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 2011-2016 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 < 2.12 only provided _np API */
260 # if defined(__GLIBC__) && GLIBC_VER < 0x02000c
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 (0x40000000U >> (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.
1420 #define MSGSIZE 1024
1421 #define PADSIZE 4096
1422 char buf[MSGSIZE+PADSIZE], *ptr = buf;
1426 return ("Successful return: 0");
1428 if (err >= MDB_KEYEXIST && err <= MDB_LAST_ERRCODE) {
1429 i = err - MDB_KEYEXIST;
1430 return mdb_errstr[i];
1434 /* These are the C-runtime error codes we use. The comment indicates
1435 * their numeric value, and the Win32 error they would correspond to
1436 * if the error actually came from a Win32 API. A major mess, we should
1437 * have used LMDB-specific error codes for everything.
1440 case ENOENT: /* 2, FILE_NOT_FOUND */
1441 case EIO: /* 5, ACCESS_DENIED */
1442 case ENOMEM: /* 12, INVALID_ACCESS */
1443 case EACCES: /* 13, INVALID_DATA */
1444 case EBUSY: /* 16, CURRENT_DIRECTORY */
1445 case EINVAL: /* 22, BAD_COMMAND */
1446 case ENOSPC: /* 28, OUT_OF_PAPER */
1447 return strerror(err);
1452 FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM |
1453 FORMAT_MESSAGE_IGNORE_INSERTS,
1454 NULL, err, 0, ptr, MSGSIZE, (va_list *)buf+MSGSIZE);
1457 return strerror(err);
1461 /** assert(3) variant in cursor context */
1462 #define mdb_cassert(mc, expr) mdb_assert0((mc)->mc_txn->mt_env, expr, #expr)
1463 /** assert(3) variant in transaction context */
1464 #define mdb_tassert(txn, expr) mdb_assert0((txn)->mt_env, expr, #expr)
1465 /** assert(3) variant in environment context */
1466 #define mdb_eassert(env, expr) mdb_assert0(env, expr, #expr)
1469 # define mdb_assert0(env, expr, expr_txt) ((expr) ? (void)0 : \
1470 mdb_assert_fail(env, expr_txt, mdb_func_, __FILE__, __LINE__))
1473 mdb_assert_fail(MDB_env *env, const char *expr_txt,
1474 const char *func, const char *file, int line)
1477 sprintf(buf, "%.100s:%d: Assertion '%.200s' failed in %.40s()",
1478 file, line, expr_txt, func);
1479 if (env->me_assert_func)
1480 env->me_assert_func(env, buf);
1481 fprintf(stderr, "%s\n", buf);
1485 # define mdb_assert0(env, expr, expr_txt) ((void) 0)
1489 /** Return the page number of \b mp which may be sub-page, for debug output */
1491 mdb_dbg_pgno(MDB_page *mp)
1494 COPY_PGNO(ret, mp->mp_pgno);
1498 /** Display a key in hexadecimal and return the address of the result.
1499 * @param[in] key the key to display
1500 * @param[in] buf the buffer to write into. Should always be #DKBUF.
1501 * @return The key in hexadecimal form.
1504 mdb_dkey(MDB_val *key, char *buf)
1507 unsigned char *c = key->mv_data;
1513 if (key->mv_size > DKBUF_MAXKEYSIZE)
1514 return "MDB_MAXKEYSIZE";
1515 /* may want to make this a dynamic check: if the key is mostly
1516 * printable characters, print it as-is instead of converting to hex.
1520 for (i=0; i<key->mv_size; i++)
1521 ptr += sprintf(ptr, "%02x", *c++);
1523 sprintf(buf, "%.*s", key->mv_size, key->mv_data);
1529 mdb_leafnode_type(MDB_node *n)
1531 static char *const tp[2][2] = {{"", ": DB"}, {": sub-page", ": sub-DB"}};
1532 return F_ISSET(n->mn_flags, F_BIGDATA) ? ": overflow page" :
1533 tp[F_ISSET(n->mn_flags, F_DUPDATA)][F_ISSET(n->mn_flags, F_SUBDATA)];
1536 /** Display all the keys in the page. */
1538 mdb_page_list(MDB_page *mp)
1540 pgno_t pgno = mdb_dbg_pgno(mp);
1541 const char *type, *state = (mp->mp_flags & P_DIRTY) ? ", dirty" : "";
1543 unsigned int i, nkeys, nsize, total = 0;
1547 switch (mp->mp_flags & (P_BRANCH|P_LEAF|P_LEAF2|P_META|P_OVERFLOW|P_SUBP)) {
1548 case P_BRANCH: type = "Branch page"; break;
1549 case P_LEAF: type = "Leaf page"; break;
1550 case P_LEAF|P_SUBP: type = "Sub-page"; break;
1551 case P_LEAF|P_LEAF2: type = "LEAF2 page"; break;
1552 case P_LEAF|P_LEAF2|P_SUBP: type = "LEAF2 sub-page"; break;
1554 fprintf(stderr, "Overflow page %"Z"u pages %u%s\n",
1555 pgno, mp->mp_pages, state);
1558 fprintf(stderr, "Meta-page %"Z"u txnid %"Z"u\n",
1559 pgno, ((MDB_meta *)METADATA(mp))->mm_txnid);
1562 fprintf(stderr, "Bad page %"Z"u flags 0x%u\n", pgno, mp->mp_flags);
1566 nkeys = NUMKEYS(mp);
1567 fprintf(stderr, "%s %"Z"u numkeys %d%s\n", type, pgno, nkeys, state);
1569 for (i=0; i<nkeys; i++) {
1570 if (IS_LEAF2(mp)) { /* LEAF2 pages have no mp_ptrs[] or node headers */
1571 key.mv_size = nsize = mp->mp_pad;
1572 key.mv_data = LEAF2KEY(mp, i, nsize);
1574 fprintf(stderr, "key %d: nsize %d, %s\n", i, nsize, DKEY(&key));
1577 node = NODEPTR(mp, i);
1578 key.mv_size = node->mn_ksize;
1579 key.mv_data = node->mn_data;
1580 nsize = NODESIZE + key.mv_size;
1581 if (IS_BRANCH(mp)) {
1582 fprintf(stderr, "key %d: page %"Z"u, %s\n", i, NODEPGNO(node),
1586 if (F_ISSET(node->mn_flags, F_BIGDATA))
1587 nsize += sizeof(pgno_t);
1589 nsize += NODEDSZ(node);
1591 nsize += sizeof(indx_t);
1592 fprintf(stderr, "key %d: nsize %d, %s%s\n",
1593 i, nsize, DKEY(&key), mdb_leafnode_type(node));
1595 total = EVEN(total);
1597 fprintf(stderr, "Total: header %d + contents %d + unused %d\n",
1598 IS_LEAF2(mp) ? PAGEHDRSZ : PAGEBASE + mp->mp_lower, total, SIZELEFT(mp));
1602 mdb_cursor_chk(MDB_cursor *mc)
1608 if (!mc->mc_snum || !(mc->mc_flags & C_INITIALIZED)) return;
1609 for (i=0; i<mc->mc_top; i++) {
1611 node = NODEPTR(mp, mc->mc_ki[i]);
1612 if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno)
1615 if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i]))
1617 if (mc->mc_xcursor && (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
1618 node = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
1619 if (((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA) &&
1620 mc->mc_xcursor->mx_cursor.mc_pg[0] != NODEDATA(node)) {
1628 /** Count all the pages in each DB and in the freelist
1629 * and make sure it matches the actual number of pages
1631 * All named DBs must be open for a correct count.
1633 static void mdb_audit(MDB_txn *txn)
1637 MDB_ID freecount, count;
1642 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
1643 while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
1644 freecount += *(MDB_ID *)data.mv_data;
1645 mdb_tassert(txn, rc == MDB_NOTFOUND);
1648 for (i = 0; i<txn->mt_numdbs; i++) {
1650 if (!(txn->mt_dbflags[i] & DB_VALID))
1652 mdb_cursor_init(&mc, txn, i, &mx);
1653 if (txn->mt_dbs[i].md_root == P_INVALID)
1655 count += txn->mt_dbs[i].md_branch_pages +
1656 txn->mt_dbs[i].md_leaf_pages +
1657 txn->mt_dbs[i].md_overflow_pages;
1658 if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) {
1659 rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST);
1660 for (; rc == MDB_SUCCESS; rc = mdb_cursor_sibling(&mc, 1)) {
1663 mp = mc.mc_pg[mc.mc_top];
1664 for (j=0; j<NUMKEYS(mp); j++) {
1665 MDB_node *leaf = NODEPTR(mp, j);
1666 if (leaf->mn_flags & F_SUBDATA) {
1668 memcpy(&db, NODEDATA(leaf), sizeof(db));
1669 count += db.md_branch_pages + db.md_leaf_pages +
1670 db.md_overflow_pages;
1674 mdb_tassert(txn, rc == MDB_NOTFOUND);
1677 if (freecount + count + NUM_METAS != txn->mt_next_pgno) {
1678 fprintf(stderr, "audit: %lu freecount: %lu count: %lu total: %lu next_pgno: %lu\n",
1679 txn->mt_txnid, freecount, count+NUM_METAS,
1680 freecount+count+NUM_METAS, txn->mt_next_pgno);
1686 mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1688 return txn->mt_dbxs[dbi].md_cmp(a, b);
1692 mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1694 MDB_cmp_func *dcmp = txn->mt_dbxs[dbi].md_dcmp;
1695 #if UINT_MAX < SIZE_MAX
1696 if (dcmp == mdb_cmp_int && a->mv_size == sizeof(size_t))
1697 dcmp = mdb_cmp_clong;
1702 /** Allocate memory for a page.
1703 * Re-use old malloc'd pages first for singletons, otherwise just malloc.
1706 mdb_page_malloc(MDB_txn *txn, unsigned num)
1708 MDB_env *env = txn->mt_env;
1709 MDB_page *ret = env->me_dpages;
1710 size_t psize = env->me_psize, sz = psize, off;
1711 /* For ! #MDB_NOMEMINIT, psize counts how much to init.
1712 * For a single page alloc, we init everything after the page header.
1713 * For multi-page, we init the final page; if the caller needed that
1714 * many pages they will be filling in at least up to the last page.
1718 VGMEMP_ALLOC(env, ret, sz);
1719 VGMEMP_DEFINED(ret, sizeof(ret->mp_next));
1720 env->me_dpages = ret->mp_next;
1723 psize -= off = PAGEHDRSZ;
1728 if ((ret = malloc(sz)) != NULL) {
1729 VGMEMP_ALLOC(env, ret, sz);
1730 if (!(env->me_flags & MDB_NOMEMINIT)) {
1731 memset((char *)ret + off, 0, psize);
1735 txn->mt_flags |= MDB_TXN_ERROR;
1739 /** Free a single page.
1740 * Saves single pages to a list, for future reuse.
1741 * (This is not used for multi-page overflow pages.)
1744 mdb_page_free(MDB_env *env, MDB_page *mp)
1746 mp->mp_next = env->me_dpages;
1747 VGMEMP_FREE(env, mp);
1748 env->me_dpages = mp;
1751 /** Free a dirty page */
1753 mdb_dpage_free(MDB_env *env, MDB_page *dp)
1755 if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
1756 mdb_page_free(env, dp);
1758 /* large pages just get freed directly */
1759 VGMEMP_FREE(env, dp);
1764 /** Return all dirty pages to dpage list */
1766 mdb_dlist_free(MDB_txn *txn)
1768 MDB_env *env = txn->mt_env;
1769 MDB_ID2L dl = txn->mt_u.dirty_list;
1770 unsigned i, n = dl[0].mid;
1772 for (i = 1; i <= n; i++) {
1773 mdb_dpage_free(env, dl[i].mptr);
1778 /** Loosen or free a single page.
1779 * Saves single pages to a list for future reuse
1780 * in this same txn. It has been pulled from the freeDB
1781 * and already resides on the dirty list, but has been
1782 * deleted. Use these pages first before pulling again
1785 * If the page wasn't dirtied in this txn, just add it
1786 * to this txn's free list.
1789 mdb_page_loose(MDB_cursor *mc, MDB_page *mp)
1792 pgno_t pgno = mp->mp_pgno;
1793 MDB_txn *txn = mc->mc_txn;
1795 if ((mp->mp_flags & P_DIRTY) && mc->mc_dbi != FREE_DBI) {
1796 if (txn->mt_parent) {
1797 MDB_ID2 *dl = txn->mt_u.dirty_list;
1798 /* If txn has a parent, make sure the page is in our
1802 unsigned x = mdb_mid2l_search(dl, pgno);
1803 if (x <= dl[0].mid && dl[x].mid == pgno) {
1804 if (mp != dl[x].mptr) { /* bad cursor? */
1805 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
1806 txn->mt_flags |= MDB_TXN_ERROR;
1807 return MDB_CORRUPTED;
1814 /* no parent txn, so it's just ours */
1819 DPRINTF(("loosen db %d page %"Z"u", DDBI(mc),
1821 NEXT_LOOSE_PAGE(mp) = txn->mt_loose_pgs;
1822 txn->mt_loose_pgs = mp;
1823 txn->mt_loose_count++;
1824 mp->mp_flags |= P_LOOSE;
1826 int rc = mdb_midl_append(&txn->mt_free_pgs, pgno);
1834 /** Set or clear P_KEEP in dirty, non-overflow, non-sub pages watched by txn.
1835 * @param[in] mc A cursor handle for the current operation.
1836 * @param[in] pflags Flags of the pages to update:
1837 * P_DIRTY to set P_KEEP, P_DIRTY|P_KEEP to clear it.
1838 * @param[in] all No shortcuts. Needed except after a full #mdb_page_flush().
1839 * @return 0 on success, non-zero on failure.
1842 mdb_pages_xkeep(MDB_cursor *mc, unsigned pflags, int all)
1844 enum { Mask = P_SUBP|P_DIRTY|P_LOOSE|P_KEEP };
1845 MDB_txn *txn = mc->mc_txn;
1851 int rc = MDB_SUCCESS, level;
1853 /* Mark pages seen by cursors */
1854 if (mc->mc_flags & C_UNTRACK)
1855 mc = NULL; /* will find mc in mt_cursors */
1856 for (i = txn->mt_numdbs;; mc = txn->mt_cursors[--i]) {
1857 for (; mc; mc=mc->mc_next) {
1858 if (!(mc->mc_flags & C_INITIALIZED))
1860 for (m3 = mc;; m3 = &mx->mx_cursor) {
1862 for (j=0; j<m3->mc_snum; j++) {
1864 if ((mp->mp_flags & Mask) == pflags)
1865 mp->mp_flags ^= P_KEEP;
1867 mx = m3->mc_xcursor;
1868 /* Proceed to mx if it is at a sub-database */
1869 if (! (mx && (mx->mx_cursor.mc_flags & C_INITIALIZED)))
1871 if (! (mp && (mp->mp_flags & P_LEAF)))
1873 leaf = NODEPTR(mp, m3->mc_ki[j-1]);
1874 if (!(leaf->mn_flags & F_SUBDATA))
1883 /* Mark dirty root pages */
1884 for (i=0; i<txn->mt_numdbs; i++) {
1885 if (txn->mt_dbflags[i] & DB_DIRTY) {
1886 pgno_t pgno = txn->mt_dbs[i].md_root;
1887 if (pgno == P_INVALID)
1889 if ((rc = mdb_page_get(txn, pgno, &dp, &level)) != MDB_SUCCESS)
1891 if ((dp->mp_flags & Mask) == pflags && level <= 1)
1892 dp->mp_flags ^= P_KEEP;
1900 static int mdb_page_flush(MDB_txn *txn, int keep);
1902 /** Spill pages from the dirty list back to disk.
1903 * This is intended to prevent running into #MDB_TXN_FULL situations,
1904 * but note that they may still occur in a few cases:
1905 * 1) our estimate of the txn size could be too small. Currently this
1906 * seems unlikely, except with a large number of #MDB_MULTIPLE items.
1907 * 2) child txns may run out of space if their parents dirtied a
1908 * lot of pages and never spilled them. TODO: we probably should do
1909 * a preemptive spill during #mdb_txn_begin() of a child txn, if
1910 * the parent's dirty_room is below a given threshold.
1912 * Otherwise, if not using nested txns, it is expected that apps will
1913 * not run into #MDB_TXN_FULL any more. The pages are flushed to disk
1914 * the same way as for a txn commit, e.g. their P_DIRTY flag is cleared.
1915 * If the txn never references them again, they can be left alone.
1916 * If the txn only reads them, they can be used without any fuss.
1917 * If the txn writes them again, they can be dirtied immediately without
1918 * going thru all of the work of #mdb_page_touch(). Such references are
1919 * handled by #mdb_page_unspill().
1921 * Also note, we never spill DB root pages, nor pages of active cursors,
1922 * because we'll need these back again soon anyway. And in nested txns,
1923 * we can't spill a page in a child txn if it was already spilled in a
1924 * parent txn. That would alter the parent txns' data even though
1925 * the child hasn't committed yet, and we'd have no way to undo it if
1926 * the child aborted.
1928 * @param[in] m0 cursor A cursor handle identifying the transaction and
1929 * database for which we are checking space.
1930 * @param[in] key For a put operation, the key being stored.
1931 * @param[in] data For a put operation, the data being stored.
1932 * @return 0 on success, non-zero on failure.
1935 mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
1937 MDB_txn *txn = m0->mc_txn;
1939 MDB_ID2L dl = txn->mt_u.dirty_list;
1940 unsigned int i, j, need;
1943 if (m0->mc_flags & C_SUB)
1946 /* Estimate how much space this op will take */
1947 i = m0->mc_db->md_depth;
1948 /* Named DBs also dirty the main DB */
1949 if (m0->mc_dbi >= CORE_DBS)
1950 i += txn->mt_dbs[MAIN_DBI].md_depth;
1951 /* For puts, roughly factor in the key+data size */
1953 i += (LEAFSIZE(key, data) + txn->mt_env->me_psize) / txn->mt_env->me_psize;
1954 i += i; /* double it for good measure */
1957 if (txn->mt_dirty_room > i)
1960 if (!txn->mt_spill_pgs) {
1961 txn->mt_spill_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX);
1962 if (!txn->mt_spill_pgs)
1965 /* purge deleted slots */
1966 MDB_IDL sl = txn->mt_spill_pgs;
1967 unsigned int num = sl[0];
1969 for (i=1; i<=num; i++) {
1976 /* Preserve pages which may soon be dirtied again */
1977 if ((rc = mdb_pages_xkeep(m0, P_DIRTY, 1)) != MDB_SUCCESS)
1980 /* Less aggressive spill - we originally spilled the entire dirty list,
1981 * with a few exceptions for cursor pages and DB root pages. But this
1982 * turns out to be a lot of wasted effort because in a large txn many
1983 * of those pages will need to be used again. So now we spill only 1/8th
1984 * of the dirty pages. Testing revealed this to be a good tradeoff,
1985 * better than 1/2, 1/4, or 1/10.
1987 if (need < MDB_IDL_UM_MAX / 8)
1988 need = MDB_IDL_UM_MAX / 8;
1990 /* Save the page IDs of all the pages we're flushing */
1991 /* flush from the tail forward, this saves a lot of shifting later on. */
1992 for (i=dl[0].mid; i && need; i--) {
1993 MDB_ID pn = dl[i].mid << 1;
1995 if (dp->mp_flags & (P_LOOSE|P_KEEP))
1997 /* Can't spill twice, make sure it's not already in a parent's
2000 if (txn->mt_parent) {
2002 for (tx2 = txn->mt_parent; tx2; tx2 = tx2->mt_parent) {
2003 if (tx2->mt_spill_pgs) {
2004 j = mdb_midl_search(tx2->mt_spill_pgs, pn);
2005 if (j <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[j] == pn) {
2006 dp->mp_flags |= P_KEEP;
2014 if ((rc = mdb_midl_append(&txn->mt_spill_pgs, pn)))
2018 mdb_midl_sort(txn->mt_spill_pgs);
2020 /* Flush the spilled part of dirty list */
2021 if ((rc = mdb_page_flush(txn, i)) != MDB_SUCCESS)
2024 /* Reset any dirty pages we kept that page_flush didn't see */
2025 rc = mdb_pages_xkeep(m0, P_DIRTY|P_KEEP, i);
2028 txn->mt_flags |= rc ? MDB_TXN_ERROR : MDB_TXN_SPILLS;
2032 /** Find oldest txnid still referenced. Expects txn->mt_txnid > 0. */
2034 mdb_find_oldest(MDB_txn *txn)
2037 txnid_t mr, oldest = txn->mt_txnid - 1;
2038 if (txn->mt_env->me_txns) {
2039 MDB_reader *r = txn->mt_env->me_txns->mti_readers;
2040 for (i = txn->mt_env->me_txns->mti_numreaders; --i >= 0; ) {
2051 /** Add a page to the txn's dirty list */
2053 mdb_page_dirty(MDB_txn *txn, MDB_page *mp)
2056 int rc, (*insert)(MDB_ID2L, MDB_ID2 *);
2058 if (txn->mt_flags & MDB_TXN_WRITEMAP) {
2059 insert = mdb_mid2l_append;
2061 insert = mdb_mid2l_insert;
2063 mid.mid = mp->mp_pgno;
2065 rc = insert(txn->mt_u.dirty_list, &mid);
2066 mdb_tassert(txn, rc == 0);
2067 txn->mt_dirty_room--;
2070 /** Allocate page numbers and memory for writing. Maintain me_pglast,
2071 * me_pghead and mt_next_pgno.
2073 * If there are free pages available from older transactions, they
2074 * are re-used first. Otherwise allocate a new page at mt_next_pgno.
2075 * Do not modify the freedB, just merge freeDB records into me_pghead[]
2076 * and move me_pglast to say which records were consumed. Only this
2077 * function can create me_pghead and move me_pglast/mt_next_pgno.
2078 * @param[in] mc cursor A cursor handle identifying the transaction and
2079 * database for which we are allocating.
2080 * @param[in] num the number of pages to allocate.
2081 * @param[out] mp Address of the allocated page(s). Requests for multiple pages
2082 * will always be satisfied by a single contiguous chunk of memory.
2083 * @return 0 on success, non-zero on failure.
2086 mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
2088 #ifdef MDB_PARANOID /* Seems like we can ignore this now */
2089 /* Get at most <Max_retries> more freeDB records once me_pghead
2090 * has enough pages. If not enough, use new pages from the map.
2091 * If <Paranoid> and mc is updating the freeDB, only get new
2092 * records if me_pghead is empty. Then the freelist cannot play
2093 * catch-up with itself by growing while trying to save it.
2095 enum { Paranoid = 1, Max_retries = 500 };
2097 enum { Paranoid = 0, Max_retries = INT_MAX /*infinite*/ };
2099 int rc, retry = num * 60;
2100 MDB_txn *txn = mc->mc_txn;
2101 MDB_env *env = txn->mt_env;
2102 pgno_t pgno, *mop = env->me_pghead;
2103 unsigned i, j, mop_len = mop ? mop[0] : 0, n2 = num-1;
2105 txnid_t oldest = 0, last;
2110 /* If there are any loose pages, just use them */
2111 if (num == 1 && txn->mt_loose_pgs) {
2112 np = txn->mt_loose_pgs;
2113 txn->mt_loose_pgs = NEXT_LOOSE_PAGE(np);
2114 txn->mt_loose_count--;
2115 DPRINTF(("db %d use loose page %"Z"u", DDBI(mc),
2123 /* If our dirty list is already full, we can't do anything */
2124 if (txn->mt_dirty_room == 0) {
2129 for (op = MDB_FIRST;; op = MDB_NEXT) {
2134 /* Seek a big enough contiguous page range. Prefer
2135 * pages at the tail, just truncating the list.
2141 if (mop[i-n2] == pgno+n2)
2148 if (op == MDB_FIRST) { /* 1st iteration */
2149 /* Prepare to fetch more and coalesce */
2150 last = env->me_pglast;
2151 oldest = env->me_pgoldest;
2152 mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
2155 key.mv_data = &last; /* will look up last+1 */
2156 key.mv_size = sizeof(last);
2158 if (Paranoid && mc->mc_dbi == FREE_DBI)
2161 if (Paranoid && retry < 0 && mop_len)
2165 /* Do not fetch more if the record will be too recent */
2166 if (oldest <= last) {
2168 oldest = mdb_find_oldest(txn);
2169 env->me_pgoldest = oldest;
2175 rc = mdb_cursor_get(&m2, &key, NULL, op);
2177 if (rc == MDB_NOTFOUND)
2181 last = *(txnid_t*)key.mv_data;
2182 if (oldest <= last) {
2184 oldest = mdb_find_oldest(txn);
2185 env->me_pgoldest = oldest;
2191 np = m2.mc_pg[m2.mc_top];
2192 leaf = NODEPTR(np, m2.mc_ki[m2.mc_top]);
2193 if ((rc = mdb_node_read(txn, leaf, &data)) != MDB_SUCCESS)
2196 idl = (MDB_ID *) data.mv_data;
2199 if (!(env->me_pghead = mop = mdb_midl_alloc(i))) {
2204 if ((rc = mdb_midl_need(&env->me_pghead, i)) != 0)
2206 mop = env->me_pghead;
2208 env->me_pglast = last;
2210 DPRINTF(("IDL read txn %"Z"u root %"Z"u num %u",
2211 last, txn->mt_dbs[FREE_DBI].md_root, i));
2213 DPRINTF(("IDL %"Z"u", idl[j]));
2215 /* Merge in descending sorted order */
2216 mdb_midl_xmerge(mop, idl);
2220 /* Use new pages from the map when nothing suitable in the freeDB */
2222 pgno = txn->mt_next_pgno;
2223 if (pgno + num >= env->me_maxpg) {
2224 DPUTS("DB size maxed out");
2230 if (env->me_flags & MDB_WRITEMAP) {
2231 np = (MDB_page *)(env->me_map + env->me_psize * pgno);
2233 if (!(np = mdb_page_malloc(txn, num))) {
2239 mop[0] = mop_len -= num;
2240 /* Move any stragglers down */
2241 for (j = i-num; j < mop_len; )
2242 mop[++j] = mop[++i];
2244 txn->mt_next_pgno = pgno + num;
2247 mdb_page_dirty(txn, np);
2253 txn->mt_flags |= MDB_TXN_ERROR;
2257 /** Copy the used portions of a non-overflow page.
2258 * @param[in] dst page to copy into
2259 * @param[in] src page to copy from
2260 * @param[in] psize size of a page
2263 mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize)
2265 enum { Align = sizeof(pgno_t) };
2266 indx_t upper = src->mp_upper, lower = src->mp_lower, unused = upper-lower;
2268 /* If page isn't full, just copy the used portion. Adjust
2269 * alignment so memcpy may copy words instead of bytes.
2271 if ((unused &= -Align) && !IS_LEAF2(src)) {
2272 upper = (upper + PAGEBASE) & -Align;
2273 memcpy(dst, src, (lower + PAGEBASE + (Align-1)) & -Align);
2274 memcpy((pgno_t *)((char *)dst+upper), (pgno_t *)((char *)src+upper),
2277 memcpy(dst, src, psize - unused);
2281 /** Pull a page off the txn's spill list, if present.
2282 * If a page being referenced was spilled to disk in this txn, bring
2283 * it back and make it dirty/writable again.
2284 * @param[in] txn the transaction handle.
2285 * @param[in] mp the page being referenced. It must not be dirty.
2286 * @param[out] ret the writable page, if any. ret is unchanged if
2287 * mp wasn't spilled.
2290 mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret)
2292 MDB_env *env = txn->mt_env;
2295 pgno_t pgno = mp->mp_pgno, pn = pgno << 1;
2297 for (tx2 = txn; tx2; tx2=tx2->mt_parent) {
2298 if (!tx2->mt_spill_pgs)
2300 x = mdb_midl_search(tx2->mt_spill_pgs, pn);
2301 if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
2304 if (txn->mt_dirty_room == 0)
2305 return MDB_TXN_FULL;
2306 if (IS_OVERFLOW(mp))
2310 if (env->me_flags & MDB_WRITEMAP) {
2313 np = mdb_page_malloc(txn, num);
2317 memcpy(np, mp, num * env->me_psize);
2319 mdb_page_copy(np, mp, env->me_psize);
2322 /* If in current txn, this page is no longer spilled.
2323 * If it happens to be the last page, truncate the spill list.
2324 * Otherwise mark it as deleted by setting the LSB.
2326 if (x == txn->mt_spill_pgs[0])
2327 txn->mt_spill_pgs[0]--;
2329 txn->mt_spill_pgs[x] |= 1;
2330 } /* otherwise, if belonging to a parent txn, the
2331 * page remains spilled until child commits
2334 mdb_page_dirty(txn, np);
2335 np->mp_flags |= P_DIRTY;
2343 /** Touch a page: make it dirty and re-insert into tree with updated pgno.
2344 * @param[in] mc cursor pointing to the page to be touched
2345 * @return 0 on success, non-zero on failure.
2348 mdb_page_touch(MDB_cursor *mc)
2350 MDB_page *mp = mc->mc_pg[mc->mc_top], *np;
2351 MDB_txn *txn = mc->mc_txn;
2352 MDB_cursor *m2, *m3;
2356 if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
2357 if (txn->mt_flags & MDB_TXN_SPILLS) {
2359 rc = mdb_page_unspill(txn, mp, &np);
2365 if ((rc = mdb_midl_need(&txn->mt_free_pgs, 1)) ||
2366 (rc = mdb_page_alloc(mc, 1, &np)))
2369 DPRINTF(("touched db %d page %"Z"u -> %"Z"u", DDBI(mc),
2370 mp->mp_pgno, pgno));
2371 mdb_cassert(mc, mp->mp_pgno != pgno);
2372 mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
2373 /* Update the parent page, if any, to point to the new page */
2375 MDB_page *parent = mc->mc_pg[mc->mc_top-1];
2376 MDB_node *node = NODEPTR(parent, mc->mc_ki[mc->mc_top-1]);
2377 SETPGNO(node, pgno);
2379 mc->mc_db->md_root = pgno;
2381 } else if (txn->mt_parent && !IS_SUBP(mp)) {
2382 MDB_ID2 mid, *dl = txn->mt_u.dirty_list;
2384 /* If txn has a parent, make sure the page is in our
2388 unsigned x = mdb_mid2l_search(dl, pgno);
2389 if (x <= dl[0].mid && dl[x].mid == pgno) {
2390 if (mp != dl[x].mptr) { /* bad cursor? */
2391 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
2392 txn->mt_flags |= MDB_TXN_ERROR;
2393 return MDB_CORRUPTED;
2398 mdb_cassert(mc, dl[0].mid < MDB_IDL_UM_MAX);
2400 np = mdb_page_malloc(txn, 1);
2405 rc = mdb_mid2l_insert(dl, &mid);
2406 mdb_cassert(mc, rc == 0);
2411 mdb_page_copy(np, mp, txn->mt_env->me_psize);
2413 np->mp_flags |= P_DIRTY;
2416 /* Adjust cursors pointing to mp */
2417 mc->mc_pg[mc->mc_top] = np;
2418 m2 = txn->mt_cursors[mc->mc_dbi];
2419 if (mc->mc_flags & C_SUB) {
2420 for (; m2; m2=m2->mc_next) {
2421 m3 = &m2->mc_xcursor->mx_cursor;
2422 if (m3->mc_snum < mc->mc_snum) continue;
2423 if (m3->mc_pg[mc->mc_top] == mp)
2424 m3->mc_pg[mc->mc_top] = np;
2427 for (; m2; m2=m2->mc_next) {
2428 if (m2->mc_snum < mc->mc_snum) continue;
2429 if (m2 == mc) continue;
2430 if (m2->mc_pg[mc->mc_top] == mp) {
2431 m2->mc_pg[mc->mc_top] = np;
2432 if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
2434 (m2->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
2436 MDB_node *leaf = NODEPTR(np, m2->mc_ki[mc->mc_top]);
2437 if ((leaf->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
2438 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
2446 txn->mt_flags |= MDB_TXN_ERROR;
2451 mdb_env_sync(MDB_env *env, int force)
2454 if (env->me_flags & MDB_RDONLY)
2456 if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) {
2457 if (env->me_flags & MDB_WRITEMAP) {
2458 int flags = ((env->me_flags & MDB_MAPASYNC) && !force)
2459 ? MS_ASYNC : MS_SYNC;
2460 if (MDB_MSYNC(env->me_map, env->me_mapsize, flags))
2463 else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd))
2467 #ifdef BROKEN_FDATASYNC
2468 if (env->me_flags & MDB_FSYNCONLY) {
2469 if (fsync(env->me_fd))
2473 if (MDB_FDATASYNC(env->me_fd))
2480 /** Back up parent txn's cursors, then grab the originals for tracking */
2482 mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst)
2484 MDB_cursor *mc, *bk;
2489 for (i = src->mt_numdbs; --i >= 0; ) {
2490 if ((mc = src->mt_cursors[i]) != NULL) {
2491 size = sizeof(MDB_cursor);
2493 size += sizeof(MDB_xcursor);
2494 for (; mc; mc = bk->mc_next) {
2500 mc->mc_db = &dst->mt_dbs[i];
2501 /* Kill pointers into src to reduce abuse: The
2502 * user may not use mc until dst ends. But we need a valid
2503 * txn pointer here for cursor fixups to keep working.
2506 mc->mc_dbflag = &dst->mt_dbflags[i];
2507 if ((mx = mc->mc_xcursor) != NULL) {
2508 *(MDB_xcursor *)(bk+1) = *mx;
2509 mx->mx_cursor.mc_txn = dst;
2511 mc->mc_next = dst->mt_cursors[i];
2512 dst->mt_cursors[i] = mc;
2519 /** Close this write txn's cursors, give parent txn's cursors back to parent.
2520 * @param[in] txn the transaction handle.
2521 * @param[in] merge true to keep changes to parent cursors, false to revert.
2522 * @return 0 on success, non-zero on failure.
2525 mdb_cursors_close(MDB_txn *txn, unsigned merge)
2527 MDB_cursor **cursors = txn->mt_cursors, *mc, *next, *bk;
2531 for (i = txn->mt_numdbs; --i >= 0; ) {
2532 for (mc = cursors[i]; mc; mc = next) {
2534 if ((bk = mc->mc_backup) != NULL) {
2536 /* Commit changes to parent txn */
2537 mc->mc_next = bk->mc_next;
2538 mc->mc_backup = bk->mc_backup;
2539 mc->mc_txn = bk->mc_txn;
2540 mc->mc_db = bk->mc_db;
2541 mc->mc_dbflag = bk->mc_dbflag;
2542 if ((mx = mc->mc_xcursor) != NULL)
2543 mx->mx_cursor.mc_txn = bk->mc_txn;
2545 /* Abort nested txn */
2547 if ((mx = mc->mc_xcursor) != NULL)
2548 *mx = *(MDB_xcursor *)(bk+1);
2552 /* Only malloced cursors are permanently tracked. */
2559 #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
2565 Pidset = F_SETLK, Pidcheck = F_GETLK
2569 /** Set or check a pid lock. Set returns 0 on success.
2570 * Check returns 0 if the process is certainly dead, nonzero if it may
2571 * be alive (the lock exists or an error happened so we do not know).
2573 * On Windows Pidset is a no-op, we merely check for the existence
2574 * of the process with the given pid. On POSIX we use a single byte
2575 * lock on the lockfile, set at an offset equal to the pid.
2578 mdb_reader_pid(MDB_env *env, enum Pidlock_op op, MDB_PID_T pid)
2580 #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
2583 if (op == Pidcheck) {
2584 h = OpenProcess(env->me_pidquery, FALSE, pid);
2585 /* No documented "no such process" code, but other program use this: */
2587 return ErrCode() != ERROR_INVALID_PARAMETER;
2588 /* A process exists until all handles to it close. Has it exited? */
2589 ret = WaitForSingleObject(h, 0) != 0;
2596 struct flock lock_info;
2597 memset(&lock_info, 0, sizeof(lock_info));
2598 lock_info.l_type = F_WRLCK;
2599 lock_info.l_whence = SEEK_SET;
2600 lock_info.l_start = pid;
2601 lock_info.l_len = 1;
2602 if ((rc = fcntl(env->me_lfd, op, &lock_info)) == 0) {
2603 if (op == F_GETLK && lock_info.l_type != F_UNLCK)
2605 } else if ((rc = ErrCode()) == EINTR) {
2613 /** Common code for #mdb_txn_begin() and #mdb_txn_renew().
2614 * @param[in] txn the transaction handle to initialize
2615 * @return 0 on success, non-zero on failure.
2618 mdb_txn_renew0(MDB_txn *txn)
2620 MDB_env *env = txn->mt_env;
2621 MDB_txninfo *ti = env->me_txns;
2623 unsigned int i, nr, flags = txn->mt_flags;
2625 int rc, new_notls = 0;
2627 if ((flags &= MDB_TXN_RDONLY) != 0) {
2629 meta = mdb_env_pick_meta(env);
2630 txn->mt_txnid = meta->mm_txnid;
2631 txn->mt_u.reader = NULL;
2633 MDB_reader *r = (env->me_flags & MDB_NOTLS) ? txn->mt_u.reader :
2634 pthread_getspecific(env->me_txkey);
2636 if (r->mr_pid != env->me_pid || r->mr_txnid != (txnid_t)-1)
2637 return MDB_BAD_RSLOT;
2639 MDB_PID_T pid = env->me_pid;
2640 MDB_THR_T tid = pthread_self();
2641 mdb_mutexref_t rmutex = env->me_rmutex;
2643 if (!env->me_live_reader) {
2644 rc = mdb_reader_pid(env, Pidset, pid);
2647 env->me_live_reader = 1;
2650 if (LOCK_MUTEX(rc, env, rmutex))
2652 nr = ti->mti_numreaders;
2653 for (i=0; i<nr; i++)
2654 if (ti->mti_readers[i].mr_pid == 0)
2656 if (i == env->me_maxreaders) {
2657 UNLOCK_MUTEX(rmutex);
2658 return MDB_READERS_FULL;
2660 r = &ti->mti_readers[i];
2661 /* Claim the reader slot, carefully since other code
2662 * uses the reader table un-mutexed: First reset the
2663 * slot, next publish it in mti_numreaders. After
2664 * that, it is safe for mdb_env_close() to touch it.
2665 * When it will be closed, we can finally claim it.
2668 r->mr_txnid = (txnid_t)-1;
2671 ti->mti_numreaders = ++nr;
2672 env->me_close_readers = nr;
2674 UNLOCK_MUTEX(rmutex);
2676 new_notls = (env->me_flags & MDB_NOTLS);
2677 if (!new_notls && (rc=pthread_setspecific(env->me_txkey, r))) {
2682 do /* LY: Retry on a race, ITS#7970. */
2683 r->mr_txnid = ti->mti_txnid;
2684 while(r->mr_txnid != ti->mti_txnid);
2685 txn->mt_txnid = r->mr_txnid;
2686 txn->mt_u.reader = r;
2687 meta = env->me_metas[txn->mt_txnid & 1];
2691 /* Not yet touching txn == env->me_txn0, it may be active */
2693 if (LOCK_MUTEX(rc, env, env->me_wmutex))
2695 txn->mt_txnid = ti->mti_txnid;
2696 meta = env->me_metas[txn->mt_txnid & 1];
2698 meta = mdb_env_pick_meta(env);
2699 txn->mt_txnid = meta->mm_txnid;
2703 if (txn->mt_txnid == mdb_debug_start)
2706 txn->mt_child = NULL;
2707 txn->mt_loose_pgs = NULL;
2708 txn->mt_loose_count = 0;
2709 txn->mt_dirty_room = MDB_IDL_UM_MAX;
2710 txn->mt_u.dirty_list = env->me_dirty_list;
2711 txn->mt_u.dirty_list[0].mid = 0;
2712 txn->mt_free_pgs = env->me_free_pgs;
2713 txn->mt_free_pgs[0] = 0;
2714 txn->mt_spill_pgs = NULL;
2716 memcpy(txn->mt_dbiseqs, env->me_dbiseqs, env->me_maxdbs * sizeof(unsigned int));
2719 /* Copy the DB info and flags */
2720 memcpy(txn->mt_dbs, meta->mm_dbs, CORE_DBS * sizeof(MDB_db));
2722 /* Moved to here to avoid a data race in read TXNs */
2723 txn->mt_next_pgno = meta->mm_last_pg+1;
2725 txn->mt_flags = flags;
2728 txn->mt_numdbs = env->me_numdbs;
2729 for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
2730 x = env->me_dbflags[i];
2731 txn->mt_dbs[i].md_flags = x & PERSISTENT_FLAGS;
2732 txn->mt_dbflags[i] = (x & MDB_VALID) ? DB_VALID|DB_USRVALID|DB_STALE : 0;
2734 txn->mt_dbflags[MAIN_DBI] = DB_VALID|DB_USRVALID;
2735 txn->mt_dbflags[FREE_DBI] = DB_VALID;
2737 if (env->me_flags & MDB_FATAL_ERROR) {
2738 DPUTS("environment had fatal error, must shutdown!");
2740 } else if (env->me_maxpg < txn->mt_next_pgno) {
2741 rc = MDB_MAP_RESIZED;
2745 mdb_txn_end(txn, new_notls /*0 or MDB_END_SLOT*/ | MDB_END_FAIL_BEGIN);
2750 mdb_txn_renew(MDB_txn *txn)
2754 if (!txn || !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY|MDB_TXN_FINISHED))
2757 rc = mdb_txn_renew0(txn);
2758 if (rc == MDB_SUCCESS) {
2759 DPRINTF(("renew txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2760 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2761 (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root));
2767 mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
2771 int rc, size, tsize;
2773 flags &= MDB_TXN_BEGIN_FLAGS;
2774 flags |= env->me_flags & MDB_WRITEMAP;
2776 if (env->me_flags & MDB_RDONLY & ~flags) /* write txn in RDONLY env */
2780 /* Nested transactions: Max 1 child, write txns only, no writemap */
2781 flags |= parent->mt_flags;
2782 if (flags & (MDB_RDONLY|MDB_WRITEMAP|MDB_TXN_BLOCKED)) {
2783 return (parent->mt_flags & MDB_TXN_RDONLY) ? EINVAL : MDB_BAD_TXN;
2785 /* Child txns save MDB_pgstate and use own copy of cursors */
2786 size = env->me_maxdbs * (sizeof(MDB_db)+sizeof(MDB_cursor *)+1);
2787 size += tsize = sizeof(MDB_ntxn);
2788 } else if (flags & MDB_RDONLY) {
2789 size = env->me_maxdbs * (sizeof(MDB_db)+1);
2790 size += tsize = sizeof(MDB_txn);
2792 /* Reuse preallocated write txn. However, do not touch it until
2793 * mdb_txn_renew0() succeeds, since it currently may be active.
2798 if ((txn = calloc(1, size)) == NULL) {
2799 DPRINTF(("calloc: %s", strerror(errno)));
2802 txn->mt_dbxs = env->me_dbxs; /* static */
2803 txn->mt_dbs = (MDB_db *) ((char *)txn + tsize);
2804 txn->mt_dbflags = (unsigned char *)txn + size - env->me_maxdbs;
2805 txn->mt_flags = flags;
2810 txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
2811 txn->mt_dbiseqs = parent->mt_dbiseqs;
2812 txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE);
2813 if (!txn->mt_u.dirty_list ||
2814 !(txn->mt_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)))
2816 free(txn->mt_u.dirty_list);
2820 txn->mt_txnid = parent->mt_txnid;
2821 txn->mt_dirty_room = parent->mt_dirty_room;
2822 txn->mt_u.dirty_list[0].mid = 0;
2823 txn->mt_spill_pgs = NULL;
2824 txn->mt_next_pgno = parent->mt_next_pgno;
2825 parent->mt_flags |= MDB_TXN_HAS_CHILD;
2826 parent->mt_child = txn;
2827 txn->mt_parent = parent;
2828 txn->mt_numdbs = parent->mt_numdbs;
2829 memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
2830 /* Copy parent's mt_dbflags, but clear DB_NEW */
2831 for (i=0; i<txn->mt_numdbs; i++)
2832 txn->mt_dbflags[i] = parent->mt_dbflags[i] & ~DB_NEW;
2834 ntxn = (MDB_ntxn *)txn;
2835 ntxn->mnt_pgstate = env->me_pgstate; /* save parent me_pghead & co */
2836 if (env->me_pghead) {
2837 size = MDB_IDL_SIZEOF(env->me_pghead);
2838 env->me_pghead = mdb_midl_alloc(env->me_pghead[0]);
2840 memcpy(env->me_pghead, ntxn->mnt_pgstate.mf_pghead, size);
2845 rc = mdb_cursor_shadow(parent, txn);
2847 mdb_txn_end(txn, MDB_END_FAIL_BEGINCHILD);
2848 } else { /* MDB_RDONLY */
2849 txn->mt_dbiseqs = env->me_dbiseqs;
2851 rc = mdb_txn_renew0(txn);
2854 if (txn != env->me_txn0)
2857 txn->mt_flags |= flags; /* could not change txn=me_txn0 earlier */
2859 DPRINTF(("begin txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2860 txn->mt_txnid, (flags & MDB_RDONLY) ? 'r' : 'w',
2861 (void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root));
2868 mdb_txn_env(MDB_txn *txn)
2870 if(!txn) return NULL;
2875 mdb_txn_id(MDB_txn *txn)
2878 return txn->mt_txnid;
2881 /** Export or close DBI handles opened in this txn. */
2883 mdb_dbis_update(MDB_txn *txn, int keep)
2886 MDB_dbi n = txn->mt_numdbs;
2887 MDB_env *env = txn->mt_env;
2888 unsigned char *tdbflags = txn->mt_dbflags;
2890 for (i = n; --i >= CORE_DBS;) {
2891 if (tdbflags[i] & DB_NEW) {
2893 env->me_dbflags[i] = txn->mt_dbs[i].md_flags | MDB_VALID;
2895 char *ptr = env->me_dbxs[i].md_name.mv_data;
2897 env->me_dbxs[i].md_name.mv_data = NULL;
2898 env->me_dbxs[i].md_name.mv_size = 0;
2899 env->me_dbflags[i] = 0;
2900 env->me_dbiseqs[i]++;
2906 if (keep && env->me_numdbs < n)
2910 /** End a transaction, except successful commit of a nested transaction.
2911 * May be called twice for readonly txns: First reset it, then abort.
2912 * @param[in] txn the transaction handle to end
2913 * @param[in] mode why and how to end the transaction
2916 mdb_txn_end(MDB_txn *txn, unsigned mode)
2918 MDB_env *env = txn->mt_env;
2920 static const char *const names[] = MDB_END_NAMES;
2923 /* Export or close DBI handles opened in this txn */
2924 mdb_dbis_update(txn, mode & MDB_END_UPDATE);
2926 DPRINTF(("%s txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2927 names[mode & MDB_END_OPMASK],
2928 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2929 (void *) txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root));
2931 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
2932 if (txn->mt_u.reader) {
2933 txn->mt_u.reader->mr_txnid = (txnid_t)-1;
2934 if (!(env->me_flags & MDB_NOTLS)) {
2935 txn->mt_u.reader = NULL; /* txn does not own reader */
2936 } else if (mode & MDB_END_SLOT) {
2937 txn->mt_u.reader->mr_pid = 0;
2938 txn->mt_u.reader = NULL;
2939 } /* else txn owns the slot until it does MDB_END_SLOT */
2941 txn->mt_numdbs = 0; /* prevent further DBI activity */
2942 txn->mt_flags |= MDB_TXN_FINISHED;
2944 } else if (!F_ISSET(txn->mt_flags, MDB_TXN_FINISHED)) {
2945 pgno_t *pghead = env->me_pghead;
2947 if (!(mode & MDB_END_UPDATE)) /* !(already closed cursors) */
2948 mdb_cursors_close(txn, 0);
2949 if (!(env->me_flags & MDB_WRITEMAP)) {
2950 mdb_dlist_free(txn);
2954 txn->mt_flags = MDB_TXN_FINISHED;
2956 if (!txn->mt_parent) {
2957 mdb_midl_shrink(&txn->mt_free_pgs);
2958 env->me_free_pgs = txn->mt_free_pgs;
2960 env->me_pghead = NULL;
2964 mode = 0; /* txn == env->me_txn0, do not free() it */
2966 /* The writer mutex was locked in mdb_txn_begin. */
2968 UNLOCK_MUTEX(env->me_wmutex);
2970 txn->mt_parent->mt_child = NULL;
2971 txn->mt_parent->mt_flags &= ~MDB_TXN_HAS_CHILD;
2972 env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate;
2973 mdb_midl_free(txn->mt_free_pgs);
2974 mdb_midl_free(txn->mt_spill_pgs);
2975 free(txn->mt_u.dirty_list);
2978 mdb_midl_free(pghead);
2981 if (mode & MDB_END_FREE)
2986 mdb_txn_reset(MDB_txn *txn)
2991 /* This call is only valid for read-only txns */
2992 if (!(txn->mt_flags & MDB_TXN_RDONLY))
2995 mdb_txn_end(txn, MDB_END_RESET);
2999 mdb_txn_abort(MDB_txn *txn)
3005 mdb_txn_abort(txn->mt_child);
3007 mdb_txn_end(txn, MDB_END_ABORT|MDB_END_SLOT|MDB_END_FREE);
3010 /** Save the freelist as of this transaction to the freeDB.
3011 * This changes the freelist. Keep trying until it stabilizes.
3014 mdb_freelist_save(MDB_txn *txn)
3016 /* env->me_pghead[] can grow and shrink during this call.
3017 * env->me_pglast and txn->mt_free_pgs[] can only grow.
3018 * Page numbers cannot disappear from txn->mt_free_pgs[].
3021 MDB_env *env = txn->mt_env;
3022 int rc, maxfree_1pg = env->me_maxfree_1pg, more = 1;
3023 txnid_t pglast = 0, head_id = 0;
3024 pgno_t freecnt = 0, *free_pgs, *mop;
3025 ssize_t head_room = 0, total_room = 0, mop_len, clean_limit;
3027 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
3029 if (env->me_pghead) {
3030 /* Make sure first page of freeDB is touched and on freelist */
3031 rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST|MDB_PS_MODIFY);
3032 if (rc && rc != MDB_NOTFOUND)
3036 if (!env->me_pghead && txn->mt_loose_pgs) {
3037 /* Put loose page numbers in mt_free_pgs, since
3038 * we may be unable to return them to me_pghead.
3040 MDB_page *mp = txn->mt_loose_pgs;
3041 if ((rc = mdb_midl_need(&txn->mt_free_pgs, txn->mt_loose_count)) != 0)
3043 for (; mp; mp = NEXT_LOOSE_PAGE(mp))
3044 mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
3045 txn->mt_loose_pgs = NULL;
3046 txn->mt_loose_count = 0;
3049 /* MDB_RESERVE cancels meminit in ovpage malloc (when no WRITEMAP) */
3050 clean_limit = (env->me_flags & (MDB_NOMEMINIT|MDB_WRITEMAP))
3051 ? SSIZE_MAX : maxfree_1pg;
3054 /* Come back here after each Put() in case freelist changed */
3059 /* If using records from freeDB which we have not yet
3060 * deleted, delete them and any we reserved for me_pghead.
3062 while (pglast < env->me_pglast) {
3063 rc = mdb_cursor_first(&mc, &key, NULL);
3066 pglast = head_id = *(txnid_t *)key.mv_data;
3067 total_room = head_room = 0;
3068 mdb_tassert(txn, pglast <= env->me_pglast);
3069 rc = mdb_cursor_del(&mc, 0);
3074 /* Save the IDL of pages freed by this txn, to a single record */
3075 if (freecnt < txn->mt_free_pgs[0]) {
3077 /* Make sure last page of freeDB is touched and on freelist */
3078 rc = mdb_page_search(&mc, NULL, MDB_PS_LAST|MDB_PS_MODIFY);
3079 if (rc && rc != MDB_NOTFOUND)
3082 free_pgs = txn->mt_free_pgs;
3083 /* Write to last page of freeDB */
3084 key.mv_size = sizeof(txn->mt_txnid);
3085 key.mv_data = &txn->mt_txnid;
3087 freecnt = free_pgs[0];
3088 data.mv_size = MDB_IDL_SIZEOF(free_pgs);
3089 rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
3092 /* Retry if mt_free_pgs[] grew during the Put() */
3093 free_pgs = txn->mt_free_pgs;
3094 } while (freecnt < free_pgs[0]);
3095 mdb_midl_sort(free_pgs);
3096 memcpy(data.mv_data, free_pgs, data.mv_size);
3099 unsigned int i = free_pgs[0];
3100 DPRINTF(("IDL write txn %"Z"u root %"Z"u num %u",
3101 txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, i));
3103 DPRINTF(("IDL %"Z"u", free_pgs[i]));
3109 mop = env->me_pghead;
3110 mop_len = (mop ? mop[0] : 0) + txn->mt_loose_count;
3112 /* Reserve records for me_pghead[]. Split it if multi-page,
3113 * to avoid searching freeDB for a page range. Use keys in
3114 * range [1,me_pglast]: Smaller than txnid of oldest reader.
3116 if (total_room >= mop_len) {
3117 if (total_room == mop_len || --more < 0)
3119 } else if (head_room >= maxfree_1pg && head_id > 1) {
3120 /* Keep current record (overflow page), add a new one */
3124 /* (Re)write {key = head_id, IDL length = head_room} */
3125 total_room -= head_room;
3126 head_room = mop_len - total_room;
3127 if (head_room > maxfree_1pg && head_id > 1) {
3128 /* Overflow multi-page for part of me_pghead */
3129 head_room /= head_id; /* amortize page sizes */
3130 head_room += maxfree_1pg - head_room % (maxfree_1pg + 1);
3131 } else if (head_room < 0) {
3132 /* Rare case, not bothering to delete this record */
3135 key.mv_size = sizeof(head_id);
3136 key.mv_data = &head_id;
3137 data.mv_size = (head_room + 1) * sizeof(pgno_t);
3138 rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
3141 /* IDL is initially empty, zero out at least the length */
3142 pgs = (pgno_t *)data.mv_data;
3143 j = head_room > clean_limit ? head_room : 0;
3147 total_room += head_room;
3150 /* Return loose page numbers to me_pghead, though usually none are
3151 * left at this point. The pages themselves remain in dirty_list.
3153 if (txn->mt_loose_pgs) {
3154 MDB_page *mp = txn->mt_loose_pgs;
3155 unsigned count = txn->mt_loose_count;
3157 /* Room for loose pages + temp IDL with same */
3158 if ((rc = mdb_midl_need(&env->me_pghead, 2*count+1)) != 0)
3160 mop = env->me_pghead;
3161 loose = mop + MDB_IDL_ALLOCLEN(mop) - count;
3162 for (count = 0; mp; mp = NEXT_LOOSE_PAGE(mp))
3163 loose[ ++count ] = mp->mp_pgno;
3165 mdb_midl_sort(loose);
3166 mdb_midl_xmerge(mop, loose);
3167 txn->mt_loose_pgs = NULL;
3168 txn->mt_loose_count = 0;
3172 /* Fill in the reserved me_pghead records */
3178 rc = mdb_cursor_first(&mc, &key, &data);
3179 for (; !rc; rc = mdb_cursor_next(&mc, &key, &data, MDB_NEXT)) {
3180 txnid_t id = *(txnid_t *)key.mv_data;
3181 ssize_t len = (ssize_t)(data.mv_size / sizeof(MDB_ID)) - 1;
3184 mdb_tassert(txn, len >= 0 && id <= env->me_pglast);
3186 if (len > mop_len) {
3188 data.mv_size = (len + 1) * sizeof(MDB_ID);
3190 data.mv_data = mop -= len;
3193 rc = mdb_cursor_put(&mc, &key, &data, MDB_CURRENT);
3195 if (rc || !(mop_len -= len))
3202 /** Flush (some) dirty pages to the map, after clearing their dirty flag.
3203 * @param[in] txn the transaction that's being committed
3204 * @param[in] keep number of initial pages in dirty_list to keep dirty.
3205 * @return 0 on success, non-zero on failure.
3208 mdb_page_flush(MDB_txn *txn, int keep)
3210 MDB_env *env = txn->mt_env;
3211 MDB_ID2L dl = txn->mt_u.dirty_list;
3212 unsigned psize = env->me_psize, j;
3213 int i, pagecount = dl[0].mid, rc;
3214 size_t size = 0, pos = 0;
3216 MDB_page *dp = NULL;
3220 struct iovec iov[MDB_COMMIT_PAGES];
3221 ssize_t wpos = 0, wsize = 0, wres;
3222 size_t next_pos = 1; /* impossible pos, so pos != next_pos */
3228 if (env->me_flags & MDB_WRITEMAP) {
3229 /* Clear dirty flags */
3230 while (++i <= pagecount) {
3232 /* Don't flush this page yet */
3233 if (dp->mp_flags & (P_LOOSE|P_KEEP)) {
3234 dp->mp_flags &= ~P_KEEP;
3238 dp->mp_flags &= ~P_DIRTY;
3243 /* Write the pages */
3245 if (++i <= pagecount) {
3247 /* Don't flush this page yet */
3248 if (dp->mp_flags & (P_LOOSE|P_KEEP)) {
3249 dp->mp_flags &= ~P_KEEP;
3254 /* clear dirty flag */
3255 dp->mp_flags &= ~P_DIRTY;
3258 if (IS_OVERFLOW(dp)) size *= dp->mp_pages;
3263 /* Windows actually supports scatter/gather I/O, but only on
3264 * unbuffered file handles. Since we're relying on the OS page
3265 * cache for all our data, that's self-defeating. So we just
3266 * write pages one at a time. We use the ov structure to set
3267 * the write offset, to at least save the overhead of a Seek
3270 DPRINTF(("committing page %"Z"u", pgno));
3271 memset(&ov, 0, sizeof(ov));
3272 ov.Offset = pos & 0xffffffff;
3273 ov.OffsetHigh = pos >> 16 >> 16;
3274 if (!WriteFile(env->me_fd, dp, size, NULL, &ov)) {
3276 DPRINTF(("WriteFile: %d", rc));
3280 /* Write up to MDB_COMMIT_PAGES dirty pages at a time. */
3281 if (pos!=next_pos || n==MDB_COMMIT_PAGES || wsize+size>MAX_WRITE) {
3284 /* Write previous page(s) */
3285 #ifdef MDB_USE_PWRITEV
3286 wres = pwritev(env->me_fd, iov, n, wpos);
3289 wres = pwrite(env->me_fd, iov[0].iov_base, wsize, wpos);
3292 if (lseek(env->me_fd, wpos, SEEK_SET) == -1) {
3296 DPRINTF(("lseek: %s", strerror(rc)));
3299 wres = writev(env->me_fd, iov, n);
3302 if (wres != wsize) {
3307 DPRINTF(("Write error: %s", strerror(rc)));
3309 rc = EIO; /* TODO: Use which error code? */
3310 DPUTS("short write, filesystem full?");
3321 DPRINTF(("committing page %"Z"u", pgno));
3322 next_pos = pos + size;
3323 iov[n].iov_len = size;
3324 iov[n].iov_base = (char *)dp;
3330 /* MIPS has cache coherency issues, this is a no-op everywhere else
3331 * Note: for any size >= on-chip cache size, entire on-chip cache is
3334 CACHEFLUSH(env->me_map, txn->mt_next_pgno * env->me_psize, DCACHE);
3336 for (i = keep; ++i <= pagecount; ) {
3338 /* This is a page we skipped above */
3341 dl[j].mid = dp->mp_pgno;
3344 mdb_dpage_free(env, dp);
3349 txn->mt_dirty_room += i - j;
3355 mdb_txn_commit(MDB_txn *txn)
3358 unsigned int i, end_mode;
3364 /* mdb_txn_end() mode for a commit which writes nothing */
3365 end_mode = MDB_END_EMPTY_COMMIT|MDB_END_UPDATE|MDB_END_SLOT|MDB_END_FREE;
3367 if (txn->mt_child) {
3368 rc = mdb_txn_commit(txn->mt_child);
3375 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
3379 if (txn->mt_flags & (MDB_TXN_FINISHED|MDB_TXN_ERROR)) {
3380 DPUTS("txn has failed/finished, can't commit");
3382 txn->mt_parent->mt_flags |= MDB_TXN_ERROR;
3387 if (txn->mt_parent) {
3388 MDB_txn *parent = txn->mt_parent;
3392 unsigned x, y, len, ps_len;
3394 /* Append our free list to parent's */
3395 rc = mdb_midl_append_list(&parent->mt_free_pgs, txn->mt_free_pgs);
3398 mdb_midl_free(txn->mt_free_pgs);
3399 /* Failures after this must either undo the changes
3400 * to the parent or set MDB_TXN_ERROR in the parent.
3403 parent->mt_next_pgno = txn->mt_next_pgno;
3404 parent->mt_flags = txn->mt_flags;
3406 /* Merge our cursors into parent's and close them */
3407 mdb_cursors_close(txn, 1);
3409 /* Update parent's DB table. */
3410 memcpy(parent->mt_dbs, txn->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
3411 parent->mt_numdbs = txn->mt_numdbs;
3412 parent->mt_dbflags[FREE_DBI] = txn->mt_dbflags[FREE_DBI];
3413 parent->mt_dbflags[MAIN_DBI] = txn->mt_dbflags[MAIN_DBI];
3414 for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
3415 /* preserve parent's DB_NEW status */
3416 x = parent->mt_dbflags[i] & DB_NEW;
3417 parent->mt_dbflags[i] = txn->mt_dbflags[i] | x;
3420 dst = parent->mt_u.dirty_list;
3421 src = txn->mt_u.dirty_list;
3422 /* Remove anything in our dirty list from parent's spill list */
3423 if ((pspill = parent->mt_spill_pgs) && (ps_len = pspill[0])) {
3425 pspill[0] = (pgno_t)-1;
3426 /* Mark our dirty pages as deleted in parent spill list */
3427 for (i=0, len=src[0].mid; ++i <= len; ) {
3428 MDB_ID pn = src[i].mid << 1;
3429 while (pn > pspill[x])
3431 if (pn == pspill[x]) {
3436 /* Squash deleted pagenums if we deleted any */
3437 for (x=y; ++x <= ps_len; )
3438 if (!(pspill[x] & 1))
3439 pspill[++y] = pspill[x];
3443 /* Remove anything in our spill list from parent's dirty list */
3444 if (txn->mt_spill_pgs && txn->mt_spill_pgs[0]) {
3445 for (i=1; i<=txn->mt_spill_pgs[0]; i++) {
3446 MDB_ID pn = txn->mt_spill_pgs[i];
3448 continue; /* deleted spillpg */
3450 y = mdb_mid2l_search(dst, pn);
3451 if (y <= dst[0].mid && dst[y].mid == pn) {
3453 while (y < dst[0].mid) {
3462 /* Find len = length of merging our dirty list with parent's */
3464 dst[0].mid = 0; /* simplify loops */
3465 if (parent->mt_parent) {
3466 len = x + src[0].mid;
3467 y = mdb_mid2l_search(src, dst[x].mid + 1) - 1;
3468 for (i = x; y && i; y--) {
3469 pgno_t yp = src[y].mid;
3470 while (yp < dst[i].mid)
3472 if (yp == dst[i].mid) {
3477 } else { /* Simplify the above for single-ancestor case */
3478 len = MDB_IDL_UM_MAX - txn->mt_dirty_room;
3480 /* Merge our dirty list with parent's */
3482 for (i = len; y; dst[i--] = src[y--]) {
3483 pgno_t yp = src[y].mid;
3484 while (yp < dst[x].mid)
3485 dst[i--] = dst[x--];
3486 if (yp == dst[x].mid)
3487 free(dst[x--].mptr);
3489 mdb_tassert(txn, i == x);
3491 free(txn->mt_u.dirty_list);
3492 parent->mt_dirty_room = txn->mt_dirty_room;
3493 if (txn->mt_spill_pgs) {
3494 if (parent->mt_spill_pgs) {
3495 /* TODO: Prevent failure here, so parent does not fail */
3496 rc = mdb_midl_append_list(&parent->mt_spill_pgs, txn->mt_spill_pgs);
3498 parent->mt_flags |= MDB_TXN_ERROR;
3499 mdb_midl_free(txn->mt_spill_pgs);
3500 mdb_midl_sort(parent->mt_spill_pgs);
3502 parent->mt_spill_pgs = txn->mt_spill_pgs;
3506 /* Append our loose page list to parent's */
3507 for (lp = &parent->mt_loose_pgs; *lp; lp = &NEXT_LOOSE_PAGE(*lp))
3509 *lp = txn->mt_loose_pgs;
3510 parent->mt_loose_count += txn->mt_loose_count;
3512 parent->mt_child = NULL;
3513 mdb_midl_free(((MDB_ntxn *)txn)->mnt_pgstate.mf_pghead);
3518 if (txn != env->me_txn) {
3519 DPUTS("attempt to commit unknown transaction");
3524 mdb_cursors_close(txn, 0);
3526 if (!txn->mt_u.dirty_list[0].mid &&
3527 !(txn->mt_flags & (MDB_TXN_DIRTY|MDB_TXN_SPILLS)))
3530 DPRINTF(("committing txn %"Z"u %p on mdbenv %p, root page %"Z"u",
3531 txn->mt_txnid, (void*)txn, (void*)env, txn->mt_dbs[MAIN_DBI].md_root));
3533 /* Update DB root pointers */
3534 if (txn->mt_numdbs > CORE_DBS) {
3538 data.mv_size = sizeof(MDB_db);
3540 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
3541 for (i = CORE_DBS; i < txn->mt_numdbs; i++) {
3542 if (txn->mt_dbflags[i] & DB_DIRTY) {
3543 if (TXN_DBI_CHANGED(txn, i)) {
3547 data.mv_data = &txn->mt_dbs[i];
3548 rc = mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data,
3556 rc = mdb_freelist_save(txn);
3560 mdb_midl_free(env->me_pghead);
3561 env->me_pghead = NULL;
3562 mdb_midl_shrink(&txn->mt_free_pgs);
3568 if ((rc = mdb_page_flush(txn, 0)) ||
3569 (rc = mdb_env_sync(env, 0)) ||
3570 (rc = mdb_env_write_meta(txn)))
3572 end_mode = MDB_END_COMMITTED|MDB_END_UPDATE;
3575 mdb_txn_end(txn, end_mode);
3583 /** Read the environment parameters of a DB environment before
3584 * mapping it into memory.
3585 * @param[in] env the environment handle
3586 * @param[out] meta address of where to store the meta information
3587 * @return 0 on success, non-zero on failure.
3590 mdb_env_read_header(MDB_env *env, MDB_meta *meta)
3596 enum { Size = sizeof(pbuf) };
3598 /* We don't know the page size yet, so use a minimum value.
3599 * Read both meta pages so we can use the latest one.
3602 for (i=off=0; i<NUM_METAS; i++, off += meta->mm_psize) {
3606 memset(&ov, 0, sizeof(ov));
3608 rc = ReadFile(env->me_fd, &pbuf, Size, &len, &ov) ? (int)len : -1;
3609 if (rc == -1 && ErrCode() == ERROR_HANDLE_EOF)
3612 rc = pread(env->me_fd, &pbuf, Size, off);
3615 if (rc == 0 && off == 0)
3617 rc = rc < 0 ? (int) ErrCode() : MDB_INVALID;
3618 DPRINTF(("read: %s", mdb_strerror(rc)));
3622 p = (MDB_page *)&pbuf;
3624 if (!F_ISSET(p->mp_flags, P_META)) {
3625 DPRINTF(("page %"Z"u not a meta page", p->mp_pgno));
3630 if (m->mm_magic != MDB_MAGIC) {
3631 DPUTS("meta has invalid magic");
3635 if (m->mm_version != MDB_DATA_VERSION) {
3636 DPRINTF(("database is version %u, expected version %u",
3637 m->mm_version, MDB_DATA_VERSION));
3638 return MDB_VERSION_MISMATCH;
3641 if (off == 0 || m->mm_txnid > meta->mm_txnid)
3647 /** Fill in most of the zeroed #MDB_meta for an empty database environment */
3649 mdb_env_init_meta0(MDB_env *env, MDB_meta *meta)
3651 meta->mm_magic = MDB_MAGIC;
3652 meta->mm_version = MDB_DATA_VERSION;
3653 meta->mm_mapsize = env->me_mapsize;
3654 meta->mm_psize = env->me_psize;
3655 meta->mm_last_pg = NUM_METAS-1;
3656 meta->mm_flags = env->me_flags & 0xffff;
3657 meta->mm_flags |= MDB_INTEGERKEY; /* this is mm_dbs[FREE_DBI].md_flags */
3658 meta->mm_dbs[FREE_DBI].md_root = P_INVALID;
3659 meta->mm_dbs[MAIN_DBI].md_root = P_INVALID;
3662 /** Write the environment parameters of a freshly created DB environment.
3663 * @param[in] env the environment handle
3664 * @param[in] meta the #MDB_meta to write
3665 * @return 0 on success, non-zero on failure.
3668 mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
3676 memset(&ov, 0, sizeof(ov));
3677 #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
3679 rc = WriteFile(fd, ptr, size, &len, &ov); } while(0)
3682 #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
3683 len = pwrite(fd, ptr, size, pos); \
3684 if (len == -1 && ErrCode() == EINTR) continue; \
3685 rc = (len >= 0); break; } while(1)
3688 DPUTS("writing new meta page");
3690 psize = env->me_psize;
3692 p = calloc(NUM_METAS, psize);
3697 p->mp_flags = P_META;
3698 *(MDB_meta *)METADATA(p) = *meta;
3700 q = (MDB_page *)((char *)p + psize);
3702 q->mp_flags = P_META;
3703 *(MDB_meta *)METADATA(q) = *meta;
3705 DO_PWRITE(rc, env->me_fd, p, psize * NUM_METAS, len, 0);
3708 else if ((unsigned) len == psize * NUM_METAS)
3716 /** Update the environment info to commit a transaction.
3717 * @param[in] txn the transaction that's being committed
3718 * @return 0 on success, non-zero on failure.
3721 mdb_env_write_meta(MDB_txn *txn)
3724 MDB_meta meta, metab, *mp;
3728 int rc, len, toggle;
3737 toggle = txn->mt_txnid & 1;
3738 DPRINTF(("writing meta page %d for root page %"Z"u",
3739 toggle, txn->mt_dbs[MAIN_DBI].md_root));
3742 flags = env->me_flags;
3743 mp = env->me_metas[toggle];
3744 mapsize = env->me_metas[toggle ^ 1]->mm_mapsize;
3745 /* Persist any increases of mapsize config */
3746 if (mapsize < env->me_mapsize)
3747 mapsize = env->me_mapsize;
3749 if (flags & MDB_WRITEMAP) {
3750 mp->mm_mapsize = mapsize;
3751 mp->mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI];
3752 mp->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
3753 mp->mm_last_pg = txn->mt_next_pgno - 1;
3754 #if (__GNUC__ * 100 + __GNUC_MINOR__ >= 404) && /* TODO: portability */ \
3755 !(defined(__i386__) || defined(__x86_64__))
3756 /* LY: issue a memory barrier, if not x86. ITS#7969 */
3757 __sync_synchronize();
3759 mp->mm_txnid = txn->mt_txnid;
3760 if (!(flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {
3761 unsigned meta_size = env->me_psize;
3762 rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;
3763 ptr = (char *)mp - PAGEHDRSZ;
3764 #ifndef _WIN32 /* POSIX msync() requires ptr = start of OS page */
3765 r2 = (ptr - env->me_map) & (env->me_os_psize - 1);
3769 if (MDB_MSYNC(ptr, meta_size, rc)) {
3776 metab.mm_txnid = mp->mm_txnid;
3777 metab.mm_last_pg = mp->mm_last_pg;
3779 meta.mm_mapsize = mapsize;
3780 meta.mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI];
3781 meta.mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
3782 meta.mm_last_pg = txn->mt_next_pgno - 1;
3783 meta.mm_txnid = txn->mt_txnid;
3785 off = offsetof(MDB_meta, mm_mapsize);
3786 ptr = (char *)&meta + off;
3787 len = sizeof(MDB_meta) - off;
3788 off += (char *)mp - env->me_map;
3790 /* Write to the SYNC fd */
3791 mfd = (flags & (MDB_NOSYNC|MDB_NOMETASYNC)) ? env->me_fd : env->me_mfd;
3794 memset(&ov, 0, sizeof(ov));
3796 if (!WriteFile(mfd, ptr, len, (DWORD *)&rc, &ov))
3801 rc = pwrite(mfd, ptr, len, off);
3804 rc = rc < 0 ? ErrCode() : EIO;
3809 DPUTS("write failed, disk error?");
3810 /* On a failure, the pagecache still contains the new data.
3811 * Write some old data back, to prevent it from being used.
3812 * Use the non-SYNC fd; we know it will fail anyway.
3814 meta.mm_last_pg = metab.mm_last_pg;
3815 meta.mm_txnid = metab.mm_txnid;
3817 memset(&ov, 0, sizeof(ov));
3819 WriteFile(env->me_fd, ptr, len, NULL, &ov);
3821 r2 = pwrite(env->me_fd, ptr, len, off);
3822 (void)r2; /* Silence warnings. We don't care about pwrite's return value */
3825 env->me_flags |= MDB_FATAL_ERROR;
3828 /* MIPS has cache coherency issues, this is a no-op everywhere else */
3829 CACHEFLUSH(env->me_map + off, len, DCACHE);
3831 /* Memory ordering issues are irrelevant; since the entire writer
3832 * is wrapped by wmutex, all of these changes will become visible
3833 * after the wmutex is unlocked. Since the DB is multi-version,
3834 * readers will get consistent data regardless of how fresh or
3835 * how stale their view of these values is.
3838 env->me_txns->mti_txnid = txn->mt_txnid;
3843 /** Check both meta pages to see which one is newer.
3844 * @param[in] env the environment handle
3845 * @return newest #MDB_meta.
3848 mdb_env_pick_meta(const MDB_env *env)
3850 MDB_meta *const *metas = env->me_metas;
3851 return metas[ metas[0]->mm_txnid < metas[1]->mm_txnid ];
3855 mdb_env_create(MDB_env **env)
3859 e = calloc(1, sizeof(MDB_env));
3863 e->me_maxreaders = DEFAULT_READERS;
3864 e->me_maxdbs = e->me_numdbs = CORE_DBS;
3865 e->me_fd = INVALID_HANDLE_VALUE;
3866 e->me_lfd = INVALID_HANDLE_VALUE;
3867 e->me_mfd = INVALID_HANDLE_VALUE;
3868 #ifdef MDB_USE_POSIX_SEM
3869 e->me_rmutex = SEM_FAILED;
3870 e->me_wmutex = SEM_FAILED;
3872 e->me_pid = getpid();
3873 GET_PAGESIZE(e->me_os_psize);
3874 VGMEMP_CREATE(e,0,0);
3880 mdb_env_map(MDB_env *env, void *addr)
3883 unsigned int flags = env->me_flags;
3887 LONG sizelo, sizehi;
3890 if (flags & MDB_RDONLY) {
3891 /* Don't set explicit map size, use whatever exists */
3896 msize = env->me_mapsize;
3897 sizelo = msize & 0xffffffff;
3898 sizehi = msize >> 16 >> 16; /* only needed on Win64 */
3900 /* Windows won't create mappings for zero length files.
3901 * and won't map more than the file size.
3902 * Just set the maxsize right now.
3904 if (SetFilePointer(env->me_fd, sizelo, &sizehi, 0) != (DWORD)sizelo
3905 || !SetEndOfFile(env->me_fd)
3906 || SetFilePointer(env->me_fd, 0, NULL, 0) != 0)
3910 mh = CreateFileMapping(env->me_fd, NULL, flags & MDB_WRITEMAP ?
3911 PAGE_READWRITE : PAGE_READONLY,
3912 sizehi, sizelo, NULL);
3915 env->me_map = MapViewOfFileEx(mh, flags & MDB_WRITEMAP ?
3916 FILE_MAP_WRITE : FILE_MAP_READ,
3918 rc = env->me_map ? 0 : ErrCode();
3923 int prot = PROT_READ;
3924 if (flags & MDB_WRITEMAP) {
3926 if (ftruncate(env->me_fd, env->me_mapsize) < 0)
3929 env->me_map = mmap(addr, env->me_mapsize, prot, MAP_SHARED,
3931 if (env->me_map == MAP_FAILED) {
3936 if (flags & MDB_NORDAHEAD) {
3937 /* Turn off readahead. It's harmful when the DB is larger than RAM. */
3939 madvise(env->me_map, env->me_mapsize, MADV_RANDOM);
3941 #ifdef POSIX_MADV_RANDOM
3942 posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM);
3943 #endif /* POSIX_MADV_RANDOM */
3944 #endif /* MADV_RANDOM */
3948 /* Can happen because the address argument to mmap() is just a
3949 * hint. mmap() can pick another, e.g. if the range is in use.
3950 * The MAP_FIXED flag would prevent that, but then mmap could
3951 * instead unmap existing pages to make room for the new map.
3953 if (addr && env->me_map != addr)
3954 return EBUSY; /* TODO: Make a new MDB_* error code? */
3956 p = (MDB_page *)env->me_map;
3957 env->me_metas[0] = METADATA(p);
3958 env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + env->me_psize);
3964 mdb_env_set_mapsize(MDB_env *env, size_t size)
3966 /* If env is already open, caller is responsible for making
3967 * sure there are no active txns.
3975 meta = mdb_env_pick_meta(env);
3977 size = meta->mm_mapsize;
3979 /* Silently round up to minimum if the size is too small */
3980 size_t minsize = (meta->mm_last_pg + 1) * env->me_psize;
3984 munmap(env->me_map, env->me_mapsize);
3985 env->me_mapsize = size;
3986 old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL;
3987 rc = mdb_env_map(env, old);
3991 env->me_mapsize = size;
3993 env->me_maxpg = env->me_mapsize / env->me_psize;
3998 mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs)
4002 env->me_maxdbs = dbs + CORE_DBS;
4007 mdb_env_set_maxreaders(MDB_env *env, unsigned int readers)
4009 if (env->me_map || readers < 1)
4011 env->me_maxreaders = readers;
4016 mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)
4018 if (!env || !readers)
4020 *readers = env->me_maxreaders;
4025 mdb_fsize(HANDLE fd, size_t *size)
4028 LARGE_INTEGER fsize;
4030 if (!GetFileSizeEx(fd, &fsize))
4033 *size = fsize.QuadPart;
4045 #ifdef BROKEN_FDATASYNC
4046 #include <sys/utsname.h>
4047 #include <sys/vfs.h>
4050 /** Further setup required for opening an LMDB environment
4053 mdb_env_open2(MDB_env *env)
4055 unsigned int flags = env->me_flags;
4056 int i, newenv = 0, rc;
4060 /* See if we should use QueryLimited */
4062 if ((rc & 0xff) > 5)
4063 env->me_pidquery = MDB_PROCESS_QUERY_LIMITED_INFORMATION;
4065 env->me_pidquery = PROCESS_QUERY_INFORMATION;
4068 #ifdef BROKEN_FDATASYNC
4069 /* ext3/ext4 fdatasync is broken on some older Linux kernels.
4070 * https://lkml.org/lkml/2012/9/3/83
4071 * Kernels after 3.6-rc6 are known good.
4072 * https://lkml.org/lkml/2012/9/10/556
4073 * See if the DB is on ext3/ext4, then check for new enough kernel
4074 * Kernels 2.6.32.60, 2.6.34.15, 3.2.30, and 3.5.4 are also known
4079 fstatfs(env->me_fd, &st);
4080 while (st.f_type == 0xEF53) {
4084 if (uts.release[0] < '3') {
4085 if (!strncmp(uts.release, "2.6.32.", 7)) {
4086 i = atoi(uts.release+7);
4088 break; /* 2.6.32.60 and newer is OK */
4089 } else if (!strncmp(uts.release, "2.6.34.", 7)) {
4090 i = atoi(uts.release+7);
4092 break; /* 2.6.34.15 and newer is OK */
4094 } else if (uts.release[0] == '3') {
4095 i = atoi(uts.release+2);
4097 break; /* 3.6 and newer is OK */
4099 i = atoi(uts.release+4);
4101 break; /* 3.5.4 and newer is OK */
4102 } else if (i == 2) {
4103 i = atoi(uts.release+4);
4105 break; /* 3.2.30 and newer is OK */
4107 } else { /* 4.x and newer is OK */
4110 env->me_flags |= MDB_FSYNCONLY;
4116 if ((i = mdb_env_read_header(env, &meta)) != 0) {
4119 DPUTS("new mdbenv");
4121 env->me_psize = env->me_os_psize;
4122 if (env->me_psize > MAX_PAGESIZE)
4123 env->me_psize = MAX_PAGESIZE;
4124 memset(&meta, 0, sizeof(meta));
4125 mdb_env_init_meta0(env, &meta);
4126 meta.mm_mapsize = DEFAULT_MAPSIZE;
4128 env->me_psize = meta.mm_psize;
4131 /* Was a mapsize configured? */
4132 if (!env->me_mapsize) {
4133 env->me_mapsize = meta.mm_mapsize;
4136 /* Make sure mapsize >= committed data size. Even when using
4137 * mm_mapsize, which could be broken in old files (ITS#7789).
4139 size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize;
4140 if (env->me_mapsize < minsize)
4141 env->me_mapsize = minsize;
4143 meta.mm_mapsize = env->me_mapsize;
4145 if (newenv && !(flags & MDB_FIXEDMAP)) {
4146 /* mdb_env_map() may grow the datafile. Write the metapages
4147 * first, so the file will be valid if initialization fails.
4148 * Except with FIXEDMAP, since we do not yet know mm_address.
4149 * We could fill in mm_address later, but then a different
4150 * program might end up doing that - one with a memory layout
4151 * and map address which does not suit the main program.
4153 rc = mdb_env_init_meta(env, &meta);
4159 rc = mdb_env_map(env, (flags & MDB_FIXEDMAP) ? meta.mm_address : NULL);
4164 if (flags & MDB_FIXEDMAP)
4165 meta.mm_address = env->me_map;
4166 i = mdb_env_init_meta(env, &meta);
4167 if (i != MDB_SUCCESS) {
4172 env->me_maxfree_1pg = (env->me_psize - PAGEHDRSZ) / sizeof(pgno_t) - 1;
4173 env->me_nodemax = (((env->me_psize - PAGEHDRSZ) / MDB_MINKEYS) & -2)
4175 #if !(MDB_MAXKEYSIZE)
4176 env->me_maxkey = env->me_nodemax - (NODESIZE + sizeof(MDB_db));
4178 env->me_maxpg = env->me_mapsize / env->me_psize;
4182 MDB_meta *meta = mdb_env_pick_meta(env);
4183 MDB_db *db = &meta->mm_dbs[MAIN_DBI];
4185 DPRINTF(("opened database version %u, pagesize %u",
4186 meta->mm_version, env->me_psize));
4187 DPRINTF(("using meta page %d", (int) (meta->mm_txnid & 1)));
4188 DPRINTF(("depth: %u", db->md_depth));
4189 DPRINTF(("entries: %"Z"u", db->md_entries));
4190 DPRINTF(("branch pages: %"Z"u", db->md_branch_pages));
4191 DPRINTF(("leaf pages: %"Z"u", db->md_leaf_pages));
4192 DPRINTF(("overflow pages: %"Z"u", db->md_overflow_pages));
4193 DPRINTF(("root: %"Z"u", db->md_root));
4201 /** Release a reader thread's slot in the reader lock table.
4202 * This function is called automatically when a thread exits.
4203 * @param[in] ptr This points to the slot in the reader lock table.
4206 mdb_env_reader_dest(void *ptr)
4208 MDB_reader *reader = ptr;
4214 /** Junk for arranging thread-specific callbacks on Windows. This is
4215 * necessarily platform and compiler-specific. Windows supports up
4216 * to 1088 keys. Let's assume nobody opens more than 64 environments
4217 * in a single process, for now. They can override this if needed.
4219 #ifndef MAX_TLS_KEYS
4220 #define MAX_TLS_KEYS 64
4222 static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS];
4223 static int mdb_tls_nkeys;
4225 static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr)
4229 case DLL_PROCESS_ATTACH: break;
4230 case DLL_THREAD_ATTACH: break;
4231 case DLL_THREAD_DETACH:
4232 for (i=0; i<mdb_tls_nkeys; i++) {
4233 MDB_reader *r = pthread_getspecific(mdb_tls_keys[i]);
4235 mdb_env_reader_dest(r);
4239 case DLL_PROCESS_DETACH: break;
4244 const PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
4246 PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
4250 /* Force some symbol references.
4251 * _tls_used forces the linker to create the TLS directory if not already done
4252 * mdb_tls_cbp prevents whole-program-optimizer from dropping the symbol.
4254 #pragma comment(linker, "/INCLUDE:_tls_used")
4255 #pragma comment(linker, "/INCLUDE:mdb_tls_cbp")
4256 #pragma const_seg(".CRT$XLB")
4257 extern const PIMAGE_TLS_CALLBACK mdb_tls_cbp;
4258 const PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
4261 #pragma comment(linker, "/INCLUDE:__tls_used")
4262 #pragma comment(linker, "/INCLUDE:_mdb_tls_cbp")
4263 #pragma data_seg(".CRT$XLB")
4264 PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
4266 #endif /* WIN 32/64 */
4267 #endif /* !__GNUC__ */
4270 /** Downgrade the exclusive lock on the region back to shared */
4272 mdb_env_share_locks(MDB_env *env, int *excl)
4275 MDB_meta *meta = mdb_env_pick_meta(env);
4277 env->me_txns->mti_txnid = meta->mm_txnid;
4282 /* First acquire a shared lock. The Unlock will
4283 * then release the existing exclusive lock.
4285 memset(&ov, 0, sizeof(ov));
4286 if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
4289 UnlockFile(env->me_lfd, 0, 0, 1, 0);
4295 struct flock lock_info;
4296 /* The shared lock replaces the existing lock */
4297 memset((void *)&lock_info, 0, sizeof(lock_info));
4298 lock_info.l_type = F_RDLCK;
4299 lock_info.l_whence = SEEK_SET;
4300 lock_info.l_start = 0;
4301 lock_info.l_len = 1;
4302 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
4303 (rc = ErrCode()) == EINTR) ;
4304 *excl = rc ? -1 : 0; /* error may mean we lost the lock */
4311 /** Try to get exclusive lock, otherwise shared.
4312 * Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive.
4315 mdb_env_excl_lock(MDB_env *env, int *excl)
4319 if (LockFile(env->me_lfd, 0, 0, 1, 0)) {
4323 memset(&ov, 0, sizeof(ov));
4324 if (LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
4331 struct flock lock_info;
4332 memset((void *)&lock_info, 0, sizeof(lock_info));
4333 lock_info.l_type = F_WRLCK;
4334 lock_info.l_whence = SEEK_SET;
4335 lock_info.l_start = 0;
4336 lock_info.l_len = 1;
4337 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
4338 (rc = ErrCode()) == EINTR) ;
4342 # ifndef MDB_USE_POSIX_MUTEX
4343 if (*excl < 0) /* always true when MDB_USE_POSIX_MUTEX */
4346 lock_info.l_type = F_RDLCK;
4347 while ((rc = fcntl(env->me_lfd, F_SETLKW, &lock_info)) &&
4348 (rc = ErrCode()) == EINTR) ;
4358 * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code
4360 * @(#) $Revision: 5.1 $
4361 * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $
4362 * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $
4364 * http://www.isthe.com/chongo/tech/comp/fnv/index.html
4368 * Please do not copyright this code. This code is in the public domain.
4370 * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
4371 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
4372 * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
4373 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
4374 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
4375 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
4376 * PERFORMANCE OF THIS SOFTWARE.
4379 * chongo <Landon Curt Noll> /\oo/\
4380 * http://www.isthe.com/chongo/
4382 * Share and Enjoy! :-)
4385 typedef unsigned long long mdb_hash_t;
4386 #define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL)
4388 /** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer
4389 * @param[in] val value to hash
4390 * @param[in] hval initial value for hash
4391 * @return 64 bit hash
4393 * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the
4394 * hval arg on the first call.
4397 mdb_hash_val(MDB_val *val, mdb_hash_t hval)
4399 unsigned char *s = (unsigned char *)val->mv_data; /* unsigned string */
4400 unsigned char *end = s + val->mv_size;
4402 * FNV-1a hash each octet of the string
4405 /* xor the bottom with the current octet */
4406 hval ^= (mdb_hash_t)*s++;
4408 /* multiply by the 64 bit FNV magic prime mod 2^64 */
4409 hval += (hval << 1) + (hval << 4) + (hval << 5) +
4410 (hval << 7) + (hval << 8) + (hval << 40);
4412 /* return our new hash value */
4416 /** Hash the string and output the encoded hash.
4417 * This uses modified RFC1924 Ascii85 encoding to accommodate systems with
4418 * very short name limits. We don't care about the encoding being reversible,
4419 * we just want to preserve as many bits of the input as possible in a
4420 * small printable string.
4421 * @param[in] str string to hash
4422 * @param[out] encbuf an array of 11 chars to hold the hash
4424 static const char mdb_a85[]= "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";
4427 mdb_pack85(unsigned long l, char *out)
4431 for (i=0; i<5; i++) {
4432 *out++ = mdb_a85[l % 85];
4438 mdb_hash_enc(MDB_val *val, char *encbuf)
4440 mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT);
4442 mdb_pack85(h, encbuf);
4443 mdb_pack85(h>>32, encbuf+5);
4448 /** Open and/or initialize the lock region for the environment.
4449 * @param[in] env The LMDB environment.
4450 * @param[in] lpath The pathname of the file used for the lock region.
4451 * @param[in] mode The Unix permissions for the file, if we create it.
4452 * @param[in,out] excl In -1, out lock type: -1 none, 0 shared, 1 exclusive
4453 * @return 0 on success, non-zero on failure.
4456 mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
4459 # define MDB_ERRCODE_ROFS ERROR_WRITE_PROTECT
4461 # define MDB_ERRCODE_ROFS EROFS
4462 #ifdef O_CLOEXEC /* Linux: Open file and set FD_CLOEXEC atomically */
4463 # define MDB_CLOEXEC O_CLOEXEC
4466 # define MDB_CLOEXEC 0
4474 rc = utf8_to_utf16(lpath, -1, &wlpath, NULL);
4477 env->me_lfd = CreateFileW(wlpath, GENERIC_READ|GENERIC_WRITE,
4478 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
4479 FILE_ATTRIBUTE_NORMAL, NULL);
4482 env->me_lfd = open(lpath, O_RDWR|O_CREAT|MDB_CLOEXEC, mode);
4484 if (env->me_lfd == INVALID_HANDLE_VALUE) {
4486 if (rc == MDB_ERRCODE_ROFS && (env->me_flags & MDB_RDONLY)) {
4491 #if ! ((MDB_CLOEXEC) || defined(_WIN32))
4492 /* Lose record locks when exec*() */
4493 if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0)
4494 fcntl(env->me_lfd, F_SETFD, fdflags);
4497 if (!(env->me_flags & MDB_NOTLS)) {
4498 rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
4501 env->me_flags |= MDB_ENV_TXKEY;
4503 /* Windows TLS callbacks need help finding their TLS info. */
4504 if (mdb_tls_nkeys >= MAX_TLS_KEYS) {
4508 mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey;
4512 /* Try to get exclusive lock. If we succeed, then
4513 * nobody is using the lock region and we should initialize it.
4515 if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
4518 size = GetFileSize(env->me_lfd, NULL);
4520 size = lseek(env->me_lfd, 0, SEEK_END);
4521 if (size == -1) goto fail_errno;
4523 rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
4524 if (size < rsize && *excl > 0) {
4526 if (SetFilePointer(env->me_lfd, rsize, NULL, FILE_BEGIN) != (DWORD)rsize
4527 || !SetEndOfFile(env->me_lfd))
4530 if (ftruncate(env->me_lfd, rsize) != 0) goto fail_errno;
4534 size = rsize - sizeof(MDB_txninfo);
4535 env->me_maxreaders = size/sizeof(MDB_reader) + 1;
4540 mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,
4542 if (!mh) goto fail_errno;
4543 env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL);
4545 if (!env->me_txns) goto fail_errno;
4547 void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
4549 if (m == MAP_FAILED) goto fail_errno;
4555 BY_HANDLE_FILE_INFORMATION stbuf;
4564 if (!mdb_sec_inited) {
4565 InitializeSecurityDescriptor(&mdb_null_sd,
4566 SECURITY_DESCRIPTOR_REVISION);
4567 SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE);
4568 mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);
4569 mdb_all_sa.bInheritHandle = FALSE;
4570 mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;
4573 if (!GetFileInformationByHandle(env->me_lfd, &stbuf)) goto fail_errno;
4574 idbuf.volume = stbuf.dwVolumeSerialNumber;
4575 idbuf.nhigh = stbuf.nFileIndexHigh;
4576 idbuf.nlow = stbuf.nFileIndexLow;
4577 val.mv_data = &idbuf;
4578 val.mv_size = sizeof(idbuf);
4579 mdb_hash_enc(&val, encbuf);
4580 sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", encbuf);
4581 sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", encbuf);
4582 env->me_rmutex = CreateMutexA(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
4583 if (!env->me_rmutex) goto fail_errno;
4584 env->me_wmutex = CreateMutexA(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);
4585 if (!env->me_wmutex) goto fail_errno;
4586 #elif defined(MDB_USE_POSIX_SEM)
4595 #if defined(__NetBSD__)
4596 #define MDB_SHORT_SEMNAMES 1 /* limited to 14 chars */
4598 if (fstat(env->me_lfd, &stbuf)) goto fail_errno;
4599 idbuf.dev = stbuf.st_dev;
4600 idbuf.ino = stbuf.st_ino;
4601 val.mv_data = &idbuf;
4602 val.mv_size = sizeof(idbuf);
4603 mdb_hash_enc(&val, encbuf);
4604 #ifdef MDB_SHORT_SEMNAMES
4605 encbuf[9] = '\0'; /* drop name from 15 chars to 14 chars */
4607 sprintf(env->me_txns->mti_rmname, "/MDBr%s", encbuf);
4608 sprintf(env->me_txns->mti_wmname, "/MDBw%s", encbuf);
4609 /* Clean up after a previous run, if needed: Try to
4610 * remove both semaphores before doing anything else.
4612 sem_unlink(env->me_txns->mti_rmname);
4613 sem_unlink(env->me_txns->mti_wmname);
4614 env->me_rmutex = sem_open(env->me_txns->mti_rmname,
4615 O_CREAT|O_EXCL, mode, 1);
4616 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
4617 env->me_wmutex = sem_open(env->me_txns->mti_wmname,
4618 O_CREAT|O_EXCL, mode, 1);
4619 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
4620 #else /* MDB_USE_POSIX_MUTEX: */
4621 pthread_mutexattr_t mattr;
4623 if ((rc = pthread_mutexattr_init(&mattr))
4624 || (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED))
4625 #ifdef MDB_ROBUST_SUPPORTED
4626 || (rc = pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST))
4628 || (rc = pthread_mutex_init(env->me_txns->mti_rmutex, &mattr))
4629 || (rc = pthread_mutex_init(env->me_txns->mti_wmutex, &mattr)))
4631 pthread_mutexattr_destroy(&mattr);
4632 #endif /* _WIN32 || MDB_USE_POSIX_SEM */
4634 env->me_txns->mti_magic = MDB_MAGIC;
4635 env->me_txns->mti_format = MDB_LOCK_FORMAT;
4636 env->me_txns->mti_txnid = 0;
4637 env->me_txns->mti_numreaders = 0;
4640 if (env->me_txns->mti_magic != MDB_MAGIC) {
4641 DPUTS("lock region has invalid magic");
4645 if (env->me_txns->mti_format != MDB_LOCK_FORMAT) {
4646 DPRINTF(("lock region has format+version 0x%x, expected 0x%x",
4647 env->me_txns->mti_format, MDB_LOCK_FORMAT));
4648 rc = MDB_VERSION_MISMATCH;
4652 if (rc && rc != EACCES && rc != EAGAIN) {
4656 env->me_rmutex = OpenMutexA(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);
4657 if (!env->me_rmutex) goto fail_errno;
4658 env->me_wmutex = OpenMutexA(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
4659 if (!env->me_wmutex) goto fail_errno;
4660 #elif defined(MDB_USE_POSIX_SEM)
4661 env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0);
4662 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
4663 env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0);
4664 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
4675 /** The name of the lock file in the DB environment */
4676 #define LOCKNAME "/lock.mdb"
4677 /** The name of the data file in the DB environment */
4678 #define DATANAME "/data.mdb"
4679 /** The suffix of the lock file when no subdir is used */
4680 #define LOCKSUFF "-lock"
4681 /** Only a subset of the @ref mdb_env flags can be changed
4682 * at runtime. Changing other flags requires closing the
4683 * environment and re-opening it with the new flags.
4685 #define CHANGEABLE (MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC|MDB_NOMEMINIT)
4686 #define CHANGELESS (MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY| \
4687 MDB_WRITEMAP|MDB_NOTLS|MDB_NOLOCK|MDB_NORDAHEAD)
4689 #if VALID_FLAGS & PERSISTENT_FLAGS & (CHANGEABLE|CHANGELESS)
4690 # error "Persistent DB flags & env flags overlap, but both go in mm_flags"
4694 mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode)
4696 int oflags, rc, len, excl = -1;
4697 char *lpath, *dpath;
4702 if (env->me_fd!=INVALID_HANDLE_VALUE || (flags & ~(CHANGEABLE|CHANGELESS)))
4706 if (flags & MDB_NOSUBDIR) {
4707 rc = len + sizeof(LOCKSUFF) + len + 1;
4709 rc = len + sizeof(LOCKNAME) + len + sizeof(DATANAME);
4714 if (flags & MDB_NOSUBDIR) {
4715 dpath = lpath + len + sizeof(LOCKSUFF);
4716 sprintf(lpath, "%s" LOCKSUFF, path);
4717 strcpy(dpath, path);
4719 dpath = lpath + len + sizeof(LOCKNAME);
4720 sprintf(lpath, "%s" LOCKNAME, path);
4721 sprintf(dpath, "%s" DATANAME, path);
4725 flags |= env->me_flags;
4726 if (flags & MDB_RDONLY) {
4727 /* silently ignore WRITEMAP when we're only getting read access */
4728 flags &= ~MDB_WRITEMAP;
4730 if (!((env->me_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)) &&
4731 (env->me_dirty_list = calloc(MDB_IDL_UM_SIZE, sizeof(MDB_ID2)))))
4734 env->me_flags = flags |= MDB_ENV_ACTIVE;
4738 env->me_path = strdup(path);
4739 env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx));
4740 env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t));
4741 env->me_dbiseqs = calloc(env->me_maxdbs, sizeof(unsigned int));
4742 if (!(env->me_dbxs && env->me_path && env->me_dbflags && env->me_dbiseqs)) {
4746 env->me_dbxs[FREE_DBI].md_cmp = mdb_cmp_long; /* aligned MDB_INTEGERKEY */
4748 /* For RDONLY, get lockfile after we know datafile exists */
4749 if (!(flags & (MDB_RDONLY|MDB_NOLOCK))) {
4750 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
4756 if (F_ISSET(flags, MDB_RDONLY)) {
4757 oflags = GENERIC_READ;
4758 len = OPEN_EXISTING;
4760 oflags = GENERIC_READ|GENERIC_WRITE;
4763 mode = FILE_ATTRIBUTE_NORMAL;
4764 rc = utf8_to_utf16(dpath, -1, &wpath, NULL);
4767 env->me_fd = CreateFileW(wpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
4768 NULL, len, mode, NULL);
4771 if (F_ISSET(flags, MDB_RDONLY))
4774 oflags = O_RDWR | O_CREAT;
4776 env->me_fd = open(dpath, oflags, mode);
4778 if (env->me_fd == INVALID_HANDLE_VALUE) {
4783 if ((flags & (MDB_RDONLY|MDB_NOLOCK)) == MDB_RDONLY) {
4784 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
4789 if ((rc = mdb_env_open2(env)) == MDB_SUCCESS) {
4790 if (flags & (MDB_RDONLY|MDB_WRITEMAP)) {
4791 env->me_mfd = env->me_fd;
4793 /* Synchronous fd for meta writes. Needed even with
4794 * MDB_NOSYNC/MDB_NOMETASYNC, in case these get reset.
4797 len = OPEN_EXISTING;
4798 rc = utf8_to_utf16(dpath, -1, &wpath, NULL);
4801 env->me_mfd = CreateFileW(wpath, oflags,
4802 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len,
4803 mode | FILE_FLAG_WRITE_THROUGH, NULL);
4807 env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode);
4809 if (env->me_mfd == INVALID_HANDLE_VALUE) {
4814 DPRINTF(("opened dbenv %p", (void *) env));
4816 rc = mdb_env_share_locks(env, &excl);
4820 if (!(flags & MDB_RDONLY)) {
4822 int tsize = sizeof(MDB_txn), size = tsize + env->me_maxdbs *
4823 (sizeof(MDB_db)+sizeof(MDB_cursor *)+sizeof(unsigned int)+1);
4824 if ((env->me_pbuf = calloc(1, env->me_psize)) &&
4825 (txn = calloc(1, size)))
4827 txn->mt_dbs = (MDB_db *)((char *)txn + tsize);
4828 txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
4829 txn->mt_dbiseqs = (unsigned int *)(txn->mt_cursors + env->me_maxdbs);
4830 txn->mt_dbflags = (unsigned char *)(txn->mt_dbiseqs + env->me_maxdbs);
4832 txn->mt_dbxs = env->me_dbxs;
4833 txn->mt_flags = MDB_TXN_FINISHED;
4843 mdb_env_close0(env, excl);
4849 /** Destroy resources from mdb_env_open(), clear our readers & DBIs */
4851 mdb_env_close0(MDB_env *env, int excl)
4855 if (!(env->me_flags & MDB_ENV_ACTIVE))
4858 /* Doing this here since me_dbxs may not exist during mdb_env_close */
4860 for (i = env->me_maxdbs; --i >= CORE_DBS; )
4861 free(env->me_dbxs[i].md_name.mv_data);
4866 free(env->me_dbiseqs);
4867 free(env->me_dbflags);
4869 free(env->me_dirty_list);
4871 mdb_midl_free(env->me_free_pgs);
4873 if (env->me_flags & MDB_ENV_TXKEY) {
4874 pthread_key_delete(env->me_txkey);
4876 /* Delete our key from the global list */
4877 for (i=0; i<mdb_tls_nkeys; i++)
4878 if (mdb_tls_keys[i] == env->me_txkey) {
4879 mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1];
4887 munmap(env->me_map, env->me_mapsize);
4889 if (env->me_mfd != env->me_fd && env->me_mfd != INVALID_HANDLE_VALUE)
4890 (void) close(env->me_mfd);
4891 if (env->me_fd != INVALID_HANDLE_VALUE)
4892 (void) close(env->me_fd);
4894 MDB_PID_T pid = env->me_pid;
4895 /* Clearing readers is done in this function because
4896 * me_txkey with its destructor must be disabled first.
4898 * We skip the the reader mutex, so we touch only
4899 * data owned by this process (me_close_readers and
4900 * our readers), and clear each reader atomically.
4902 for (i = env->me_close_readers; --i >= 0; )
4903 if (env->me_txns->mti_readers[i].mr_pid == pid)
4904 env->me_txns->mti_readers[i].mr_pid = 0;
4906 if (env->me_rmutex) {
4907 CloseHandle(env->me_rmutex);
4908 if (env->me_wmutex) CloseHandle(env->me_wmutex);
4910 /* Windows automatically destroys the mutexes when
4911 * the last handle closes.
4913 #elif defined(MDB_USE_POSIX_SEM)
4914 if (env->me_rmutex != SEM_FAILED) {
4915 sem_close(env->me_rmutex);
4916 if (env->me_wmutex != SEM_FAILED)
4917 sem_close(env->me_wmutex);
4918 /* If we have the filelock: If we are the
4919 * only remaining user, clean up semaphores.
4922 mdb_env_excl_lock(env, &excl);
4924 sem_unlink(env->me_txns->mti_rmname);
4925 sem_unlink(env->me_txns->mti_wmname);
4929 munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
4931 if (env->me_lfd != INVALID_HANDLE_VALUE) {
4934 /* Unlock the lockfile. Windows would have unlocked it
4935 * after closing anyway, but not necessarily at once.
4937 UnlockFile(env->me_lfd, 0, 0, 1, 0);
4940 (void) close(env->me_lfd);
4943 env->me_flags &= ~(MDB_ENV_ACTIVE|MDB_ENV_TXKEY);
4947 mdb_env_close(MDB_env *env)
4954 VGMEMP_DESTROY(env);
4955 while ((dp = env->me_dpages) != NULL) {
4956 VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next));
4957 env->me_dpages = dp->mp_next;
4961 mdb_env_close0(env, 0);
4965 /** Compare two items pointing at aligned size_t's */
4967 mdb_cmp_long(const MDB_val *a, const MDB_val *b)
4969 return (*(size_t *)a->mv_data < *(size_t *)b->mv_data) ? -1 :
4970 *(size_t *)a->mv_data > *(size_t *)b->mv_data;
4973 /** Compare two items pointing at aligned unsigned int's.
4975 * This is also set as #MDB_INTEGERDUP|#MDB_DUPFIXED's #MDB_dbx.%md_dcmp,
4976 * but #mdb_cmp_clong() is called instead if the data type is size_t.
4979 mdb_cmp_int(const MDB_val *a, const MDB_val *b)
4981 return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 :
4982 *(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data;
4985 /** Compare two items pointing at unsigned ints of unknown alignment.
4986 * Nodes and keys are guaranteed to be 2-byte aligned.
4989 mdb_cmp_cint(const MDB_val *a, const MDB_val *b)
4991 #if BYTE_ORDER == LITTLE_ENDIAN
4992 unsigned short *u, *c;
4995 u = (unsigned short *) ((char *) a->mv_data + a->mv_size);
4996 c = (unsigned short *) ((char *) b->mv_data + a->mv_size);
4999 } while(!x && u > (unsigned short *)a->mv_data);
5002 unsigned short *u, *c, *end;
5005 end = (unsigned short *) ((char *) a->mv_data + a->mv_size);
5006 u = (unsigned short *)a->mv_data;
5007 c = (unsigned short *)b->mv_data;
5010 } while(!x && u < end);
5015 /** Compare two items lexically */
5017 mdb_cmp_memn(const MDB_val *a, const MDB_val *b)
5024 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
5030 diff = memcmp(a->mv_data, b->mv_data, len);
5031 return diff ? diff : len_diff<0 ? -1 : len_diff;
5034 /** Compare two items in reverse byte order */
5036 mdb_cmp_memnr(const MDB_val *a, const MDB_val *b)
5038 const unsigned char *p1, *p2, *p1_lim;
5042 p1_lim = (const unsigned char *)a->mv_data;
5043 p1 = (const unsigned char *)a->mv_data + a->mv_size;
5044 p2 = (const unsigned char *)b->mv_data + b->mv_size;
5046 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
5052 while (p1 > p1_lim) {
5053 diff = *--p1 - *--p2;
5057 return len_diff<0 ? -1 : len_diff;
5060 /** Search for key within a page, using binary search.
5061 * Returns the smallest entry larger or equal to the key.
5062 * If exactp is non-null, stores whether the found entry was an exact match
5063 * in *exactp (1 or 0).
5064 * Updates the cursor index with the index of the found entry.
5065 * If no entry larger or equal to the key is found, returns NULL.
5068 mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)
5070 unsigned int i = 0, nkeys;
5073 MDB_page *mp = mc->mc_pg[mc->mc_top];
5074 MDB_node *node = NULL;
5079 nkeys = NUMKEYS(mp);
5081 DPRINTF(("searching %u keys in %s %spage %"Z"u",
5082 nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "",
5085 low = IS_LEAF(mp) ? 0 : 1;
5087 cmp = mc->mc_dbx->md_cmp;
5089 /* Branch pages have no data, so if using integer keys,
5090 * alignment is guaranteed. Use faster mdb_cmp_int.
5092 if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) {
5093 if (NODEPTR(mp, 1)->mn_ksize == sizeof(size_t))
5100 nodekey.mv_size = mc->mc_db->md_pad;
5101 node = NODEPTR(mp, 0); /* fake */
5102 while (low <= high) {
5103 i = (low + high) >> 1;
5104 nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size);
5105 rc = cmp(key, &nodekey);
5106 DPRINTF(("found leaf index %u [%s], rc = %i",
5107 i, DKEY(&nodekey), rc));
5116 while (low <= high) {
5117 i = (low + high) >> 1;
5119 node = NODEPTR(mp, i);
5120 nodekey.mv_size = NODEKSZ(node);
5121 nodekey.mv_data = NODEKEY(node);
5123 rc = cmp(key, &nodekey);
5126 DPRINTF(("found leaf index %u [%s], rc = %i",
5127 i, DKEY(&nodekey), rc));
5129 DPRINTF(("found branch index %u [%s -> %"Z"u], rc = %i",
5130 i, DKEY(&nodekey), NODEPGNO(node), rc));
5141 if (rc > 0) { /* Found entry is less than the key. */
5142 i++; /* Skip to get the smallest entry larger than key. */
5144 node = NODEPTR(mp, i);
5147 *exactp = (rc == 0 && nkeys > 0);
5148 /* store the key index */
5149 mc->mc_ki[mc->mc_top] = i;
5151 /* There is no entry larger or equal to the key. */
5154 /* nodeptr is fake for LEAF2 */
5160 mdb_cursor_adjust(MDB_cursor *mc, func)
5164 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
5165 if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) {
5172 /** Pop a page off the top of the cursor's stack. */
5174 mdb_cursor_pop(MDB_cursor *mc)
5177 DPRINTF(("popping page %"Z"u off db %d cursor %p",
5178 mc->mc_pg[mc->mc_top]->mp_pgno, DDBI(mc), (void *) mc));
5184 mc->mc_flags &= ~C_INITIALIZED;
5189 /** Push a page onto the top of the cursor's stack. */
5191 mdb_cursor_push(MDB_cursor *mc, MDB_page *mp)
5193 DPRINTF(("pushing page %"Z"u on db %d cursor %p", mp->mp_pgno,
5194 DDBI(mc), (void *) mc));
5196 if (mc->mc_snum >= CURSOR_STACK) {
5197 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
5198 return MDB_CURSOR_FULL;
5201 mc->mc_top = mc->mc_snum++;
5202 mc->mc_pg[mc->mc_top] = mp;
5203 mc->mc_ki[mc->mc_top] = 0;
5208 /** Find the address of the page corresponding to a given page number.
5209 * @param[in] txn the transaction for this access.
5210 * @param[in] pgno the page number for the page to retrieve.
5211 * @param[out] ret address of a pointer where the page's address will be stored.
5212 * @param[out] lvl dirty_list inheritance level of found page. 1=current txn, 0=mapped page.
5213 * @return 0 on success, non-zero on failure.
5216 mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret, int *lvl)
5218 MDB_env *env = txn->mt_env;
5222 if (! (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_WRITEMAP))) {
5226 MDB_ID2L dl = tx2->mt_u.dirty_list;
5228 /* Spilled pages were dirtied in this txn and flushed
5229 * because the dirty list got full. Bring this page
5230 * back in from the map (but don't unspill it here,
5231 * leave that unless page_touch happens again).
5233 if (tx2->mt_spill_pgs) {
5234 MDB_ID pn = pgno << 1;
5235 x = mdb_midl_search(tx2->mt_spill_pgs, pn);
5236 if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
5237 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
5242 unsigned x = mdb_mid2l_search(dl, pgno);
5243 if (x <= dl[0].mid && dl[x].mid == pgno) {
5249 } while ((tx2 = tx2->mt_parent) != NULL);
5252 if (pgno < txn->mt_next_pgno) {
5254 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
5256 DPRINTF(("page %"Z"u not found", pgno));
5257 txn->mt_flags |= MDB_TXN_ERROR;
5258 return MDB_PAGE_NOTFOUND;
5268 /** Finish #mdb_page_search() / #mdb_page_search_lowest().
5269 * The cursor is at the root page, set up the rest of it.
5272 mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags)
5274 MDB_page *mp = mc->mc_pg[mc->mc_top];
5278 while (IS_BRANCH(mp)) {
5282 DPRINTF(("branch page %"Z"u has %u keys", mp->mp_pgno, NUMKEYS(mp)));
5283 /* Don't assert on branch pages in the FreeDB. We can get here
5284 * while in the process of rebalancing a FreeDB branch page; we must
5285 * let that proceed. ITS#8336
5287 mdb_cassert(mc, !mc->mc_dbi || NUMKEYS(mp) > 1);
5288 DPRINTF(("found index 0 to page %"Z"u", NODEPGNO(NODEPTR(mp, 0))));
5290 if (flags & (MDB_PS_FIRST|MDB_PS_LAST)) {
5292 if (flags & MDB_PS_LAST)
5293 i = NUMKEYS(mp) - 1;
5296 node = mdb_node_search(mc, key, &exact);
5298 i = NUMKEYS(mp) - 1;
5300 i = mc->mc_ki[mc->mc_top];
5302 mdb_cassert(mc, i > 0);
5306 DPRINTF(("following index %u for key [%s]", i, DKEY(key)));
5309 mdb_cassert(mc, i < NUMKEYS(mp));
5310 node = NODEPTR(mp, i);
5312 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
5315 mc->mc_ki[mc->mc_top] = i;
5316 if ((rc = mdb_cursor_push(mc, mp)))
5319 if (flags & MDB_PS_MODIFY) {
5320 if ((rc = mdb_page_touch(mc)) != 0)
5322 mp = mc->mc_pg[mc->mc_top];
5327 DPRINTF(("internal error, index points to a %02X page!?",
5329 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
5330 return MDB_CORRUPTED;
5333 DPRINTF(("found leaf page %"Z"u for key [%s]", mp->mp_pgno,
5334 key ? DKEY(key) : "null"));
5335 mc->mc_flags |= C_INITIALIZED;
5336 mc->mc_flags &= ~C_EOF;
5341 /** Search for the lowest key under the current branch page.
5342 * This just bypasses a NUMKEYS check in the current page
5343 * before calling mdb_page_search_root(), because the callers
5344 * are all in situations where the current page is known to
5348 mdb_page_search_lowest(MDB_cursor *mc)
5350 MDB_page *mp = mc->mc_pg[mc->mc_top];
5351 MDB_node *node = NODEPTR(mp, 0);
5354 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
5357 mc->mc_ki[mc->mc_top] = 0;
5358 if ((rc = mdb_cursor_push(mc, mp)))
5360 return mdb_page_search_root(mc, NULL, MDB_PS_FIRST);
5363 /** Search for the page a given key should be in.
5364 * Push it and its parent pages on the cursor stack.
5365 * @param[in,out] mc the cursor for this operation.
5366 * @param[in] key the key to search for, or NULL for first/last page.
5367 * @param[in] flags If MDB_PS_MODIFY is set, visited pages in the DB
5368 * are touched (updated with new page numbers).
5369 * If MDB_PS_FIRST or MDB_PS_LAST is set, find first or last leaf.
5370 * This is used by #mdb_cursor_first() and #mdb_cursor_last().
5371 * If MDB_PS_ROOTONLY set, just fetch root node, no further lookups.
5372 * @return 0 on success, non-zero on failure.
5375 mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)
5380 /* Make sure the txn is still viable, then find the root from
5381 * the txn's db table and set it as the root of the cursor's stack.
5383 if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED) {
5384 DPUTS("transaction may not be used now");
5387 /* Make sure we're using an up-to-date root */
5388 if (*mc->mc_dbflag & DB_STALE) {
5390 if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))
5392 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);
5393 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, 0);
5400 MDB_node *leaf = mdb_node_search(&mc2,
5401 &mc->mc_dbx->md_name, &exact);
5403 return MDB_NOTFOUND;
5404 if ((leaf->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)
5405 return MDB_INCOMPATIBLE; /* not a named DB */
5406 rc = mdb_node_read(mc->mc_txn, leaf, &data);
5409 memcpy(&flags, ((char *) data.mv_data + offsetof(MDB_db, md_flags)),
5411 /* The txn may not know this DBI, or another process may
5412 * have dropped and recreated the DB with other flags.
5414 if ((mc->mc_db->md_flags & PERSISTENT_FLAGS) != flags)
5415 return MDB_INCOMPATIBLE;
5416 memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db));
5418 *mc->mc_dbflag &= ~DB_STALE;
5420 root = mc->mc_db->md_root;
5422 if (root == P_INVALID) { /* Tree is empty. */
5423 DPUTS("tree is empty");
5424 return MDB_NOTFOUND;
5428 mdb_cassert(mc, root > 1);
5429 if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root)
5430 if ((rc = mdb_page_get(mc->mc_txn, root, &mc->mc_pg[0], NULL)) != 0)
5436 DPRINTF(("db %d root page %"Z"u has flags 0x%X",
5437 DDBI(mc), root, mc->mc_pg[0]->mp_flags));
5439 if (flags & MDB_PS_MODIFY) {
5440 if ((rc = mdb_page_touch(mc)))
5444 if (flags & MDB_PS_ROOTONLY)
5447 return mdb_page_search_root(mc, key, flags);
5451 mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
5453 MDB_txn *txn = mc->mc_txn;
5454 pgno_t pg = mp->mp_pgno;
5455 unsigned x = 0, ovpages = mp->mp_pages;
5456 MDB_env *env = txn->mt_env;
5457 MDB_IDL sl = txn->mt_spill_pgs;
5458 MDB_ID pn = pg << 1;
5461 DPRINTF(("free ov page %"Z"u (%d)", pg, ovpages));
5462 /* If the page is dirty or on the spill list we just acquired it,
5463 * so we should give it back to our current free list, if any.
5464 * Otherwise put it onto the list of pages we freed in this txn.
5466 * Won't create me_pghead: me_pglast must be inited along with it.
5467 * Unsupported in nested txns: They would need to hide the page
5468 * range in ancestor txns' dirty and spilled lists.
5470 if (env->me_pghead &&
5472 ((mp->mp_flags & P_DIRTY) ||
5473 (sl && (x = mdb_midl_search(sl, pn)) <= sl[0] && sl[x] == pn)))
5477 MDB_ID2 *dl, ix, iy;
5478 rc = mdb_midl_need(&env->me_pghead, ovpages);
5481 if (!(mp->mp_flags & P_DIRTY)) {
5482 /* This page is no longer spilled */
5489 /* Remove from dirty list */
5490 dl = txn->mt_u.dirty_list;
5492 for (ix = dl[x]; ix.mptr != mp; ix = iy) {
5498 mdb_cassert(mc, x > 1);
5500 dl[j] = ix; /* Unsorted. OK when MDB_TXN_ERROR. */
5501 txn->mt_flags |= MDB_TXN_ERROR;
5502 return MDB_CORRUPTED;
5505 txn->mt_dirty_room++;
5506 if (!(env->me_flags & MDB_WRITEMAP))
5507 mdb_dpage_free(env, mp);
5509 /* Insert in me_pghead */
5510 mop = env->me_pghead;
5511 j = mop[0] + ovpages;
5512 for (i = mop[0]; i && mop[i] < pg; i--)
5518 rc = mdb_midl_append_range(&txn->mt_free_pgs, pg, ovpages);
5522 mc->mc_db->md_overflow_pages -= ovpages;
5526 /** Return the data associated with a given node.
5527 * @param[in] txn The transaction for this operation.
5528 * @param[in] leaf The node being read.
5529 * @param[out] data Updated to point to the node's data.
5530 * @return 0 on success, non-zero on failure.
5533 mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data)
5535 MDB_page *omp; /* overflow page */
5539 if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
5540 data->mv_size = NODEDSZ(leaf);
5541 data->mv_data = NODEDATA(leaf);
5545 /* Read overflow data.
5547 data->mv_size = NODEDSZ(leaf);
5548 memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
5549 if ((rc = mdb_page_get(txn, pgno, &omp, NULL)) != 0) {
5550 DPRINTF(("read overflow page %"Z"u failed", pgno));
5553 data->mv_data = METADATA(omp);
5559 mdb_get(MDB_txn *txn, MDB_dbi dbi,
5560 MDB_val *key, MDB_val *data)
5567 DPRINTF(("===> get db %u key [%s]", dbi, DKEY(key)));
5569 if (!key || !data || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
5572 if (txn->mt_flags & MDB_TXN_BLOCKED)
5575 mdb_cursor_init(&mc, txn, dbi, &mx);
5576 return mdb_cursor_set(&mc, key, data, MDB_SET, &exact);
5579 /** Find a sibling for a page.
5580 * Replaces the page at the top of the cursor's stack with the
5581 * specified sibling, if one exists.
5582 * @param[in] mc The cursor for this operation.
5583 * @param[in] move_right Non-zero if the right sibling is requested,
5584 * otherwise the left sibling.
5585 * @return 0 on success, non-zero on failure.
5588 mdb_cursor_sibling(MDB_cursor *mc, int move_right)
5594 if (mc->mc_snum < 2) {
5595 return MDB_NOTFOUND; /* root has no siblings */
5599 DPRINTF(("parent page is page %"Z"u, index %u",
5600 mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]));
5602 if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top]))
5603 : (mc->mc_ki[mc->mc_top] == 0)) {
5604 DPRINTF(("no more keys left, moving to %s sibling",
5605 move_right ? "right" : "left"));
5606 if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) {
5607 /* undo cursor_pop before returning */
5614 mc->mc_ki[mc->mc_top]++;
5616 mc->mc_ki[mc->mc_top]--;
5617 DPRINTF(("just moving to %s index key %u",
5618 move_right ? "right" : "left", mc->mc_ki[mc->mc_top]));
5620 mdb_cassert(mc, IS_BRANCH(mc->mc_pg[mc->mc_top]));
5622 indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5623 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(indx), &mp, NULL)) != 0) {
5624 /* mc will be inconsistent if caller does mc_snum++ as above */
5625 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
5629 mdb_cursor_push(mc, mp);
5631 mc->mc_ki[mc->mc_top] = NUMKEYS(mp)-1;
5636 /** Move the cursor to the next data item. */
5638 mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
5644 if ((mc->mc_flags & C_EOF) ||
5645 ((mc->mc_flags & C_DEL) && op == MDB_NEXT_DUP)) {
5646 return MDB_NOTFOUND;
5648 if (!(mc->mc_flags & C_INITIALIZED))
5649 return mdb_cursor_first(mc, key, data);
5651 mp = mc->mc_pg[mc->mc_top];
5653 if (mc->mc_db->md_flags & MDB_DUPSORT) {
5654 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5655 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5656 if (op == MDB_NEXT || op == MDB_NEXT_DUP) {
5657 rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);
5658 if (op != MDB_NEXT || rc != MDB_NOTFOUND) {
5659 if (rc == MDB_SUCCESS)
5660 MDB_GET_KEY(leaf, key);
5665 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5666 if (op == MDB_NEXT_DUP)
5667 return MDB_NOTFOUND;
5671 DPRINTF(("cursor_next: top page is %"Z"u in cursor %p",
5672 mdb_dbg_pgno(mp), (void *) mc));
5673 if (mc->mc_flags & C_DEL) {
5674 mc->mc_flags ^= C_DEL;
5678 if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) {
5679 DPUTS("=====> move to next sibling page");
5680 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
5681 mc->mc_flags |= C_EOF;
5684 mp = mc->mc_pg[mc->mc_top];
5685 DPRINTF(("next page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
5687 mc->mc_ki[mc->mc_top]++;
5690 DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
5691 mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
5694 key->mv_size = mc->mc_db->md_pad;
5695 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5699 mdb_cassert(mc, IS_LEAF(mp));
5700 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5702 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5703 mdb_xcursor_init1(mc, leaf);
5706 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5709 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5710 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
5711 if (rc != MDB_SUCCESS)
5716 MDB_GET_KEY(leaf, key);
5720 /** Move the cursor to the previous data item. */
5722 mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
5728 if (!(mc->mc_flags & C_INITIALIZED)) {
5729 rc = mdb_cursor_last(mc, key, data);
5732 mc->mc_ki[mc->mc_top]++;
5735 mp = mc->mc_pg[mc->mc_top];
5737 if (mc->mc_db->md_flags & MDB_DUPSORT) {
5738 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5739 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5740 if (op == MDB_PREV || op == MDB_PREV_DUP) {
5741 rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
5742 if (op != MDB_PREV || rc != MDB_NOTFOUND) {
5743 if (rc == MDB_SUCCESS) {
5744 MDB_GET_KEY(leaf, key);
5745 mc->mc_flags &= ~C_EOF;
5751 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5752 if (op == MDB_PREV_DUP)
5753 return MDB_NOTFOUND;
5757 DPRINTF(("cursor_prev: top page is %"Z"u in cursor %p",
5758 mdb_dbg_pgno(mp), (void *) mc));
5760 mc->mc_flags &= ~(C_EOF|C_DEL);
5762 if (mc->mc_ki[mc->mc_top] == 0) {
5763 DPUTS("=====> move to prev sibling page");
5764 if ((rc = mdb_cursor_sibling(mc, 0)) != MDB_SUCCESS) {
5767 mp = mc->mc_pg[mc->mc_top];
5768 mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;
5769 DPRINTF(("prev page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
5771 mc->mc_ki[mc->mc_top]--;
5773 DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
5774 mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
5777 key->mv_size = mc->mc_db->md_pad;
5778 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5782 mdb_cassert(mc, IS_LEAF(mp));
5783 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5785 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5786 mdb_xcursor_init1(mc, leaf);
5789 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5792 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5793 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
5794 if (rc != MDB_SUCCESS)
5799 MDB_GET_KEY(leaf, key);
5803 /** Set the cursor on a specific data item. */
5805 mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data,
5806 MDB_cursor_op op, int *exactp)
5810 MDB_node *leaf = NULL;
5813 if (key->mv_size == 0)
5814 return MDB_BAD_VALSIZE;
5817 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5819 /* See if we're already on the right page */
5820 if (mc->mc_flags & C_INITIALIZED) {
5823 mp = mc->mc_pg[mc->mc_top];
5825 mc->mc_ki[mc->mc_top] = 0;
5826 return MDB_NOTFOUND;
5828 if (mp->mp_flags & P_LEAF2) {
5829 nodekey.mv_size = mc->mc_db->md_pad;
5830 nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size);
5832 leaf = NODEPTR(mp, 0);
5833 MDB_GET_KEY2(leaf, nodekey);
5835 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5837 /* Probably happens rarely, but first node on the page
5838 * was the one we wanted.
5840 mc->mc_ki[mc->mc_top] = 0;
5847 unsigned int nkeys = NUMKEYS(mp);
5849 if (mp->mp_flags & P_LEAF2) {
5850 nodekey.mv_data = LEAF2KEY(mp,
5851 nkeys-1, nodekey.mv_size);
5853 leaf = NODEPTR(mp, nkeys-1);
5854 MDB_GET_KEY2(leaf, nodekey);
5856 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5858 /* last node was the one we wanted */
5859 mc->mc_ki[mc->mc_top] = nkeys-1;
5865 if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) {
5866 /* This is definitely the right page, skip search_page */
5867 if (mp->mp_flags & P_LEAF2) {
5868 nodekey.mv_data = LEAF2KEY(mp,
5869 mc->mc_ki[mc->mc_top], nodekey.mv_size);
5871 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5872 MDB_GET_KEY2(leaf, nodekey);
5874 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5876 /* current node was the one we wanted */
5886 /* If any parents have right-sibs, search.
5887 * Otherwise, there's nothing further.
5889 for (i=0; i<mc->mc_top; i++)
5891 NUMKEYS(mc->mc_pg[i])-1)
5893 if (i == mc->mc_top) {
5894 /* There are no other pages */
5895 mc->mc_ki[mc->mc_top] = nkeys;
5896 return MDB_NOTFOUND;
5900 /* There are no other pages */
5901 mc->mc_ki[mc->mc_top] = 0;
5902 if (op == MDB_SET_RANGE && !exactp) {
5906 return MDB_NOTFOUND;
5912 rc = mdb_page_search(mc, key, 0);
5913 if (rc != MDB_SUCCESS)
5916 mp = mc->mc_pg[mc->mc_top];
5917 mdb_cassert(mc, IS_LEAF(mp));
5920 leaf = mdb_node_search(mc, key, exactp);
5921 if (exactp != NULL && !*exactp) {
5922 /* MDB_SET specified and not an exact match. */
5923 return MDB_NOTFOUND;
5927 DPUTS("===> inexact leaf not found, goto sibling");
5928 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
5929 mc->mc_flags |= C_EOF;
5930 return rc; /* no entries matched */
5932 mp = mc->mc_pg[mc->mc_top];
5933 mdb_cassert(mc, IS_LEAF(mp));
5934 leaf = NODEPTR(mp, 0);
5938 mc->mc_flags |= C_INITIALIZED;
5939 mc->mc_flags &= ~C_EOF;
5942 if (op == MDB_SET_RANGE || op == MDB_SET_KEY) {
5943 key->mv_size = mc->mc_db->md_pad;
5944 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5949 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5950 mdb_xcursor_init1(mc, leaf);
5953 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5954 if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) {
5955 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
5958 if (op == MDB_GET_BOTH) {
5964 rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p);
5965 if (rc != MDB_SUCCESS)
5968 } else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {
5971 if ((rc = mdb_node_read(mc->mc_txn, leaf, &olddata)) != MDB_SUCCESS)
5973 dcmp = mc->mc_dbx->md_dcmp;
5974 #if UINT_MAX < SIZE_MAX
5975 if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
5976 dcmp = mdb_cmp_clong;
5978 rc = dcmp(data, &olddata);
5980 if (op == MDB_GET_BOTH || rc > 0)
5981 return MDB_NOTFOUND;
5988 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5989 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5994 /* The key already matches in all other cases */
5995 if (op == MDB_SET_RANGE || op == MDB_SET_KEY)
5996 MDB_GET_KEY(leaf, key);
5997 DPRINTF(("==> cursor placed on key [%s]", DKEY(key)));
6002 /** Move the cursor to the first item in the database. */
6004 mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data)
6010 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
6012 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
6013 rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
6014 if (rc != MDB_SUCCESS)
6017 mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
6019 leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0);
6020 mc->mc_flags |= C_INITIALIZED;
6021 mc->mc_flags &= ~C_EOF;
6023 mc->mc_ki[mc->mc_top] = 0;
6025 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
6026 key->mv_size = mc->mc_db->md_pad;
6027 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size);
6032 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6033 mdb_xcursor_init1(mc, leaf);
6034 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
6038 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
6042 MDB_GET_KEY(leaf, key);
6046 /** Move the cursor to the last item in the database. */
6048 mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)
6054 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
6056 if (!(mc->mc_flags & C_EOF)) {
6058 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
6059 rc = mdb_page_search(mc, NULL, MDB_PS_LAST);
6060 if (rc != MDB_SUCCESS)
6063 mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
6066 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;
6067 mc->mc_flags |= C_INITIALIZED|C_EOF;
6068 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6070 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
6071 key->mv_size = mc->mc_db->md_pad;
6072 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size);
6077 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6078 mdb_xcursor_init1(mc, leaf);
6079 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
6083 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
6088 MDB_GET_KEY(leaf, key);
6093 mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,
6098 int (*mfunc)(MDB_cursor *mc, MDB_val *key, MDB_val *data);
6103 if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)
6107 case MDB_GET_CURRENT:
6108 if (!(mc->mc_flags & C_INITIALIZED)) {
6111 MDB_page *mp = mc->mc_pg[mc->mc_top];
6112 int nkeys = NUMKEYS(mp);
6113 if (!nkeys || mc->mc_ki[mc->mc_top] >= nkeys) {
6114 mc->mc_ki[mc->mc_top] = nkeys;
6120 key->mv_size = mc->mc_db->md_pad;
6121 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
6123 MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6124 MDB_GET_KEY(leaf, key);
6126 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6127 rc = mdb_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT);
6129 rc = mdb_node_read(mc->mc_txn, leaf, data);
6136 case MDB_GET_BOTH_RANGE:
6141 if (mc->mc_xcursor == NULL) {
6142 rc = MDB_INCOMPATIBLE;
6152 rc = mdb_cursor_set(mc, key, data, op,
6153 op == MDB_SET_RANGE ? NULL : &exact);
6156 case MDB_GET_MULTIPLE:
6157 if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
6161 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
6162 rc = MDB_INCOMPATIBLE;
6166 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) ||
6167 (mc->mc_xcursor->mx_cursor.mc_flags & C_EOF))
6170 case MDB_NEXT_MULTIPLE:
6175 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
6176 rc = MDB_INCOMPATIBLE;
6179 rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP);
6180 if (rc == MDB_SUCCESS) {
6181 if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
6184 mx = &mc->mc_xcursor->mx_cursor;
6185 data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) *
6187 data->mv_data = METADATA(mx->mc_pg[mx->mc_top]);
6188 mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1;
6196 case MDB_NEXT_NODUP:
6197 rc = mdb_cursor_next(mc, key, data, op);
6201 case MDB_PREV_NODUP:
6202 rc = mdb_cursor_prev(mc, key, data, op);
6205 rc = mdb_cursor_first(mc, key, data);
6208 mfunc = mdb_cursor_first;
6210 if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
6214 if (mc->mc_xcursor == NULL) {
6215 rc = MDB_INCOMPATIBLE;
6219 MDB_node *leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6220 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6221 MDB_GET_KEY(leaf, key);
6222 rc = mdb_node_read(mc->mc_txn, leaf, data);
6226 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
6230 rc = mfunc(&mc->mc_xcursor->mx_cursor, data, NULL);
6233 rc = mdb_cursor_last(mc, key, data);
6236 mfunc = mdb_cursor_last;
6239 DPRINTF(("unhandled/unimplemented cursor operation %u", op));
6244 if (mc->mc_flags & C_DEL)
6245 mc->mc_flags ^= C_DEL;
6250 /** Touch all the pages in the cursor stack. Set mc_top.
6251 * Makes sure all the pages are writable, before attempting a write operation.
6252 * @param[in] mc The cursor to operate on.
6255 mdb_cursor_touch(MDB_cursor *mc)
6257 int rc = MDB_SUCCESS;
6259 if (mc->mc_dbi >= CORE_DBS && !(*mc->mc_dbflag & DB_DIRTY)) {
6262 if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))
6264 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, &mcx);
6265 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY);
6268 *mc->mc_dbflag |= DB_DIRTY;
6273 rc = mdb_page_touch(mc);
6274 } while (!rc && ++(mc->mc_top) < mc->mc_snum);
6275 mc->mc_top = mc->mc_snum-1;
6280 /** Do not spill pages to disk if txn is getting full, may fail instead */
6281 #define MDB_NOSPILL 0x8000
6284 mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
6288 MDB_node *leaf = NULL;
6289 MDB_page *fp, *mp, *sub_root = NULL;
6291 MDB_val xdata, *rdata, dkey, olddata;
6293 int do_sub = 0, insert_key, insert_data;
6294 unsigned int mcount = 0, dcount = 0, nospill;
6297 unsigned int nflags;
6300 if (mc == NULL || key == NULL)
6303 env = mc->mc_txn->mt_env;
6305 /* Check this first so counter will always be zero on any
6308 if (flags & MDB_MULTIPLE) {
6309 dcount = data[1].mv_size;
6310 data[1].mv_size = 0;
6311 if (!F_ISSET(mc->mc_db->md_flags, MDB_DUPFIXED))
6312 return MDB_INCOMPATIBLE;
6315 nospill = flags & MDB_NOSPILL;
6316 flags &= ~MDB_NOSPILL;
6318 if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
6319 return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
6321 if (key->mv_size-1 >= ENV_MAXKEY(env))
6322 return MDB_BAD_VALSIZE;
6324 #if SIZE_MAX > MAXDATASIZE
6325 if (data->mv_size > ((mc->mc_db->md_flags & MDB_DUPSORT) ? ENV_MAXKEY(env) : MAXDATASIZE))
6326 return MDB_BAD_VALSIZE;
6328 if ((mc->mc_db->md_flags & MDB_DUPSORT) && data->mv_size > ENV_MAXKEY(env))
6329 return MDB_BAD_VALSIZE;
6332 DPRINTF(("==> put db %d key [%s], size %"Z"u, data size %"Z"u",
6333 DDBI(mc), DKEY(key), key ? key->mv_size : 0, data->mv_size));
6337 if (flags == MDB_CURRENT) {
6338 if (!(mc->mc_flags & C_INITIALIZED))
6341 } else if (mc->mc_db->md_root == P_INVALID) {
6342 /* new database, cursor has nothing to point to */
6345 mc->mc_flags &= ~C_INITIALIZED;
6350 if (flags & MDB_APPEND) {
6352 rc = mdb_cursor_last(mc, &k2, &d2);
6354 rc = mc->mc_dbx->md_cmp(key, &k2);
6357 mc->mc_ki[mc->mc_top]++;
6359 /* new key is <= last key */
6364 rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact);
6366 if ((flags & MDB_NOOVERWRITE) && rc == 0) {
6367 DPRINTF(("duplicate key [%s]", DKEY(key)));
6369 return MDB_KEYEXIST;
6371 if (rc && rc != MDB_NOTFOUND)
6375 if (mc->mc_flags & C_DEL)
6376 mc->mc_flags ^= C_DEL;
6378 /* Cursor is positioned, check for room in the dirty list */
6380 if (flags & MDB_MULTIPLE) {
6382 xdata.mv_size = data->mv_size * dcount;
6386 if ((rc2 = mdb_page_spill(mc, key, rdata)))
6390 if (rc == MDB_NO_ROOT) {
6392 /* new database, write a root leaf page */
6393 DPUTS("allocating new root leaf page");
6394 if ((rc2 = mdb_page_new(mc, P_LEAF, 1, &np))) {
6397 mdb_cursor_push(mc, np);
6398 mc->mc_db->md_root = np->mp_pgno;
6399 mc->mc_db->md_depth++;
6400 *mc->mc_dbflag |= DB_DIRTY;
6401 if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED))
6403 np->mp_flags |= P_LEAF2;
6404 mc->mc_flags |= C_INITIALIZED;
6406 /* make sure all cursor pages are writable */
6407 rc2 = mdb_cursor_touch(mc);
6412 insert_key = insert_data = rc;
6414 /* The key does not exist */
6415 DPRINTF(("inserting key at index %i", mc->mc_ki[mc->mc_top]));
6416 if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
6417 LEAFSIZE(key, data) > env->me_nodemax)
6419 /* Too big for a node, insert in sub-DB. Set up an empty
6420 * "old sub-page" for prep_subDB to expand to a full page.
6422 fp_flags = P_LEAF|P_DIRTY;
6424 fp->mp_pad = data->mv_size; /* used if MDB_DUPFIXED */
6425 fp->mp_lower = fp->mp_upper = (PAGEHDRSZ-PAGEBASE);
6426 olddata.mv_size = PAGEHDRSZ;
6430 /* there's only a key anyway, so this is a no-op */
6431 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
6433 unsigned int ksize = mc->mc_db->md_pad;
6434 if (key->mv_size != ksize)
6435 return MDB_BAD_VALSIZE;
6436 ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize);
6437 memcpy(ptr, key->mv_data, ksize);
6439 /* if overwriting slot 0 of leaf, need to
6440 * update branch key if there is a parent page
6442 if (mc->mc_top && !mc->mc_ki[mc->mc_top]) {
6443 unsigned short dtop = 1;
6445 /* slot 0 is always an empty key, find real slot */
6446 while (mc->mc_top && !mc->mc_ki[mc->mc_top]) {
6450 if (mc->mc_ki[mc->mc_top])
6451 rc2 = mdb_update_key(mc, key);
6462 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6463 olddata.mv_size = NODEDSZ(leaf);
6464 olddata.mv_data = NODEDATA(leaf);
6467 if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) {
6468 /* Prepare (sub-)page/sub-DB to accept the new item,
6469 * if needed. fp: old sub-page or a header faking
6470 * it. mp: new (sub-)page. offset: growth in page
6471 * size. xdata: node data with new page or DB.
6473 unsigned i, offset = 0;
6474 mp = fp = xdata.mv_data = env->me_pbuf;
6475 mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
6477 /* Was a single item before, must convert now */
6478 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6480 /* Just overwrite the current item */
6481 if (flags == MDB_CURRENT)
6483 dcmp = mc->mc_dbx->md_dcmp;
6484 #if UINT_MAX < SIZE_MAX
6485 if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
6486 dcmp = mdb_cmp_clong;
6488 /* does data match? */
6489 if (!dcmp(data, &olddata)) {
6490 if (flags & (MDB_NODUPDATA|MDB_APPENDDUP))
6491 return MDB_KEYEXIST;
6496 /* Back up original data item */
6497 dkey.mv_size = olddata.mv_size;
6498 dkey.mv_data = memcpy(fp+1, olddata.mv_data, olddata.mv_size);
6500 /* Make sub-page header for the dup items, with dummy body */
6501 fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP;
6502 fp->mp_lower = (PAGEHDRSZ-PAGEBASE);
6503 xdata.mv_size = PAGEHDRSZ + dkey.mv_size + data->mv_size;
6504 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
6505 fp->mp_flags |= P_LEAF2;
6506 fp->mp_pad = data->mv_size;
6507 xdata.mv_size += 2 * data->mv_size; /* leave space for 2 more */
6509 xdata.mv_size += 2 * (sizeof(indx_t) + NODESIZE) +
6510 (dkey.mv_size & 1) + (data->mv_size & 1);
6512 fp->mp_upper = xdata.mv_size - PAGEBASE;
6513 olddata.mv_size = xdata.mv_size; /* pretend olddata is fp */
6514 } else if (leaf->mn_flags & F_SUBDATA) {
6515 /* Data is on sub-DB, just store it */
6516 flags |= F_DUPDATA|F_SUBDATA;
6519 /* Data is on sub-page */
6520 fp = olddata.mv_data;
6523 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
6524 offset = EVEN(NODESIZE + sizeof(indx_t) +
6528 offset = fp->mp_pad;
6529 if (SIZELEFT(fp) < offset) {
6530 offset *= 4; /* space for 4 more */
6533 /* FALLTHRU: Big enough MDB_DUPFIXED sub-page */
6535 fp->mp_flags |= P_DIRTY;
6536 COPY_PGNO(fp->mp_pgno, mp->mp_pgno);
6537 mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;
6541 xdata.mv_size = olddata.mv_size + offset;
6544 fp_flags = fp->mp_flags;
6545 if (NODESIZE + NODEKSZ(leaf) + xdata.mv_size > env->me_nodemax) {
6546 /* Too big for a sub-page, convert to sub-DB */
6547 fp_flags &= ~P_SUBP;
6549 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
6550 fp_flags |= P_LEAF2;
6551 dummy.md_pad = fp->mp_pad;
6552 dummy.md_flags = MDB_DUPFIXED;
6553 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
6554 dummy.md_flags |= MDB_INTEGERKEY;
6560 dummy.md_branch_pages = 0;
6561 dummy.md_leaf_pages = 1;
6562 dummy.md_overflow_pages = 0;
6563 dummy.md_entries = NUMKEYS(fp);
6564 xdata.mv_size = sizeof(MDB_db);
6565 xdata.mv_data = &dummy;
6566 if ((rc = mdb_page_alloc(mc, 1, &mp)))
6568 offset = env->me_psize - olddata.mv_size;
6569 flags |= F_DUPDATA|F_SUBDATA;
6570 dummy.md_root = mp->mp_pgno;
6574 mp->mp_flags = fp_flags | P_DIRTY;
6575 mp->mp_pad = fp->mp_pad;
6576 mp->mp_lower = fp->mp_lower;
6577 mp->mp_upper = fp->mp_upper + offset;
6578 if (fp_flags & P_LEAF2) {
6579 memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad);
6581 memcpy((char *)mp + mp->mp_upper + PAGEBASE, (char *)fp + fp->mp_upper + PAGEBASE,
6582 olddata.mv_size - fp->mp_upper - PAGEBASE);
6583 for (i=0; i<NUMKEYS(fp); i++)
6584 mp->mp_ptrs[i] = fp->mp_ptrs[i] + offset;
6592 mdb_node_del(mc, 0);
6596 /* LMDB passes F_SUBDATA in 'flags' to write a DB record */
6597 if ((leaf->mn_flags ^ flags) & F_SUBDATA)
6598 return MDB_INCOMPATIBLE;
6599 /* overflow page overwrites need special handling */
6600 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
6603 int level, ovpages, dpages = OVPAGES(data->mv_size, env->me_psize);
6605 memcpy(&pg, olddata.mv_data, sizeof(pg));
6606 if ((rc2 = mdb_page_get(mc->mc_txn, pg, &omp, &level)) != 0)
6608 ovpages = omp->mp_pages;
6610 /* Is the ov page large enough? */
6611 if (ovpages >= dpages) {
6612 if (!(omp->mp_flags & P_DIRTY) &&
6613 (level || (env->me_flags & MDB_WRITEMAP)))
6615 rc = mdb_page_unspill(mc->mc_txn, omp, &omp);
6618 level = 0; /* dirty in this txn or clean */
6621 if (omp->mp_flags & P_DIRTY) {
6622 /* yes, overwrite it. Note in this case we don't
6623 * bother to try shrinking the page if the new data
6624 * is smaller than the overflow threshold.
6627 /* It is writable only in a parent txn */
6628 size_t sz = (size_t) env->me_psize * ovpages, off;
6629 MDB_page *np = mdb_page_malloc(mc->mc_txn, ovpages);
6635 /* Note - this page is already counted in parent's dirty_room */
6636 rc2 = mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);
6637 mdb_cassert(mc, rc2 == 0);
6638 /* Currently we make the page look as with put() in the
6639 * parent txn, in case the user peeks at MDB_RESERVEd
6640 * or unused parts. Some users treat ovpages specially.
6642 if (!(flags & MDB_RESERVE)) {
6643 /* Skip the part where LMDB will put *data.
6644 * Copy end of page, adjusting alignment so
6645 * compiler may copy words instead of bytes.
6647 off = (PAGEHDRSZ + data->mv_size) & -sizeof(size_t);
6648 memcpy((size_t *)((char *)np + off),
6649 (size_t *)((char *)omp + off), sz - off);
6652 memcpy(np, omp, sz); /* Copy beginning of page */
6655 SETDSZ(leaf, data->mv_size);
6656 if (F_ISSET(flags, MDB_RESERVE))
6657 data->mv_data = METADATA(omp);
6659 memcpy(METADATA(omp), data->mv_data, data->mv_size);
6663 if ((rc2 = mdb_ovpage_free(mc, omp)) != MDB_SUCCESS)
6665 } else if (data->mv_size == olddata.mv_size) {
6666 /* same size, just replace it. Note that we could
6667 * also reuse this node if the new data is smaller,
6668 * but instead we opt to shrink the node in that case.
6670 if (F_ISSET(flags, MDB_RESERVE))
6671 data->mv_data = olddata.mv_data;
6672 else if (!(mc->mc_flags & C_SUB))
6673 memcpy(olddata.mv_data, data->mv_data, data->mv_size);
6675 memcpy(NODEKEY(leaf), key->mv_data, key->mv_size);
6680 mdb_node_del(mc, 0);
6686 nflags = flags & NODE_ADD_FLAGS;
6687 nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(env, key, rdata);
6688 if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) {
6689 if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA )
6690 nflags &= ~MDB_APPEND; /* sub-page may need room to grow */
6692 nflags |= MDB_SPLIT_REPLACE;
6693 rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags);
6695 /* There is room already in this leaf page. */
6696 rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);
6698 /* Adjust other cursors pointing to mp */
6699 MDB_cursor *m2, *m3;
6700 MDB_dbi dbi = mc->mc_dbi;
6701 unsigned i = mc->mc_top;
6702 MDB_page *mp = mc->mc_pg[i];
6704 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
6705 if (mc->mc_flags & C_SUB)
6706 m3 = &m2->mc_xcursor->mx_cursor;
6709 if (m3 == mc || m3->mc_snum < mc->mc_snum || m3->mc_pg[i] != mp) continue;
6710 if (m3->mc_ki[i] >= mc->mc_ki[i] && insert_key) {
6713 if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
6714 MDB_node *n2 = NODEPTR(mp, m3->mc_ki[i]);
6715 if ((n2->mn_flags & (F_SUBDATA|F_DUPDATA)) == F_DUPDATA)
6716 m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
6722 if (rc == MDB_SUCCESS) {
6723 /* Now store the actual data in the child DB. Note that we're
6724 * storing the user data in the keys field, so there are strict
6725 * size limits on dupdata. The actual data fields of the child
6726 * DB are all zero size.
6729 int xflags, new_dupdata;
6734 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6735 if (flags & MDB_CURRENT) {
6736 xflags = MDB_CURRENT|MDB_NOSPILL;
6738 mdb_xcursor_init1(mc, leaf);
6739 xflags = (flags & MDB_NODUPDATA) ?
6740 MDB_NOOVERWRITE|MDB_NOSPILL : MDB_NOSPILL;
6743 mc->mc_xcursor->mx_cursor.mc_pg[0] = sub_root;
6744 new_dupdata = (int)dkey.mv_size;
6745 /* converted, write the original data first */
6747 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);
6750 /* we've done our job */
6753 if (!(leaf->mn_flags & F_SUBDATA) || sub_root) {
6754 /* Adjust other cursors pointing to mp */
6756 MDB_xcursor *mx = mc->mc_xcursor;
6757 unsigned i = mc->mc_top;
6758 MDB_page *mp = mc->mc_pg[i];
6759 int nkeys = NUMKEYS(mp);
6761 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
6762 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
6763 if (!(m2->mc_flags & C_INITIALIZED)) continue;
6764 if (m2->mc_pg[i] == mp) {
6765 if (m2->mc_ki[i] == mc->mc_ki[i]) {
6766 mdb_xcursor_init2(m2, mx, new_dupdata);
6767 } else if (!insert_key && m2->mc_ki[i] < nkeys) {
6768 MDB_node *n2 = NODEPTR(mp, m2->mc_ki[i]);
6769 if ((n2->mn_flags & (F_SUBDATA|F_DUPDATA)) == F_DUPDATA)
6770 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
6775 ecount = mc->mc_xcursor->mx_db.md_entries;
6776 if (flags & MDB_APPENDDUP)
6777 xflags |= MDB_APPEND;
6778 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);
6779 if (flags & F_SUBDATA) {
6780 void *db = NODEDATA(leaf);
6781 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
6783 insert_data = mc->mc_xcursor->mx_db.md_entries - ecount;
6785 /* Increment count unless we just replaced an existing item. */
6787 mc->mc_db->md_entries++;
6789 /* Invalidate txn if we created an empty sub-DB */
6792 /* If we succeeded and the key didn't exist before,
6793 * make sure the cursor is marked valid.
6795 mc->mc_flags |= C_INITIALIZED;
6797 if (flags & MDB_MULTIPLE) {
6800 /* let caller know how many succeeded, if any */
6801 data[1].mv_size = mcount;
6802 if (mcount < dcount) {
6803 data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size;
6804 insert_key = insert_data = 0;
6811 if (rc == MDB_KEYEXIST) /* should not happen, we deleted that item */
6814 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
6819 mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
6825 if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
6826 return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
6828 if (!(mc->mc_flags & C_INITIALIZED))
6831 if (mc->mc_ki[mc->mc_top] >= NUMKEYS(mc->mc_pg[mc->mc_top]))
6832 return MDB_NOTFOUND;
6834 if (!(flags & MDB_NOSPILL) && (rc = mdb_page_spill(mc, NULL, NULL)))
6837 rc = mdb_cursor_touch(mc);
6841 mp = mc->mc_pg[mc->mc_top];
6844 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6846 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6847 if (flags & MDB_NODUPDATA) {
6848 /* mdb_cursor_del0() will subtract the final entry */
6849 mc->mc_db->md_entries -= mc->mc_xcursor->mx_db.md_entries - 1;
6850 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
6852 if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
6853 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6855 rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, MDB_NOSPILL);
6858 /* If sub-DB still has entries, we're done */
6859 if (mc->mc_xcursor->mx_db.md_entries) {
6860 if (leaf->mn_flags & F_SUBDATA) {
6861 /* update subDB info */
6862 void *db = NODEDATA(leaf);
6863 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
6866 /* shrink fake page */
6867 mdb_node_shrink(mp, mc->mc_ki[mc->mc_top]);
6868 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6869 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6870 /* fix other sub-DB cursors pointed at fake pages on this page */
6871 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
6872 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
6873 if (!(m2->mc_flags & C_INITIALIZED)) continue;
6874 if (m2->mc_pg[mc->mc_top] == mp) {
6875 if (m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top]) {
6876 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6878 MDB_node *n2 = NODEPTR(mp, m2->mc_ki[mc->mc_top]);
6879 if (!(n2->mn_flags & F_SUBDATA))
6880 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
6885 mc->mc_db->md_entries--;
6888 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
6890 /* otherwise fall thru and delete the sub-DB */
6893 if (leaf->mn_flags & F_SUBDATA) {
6894 /* add all the child DB's pages to the free list */
6895 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
6900 /* LMDB passes F_SUBDATA in 'flags' to delete a DB record */
6901 else if ((leaf->mn_flags ^ flags) & F_SUBDATA) {
6902 rc = MDB_INCOMPATIBLE;
6906 /* add overflow pages to free list */
6907 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
6911 memcpy(&pg, NODEDATA(leaf), sizeof(pg));
6912 if ((rc = mdb_page_get(mc->mc_txn, pg, &omp, NULL)) ||
6913 (rc = mdb_ovpage_free(mc, omp)))
6918 return mdb_cursor_del0(mc);
6921 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
6925 /** Allocate and initialize new pages for a database.
6926 * @param[in] mc a cursor on the database being added to.
6927 * @param[in] flags flags defining what type of page is being allocated.
6928 * @param[in] num the number of pages to allocate. This is usually 1,
6929 * unless allocating overflow pages for a large record.
6930 * @param[out] mp Address of a page, or NULL on failure.
6931 * @return 0 on success, non-zero on failure.
6934 mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp)
6939 if ((rc = mdb_page_alloc(mc, num, &np)))
6941 DPRINTF(("allocated new mpage %"Z"u, page size %u",
6942 np->mp_pgno, mc->mc_txn->mt_env->me_psize));
6943 np->mp_flags = flags | P_DIRTY;
6944 np->mp_lower = (PAGEHDRSZ-PAGEBASE);
6945 np->mp_upper = mc->mc_txn->mt_env->me_psize - PAGEBASE;
6948 mc->mc_db->md_branch_pages++;
6949 else if (IS_LEAF(np))
6950 mc->mc_db->md_leaf_pages++;
6951 else if (IS_OVERFLOW(np)) {
6952 mc->mc_db->md_overflow_pages += num;
6960 /** Calculate the size of a leaf node.
6961 * The size depends on the environment's page size; if a data item
6962 * is too large it will be put onto an overflow page and the node
6963 * size will only include the key and not the data. Sizes are always
6964 * rounded up to an even number of bytes, to guarantee 2-byte alignment
6965 * of the #MDB_node headers.
6966 * @param[in] env The environment handle.
6967 * @param[in] key The key for the node.
6968 * @param[in] data The data for the node.
6969 * @return The number of bytes needed to store the node.
6972 mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data)
6976 sz = LEAFSIZE(key, data);
6977 if (sz > env->me_nodemax) {
6978 /* put on overflow page */
6979 sz -= data->mv_size - sizeof(pgno_t);
6982 return EVEN(sz + sizeof(indx_t));
6985 /** Calculate the size of a branch node.
6986 * The size should depend on the environment's page size but since
6987 * we currently don't support spilling large keys onto overflow
6988 * pages, it's simply the size of the #MDB_node header plus the
6989 * size of the key. Sizes are always rounded up to an even number
6990 * of bytes, to guarantee 2-byte alignment of the #MDB_node headers.
6991 * @param[in] env The environment handle.
6992 * @param[in] key The key for the node.
6993 * @return The number of bytes needed to store the node.
6996 mdb_branch_size(MDB_env *env, MDB_val *key)
7001 if (sz > env->me_nodemax) {
7002 /* put on overflow page */
7003 /* not implemented */
7004 /* sz -= key->size - sizeof(pgno_t); */
7007 return sz + sizeof(indx_t);
7010 /** Add a node to the page pointed to by the cursor.
7011 * @param[in] mc The cursor for this operation.
7012 * @param[in] indx The index on the page where the new node should be added.
7013 * @param[in] key The key for the new node.
7014 * @param[in] data The data for the new node, if any.
7015 * @param[in] pgno The page number, if adding a branch node.
7016 * @param[in] flags Flags for the node.
7017 * @return 0 on success, non-zero on failure. Possible errors are:
7019 * <li>ENOMEM - failed to allocate overflow pages for the node.
7020 * <li>MDB_PAGE_FULL - there is insufficient room in the page. This error
7021 * should never happen since all callers already calculate the
7022 * page's free space before calling this function.
7026 mdb_node_add(MDB_cursor *mc, indx_t indx,
7027 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags)
7030 size_t node_size = NODESIZE;
7034 MDB_page *mp = mc->mc_pg[mc->mc_top];
7035 MDB_page *ofp = NULL; /* overflow page */
7039 mdb_cassert(mc, mp->mp_upper >= mp->mp_lower);
7041 DPRINTF(("add to %s %spage %"Z"u index %i, data size %"Z"u key size %"Z"u [%s]",
7042 IS_LEAF(mp) ? "leaf" : "branch",
7043 IS_SUBP(mp) ? "sub-" : "",
7044 mdb_dbg_pgno(mp), indx, data ? data->mv_size : 0,
7045 key ? key->mv_size : 0, key ? DKEY(key) : "null"));
7048 /* Move higher keys up one slot. */
7049 int ksize = mc->mc_db->md_pad, dif;
7050 char *ptr = LEAF2KEY(mp, indx, ksize);
7051 dif = NUMKEYS(mp) - indx;
7053 memmove(ptr+ksize, ptr, dif*ksize);
7054 /* insert new key */
7055 memcpy(ptr, key->mv_data, ksize);
7057 /* Just using these for counting */
7058 mp->mp_lower += sizeof(indx_t);
7059 mp->mp_upper -= ksize - sizeof(indx_t);
7063 room = (ssize_t)SIZELEFT(mp) - (ssize_t)sizeof(indx_t);
7065 node_size += key->mv_size;
7067 mdb_cassert(mc, key && data);
7068 if (F_ISSET(flags, F_BIGDATA)) {
7069 /* Data already on overflow page. */
7070 node_size += sizeof(pgno_t);
7071 } else if (node_size + data->mv_size > mc->mc_txn->mt_env->me_nodemax) {
7072 int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
7074 /* Put data on overflow page. */
7075 DPRINTF(("data size is %"Z"u, node would be %"Z"u, put data on overflow page",
7076 data->mv_size, node_size+data->mv_size));
7077 node_size = EVEN(node_size + sizeof(pgno_t));
7078 if ((ssize_t)node_size > room)
7080 if ((rc = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp)))
7082 DPRINTF(("allocated overflow page %"Z"u", ofp->mp_pgno));
7086 node_size += data->mv_size;
7089 node_size = EVEN(node_size);
7090 if ((ssize_t)node_size > room)
7094 /* Move higher pointers up one slot. */
7095 for (i = NUMKEYS(mp); i > indx; i--)
7096 mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];
7098 /* Adjust free space offsets. */
7099 ofs = mp->mp_upper - node_size;
7100 mdb_cassert(mc, ofs >= mp->mp_lower + sizeof(indx_t));
7101 mp->mp_ptrs[indx] = ofs;
7103 mp->mp_lower += sizeof(indx_t);
7105 /* Write the node data. */
7106 node = NODEPTR(mp, indx);
7107 node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
7108 node->mn_flags = flags;
7110 SETDSZ(node,data->mv_size);
7115 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
7118 ndata = NODEDATA(node);
7120 if (F_ISSET(flags, F_BIGDATA))
7121 memcpy(ndata, data->mv_data, sizeof(pgno_t));
7122 else if (F_ISSET(flags, MDB_RESERVE))
7123 data->mv_data = ndata;
7125 memcpy(ndata, data->mv_data, data->mv_size);
7127 memcpy(ndata, &ofp->mp_pgno, sizeof(pgno_t));
7128 ndata = METADATA(ofp);
7129 if (F_ISSET(flags, MDB_RESERVE))
7130 data->mv_data = ndata;
7132 memcpy(ndata, data->mv_data, data->mv_size);
7139 DPRINTF(("not enough room in page %"Z"u, got %u ptrs",
7140 mdb_dbg_pgno(mp), NUMKEYS(mp)));
7141 DPRINTF(("upper-lower = %u - %u = %"Z"d", mp->mp_upper,mp->mp_lower,room));
7142 DPRINTF(("node size = %"Z"u", node_size));
7143 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
7144 return MDB_PAGE_FULL;
7147 /** Delete the specified node from a page.
7148 * @param[in] mc Cursor pointing to the node to delete.
7149 * @param[in] ksize The size of a node. Only used if the page is
7150 * part of a #MDB_DUPFIXED database.
7153 mdb_node_del(MDB_cursor *mc, int ksize)
7155 MDB_page *mp = mc->mc_pg[mc->mc_top];
7156 indx_t indx = mc->mc_ki[mc->mc_top];
7158 indx_t i, j, numkeys, ptr;
7162 DPRINTF(("delete node %u on %s page %"Z"u", indx,
7163 IS_LEAF(mp) ? "leaf" : "branch", mdb_dbg_pgno(mp)));
7164 numkeys = NUMKEYS(mp);
7165 mdb_cassert(mc, indx < numkeys);
7168 int x = numkeys - 1 - indx;
7169 base = LEAF2KEY(mp, indx, ksize);
7171 memmove(base, base + ksize, x * ksize);
7172 mp->mp_lower -= sizeof(indx_t);
7173 mp->mp_upper += ksize - sizeof(indx_t);
7177 node = NODEPTR(mp, indx);
7178 sz = NODESIZE + node->mn_ksize;
7180 if (F_ISSET(node->mn_flags, F_BIGDATA))
7181 sz += sizeof(pgno_t);
7183 sz += NODEDSZ(node);
7187 ptr = mp->mp_ptrs[indx];
7188 for (i = j = 0; i < numkeys; i++) {
7190 mp->mp_ptrs[j] = mp->mp_ptrs[i];
7191 if (mp->mp_ptrs[i] < ptr)
7192 mp->mp_ptrs[j] += sz;
7197 base = (char *)mp + mp->mp_upper + PAGEBASE;
7198 memmove(base + sz, base, ptr - mp->mp_upper);
7200 mp->mp_lower -= sizeof(indx_t);
7204 /** Compact the main page after deleting a node on a subpage.
7205 * @param[in] mp The main page to operate on.
7206 * @param[in] indx The index of the subpage on the main page.
7209 mdb_node_shrink(MDB_page *mp, indx_t indx)
7214 indx_t delta, nsize, len, ptr;
7217 node = NODEPTR(mp, indx);
7218 sp = (MDB_page *)NODEDATA(node);
7219 delta = SIZELEFT(sp);
7220 nsize = NODEDSZ(node) - delta;
7222 /* Prepare to shift upward, set len = length(subpage part to shift) */
7226 return; /* do not make the node uneven-sized */
7228 xp = (MDB_page *)((char *)sp + delta); /* destination subpage */
7229 for (i = NUMKEYS(sp); --i >= 0; )
7230 xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta;
7233 sp->mp_upper = sp->mp_lower;
7234 COPY_PGNO(sp->mp_pgno, mp->mp_pgno);
7235 SETDSZ(node, nsize);
7237 /* Shift <lower nodes...initial part of subpage> upward */
7238 base = (char *)mp + mp->mp_upper + PAGEBASE;
7239 memmove(base + delta, base, (char *)sp + len - base);
7241 ptr = mp->mp_ptrs[indx];
7242 for (i = NUMKEYS(mp); --i >= 0; ) {
7243 if (mp->mp_ptrs[i] <= ptr)
7244 mp->mp_ptrs[i] += delta;
7246 mp->mp_upper += delta;
7249 /** Initial setup of a sorted-dups cursor.
7250 * Sorted duplicates are implemented as a sub-database for the given key.
7251 * The duplicate data items are actually keys of the sub-database.
7252 * Operations on the duplicate data items are performed using a sub-cursor
7253 * initialized when the sub-database is first accessed. This function does
7254 * the preliminary setup of the sub-cursor, filling in the fields that
7255 * depend only on the parent DB.
7256 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
7259 mdb_xcursor_init0(MDB_cursor *mc)
7261 MDB_xcursor *mx = mc->mc_xcursor;
7263 mx->mx_cursor.mc_xcursor = NULL;
7264 mx->mx_cursor.mc_txn = mc->mc_txn;
7265 mx->mx_cursor.mc_db = &mx->mx_db;
7266 mx->mx_cursor.mc_dbx = &mx->mx_dbx;
7267 mx->mx_cursor.mc_dbi = mc->mc_dbi;
7268 mx->mx_cursor.mc_dbflag = &mx->mx_dbflag;
7269 mx->mx_cursor.mc_snum = 0;
7270 mx->mx_cursor.mc_top = 0;
7271 mx->mx_cursor.mc_flags = C_SUB;
7272 mx->mx_dbx.md_name.mv_size = 0;
7273 mx->mx_dbx.md_name.mv_data = NULL;
7274 mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp;
7275 mx->mx_dbx.md_dcmp = NULL;
7276 mx->mx_dbx.md_rel = mc->mc_dbx->md_rel;
7279 /** Final setup of a sorted-dups cursor.
7280 * Sets up the fields that depend on the data from the main cursor.
7281 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
7282 * @param[in] node The data containing the #MDB_db record for the
7283 * sorted-dup database.
7286 mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)
7288 MDB_xcursor *mx = mc->mc_xcursor;
7290 if (node->mn_flags & F_SUBDATA) {
7291 memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db));
7292 mx->mx_cursor.mc_pg[0] = 0;
7293 mx->mx_cursor.mc_snum = 0;
7294 mx->mx_cursor.mc_top = 0;
7295 mx->mx_cursor.mc_flags = C_SUB;
7297 MDB_page *fp = NODEDATA(node);
7298 mx->mx_db.md_pad = 0;
7299 mx->mx_db.md_flags = 0;
7300 mx->mx_db.md_depth = 1;
7301 mx->mx_db.md_branch_pages = 0;
7302 mx->mx_db.md_leaf_pages = 1;
7303 mx->mx_db.md_overflow_pages = 0;
7304 mx->mx_db.md_entries = NUMKEYS(fp);
7305 COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno);
7306 mx->mx_cursor.mc_snum = 1;
7307 mx->mx_cursor.mc_top = 0;
7308 mx->mx_cursor.mc_flags = C_INITIALIZED|C_SUB;
7309 mx->mx_cursor.mc_pg[0] = fp;
7310 mx->mx_cursor.mc_ki[0] = 0;
7311 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
7312 mx->mx_db.md_flags = MDB_DUPFIXED;
7313 mx->mx_db.md_pad = fp->mp_pad;
7314 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
7315 mx->mx_db.md_flags |= MDB_INTEGERKEY;
7318 DPRINTF(("Sub-db -%u root page %"Z"u", mx->mx_cursor.mc_dbi,
7319 mx->mx_db.md_root));
7320 mx->mx_dbflag = DB_VALID|DB_USRVALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
7321 #if UINT_MAX < SIZE_MAX
7322 if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(size_t))
7323 mx->mx_dbx.md_cmp = mdb_cmp_clong;
7328 /** Fixup a sorted-dups cursor due to underlying update.
7329 * Sets up some fields that depend on the data from the main cursor.
7330 * Almost the same as init1, but skips initialization steps if the
7331 * xcursor had already been used.
7332 * @param[in] mc The main cursor whose sorted-dups cursor is to be fixed up.
7333 * @param[in] src_mx The xcursor of an up-to-date cursor.
7334 * @param[in] new_dupdata True if converting from a non-#F_DUPDATA item.
7337 mdb_xcursor_init2(MDB_cursor *mc, MDB_xcursor *src_mx, int new_dupdata)
7339 MDB_xcursor *mx = mc->mc_xcursor;
7342 mx->mx_cursor.mc_snum = 1;
7343 mx->mx_cursor.mc_top = 0;
7344 mx->mx_cursor.mc_flags |= C_INITIALIZED;
7345 mx->mx_cursor.mc_ki[0] = 0;
7346 mx->mx_dbflag = DB_VALID|DB_USRVALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
7347 #if UINT_MAX < SIZE_MAX
7348 mx->mx_dbx.md_cmp = src_mx->mx_dbx.md_cmp;
7350 } else if (!(mx->mx_cursor.mc_flags & C_INITIALIZED)) {
7353 mx->mx_db = src_mx->mx_db;
7354 mx->mx_cursor.mc_pg[0] = src_mx->mx_cursor.mc_pg[0];
7355 DPRINTF(("Sub-db -%u root page %"Z"u", mx->mx_cursor.mc_dbi,
7356 mx->mx_db.md_root));
7359 /** Initialize a cursor for a given transaction and database. */
7361 mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
7364 mc->mc_backup = NULL;
7367 mc->mc_db = &txn->mt_dbs[dbi];
7368 mc->mc_dbx = &txn->mt_dbxs[dbi];
7369 mc->mc_dbflag = &txn->mt_dbflags[dbi];
7375 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
7376 mdb_tassert(txn, mx != NULL);
7377 mc->mc_xcursor = mx;
7378 mdb_xcursor_init0(mc);
7380 mc->mc_xcursor = NULL;
7382 if (*mc->mc_dbflag & DB_STALE) {
7383 mdb_page_search(mc, NULL, MDB_PS_ROOTONLY);
7388 mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
7391 size_t size = sizeof(MDB_cursor);
7393 if (!ret || !TXN_DBI_EXIST(txn, dbi, DB_VALID))
7396 if (txn->mt_flags & MDB_TXN_BLOCKED)
7399 if (dbi == FREE_DBI && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
7402 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)
7403 size += sizeof(MDB_xcursor);
7405 if ((mc = malloc(size)) != NULL) {
7406 mdb_cursor_init(mc, txn, dbi, (MDB_xcursor *)(mc + 1));
7407 if (txn->mt_cursors) {
7408 mc->mc_next = txn->mt_cursors[dbi];
7409 txn->mt_cursors[dbi] = mc;
7410 mc->mc_flags |= C_UNTRACK;
7422 mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)
7424 if (!mc || !TXN_DBI_EXIST(txn, mc->mc_dbi, DB_VALID))
7427 if ((mc->mc_flags & C_UNTRACK) || txn->mt_cursors)
7430 if (txn->mt_flags & MDB_TXN_BLOCKED)
7433 mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor);
7437 /* Return the count of duplicate data items for the current key */
7439 mdb_cursor_count(MDB_cursor *mc, size_t *countp)
7443 if (mc == NULL || countp == NULL)
7446 if (mc->mc_xcursor == NULL)
7447 return MDB_INCOMPATIBLE;
7449 if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)
7452 if (!(mc->mc_flags & C_INITIALIZED))
7455 if (!mc->mc_snum || (mc->mc_flags & C_EOF))
7456 return MDB_NOTFOUND;
7458 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
7459 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
7462 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
7465 *countp = mc->mc_xcursor->mx_db.md_entries;
7471 mdb_cursor_close(MDB_cursor *mc)
7473 if (mc && !mc->mc_backup) {
7474 /* remove from txn, if tracked */
7475 if ((mc->mc_flags & C_UNTRACK) && mc->mc_txn->mt_cursors) {
7476 MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi];
7477 while (*prev && *prev != mc) prev = &(*prev)->mc_next;
7479 *prev = mc->mc_next;
7486 mdb_cursor_txn(MDB_cursor *mc)
7488 if (!mc) return NULL;
7493 mdb_cursor_dbi(MDB_cursor *mc)
7498 /** Replace the key for a branch node with a new key.
7499 * @param[in] mc Cursor pointing to the node to operate on.
7500 * @param[in] key The new key to use.
7501 * @return 0 on success, non-zero on failure.
7504 mdb_update_key(MDB_cursor *mc, MDB_val *key)
7510 int delta, ksize, oksize;
7511 indx_t ptr, i, numkeys, indx;
7514 indx = mc->mc_ki[mc->mc_top];
7515 mp = mc->mc_pg[mc->mc_top];
7516 node = NODEPTR(mp, indx);
7517 ptr = mp->mp_ptrs[indx];
7521 char kbuf2[DKBUF_MAXKEYSIZE*2+1];
7522 k2.mv_data = NODEKEY(node);
7523 k2.mv_size = node->mn_ksize;
7524 DPRINTF(("update key %u (ofs %u) [%s] to [%s] on page %"Z"u",
7526 mdb_dkey(&k2, kbuf2),
7532 /* Sizes must be 2-byte aligned. */
7533 ksize = EVEN(key->mv_size);
7534 oksize = EVEN(node->mn_ksize);
7535 delta = ksize - oksize;
7537 /* Shift node contents if EVEN(key length) changed. */
7539 if (delta > 0 && SIZELEFT(mp) < delta) {
7541 /* not enough space left, do a delete and split */
7542 DPRINTF(("Not enough room, delta = %d, splitting...", delta));
7543 pgno = NODEPGNO(node);
7544 mdb_node_del(mc, 0);
7545 return mdb_page_split(mc, key, NULL, pgno, MDB_SPLIT_REPLACE);
7548 numkeys = NUMKEYS(mp);
7549 for (i = 0; i < numkeys; i++) {
7550 if (mp->mp_ptrs[i] <= ptr)
7551 mp->mp_ptrs[i] -= delta;
7554 base = (char *)mp + mp->mp_upper + PAGEBASE;
7555 len = ptr - mp->mp_upper + NODESIZE;
7556 memmove(base - delta, base, len);
7557 mp->mp_upper -= delta;
7559 node = NODEPTR(mp, indx);
7562 /* But even if no shift was needed, update ksize */
7563 if (node->mn_ksize != key->mv_size)
7564 node->mn_ksize = key->mv_size;
7567 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
7573 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst);
7575 /** Perform \b act while tracking temporary cursor \b mn */
7576 #define WITH_CURSOR_TRACKING(mn, act) do { \
7577 MDB_cursor dummy, *tracked, **tp = &(mn).mc_txn->mt_cursors[mn.mc_dbi]; \
7578 if ((mn).mc_flags & C_SUB) { \
7579 dummy.mc_flags = C_INITIALIZED; \
7580 dummy.mc_xcursor = (MDB_xcursor *)&(mn); \
7585 tracked->mc_next = *tp; \
7588 *tp = tracked->mc_next; \
7591 /** Move a node from csrc to cdst.
7594 mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft)
7601 unsigned short flags;
7605 /* Mark src and dst as dirty. */
7606 if ((rc = mdb_page_touch(csrc)) ||
7607 (rc = mdb_page_touch(cdst)))
7610 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7611 key.mv_size = csrc->mc_db->md_pad;
7612 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
7614 data.mv_data = NULL;
7618 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]);
7619 mdb_cassert(csrc, !((size_t)srcnode & 1));
7620 srcpg = NODEPGNO(srcnode);
7621 flags = srcnode->mn_flags;
7622 if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
7623 unsigned int snum = csrc->mc_snum;
7625 /* must find the lowest key below src */
7626 rc = mdb_page_search_lowest(csrc);
7629 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7630 key.mv_size = csrc->mc_db->md_pad;
7631 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
7633 s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
7634 key.mv_size = NODEKSZ(s2);
7635 key.mv_data = NODEKEY(s2);
7637 csrc->mc_snum = snum--;
7638 csrc->mc_top = snum;
7640 key.mv_size = NODEKSZ(srcnode);
7641 key.mv_data = NODEKEY(srcnode);
7643 data.mv_size = NODEDSZ(srcnode);
7644 data.mv_data = NODEDATA(srcnode);
7646 mn.mc_xcursor = NULL;
7647 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) {
7648 unsigned int snum = cdst->mc_snum;
7651 /* must find the lowest key below dst */
7652 mdb_cursor_copy(cdst, &mn);
7653 rc = mdb_page_search_lowest(&mn);
7656 if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {
7657 bkey.mv_size = mn.mc_db->md_pad;
7658 bkey.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, bkey.mv_size);
7660 s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);
7661 bkey.mv_size = NODEKSZ(s2);
7662 bkey.mv_data = NODEKEY(s2);
7664 mn.mc_snum = snum--;
7667 rc = mdb_update_key(&mn, &bkey);
7672 DPRINTF(("moving %s node %u [%s] on page %"Z"u to node %u on page %"Z"u",
7673 IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch",
7674 csrc->mc_ki[csrc->mc_top],
7676 csrc->mc_pg[csrc->mc_top]->mp_pgno,
7677 cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno));
7679 /* Add the node to the destination page.
7681 rc = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags);
7682 if (rc != MDB_SUCCESS)
7685 /* Delete the node from the source page.
7687 mdb_node_del(csrc, key.mv_size);
7690 /* Adjust other cursors pointing to mp */
7691 MDB_cursor *m2, *m3;
7692 MDB_dbi dbi = csrc->mc_dbi;
7693 MDB_page *mpd, *mps;
7695 mps = csrc->mc_pg[csrc->mc_top];
7696 /* If we're adding on the left, bump others up */
7698 mpd = cdst->mc_pg[csrc->mc_top];
7699 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7700 if (csrc->mc_flags & C_SUB)
7701 m3 = &m2->mc_xcursor->mx_cursor;
7704 if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)
7707 m3->mc_pg[csrc->mc_top] == mpd &&
7708 m3->mc_ki[csrc->mc_top] >= cdst->mc_ki[csrc->mc_top]) {
7709 m3->mc_ki[csrc->mc_top]++;
7712 m3->mc_pg[csrc->mc_top] == mps &&
7713 m3->mc_ki[csrc->mc_top] == csrc->mc_ki[csrc->mc_top]) {
7714 m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
7715 m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
7716 m3->mc_ki[csrc->mc_top-1]++;
7718 if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
7720 MDB_node *node = NODEPTR(m3->mc_pg[csrc->mc_top], m3->mc_ki[csrc->mc_top]);
7721 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
7722 m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
7726 /* Adding on the right, bump others down */
7728 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7729 if (csrc->mc_flags & C_SUB)
7730 m3 = &m2->mc_xcursor->mx_cursor;
7733 if (m3 == csrc) continue;
7734 if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)
7736 if (m3->mc_pg[csrc->mc_top] == mps) {
7737 if (!m3->mc_ki[csrc->mc_top]) {
7738 m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
7739 m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
7740 m3->mc_ki[csrc->mc_top-1]--;
7742 m3->mc_ki[csrc->mc_top]--;
7744 if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
7746 MDB_node *node = NODEPTR(m3->mc_pg[csrc->mc_top], m3->mc_ki[csrc->mc_top]);
7747 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
7748 m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
7755 /* Update the parent separators.
7757 if (csrc->mc_ki[csrc->mc_top] == 0) {
7758 if (csrc->mc_ki[csrc->mc_top-1] != 0) {
7759 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7760 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
7762 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
7763 key.mv_size = NODEKSZ(srcnode);
7764 key.mv_data = NODEKEY(srcnode);
7766 DPRINTF(("update separator for source page %"Z"u to [%s]",
7767 csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key)));
7768 mdb_cursor_copy(csrc, &mn);
7771 /* We want mdb_rebalance to find mn when doing fixups */
7772 WITH_CURSOR_TRACKING(mn,
7773 rc = mdb_update_key(&mn, &key));
7777 if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
7779 indx_t ix = csrc->mc_ki[csrc->mc_top];
7780 nullkey.mv_size = 0;
7781 csrc->mc_ki[csrc->mc_top] = 0;
7782 rc = mdb_update_key(csrc, &nullkey);
7783 csrc->mc_ki[csrc->mc_top] = ix;
7784 mdb_cassert(csrc, rc == MDB_SUCCESS);
7788 if (cdst->mc_ki[cdst->mc_top] == 0) {
7789 if (cdst->mc_ki[cdst->mc_top-1] != 0) {
7790 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7791 key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size);
7793 srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
7794 key.mv_size = NODEKSZ(srcnode);
7795 key.mv_data = NODEKEY(srcnode);
7797 DPRINTF(("update separator for destination page %"Z"u to [%s]",
7798 cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key)));
7799 mdb_cursor_copy(cdst, &mn);
7802 /* We want mdb_rebalance to find mn when doing fixups */
7803 WITH_CURSOR_TRACKING(mn,
7804 rc = mdb_update_key(&mn, &key));
7808 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) {
7810 indx_t ix = cdst->mc_ki[cdst->mc_top];
7811 nullkey.mv_size = 0;
7812 cdst->mc_ki[cdst->mc_top] = 0;
7813 rc = mdb_update_key(cdst, &nullkey);
7814 cdst->mc_ki[cdst->mc_top] = ix;
7815 mdb_cassert(cdst, rc == MDB_SUCCESS);
7822 /** Merge one page into another.
7823 * The nodes from the page pointed to by \b csrc will
7824 * be copied to the page pointed to by \b cdst and then
7825 * the \b csrc page will be freed.
7826 * @param[in] csrc Cursor pointing to the source page.
7827 * @param[in] cdst Cursor pointing to the destination page.
7828 * @return 0 on success, non-zero on failure.
7831 mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
7833 MDB_page *psrc, *pdst;
7840 psrc = csrc->mc_pg[csrc->mc_top];
7841 pdst = cdst->mc_pg[cdst->mc_top];
7843 DPRINTF(("merging page %"Z"u into %"Z"u", psrc->mp_pgno, pdst->mp_pgno));
7845 mdb_cassert(csrc, csrc->mc_snum > 1); /* can't merge root page */
7846 mdb_cassert(csrc, cdst->mc_snum > 1);
7848 /* Mark dst as dirty. */
7849 if ((rc = mdb_page_touch(cdst)))
7852 /* get dst page again now that we've touched it. */
7853 pdst = cdst->mc_pg[cdst->mc_top];
7855 /* Move all nodes from src to dst.
7857 j = nkeys = NUMKEYS(pdst);
7858 if (IS_LEAF2(psrc)) {
7859 key.mv_size = csrc->mc_db->md_pad;
7860 key.mv_data = METADATA(psrc);
7861 for (i = 0; i < NUMKEYS(psrc); i++, j++) {
7862 rc = mdb_node_add(cdst, j, &key, NULL, 0, 0);
7863 if (rc != MDB_SUCCESS)
7865 key.mv_data = (char *)key.mv_data + key.mv_size;
7868 for (i = 0; i < NUMKEYS(psrc); i++, j++) {
7869 srcnode = NODEPTR(psrc, i);
7870 if (i == 0 && IS_BRANCH(psrc)) {
7873 mdb_cursor_copy(csrc, &mn);
7874 mn.mc_xcursor = NULL;
7875 /* must find the lowest key below src */
7876 rc = mdb_page_search_lowest(&mn);
7879 if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {
7880 key.mv_size = mn.mc_db->md_pad;
7881 key.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, key.mv_size);
7883 s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);
7884 key.mv_size = NODEKSZ(s2);
7885 key.mv_data = NODEKEY(s2);
7888 key.mv_size = srcnode->mn_ksize;
7889 key.mv_data = NODEKEY(srcnode);
7892 data.mv_size = NODEDSZ(srcnode);
7893 data.mv_data = NODEDATA(srcnode);
7894 rc = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags);
7895 if (rc != MDB_SUCCESS)
7900 DPRINTF(("dst page %"Z"u now has %u keys (%.1f%% filled)",
7901 pdst->mp_pgno, NUMKEYS(pdst),
7902 (float)PAGEFILL(cdst->mc_txn->mt_env, pdst) / 10));
7904 /* Unlink the src page from parent and add to free list.
7907 mdb_node_del(csrc, 0);
7908 if (csrc->mc_ki[csrc->mc_top] == 0) {
7910 rc = mdb_update_key(csrc, &key);
7918 psrc = csrc->mc_pg[csrc->mc_top];
7919 /* If not operating on FreeDB, allow this page to be reused
7920 * in this txn. Otherwise just add to free list.
7922 rc = mdb_page_loose(csrc, psrc);
7926 csrc->mc_db->md_leaf_pages--;
7928 csrc->mc_db->md_branch_pages--;
7930 /* Adjust other cursors pointing to mp */
7931 MDB_cursor *m2, *m3;
7932 MDB_dbi dbi = csrc->mc_dbi;
7933 unsigned int top = csrc->mc_top;
7935 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7936 if (csrc->mc_flags & C_SUB)
7937 m3 = &m2->mc_xcursor->mx_cursor;
7940 if (m3 == csrc) continue;
7941 if (m3->mc_snum < csrc->mc_snum) continue;
7942 if (m3->mc_pg[top] == psrc) {
7943 m3->mc_pg[top] = pdst;
7944 m3->mc_ki[top] += nkeys;
7945 m3->mc_ki[top-1] = cdst->mc_ki[top-1];
7946 } else if (m3->mc_pg[top-1] == csrc->mc_pg[top-1] &&
7947 m3->mc_ki[top-1] > csrc->mc_ki[top-1]) {
7950 if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
7952 MDB_node *node = NODEPTR(m3->mc_pg[top], m3->mc_ki[top]);
7953 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
7954 m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
7959 unsigned int snum = cdst->mc_snum;
7960 uint16_t depth = cdst->mc_db->md_depth;
7961 mdb_cursor_pop(cdst);
7962 rc = mdb_rebalance(cdst);
7963 /* Did the tree height change? */
7964 if (depth != cdst->mc_db->md_depth)
7965 snum += cdst->mc_db->md_depth - depth;
7966 cdst->mc_snum = snum;
7967 cdst->mc_top = snum-1;
7972 /** Copy the contents of a cursor.
7973 * @param[in] csrc The cursor to copy from.
7974 * @param[out] cdst The cursor to copy to.
7977 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst)
7981 cdst->mc_txn = csrc->mc_txn;
7982 cdst->mc_dbi = csrc->mc_dbi;
7983 cdst->mc_db = csrc->mc_db;
7984 cdst->mc_dbx = csrc->mc_dbx;
7985 cdst->mc_snum = csrc->mc_snum;
7986 cdst->mc_top = csrc->mc_top;
7987 cdst->mc_flags = csrc->mc_flags;
7989 for (i=0; i<csrc->mc_snum; i++) {
7990 cdst->mc_pg[i] = csrc->mc_pg[i];
7991 cdst->mc_ki[i] = csrc->mc_ki[i];
7995 /** Rebalance the tree after a delete operation.
7996 * @param[in] mc Cursor pointing to the page where rebalancing
7998 * @return 0 on success, non-zero on failure.
8001 mdb_rebalance(MDB_cursor *mc)
8005 unsigned int ptop, minkeys, thresh;
8009 if (IS_BRANCH(mc->mc_pg[mc->mc_top])) {
8014 thresh = FILL_THRESHOLD;
8016 DPRINTF(("rebalancing %s page %"Z"u (has %u keys, %.1f%% full)",
8017 IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",
8018 mdb_dbg_pgno(mc->mc_pg[mc->mc_top]), NUMKEYS(mc->mc_pg[mc->mc_top]),
8019 (float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10));
8021 if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= thresh &&
8022 NUMKEYS(mc->mc_pg[mc->mc_top]) >= minkeys) {
8023 DPRINTF(("no need to rebalance page %"Z"u, above fill threshold",
8024 mdb_dbg_pgno(mc->mc_pg[mc->mc_top])));
8028 if (mc->mc_snum < 2) {
8029 MDB_page *mp = mc->mc_pg[0];
8031 DPUTS("Can't rebalance a subpage, ignoring");
8034 if (NUMKEYS(mp) == 0) {
8035 DPUTS("tree is completely empty");
8036 mc->mc_db->md_root = P_INVALID;
8037 mc->mc_db->md_depth = 0;
8038 mc->mc_db->md_leaf_pages = 0;
8039 rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
8042 /* Adjust cursors pointing to mp */
8045 mc->mc_flags &= ~C_INITIALIZED;
8047 MDB_cursor *m2, *m3;
8048 MDB_dbi dbi = mc->mc_dbi;
8050 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8051 if (mc->mc_flags & C_SUB)
8052 m3 = &m2->mc_xcursor->mx_cursor;
8055 if (!(m3->mc_flags & C_INITIALIZED) || (m3->mc_snum < mc->mc_snum))
8057 if (m3->mc_pg[0] == mp) {
8060 m3->mc_flags &= ~C_INITIALIZED;
8064 } else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) {
8066 DPUTS("collapsing root page!");
8067 rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
8070 mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0));
8071 rc = mdb_page_get(mc->mc_txn,mc->mc_db->md_root,&mc->mc_pg[0],NULL);
8074 mc->mc_db->md_depth--;
8075 mc->mc_db->md_branch_pages--;
8076 mc->mc_ki[0] = mc->mc_ki[1];
8077 for (i = 1; i<mc->mc_db->md_depth; i++) {
8078 mc->mc_pg[i] = mc->mc_pg[i+1];
8079 mc->mc_ki[i] = mc->mc_ki[i+1];
8082 /* Adjust other cursors pointing to mp */
8083 MDB_cursor *m2, *m3;
8084 MDB_dbi dbi = mc->mc_dbi;
8086 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8087 if (mc->mc_flags & C_SUB)
8088 m3 = &m2->mc_xcursor->mx_cursor;
8091 if (m3 == mc) continue;
8092 if (!(m3->mc_flags & C_INITIALIZED))
8094 if (m3->mc_pg[0] == mp) {
8095 for (i=0; i<mc->mc_db->md_depth; i++) {
8096 m3->mc_pg[i] = m3->mc_pg[i+1];
8097 m3->mc_ki[i] = m3->mc_ki[i+1];
8105 DPUTS("root page doesn't need rebalancing");
8109 /* The parent (branch page) must have at least 2 pointers,
8110 * otherwise the tree is invalid.
8112 ptop = mc->mc_top-1;
8113 mdb_cassert(mc, NUMKEYS(mc->mc_pg[ptop]) > 1);
8115 /* Leaf page fill factor is below the threshold.
8116 * Try to move keys from left or right neighbor, or
8117 * merge with a neighbor page.
8122 mdb_cursor_copy(mc, &mn);
8123 mn.mc_xcursor = NULL;
8125 oldki = mc->mc_ki[mc->mc_top];
8126 if (mc->mc_ki[ptop] == 0) {
8127 /* We're the leftmost leaf in our parent.
8129 DPUTS("reading right neighbor");
8131 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
8132 rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
8135 mn.mc_ki[mn.mc_top] = 0;
8136 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);
8139 /* There is at least one neighbor to the left.
8141 DPUTS("reading left neighbor");
8143 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
8144 rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
8147 mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;
8148 mc->mc_ki[mc->mc_top] = 0;
8152 DPRINTF(("found neighbor page %"Z"u (%u keys, %.1f%% full)",
8153 mn.mc_pg[mn.mc_top]->mp_pgno, NUMKEYS(mn.mc_pg[mn.mc_top]),
8154 (float)PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) / 10));
8156 /* If the neighbor page is above threshold and has enough keys,
8157 * move one key from it. Otherwise we should try to merge them.
8158 * (A branch page must never have less than 2 keys.)
8160 if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= thresh && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) {
8161 rc = mdb_node_move(&mn, mc, fromleft);
8163 /* if we inserted on left, bump position up */
8168 rc = mdb_page_merge(&mn, mc);
8170 oldki += NUMKEYS(mn.mc_pg[mn.mc_top]);
8171 mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1;
8172 /* We want mdb_rebalance to find mn when doing fixups */
8173 WITH_CURSOR_TRACKING(mn,
8174 rc = mdb_page_merge(mc, &mn));
8175 mdb_cursor_copy(&mn, mc);
8177 mc->mc_flags &= ~C_EOF;
8179 mc->mc_ki[mc->mc_top] = oldki;
8183 /** Complete a delete operation started by #mdb_cursor_del(). */
8185 mdb_cursor_del0(MDB_cursor *mc)
8191 MDB_cursor *m2, *m3;
8192 MDB_dbi dbi = mc->mc_dbi;
8194 ki = mc->mc_ki[mc->mc_top];
8195 mp = mc->mc_pg[mc->mc_top];
8196 mdb_node_del(mc, mc->mc_db->md_pad);
8197 mc->mc_db->md_entries--;
8199 /* Adjust other cursors pointing to mp */
8200 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8201 m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;
8202 if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))
8204 if (m3 == mc || m3->mc_snum < mc->mc_snum)
8206 if (m3->mc_pg[mc->mc_top] == mp) {
8207 if (m3->mc_ki[mc->mc_top] == ki) {
8208 m3->mc_flags |= C_DEL;
8209 } else if (m3->mc_ki[mc->mc_top] > ki) {
8210 m3->mc_ki[mc->mc_top]--;
8212 if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
8213 MDB_node *node = NODEPTR(m3->mc_pg[mc->mc_top], m3->mc_ki[mc->mc_top]);
8214 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
8215 m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
8220 rc = mdb_rebalance(mc);
8222 if (rc == MDB_SUCCESS) {
8223 /* DB is totally empty now, just bail out.
8224 * Other cursors adjustments were already done
8225 * by mdb_rebalance and aren't needed here.
8230 mp = mc->mc_pg[mc->mc_top];
8231 nkeys = NUMKEYS(mp);
8233 /* Adjust other cursors pointing to mp */
8234 for (m2 = mc->mc_txn->mt_cursors[dbi]; !rc && m2; m2=m2->mc_next) {
8235 m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;
8236 if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))
8238 if (m3->mc_snum < mc->mc_snum)
8240 if (m3->mc_pg[mc->mc_top] == mp) {
8241 /* if m3 points past last node in page, find next sibling */
8242 if (m3->mc_ki[mc->mc_top] >= mc->mc_ki[mc->mc_top]) {
8243 if (m3->mc_ki[mc->mc_top] >= nkeys) {
8244 rc = mdb_cursor_sibling(m3, 1);
8245 if (rc == MDB_NOTFOUND) {
8246 m3->mc_flags |= C_EOF;
8251 if (mc->mc_db->md_flags & MDB_DUPSORT) {
8252 MDB_node *node = NODEPTR(m3->mc_pg[m3->mc_top], m3->mc_ki[m3->mc_top]);
8253 if (node->mn_flags & F_DUPDATA) {
8254 mdb_xcursor_init1(m3, node);
8255 m3->mc_xcursor->mx_cursor.mc_flags |= C_DEL;
8261 mc->mc_flags |= C_DEL;
8265 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
8270 mdb_del(MDB_txn *txn, MDB_dbi dbi,
8271 MDB_val *key, MDB_val *data)
8273 if (!key || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
8276 if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
8277 return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
8279 if (!F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
8280 /* must ignore any data */
8284 return mdb_del0(txn, dbi, key, data, 0);
8288 mdb_del0(MDB_txn *txn, MDB_dbi dbi,
8289 MDB_val *key, MDB_val *data, unsigned flags)
8294 MDB_val rdata, *xdata;
8298 DPRINTF(("====> delete db %u key [%s]", dbi, DKEY(key)));
8300 mdb_cursor_init(&mc, txn, dbi, &mx);
8309 flags |= MDB_NODUPDATA;
8311 rc = mdb_cursor_set(&mc, key, xdata, op, &exact);
8313 /* let mdb_page_split know about this cursor if needed:
8314 * delete will trigger a rebalance; if it needs to move
8315 * a node from one page to another, it will have to
8316 * update the parent's separator key(s). If the new sepkey
8317 * is larger than the current one, the parent page may
8318 * run out of space, triggering a split. We need this
8319 * cursor to be consistent until the end of the rebalance.
8321 mc.mc_flags |= C_UNTRACK;
8322 mc.mc_next = txn->mt_cursors[dbi];
8323 txn->mt_cursors[dbi] = &mc;
8324 rc = mdb_cursor_del(&mc, flags);
8325 txn->mt_cursors[dbi] = mc.mc_next;
8330 /** Split a page and insert a new node.
8331 * @param[in,out] mc Cursor pointing to the page and desired insertion index.
8332 * The cursor will be updated to point to the actual page and index where
8333 * the node got inserted after the split.
8334 * @param[in] newkey The key for the newly inserted node.
8335 * @param[in] newdata The data for the newly inserted node.
8336 * @param[in] newpgno The page number, if the new node is a branch node.
8337 * @param[in] nflags The #NODE_ADD_FLAGS for the new node.
8338 * @return 0 on success, non-zero on failure.
8341 mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno,
8342 unsigned int nflags)
8345 int rc = MDB_SUCCESS, new_root = 0, did_split = 0;
8348 int i, j, split_indx, nkeys, pmax;
8349 MDB_env *env = mc->mc_txn->mt_env;
8351 MDB_val sepkey, rkey, xdata, *rdata = &xdata;
8352 MDB_page *copy = NULL;
8353 MDB_page *mp, *rp, *pp;
8358 mp = mc->mc_pg[mc->mc_top];
8359 newindx = mc->mc_ki[mc->mc_top];
8360 nkeys = NUMKEYS(mp);
8362 DPRINTF(("-----> splitting %s page %"Z"u and adding [%s] at index %i/%i",
8363 IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno,
8364 DKEY(newkey), mc->mc_ki[mc->mc_top], nkeys));
8366 /* Create a right sibling. */
8367 if ((rc = mdb_page_new(mc, mp->mp_flags, 1, &rp)))
8369 rp->mp_pad = mp->mp_pad;
8370 DPRINTF(("new right sibling: page %"Z"u", rp->mp_pgno));
8372 /* Usually when splitting the root page, the cursor
8373 * height is 1. But when called from mdb_update_key,
8374 * the cursor height may be greater because it walks
8375 * up the stack while finding the branch slot to update.
8377 if (mc->mc_top < 1) {
8378 if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp)))
8380 /* shift current top to make room for new parent */
8381 for (i=mc->mc_snum; i>0; i--) {
8382 mc->mc_pg[i] = mc->mc_pg[i-1];
8383 mc->mc_ki[i] = mc->mc_ki[i-1];
8387 mc->mc_db->md_root = pp->mp_pgno;
8388 DPRINTF(("root split! new root = %"Z"u", pp->mp_pgno));
8389 new_root = mc->mc_db->md_depth++;
8391 /* Add left (implicit) pointer. */
8392 if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) {
8393 /* undo the pre-push */
8394 mc->mc_pg[0] = mc->mc_pg[1];
8395 mc->mc_ki[0] = mc->mc_ki[1];
8396 mc->mc_db->md_root = mp->mp_pgno;
8397 mc->mc_db->md_depth--;
8404 ptop = mc->mc_top-1;
8405 DPRINTF(("parent branch page is %"Z"u", mc->mc_pg[ptop]->mp_pgno));
8408 mdb_cursor_copy(mc, &mn);
8409 mn.mc_xcursor = NULL;
8410 mn.mc_pg[mn.mc_top] = rp;
8411 mn.mc_ki[ptop] = mc->mc_ki[ptop]+1;
8413 if (nflags & MDB_APPEND) {
8414 mn.mc_ki[mn.mc_top] = 0;
8416 split_indx = newindx;
8420 split_indx = (nkeys+1) / 2;
8425 unsigned int lsize, rsize, ksize;
8426 /* Move half of the keys to the right sibling */
8427 x = mc->mc_ki[mc->mc_top] - split_indx;
8428 ksize = mc->mc_db->md_pad;
8429 split = LEAF2KEY(mp, split_indx, ksize);
8430 rsize = (nkeys - split_indx) * ksize;
8431 lsize = (nkeys - split_indx) * sizeof(indx_t);
8432 mp->mp_lower -= lsize;
8433 rp->mp_lower += lsize;
8434 mp->mp_upper += rsize - lsize;
8435 rp->mp_upper -= rsize - lsize;
8436 sepkey.mv_size = ksize;
8437 if (newindx == split_indx) {
8438 sepkey.mv_data = newkey->mv_data;
8440 sepkey.mv_data = split;
8443 ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize);
8444 memcpy(rp->mp_ptrs, split, rsize);
8445 sepkey.mv_data = rp->mp_ptrs;
8446 memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize);
8447 memcpy(ins, newkey->mv_data, ksize);
8448 mp->mp_lower += sizeof(indx_t);
8449 mp->mp_upper -= ksize - sizeof(indx_t);
8452 memcpy(rp->mp_ptrs, split, x * ksize);
8453 ins = LEAF2KEY(rp, x, ksize);
8454 memcpy(ins, newkey->mv_data, ksize);
8455 memcpy(ins+ksize, split + x * ksize, rsize - x * ksize);
8456 rp->mp_lower += sizeof(indx_t);
8457 rp->mp_upper -= ksize - sizeof(indx_t);
8458 mc->mc_ki[mc->mc_top] = x;
8461 int psize, nsize, k;
8462 /* Maximum free space in an empty page */
8463 pmax = env->me_psize - PAGEHDRSZ;
8465 nsize = mdb_leaf_size(env, newkey, newdata);
8467 nsize = mdb_branch_size(env, newkey);
8468 nsize = EVEN(nsize);
8470 /* grab a page to hold a temporary copy */
8471 copy = mdb_page_malloc(mc->mc_txn, 1);
8476 copy->mp_pgno = mp->mp_pgno;
8477 copy->mp_flags = mp->mp_flags;
8478 copy->mp_lower = (PAGEHDRSZ-PAGEBASE);
8479 copy->mp_upper = env->me_psize - PAGEBASE;
8481 /* prepare to insert */
8482 for (i=0, j=0; i<nkeys; i++) {
8484 copy->mp_ptrs[j++] = 0;
8486 copy->mp_ptrs[j++] = mp->mp_ptrs[i];
8489 /* When items are relatively large the split point needs
8490 * to be checked, because being off-by-one will make the
8491 * difference between success or failure in mdb_node_add.
8493 * It's also relevant if a page happens to be laid out
8494 * such that one half of its nodes are all "small" and
8495 * the other half of its nodes are "large." If the new
8496 * item is also "large" and falls on the half with
8497 * "large" nodes, it also may not fit.
8499 * As a final tweak, if the new item goes on the last
8500 * spot on the page (and thus, onto the new page), bias
8501 * the split so the new page is emptier than the old page.
8502 * This yields better packing during sequential inserts.
8504 if (nkeys < 20 || nsize > pmax/16 || newindx >= nkeys) {
8505 /* Find split point */
8507 if (newindx <= split_indx || newindx >= nkeys) {
8509 k = newindx >= nkeys ? nkeys : split_indx+1+IS_LEAF(mp);
8514 for (; i!=k; i+=j) {
8519 node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);
8520 psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
8522 if (F_ISSET(node->mn_flags, F_BIGDATA))
8523 psize += sizeof(pgno_t);
8525 psize += NODEDSZ(node);
8527 psize = EVEN(psize);
8529 if (psize > pmax || i == k-j) {
8530 split_indx = i + (j<0);
8535 if (split_indx == newindx) {
8536 sepkey.mv_size = newkey->mv_size;
8537 sepkey.mv_data = newkey->mv_data;
8539 node = (MDB_node *)((char *)mp + copy->mp_ptrs[split_indx] + PAGEBASE);
8540 sepkey.mv_size = node->mn_ksize;
8541 sepkey.mv_data = NODEKEY(node);
8546 DPRINTF(("separator is %d [%s]", split_indx, DKEY(&sepkey)));
8548 /* Copy separator key to the parent.
8550 if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(env, &sepkey)) {
8551 int snum = mc->mc_snum;
8555 /* We want other splits to find mn when doing fixups */
8556 WITH_CURSOR_TRACKING(mn,
8557 rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0));
8562 if (mc->mc_snum > snum) {
8565 /* Right page might now have changed parent.
8566 * Check if left page also changed parent.
8568 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
8569 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
8570 for (i=0; i<ptop; i++) {
8571 mc->mc_pg[i] = mn.mc_pg[i];
8572 mc->mc_ki[i] = mn.mc_ki[i];
8574 mc->mc_pg[ptop] = mn.mc_pg[ptop];
8575 if (mn.mc_ki[ptop]) {
8576 mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;
8578 /* find right page's left sibling */
8579 mc->mc_ki[ptop] = mn.mc_ki[ptop];
8580 mdb_cursor_sibling(mc, 0);
8585 rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);
8588 if (rc != MDB_SUCCESS) {
8591 if (nflags & MDB_APPEND) {
8592 mc->mc_pg[mc->mc_top] = rp;
8593 mc->mc_ki[mc->mc_top] = 0;
8594 rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags);
8597 for (i=0; i<mc->mc_top; i++)
8598 mc->mc_ki[i] = mn.mc_ki[i];
8599 } else if (!IS_LEAF2(mp)) {
8601 mc->mc_pg[mc->mc_top] = rp;
8606 rkey.mv_data = newkey->mv_data;
8607 rkey.mv_size = newkey->mv_size;
8613 /* Update index for the new key. */
8614 mc->mc_ki[mc->mc_top] = j;
8616 node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);
8617 rkey.mv_data = NODEKEY(node);
8618 rkey.mv_size = node->mn_ksize;
8620 xdata.mv_data = NODEDATA(node);
8621 xdata.mv_size = NODEDSZ(node);
8624 pgno = NODEPGNO(node);
8625 flags = node->mn_flags;
8628 if (!IS_LEAF(mp) && j == 0) {
8629 /* First branch index doesn't need key data. */
8633 rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags);
8639 mc->mc_pg[mc->mc_top] = copy;
8644 } while (i != split_indx);
8646 nkeys = NUMKEYS(copy);
8647 for (i=0; i<nkeys; i++)
8648 mp->mp_ptrs[i] = copy->mp_ptrs[i];
8649 mp->mp_lower = copy->mp_lower;
8650 mp->mp_upper = copy->mp_upper;
8651 memcpy(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1),
8652 env->me_psize - copy->mp_upper - PAGEBASE);
8654 /* reset back to original page */
8655 if (newindx < split_indx) {
8656 mc->mc_pg[mc->mc_top] = mp;
8658 mc->mc_pg[mc->mc_top] = rp;
8660 /* Make sure mc_ki is still valid.
8662 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
8663 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
8664 for (i=0; i<=ptop; i++) {
8665 mc->mc_pg[i] = mn.mc_pg[i];
8666 mc->mc_ki[i] = mn.mc_ki[i];
8670 if (nflags & MDB_RESERVE) {
8671 node = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
8672 if (!(node->mn_flags & F_BIGDATA))
8673 newdata->mv_data = NODEDATA(node);
8676 if (newindx >= split_indx) {
8677 mc->mc_pg[mc->mc_top] = rp;
8679 /* Make sure mc_ki is still valid.
8681 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
8682 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
8683 for (i=0; i<=ptop; i++) {
8684 mc->mc_pg[i] = mn.mc_pg[i];
8685 mc->mc_ki[i] = mn.mc_ki[i];
8692 /* Adjust other cursors pointing to mp */
8693 MDB_cursor *m2, *m3;
8694 MDB_dbi dbi = mc->mc_dbi;
8695 nkeys = NUMKEYS(mp);
8697 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8698 if (mc->mc_flags & C_SUB)
8699 m3 = &m2->mc_xcursor->mx_cursor;
8704 if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED))
8708 /* sub cursors may be on different DB */
8709 if (m3->mc_pg[0] != mp)
8712 for (k=new_root; k>=0; k--) {
8713 m3->mc_ki[k+1] = m3->mc_ki[k];
8714 m3->mc_pg[k+1] = m3->mc_pg[k];
8716 if (m3->mc_ki[0] >= nkeys) {
8721 m3->mc_pg[0] = mc->mc_pg[0];
8725 if (m3->mc_top >= mc->mc_top && m3->mc_pg[mc->mc_top] == mp) {
8726 if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE))
8727 m3->mc_ki[mc->mc_top]++;
8728 if (m3->mc_ki[mc->mc_top] >= nkeys) {
8729 m3->mc_pg[mc->mc_top] = rp;
8730 m3->mc_ki[mc->mc_top] -= nkeys;
8731 for (i=0; i<mc->mc_top; i++) {
8732 m3->mc_ki[i] = mn.mc_ki[i];
8733 m3->mc_pg[i] = mn.mc_pg[i];
8736 } else if (!did_split && m3->mc_top >= ptop && m3->mc_pg[ptop] == mc->mc_pg[ptop] &&
8737 m3->mc_ki[ptop] >= mc->mc_ki[ptop]) {
8740 if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
8742 MDB_node *node = NODEPTR(m3->mc_pg[mc->mc_top], m3->mc_ki[mc->mc_top]);
8743 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
8744 m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
8748 DPRINTF(("mp left: %d, rp left: %d", SIZELEFT(mp), SIZELEFT(rp)));
8751 if (copy) /* tmp page */
8752 mdb_page_free(env, copy);
8754 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
8759 mdb_put(MDB_txn *txn, MDB_dbi dbi,
8760 MDB_val *key, MDB_val *data, unsigned int flags)
8766 if (!key || !data || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
8769 if (flags & ~(MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND|MDB_APPENDDUP))
8772 if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
8773 return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
8775 mdb_cursor_init(&mc, txn, dbi, &mx);
8776 mc.mc_next = txn->mt_cursors[dbi];
8777 txn->mt_cursors[dbi] = &mc;
8778 rc = mdb_cursor_put(&mc, key, data, flags);
8779 txn->mt_cursors[dbi] = mc.mc_next;
8784 #define MDB_WBUF (1024*1024)
8787 /** State needed for a compacting copy. */
8788 typedef struct mdb_copy {
8789 pthread_mutex_t mc_mutex;
8790 pthread_cond_t mc_cond;
8797 pgno_t mc_next_pgno;
8800 volatile int mc_new;
8805 /** Dedicated writer thread for compacting copy. */
8806 static THREAD_RET ESECT CALL_CONV
8807 mdb_env_copythr(void *arg)
8811 int toggle = 0, wsize, rc;
8814 #define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL)
8817 #define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0)
8820 pthread_mutex_lock(&my->mc_mutex);
8822 pthread_cond_signal(&my->mc_cond);
8825 pthread_cond_wait(&my->mc_cond, &my->mc_mutex);
8826 if (my->mc_new < 0) {
8831 wsize = my->mc_wlen[toggle];
8832 ptr = my->mc_wbuf[toggle];
8835 DO_WRITE(rc, my->mc_fd, ptr, wsize, len);
8839 } else if (len > 0) {
8853 /* If there's an overflow page tail, write it too */
8854 if (my->mc_olen[toggle]) {
8855 wsize = my->mc_olen[toggle];
8856 ptr = my->mc_over[toggle];
8857 my->mc_olen[toggle] = 0;
8860 my->mc_wlen[toggle] = 0;
8862 pthread_cond_signal(&my->mc_cond);
8864 pthread_cond_signal(&my->mc_cond);
8865 pthread_mutex_unlock(&my->mc_mutex);
8866 return (THREAD_RET)0;
8870 /** Tell the writer thread there's a buffer ready to write */
8872 mdb_env_cthr_toggle(mdb_copy *my, int st)
8874 int toggle = my->mc_toggle ^ 1;
8875 pthread_mutex_lock(&my->mc_mutex);
8876 if (my->mc_status) {
8877 pthread_mutex_unlock(&my->mc_mutex);
8878 return my->mc_status;
8880 while (my->mc_new == 1)
8881 pthread_cond_wait(&my->mc_cond, &my->mc_mutex);
8883 my->mc_toggle = toggle;
8884 pthread_cond_signal(&my->mc_cond);
8885 pthread_mutex_unlock(&my->mc_mutex);
8889 /** Depth-first tree traversal for compacting copy. */
8891 mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)
8893 MDB_cursor mc = {0};
8894 MDB_txn *txn = my->mc_txn;
8896 MDB_page *mo, *mp, *leaf;
8901 /* Empty DB, nothing to do */
8902 if (*pg == P_INVALID)
8908 rc = mdb_page_get(my->mc_txn, *pg, &mc.mc_pg[0], NULL);
8911 rc = mdb_page_search_root(&mc, NULL, MDB_PS_FIRST);
8915 /* Make cursor pages writable */
8916 buf = ptr = malloc(my->mc_env->me_psize * mc.mc_snum);
8920 for (i=0; i<mc.mc_top; i++) {
8921 mdb_page_copy((MDB_page *)ptr, mc.mc_pg[i], my->mc_env->me_psize);
8922 mc.mc_pg[i] = (MDB_page *)ptr;
8923 ptr += my->mc_env->me_psize;
8926 /* This is writable space for a leaf page. Usually not needed. */
8927 leaf = (MDB_page *)ptr;
8929 toggle = my->mc_toggle;
8930 while (mc.mc_snum > 0) {
8932 mp = mc.mc_pg[mc.mc_top];
8936 if (!IS_LEAF2(mp) && !(flags & F_DUPDATA)) {
8937 for (i=0; i<n; i++) {
8938 ni = NODEPTR(mp, i);
8939 if (ni->mn_flags & F_BIGDATA) {
8943 /* Need writable leaf */
8945 mc.mc_pg[mc.mc_top] = leaf;
8946 mdb_page_copy(leaf, mp, my->mc_env->me_psize);
8948 ni = NODEPTR(mp, i);
8951 memcpy(&pg, NODEDATA(ni), sizeof(pg));
8952 rc = mdb_page_get(txn, pg, &omp, NULL);
8955 if (my->mc_wlen[toggle] >= MDB_WBUF) {
8956 rc = mdb_env_cthr_toggle(my, 1);
8959 toggle = my->mc_toggle;
8961 mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);
8962 memcpy(mo, omp, my->mc_env->me_psize);
8963 mo->mp_pgno = my->mc_next_pgno;
8964 my->mc_next_pgno += omp->mp_pages;
8965 my->mc_wlen[toggle] += my->mc_env->me_psize;
8966 if (omp->mp_pages > 1) {
8967 my->mc_olen[toggle] = my->mc_env->me_psize * (omp->mp_pages - 1);
8968 my->mc_over[toggle] = (char *)omp + my->mc_env->me_psize;
8969 rc = mdb_env_cthr_toggle(my, 1);
8972 toggle = my->mc_toggle;
8974 memcpy(NODEDATA(ni), &mo->mp_pgno, sizeof(pgno_t));
8975 } else if (ni->mn_flags & F_SUBDATA) {
8978 /* Need writable leaf */
8980 mc.mc_pg[mc.mc_top] = leaf;
8981 mdb_page_copy(leaf, mp, my->mc_env->me_psize);
8983 ni = NODEPTR(mp, i);
8986 memcpy(&db, NODEDATA(ni), sizeof(db));
8987 my->mc_toggle = toggle;
8988 rc = mdb_env_cwalk(my, &db.md_root, ni->mn_flags & F_DUPDATA);
8991 toggle = my->mc_toggle;
8992 memcpy(NODEDATA(ni), &db, sizeof(db));
8997 mc.mc_ki[mc.mc_top]++;
8998 if (mc.mc_ki[mc.mc_top] < n) {
9001 ni = NODEPTR(mp, mc.mc_ki[mc.mc_top]);
9003 rc = mdb_page_get(txn, pg, &mp, NULL);
9008 mc.mc_ki[mc.mc_top] = 0;
9009 if (IS_BRANCH(mp)) {
9010 /* Whenever we advance to a sibling branch page,
9011 * we must proceed all the way down to its first leaf.
9013 mdb_page_copy(mc.mc_pg[mc.mc_top], mp, my->mc_env->me_psize);
9016 mc.mc_pg[mc.mc_top] = mp;
9020 if (my->mc_wlen[toggle] >= MDB_WBUF) {
9021 rc = mdb_env_cthr_toggle(my, 1);
9024 toggle = my->mc_toggle;
9026 mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);
9027 mdb_page_copy(mo, mp, my->mc_env->me_psize);
9028 mo->mp_pgno = my->mc_next_pgno++;
9029 my->mc_wlen[toggle] += my->mc_env->me_psize;
9031 /* Update parent if there is one */
9032 ni = NODEPTR(mc.mc_pg[mc.mc_top-1], mc.mc_ki[mc.mc_top-1]);
9033 SETPGNO(ni, mo->mp_pgno);
9034 mdb_cursor_pop(&mc);
9036 /* Otherwise we're done */
9046 /** Copy environment with compaction. */
9048 mdb_env_copyfd1(MDB_env *env, HANDLE fd)
9053 MDB_txn *txn = NULL;
9058 my.mc_mutex = CreateMutex(NULL, FALSE, NULL);
9059 my.mc_cond = CreateEvent(NULL, FALSE, FALSE, NULL);
9060 my.mc_wbuf[0] = _aligned_malloc(MDB_WBUF*2, env->me_os_psize);
9061 if (my.mc_wbuf[0] == NULL)
9064 pthread_mutex_init(&my.mc_mutex, NULL);
9065 pthread_cond_init(&my.mc_cond, NULL);
9066 #ifdef HAVE_MEMALIGN
9067 my.mc_wbuf[0] = memalign(env->me_os_psize, MDB_WBUF*2);
9068 if (my.mc_wbuf[0] == NULL)
9071 rc = posix_memalign((void **)&my.mc_wbuf[0], env->me_os_psize, MDB_WBUF*2);
9076 memset(my.mc_wbuf[0], 0, MDB_WBUF*2);
9077 my.mc_wbuf[1] = my.mc_wbuf[0] + MDB_WBUF;
9082 my.mc_next_pgno = NUM_METAS;
9088 THREAD_CREATE(thr, mdb_env_copythr, &my);
9090 rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
9094 mp = (MDB_page *)my.mc_wbuf[0];
9095 memset(mp, 0, NUM_METAS * env->me_psize);
9097 mp->mp_flags = P_META;
9098 mm = (MDB_meta *)METADATA(mp);
9099 mdb_env_init_meta0(env, mm);
9100 mm->mm_address = env->me_metas[0]->mm_address;
9102 mp = (MDB_page *)(my.mc_wbuf[0] + env->me_psize);
9104 mp->mp_flags = P_META;
9105 *(MDB_meta *)METADATA(mp) = *mm;
9106 mm = (MDB_meta *)METADATA(mp);
9108 /* Count the number of free pages, subtract from lastpg to find
9109 * number of active pages
9112 MDB_ID freecount = 0;
9115 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
9116 while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
9117 freecount += *(MDB_ID *)data.mv_data;
9118 freecount += txn->mt_dbs[FREE_DBI].md_branch_pages +
9119 txn->mt_dbs[FREE_DBI].md_leaf_pages +
9120 txn->mt_dbs[FREE_DBI].md_overflow_pages;
9122 /* Set metapage 1 */
9123 mm->mm_last_pg = txn->mt_next_pgno - freecount - 1;
9124 mm->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
9125 if (mm->mm_last_pg > NUM_METAS-1) {
9126 mm->mm_dbs[MAIN_DBI].md_root = mm->mm_last_pg;
9129 mm->mm_dbs[MAIN_DBI].md_root = P_INVALID;
9132 my.mc_wlen[0] = env->me_psize * NUM_METAS;
9134 pthread_mutex_lock(&my.mc_mutex);
9136 pthread_cond_wait(&my.mc_cond, &my.mc_mutex);
9137 pthread_mutex_unlock(&my.mc_mutex);
9138 rc = mdb_env_cwalk(&my, &txn->mt_dbs[MAIN_DBI].md_root, 0);
9139 if (rc == MDB_SUCCESS && my.mc_wlen[my.mc_toggle])
9140 rc = mdb_env_cthr_toggle(&my, 1);
9141 mdb_env_cthr_toggle(&my, -1);
9142 pthread_mutex_lock(&my.mc_mutex);
9144 pthread_cond_wait(&my.mc_cond, &my.mc_mutex);
9145 pthread_mutex_unlock(&my.mc_mutex);
9150 CloseHandle(my.mc_cond);
9151 CloseHandle(my.mc_mutex);
9152 _aligned_free(my.mc_wbuf[0]);
9154 pthread_cond_destroy(&my.mc_cond);
9155 pthread_mutex_destroy(&my.mc_mutex);
9156 free(my.mc_wbuf[0]);
9161 /** Copy environment as-is. */
9163 mdb_env_copyfd0(MDB_env *env, HANDLE fd)
9165 MDB_txn *txn = NULL;
9166 mdb_mutexref_t wmutex = NULL;
9172 #define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL)
9176 #define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0)
9179 /* Do the lock/unlock of the reader mutex before starting the
9180 * write txn. Otherwise other read txns could block writers.
9182 rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
9187 /* We must start the actual read txn after blocking writers */
9188 mdb_txn_end(txn, MDB_END_RESET_TMP);
9190 /* Temporarily block writers until we snapshot the meta pages */
9191 wmutex = env->me_wmutex;
9192 if (LOCK_MUTEX(rc, env, wmutex))
9195 rc = mdb_txn_renew0(txn);
9197 UNLOCK_MUTEX(wmutex);
9202 wsize = env->me_psize * NUM_METAS;
9206 DO_WRITE(rc, fd, ptr, w2, len);
9210 } else if (len > 0) {
9216 /* Non-blocking or async handles are not supported */
9222 UNLOCK_MUTEX(wmutex);
9227 w3 = txn->mt_next_pgno * env->me_psize;
9230 if ((rc = mdb_fsize(env->me_fd, &fsize)))
9237 if (wsize > MAX_WRITE)
9241 DO_WRITE(rc, fd, ptr, w2, len);
9245 } else if (len > 0) {
9262 mdb_env_copyfd2(MDB_env *env, HANDLE fd, unsigned int flags)
9264 if (flags & MDB_CP_COMPACT)
9265 return mdb_env_copyfd1(env, fd);
9267 return mdb_env_copyfd0(env, fd);
9271 mdb_env_copyfd(MDB_env *env, HANDLE fd)
9273 return mdb_env_copyfd2(env, fd, 0);
9277 mdb_env_copy2(MDB_env *env, const char *path, unsigned int flags)
9281 HANDLE newfd = INVALID_HANDLE_VALUE;
9286 if (env->me_flags & MDB_NOSUBDIR) {
9287 lpath = (char *)path;
9290 len += sizeof(DATANAME);
9291 lpath = malloc(len);
9294 sprintf(lpath, "%s" DATANAME, path);
9297 /* The destination path must exist, but the destination file must not.
9298 * We don't want the OS to cache the writes, since the source data is
9299 * already in the OS cache.
9302 rc = utf8_to_utf16(lpath, -1, &wpath, NULL);
9305 newfd = CreateFileW(wpath, GENERIC_WRITE, 0, NULL, CREATE_NEW,
9306 FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL);
9309 newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL, 0666);
9311 if (newfd == INVALID_HANDLE_VALUE) {
9316 if (env->me_psize >= env->me_os_psize) {
9318 /* Set O_DIRECT if the file system supports it */
9319 if ((rc = fcntl(newfd, F_GETFL)) != -1)
9320 (void) fcntl(newfd, F_SETFL, rc | O_DIRECT);
9322 #ifdef F_NOCACHE /* __APPLE__ */
9323 rc = fcntl(newfd, F_NOCACHE, 1);
9331 rc = mdb_env_copyfd2(env, newfd, flags);
9334 if (!(env->me_flags & MDB_NOSUBDIR))
9336 if (newfd != INVALID_HANDLE_VALUE)
9337 if (close(newfd) < 0 && rc == MDB_SUCCESS)
9344 mdb_env_copy(MDB_env *env, const char *path)
9346 return mdb_env_copy2(env, path, 0);
9350 mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)
9352 if (flag & ~CHANGEABLE)
9355 env->me_flags |= flag;
9357 env->me_flags &= ~flag;
9362 mdb_env_get_flags(MDB_env *env, unsigned int *arg)
9367 *arg = env->me_flags & (CHANGEABLE|CHANGELESS);
9372 mdb_env_set_userctx(MDB_env *env, void *ctx)
9376 env->me_userctx = ctx;
9381 mdb_env_get_userctx(MDB_env *env)
9383 return env ? env->me_userctx : NULL;
9387 mdb_env_set_assert(MDB_env *env, MDB_assert_func *func)
9392 env->me_assert_func = func;
9398 mdb_env_get_path(MDB_env *env, const char **arg)
9403 *arg = env->me_path;
9408 mdb_env_get_fd(MDB_env *env, mdb_filehandle_t *arg)
9417 /** Common code for #mdb_stat() and #mdb_env_stat().
9418 * @param[in] env the environment to operate in.
9419 * @param[in] db the #MDB_db record containing the stats to return.
9420 * @param[out] arg the address of an #MDB_stat structure to receive the stats.
9421 * @return 0, this function always succeeds.
9424 mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)
9426 arg->ms_psize = env->me_psize;
9427 arg->ms_depth = db->md_depth;
9428 arg->ms_branch_pages = db->md_branch_pages;
9429 arg->ms_leaf_pages = db->md_leaf_pages;
9430 arg->ms_overflow_pages = db->md_overflow_pages;
9431 arg->ms_entries = db->md_entries;
9437 mdb_env_stat(MDB_env *env, MDB_stat *arg)
9441 if (env == NULL || arg == NULL)
9444 meta = mdb_env_pick_meta(env);
9446 return mdb_stat0(env, &meta->mm_dbs[MAIN_DBI], arg);
9450 mdb_env_info(MDB_env *env, MDB_envinfo *arg)
9454 if (env == NULL || arg == NULL)
9457 meta = mdb_env_pick_meta(env);
9458 arg->me_mapaddr = meta->mm_address;
9459 arg->me_last_pgno = meta->mm_last_pg;
9460 arg->me_last_txnid = meta->mm_txnid;
9462 arg->me_mapsize = env->me_mapsize;
9463 arg->me_maxreaders = env->me_maxreaders;
9464 arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : 0;
9468 /** Set the default comparison functions for a database.
9469 * Called immediately after a database is opened to set the defaults.
9470 * The user can then override them with #mdb_set_compare() or
9471 * #mdb_set_dupsort().
9472 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
9473 * @param[in] dbi A database handle returned by #mdb_dbi_open()
9476 mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi)
9478 uint16_t f = txn->mt_dbs[dbi].md_flags;
9480 txn->mt_dbxs[dbi].md_cmp =
9481 (f & MDB_REVERSEKEY) ? mdb_cmp_memnr :
9482 (f & MDB_INTEGERKEY) ? mdb_cmp_cint : mdb_cmp_memn;
9484 txn->mt_dbxs[dbi].md_dcmp =
9485 !(f & MDB_DUPSORT) ? 0 :
9486 ((f & MDB_INTEGERDUP)
9487 ? ((f & MDB_DUPFIXED) ? mdb_cmp_int : mdb_cmp_cint)
9488 : ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn));
9491 int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
9497 int rc, dbflag, exact;
9498 unsigned int unused = 0, seq;
9502 if (flags & ~VALID_FLAGS)
9504 if (txn->mt_flags & MDB_TXN_BLOCKED)
9510 if (flags & PERSISTENT_FLAGS) {
9511 uint16_t f2 = flags & PERSISTENT_FLAGS;
9512 /* make sure flag changes get committed */
9513 if ((txn->mt_dbs[MAIN_DBI].md_flags | f2) != txn->mt_dbs[MAIN_DBI].md_flags) {
9514 txn->mt_dbs[MAIN_DBI].md_flags |= f2;
9515 txn->mt_flags |= MDB_TXN_DIRTY;
9518 mdb_default_cmp(txn, MAIN_DBI);
9522 if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {
9523 mdb_default_cmp(txn, MAIN_DBI);
9526 /* Is the DB already open? */
9528 for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
9529 if (!txn->mt_dbxs[i].md_name.mv_size) {
9530 /* Remember this free slot */
9531 if (!unused) unused = i;
9534 if (len == txn->mt_dbxs[i].md_name.mv_size &&
9535 !strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) {
9541 /* If no free slot and max hit, fail */
9542 if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs)
9543 return MDB_DBS_FULL;
9545 /* Cannot mix named databases with some mainDB flags */
9546 if (txn->mt_dbs[MAIN_DBI].md_flags & (MDB_DUPSORT|MDB_INTEGERKEY))
9547 return (flags & MDB_CREATE) ? MDB_INCOMPATIBLE : MDB_NOTFOUND;
9549 /* Find the DB info */
9550 dbflag = DB_NEW|DB_VALID|DB_USRVALID;
9553 key.mv_data = (void *)name;
9554 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
9555 rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact);
9556 if (rc == MDB_SUCCESS) {
9557 /* make sure this is actually a DB */
9558 MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]);
9559 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)
9560 return MDB_INCOMPATIBLE;
9561 } else if (! (rc == MDB_NOTFOUND && (flags & MDB_CREATE))) {
9565 /* Done here so we cannot fail after creating a new DB */
9566 if ((namedup = strdup(name)) == NULL)
9570 /* MDB_NOTFOUND and MDB_CREATE: Create new DB */
9571 data.mv_size = sizeof(MDB_db);
9572 data.mv_data = &dummy;
9573 memset(&dummy, 0, sizeof(dummy));
9574 dummy.md_root = P_INVALID;
9575 dummy.md_flags = flags & PERSISTENT_FLAGS;
9576 rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA);
9583 /* Got info, register DBI in this txn */
9584 unsigned int slot = unused ? unused : txn->mt_numdbs;
9585 txn->mt_dbxs[slot].md_name.mv_data = namedup;
9586 txn->mt_dbxs[slot].md_name.mv_size = len;
9587 txn->mt_dbxs[slot].md_rel = NULL;
9588 txn->mt_dbflags[slot] = dbflag;
9589 /* txn-> and env-> are the same in read txns, use
9590 * tmp variable to avoid undefined assignment
9592 seq = ++txn->mt_env->me_dbiseqs[slot];
9593 txn->mt_dbiseqs[slot] = seq;
9595 memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db));
9597 mdb_default_cmp(txn, slot);
9607 mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
9609 if (!arg || !TXN_DBI_EXIST(txn, dbi, DB_VALID))
9612 if (txn->mt_flags & MDB_TXN_BLOCKED)
9615 if (txn->mt_dbflags[dbi] & DB_STALE) {
9618 /* Stale, must read the DB's root. cursor_init does it for us. */
9619 mdb_cursor_init(&mc, txn, dbi, &mx);
9621 return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg);
9624 void mdb_dbi_close(MDB_env *env, MDB_dbi dbi)
9627 if (dbi < CORE_DBS || dbi >= env->me_maxdbs)
9629 ptr = env->me_dbxs[dbi].md_name.mv_data;
9630 /* If there was no name, this was already closed */
9632 env->me_dbxs[dbi].md_name.mv_data = NULL;
9633 env->me_dbxs[dbi].md_name.mv_size = 0;
9634 env->me_dbflags[dbi] = 0;
9635 env->me_dbiseqs[dbi]++;
9640 int mdb_dbi_flags(MDB_txn *txn, MDB_dbi dbi, unsigned int *flags)
9642 /* We could return the flags for the FREE_DBI too but what's the point? */
9643 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9645 *flags = txn->mt_dbs[dbi].md_flags & PERSISTENT_FLAGS;
9649 /** Add all the DB's pages to the free list.
9650 * @param[in] mc Cursor on the DB to free.
9651 * @param[in] subs non-Zero to check for sub-DBs in this DB.
9652 * @return 0 on success, non-zero on failure.
9655 mdb_drop0(MDB_cursor *mc, int subs)
9659 rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
9660 if (rc == MDB_SUCCESS) {
9661 MDB_txn *txn = mc->mc_txn;
9666 /* DUPSORT sub-DBs have no ovpages/DBs. Omit scanning leaves.
9667 * This also avoids any P_LEAF2 pages, which have no nodes.
9668 * Also if the DB doesn't have sub-DBs and has no overflow
9669 * pages, omit scanning leaves.
9671 if ((mc->mc_flags & C_SUB) ||
9672 (!subs && !mc->mc_db->md_overflow_pages))
9675 mdb_cursor_copy(mc, &mx);
9676 while (mc->mc_snum > 0) {
9677 MDB_page *mp = mc->mc_pg[mc->mc_top];
9678 unsigned n = NUMKEYS(mp);
9680 for (i=0; i<n; i++) {
9681 ni = NODEPTR(mp, i);
9682 if (ni->mn_flags & F_BIGDATA) {
9685 memcpy(&pg, NODEDATA(ni), sizeof(pg));
9686 rc = mdb_page_get(txn, pg, &omp, NULL);
9689 mdb_cassert(mc, IS_OVERFLOW(omp));
9690 rc = mdb_midl_append_range(&txn->mt_free_pgs,
9694 mc->mc_db->md_overflow_pages -= omp->mp_pages;
9695 if (!mc->mc_db->md_overflow_pages && !subs)
9697 } else if (subs && (ni->mn_flags & F_SUBDATA)) {
9698 mdb_xcursor_init1(mc, ni);
9699 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
9704 if (!subs && !mc->mc_db->md_overflow_pages)
9707 if ((rc = mdb_midl_need(&txn->mt_free_pgs, n)) != 0)
9709 for (i=0; i<n; i++) {
9711 ni = NODEPTR(mp, i);
9714 mdb_midl_xappend(txn->mt_free_pgs, pg);
9719 mc->mc_ki[mc->mc_top] = i;
9720 rc = mdb_cursor_sibling(mc, 1);
9722 if (rc != MDB_NOTFOUND)
9724 /* no more siblings, go back to beginning
9725 * of previous level.
9730 for (i=1; i<mc->mc_snum; i++) {
9732 mc->mc_pg[i] = mx.mc_pg[i];
9737 rc = mdb_midl_append(&txn->mt_free_pgs, mc->mc_db->md_root);
9740 txn->mt_flags |= MDB_TXN_ERROR;
9741 } else if (rc == MDB_NOTFOUND) {
9744 mc->mc_flags &= ~C_INITIALIZED;
9748 int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)
9750 MDB_cursor *mc, *m2;
9753 if ((unsigned)del > 1 || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9756 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
9759 if (TXN_DBI_CHANGED(txn, dbi))
9762 rc = mdb_cursor_open(txn, dbi, &mc);
9766 rc = mdb_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT);
9767 /* Invalidate the dropped DB's cursors */
9768 for (m2 = txn->mt_cursors[dbi]; m2; m2 = m2->mc_next)
9769 m2->mc_flags &= ~(C_INITIALIZED|C_EOF);
9773 /* Can't delete the main DB */
9774 if (del && dbi >= CORE_DBS) {
9775 rc = mdb_del0(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL, F_SUBDATA);
9777 txn->mt_dbflags[dbi] = DB_STALE;
9778 mdb_dbi_close(txn->mt_env, dbi);
9780 txn->mt_flags |= MDB_TXN_ERROR;
9783 /* reset the DB record, mark it dirty */
9784 txn->mt_dbflags[dbi] |= DB_DIRTY;
9785 txn->mt_dbs[dbi].md_depth = 0;
9786 txn->mt_dbs[dbi].md_branch_pages = 0;
9787 txn->mt_dbs[dbi].md_leaf_pages = 0;
9788 txn->mt_dbs[dbi].md_overflow_pages = 0;
9789 txn->mt_dbs[dbi].md_entries = 0;
9790 txn->mt_dbs[dbi].md_root = P_INVALID;
9792 txn->mt_flags |= MDB_TXN_DIRTY;
9795 mdb_cursor_close(mc);
9799 int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
9801 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9804 txn->mt_dbxs[dbi].md_cmp = cmp;
9808 int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
9810 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9813 txn->mt_dbxs[dbi].md_dcmp = cmp;
9817 int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
9819 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9822 txn->mt_dbxs[dbi].md_rel = rel;
9826 int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx)
9828 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9831 txn->mt_dbxs[dbi].md_relctx = ctx;
9836 mdb_env_get_maxkeysize(MDB_env *env)
9838 return ENV_MAXKEY(env);
9842 mdb_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx)
9844 unsigned int i, rdrs;
9847 int rc = 0, first = 1;
9851 if (!env->me_txns) {
9852 return func("(no reader locks)\n", ctx);
9854 rdrs = env->me_txns->mti_numreaders;
9855 mr = env->me_txns->mti_readers;
9856 for (i=0; i<rdrs; i++) {
9858 txnid_t txnid = mr[i].mr_txnid;
9859 sprintf(buf, txnid == (txnid_t)-1 ?
9860 "%10d %"Z"x -\n" : "%10d %"Z"x %"Z"u\n",
9861 (int)mr[i].mr_pid, (size_t)mr[i].mr_tid, txnid);
9864 rc = func(" pid thread txnid\n", ctx);
9868 rc = func(buf, ctx);
9874 rc = func("(no active readers)\n", ctx);
9879 /** Insert pid into list if not already present.
9880 * return -1 if already present.
9883 mdb_pid_insert(MDB_PID_T *ids, MDB_PID_T pid)
9885 /* binary search of pid in list */
9887 unsigned cursor = 1;
9889 unsigned n = ids[0];
9892 unsigned pivot = n >> 1;
9893 cursor = base + pivot + 1;
9894 val = pid - ids[cursor];
9899 } else if ( val > 0 ) {
9904 /* found, so it's a duplicate */
9913 for (n = ids[0]; n > cursor; n--)
9920 mdb_reader_check(MDB_env *env, int *dead)
9926 return env->me_txns ? mdb_reader_check0(env, 0, dead) : MDB_SUCCESS;
9929 /** As #mdb_reader_check(). rlocked = <caller locked the reader mutex>. */
9931 mdb_reader_check0(MDB_env *env, int rlocked, int *dead)
9933 mdb_mutexref_t rmutex = rlocked ? NULL : env->me_rmutex;
9934 unsigned int i, j, rdrs;
9936 MDB_PID_T *pids, pid;
9937 int rc = MDB_SUCCESS, count = 0;
9939 rdrs = env->me_txns->mti_numreaders;
9940 pids = malloc((rdrs+1) * sizeof(MDB_PID_T));
9944 mr = env->me_txns->mti_readers;
9945 for (i=0; i<rdrs; i++) {
9947 if (pid && pid != env->me_pid) {
9948 if (mdb_pid_insert(pids, pid) == 0) {
9949 if (!mdb_reader_pid(env, Pidcheck, pid)) {
9950 /* Stale reader found */
9953 if ((rc = LOCK_MUTEX0(rmutex)) != 0) {
9954 if ((rc = mdb_mutex_failed(env, rmutex, rc)))
9956 rdrs = 0; /* the above checked all readers */
9958 /* Recheck, a new process may have reused pid */
9959 if (mdb_reader_pid(env, Pidcheck, pid))
9964 if (mr[j].mr_pid == pid) {
9965 DPRINTF(("clear stale reader pid %u txn %"Z"d",
9966 (unsigned) pid, mr[j].mr_txnid));
9971 UNLOCK_MUTEX(rmutex);
9982 #ifdef MDB_ROBUST_SUPPORTED
9983 /** Handle #LOCK_MUTEX0() failure.
9984 * Try to repair the lock file if the mutex owner died.
9985 * @param[in] env the environment handle
9986 * @param[in] mutex LOCK_MUTEX0() mutex
9987 * @param[in] rc LOCK_MUTEX0() error (nonzero)
9988 * @return 0 on success with the mutex locked, or an error code on failure.
9991 mdb_mutex_failed(MDB_env *env, mdb_mutexref_t mutex, int rc)
9996 if (rc == MDB_OWNERDEAD) {
9997 /* We own the mutex. Clean up after dead previous owner. */
9999 rlocked = (mutex == env->me_rmutex);
10001 /* Keep mti_txnid updated, otherwise next writer can
10002 * overwrite data which latest meta page refers to.
10004 meta = mdb_env_pick_meta(env);
10005 env->me_txns->mti_txnid = meta->mm_txnid;
10006 /* env is hosed if the dead thread was ours */
10008 env->me_flags |= MDB_FATAL_ERROR;
10009 env->me_txn = NULL;
10013 DPRINTF(("%cmutex owner died, %s", (rlocked ? 'r' : 'w'),
10014 (rc ? "this process' env is hosed" : "recovering")));
10015 rc2 = mdb_reader_check0(env, rlocked, NULL);
10017 rc2 = mdb_mutex_consistent(mutex);
10018 if (rc || (rc = rc2)) {
10019 DPRINTF(("LOCK_MUTEX recovery failed, %s", mdb_strerror(rc)));
10020 UNLOCK_MUTEX(mutex);
10026 DPRINTF(("LOCK_MUTEX failed, %s", mdb_strerror(rc)));
10031 #endif /* MDB_ROBUST_SUPPORTED */
10034 #if defined(_WIN32)
10035 static int utf8_to_utf16(const char *src, int srcsize, wchar_t **dst, int *dstsize)
10039 need = MultiByteToWideChar(CP_UTF8, 0, src, srcsize, NULL, 0);
10040 if (need == 0xFFFD)
10044 result = malloc(sizeof(wchar_t) * need);
10047 MultiByteToWideChar(CP_UTF8, 0, src, srcsize, result, need);
10053 #endif /* defined(_WIN32) */
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