_get_maxkeysize(MDB_env *env)
9749 return ENV_MAXKEY(env);
9753 mdb_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx)
9755 unsigned int i, rdrs;
9758 int rc = 0, first = 1;
9762 if (!env->me_txns) {
9763 return func("(no reader locks)\n", ctx);
9765 rdrs = env->me_txns->mti_numreaders;
9766 mr = env->me_txns->mti_readers;
9767 for (i=0; i<rdrs; i++) {
9769 txnid_t txnid = mr[i].mr_txnid;
9770 sprintf(buf, txnid == (txnid_t)-1 ?
9771 "%10d %"Z"x -\n" : "%10d %"Z"x %"Z"u\n",
9772 (int)mr[i].mr_pid, (size_t)mr[i].mr_tid, txnid);
9775 rc = func(" pid thread txnid\n", ctx);
9779 rc = func(buf, ctx);
9785 rc = func("(no active readers)\n", ctx);
9790 /** Insert pid into list if not already present.
9791 * return -1 if already present.
9794 mdb_pid_insert(MDB_PID_T *ids, MDB_PID_T pid)
9796 /* binary search of pid in list */
9798 unsigned cursor = 1;
9800 unsigned n = ids[0];
9803 unsigned pivot = n >> 1;
9804 cursor = base + pivot + 1;
9805 val = pid - ids[cursor];
9810 } else if ( val > 0 ) {
9815 /* found, so it's a duplicate */
9824 for (n = ids[0]; n > cursor; n--)
9831 mdb_reader_check(MDB_env *env, int *dead)
9837 return env->me_txns ? mdb_reader_check0(env, 0, dead) : MDB_SUCCESS;
9840 /** As #mdb_reader_check(). rlocked = <caller locked the reader mutex>. */
9842 mdb_reader_check0(MDB_env *env, int rlocked, int *dead)
9844 mdb_mutexref_t rmutex = rlocked ? NULL : env->me_rmutex;
9845 unsigned int i, j, rdrs;
9847 MDB_PID_T *pids, pid;
9848 int rc = MDB_SUCCESS, count = 0;
9850 rdrs = env->me_txns->mti_numreaders;
9851 pids = malloc((rdrs+1) * sizeof(MDB_PID_T));
9855 mr = env->me_txns->mti_readers;
9856 for (i=0; i<rdrs; i++) {
9858 if (pid && pid != env->me_pid) {
9859 if (mdb_pid_insert(pids, pid) == 0) {
9860 if (!mdb_reader_pid(env, Pidcheck, pid)) {
9861 /* Stale reader found */
9864 if ((rc = LOCK_MUTEX0(rmutex)) != 0) {
9865 if ((rc = mdb_mutex_failed(env, rmutex, rc)))
9867 rdrs = 0; /* the above checked all readers */
9869 /* Recheck, a new process may have reused pid */
9870 if (mdb_reader_pid(env, Pidcheck, pid))
9875 if (mr[j].mr_pid == pid) {
9876 DPRINTF(("clear stale reader pid %u txn %"Z"d",
9877 (unsigned) pid, mr[j].mr_txnid));
9882 UNLOCK_MUTEX(rmutex);
9893 #ifdef MDB_ROBUST_SUPPORTED
9894 /** Handle #LOCK_MUTEX0() failure.
9895 * Try to repair the lock file if the mutex owner died.
9896 * @param[in] env the environment handle
9897 * @param[in] mutex LOCK_MUTEX0() mutex
9898 * @param[in] rc LOCK_MUTEX0() error (nonzero)
9899 * @return 0 on success with the mutex locked, or an error code on failure.
9902 mdb_mutex_failed(MDB_env *env, mdb_mutexref_t mutex, int rc)
9907 if (rc == MDB_OWNERDEAD) {
9908 /* We own the mutex. Clean up after dead previous owner. */
9910 rlocked = (mutex == env->me_rmutex);
9912 /* Keep mti_txnid updated, otherwise next writer can
9913 * overwrite data which latest meta page refers to.
9915 meta = mdb_env_pick_meta(env);
9916 env->me_txns->mti_txnid = meta->mm_txnid;
9917 /* env is hosed if the dead thread was ours */
9919 env->me_flags |= MDB_FATAL_ERROR;
9924 DPRINTF(("%cmutex owner died, %s", (rlocked ? 'r' : 'w'),
9925 (rc ? "this process' env is hosed" : "recovering")));
9926 rc2 = mdb_reader_check0(env, rlocked, NULL);
9928 rc2 = mdb_mutex_consistent(mutex);
9929 if (rc || (rc = rc2)) {
9930 DPRINTF(("LOCK_MUTEX recovery failed, %s", mdb_strerror(rc)));
9931 UNLOCK_MUTEX(mutex);
9937 DPRINTF(("LOCK_MUTEX failed, %s", mdb_strerror(rc)));
9942 #endif /* MDB_ROBUST_SUPPORTED */
9946 static int utf8_to_utf16(const char *src, int srcsize, wchar_t **dst, int *dstsize)
9950 need = MultiByteToWideChar(CP_UTF8, 0, src, srcsize, NULL, 0);
9955 result = malloc(sizeof(wchar_t) * need);
9956 MultiByteToWideChar(CP_UTF8, 0, src, srcsize, result, need);
9962 #endif /* defined(_WIN32) */
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