2 * @brief Lightning memory-mapped database library
4 * A Btree-based database management library modeled loosely on the
5 * BerkeleyDB API, but much simplified.
8 * Copyright 2011-2015 Howard Chu, Symas Corp.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted only as authorized by the OpenLDAP
15 * A copy of this license is available in the file LICENSE in the
16 * top-level directory of the distribution or, alternatively, at
17 * <http://www.OpenLDAP.org/license.html>.
19 * This code is derived from btree.c written by Martin Hedenfalk.
21 * Copyright (c) 2009, 2010 Martin Hedenfalk <martin@bzero.se>
23 * Permission to use, copy, modify, and distribute this software for any
24 * purpose with or without fee is hereby granted, provided that the above
25 * copyright notice and this permission notice appear in all copies.
27 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
28 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
29 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
30 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
31 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
32 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
33 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
41 /** getpid() returns int; MinGW defines pid_t but MinGW64 typedefs it
42 * as int64 which is wrong. MSVC doesn't define it at all, so just
46 #define MDB_THR_T DWORD
47 #include <sys/types.h>
50 # include <sys/param.h>
52 # define LITTLE_ENDIAN 1234
53 # define BIG_ENDIAN 4321
54 # define BYTE_ORDER LITTLE_ENDIAN
56 # define SSIZE_MAX INT_MAX
60 #include <sys/types.h>
62 #define MDB_PID_T pid_t
63 #define MDB_THR_T pthread_t
64 #include <sys/param.h>
67 #ifdef HAVE_SYS_FILE_H
73 #if defined(__mips) && defined(__linux)
74 /* MIPS has cache coherency issues, requires explicit cache control */
75 #include <asm/cachectl.h>
76 extern int cacheflush(char *addr, int nbytes, int cache);
77 #define CACHEFLUSH(addr, bytes, cache) cacheflush(addr, bytes, cache)
79 #define CACHEFLUSH(addr, bytes, cache)
82 #if defined(__linux) && !defined(MDB_FDATASYNC_WORKS)
83 /** fdatasync is broken on ext3/ext4fs on older kernels, see
84 * description in #mdb_env_open2 comments. You can safely
85 * define MDB_FDATASYNC_WORKS if this code will only be run
86 * on kernels 3.6 and newer.
88 #define BROKEN_FDATASYNC
102 typedef SSIZE_T ssize_t;
107 #if defined(__sun) || defined(ANDROID)
108 /* Most platforms have posix_memalign, older may only have memalign */
109 #define HAVE_MEMALIGN 1
113 #if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER))
114 #include <netinet/in.h>
115 #include <resolv.h> /* defines BYTE_ORDER on HPUX and Solaris */
118 #if defined(__APPLE__) || defined (BSD)
119 # if !(defined(MDB_USE_POSIX_MUTEX) || defined(MDB_USE_POSIX_SEM))
120 # define MDB_USE_SYSV_SEM 1
122 # define MDB_FDATASYNC fsync
123 #elif defined(ANDROID)
124 # define MDB_FDATASYNC fsync
129 #ifdef MDB_USE_POSIX_SEM
130 # define MDB_USE_HASH 1
131 #include <semaphore.h>
132 #elif defined(MDB_USE_SYSV_SEM)
135 #ifdef _SEM_SEMUN_UNDEFINED
138 struct semid_ds *buf;
139 unsigned short *array;
141 #endif /* _SEM_SEMUN_UNDEFINED */
143 #define MDB_USE_POSIX_MUTEX 1
144 #endif /* MDB_USE_POSIX_SEM */
147 #if defined(_WIN32) + defined(MDB_USE_POSIX_SEM) + defined(MDB_USE_SYSV_SEM) \
148 + defined(MDB_USE_POSIX_MUTEX) != 1
149 # error "Ambiguous shared-lock implementation"
153 #include <valgrind/memcheck.h>
154 #define VGMEMP_CREATE(h,r,z) VALGRIND_CREATE_MEMPOOL(h,r,z)
155 #define VGMEMP_ALLOC(h,a,s) VALGRIND_MEMPOOL_ALLOC(h,a,s)
156 #define VGMEMP_FREE(h,a) VALGRIND_MEMPOOL_FREE(h,a)
157 #define VGMEMP_DESTROY(h) VALGRIND_DESTROY_MEMPOOL(h)
158 #define VGMEMP_DEFINED(a,s) VALGRIND_MAKE_MEM_DEFINED(a,s)
160 #define VGMEMP_CREATE(h,r,z)
161 #define VGMEMP_ALLOC(h,a,s)
162 #define VGMEMP_FREE(h,a)
163 #define VGMEMP_DESTROY(h)
164 #define VGMEMP_DEFINED(a,s)
168 # if (defined(_LITTLE_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN))
169 /* Solaris just defines one or the other */
170 # define LITTLE_ENDIAN 1234
171 # define BIG_ENDIAN 4321
172 # ifdef _LITTLE_ENDIAN
173 # define BYTE_ORDER LITTLE_ENDIAN
175 # define BYTE_ORDER BIG_ENDIAN
178 # define BYTE_ORDER __BYTE_ORDER
182 #ifndef LITTLE_ENDIAN
183 #define LITTLE_ENDIAN __LITTLE_ENDIAN
186 #define BIG_ENDIAN __BIG_ENDIAN
189 #if defined(__i386) || defined(__x86_64) || defined(_M_IX86)
190 #define MISALIGNED_OK 1
196 #if (BYTE_ORDER == LITTLE_ENDIAN) == (BYTE_ORDER == BIG_ENDIAN)
197 # error "Unknown or unsupported endianness (BYTE_ORDER)"
198 #elif (-6 & 5) || CHAR_BIT != 8 || UINT_MAX < 0xffffffff || ULONG_MAX % 0xFFFF
199 # error "Two's complement, reasonably sized integer types, please"
203 /** Put infrequently used env functions in separate section */
205 # define ESECT __attribute__ ((section("__TEXT,text_env")))
207 # define ESECT __attribute__ ((section("text_env")))
214 #define CALL_CONV WINAPI
219 /** @defgroup internal LMDB Internals
222 /** @defgroup compat Compatibility Macros
223 * A bunch of macros to minimize the amount of platform-specific ifdefs
224 * needed throughout the rest of the code. When the features this library
225 * needs are similar enough to POSIX to be hidden in a one-or-two line
226 * replacement, this macro approach is used.
230 /** Features under development */
235 /** Wrapper around __func__, which is a C99 feature */
236 #if __STDC_VERSION__ >= 199901L
237 # define mdb_func_ __func__
238 #elif __GNUC__ >= 2 || _MSC_VER >= 1300
239 # define mdb_func_ __FUNCTION__
241 /* If a debug message says <mdb_unknown>(), update the #if statements above */
242 # define mdb_func_ "<mdb_unknown>"
245 /* Internal error codes, not exposed outside liblmdb */
246 #define MDB_NO_ROOT (MDB_LAST_ERRCODE + 10)
248 #define MDB_OWNERDEAD ((int) WAIT_ABANDONED)
249 #elif defined MDB_USE_SYSV_SEM
250 #define MDB_OWNERDEAD (MDB_LAST_ERRCODE + 11)
251 #elif defined(MDB_USE_POSIX_MUTEX) && defined(EOWNERDEAD)
252 #define MDB_OWNERDEAD EOWNERDEAD /**< #LOCK_MUTEX0() result if dead owner */
256 #define GLIBC_VER ((__GLIBC__ << 16 )| __GLIBC_MINOR__)
258 /** Some platforms define the EOWNERDEAD error code
259 * even though they don't support Robust Mutexes.
260 * Compile with -DMDB_USE_ROBUST=0, or use some other
261 * mechanism like -DMDB_USE_SYSV_SEM instead of
262 * -DMDB_USE_POSIX_MUTEX. (SysV semaphores are
263 * also Robust, but some systems don't support them
266 #ifndef MDB_USE_ROBUST
267 /* Android currently lacks Robust Mutex support. So does glibc < 2.4. */
268 # if defined(MDB_USE_POSIX_MUTEX) && (defined(ANDROID) || \
269 (defined(__GLIBC__) && GLIBC_VER < 0x020004))
270 # define MDB_USE_ROBUST 0
272 # define MDB_USE_ROBUST 1
273 /* glibc < 2.10 only provided _np API */
274 # if defined(__GLIBC__) && GLIBC_VER < 0x02000a
275 # define PTHREAD_MUTEX_ROBUST PTHREAD_MUTEX_ROBUST_NP
276 # define pthread_mutexattr_setrobust(attr, flag) pthread_mutexattr_setrobust_np(attr, flag)
277 # define pthread_mutex_consistent(mutex) pthread_mutex_consistent_np(mutex)
280 #endif /* MDB_USE_ROBUST */
282 #if defined(MDB_OWNERDEAD) && MDB_USE_ROBUST
283 #define MDB_ROBUST_SUPPORTED 1
287 #define MDB_USE_HASH 1
288 #define MDB_PIDLOCK 0
289 #define THREAD_RET DWORD
290 #define pthread_t HANDLE
291 #define pthread_mutex_t HANDLE
292 #define pthread_cond_t HANDLE
293 typedef HANDLE mdb_mutex_t, mdb_mutexref_t;
294 #define pthread_key_t DWORD
295 #define pthread_self() GetCurrentThreadId()
296 #define pthread_key_create(x,y) \
297 ((*(x) = TlsAlloc()) == TLS_OUT_OF_INDEXES ? ErrCode() : 0)
298 #define pthread_key_delete(x) TlsFree(x)
299 #define pthread_getspecific(x) TlsGetValue(x)
300 #define pthread_setspecific(x,y) (TlsSetValue(x,y) ? 0 : ErrCode())
301 #define pthread_mutex_unlock(x) ReleaseMutex(*x)
302 #define pthread_mutex_lock(x) WaitForSingleObject(*x, INFINITE)
303 #define pthread_cond_signal(x) SetEvent(*x)
304 #define pthread_cond_wait(cond,mutex) do{SignalObjectAndWait(*mutex, *cond, INFINITE, FALSE); WaitForSingleObject(*mutex, INFINITE);}while(0)
305 #define THREAD_CREATE(thr,start,arg) thr=CreateThread(NULL,0,start,arg,0,NULL)
306 #define THREAD_FINISH(thr) WaitForSingleObject(thr, INFINITE)
307 #define LOCK_MUTEX0(mutex) WaitForSingleObject(mutex, INFINITE)
308 #define UNLOCK_MUTEX(mutex) ReleaseMutex(mutex)
309 #define mdb_mutex_consistent(mutex) 0
310 #define getpid() GetCurrentProcessId()
311 #define MDB_FDATASYNC(fd) (!FlushFileBuffers(fd))
312 #define MDB_MSYNC(addr,len,flags) (!FlushViewOfFile(addr,len))
313 #define ErrCode() GetLastError()
314 #define GET_PAGESIZE(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;}
315 #define close(fd) (CloseHandle(fd) ? 0 : -1)
316 #define munmap(ptr,len) UnmapViewOfFile(ptr)
317 #ifdef PROCESS_QUERY_LIMITED_INFORMATION
318 #define MDB_PROCESS_QUERY_LIMITED_INFORMATION PROCESS_QUERY_LIMITED_INFORMATION
320 #define MDB_PROCESS_QUERY_LIMITED_INFORMATION 0x1000
324 #define THREAD_RET void *
325 #define THREAD_CREATE(thr,start,arg) pthread_create(&thr,NULL,start,arg)
326 #define THREAD_FINISH(thr) pthread_join(thr,NULL)
327 #define Z "z" /**< printf format modifier for size_t */
329 /** For MDB_LOCK_FORMAT: True if readers take a pid lock in the lockfile */
330 #define MDB_PIDLOCK 1
332 #ifdef MDB_USE_POSIX_SEM
334 typedef sem_t *mdb_mutex_t, *mdb_mutexref_t;
335 #define LOCK_MUTEX0(mutex) mdb_sem_wait(mutex)
336 #define UNLOCK_MUTEX(mutex) sem_post(mutex)
339 mdb_sem_wait(sem_t *sem)
342 while ((rc = sem_wait(sem)) && (rc = errno) == EINTR) ;
346 #elif defined MDB_USE_SYSV_SEM
348 typedef struct mdb_mutex {
352 } mdb_mutex_t[1], *mdb_mutexref_t;
354 #define LOCK_MUTEX0(mutex) mdb_sem_wait(mutex)
355 #define UNLOCK_MUTEX(mutex) do { \
356 struct sembuf sb = { 0, 1, SEM_UNDO }; \
357 sb.sem_num = (mutex)->semnum; \
358 *(mutex)->locked = 0; \
359 semop((mutex)->semid, &sb, 1); \
363 mdb_sem_wait(mdb_mutexref_t sem)
365 int rc, *locked = sem->locked;
366 struct sembuf sb = { 0, -1, SEM_UNDO };
367 sb.sem_num = sem->semnum;
369 if (!semop(sem->semid, &sb, 1)) {
370 rc = *locked ? MDB_OWNERDEAD : MDB_SUCCESS;
374 } while ((rc = errno) == EINTR);
378 #define mdb_mutex_consistent(mutex) 0
380 #else /* MDB_USE_POSIX_MUTEX: */
381 /** Shared mutex/semaphore as it is stored (mdb_mutex_t), and as
382 * local variables keep it (mdb_mutexref_t).
384 * An mdb_mutex_t can be assigned to an mdb_mutexref_t. They can
385 * be the same, or an array[size 1] and a pointer.
388 typedef pthread_mutex_t mdb_mutex_t[1], *mdb_mutexref_t;
390 /** Lock the reader or writer mutex.
391 * Returns 0 or a code to give #mdb_mutex_failed(), as in #LOCK_MUTEX().
393 #define LOCK_MUTEX0(mutex) pthread_mutex_lock(mutex)
394 /** Unlock the reader or writer mutex.
396 #define UNLOCK_MUTEX(mutex) pthread_mutex_unlock(mutex)
397 /** Mark mutex-protected data as repaired, after death of previous owner.
399 #define mdb_mutex_consistent(mutex) pthread_mutex_consistent(mutex)
400 #endif /* MDB_USE_POSIX_SEM || MDB_USE_SYSV_SEM */
402 /** Get the error code for the last failed system function.
404 #define ErrCode() errno
406 /** An abstraction for a file handle.
407 * On POSIX systems file handles are small integers. On Windows
408 * they're opaque pointers.
412 /** A value for an invalid file handle.
413 * Mainly used to initialize file variables and signify that they are
416 #define INVALID_HANDLE_VALUE (-1)
418 /** Get the size of a memory page for the system.
419 * This is the basic size that the platform's memory manager uses, and is
420 * fundamental to the use of memory-mapped files.
422 #define GET_PAGESIZE(x) ((x) = sysconf(_SC_PAGE_SIZE))
425 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
427 #elif defined(MDB_USE_SYSV_SEM)
428 #define MNAME_LEN (sizeof(int))
430 #define MNAME_LEN (sizeof(pthread_mutex_t))
433 #ifdef MDB_USE_SYSV_SEM
434 #define SYSV_SEM_FLAG 1 /**< SysV sems in lockfile format */
436 #define SYSV_SEM_FLAG 0
441 #ifdef MDB_ROBUST_SUPPORTED
442 /** Lock mutex, handle any error, set rc = result.
443 * Return 0 on success, nonzero (not rc) on error.
445 #define LOCK_MUTEX(rc, env, mutex) \
446 (((rc) = LOCK_MUTEX0(mutex)) && \
447 ((rc) = mdb_mutex_failed(env, mutex, rc)))
448 static int mdb_mutex_failed(MDB_env *env, mdb_mutexref_t mutex, int rc);
450 #define LOCK_MUTEX(rc, env, mutex) ((rc) = LOCK_MUTEX0(mutex))
451 #define mdb_mutex_failed(env, mutex, rc) (rc)
455 /** A flag for opening a file and requesting synchronous data writes.
456 * This is only used when writing a meta page. It's not strictly needed;
457 * we could just do a normal write and then immediately perform a flush.
458 * But if this flag is available it saves us an extra system call.
460 * @note If O_DSYNC is undefined but exists in /usr/include,
461 * preferably set some compiler flag to get the definition.
465 # define MDB_DSYNC O_DSYNC
467 # define MDB_DSYNC O_SYNC
472 /** Function for flushing the data of a file. Define this to fsync
473 * if fdatasync() is not supported.
475 #ifndef MDB_FDATASYNC
476 # define MDB_FDATASYNC fdatasync
480 # define MDB_MSYNC(addr,len,flags) msync(addr,len,flags)
491 /** A page number in the database.
492 * Note that 64 bit page numbers are overkill, since pages themselves
493 * already represent 12-13 bits of addressable memory, and the OS will
494 * always limit applications to a maximum of 63 bits of address space.
496 * @note In the #MDB_node structure, we only store 48 bits of this value,
497 * which thus limits us to only 60 bits of addressable data.
499 typedef MDB_ID pgno_t;
501 /** A transaction ID.
502 * See struct MDB_txn.mt_txnid for details.
504 typedef MDB_ID txnid_t;
506 /** @defgroup debug Debug Macros
510 /** Enable debug output. Needs variable argument macros (a C99 feature).
511 * Set this to 1 for copious tracing. Set to 2 to add dumps of all IDLs
512 * read from and written to the database (used for free space management).
518 static int mdb_debug;
519 static txnid_t mdb_debug_start;
521 /** Print a debug message with printf formatting.
522 * Requires double parenthesis around 2 or more args.
524 # define DPRINTF(args) ((void) ((mdb_debug) && DPRINTF0 args))
525 # define DPRINTF0(fmt, ...) \
526 fprintf(stderr, "%s:%d " fmt "\n", mdb_func_, __LINE__, __VA_ARGS__)
528 # define DPRINTF(args) ((void) 0)
530 /** Print a debug string.
531 * The string is printed literally, with no format processing.
533 #define DPUTS(arg) DPRINTF(("%s", arg))
534 /** Debuging output value of a cursor DBI: Negative in a sub-cursor. */
536 (((mc)->mc_flags & C_SUB) ? -(int)(mc)->mc_dbi : (int)(mc)->mc_dbi)
539 /** @brief The maximum size of a database page.
541 * It is 32k or 64k, since value-PAGEBASE must fit in
542 * #MDB_page.%mp_upper.
544 * LMDB will use database pages < OS pages if needed.
545 * That causes more I/O in write transactions: The OS must
546 * know (read) the whole page before writing a partial page.
548 * Note that we don't currently support Huge pages. On Linux,
549 * regular data files cannot use Huge pages, and in general
550 * Huge pages aren't actually pageable. We rely on the OS
551 * demand-pager to read our data and page it out when memory
552 * pressure from other processes is high. So until OSs have
553 * actual paging support for Huge pages, they're not viable.
555 #define MAX_PAGESIZE (PAGEBASE ? 0x10000 : 0x8000)
557 /** The minimum number of keys required in a database page.
558 * Setting this to a larger value will place a smaller bound on the
559 * maximum size of a data item. Data items larger than this size will
560 * be pushed into overflow pages instead of being stored directly in
561 * the B-tree node. This value used to default to 4. With a page size
562 * of 4096 bytes that meant that any item larger than 1024 bytes would
563 * go into an overflow page. That also meant that on average 2-3KB of
564 * each overflow page was wasted space. The value cannot be lower than
565 * 2 because then there would no longer be a tree structure. With this
566 * value, items larger than 2KB will go into overflow pages, and on
567 * average only 1KB will be wasted.
569 #define MDB_MINKEYS 2
571 /** A stamp that identifies a file as an LMDB file.
572 * There's nothing special about this value other than that it is easily
573 * recognizable, and it will reflect any byte order mismatches.
575 #define MDB_MAGIC 0xBEEFC0DE
577 /** The version number for a database's datafile format. */
578 #define MDB_DATA_VERSION ((MDB_DEVEL) ? 999 : 1)
579 /** The version number for a database's lockfile format. */
580 #define MDB_LOCK_VERSION ((MDB_DEVEL) ? 999 : 1)
582 /** @brief The max size of a key we can write, or 0 for computed max.
584 * This macro should normally be left alone or set to 0.
585 * Note that a database with big keys or dupsort data cannot be
586 * reliably modified by a liblmdb which uses a smaller max.
587 * The default is 511 for backwards compat, or 0 when #MDB_DEVEL.
589 * Other values are allowed, for backwards compat. However:
590 * A value bigger than the computed max can break if you do not
591 * know what you are doing, and liblmdb <= 0.9.10 can break when
592 * modifying a DB with keys/dupsort data bigger than its max.
594 * Data items in an #MDB_DUPSORT database are also limited to
595 * this size, since they're actually keys of a sub-DB. Keys and
596 * #MDB_DUPSORT data items must fit on a node in a regular page.
598 #ifndef MDB_MAXKEYSIZE
599 #define MDB_MAXKEYSIZE ((MDB_DEVEL) ? 0 : 511)
602 /** The maximum size of a key we can write to the environment. */
604 #define ENV_MAXKEY(env) (MDB_MAXKEYSIZE)
606 #define ENV_MAXKEY(env) ((env)->me_maxkey)
609 /** @brief The maximum size of a data item.
611 * We only store a 32 bit value for node sizes.
613 #define MAXDATASIZE 0xffffffffUL
616 /** Key size which fits in a #DKBUF.
619 #define DKBUF_MAXKEYSIZE ((MDB_MAXKEYSIZE) > 0 ? (MDB_MAXKEYSIZE) : 511)
622 * This is used for printing a hex dump of a key's contents.
624 #define DKBUF char kbuf[DKBUF_MAXKEYSIZE*2+1]
625 /** Display a key in hex.
627 * Invoke a function to display a key in hex.
629 #define DKEY(x) mdb_dkey(x, kbuf)
635 /** An invalid page number.
636 * Mainly used to denote an empty tree.
638 #define P_INVALID (~(pgno_t)0)
640 /** Test if the flags \b f are set in a flag word \b w. */
641 #define F_ISSET(w, f) (((w) & (f)) == (f))
643 /** Round \b n up to an even number. */
644 #define EVEN(n) (((n) + 1U) & -2) /* sign-extending -2 to match n+1U */
646 /** Used for offsets within a single page.
647 * Since memory pages are typically 4 or 8KB in size, 12-13 bits,
650 typedef uint16_t indx_t;
652 /** Default size of memory map.
653 * This is certainly too small for any actual applications. Apps should always set
654 * the size explicitly using #mdb_env_set_mapsize().
656 #define DEFAULT_MAPSIZE 1048576
658 /** @defgroup readers Reader Lock Table
659 * Readers don't acquire any locks for their data access. Instead, they
660 * simply record their transaction ID in the reader table. The reader
661 * mutex is needed just to find an empty slot in the reader table. The
662 * slot's address is saved in thread-specific data so that subsequent read
663 * transactions started by the same thread need no further locking to proceed.
665 * If #MDB_NOTLS is set, the slot address is not saved in thread-specific data.
667 * No reader table is used if the database is on a read-only filesystem, or
668 * if #MDB_NOLOCK is set.
670 * Since the database uses multi-version concurrency control, readers don't
671 * actually need any locking. This table is used to keep track of which
672 * readers are using data from which old transactions, so that we'll know
673 * when a particular old transaction is no longer in use. Old transactions
674 * that have discarded any data pages can then have those pages reclaimed
675 * for use by a later write transaction.
677 * The lock table is constructed such that reader slots are aligned with the
678 * processor's cache line size. Any slot is only ever used by one thread.
679 * This alignment guarantees that there will be no contention or cache
680 * thrashing as threads update their own slot info, and also eliminates
681 * any need for locking when accessing a slot.
683 * A writer thread will scan every slot in the table to determine the oldest
684 * outstanding reader transaction. Any freed pages older than this will be
685 * reclaimed by the writer. The writer doesn't use any locks when scanning
686 * this table. This means that there's no guarantee that the writer will
687 * see the most up-to-date reader info, but that's not required for correct
688 * operation - all we need is to know the upper bound on the oldest reader,
689 * we don't care at all about the newest reader. So the only consequence of
690 * reading stale information here is that old pages might hang around a
691 * while longer before being reclaimed. That's actually good anyway, because
692 * the longer we delay reclaiming old pages, the more likely it is that a
693 * string of contiguous pages can be found after coalescing old pages from
694 * many old transactions together.
697 /** Number of slots in the reader table.
698 * This value was chosen somewhat arbitrarily. 126 readers plus a
699 * couple mutexes fit exactly into 8KB on my development machine.
700 * Applications should set the table size using #mdb_env_set_maxreaders().
702 #define DEFAULT_READERS 126
704 /** The size of a CPU cache line in bytes. We want our lock structures
705 * aligned to this size to avoid false cache line sharing in the
707 * This value works for most CPUs. For Itanium this should be 128.
713 /** The information we store in a single slot of the reader table.
714 * In addition to a transaction ID, we also record the process and
715 * thread ID that owns a slot, so that we can detect stale information,
716 * e.g. threads or processes that went away without cleaning up.
717 * @note We currently don't check for stale records. We simply re-init
718 * the table when we know that we're the only process opening the
721 typedef struct MDB_rxbody {
722 /** Current Transaction ID when this transaction began, or (txnid_t)-1.
723 * Multiple readers that start at the same time will probably have the
724 * same ID here. Again, it's not important to exclude them from
725 * anything; all we need to know is which version of the DB they
726 * started from so we can avoid overwriting any data used in that
727 * particular version.
729 volatile txnid_t mrb_txnid;
730 /** The process ID of the process owning this reader txn. */
731 volatile MDB_PID_T mrb_pid;
732 /** The thread ID of the thread owning this txn. */
733 volatile MDB_THR_T mrb_tid;
736 /** The actual reader record, with cacheline padding. */
737 typedef struct MDB_reader {
740 /** shorthand for mrb_txnid */
741 #define mr_txnid mru.mrx.mrb_txnid
742 #define mr_pid mru.mrx.mrb_pid
743 #define mr_tid mru.mrx.mrb_tid
744 /** cache line alignment */
745 char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)];
749 /** The header for the reader table.
750 * The table resides in a memory-mapped file. (This is a different file
751 * than is used for the main database.)
753 * For POSIX the actual mutexes reside in the shared memory of this
754 * mapped file. On Windows, mutexes are named objects allocated by the
755 * kernel; we store the mutex names in this mapped file so that other
756 * processes can grab them. This same approach is also used on
757 * MacOSX/Darwin (using named semaphores) since MacOSX doesn't support
758 * process-shared POSIX mutexes. For these cases where a named object
759 * is used, the object name is derived from a 64 bit FNV hash of the
760 * environment pathname. As such, naming collisions are extremely
761 * unlikely. If a collision occurs, the results are unpredictable.
763 typedef struct MDB_txbody {
764 /** Stamp identifying this as an LMDB file. It must be set
767 /** Format of this lock file. Must be set to #MDB_LOCK_FORMAT. */
769 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
770 char mtb_rmname[MNAME_LEN];
771 #elif defined(MDB_USE_SYSV_SEM)
775 /** Mutex protecting access to this table.
776 * This is the reader table lock used with LOCK_MUTEX().
778 mdb_mutex_t mtb_rmutex;
780 /** The ID of the last transaction committed to the database.
781 * This is recorded here only for convenience; the value can always
782 * be determined by reading the main database meta pages.
784 volatile txnid_t mtb_txnid;
785 /** The number of slots that have been used in the reader table.
786 * This always records the maximum count, it is not decremented
787 * when readers release their slots.
789 volatile unsigned mtb_numreaders;
792 /** The actual reader table definition. */
793 typedef struct MDB_txninfo {
796 #define mti_magic mt1.mtb.mtb_magic
797 #define mti_format mt1.mtb.mtb_format
798 #define mti_rmutex mt1.mtb.mtb_rmutex
799 #define mti_rmname mt1.mtb.mtb_rmname
800 #define mti_txnid mt1.mtb.mtb_txnid
801 #define mti_numreaders mt1.mtb.mtb_numreaders
802 #ifdef MDB_USE_SYSV_SEM
803 #define mti_semid mt1.mtb.mtb_semid
804 #define mti_rlocked mt1.mtb.mtb_rlocked
806 char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];
809 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
810 char mt2_wmname[MNAME_LEN];
811 #define mti_wmname mt2.mt2_wmname
812 #elif defined MDB_USE_SYSV_SEM
814 #define mti_wlocked mt2.mt2_wlocked
816 mdb_mutex_t mt2_wmutex;
817 #define mti_wmutex mt2.mt2_wmutex
819 char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)];
821 MDB_reader mti_readers[1];
824 /** Lockfile format signature: version, features and field layout */
825 #define MDB_LOCK_FORMAT \
827 ((MDB_LOCK_VERSION) \
828 /* Flags which describe functionality */ \
829 + (SYSV_SEM_FLAG << 18) \
830 + (((MDB_PIDLOCK) != 0) << 16)))
833 /** Common header for all page types.
834 * Overflow records occupy a number of contiguous pages with no
835 * headers on any page after the first.
837 typedef struct MDB_page {
838 #define mp_pgno mp_p.p_pgno
839 #define mp_next mp_p.p_next
841 pgno_t p_pgno; /**< page number */
842 struct MDB_page *p_next; /**< for in-memory list of freed pages */
845 /** @defgroup mdb_page Page Flags
847 * Flags for the page headers.
850 #define P_BRANCH 0x01 /**< branch page */
851 #define P_LEAF 0x02 /**< leaf page */
852 #define P_OVERFLOW 0x04 /**< overflow page */
853 #define P_META 0x08 /**< meta page */
854 #define P_DIRTY 0x10 /**< dirty page, also set for #P_SUBP pages */
855 #define P_LEAF2 0x20 /**< for #MDB_DUPFIXED records */
856 #define P_SUBP 0x40 /**< for #MDB_DUPSORT sub-pages */
857 #define P_LOOSE 0x4000 /**< page was dirtied then freed, can be reused */
858 #define P_KEEP 0x8000 /**< leave this page alone during spill */
860 uint16_t mp_flags; /**< @ref mdb_page */
861 #define mp_lower mp_pb.pb.pb_lower
862 #define mp_upper mp_pb.pb.pb_upper
863 #define mp_pages mp_pb.pb_pages
866 indx_t pb_lower; /**< lower bound of free space */
867 indx_t pb_upper; /**< upper bound of free space */
869 uint32_t pb_pages; /**< number of overflow pages */
871 indx_t mp_ptrs[1]; /**< dynamic size */
874 /** Size of the page header, excluding dynamic data at the end */
875 #define PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs))
877 /** Address of first usable data byte in a page, after the header */
878 #define METADATA(p) ((void *)((char *)(p) + PAGEHDRSZ))
880 /** ITS#7713, change PAGEBASE to handle 65536 byte pages */
881 #define PAGEBASE ((MDB_DEVEL) ? PAGEHDRSZ : 0)
883 /** Number of nodes on a page */
884 #define NUMKEYS(p) (((p)->mp_lower - (PAGEHDRSZ-PAGEBASE)) >> 1)
886 /** The amount of space remaining in the page */
887 #define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower)
889 /** The percentage of space used in the page, in tenths of a percent. */
890 #define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \
891 ((env)->me_psize - PAGEHDRSZ))
892 /** The minimum page fill factor, in tenths of a percent.
893 * Pages emptier than this are candidates for merging.
895 #define FILL_THRESHOLD 250
897 /** Test if a page is a leaf page */
898 #define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF)
899 /** Test if a page is a LEAF2 page */
900 #define IS_LEAF2(p) F_ISSET((p)->mp_flags, P_LEAF2)
901 /** Test if a page is a branch page */
902 #define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH)
903 /** Test if a page is an overflow page */
904 #define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW)
905 /** Test if a page is a sub page */
906 #define IS_SUBP(p) F_ISSET((p)->mp_flags, P_SUBP)
908 /** The number of overflow pages needed to store the given size. */
909 #define OVPAGES(size, psize) ((PAGEHDRSZ-1 + (size)) / (psize) + 1)
911 /** Link in #MDB_txn.%mt_loose_pgs list */
912 #define NEXT_LOOSE_PAGE(p) (*(MDB_page **)((p) + 2))
914 /** Header for a single key/data pair within a page.
915 * Used in pages of type #P_BRANCH and #P_LEAF without #P_LEAF2.
916 * We guarantee 2-byte alignment for 'MDB_node's.
918 typedef struct MDB_node {
919 /** lo and hi are used for data size on leaf nodes and for
920 * child pgno on branch nodes. On 64 bit platforms, flags
921 * is also used for pgno. (Branch nodes have no flags).
922 * They are in host byte order in case that lets some
923 * accesses be optimized into a 32-bit word access.
925 #if BYTE_ORDER == LITTLE_ENDIAN
926 unsigned short mn_lo, mn_hi; /**< part of data size or pgno */
928 unsigned short mn_hi, mn_lo;
930 /** @defgroup mdb_node Node Flags
932 * Flags for node headers.
935 #define F_BIGDATA 0x01 /**< data put on overflow page */
936 #define F_SUBDATA 0x02 /**< data is a sub-database */
937 #define F_DUPDATA 0x04 /**< data has duplicates */
939 /** valid flags for #mdb_node_add() */
940 #define NODE_ADD_FLAGS (F_DUPDATA|F_SUBDATA|MDB_RESERVE|MDB_APPEND)
943 unsigned short mn_flags; /**< @ref mdb_node */
944 unsigned short mn_ksize; /**< key size */
945 char mn_data[1]; /**< key and data are appended here */
948 /** Size of the node header, excluding dynamic data at the end */
949 #define NODESIZE offsetof(MDB_node, mn_data)
951 /** Bit position of top word in page number, for shifting mn_flags */
952 #define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0)
954 /** Size of a node in a branch page with a given key.
955 * This is just the node header plus the key, there is no data.
957 #define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))
959 /** Size of a node in a leaf page with a given key and data.
960 * This is node header plus key plus data size.
962 #define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size)
964 /** Address of node \b i in page \b p */
965 #define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i] + PAGEBASE))
967 /** Address of the key for the node */
968 #define NODEKEY(node) (void *)((node)->mn_data)
970 /** Address of the data for a node */
971 #define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize)
973 /** Get the page number pointed to by a branch node */
974 #define NODEPGNO(node) \
975 ((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | \
976 (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0))
977 /** Set the page number in a branch node */
978 #define SETPGNO(node,pgno) do { \
979 (node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \
980 if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0)
982 /** Get the size of the data in a leaf node */
983 #define NODEDSZ(node) ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16))
984 /** Set the size of the data for a leaf node */
985 #define SETDSZ(node,size) do { \
986 (node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)
987 /** The size of a key in a node */
988 #define NODEKSZ(node) ((node)->mn_ksize)
990 /** Copy a page number from src to dst */
992 #define COPY_PGNO(dst,src) dst = src
994 #if SIZE_MAX > 4294967295UL
995 #define COPY_PGNO(dst,src) do { \
996 unsigned short *s, *d; \
997 s = (unsigned short *)&(src); \
998 d = (unsigned short *)&(dst); \
1005 #define COPY_PGNO(dst,src) do { \
1006 unsigned short *s, *d; \
1007 s = (unsigned short *)&(src); \
1008 d = (unsigned short *)&(dst); \
1014 /** The address of a key in a LEAF2 page.
1015 * LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate sub-DBs.
1016 * There are no node headers, keys are stored contiguously.
1018 #define LEAF2KEY(p, i, ks) ((char *)(p) + PAGEHDRSZ + ((i)*(ks)))
1020 /** Set the \b node's key into \b keyptr, if requested. */
1021 #define MDB_GET_KEY(node, keyptr) { if ((keyptr) != NULL) { \
1022 (keyptr)->mv_size = NODEKSZ(node); (keyptr)->mv_data = NODEKEY(node); } }
1024 /** Set the \b node's key into \b key. */
1025 #define MDB_GET_KEY2(node, key) { key.mv_size = NODEKSZ(node); key.mv_data = NODEKEY(node); }
1027 /** Information about a single database in the environment. */
1028 typedef struct MDB_db {
1029 uint32_t md_pad; /**< also ksize for LEAF2 pages */
1030 uint16_t md_flags; /**< @ref mdb_dbi_open */
1031 uint16_t md_depth; /**< depth of this tree */
1032 pgno_t md_branch_pages; /**< number of internal pages */
1033 pgno_t md_leaf_pages; /**< number of leaf pages */
1034 pgno_t md_overflow_pages; /**< number of overflow pages */
1035 size_t md_entries; /**< number of data items */
1036 pgno_t md_root; /**< the root page of this tree */
1039 /** mdb_dbi_open flags */
1040 #define MDB_VALID 0x8000 /**< DB handle is valid, for me_dbflags */
1041 #define PERSISTENT_FLAGS (0xffff & ~(MDB_VALID))
1042 #define VALID_FLAGS (MDB_REVERSEKEY|MDB_DUPSORT|MDB_INTEGERKEY|MDB_DUPFIXED|\
1043 MDB_INTEGERDUP|MDB_REVERSEDUP|MDB_CREATE)
1045 /** Handle for the DB used to track free pages. */
1047 /** Handle for the default DB. */
1049 /** Number of DBs in metapage (free and main) - also hardcoded elsewhere */
1052 /** Number of meta pages - also hardcoded elsewhere */
1055 /** Meta page content.
1056 * A meta page is the start point for accessing a database snapshot.
1057 * Pages 0-1 are meta pages. Transaction N writes meta page #(N % 2).
1059 typedef struct MDB_meta {
1060 /** Stamp identifying this as an LMDB file. It must be set
1063 /** Version number of this file. Must be set to #MDB_DATA_VERSION. */
1064 uint32_t mm_version;
1065 void *mm_address; /**< address for fixed mapping */
1066 size_t mm_mapsize; /**< size of mmap region */
1067 MDB_db mm_dbs[CORE_DBS]; /**< first is free space, 2nd is main db */
1068 /** The size of pages used in this DB */
1069 #define mm_psize mm_dbs[FREE_DBI].md_pad
1070 /** Any persistent environment flags. @ref mdb_env */
1071 #define mm_flags mm_dbs[FREE_DBI].md_flags
1072 pgno_t mm_last_pg; /**< last used page in file */
1073 volatile txnid_t mm_txnid; /**< txnid that committed this page */
1076 /** Buffer for a stack-allocated meta page.
1077 * The members define size and alignment, and silence type
1078 * aliasing warnings. They are not used directly; that could
1079 * mean incorrectly using several union members in parallel.
1081 typedef union MDB_metabuf {
1084 char mm_pad[PAGEHDRSZ];
1089 /** Auxiliary DB info.
1090 * The information here is mostly static/read-only. There is
1091 * only a single copy of this record in the environment.
1093 typedef struct MDB_dbx {
1094 MDB_val md_name; /**< name of the database */
1095 MDB_cmp_func *md_cmp; /**< function for comparing keys */
1096 MDB_cmp_func *md_dcmp; /**< function for comparing data items */
1097 MDB_rel_func *md_rel; /**< user relocate function */
1098 void *md_relctx; /**< user-provided context for md_rel */
1101 /** A database transaction.
1102 * Every operation requires a transaction handle.
1105 MDB_txn *mt_parent; /**< parent of a nested txn */
1106 /** Nested txn under this txn, set together with flag #MDB_TXN_HAS_CHILD */
1108 pgno_t mt_next_pgno; /**< next unallocated page */
1109 /** The ID of this transaction. IDs are integers incrementing from 1.
1110 * Only committed write transactions increment the ID. If a transaction
1111 * aborts, the ID may be re-used by the next writer.
1114 MDB_env *mt_env; /**< the DB environment */
1115 /** The list of pages that became unused during this transaction.
1117 MDB_IDL mt_free_pgs;
1118 /** The list of loose pages that became unused and may be reused
1119 * in this transaction, linked through #NEXT_LOOSE_PAGE(page).
1121 MDB_page *mt_loose_pgs;
1122 /* #Number of loose pages (#mt_loose_pgs) */
1124 /** The sorted list of dirty pages we temporarily wrote to disk
1125 * because the dirty list was full. page numbers in here are
1126 * shifted left by 1, deleted slots have the LSB set.
1128 MDB_IDL mt_spill_pgs;
1130 /** For write txns: Modified pages. Sorted when not MDB_WRITEMAP. */
1131 MDB_ID2L dirty_list;
1132 /** For read txns: This thread/txn's reader table slot, or NULL. */
1135 /** Array of records for each DB known in the environment. */
1137 /** Array of MDB_db records for each known DB */
1139 /** Array of sequence numbers for each DB handle */
1140 unsigned int *mt_dbiseqs;
1141 /** @defgroup mt_dbflag Transaction DB Flags
1145 #define DB_DIRTY 0x01 /**< DB was modified or is DUPSORT data */
1146 #define DB_STALE 0x02 /**< Named-DB record is older than txnID */
1147 #define DB_NEW 0x04 /**< Named-DB handle opened in this txn */
1148 #define DB_VALID 0x08 /**< DB handle is valid, see also #MDB_VALID */
1149 #define DB_USRVALID 0x10 /**< As #DB_VALID, but not set for #FREE_DBI */
1151 /** In write txns, array of cursors for each DB */
1152 MDB_cursor **mt_cursors;
1153 /** Array of flags for each DB */
1154 unsigned char *mt_dbflags;
1155 /** Number of DB records in use, or 0 when the txn is finished.
1156 * This number only ever increments until the txn finishes; we
1157 * don't decrement it when individual DB handles are closed.
1161 /** @defgroup mdb_txn Transaction Flags
1165 /** #mdb_txn_begin() flags */
1166 #define MDB_TXN_BEGIN_FLAGS (MDB_NOMETASYNC|MDB_NOSYNC|MDB_RDONLY)
1167 #define MDB_TXN_NOMETASYNC MDB_NOMETASYNC /**< don't sync meta for this txn on commit */
1168 #define MDB_TXN_NOSYNC MDB_NOSYNC /**< don't sync this txn on commit */
1169 #define MDB_TXN_RDONLY MDB_RDONLY /**< read-only transaction */
1170 /* internal txn flags */
1171 #define MDB_TXN_WRITEMAP MDB_WRITEMAP /**< copy of #MDB_env flag in writers */
1172 #define MDB_TXN_FINISHED 0x01 /**< txn is finished or never began */
1173 #define MDB_TXN_ERROR 0x02 /**< txn is unusable after an error */
1174 #define MDB_TXN_DIRTY 0x04 /**< must write, even if dirty list is empty */
1175 #define MDB_TXN_SPILLS 0x08 /**< txn or a parent has spilled pages */
1176 #define MDB_TXN_HAS_CHILD 0x10 /**< txn has an #MDB_txn.%mt_child */
1177 /** most operations on the txn are currently illegal */
1178 #define MDB_TXN_BLOCKED (MDB_TXN_FINISHED|MDB_TXN_ERROR|MDB_TXN_HAS_CHILD)
1180 unsigned int mt_flags; /**< @ref mdb_txn */
1181 /** #dirty_list room: Array size - \#dirty pages visible to this txn.
1182 * Includes ancestor txns' dirty pages not hidden by other txns'
1183 * dirty/spilled pages. Thus commit(nested txn) has room to merge
1184 * dirty_list into mt_parent after freeing hidden mt_parent pages.
1186 unsigned int mt_dirty_room;
1189 /** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty.
1190 * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to
1191 * raise this on a 64 bit machine.
1193 #define CURSOR_STACK 32
1197 /** Cursors are used for all DB operations.
1198 * A cursor holds a path of (page pointer, key index) from the DB
1199 * root to a position in the DB, plus other state. #MDB_DUPSORT
1200 * cursors include an xcursor to the current data item. Write txns
1201 * track their cursors and keep them up to date when data moves.
1202 * Exception: An xcursor's pointer to a #P_SUBP page can be stale.
1203 * (A node with #F_DUPDATA but no #F_SUBDATA contains a subpage).
1206 /** Next cursor on this DB in this txn */
1207 MDB_cursor *mc_next;
1208 /** Backup of the original cursor if this cursor is a shadow */
1209 MDB_cursor *mc_backup;
1210 /** Context used for databases with #MDB_DUPSORT, otherwise NULL */
1211 struct MDB_xcursor *mc_xcursor;
1212 /** The transaction that owns this cursor */
1214 /** The database handle this cursor operates on */
1216 /** The database record for this cursor */
1218 /** The database auxiliary record for this cursor */
1220 /** The @ref mt_dbflag for this database */
1221 unsigned char *mc_dbflag;
1222 unsigned short mc_snum; /**< number of pushed pages */
1223 unsigned short mc_top; /**< index of top page, normally mc_snum-1 */
1224 /** @defgroup mdb_cursor Cursor Flags
1226 * Cursor state flags.
1229 #define C_INITIALIZED 0x01 /**< cursor has been initialized and is valid */
1230 #define C_EOF 0x02 /**< No more data */
1231 #define C_SUB 0x04 /**< Cursor is a sub-cursor */
1232 #define C_DEL 0x08 /**< last op was a cursor_del */
1233 #define C_UNTRACK 0x40 /**< Un-track cursor when closing */
1235 unsigned int mc_flags; /**< @ref mdb_cursor */
1236 MDB_page *mc_pg[CURSOR_STACK]; /**< stack of pushed pages */
1237 indx_t mc_ki[CURSOR_STACK]; /**< stack of page indices */
1240 /** Context for sorted-dup records.
1241 * We could have gone to a fully recursive design, with arbitrarily
1242 * deep nesting of sub-databases. But for now we only handle these
1243 * levels - main DB, optional sub-DB, sorted-duplicate DB.
1245 typedef struct MDB_xcursor {
1246 /** A sub-cursor for traversing the Dup DB */
1247 MDB_cursor mx_cursor;
1248 /** The database record for this Dup DB */
1250 /** The auxiliary DB record for this Dup DB */
1252 /** The @ref mt_dbflag for this Dup DB */
1253 unsigned char mx_dbflag;
1256 /** State of FreeDB old pages, stored in the MDB_env */
1257 typedef struct MDB_pgstate {
1258 pgno_t *mf_pghead; /**< Reclaimed freeDB pages, or NULL before use */
1259 txnid_t mf_pglast; /**< ID of last used record, or 0 if !mf_pghead */
1262 /** The database environment. */
1264 HANDLE me_fd; /**< The main data file */
1265 HANDLE me_lfd; /**< The lock file */
1266 HANDLE me_mfd; /**< just for writing the meta pages */
1267 /** Failed to update the meta page. Probably an I/O error. */
1268 #define MDB_FATAL_ERROR 0x80000000U
1269 /** Some fields are initialized. */
1270 #define MDB_ENV_ACTIVE 0x20000000U
1271 /** me_txkey is set */
1272 #define MDB_ENV_TXKEY 0x10000000U
1273 /** fdatasync is unreliable */
1274 #define MDB_FSYNCONLY 0x08000000U
1275 uint32_t me_flags; /**< @ref mdb_env */
1276 unsigned int me_psize; /**< DB page size, inited from me_os_psize */
1277 unsigned int me_os_psize; /**< OS page size, from #GET_PAGESIZE */
1278 unsigned int me_maxreaders; /**< size of the reader table */
1279 /** Max #MDB_txninfo.%mti_numreaders of interest to #mdb_env_close() */
1280 volatile int me_close_readers;
1281 MDB_dbi me_numdbs; /**< number of DBs opened */
1282 MDB_dbi me_maxdbs; /**< size of the DB table */
1283 MDB_PID_T me_pid; /**< process ID of this env */
1284 char *me_path; /**< path to the DB files */
1285 char *me_map; /**< the memory map of the data file */
1286 MDB_txninfo *me_txns; /**< the memory map of the lock file or NULL */
1287 MDB_meta *me_metas[NUM_METAS]; /**< pointers to the two meta pages */
1288 void *me_pbuf; /**< scratch area for DUPSORT put() */
1289 MDB_txn *me_txn; /**< current write transaction */
1290 MDB_txn *me_txn0; /**< prealloc'd write transaction */
1291 size_t me_mapsize; /**< size of the data memory map */
1292 off_t me_size; /**< current file size */
1293 pgno_t me_maxpg; /**< me_mapsize / me_psize */
1294 MDB_dbx *me_dbxs; /**< array of static DB info */
1295 uint16_t *me_dbflags; /**< array of flags from MDB_db.md_flags */
1296 unsigned int *me_dbiseqs; /**< array of dbi sequence numbers */
1297 pthread_key_t me_txkey; /**< thread-key for readers */
1298 txnid_t me_pgoldest; /**< ID of oldest reader last time we looked */
1299 MDB_pgstate me_pgstate; /**< state of old pages from freeDB */
1300 # define me_pglast me_pgstate.mf_pglast
1301 # define me_pghead me_pgstate.mf_pghead
1302 MDB_page *me_dpages; /**< list of malloc'd blocks for re-use */
1303 /** IDL of pages that became unused in a write txn */
1304 MDB_IDL me_free_pgs;
1305 /** ID2L of pages written during a write txn. Length MDB_IDL_UM_SIZE. */
1306 MDB_ID2L me_dirty_list;
1307 /** Max number of freelist items that can fit in a single overflow page */
1309 /** Max size of a node on a page */
1310 unsigned int me_nodemax;
1311 #if !(MDB_MAXKEYSIZE)
1312 unsigned int me_maxkey; /**< max size of a key */
1314 int me_live_reader; /**< have liveness lock in reader table */
1316 int me_pidquery; /**< Used in OpenProcess */
1318 #ifdef MDB_USE_POSIX_MUTEX /* Posix mutexes reside in shared mem */
1319 # define me_rmutex me_txns->mti_rmutex /**< Shared reader lock */
1320 # define me_wmutex me_txns->mti_wmutex /**< Shared writer lock */
1322 mdb_mutex_t me_rmutex;
1323 mdb_mutex_t me_wmutex;
1325 void *me_userctx; /**< User-settable context */
1326 MDB_assert_func *me_assert_func; /**< Callback for assertion failures */
1329 /** Nested transaction */
1330 typedef struct MDB_ntxn {
1331 MDB_txn mnt_txn; /**< the transaction */
1332 MDB_pgstate mnt_pgstate; /**< parent transaction's saved freestate */
1335 /** max number of pages to commit in one writev() call */
1336 #define MDB_COMMIT_PAGES 64
1337 #if defined(IOV_MAX) && IOV_MAX < MDB_COMMIT_PAGES
1338 #undef MDB_COMMIT_PAGES
1339 #define MDB_COMMIT_PAGES IOV_MAX
1342 /** max bytes to write in one call */
1343 #define MAX_WRITE (0x80000000U >> (sizeof(ssize_t) == 4))
1345 /** Check \b txn and \b dbi arguments to a function */
1346 #define TXN_DBI_EXIST(txn, dbi, validity) \
1347 ((txn) && (dbi)<(txn)->mt_numdbs && ((txn)->mt_dbflags[dbi] & (validity)))
1349 /** Check for misused \b dbi handles */
1350 #define TXN_DBI_CHANGED(txn, dbi) \
1351 ((txn)->mt_dbiseqs[dbi] != (txn)->mt_env->me_dbiseqs[dbi])
1353 static int mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp);
1354 static int mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp);
1355 static int mdb_page_touch(MDB_cursor *mc);
1357 #define MDB_END_NAMES {"committed", "empty-commit", "abort", "reset", \
1358 "reset-tmp", "fail-begin", "fail-beginchild"}
1360 /* mdb_txn_end operation number, for logging */
1361 MDB_END_COMMITTED, MDB_END_EMPTY_COMMIT, MDB_END_ABORT, MDB_END_RESET,
1362 MDB_END_RESET_TMP, MDB_END_FAIL_BEGIN, MDB_END_FAIL_BEGINCHILD
1364 #define MDB_END_OPMASK 0x0F /**< mask for #mdb_txn_end() operation number */
1365 #define MDB_END_UPDATE 0x10 /**< update env state (DBIs) */
1366 #define MDB_END_FREE 0x20 /**< free txn unless it is #MDB_env.%me_txn0 */
1367 #define MDB_END_SLOT MDB_NOTLS /**< release any reader slot if #MDB_NOTLS */
1368 static void mdb_txn_end(MDB_txn *txn, unsigned mode);
1370 static int mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **mp, int *lvl);
1371 static int mdb_page_search_root(MDB_cursor *mc,
1372 MDB_val *key, int modify);
1373 #define MDB_PS_MODIFY 1
1374 #define MDB_PS_ROOTONLY 2
1375 #define MDB_PS_FIRST 4
1376 #define MDB_PS_LAST 8
1377 static int mdb_page_search(MDB_cursor *mc,
1378 MDB_val *key, int flags);
1379 static int mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst);
1381 #define MDB_SPLIT_REPLACE MDB_APPENDDUP /**< newkey is not new */
1382 static int mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,
1383 pgno_t newpgno, unsigned int nflags);
1385 static int mdb_env_read_header(MDB_env *env, MDB_meta *meta);
1386 static MDB_meta *mdb_env_pick_meta(const MDB_env *env);
1387 static int mdb_env_write_meta(MDB_txn *txn);
1388 #ifdef MDB_USE_POSIX_MUTEX /* Drop unused excl arg */
1389 # define mdb_env_close0(env, excl) mdb_env_close1(env)
1391 static void mdb_env_close0(MDB_env *env, int excl);
1393 static MDB_node *mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp);
1394 static int mdb_node_add(MDB_cursor *mc, indx_t indx,
1395 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags);
1396 static void mdb_node_del(MDB_cursor *mc, int ksize);
1397 static void mdb_node_shrink(MDB_page *mp, indx_t indx);
1398 static int mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft);
1399 static int mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data);
1400 static size_t mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data);
1401 static size_t mdb_branch_size(MDB_env *env, MDB_val *key);
1403 static int mdb_rebalance(MDB_cursor *mc);
1404 static int mdb_update_key(MDB_cursor *mc, MDB_val *key);
1406 static void mdb_cursor_pop(MDB_cursor *mc);
1407 static int mdb_cursor_push(MDB_cursor *mc, MDB_page *mp);
1409 static int mdb_cursor_del0(MDB_cursor *mc);
1410 static int mdb_del0(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned flags);
1411 static int mdb_cursor_sibling(MDB_cursor *mc, int move_right);
1412 static int mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1413 static int mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1414 static int mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op,
1416 static int mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1417 static int mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1419 static void mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);
1420 static void mdb_xcursor_init0(MDB_cursor *mc);
1421 static void mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node);
1422 static void mdb_xcursor_init2(MDB_cursor *mc, MDB_xcursor *src_mx, int force);
1424 static int mdb_drop0(MDB_cursor *mc, int subs);
1425 static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi);
1426 static int mdb_reader_check0(MDB_env *env, int rlocked, int *dead);
1429 static MDB_cmp_func mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long;
1432 /** Compare two items pointing at size_t's of unknown alignment. */
1433 #ifdef MISALIGNED_OK
1434 # define mdb_cmp_clong mdb_cmp_long
1436 # define mdb_cmp_clong mdb_cmp_cint
1440 static SECURITY_DESCRIPTOR mdb_null_sd;
1441 static SECURITY_ATTRIBUTES mdb_all_sa;
1442 static int mdb_sec_inited;
1444 static int utf8_to_utf16(const char *src, int srcsize, wchar_t **dst, int *dstsize);
1447 /** Return the library version info. */
1449 mdb_version(int *major, int *minor, int *patch)
1451 if (major) *major = MDB_VERSION_MAJOR;
1452 if (minor) *minor = MDB_VERSION_MINOR;
1453 if (patch) *patch = MDB_VERSION_PATCH;
1454 return MDB_VERSION_STRING;
1457 /** Table of descriptions for LMDB @ref errors */
1458 static char *const mdb_errstr[] = {
1459 "MDB_KEYEXIST: Key/data pair already exists",
1460 "MDB_NOTFOUND: No matching key/data pair found",
1461 "MDB_PAGE_NOTFOUND: Requested page not found",
1462 "MDB_CORRUPTED: Located page was wrong type",
1463 "MDB_PANIC: Update of meta page failed or environment had fatal error",
1464 "MDB_VERSION_MISMATCH: Database environment version mismatch",
1465 "MDB_INVALID: File is not an LMDB file",
1466 "MDB_MAP_FULL: Environment mapsize limit reached",
1467 "MDB_DBS_FULL: Environment maxdbs limit reached",
1468 "MDB_READERS_FULL: Environment maxreaders limit reached",
1469 "MDB_TLS_FULL: Thread-local storage keys full - too many environments open",
1470 "MDB_TXN_FULL: Transaction has too many dirty pages - transaction too big",
1471 "MDB_CURSOR_FULL: Internal error - cursor stack limit reached",
1472 "MDB_PAGE_FULL: Internal error - page has no more space",
1473 "MDB_MAP_RESIZED: Database contents grew beyond environment mapsize",
1474 "MDB_INCOMPATIBLE: Operation and DB incompatible, or DB flags changed",
1475 "MDB_BAD_RSLOT: Invalid reuse of reader locktable slot",
1476 "MDB_BAD_TXN: Transaction must abort, has a child, or is invalid",
1477 "MDB_BAD_VALSIZE: Unsupported size of key/DB name/data, or wrong DUPFIXED size",
1478 "MDB_BAD_DBI: The specified DBI handle was closed/changed unexpectedly",
1482 mdb_strerror(int err)
1485 /** HACK: pad 4KB on stack over the buf. Return system msgs in buf.
1486 * This works as long as no function between the call to mdb_strerror
1487 * and the actual use of the message uses more than 4K of stack.
1490 char buf[1024], *ptr = buf;
1494 return ("Successful return: 0");
1496 if (err >= MDB_KEYEXIST && err <= MDB_LAST_ERRCODE) {
1497 i = err - MDB_KEYEXIST;
1498 return mdb_errstr[i];
1502 /* These are the C-runtime error codes we use. The comment indicates
1503 * their numeric value, and the Win32 error they would correspond to
1504 * if the error actually came from a Win32 API. A major mess, we should
1505 * have used LMDB-specific error codes for everything.
1508 case ENOENT: /* 2, FILE_NOT_FOUND */
1509 case EIO: /* 5, ACCESS_DENIED */
1510 case ENOMEM: /* 12, INVALID_ACCESS */
1511 case EACCES: /* 13, INVALID_DATA */
1512 case EBUSY: /* 16, CURRENT_DIRECTORY */
1513 case EINVAL: /* 22, BAD_COMMAND */
1514 case ENOSPC: /* 28, OUT_OF_PAPER */
1515 return strerror(err);
1520 FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM |
1521 FORMAT_MESSAGE_IGNORE_INSERTS,
1522 NULL, err, 0, ptr, sizeof(buf), (va_list *)pad);
1525 return strerror(err);
1529 /** assert(3) variant in cursor context */
1530 #define mdb_cassert(mc, expr) mdb_assert0((mc)->mc_txn->mt_env, expr, #expr)
1531 /** assert(3) variant in transaction context */
1532 #define mdb_tassert(txn, expr) mdb_assert0((txn)->mt_env, expr, #expr)
1533 /** assert(3) variant in environment context */
1534 #define mdb_eassert(env, expr) mdb_assert0(env, expr, #expr)
1537 # define mdb_assert0(env, expr, expr_txt) ((expr) ? (void)0 : \
1538 mdb_assert_fail(env, expr_txt, mdb_func_, __FILE__, __LINE__))
1541 mdb_assert_fail(MDB_env *env, const char *expr_txt,
1542 const char *func, const char *file, int line)
1545 sprintf(buf, "%.100s:%d: Assertion '%.200s' failed in %.40s()",
1546 file, line, expr_txt, func);
1547 if (env->me_assert_func)
1548 env->me_assert_func(env, buf);
1549 fprintf(stderr, "%s\n", buf);
1553 # define mdb_assert0(env, expr, expr_txt) ((void) 0)
1557 /** Return the page number of \b mp which may be sub-page, for debug output */
1559 mdb_dbg_pgno(MDB_page *mp)
1562 COPY_PGNO(ret, mp->mp_pgno);
1566 /** Display a key in hexadecimal and return the address of the result.
1567 * @param[in] key the key to display
1568 * @param[in] buf the buffer to write into. Should always be #DKBUF.
1569 * @return The key in hexadecimal form.
1572 mdb_dkey(MDB_val *key, char *buf)
1575 unsigned char *c = key->mv_data;
1581 if (key->mv_size > DKBUF_MAXKEYSIZE)
1582 return "MDB_MAXKEYSIZE";
1583 /* may want to make this a dynamic check: if the key is mostly
1584 * printable characters, print it as-is instead of converting to hex.
1588 for (i=0; i<key->mv_size; i++)
1589 ptr += sprintf(ptr, "%02x", *c++);
1591 sprintf(buf, "%.*s", key->mv_size, key->mv_data);
1597 mdb_leafnode_type(MDB_node *n)
1599 static char *const tp[2][2] = {{"", ": DB"}, {": sub-page", ": sub-DB"}};
1600 return F_ISSET(n->mn_flags, F_BIGDATA) ? ": overflow page" :
1601 tp[F_ISSET(n->mn_flags, F_DUPDATA)][F_ISSET(n->mn_flags, F_SUBDATA)];
1604 /** Display all the keys in the page. */
1606 mdb_page_list(MDB_page *mp)
1608 pgno_t pgno = mdb_dbg_pgno(mp);
1609 const char *type, *state = (mp->mp_flags & P_DIRTY) ? ", dirty" : "";
1611 unsigned int i, nkeys, nsize, total = 0;
1615 switch (mp->mp_flags & (P_BRANCH|P_LEAF|P_LEAF2|P_META|P_OVERFLOW|P_SUBP)) {
1616 case P_BRANCH: type = "Branch page"; break;
1617 case P_LEAF: type = "Leaf page"; break;
1618 case P_LEAF|P_SUBP: type = "Sub-page"; break;
1619 case P_LEAF|P_LEAF2: type = "LEAF2 page"; break;
1620 case P_LEAF|P_LEAF2|P_SUBP: type = "LEAF2 sub-page"; break;
1622 fprintf(stderr, "Overflow page %"Z"u pages %u%s\n",
1623 pgno, mp->mp_pages, state);
1626 fprintf(stderr, "Meta-page %"Z"u txnid %"Z"u\n",
1627 pgno, ((MDB_meta *)METADATA(mp))->mm_txnid);
1630 fprintf(stderr, "Bad page %"Z"u flags 0x%u\n", pgno, mp->mp_flags);
1634 nkeys = NUMKEYS(mp);
1635 fprintf(stderr, "%s %"Z"u numkeys %d%s\n", type, pgno, nkeys, state);
1637 for (i=0; i<nkeys; i++) {
1638 if (IS_LEAF2(mp)) { /* LEAF2 pages have no mp_ptrs[] or node headers */
1639 key.mv_size = nsize = mp->mp_pad;
1640 key.mv_data = LEAF2KEY(mp, i, nsize);
1642 fprintf(stderr, "key %d: nsize %d, %s\n", i, nsize, DKEY(&key));
1645 node = NODEPTR(mp, i);
1646 key.mv_size = node->mn_ksize;
1647 key.mv_data = node->mn_data;
1648 nsize = NODESIZE + key.mv_size;
1649 if (IS_BRANCH(mp)) {
1650 fprintf(stderr, "key %d: page %"Z"u, %s\n", i, NODEPGNO(node),
1654 if (F_ISSET(node->mn_flags, F_BIGDATA))
1655 nsize += sizeof(pgno_t);
1657 nsize += NODEDSZ(node);
1659 nsize += sizeof(indx_t);
1660 fprintf(stderr, "key %d: nsize %d, %s%s\n",
1661 i, nsize, DKEY(&key), mdb_leafnode_type(node));
1663 total = EVEN(total);
1665 fprintf(stderr, "Total: header %d + contents %d + unused %d\n",
1666 IS_LEAF2(mp) ? PAGEHDRSZ : PAGEBASE + mp->mp_lower, total, SIZELEFT(mp));
1670 mdb_cursor_chk(MDB_cursor *mc)
1676 if (!mc->mc_snum || !(mc->mc_flags & C_INITIALIZED)) return;
1677 for (i=0; i<mc->mc_top; i++) {
1679 node = NODEPTR(mp, mc->mc_ki[i]);
1680 if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno)
1683 if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i]))
1689 /** Count all the pages in each DB and in the freelist
1690 * and make sure it matches the actual number of pages
1692 * All named DBs must be open for a correct count.
1694 static void mdb_audit(MDB_txn *txn)
1698 MDB_ID freecount, count;
1703 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
1704 while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
1705 freecount += *(MDB_ID *)data.mv_data;
1706 mdb_tassert(txn, rc == MDB_NOTFOUND);
1709 for (i = 0; i<txn->mt_numdbs; i++) {
1711 if (!(txn->mt_dbflags[i] & DB_VALID))
1713 mdb_cursor_init(&mc, txn, i, &mx);
1714 if (txn->mt_dbs[i].md_root == P_INVALID)
1716 count += txn->mt_dbs[i].md_branch_pages +
1717 txn->mt_dbs[i].md_leaf_pages +
1718 txn->mt_dbs[i].md_overflow_pages;
1719 if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) {
1720 rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST);
1721 for (; rc == MDB_SUCCESS; rc = mdb_cursor_sibling(&mc, 1)) {
1724 mp = mc.mc_pg[mc.mc_top];
1725 for (j=0; j<NUMKEYS(mp); j++) {
1726 MDB_node *leaf = NODEPTR(mp, j);
1727 if (leaf->mn_flags & F_SUBDATA) {
1729 memcpy(&db, NODEDATA(leaf), sizeof(db));
1730 count += db.md_branch_pages + db.md_leaf_pages +
1731 db.md_overflow_pages;
1735 mdb_tassert(txn, rc == MDB_NOTFOUND);
1738 if (freecount + count + NUM_METAS != txn->mt_next_pgno) {
1739 fprintf(stderr, "audit: %lu freecount: %lu count: %lu total: %lu next_pgno: %lu\n",
1740 txn->mt_txnid, freecount, count+NUM_METAS,
1741 freecount+count+NUM_METAS, txn->mt_next_pgno);
1747 mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1749 return txn->mt_dbxs[dbi].md_cmp(a, b);
1753 mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1755 MDB_cmp_func *dcmp = txn->mt_dbxs[dbi].md_dcmp;
1756 #if UINT_MAX < SIZE_MAX
1757 if (dcmp == mdb_cmp_int && a->mv_size == sizeof(size_t))
1758 dcmp = mdb_cmp_clong;
1763 /** Allocate memory for a page.
1764 * Re-use old malloc'd pages first for singletons, otherwise just malloc.
1767 mdb_page_malloc(MDB_txn *txn, unsigned num)
1769 MDB_env *env = txn->mt_env;
1770 MDB_page *ret = env->me_dpages;
1771 size_t psize = env->me_psize, sz = psize, off;
1772 /* For ! #MDB_NOMEMINIT, psize counts how much to init.
1773 * For a single page alloc, we init everything after the page header.
1774 * For multi-page, we init the final page; if the caller needed that
1775 * many pages they will be filling in at least up to the last page.
1779 VGMEMP_ALLOC(env, ret, sz);
1780 VGMEMP_DEFINED(ret, sizeof(ret->mp_next));
1781 env->me_dpages = ret->mp_next;
1784 psize -= off = PAGEHDRSZ;
1789 if ((ret = malloc(sz)) != NULL) {
1790 VGMEMP_ALLOC(env, ret, sz);
1791 if (!(env->me_flags & MDB_NOMEMINIT)) {
1792 memset((char *)ret + off, 0, psize);
1796 txn->mt_flags |= MDB_TXN_ERROR;
1800 /** Free a single page.
1801 * Saves single pages to a list, for future reuse.
1802 * (This is not used for multi-page overflow pages.)
1805 mdb_page_free(MDB_env *env, MDB_page *mp)
1807 mp->mp_next = env->me_dpages;
1808 VGMEMP_FREE(env, mp);
1809 env->me_dpages = mp;
1812 /** Free a dirty page */
1814 mdb_dpage_free(MDB_env *env, MDB_page *dp)
1816 if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
1817 mdb_page_free(env, dp);
1819 /* large pages just get freed directly */
1820 VGMEMP_FREE(env, dp);
1825 /** Return all dirty pages to dpage list */
1827 mdb_dlist_free(MDB_txn *txn)
1829 MDB_env *env = txn->mt_env;
1830 MDB_ID2L dl = txn->mt_u.dirty_list;
1831 unsigned i, n = dl[0].mid;
1833 for (i = 1; i <= n; i++) {
1834 mdb_dpage_free(env, dl[i].mptr);
1839 /** Loosen or free a single page.
1840 * Saves single pages to a list for future reuse
1841 * in this same txn. It has been pulled from the freeDB
1842 * and already resides on the dirty list, but has been
1843 * deleted. Use these pages first before pulling again
1846 * If the page wasn't dirtied in this txn, just add it
1847 * to this txn's free list.
1850 mdb_page_loose(MDB_cursor *mc, MDB_page *mp)
1853 pgno_t pgno = mp->mp_pgno;
1854 MDB_txn *txn = mc->mc_txn;
1856 if ((mp->mp_flags & P_DIRTY) && mc->mc_dbi != FREE_DBI) {
1857 if (txn->mt_parent) {
1858 MDB_ID2 *dl = txn->mt_u.dirty_list;
1859 /* If txn has a parent, make sure the page is in our
1863 unsigned x = mdb_mid2l_search(dl, pgno);
1864 if (x <= dl[0].mid && dl[x].mid == pgno) {
1865 if (mp != dl[x].mptr) { /* bad cursor? */
1866 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
1867 txn->mt_flags |= MDB_TXN_ERROR;
1868 return MDB_CORRUPTED;
1875 /* no parent txn, so it's just ours */
1880 DPRINTF(("loosen db %d page %"Z"u", DDBI(mc),
1882 NEXT_LOOSE_PAGE(mp) = txn->mt_loose_pgs;
1883 txn->mt_loose_pgs = mp;
1884 txn->mt_loose_count++;
1885 mp->mp_flags |= P_LOOSE;
1887 int rc = mdb_midl_append(&txn->mt_free_pgs, pgno);
1895 /** Set or clear P_KEEP in dirty, non-overflow, non-sub pages watched by txn.
1896 * @param[in] mc A cursor handle for the current operation.
1897 * @param[in] pflags Flags of the pages to update:
1898 * P_DIRTY to set P_KEEP, P_DIRTY|P_KEEP to clear it.
1899 * @param[in] all No shortcuts. Needed except after a full #mdb_page_flush().
1900 * @return 0 on success, non-zero on failure.
1903 mdb_pages_xkeep(MDB_cursor *mc, unsigned pflags, int all)
1905 enum { Mask = P_SUBP|P_DIRTY|P_LOOSE|P_KEEP };
1906 MDB_txn *txn = mc->mc_txn;
1912 int rc = MDB_SUCCESS, level;
1914 /* Mark pages seen by cursors */
1915 if (mc->mc_flags & C_UNTRACK)
1916 mc = NULL; /* will find mc in mt_cursors */
1917 for (i = txn->mt_numdbs;; mc = txn->mt_cursors[--i]) {
1918 for (; mc; mc=mc->mc_next) {
1919 if (!(mc->mc_flags & C_INITIALIZED))
1921 for (m3 = mc;; m3 = &mx->mx_cursor) {
1923 for (j=0; j<m3->mc_snum; j++) {
1925 if ((mp->mp_flags & Mask) == pflags)
1926 mp->mp_flags ^= P_KEEP;
1928 mx = m3->mc_xcursor;
1929 /* Proceed to mx if it is at a sub-database */
1930 if (! (mx && (mx->mx_cursor.mc_flags & C_INITIALIZED)))
1932 if (! (mp && (mp->mp_flags & P_LEAF)))
1934 leaf = NODEPTR(mp, m3->mc_ki[j-1]);
1935 if (!(leaf->mn_flags & F_SUBDATA))
1944 /* Mark dirty root pages */
1945 for (i=0; i<txn->mt_numdbs; i++) {
1946 if (txn->mt_dbflags[i] & DB_DIRTY) {
1947 pgno_t pgno = txn->mt_dbs[i].md_root;
1948 if (pgno == P_INVALID)
1950 if ((rc = mdb_page_get(txn, pgno, &dp, &level)) != MDB_SUCCESS)
1952 if ((dp->mp_flags & Mask) == pflags && level <= 1)
1953 dp->mp_flags ^= P_KEEP;
1961 static int mdb_page_flush(MDB_txn *txn, int keep);
1963 /** Spill pages from the dirty list back to disk.
1964 * This is intended to prevent running into #MDB_TXN_FULL situations,
1965 * but note that they may still occur in a few cases:
1966 * 1) our estimate of the txn size could be too small. Currently this
1967 * seems unlikely, except with a large number of #MDB_MULTIPLE items.
1968 * 2) child txns may run out of space if their parents dirtied a
1969 * lot of pages and never spilled them. TODO: we probably should do
1970 * a preemptive spill during #mdb_txn_begin() of a child txn, if
1971 * the parent's dirty_room is below a given threshold.
1973 * Otherwise, if not using nested txns, it is expected that apps will
1974 * not run into #MDB_TXN_FULL any more. The pages are flushed to disk
1975 * the same way as for a txn commit, e.g. their P_DIRTY flag is cleared.
1976 * If the txn never references them again, they can be left alone.
1977 * If the txn only reads them, they can be used without any fuss.
1978 * If the txn writes them again, they can be dirtied immediately without
1979 * going thru all of the work of #mdb_page_touch(). Such references are
1980 * handled by #mdb_page_unspill().
1982 * Also note, we never spill DB root pages, nor pages of active cursors,
1983 * because we'll need these back again soon anyway. And in nested txns,
1984 * we can't spill a page in a child txn if it was already spilled in a
1985 * parent txn. That would alter the parent txns' data even though
1986 * the child hasn't committed yet, and we'd have no way to undo it if
1987 * the child aborted.
1989 * @param[in] m0 cursor A cursor handle identifying the transaction and
1990 * database for which we are checking space.
1991 * @param[in] key For a put operation, the key being stored.
1992 * @param[in] data For a put operation, the data being stored.
1993 * @return 0 on success, non-zero on failure.
1996 mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
1998 MDB_txn *txn = m0->mc_txn;
2000 MDB_ID2L dl = txn->mt_u.dirty_list;
2001 unsigned int i, j, need;
2004 if (m0->mc_flags & C_SUB)
2007 /* Estimate how much space this op will take */
2008 i = m0->mc_db->md_depth;
2009 /* Named DBs also dirty the main DB */
2010 if (m0->mc_dbi >= CORE_DBS)
2011 i += txn->mt_dbs[MAIN_DBI].md_depth;
2012 /* For puts, roughly factor in the key+data size */
2014 i += (LEAFSIZE(key, data) + txn->mt_env->me_psize) / txn->mt_env->me_psize;
2015 i += i; /* double it for good measure */
2018 if (txn->mt_dirty_room > i)
2021 if (!txn->mt_spill_pgs) {
2022 txn->mt_spill_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX);
2023 if (!txn->mt_spill_pgs)
2026 /* purge deleted slots */
2027 MDB_IDL sl = txn->mt_spill_pgs;
2028 unsigned int num = sl[0];
2030 for (i=1; i<=num; i++) {
2037 /* Preserve pages which may soon be dirtied again */
2038 if ((rc = mdb_pages_xkeep(m0, P_DIRTY, 1)) != MDB_SUCCESS)
2041 /* Less aggressive spill - we originally spilled the entire dirty list,
2042 * with a few exceptions for cursor pages and DB root pages. But this
2043 * turns out to be a lot of wasted effort because in a large txn many
2044 * of those pages will need to be used again. So now we spill only 1/8th
2045 * of the dirty pages. Testing revealed this to be a good tradeoff,
2046 * better than 1/2, 1/4, or 1/10.
2048 if (need < MDB_IDL_UM_MAX / 8)
2049 need = MDB_IDL_UM_MAX / 8;
2051 /* Save the page IDs of all the pages we're flushing */
2052 /* flush from the tail forward, this saves a lot of shifting later on. */
2053 for (i=dl[0].mid; i && need; i--) {
2054 MDB_ID pn = dl[i].mid << 1;
2056 if (dp->mp_flags & (P_LOOSE|P_KEEP))
2058 /* Can't spill twice, make sure it's not already in a parent's
2061 if (txn->mt_parent) {
2063 for (tx2 = txn->mt_parent; tx2; tx2 = tx2->mt_parent) {
2064 if (tx2->mt_spill_pgs) {
2065 j = mdb_midl_search(tx2->mt_spill_pgs, pn);
2066 if (j <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[j] == pn) {
2067 dp->mp_flags |= P_KEEP;
2075 if ((rc = mdb_midl_append(&txn->mt_spill_pgs, pn)))
2079 mdb_midl_sort(txn->mt_spill_pgs);
2081 /* Flush the spilled part of dirty list */
2082 if ((rc = mdb_page_flush(txn, i)) != MDB_SUCCESS)
2085 /* Reset any dirty pages we kept that page_flush didn't see */
2086 rc = mdb_pages_xkeep(m0, P_DIRTY|P_KEEP, i);
2089 txn->mt_flags |= rc ? MDB_TXN_ERROR : MDB_TXN_SPILLS;
2093 /** Find oldest txnid still referenced. Expects txn->mt_txnid > 0. */
2095 mdb_find_oldest(MDB_txn *txn)
2098 txnid_t mr, oldest = txn->mt_txnid - 1;
2099 if (txn->mt_env->me_txns) {
2100 MDB_reader *r = txn->mt_env->me_txns->mti_readers;
2101 for (i = txn->mt_env->me_txns->mti_numreaders; --i >= 0; ) {
2112 /** Add a page to the txn's dirty list */
2114 mdb_page_dirty(MDB_txn *txn, MDB_page *mp)
2117 int rc, (*insert)(MDB_ID2L, MDB_ID2 *);
2119 if (txn->mt_flags & MDB_TXN_WRITEMAP) {
2120 insert = mdb_mid2l_append;
2122 insert = mdb_mid2l_insert;
2124 mid.mid = mp->mp_pgno;
2126 rc = insert(txn->mt_u.dirty_list, &mid);
2127 mdb_tassert(txn, rc == 0);
2128 txn->mt_dirty_room--;
2131 /** Allocate page numbers and memory for writing. Maintain me_pglast,
2132 * me_pghead and mt_next_pgno.
2134 * If there are free pages available from older transactions, they
2135 * are re-used first. Otherwise allocate a new page at mt_next_pgno.
2136 * Do not modify the freedB, just merge freeDB records into me_pghead[]
2137 * and move me_pglast to say which records were consumed. Only this
2138 * function can create me_pghead and move me_pglast/mt_next_pgno.
2139 * @param[in] mc cursor A cursor handle identifying the transaction and
2140 * database for which we are allocating.
2141 * @param[in] num the number of pages to allocate.
2142 * @param[out] mp Address of the allocated page(s). Requests for multiple pages
2143 * will always be satisfied by a single contiguous chunk of memory.
2144 * @return 0 on success, non-zero on failure.
2147 mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
2149 #ifdef MDB_PARANOID /* Seems like we can ignore this now */
2150 /* Get at most <Max_retries> more freeDB records once me_pghead
2151 * has enough pages. If not enough, use new pages from the map.
2152 * If <Paranoid> and mc is updating the freeDB, only get new
2153 * records if me_pghead is empty. Then the freelist cannot play
2154 * catch-up with itself by growing while trying to save it.
2156 enum { Paranoid = 1, Max_retries = 500 };
2158 enum { Paranoid = 0, Max_retries = INT_MAX /*infinite*/ };
2160 int rc, retry = num * 60;
2161 MDB_txn *txn = mc->mc_txn;
2162 MDB_env *env = txn->mt_env;
2163 pgno_t pgno, *mop = env->me_pghead;
2164 unsigned i, j, mop_len = mop ? mop[0] : 0, n2 = num-1;
2166 txnid_t oldest = 0, last;
2171 /* If there are any loose pages, just use them */
2172 if (num == 1 && txn->mt_loose_pgs) {
2173 np = txn->mt_loose_pgs;
2174 txn->mt_loose_pgs = NEXT_LOOSE_PAGE(np);
2175 txn->mt_loose_count--;
2176 DPRINTF(("db %d use loose page %"Z"u", DDBI(mc),
2184 /* If our dirty list is already full, we can't do anything */
2185 if (txn->mt_dirty_room == 0) {
2190 for (op = MDB_FIRST;; op = MDB_NEXT) {
2195 /* Seek a big enough contiguous page range. Prefer
2196 * pages at the tail, just truncating the list.
2202 if (mop[i-n2] == pgno+n2)
2209 if (op == MDB_FIRST) { /* 1st iteration */
2210 /* Prepare to fetch more and coalesce */
2211 last = env->me_pglast;
2212 oldest = env->me_pgoldest;
2213 mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
2216 key.mv_data = &last; /* will look up last+1 */
2217 key.mv_size = sizeof(last);
2219 if (Paranoid && mc->mc_dbi == FREE_DBI)
2222 if (Paranoid && retry < 0 && mop_len)
2226 /* Do not fetch more if the record will be too recent */
2227 if (oldest <= last) {
2229 oldest = mdb_find_oldest(txn);
2230 env->me_pgoldest = oldest;
2236 rc = mdb_cursor_get(&m2, &key, NULL, op);
2238 if (rc == MDB_NOTFOUND)
2242 last = *(txnid_t*)key.mv_data;
2243 if (oldest <= last) {
2245 oldest = mdb_find_oldest(txn);
2246 env->me_pgoldest = oldest;
2252 np = m2.mc_pg[m2.mc_top];
2253 leaf = NODEPTR(np, m2.mc_ki[m2.mc_top]);
2254 if ((rc = mdb_node_read(txn, leaf, &data)) != MDB_SUCCESS)
2257 idl = (MDB_ID *) data.mv_data;
2260 if (!(env->me_pghead = mop = mdb_midl_alloc(i))) {
2265 if ((rc = mdb_midl_need(&env->me_pghead, i)) != 0)
2267 mop = env->me_pghead;
2269 env->me_pglast = last;
2271 DPRINTF(("IDL read txn %"Z"u root %"Z"u num %u",
2272 last, txn->mt_dbs[FREE_DBI].md_root, i));
2274 DPRINTF(("IDL %"Z"u", idl[j]));
2276 /* Merge in descending sorted order */
2277 mdb_midl_xmerge(mop, idl);
2281 /* Use new pages from the map when nothing suitable in the freeDB */
2283 pgno = txn->mt_next_pgno;
2284 if (pgno + num >= env->me_maxpg) {
2285 DPUTS("DB size maxed out");
2291 if (env->me_flags & MDB_WRITEMAP) {
2292 np = (MDB_page *)(env->me_map + env->me_psize * pgno);
2294 if (!(np = mdb_page_malloc(txn, num))) {
2300 mop[0] = mop_len -= num;
2301 /* Move any stragglers down */
2302 for (j = i-num; j < mop_len; )
2303 mop[++j] = mop[++i];
2305 txn->mt_next_pgno = pgno + num;
2308 mdb_page_dirty(txn, np);
2314 txn->mt_flags |= MDB_TXN_ERROR;
2318 /** Copy the used portions of a non-overflow page.
2319 * @param[in] dst page to copy into
2320 * @param[in] src page to copy from
2321 * @param[in] psize size of a page
2324 mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize)
2326 enum { Align = sizeof(pgno_t) };
2327 indx_t upper = src->mp_upper, lower = src->mp_lower, unused = upper-lower;
2329 /* If page isn't full, just copy the used portion. Adjust
2330 * alignment so memcpy may copy words instead of bytes.
2332 if ((unused &= -Align) && !IS_LEAF2(src)) {
2333 upper = (upper + PAGEBASE) & -Align;
2334 memcpy(dst, src, (lower + PAGEBASE + (Align-1)) & -Align);
2335 memcpy((pgno_t *)((char *)dst+upper), (pgno_t *)((char *)src+upper),
2338 memcpy(dst, src, psize - unused);
2342 /** Pull a page off the txn's spill list, if present.
2343 * If a page being referenced was spilled to disk in this txn, bring
2344 * it back and make it dirty/writable again.
2345 * @param[in] txn the transaction handle.
2346 * @param[in] mp the page being referenced. It must not be dirty.
2347 * @param[out] ret the writable page, if any. ret is unchanged if
2348 * mp wasn't spilled.
2351 mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret)
2353 MDB_env *env = txn->mt_env;
2356 pgno_t pgno = mp->mp_pgno, pn = pgno << 1;
2358 for (tx2 = txn; tx2; tx2=tx2->mt_parent) {
2359 if (!tx2->mt_spill_pgs)
2361 x = mdb_midl_search(tx2->mt_spill_pgs, pn);
2362 if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
2365 if (txn->mt_dirty_room == 0)
2366 return MDB_TXN_FULL;
2367 if (IS_OVERFLOW(mp))
2371 if (env->me_flags & MDB_WRITEMAP) {
2374 np = mdb_page_malloc(txn, num);
2378 memcpy(np, mp, num * env->me_psize);
2380 mdb_page_copy(np, mp, env->me_psize);
2383 /* If in current txn, this page is no longer spilled.
2384 * If it happens to be the last page, truncate the spill list.
2385 * Otherwise mark it as deleted by setting the LSB.
2387 if (x == txn->mt_spill_pgs[0])
2388 txn->mt_spill_pgs[0]--;
2390 txn->mt_spill_pgs[x] |= 1;
2391 } /* otherwise, if belonging to a parent txn, the
2392 * page remains spilled until child commits
2395 mdb_page_dirty(txn, np);
2396 np->mp_flags |= P_DIRTY;
2404 /** Touch a page: make it dirty and re-insert into tree with updated pgno.
2405 * @param[in] mc cursor pointing to the page to be touched
2406 * @return 0 on success, non-zero on failure.
2409 mdb_page_touch(MDB_cursor *mc)
2411 MDB_page *mp = mc->mc_pg[mc->mc_top], *np;
2412 MDB_txn *txn = mc->mc_txn;
2413 MDB_cursor *m2, *m3;
2417 if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
2418 if (txn->mt_flags & MDB_TXN_SPILLS) {
2420 rc = mdb_page_unspill(txn, mp, &np);
2426 if ((rc = mdb_midl_need(&txn->mt_free_pgs, 1)) ||
2427 (rc = mdb_page_alloc(mc, 1, &np)))
2430 DPRINTF(("touched db %d page %"Z"u -> %"Z"u", DDBI(mc),
2431 mp->mp_pgno, pgno));
2432 mdb_cassert(mc, mp->mp_pgno != pgno);
2433 mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
2434 /* Update the parent page, if any, to point to the new page */
2436 MDB_page *parent = mc->mc_pg[mc->mc_top-1];
2437 MDB_node *node = NODEPTR(parent, mc->mc_ki[mc->mc_top-1]);
2438 SETPGNO(node, pgno);
2440 mc->mc_db->md_root = pgno;
2442 } else if (txn->mt_parent && !IS_SUBP(mp)) {
2443 MDB_ID2 mid, *dl = txn->mt_u.dirty_list;
2445 /* If txn has a parent, make sure the page is in our
2449 unsigned x = mdb_mid2l_search(dl, pgno);
2450 if (x <= dl[0].mid && dl[x].mid == pgno) {
2451 if (mp != dl[x].mptr) { /* bad cursor? */
2452 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
2453 txn->mt_flags |= MDB_TXN_ERROR;
2454 return MDB_CORRUPTED;
2459 mdb_cassert(mc, dl[0].mid < MDB_IDL_UM_MAX);
2461 np = mdb_page_malloc(txn, 1);
2466 rc = mdb_mid2l_insert(dl, &mid);
2467 mdb_cassert(mc, rc == 0);
2472 mdb_page_copy(np, mp, txn->mt_env->me_psize);
2474 np->mp_flags |= P_DIRTY;
2477 /* Adjust cursors pointing to mp */
2478 mc->mc_pg[mc->mc_top] = np;
2479 m2 = txn->mt_cursors[mc->mc_dbi];
2480 if (mc->mc_flags & C_SUB) {
2481 for (; m2; m2=m2->mc_next) {
2482 m3 = &m2->mc_xcursor->mx_cursor;
2483 if (m3->mc_snum < mc->mc_snum) continue;
2484 if (m3->mc_pg[mc->mc_top] == mp)
2485 m3->mc_pg[mc->mc_top] = np;
2488 for (; m2; m2=m2->mc_next) {
2489 if (m2->mc_snum < mc->mc_snum) continue;
2490 if (m2 == mc) continue;
2491 if (m2->mc_pg[mc->mc_top] == mp) {
2492 m2->mc_pg[mc->mc_top] = np;
2493 if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
2495 m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top])
2497 MDB_node *leaf = NODEPTR(np, mc->mc_ki[mc->mc_top]);
2498 if (!(leaf->mn_flags & F_SUBDATA))
2499 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
2507 txn->mt_flags |= MDB_TXN_ERROR;
2512 mdb_env_sync(MDB_env *env, int force)
2515 if (env->me_flags & MDB_RDONLY)
2517 if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) {
2518 if (env->me_flags & MDB_WRITEMAP) {
2519 int flags = ((env->me_flags & MDB_MAPASYNC) && !force)
2520 ? MS_ASYNC : MS_SYNC;
2521 if (MDB_MSYNC(env->me_map, env->me_mapsize, flags))
2524 else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd))
2528 #ifdef BROKEN_FDATASYNC
2529 if (env->me_flags & MDB_FSYNCONLY) {
2530 if (fsync(env->me_fd))
2534 if (MDB_FDATASYNC(env->me_fd))
2541 /** Back up parent txn's cursors, then grab the originals for tracking */
2543 mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst)
2545 MDB_cursor *mc, *bk;
2550 for (i = src->mt_numdbs; --i >= 0; ) {
2551 if ((mc = src->mt_cursors[i]) != NULL) {
2552 size = sizeof(MDB_cursor);
2554 size += sizeof(MDB_xcursor);
2555 for (; mc; mc = bk->mc_next) {
2561 mc->mc_db = &dst->mt_dbs[i];
2562 /* Kill pointers into src to reduce abuse: The
2563 * user may not use mc until dst ends. But we need a valid
2564 * txn pointer here for cursor fixups to keep working.
2567 mc->mc_dbflag = &dst->mt_dbflags[i];
2568 if ((mx = mc->mc_xcursor) != NULL) {
2569 *(MDB_xcursor *)(bk+1) = *mx;
2570 mx->mx_cursor.mc_txn = dst;
2572 mc->mc_next = dst->mt_cursors[i];
2573 dst->mt_cursors[i] = mc;
2580 /** Close this write txn's cursors, give parent txn's cursors back to parent.
2581 * @param[in] txn the transaction handle.
2582 * @param[in] merge true to keep changes to parent cursors, false to revert.
2583 * @return 0 on success, non-zero on failure.
2586 mdb_cursors_close(MDB_txn *txn, unsigned merge)
2588 MDB_cursor **cursors = txn->mt_cursors, *mc, *next, *bk;
2592 for (i = txn->mt_numdbs; --i >= 0; ) {
2593 for (mc = cursors[i]; mc; mc = next) {
2595 if ((bk = mc->mc_backup) != NULL) {
2597 /* Commit changes to parent txn */
2598 mc->mc_next = bk->mc_next;
2599 mc->mc_backup = bk->mc_backup;
2600 mc->mc_txn = bk->mc_txn;
2601 mc->mc_db = bk->mc_db;
2602 mc->mc_dbflag = bk->mc_dbflag;
2603 if ((mx = mc->mc_xcursor) != NULL)
2604 mx->mx_cursor.mc_txn = bk->mc_txn;
2606 /* Abort nested txn */
2608 if ((mx = mc->mc_xcursor) != NULL)
2609 *mx = *(MDB_xcursor *)(bk+1);
2613 /* Only malloced cursors are permanently tracked. */
2620 #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
2626 Pidset = F_SETLK, Pidcheck = F_GETLK
2630 /** Set or check a pid lock. Set returns 0 on success.
2631 * Check returns 0 if the process is certainly dead, nonzero if it may
2632 * be alive (the lock exists or an error happened so we do not know).
2634 * On Windows Pidset is a no-op, we merely check for the existence
2635 * of the process with the given pid. On POSIX we use a single byte
2636 * lock on the lockfile, set at an offset equal to the pid.
2639 mdb_reader_pid(MDB_env *env, enum Pidlock_op op, MDB_PID_T pid)
2641 #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
2644 if (op == Pidcheck) {
2645 h = OpenProcess(env->me_pidquery, FALSE, pid);
2646 /* No documented "no such process" code, but other program use this: */
2648 return ErrCode() != ERROR_INVALID_PARAMETER;
2649 /* A process exists until all handles to it close. Has it exited? */
2650 ret = WaitForSingleObject(h, 0) != 0;
2657 struct flock lock_info;
2658 memset(&lock_info, 0, sizeof(lock_info));
2659 lock_info.l_type = F_WRLCK;
2660 lock_info.l_whence = SEEK_SET;
2661 lock_info.l_start = pid;
2662 lock_info.l_len = 1;
2663 if ((rc = fcntl(env->me_lfd, op, &lock_info)) == 0) {
2664 if (op == F_GETLK && lock_info.l_type != F_UNLCK)
2666 } else if ((rc = ErrCode()) == EINTR) {
2674 /** Common code for #mdb_txn_begin() and #mdb_txn_renew().
2675 * @param[in] txn the transaction handle to initialize
2676 * @return 0 on success, non-zero on failure.
2679 mdb_txn_renew0(MDB_txn *txn)
2681 MDB_env *env = txn->mt_env;
2682 MDB_txninfo *ti = env->me_txns;
2684 unsigned int i, nr, flags = txn->mt_flags;
2686 int rc, new_notls = 0;
2688 if ((flags &= MDB_TXN_RDONLY) != 0) {
2690 meta = mdb_env_pick_meta(env);
2691 txn->mt_txnid = meta->mm_txnid;
2692 txn->mt_u.reader = NULL;
2694 MDB_reader *r = (env->me_flags & MDB_NOTLS) ? txn->mt_u.reader :
2695 pthread_getspecific(env->me_txkey);
2697 if (r->mr_pid != env->me_pid || r->mr_txnid != (txnid_t)-1)
2698 return MDB_BAD_RSLOT;
2700 MDB_PID_T pid = env->me_pid;
2701 MDB_THR_T tid = pthread_self();
2702 mdb_mutexref_t rmutex = env->me_rmutex;
2704 if (!env->me_live_reader) {
2705 rc = mdb_reader_pid(env, Pidset, pid);
2708 env->me_live_reader = 1;
2711 if (LOCK_MUTEX(rc, env, rmutex))
2713 nr = ti->mti_numreaders;
2714 for (i=0; i<nr; i++)
2715 if (ti->mti_readers[i].mr_pid == 0)
2717 if (i == env->me_maxreaders) {
2718 UNLOCK_MUTEX(rmutex);
2719 return MDB_READERS_FULL;
2721 r = &ti->mti_readers[i];
2722 /* Claim the reader slot, carefully since other code
2723 * uses the reader table un-mutexed: First reset the
2724 * slot, next publish it in mti_numreaders. After
2725 * that, it is safe for mdb_env_close() to touch it.
2726 * When it will be closed, we can finally claim it.
2729 r->mr_txnid = (txnid_t)-1;
2732 ti->mti_numreaders = ++nr;
2733 env->me_close_readers = nr;
2735 UNLOCK_MUTEX(rmutex);
2737 new_notls = (env->me_flags & MDB_NOTLS);
2738 if (!new_notls && (rc=pthread_setspecific(env->me_txkey, r))) {
2743 do /* LY: Retry on a race, ITS#7970. */
2744 r->mr_txnid = ti->mti_txnid;
2745 while(r->mr_txnid != ti->mti_txnid);
2746 txn->mt_txnid = r->mr_txnid;
2747 txn->mt_u.reader = r;
2748 meta = env->me_metas[txn->mt_txnid & 1];
2752 /* Not yet touching txn == env->me_txn0, it may be active */
2754 if (LOCK_MUTEX(rc, env, env->me_wmutex))
2756 txn->mt_txnid = ti->mti_txnid;
2757 meta = env->me_metas[txn->mt_txnid & 1];
2759 meta = mdb_env_pick_meta(env);
2760 txn->mt_txnid = meta->mm_txnid;
2764 if (txn->mt_txnid == mdb_debug_start)
2767 txn->mt_child = NULL;
2768 txn->mt_loose_pgs = NULL;
2769 txn->mt_loose_count = 0;
2770 txn->mt_dirty_room = MDB_IDL_UM_MAX;
2771 txn->mt_u.dirty_list = env->me_dirty_list;
2772 txn->mt_u.dirty_list[0].mid = 0;
2773 txn->mt_free_pgs = env->me_free_pgs;
2774 txn->mt_free_pgs[0] = 0;
2775 txn->mt_spill_pgs = NULL;
2777 memcpy(txn->mt_dbiseqs, env->me_dbiseqs, env->me_maxdbs * sizeof(unsigned int));
2780 /* Copy the DB info and flags */
2781 memcpy(txn->mt_dbs, meta->mm_dbs, CORE_DBS * sizeof(MDB_db));
2783 /* Moved to here to avoid a data race in read TXNs */
2784 txn->mt_next_pgno = meta->mm_last_pg+1;
2786 txn->mt_flags = flags;
2789 txn->mt_numdbs = env->me_numdbs;
2790 for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
2791 x = env->me_dbflags[i];
2792 txn->mt_dbs[i].md_flags = x & PERSISTENT_FLAGS;
2793 txn->mt_dbflags[i] = (x & MDB_VALID) ? DB_VALID|DB_USRVALID|DB_STALE : 0;
2795 txn->mt_dbflags[MAIN_DBI] = DB_VALID|DB_USRVALID;
2796 txn->mt_dbflags[FREE_DBI] = DB_VALID;
2798 if (env->me_flags & MDB_FATAL_ERROR) {
2799 DPUTS("environment had fatal error, must shutdown!");
2801 } else if (env->me_maxpg < txn->mt_next_pgno) {
2802 rc = MDB_MAP_RESIZED;
2806 mdb_txn_end(txn, new_notls /*0 or MDB_END_SLOT*/ | MDB_END_FAIL_BEGIN);
2811 mdb_txn_renew(MDB_txn *txn)
2815 if (!txn || !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY|MDB_TXN_FINISHED))
2818 rc = mdb_txn_renew0(txn);
2819 if (rc == MDB_SUCCESS) {
2820 DPRINTF(("renew txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2821 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2822 (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root));
2828 mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
2832 int rc, size, tsize;
2834 flags &= MDB_TXN_BEGIN_FLAGS;
2835 flags |= env->me_flags & MDB_WRITEMAP;
2837 if (env->me_flags & MDB_RDONLY & ~flags) /* write txn in RDONLY env */
2841 /* Nested transactions: Max 1 child, write txns only, no writemap */
2842 flags |= parent->mt_flags;
2843 if (flags & (MDB_RDONLY|MDB_WRITEMAP|MDB_TXN_BLOCKED)) {
2844 return (parent->mt_flags & MDB_TXN_RDONLY) ? EINVAL : MDB_BAD_TXN;
2846 /* Child txns save MDB_pgstate and use own copy of cursors */
2847 size = env->me_maxdbs * (sizeof(MDB_db)+sizeof(MDB_cursor *)+1);
2848 size += tsize = sizeof(MDB_ntxn);
2849 } else if (flags & MDB_RDONLY) {
2850 size = env->me_maxdbs * (sizeof(MDB_db)+1);
2851 size += tsize = sizeof(MDB_txn);
2853 /* Reuse preallocated write txn. However, do not touch it until
2854 * mdb_txn_renew0() succeeds, since it currently may be active.
2859 if ((txn = calloc(1, size)) == NULL) {
2860 DPRINTF(("calloc: %s", strerror(errno)));
2863 txn->mt_dbxs = env->me_dbxs; /* static */
2864 txn->mt_dbs = (MDB_db *) ((char *)txn + tsize);
2865 txn->mt_dbflags = (unsigned char *)txn + size - env->me_maxdbs;
2866 txn->mt_flags = flags;
2871 txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
2872 txn->mt_dbiseqs = parent->mt_dbiseqs;
2873 txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE);
2874 if (!txn->mt_u.dirty_list ||
2875 !(txn->mt_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)))
2877 free(txn->mt_u.dirty_list);
2881 txn->mt_txnid = parent->mt_txnid;
2882 txn->mt_dirty_room = parent->mt_dirty_room;
2883 txn->mt_u.dirty_list[0].mid = 0;
2884 txn->mt_spill_pgs = NULL;
2885 txn->mt_next_pgno = parent->mt_next_pgno;
2886 parent->mt_flags |= MDB_TXN_HAS_CHILD;
2887 parent->mt_child = txn;
2888 txn->mt_parent = parent;
2889 txn->mt_numdbs = parent->mt_numdbs;
2890 memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
2891 /* Copy parent's mt_dbflags, but clear DB_NEW */
2892 for (i=0; i<txn->mt_numdbs; i++)
2893 txn->mt_dbflags[i] = parent->mt_dbflags[i] & ~DB_NEW;
2895 ntxn = (MDB_ntxn *)txn;
2896 ntxn->mnt_pgstate = env->me_pgstate; /* save parent me_pghead & co */
2897 if (env->me_pghead) {
2898 size = MDB_IDL_SIZEOF(env->me_pghead);
2899 env->me_pghead = mdb_midl_alloc(env->me_pghead[0]);
2901 memcpy(env->me_pghead, ntxn->mnt_pgstate.mf_pghead, size);
2906 rc = mdb_cursor_shadow(parent, txn);
2908 mdb_txn_end(txn, MDB_END_FAIL_BEGINCHILD);
2909 } else { /* MDB_RDONLY */
2910 txn->mt_dbiseqs = env->me_dbiseqs;
2912 rc = mdb_txn_renew0(txn);
2915 if (txn != env->me_txn0)
2918 txn->mt_flags |= flags; /* could not change txn=me_txn0 earlier */
2920 DPRINTF(("begin txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2921 txn->mt_txnid, (flags & MDB_RDONLY) ? 'r' : 'w',
2922 (void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root));
2929 mdb_txn_env(MDB_txn *txn)
2931 if(!txn) return NULL;
2936 mdb_txn_id(MDB_txn *txn)
2939 return txn->mt_txnid;
2942 /** Export or close DBI handles opened in this txn. */
2944 mdb_dbis_update(MDB_txn *txn, int keep)
2947 MDB_dbi n = txn->mt_numdbs;
2948 MDB_env *env = txn->mt_env;
2949 unsigned char *tdbflags = txn->mt_dbflags;
2951 for (i = n; --i >= CORE_DBS;) {
2952 if (tdbflags[i] & DB_NEW) {
2954 env->me_dbflags[i] = txn->mt_dbs[i].md_flags | MDB_VALID;
2956 char *ptr = env->me_dbxs[i].md_name.mv_data;
2958 env->me_dbxs[i].md_name.mv_data = NULL;
2959 env->me_dbxs[i].md_name.mv_size = 0;
2960 env->me_dbflags[i] = 0;
2961 env->me_dbiseqs[i]++;
2967 if (keep && env->me_numdbs < n)
2971 /** End a transaction, except successful commit of a nested transaction.
2972 * May be called twice for readonly txns: First reset it, then abort.
2973 * @param[in] txn the transaction handle to end
2974 * @param[in] mode why and how to end the transaction
2977 mdb_txn_end(MDB_txn *txn, unsigned mode)
2979 MDB_env *env = txn->mt_env;
2981 static const char *const names[] = MDB_END_NAMES;
2984 /* Export or close DBI handles opened in this txn */
2985 mdb_dbis_update(txn, mode & MDB_END_UPDATE);
2987 DPRINTF(("%s txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2988 names[mode & MDB_END_OPMASK],
2989 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2990 (void *) txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root));
2992 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
2993 if (txn->mt_u.reader) {
2994 txn->mt_u.reader->mr_txnid = (txnid_t)-1;
2995 if (!(env->me_flags & MDB_NOTLS)) {
2996 txn->mt_u.reader = NULL; /* txn does not own reader */
2997 } else if (mode & MDB_END_SLOT) {
2998 txn->mt_u.reader->mr_pid = 0;
2999 txn->mt_u.reader = NULL;
3000 } /* else txn owns the slot until it does MDB_END_SLOT */
3002 txn->mt_numdbs = 0; /* prevent further DBI activity */
3003 txn->mt_flags |= MDB_TXN_FINISHED;
3005 } else if (!F_ISSET(txn->mt_flags, MDB_TXN_FINISHED)) {
3006 pgno_t *pghead = env->me_pghead;
3008 if (!(mode & MDB_END_UPDATE)) /* !(already closed cursors) */
3009 mdb_cursors_close(txn, 0);
3010 if (!(env->me_flags & MDB_WRITEMAP)) {
3011 mdb_dlist_free(txn);
3015 txn->mt_flags = MDB_TXN_FINISHED;
3017 if (!txn->mt_parent) {
3018 mdb_midl_shrink(&txn->mt_free_pgs);
3019 env->me_free_pgs = txn->mt_free_pgs;
3021 env->me_pghead = NULL;
3025 mode = 0; /* txn == env->me_txn0, do not free() it */
3027 /* The writer mutex was locked in mdb_txn_begin. */
3029 UNLOCK_MUTEX(env->me_wmutex);
3031 txn->mt_parent->mt_child = NULL;
3032 txn->mt_parent->mt_flags &= ~MDB_TXN_HAS_CHILD;
3033 env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate;
3034 mdb_midl_free(txn->mt_free_pgs);
3035 mdb_midl_free(txn->mt_spill_pgs);
3036 free(txn->mt_u.dirty_list);
3039 mdb_midl_free(pghead);
3042 if (mode & MDB_END_FREE)
3047 mdb_txn_reset(MDB_txn *txn)
3052 /* This call is only valid for read-only txns */
3053 if (!(txn->mt_flags & MDB_TXN_RDONLY))
3056 mdb_txn_end(txn, MDB_END_RESET);
3060 mdb_txn_abort(MDB_txn *txn)
3066 mdb_txn_abort(txn->mt_child);
3068 mdb_txn_end(txn, MDB_END_ABORT|MDB_END_SLOT|MDB_END_FREE);
3071 /** Save the freelist as of this transaction to the freeDB.
3072 * This changes the freelist. Keep trying until it stabilizes.
3075 mdb_freelist_save(MDB_txn *txn)
3077 /* env->me_pghead[] can grow and shrink during this call.
3078 * env->me_pglast and txn->mt_free_pgs[] can only grow.
3079 * Page numbers cannot disappear from txn->mt_free_pgs[].
3082 MDB_env *env = txn->mt_env;
3083 int rc, maxfree_1pg = env->me_maxfree_1pg, more = 1;
3084 txnid_t pglast = 0, head_id = 0;
3085 pgno_t freecnt = 0, *free_pgs, *mop;
3086 ssize_t head_room = 0, total_room = 0, mop_len, clean_limit;
3088 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
3090 if (env->me_pghead) {
3091 /* Make sure first page of freeDB is touched and on freelist */
3092 rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST|MDB_PS_MODIFY);
3093 if (rc && rc != MDB_NOTFOUND)
3097 if (!env->me_pghead && txn->mt_loose_pgs) {
3098 /* Put loose page numbers in mt_free_pgs, since
3099 * we may be unable to return them to me_pghead.
3101 MDB_page *mp = txn->mt_loose_pgs;
3102 if ((rc = mdb_midl_need(&txn->mt_free_pgs, txn->mt_loose_count)) != 0)
3104 for (; mp; mp = NEXT_LOOSE_PAGE(mp))
3105 mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
3106 txn->mt_loose_pgs = NULL;
3107 txn->mt_loose_count = 0;
3110 /* MDB_RESERVE cancels meminit in ovpage malloc (when no WRITEMAP) */
3111 clean_limit = (env->me_flags & (MDB_NOMEMINIT|MDB_WRITEMAP))
3112 ? SSIZE_MAX : maxfree_1pg;
3115 /* Come back here after each Put() in case freelist changed */
3120 /* If using records from freeDB which we have not yet
3121 * deleted, delete them and any we reserved for me_pghead.
3123 while (pglast < env->me_pglast) {
3124 rc = mdb_cursor_first(&mc, &key, NULL);
3127 pglast = head_id = *(txnid_t *)key.mv_data;
3128 total_room = head_room = 0;
3129 mdb_tassert(txn, pglast <= env->me_pglast);
3130 rc = mdb_cursor_del(&mc, 0);
3135 /* Save the IDL of pages freed by this txn, to a single record */
3136 if (freecnt < txn->mt_free_pgs[0]) {
3138 /* Make sure last page of freeDB is touched and on freelist */
3139 rc = mdb_page_search(&mc, NULL, MDB_PS_LAST|MDB_PS_MODIFY);
3140 if (rc && rc != MDB_NOTFOUND)
3143 free_pgs = txn->mt_free_pgs;
3144 /* Write to last page of freeDB */
3145 key.mv_size = sizeof(txn->mt_txnid);
3146 key.mv_data = &txn->mt_txnid;
3148 freecnt = free_pgs[0];
3149 data.mv_size = MDB_IDL_SIZEOF(free_pgs);
3150 rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
3153 /* Retry if mt_free_pgs[] grew during the Put() */
3154 free_pgs = txn->mt_free_pgs;
3155 } while (freecnt < free_pgs[0]);
3156 mdb_midl_sort(free_pgs);
3157 memcpy(data.mv_data, free_pgs, data.mv_size);
3160 unsigned int i = free_pgs[0];
3161 DPRINTF(("IDL write txn %"Z"u root %"Z"u num %u",
3162 txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, i));
3164 DPRINTF(("IDL %"Z"u", free_pgs[i]));
3170 mop = env->me_pghead;
3171 mop_len = (mop ? mop[0] : 0) + txn->mt_loose_count;
3173 /* Reserve records for me_pghead[]. Split it if multi-page,
3174 * to avoid searching freeDB for a page range. Use keys in
3175 * range [1,me_pglast]: Smaller than txnid of oldest reader.
3177 if (total_room >= mop_len) {
3178 if (total_room == mop_len || --more < 0)
3180 } else if (head_room >= maxfree_1pg && head_id > 1) {
3181 /* Keep current record (overflow page), add a new one */
3185 /* (Re)write {key = head_id, IDL length = head_room} */
3186 total_room -= head_room;
3187 head_room = mop_len - total_room;
3188 if (head_room > maxfree_1pg && head_id > 1) {
3189 /* Overflow multi-page for part of me_pghead */
3190 head_room /= head_id; /* amortize page sizes */
3191 head_room += maxfree_1pg - head_room % (maxfree_1pg + 1);
3192 } else if (head_room < 0) {
3193 /* Rare case, not bothering to delete this record */
3196 key.mv_size = sizeof(head_id);
3197 key.mv_data = &head_id;
3198 data.mv_size = (head_room + 1) * sizeof(pgno_t);
3199 rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
3202 /* IDL is initially empty, zero out at least the length */
3203 pgs = (pgno_t *)data.mv_data;
3204 j = head_room > clean_limit ? head_room : 0;
3208 total_room += head_room;
3211 /* Return loose page numbers to me_pghead, though usually none are
3212 * left at this point. The pages themselves remain in dirty_list.
3214 if (txn->mt_loose_pgs) {
3215 MDB_page *mp = txn->mt_loose_pgs;
3216 unsigned count = txn->mt_loose_count;
3218 /* Room for loose pages + temp IDL with same */
3219 if ((rc = mdb_midl_need(&env->me_pghead, 2*count+1)) != 0)
3221 mop = env->me_pghead;
3222 loose = mop + MDB_IDL_ALLOCLEN(mop) - count;
3223 for (count = 0; mp; mp = NEXT_LOOSE_PAGE(mp))
3224 loose[ ++count ] = mp->mp_pgno;
3226 mdb_midl_sort(loose);
3227 mdb_midl_xmerge(mop, loose);
3228 txn->mt_loose_pgs = NULL;
3229 txn->mt_loose_count = 0;
3233 /* Fill in the reserved me_pghead records */
3239 rc = mdb_cursor_first(&mc, &key, &data);
3240 for (; !rc; rc = mdb_cursor_next(&mc, &key, &data, MDB_NEXT)) {
3241 txnid_t id = *(txnid_t *)key.mv_data;
3242 ssize_t len = (ssize_t)(data.mv_size / sizeof(MDB_ID)) - 1;
3245 mdb_tassert(txn, len >= 0 && id <= env->me_pglast);
3247 if (len > mop_len) {
3249 data.mv_size = (len + 1) * sizeof(MDB_ID);
3251 data.mv_data = mop -= len;
3254 rc = mdb_cursor_put(&mc, &key, &data, MDB_CURRENT);
3256 if (rc || !(mop_len -= len))
3263 /** Flush (some) dirty pages to the map, after clearing their dirty flag.
3264 * @param[in] txn the transaction that's being committed
3265 * @param[in] keep number of initial pages in dirty_list to keep dirty.
3266 * @return 0 on success, non-zero on failure.
3269 mdb_page_flush(MDB_txn *txn, int keep)
3271 MDB_env *env = txn->mt_env;
3272 MDB_ID2L dl = txn->mt_u.dirty_list;
3273 unsigned psize = env->me_psize, j;
3274 int i, pagecount = dl[0].mid, rc;
3275 size_t size = 0, pos = 0;
3277 MDB_page *dp = NULL;
3281 struct iovec iov[MDB_COMMIT_PAGES];
3282 ssize_t wpos = 0, wsize = 0, wres;
3283 size_t next_pos = 1; /* impossible pos, so pos != next_pos */
3289 if (env->me_flags & MDB_WRITEMAP) {
3290 /* Clear dirty flags */
3291 while (++i <= pagecount) {
3293 /* Don't flush this page yet */
3294 if (dp->mp_flags & (P_LOOSE|P_KEEP)) {
3295 dp->mp_flags &= ~P_KEEP;
3299 dp->mp_flags &= ~P_DIRTY;
3304 /* Write the pages */
3306 if (++i <= pagecount) {
3308 /* Don't flush this page yet */
3309 if (dp->mp_flags & (P_LOOSE|P_KEEP)) {
3310 dp->mp_flags &= ~P_KEEP;
3315 /* clear dirty flag */
3316 dp->mp_flags &= ~P_DIRTY;
3319 if (IS_OVERFLOW(dp)) size *= dp->mp_pages;
3324 /* Windows actually supports scatter/gather I/O, but only on
3325 * unbuffered file handles. Since we're relying on the OS page
3326 * cache for all our data, that's self-defeating. So we just
3327 * write pages one at a time. We use the ov structure to set
3328 * the write offset, to at least save the overhead of a Seek
3331 DPRINTF(("committing page %"Z"u", pgno));
3332 memset(&ov, 0, sizeof(ov));
3333 ov.Offset = pos & 0xffffffff;
3334 ov.OffsetHigh = pos >> 16 >> 16;
3335 if (!WriteFile(env->me_fd, dp, size, NULL, &ov)) {
3337 DPRINTF(("WriteFile: %d", rc));
3341 /* Write up to MDB_COMMIT_PAGES dirty pages at a time. */
3342 if (pos!=next_pos || n==MDB_COMMIT_PAGES || wsize+size>MAX_WRITE) {
3345 /* Write previous page(s) */
3346 #ifdef MDB_USE_PWRITEV
3347 wres = pwritev(env->me_fd, iov, n, wpos);
3350 wres = pwrite(env->me_fd, iov[0].iov_base, wsize, wpos);
3353 if (lseek(env->me_fd, wpos, SEEK_SET) == -1) {
3357 DPRINTF(("lseek: %s", strerror(rc)));
3360 wres = writev(env->me_fd, iov, n);
3363 if (wres != wsize) {
3368 DPRINTF(("Write error: %s", strerror(rc)));
3370 rc = EIO; /* TODO: Use which error code? */
3371 DPUTS("short write, filesystem full?");
3382 DPRINTF(("committing page %"Z"u", pgno));
3383 next_pos = pos + size;
3384 iov[n].iov_len = size;
3385 iov[n].iov_base = (char *)dp;
3391 /* MIPS has cache coherency issues, this is a no-op everywhere else
3392 * Note: for any size >= on-chip cache size, entire on-chip cache is
3395 CACHEFLUSH(env->me_map, txn->mt_next_pgno * env->me_psize, DCACHE);
3397 for (i = keep; ++i <= pagecount; ) {
3399 /* This is a page we skipped above */
3402 dl[j].mid = dp->mp_pgno;
3405 mdb_dpage_free(env, dp);
3410 txn->mt_dirty_room += i - j;
3416 mdb_txn_commit(MDB_txn *txn)
3419 unsigned int i, end_mode;
3425 /* mdb_txn_end() mode for a commit which writes nothing */
3426 end_mode = MDB_END_EMPTY_COMMIT|MDB_END_UPDATE|MDB_END_SLOT|MDB_END_FREE;
3428 if (txn->mt_child) {
3429 rc = mdb_txn_commit(txn->mt_child);
3436 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
3440 if (txn->mt_flags & (MDB_TXN_FINISHED|MDB_TXN_ERROR)) {
3441 DPUTS("txn has failed/finished, can't commit");
3443 txn->mt_parent->mt_flags |= MDB_TXN_ERROR;
3448 if (txn->mt_parent) {
3449 MDB_txn *parent = txn->mt_parent;
3453 unsigned x, y, len, ps_len;
3455 /* Append our free list to parent's */
3456 rc = mdb_midl_append_list(&parent->mt_free_pgs, txn->mt_free_pgs);
3459 mdb_midl_free(txn->mt_free_pgs);
3460 /* Failures after this must either undo the changes
3461 * to the parent or set MDB_TXN_ERROR in the parent.
3464 parent->mt_next_pgno = txn->mt_next_pgno;
3465 parent->mt_flags = txn->mt_flags;
3467 /* Merge our cursors into parent's and close them */
3468 mdb_cursors_close(txn, 1);
3470 /* Update parent's DB table. */
3471 memcpy(parent->mt_dbs, txn->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
3472 parent->mt_numdbs = txn->mt_numdbs;
3473 parent->mt_dbflags[FREE_DBI] = txn->mt_dbflags[FREE_DBI];
3474 parent->mt_dbflags[MAIN_DBI] = txn->mt_dbflags[MAIN_DBI];
3475 for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
3476 /* preserve parent's DB_NEW status */
3477 x = parent->mt_dbflags[i] & DB_NEW;
3478 parent->mt_dbflags[i] = txn->mt_dbflags[i] | x;
3481 dst = parent->mt_u.dirty_list;
3482 src = txn->mt_u.dirty_list;
3483 /* Remove anything in our dirty list from parent's spill list */
3484 if ((pspill = parent->mt_spill_pgs) && (ps_len = pspill[0])) {
3486 pspill[0] = (pgno_t)-1;
3487 /* Mark our dirty pages as deleted in parent spill list */
3488 for (i=0, len=src[0].mid; ++i <= len; ) {
3489 MDB_ID pn = src[i].mid << 1;
3490 while (pn > pspill[x])
3492 if (pn == pspill[x]) {
3497 /* Squash deleted pagenums if we deleted any */
3498 for (x=y; ++x <= ps_len; )
3499 if (!(pspill[x] & 1))
3500 pspill[++y] = pspill[x];
3504 /* Remove anything in our spill list from parent's dirty list */
3505 if (txn->mt_spill_pgs && txn->mt_spill_pgs[0]) {
3506 for (i=1; i<=txn->mt_spill_pgs[0]; i++) {
3507 MDB_ID pn = txn->mt_spill_pgs[i];
3509 continue; /* deleted spillpg */
3511 y = mdb_mid2l_search(dst, pn);
3512 if (y <= dst[0].mid && dst[y].mid == pn) {
3514 while (y < dst[0].mid) {
3523 /* Find len = length of merging our dirty list with parent's */
3525 dst[0].mid = 0; /* simplify loops */
3526 if (parent->mt_parent) {
3527 len = x + src[0].mid;
3528 y = mdb_mid2l_search(src, dst[x].mid + 1) - 1;
3529 for (i = x; y && i; y--) {
3530 pgno_t yp = src[y].mid;
3531 while (yp < dst[i].mid)
3533 if (yp == dst[i].mid) {
3538 } else { /* Simplify the above for single-ancestor case */
3539 len = MDB_IDL_UM_MAX - txn->mt_dirty_room;
3541 /* Merge our dirty list with parent's */
3543 for (i = len; y; dst[i--] = src[y--]) {
3544 pgno_t yp = src[y].mid;
3545 while (yp < dst[x].mid)
3546 dst[i--] = dst[x--];
3547 if (yp == dst[x].mid)
3548 free(dst[x--].mptr);
3550 mdb_tassert(txn, i == x);
3552 free(txn->mt_u.dirty_list);
3553 parent->mt_dirty_room = txn->mt_dirty_room;
3554 if (txn->mt_spill_pgs) {
3555 if (parent->mt_spill_pgs) {
3556 /* TODO: Prevent failure here, so parent does not fail */
3557 rc = mdb_midl_append_list(&parent->mt_spill_pgs, txn->mt_spill_pgs);
3559 parent->mt_flags |= MDB_TXN_ERROR;
3560 mdb_midl_free(txn->mt_spill_pgs);
3561 mdb_midl_sort(parent->mt_spill_pgs);
3563 parent->mt_spill_pgs = txn->mt_spill_pgs;
3567 /* Append our loose page list to parent's */
3568 for (lp = &parent->mt_loose_pgs; *lp; lp = &NEXT_LOOSE_PAGE(*lp))
3570 *lp = txn->mt_loose_pgs;
3571 parent->mt_loose_count += txn->mt_loose_count;
3573 parent->mt_child = NULL;
3574 mdb_midl_free(((MDB_ntxn *)txn)->mnt_pgstate.mf_pghead);
3579 if (txn != env->me_txn) {
3580 DPUTS("attempt to commit unknown transaction");
3585 mdb_cursors_close(txn, 0);
3587 if (!txn->mt_u.dirty_list[0].mid &&
3588 !(txn->mt_flags & (MDB_TXN_DIRTY|MDB_TXN_SPILLS)))
3591 DPRINTF(("committing txn %"Z"u %p on mdbenv %p, root page %"Z"u",
3592 txn->mt_txnid, (void*)txn, (void*)env, txn->mt_dbs[MAIN_DBI].md_root));
3594 /* Update DB root pointers */
3595 if (txn->mt_numdbs > CORE_DBS) {
3599 data.mv_size = sizeof(MDB_db);
3601 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
3602 for (i = CORE_DBS; i < txn->mt_numdbs; i++) {
3603 if (txn->mt_dbflags[i] & DB_DIRTY) {
3604 if (TXN_DBI_CHANGED(txn, i)) {
3608 data.mv_data = &txn->mt_dbs[i];
3609 rc = mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data,
3617 rc = mdb_freelist_save(txn);
3621 mdb_midl_free(env->me_pghead);
3622 env->me_pghead = NULL;
3623 mdb_midl_shrink(&txn->mt_free_pgs);
3629 if ((rc = mdb_page_flush(txn, 0)))
3631 if (!F_ISSET(txn->mt_flags, MDB_TXN_NOSYNC) &&
3632 (rc = mdb_env_sync(env, 0)))
3634 if ((rc = mdb_env_write_meta(txn)))
3636 end_mode = MDB_END_COMMITTED|MDB_END_UPDATE;
3639 mdb_txn_end(txn, end_mode);
3647 /** Read the environment parameters of a DB environment before
3648 * mapping it into memory.
3649 * @param[in] env the environment handle
3650 * @param[out] meta address of where to store the meta information
3651 * @return 0 on success, non-zero on failure.
3654 mdb_env_read_header(MDB_env *env, MDB_meta *meta)
3660 enum { Size = sizeof(pbuf) };
3662 /* We don't know the page size yet, so use a minimum value.
3663 * Read both meta pages so we can use the latest one.
3666 for (i=off=0; i<NUM_METAS; i++, off += meta->mm_psize) {
3670 memset(&ov, 0, sizeof(ov));
3672 rc = ReadFile(env->me_fd, &pbuf, Size, &len, &ov) ? (int)len : -1;
3673 if (rc == -1 && ErrCode() == ERROR_HANDLE_EOF)
3676 rc = pread(env->me_fd, &pbuf, Size, off);
3679 if (rc == 0 && off == 0)
3681 rc = rc < 0 ? (int) ErrCode() : MDB_INVALID;
3682 DPRINTF(("read: %s", mdb_strerror(rc)));
3686 p = (MDB_page *)&pbuf;
3688 if (!F_ISSET(p->mp_flags, P_META)) {
3689 DPRINTF(("page %"Z"u not a meta page", p->mp_pgno));
3694 if (m->mm_magic != MDB_MAGIC) {
3695 DPUTS("meta has invalid magic");
3699 if (m->mm_version != MDB_DATA_VERSION) {
3700 DPRINTF(("database is version %u, expected version %u",
3701 m->mm_version, MDB_DATA_VERSION));
3702 return MDB_VERSION_MISMATCH;
3705 if (off == 0 || m->mm_txnid > meta->mm_txnid)
3711 /** Fill in most of the zeroed #MDB_meta for an empty database environment */
3713 mdb_env_init_meta0(MDB_env *env, MDB_meta *meta)
3715 meta->mm_magic = MDB_MAGIC;
3716 meta->mm_version = MDB_DATA_VERSION;
3717 meta->mm_mapsize = env->me_mapsize;
3718 meta->mm_psize = env->me_psize;
3719 meta->mm_last_pg = NUM_METAS-1;
3720 meta->mm_flags = env->me_flags & 0xffff;
3721 meta->mm_flags |= MDB_INTEGERKEY; /* this is mm_dbs[FREE_DBI].md_flags */
3722 meta->mm_dbs[FREE_DBI].md_root = P_INVALID;
3723 meta->mm_dbs[MAIN_DBI].md_root = P_INVALID;
3726 /** Write the environment parameters of a freshly created DB environment.
3727 * @param[in] env the environment handle
3728 * @param[in] meta the #MDB_meta to write
3729 * @return 0 on success, non-zero on failure.
3732 mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
3740 memset(&ov, 0, sizeof(ov));
3741 #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
3743 rc = WriteFile(fd, ptr, size, &len, &ov); } while(0)
3746 #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
3747 len = pwrite(fd, ptr, size, pos); \
3748 if (len == -1 && ErrCode() == EINTR) continue; \
3749 rc = (len >= 0); break; } while(1)
3752 DPUTS("writing new meta page");
3754 psize = env->me_psize;
3756 p = calloc(NUM_METAS, psize);
3760 p->mp_flags = P_META;
3761 *(MDB_meta *)METADATA(p) = *meta;
3763 q = (MDB_page *)((char *)p + psize);
3765 q->mp_flags = P_META;
3766 *(MDB_meta *)METADATA(q) = *meta;
3768 DO_PWRITE(rc, env->me_fd, p, psize * NUM_METAS, len, 0);
3771 else if ((unsigned) len == psize * NUM_METAS)
3779 /** Update the environment info to commit a transaction.
3780 * @param[in] txn the transaction that's being committed
3781 * @return 0 on success, non-zero on failure.
3784 mdb_env_write_meta(MDB_txn *txn)
3787 MDB_meta meta, metab, *mp;
3791 int rc, len, toggle;
3800 toggle = txn->mt_txnid & 1;
3801 DPRINTF(("writing meta page %d for root page %"Z"u",
3802 toggle, txn->mt_dbs[MAIN_DBI].md_root));
3805 flags = txn->mt_flags | env->me_flags;
3806 mp = env->me_metas[toggle];
3807 mapsize = env->me_metas[toggle ^ 1]->mm_mapsize;
3808 /* Persist any increases of mapsize config */
3809 if (mapsize < env->me_mapsize)
3810 mapsize = env->me_mapsize;
3812 if (flags & MDB_WRITEMAP) {
3813 mp->mm_mapsize = mapsize;
3814 mp->mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI];
3815 mp->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
3816 mp->mm_last_pg = txn->mt_next_pgno - 1;
3817 #if (__GNUC__ * 100 + __GNUC_MINOR__ >= 404) && /* TODO: portability */ \
3818 !(defined(__i386__) || defined(__x86_64__))
3819 /* LY: issue a memory barrier, if not x86. ITS#7969 */
3820 __sync_synchronize();
3822 mp->mm_txnid = txn->mt_txnid;
3823 if (!(flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {
3824 unsigned meta_size = env->me_psize;
3825 rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;
3826 ptr = (char *)mp - PAGEHDRSZ;
3827 #ifndef _WIN32 /* POSIX msync() requires ptr = start of OS page */
3828 r2 = (ptr - env->me_map) & (env->me_os_psize - 1);
3832 if (MDB_MSYNC(ptr, meta_size, rc)) {
3839 metab.mm_txnid = mp->mm_txnid;
3840 metab.mm_last_pg = mp->mm_last_pg;
3842 meta.mm_mapsize = mapsize;
3843 meta.mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI];
3844 meta.mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
3845 meta.mm_last_pg = txn->mt_next_pgno - 1;
3846 meta.mm_txnid = txn->mt_txnid;
3848 off = offsetof(MDB_meta, mm_mapsize);
3849 ptr = (char *)&meta + off;
3850 len = sizeof(MDB_meta) - off;
3851 off += (char *)mp - env->me_map;
3853 /* Write to the SYNC fd */
3854 mfd = (flags & (MDB_NOSYNC|MDB_NOMETASYNC)) ? env->me_fd : env->me_mfd;
3857 memset(&ov, 0, sizeof(ov));
3859 if (!WriteFile(mfd, ptr, len, (DWORD *)&rc, &ov))
3864 rc = pwrite(mfd, ptr, len, off);
3867 rc = rc < 0 ? ErrCode() : EIO;
3872 DPUTS("write failed, disk error?");
3873 /* On a failure, the pagecache still contains the new data.
3874 * Write some old data back, to prevent it from being used.
3875 * Use the non-SYNC fd; we know it will fail anyway.
3877 meta.mm_last_pg = metab.mm_last_pg;
3878 meta.mm_txnid = metab.mm_txnid;
3880 memset(&ov, 0, sizeof(ov));
3882 WriteFile(env->me_fd, ptr, len, NULL, &ov);
3884 r2 = pwrite(env->me_fd, ptr, len, off);
3885 (void)r2; /* Silence warnings. We don't care about pwrite's return value */
3888 env->me_flags |= MDB_FATAL_ERROR;
3891 /* MIPS has cache coherency issues, this is a no-op everywhere else */
3892 CACHEFLUSH(env->me_map + off, len, DCACHE);
3894 /* Memory ordering issues are irrelevant; since the entire writer
3895 * is wrapped by wmutex, all of these changes will become visible
3896 * after the wmutex is unlocked. Since the DB is multi-version,
3897 * readers will get consistent data regardless of how fresh or
3898 * how stale their view of these values is.
3901 env->me_txns->mti_txnid = txn->mt_txnid;
3906 /** Check both meta pages to see which one is newer.
3907 * @param[in] env the environment handle
3908 * @return newest #MDB_meta.
3911 mdb_env_pick_meta(const MDB_env *env)
3913 MDB_meta *const *metas = env->me_metas;
3914 return metas[ metas[0]->mm_txnid < metas[1]->mm_txnid ];
3918 mdb_env_create(MDB_env **env)
3922 e = calloc(1, sizeof(MDB_env));
3926 e->me_maxreaders = DEFAULT_READERS;
3927 e->me_maxdbs = e->me_numdbs = CORE_DBS;
3928 e->me_fd = INVALID_HANDLE_VALUE;
3929 e->me_lfd = INVALID_HANDLE_VALUE;
3930 e->me_mfd = INVALID_HANDLE_VALUE;
3931 #ifdef MDB_USE_POSIX_SEM
3932 e->me_rmutex = SEM_FAILED;
3933 e->me_wmutex = SEM_FAILED;
3934 #elif defined MDB_USE_SYSV_SEM
3935 e->me_rmutex->semid = -1;
3936 e->me_wmutex->semid = -1;
3938 e->me_pid = getpid();
3939 GET_PAGESIZE(e->me_os_psize);
3940 VGMEMP_CREATE(e,0,0);
3946 mdb_env_map(MDB_env *env, void *addr)
3949 unsigned int flags = env->me_flags;
3953 LONG sizelo, sizehi;
3956 if (flags & MDB_RDONLY) {
3957 /* Don't set explicit map size, use whatever exists */
3962 msize = env->me_mapsize;
3963 sizelo = msize & 0xffffffff;
3964 sizehi = msize >> 16 >> 16; /* only needed on Win64 */
3966 /* Windows won't create mappings for zero length files.
3967 * and won't map more than the file size.
3968 * Just set the maxsize right now.
3970 if (SetFilePointer(env->me_fd, sizelo, &sizehi, 0) != (DWORD)sizelo
3971 || !SetEndOfFile(env->me_fd)
3972 || SetFilePointer(env->me_fd, 0, NULL, 0) != 0)
3976 mh = CreateFileMapping(env->me_fd, NULL, flags & MDB_WRITEMAP ?
3977 PAGE_READWRITE : PAGE_READONLY,
3978 sizehi, sizelo, NULL);
3981 env->me_map = MapViewOfFileEx(mh, flags & MDB_WRITEMAP ?
3982 FILE_MAP_WRITE : FILE_MAP_READ,
3984 rc = env->me_map ? 0 : ErrCode();
3989 int prot = PROT_READ;
3990 if (flags & MDB_WRITEMAP) {
3992 if (ftruncate(env->me_fd, env->me_mapsize) < 0)
3995 env->me_map = mmap(addr, env->me_mapsize, prot, MAP_SHARED,
3997 if (env->me_map == MAP_FAILED) {
4002 if (flags & MDB_NORDAHEAD) {
4003 /* Turn off readahead. It's harmful when the DB is larger than RAM. */
4005 madvise(env->me_map, env->me_mapsize, MADV_RANDOM);
4007 #ifdef POSIX_MADV_RANDOM
4008 posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM);
4009 #endif /* POSIX_MADV_RANDOM */
4010 #endif /* MADV_RANDOM */
4014 /* Can happen because the address argument to mmap() is just a
4015 * hint. mmap() can pick another, e.g. if the range is in use.
4016 * The MAP_FIXED flag would prevent that, but then mmap could
4017 * instead unmap existing pages to make room for the new map.
4019 if (addr && env->me_map != addr)
4020 return EBUSY; /* TODO: Make a new MDB_* error code? */
4022 p = (MDB_page *)env->me_map;
4023 env->me_metas[0] = METADATA(p);
4024 env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + env->me_psize);
4030 mdb_env_set_mapsize(MDB_env *env, size_t size)
4032 /* If env is already open, caller is responsible for making
4033 * sure there are no active txns.
4041 meta = mdb_env_pick_meta(env);
4043 size = meta->mm_mapsize;
4045 /* Silently round up to minimum if the size is too small */
4046 size_t minsize = (meta->mm_last_pg + 1) * env->me_psize;
4050 munmap(env->me_map, env->me_mapsize);
4051 env->me_mapsize = size;
4052 old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL;
4053 rc = mdb_env_map(env, old);
4057 env->me_mapsize = size;
4059 env->me_maxpg = env->me_mapsize / env->me_psize;
4064 mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs)
4068 env->me_maxdbs = dbs + CORE_DBS;
4073 mdb_env_set_maxreaders(MDB_env *env, unsigned int readers)
4075 if (env->me_map || readers < 1)
4077 env->me_maxreaders = readers;
4082 mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)
4084 if (!env || !readers)
4086 *readers = env->me_maxreaders;
4091 mdb_fsize(HANDLE fd, size_t *size)
4094 LARGE_INTEGER fsize;
4096 if (!GetFileSizeEx(fd, &fsize))
4099 *size = fsize.QuadPart;
4111 #ifdef BROKEN_FDATASYNC
4112 #include <sys/utsname.h>
4113 #include <sys/vfs.h>
4116 /** Further setup required for opening an LMDB environment
4119 mdb_env_open2(MDB_env *env)
4121 unsigned int flags = env->me_flags;
4122 int i, newenv = 0, rc;
4126 /* See if we should use QueryLimited */
4128 if ((rc & 0xff) > 5)
4129 env->me_pidquery = MDB_PROCESS_QUERY_LIMITED_INFORMATION;
4131 env->me_pidquery = PROCESS_QUERY_INFORMATION;
4134 #ifdef BROKEN_FDATASYNC
4135 /* ext3/ext4 fdatasync is broken on some older Linux kernels.
4136 * https://lkml.org/lkml/2012/9/3/83
4137 * Kernels after 3.6-rc6 are known good.
4138 * https://lkml.org/lkml/2012/9/10/556
4139 * See if the DB is on ext3/ext4, then check for new enough kernel
4140 * Kernels 2.6.32.60, 2.6.34.15, 3.2.30, and 3.5.4 are also known
4145 fstatfs(env->me_fd, &st);
4146 while (st.f_type == 0xEF53) {
4150 if (uts.release[0] < '3') {
4151 if (!strncmp(uts.release, "2.6.32.", 7)) {
4152 i = atoi(uts.release+7);
4154 break; /* 2.6.32.60 and newer is OK */
4155 } else if (!strncmp(uts.release, "2.6.34.", 7)) {
4156 i = atoi(uts.release+7);
4158 break; /* 2.6.34.15 and newer is OK */
4160 } else if (uts.release[0] == '3') {
4161 i = atoi(uts.release+2);
4163 break; /* 3.6 and newer is OK */
4165 i = atoi(uts.release+4);
4167 break; /* 3.5.4 and newer is OK */
4168 } else if (i == 2) {
4169 i = atoi(uts.release+4);
4171 break; /* 3.2.30 and newer is OK */
4173 } else { /* 4.x and newer is OK */
4176 env->me_flags |= MDB_FSYNCONLY;
4182 if ((i = mdb_env_read_header(env, &meta)) != 0) {
4185 DPUTS("new mdbenv");
4187 env->me_psize = env->me_os_psize;
4188 if (env->me_psize > MAX_PAGESIZE)
4189 env->me_psize = MAX_PAGESIZE;
4190 memset(&meta, 0, sizeof(meta));
4191 mdb_env_init_meta0(env, &meta);
4192 meta.mm_mapsize = DEFAULT_MAPSIZE;
4194 env->me_psize = meta.mm_psize;
4197 /* Was a mapsize configured? */
4198 if (!env->me_mapsize) {
4199 env->me_mapsize = meta.mm_mapsize;
4202 /* Make sure mapsize >= committed data size. Even when using
4203 * mm_mapsize, which could be broken in old files (ITS#7789).
4205 size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize;
4206 if (env->me_mapsize < minsize)
4207 env->me_mapsize = minsize;
4209 meta.mm_mapsize = env->me_mapsize;
4211 if (newenv && !(flags & MDB_FIXEDMAP)) {
4212 /* mdb_env_map() may grow the datafile. Write the metapages
4213 * first, so the file will be valid if initialization fails.
4214 * Except with FIXEDMAP, since we do not yet know mm_address.
4215 * We could fill in mm_address later, but then a different
4216 * program might end up doing that - one with a memory layout
4217 * and map address which does not suit the main program.
4219 rc = mdb_env_init_meta(env, &meta);
4225 rc = mdb_env_map(env, (flags & MDB_FIXEDMAP) ? meta.mm_address : NULL);
4230 if (flags & MDB_FIXEDMAP)
4231 meta.mm_address = env->me_map;
4232 i = mdb_env_init_meta(env, &meta);
4233 if (i != MDB_SUCCESS) {
4238 env->me_maxfree_1pg = (env->me_psize - PAGEHDRSZ) / sizeof(pgno_t) - 1;
4239 env->me_nodemax = (((env->me_psize - PAGEHDRSZ) / MDB_MINKEYS) & -2)
4241 #if !(MDB_MAXKEYSIZE)
4242 env->me_maxkey = env->me_nodemax - (NODESIZE + sizeof(MDB_db));
4244 env->me_maxpg = env->me_mapsize / env->me_psize;
4248 MDB_meta *meta = mdb_env_pick_meta(env);
4249 MDB_db *db = &meta->mm_dbs[MAIN_DBI];
4251 DPRINTF(("opened database version %u, pagesize %u",
4252 meta->mm_version, env->me_psize));
4253 DPRINTF(("using meta page %d", (int) (meta->mm_txnid & 1)));
4254 DPRINTF(("depth: %u", db->md_depth));
4255 DPRINTF(("entries: %"Z"u", db->md_entries));
4256 DPRINTF(("branch pages: %"Z"u", db->md_branch_pages));
4257 DPRINTF(("leaf pages: %"Z"u", db->md_leaf_pages));
4258 DPRINTF(("overflow pages: %"Z"u", db->md_overflow_pages));
4259 DPRINTF(("root: %"Z"u", db->md_root));
4267 /** Release a reader thread's slot in the reader lock table.
4268 * This function is called automatically when a thread exits.
4269 * @param[in] ptr This points to the slot in the reader lock table.
4272 mdb_env_reader_dest(void *ptr)
4274 MDB_reader *reader = ptr;
4280 /** Junk for arranging thread-specific callbacks on Windows. This is
4281 * necessarily platform and compiler-specific. Windows supports up
4282 * to 1088 keys. Let's assume nobody opens more than 64 environments
4283 * in a single process, for now. They can override this if needed.
4285 #ifndef MAX_TLS_KEYS
4286 #define MAX_TLS_KEYS 64
4288 static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS];
4289 static int mdb_tls_nkeys;
4291 static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr)
4295 case DLL_PROCESS_ATTACH: break;
4296 case DLL_THREAD_ATTACH: break;
4297 case DLL_THREAD_DETACH:
4298 for (i=0; i<mdb_tls_nkeys; i++) {
4299 MDB_reader *r = pthread_getspecific(mdb_tls_keys[i]);
4301 mdb_env_reader_dest(r);
4305 case DLL_PROCESS_DETACH: break;
4310 const PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
4312 PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
4316 /* Force some symbol references.
4317 * _tls_used forces the linker to create the TLS directory if not already done
4318 * mdb_tls_cbp prevents whole-program-optimizer from dropping the symbol.
4320 #pragma comment(linker, "/INCLUDE:_tls_used")
4321 #pragma comment(linker, "/INCLUDE:mdb_tls_cbp")
4322 #pragma const_seg(".CRT$XLB")
4323 extern const PIMAGE_TLS_CALLBACK mdb_tls_cbp;
4324 const PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
4327 #pragma comment(linker, "/INCLUDE:__tls_used")
4328 #pragma comment(linker, "/INCLUDE:_mdb_tls_cbp")
4329 #pragma data_seg(".CRT$XLB")
4330 PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
4332 #endif /* WIN 32/64 */
4333 #endif /* !__GNUC__ */
4336 /** Downgrade the exclusive lock on the region back to shared */
4338 mdb_env_share_locks(MDB_env *env, int *excl)
4341 MDB_meta *meta = mdb_env_pick_meta(env);
4343 env->me_txns->mti_txnid = meta->mm_txnid;
4348 /* First acquire a shared lock. The Unlock will
4349 * then release the existing exclusive lock.
4351 memset(&ov, 0, sizeof(ov));
4352 if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
4355 UnlockFile(env->me_lfd, 0, 0, 1, 0);
4361 struct flock lock_info;
4362 /* The shared lock replaces the existing lock */
4363 memset((void *)&lock_info, 0, sizeof(lock_info));
4364 lock_info.l_type = F_RDLCK;
4365 lock_info.l_whence = SEEK_SET;
4366 lock_info.l_start = 0;
4367 lock_info.l_len = 1;
4368 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
4369 (rc = ErrCode()) == EINTR) ;
4370 *excl = rc ? -1 : 0; /* error may mean we lost the lock */
4377 /** Try to get exclusive lock, otherwise shared.
4378 * Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive.
4381 mdb_env_excl_lock(MDB_env *env, int *excl)
4385 if (LockFile(env->me_lfd, 0, 0, 1, 0)) {
4389 memset(&ov, 0, sizeof(ov));
4390 if (LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
4397 struct flock lock_info;
4398 memset((void *)&lock_info, 0, sizeof(lock_info));
4399 lock_info.l_type = F_WRLCK;
4400 lock_info.l_whence = SEEK_SET;
4401 lock_info.l_start = 0;
4402 lock_info.l_len = 1;
4403 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
4404 (rc = ErrCode()) == EINTR) ;
4408 # ifndef MDB_USE_POSIX_MUTEX
4409 if (*excl < 0) /* always true when MDB_USE_POSIX_MUTEX */
4412 lock_info.l_type = F_RDLCK;
4413 while ((rc = fcntl(env->me_lfd, F_SETLKW, &lock_info)) &&
4414 (rc = ErrCode()) == EINTR) ;
4424 * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code
4426 * @(#) $Revision: 5.1 $
4427 * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $
4428 * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $
4430 * http://www.isthe.com/chongo/tech/comp/fnv/index.html
4434 * Please do not copyright this code. This code is in the public domain.
4436 * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
4437 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
4438 * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
4439 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
4440 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
4441 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
4442 * PERFORMANCE OF THIS SOFTWARE.
4445 * chongo <Landon Curt Noll> /\oo/\
4446 * http://www.isthe.com/chongo/
4448 * Share and Enjoy! :-)
4451 typedef unsigned long long mdb_hash_t;
4452 #define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL)
4454 /** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer
4455 * @param[in] val value to hash
4456 * @param[in] hval initial value for hash
4457 * @return 64 bit hash
4459 * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the
4460 * hval arg on the first call.
4463 mdb_hash_val(MDB_val *val, mdb_hash_t hval)
4465 unsigned char *s = (unsigned char *)val->mv_data; /* unsigned string */
4466 unsigned char *end = s + val->mv_size;
4468 * FNV-1a hash each octet of the string
4471 /* xor the bottom with the current octet */
4472 hval ^= (mdb_hash_t)*s++;
4474 /* multiply by the 64 bit FNV magic prime mod 2^64 */
4475 hval += (hval << 1) + (hval << 4) + (hval << 5) +
4476 (hval << 7) + (hval << 8) + (hval << 40);
4478 /* return our new hash value */
4482 /** Hash the string and output the encoded hash.
4483 * This uses modified RFC1924 Ascii85 encoding to accommodate systems with
4484 * very short name limits. We don't care about the encoding being reversible,
4485 * we just want to preserve as many bits of the input as possible in a
4486 * small printable string.
4487 * @param[in] str string to hash
4488 * @param[out] encbuf an array of 11 chars to hold the hash
4490 static const char mdb_a85[]= "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";
4493 mdb_pack85(unsigned long l, char *out)
4497 for (i=0; i<5; i++) {
4498 *out++ = mdb_a85[l % 85];
4504 mdb_hash_enc(MDB_val *val, char *encbuf)
4506 mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT);
4508 mdb_pack85(h, encbuf);
4509 mdb_pack85(h>>32, encbuf+5);
4514 /** Open and/or initialize the lock region for the environment.
4515 * @param[in] env The LMDB environment.
4516 * @param[in] lpath The pathname of the file used for the lock region.
4517 * @param[in] mode The Unix permissions for the file, if we create it.
4518 * @param[in,out] excl In -1, out lock type: -1 none, 0 shared, 1 exclusive
4519 * @return 0 on success, non-zero on failure.
4522 mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
4525 # define MDB_ERRCODE_ROFS ERROR_WRITE_PROTECT
4527 # define MDB_ERRCODE_ROFS EROFS
4528 #ifdef O_CLOEXEC /* Linux: Open file and set FD_CLOEXEC atomically */
4529 # define MDB_CLOEXEC O_CLOEXEC
4532 # define MDB_CLOEXEC 0
4535 #ifdef MDB_USE_SYSV_SEM
4544 utf8_to_utf16(lpath, -1, &wlpath, NULL);
4545 env->me_lfd = CreateFileW(wlpath, GENERIC_READ|GENERIC_WRITE,
4546 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
4547 FILE_ATTRIBUTE_NORMAL, NULL);
4550 env->me_lfd = open(lpath, O_RDWR|O_CREAT|MDB_CLOEXEC, mode);
4552 if (env->me_lfd == INVALID_HANDLE_VALUE) {
4554 if (rc == MDB_ERRCODE_ROFS && (env->me_flags & MDB_RDONLY)) {
4559 #if ! ((MDB_CLOEXEC) || defined(_WIN32))
4560 /* Lose record locks when exec*() */
4561 if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0)
4562 fcntl(env->me_lfd, F_SETFD, fdflags);
4565 if (!(env->me_flags & MDB_NOTLS)) {
4566 rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
4569 env->me_flags |= MDB_ENV_TXKEY;
4571 /* Windows TLS callbacks need help finding their TLS info. */
4572 if (mdb_tls_nkeys >= MAX_TLS_KEYS) {
4576 mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey;
4580 /* Try to get exclusive lock. If we succeed, then
4581 * nobody is using the lock region and we should initialize it.
4583 if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
4586 size = GetFileSize(env->me_lfd, NULL);
4588 size = lseek(env->me_lfd, 0, SEEK_END);
4589 if (size == -1) goto fail_errno;
4591 rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
4592 if (size < rsize && *excl > 0) {
4594 if (SetFilePointer(env->me_lfd, rsize, NULL, FILE_BEGIN) != (DWORD)rsize
4595 || !SetEndOfFile(env->me_lfd))
4598 if (ftruncate(env->me_lfd, rsize) != 0) goto fail_errno;
4602 size = rsize - sizeof(MDB_txninfo);
4603 env->me_maxreaders = size/sizeof(MDB_reader) + 1;
4608 mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,
4610 if (!mh) goto fail_errno;
4611 env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL);
4613 if (!env->me_txns) goto fail_errno;
4615 void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
4617 if (m == MAP_FAILED) goto fail_errno;
4623 BY_HANDLE_FILE_INFORMATION stbuf;
4632 if (!mdb_sec_inited) {
4633 InitializeSecurityDescriptor(&mdb_null_sd,
4634 SECURITY_DESCRIPTOR_REVISION);
4635 SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE);
4636 mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);
4637 mdb_all_sa.bInheritHandle = FALSE;
4638 mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;
4641 if (!GetFileInformationByHandle(env->me_lfd, &stbuf)) goto fail_errno;
4642 idbuf.volume = stbuf.dwVolumeSerialNumber;
4643 idbuf.nhigh = stbuf.nFileIndexHigh;
4644 idbuf.nlow = stbuf.nFileIndexLow;
4645 val.mv_data = &idbuf;
4646 val.mv_size = sizeof(idbuf);
4647 mdb_hash_enc(&val, encbuf);
4648 sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", encbuf);
4649 sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", encbuf);
4650 env->me_rmutex = CreateMutexA(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
4651 if (!env->me_rmutex) goto fail_errno;
4652 env->me_wmutex = CreateMutexA(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);
4653 if (!env->me_wmutex) goto fail_errno;
4654 #elif defined(MDB_USE_POSIX_SEM)
4663 #if defined(__NetBSD__)
4664 #define MDB_SHORT_SEMNAMES 1 /* limited to 14 chars */
4666 if (fstat(env->me_lfd, &stbuf)) goto fail_errno;
4667 idbuf.dev = stbuf.st_dev;
4668 idbuf.ino = stbuf.st_ino;
4669 val.mv_data = &idbuf;
4670 val.mv_size = sizeof(idbuf);
4671 mdb_hash_enc(&val, encbuf);
4672 #ifdef MDB_SHORT_SEMNAMES
4673 encbuf[9] = '\0'; /* drop name from 15 chars to 14 chars */
4675 sprintf(env->me_txns->mti_rmname, "/MDBr%s", encbuf);
4676 sprintf(env->me_txns->mti_wmname, "/MDBw%s", encbuf);
4677 /* Clean up after a previous run, if needed: Try to
4678 * remove both semaphores before doing anything else.
4680 sem_unlink(env->me_txns->mti_rmname);
4681 sem_unlink(env->me_txns->mti_wmname);
4682 env->me_rmutex = sem_open(env->me_txns->mti_rmname,
4683 O_CREAT|O_EXCL, mode, 1);
4684 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
4685 env->me_wmutex = sem_open(env->me_txns->mti_wmname,
4686 O_CREAT|O_EXCL, mode, 1);
4687 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
4688 #elif defined(MDB_USE_SYSV_SEM)
4689 unsigned short vals[2] = {1, 1};
4690 key_t key = ftok(lpath, 'M');
4693 semid = semget(key, 2, (mode & 0777) | IPC_CREAT);
4697 if (semctl(semid, 0, SETALL, semu) < 0)
4699 env->me_txns->mti_semid = semid;
4700 #else /* MDB_USE_POSIX_MUTEX: */
4701 pthread_mutexattr_t mattr;
4703 if ((rc = pthread_mutexattr_init(&mattr))
4704 || (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED))
4705 #ifdef MDB_ROBUST_SUPPORTED
4706 || (rc = pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST))
4708 || (rc = pthread_mutex_init(env->me_txns->mti_rmutex, &mattr))
4709 || (rc = pthread_mutex_init(env->me_txns->mti_wmutex, &mattr)))
4711 pthread_mutexattr_destroy(&mattr);
4712 #endif /* _WIN32 || ... */
4714 env->me_txns->mti_magic = MDB_MAGIC;
4715 env->me_txns->mti_format = MDB_LOCK_FORMAT;
4716 env->me_txns->mti_txnid = 0;
4717 env->me_txns->mti_numreaders = 0;
4720 #ifdef MDB_USE_SYSV_SEM
4721 struct semid_ds buf;
4723 if (env->me_txns->mti_magic != MDB_MAGIC) {
4724 DPUTS("lock region has invalid magic");
4728 if (env->me_txns->mti_format != MDB_LOCK_FORMAT) {
4729 DPRINTF(("lock region has format+version 0x%x, expected 0x%x",
4730 env->me_txns->mti_format, MDB_LOCK_FORMAT));
4731 rc = MDB_VERSION_MISMATCH;
4735 if (rc && rc != EACCES && rc != EAGAIN) {
4739 env->me_rmutex = OpenMutexA(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);
4740 if (!env->me_rmutex) goto fail_errno;
4741 env->me_wmutex = OpenMutexA(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
4742 if (!env->me_wmutex) goto fail_errno;
4743 #elif defined(MDB_USE_POSIX_SEM)
4744 env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0);
4745 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
4746 env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0);
4747 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
4748 #elif defined(MDB_USE_SYSV_SEM)
4749 semid = env->me_txns->mti_semid;
4751 /* check for read access */
4752 if (semctl(semid, 0, IPC_STAT, semu) < 0)
4754 /* check for write access */
4755 if (semctl(semid, 0, IPC_SET, semu) < 0)
4759 #ifdef MDB_USE_SYSV_SEM
4760 env->me_rmutex->semid = semid;
4761 env->me_wmutex->semid = semid;
4762 env->me_rmutex->semnum = 0;
4763 env->me_wmutex->semnum = 1;
4764 env->me_rmutex->locked = &env->me_txns->mti_rlocked;
4765 env->me_wmutex->locked = &env->me_txns->mti_wlocked;
4776 /** The name of the lock file in the DB environment */
4777 #define LOCKNAME "/lock.mdb"
4778 /** The name of the data file in the DB environment */
4779 #define DATANAME "/data.mdb"
4780 /** The suffix of the lock file when no subdir is used */
4781 #define LOCKSUFF "-lock"
4782 /** Only a subset of the @ref mdb_env flags can be changed
4783 * at runtime. Changing other flags requires closing the
4784 * environment and re-opening it with the new flags.
4786 #define CHANGEABLE (MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC|MDB_NOMEMINIT)
4787 #define CHANGELESS (MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY| \
4788 MDB_WRITEMAP|MDB_NOTLS|MDB_NOLOCK|MDB_NORDAHEAD)
4790 #if VALID_FLAGS & PERSISTENT_FLAGS & (CHANGEABLE|CHANGELESS)
4791 # error "Persistent DB flags & env flags overlap, but both go in mm_flags"
4795 mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode)
4797 int oflags, rc, len, excl = -1;
4798 char *lpath, *dpath;
4803 if (env->me_fd!=INVALID_HANDLE_VALUE || (flags & ~(CHANGEABLE|CHANGELESS)))
4807 if (flags & MDB_NOSUBDIR) {
4808 rc = len + sizeof(LOCKSUFF) + len + 1;
4810 rc = len + sizeof(LOCKNAME) + len + sizeof(DATANAME);
4815 if (flags & MDB_NOSUBDIR) {
4816 dpath = lpath + len + sizeof(LOCKSUFF);
4817 sprintf(lpath, "%s" LOCKSUFF, path);
4818 strcpy(dpath, path);
4820 dpath = lpath + len + sizeof(LOCKNAME);
4821 sprintf(lpath, "%s" LOCKNAME, path);
4822 sprintf(dpath, "%s" DATANAME, path);
4826 flags |= env->me_flags;
4827 if (flags & MDB_RDONLY) {
4828 /* silently ignore WRITEMAP when we're only getting read access */
4829 flags &= ~MDB_WRITEMAP;
4831 if (!((env->me_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)) &&
4832 (env->me_dirty_list = calloc(MDB_IDL_UM_SIZE, sizeof(MDB_ID2)))))
4835 env->me_flags = flags |= MDB_ENV_ACTIVE;
4839 env->me_path = strdup(path);
4840 env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx));
4841 env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t));
4842 env->me_dbiseqs = calloc(env->me_maxdbs, sizeof(unsigned int));
4843 if (!(env->me_dbxs && env->me_path && env->me_dbflags && env->me_dbiseqs)) {
4847 env->me_dbxs[FREE_DBI].md_cmp = mdb_cmp_long; /* aligned MDB_INTEGERKEY */
4849 /* For RDONLY, get lockfile after we know datafile exists */
4850 if (!(flags & (MDB_RDONLY|MDB_NOLOCK))) {
4851 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
4857 if (F_ISSET(flags, MDB_RDONLY)) {
4858 oflags = GENERIC_READ;
4859 len = OPEN_EXISTING;
4861 oflags = GENERIC_READ|GENERIC_WRITE;
4864 mode = FILE_ATTRIBUTE_NORMAL;
4865 utf8_to_utf16(dpath, -1, &wpath, NULL);
4866 env->me_fd = CreateFileW(wpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
4867 NULL, len, mode, NULL);
4870 if (F_ISSET(flags, MDB_RDONLY))
4873 oflags = O_RDWR | O_CREAT;
4875 env->me_fd = open(dpath, oflags, mode);
4877 if (env->me_fd == INVALID_HANDLE_VALUE) {
4882 if ((flags & (MDB_RDONLY|MDB_NOLOCK)) == MDB_RDONLY) {
4883 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
4888 if ((rc = mdb_env_open2(env)) == MDB_SUCCESS) {
4889 if (flags & (MDB_RDONLY|MDB_WRITEMAP)) {
4890 env->me_mfd = env->me_fd;
4892 /* Synchronous fd for meta writes. Needed even with
4893 * MDB_NOSYNC/MDB_NOMETASYNC, in case these get reset.
4896 len = OPEN_EXISTING;
4897 utf8_to_utf16(dpath, -1, &wpath, NULL);
4898 env->me_mfd = CreateFileW(wpath, oflags,
4899 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len,
4900 mode | FILE_FLAG_WRITE_THROUGH, NULL);
4904 env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode);
4906 if (env->me_mfd == INVALID_HANDLE_VALUE) {
4911 DPRINTF(("opened dbenv %p", (void *) env));
4913 rc = mdb_env_share_locks(env, &excl);
4917 if (!(flags & MDB_RDONLY)) {
4919 int tsize = sizeof(MDB_txn), size = tsize + env->me_maxdbs *
4920 (sizeof(MDB_db)+sizeof(MDB_cursor *)+sizeof(unsigned int)+1);
4921 if ((env->me_pbuf = calloc(1, env->me_psize)) &&
4922 (txn = calloc(1, size)))
4924 txn->mt_dbs = (MDB_db *)((char *)txn + tsize);
4925 txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
4926 txn->mt_dbiseqs = (unsigned int *)(txn->mt_cursors + env->me_maxdbs);
4927 txn->mt_dbflags = (unsigned char *)(txn->mt_dbiseqs + env->me_maxdbs);
4929 txn->mt_dbxs = env->me_dbxs;
4930 txn->mt_flags = MDB_TXN_FINISHED;
4940 mdb_env_close0(env, excl);
4946 /** Destroy resources from mdb_env_open(), clear our readers & DBIs */
4948 mdb_env_close0(MDB_env *env, int excl)
4952 if (!(env->me_flags & MDB_ENV_ACTIVE))
4955 /* Doing this here since me_dbxs may not exist during mdb_env_close */
4957 for (i = env->me_maxdbs; --i >= CORE_DBS; )
4958 free(env->me_dbxs[i].md_name.mv_data);
4963 free(env->me_dbiseqs);
4964 free(env->me_dbflags);
4966 free(env->me_dirty_list);
4968 mdb_midl_free(env->me_free_pgs);
4970 if (env->me_flags & MDB_ENV_TXKEY) {
4971 pthread_key_delete(env->me_txkey);
4973 /* Delete our key from the global list */
4974 for (i=0; i<mdb_tls_nkeys; i++)
4975 if (mdb_tls_keys[i] == env->me_txkey) {
4976 mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1];
4984 munmap(env->me_map, env->me_mapsize);
4986 if (env->me_mfd != env->me_fd && env->me_mfd != INVALID_HANDLE_VALUE)
4987 (void) close(env->me_mfd);
4988 if (env->me_fd != INVALID_HANDLE_VALUE)
4989 (void) close(env->me_fd);
4991 MDB_PID_T pid = env->me_pid;
4992 /* Clearing readers is done in this function because
4993 * me_txkey with its destructor must be disabled first.
4995 * We skip the the reader mutex, so we touch only
4996 * data owned by this process (me_close_readers and
4997 * our readers), and clear each reader atomically.
4999 for (i = env->me_close_readers; --i >= 0; )
5000 if (env->me_txns->mti_readers[i].mr_pid == pid)
5001 env->me_txns->mti_readers[i].mr_pid = 0;
5003 if (env->me_rmutex) {
5004 CloseHandle(env->me_rmutex);
5005 if (env->me_wmutex) CloseHandle(env->me_wmutex);
5007 /* Windows automatically destroys the mutexes when
5008 * the last handle closes.
5010 #elif defined(MDB_USE_POSIX_SEM)
5011 if (env->me_rmutex != SEM_FAILED) {
5012 sem_close(env->me_rmutex);
5013 if (env->me_wmutex != SEM_FAILED)
5014 sem_close(env->me_wmutex);
5015 /* If we have the filelock: If we are the
5016 * only remaining user, clean up semaphores.
5019 mdb_env_excl_lock(env, &excl);
5021 sem_unlink(env->me_txns->mti_rmname);
5022 sem_unlink(env->me_txns->mti_wmname);
5025 #elif defined(MDB_USE_SYSV_SEM)
5026 if (env->me_rmutex->semid != -1) {
5027 /* If we have the filelock: If we are the
5028 * only remaining user, clean up semaphores.
5031 mdb_env_excl_lock(env, &excl);
5033 semctl(env->me_rmutex->semid, 0, IPC_RMID);
5036 munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
5038 if (env->me_lfd != INVALID_HANDLE_VALUE) {
5041 /* Unlock the lockfile. Windows would have unlocked it
5042 * after closing anyway, but not necessarily at once.
5044 UnlockFile(env->me_lfd, 0, 0, 1, 0);
5047 (void) close(env->me_lfd);
5050 env->me_flags &= ~(MDB_ENV_ACTIVE|MDB_ENV_TXKEY);
5054 mdb_env_close(MDB_env *env)
5061 VGMEMP_DESTROY(env);
5062 while ((dp = env->me_dpages) != NULL) {
5063 VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next));
5064 env->me_dpages = dp->mp_next;
5068 mdb_env_close0(env, 0);
5072 /** Compare two items pointing at aligned size_t's */
5074 mdb_cmp_long(const MDB_val *a, const MDB_val *b)
5076 return (*(size_t *)a->mv_data < *(size_t *)b->mv_data) ? -1 :
5077 *(size_t *)a->mv_data > *(size_t *)b->mv_data;
5080 /** Compare two items pointing at aligned unsigned int's.
5082 * This is also set as #MDB_INTEGERDUP|#MDB_DUPFIXED's #MDB_dbx.%md_dcmp,
5083 * but #mdb_cmp_clong() is called instead if the data type is size_t.
5086 mdb_cmp_int(const MDB_val *a, const MDB_val *b)
5088 return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 :
5089 *(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data;
5092 /** Compare two items pointing at unsigned ints of unknown alignment.
5093 * Nodes and keys are guaranteed to be 2-byte aligned.
5096 mdb_cmp_cint(const MDB_val *a, const MDB_val *b)
5098 #if BYTE_ORDER == LITTLE_ENDIAN
5099 unsigned short *u, *c;
5102 u = (unsigned short *) ((char *) a->mv_data + a->mv_size);
5103 c = (unsigned short *) ((char *) b->mv_data + a->mv_size);
5106 } while(!x && u > (unsigned short *)a->mv_data);
5109 unsigned short *u, *c, *end;
5112 end = (unsigned short *) ((char *) a->mv_data + a->mv_size);
5113 u = (unsigned short *)a->mv_data;
5114 c = (unsigned short *)b->mv_data;
5117 } while(!x && u < end);
5122 /** Compare two items lexically */
5124 mdb_cmp_memn(const MDB_val *a, const MDB_val *b)
5131 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
5137 diff = memcmp(a->mv_data, b->mv_data, len);
5138 return diff ? diff : len_diff<0 ? -1 : len_diff;
5141 /** Compare two items in reverse byte order */
5143 mdb_cmp_memnr(const MDB_val *a, const MDB_val *b)
5145 const unsigned char *p1, *p2, *p1_lim;
5149 p1_lim = (const unsigned char *)a->mv_data;
5150 p1 = (const unsigned char *)a->mv_data + a->mv_size;
5151 p2 = (const unsigned char *)b->mv_data + b->mv_size;
5153 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
5159 while (p1 > p1_lim) {
5160 diff = *--p1 - *--p2;
5164 return len_diff<0 ? -1 : len_diff;
5167 /** Search for key within a page, using binary search.
5168 * Returns the smallest entry larger or equal to the key.
5169 * If exactp is non-null, stores whether the found entry was an exact match
5170 * in *exactp (1 or 0).
5171 * Updates the cursor index with the index of the found entry.
5172 * If no entry larger or equal to the key is found, returns NULL.
5175 mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)
5177 unsigned int i = 0, nkeys;
5180 MDB_page *mp = mc->mc_pg[mc->mc_top];
5181 MDB_node *node = NULL;
5186 nkeys = NUMKEYS(mp);
5188 DPRINTF(("searching %u keys in %s %spage %"Z"u",
5189 nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "",
5192 low = IS_LEAF(mp) ? 0 : 1;
5194 cmp = mc->mc_dbx->md_cmp;
5196 /* Branch pages have no data, so if using integer keys,
5197 * alignment is guaranteed. Use faster mdb_cmp_int.
5199 if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) {
5200 if (NODEPTR(mp, 1)->mn_ksize == sizeof(size_t))
5207 nodekey.mv_size = mc->mc_db->md_pad;
5208 node = NODEPTR(mp, 0); /* fake */
5209 while (low <= high) {
5210 i = (low + high) >> 1;
5211 nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size);
5212 rc = cmp(key, &nodekey);
5213 DPRINTF(("found leaf index %u [%s], rc = %i",
5214 i, DKEY(&nodekey), rc));
5223 while (low <= high) {
5224 i = (low + high) >> 1;
5226 node = NODEPTR(mp, i);
5227 nodekey.mv_size = NODEKSZ(node);
5228 nodekey.mv_data = NODEKEY(node);
5230 rc = cmp(key, &nodekey);
5233 DPRINTF(("found leaf index %u [%s], rc = %i",
5234 i, DKEY(&nodekey), rc));
5236 DPRINTF(("found branch index %u [%s -> %"Z"u], rc = %i",
5237 i, DKEY(&nodekey), NODEPGNO(node), rc));
5248 if (rc > 0) { /* Found entry is less than the key. */
5249 i++; /* Skip to get the smallest entry larger than key. */
5251 node = NODEPTR(mp, i);
5254 *exactp = (rc == 0 && nkeys > 0);
5255 /* store the key index */
5256 mc->mc_ki[mc->mc_top] = i;
5258 /* There is no entry larger or equal to the key. */
5261 /* nodeptr is fake for LEAF2 */
5267 mdb_cursor_adjust(MDB_cursor *mc, func)
5271 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
5272 if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) {
5279 /** Pop a page off the top of the cursor's stack. */
5281 mdb_cursor_pop(MDB_cursor *mc)
5284 DPRINTF(("popping page %"Z"u off db %d cursor %p",
5285 mc->mc_pg[mc->mc_top]->mp_pgno, DDBI(mc), (void *) mc));
5291 mc->mc_flags &= ~C_INITIALIZED;
5296 /** Push a page onto the top of the cursor's stack. */
5298 mdb_cursor_push(MDB_cursor *mc, MDB_page *mp)
5300 DPRINTF(("pushing page %"Z"u on db %d cursor %p", mp->mp_pgno,
5301 DDBI(mc), (void *) mc));
5303 if (mc->mc_snum >= CURSOR_STACK) {
5304 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
5305 return MDB_CURSOR_FULL;
5308 mc->mc_top = mc->mc_snum++;
5309 mc->mc_pg[mc->mc_top] = mp;
5310 mc->mc_ki[mc->mc_top] = 0;
5315 /** Find the address of the page corresponding to a given page number.
5316 * @param[in] txn the transaction for this access.
5317 * @param[in] pgno the page number for the page to retrieve.
5318 * @param[out] ret address of a pointer where the page's address will be stored.
5319 * @param[out] lvl dirty_list inheritance level of found page. 1=current txn, 0=mapped page.
5320 * @return 0 on success, non-zero on failure.
5323 mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret, int *lvl)
5325 MDB_env *env = txn->mt_env;
5329 if (! (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_WRITEMAP))) {
5333 MDB_ID2L dl = tx2->mt_u.dirty_list;
5335 /* Spilled pages were dirtied in this txn and flushed
5336 * because the dirty list got full. Bring this page
5337 * back in from the map (but don't unspill it here,
5338 * leave that unless page_touch happens again).
5340 if (tx2->mt_spill_pgs) {
5341 MDB_ID pn = pgno << 1;
5342 x = mdb_midl_search(tx2->mt_spill_pgs, pn);
5343 if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
5344 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
5349 unsigned x = mdb_mid2l_search(dl, pgno);
5350 if (x <= dl[0].mid && dl[x].mid == pgno) {
5356 } while ((tx2 = tx2->mt_parent) != NULL);
5359 if (pgno < txn->mt_next_pgno) {
5361 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
5363 DPRINTF(("page %"Z"u not found", pgno));
5364 txn->mt_flags |= MDB_TXN_ERROR;
5365 return MDB_PAGE_NOTFOUND;
5375 /** Finish #mdb_page_search() / #mdb_page_search_lowest().
5376 * The cursor is at the root page, set up the rest of it.
5379 mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags)
5381 MDB_page *mp = mc->mc_pg[mc->mc_top];
5385 while (IS_BRANCH(mp)) {
5389 DPRINTF(("branch page %"Z"u has %u keys", mp->mp_pgno, NUMKEYS(mp)));
5390 mdb_cassert(mc, NUMKEYS(mp) > 1);
5391 DPRINTF(("found index 0 to page %"Z"u", NODEPGNO(NODEPTR(mp, 0))));
5393 if (flags & (MDB_PS_FIRST|MDB_PS_LAST)) {
5395 if (flags & MDB_PS_LAST)
5396 i = NUMKEYS(mp) - 1;
5399 node = mdb_node_search(mc, key, &exact);
5401 i = NUMKEYS(mp) - 1;
5403 i = mc->mc_ki[mc->mc_top];
5405 mdb_cassert(mc, i > 0);
5409 DPRINTF(("following index %u for key [%s]", i, DKEY(key)));
5412 mdb_cassert(mc, i < NUMKEYS(mp));
5413 node = NODEPTR(mp, i);
5415 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
5418 mc->mc_ki[mc->mc_top] = i;
5419 if ((rc = mdb_cursor_push(mc, mp)))
5422 if (flags & MDB_PS_MODIFY) {
5423 if ((rc = mdb_page_touch(mc)) != 0)
5425 mp = mc->mc_pg[mc->mc_top];
5430 DPRINTF(("internal error, index points to a %02X page!?",
5432 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
5433 return MDB_CORRUPTED;
5436 DPRINTF(("found leaf page %"Z"u for key [%s]", mp->mp_pgno,
5437 key ? DKEY(key) : "null"));
5438 mc->mc_flags |= C_INITIALIZED;
5439 mc->mc_flags &= ~C_EOF;
5444 /** Search for the lowest key under the current branch page.
5445 * This just bypasses a NUMKEYS check in the current page
5446 * before calling mdb_page_search_root(), because the callers
5447 * are all in situations where the current page is known to
5451 mdb_page_search_lowest(MDB_cursor *mc)
5453 MDB_page *mp = mc->mc_pg[mc->mc_top];
5454 MDB_node *node = NODEPTR(mp, 0);
5457 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
5460 mc->mc_ki[mc->mc_top] = 0;
5461 if ((rc = mdb_cursor_push(mc, mp)))
5463 return mdb_page_search_root(mc, NULL, MDB_PS_FIRST);
5466 /** Search for the page a given key should be in.
5467 * Push it and its parent pages on the cursor stack.
5468 * @param[in,out] mc the cursor for this operation.
5469 * @param[in] key the key to search for, or NULL for first/last page.
5470 * @param[in] flags If MDB_PS_MODIFY is set, visited pages in the DB
5471 * are touched (updated with new page numbers).
5472 * If MDB_PS_FIRST or MDB_PS_LAST is set, find first or last leaf.
5473 * This is used by #mdb_cursor_first() and #mdb_cursor_last().
5474 * If MDB_PS_ROOTONLY set, just fetch root node, no further lookups.
5475 * @return 0 on success, non-zero on failure.
5478 mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)
5483 /* Make sure the txn is still viable, then find the root from
5484 * the txn's db table and set it as the root of the cursor's stack.
5486 if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED) {
5487 DPUTS("transaction may not be used now");
5490 /* Make sure we're using an up-to-date root */
5491 if (*mc->mc_dbflag & DB_STALE) {
5493 if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))
5495 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);
5496 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, 0);
5503 MDB_node *leaf = mdb_node_search(&mc2,
5504 &mc->mc_dbx->md_name, &exact);
5506 return MDB_NOTFOUND;
5507 if ((leaf->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)
5508 return MDB_INCOMPATIBLE; /* not a named DB */
5509 rc = mdb_node_read(mc->mc_txn, leaf, &data);
5512 memcpy(&flags, ((char *) data.mv_data + offsetof(MDB_db, md_flags)),
5514 /* The txn may not know this DBI, or another process may
5515 * have dropped and recreated the DB with other flags.
5517 if ((mc->mc_db->md_flags & PERSISTENT_FLAGS) != flags)
5518 return MDB_INCOMPATIBLE;
5519 memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db));
5521 *mc->mc_dbflag &= ~DB_STALE;
5523 root = mc->mc_db->md_root;
5525 if (root == P_INVALID) { /* Tree is empty. */
5526 DPUTS("tree is empty");
5527 return MDB_NOTFOUND;
5531 mdb_cassert(mc, root > 1);
5532 if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root)
5533 if ((rc = mdb_page_get(mc->mc_txn, root, &mc->mc_pg[0], NULL)) != 0)
5539 DPRINTF(("db %d root page %"Z"u has flags 0x%X",
5540 DDBI(mc), root, mc->mc_pg[0]->mp_flags));
5542 if (flags & MDB_PS_MODIFY) {
5543 if ((rc = mdb_page_touch(mc)))
5547 if (flags & MDB_PS_ROOTONLY)
5550 return mdb_page_search_root(mc, key, flags);
5554 mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
5556 MDB_txn *txn = mc->mc_txn;
5557 pgno_t pg = mp->mp_pgno;
5558 unsigned x = 0, ovpages = mp->mp_pages;
5559 MDB_env *env = txn->mt_env;
5560 MDB_IDL sl = txn->mt_spill_pgs;
5561 MDB_ID pn = pg << 1;
5564 DPRINTF(("free ov page %"Z"u (%d)", pg, ovpages));
5565 /* If the page is dirty or on the spill list we just acquired it,
5566 * so we should give it back to our current free list, if any.
5567 * Otherwise put it onto the list of pages we freed in this txn.
5569 * Won't create me_pghead: me_pglast must be inited along with it.
5570 * Unsupported in nested txns: They would need to hide the page
5571 * range in ancestor txns' dirty and spilled lists.
5573 if (env->me_pghead &&
5575 ((mp->mp_flags & P_DIRTY) ||
5576 (sl && (x = mdb_midl_search(sl, pn)) <= sl[0] && sl[x] == pn)))
5580 MDB_ID2 *dl, ix, iy;
5581 rc = mdb_midl_need(&env->me_pghead, ovpages);
5584 if (!(mp->mp_flags & P_DIRTY)) {
5585 /* This page is no longer spilled */
5592 /* Remove from dirty list */
5593 dl = txn->mt_u.dirty_list;
5595 for (ix = dl[x]; ix.mptr != mp; ix = iy) {
5601 mdb_cassert(mc, x > 1);
5603 dl[j] = ix; /* Unsorted. OK when MDB_TXN_ERROR. */
5604 txn->mt_flags |= MDB_TXN_ERROR;
5605 return MDB_CORRUPTED;
5608 txn->mt_dirty_room++;
5609 if (!(env->me_flags & MDB_WRITEMAP))
5610 mdb_dpage_free(env, mp);
5612 /* Insert in me_pghead */
5613 mop = env->me_pghead;
5614 j = mop[0] + ovpages;
5615 for (i = mop[0]; i && mop[i] < pg; i--)
5621 rc = mdb_midl_append_range(&txn->mt_free_pgs, pg, ovpages);
5625 mc->mc_db->md_overflow_pages -= ovpages;
5629 /** Return the data associated with a given node.
5630 * @param[in] txn The transaction for this operation.
5631 * @param[in] leaf The node being read.
5632 * @param[out] data Updated to point to the node's data.
5633 * @return 0 on success, non-zero on failure.
5636 mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data)
5638 MDB_page *omp; /* overflow page */
5642 if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
5643 data->mv_size = NODEDSZ(leaf);
5644 data->mv_data = NODEDATA(leaf);
5648 /* Read overflow data.
5650 data->mv_size = NODEDSZ(leaf);
5651 memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
5652 if ((rc = mdb_page_get(txn, pgno, &omp, NULL)) != 0) {
5653 DPRINTF(("read overflow page %"Z"u failed", pgno));
5656 data->mv_data = METADATA(omp);
5662 mdb_get(MDB_txn *txn, MDB_dbi dbi,
5663 MDB_val *key, MDB_val *data)
5670 DPRINTF(("===> get db %u key [%s]", dbi, DKEY(key)));
5672 if (!key || !data || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
5675 if (txn->mt_flags & MDB_TXN_BLOCKED)
5678 mdb_cursor_init(&mc, txn, dbi, &mx);
5679 return mdb_cursor_set(&mc, key, data, MDB_SET, &exact);
5682 /** Find a sibling for a page.
5683 * Replaces the page at the top of the cursor's stack with the
5684 * specified sibling, if one exists.
5685 * @param[in] mc The cursor for this operation.
5686 * @param[in] move_right Non-zero if the right sibling is requested,
5687 * otherwise the left sibling.
5688 * @return 0 on success, non-zero on failure.
5691 mdb_cursor_sibling(MDB_cursor *mc, int move_right)
5697 if (mc->mc_snum < 2) {
5698 return MDB_NOTFOUND; /* root has no siblings */
5702 DPRINTF(("parent page is page %"Z"u, index %u",
5703 mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]));
5705 if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top]))
5706 : (mc->mc_ki[mc->mc_top] == 0)) {
5707 DPRINTF(("no more keys left, moving to %s sibling",
5708 move_right ? "right" : "left"));
5709 if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) {
5710 /* undo cursor_pop before returning */
5717 mc->mc_ki[mc->mc_top]++;
5719 mc->mc_ki[mc->mc_top]--;
5720 DPRINTF(("just moving to %s index key %u",
5721 move_right ? "right" : "left", mc->mc_ki[mc->mc_top]));
5723 mdb_cassert(mc, IS_BRANCH(mc->mc_pg[mc->mc_top]));
5725 indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5726 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(indx), &mp, NULL)) != 0) {
5727 /* mc will be inconsistent if caller does mc_snum++ as above */
5728 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
5732 mdb_cursor_push(mc, mp);
5734 mc->mc_ki[mc->mc_top] = NUMKEYS(mp)-1;
5739 /** Move the cursor to the next data item. */
5741 mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
5747 if (mc->mc_flags & C_EOF) {
5748 return MDB_NOTFOUND;
5751 mdb_cassert(mc, mc->mc_flags & C_INITIALIZED);
5753 mp = mc->mc_pg[mc->mc_top];
5755 if (mc->mc_db->md_flags & MDB_DUPSORT) {
5756 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5757 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5758 if (op == MDB_NEXT || op == MDB_NEXT_DUP) {
5759 rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);
5760 if (op != MDB_NEXT || rc != MDB_NOTFOUND) {
5761 if (rc == MDB_SUCCESS)
5762 MDB_GET_KEY(leaf, key);
5767 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5768 if (op == MDB_NEXT_DUP)
5769 return MDB_NOTFOUND;
5773 DPRINTF(("cursor_next: top page is %"Z"u in cursor %p",
5774 mdb_dbg_pgno(mp), (void *) mc));
5775 if (mc->mc_flags & C_DEL)
5778 if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) {
5779 DPUTS("=====> move to next sibling page");
5780 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
5781 mc->mc_flags |= C_EOF;
5784 mp = mc->mc_pg[mc->mc_top];
5785 DPRINTF(("next page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
5787 mc->mc_ki[mc->mc_top]++;
5790 DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
5791 mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
5794 key->mv_size = mc->mc_db->md_pad;
5795 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5799 mdb_cassert(mc, IS_LEAF(mp));
5800 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5802 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5803 mdb_xcursor_init1(mc, leaf);
5806 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5809 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5810 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
5811 if (rc != MDB_SUCCESS)
5816 MDB_GET_KEY(leaf, key);
5820 /** Move the cursor to the previous data item. */
5822 mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
5828 mdb_cassert(mc, mc->mc_flags & C_INITIALIZED);
5830 mp = mc->mc_pg[mc->mc_top];
5832 if (mc->mc_db->md_flags & MDB_DUPSORT) {
5833 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5834 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5835 if (op == MDB_PREV || op == MDB_PREV_DUP) {
5836 rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
5837 if (op != MDB_PREV || rc != MDB_NOTFOUND) {
5838 if (rc == MDB_SUCCESS) {
5839 MDB_GET_KEY(leaf, key);
5840 mc->mc_flags &= ~C_EOF;
5846 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5847 if (op == MDB_PREV_DUP)
5848 return MDB_NOTFOUND;
5852 DPRINTF(("cursor_prev: top page is %"Z"u in cursor %p",
5853 mdb_dbg_pgno(mp), (void *) mc));
5855 if (mc->mc_ki[mc->mc_top] == 0) {
5856 DPUTS("=====> move to prev sibling page");
5857 if ((rc = mdb_cursor_sibling(mc, 0)) != MDB_SUCCESS) {
5860 mp = mc->mc_pg[mc->mc_top];
5861 mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;
5862 DPRINTF(("prev page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
5864 mc->mc_ki[mc->mc_top]--;
5866 mc->mc_flags &= ~C_EOF;
5868 DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
5869 mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
5872 key->mv_size = mc->mc_db->md_pad;
5873 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5877 mdb_cassert(mc, IS_LEAF(mp));
5878 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5880 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5881 mdb_xcursor_init1(mc, leaf);
5884 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5887 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5888 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
5889 if (rc != MDB_SUCCESS)
5894 MDB_GET_KEY(leaf, key);
5898 /** Set the cursor on a specific data item. */
5900 mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data,
5901 MDB_cursor_op op, int *exactp)
5905 MDB_node *leaf = NULL;
5908 if (key->mv_size == 0)
5909 return MDB_BAD_VALSIZE;
5912 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5914 /* See if we're already on the right page */
5915 if (mc->mc_flags & C_INITIALIZED) {
5918 mp = mc->mc_pg[mc->mc_top];
5920 mc->mc_ki[mc->mc_top] = 0;
5921 return MDB_NOTFOUND;
5923 if (mp->mp_flags & P_LEAF2) {
5924 nodekey.mv_size = mc->mc_db->md_pad;
5925 nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size);
5927 leaf = NODEPTR(mp, 0);
5928 MDB_GET_KEY2(leaf, nodekey);
5930 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5932 /* Probably happens rarely, but first node on the page
5933 * was the one we wanted.
5935 mc->mc_ki[mc->mc_top] = 0;
5942 unsigned int nkeys = NUMKEYS(mp);
5944 if (mp->mp_flags & P_LEAF2) {
5945 nodekey.mv_data = LEAF2KEY(mp,
5946 nkeys-1, nodekey.mv_size);
5948 leaf = NODEPTR(mp, nkeys-1);
5949 MDB_GET_KEY2(leaf, nodekey);
5951 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5953 /* last node was the one we wanted */
5954 mc->mc_ki[mc->mc_top] = nkeys-1;
5960 if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) {
5961 /* This is definitely the right page, skip search_page */
5962 if (mp->mp_flags & P_LEAF2) {
5963 nodekey.mv_data = LEAF2KEY(mp,
5964 mc->mc_ki[mc->mc_top], nodekey.mv_size);
5966 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5967 MDB_GET_KEY2(leaf, nodekey);
5969 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5971 /* current node was the one we wanted */
5981 /* If any parents have right-sibs, search.
5982 * Otherwise, there's nothing further.
5984 for (i=0; i<mc->mc_top; i++)
5986 NUMKEYS(mc->mc_pg[i])-1)
5988 if (i == mc->mc_top) {
5989 /* There are no other pages */
5990 mc->mc_ki[mc->mc_top] = nkeys;
5991 return MDB_NOTFOUND;
5995 /* There are no other pages */
5996 mc->mc_ki[mc->mc_top] = 0;
5997 if (op == MDB_SET_RANGE && !exactp) {
6001 return MDB_NOTFOUND;
6007 rc = mdb_page_search(mc, key, 0);
6008 if (rc != MDB_SUCCESS)
6011 mp = mc->mc_pg[mc->mc_top];
6012 mdb_cassert(mc, IS_LEAF(mp));
6015 leaf = mdb_node_search(mc, key, exactp);
6016 if (exactp != NULL && !*exactp) {
6017 /* MDB_SET specified and not an exact match. */
6018 return MDB_NOTFOUND;
6022 DPUTS("===> inexact leaf not found, goto sibling");
6023 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
6024 mc->mc_flags |= C_EOF;
6025 return rc; /* no entries matched */
6027 mp = mc->mc_pg[mc->mc_top];
6028 mdb_cassert(mc, IS_LEAF(mp));
6029 leaf = NODEPTR(mp, 0);
6033 mc->mc_flags |= C_INITIALIZED;
6034 mc->mc_flags &= ~C_EOF;
6037 if (op == MDB_SET_RANGE || op == MDB_SET_KEY) {
6038 key->mv_size = mc->mc_db->md_pad;
6039 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
6044 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6045 mdb_xcursor_init1(mc, leaf);
6048 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6049 if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) {
6050 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
6053 if (op == MDB_GET_BOTH) {
6059 rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p);
6060 if (rc != MDB_SUCCESS)
6063 } else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {
6066 if ((rc = mdb_node_read(mc->mc_txn, leaf, &olddata)) != MDB_SUCCESS)
6068 dcmp = mc->mc_dbx->md_dcmp;
6069 #if UINT_MAX < SIZE_MAX
6070 if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
6071 dcmp = mdb_cmp_clong;
6073 rc = dcmp(data, &olddata);
6075 if (op == MDB_GET_BOTH || rc > 0)
6076 return MDB_NOTFOUND;
6083 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
6084 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
6089 /* The key already matches in all other cases */
6090 if (op == MDB_SET_RANGE || op == MDB_SET_KEY)
6091 MDB_GET_KEY(leaf, key);
6092 DPRINTF(("==> cursor placed on key [%s]", DKEY(key)));
6097 /** Move the cursor to the first item in the database. */
6099 mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data)
6105 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
6107 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
6108 rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
6109 if (rc != MDB_SUCCESS)
6112 mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
6114 leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0);
6115 mc->mc_flags |= C_INITIALIZED;
6116 mc->mc_flags &= ~C_EOF;
6118 mc->mc_ki[mc->mc_top] = 0;
6120 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
6121 key->mv_size = mc->mc_db->md_pad;
6122 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size);
6127 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6128 mdb_xcursor_init1(mc, leaf);
6129 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
6133 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
6137 MDB_GET_KEY(leaf, key);
6141 /** Move the cursor to the last item in the database. */
6143 mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)
6149 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
6151 if (!(mc->mc_flags & C_EOF)) {
6153 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
6154 rc = mdb_page_search(mc, NULL, MDB_PS_LAST);
6155 if (rc != MDB_SUCCESS)
6158 mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
6161 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;
6162 mc->mc_flags |= C_INITIALIZED|C_EOF;
6163 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6165 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
6166 key->mv_size = mc->mc_db->md_pad;
6167 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size);
6172 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6173 mdb_xcursor_init1(mc, leaf);
6174 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
6178 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
6183 MDB_GET_KEY(leaf, key);
6188 mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,
6193 int (*mfunc)(MDB_cursor *mc, MDB_val *key, MDB_val *data);
6198 if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)
6202 case MDB_GET_CURRENT:
6203 if (!(mc->mc_flags & C_INITIALIZED)) {
6206 MDB_page *mp = mc->mc_pg[mc->mc_top];
6207 int nkeys = NUMKEYS(mp);
6208 if (!nkeys || mc->mc_ki[mc->mc_top] >= nkeys) {
6209 mc->mc_ki[mc->mc_top] = nkeys;
6215 key->mv_size = mc->mc_db->md_pad;
6216 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
6218 MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6219 MDB_GET_KEY(leaf, key);
6221 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6222 if (mc->mc_flags & C_DEL)
6223 mdb_xcursor_init1(mc, leaf);
6224 rc = mdb_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT);
6226 rc = mdb_node_read(mc->mc_txn, leaf, data);
6233 case MDB_GET_BOTH_RANGE:
6238 if (mc->mc_xcursor == NULL) {
6239 rc = MDB_INCOMPATIBLE;
6249 rc = mdb_cursor_set(mc, key, data, op,
6250 op == MDB_SET_RANGE ? NULL : &exact);
6253 case MDB_GET_MULTIPLE:
6254 if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
6258 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
6259 rc = MDB_INCOMPATIBLE;
6263 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) ||
6264 (mc->mc_xcursor->mx_cursor.mc_flags & C_EOF))
6267 case MDB_NEXT_MULTIPLE:
6272 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
6273 rc = MDB_INCOMPATIBLE;
6276 if (!(mc->mc_flags & C_INITIALIZED))
6277 rc = mdb_cursor_first(mc, key, data);
6279 rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP);
6280 if (rc == MDB_SUCCESS) {
6281 if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
6284 mx = &mc->mc_xcursor->mx_cursor;
6285 data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) *
6287 data->mv_data = METADATA(mx->mc_pg[mx->mc_top]);
6288 mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1;
6296 case MDB_NEXT_NODUP:
6297 if (!(mc->mc_flags & C_INITIALIZED))
6298 rc = mdb_cursor_first(mc, key, data);
6300 rc = mdb_cursor_next(mc, key, data, op);
6304 case MDB_PREV_NODUP:
6305 if (!(mc->mc_flags & C_INITIALIZED)) {
6306 rc = mdb_cursor_last(mc, key, data);
6309 mc->mc_flags |= C_INITIALIZED;
6310 mc->mc_ki[mc->mc_top]++;
6312 rc = mdb_cursor_prev(mc, key, data, op);
6315 rc = mdb_cursor_first(mc, key, data);
6318 mfunc = mdb_cursor_first;
6320 if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
6324 if (mc->mc_xcursor == NULL) {
6325 rc = MDB_INCOMPATIBLE;
6329 MDB_node *leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6330 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6331 MDB_GET_KEY(leaf, key);
6332 rc = mdb_node_read(mc->mc_txn, leaf, data);
6336 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
6340 rc = mfunc(&mc->mc_xcursor->mx_cursor, data, NULL);
6343 rc = mdb_cursor_last(mc, key, data);
6346 mfunc = mdb_cursor_last;
6349 DPRINTF(("unhandled/unimplemented cursor operation %u", op));
6354 if (mc->mc_flags & C_DEL)
6355 mc->mc_flags ^= C_DEL;
6360 /** Touch all the pages in the cursor stack. Set mc_top.
6361 * Makes sure all the pages are writable, before attempting a write operation.
6362 * @param[in] mc The cursor to operate on.
6365 mdb_cursor_touch(MDB_cursor *mc)
6367 int rc = MDB_SUCCESS;
6369 if (mc->mc_dbi >= CORE_DBS && !(*mc->mc_dbflag & DB_DIRTY)) {
6372 if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))
6374 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, &mcx);
6375 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY);
6378 *mc->mc_dbflag |= DB_DIRTY;
6383 rc = mdb_page_touch(mc);
6384 } while (!rc && ++(mc->mc_top) < mc->mc_snum);
6385 mc->mc_top = mc->mc_snum-1;
6390 /** Do not spill pages to disk if txn is getting full, may fail instead */
6391 #define MDB_NOSPILL 0x8000
6394 mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
6398 MDB_node *leaf = NULL;
6399 MDB_page *fp, *mp, *sub_root = NULL;
6401 MDB_val xdata, *rdata, dkey, olddata;
6403 int do_sub = 0, insert_key, insert_data;
6404 unsigned int mcount = 0, dcount = 0, nospill;
6407 unsigned int nflags;
6410 if (mc == NULL || key == NULL)
6413 env = mc->mc_txn->mt_env;
6415 /* Check this first so counter will always be zero on any
6418 if (flags & MDB_MULTIPLE) {
6419 dcount = data[1].mv_size;
6420 data[1].mv_size = 0;
6421 if (!F_ISSET(mc->mc_db->md_flags, MDB_DUPFIXED))
6422 return MDB_INCOMPATIBLE;
6425 nospill = flags & MDB_NOSPILL;
6426 flags &= ~MDB_NOSPILL;
6428 if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
6429 return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
6431 if (key->mv_size-1 >= ENV_MAXKEY(env))
6432 return MDB_BAD_VALSIZE;
6434 #if SIZE_MAX > MAXDATASIZE
6435 if (data->mv_size > ((mc->mc_db->md_flags & MDB_DUPSORT) ? ENV_MAXKEY(env) : MAXDATASIZE))
6436 return MDB_BAD_VALSIZE;
6438 if ((mc->mc_db->md_flags & MDB_DUPSORT) && data->mv_size > ENV_MAXKEY(env))
6439 return MDB_BAD_VALSIZE;
6442 DPRINTF(("==> put db %d key [%s], size %"Z"u, data size %"Z"u",
6443 DDBI(mc), DKEY(key), key ? key->mv_size : 0, data->mv_size));
6447 if (flags == MDB_CURRENT) {
6448 if (!(mc->mc_flags & C_INITIALIZED))
6451 } else if (mc->mc_db->md_root == P_INVALID) {
6452 /* new database, cursor has nothing to point to */
6455 mc->mc_flags &= ~C_INITIALIZED;
6460 if (flags & MDB_APPEND) {
6462 rc = mdb_cursor_last(mc, &k2, &d2);
6464 rc = mc->mc_dbx->md_cmp(key, &k2);
6467 mc->mc_ki[mc->mc_top]++;
6469 /* new key is <= last key */
6474 rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact);
6476 if ((flags & MDB_NOOVERWRITE) && rc == 0) {
6477 DPRINTF(("duplicate key [%s]", DKEY(key)));
6479 return MDB_KEYEXIST;
6481 if (rc && rc != MDB_NOTFOUND)
6485 if (mc->mc_flags & C_DEL)
6486 mc->mc_flags ^= C_DEL;
6488 /* Cursor is positioned, check for room in the dirty list */
6490 if (flags & MDB_MULTIPLE) {
6492 xdata.mv_size = data->mv_size * dcount;
6496 if ((rc2 = mdb_page_spill(mc, key, rdata)))
6500 if (rc == MDB_NO_ROOT) {
6502 /* new database, write a root leaf page */
6503 DPUTS("allocating new root leaf page");
6504 if ((rc2 = mdb_page_new(mc, P_LEAF, 1, &np))) {
6507 mdb_cursor_push(mc, np);
6508 mc->mc_db->md_root = np->mp_pgno;
6509 mc->mc_db->md_depth++;
6510 *mc->mc_dbflag |= DB_DIRTY;
6511 if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED))
6513 np->mp_flags |= P_LEAF2;
6514 mc->mc_flags |= C_INITIALIZED;
6516 /* make sure all cursor pages are writable */
6517 rc2 = mdb_cursor_touch(mc);
6522 insert_key = insert_data = rc;
6524 /* The key does not exist */
6525 DPRINTF(("inserting key at index %i", mc->mc_ki[mc->mc_top]));
6526 if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
6527 LEAFSIZE(key, data) > env->me_nodemax)
6529 /* Too big for a node, insert in sub-DB. Set up an empty
6530 * "old sub-page" for prep_subDB to expand to a full page.
6532 fp_flags = P_LEAF|P_DIRTY;
6534 fp->mp_pad = data->mv_size; /* used if MDB_DUPFIXED */
6535 fp->mp_lower = fp->mp_upper = (PAGEHDRSZ-PAGEBASE);
6536 olddata.mv_size = PAGEHDRSZ;
6540 /* there's only a key anyway, so this is a no-op */
6541 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
6543 unsigned int ksize = mc->mc_db->md_pad;
6544 if (key->mv_size != ksize)
6545 return MDB_BAD_VALSIZE;
6546 ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize);
6547 memcpy(ptr, key->mv_data, ksize);
6549 /* if overwriting slot 0 of leaf, need to
6550 * update branch key if there is a parent page
6552 if (mc->mc_top && !mc->mc_ki[mc->mc_top]) {
6553 unsigned short dtop = 1;
6555 /* slot 0 is always an empty key, find real slot */
6556 while (mc->mc_top && !mc->mc_ki[mc->mc_top]) {
6560 if (mc->mc_ki[mc->mc_top])
6561 rc2 = mdb_update_key(mc, key);
6572 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6573 olddata.mv_size = NODEDSZ(leaf);
6574 olddata.mv_data = NODEDATA(leaf);
6577 if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) {
6578 /* Prepare (sub-)page/sub-DB to accept the new item,
6579 * if needed. fp: old sub-page or a header faking
6580 * it. mp: new (sub-)page. offset: growth in page
6581 * size. xdata: node data with new page or DB.
6583 unsigned i, offset = 0;
6584 mp = fp = xdata.mv_data = env->me_pbuf;
6585 mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
6587 /* Was a single item before, must convert now */
6588 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6590 /* Just overwrite the current item */
6591 if (flags == MDB_CURRENT)
6593 dcmp = mc->mc_dbx->md_dcmp;
6594 #if UINT_MAX < SIZE_MAX
6595 if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
6596 dcmp = mdb_cmp_clong;
6598 /* does data match? */
6599 if (!dcmp(data, &olddata)) {
6600 if (flags & MDB_NODUPDATA)
6601 return MDB_KEYEXIST;
6606 /* Back up original data item */
6607 dkey.mv_size = olddata.mv_size;
6608 dkey.mv_data = memcpy(fp+1, olddata.mv_data, olddata.mv_size);
6610 /* Make sub-page header for the dup items, with dummy body */
6611 fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP;
6612 fp->mp_lower = (PAGEHDRSZ-PAGEBASE);
6613 xdata.mv_size = PAGEHDRSZ + dkey.mv_size + data->mv_size;
6614 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
6615 fp->mp_flags |= P_LEAF2;
6616 fp->mp_pad = data->mv_size;
6617 xdata.mv_size += 2 * data->mv_size; /* leave space for 2 more */
6619 xdata.mv_size += 2 * (sizeof(indx_t) + NODESIZE) +
6620 (dkey.mv_size & 1) + (data->mv_size & 1);
6622 fp->mp_upper = xdata.mv_size - PAGEBASE;
6623 olddata.mv_size = xdata.mv_size; /* pretend olddata is fp */
6624 } else if (leaf->mn_flags & F_SUBDATA) {
6625 /* Data is on sub-DB, just store it */
6626 flags |= F_DUPDATA|F_SUBDATA;
6629 /* Data is on sub-page */
6630 fp = olddata.mv_data;
6633 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
6634 offset = EVEN(NODESIZE + sizeof(indx_t) +
6638 offset = fp->mp_pad;
6639 if (SIZELEFT(fp) < offset) {
6640 offset *= 4; /* space for 4 more */
6643 /* FALLTHRU: Big enough MDB_DUPFIXED sub-page */
6645 fp->mp_flags |= P_DIRTY;
6646 COPY_PGNO(fp->mp_pgno, mp->mp_pgno);
6647 mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;
6651 xdata.mv_size = olddata.mv_size + offset;
6654 fp_flags = fp->mp_flags;
6655 if (NODESIZE + NODEKSZ(leaf) + xdata.mv_size > env->me_nodemax) {
6656 /* Too big for a sub-page, convert to sub-DB */
6657 fp_flags &= ~P_SUBP;
6659 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
6660 fp_flags |= P_LEAF2;
6661 dummy.md_pad = fp->mp_pad;
6662 dummy.md_flags = MDB_DUPFIXED;
6663 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
6664 dummy.md_flags |= MDB_INTEGERKEY;
6670 dummy.md_branch_pages = 0;
6671 dummy.md_leaf_pages = 1;
6672 dummy.md_overflow_pages = 0;
6673 dummy.md_entries = NUMKEYS(fp);
6674 xdata.mv_size = sizeof(MDB_db);
6675 xdata.mv_data = &dummy;
6676 if ((rc = mdb_page_alloc(mc, 1, &mp)))
6678 offset = env->me_psize - olddata.mv_size;
6679 flags |= F_DUPDATA|F_SUBDATA;
6680 dummy.md_root = mp->mp_pgno;
6684 mp->mp_flags = fp_flags | P_DIRTY;
6685 mp->mp_pad = fp->mp_pad;
6686 mp->mp_lower = fp->mp_lower;
6687 mp->mp_upper = fp->mp_upper + offset;
6688 if (fp_flags & P_LEAF2) {
6689 memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad);
6691 memcpy((char *)mp + mp->mp_upper + PAGEBASE, (char *)fp + fp->mp_upper + PAGEBASE,
6692 olddata.mv_size - fp->mp_upper - PAGEBASE);
6693 for (i=0; i<NUMKEYS(fp); i++)
6694 mp->mp_ptrs[i] = fp->mp_ptrs[i] + offset;
6702 mdb_node_del(mc, 0);
6706 /* LMDB passes F_SUBDATA in 'flags' to write a DB record */
6707 if ((leaf->mn_flags ^ flags) & F_SUBDATA)
6708 return MDB_INCOMPATIBLE;
6709 /* overflow page overwrites need special handling */
6710 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
6713 int level, ovpages, dpages = OVPAGES(data->mv_size, env->me_psize);
6715 memcpy(&pg, olddata.mv_data, sizeof(pg));
6716 if ((rc2 = mdb_page_get(mc->mc_txn, pg, &omp, &level)) != 0)
6718 ovpages = omp->mp_pages;
6720 /* Is the ov page large enough? */
6721 if (ovpages >= dpages) {
6722 if (!(omp->mp_flags & P_DIRTY) &&
6723 (level || (env->me_flags & MDB_WRITEMAP)))
6725 rc = mdb_page_unspill(mc->mc_txn, omp, &omp);
6728 level = 0; /* dirty in this txn or clean */
6731 if (omp->mp_flags & P_DIRTY) {
6732 /* yes, overwrite it. Note in this case we don't
6733 * bother to try shrinking the page if the new data
6734 * is smaller than the overflow threshold.
6737 /* It is writable only in a parent txn */
6738 size_t sz = (size_t) env->me_psize * ovpages, off;
6739 MDB_page *np = mdb_page_malloc(mc->mc_txn, ovpages);
6745 /* Note - this page is already counted in parent's dirty_room */
6746 rc2 = mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);
6747 mdb_cassert(mc, rc2 == 0);
6748 if (!(flags & MDB_RESERVE)) {
6749 /* Copy end of page, adjusting alignment so
6750 * compiler may copy words instead of bytes.
6752 off = (PAGEHDRSZ + data->mv_size) & -sizeof(size_t);
6753 memcpy((size_t *)((char *)np + off),
6754 (size_t *)((char *)omp + off), sz - off);
6757 memcpy(np, omp, sz); /* Copy beginning of page */
6760 SETDSZ(leaf, data->mv_size);
6761 if (F_ISSET(flags, MDB_RESERVE))
6762 data->mv_data = METADATA(omp);
6764 memcpy(METADATA(omp), data->mv_data, data->mv_size);
6768 if ((rc2 = mdb_ovpage_free(mc, omp)) != MDB_SUCCESS)
6770 } else if (data->mv_size == olddata.mv_size) {
6771 /* same size, just replace it. Note that we could
6772 * also reuse this node if the new data is smaller,
6773 * but instead we opt to shrink the node in that case.
6775 if (F_ISSET(flags, MDB_RESERVE))
6776 data->mv_data = olddata.mv_data;
6777 else if (!(mc->mc_flags & C_SUB))
6778 memcpy(olddata.mv_data, data->mv_data, data->mv_size);
6780 memcpy(NODEKEY(leaf), key->mv_data, key->mv_size);
6785 mdb_node_del(mc, 0);
6791 nflags = flags & NODE_ADD_FLAGS;
6792 nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(env, key, rdata);
6793 if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) {
6794 if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA )
6795 nflags &= ~MDB_APPEND; /* sub-page may need room to grow */
6797 nflags |= MDB_SPLIT_REPLACE;
6798 rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags);
6800 /* There is room already in this leaf page. */
6801 rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);
6802 if (rc == 0 && insert_key) {
6803 /* Adjust other cursors pointing to mp */
6804 MDB_cursor *m2, *m3;
6805 MDB_dbi dbi = mc->mc_dbi;
6806 unsigned i = mc->mc_top;
6807 MDB_page *mp = mc->mc_pg[i];
6809 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
6810 if (mc->mc_flags & C_SUB)
6811 m3 = &m2->mc_xcursor->mx_cursor;
6814 if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
6815 if (m3->mc_pg[i] == mp && m3->mc_ki[i] >= mc->mc_ki[i]) {
6822 if (rc == MDB_SUCCESS) {
6823 /* Now store the actual data in the child DB. Note that we're
6824 * storing the user data in the keys field, so there are strict
6825 * size limits on dupdata. The actual data fields of the child
6826 * DB are all zero size.
6829 int xflags, new_dupdata;
6834 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6835 if (flags & MDB_CURRENT) {
6836 xflags = MDB_CURRENT|MDB_NOSPILL;
6838 mdb_xcursor_init1(mc, leaf);
6839 xflags = (flags & MDB_NODUPDATA) ?
6840 MDB_NOOVERWRITE|MDB_NOSPILL : MDB_NOSPILL;
6843 mc->mc_xcursor->mx_cursor.mc_pg[0] = sub_root;
6844 new_dupdata = (int)dkey.mv_size;
6845 /* converted, write the original data first */
6847 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);
6850 /* we've done our job */
6853 if (!(leaf->mn_flags & F_SUBDATA) || sub_root) {
6854 /* Adjust other cursors pointing to mp */
6856 MDB_xcursor *mx = mc->mc_xcursor;
6857 unsigned i = mc->mc_top;
6858 MDB_page *mp = mc->mc_pg[i];
6859 int nkeys = NUMKEYS(mp);
6861 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
6862 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
6863 if (!(m2->mc_flags & C_INITIALIZED)) continue;
6864 if (m2->mc_pg[i] == mp) {
6865 if (m2->mc_ki[i] == mc->mc_ki[i]) {
6866 mdb_xcursor_init2(m2, mx, new_dupdata);
6867 } else if (!insert_key && m2->mc_ki[i] < nkeys) {
6868 MDB_node *n2 = NODEPTR(mp, m2->mc_ki[i]);
6869 if ((n2->mn_flags & (F_SUBDATA|F_DUPDATA)) == F_DUPDATA)
6870 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
6875 ecount = mc->mc_xcursor->mx_db.md_entries;
6876 if (flags & MDB_APPENDDUP)
6877 xflags |= MDB_APPEND;
6878 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);
6879 if (flags & F_SUBDATA) {
6880 void *db = NODEDATA(leaf);
6881 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
6883 insert_data = mc->mc_xcursor->mx_db.md_entries - ecount;
6885 /* Increment count unless we just replaced an existing item. */
6887 mc->mc_db->md_entries++;
6889 /* Invalidate txn if we created an empty sub-DB */
6892 /* If we succeeded and the key didn't exist before,
6893 * make sure the cursor is marked valid.
6895 mc->mc_flags |= C_INITIALIZED;
6897 if (flags & MDB_MULTIPLE) {
6900 /* let caller know how many succeeded, if any */
6901 data[1].mv_size = mcount;
6902 if (mcount < dcount) {
6903 data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size;
6904 insert_key = insert_data = 0;
6911 if (rc == MDB_KEYEXIST) /* should not happen, we deleted that item */
6914 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
6919 mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
6925 if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
6926 return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
6928 if (!(mc->mc_flags & C_INITIALIZED))
6931 if (mc->mc_ki[mc->mc_top] >= NUMKEYS(mc->mc_pg[mc->mc_top]))
6932 return MDB_NOTFOUND;
6934 if (!(flags & MDB_NOSPILL) && (rc = mdb_page_spill(mc, NULL, NULL)))
6937 rc = mdb_cursor_touch(mc);
6941 mp = mc->mc_pg[mc->mc_top];
6944 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6946 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6947 if (flags & MDB_NODUPDATA) {
6948 /* mdb_cursor_del0() will subtract the final entry */
6949 mc->mc_db->md_entries -= mc->mc_xcursor->mx_db.md_entries - 1;
6950 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
6952 if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
6953 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6955 rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, MDB_NOSPILL);
6958 /* If sub-DB still has entries, we're done */
6959 if (mc->mc_xcursor->mx_db.md_entries) {
6960 if (leaf->mn_flags & F_SUBDATA) {
6961 /* update subDB info */
6962 void *db = NODEDATA(leaf);
6963 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
6966 /* shrink fake page */
6967 mdb_node_shrink(mp, mc->mc_ki[mc->mc_top]);
6968 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6969 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6970 /* fix other sub-DB cursors pointed at fake pages on this page */
6971 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
6972 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
6973 if (!(m2->mc_flags & C_INITIALIZED)) continue;
6974 if (m2->mc_pg[mc->mc_top] == mp) {
6975 if (m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top]) {
6976 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6978 MDB_node *n2 = NODEPTR(mp, m2->mc_ki[mc->mc_top]);
6979 if (!(n2->mn_flags & F_SUBDATA))
6980 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
6985 mc->mc_db->md_entries--;
6986 mc->mc_flags |= C_DEL;
6989 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
6991 /* otherwise fall thru and delete the sub-DB */
6994 if (leaf->mn_flags & F_SUBDATA) {
6995 /* add all the child DB's pages to the free list */
6996 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
7001 /* LMDB passes F_SUBDATA in 'flags' to delete a DB record */
7002 else if ((leaf->mn_flags ^ flags) & F_SUBDATA) {
7003 rc = MDB_INCOMPATIBLE;
7007 /* add overflow pages to free list */
7008 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
7012 memcpy(&pg, NODEDATA(leaf), sizeof(pg));
7013 if ((rc = mdb_page_get(mc->mc_txn, pg, &omp, NULL)) ||
7014 (rc = mdb_ovpage_free(mc, omp)))
7019 return mdb_cursor_del0(mc);
7022 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
7026 /** Allocate and initialize new pages for a database.
7027 * @param[in] mc a cursor on the database being added to.
7028 * @param[in] flags flags defining what type of page is being allocated.
7029 * @param[in] num the number of pages to allocate. This is usually 1,
7030 * unless allocating overflow pages for a large record.
7031 * @param[out] mp Address of a page, or NULL on failure.
7032 * @return 0 on success, non-zero on failure.
7035 mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp)
7040 if ((rc = mdb_page_alloc(mc, num, &np)))
7042 DPRINTF(("allocated new mpage %"Z"u, page size %u",
7043 np->mp_pgno, mc->mc_txn->mt_env->me_psize));
7044 np->mp_flags = flags | P_DIRTY;
7045 np->mp_lower = (PAGEHDRSZ-PAGEBASE);
7046 np->mp_upper = mc->mc_txn->mt_env->me_psize - PAGEBASE;
7049 mc->mc_db->md_branch_pages++;
7050 else if (IS_LEAF(np))
7051 mc->mc_db->md_leaf_pages++;
7052 else if (IS_OVERFLOW(np)) {
7053 mc->mc_db->md_overflow_pages += num;
7061 /** Calculate the size of a leaf node.
7062 * The size depends on the environment's page size; if a data item
7063 * is too large it will be put onto an overflow page and the node
7064 * size will only include the key and not the data. Sizes are always
7065 * rounded up to an even number of bytes, to guarantee 2-byte alignment
7066 * of the #MDB_node headers.
7067 * @param[in] env The environment handle.
7068 * @param[in] key The key for the node.
7069 * @param[in] data The data for the node.
7070 * @return The number of bytes needed to store the node.
7073 mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data)
7077 sz = LEAFSIZE(key, data);
7078 if (sz > env->me_nodemax) {
7079 /* put on overflow page */
7080 sz -= data->mv_size - sizeof(pgno_t);
7083 return EVEN(sz + sizeof(indx_t));
7086 /** Calculate the size of a branch node.
7087 * The size should depend on the environment's page size but since
7088 * we currently don't support spilling large keys onto overflow
7089 * pages, it's simply the size of the #MDB_node header plus the
7090 * size of the key. Sizes are always rounded up to an even number
7091 * of bytes, to guarantee 2-byte alignment of the #MDB_node headers.
7092 * @param[in] env The environment handle.
7093 * @param[in] key The key for the node.
7094 * @return The number of bytes needed to store the node.
7097 mdb_branch_size(MDB_env *env, MDB_val *key)
7102 if (sz > env->me_nodemax) {
7103 /* put on overflow page */
7104 /* not implemented */
7105 /* sz -= key->size - sizeof(pgno_t); */
7108 return sz + sizeof(indx_t);
7111 /** Add a node to the page pointed to by the cursor.
7112 * @param[in] mc The cursor for this operation.
7113 * @param[in] indx The index on the page where the new node should be added.
7114 * @param[in] key The key for the new node.
7115 * @param[in] data The data for the new node, if any.
7116 * @param[in] pgno The page number, if adding a branch node.
7117 * @param[in] flags Flags for the node.
7118 * @return 0 on success, non-zero on failure. Possible errors are:
7120 * <li>ENOMEM - failed to allocate overflow pages for the node.
7121 * <li>MDB_PAGE_FULL - there is insufficient room in the page. This error
7122 * should never happen since all callers already calculate the
7123 * page's free space before calling this function.
7127 mdb_node_add(MDB_cursor *mc, indx_t indx,
7128 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags)
7131 size_t node_size = NODESIZE;
7135 MDB_page *mp = mc->mc_pg[mc->mc_top];
7136 MDB_page *ofp = NULL; /* overflow page */
7140 mdb_cassert(mc, mp->mp_upper >= mp->mp_lower);
7142 DPRINTF(("add to %s %spage %"Z"u index %i, data size %"Z"u key size %"Z"u [%s]",
7143 IS_LEAF(mp) ? "leaf" : "branch",
7144 IS_SUBP(mp) ? "sub-" : "",
7145 mdb_dbg_pgno(mp), indx, data ? data->mv_size : 0,
7146 key ? key->mv_size : 0, key ? DKEY(key) : "null"));
7149 /* Move higher keys up one slot. */
7150 int ksize = mc->mc_db->md_pad, dif;
7151 char *ptr = LEAF2KEY(mp, indx, ksize);
7152 dif = NUMKEYS(mp) - indx;
7154 memmove(ptr+ksize, ptr, dif*ksize);
7155 /* insert new key */
7156 memcpy(ptr, key->mv_data, ksize);
7158 /* Just using these for counting */
7159 mp->mp_lower += sizeof(indx_t);
7160 mp->mp_upper -= ksize - sizeof(indx_t);
7164 room = (ssize_t)SIZELEFT(mp) - (ssize_t)sizeof(indx_t);
7166 node_size += key->mv_size;
7168 mdb_cassert(mc, key && data);
7169 if (F_ISSET(flags, F_BIGDATA)) {
7170 /* Data already on overflow page. */
7171 node_size += sizeof(pgno_t);
7172 } else if (node_size + data->mv_size > mc->mc_txn->mt_env->me_nodemax) {
7173 int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
7175 /* Put data on overflow page. */
7176 DPRINTF(("data size is %"Z"u, node would be %"Z"u, put data on overflow page",
7177 data->mv_size, node_size+data->mv_size));
7178 node_size = EVEN(node_size + sizeof(pgno_t));
7179 if ((ssize_t)node_size > room)
7181 if ((rc = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp)))
7183 DPRINTF(("allocated overflow page %"Z"u", ofp->mp_pgno));
7187 node_size += data->mv_size;
7190 node_size = EVEN(node_size);
7191 if ((ssize_t)node_size > room)
7195 /* Move higher pointers up one slot. */
7196 for (i = NUMKEYS(mp); i > indx; i--)
7197 mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];
7199 /* Adjust free space offsets. */
7200 ofs = mp->mp_upper - node_size;
7201 mdb_cassert(mc, ofs >= mp->mp_lower + sizeof(indx_t));
7202 mp->mp_ptrs[indx] = ofs;
7204 mp->mp_lower += sizeof(indx_t);
7206 /* Write the node data. */
7207 node = NODEPTR(mp, indx);
7208 node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
7209 node->mn_flags = flags;
7211 SETDSZ(node,data->mv_size);
7216 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
7219 ndata = NODEDATA(node);
7221 if (F_ISSET(flags, F_BIGDATA))
7222 memcpy(ndata, data->mv_data, sizeof(pgno_t));
7223 else if (F_ISSET(flags, MDB_RESERVE))
7224 data->mv_data = ndata;
7226 memcpy(ndata, data->mv_data, data->mv_size);
7228 memcpy(ndata, &ofp->mp_pgno, sizeof(pgno_t));
7229 ndata = METADATA(ofp);
7230 if (F_ISSET(flags, MDB_RESERVE))
7231 data->mv_data = ndata;
7233 memcpy(ndata, data->mv_data, data->mv_size);
7240 DPRINTF(("not enough room in page %"Z"u, got %u ptrs",
7241 mdb_dbg_pgno(mp), NUMKEYS(mp)));
7242 DPRINTF(("upper-lower = %u - %u = %"Z"d", mp->mp_upper,mp->mp_lower,room));
7243 DPRINTF(("node size = %"Z"u", node_size));
7244 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
7245 return MDB_PAGE_FULL;
7248 /** Delete the specified node from a page.
7249 * @param[in] mc Cursor pointing to the node to delete.
7250 * @param[in] ksize The size of a node. Only used if the page is
7251 * part of a #MDB_DUPFIXED database.
7254 mdb_node_del(MDB_cursor *mc, int ksize)
7256 MDB_page *mp = mc->mc_pg[mc->mc_top];
7257 indx_t indx = mc->mc_ki[mc->mc_top];
7259 indx_t i, j, numkeys, ptr;
7263 DPRINTF(("delete node %u on %s page %"Z"u", indx,
7264 IS_LEAF(mp) ? "leaf" : "branch", mdb_dbg_pgno(mp)));
7265 numkeys = NUMKEYS(mp);
7266 mdb_cassert(mc, indx < numkeys);
7269 int x = numkeys - 1 - indx;
7270 base = LEAF2KEY(mp, indx, ksize);
7272 memmove(base, base + ksize, x * ksize);
7273 mp->mp_lower -= sizeof(indx_t);
7274 mp->mp_upper += ksize - sizeof(indx_t);
7278 node = NODEPTR(mp, indx);
7279 sz = NODESIZE + node->mn_ksize;
7281 if (F_ISSET(node->mn_flags, F_BIGDATA))
7282 sz += sizeof(pgno_t);
7284 sz += NODEDSZ(node);
7288 ptr = mp->mp_ptrs[indx];
7289 for (i = j = 0; i < numkeys; i++) {
7291 mp->mp_ptrs[j] = mp->mp_ptrs[i];
7292 if (mp->mp_ptrs[i] < ptr)
7293 mp->mp_ptrs[j] += sz;
7298 base = (char *)mp + mp->mp_upper + PAGEBASE;
7299 memmove(base + sz, base, ptr - mp->mp_upper);
7301 mp->mp_lower -= sizeof(indx_t);
7305 /** Compact the main page after deleting a node on a subpage.
7306 * @param[in] mp The main page to operate on.
7307 * @param[in] indx The index of the subpage on the main page.
7310 mdb_node_shrink(MDB_page *mp, indx_t indx)
7315 indx_t delta, nsize, len, ptr;
7318 node = NODEPTR(mp, indx);
7319 sp = (MDB_page *)NODEDATA(node);
7320 delta = SIZELEFT(sp);
7321 nsize = NODEDSZ(node) - delta;
7323 /* Prepare to shift upward, set len = length(subpage part to shift) */
7327 return; /* do not make the node uneven-sized */
7329 xp = (MDB_page *)((char *)sp + delta); /* destination subpage */
7330 for (i = NUMKEYS(sp); --i >= 0; )
7331 xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta;
7334 sp->mp_upper = sp->mp_lower;
7335 COPY_PGNO(sp->mp_pgno, mp->mp_pgno);
7336 SETDSZ(node, nsize);
7338 /* Shift <lower nodes...initial part of subpage> upward */
7339 base = (char *)mp + mp->mp_upper + PAGEBASE;
7340 memmove(base + delta, base, (char *)sp + len - base);
7342 ptr = mp->mp_ptrs[indx];
7343 for (i = NUMKEYS(mp); --i >= 0; ) {
7344 if (mp->mp_ptrs[i] <= ptr)
7345 mp->mp_ptrs[i] += delta;
7347 mp->mp_upper += delta;
7350 /** Initial setup of a sorted-dups cursor.
7351 * Sorted duplicates are implemented as a sub-database for the given key.
7352 * The duplicate data items are actually keys of the sub-database.
7353 * Operations on the duplicate data items are performed using a sub-cursor
7354 * initialized when the sub-database is first accessed. This function does
7355 * the preliminary setup of the sub-cursor, filling in the fields that
7356 * depend only on the parent DB.
7357 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
7360 mdb_xcursor_init0(MDB_cursor *mc)
7362 MDB_xcursor *mx = mc->mc_xcursor;
7364 mx->mx_cursor.mc_xcursor = NULL;
7365 mx->mx_cursor.mc_txn = mc->mc_txn;
7366 mx->mx_cursor.mc_db = &mx->mx_db;
7367 mx->mx_cursor.mc_dbx = &mx->mx_dbx;
7368 mx->mx_cursor.mc_dbi = mc->mc_dbi;
7369 mx->mx_cursor.mc_dbflag = &mx->mx_dbflag;
7370 mx->mx_cursor.mc_snum = 0;
7371 mx->mx_cursor.mc_top = 0;
7372 mx->mx_cursor.mc_flags = C_SUB;
7373 mx->mx_dbx.md_name.mv_size = 0;
7374 mx->mx_dbx.md_name.mv_data = NULL;
7375 mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp;
7376 mx->mx_dbx.md_dcmp = NULL;
7377 mx->mx_dbx.md_rel = mc->mc_dbx->md_rel;
7380 /** Final setup of a sorted-dups cursor.
7381 * Sets up the fields that depend on the data from the main cursor.
7382 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
7383 * @param[in] node The data containing the #MDB_db record for the
7384 * sorted-dup database.
7387 mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)
7389 MDB_xcursor *mx = mc->mc_xcursor;
7391 if (node->mn_flags & F_SUBDATA) {
7392 memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db));
7393 mx->mx_cursor.mc_pg[0] = 0;
7394 mx->mx_cursor.mc_snum = 0;
7395 mx->mx_cursor.mc_top = 0;
7396 mx->mx_cursor.mc_flags = C_SUB;
7398 MDB_page *fp = NODEDATA(node);
7399 mx->mx_db.md_pad = 0;
7400 mx->mx_db.md_flags = 0;
7401 mx->mx_db.md_depth = 1;
7402 mx->mx_db.md_branch_pages = 0;
7403 mx->mx_db.md_leaf_pages = 1;
7404 mx->mx_db.md_overflow_pages = 0;
7405 mx->mx_db.md_entries = NUMKEYS(fp);
7406 COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno);
7407 mx->mx_cursor.mc_snum = 1;
7408 mx->mx_cursor.mc_top = 0;
7409 mx->mx_cursor.mc_flags = C_INITIALIZED|C_SUB;
7410 mx->mx_cursor.mc_pg[0] = fp;
7411 mx->mx_cursor.mc_ki[0] = 0;
7412 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
7413 mx->mx_db.md_flags = MDB_DUPFIXED;
7414 mx->mx_db.md_pad = fp->mp_pad;
7415 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
7416 mx->mx_db.md_flags |= MDB_INTEGERKEY;
7419 DPRINTF(("Sub-db -%u root page %"Z"u", mx->mx_cursor.mc_dbi,
7420 mx->mx_db.md_root));
7421 mx->mx_dbflag = DB_VALID|DB_USRVALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
7422 #if UINT_MAX < SIZE_MAX
7423 if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(size_t))
7424 mx->mx_dbx.md_cmp = mdb_cmp_clong;
7429 /** Fixup a sorted-dups cursor due to underlying update.
7430 * Sets up some fields that depend on the data from the main cursor.
7431 * Almost the same as init1, but skips initialization steps if the
7432 * xcursor had already been used.
7433 * @param[in] mc The main cursor whose sorted-dups cursor is to be fixed up.
7434 * @param[in] src_mx The xcursor of an up-to-date cursor.
7435 * @param[in] new_dupdata True if converting from a non-#F_DUPDATA item.
7438 mdb_xcursor_init2(MDB_cursor *mc, MDB_xcursor *src_mx, int new_dupdata)
7440 MDB_xcursor *mx = mc->mc_xcursor;
7443 mx->mx_cursor.mc_snum = 1;
7444 mx->mx_cursor.mc_top = 0;
7445 mx->mx_cursor.mc_flags |= C_INITIALIZED;
7446 mx->mx_cursor.mc_ki[0] = 0;
7447 mx->mx_dbflag = DB_VALID|DB_USRVALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
7448 #if UINT_MAX < SIZE_MAX
7449 mx->mx_dbx.md_cmp = src_mx->mx_dbx.md_cmp;
7451 } else if (!(mx->mx_cursor.mc_flags & C_INITIALIZED)) {
7454 mx->mx_db = src_mx->mx_db;
7455 mx->mx_cursor.mc_pg[0] = src_mx->mx_cursor.mc_pg[0];
7456 DPRINTF(("Sub-db -%u root page %"Z"u", mx->mx_cursor.mc_dbi,
7457 mx->mx_db.md_root));
7460 /** Initialize a cursor for a given transaction and database. */
7462 mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
7465 mc->mc_backup = NULL;
7468 mc->mc_db = &txn->mt_dbs[dbi];
7469 mc->mc_dbx = &txn->mt_dbxs[dbi];
7470 mc->mc_dbflag = &txn->mt_dbflags[dbi];
7476 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
7477 mdb_tassert(txn, mx != NULL);
7478 mc->mc_xcursor = mx;
7479 mdb_xcursor_init0(mc);
7481 mc->mc_xcursor = NULL;
7483 if (*mc->mc_dbflag & DB_STALE) {
7484 mdb_page_search(mc, NULL, MDB_PS_ROOTONLY);
7489 mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
7492 size_t size = sizeof(MDB_cursor);
7494 if (!ret || !TXN_DBI_EXIST(txn, dbi, DB_VALID))
7497 if (txn->mt_flags & MDB_TXN_BLOCKED)
7500 if (dbi == FREE_DBI && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
7503 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)
7504 size += sizeof(MDB_xcursor);
7506 if ((mc = malloc(size)) != NULL) {
7507 mdb_cursor_init(mc, txn, dbi, (MDB_xcursor *)(mc + 1));
7508 if (txn->mt_cursors) {
7509 mc->mc_next = txn->mt_cursors[dbi];
7510 txn->mt_cursors[dbi] = mc;
7511 mc->mc_flags |= C_UNTRACK;
7523 mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)
7525 if (!mc || !TXN_DBI_EXIST(txn, mc->mc_dbi, DB_VALID))
7528 if ((mc->mc_flags & C_UNTRACK) || txn->mt_cursors)
7531 if (txn->mt_flags & MDB_TXN_BLOCKED)
7534 mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor);
7538 /* Return the count of duplicate data items for the current key */
7540 mdb_cursor_count(MDB_cursor *mc, size_t *countp)
7544 if (mc == NULL || countp == NULL)
7547 if (mc->mc_xcursor == NULL)
7548 return MDB_INCOMPATIBLE;
7550 if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)
7553 if (!(mc->mc_flags & C_INITIALIZED))
7556 if (!mc->mc_snum || (mc->mc_flags & C_EOF))
7557 return MDB_NOTFOUND;
7559 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
7560 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
7563 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
7566 *countp = mc->mc_xcursor->mx_db.md_entries;
7572 mdb_cursor_close(MDB_cursor *mc)
7574 if (mc && !mc->mc_backup) {
7575 /* remove from txn, if tracked */
7576 if ((mc->mc_flags & C_UNTRACK) && mc->mc_txn->mt_cursors) {
7577 MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi];
7578 while (*prev && *prev != mc) prev = &(*prev)->mc_next;
7580 *prev = mc->mc_next;
7587 mdb_cursor_txn(MDB_cursor *mc)
7589 if (!mc) return NULL;
7594 mdb_cursor_dbi(MDB_cursor *mc)
7599 /** Replace the key for a branch node with a new key.
7600 * @param[in] mc Cursor pointing to the node to operate on.
7601 * @param[in] key The new key to use.
7602 * @return 0 on success, non-zero on failure.
7605 mdb_update_key(MDB_cursor *mc, MDB_val *key)
7611 int delta, ksize, oksize;
7612 indx_t ptr, i, numkeys, indx;
7615 indx = mc->mc_ki[mc->mc_top];
7616 mp = mc->mc_pg[mc->mc_top];
7617 node = NODEPTR(mp, indx);
7618 ptr = mp->mp_ptrs[indx];
7622 char kbuf2[DKBUF_MAXKEYSIZE*2+1];
7623 k2.mv_data = NODEKEY(node);
7624 k2.mv_size = node->mn_ksize;
7625 DPRINTF(("update key %u (ofs %u) [%s] to [%s] on page %"Z"u",
7627 mdb_dkey(&k2, kbuf2),
7633 /* Sizes must be 2-byte aligned. */
7634 ksize = EVEN(key->mv_size);
7635 oksize = EVEN(node->mn_ksize);
7636 delta = ksize - oksize;
7638 /* Shift node contents if EVEN(key length) changed. */
7640 if (delta > 0 && SIZELEFT(mp) < delta) {
7642 /* not enough space left, do a delete and split */
7643 DPRINTF(("Not enough room, delta = %d, splitting...", delta));
7644 pgno = NODEPGNO(node);
7645 mdb_node_del(mc, 0);
7646 return mdb_page_split(mc, key, NULL, pgno, MDB_SPLIT_REPLACE);
7649 numkeys = NUMKEYS(mp);
7650 for (i = 0; i < numkeys; i++) {
7651 if (mp->mp_ptrs[i] <= ptr)
7652 mp->mp_ptrs[i] -= delta;
7655 base = (char *)mp + mp->mp_upper + PAGEBASE;
7656 len = ptr - mp->mp_upper + NODESIZE;
7657 memmove(base - delta, base, len);
7658 mp->mp_upper -= delta;
7660 node = NODEPTR(mp, indx);
7663 /* But even if no shift was needed, update ksize */
7664 if (node->mn_ksize != key->mv_size)
7665 node->mn_ksize = key->mv_size;
7668 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
7674 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst);
7676 /** Perform \b act while tracking temporary cursor \b mn */
7677 #define WITH_CURSOR_TRACKING(mn, act) do { \
7678 MDB_cursor dummy, *tracked, **tp = &(mn).mc_txn->mt_cursors[mn.mc_dbi]; \
7679 if ((mn).mc_flags & C_SUB) { \
7680 dummy.mc_flags = C_INITIALIZED; \
7681 dummy.mc_xcursor = (MDB_xcursor *)&(mn); \
7686 tracked->mc_next = *tp; \
7689 *tp = tracked->mc_next; \
7692 /** Move a node from csrc to cdst.
7695 mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft)
7702 unsigned short flags;
7706 /* Mark src and dst as dirty. */
7707 if ((rc = mdb_page_touch(csrc)) ||
7708 (rc = mdb_page_touch(cdst)))
7711 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7712 key.mv_size = csrc->mc_db->md_pad;
7713 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
7715 data.mv_data = NULL;
7719 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]);
7720 mdb_cassert(csrc, !((size_t)srcnode & 1));
7721 srcpg = NODEPGNO(srcnode);
7722 flags = srcnode->mn_flags;
7723 if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
7724 unsigned int snum = csrc->mc_snum;
7726 /* must find the lowest key below src */
7727 rc = mdb_page_search_lowest(csrc);
7730 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7731 key.mv_size = csrc->mc_db->md_pad;
7732 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
7734 s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
7735 key.mv_size = NODEKSZ(s2);
7736 key.mv_data = NODEKEY(s2);
7738 csrc->mc_snum = snum--;
7739 csrc->mc_top = snum;
7741 key.mv_size = NODEKSZ(srcnode);
7742 key.mv_data = NODEKEY(srcnode);
7744 data.mv_size = NODEDSZ(srcnode);
7745 data.mv_data = NODEDATA(srcnode);
7747 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) {
7748 unsigned int snum = cdst->mc_snum;
7751 /* must find the lowest key below dst */
7752 mdb_cursor_copy(cdst, &mn);
7753 rc = mdb_page_search_lowest(&mn);
7756 if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {
7757 bkey.mv_size = mn.mc_db->md_pad;
7758 bkey.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, bkey.mv_size);
7760 s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);
7761 bkey.mv_size = NODEKSZ(s2);
7762 bkey.mv_data = NODEKEY(s2);
7764 mn.mc_snum = snum--;
7767 rc = mdb_update_key(&mn, &bkey);
7772 DPRINTF(("moving %s node %u [%s] on page %"Z"u to node %u on page %"Z"u",
7773 IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch",
7774 csrc->mc_ki[csrc->mc_top],
7776 csrc->mc_pg[csrc->mc_top]->mp_pgno,
7777 cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno));
7779 /* Add the node to the destination page.
7781 rc = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags);
7782 if (rc != MDB_SUCCESS)
7785 /* Delete the node from the source page.
7787 mdb_node_del(csrc, key.mv_size);
7790 /* Adjust other cursors pointing to mp */
7791 MDB_cursor *m2, *m3;
7792 MDB_dbi dbi = csrc->mc_dbi;
7793 MDB_page *mpd, *mps;
7795 mps = csrc->mc_pg[csrc->mc_top];
7796 /* If we're adding on the left, bump others up */
7798 mpd = cdst->mc_pg[csrc->mc_top];
7799 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7800 if (csrc->mc_flags & C_SUB)
7801 m3 = &m2->mc_xcursor->mx_cursor;
7804 if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)
7807 m3->mc_pg[csrc->mc_top] == mpd &&
7808 m3->mc_ki[csrc->mc_top] >= cdst->mc_ki[csrc->mc_top]) {
7809 m3->mc_ki[csrc->mc_top]++;
7812 m3->mc_pg[csrc->mc_top] == mps &&
7813 m3->mc_ki[csrc->mc_top] == csrc->mc_ki[csrc->mc_top]) {
7814 m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
7815 m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
7816 m3->mc_ki[csrc->mc_top-1]++;
7820 /* Adding on the right, bump others down */
7822 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7823 if (csrc->mc_flags & C_SUB)
7824 m3 = &m2->mc_xcursor->mx_cursor;
7827 if (m3 == csrc) continue;
7828 if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)
7830 if (m3->mc_pg[csrc->mc_top] == mps) {
7831 if (!m3->mc_ki[csrc->mc_top]) {
7832 m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
7833 m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
7834 m3->mc_ki[csrc->mc_top-1]--;
7836 m3->mc_ki[csrc->mc_top]--;
7843 /* Update the parent separators.
7845 if (csrc->mc_ki[csrc->mc_top] == 0) {
7846 if (csrc->mc_ki[csrc->mc_top-1] != 0) {
7847 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7848 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
7850 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
7851 key.mv_size = NODEKSZ(srcnode);
7852 key.mv_data = NODEKEY(srcnode);
7854 DPRINTF(("update separator for source page %"Z"u to [%s]",
7855 csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key)));
7856 mdb_cursor_copy(csrc, &mn);
7859 /* We want mdb_rebalance to find mn when doing fixups */
7860 WITH_CURSOR_TRACKING(mn,
7861 rc = mdb_update_key(&mn, &key));
7865 if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
7867 indx_t ix = csrc->mc_ki[csrc->mc_top];
7868 nullkey.mv_size = 0;
7869 csrc->mc_ki[csrc->mc_top] = 0;
7870 rc = mdb_update_key(csrc, &nullkey);
7871 csrc->mc_ki[csrc->mc_top] = ix;
7872 mdb_cassert(csrc, rc == MDB_SUCCESS);
7876 if (cdst->mc_ki[cdst->mc_top] == 0) {
7877 if (cdst->mc_ki[cdst->mc_top-1] != 0) {
7878 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7879 key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size);
7881 srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
7882 key.mv_size = NODEKSZ(srcnode);
7883 key.mv_data = NODEKEY(srcnode);
7885 DPRINTF(("update separator for destination page %"Z"u to [%s]",
7886 cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key)));
7887 mdb_cursor_copy(cdst, &mn);
7890 /* We want mdb_rebalance to find mn when doing fixups */
7891 WITH_CURSOR_TRACKING(mn,
7892 rc = mdb_update_key(&mn, &key));
7896 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) {
7898 indx_t ix = cdst->mc_ki[cdst->mc_top];
7899 nullkey.mv_size = 0;
7900 cdst->mc_ki[cdst->mc_top] = 0;
7901 rc = mdb_update_key(cdst, &nullkey);
7902 cdst->mc_ki[cdst->mc_top] = ix;
7903 mdb_cassert(cdst, rc == MDB_SUCCESS);
7910 /** Merge one page into another.
7911 * The nodes from the page pointed to by \b csrc will
7912 * be copied to the page pointed to by \b cdst and then
7913 * the \b csrc page will be freed.
7914 * @param[in] csrc Cursor pointing to the source page.
7915 * @param[in] cdst Cursor pointing to the destination page.
7916 * @return 0 on success, non-zero on failure.
7919 mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
7921 MDB_page *psrc, *pdst;
7928 psrc = csrc->mc_pg[csrc->mc_top];
7929 pdst = cdst->mc_pg[cdst->mc_top];
7931 DPRINTF(("merging page %"Z"u into %"Z"u", psrc->mp_pgno, pdst->mp_pgno));
7933 mdb_cassert(csrc, csrc->mc_snum > 1); /* can't merge root page */
7934 mdb_cassert(csrc, cdst->mc_snum > 1);
7936 /* Mark dst as dirty. */
7937 if ((rc = mdb_page_touch(cdst)))
7940 /* get dst page again now that we've touched it. */
7941 pdst = cdst->mc_pg[cdst->mc_top];
7943 /* Move all nodes from src to dst.
7945 j = nkeys = NUMKEYS(pdst);
7946 if (IS_LEAF2(psrc)) {
7947 key.mv_size = csrc->mc_db->md_pad;
7948 key.mv_data = METADATA(psrc);
7949 for (i = 0; i < NUMKEYS(psrc); i++, j++) {
7950 rc = mdb_node_add(cdst, j, &key, NULL, 0, 0);
7951 if (rc != MDB_SUCCESS)
7953 key.mv_data = (char *)key.mv_data + key.mv_size;
7956 for (i = 0; i < NUMKEYS(psrc); i++, j++) {
7957 srcnode = NODEPTR(psrc, i);
7958 if (i == 0 && IS_BRANCH(psrc)) {
7961 mdb_cursor_copy(csrc, &mn);
7962 /* must find the lowest key below src */
7963 rc = mdb_page_search_lowest(&mn);
7966 if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {
7967 key.mv_size = mn.mc_db->md_pad;
7968 key.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, key.mv_size);
7970 s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);
7971 key.mv_size = NODEKSZ(s2);
7972 key.mv_data = NODEKEY(s2);
7975 key.mv_size = srcnode->mn_ksize;
7976 key.mv_data = NODEKEY(srcnode);
7979 data.mv_size = NODEDSZ(srcnode);
7980 data.mv_data = NODEDATA(srcnode);
7981 rc = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags);
7982 if (rc != MDB_SUCCESS)
7987 DPRINTF(("dst page %"Z"u now has %u keys (%.1f%% filled)",
7988 pdst->mp_pgno, NUMKEYS(pdst),
7989 (float)PAGEFILL(cdst->mc_txn->mt_env, pdst) / 10));
7991 /* Unlink the src page from parent and add to free list.
7994 mdb_node_del(csrc, 0);
7995 if (csrc->mc_ki[csrc->mc_top] == 0) {
7997 rc = mdb_update_key(csrc, &key);
8005 psrc = csrc->mc_pg[csrc->mc_top];
8006 /* If not operating on FreeDB, allow this page to be reused
8007 * in this txn. Otherwise just add to free list.
8009 rc = mdb_page_loose(csrc, psrc);
8013 csrc->mc_db->md_leaf_pages--;
8015 csrc->mc_db->md_branch_pages--;
8017 /* Adjust other cursors pointing to mp */
8018 MDB_cursor *m2, *m3;
8019 MDB_dbi dbi = csrc->mc_dbi;
8020 unsigned int top = csrc->mc_top;
8022 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8023 if (csrc->mc_flags & C_SUB)
8024 m3 = &m2->mc_xcursor->mx_cursor;
8027 if (m3 == csrc) continue;
8028 if (m3->mc_snum < csrc->mc_snum) continue;
8029 if (m3->mc_pg[top] == psrc) {
8030 m3->mc_pg[top] = pdst;
8031 m3->mc_ki[top] += nkeys;
8032 m3->mc_ki[top-1] = cdst->mc_ki[top-1];
8033 } else if (m3->mc_pg[top-1] == csrc->mc_pg[top-1] &&
8034 m3->mc_ki[top-1] > csrc->mc_ki[top-1]) {
8040 unsigned int snum = cdst->mc_snum;
8041 uint16_t depth = cdst->mc_db->md_depth;
8042 mdb_cursor_pop(cdst);
8043 rc = mdb_rebalance(cdst);
8044 /* Did the tree height change? */
8045 if (depth != cdst->mc_db->md_depth)
8046 snum += cdst->mc_db->md_depth - depth;
8047 cdst->mc_snum = snum;
8048 cdst->mc_top = snum-1;
8053 /** Copy the contents of a cursor.
8054 * @param[in] csrc The cursor to copy from.
8055 * @param[out] cdst The cursor to copy to.
8058 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst)
8062 cdst->mc_txn = csrc->mc_txn;
8063 cdst->mc_dbi = csrc->mc_dbi;
8064 cdst->mc_db = csrc->mc_db;
8065 cdst->mc_dbx = csrc->mc_dbx;
8066 cdst->mc_snum = csrc->mc_snum;
8067 cdst->mc_top = csrc->mc_top;
8068 cdst->mc_flags = csrc->mc_flags;
8070 for (i=0; i<csrc->mc_snum; i++) {
8071 cdst->mc_pg[i] = csrc->mc_pg[i];
8072 cdst->mc_ki[i] = csrc->mc_ki[i];
8076 /** Rebalance the tree after a delete operation.
8077 * @param[in] mc Cursor pointing to the page where rebalancing
8079 * @return 0 on success, non-zero on failure.
8082 mdb_rebalance(MDB_cursor *mc)
8086 unsigned int ptop, minkeys, thresh;
8090 if (IS_BRANCH(mc->mc_pg[mc->mc_top])) {
8095 thresh = FILL_THRESHOLD;
8097 DPRINTF(("rebalancing %s page %"Z"u (has %u keys, %.1f%% full)",
8098 IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",
8099 mdb_dbg_pgno(mc->mc_pg[mc->mc_top]), NUMKEYS(mc->mc_pg[mc->mc_top]),
8100 (float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10));
8102 if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= thresh &&
8103 NUMKEYS(mc->mc_pg[mc->mc_top]) >= minkeys) {
8104 DPRINTF(("no need to rebalance page %"Z"u, above fill threshold",
8105 mdb_dbg_pgno(mc->mc_pg[mc->mc_top])));
8109 if (mc->mc_snum < 2) {
8110 MDB_page *mp = mc->mc_pg[0];
8112 DPUTS("Can't rebalance a subpage, ignoring");
8115 if (NUMKEYS(mp) == 0) {
8116 DPUTS("tree is completely empty");
8117 mc->mc_db->md_root = P_INVALID;
8118 mc->mc_db->md_depth = 0;
8119 mc->mc_db->md_leaf_pages = 0;
8120 rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
8123 /* Adjust cursors pointing to mp */
8126 mc->mc_flags &= ~C_INITIALIZED;
8128 MDB_cursor *m2, *m3;
8129 MDB_dbi dbi = mc->mc_dbi;
8131 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8132 if (mc->mc_flags & C_SUB)
8133 m3 = &m2->mc_xcursor->mx_cursor;
8136 if (!(m3->mc_flags & C_INITIALIZED) || (m3->mc_snum < mc->mc_snum))
8138 if (m3->mc_pg[0] == mp) {
8141 m3->mc_flags &= ~C_INITIALIZED;
8145 } else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) {
8147 DPUTS("collapsing root page!");
8148 rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
8151 mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0));
8152 rc = mdb_page_get(mc->mc_txn,mc->mc_db->md_root,&mc->mc_pg[0],NULL);
8155 mc->mc_db->md_depth--;
8156 mc->mc_db->md_branch_pages--;
8157 mc->mc_ki[0] = mc->mc_ki[1];
8158 for (i = 1; i<mc->mc_db->md_depth; i++) {
8159 mc->mc_pg[i] = mc->mc_pg[i+1];
8160 mc->mc_ki[i] = mc->mc_ki[i+1];
8163 /* Adjust other cursors pointing to mp */
8164 MDB_cursor *m2, *m3;
8165 MDB_dbi dbi = mc->mc_dbi;
8167 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8168 if (mc->mc_flags & C_SUB)
8169 m3 = &m2->mc_xcursor->mx_cursor;
8172 if (m3 == mc) continue;
8173 if (!(m3->mc_flags & C_INITIALIZED))
8175 if (m3->mc_pg[0] == mp) {
8176 for (i=0; i<mc->mc_db->md_depth; i++) {
8177 m3->mc_pg[i] = m3->mc_pg[i+1];
8178 m3->mc_ki[i] = m3->mc_ki[i+1];
8186 DPUTS("root page doesn't need rebalancing");
8190 /* The parent (branch page) must have at least 2 pointers,
8191 * otherwise the tree is invalid.
8193 ptop = mc->mc_top-1;
8194 mdb_cassert(mc, NUMKEYS(mc->mc_pg[ptop]) > 1);
8196 /* Leaf page fill factor is below the threshold.
8197 * Try to move keys from left or right neighbor, or
8198 * merge with a neighbor page.
8203 mdb_cursor_copy(mc, &mn);
8204 mn.mc_xcursor = NULL;
8206 oldki = mc->mc_ki[mc->mc_top];
8207 if (mc->mc_ki[ptop] == 0) {
8208 /* We're the leftmost leaf in our parent.
8210 DPUTS("reading right neighbor");
8212 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
8213 rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
8216 mn.mc_ki[mn.mc_top] = 0;
8217 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);
8220 /* There is at least one neighbor to the left.
8222 DPUTS("reading left neighbor");
8224 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
8225 rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
8228 mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;
8229 mc->mc_ki[mc->mc_top] = 0;
8233 DPRINTF(("found neighbor page %"Z"u (%u keys, %.1f%% full)",
8234 mn.mc_pg[mn.mc_top]->mp_pgno, NUMKEYS(mn.mc_pg[mn.mc_top]),
8235 (float)PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) / 10));
8237 /* If the neighbor page is above threshold and has enough keys,
8238 * move one key from it. Otherwise we should try to merge them.
8239 * (A branch page must never have less than 2 keys.)
8241 if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= thresh && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) {
8242 rc = mdb_node_move(&mn, mc, fromleft);
8244 /* if we inserted on left, bump position up */
8249 rc = mdb_page_merge(&mn, mc);
8251 oldki += NUMKEYS(mn.mc_pg[mn.mc_top]);
8252 mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1;
8253 /* We want mdb_rebalance to find mn when doing fixups */
8254 WITH_CURSOR_TRACKING(mn,
8255 rc = mdb_page_merge(mc, &mn));
8256 mdb_cursor_copy(&mn, mc);
8258 mc->mc_flags &= ~C_EOF;
8260 mc->mc_ki[mc->mc_top] = oldki;
8264 /** Complete a delete operation started by #mdb_cursor_del(). */
8266 mdb_cursor_del0(MDB_cursor *mc)
8272 MDB_cursor *m2, *m3;
8273 MDB_dbi dbi = mc->mc_dbi;
8275 ki = mc->mc_ki[mc->mc_top];
8276 mp = mc->mc_pg[mc->mc_top];
8277 mdb_node_del(mc, mc->mc_db->md_pad);
8278 mc->mc_db->md_entries--;
8280 /* Adjust other cursors pointing to mp */
8281 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8282 m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;
8283 if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))
8285 if (m3 == mc || m3->mc_snum < mc->mc_snum)
8287 if (m3->mc_pg[mc->mc_top] == mp) {
8288 if (m3->mc_ki[mc->mc_top] >= ki) {
8289 m3->mc_flags |= C_DEL;
8290 if (m3->mc_ki[mc->mc_top] > ki)
8291 m3->mc_ki[mc->mc_top]--;
8292 else if (mc->mc_db->md_flags & MDB_DUPSORT)
8293 m3->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
8298 rc = mdb_rebalance(mc);
8300 if (rc == MDB_SUCCESS) {
8301 /* DB is totally empty now, just bail out.
8302 * Other cursors adjustments were already done
8303 * by mdb_rebalance and aren't needed here.
8308 mp = mc->mc_pg[mc->mc_top];
8309 nkeys = NUMKEYS(mp);
8311 /* Adjust other cursors pointing to mp */
8312 for (m2 = mc->mc_txn->mt_cursors[dbi]; !rc && m2; m2=m2->mc_next) {
8313 m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;
8314 if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))
8316 if (m3->mc_snum < mc->mc_snum)
8318 if (m3->mc_pg[mc->mc_top] == mp) {
8319 /* if m3 points past last node in page, find next sibling */
8320 if (m3->mc_ki[mc->mc_top] >= nkeys) {
8321 rc = mdb_cursor_sibling(m3, 1);
8322 if (rc == MDB_NOTFOUND) {
8323 m3->mc_flags |= C_EOF;
8329 mc->mc_flags |= C_DEL;
8333 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
8338 mdb_del(MDB_txn *txn, MDB_dbi dbi,
8339 MDB_val *key, MDB_val *data)
8341 if (!key || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
8344 if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
8345 return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
8347 if (!F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
8348 /* must ignore any data */
8352 return mdb_del0(txn, dbi, key, data, 0);
8356 mdb_del0(MDB_txn *txn, MDB_dbi dbi,
8357 MDB_val *key, MDB_val *data, unsigned flags)
8362 MDB_val rdata, *xdata;
8366 DPRINTF(("====> delete db %u key [%s]", dbi, DKEY(key)));
8368 mdb_cursor_init(&mc, txn, dbi, &mx);
8377 flags |= MDB_NODUPDATA;
8379 rc = mdb_cursor_set(&mc, key, xdata, op, &exact);
8381 /* let mdb_page_split know about this cursor if needed:
8382 * delete will trigger a rebalance; if it needs to move
8383 * a node from one page to another, it will have to
8384 * update the parent's separator key(s). If the new sepkey
8385 * is larger than the current one, the parent page may
8386 * run out of space, triggering a split. We need this
8387 * cursor to be consistent until the end of the rebalance.
8389 mc.mc_flags |= C_UNTRACK;
8390 mc.mc_next = txn->mt_cursors[dbi];
8391 txn->mt_cursors[dbi] = &mc;
8392 rc = mdb_cursor_del(&mc, flags);
8393 txn->mt_cursors[dbi] = mc.mc_next;
8398 /** Split a page and insert a new node.
8399 * @param[in,out] mc Cursor pointing to the page and desired insertion index.
8400 * The cursor will be updated to point to the actual page and index where
8401 * the node got inserted after the split.
8402 * @param[in] newkey The key for the newly inserted node.
8403 * @param[in] newdata The data for the newly inserted node.
8404 * @param[in] newpgno The page number, if the new node is a branch node.
8405 * @param[in] nflags The #NODE_ADD_FLAGS for the new node.
8406 * @return 0 on success, non-zero on failure.
8409 mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno,
8410 unsigned int nflags)
8413 int rc = MDB_SUCCESS, new_root = 0, did_split = 0;
8416 int i, j, split_indx, nkeys, pmax;
8417 MDB_env *env = mc->mc_txn->mt_env;
8419 MDB_val sepkey, rkey, xdata, *rdata = &xdata;
8420 MDB_page *copy = NULL;
8421 MDB_page *mp, *rp, *pp;
8426 mp = mc->mc_pg[mc->mc_top];
8427 newindx = mc->mc_ki[mc->mc_top];
8428 nkeys = NUMKEYS(mp);
8430 DPRINTF(("-----> splitting %s page %"Z"u and adding [%s] at index %i/%i",
8431 IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno,
8432 DKEY(newkey), mc->mc_ki[mc->mc_top], nkeys));
8434 /* Create a right sibling. */
8435 if ((rc = mdb_page_new(mc, mp->mp_flags, 1, &rp)))
8437 rp->mp_pad = mp->mp_pad;
8438 DPRINTF(("new right sibling: page %"Z"u", rp->mp_pgno));
8440 /* Usually when splitting the root page, the cursor
8441 * height is 1. But when called from mdb_update_key,
8442 * the cursor height may be greater because it walks
8443 * up the stack while finding the branch slot to update.
8445 if (mc->mc_top < 1) {
8446 if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp)))
8448 /* shift current top to make room for new parent */
8449 for (i=mc->mc_snum; i>0; i--) {
8450 mc->mc_pg[i] = mc->mc_pg[i-1];
8451 mc->mc_ki[i] = mc->mc_ki[i-1];
8455 mc->mc_db->md_root = pp->mp_pgno;
8456 DPRINTF(("root split! new root = %"Z"u", pp->mp_pgno));
8457 new_root = mc->mc_db->md_depth++;
8459 /* Add left (implicit) pointer. */
8460 if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) {
8461 /* undo the pre-push */
8462 mc->mc_pg[0] = mc->mc_pg[1];
8463 mc->mc_ki[0] = mc->mc_ki[1];
8464 mc->mc_db->md_root = mp->mp_pgno;
8465 mc->mc_db->md_depth--;
8472 ptop = mc->mc_top-1;
8473 DPRINTF(("parent branch page is %"Z"u", mc->mc_pg[ptop]->mp_pgno));
8476 mdb_cursor_copy(mc, &mn);
8477 mn.mc_pg[mn.mc_top] = rp;
8478 mn.mc_ki[ptop] = mc->mc_ki[ptop]+1;
8480 if (nflags & MDB_APPEND) {
8481 mn.mc_ki[mn.mc_top] = 0;
8483 split_indx = newindx;
8487 split_indx = (nkeys+1) / 2;
8492 unsigned int lsize, rsize, ksize;
8493 /* Move half of the keys to the right sibling */
8494 x = mc->mc_ki[mc->mc_top] - split_indx;
8495 ksize = mc->mc_db->md_pad;
8496 split = LEAF2KEY(mp, split_indx, ksize);
8497 rsize = (nkeys - split_indx) * ksize;
8498 lsize = (nkeys - split_indx) * sizeof(indx_t);
8499 mp->mp_lower -= lsize;
8500 rp->mp_lower += lsize;
8501 mp->mp_upper += rsize - lsize;
8502 rp->mp_upper -= rsize - lsize;
8503 sepkey.mv_size = ksize;
8504 if (newindx == split_indx) {
8505 sepkey.mv_data = newkey->mv_data;
8507 sepkey.mv_data = split;
8510 ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize);
8511 memcpy(rp->mp_ptrs, split, rsize);
8512 sepkey.mv_data = rp->mp_ptrs;
8513 memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize);
8514 memcpy(ins, newkey->mv_data, ksize);
8515 mp->mp_lower += sizeof(indx_t);
8516 mp->mp_upper -= ksize - sizeof(indx_t);
8519 memcpy(rp->mp_ptrs, split, x * ksize);
8520 ins = LEAF2KEY(rp, x, ksize);
8521 memcpy(ins, newkey->mv_data, ksize);
8522 memcpy(ins+ksize, split + x * ksize, rsize - x * ksize);
8523 rp->mp_lower += sizeof(indx_t);
8524 rp->mp_upper -= ksize - sizeof(indx_t);
8525 mc->mc_ki[mc->mc_top] = x;
8528 int psize, nsize, k;
8529 /* Maximum free space in an empty page */
8530 pmax = env->me_psize - PAGEHDRSZ;
8532 nsize = mdb_leaf_size(env, newkey, newdata);
8534 nsize = mdb_branch_size(env, newkey);
8535 nsize = EVEN(nsize);
8537 /* grab a page to hold a temporary copy */
8538 copy = mdb_page_malloc(mc->mc_txn, 1);
8543 copy->mp_pgno = mp->mp_pgno;
8544 copy->mp_flags = mp->mp_flags;
8545 copy->mp_lower = (PAGEHDRSZ-PAGEBASE);
8546 copy->mp_upper = env->me_psize - PAGEBASE;
8548 /* prepare to insert */
8549 for (i=0, j=0; i<nkeys; i++) {
8551 copy->mp_ptrs[j++] = 0;
8553 copy->mp_ptrs[j++] = mp->mp_ptrs[i];
8556 /* When items are relatively large the split point needs
8557 * to be checked, because being off-by-one will make the
8558 * difference between success or failure in mdb_node_add.
8560 * It's also relevant if a page happens to be laid out
8561 * such that one half of its nodes are all "small" and
8562 * the other half of its nodes are "large." If the new
8563 * item is also "large" and falls on the half with
8564 * "large" nodes, it also may not fit.
8566 * As a final tweak, if the new item goes on the last
8567 * spot on the page (and thus, onto the new page), bias
8568 * the split so the new page is emptier than the old page.
8569 * This yields better packing during sequential inserts.
8571 if (nkeys < 20 || nsize > pmax/16 || newindx >= nkeys) {
8572 /* Find split point */
8574 if (newindx <= split_indx || newindx >= nkeys) {
8576 k = newindx >= nkeys ? nkeys : split_indx+1+IS_LEAF(mp);
8581 for (; i!=k; i+=j) {
8586 node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);
8587 psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
8589 if (F_ISSET(node->mn_flags, F_BIGDATA))
8590 psize += sizeof(pgno_t);
8592 psize += NODEDSZ(node);
8594 psize = EVEN(psize);
8596 if (psize > pmax || i == k-j) {
8597 split_indx = i + (j<0);
8602 if (split_indx == newindx) {
8603 sepkey.mv_size = newkey->mv_size;
8604 sepkey.mv_data = newkey->mv_data;
8606 node = (MDB_node *)((char *)mp + copy->mp_ptrs[split_indx] + PAGEBASE);
8607 sepkey.mv_size = node->mn_ksize;
8608 sepkey.mv_data = NODEKEY(node);
8613 DPRINTF(("separator is %d [%s]", split_indx, DKEY(&sepkey)));
8615 /* Copy separator key to the parent.
8617 if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(env, &sepkey)) {
8618 int snum = mc->mc_snum;
8622 /* We want other splits to find mn when doing fixups */
8623 WITH_CURSOR_TRACKING(mn,
8624 rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0));
8629 if (mc->mc_snum > snum) {
8632 /* Right page might now have changed parent.
8633 * Check if left page also changed parent.
8635 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
8636 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
8637 for (i=0; i<ptop; i++) {
8638 mc->mc_pg[i] = mn.mc_pg[i];
8639 mc->mc_ki[i] = mn.mc_ki[i];
8641 mc->mc_pg[ptop] = mn.mc_pg[ptop];
8642 if (mn.mc_ki[ptop]) {
8643 mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;
8645 /* find right page's left sibling */
8646 mc->mc_ki[ptop] = mn.mc_ki[ptop];
8647 mdb_cursor_sibling(mc, 0);
8652 rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);
8655 if (rc != MDB_SUCCESS) {
8658 if (nflags & MDB_APPEND) {
8659 mc->mc_pg[mc->mc_top] = rp;
8660 mc->mc_ki[mc->mc_top] = 0;
8661 rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags);
8664 for (i=0; i<mc->mc_top; i++)
8665 mc->mc_ki[i] = mn.mc_ki[i];
8666 } else if (!IS_LEAF2(mp)) {
8668 mc->mc_pg[mc->mc_top] = rp;
8673 rkey.mv_data = newkey->mv_data;
8674 rkey.mv_size = newkey->mv_size;
8680 /* Update index for the new key. */
8681 mc->mc_ki[mc->mc_top] = j;
8683 node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);
8684 rkey.mv_data = NODEKEY(node);
8685 rkey.mv_size = node->mn_ksize;
8687 xdata.mv_data = NODEDATA(node);
8688 xdata.mv_size = NODEDSZ(node);
8691 pgno = NODEPGNO(node);
8692 flags = node->mn_flags;
8695 if (!IS_LEAF(mp) && j == 0) {
8696 /* First branch index doesn't need key data. */
8700 rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags);
8706 mc->mc_pg[mc->mc_top] = copy;
8711 } while (i != split_indx);
8713 nkeys = NUMKEYS(copy);
8714 for (i=0; i<nkeys; i++)
8715 mp->mp_ptrs[i] = copy->mp_ptrs[i];
8716 mp->mp_lower = copy->mp_lower;
8717 mp->mp_upper = copy->mp_upper;
8718 memcpy(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1),
8719 env->me_psize - copy->mp_upper - PAGEBASE);
8721 /* reset back to original page */
8722 if (newindx < split_indx) {
8723 mc->mc_pg[mc->mc_top] = mp;
8725 mc->mc_pg[mc->mc_top] = rp;
8727 /* Make sure mc_ki is still valid.
8729 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
8730 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
8731 for (i=0; i<=ptop; i++) {
8732 mc->mc_pg[i] = mn.mc_pg[i];
8733 mc->mc_ki[i] = mn.mc_ki[i];
8737 if (nflags & MDB_RESERVE) {
8738 node = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
8739 if (!(node->mn_flags & F_BIGDATA))
8740 newdata->mv_data = NODEDATA(node);
8743 if (newindx >= split_indx) {
8744 mc->mc_pg[mc->mc_top] = rp;
8746 /* Make sure mc_ki is still valid.
8748 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
8749 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
8750 for (i=0; i<=ptop; i++) {
8751 mc->mc_pg[i] = mn.mc_pg[i];
8752 mc->mc_ki[i] = mn.mc_ki[i];
8759 /* Adjust other cursors pointing to mp */
8760 MDB_cursor *m2, *m3;
8761 MDB_dbi dbi = mc->mc_dbi;
8762 nkeys = NUMKEYS(mp);
8764 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8765 if (mc->mc_flags & C_SUB)
8766 m3 = &m2->mc_xcursor->mx_cursor;
8771 if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED))
8775 /* sub cursors may be on different DB */
8776 if (m3->mc_pg[0] != mp)
8779 for (k=new_root; k>=0; k--) {
8780 m3->mc_ki[k+1] = m3->mc_ki[k];
8781 m3->mc_pg[k+1] = m3->mc_pg[k];
8783 if (m3->mc_ki[0] >= nkeys) {
8788 m3->mc_pg[0] = mc->mc_pg[0];
8792 if (m3->mc_top >= mc->mc_top && m3->mc_pg[mc->mc_top] == mp) {
8793 if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE))
8794 m3->mc_ki[mc->mc_top]++;
8795 if (m3->mc_ki[mc->mc_top] >= nkeys) {
8796 m3->mc_pg[mc->mc_top] = rp;
8797 m3->mc_ki[mc->mc_top] -= nkeys;
8798 for (i=0; i<mc->mc_top; i++) {
8799 m3->mc_ki[i] = mn.mc_ki[i];
8800 m3->mc_pg[i] = mn.mc_pg[i];
8803 } else if (!did_split && m3->mc_top >= ptop && m3->mc_pg[ptop] == mc->mc_pg[ptop] &&
8804 m3->mc_ki[ptop] >= mc->mc_ki[ptop]) {
8809 DPRINTF(("mp left: %d, rp left: %d", SIZELEFT(mp), SIZELEFT(rp)));
8812 if (copy) /* tmp page */
8813 mdb_page_free(env, copy);
8815 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
8820 mdb_put(MDB_txn *txn, MDB_dbi dbi,
8821 MDB_val *key, MDB_val *data, unsigned int flags)
8827 if (!key || !data || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
8830 if (flags & ~(MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND|MDB_APPENDDUP))
8833 if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
8834 return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
8836 mdb_cursor_init(&mc, txn, dbi, &mx);
8837 mc.mc_next = txn->mt_cursors[dbi];
8838 txn->mt_cursors[dbi] = &mc;
8839 rc = mdb_cursor_put(&mc, key, data, flags);
8840 txn->mt_cursors[dbi] = mc.mc_next;
8845 #define MDB_WBUF (1024*1024)
8848 /** State needed for a compacting copy. */
8849 typedef struct mdb_copy {
8850 pthread_mutex_t mc_mutex;
8851 pthread_cond_t mc_cond;
8858 pgno_t mc_next_pgno;
8861 volatile int mc_new;
8866 /** Dedicated writer thread for compacting copy. */
8867 static THREAD_RET ESECT CALL_CONV
8868 mdb_env_copythr(void *arg)
8872 int toggle = 0, wsize, rc;
8875 #define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL)
8878 #define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0)
8881 pthread_mutex_lock(&my->mc_mutex);
8883 pthread_cond_signal(&my->mc_cond);
8886 pthread_cond_wait(&my->mc_cond, &my->mc_mutex);
8887 if (my->mc_new < 0) {
8892 wsize = my->mc_wlen[toggle];
8893 ptr = my->mc_wbuf[toggle];
8896 DO_WRITE(rc, my->mc_fd, ptr, wsize, len);
8900 } else if (len > 0) {
8914 /* If there's an overflow page tail, write it too */
8915 if (my->mc_olen[toggle]) {
8916 wsize = my->mc_olen[toggle];
8917 ptr = my->mc_over[toggle];
8918 my->mc_olen[toggle] = 0;
8921 my->mc_wlen[toggle] = 0;
8923 pthread_cond_signal(&my->mc_cond);
8925 pthread_cond_signal(&my->mc_cond);
8926 pthread_mutex_unlock(&my->mc_mutex);
8927 return (THREAD_RET)0;
8931 /** Tell the writer thread there's a buffer ready to write */
8933 mdb_env_cthr_toggle(mdb_copy *my, int st)
8935 int toggle = my->mc_toggle ^ 1;
8936 pthread_mutex_lock(&my->mc_mutex);
8937 if (my->mc_status) {
8938 pthread_mutex_unlock(&my->mc_mutex);
8939 return my->mc_status;
8941 while (my->mc_new == 1)
8942 pthread_cond_wait(&my->mc_cond, &my->mc_mutex);
8944 my->mc_toggle = toggle;
8945 pthread_cond_signal(&my->mc_cond);
8946 pthread_mutex_unlock(&my->mc_mutex);
8950 /** Depth-first tree traversal for compacting copy. */
8952 mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)
8955 MDB_txn *txn = my->mc_txn;
8957 MDB_page *mo, *mp, *leaf;
8962 /* Empty DB, nothing to do */
8963 if (*pg == P_INVALID)
8970 rc = mdb_page_get(my->mc_txn, *pg, &mc.mc_pg[0], NULL);
8973 rc = mdb_page_search_root(&mc, NULL, MDB_PS_FIRST);
8977 /* Make cursor pages writable */
8978 buf = ptr = malloc(my->mc_env->me_psize * mc.mc_snum);
8982 for (i=0; i<mc.mc_top; i++) {
8983 mdb_page_copy((MDB_page *)ptr, mc.mc_pg[i], my->mc_env->me_psize);
8984 mc.mc_pg[i] = (MDB_page *)ptr;
8985 ptr += my->mc_env->me_psize;
8988 /* This is writable space for a leaf page. Usually not needed. */
8989 leaf = (MDB_page *)ptr;
8991 toggle = my->mc_toggle;
8992 while (mc.mc_snum > 0) {
8994 mp = mc.mc_pg[mc.mc_top];
8998 if (!IS_LEAF2(mp) && !(flags & F_DUPDATA)) {
8999 for (i=0; i<n; i++) {
9000 ni = NODEPTR(mp, i);
9001 if (ni->mn_flags & F_BIGDATA) {
9005 /* Need writable leaf */
9007 mc.mc_pg[mc.mc_top] = leaf;
9008 mdb_page_copy(leaf, mp, my->mc_env->me_psize);
9010 ni = NODEPTR(mp, i);
9013 memcpy(&pg, NODEDATA(ni), sizeof(pg));
9014 rc = mdb_page_get(txn, pg, &omp, NULL);
9017 if (my->mc_wlen[toggle] >= MDB_WBUF) {
9018 rc = mdb_env_cthr_toggle(my, 1);
9021 toggle = my->mc_toggle;
9023 mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);
9024 memcpy(mo, omp, my->mc_env->me_psize);
9025 mo->mp_pgno = my->mc_next_pgno;
9026 my->mc_next_pgno += omp->mp_pages;
9027 my->mc_wlen[toggle] += my->mc_env->me_psize;
9028 if (omp->mp_pages > 1) {
9029 my->mc_olen[toggle] = my->mc_env->me_psize * (omp->mp_pages - 1);
9030 my->mc_over[toggle] = (char *)omp + my->mc_env->me_psize;
9031 rc = mdb_env_cthr_toggle(my, 1);
9034 toggle = my->mc_toggle;
9036 memcpy(NODEDATA(ni), &mo->mp_pgno, sizeof(pgno_t));
9037 } else if (ni->mn_flags & F_SUBDATA) {
9040 /* Need writable leaf */
9042 mc.mc_pg[mc.mc_top] = leaf;
9043 mdb_page_copy(leaf, mp, my->mc_env->me_psize);
9045 ni = NODEPTR(mp, i);
9048 memcpy(&db, NODEDATA(ni), sizeof(db));
9049 my->mc_toggle = toggle;
9050 rc = mdb_env_cwalk(my, &db.md_root, ni->mn_flags & F_DUPDATA);
9053 toggle = my->mc_toggle;
9054 memcpy(NODEDATA(ni), &db, sizeof(db));
9059 mc.mc_ki[mc.mc_top]++;
9060 if (mc.mc_ki[mc.mc_top] < n) {
9063 ni = NODEPTR(mp, mc.mc_ki[mc.mc_top]);
9065 rc = mdb_page_get(txn, pg, &mp, NULL);
9070 mc.mc_ki[mc.mc_top] = 0;
9071 if (IS_BRANCH(mp)) {
9072 /* Whenever we advance to a sibling branch page,
9073 * we must proceed all the way down to its first leaf.
9075 mdb_page_copy(mc.mc_pg[mc.mc_top], mp, my->mc_env->me_psize);
9078 mc.mc_pg[mc.mc_top] = mp;
9082 if (my->mc_wlen[toggle] >= MDB_WBUF) {
9083 rc = mdb_env_cthr_toggle(my, 1);
9086 toggle = my->mc_toggle;
9088 mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);
9089 mdb_page_copy(mo, mp, my->mc_env->me_psize);
9090 mo->mp_pgno = my->mc_next_pgno++;
9091 my->mc_wlen[toggle] += my->mc_env->me_psize;
9093 /* Update parent if there is one */
9094 ni = NODEPTR(mc.mc_pg[mc.mc_top-1], mc.mc_ki[mc.mc_top-1]);
9095 SETPGNO(ni, mo->mp_pgno);
9096 mdb_cursor_pop(&mc);
9098 /* Otherwise we're done */
9108 /** Copy environment with compaction. */
9110 mdb_env_copyfd1(MDB_env *env, HANDLE fd)
9115 MDB_txn *txn = NULL;
9120 my.mc_mutex = CreateMutex(NULL, FALSE, NULL);
9121 my.mc_cond = CreateEvent(NULL, FALSE, FALSE, NULL);
9122 my.mc_wbuf[0] = _aligned_malloc(MDB_WBUF*2, env->me_os_psize);
9123 if (my.mc_wbuf[0] == NULL)
9126 pthread_mutex_init(&my.mc_mutex, NULL);
9127 pthread_cond_init(&my.mc_cond, NULL);
9128 #ifdef HAVE_MEMALIGN
9129 my.mc_wbuf[0] = memalign(env->me_os_psize, MDB_WBUF*2);
9130 if (my.mc_wbuf[0] == NULL)
9133 rc = posix_memalign((void **)&my.mc_wbuf[0], env->me_os_psize, MDB_WBUF*2);
9138 memset(my.mc_wbuf[0], 0, MDB_WBUF*2);
9139 my.mc_wbuf[1] = my.mc_wbuf[0] + MDB_WBUF;
9144 my.mc_next_pgno = NUM_METAS;
9150 THREAD_CREATE(thr, mdb_env_copythr, &my);
9152 rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
9156 mp = (MDB_page *)my.mc_wbuf[0];
9157 memset(mp, 0, NUM_METAS * env->me_psize);
9159 mp->mp_flags = P_META;
9160 mm = (MDB_meta *)METADATA(mp);
9161 mdb_env_init_meta0(env, mm);
9162 mm->mm_address = env->me_metas[0]->mm_address;
9164 mp = (MDB_page *)(my.mc_wbuf[0] + env->me_psize);
9166 mp->mp_flags = P_META;
9167 *(MDB_meta *)METADATA(mp) = *mm;
9168 mm = (MDB_meta *)METADATA(mp);
9170 /* Count the number of free pages, subtract from lastpg to find
9171 * number of active pages
9174 MDB_ID freecount = 0;
9177 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
9178 while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
9179 freecount += *(MDB_ID *)data.mv_data;
9180 freecount += txn->mt_dbs[FREE_DBI].md_branch_pages +
9181 txn->mt_dbs[FREE_DBI].md_leaf_pages +
9182 txn->mt_dbs[FREE_DBI].md_overflow_pages;
9184 /* Set metapage 1 */
9185 mm->mm_last_pg = txn->mt_next_pgno - freecount - 1;
9186 mm->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
9187 if (mm->mm_last_pg > NUM_METAS-1) {
9188 mm->mm_dbs[MAIN_DBI].md_root = mm->mm_last_pg;
9191 mm->mm_dbs[MAIN_DBI].md_root = P_INVALID;
9194 my.mc_wlen[0] = env->me_psize * NUM_METAS;
9196 pthread_mutex_lock(&my.mc_mutex);
9198 pthread_cond_wait(&my.mc_cond, &my.mc_mutex);
9199 pthread_mutex_unlock(&my.mc_mutex);
9200 rc = mdb_env_cwalk(&my, &txn->mt_dbs[MAIN_DBI].md_root, 0);
9201 if (rc == MDB_SUCCESS && my.mc_wlen[my.mc_toggle])
9202 rc = mdb_env_cthr_toggle(&my, 1);
9203 mdb_env_cthr_toggle(&my, -1);
9204 pthread_mutex_lock(&my.mc_mutex);
9206 pthread_cond_wait(&my.mc_cond, &my.mc_mutex);
9207 pthread_mutex_unlock(&my.mc_mutex);
9212 CloseHandle(my.mc_cond);
9213 CloseHandle(my.mc_mutex);
9214 _aligned_free(my.mc_wbuf[0]);
9216 pthread_cond_destroy(&my.mc_cond);
9217 pthread_mutex_destroy(&my.mc_mutex);
9218 free(my.mc_wbuf[0]);
9223 /** Copy environment as-is. */
9225 mdb_env_copyfd0(MDB_env *env, HANDLE fd)
9227 MDB_txn *txn = NULL;
9228 mdb_mutexref_t wmutex = NULL;
9234 #define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL)
9238 #define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0)
9241 /* Do the lock/unlock of the reader mutex before starting the
9242 * write txn. Otherwise other read txns could block writers.
9244 rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
9249 /* We must start the actual read txn after blocking writers */
9250 mdb_txn_end(txn, MDB_END_RESET_TMP);
9252 /* Temporarily block writers until we snapshot the meta pages */
9253 wmutex = env->me_wmutex;
9254 if (LOCK_MUTEX(rc, env, wmutex))
9257 rc = mdb_txn_renew0(txn);
9259 UNLOCK_MUTEX(wmutex);
9264 wsize = env->me_psize * NUM_METAS;
9268 DO_WRITE(rc, fd, ptr, w2, len);
9272 } else if (len > 0) {
9278 /* Non-blocking or async handles are not supported */
9284 UNLOCK_MUTEX(wmutex);
9289 w2 = txn->mt_next_pgno * env->me_psize;
9292 if ((rc = mdb_fsize(env->me_fd, &fsize)))
9299 if (wsize > MAX_WRITE)
9303 DO_WRITE(rc, fd, ptr, w2, len);
9307 } else if (len > 0) {
9324 mdb_env_copyfd2(MDB_env *env, HANDLE fd, unsigned int flags)
9326 if (flags & MDB_CP_COMPACT)
9327 return mdb_env_copyfd1(env, fd);
9329 return mdb_env_copyfd0(env, fd);
9333 mdb_env_copyfd(MDB_env *env, HANDLE fd)
9335 return mdb_env_copyfd2(env, fd, 0);
9339 mdb_env_copy2(MDB_env *env, const char *path, unsigned int flags)
9343 HANDLE newfd = INVALID_HANDLE_VALUE;
9348 if (env->me_flags & MDB_NOSUBDIR) {
9349 lpath = (char *)path;
9352 len += sizeof(DATANAME);
9353 lpath = malloc(len);
9356 sprintf(lpath, "%s" DATANAME, path);
9359 /* The destination path must exist, but the destination file must not.
9360 * We don't want the OS to cache the writes, since the source data is
9361 * already in the OS cache.
9364 utf8_to_utf16(lpath, -1, &wpath, NULL);
9365 newfd = CreateFileW(wpath, GENERIC_WRITE, 0, NULL, CREATE_NEW,
9366 FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL);
9369 newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL, 0666);
9371 if (newfd == INVALID_HANDLE_VALUE) {
9376 if (env->me_psize >= env->me_os_psize) {
9378 /* Set O_DIRECT if the file system supports it */
9379 if ((rc = fcntl(newfd, F_GETFL)) != -1)
9380 (void) fcntl(newfd, F_SETFL, rc | O_DIRECT);
9382 #ifdef F_NOCACHE /* __APPLE__ */
9383 rc = fcntl(newfd, F_NOCACHE, 1);
9391 rc = mdb_env_copyfd2(env, newfd, flags);
9394 if (!(env->me_flags & MDB_NOSUBDIR))
9396 if (newfd != INVALID_HANDLE_VALUE)
9397 if (close(newfd) < 0 && rc == MDB_SUCCESS)
9404 mdb_env_copy(MDB_env *env, const char *path)
9406 return mdb_env_copy2(env, path, 0);
9410 mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)
9412 if (flag & ~CHANGEABLE)
9415 env->me_flags |= flag;
9417 env->me_flags &= ~flag;
9422 mdb_env_get_flags(MDB_env *env, unsigned int *arg)
9427 *arg = env->me_flags & (CHANGEABLE|CHANGELESS);
9432 mdb_env_set_userctx(MDB_env *env, void *ctx)
9436 env->me_userctx = ctx;
9441 mdb_env_get_userctx(MDB_env *env)
9443 return env ? env->me_userctx : NULL;
9447 mdb_env_set_assert(MDB_env *env, MDB_assert_func *func)
9452 env->me_assert_func = func;
9458 mdb_env_get_path(MDB_env *env, const char **arg)
9463 *arg = env->me_path;
9468 mdb_env_get_fd(MDB_env *env, mdb_filehandle_t *arg)
9477 /** Common code for #mdb_stat() and #mdb_env_stat().
9478 * @param[in] env the environment to operate in.
9479 * @param[in] db the #MDB_db record containing the stats to return.
9480 * @param[out] arg the address of an #MDB_stat structure to receive the stats.
9481 * @return 0, this function always succeeds.
9484 mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)
9486 arg->ms_psize = env->me_psize;
9487 arg->ms_depth = db->md_depth;
9488 arg->ms_branch_pages = db->md_branch_pages;
9489 arg->ms_leaf_pages = db->md_leaf_pages;
9490 arg->ms_overflow_pages = db->md_overflow_pages;
9491 arg->ms_entries = db->md_entries;
9497 mdb_env_stat(MDB_env *env, MDB_stat *arg)
9501 if (env == NULL || arg == NULL)
9504 meta = mdb_env_pick_meta(env);
9506 return mdb_stat0(env, &meta->mm_dbs[MAIN_DBI], arg);
9510 mdb_env_info(MDB_env *env, MDB_envinfo *arg)
9514 if (env == NULL || arg == NULL)
9517 meta = mdb_env_pick_meta(env);
9518 arg->me_mapaddr = meta->mm_address;
9519 arg->me_last_pgno = meta->mm_last_pg;
9520 arg->me_last_txnid = meta->mm_txnid;
9522 arg->me_mapsize = env->me_mapsize;
9523 arg->me_maxreaders = env->me_maxreaders;
9524 arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : 0;
9528 /** Set the default comparison functions for a database.
9529 * Called immediately after a database is opened to set the defaults.
9530 * The user can then override them with #mdb_set_compare() or
9531 * #mdb_set_dupsort().
9532 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
9533 * @param[in] dbi A database handle returned by #mdb_dbi_open()
9536 mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi)
9538 uint16_t f = txn->mt_dbs[dbi].md_flags;
9540 txn->mt_dbxs[dbi].md_cmp =
9541 (f & MDB_REVERSEKEY) ? mdb_cmp_memnr :
9542 (f & MDB_INTEGERKEY) ? mdb_cmp_cint : mdb_cmp_memn;
9544 txn->mt_dbxs[dbi].md_dcmp =
9545 !(f & MDB_DUPSORT) ? 0 :
9546 ((f & MDB_INTEGERDUP)
9547 ? ((f & MDB_DUPFIXED) ? mdb_cmp_int : mdb_cmp_cint)
9548 : ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn));
9551 int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
9557 int rc, dbflag, exact;
9558 unsigned int unused = 0, seq;
9561 if (flags & ~VALID_FLAGS)
9563 if (txn->mt_flags & MDB_TXN_BLOCKED)
9569 if (flags & PERSISTENT_FLAGS) {
9570 uint16_t f2 = flags & PERSISTENT_FLAGS;
9571 /* make sure flag changes get committed */
9572 if ((txn->mt_dbs[MAIN_DBI].md_flags | f2) != txn->mt_dbs[MAIN_DBI].md_flags) {
9573 txn->mt_dbs[MAIN_DBI].md_flags |= f2;
9574 txn->mt_flags |= MDB_TXN_DIRTY;
9577 mdb_default_cmp(txn, MAIN_DBI);
9581 if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {
9582 mdb_default_cmp(txn, MAIN_DBI);
9585 /* Is the DB already open? */
9587 for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
9588 if (!txn->mt_dbxs[i].md_name.mv_size) {
9589 /* Remember this free slot */
9590 if (!unused) unused = i;
9593 if (len == txn->mt_dbxs[i].md_name.mv_size &&
9594 !strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) {
9600 /* If no free slot and max hit, fail */
9601 if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs)
9602 return MDB_DBS_FULL;
9604 /* Cannot mix named databases with some mainDB flags */
9605 if (txn->mt_dbs[MAIN_DBI].md_flags & (MDB_DUPSORT|MDB_INTEGERKEY))
9606 return (flags & MDB_CREATE) ? MDB_INCOMPATIBLE : MDB_NOTFOUND;
9608 /* Find the DB info */
9609 dbflag = DB_NEW|DB_VALID|DB_USRVALID;
9612 key.mv_data = (void *)name;
9613 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
9614 rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact);
9615 if (rc == MDB_SUCCESS) {
9616 /* make sure this is actually a DB */
9617 MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]);
9618 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)
9619 return MDB_INCOMPATIBLE;
9620 } else if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) {
9621 /* Create if requested */
9622 data.mv_size = sizeof(MDB_db);
9623 data.mv_data = &dummy;
9624 memset(&dummy, 0, sizeof(dummy));
9625 dummy.md_root = P_INVALID;
9626 dummy.md_flags = flags & PERSISTENT_FLAGS;
9627 rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA);
9631 /* OK, got info, add to table */
9632 if (rc == MDB_SUCCESS) {
9633 unsigned int slot = unused ? unused : txn->mt_numdbs;
9634 txn->mt_dbxs[slot].md_name.mv_data = strdup(name);
9635 txn->mt_dbxs[slot].md_name.mv_size = len;
9636 txn->mt_dbxs[slot].md_rel = NULL;
9637 txn->mt_dbflags[slot] = dbflag;
9638 /* txn-> and env-> are the same in read txns, use
9639 * tmp variable to avoid undefined assignment
9641 seq = ++txn->mt_env->me_dbiseqs[slot];
9642 txn->mt_dbiseqs[slot] = seq;
9644 memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db));
9646 mdb_default_cmp(txn, slot);
9656 mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
9658 if (!arg || !TXN_DBI_EXIST(txn, dbi, DB_VALID))
9661 if (txn->mt_flags & MDB_TXN_BLOCKED)
9664 if (txn->mt_dbflags[dbi] & DB_STALE) {
9667 /* Stale, must read the DB's root. cursor_init does it for us. */
9668 mdb_cursor_init(&mc, txn, dbi, &mx);
9670 return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg);
9673 void mdb_dbi_close(MDB_env *env, MDB_dbi dbi)
9676 if (dbi < CORE_DBS || dbi >= env->me_maxdbs)
9678 ptr = env->me_dbxs[dbi].md_name.mv_data;
9679 /* If there was no name, this was already closed */
9681 env->me_dbxs[dbi].md_name.mv_data = NULL;
9682 env->me_dbxs[dbi].md_name.mv_size = 0;
9683 env->me_dbflags[dbi] = 0;
9684 env->me_dbiseqs[dbi]++;
9689 int mdb_dbi_flags(MDB_txn *txn, MDB_dbi dbi, unsigned int *flags)
9691 /* We could return the flags for the FREE_DBI too but what's the point? */
9692 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9694 *flags = txn->mt_dbs[dbi].md_flags & PERSISTENT_FLAGS;
9698 /** Add all the DB's pages to the free list.
9699 * @param[in] mc Cursor on the DB to free.
9700 * @param[in] subs non-Zero to check for sub-DBs in this DB.
9701 * @return 0 on success, non-zero on failure.
9704 mdb_drop0(MDB_cursor *mc, int subs)
9708 rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
9709 if (rc == MDB_SUCCESS) {
9710 MDB_txn *txn = mc->mc_txn;
9715 /* DUPSORT sub-DBs have no ovpages/DBs. Omit scanning leaves.
9716 * This also avoids any P_LEAF2 pages, which have no nodes.
9718 if (mc->mc_flags & C_SUB)
9721 mdb_cursor_copy(mc, &mx);
9722 while (mc->mc_snum > 0) {
9723 MDB_page *mp = mc->mc_pg[mc->mc_top];
9724 unsigned n = NUMKEYS(mp);
9726 for (i=0; i<n; i++) {
9727 ni = NODEPTR(mp, i);
9728 if (ni->mn_flags & F_BIGDATA) {
9731 memcpy(&pg, NODEDATA(ni), sizeof(pg));
9732 rc = mdb_page_get(txn, pg, &omp, NULL);
9735 mdb_cassert(mc, IS_OVERFLOW(omp));
9736 rc = mdb_midl_append_range(&txn->mt_free_pgs,
9740 } else if (subs && (ni->mn_flags & F_SUBDATA)) {
9741 mdb_xcursor_init1(mc, ni);
9742 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
9748 if ((rc = mdb_midl_need(&txn->mt_free_pgs, n)) != 0)
9750 for (i=0; i<n; i++) {
9752 ni = NODEPTR(mp, i);
9755 mdb_midl_xappend(txn->mt_free_pgs, pg);
9760 mc->mc_ki[mc->mc_top] = i;
9761 rc = mdb_cursor_sibling(mc, 1);
9763 if (rc != MDB_NOTFOUND)
9765 /* no more siblings, go back to beginning
9766 * of previous level.
9770 for (i=1; i<mc->mc_snum; i++) {
9772 mc->mc_pg[i] = mx.mc_pg[i];
9777 rc = mdb_midl_append(&txn->mt_free_pgs, mc->mc_db->md_root);
9780 txn->mt_flags |= MDB_TXN_ERROR;
9781 } else if (rc == MDB_NOTFOUND) {
9784 mc->mc_flags &= ~C_INITIALIZED;
9788 int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)
9790 MDB_cursor *mc, *m2;
9793 if ((unsigned)del > 1 || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9796 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
9799 if (TXN_DBI_CHANGED(txn, dbi))
9802 rc = mdb_cursor_open(txn, dbi, &mc);
9806 rc = mdb_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT);
9807 /* Invalidate the dropped DB's cursors */
9808 for (m2 = txn->mt_cursors[dbi]; m2; m2 = m2->mc_next)
9809 m2->mc_flags &= ~(C_INITIALIZED|C_EOF);
9813 /* Can't delete the main DB */
9814 if (del && dbi >= CORE_DBS) {
9815 rc = mdb_del0(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL, F_SUBDATA);
9817 txn->mt_dbflags[dbi] = DB_STALE;
9818 mdb_dbi_close(txn->mt_env, dbi);
9820 txn->mt_flags |= MDB_TXN_ERROR;
9823 /* reset the DB record, mark it dirty */
9824 txn->mt_dbflags[dbi] |= DB_DIRTY;
9825 txn->mt_dbs[dbi].md_depth = 0;
9826 txn->mt_dbs[dbi].md_branch_pages = 0;
9827 txn->mt_dbs[dbi].md_leaf_pages = 0;
9828 txn->mt_dbs[dbi].md_overflow_pages = 0;
9829 txn->mt_dbs[dbi].md_entries = 0;
9830 txn->mt_dbs[dbi].md_root = P_INVALID;
9832 txn->mt_flags |= MDB_TXN_DIRTY;
9835 mdb_cursor_close(mc);
9839 int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
9841 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9844 txn->mt_dbxs[dbi].md_cmp = cmp;
9848 int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
9850 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9853 txn->mt_dbxs[dbi].md_dcmp = cmp;
9857 int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
9859 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9862 txn->mt_dbxs[dbi].md_rel = rel;
9866 int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx)
9868 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9871 txn->mt_dbxs[dbi].md_relctx = ctx;
9876 mdb_env_get_maxkeysize(MDB_env *env)
9878 return ENV_MAXKEY(env);
9882 mdb_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx)
9884 unsigned int i, rdrs;
9887 int rc = 0, first = 1;
9891 if (!env->me_txns) {
9892 return func("(no reader locks)\n", ctx);
9894 rdrs = env->me_txns->mti_numreaders;
9895 mr = env->me_txns->mti_readers;
9896 for (i=0; i<rdrs; i++) {
9898 txnid_t txnid = mr[i].mr_txnid;
9899 sprintf(buf, txnid == (txnid_t)-1 ?
9900 "%10d %"Z"x -\n" : "%10d %"Z"x %"Z"u\n",
9901 (int)mr[i].mr_pid, (size_t)mr[i].mr_tid, txnid);
9904 rc = func(" pid thread txnid\n", ctx);
9908 rc = func(buf, ctx);
9914 rc = func("(no active readers)\n", ctx);
9919 /** Insert pid into list if not already present.
9920 * return -1 if already present.
9923 mdb_pid_insert(MDB_PID_T *ids, MDB_PID_T pid)
9925 /* binary search of pid in list */
9927 unsigned cursor = 1;
9929 unsigned n = ids[0];
9932 unsigned pivot = n >> 1;
9933 cursor = base + pivot + 1;
9934 val = pid - ids[cursor];
9939 } else if ( val > 0 ) {
9944 /* found, so it's a duplicate */
9953 for (n = ids[0]; n > cursor; n--)
9960 mdb_reader_check(MDB_env *env, int *dead)
9966 return env->me_txns ? mdb_reader_check0(env, 0, dead) : MDB_SUCCESS;
9969 /** As #mdb_reader_check(). rlocked = <caller locked the reader mutex>. */
9971 mdb_reader_check0(MDB_env *env, int rlocked, int *dead)
9973 mdb_mutexref_t rmutex = rlocked ? NULL : env->me_rmutex;
9974 unsigned int i, j, rdrs;
9976 MDB_PID_T *pids, pid;
9977 int rc = MDB_SUCCESS, count = 0;
9979 rdrs = env->me_txns->mti_numreaders;
9980 pids = malloc((rdrs+1) * sizeof(MDB_PID_T));
9984 mr = env->me_txns->mti_readers;
9985 for (i=0; i<rdrs; i++) {
9987 if (pid && pid != env->me_pid) {
9988 if (mdb_pid_insert(pids, pid) == 0) {
9989 if (!mdb_reader_pid(env, Pidcheck, pid)) {
9990 /* Stale reader found */
9993 if ((rc = LOCK_MUTEX0(rmutex)) != 0) {
9994 if ((rc = mdb_mutex_failed(env, rmutex, rc)))
9996 rdrs = 0; /* the above checked all readers */
9998 /* Recheck, a new process may have reused pid */
9999 if (mdb_reader_pid(env, Pidcheck, pid))
10003 for (; j<rdrs; j++)
10004 if (mr[j].mr_pid == pid) {
10005 DPRINTF(("clear stale reader pid %u txn %"Z"d",
10006 (unsigned) pid, mr[j].mr_txnid));
10011 UNLOCK_MUTEX(rmutex);
10022 #ifdef MDB_ROBUST_SUPPORTED
10023 /** Handle #LOCK_MUTEX0() failure.
10024 * Try to repair the lock file if the mutex owner died.
10025 * @param[in] env the environment handle
10026 * @param[in] mutex LOCK_MUTEX0() mutex
10027 * @param[in] rc LOCK_MUTEX0() error (nonzero)
10028 * @return 0 on success with the mutex locked, or an error code on failure.
10031 mdb_mutex_failed(MDB_env *env, mdb_mutexref_t mutex, int rc)
10036 if (rc == MDB_OWNERDEAD) {
10037 /* We own the mutex. Clean up after dead previous owner. */
10039 rlocked = (mutex == env->me_rmutex);
10041 /* Keep mti_txnid updated, otherwise next writer can
10042 * overwrite data which latest meta page refers to.
10044 meta = mdb_env_pick_meta(env);
10045 env->me_txns->mti_txnid = meta->mm_txnid;
10046 /* env is hosed if the dead thread was ours */
10048 env->me_flags |= MDB_FATAL_ERROR;
10049 env->me_txn = NULL;
10053 DPRINTF(("%cmutex owner died, %s", (rlocked ? 'r' : 'w'),
10054 (rc ? "this process' env is hosed" : "recovering")));
10055 rc2 = mdb_reader_check0(env, rlocked, NULL);
10057 rc2 = mdb_mutex_consistent(mutex);
10058 if (rc || (rc = rc2)) {
10059 DPRINTF(("LOCK_MUTEX recovery failed, %s", mdb_strerror(rc)));
10060 UNLOCK_MUTEX(mutex);
10066 DPRINTF(("LOCK_MUTEX failed, %s", mdb_strerror(rc)));
10071 #endif /* MDB_ROBUST_SUPPORTED */
10074 #if defined(_WIN32)
10075 static int utf8_to_utf16(const char *src, int srcsize, wchar_t **dst, int *dstsize)
10079 need = MultiByteToWideChar(CP_UTF8, 0, src, srcsize, NULL, 0);
10080 if (need == 0xFFFD)
10084 result = malloc(sizeof(wchar_t) * need);
10085 MultiByteToWideChar(CP_UTF8, 0, src, srcsize, result, need);
10091 #endif /* defined(_WIN32) */
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