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 2011-2014 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
83 #if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER))
84 #include <netinet/in.h>
85 #include <resolv.h> /* defines BYTE_ORDER on HPUX and Solaris */
88 #if defined(__APPLE__) || defined (BSD)
89 # define MDB_USE_POSIX_SEM 1
90 # define MDB_FDATASYNC fsync
91 #elif defined(ANDROID)
92 # define MDB_FDATASYNC fsync
97 #ifdef MDB_USE_POSIX_SEM
98 # define MDB_USE_HASH 1
99 #include <semaphore.h>
104 #include <valgrind/memcheck.h>
105 #define VGMEMP_CREATE(h,r,z) VALGRIND_CREATE_MEMPOOL(h,r,z)
106 #define VGMEMP_ALLOC(h,a,s) VALGRIND_MEMPOOL_ALLOC(h,a,s)
107 #define VGMEMP_FREE(h,a) VALGRIND_MEMPOOL_FREE(h,a)
108 #define VGMEMP_DESTROY(h) VALGRIND_DESTROY_MEMPOOL(h)
109 #define VGMEMP_DEFINED(a,s) VALGRIND_MAKE_MEM_DEFINED(a,s)
111 #define VGMEMP_CREATE(h,r,z)
112 #define VGMEMP_ALLOC(h,a,s)
113 #define VGMEMP_FREE(h,a)
114 #define VGMEMP_DESTROY(h)
115 #define VGMEMP_DEFINED(a,s)
119 # if (defined(_LITTLE_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN))
120 /* Solaris just defines one or the other */
121 # define LITTLE_ENDIAN 1234
122 # define BIG_ENDIAN 4321
123 # ifdef _LITTLE_ENDIAN
124 # define BYTE_ORDER LITTLE_ENDIAN
126 # define BYTE_ORDER BIG_ENDIAN
129 # define BYTE_ORDER __BYTE_ORDER
133 #ifndef LITTLE_ENDIAN
134 #define LITTLE_ENDIAN __LITTLE_ENDIAN
137 #define BIG_ENDIAN __BIG_ENDIAN
140 #if defined(__i386) || defined(__x86_64) || defined(_M_IX86)
141 #define MISALIGNED_OK 1
147 #if (BYTE_ORDER == LITTLE_ENDIAN) == (BYTE_ORDER == BIG_ENDIAN)
148 # error "Unknown or unsupported endianness (BYTE_ORDER)"
149 #elif (-6 & 5) || CHAR_BIT != 8 || UINT_MAX < 0xffffffff || ULONG_MAX % 0xFFFF
150 # error "Two's complement, reasonably sized integer types, please"
154 /** Put infrequently used env functions in separate section */
156 # define ESECT __attribute__ ((section("__TEXT,text_env")))
158 # define ESECT __attribute__ ((section("text_env")))
164 /** @defgroup internal LMDB Internals
167 /** @defgroup compat Compatibility Macros
168 * A bunch of macros to minimize the amount of platform-specific ifdefs
169 * needed throughout the rest of the code. When the features this library
170 * needs are similar enough to POSIX to be hidden in a one-or-two line
171 * replacement, this macro approach is used.
175 /** Features under development */
180 /** Wrapper around __func__, which is a C99 feature */
181 #if __STDC_VERSION__ >= 199901L
182 # define mdb_func_ __func__
183 #elif __GNUC__ >= 2 || _MSC_VER >= 1300
184 # define mdb_func_ __FUNCTION__
186 /* If a debug message says <mdb_unknown>(), update the #if statements above */
187 # define mdb_func_ "<mdb_unknown>"
191 #define MDB_USE_HASH 1
192 #define MDB_PIDLOCK 0
193 #define THREAD_RET DWORD
194 #define pthread_t HANDLE
195 #define pthread_mutex_t HANDLE
196 #define pthread_cond_t HANDLE
197 #define pthread_key_t DWORD
198 #define pthread_self() GetCurrentThreadId()
199 #define pthread_key_create(x,y) \
200 ((*(x) = TlsAlloc()) == TLS_OUT_OF_INDEXES ? ErrCode() : 0)
201 #define pthread_key_delete(x) TlsFree(x)
202 #define pthread_getspecific(x) TlsGetValue(x)
203 #define pthread_setspecific(x,y) (TlsSetValue(x,y) ? 0 : ErrCode())
204 #define pthread_mutex_unlock(x) ReleaseMutex(*x)
205 #define pthread_mutex_lock(x) WaitForSingleObject(*x, INFINITE)
206 #define pthread_cond_signal(x) SetEvent(*x)
207 #define pthread_cond_wait(cond,mutex) do{SignalObjectAndWait(*mutex, *cond, INFINITE, FALSE); WaitForSingleObject(*mutex, INFINITE);}while(0)
208 #define THREAD_CREATE(thr,start,arg) thr=CreateThread(NULL,0,start,arg,0,NULL)
209 #define THREAD_FINISH(thr) WaitForSingleObject(thr, INFINITE)
210 #define LOCK_MUTEX_R(env) pthread_mutex_lock(&(env)->me_rmutex)
211 #define UNLOCK_MUTEX_R(env) pthread_mutex_unlock(&(env)->me_rmutex)
212 #define LOCK_MUTEX_W(env) pthread_mutex_lock(&(env)->me_wmutex)
213 #define UNLOCK_MUTEX_W(env) pthread_mutex_unlock(&(env)->me_wmutex)
214 #define getpid() GetCurrentProcessId()
215 #define MDB_FDATASYNC(fd) (!FlushFileBuffers(fd))
216 #define MDB_MSYNC(addr,len,flags) (!FlushViewOfFile(addr,len))
217 #define ErrCode() GetLastError()
218 #define GET_PAGESIZE(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;}
219 #define close(fd) (CloseHandle(fd) ? 0 : -1)
220 #define munmap(ptr,len) UnmapViewOfFile(ptr)
221 #ifdef PROCESS_QUERY_LIMITED_INFORMATION
222 #define MDB_PROCESS_QUERY_LIMITED_INFORMATION PROCESS_QUERY_LIMITED_INFORMATION
224 #define MDB_PROCESS_QUERY_LIMITED_INFORMATION 0x1000
228 #define THREAD_RET void *
229 #define THREAD_CREATE(thr,start,arg) pthread_create(&thr,NULL,start,arg)
230 #define THREAD_FINISH(thr) pthread_join(thr,NULL)
231 #define Z "z" /**< printf format modifier for size_t */
233 /** For MDB_LOCK_FORMAT: True if readers take a pid lock in the lockfile */
234 #define MDB_PIDLOCK 1
236 #ifdef MDB_USE_POSIX_SEM
238 #define LOCK_MUTEX_R(env) mdb_sem_wait((env)->me_rmutex)
239 #define UNLOCK_MUTEX_R(env) sem_post((env)->me_rmutex)
240 #define LOCK_MUTEX_W(env) mdb_sem_wait((env)->me_wmutex)
241 #define UNLOCK_MUTEX_W(env) sem_post((env)->me_wmutex)
244 mdb_sem_wait(sem_t *sem)
247 while ((rc = sem_wait(sem)) && (rc = errno) == EINTR) ;
252 /** Lock the reader mutex.
254 #define LOCK_MUTEX_R(env) pthread_mutex_lock(&(env)->me_txns->mti_mutex)
255 /** Unlock the reader mutex.
257 #define UNLOCK_MUTEX_R(env) pthread_mutex_unlock(&(env)->me_txns->mti_mutex)
259 /** Lock the writer mutex.
260 * Only a single write transaction is allowed at a time. Other writers
261 * will block waiting for this mutex.
263 #define LOCK_MUTEX_W(env) pthread_mutex_lock(&(env)->me_txns->mti_wmutex)
264 /** Unlock the writer mutex.
266 #define UNLOCK_MUTEX_W(env) pthread_mutex_unlock(&(env)->me_txns->mti_wmutex)
267 #endif /* MDB_USE_POSIX_SEM */
269 /** Get the error code for the last failed system function.
271 #define ErrCode() errno
273 /** An abstraction for a file handle.
274 * On POSIX systems file handles are small integers. On Windows
275 * they're opaque pointers.
279 /** A value for an invalid file handle.
280 * Mainly used to initialize file variables and signify that they are
283 #define INVALID_HANDLE_VALUE (-1)
285 /** Get the size of a memory page for the system.
286 * This is the basic size that the platform's memory manager uses, and is
287 * fundamental to the use of memory-mapped files.
289 #define GET_PAGESIZE(x) ((x) = sysconf(_SC_PAGE_SIZE))
292 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
295 #define MNAME_LEN (sizeof(pthread_mutex_t))
301 /** A flag for opening a file and requesting synchronous data writes.
302 * This is only used when writing a meta page. It's not strictly needed;
303 * we could just do a normal write and then immediately perform a flush.
304 * But if this flag is available it saves us an extra system call.
306 * @note If O_DSYNC is undefined but exists in /usr/include,
307 * preferably set some compiler flag to get the definition.
308 * Otherwise compile with the less efficient -DMDB_DSYNC=O_SYNC.
311 # define MDB_DSYNC O_DSYNC
315 /** Function for flushing the data of a file. Define this to fsync
316 * if fdatasync() is not supported.
318 #ifndef MDB_FDATASYNC
319 # define MDB_FDATASYNC fdatasync
323 # define MDB_MSYNC(addr,len,flags) msync(addr,len,flags)
334 /** A page number in the database.
335 * Note that 64 bit page numbers are overkill, since pages themselves
336 * already represent 12-13 bits of addressable memory, and the OS will
337 * always limit applications to a maximum of 63 bits of address space.
339 * @note In the #MDB_node structure, we only store 48 bits of this value,
340 * which thus limits us to only 60 bits of addressable data.
342 typedef MDB_ID pgno_t;
344 /** A transaction ID.
345 * See struct MDB_txn.mt_txnid for details.
347 typedef MDB_ID txnid_t;
349 /** @defgroup debug Debug Macros
353 /** Enable debug output. Needs variable argument macros (a C99 feature).
354 * Set this to 1 for copious tracing. Set to 2 to add dumps of all IDLs
355 * read from and written to the database (used for free space management).
361 static int mdb_debug;
362 static txnid_t mdb_debug_start;
364 /** Print a debug message with printf formatting.
365 * Requires double parenthesis around 2 or more args.
367 # define DPRINTF(args) ((void) ((mdb_debug) && DPRINTF0 args))
368 # define DPRINTF0(fmt, ...) \
369 fprintf(stderr, "%s:%d " fmt "\n", mdb_func_, __LINE__, __VA_ARGS__)
371 # define DPRINTF(args) ((void) 0)
373 /** Print a debug string.
374 * The string is printed literally, with no format processing.
376 #define DPUTS(arg) DPRINTF(("%s", arg))
377 /** Debuging output value of a cursor DBI: Negative in a sub-cursor. */
379 (((mc)->mc_flags & C_SUB) ? -(int)(mc)->mc_dbi : (int)(mc)->mc_dbi)
382 /** @brief The maximum size of a database page.
384 * It is 32k or 64k, since value-PAGEBASE must fit in
385 * #MDB_page.%mp_upper.
387 * LMDB will use database pages < OS pages if needed.
388 * That causes more I/O in write transactions: The OS must
389 * know (read) the whole page before writing a partial page.
391 * Note that we don't currently support Huge pages. On Linux,
392 * regular data files cannot use Huge pages, and in general
393 * Huge pages aren't actually pageable. We rely on the OS
394 * demand-pager to read our data and page it out when memory
395 * pressure from other processes is high. So until OSs have
396 * actual paging support for Huge pages, they're not viable.
398 #define MAX_PAGESIZE (PAGEBASE ? 0x10000 : 0x8000)
400 /** The minimum number of keys required in a database page.
401 * Setting this to a larger value will place a smaller bound on the
402 * maximum size of a data item. Data items larger than this size will
403 * be pushed into overflow pages instead of being stored directly in
404 * the B-tree node. This value used to default to 4. With a page size
405 * of 4096 bytes that meant that any item larger than 1024 bytes would
406 * go into an overflow page. That also meant that on average 2-3KB of
407 * each overflow page was wasted space. The value cannot be lower than
408 * 2 because then there would no longer be a tree structure. With this
409 * value, items larger than 2KB will go into overflow pages, and on
410 * average only 1KB will be wasted.
412 #define MDB_MINKEYS 2
414 /** A stamp that identifies a file as an LMDB file.
415 * There's nothing special about this value other than that it is easily
416 * recognizable, and it will reflect any byte order mismatches.
418 #define MDB_MAGIC 0xBEEFC0DE
420 /** The version number for a database's datafile format. */
421 #define MDB_DATA_VERSION ((MDB_DEVEL) ? 999 : 1)
422 /** The version number for a database's lockfile format. */
423 #define MDB_LOCK_VERSION 1
425 /** @brief The max size of a key we can write, or 0 for dynamic max.
427 * Define this as 0 to compute the max from the page size. 511
428 * is default for backwards compat: liblmdb <= 0.9.10 can break
429 * when modifying a DB with keys/dupsort data bigger than its max.
430 * #MDB_DEVEL sets the default to 0.
432 * Data items in an #MDB_DUPSORT database are also limited to
433 * this size, since they're actually keys of a sub-DB. Keys and
434 * #MDB_DUPSORT data items must fit on a node in a regular page.
436 #ifndef MDB_MAXKEYSIZE
437 #define MDB_MAXKEYSIZE ((MDB_DEVEL) ? 0 : 511)
440 /** The maximum size of a key we can write to the environment. */
442 #define ENV_MAXKEY(env) (MDB_MAXKEYSIZE)
444 #define ENV_MAXKEY(env) ((env)->me_maxkey)
447 /** @brief The maximum size of a data item.
449 * We only store a 32 bit value for node sizes.
451 #define MAXDATASIZE 0xffffffffUL
454 /** Key size which fits in a #DKBUF.
457 #define DKBUF_MAXKEYSIZE ((MDB_MAXKEYSIZE) > 0 ? (MDB_MAXKEYSIZE) : 511)
460 * This is used for printing a hex dump of a key's contents.
462 #define DKBUF char kbuf[DKBUF_MAXKEYSIZE*2+1]
463 /** Display a key in hex.
465 * Invoke a function to display a key in hex.
467 #define DKEY(x) mdb_dkey(x, kbuf)
473 /** An invalid page number.
474 * Mainly used to denote an empty tree.
476 #define P_INVALID (~(pgno_t)0)
478 /** Test if the flags \b f are set in a flag word \b w. */
479 #define F_ISSET(w, f) (((w) & (f)) == (f))
481 /** Round \b n up to an even number. */
482 #define EVEN(n) (((n) + 1U) & -2) /* sign-extending -2 to match n+1U */
484 /** Used for offsets within a single page.
485 * Since memory pages are typically 4 or 8KB in size, 12-13 bits,
488 typedef uint16_t indx_t;
490 /** Default size of memory map.
491 * This is certainly too small for any actual applications. Apps should always set
492 * the size explicitly using #mdb_env_set_mapsize().
494 #define DEFAULT_MAPSIZE 1048576
496 /** @defgroup readers Reader Lock Table
497 * Readers don't acquire any locks for their data access. Instead, they
498 * simply record their transaction ID in the reader table. The reader
499 * mutex is needed just to find an empty slot in the reader table. The
500 * slot's address is saved in thread-specific data so that subsequent read
501 * transactions started by the same thread need no further locking to proceed.
503 * If #MDB_NOTLS is set, the slot address is not saved in thread-specific data.
505 * No reader table is used if the database is on a read-only filesystem, or
506 * if #MDB_NOLOCK is set.
508 * Since the database uses multi-version concurrency control, readers don't
509 * actually need any locking. This table is used to keep track of which
510 * readers are using data from which old transactions, so that we'll know
511 * when a particular old transaction is no longer in use. Old transactions
512 * that have discarded any data pages can then have those pages reclaimed
513 * for use by a later write transaction.
515 * The lock table is constructed such that reader slots are aligned with the
516 * processor's cache line size. Any slot is only ever used by one thread.
517 * This alignment guarantees that there will be no contention or cache
518 * thrashing as threads update their own slot info, and also eliminates
519 * any need for locking when accessing a slot.
521 * A writer thread will scan every slot in the table to determine the oldest
522 * outstanding reader transaction. Any freed pages older than this will be
523 * reclaimed by the writer. The writer doesn't use any locks when scanning
524 * this table. This means that there's no guarantee that the writer will
525 * see the most up-to-date reader info, but that's not required for correct
526 * operation - all we need is to know the upper bound on the oldest reader,
527 * we don't care at all about the newest reader. So the only consequence of
528 * reading stale information here is that old pages might hang around a
529 * while longer before being reclaimed. That's actually good anyway, because
530 * the longer we delay reclaiming old pages, the more likely it is that a
531 * string of contiguous pages can be found after coalescing old pages from
532 * many old transactions together.
535 /** Number of slots in the reader table.
536 * This value was chosen somewhat arbitrarily. 126 readers plus a
537 * couple mutexes fit exactly into 8KB on my development machine.
538 * Applications should set the table size using #mdb_env_set_maxreaders().
540 #define DEFAULT_READERS 126
542 /** The size of a CPU cache line in bytes. We want our lock structures
543 * aligned to this size to avoid false cache line sharing in the
545 * This value works for most CPUs. For Itanium this should be 128.
551 /** The information we store in a single slot of the reader table.
552 * In addition to a transaction ID, we also record the process and
553 * thread ID that owns a slot, so that we can detect stale information,
554 * e.g. threads or processes that went away without cleaning up.
555 * @note We currently don't check for stale records. We simply re-init
556 * the table when we know that we're the only process opening the
559 typedef struct MDB_rxbody {
560 /** Current Transaction ID when this transaction began, or (txnid_t)-1.
561 * Multiple readers that start at the same time will probably have the
562 * same ID here. Again, it's not important to exclude them from
563 * anything; all we need to know is which version of the DB they
564 * started from so we can avoid overwriting any data used in that
565 * particular version.
568 /** The process ID of the process owning this reader txn. */
570 /** The thread ID of the thread owning this txn. */
574 /** The actual reader record, with cacheline padding. */
575 typedef struct MDB_reader {
578 /** shorthand for mrb_txnid */
579 #define mr_txnid mru.mrx.mrb_txnid
580 #define mr_pid mru.mrx.mrb_pid
581 #define mr_tid mru.mrx.mrb_tid
582 /** cache line alignment */
583 char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)];
587 /** The header for the reader table.
588 * The table resides in a memory-mapped file. (This is a different file
589 * than is used for the main database.)
591 * For POSIX the actual mutexes reside in the shared memory of this
592 * mapped file. On Windows, mutexes are named objects allocated by the
593 * kernel; we store the mutex names in this mapped file so that other
594 * processes can grab them. This same approach is also used on
595 * MacOSX/Darwin (using named semaphores) since MacOSX doesn't support
596 * process-shared POSIX mutexes. For these cases where a named object
597 * is used, the object name is derived from a 64 bit FNV hash of the
598 * environment pathname. As such, naming collisions are extremely
599 * unlikely. If a collision occurs, the results are unpredictable.
601 typedef struct MDB_txbody {
602 /** Stamp identifying this as an LMDB file. It must be set
605 /** Format of this lock file. Must be set to #MDB_LOCK_FORMAT. */
607 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
608 char mtb_rmname[MNAME_LEN];
610 /** Mutex protecting access to this table.
611 * This is the reader lock that #LOCK_MUTEX_R acquires.
613 pthread_mutex_t mtb_mutex;
615 /** The ID of the last transaction committed to the database.
616 * This is recorded here only for convenience; the value can always
617 * be determined by reading the main database meta pages.
620 /** The number of slots that have been used in the reader table.
621 * This always records the maximum count, it is not decremented
622 * when readers release their slots.
624 unsigned mtb_numreaders;
627 /** The actual reader table definition. */
628 typedef struct MDB_txninfo {
631 #define mti_magic mt1.mtb.mtb_magic
632 #define mti_format mt1.mtb.mtb_format
633 #define mti_mutex mt1.mtb.mtb_mutex
634 #define mti_rmname mt1.mtb.mtb_rmname
635 #define mti_txnid mt1.mtb.mtb_txnid
636 #define mti_numreaders mt1.mtb.mtb_numreaders
637 char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];
640 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
641 char mt2_wmname[MNAME_LEN];
642 #define mti_wmname mt2.mt2_wmname
644 pthread_mutex_t mt2_wmutex;
645 #define mti_wmutex mt2.mt2_wmutex
647 char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)];
649 MDB_reader mti_readers[1];
652 /** Lockfile format signature: version, features and field layout */
653 #define MDB_LOCK_FORMAT \
655 ((MDB_LOCK_VERSION) \
656 /* Flags which describe functionality */ \
657 + (((MDB_PIDLOCK) != 0) << 16)))
660 /** Common header for all page types.
661 * Overflow records occupy a number of contiguous pages with no
662 * headers on any page after the first.
664 typedef struct MDB_page {
665 #define mp_pgno mp_p.p_pgno
666 #define mp_next mp_p.p_next
668 pgno_t p_pgno; /**< page number */
669 struct MDB_page *p_next; /**< for in-memory list of freed pages */
672 /** @defgroup mdb_page Page Flags
674 * Flags for the page headers.
677 #define P_BRANCH 0x01 /**< branch page */
678 #define P_LEAF 0x02 /**< leaf page */
679 #define P_OVERFLOW 0x04 /**< overflow page */
680 #define P_META 0x08 /**< meta page */
681 #define P_DIRTY 0x10 /**< dirty page, also set for #P_SUBP pages */
682 #define P_LEAF2 0x20 /**< for #MDB_DUPFIXED records */
683 #define P_SUBP 0x40 /**< for #MDB_DUPSORT sub-pages */
684 #define P_LOOSE 0x4000 /**< page was dirtied then freed, can be reused */
685 #define P_KEEP 0x8000 /**< leave this page alone during spill */
687 uint16_t mp_flags; /**< @ref mdb_page */
688 #define mp_lower mp_pb.pb.pb_lower
689 #define mp_upper mp_pb.pb.pb_upper
690 #define mp_pages mp_pb.pb_pages
693 indx_t pb_lower; /**< lower bound of free space */
694 indx_t pb_upper; /**< upper bound of free space */
696 uint32_t pb_pages; /**< number of overflow pages */
698 indx_t mp_ptrs[1]; /**< dynamic size */
701 /** Size of the page header, excluding dynamic data at the end */
702 #define PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs))
704 /** Address of first usable data byte in a page, after the header */
705 #define METADATA(p) ((void *)((char *)(p) + PAGEHDRSZ))
707 /** ITS#7713, change PAGEBASE to handle 65536 byte pages */
708 #define PAGEBASE ((MDB_DEVEL) ? PAGEHDRSZ : 0)
710 /** Number of nodes on a page */
711 #define NUMKEYS(p) (((p)->mp_lower - (PAGEHDRSZ-PAGEBASE)) >> 1)
713 /** The amount of space remaining in the page */
714 #define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower)
716 /** The percentage of space used in the page, in tenths of a percent. */
717 #define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \
718 ((env)->me_psize - PAGEHDRSZ))
719 /** The minimum page fill factor, in tenths of a percent.
720 * Pages emptier than this are candidates for merging.
722 #define FILL_THRESHOLD 250
724 /** Test if a page is a leaf page */
725 #define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF)
726 /** Test if a page is a LEAF2 page */
727 #define IS_LEAF2(p) F_ISSET((p)->mp_flags, P_LEAF2)
728 /** Test if a page is a branch page */
729 #define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH)
730 /** Test if a page is an overflow page */
731 #define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW)
732 /** Test if a page is a sub page */
733 #define IS_SUBP(p) F_ISSET((p)->mp_flags, P_SUBP)
735 /** The number of overflow pages needed to store the given size. */
736 #define OVPAGES(size, psize) ((PAGEHDRSZ-1 + (size)) / (psize) + 1)
738 /** Link in #MDB_txn.%mt_loose_pages list */
739 #define NEXT_LOOSE_PAGE(p) (*(MDB_page **)((p) + 2))
741 /** Header for a single key/data pair within a page.
742 * Used in pages of type #P_BRANCH and #P_LEAF without #P_LEAF2.
743 * We guarantee 2-byte alignment for 'MDB_node's.
745 typedef struct MDB_node {
746 /** lo and hi are used for data size on leaf nodes and for
747 * child pgno on branch nodes. On 64 bit platforms, flags
748 * is also used for pgno. (Branch nodes have no flags).
749 * They are in host byte order in case that lets some
750 * accesses be optimized into a 32-bit word access.
752 #if BYTE_ORDER == LITTLE_ENDIAN
753 unsigned short mn_lo, mn_hi; /**< part of data size or pgno */
755 unsigned short mn_hi, mn_lo;
757 /** @defgroup mdb_node Node Flags
759 * Flags for node headers.
762 #define F_BIGDATA 0x01 /**< data put on overflow page */
763 #define F_SUBDATA 0x02 /**< data is a sub-database */
764 #define F_DUPDATA 0x04 /**< data has duplicates */
766 /** valid flags for #mdb_node_add() */
767 #define NODE_ADD_FLAGS (F_DUPDATA|F_SUBDATA|MDB_RESERVE|MDB_APPEND)
770 unsigned short mn_flags; /**< @ref mdb_node */
771 unsigned short mn_ksize; /**< key size */
772 char mn_data[1]; /**< key and data are appended here */
775 /** Size of the node header, excluding dynamic data at the end */
776 #define NODESIZE offsetof(MDB_node, mn_data)
778 /** Bit position of top word in page number, for shifting mn_flags */
779 #define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0)
781 /** Size of a node in a branch page with a given key.
782 * This is just the node header plus the key, there is no data.
784 #define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))
786 /** Size of a node in a leaf page with a given key and data.
787 * This is node header plus key plus data size.
789 #define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size)
791 /** Address of node \b i in page \b p */
792 #define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i] + PAGEBASE))
794 /** Address of the key for the node */
795 #define NODEKEY(node) (void *)((node)->mn_data)
797 /** Address of the data for a node */
798 #define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize)
800 /** Get the page number pointed to by a branch node */
801 #define NODEPGNO(node) \
802 ((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | \
803 (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0))
804 /** Set the page number in a branch node */
805 #define SETPGNO(node,pgno) do { \
806 (node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \
807 if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0)
809 /** Get the size of the data in a leaf node */
810 #define NODEDSZ(node) ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16))
811 /** Set the size of the data for a leaf node */
812 #define SETDSZ(node,size) do { \
813 (node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)
814 /** The size of a key in a node */
815 #define NODEKSZ(node) ((node)->mn_ksize)
817 /** Copy a page number from src to dst */
819 #define COPY_PGNO(dst,src) dst = src
821 #if SIZE_MAX > 4294967295UL
822 #define COPY_PGNO(dst,src) do { \
823 unsigned short *s, *d; \
824 s = (unsigned short *)&(src); \
825 d = (unsigned short *)&(dst); \
832 #define COPY_PGNO(dst,src) do { \
833 unsigned short *s, *d; \
834 s = (unsigned short *)&(src); \
835 d = (unsigned short *)&(dst); \
841 /** The address of a key in a LEAF2 page.
842 * LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate sub-DBs.
843 * There are no node headers, keys are stored contiguously.
845 #define LEAF2KEY(p, i, ks) ((char *)(p) + PAGEHDRSZ + ((i)*(ks)))
847 /** Set the \b node's key into \b keyptr, if requested. */
848 #define MDB_GET_KEY(node, keyptr) { if ((keyptr) != NULL) { \
849 (keyptr)->mv_size = NODEKSZ(node); (keyptr)->mv_data = NODEKEY(node); } }
851 /** Set the \b node's key into \b key. */
852 #define MDB_GET_KEY2(node, key) { key.mv_size = NODEKSZ(node); key.mv_data = NODEKEY(node); }
854 /** Information about a single database in the environment. */
855 typedef struct MDB_db {
856 uint32_t md_pad; /**< also ksize for LEAF2 pages */
857 uint16_t md_flags; /**< @ref mdb_dbi_open */
858 uint16_t md_depth; /**< depth of this tree */
859 pgno_t md_branch_pages; /**< number of internal pages */
860 pgno_t md_leaf_pages; /**< number of leaf pages */
861 pgno_t md_overflow_pages; /**< number of overflow pages */
862 size_t md_entries; /**< number of data items */
863 pgno_t md_root; /**< the root page of this tree */
866 /** mdb_dbi_open flags */
867 #define MDB_VALID 0x8000 /**< DB handle is valid, for me_dbflags */
868 #define PERSISTENT_FLAGS (0xffff & ~(MDB_VALID))
869 #define VALID_FLAGS (MDB_REVERSEKEY|MDB_DUPSORT|MDB_INTEGERKEY|MDB_DUPFIXED|\
870 MDB_INTEGERDUP|MDB_REVERSEDUP|MDB_CREATE)
872 /** Handle for the DB used to track free pages. */
874 /** Handle for the default DB. */
877 /** Meta page content.
878 * A meta page is the start point for accessing a database snapshot.
879 * Pages 0-1 are meta pages. Transaction N writes meta page #(N % 2).
881 typedef struct MDB_meta {
882 /** Stamp identifying this as an LMDB file. It must be set
885 /** Version number of this lock file. Must be set to #MDB_DATA_VERSION. */
887 void *mm_address; /**< address for fixed mapping */
888 size_t mm_mapsize; /**< size of mmap region */
889 MDB_db mm_dbs[2]; /**< first is free space, 2nd is main db */
890 /** The size of pages used in this DB */
891 #define mm_psize mm_dbs[0].md_pad
892 /** Any persistent environment flags. @ref mdb_env */
893 #define mm_flags mm_dbs[0].md_flags
894 pgno_t mm_last_pg; /**< last used page in file */
895 txnid_t mm_txnid; /**< txnid that committed this page */
898 /** Buffer for a stack-allocated meta page.
899 * The members define size and alignment, and silence type
900 * aliasing warnings. They are not used directly; that could
901 * mean incorrectly using several union members in parallel.
903 typedef union MDB_metabuf {
906 char mm_pad[PAGEHDRSZ];
911 /** Auxiliary DB info.
912 * The information here is mostly static/read-only. There is
913 * only a single copy of this record in the environment.
915 typedef struct MDB_dbx {
916 MDB_val md_name; /**< name of the database */
917 MDB_cmp_func *md_cmp; /**< function for comparing keys */
918 MDB_cmp_func *md_dcmp; /**< function for comparing data items */
919 MDB_rel_func *md_rel; /**< user relocate function */
920 void *md_relctx; /**< user-provided context for md_rel */
923 /** A database transaction.
924 * Every operation requires a transaction handle.
927 MDB_txn *mt_parent; /**< parent of a nested txn */
928 MDB_txn *mt_child; /**< nested txn under this txn */
929 pgno_t mt_next_pgno; /**< next unallocated page */
930 /** The ID of this transaction. IDs are integers incrementing from 1.
931 * Only committed write transactions increment the ID. If a transaction
932 * aborts, the ID may be re-used by the next writer.
935 MDB_env *mt_env; /**< the DB environment */
936 /** The list of pages that became unused during this transaction.
939 /** The list of loose pages that became unused and may be reused
940 * in this transaction, linked through #NEXT_LOOSE_PAGE(page).
942 MDB_page *mt_loose_pgs;
943 /** The sorted list of dirty pages we temporarily wrote to disk
944 * because the dirty list was full. page numbers in here are
945 * shifted left by 1, deleted slots have the LSB set.
947 MDB_IDL mt_spill_pgs;
949 /** For write txns: Modified pages. Sorted when not MDB_WRITEMAP. */
951 /** For read txns: This thread/txn's reader table slot, or NULL. */
954 /** Array of records for each DB known in the environment. */
956 /** Array of MDB_db records for each known DB */
958 /** Array of sequence numbers for each DB handle */
959 unsigned int *mt_dbiseqs;
960 /** @defgroup mt_dbflag Transaction DB Flags
964 #define DB_DIRTY 0x01 /**< DB was modified or is DUPSORT data */
965 #define DB_STALE 0x02 /**< Named-DB record is older than txnID */
966 #define DB_NEW 0x04 /**< Named-DB handle opened in this txn */
967 #define DB_VALID 0x08 /**< DB handle is valid, see also #MDB_VALID */
969 /** In write txns, array of cursors for each DB */
970 MDB_cursor **mt_cursors;
971 /** Array of flags for each DB */
972 unsigned char *mt_dbflags;
973 /** Number of DB records in use. This number only ever increments;
974 * we don't decrement it when individual DB handles are closed.
978 /** @defgroup mdb_txn Transaction Flags
982 #define MDB_TXN_RDONLY 0x01 /**< read-only transaction */
983 #define MDB_TXN_ERROR 0x02 /**< txn is unusable after an error */
984 #define MDB_TXN_DIRTY 0x04 /**< must write, even if dirty list is empty */
985 #define MDB_TXN_SPILLS 0x08 /**< txn or a parent has spilled pages */
987 unsigned int mt_flags; /**< @ref mdb_txn */
988 /** #dirty_list room: Array size - \#dirty pages visible to this txn.
989 * Includes ancestor txns' dirty pages not hidden by other txns'
990 * dirty/spilled pages. Thus commit(nested txn) has room to merge
991 * dirty_list into mt_parent after freeing hidden mt_parent pages.
993 unsigned int mt_dirty_room;
996 /** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty.
997 * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to
998 * raise this on a 64 bit machine.
1000 #define CURSOR_STACK 32
1004 /** Cursors are used for all DB operations.
1005 * A cursor holds a path of (page pointer, key index) from the DB
1006 * root to a position in the DB, plus other state. #MDB_DUPSORT
1007 * cursors include an xcursor to the current data item. Write txns
1008 * track their cursors and keep them up to date when data moves.
1009 * Exception: An xcursor's pointer to a #P_SUBP page can be stale.
1010 * (A node with #F_DUPDATA but no #F_SUBDATA contains a subpage).
1013 /** Next cursor on this DB in this txn */
1014 MDB_cursor *mc_next;
1015 /** Backup of the original cursor if this cursor is a shadow */
1016 MDB_cursor *mc_backup;
1017 /** Context used for databases with #MDB_DUPSORT, otherwise NULL */
1018 struct MDB_xcursor *mc_xcursor;
1019 /** The transaction that owns this cursor */
1021 /** The database handle this cursor operates on */
1023 /** The database record for this cursor */
1025 /** The database auxiliary record for this cursor */
1027 /** The @ref mt_dbflag for this database */
1028 unsigned char *mc_dbflag;
1029 unsigned short mc_snum; /**< number of pushed pages */
1030 unsigned short mc_top; /**< index of top page, normally mc_snum-1 */
1031 /** @defgroup mdb_cursor Cursor Flags
1033 * Cursor state flags.
1036 #define C_INITIALIZED 0x01 /**< cursor has been initialized and is valid */
1037 #define C_EOF 0x02 /**< No more data */
1038 #define C_SUB 0x04 /**< Cursor is a sub-cursor */
1039 #define C_DEL 0x08 /**< last op was a cursor_del */
1040 #define C_SPLITTING 0x20 /**< Cursor is in page_split */
1041 #define C_UNTRACK 0x40 /**< Un-track cursor when closing */
1043 unsigned int mc_flags; /**< @ref mdb_cursor */
1044 MDB_page *mc_pg[CURSOR_STACK]; /**< stack of pushed pages */
1045 indx_t mc_ki[CURSOR_STACK]; /**< stack of page indices */
1048 /** Context for sorted-dup records.
1049 * We could have gone to a fully recursive design, with arbitrarily
1050 * deep nesting of sub-databases. But for now we only handle these
1051 * levels - main DB, optional sub-DB, sorted-duplicate DB.
1053 typedef struct MDB_xcursor {
1054 /** A sub-cursor for traversing the Dup DB */
1055 MDB_cursor mx_cursor;
1056 /** The database record for this Dup DB */
1058 /** The auxiliary DB record for this Dup DB */
1060 /** The @ref mt_dbflag for this Dup DB */
1061 unsigned char mx_dbflag;
1064 /** State of FreeDB old pages, stored in the MDB_env */
1065 typedef struct MDB_pgstate {
1066 pgno_t *mf_pghead; /**< Reclaimed freeDB pages, or NULL before use */
1067 txnid_t mf_pglast; /**< ID of last used record, or 0 if !mf_pghead */
1070 /** The database environment. */
1072 HANDLE me_fd; /**< The main data file */
1073 HANDLE me_lfd; /**< The lock file */
1074 HANDLE me_mfd; /**< just for writing the meta pages */
1075 /** Failed to update the meta page. Probably an I/O error. */
1076 #define MDB_FATAL_ERROR 0x80000000U
1077 /** Some fields are initialized. */
1078 #define MDB_ENV_ACTIVE 0x20000000U
1079 /** me_txkey is set */
1080 #define MDB_ENV_TXKEY 0x10000000U
1081 uint32_t me_flags; /**< @ref mdb_env */
1082 unsigned int me_psize; /**< DB page size, inited from me_os_psize */
1083 unsigned int me_os_psize; /**< OS page size, from #GET_PAGESIZE */
1084 unsigned int me_maxreaders; /**< size of the reader table */
1085 unsigned int me_numreaders; /**< max numreaders set by this env */
1086 MDB_dbi me_numdbs; /**< number of DBs opened */
1087 MDB_dbi me_maxdbs; /**< size of the DB table */
1088 MDB_PID_T me_pid; /**< process ID of this env */
1089 char *me_path; /**< path to the DB files */
1090 char *me_map; /**< the memory map of the data file */
1091 MDB_txninfo *me_txns; /**< the memory map of the lock file or NULL */
1092 MDB_meta *me_metas[2]; /**< pointers to the two meta pages */
1093 void *me_pbuf; /**< scratch area for DUPSORT put() */
1094 MDB_txn *me_txn; /**< current write transaction */
1095 size_t me_mapsize; /**< size of the data memory map */
1096 off_t me_size; /**< current file size */
1097 pgno_t me_maxpg; /**< me_mapsize / me_psize */
1098 MDB_dbx *me_dbxs; /**< array of static DB info */
1099 uint16_t *me_dbflags; /**< array of flags from MDB_db.md_flags */
1100 unsigned int *me_dbiseqs; /**< array of dbi sequence numbers */
1101 pthread_key_t me_txkey; /**< thread-key for readers */
1102 MDB_pgstate me_pgstate; /**< state of old pages from freeDB */
1103 # define me_pglast me_pgstate.mf_pglast
1104 # define me_pghead me_pgstate.mf_pghead
1105 MDB_page *me_dpages; /**< list of malloc'd blocks for re-use */
1106 /** IDL of pages that became unused in a write txn */
1107 MDB_IDL me_free_pgs;
1108 /** ID2L of pages written during a write txn. Length MDB_IDL_UM_SIZE. */
1109 MDB_ID2L me_dirty_list;
1110 /** Max number of freelist items that can fit in a single overflow page */
1112 /** Max size of a node on a page */
1113 unsigned int me_nodemax;
1114 #if !(MDB_MAXKEYSIZE)
1115 unsigned int me_maxkey; /**< max size of a key */
1117 int me_live_reader; /**< have liveness lock in reader table */
1119 int me_pidquery; /**< Used in OpenProcess */
1120 HANDLE me_rmutex; /* Windows mutexes don't reside in shared mem */
1122 #elif defined(MDB_USE_POSIX_SEM)
1123 sem_t *me_rmutex; /* Shared mutexes are not supported */
1126 void *me_userctx; /**< User-settable context */
1127 MDB_assert_func *me_assert_func; /**< Callback for assertion failures */
1130 /** Nested transaction */
1131 typedef struct MDB_ntxn {
1132 MDB_txn mnt_txn; /**< the transaction */
1133 MDB_pgstate mnt_pgstate; /**< parent transaction's saved freestate */
1136 /** max number of pages to commit in one writev() call */
1137 #define MDB_COMMIT_PAGES 64
1138 #if defined(IOV_MAX) && IOV_MAX < MDB_COMMIT_PAGES
1139 #undef MDB_COMMIT_PAGES
1140 #define MDB_COMMIT_PAGES IOV_MAX
1143 /** max bytes to write in one call */
1144 #define MAX_WRITE (0x80000000U >> (sizeof(ssize_t) == 4))
1146 /** Check \b txn and \b dbi arguments to a function */
1147 #define TXN_DBI_EXIST(txn, dbi) \
1148 ((txn) && (dbi) < (txn)->mt_numdbs && ((txn)->mt_dbflags[dbi] & DB_VALID))
1150 /** Check for misused \b dbi handles */
1151 #define TXN_DBI_CHANGED(txn, dbi) \
1152 ((txn)->mt_dbiseqs[dbi] != (txn)->mt_env->me_dbiseqs[dbi])
1154 static int mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp);
1155 static int mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp);
1156 static int mdb_page_touch(MDB_cursor *mc);
1158 static int mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **mp, int *lvl);
1159 static int mdb_page_search_root(MDB_cursor *mc,
1160 MDB_val *key, int modify);
1161 #define MDB_PS_MODIFY 1
1162 #define MDB_PS_ROOTONLY 2
1163 #define MDB_PS_FIRST 4
1164 #define MDB_PS_LAST 8
1165 static int mdb_page_search(MDB_cursor *mc,
1166 MDB_val *key, int flags);
1167 static int mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst);
1169 #define MDB_SPLIT_REPLACE MDB_APPENDDUP /**< newkey is not new */
1170 static int mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,
1171 pgno_t newpgno, unsigned int nflags);
1173 static int mdb_env_read_header(MDB_env *env, MDB_meta *meta);
1174 static int mdb_env_pick_meta(const MDB_env *env);
1175 static int mdb_env_write_meta(MDB_txn *txn);
1176 #if !(defined(_WIN32) || defined(MDB_USE_POSIX_SEM)) /* Drop unused excl arg */
1177 # define mdb_env_close0(env, excl) mdb_env_close1(env)
1179 static void mdb_env_close0(MDB_env *env, int excl);
1181 static MDB_node *mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp);
1182 static int mdb_node_add(MDB_cursor *mc, indx_t indx,
1183 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags);
1184 static void mdb_node_del(MDB_cursor *mc, int ksize);
1185 static void mdb_node_shrink(MDB_page *mp, indx_t indx);
1186 static int mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst);
1187 static int mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data);
1188 static size_t mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data);
1189 static size_t mdb_branch_size(MDB_env *env, MDB_val *key);
1191 static int mdb_rebalance(MDB_cursor *mc);
1192 static int mdb_update_key(MDB_cursor *mc, MDB_val *key);
1194 static void mdb_cursor_pop(MDB_cursor *mc);
1195 static int mdb_cursor_push(MDB_cursor *mc, MDB_page *mp);
1197 static int mdb_cursor_del0(MDB_cursor *mc);
1198 static int mdb_del0(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned flags);
1199 static int mdb_cursor_sibling(MDB_cursor *mc, int move_right);
1200 static int mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1201 static int mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1202 static int mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op,
1204 static int mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1205 static int mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1207 static void mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);
1208 static void mdb_xcursor_init0(MDB_cursor *mc);
1209 static void mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node);
1211 static int mdb_drop0(MDB_cursor *mc, int subs);
1212 static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi);
1215 static MDB_cmp_func mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long;
1219 static SECURITY_DESCRIPTOR mdb_null_sd;
1220 static SECURITY_ATTRIBUTES mdb_all_sa;
1221 static int mdb_sec_inited;
1224 /** Return the library version info. */
1226 mdb_version(int *major, int *minor, int *patch)
1228 if (major) *major = MDB_VERSION_MAJOR;
1229 if (minor) *minor = MDB_VERSION_MINOR;
1230 if (patch) *patch = MDB_VERSION_PATCH;
1231 return MDB_VERSION_STRING;
1234 /** Table of descriptions for LMDB @ref errors */
1235 static char *const mdb_errstr[] = {
1236 "MDB_KEYEXIST: Key/data pair already exists",
1237 "MDB_NOTFOUND: No matching key/data pair found",
1238 "MDB_PAGE_NOTFOUND: Requested page not found",
1239 "MDB_CORRUPTED: Located page was wrong type",
1240 "MDB_PANIC: Update of meta page failed",
1241 "MDB_VERSION_MISMATCH: Database environment version mismatch",
1242 "MDB_INVALID: File is not an LMDB file",
1243 "MDB_MAP_FULL: Environment mapsize limit reached",
1244 "MDB_DBS_FULL: Environment maxdbs limit reached",
1245 "MDB_READERS_FULL: Environment maxreaders limit reached",
1246 "MDB_TLS_FULL: Thread-local storage keys full - too many environments open",
1247 "MDB_TXN_FULL: Transaction has too many dirty pages - transaction too big",
1248 "MDB_CURSOR_FULL: Internal error - cursor stack limit reached",
1249 "MDB_PAGE_FULL: Internal error - page has no more space",
1250 "MDB_MAP_RESIZED: Database contents grew beyond environment mapsize",
1251 "MDB_INCOMPATIBLE: Operation and DB incompatible, or DB flags changed",
1252 "MDB_BAD_RSLOT: Invalid reuse of reader locktable slot",
1253 "MDB_BAD_TXN: Transaction cannot recover - it must be aborted",
1254 "MDB_BAD_VALSIZE: Unsupported size of key/DB name/data, or wrong DUPFIXED size",
1255 "MDB_BAD_DBI: The specified DBI handle was closed/changed unexpectedly",
1259 mdb_strerror(int err)
1262 /** HACK: pad 4KB on stack over the buf. Return system msgs in buf.
1263 * This works as long as no function between the call to mdb_strerror
1264 * and the actual use of the message uses more than 4K of stack.
1267 char buf[1024], *ptr = buf;
1271 return ("Successful return: 0");
1273 if (err >= MDB_KEYEXIST && err <= MDB_LAST_ERRCODE) {
1274 i = err - MDB_KEYEXIST;
1275 return mdb_errstr[i];
1279 /* These are the C-runtime error codes we use. The comment indicates
1280 * their numeric value, and the Win32 error they would correspond to
1281 * if the error actually came from a Win32 API. A major mess, we should
1282 * have used LMDB-specific error codes for everything.
1285 case ENOENT: /* 2, FILE_NOT_FOUND */
1286 case EIO: /* 5, ACCESS_DENIED */
1287 case ENOMEM: /* 12, INVALID_ACCESS */
1288 case EACCES: /* 13, INVALID_DATA */
1289 case EBUSY: /* 16, CURRENT_DIRECTORY */
1290 case EINVAL: /* 22, BAD_COMMAND */
1291 case ENOSPC: /* 28, OUT_OF_PAPER */
1292 return strerror(err);
1297 FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
1298 FORMAT_MESSAGE_IGNORE_INSERTS,
1299 NULL, err, 0, ptr, sizeof(buf), pad);
1302 return strerror(err);
1306 /** assert(3) variant in cursor context */
1307 #define mdb_cassert(mc, expr) mdb_assert0((mc)->mc_txn->mt_env, expr, #expr)
1308 /** assert(3) variant in transaction context */
1309 #define mdb_tassert(mc, expr) mdb_assert0((txn)->mt_env, expr, #expr)
1310 /** assert(3) variant in environment context */
1311 #define mdb_eassert(env, expr) mdb_assert0(env, expr, #expr)
1314 # define mdb_assert0(env, expr, expr_txt) ((expr) ? (void)0 : \
1315 mdb_assert_fail(env, expr_txt, mdb_func_, __FILE__, __LINE__))
1318 mdb_assert_fail(MDB_env *env, const char *expr_txt,
1319 const char *func, const char *file, int line)
1322 sprintf(buf, "%.100s:%d: Assertion '%.200s' failed in %.40s()",
1323 file, line, expr_txt, func);
1324 if (env->me_assert_func)
1325 env->me_assert_func(env, buf);
1326 fprintf(stderr, "%s\n", buf);
1330 # define mdb_assert0(env, expr, expr_txt) ((void) 0)
1334 /** Return the page number of \b mp which may be sub-page, for debug output */
1336 mdb_dbg_pgno(MDB_page *mp)
1339 COPY_PGNO(ret, mp->mp_pgno);
1343 /** Display a key in hexadecimal and return the address of the result.
1344 * @param[in] key the key to display
1345 * @param[in] buf the buffer to write into. Should always be #DKBUF.
1346 * @return The key in hexadecimal form.
1349 mdb_dkey(MDB_val *key, char *buf)
1352 unsigned char *c = key->mv_data;
1358 if (key->mv_size > DKBUF_MAXKEYSIZE)
1359 return "MDB_MAXKEYSIZE";
1360 /* may want to make this a dynamic check: if the key is mostly
1361 * printable characters, print it as-is instead of converting to hex.
1365 for (i=0; i<key->mv_size; i++)
1366 ptr += sprintf(ptr, "%02x", *c++);
1368 sprintf(buf, "%.*s", key->mv_size, key->mv_data);
1374 mdb_leafnode_type(MDB_node *n)
1376 static char *const tp[2][2] = {{"", ": DB"}, {": sub-page", ": sub-DB"}};
1377 return F_ISSET(n->mn_flags, F_BIGDATA) ? ": overflow page" :
1378 tp[F_ISSET(n->mn_flags, F_DUPDATA)][F_ISSET(n->mn_flags, F_SUBDATA)];
1381 /** Display all the keys in the page. */
1383 mdb_page_list(MDB_page *mp)
1385 pgno_t pgno = mdb_dbg_pgno(mp);
1386 const char *type, *state = (mp->mp_flags & P_DIRTY) ? ", dirty" : "";
1388 unsigned int i, nkeys, nsize, total = 0;
1392 switch (mp->mp_flags & (P_BRANCH|P_LEAF|P_LEAF2|P_META|P_OVERFLOW|P_SUBP)) {
1393 case P_BRANCH: type = "Branch page"; break;
1394 case P_LEAF: type = "Leaf page"; break;
1395 case P_LEAF|P_SUBP: type = "Sub-page"; break;
1396 case P_LEAF|P_LEAF2: type = "LEAF2 page"; break;
1397 case P_LEAF|P_LEAF2|P_SUBP: type = "LEAF2 sub-page"; break;
1399 fprintf(stderr, "Overflow page %"Z"u pages %u%s\n",
1400 pgno, mp->mp_pages, state);
1403 fprintf(stderr, "Meta-page %"Z"u txnid %"Z"u\n",
1404 pgno, ((MDB_meta *)METADATA(mp))->mm_txnid);
1407 fprintf(stderr, "Bad page %"Z"u flags 0x%u\n", pgno, mp->mp_flags);
1411 nkeys = NUMKEYS(mp);
1412 fprintf(stderr, "%s %"Z"u numkeys %d%s\n", type, pgno, nkeys, state);
1414 for (i=0; i<nkeys; i++) {
1415 if (IS_LEAF2(mp)) { /* LEAF2 pages have no mp_ptrs[] or node headers */
1416 key.mv_size = nsize = mp->mp_pad;
1417 key.mv_data = LEAF2KEY(mp, i, nsize);
1419 fprintf(stderr, "key %d: nsize %d, %s\n", i, nsize, DKEY(&key));
1422 node = NODEPTR(mp, i);
1423 key.mv_size = node->mn_ksize;
1424 key.mv_data = node->mn_data;
1425 nsize = NODESIZE + key.mv_size;
1426 if (IS_BRANCH(mp)) {
1427 fprintf(stderr, "key %d: page %"Z"u, %s\n", i, NODEPGNO(node),
1431 if (F_ISSET(node->mn_flags, F_BIGDATA))
1432 nsize += sizeof(pgno_t);
1434 nsize += NODEDSZ(node);
1436 nsize += sizeof(indx_t);
1437 fprintf(stderr, "key %d: nsize %d, %s%s\n",
1438 i, nsize, DKEY(&key), mdb_leafnode_type(node));
1440 total = EVEN(total);
1442 fprintf(stderr, "Total: header %d + contents %d + unused %d\n",
1443 IS_LEAF2(mp) ? PAGEHDRSZ : PAGEBASE + mp->mp_lower, total, SIZELEFT(mp));
1447 mdb_cursor_chk(MDB_cursor *mc)
1453 if (!mc->mc_snum && !(mc->mc_flags & C_INITIALIZED)) return;
1454 for (i=0; i<mc->mc_top; i++) {
1456 node = NODEPTR(mp, mc->mc_ki[i]);
1457 if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno)
1460 if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i]))
1466 /** Count all the pages in each DB and in the freelist
1467 * and make sure it matches the actual number of pages
1469 * All named DBs must be open for a correct count.
1471 static void mdb_audit(MDB_txn *txn)
1475 MDB_ID freecount, count;
1480 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
1481 while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
1482 freecount += *(MDB_ID *)data.mv_data;
1483 mdb_tassert(txn, rc == MDB_NOTFOUND);
1486 for (i = 0; i<txn->mt_numdbs; i++) {
1488 if (!(txn->mt_dbflags[i] & DB_VALID))
1490 mdb_cursor_init(&mc, txn, i, &mx);
1491 if (txn->mt_dbs[i].md_root == P_INVALID)
1493 count += txn->mt_dbs[i].md_branch_pages +
1494 txn->mt_dbs[i].md_leaf_pages +
1495 txn->mt_dbs[i].md_overflow_pages;
1496 if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) {
1497 rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST);
1498 for (; rc == MDB_SUCCESS; rc = mdb_cursor_sibling(&mc, 1)) {
1501 mp = mc.mc_pg[mc.mc_top];
1502 for (j=0; j<NUMKEYS(mp); j++) {
1503 MDB_node *leaf = NODEPTR(mp, j);
1504 if (leaf->mn_flags & F_SUBDATA) {
1506 memcpy(&db, NODEDATA(leaf), sizeof(db));
1507 count += db.md_branch_pages + db.md_leaf_pages +
1508 db.md_overflow_pages;
1512 mdb_tassert(txn, rc == MDB_NOTFOUND);
1515 if (freecount + count + 2 /* metapages */ != txn->mt_next_pgno) {
1516 fprintf(stderr, "audit: %lu freecount: %lu count: %lu total: %lu next_pgno: %lu\n",
1517 txn->mt_txnid, freecount, count+2, freecount+count+2, txn->mt_next_pgno);
1523 mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1525 return txn->mt_dbxs[dbi].md_cmp(a, b);
1529 mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1531 return txn->mt_dbxs[dbi].md_dcmp(a, b);
1534 /** Allocate memory for a page.
1535 * Re-use old malloc'd pages first for singletons, otherwise just malloc.
1538 mdb_page_malloc(MDB_txn *txn, unsigned num)
1540 MDB_env *env = txn->mt_env;
1541 MDB_page *ret = env->me_dpages;
1542 size_t psize = env->me_psize, sz = psize, off;
1543 /* For ! #MDB_NOMEMINIT, psize counts how much to init.
1544 * For a single page alloc, we init everything after the page header.
1545 * For multi-page, we init the final page; if the caller needed that
1546 * many pages they will be filling in at least up to the last page.
1550 VGMEMP_ALLOC(env, ret, sz);
1551 VGMEMP_DEFINED(ret, sizeof(ret->mp_next));
1552 env->me_dpages = ret->mp_next;
1555 psize -= off = PAGEHDRSZ;
1560 if ((ret = malloc(sz)) != NULL) {
1561 VGMEMP_ALLOC(env, ret, sz);
1562 if (!(env->me_flags & MDB_NOMEMINIT)) {
1563 memset((char *)ret + off, 0, psize);
1567 txn->mt_flags |= MDB_TXN_ERROR;
1571 /** Free a single page.
1572 * Saves single pages to a list, for future reuse.
1573 * (This is not used for multi-page overflow pages.)
1576 mdb_page_free(MDB_env *env, MDB_page *mp)
1578 mp->mp_next = env->me_dpages;
1579 VGMEMP_FREE(env, mp);
1580 env->me_dpages = mp;
1583 /** Free a dirty page */
1585 mdb_dpage_free(MDB_env *env, MDB_page *dp)
1587 if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
1588 mdb_page_free(env, dp);
1590 /* large pages just get freed directly */
1591 VGMEMP_FREE(env, dp);
1596 /** Return all dirty pages to dpage list */
1598 mdb_dlist_free(MDB_txn *txn)
1600 MDB_env *env = txn->mt_env;
1601 MDB_ID2L dl = txn->mt_u.dirty_list;
1602 unsigned i, n = dl[0].mid;
1604 for (i = 1; i <= n; i++) {
1605 mdb_dpage_free(env, dl[i].mptr);
1610 /** Loosen or free a single page.
1611 * Saves single pages to a list for future reuse
1612 * in this same txn. It has been pulled from the freeDB
1613 * and already resides on the dirty list, but has been
1614 * deleted. Use these pages first before pulling again
1617 * If the page wasn't dirtied in this txn, just add it
1618 * to this txn's free list.
1621 mdb_page_loose(MDB_cursor *mc, MDB_page *mp)
1624 pgno_t pgno = mp->mp_pgno;
1626 if ((mp->mp_flags & P_DIRTY) && mc->mc_dbi != FREE_DBI) {
1627 if (mc->mc_txn->mt_parent) {
1628 MDB_ID2 *dl = mc->mc_txn->mt_u.dirty_list;
1629 /* If txn has a parent, make sure the page is in our
1633 unsigned x = mdb_mid2l_search(dl, pgno);
1634 if (x <= dl[0].mid && dl[x].mid == pgno) {
1635 if (mp != dl[x].mptr) { /* bad cursor? */
1636 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
1637 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
1638 return MDB_CORRUPTED;
1645 /* no parent txn, so it's just ours */
1650 DPRINTF(("loosen db %d page %"Z"u", DDBI(mc),
1652 NEXT_LOOSE_PAGE(mp) = mc->mc_txn->mt_loose_pgs;
1653 mc->mc_txn->mt_loose_pgs = mp;
1654 mp->mp_flags |= P_LOOSE;
1656 int rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, pgno);
1664 /** Set or clear P_KEEP in dirty, non-overflow, non-sub pages watched by txn.
1665 * @param[in] mc A cursor handle for the current operation.
1666 * @param[in] pflags Flags of the pages to update:
1667 * P_DIRTY to set P_KEEP, P_DIRTY|P_KEEP to clear it.
1668 * @param[in] all No shortcuts. Needed except after a full #mdb_page_flush().
1669 * @return 0 on success, non-zero on failure.
1672 mdb_pages_xkeep(MDB_cursor *mc, unsigned pflags, int all)
1674 enum { Mask = P_SUBP|P_DIRTY|P_LOOSE|P_KEEP };
1675 MDB_txn *txn = mc->mc_txn;
1681 int rc = MDB_SUCCESS, level;
1683 /* Mark pages seen by cursors */
1684 if (mc->mc_flags & C_UNTRACK)
1685 mc = NULL; /* will find mc in mt_cursors */
1686 for (i = txn->mt_numdbs;; mc = txn->mt_cursors[--i]) {
1687 for (; mc; mc=mc->mc_next) {
1688 if (!(mc->mc_flags & C_INITIALIZED))
1690 for (m3 = mc;; m3 = &mx->mx_cursor) {
1692 for (j=0; j<m3->mc_snum; j++) {
1694 if ((mp->mp_flags & Mask) == pflags)
1695 mp->mp_flags ^= P_KEEP;
1697 mx = m3->mc_xcursor;
1698 /* Proceed to mx if it is at a sub-database */
1699 if (! (mx && (mx->mx_cursor.mc_flags & C_INITIALIZED)))
1701 if (! (mp && (mp->mp_flags & P_LEAF)))
1703 leaf = NODEPTR(mp, m3->mc_ki[j-1]);
1704 if (!(leaf->mn_flags & F_SUBDATA))
1713 /* Mark dirty root pages */
1714 for (i=0; i<txn->mt_numdbs; i++) {
1715 if (txn->mt_dbflags[i] & DB_DIRTY) {
1716 pgno_t pgno = txn->mt_dbs[i].md_root;
1717 if (pgno == P_INVALID)
1719 if ((rc = mdb_page_get(txn, pgno, &dp, &level)) != MDB_SUCCESS)
1721 if ((dp->mp_flags & Mask) == pflags && level <= 1)
1722 dp->mp_flags ^= P_KEEP;
1730 static int mdb_page_flush(MDB_txn *txn, int keep);
1732 /** Spill pages from the dirty list back to disk.
1733 * This is intended to prevent running into #MDB_TXN_FULL situations,
1734 * but note that they may still occur in a few cases:
1735 * 1) our estimate of the txn size could be too small. Currently this
1736 * seems unlikely, except with a large number of #MDB_MULTIPLE items.
1737 * 2) child txns may run out of space if their parents dirtied a
1738 * lot of pages and never spilled them. TODO: we probably should do
1739 * a preemptive spill during #mdb_txn_begin() of a child txn, if
1740 * the parent's dirty_room is below a given threshold.
1742 * Otherwise, if not using nested txns, it is expected that apps will
1743 * not run into #MDB_TXN_FULL any more. The pages are flushed to disk
1744 * the same way as for a txn commit, e.g. their P_DIRTY flag is cleared.
1745 * If the txn never references them again, they can be left alone.
1746 * If the txn only reads them, they can be used without any fuss.
1747 * If the txn writes them again, they can be dirtied immediately without
1748 * going thru all of the work of #mdb_page_touch(). Such references are
1749 * handled by #mdb_page_unspill().
1751 * Also note, we never spill DB root pages, nor pages of active cursors,
1752 * because we'll need these back again soon anyway. And in nested txns,
1753 * we can't spill a page in a child txn if it was already spilled in a
1754 * parent txn. That would alter the parent txns' data even though
1755 * the child hasn't committed yet, and we'd have no way to undo it if
1756 * the child aborted.
1758 * @param[in] m0 cursor A cursor handle identifying the transaction and
1759 * database for which we are checking space.
1760 * @param[in] key For a put operation, the key being stored.
1761 * @param[in] data For a put operation, the data being stored.
1762 * @return 0 on success, non-zero on failure.
1765 mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
1767 MDB_txn *txn = m0->mc_txn;
1769 MDB_ID2L dl = txn->mt_u.dirty_list;
1770 unsigned int i, j, need;
1773 if (m0->mc_flags & C_SUB)
1776 /* Estimate how much space this op will take */
1777 i = m0->mc_db->md_depth;
1778 /* Named DBs also dirty the main DB */
1779 if (m0->mc_dbi > MAIN_DBI)
1780 i += txn->mt_dbs[MAIN_DBI].md_depth;
1781 /* For puts, roughly factor in the key+data size */
1783 i += (LEAFSIZE(key, data) + txn->mt_env->me_psize) / txn->mt_env->me_psize;
1784 i += i; /* double it for good measure */
1787 if (txn->mt_dirty_room > i)
1790 if (!txn->mt_spill_pgs) {
1791 txn->mt_spill_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX);
1792 if (!txn->mt_spill_pgs)
1795 /* purge deleted slots */
1796 MDB_IDL sl = txn->mt_spill_pgs;
1797 unsigned int num = sl[0];
1799 for (i=1; i<=num; i++) {
1806 /* Preserve pages which may soon be dirtied again */
1807 if ((rc = mdb_pages_xkeep(m0, P_DIRTY, 1)) != MDB_SUCCESS)
1810 /* Less aggressive spill - we originally spilled the entire dirty list,
1811 * with a few exceptions for cursor pages and DB root pages. But this
1812 * turns out to be a lot of wasted effort because in a large txn many
1813 * of those pages will need to be used again. So now we spill only 1/8th
1814 * of the dirty pages. Testing revealed this to be a good tradeoff,
1815 * better than 1/2, 1/4, or 1/10.
1817 if (need < MDB_IDL_UM_MAX / 8)
1818 need = MDB_IDL_UM_MAX / 8;
1820 /* Save the page IDs of all the pages we're flushing */
1821 /* flush from the tail forward, this saves a lot of shifting later on. */
1822 for (i=dl[0].mid; i && need; i--) {
1823 MDB_ID pn = dl[i].mid << 1;
1825 if (dp->mp_flags & (P_LOOSE|P_KEEP))
1827 /* Can't spill twice, make sure it's not already in a parent's
1830 if (txn->mt_parent) {
1832 for (tx2 = txn->mt_parent; tx2; tx2 = tx2->mt_parent) {
1833 if (tx2->mt_spill_pgs) {
1834 j = mdb_midl_search(tx2->mt_spill_pgs, pn);
1835 if (j <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[j] == pn) {
1836 dp->mp_flags |= P_KEEP;
1844 if ((rc = mdb_midl_append(&txn->mt_spill_pgs, pn)))
1848 mdb_midl_sort(txn->mt_spill_pgs);
1850 /* Flush the spilled part of dirty list */
1851 if ((rc = mdb_page_flush(txn, i)) != MDB_SUCCESS)
1854 /* Reset any dirty pages we kept that page_flush didn't see */
1855 rc = mdb_pages_xkeep(m0, P_DIRTY|P_KEEP, i);
1858 txn->mt_flags |= rc ? MDB_TXN_ERROR : MDB_TXN_SPILLS;
1862 /** Find oldest txnid still referenced. Expects txn->mt_txnid > 0. */
1864 mdb_find_oldest(MDB_txn *txn)
1867 txnid_t mr, oldest = txn->mt_txnid - 1;
1868 if (txn->mt_env->me_txns) {
1869 MDB_reader *r = txn->mt_env->me_txns->mti_readers;
1870 for (i = txn->mt_env->me_txns->mti_numreaders; --i >= 0; ) {
1881 /** Add a page to the txn's dirty list */
1883 mdb_page_dirty(MDB_txn *txn, MDB_page *mp)
1886 int rc, (*insert)(MDB_ID2L, MDB_ID2 *);
1888 if (txn->mt_env->me_flags & MDB_WRITEMAP) {
1889 insert = mdb_mid2l_append;
1891 insert = mdb_mid2l_insert;
1893 mid.mid = mp->mp_pgno;
1895 rc = insert(txn->mt_u.dirty_list, &mid);
1896 mdb_tassert(txn, rc == 0);
1897 txn->mt_dirty_room--;
1900 /** Allocate page numbers and memory for writing. Maintain me_pglast,
1901 * me_pghead and mt_next_pgno.
1903 * If there are free pages available from older transactions, they
1904 * are re-used first. Otherwise allocate a new page at mt_next_pgno.
1905 * Do not modify the freedB, just merge freeDB records into me_pghead[]
1906 * and move me_pglast to say which records were consumed. Only this
1907 * function can create me_pghead and move me_pglast/mt_next_pgno.
1908 * @param[in] mc cursor A cursor handle identifying the transaction and
1909 * database for which we are allocating.
1910 * @param[in] num the number of pages to allocate.
1911 * @param[out] mp Address of the allocated page(s). Requests for multiple pages
1912 * will always be satisfied by a single contiguous chunk of memory.
1913 * @return 0 on success, non-zero on failure.
1916 mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
1918 #ifdef MDB_PARANOID /* Seems like we can ignore this now */
1919 /* Get at most <Max_retries> more freeDB records once me_pghead
1920 * has enough pages. If not enough, use new pages from the map.
1921 * If <Paranoid> and mc is updating the freeDB, only get new
1922 * records if me_pghead is empty. Then the freelist cannot play
1923 * catch-up with itself by growing while trying to save it.
1925 enum { Paranoid = 1, Max_retries = 500 };
1927 enum { Paranoid = 0, Max_retries = INT_MAX /*infinite*/ };
1929 int rc, retry = num * 20;
1930 MDB_txn *txn = mc->mc_txn;
1931 MDB_env *env = txn->mt_env;
1932 pgno_t pgno, *mop = env->me_pghead;
1933 unsigned i, j, k, mop_len = mop ? mop[0] : 0, n2 = num-1;
1935 txnid_t oldest = 0, last;
1939 /* If there are any loose pages, just use them */
1940 if (num == 1 && txn->mt_loose_pgs) {
1941 np = txn->mt_loose_pgs;
1942 txn->mt_loose_pgs = NEXT_LOOSE_PAGE(np);
1943 DPRINTF(("db %d use loose page %"Z"u", DDBI(mc),
1951 /* If our dirty list is already full, we can't do anything */
1952 if (txn->mt_dirty_room == 0) {
1957 for (op = MDB_FIRST;; op = MDB_NEXT) {
1960 pgno_t *idl, old_id, new_id;
1962 /* Seek a big enough contiguous page range. Prefer
1963 * pages at the tail, just truncating the list.
1969 if (mop[i-n2] == pgno+n2)
1976 if (op == MDB_FIRST) { /* 1st iteration */
1977 /* Prepare to fetch more and coalesce */
1978 oldest = mdb_find_oldest(txn);
1979 last = env->me_pglast;
1980 mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
1983 key.mv_data = &last; /* will look up last+1 */
1984 key.mv_size = sizeof(last);
1986 if (Paranoid && mc->mc_dbi == FREE_DBI)
1989 if (Paranoid && retry < 0 && mop_len)
1993 /* Do not fetch more if the record will be too recent */
1996 rc = mdb_cursor_get(&m2, &key, NULL, op);
1998 if (rc == MDB_NOTFOUND)
2002 last = *(txnid_t*)key.mv_data;
2005 np = m2.mc_pg[m2.mc_top];
2006 leaf = NODEPTR(np, m2.mc_ki[m2.mc_top]);
2007 if ((rc = mdb_node_read(txn, leaf, &data)) != MDB_SUCCESS)
2010 idl = (MDB_ID *) data.mv_data;
2013 if (!(env->me_pghead = mop = mdb_midl_alloc(i))) {
2018 if ((rc = mdb_midl_need(&env->me_pghead, i)) != 0)
2020 mop = env->me_pghead;
2022 env->me_pglast = last;
2024 DPRINTF(("IDL read txn %"Z"u root %"Z"u num %u",
2025 last, txn->mt_dbs[FREE_DBI].md_root, i));
2027 DPRINTF(("IDL %"Z"u", idl[k]));
2029 /* Merge in descending sorted order */
2032 mop[0] = (pgno_t)-1;
2036 for (; old_id < new_id; old_id = mop[--j])
2043 /* Use new pages from the map when nothing suitable in the freeDB */
2045 pgno = txn->mt_next_pgno;
2046 if (pgno + num >= env->me_maxpg) {
2047 DPUTS("DB size maxed out");
2053 if (env->me_flags & MDB_WRITEMAP) {
2054 np = (MDB_page *)(env->me_map + env->me_psize * pgno);
2056 if (!(np = mdb_page_malloc(txn, num))) {
2062 mop[0] = mop_len -= num;
2063 /* Move any stragglers down */
2064 for (j = i-num; j < mop_len; )
2065 mop[++j] = mop[++i];
2067 txn->mt_next_pgno = pgno + num;
2070 mdb_page_dirty(txn, np);
2076 txn->mt_flags |= MDB_TXN_ERROR;
2080 /** Copy the used portions of a non-overflow page.
2081 * @param[in] dst page to copy into
2082 * @param[in] src page to copy from
2083 * @param[in] psize size of a page
2086 mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize)
2088 enum { Align = sizeof(pgno_t) };
2089 indx_t upper = src->mp_upper, lower = src->mp_lower, unused = upper-lower;
2091 /* If page isn't full, just copy the used portion. Adjust
2092 * alignment so memcpy may copy words instead of bytes.
2094 if ((unused &= -Align) && !IS_LEAF2(src)) {
2095 upper = (upper + PAGEBASE) & -Align;
2096 memcpy(dst, src, (lower + PAGEBASE + (Align-1)) & -Align);
2097 memcpy((pgno_t *)((char *)dst+upper), (pgno_t *)((char *)src+upper),
2100 memcpy(dst, src, psize - unused);
2104 /** Pull a page off the txn's spill list, if present.
2105 * If a page being referenced was spilled to disk in this txn, bring
2106 * it back and make it dirty/writable again.
2107 * @param[in] txn the transaction handle.
2108 * @param[in] mp the page being referenced. It must not be dirty.
2109 * @param[out] ret the writable page, if any. ret is unchanged if
2110 * mp wasn't spilled.
2113 mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret)
2115 MDB_env *env = txn->mt_env;
2118 pgno_t pgno = mp->mp_pgno, pn = pgno << 1;
2120 for (tx2 = txn; tx2; tx2=tx2->mt_parent) {
2121 if (!tx2->mt_spill_pgs)
2123 x = mdb_midl_search(tx2->mt_spill_pgs, pn);
2124 if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
2127 if (txn->mt_dirty_room == 0)
2128 return MDB_TXN_FULL;
2129 if (IS_OVERFLOW(mp))
2133 if (env->me_flags & MDB_WRITEMAP) {
2136 np = mdb_page_malloc(txn, num);
2140 memcpy(np, mp, num * env->me_psize);
2142 mdb_page_copy(np, mp, env->me_psize);
2145 /* If in current txn, this page is no longer spilled.
2146 * If it happens to be the last page, truncate the spill list.
2147 * Otherwise mark it as deleted by setting the LSB.
2149 if (x == txn->mt_spill_pgs[0])
2150 txn->mt_spill_pgs[0]--;
2152 txn->mt_spill_pgs[x] |= 1;
2153 } /* otherwise, if belonging to a parent txn, the
2154 * page remains spilled until child commits
2157 mdb_page_dirty(txn, np);
2158 np->mp_flags |= P_DIRTY;
2166 /** Touch a page: make it dirty and re-insert into tree with updated pgno.
2167 * @param[in] mc cursor pointing to the page to be touched
2168 * @return 0 on success, non-zero on failure.
2171 mdb_page_touch(MDB_cursor *mc)
2173 MDB_page *mp = mc->mc_pg[mc->mc_top], *np;
2174 MDB_txn *txn = mc->mc_txn;
2175 MDB_cursor *m2, *m3;
2179 if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
2180 if (txn->mt_flags & MDB_TXN_SPILLS) {
2182 rc = mdb_page_unspill(txn, mp, &np);
2188 if ((rc = mdb_midl_need(&txn->mt_free_pgs, 1)) ||
2189 (rc = mdb_page_alloc(mc, 1, &np)))
2192 DPRINTF(("touched db %d page %"Z"u -> %"Z"u", DDBI(mc),
2193 mp->mp_pgno, pgno));
2194 mdb_cassert(mc, mp->mp_pgno != pgno);
2195 mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
2196 /* Update the parent page, if any, to point to the new page */
2198 MDB_page *parent = mc->mc_pg[mc->mc_top-1];
2199 MDB_node *node = NODEPTR(parent, mc->mc_ki[mc->mc_top-1]);
2200 SETPGNO(node, pgno);
2202 mc->mc_db->md_root = pgno;
2204 } else if (txn->mt_parent && !IS_SUBP(mp)) {
2205 MDB_ID2 mid, *dl = txn->mt_u.dirty_list;
2207 /* If txn has a parent, make sure the page is in our
2211 unsigned x = mdb_mid2l_search(dl, pgno);
2212 if (x <= dl[0].mid && dl[x].mid == pgno) {
2213 if (mp != dl[x].mptr) { /* bad cursor? */
2214 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
2215 txn->mt_flags |= MDB_TXN_ERROR;
2216 return MDB_CORRUPTED;
2221 mdb_cassert(mc, dl[0].mid < MDB_IDL_UM_MAX);
2223 np = mdb_page_malloc(txn, 1);
2228 rc = mdb_mid2l_insert(dl, &mid);
2229 mdb_cassert(mc, rc == 0);
2234 mdb_page_copy(np, mp, txn->mt_env->me_psize);
2236 np->mp_flags |= P_DIRTY;
2239 /* Adjust cursors pointing to mp */
2240 mc->mc_pg[mc->mc_top] = np;
2241 m2 = txn->mt_cursors[mc->mc_dbi];
2242 if (mc->mc_flags & C_SUB) {
2243 for (; m2; m2=m2->mc_next) {
2244 m3 = &m2->mc_xcursor->mx_cursor;
2245 if (m3->mc_snum < mc->mc_snum) continue;
2246 if (m3->mc_pg[mc->mc_top] == mp)
2247 m3->mc_pg[mc->mc_top] = np;
2250 for (; m2; m2=m2->mc_next) {
2251 if (m2->mc_snum < mc->mc_snum) continue;
2252 if (m2->mc_pg[mc->mc_top] == mp) {
2253 m2->mc_pg[mc->mc_top] = np;
2254 if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
2256 m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top])
2258 MDB_node *leaf = NODEPTR(np, mc->mc_ki[mc->mc_top]);
2259 if (!(leaf->mn_flags & F_SUBDATA))
2260 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
2268 txn->mt_flags |= MDB_TXN_ERROR;
2273 mdb_env_sync(MDB_env *env, int force)
2276 if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) {
2277 if (env->me_flags & MDB_WRITEMAP) {
2278 int flags = ((env->me_flags & MDB_MAPASYNC) && !force)
2279 ? MS_ASYNC : MS_SYNC;
2280 if (MDB_MSYNC(env->me_map, env->me_mapsize, flags))
2283 else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd))
2287 if (MDB_FDATASYNC(env->me_fd))
2294 /** Back up parent txn's cursors, then grab the originals for tracking */
2296 mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst)
2298 MDB_cursor *mc, *bk;
2303 for (i = src->mt_numdbs; --i >= 0; ) {
2304 if ((mc = src->mt_cursors[i]) != NULL) {
2305 size = sizeof(MDB_cursor);
2307 size += sizeof(MDB_xcursor);
2308 for (; mc; mc = bk->mc_next) {
2314 mc->mc_db = &dst->mt_dbs[i];
2315 /* Kill pointers into src - and dst to reduce abuse: The
2316 * user may not use mc until dst ends. Otherwise we'd...
2318 mc->mc_txn = NULL; /* ...set this to dst */
2319 mc->mc_dbflag = NULL; /* ...and &dst->mt_dbflags[i] */
2320 if ((mx = mc->mc_xcursor) != NULL) {
2321 *(MDB_xcursor *)(bk+1) = *mx;
2322 mx->mx_cursor.mc_txn = NULL; /* ...and dst. */
2324 mc->mc_next = dst->mt_cursors[i];
2325 dst->mt_cursors[i] = mc;
2332 /** Close this write txn's cursors, give parent txn's cursors back to parent.
2333 * @param[in] txn the transaction handle.
2334 * @param[in] merge true to keep changes to parent cursors, false to revert.
2335 * @return 0 on success, non-zero on failure.
2338 mdb_cursors_close(MDB_txn *txn, unsigned merge)
2340 MDB_cursor **cursors = txn->mt_cursors, *mc, *next, *bk;
2344 for (i = txn->mt_numdbs; --i >= 0; ) {
2345 for (mc = cursors[i]; mc; mc = next) {
2347 if ((bk = mc->mc_backup) != NULL) {
2349 /* Commit changes to parent txn */
2350 mc->mc_next = bk->mc_next;
2351 mc->mc_backup = bk->mc_backup;
2352 mc->mc_txn = bk->mc_txn;
2353 mc->mc_db = bk->mc_db;
2354 mc->mc_dbflag = bk->mc_dbflag;
2355 if ((mx = mc->mc_xcursor) != NULL)
2356 mx->mx_cursor.mc_txn = bk->mc_txn;
2358 /* Abort nested txn */
2360 if ((mx = mc->mc_xcursor) != NULL)
2361 *mx = *(MDB_xcursor *)(bk+1);
2365 /* Only malloced cursors are permanently tracked. */
2373 #define mdb_txn_reset0(txn, act) mdb_txn_reset0(txn)
2376 mdb_txn_reset0(MDB_txn *txn, const char *act);
2378 #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
2384 Pidset = F_SETLK, Pidcheck = F_GETLK
2388 /** Set or check a pid lock. Set returns 0 on success.
2389 * Check returns 0 if the process is certainly dead, nonzero if it may
2390 * be alive (the lock exists or an error happened so we do not know).
2392 * On Windows Pidset is a no-op, we merely check for the existence
2393 * of the process with the given pid. On POSIX we use a single byte
2394 * lock on the lockfile, set at an offset equal to the pid.
2397 mdb_reader_pid(MDB_env *env, enum Pidlock_op op, MDB_PID_T pid)
2399 #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
2402 if (op == Pidcheck) {
2403 h = OpenProcess(env->me_pidquery, FALSE, pid);
2404 /* No documented "no such process" code, but other program use this: */
2406 return ErrCode() != ERROR_INVALID_PARAMETER;
2407 /* A process exists until all handles to it close. Has it exited? */
2408 ret = WaitForSingleObject(h, 0) != 0;
2415 struct flock lock_info;
2416 memset(&lock_info, 0, sizeof(lock_info));
2417 lock_info.l_type = F_WRLCK;
2418 lock_info.l_whence = SEEK_SET;
2419 lock_info.l_start = pid;
2420 lock_info.l_len = 1;
2421 if ((rc = fcntl(env->me_lfd, op, &lock_info)) == 0) {
2422 if (op == F_GETLK && lock_info.l_type != F_UNLCK)
2424 } else if ((rc = ErrCode()) == EINTR) {
2432 /** Common code for #mdb_txn_begin() and #mdb_txn_renew().
2433 * @param[in] txn the transaction handle to initialize
2434 * @return 0 on success, non-zero on failure.
2437 mdb_txn_renew0(MDB_txn *txn)
2439 MDB_env *env = txn->mt_env;
2440 MDB_txninfo *ti = env->me_txns;
2444 int rc, new_notls = 0;
2447 txn->mt_numdbs = env->me_numdbs;
2448 txn->mt_dbxs = env->me_dbxs; /* mostly static anyway */
2450 if (txn->mt_flags & MDB_TXN_RDONLY) {
2452 meta = env->me_metas[ mdb_env_pick_meta(env) ];
2453 txn->mt_txnid = meta->mm_txnid;
2454 txn->mt_u.reader = NULL;
2456 MDB_reader *r = (env->me_flags & MDB_NOTLS) ? txn->mt_u.reader :
2457 pthread_getspecific(env->me_txkey);
2459 if (r->mr_pid != env->me_pid || r->mr_txnid != (txnid_t)-1)
2460 return MDB_BAD_RSLOT;
2462 MDB_PID_T pid = env->me_pid;
2463 MDB_THR_T tid = pthread_self();
2465 if (!env->me_live_reader) {
2466 rc = mdb_reader_pid(env, Pidset, pid);
2469 env->me_live_reader = 1;
2473 nr = ti->mti_numreaders;
2474 for (i=0; i<nr; i++)
2475 if (ti->mti_readers[i].mr_pid == 0)
2477 if (i == env->me_maxreaders) {
2478 UNLOCK_MUTEX_R(env);
2479 return MDB_READERS_FULL;
2481 ti->mti_readers[i].mr_pid = pid;
2482 ti->mti_readers[i].mr_tid = tid;
2484 ti->mti_numreaders = ++nr;
2485 /* Save numreaders for un-mutexed mdb_env_close() */
2486 env->me_numreaders = nr;
2487 UNLOCK_MUTEX_R(env);
2489 r = &ti->mti_readers[i];
2490 new_notls = (env->me_flags & MDB_NOTLS);
2491 if (!new_notls && (rc=pthread_setspecific(env->me_txkey, r))) {
2496 txn->mt_txnid = r->mr_txnid = ti->mti_txnid;
2497 txn->mt_u.reader = r;
2498 meta = env->me_metas[txn->mt_txnid & 1];
2504 txn->mt_txnid = ti->mti_txnid;
2505 meta = env->me_metas[txn->mt_txnid & 1];
2507 meta = env->me_metas[ mdb_env_pick_meta(env) ];
2508 txn->mt_txnid = meta->mm_txnid;
2512 if (txn->mt_txnid == mdb_debug_start)
2515 txn->mt_dirty_room = MDB_IDL_UM_MAX;
2516 txn->mt_u.dirty_list = env->me_dirty_list;
2517 txn->mt_u.dirty_list[0].mid = 0;
2518 txn->mt_free_pgs = env->me_free_pgs;
2519 txn->mt_free_pgs[0] = 0;
2520 txn->mt_spill_pgs = NULL;
2522 memcpy(txn->mt_dbiseqs, env->me_dbiseqs, env->me_maxdbs * sizeof(unsigned int));
2525 /* Copy the DB info and flags */
2526 memcpy(txn->mt_dbs, meta->mm_dbs, 2 * sizeof(MDB_db));
2528 /* Moved to here to avoid a data race in read TXNs */
2529 txn->mt_next_pgno = meta->mm_last_pg+1;
2531 for (i=2; i<txn->mt_numdbs; i++) {
2532 x = env->me_dbflags[i];
2533 txn->mt_dbs[i].md_flags = x & PERSISTENT_FLAGS;
2534 txn->mt_dbflags[i] = (x & MDB_VALID) ? DB_VALID|DB_STALE : 0;
2536 txn->mt_dbflags[0] = txn->mt_dbflags[1] = DB_VALID;
2538 if (env->me_maxpg < txn->mt_next_pgno) {
2539 mdb_txn_reset0(txn, "renew0-mapfail");
2541 txn->mt_u.reader->mr_pid = 0;
2542 txn->mt_u.reader = NULL;
2544 return MDB_MAP_RESIZED;
2551 mdb_txn_renew(MDB_txn *txn)
2555 if (!txn || txn->mt_dbxs) /* A reset txn has mt_dbxs==NULL */
2558 if (txn->mt_env->me_flags & MDB_FATAL_ERROR) {
2559 DPUTS("environment had fatal error, must shutdown!");
2563 rc = mdb_txn_renew0(txn);
2564 if (rc == MDB_SUCCESS) {
2565 DPRINTF(("renew txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2566 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2567 (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root));
2573 mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
2577 int rc, size, tsize = sizeof(MDB_txn);
2579 if (env->me_flags & MDB_FATAL_ERROR) {
2580 DPUTS("environment had fatal error, must shutdown!");
2583 if ((env->me_flags & MDB_RDONLY) && !(flags & MDB_RDONLY))
2586 /* Nested transactions: Max 1 child, write txns only, no writemap */
2587 if (parent->mt_child ||
2588 (flags & MDB_RDONLY) ||
2589 (parent->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR)) ||
2590 (env->me_flags & MDB_WRITEMAP))
2592 return (parent->mt_flags & MDB_TXN_RDONLY) ? EINVAL : MDB_BAD_TXN;
2594 tsize = sizeof(MDB_ntxn);
2596 size = tsize + env->me_maxdbs * (sizeof(MDB_db)+1);
2597 if (!(flags & MDB_RDONLY)) {
2598 size += env->me_maxdbs * sizeof(MDB_cursor *);
2599 /* child txns use parent's dbiseqs */
2601 size += env->me_maxdbs * sizeof(unsigned int);
2604 if ((txn = calloc(1, size)) == NULL) {
2605 DPRINTF(("calloc: %s", strerror(errno)));
2608 txn->mt_dbs = (MDB_db *) ((char *)txn + tsize);
2609 if (flags & MDB_RDONLY) {
2610 txn->mt_flags |= MDB_TXN_RDONLY;
2611 txn->mt_dbflags = (unsigned char *)(txn->mt_dbs + env->me_maxdbs);
2612 txn->mt_dbiseqs = env->me_dbiseqs;
2614 txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
2616 txn->mt_dbiseqs = parent->mt_dbiseqs;
2617 txn->mt_dbflags = (unsigned char *)(txn->mt_cursors + env->me_maxdbs);
2619 txn->mt_dbiseqs = (unsigned int *)(txn->mt_cursors + env->me_maxdbs);
2620 txn->mt_dbflags = (unsigned char *)(txn->mt_dbiseqs + env->me_maxdbs);
2627 txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE);
2628 if (!txn->mt_u.dirty_list ||
2629 !(txn->mt_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)))
2631 free(txn->mt_u.dirty_list);
2635 txn->mt_txnid = parent->mt_txnid;
2636 txn->mt_dirty_room = parent->mt_dirty_room;
2637 txn->mt_u.dirty_list[0].mid = 0;
2638 txn->mt_spill_pgs = NULL;
2639 txn->mt_next_pgno = parent->mt_next_pgno;
2640 parent->mt_child = txn;
2641 txn->mt_parent = parent;
2642 txn->mt_numdbs = parent->mt_numdbs;
2643 txn->mt_flags = parent->mt_flags;
2644 txn->mt_dbxs = parent->mt_dbxs;
2645 memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
2646 /* Copy parent's mt_dbflags, but clear DB_NEW */
2647 for (i=0; i<txn->mt_numdbs; i++)
2648 txn->mt_dbflags[i] = parent->mt_dbflags[i] & ~DB_NEW;
2650 ntxn = (MDB_ntxn *)txn;
2651 ntxn->mnt_pgstate = env->me_pgstate; /* save parent me_pghead & co */
2652 if (env->me_pghead) {
2653 size = MDB_IDL_SIZEOF(env->me_pghead);
2654 env->me_pghead = mdb_midl_alloc(env->me_pghead[0]);
2656 memcpy(env->me_pghead, ntxn->mnt_pgstate.mf_pghead, size);
2661 rc = mdb_cursor_shadow(parent, txn);
2663 mdb_txn_reset0(txn, "beginchild-fail");
2665 rc = mdb_txn_renew0(txn);
2671 DPRINTF(("begin txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2672 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2673 (void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root));
2680 mdb_txn_env(MDB_txn *txn)
2682 if(!txn) return NULL;
2686 /** Export or close DBI handles opened in this txn. */
2688 mdb_dbis_update(MDB_txn *txn, int keep)
2691 MDB_dbi n = txn->mt_numdbs;
2692 MDB_env *env = txn->mt_env;
2693 unsigned char *tdbflags = txn->mt_dbflags;
2695 for (i = n; --i >= 2;) {
2696 if (tdbflags[i] & DB_NEW) {
2698 env->me_dbflags[i] = txn->mt_dbs[i].md_flags | MDB_VALID;
2700 char *ptr = env->me_dbxs[i].md_name.mv_data;
2702 env->me_dbxs[i].md_name.mv_data = NULL;
2703 env->me_dbxs[i].md_name.mv_size = 0;
2704 env->me_dbflags[i] = 0;
2705 env->me_dbiseqs[i]++;
2711 if (keep && env->me_numdbs < n)
2715 /** Common code for #mdb_txn_reset() and #mdb_txn_abort().
2716 * May be called twice for readonly txns: First reset it, then abort.
2717 * @param[in] txn the transaction handle to reset
2718 * @param[in] act why the transaction is being reset
2721 mdb_txn_reset0(MDB_txn *txn, const char *act)
2723 MDB_env *env = txn->mt_env;
2725 /* Close any DBI handles opened in this txn */
2726 mdb_dbis_update(txn, 0);
2728 DPRINTF(("%s txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2729 act, txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2730 (void *) txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root));
2732 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
2733 if (txn->mt_u.reader) {
2734 txn->mt_u.reader->mr_txnid = (txnid_t)-1;
2735 if (!(env->me_flags & MDB_NOTLS))
2736 txn->mt_u.reader = NULL; /* txn does not own reader */
2738 txn->mt_numdbs = 0; /* close nothing if called again */
2739 txn->mt_dbxs = NULL; /* mark txn as reset */
2741 mdb_cursors_close(txn, 0);
2743 if (!(env->me_flags & MDB_WRITEMAP)) {
2744 mdb_dlist_free(txn);
2746 mdb_midl_free(env->me_pghead);
2748 if (txn->mt_parent) {
2749 txn->mt_parent->mt_child = NULL;
2750 env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate;
2751 mdb_midl_free(txn->mt_free_pgs);
2752 mdb_midl_free(txn->mt_spill_pgs);
2753 free(txn->mt_u.dirty_list);
2757 if (mdb_midl_shrink(&txn->mt_free_pgs))
2758 env->me_free_pgs = txn->mt_free_pgs;
2759 env->me_pghead = NULL;
2763 /* The writer mutex was locked in mdb_txn_begin. */
2765 UNLOCK_MUTEX_W(env);
2770 mdb_txn_reset(MDB_txn *txn)
2775 /* This call is only valid for read-only txns */
2776 if (!(txn->mt_flags & MDB_TXN_RDONLY))
2779 mdb_txn_reset0(txn, "reset");
2783 mdb_txn_abort(MDB_txn *txn)
2789 mdb_txn_abort(txn->mt_child);
2791 mdb_txn_reset0(txn, "abort");
2792 /* Free reader slot tied to this txn (if MDB_NOTLS && writable FS) */
2793 if ((txn->mt_flags & MDB_TXN_RDONLY) && txn->mt_u.reader)
2794 txn->mt_u.reader->mr_pid = 0;
2799 /** Save the freelist as of this transaction to the freeDB.
2800 * This changes the freelist. Keep trying until it stabilizes.
2803 mdb_freelist_save(MDB_txn *txn)
2805 /* env->me_pghead[] can grow and shrink during this call.
2806 * env->me_pglast and txn->mt_free_pgs[] can only grow.
2807 * Page numbers cannot disappear from txn->mt_free_pgs[].
2810 MDB_env *env = txn->mt_env;
2811 int rc, maxfree_1pg = env->me_maxfree_1pg, more = 1;
2812 txnid_t pglast = 0, head_id = 0;
2813 pgno_t freecnt = 0, *free_pgs, *mop;
2814 ssize_t head_room = 0, total_room = 0, mop_len, clean_limit;
2816 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
2818 if (env->me_pghead) {
2819 /* Make sure first page of freeDB is touched and on freelist */
2820 rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST|MDB_PS_MODIFY);
2821 if (rc && rc != MDB_NOTFOUND)
2825 /* Dispose of loose pages. Usually they will have all
2826 * been used up by the time we get here.
2828 if (txn->mt_loose_pgs) {
2829 MDB_page *mp = txn->mt_loose_pgs;
2830 /* Just return them to freeDB */
2831 if (env->me_pghead) {
2833 mop = env->me_pghead;
2834 for (; mp; mp = NEXT_LOOSE_PAGE(mp)) {
2835 pgno_t pg = mp->mp_pgno;
2837 for (i = mop[0]; i && mop[i] < pg; i--)
2843 /* Oh well, they were wasted. Put on freelist */
2844 for (; mp; mp = NEXT_LOOSE_PAGE(mp)) {
2845 mdb_midl_append(&txn->mt_free_pgs, mp->mp_pgno);
2848 txn->mt_loose_pgs = NULL;
2851 /* MDB_RESERVE cancels meminit in ovpage malloc (when no WRITEMAP) */
2852 clean_limit = (env->me_flags & (MDB_NOMEMINIT|MDB_WRITEMAP))
2853 ? SSIZE_MAX : maxfree_1pg;
2856 /* Come back here after each Put() in case freelist changed */
2861 /* If using records from freeDB which we have not yet
2862 * deleted, delete them and any we reserved for me_pghead.
2864 while (pglast < env->me_pglast) {
2865 rc = mdb_cursor_first(&mc, &key, NULL);
2868 pglast = head_id = *(txnid_t *)key.mv_data;
2869 total_room = head_room = 0;
2870 mdb_tassert(txn, pglast <= env->me_pglast);
2871 rc = mdb_cursor_del(&mc, 0);
2876 /* Save the IDL of pages freed by this txn, to a single record */
2877 if (freecnt < txn->mt_free_pgs[0]) {
2879 /* Make sure last page of freeDB is touched and on freelist */
2880 rc = mdb_page_search(&mc, NULL, MDB_PS_LAST|MDB_PS_MODIFY);
2881 if (rc && rc != MDB_NOTFOUND)
2884 free_pgs = txn->mt_free_pgs;
2885 /* Write to last page of freeDB */
2886 key.mv_size = sizeof(txn->mt_txnid);
2887 key.mv_data = &txn->mt_txnid;
2889 freecnt = free_pgs[0];
2890 data.mv_size = MDB_IDL_SIZEOF(free_pgs);
2891 rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
2894 /* Retry if mt_free_pgs[] grew during the Put() */
2895 free_pgs = txn->mt_free_pgs;
2896 } while (freecnt < free_pgs[0]);
2897 mdb_midl_sort(free_pgs);
2898 memcpy(data.mv_data, free_pgs, data.mv_size);
2901 unsigned int i = free_pgs[0];
2902 DPRINTF(("IDL write txn %"Z"u root %"Z"u num %u",
2903 txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, i));
2905 DPRINTF(("IDL %"Z"u", free_pgs[i]));
2911 mop = env->me_pghead;
2912 mop_len = mop ? mop[0] : 0;
2914 /* Reserve records for me_pghead[]. Split it if multi-page,
2915 * to avoid searching freeDB for a page range. Use keys in
2916 * range [1,me_pglast]: Smaller than txnid of oldest reader.
2918 if (total_room >= mop_len) {
2919 if (total_room == mop_len || --more < 0)
2921 } else if (head_room >= maxfree_1pg && head_id > 1) {
2922 /* Keep current record (overflow page), add a new one */
2926 /* (Re)write {key = head_id, IDL length = head_room} */
2927 total_room -= head_room;
2928 head_room = mop_len - total_room;
2929 if (head_room > maxfree_1pg && head_id > 1) {
2930 /* Overflow multi-page for part of me_pghead */
2931 head_room /= head_id; /* amortize page sizes */
2932 head_room += maxfree_1pg - head_room % (maxfree_1pg + 1);
2933 } else if (head_room < 0) {
2934 /* Rare case, not bothering to delete this record */
2937 key.mv_size = sizeof(head_id);
2938 key.mv_data = &head_id;
2939 data.mv_size = (head_room + 1) * sizeof(pgno_t);
2940 rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
2943 /* IDL is initially empty, zero out at least the length */
2944 pgs = (pgno_t *)data.mv_data;
2945 j = head_room > clean_limit ? head_room : 0;
2949 total_room += head_room;
2952 /* Fill in the reserved me_pghead records */
2958 rc = mdb_cursor_first(&mc, &key, &data);
2959 for (; !rc; rc = mdb_cursor_next(&mc, &key, &data, MDB_NEXT)) {
2960 txnid_t id = *(txnid_t *)key.mv_data;
2961 ssize_t len = (ssize_t)(data.mv_size / sizeof(MDB_ID)) - 1;
2964 mdb_tassert(txn, len >= 0 && id <= env->me_pglast);
2966 if (len > mop_len) {
2968 data.mv_size = (len + 1) * sizeof(MDB_ID);
2970 data.mv_data = mop -= len;
2973 rc = mdb_cursor_put(&mc, &key, &data, MDB_CURRENT);
2975 if (rc || !(mop_len -= len))
2982 /** Flush (some) dirty pages to the map, after clearing their dirty flag.
2983 * @param[in] txn the transaction that's being committed
2984 * @param[in] keep number of initial pages in dirty_list to keep dirty.
2985 * @return 0 on success, non-zero on failure.
2988 mdb_page_flush(MDB_txn *txn, int keep)
2990 MDB_env *env = txn->mt_env;
2991 MDB_ID2L dl = txn->mt_u.dirty_list;
2992 unsigned psize = env->me_psize, j;
2993 int i, pagecount = dl[0].mid, rc;
2994 size_t size = 0, pos = 0;
2996 MDB_page *dp = NULL;
3000 struct iovec iov[MDB_COMMIT_PAGES];
3001 ssize_t wpos = 0, wsize = 0, wres;
3002 size_t next_pos = 1; /* impossible pos, so pos != next_pos */
3008 if (env->me_flags & MDB_WRITEMAP) {
3009 /* Clear dirty flags */
3010 while (++i <= pagecount) {
3012 /* Don't flush this page yet */
3013 if (dp->mp_flags & (P_LOOSE|P_KEEP)) {
3014 dp->mp_flags &= ~P_KEEP;
3018 dp->mp_flags &= ~P_DIRTY;
3023 /* Write the pages */
3025 if (++i <= pagecount) {
3027 /* Don't flush this page yet */
3028 if (dp->mp_flags & (P_LOOSE|P_KEEP)) {
3029 dp->mp_flags &= ~P_KEEP;
3034 /* clear dirty flag */
3035 dp->mp_flags &= ~P_DIRTY;
3038 if (IS_OVERFLOW(dp)) size *= dp->mp_pages;
3043 /* Windows actually supports scatter/gather I/O, but only on
3044 * unbuffered file handles. Since we're relying on the OS page
3045 * cache for all our data, that's self-defeating. So we just
3046 * write pages one at a time. We use the ov structure to set
3047 * the write offset, to at least save the overhead of a Seek
3050 DPRINTF(("committing page %"Z"u", pgno));
3051 memset(&ov, 0, sizeof(ov));
3052 ov.Offset = pos & 0xffffffff;
3053 ov.OffsetHigh = pos >> 16 >> 16;
3054 if (!WriteFile(env->me_fd, dp, size, NULL, &ov)) {
3056 DPRINTF(("WriteFile: %d", rc));
3060 /* Write up to MDB_COMMIT_PAGES dirty pages at a time. */
3061 if (pos!=next_pos || n==MDB_COMMIT_PAGES || wsize+size>MAX_WRITE) {
3063 /* Write previous page(s) */
3064 #ifdef MDB_USE_PWRITEV
3065 wres = pwritev(env->me_fd, iov, n, wpos);
3068 wres = pwrite(env->me_fd, iov[0].iov_base, wsize, wpos);
3070 if (lseek(env->me_fd, wpos, SEEK_SET) == -1) {
3072 DPRINTF(("lseek: %s", strerror(rc)));
3075 wres = writev(env->me_fd, iov, n);
3078 if (wres != wsize) {
3081 DPRINTF(("Write error: %s", strerror(rc)));
3083 rc = EIO; /* TODO: Use which error code? */
3084 DPUTS("short write, filesystem full?");
3095 DPRINTF(("committing page %"Z"u", pgno));
3096 next_pos = pos + size;
3097 iov[n].iov_len = size;
3098 iov[n].iov_base = (char *)dp;
3104 for (i = keep; ++i <= pagecount; ) {
3106 /* This is a page we skipped above */
3109 dl[j].mid = dp->mp_pgno;
3112 mdb_dpage_free(env, dp);
3117 txn->mt_dirty_room += i - j;
3123 mdb_txn_commit(MDB_txn *txn)
3129 if (txn == NULL || txn->mt_env == NULL)
3132 if (txn->mt_child) {
3133 rc = mdb_txn_commit(txn->mt_child);
3134 txn->mt_child = NULL;
3141 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
3142 mdb_dbis_update(txn, 1);
3143 txn->mt_numdbs = 2; /* so txn_abort() doesn't close any new handles */
3148 if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
3149 DPUTS("error flag is set, can't commit");
3151 txn->mt_parent->mt_flags |= MDB_TXN_ERROR;
3156 if (txn->mt_parent) {
3157 MDB_txn *parent = txn->mt_parent;
3161 unsigned x, y, len, ps_len;
3163 /* Append our free list to parent's */
3164 rc = mdb_midl_append_list(&parent->mt_free_pgs, txn->mt_free_pgs);
3167 mdb_midl_free(txn->mt_free_pgs);
3168 /* Failures after this must either undo the changes
3169 * to the parent or set MDB_TXN_ERROR in the parent.
3172 parent->mt_next_pgno = txn->mt_next_pgno;
3173 parent->mt_flags = txn->mt_flags;
3175 /* Merge our cursors into parent's and close them */
3176 mdb_cursors_close(txn, 1);
3178 /* Update parent's DB table. */
3179 memcpy(parent->mt_dbs, txn->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
3180 parent->mt_numdbs = txn->mt_numdbs;
3181 parent->mt_dbflags[0] = txn->mt_dbflags[0];
3182 parent->mt_dbflags[1] = txn->mt_dbflags[1];
3183 for (i=2; i<txn->mt_numdbs; i++) {
3184 /* preserve parent's DB_NEW status */
3185 x = parent->mt_dbflags[i] & DB_NEW;
3186 parent->mt_dbflags[i] = txn->mt_dbflags[i] | x;
3189 dst = parent->mt_u.dirty_list;
3190 src = txn->mt_u.dirty_list;
3191 /* Remove anything in our dirty list from parent's spill list */
3192 if ((pspill = parent->mt_spill_pgs) && (ps_len = pspill[0])) {
3194 pspill[0] = (pgno_t)-1;
3195 /* Mark our dirty pages as deleted in parent spill list */
3196 for (i=0, len=src[0].mid; ++i <= len; ) {
3197 MDB_ID pn = src[i].mid << 1;
3198 while (pn > pspill[x])
3200 if (pn == pspill[x]) {
3205 /* Squash deleted pagenums if we deleted any */
3206 for (x=y; ++x <= ps_len; )
3207 if (!(pspill[x] & 1))
3208 pspill[++y] = pspill[x];
3212 /* Find len = length of merging our dirty list with parent's */
3214 dst[0].mid = 0; /* simplify loops */
3215 if (parent->mt_parent) {
3216 len = x + src[0].mid;
3217 y = mdb_mid2l_search(src, dst[x].mid + 1) - 1;
3218 for (i = x; y && i; y--) {
3219 pgno_t yp = src[y].mid;
3220 while (yp < dst[i].mid)
3222 if (yp == dst[i].mid) {
3227 } else { /* Simplify the above for single-ancestor case */
3228 len = MDB_IDL_UM_MAX - txn->mt_dirty_room;
3230 /* Merge our dirty list with parent's */
3232 for (i = len; y; dst[i--] = src[y--]) {
3233 pgno_t yp = src[y].mid;
3234 while (yp < dst[x].mid)
3235 dst[i--] = dst[x--];
3236 if (yp == dst[x].mid)
3237 free(dst[x--].mptr);
3239 mdb_tassert(txn, i == x);
3241 free(txn->mt_u.dirty_list);
3242 parent->mt_dirty_room = txn->mt_dirty_room;
3243 if (txn->mt_spill_pgs) {
3244 if (parent->mt_spill_pgs) {
3245 /* TODO: Prevent failure here, so parent does not fail */
3246 rc = mdb_midl_append_list(&parent->mt_spill_pgs, txn->mt_spill_pgs);
3248 parent->mt_flags |= MDB_TXN_ERROR;
3249 mdb_midl_free(txn->mt_spill_pgs);
3250 mdb_midl_sort(parent->mt_spill_pgs);
3252 parent->mt_spill_pgs = txn->mt_spill_pgs;
3256 /* Append our loose page list to parent's */
3257 for (lp = &parent->mt_loose_pgs; *lp; lp = &NEXT_LOOSE_PAGE(lp))
3259 *lp = txn->mt_loose_pgs;
3261 parent->mt_child = NULL;
3262 mdb_midl_free(((MDB_ntxn *)txn)->mnt_pgstate.mf_pghead);
3267 if (txn != env->me_txn) {
3268 DPUTS("attempt to commit unknown transaction");
3273 mdb_cursors_close(txn, 0);
3275 if (!txn->mt_u.dirty_list[0].mid &&
3276 !(txn->mt_flags & (MDB_TXN_DIRTY|MDB_TXN_SPILLS)))
3279 DPRINTF(("committing txn %"Z"u %p on mdbenv %p, root page %"Z"u",
3280 txn->mt_txnid, (void*)txn, (void*)env, txn->mt_dbs[MAIN_DBI].md_root));
3282 /* Update DB root pointers */
3283 if (txn->mt_numdbs > 2) {
3287 data.mv_size = sizeof(MDB_db);
3289 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
3290 for (i = 2; i < txn->mt_numdbs; i++) {
3291 if (txn->mt_dbflags[i] & DB_DIRTY) {
3292 if (TXN_DBI_CHANGED(txn, i)) {
3296 data.mv_data = &txn->mt_dbs[i];
3297 rc = mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data, 0);
3304 rc = mdb_freelist_save(txn);
3308 mdb_midl_free(env->me_pghead);
3309 env->me_pghead = NULL;
3310 if (mdb_midl_shrink(&txn->mt_free_pgs))
3311 env->me_free_pgs = txn->mt_free_pgs;
3317 if ((rc = mdb_page_flush(txn, 0)) ||
3318 (rc = mdb_env_sync(env, 0)) ||
3319 (rc = mdb_env_write_meta(txn)))
3325 mdb_dbis_update(txn, 1);
3328 UNLOCK_MUTEX_W(env);
3338 /** Read the environment parameters of a DB environment before
3339 * mapping it into memory.
3340 * @param[in] env the environment handle
3341 * @param[out] meta address of where to store the meta information
3342 * @return 0 on success, non-zero on failure.
3345 mdb_env_read_header(MDB_env *env, MDB_meta *meta)
3351 enum { Size = sizeof(pbuf) };
3353 /* We don't know the page size yet, so use a minimum value.
3354 * Read both meta pages so we can use the latest one.
3357 for (i=off=0; i<2; i++, off = meta->mm_psize) {
3361 memset(&ov, 0, sizeof(ov));
3363 rc = ReadFile(env->me_fd, &pbuf, Size, &len, &ov) ? (int)len : -1;
3364 if (rc == -1 && ErrCode() == ERROR_HANDLE_EOF)
3367 rc = pread(env->me_fd, &pbuf, Size, off);
3370 if (rc == 0 && off == 0)
3372 rc = rc < 0 ? (int) ErrCode() : MDB_INVALID;
3373 DPRINTF(("read: %s", mdb_strerror(rc)));
3377 p = (MDB_page *)&pbuf;
3379 if (!F_ISSET(p->mp_flags, P_META)) {
3380 DPRINTF(("page %"Z"u not a meta page", p->mp_pgno));
3385 if (m->mm_magic != MDB_MAGIC) {
3386 DPUTS("meta has invalid magic");
3390 if (m->mm_version != MDB_DATA_VERSION) {
3391 DPRINTF(("database is version %u, expected version %u",
3392 m->mm_version, MDB_DATA_VERSION));
3393 return MDB_VERSION_MISMATCH;
3396 if (off == 0 || m->mm_txnid > meta->mm_txnid)
3403 mdb_env_init_meta0(MDB_env *env, MDB_meta *meta)
3405 meta->mm_magic = MDB_MAGIC;
3406 meta->mm_version = MDB_DATA_VERSION;
3407 meta->mm_mapsize = env->me_mapsize;
3408 meta->mm_psize = env->me_psize;
3409 meta->mm_last_pg = 1;
3410 meta->mm_flags = env->me_flags & 0xffff;
3411 meta->mm_flags |= MDB_INTEGERKEY;
3412 meta->mm_dbs[0].md_root = P_INVALID;
3413 meta->mm_dbs[1].md_root = P_INVALID;
3416 /** Write the environment parameters of a freshly created DB environment.
3417 * @param[in] env the environment handle
3418 * @param[out] meta address of where to store the meta information
3419 * @return 0 on success, non-zero on failure.
3422 mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
3430 memset(&ov, 0, sizeof(ov));
3431 #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
3433 rc = WriteFile(fd, ptr, size, &len, &ov); } while(0)
3436 #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
3437 len = pwrite(fd, ptr, size, pos); \
3438 rc = (len >= 0); } while(0)
3441 DPUTS("writing new meta page");
3443 psize = env->me_psize;
3445 mdb_env_init_meta0(env, meta);
3447 p = calloc(2, psize);
3449 p->mp_flags = P_META;
3450 *(MDB_meta *)METADATA(p) = *meta;
3452 q = (MDB_page *)((char *)p + psize);
3454 q->mp_flags = P_META;
3455 *(MDB_meta *)METADATA(q) = *meta;
3457 DO_PWRITE(rc, env->me_fd, p, psize * 2, len, 0);
3460 else if ((unsigned) len == psize * 2)
3468 /** Update the environment info to commit a transaction.
3469 * @param[in] txn the transaction that's being committed
3470 * @return 0 on success, non-zero on failure.
3473 mdb_env_write_meta(MDB_txn *txn)
3476 MDB_meta meta, metab, *mp;
3479 int rc, len, toggle;
3488 toggle = txn->mt_txnid & 1;
3489 DPRINTF(("writing meta page %d for root page %"Z"u",
3490 toggle, txn->mt_dbs[MAIN_DBI].md_root));
3493 mp = env->me_metas[toggle];
3494 mapsize = env->me_metas[toggle ^ 1]->mm_mapsize;
3495 /* Persist any increases of mapsize config */
3496 if (mapsize < env->me_mapsize)
3497 mapsize = env->me_mapsize;
3499 if (env->me_flags & MDB_WRITEMAP) {
3500 mp->mm_mapsize = mapsize;
3501 mp->mm_dbs[0] = txn->mt_dbs[0];
3502 mp->mm_dbs[1] = txn->mt_dbs[1];
3503 mp->mm_last_pg = txn->mt_next_pgno - 1;
3504 mp->mm_txnid = txn->mt_txnid;
3505 if (!(env->me_flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {
3506 unsigned meta_size = env->me_psize;
3507 rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;
3510 #ifndef _WIN32 /* POSIX msync() requires ptr = start of OS page */
3511 if (meta_size < env->me_os_psize)
3512 meta_size += meta_size;
3517 if (MDB_MSYNC(ptr, meta_size, rc)) {
3524 metab.mm_txnid = env->me_metas[toggle]->mm_txnid;
3525 metab.mm_last_pg = env->me_metas[toggle]->mm_last_pg;
3527 meta.mm_mapsize = mapsize;
3528 meta.mm_dbs[0] = txn->mt_dbs[0];
3529 meta.mm_dbs[1] = txn->mt_dbs[1];
3530 meta.mm_last_pg = txn->mt_next_pgno - 1;
3531 meta.mm_txnid = txn->mt_txnid;
3533 off = offsetof(MDB_meta, mm_mapsize);
3534 ptr = (char *)&meta + off;
3535 len = sizeof(MDB_meta) - off;
3537 off += env->me_psize;
3540 /* Write to the SYNC fd */
3541 mfd = env->me_flags & (MDB_NOSYNC|MDB_NOMETASYNC) ?
3542 env->me_fd : env->me_mfd;
3545 memset(&ov, 0, sizeof(ov));
3547 if (!WriteFile(mfd, ptr, len, (DWORD *)&rc, &ov))
3551 rc = pwrite(mfd, ptr, len, off);
3554 rc = rc < 0 ? ErrCode() : EIO;
3555 DPUTS("write failed, disk error?");
3556 /* On a failure, the pagecache still contains the new data.
3557 * Write some old data back, to prevent it from being used.
3558 * Use the non-SYNC fd; we know it will fail anyway.
3560 meta.mm_last_pg = metab.mm_last_pg;
3561 meta.mm_txnid = metab.mm_txnid;
3563 memset(&ov, 0, sizeof(ov));
3565 WriteFile(env->me_fd, ptr, len, NULL, &ov);
3567 r2 = pwrite(env->me_fd, ptr, len, off);
3568 (void)r2; /* Silence warnings. We don't care about pwrite's return value */
3571 env->me_flags |= MDB_FATAL_ERROR;
3575 /* Memory ordering issues are irrelevant; since the entire writer
3576 * is wrapped by wmutex, all of these changes will become visible
3577 * after the wmutex is unlocked. Since the DB is multi-version,
3578 * readers will get consistent data regardless of how fresh or
3579 * how stale their view of these values is.
3582 env->me_txns->mti_txnid = txn->mt_txnid;
3587 /** Check both meta pages to see which one is newer.
3588 * @param[in] env the environment handle
3589 * @return meta toggle (0 or 1).
3592 mdb_env_pick_meta(const MDB_env *env)
3594 return (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid);
3598 mdb_env_create(MDB_env **env)
3602 e = calloc(1, sizeof(MDB_env));
3606 e->me_maxreaders = DEFAULT_READERS;
3607 e->me_maxdbs = e->me_numdbs = 2;
3608 e->me_fd = INVALID_HANDLE_VALUE;
3609 e->me_lfd = INVALID_HANDLE_VALUE;
3610 e->me_mfd = INVALID_HANDLE_VALUE;
3611 #ifdef MDB_USE_POSIX_SEM
3612 e->me_rmutex = SEM_FAILED;
3613 e->me_wmutex = SEM_FAILED;
3615 e->me_pid = getpid();
3616 GET_PAGESIZE(e->me_os_psize);
3617 VGMEMP_CREATE(e,0,0);
3623 mdb_env_map(MDB_env *env, void *addr)
3626 unsigned int flags = env->me_flags;
3630 LONG sizelo, sizehi;
3633 if (flags & MDB_RDONLY) {
3634 /* Don't set explicit map size, use whatever exists */
3639 msize = env->me_mapsize;
3640 sizelo = msize & 0xffffffff;
3641 sizehi = msize >> 16 >> 16; /* only needed on Win64 */
3643 /* Windows won't create mappings for zero length files.
3644 * and won't map more than the file size.
3645 * Just set the maxsize right now.
3647 if (SetFilePointer(env->me_fd, sizelo, &sizehi, 0) != (DWORD)sizelo
3648 || !SetEndOfFile(env->me_fd)
3649 || SetFilePointer(env->me_fd, 0, NULL, 0) != 0)
3653 mh = CreateFileMapping(env->me_fd, NULL, flags & MDB_WRITEMAP ?
3654 PAGE_READWRITE : PAGE_READONLY,
3655 sizehi, sizelo, NULL);
3658 env->me_map = MapViewOfFileEx(mh, flags & MDB_WRITEMAP ?
3659 FILE_MAP_WRITE : FILE_MAP_READ,
3661 rc = env->me_map ? 0 : ErrCode();
3666 int prot = PROT_READ;
3667 if (flags & MDB_WRITEMAP) {
3669 if (ftruncate(env->me_fd, env->me_mapsize) < 0)
3672 env->me_map = mmap(addr, env->me_mapsize, prot, MAP_SHARED,
3674 if (env->me_map == MAP_FAILED) {
3679 if (flags & MDB_NORDAHEAD) {
3680 /* Turn off readahead. It's harmful when the DB is larger than RAM. */
3682 madvise(env->me_map, env->me_mapsize, MADV_RANDOM);
3684 #ifdef POSIX_MADV_RANDOM
3685 posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM);
3686 #endif /* POSIX_MADV_RANDOM */
3687 #endif /* MADV_RANDOM */
3691 /* Can happen because the address argument to mmap() is just a
3692 * hint. mmap() can pick another, e.g. if the range is in use.
3693 * The MAP_FIXED flag would prevent that, but then mmap could
3694 * instead unmap existing pages to make room for the new map.
3696 if (addr && env->me_map != addr)
3697 return EBUSY; /* TODO: Make a new MDB_* error code? */
3699 p = (MDB_page *)env->me_map;
3700 env->me_metas[0] = METADATA(p);
3701 env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + env->me_psize);
3707 mdb_env_set_mapsize(MDB_env *env, size_t size)
3709 /* If env is already open, caller is responsible for making
3710 * sure there are no active txns.
3718 size = env->me_metas[mdb_env_pick_meta(env)]->mm_mapsize;
3719 else if (size < env->me_mapsize) {
3720 /* If the configured size is smaller, make sure it's
3721 * still big enough. Silently round up to minimum if not.
3723 size_t minsize = (env->me_metas[mdb_env_pick_meta(env)]->mm_last_pg + 1) * env->me_psize;
3727 munmap(env->me_map, env->me_mapsize);
3728 env->me_mapsize = size;
3729 old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL;
3730 rc = mdb_env_map(env, old);
3734 env->me_mapsize = size;
3736 env->me_maxpg = env->me_mapsize / env->me_psize;
3741 mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs)
3745 env->me_maxdbs = dbs + 2; /* Named databases + main and free DB */
3750 mdb_env_set_maxreaders(MDB_env *env, unsigned int readers)
3752 if (env->me_map || readers < 1)
3754 env->me_maxreaders = readers;
3759 mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)
3761 if (!env || !readers)
3763 *readers = env->me_maxreaders;
3767 /** Further setup required for opening an LMDB environment
3770 mdb_env_open2(MDB_env *env)
3772 unsigned int flags = env->me_flags;
3773 int i, newenv = 0, rc;
3777 /* See if we should use QueryLimited */
3779 if ((rc & 0xff) > 5)
3780 env->me_pidquery = MDB_PROCESS_QUERY_LIMITED_INFORMATION;
3782 env->me_pidquery = PROCESS_QUERY_INFORMATION;
3785 memset(&meta, 0, sizeof(meta));
3787 if ((i = mdb_env_read_header(env, &meta)) != 0) {
3790 DPUTS("new mdbenv");
3792 env->me_psize = env->me_os_psize;
3793 if (env->me_psize > MAX_PAGESIZE)
3794 env->me_psize = MAX_PAGESIZE;
3796 env->me_psize = meta.mm_psize;
3799 /* Was a mapsize configured? */
3800 if (!env->me_mapsize) {
3801 /* If this is a new environment, take the default,
3802 * else use the size recorded in the existing env.
3804 env->me_mapsize = newenv ? DEFAULT_MAPSIZE : meta.mm_mapsize;
3805 } else if (env->me_mapsize < meta.mm_mapsize) {
3806 /* If the configured size is smaller, make sure it's
3807 * still big enough. Silently round up to minimum if not.
3809 size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize;
3810 if (env->me_mapsize < minsize)
3811 env->me_mapsize = minsize;
3814 rc = mdb_env_map(env, (flags & MDB_FIXEDMAP) ? meta.mm_address : NULL);
3819 if (flags & MDB_FIXEDMAP)
3820 meta.mm_address = env->me_map;
3821 i = mdb_env_init_meta(env, &meta);
3822 if (i != MDB_SUCCESS) {
3827 env->me_maxfree_1pg = (env->me_psize - PAGEHDRSZ) / sizeof(pgno_t) - 1;
3828 env->me_nodemax = (((env->me_psize - PAGEHDRSZ) / MDB_MINKEYS) & -2)
3830 #if !(MDB_MAXKEYSIZE)
3831 env->me_maxkey = env->me_nodemax - (NODESIZE + sizeof(MDB_db));
3833 env->me_maxpg = env->me_mapsize / env->me_psize;
3837 int toggle = mdb_env_pick_meta(env);
3838 MDB_db *db = &env->me_metas[toggle]->mm_dbs[MAIN_DBI];
3840 DPRINTF(("opened database version %u, pagesize %u",
3841 env->me_metas[0]->mm_version, env->me_psize));
3842 DPRINTF(("using meta page %d", toggle));
3843 DPRINTF(("depth: %u", db->md_depth));
3844 DPRINTF(("entries: %"Z"u", db->md_entries));
3845 DPRINTF(("branch pages: %"Z"u", db->md_branch_pages));
3846 DPRINTF(("leaf pages: %"Z"u", db->md_leaf_pages));
3847 DPRINTF(("overflow pages: %"Z"u", db->md_overflow_pages));
3848 DPRINTF(("root: %"Z"u", db->md_root));
3856 /** Release a reader thread's slot in the reader lock table.
3857 * This function is called automatically when a thread exits.
3858 * @param[in] ptr This points to the slot in the reader lock table.
3861 mdb_env_reader_dest(void *ptr)
3863 MDB_reader *reader = ptr;
3869 /** Junk for arranging thread-specific callbacks on Windows. This is
3870 * necessarily platform and compiler-specific. Windows supports up
3871 * to 1088 keys. Let's assume nobody opens more than 64 environments
3872 * in a single process, for now. They can override this if needed.
3874 #ifndef MAX_TLS_KEYS
3875 #define MAX_TLS_KEYS 64
3877 static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS];
3878 static int mdb_tls_nkeys;
3880 static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr)
3884 case DLL_PROCESS_ATTACH: break;
3885 case DLL_THREAD_ATTACH: break;
3886 case DLL_THREAD_DETACH:
3887 for (i=0; i<mdb_tls_nkeys; i++) {
3888 MDB_reader *r = pthread_getspecific(mdb_tls_keys[i]);
3890 mdb_env_reader_dest(r);
3894 case DLL_PROCESS_DETACH: break;
3899 const PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
3901 PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
3905 /* Force some symbol references.
3906 * _tls_used forces the linker to create the TLS directory if not already done
3907 * mdb_tls_cbp prevents whole-program-optimizer from dropping the symbol.
3909 #pragma comment(linker, "/INCLUDE:_tls_used")
3910 #pragma comment(linker, "/INCLUDE:mdb_tls_cbp")
3911 #pragma const_seg(".CRT$XLB")
3912 extern const PIMAGE_TLS_CALLBACK mdb_tls_cbp;
3913 const PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
3916 #pragma comment(linker, "/INCLUDE:__tls_used")
3917 #pragma comment(linker, "/INCLUDE:_mdb_tls_cbp")
3918 #pragma data_seg(".CRT$XLB")
3919 PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
3921 #endif /* WIN 32/64 */
3922 #endif /* !__GNUC__ */
3925 /** Downgrade the exclusive lock on the region back to shared */
3927 mdb_env_share_locks(MDB_env *env, int *excl)
3929 int rc = 0, toggle = mdb_env_pick_meta(env);
3931 env->me_txns->mti_txnid = env->me_metas[toggle]->mm_txnid;
3936 /* First acquire a shared lock. The Unlock will
3937 * then release the existing exclusive lock.
3939 memset(&ov, 0, sizeof(ov));
3940 if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
3943 UnlockFile(env->me_lfd, 0, 0, 1, 0);
3949 struct flock lock_info;
3950 /* The shared lock replaces the existing lock */
3951 memset((void *)&lock_info, 0, sizeof(lock_info));
3952 lock_info.l_type = F_RDLCK;
3953 lock_info.l_whence = SEEK_SET;
3954 lock_info.l_start = 0;
3955 lock_info.l_len = 1;
3956 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
3957 (rc = ErrCode()) == EINTR) ;
3958 *excl = rc ? -1 : 0; /* error may mean we lost the lock */
3965 /** Try to get exlusive lock, otherwise shared.
3966 * Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive.
3969 mdb_env_excl_lock(MDB_env *env, int *excl)
3973 if (LockFile(env->me_lfd, 0, 0, 1, 0)) {
3977 memset(&ov, 0, sizeof(ov));
3978 if (LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
3985 struct flock lock_info;
3986 memset((void *)&lock_info, 0, sizeof(lock_info));
3987 lock_info.l_type = F_WRLCK;
3988 lock_info.l_whence = SEEK_SET;
3989 lock_info.l_start = 0;
3990 lock_info.l_len = 1;
3991 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
3992 (rc = ErrCode()) == EINTR) ;
3996 # ifdef MDB_USE_POSIX_SEM
3997 if (*excl < 0) /* always true when !MDB_USE_POSIX_SEM */
4000 lock_info.l_type = F_RDLCK;
4001 while ((rc = fcntl(env->me_lfd, F_SETLKW, &lock_info)) &&
4002 (rc = ErrCode()) == EINTR) ;
4012 * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code
4014 * @(#) $Revision: 5.1 $
4015 * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $
4016 * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $
4018 * http://www.isthe.com/chongo/tech/comp/fnv/index.html
4022 * Please do not copyright this code. This code is in the public domain.
4024 * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
4025 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
4026 * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
4027 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
4028 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
4029 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
4030 * PERFORMANCE OF THIS SOFTWARE.
4033 * chongo <Landon Curt Noll> /\oo/\
4034 * http://www.isthe.com/chongo/
4036 * Share and Enjoy! :-)
4039 typedef unsigned long long mdb_hash_t;
4040 #define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL)
4042 /** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer
4043 * @param[in] val value to hash
4044 * @param[in] hval initial value for hash
4045 * @return 64 bit hash
4047 * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the
4048 * hval arg on the first call.
4051 mdb_hash_val(MDB_val *val, mdb_hash_t hval)
4053 unsigned char *s = (unsigned char *)val->mv_data; /* unsigned string */
4054 unsigned char *end = s + val->mv_size;
4056 * FNV-1a hash each octet of the string
4059 /* xor the bottom with the current octet */
4060 hval ^= (mdb_hash_t)*s++;
4062 /* multiply by the 64 bit FNV magic prime mod 2^64 */
4063 hval += (hval << 1) + (hval << 4) + (hval << 5) +
4064 (hval << 7) + (hval << 8) + (hval << 40);
4066 /* return our new hash value */
4070 /** Hash the string and output the encoded hash.
4071 * This uses modified RFC1924 Ascii85 encoding to accommodate systems with
4072 * very short name limits. We don't care about the encoding being reversible,
4073 * we just want to preserve as many bits of the input as possible in a
4074 * small printable string.
4075 * @param[in] str string to hash
4076 * @param[out] encbuf an array of 11 chars to hold the hash
4078 static const char mdb_a85[]= "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";
4081 mdb_pack85(unsigned long l, char *out)
4085 for (i=0; i<5; i++) {
4086 *out++ = mdb_a85[l % 85];
4092 mdb_hash_enc(MDB_val *val, char *encbuf)
4094 mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT);
4096 mdb_pack85(h, encbuf);
4097 mdb_pack85(h>>32, encbuf+5);
4102 /** Open and/or initialize the lock region for the environment.
4103 * @param[in] env The LMDB environment.
4104 * @param[in] lpath The pathname of the file used for the lock region.
4105 * @param[in] mode The Unix permissions for the file, if we create it.
4106 * @param[out] excl Resulting file lock type: -1 none, 0 shared, 1 exclusive
4107 * @param[in,out] excl In -1, out lock type: -1 none, 0 shared, 1 exclusive
4108 * @return 0 on success, non-zero on failure.
4111 mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
4114 # define MDB_ERRCODE_ROFS ERROR_WRITE_PROTECT
4116 # define MDB_ERRCODE_ROFS EROFS
4117 #ifdef O_CLOEXEC /* Linux: Open file and set FD_CLOEXEC atomically */
4118 # define MDB_CLOEXEC O_CLOEXEC
4121 # define MDB_CLOEXEC 0
4128 env->me_lfd = CreateFile(lpath, GENERIC_READ|GENERIC_WRITE,
4129 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
4130 FILE_ATTRIBUTE_NORMAL, NULL);
4132 env->me_lfd = open(lpath, O_RDWR|O_CREAT|MDB_CLOEXEC, mode);
4134 if (env->me_lfd == INVALID_HANDLE_VALUE) {
4136 if (rc == MDB_ERRCODE_ROFS && (env->me_flags & MDB_RDONLY)) {
4141 #if ! ((MDB_CLOEXEC) || defined(_WIN32))
4142 /* Lose record locks when exec*() */
4143 if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0)
4144 fcntl(env->me_lfd, F_SETFD, fdflags);
4147 if (!(env->me_flags & MDB_NOTLS)) {
4148 rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
4151 env->me_flags |= MDB_ENV_TXKEY;
4153 /* Windows TLS callbacks need help finding their TLS info. */
4154 if (mdb_tls_nkeys >= MAX_TLS_KEYS) {
4158 mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey;
4162 /* Try to get exclusive lock. If we succeed, then
4163 * nobody is using the lock region and we should initialize it.
4165 if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
4168 size = GetFileSize(env->me_lfd, NULL);
4170 size = lseek(env->me_lfd, 0, SEEK_END);
4171 if (size == -1) goto fail_errno;
4173 rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
4174 if (size < rsize && *excl > 0) {
4176 if (SetFilePointer(env->me_lfd, rsize, NULL, FILE_BEGIN) != (DWORD)rsize
4177 || !SetEndOfFile(env->me_lfd))
4180 if (ftruncate(env->me_lfd, rsize) != 0) goto fail_errno;
4184 size = rsize - sizeof(MDB_txninfo);
4185 env->me_maxreaders = size/sizeof(MDB_reader) + 1;
4190 mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,
4192 if (!mh) goto fail_errno;
4193 env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL);
4195 if (!env->me_txns) goto fail_errno;
4197 void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
4199 if (m == MAP_FAILED) goto fail_errno;
4205 BY_HANDLE_FILE_INFORMATION stbuf;
4214 if (!mdb_sec_inited) {
4215 InitializeSecurityDescriptor(&mdb_null_sd,
4216 SECURITY_DESCRIPTOR_REVISION);
4217 SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE);
4218 mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);
4219 mdb_all_sa.bInheritHandle = FALSE;
4220 mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;
4223 if (!GetFileInformationByHandle(env->me_lfd, &stbuf)) goto fail_errno;
4224 idbuf.volume = stbuf.dwVolumeSerialNumber;
4225 idbuf.nhigh = stbuf.nFileIndexHigh;
4226 idbuf.nlow = stbuf.nFileIndexLow;
4227 val.mv_data = &idbuf;
4228 val.mv_size = sizeof(idbuf);
4229 mdb_hash_enc(&val, encbuf);
4230 sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", encbuf);
4231 sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", encbuf);
4232 env->me_rmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
4233 if (!env->me_rmutex) goto fail_errno;
4234 env->me_wmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);
4235 if (!env->me_wmutex) goto fail_errno;
4236 #elif defined(MDB_USE_POSIX_SEM)
4245 #if defined(__NetBSD__)
4246 #define MDB_SHORT_SEMNAMES 1 /* limited to 14 chars */
4248 if (fstat(env->me_lfd, &stbuf)) goto fail_errno;
4249 idbuf.dev = stbuf.st_dev;
4250 idbuf.ino = stbuf.st_ino;
4251 val.mv_data = &idbuf;
4252 val.mv_size = sizeof(idbuf);
4253 mdb_hash_enc(&val, encbuf);
4254 #ifdef MDB_SHORT_SEMNAMES
4255 encbuf[9] = '\0'; /* drop name from 15 chars to 14 chars */
4257 sprintf(env->me_txns->mti_rmname, "/MDBr%s", encbuf);
4258 sprintf(env->me_txns->mti_wmname, "/MDBw%s", encbuf);
4259 /* Clean up after a previous run, if needed: Try to
4260 * remove both semaphores before doing anything else.
4262 sem_unlink(env->me_txns->mti_rmname);
4263 sem_unlink(env->me_txns->mti_wmname);
4264 env->me_rmutex = sem_open(env->me_txns->mti_rmname,
4265 O_CREAT|O_EXCL, mode, 1);
4266 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
4267 env->me_wmutex = sem_open(env->me_txns->mti_wmname,
4268 O_CREAT|O_EXCL, mode, 1);
4269 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
4270 #else /* MDB_USE_POSIX_SEM */
4271 pthread_mutexattr_t mattr;
4273 if ((rc = pthread_mutexattr_init(&mattr))
4274 || (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED))
4275 || (rc = pthread_mutex_init(&env->me_txns->mti_mutex, &mattr))
4276 || (rc = pthread_mutex_init(&env->me_txns->mti_wmutex, &mattr)))
4278 pthread_mutexattr_destroy(&mattr);
4279 #endif /* _WIN32 || MDB_USE_POSIX_SEM */
4281 env->me_txns->mti_magic = MDB_MAGIC;
4282 env->me_txns->mti_format = MDB_LOCK_FORMAT;
4283 env->me_txns->mti_txnid = 0;
4284 env->me_txns->mti_numreaders = 0;
4287 if (env->me_txns->mti_magic != MDB_MAGIC) {
4288 DPUTS("lock region has invalid magic");
4292 if (env->me_txns->mti_format != MDB_LOCK_FORMAT) {
4293 DPRINTF(("lock region has format+version 0x%x, expected 0x%x",
4294 env->me_txns->mti_format, MDB_LOCK_FORMAT));
4295 rc = MDB_VERSION_MISMATCH;
4299 if (rc && rc != EACCES && rc != EAGAIN) {
4303 env->me_rmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);
4304 if (!env->me_rmutex) goto fail_errno;
4305 env->me_wmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
4306 if (!env->me_wmutex) goto fail_errno;
4307 #elif defined(MDB_USE_POSIX_SEM)
4308 env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0);
4309 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
4310 env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0);
4311 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
4322 /** The name of the lock file in the DB environment */
4323 #define LOCKNAME "/lock.mdb"
4324 /** The name of the data file in the DB environment */
4325 #define DATANAME "/data.mdb"
4326 /** The suffix of the lock file when no subdir is used */
4327 #define LOCKSUFF "-lock"
4328 /** Only a subset of the @ref mdb_env flags can be changed
4329 * at runtime. Changing other flags requires closing the
4330 * environment and re-opening it with the new flags.
4332 #define CHANGEABLE (MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC|MDB_NOMEMINIT)
4333 #define CHANGELESS (MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY|MDB_WRITEMAP| \
4334 MDB_NOTLS|MDB_NOLOCK|MDB_NORDAHEAD)
4336 #if VALID_FLAGS & PERSISTENT_FLAGS & (CHANGEABLE|CHANGELESS)
4337 # error "Persistent DB flags & env flags overlap, but both go in mm_flags"
4341 mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode)
4343 int oflags, rc, len, excl = -1;
4344 char *lpath, *dpath;
4346 if (env->me_fd!=INVALID_HANDLE_VALUE || (flags & ~(CHANGEABLE|CHANGELESS)))
4350 if (flags & MDB_NOSUBDIR) {
4351 rc = len + sizeof(LOCKSUFF) + len + 1;
4353 rc = len + sizeof(LOCKNAME) + len + sizeof(DATANAME);
4358 if (flags & MDB_NOSUBDIR) {
4359 dpath = lpath + len + sizeof(LOCKSUFF);
4360 sprintf(lpath, "%s" LOCKSUFF, path);
4361 strcpy(dpath, path);
4363 dpath = lpath + len + sizeof(LOCKNAME);
4364 sprintf(lpath, "%s" LOCKNAME, path);
4365 sprintf(dpath, "%s" DATANAME, path);
4369 flags |= env->me_flags;
4370 if (flags & MDB_RDONLY) {
4371 /* silently ignore WRITEMAP when we're only getting read access */
4372 flags &= ~MDB_WRITEMAP;
4374 if (!((env->me_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)) &&
4375 (env->me_dirty_list = calloc(MDB_IDL_UM_SIZE, sizeof(MDB_ID2)))))
4378 env->me_flags = flags |= MDB_ENV_ACTIVE;
4382 env->me_path = strdup(path);
4383 env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx));
4384 env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t));
4385 env->me_dbiseqs = calloc(env->me_maxdbs, sizeof(unsigned int));
4386 if (!(env->me_dbxs && env->me_path && env->me_dbflags && env->me_dbiseqs)) {
4391 /* For RDONLY, get lockfile after we know datafile exists */
4392 if (!(flags & (MDB_RDONLY|MDB_NOLOCK))) {
4393 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
4399 if (F_ISSET(flags, MDB_RDONLY)) {
4400 oflags = GENERIC_READ;
4401 len = OPEN_EXISTING;
4403 oflags = GENERIC_READ|GENERIC_WRITE;
4406 mode = FILE_ATTRIBUTE_NORMAL;
4407 env->me_fd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
4408 NULL, len, mode, NULL);
4410 if (F_ISSET(flags, MDB_RDONLY))
4413 oflags = O_RDWR | O_CREAT;
4415 env->me_fd = open(dpath, oflags, mode);
4417 if (env->me_fd == INVALID_HANDLE_VALUE) {
4422 if ((flags & (MDB_RDONLY|MDB_NOLOCK)) == MDB_RDONLY) {
4423 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
4428 if ((rc = mdb_env_open2(env)) == MDB_SUCCESS) {
4429 if (flags & (MDB_RDONLY|MDB_WRITEMAP)) {
4430 env->me_mfd = env->me_fd;
4432 /* Synchronous fd for meta writes. Needed even with
4433 * MDB_NOSYNC/MDB_NOMETASYNC, in case these get reset.
4436 len = OPEN_EXISTING;
4437 env->me_mfd = CreateFile(dpath, oflags,
4438 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len,
4439 mode | FILE_FLAG_WRITE_THROUGH, NULL);
4442 env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode);
4444 if (env->me_mfd == INVALID_HANDLE_VALUE) {
4449 DPRINTF(("opened dbenv %p", (void *) env));
4451 rc = mdb_env_share_locks(env, &excl);
4455 if (!((flags & MDB_RDONLY) ||
4456 (env->me_pbuf = calloc(1, env->me_psize))))
4462 mdb_env_close0(env, excl);
4468 /** Destroy resources from mdb_env_open(), clear our readers & DBIs */
4470 mdb_env_close0(MDB_env *env, int excl)
4474 if (!(env->me_flags & MDB_ENV_ACTIVE))
4477 /* Doing this here since me_dbxs may not exist during mdb_env_close */
4478 for (i = env->me_maxdbs; --i > MAIN_DBI; )
4479 free(env->me_dbxs[i].md_name.mv_data);
4482 free(env->me_dbiseqs);
4483 free(env->me_dbflags);
4486 free(env->me_dirty_list);
4487 mdb_midl_free(env->me_free_pgs);
4489 if (env->me_flags & MDB_ENV_TXKEY) {
4490 pthread_key_delete(env->me_txkey);
4492 /* Delete our key from the global list */
4493 for (i=0; i<mdb_tls_nkeys; i++)
4494 if (mdb_tls_keys[i] == env->me_txkey) {
4495 mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1];
4503 munmap(env->me_map, env->me_mapsize);
4505 if (env->me_mfd != env->me_fd && env->me_mfd != INVALID_HANDLE_VALUE)
4506 (void) close(env->me_mfd);
4507 if (env->me_fd != INVALID_HANDLE_VALUE)
4508 (void) close(env->me_fd);
4510 MDB_PID_T pid = env->me_pid;
4511 /* Clearing readers is done in this function because
4512 * me_txkey with its destructor must be disabled first.
4514 for (i = env->me_numreaders; --i >= 0; )
4515 if (env->me_txns->mti_readers[i].mr_pid == pid)
4516 env->me_txns->mti_readers[i].mr_pid = 0;
4518 if (env->me_rmutex) {
4519 CloseHandle(env->me_rmutex);
4520 if (env->me_wmutex) CloseHandle(env->me_wmutex);
4522 /* Windows automatically destroys the mutexes when
4523 * the last handle closes.
4525 #elif defined(MDB_USE_POSIX_SEM)
4526 if (env->me_rmutex != SEM_FAILED) {
4527 sem_close(env->me_rmutex);
4528 if (env->me_wmutex != SEM_FAILED)
4529 sem_close(env->me_wmutex);
4530 /* If we have the filelock: If we are the
4531 * only remaining user, clean up semaphores.
4534 mdb_env_excl_lock(env, &excl);
4536 sem_unlink(env->me_txns->mti_rmname);
4537 sem_unlink(env->me_txns->mti_wmname);
4541 munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
4543 if (env->me_lfd != INVALID_HANDLE_VALUE) {
4546 /* Unlock the lockfile. Windows would have unlocked it
4547 * after closing anyway, but not necessarily at once.
4549 UnlockFile(env->me_lfd, 0, 0, 1, 0);
4552 (void) close(env->me_lfd);
4555 env->me_flags &= ~(MDB_ENV_ACTIVE|MDB_ENV_TXKEY);
4560 mdb_env_close(MDB_env *env)
4567 VGMEMP_DESTROY(env);
4568 while ((dp = env->me_dpages) != NULL) {
4569 VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next));
4570 env->me_dpages = dp->mp_next;
4574 mdb_env_close0(env, 0);
4578 /** Compare two items pointing at aligned size_t's */
4580 mdb_cmp_long(const MDB_val *a, const MDB_val *b)
4582 return (*(size_t *)a->mv_data < *(size_t *)b->mv_data) ? -1 :
4583 *(size_t *)a->mv_data > *(size_t *)b->mv_data;
4586 /** Compare two items pointing at aligned unsigned int's */
4588 mdb_cmp_int(const MDB_val *a, const MDB_val *b)
4590 return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 :
4591 *(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data;
4594 /** Compare two items pointing at unsigned ints of unknown alignment.
4595 * Nodes and keys are guaranteed to be 2-byte aligned.
4598 mdb_cmp_cint(const MDB_val *a, const MDB_val *b)
4600 #if BYTE_ORDER == LITTLE_ENDIAN
4601 unsigned short *u, *c;
4604 u = (unsigned short *) ((char *) a->mv_data + a->mv_size);
4605 c = (unsigned short *) ((char *) b->mv_data + a->mv_size);
4608 } while(!x && u > (unsigned short *)a->mv_data);
4611 unsigned short *u, *c, *end;
4614 end = (unsigned short *) ((char *) a->mv_data + a->mv_size);
4615 u = (unsigned short *)a->mv_data;
4616 c = (unsigned short *)b->mv_data;
4619 } while(!x && u < end);
4624 /** Compare two items pointing at size_t's of unknown alignment. */
4625 #ifdef MISALIGNED_OK
4626 # define mdb_cmp_clong mdb_cmp_long
4628 # define mdb_cmp_clong mdb_cmp_cint
4631 /** Compare two items lexically */
4633 mdb_cmp_memn(const MDB_val *a, const MDB_val *b)
4640 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
4646 diff = memcmp(a->mv_data, b->mv_data, len);
4647 return diff ? diff : len_diff<0 ? -1 : len_diff;
4650 /** Compare two items in reverse byte order */
4652 mdb_cmp_memnr(const MDB_val *a, const MDB_val *b)
4654 const unsigned char *p1, *p2, *p1_lim;
4658 p1_lim = (const unsigned char *)a->mv_data;
4659 p1 = (const unsigned char *)a->mv_data + a->mv_size;
4660 p2 = (const unsigned char *)b->mv_data + b->mv_size;
4662 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
4668 while (p1 > p1_lim) {
4669 diff = *--p1 - *--p2;
4673 return len_diff<0 ? -1 : len_diff;
4676 /** Search for key within a page, using binary search.
4677 * Returns the smallest entry larger or equal to the key.
4678 * If exactp is non-null, stores whether the found entry was an exact match
4679 * in *exactp (1 or 0).
4680 * Updates the cursor index with the index of the found entry.
4681 * If no entry larger or equal to the key is found, returns NULL.
4684 mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)
4686 unsigned int i = 0, nkeys;
4689 MDB_page *mp = mc->mc_pg[mc->mc_top];
4690 MDB_node *node = NULL;
4695 nkeys = NUMKEYS(mp);
4697 DPRINTF(("searching %u keys in %s %spage %"Z"u",
4698 nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "",
4701 low = IS_LEAF(mp) ? 0 : 1;
4703 cmp = mc->mc_dbx->md_cmp;
4705 /* Branch pages have no data, so if using integer keys,
4706 * alignment is guaranteed. Use faster mdb_cmp_int.
4708 if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) {
4709 if (NODEPTR(mp, 1)->mn_ksize == sizeof(size_t))
4716 nodekey.mv_size = mc->mc_db->md_pad;
4717 node = NODEPTR(mp, 0); /* fake */
4718 while (low <= high) {
4719 i = (low + high) >> 1;
4720 nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size);
4721 rc = cmp(key, &nodekey);
4722 DPRINTF(("found leaf index %u [%s], rc = %i",
4723 i, DKEY(&nodekey), rc));
4732 while (low <= high) {
4733 i = (low + high) >> 1;
4735 node = NODEPTR(mp, i);
4736 nodekey.mv_size = NODEKSZ(node);
4737 nodekey.mv_data = NODEKEY(node);
4739 rc = cmp(key, &nodekey);
4742 DPRINTF(("found leaf index %u [%s], rc = %i",
4743 i, DKEY(&nodekey), rc));
4745 DPRINTF(("found branch index %u [%s -> %"Z"u], rc = %i",
4746 i, DKEY(&nodekey), NODEPGNO(node), rc));
4757 if (rc > 0) { /* Found entry is less than the key. */
4758 i++; /* Skip to get the smallest entry larger than key. */
4760 node = NODEPTR(mp, i);
4763 *exactp = (rc == 0 && nkeys > 0);
4764 /* store the key index */
4765 mc->mc_ki[mc->mc_top] = i;
4767 /* There is no entry larger or equal to the key. */
4770 /* nodeptr is fake for LEAF2 */
4776 mdb_cursor_adjust(MDB_cursor *mc, func)
4780 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
4781 if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) {
4788 /** Pop a page off the top of the cursor's stack. */
4790 mdb_cursor_pop(MDB_cursor *mc)
4794 MDB_page *top = mc->mc_pg[mc->mc_top];
4800 DPRINTF(("popped page %"Z"u off db %d cursor %p", top->mp_pgno,
4801 DDBI(mc), (void *) mc));
4805 /** Push a page onto the top of the cursor's stack. */
4807 mdb_cursor_push(MDB_cursor *mc, MDB_page *mp)
4809 DPRINTF(("pushing page %"Z"u on db %d cursor %p", mp->mp_pgno,
4810 DDBI(mc), (void *) mc));
4812 if (mc->mc_snum >= CURSOR_STACK) {
4813 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
4814 return MDB_CURSOR_FULL;
4817 mc->mc_top = mc->mc_snum++;
4818 mc->mc_pg[mc->mc_top] = mp;
4819 mc->mc_ki[mc->mc_top] = 0;
4824 /** Find the address of the page corresponding to a given page number.
4825 * @param[in] txn the transaction for this access.
4826 * @param[in] pgno the page number for the page to retrieve.
4827 * @param[out] ret address of a pointer where the page's address will be stored.
4828 * @param[out] lvl dirty_list inheritance level of found page. 1=current txn, 0=mapped page.
4829 * @return 0 on success, non-zero on failure.
4832 mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret, int *lvl)
4834 MDB_env *env = txn->mt_env;
4838 if (!((txn->mt_flags & MDB_TXN_RDONLY) | (env->me_flags & MDB_WRITEMAP))) {
4842 MDB_ID2L dl = tx2->mt_u.dirty_list;
4844 /* Spilled pages were dirtied in this txn and flushed
4845 * because the dirty list got full. Bring this page
4846 * back in from the map (but don't unspill it here,
4847 * leave that unless page_touch happens again).
4849 if (tx2->mt_spill_pgs) {
4850 MDB_ID pn = pgno << 1;
4851 x = mdb_midl_search(tx2->mt_spill_pgs, pn);
4852 if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
4853 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
4858 unsigned x = mdb_mid2l_search(dl, pgno);
4859 if (x <= dl[0].mid && dl[x].mid == pgno) {
4865 } while ((tx2 = tx2->mt_parent) != NULL);
4868 if (pgno < txn->mt_next_pgno) {
4870 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
4872 DPRINTF(("page %"Z"u not found", pgno));
4873 txn->mt_flags |= MDB_TXN_ERROR;
4874 return MDB_PAGE_NOTFOUND;
4884 /** Finish #mdb_page_search() / #mdb_page_search_lowest().
4885 * The cursor is at the root page, set up the rest of it.
4888 mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags)
4890 MDB_page *mp = mc->mc_pg[mc->mc_top];
4894 while (IS_BRANCH(mp)) {
4898 DPRINTF(("branch page %"Z"u has %u keys", mp->mp_pgno, NUMKEYS(mp)));
4899 mdb_cassert(mc, NUMKEYS(mp) > 1);
4900 DPRINTF(("found index 0 to page %"Z"u", NODEPGNO(NODEPTR(mp, 0))));
4902 if (flags & (MDB_PS_FIRST|MDB_PS_LAST)) {
4904 if (flags & MDB_PS_LAST)
4905 i = NUMKEYS(mp) - 1;
4908 node = mdb_node_search(mc, key, &exact);
4910 i = NUMKEYS(mp) - 1;
4912 i = mc->mc_ki[mc->mc_top];
4914 mdb_cassert(mc, i > 0);
4918 DPRINTF(("following index %u for key [%s]", i, DKEY(key)));
4921 mdb_cassert(mc, i < NUMKEYS(mp));
4922 node = NODEPTR(mp, i);
4924 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
4927 mc->mc_ki[mc->mc_top] = i;
4928 if ((rc = mdb_cursor_push(mc, mp)))
4931 if (flags & MDB_PS_MODIFY) {
4932 if ((rc = mdb_page_touch(mc)) != 0)
4934 mp = mc->mc_pg[mc->mc_top];
4939 DPRINTF(("internal error, index points to a %02X page!?",
4941 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
4942 return MDB_CORRUPTED;
4945 DPRINTF(("found leaf page %"Z"u for key [%s]", mp->mp_pgno,
4946 key ? DKEY(key) : "null"));
4947 mc->mc_flags |= C_INITIALIZED;
4948 mc->mc_flags &= ~C_EOF;
4953 /** Search for the lowest key under the current branch page.
4954 * This just bypasses a NUMKEYS check in the current page
4955 * before calling mdb_page_search_root(), because the callers
4956 * are all in situations where the current page is known to
4960 mdb_page_search_lowest(MDB_cursor *mc)
4962 MDB_page *mp = mc->mc_pg[mc->mc_top];
4963 MDB_node *node = NODEPTR(mp, 0);
4966 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
4969 mc->mc_ki[mc->mc_top] = 0;
4970 if ((rc = mdb_cursor_push(mc, mp)))
4972 return mdb_page_search_root(mc, NULL, MDB_PS_FIRST);
4975 /** Search for the page a given key should be in.
4976 * Push it and its parent pages on the cursor stack.
4977 * @param[in,out] mc the cursor for this operation.
4978 * @param[in] key the key to search for, or NULL for first/last page.
4979 * @param[in] flags If MDB_PS_MODIFY is set, visited pages in the DB
4980 * are touched (updated with new page numbers).
4981 * If MDB_PS_FIRST or MDB_PS_LAST is set, find first or last leaf.
4982 * This is used by #mdb_cursor_first() and #mdb_cursor_last().
4983 * If MDB_PS_ROOTONLY set, just fetch root node, no further lookups.
4984 * @return 0 on success, non-zero on failure.
4987 mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)
4992 /* Make sure the txn is still viable, then find the root from
4993 * the txn's db table and set it as the root of the cursor's stack.
4995 if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_ERROR)) {
4996 DPUTS("transaction has failed, must abort");
4999 /* Make sure we're using an up-to-date root */
5000 if (*mc->mc_dbflag & DB_STALE) {
5002 if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))
5004 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);
5005 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, 0);
5012 MDB_node *leaf = mdb_node_search(&mc2,
5013 &mc->mc_dbx->md_name, &exact);
5015 return MDB_NOTFOUND;
5016 rc = mdb_node_read(mc->mc_txn, leaf, &data);
5019 memcpy(&flags, ((char *) data.mv_data + offsetof(MDB_db, md_flags)),
5021 /* The txn may not know this DBI, or another process may
5022 * have dropped and recreated the DB with other flags.
5024 if ((mc->mc_db->md_flags & PERSISTENT_FLAGS) != flags)
5025 return MDB_INCOMPATIBLE;
5026 memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db));
5028 *mc->mc_dbflag &= ~DB_STALE;
5030 root = mc->mc_db->md_root;
5032 if (root == P_INVALID) { /* Tree is empty. */
5033 DPUTS("tree is empty");
5034 return MDB_NOTFOUND;
5038 mdb_cassert(mc, root > 1);
5039 if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root)
5040 if ((rc = mdb_page_get(mc->mc_txn, root, &mc->mc_pg[0], NULL)) != 0)
5046 DPRINTF(("db %d root page %"Z"u has flags 0x%X",
5047 DDBI(mc), root, mc->mc_pg[0]->mp_flags));
5049 if (flags & MDB_PS_MODIFY) {
5050 if ((rc = mdb_page_touch(mc)))
5054 if (flags & MDB_PS_ROOTONLY)
5057 return mdb_page_search_root(mc, key, flags);
5061 mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
5063 MDB_txn *txn = mc->mc_txn;
5064 pgno_t pg = mp->mp_pgno;
5065 unsigned x = 0, ovpages = mp->mp_pages;
5066 MDB_env *env = txn->mt_env;
5067 MDB_IDL sl = txn->mt_spill_pgs;
5068 MDB_ID pn = pg << 1;
5071 DPRINTF(("free ov page %"Z"u (%d)", pg, ovpages));
5072 /* If the page is dirty or on the spill list we just acquired it,
5073 * so we should give it back to our current free list, if any.
5074 * Otherwise put it onto the list of pages we freed in this txn.
5076 * Won't create me_pghead: me_pglast must be inited along with it.
5077 * Unsupported in nested txns: They would need to hide the page
5078 * range in ancestor txns' dirty and spilled lists.
5080 if (env->me_pghead &&
5082 ((mp->mp_flags & P_DIRTY) ||
5083 (sl && (x = mdb_midl_search(sl, pn)) <= sl[0] && sl[x] == pn)))
5087 MDB_ID2 *dl, ix, iy;
5088 rc = mdb_midl_need(&env->me_pghead, ovpages);
5091 if (!(mp->mp_flags & P_DIRTY)) {
5092 /* This page is no longer spilled */
5099 /* Remove from dirty list */
5100 dl = txn->mt_u.dirty_list;
5102 for (ix = dl[x]; ix.mptr != mp; ix = iy) {
5108 mdb_cassert(mc, x > 1);
5110 dl[j] = ix; /* Unsorted. OK when MDB_TXN_ERROR. */
5111 txn->mt_flags |= MDB_TXN_ERROR;
5112 return MDB_CORRUPTED;
5115 if (!(env->me_flags & MDB_WRITEMAP))
5116 mdb_dpage_free(env, mp);
5118 /* Insert in me_pghead */
5119 mop = env->me_pghead;
5120 j = mop[0] + ovpages;
5121 for (i = mop[0]; i && mop[i] < pg; i--)
5127 rc = mdb_midl_append_range(&txn->mt_free_pgs, pg, ovpages);
5131 mc->mc_db->md_overflow_pages -= ovpages;
5135 /** Return the data associated with a given node.
5136 * @param[in] txn The transaction for this operation.
5137 * @param[in] leaf The node being read.
5138 * @param[out] data Updated to point to the node's data.
5139 * @return 0 on success, non-zero on failure.
5142 mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data)
5144 MDB_page *omp; /* overflow page */
5148 if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
5149 data->mv_size = NODEDSZ(leaf);
5150 data->mv_data = NODEDATA(leaf);
5154 /* Read overflow data.
5156 data->mv_size = NODEDSZ(leaf);
5157 memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
5158 if ((rc = mdb_page_get(txn, pgno, &omp, NULL)) != 0) {
5159 DPRINTF(("read overflow page %"Z"u failed", pgno));
5162 data->mv_data = METADATA(omp);
5168 mdb_get(MDB_txn *txn, MDB_dbi dbi,
5169 MDB_val *key, MDB_val *data)
5176 DPRINTF(("===> get db %u key [%s]", dbi, DKEY(key)));
5178 if (!key || !data || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
5181 if (txn->mt_flags & MDB_TXN_ERROR)
5184 mdb_cursor_init(&mc, txn, dbi, &mx);
5185 return mdb_cursor_set(&mc, key, data, MDB_SET, &exact);
5188 /** Find a sibling for a page.
5189 * Replaces the page at the top of the cursor's stack with the
5190 * specified sibling, if one exists.
5191 * @param[in] mc The cursor for this operation.
5192 * @param[in] move_right Non-zero if the right sibling is requested,
5193 * otherwise the left sibling.
5194 * @return 0 on success, non-zero on failure.
5197 mdb_cursor_sibling(MDB_cursor *mc, int move_right)
5203 if (mc->mc_snum < 2) {
5204 return MDB_NOTFOUND; /* root has no siblings */
5208 DPRINTF(("parent page is page %"Z"u, index %u",
5209 mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]));
5211 if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top]))
5212 : (mc->mc_ki[mc->mc_top] == 0)) {
5213 DPRINTF(("no more keys left, moving to %s sibling",
5214 move_right ? "right" : "left"));
5215 if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) {
5216 /* undo cursor_pop before returning */
5223 mc->mc_ki[mc->mc_top]++;
5225 mc->mc_ki[mc->mc_top]--;
5226 DPRINTF(("just moving to %s index key %u",
5227 move_right ? "right" : "left", mc->mc_ki[mc->mc_top]));
5229 mdb_cassert(mc, IS_BRANCH(mc->mc_pg[mc->mc_top]));
5231 indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5232 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(indx), &mp, NULL)) != 0) {
5233 /* mc will be inconsistent if caller does mc_snum++ as above */
5234 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
5238 mdb_cursor_push(mc, mp);
5240 mc->mc_ki[mc->mc_top] = NUMKEYS(mp)-1;
5245 /** Move the cursor to the next data item. */
5247 mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
5253 if (mc->mc_flags & C_EOF) {
5254 return MDB_NOTFOUND;
5257 mdb_cassert(mc, mc->mc_flags & C_INITIALIZED);
5259 mp = mc->mc_pg[mc->mc_top];
5261 if (mc->mc_db->md_flags & MDB_DUPSORT) {
5262 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5263 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5264 if (op == MDB_NEXT || op == MDB_NEXT_DUP) {
5265 rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);
5266 if (op != MDB_NEXT || rc != MDB_NOTFOUND) {
5267 if (rc == MDB_SUCCESS)
5268 MDB_GET_KEY(leaf, key);
5273 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5274 if (op == MDB_NEXT_DUP)
5275 return MDB_NOTFOUND;
5279 DPRINTF(("cursor_next: top page is %"Z"u in cursor %p",
5280 mdb_dbg_pgno(mp), (void *) mc));
5281 if (mc->mc_flags & C_DEL)
5284 if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) {
5285 DPUTS("=====> move to next sibling page");
5286 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
5287 mc->mc_flags |= C_EOF;
5290 mp = mc->mc_pg[mc->mc_top];
5291 DPRINTF(("next page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
5293 mc->mc_ki[mc->mc_top]++;
5296 DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
5297 mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
5300 key->mv_size = mc->mc_db->md_pad;
5301 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5305 mdb_cassert(mc, IS_LEAF(mp));
5306 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5308 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5309 mdb_xcursor_init1(mc, leaf);
5312 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5315 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5316 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
5317 if (rc != MDB_SUCCESS)
5322 MDB_GET_KEY(leaf, key);
5326 /** Move the cursor to the previous data item. */
5328 mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
5334 mdb_cassert(mc, mc->mc_flags & C_INITIALIZED);
5336 mp = mc->mc_pg[mc->mc_top];
5338 if (mc->mc_db->md_flags & MDB_DUPSORT) {
5339 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5340 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5341 if (op == MDB_PREV || op == MDB_PREV_DUP) {
5342 rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
5343 if (op != MDB_PREV || rc != MDB_NOTFOUND) {
5344 if (rc == MDB_SUCCESS)
5345 MDB_GET_KEY(leaf, key);
5349 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5350 if (op == MDB_PREV_DUP)
5351 return MDB_NOTFOUND;
5356 DPRINTF(("cursor_prev: top page is %"Z"u in cursor %p",
5357 mdb_dbg_pgno(mp), (void *) mc));
5359 if (mc->mc_ki[mc->mc_top] == 0) {
5360 DPUTS("=====> move to prev sibling page");
5361 if ((rc = mdb_cursor_sibling(mc, 0)) != MDB_SUCCESS) {
5364 mp = mc->mc_pg[mc->mc_top];
5365 mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;
5366 DPRINTF(("prev page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
5368 mc->mc_ki[mc->mc_top]--;
5370 mc->mc_flags &= ~C_EOF;
5372 DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
5373 mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
5376 key->mv_size = mc->mc_db->md_pad;
5377 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5381 mdb_cassert(mc, IS_LEAF(mp));
5382 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5384 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5385 mdb_xcursor_init1(mc, leaf);
5388 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5391 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5392 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
5393 if (rc != MDB_SUCCESS)
5398 MDB_GET_KEY(leaf, key);
5402 /** Set the cursor on a specific data item. */
5404 mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data,
5405 MDB_cursor_op op, int *exactp)
5409 MDB_node *leaf = NULL;
5412 if (key->mv_size == 0)
5413 return MDB_BAD_VALSIZE;
5416 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5418 /* See if we're already on the right page */
5419 if (mc->mc_flags & C_INITIALIZED) {
5422 mp = mc->mc_pg[mc->mc_top];
5424 mc->mc_ki[mc->mc_top] = 0;
5425 return MDB_NOTFOUND;
5427 if (mp->mp_flags & P_LEAF2) {
5428 nodekey.mv_size = mc->mc_db->md_pad;
5429 nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size);
5431 leaf = NODEPTR(mp, 0);
5432 MDB_GET_KEY2(leaf, nodekey);
5434 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5436 /* Probably happens rarely, but first node on the page
5437 * was the one we wanted.
5439 mc->mc_ki[mc->mc_top] = 0;
5446 unsigned int nkeys = NUMKEYS(mp);
5448 if (mp->mp_flags & P_LEAF2) {
5449 nodekey.mv_data = LEAF2KEY(mp,
5450 nkeys-1, nodekey.mv_size);
5452 leaf = NODEPTR(mp, nkeys-1);
5453 MDB_GET_KEY2(leaf, nodekey);
5455 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5457 /* last node was the one we wanted */
5458 mc->mc_ki[mc->mc_top] = nkeys-1;
5464 if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) {
5465 /* This is definitely the right page, skip search_page */
5466 if (mp->mp_flags & P_LEAF2) {
5467 nodekey.mv_data = LEAF2KEY(mp,
5468 mc->mc_ki[mc->mc_top], nodekey.mv_size);
5470 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5471 MDB_GET_KEY2(leaf, nodekey);
5473 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5475 /* current node was the one we wanted */
5485 /* If any parents have right-sibs, search.
5486 * Otherwise, there's nothing further.
5488 for (i=0; i<mc->mc_top; i++)
5490 NUMKEYS(mc->mc_pg[i])-1)
5492 if (i == mc->mc_top) {
5493 /* There are no other pages */
5494 mc->mc_ki[mc->mc_top] = nkeys;
5495 return MDB_NOTFOUND;
5499 /* There are no other pages */
5500 mc->mc_ki[mc->mc_top] = 0;
5501 if (op == MDB_SET_RANGE && !exactp) {
5505 return MDB_NOTFOUND;
5509 rc = mdb_page_search(mc, key, 0);
5510 if (rc != MDB_SUCCESS)
5513 mp = mc->mc_pg[mc->mc_top];
5514 mdb_cassert(mc, IS_LEAF(mp));
5517 leaf = mdb_node_search(mc, key, exactp);
5518 if (exactp != NULL && !*exactp) {
5519 /* MDB_SET specified and not an exact match. */
5520 return MDB_NOTFOUND;
5524 DPUTS("===> inexact leaf not found, goto sibling");
5525 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS)
5526 return rc; /* no entries matched */
5527 mp = mc->mc_pg[mc->mc_top];
5528 mdb_cassert(mc, IS_LEAF(mp));
5529 leaf = NODEPTR(mp, 0);
5533 mc->mc_flags |= C_INITIALIZED;
5534 mc->mc_flags &= ~C_EOF;
5537 if (op == MDB_SET_RANGE || op == MDB_SET_KEY) {
5538 key->mv_size = mc->mc_db->md_pad;
5539 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5544 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5545 mdb_xcursor_init1(mc, leaf);
5548 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5549 if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) {
5550 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
5553 if (op == MDB_GET_BOTH) {
5559 rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p);
5560 if (rc != MDB_SUCCESS)
5563 } else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {
5565 if ((rc = mdb_node_read(mc->mc_txn, leaf, &d2)) != MDB_SUCCESS)
5567 rc = mc->mc_dbx->md_dcmp(data, &d2);
5569 if (op == MDB_GET_BOTH || rc > 0)
5570 return MDB_NOTFOUND;
5577 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5578 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5583 /* The key already matches in all other cases */
5584 if (op == MDB_SET_RANGE || op == MDB_SET_KEY)
5585 MDB_GET_KEY(leaf, key);
5586 DPRINTF(("==> cursor placed on key [%s]", DKEY(key)));
5591 /** Move the cursor to the first item in the database. */
5593 mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data)
5599 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5601 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
5602 rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
5603 if (rc != MDB_SUCCESS)
5606 mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
5608 leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0);
5609 mc->mc_flags |= C_INITIALIZED;
5610 mc->mc_flags &= ~C_EOF;
5612 mc->mc_ki[mc->mc_top] = 0;
5614 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
5615 key->mv_size = mc->mc_db->md_pad;
5616 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size);
5621 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5622 mdb_xcursor_init1(mc, leaf);
5623 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
5627 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5631 MDB_GET_KEY(leaf, key);
5635 /** Move the cursor to the last item in the database. */
5637 mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)
5643 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5645 if (!(mc->mc_flags & C_EOF)) {
5647 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
5648 rc = mdb_page_search(mc, NULL, MDB_PS_LAST);
5649 if (rc != MDB_SUCCESS)
5652 mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
5655 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;
5656 mc->mc_flags |= C_INITIALIZED|C_EOF;
5657 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5659 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
5660 key->mv_size = mc->mc_db->md_pad;
5661 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size);
5666 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5667 mdb_xcursor_init1(mc, leaf);
5668 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
5672 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5677 MDB_GET_KEY(leaf, key);
5682 mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,
5687 int (*mfunc)(MDB_cursor *mc, MDB_val *key, MDB_val *data);
5692 if (mc->mc_txn->mt_flags & MDB_TXN_ERROR)
5696 case MDB_GET_CURRENT:
5697 if (!(mc->mc_flags & C_INITIALIZED)) {
5700 MDB_page *mp = mc->mc_pg[mc->mc_top];
5701 int nkeys = NUMKEYS(mp);
5702 if (!nkeys || mc->mc_ki[mc->mc_top] >= nkeys) {
5703 mc->mc_ki[mc->mc_top] = nkeys;
5709 key->mv_size = mc->mc_db->md_pad;
5710 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5712 MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5713 MDB_GET_KEY(leaf, key);
5715 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5716 if (mc->mc_flags & C_DEL)
5717 mdb_xcursor_init1(mc, leaf);
5718 rc = mdb_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT);
5720 rc = mdb_node_read(mc->mc_txn, leaf, data);
5727 case MDB_GET_BOTH_RANGE:
5732 if (mc->mc_xcursor == NULL) {
5733 rc = MDB_INCOMPATIBLE;
5743 rc = mdb_cursor_set(mc, key, data, op,
5744 op == MDB_SET_RANGE ? NULL : &exact);
5747 case MDB_GET_MULTIPLE:
5748 if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
5752 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
5753 rc = MDB_INCOMPATIBLE;
5757 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) ||
5758 (mc->mc_xcursor->mx_cursor.mc_flags & C_EOF))
5761 case MDB_NEXT_MULTIPLE:
5766 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
5767 rc = MDB_INCOMPATIBLE;
5770 if (!(mc->mc_flags & C_INITIALIZED))
5771 rc = mdb_cursor_first(mc, key, data);
5773 rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP);
5774 if (rc == MDB_SUCCESS) {
5775 if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
5778 mx = &mc->mc_xcursor->mx_cursor;
5779 data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) *
5781 data->mv_data = METADATA(mx->mc_pg[mx->mc_top]);
5782 mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1;
5790 case MDB_NEXT_NODUP:
5791 if (!(mc->mc_flags & C_INITIALIZED))
5792 rc = mdb_cursor_first(mc, key, data);
5794 rc = mdb_cursor_next(mc, key, data, op);
5798 case MDB_PREV_NODUP:
5799 if (!(mc->mc_flags & C_INITIALIZED)) {
5800 rc = mdb_cursor_last(mc, key, data);
5803 mc->mc_flags |= C_INITIALIZED;
5804 mc->mc_ki[mc->mc_top]++;
5806 rc = mdb_cursor_prev(mc, key, data, op);
5809 rc = mdb_cursor_first(mc, key, data);
5812 mfunc = mdb_cursor_first;
5814 if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
5818 if (mc->mc_xcursor == NULL) {
5819 rc = MDB_INCOMPATIBLE;
5822 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
5826 rc = mfunc(&mc->mc_xcursor->mx_cursor, data, NULL);
5829 rc = mdb_cursor_last(mc, key, data);
5832 mfunc = mdb_cursor_last;
5835 DPRINTF(("unhandled/unimplemented cursor operation %u", op));
5840 if (mc->mc_flags & C_DEL)
5841 mc->mc_flags ^= C_DEL;
5846 /** Touch all the pages in the cursor stack. Set mc_top.
5847 * Makes sure all the pages are writable, before attempting a write operation.
5848 * @param[in] mc The cursor to operate on.
5851 mdb_cursor_touch(MDB_cursor *mc)
5853 int rc = MDB_SUCCESS;
5855 if (mc->mc_dbi > MAIN_DBI && !(*mc->mc_dbflag & DB_DIRTY)) {
5858 if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))
5860 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, &mcx);
5861 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY);
5864 *mc->mc_dbflag |= DB_DIRTY;
5869 rc = mdb_page_touch(mc);
5870 } while (!rc && ++(mc->mc_top) < mc->mc_snum);
5871 mc->mc_top = mc->mc_snum-1;
5876 /** Do not spill pages to disk if txn is getting full, may fail instead */
5877 #define MDB_NOSPILL 0x8000
5880 mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
5883 enum { MDB_NO_ROOT = MDB_LAST_ERRCODE+10 }; /* internal code */
5885 MDB_node *leaf = NULL;
5888 MDB_val xdata, *rdata, dkey, olddata;
5890 int do_sub = 0, insert_key, insert_data;
5891 unsigned int mcount = 0, dcount = 0, nospill;
5894 unsigned int nflags;
5897 if (mc == NULL || key == NULL)
5900 env = mc->mc_txn->mt_env;
5902 /* Check this first so counter will always be zero on any
5905 if (flags & MDB_MULTIPLE) {
5906 dcount = data[1].mv_size;
5907 data[1].mv_size = 0;
5908 if (!F_ISSET(mc->mc_db->md_flags, MDB_DUPFIXED))
5909 return MDB_INCOMPATIBLE;
5912 nospill = flags & MDB_NOSPILL;
5913 flags &= ~MDB_NOSPILL;
5915 if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
5916 return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
5918 if (key->mv_size-1 >= ENV_MAXKEY(env))
5919 return MDB_BAD_VALSIZE;
5921 #if SIZE_MAX > MAXDATASIZE
5922 if (data->mv_size > ((mc->mc_db->md_flags & MDB_DUPSORT) ? ENV_MAXKEY(env) : MAXDATASIZE))
5923 return MDB_BAD_VALSIZE;
5925 if ((mc->mc_db->md_flags & MDB_DUPSORT) && data->mv_size > ENV_MAXKEY(env))
5926 return MDB_BAD_VALSIZE;
5929 DPRINTF(("==> put db %d key [%s], size %"Z"u, data size %"Z"u",
5930 DDBI(mc), DKEY(key), key ? key->mv_size : 0, data->mv_size));
5934 if (flags == MDB_CURRENT) {
5935 if (!(mc->mc_flags & C_INITIALIZED))
5938 } else if (mc->mc_db->md_root == P_INVALID) {
5939 /* new database, cursor has nothing to point to */
5942 mc->mc_flags &= ~C_INITIALIZED;
5947 if (flags & MDB_APPEND) {
5949 rc = mdb_cursor_last(mc, &k2, &d2);
5951 rc = mc->mc_dbx->md_cmp(key, &k2);
5954 mc->mc_ki[mc->mc_top]++;
5956 /* new key is <= last key */
5961 rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact);
5963 if ((flags & MDB_NOOVERWRITE) && rc == 0) {
5964 DPRINTF(("duplicate key [%s]", DKEY(key)));
5966 return MDB_KEYEXIST;
5968 if (rc && rc != MDB_NOTFOUND)
5972 if (mc->mc_flags & C_DEL)
5973 mc->mc_flags ^= C_DEL;
5975 /* Cursor is positioned, check for room in the dirty list */
5977 if (flags & MDB_MULTIPLE) {
5979 xdata.mv_size = data->mv_size * dcount;
5983 if ((rc2 = mdb_page_spill(mc, key, rdata)))
5987 if (rc == MDB_NO_ROOT) {
5989 /* new database, write a root leaf page */
5990 DPUTS("allocating new root leaf page");
5991 if ((rc2 = mdb_page_new(mc, P_LEAF, 1, &np))) {
5994 mdb_cursor_push(mc, np);
5995 mc->mc_db->md_root = np->mp_pgno;
5996 mc->mc_db->md_depth++;
5997 *mc->mc_dbflag |= DB_DIRTY;
5998 if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED))
6000 np->mp_flags |= P_LEAF2;
6001 mc->mc_flags |= C_INITIALIZED;
6003 /* make sure all cursor pages are writable */
6004 rc2 = mdb_cursor_touch(mc);
6009 insert_key = insert_data = rc;
6011 /* The key does not exist */
6012 DPRINTF(("inserting key at index %i", mc->mc_ki[mc->mc_top]));
6013 if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
6014 LEAFSIZE(key, data) > env->me_nodemax)
6016 /* Too big for a node, insert in sub-DB. Set up an empty
6017 * "old sub-page" for prep_subDB to expand to a full page.
6019 fp_flags = P_LEAF|P_DIRTY;
6021 fp->mp_pad = data->mv_size; /* used if MDB_DUPFIXED */
6022 fp->mp_lower = fp->mp_upper = (PAGEHDRSZ-PAGEBASE);
6023 olddata.mv_size = PAGEHDRSZ;
6027 /* there's only a key anyway, so this is a no-op */
6028 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
6030 unsigned int ksize = mc->mc_db->md_pad;
6031 if (key->mv_size != ksize)
6032 return MDB_BAD_VALSIZE;
6033 ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize);
6034 memcpy(ptr, key->mv_data, ksize);
6039 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6040 olddata.mv_size = NODEDSZ(leaf);
6041 olddata.mv_data = NODEDATA(leaf);
6044 if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) {
6045 /* Prepare (sub-)page/sub-DB to accept the new item,
6046 * if needed. fp: old sub-page or a header faking
6047 * it. mp: new (sub-)page. offset: growth in page
6048 * size. xdata: node data with new page or DB.
6050 unsigned i, offset = 0;
6051 mp = fp = xdata.mv_data = env->me_pbuf;
6052 mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
6054 /* Was a single item before, must convert now */
6055 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6056 /* Just overwrite the current item */
6057 if (flags == MDB_CURRENT)
6060 #if UINT_MAX < SIZE_MAX
6061 if (mc->mc_dbx->md_dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
6062 mc->mc_dbx->md_dcmp = mdb_cmp_clong;
6064 /* does data match? */
6065 if (!mc->mc_dbx->md_dcmp(data, &olddata)) {
6066 if (flags & MDB_NODUPDATA)
6067 return MDB_KEYEXIST;
6072 /* Back up original data item */
6073 dkey.mv_size = olddata.mv_size;
6074 dkey.mv_data = memcpy(fp+1, olddata.mv_data, olddata.mv_size);
6076 /* Make sub-page header for the dup items, with dummy body */
6077 fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP;
6078 fp->mp_lower = (PAGEHDRSZ-PAGEBASE);
6079 xdata.mv_size = PAGEHDRSZ + dkey.mv_size + data->mv_size;
6080 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
6081 fp->mp_flags |= P_LEAF2;
6082 fp->mp_pad = data->mv_size;
6083 xdata.mv_size += 2 * data->mv_size; /* leave space for 2 more */
6085 xdata.mv_size += 2 * (sizeof(indx_t) + NODESIZE) +
6086 (dkey.mv_size & 1) + (data->mv_size & 1);
6088 fp->mp_upper = xdata.mv_size - PAGEBASE;
6089 olddata.mv_size = xdata.mv_size; /* pretend olddata is fp */
6090 } else if (leaf->mn_flags & F_SUBDATA) {
6091 /* Data is on sub-DB, just store it */
6092 flags |= F_DUPDATA|F_SUBDATA;
6095 /* Data is on sub-page */
6096 fp = olddata.mv_data;
6099 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
6100 offset = EVEN(NODESIZE + sizeof(indx_t) +
6104 offset = fp->mp_pad;
6105 if (SIZELEFT(fp) < offset) {
6106 offset *= 4; /* space for 4 more */
6109 /* FALLTHRU: Big enough MDB_DUPFIXED sub-page */
6111 fp->mp_flags |= P_DIRTY;
6112 COPY_PGNO(fp->mp_pgno, mp->mp_pgno);
6113 mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;
6117 xdata.mv_size = olddata.mv_size + offset;
6120 fp_flags = fp->mp_flags;
6121 if (NODESIZE + NODEKSZ(leaf) + xdata.mv_size > env->me_nodemax) {
6122 /* Too big for a sub-page, convert to sub-DB */
6123 fp_flags &= ~P_SUBP;
6125 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
6126 fp_flags |= P_LEAF2;
6127 dummy.md_pad = fp->mp_pad;
6128 dummy.md_flags = MDB_DUPFIXED;
6129 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
6130 dummy.md_flags |= MDB_INTEGERKEY;
6136 dummy.md_branch_pages = 0;
6137 dummy.md_leaf_pages = 1;
6138 dummy.md_overflow_pages = 0;
6139 dummy.md_entries = NUMKEYS(fp);
6140 xdata.mv_size = sizeof(MDB_db);
6141 xdata.mv_data = &dummy;
6142 if ((rc = mdb_page_alloc(mc, 1, &mp)))
6144 offset = env->me_psize - olddata.mv_size;
6145 flags |= F_DUPDATA|F_SUBDATA;
6146 dummy.md_root = mp->mp_pgno;
6149 mp->mp_flags = fp_flags | P_DIRTY;
6150 mp->mp_pad = fp->mp_pad;
6151 mp->mp_lower = fp->mp_lower;
6152 mp->mp_upper = fp->mp_upper + offset;
6153 if (fp_flags & P_LEAF2) {
6154 memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad);
6156 memcpy((char *)mp + mp->mp_upper + PAGEBASE, (char *)fp + fp->mp_upper + PAGEBASE,
6157 olddata.mv_size - fp->mp_upper - PAGEBASE);
6158 for (i=0; i<NUMKEYS(fp); i++)
6159 mp->mp_ptrs[i] = fp->mp_ptrs[i] + offset;
6167 mdb_node_del(mc, 0);
6171 /* overflow page overwrites need special handling */
6172 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
6175 int level, ovpages, dpages = OVPAGES(data->mv_size, env->me_psize);
6177 memcpy(&pg, olddata.mv_data, sizeof(pg));
6178 if ((rc2 = mdb_page_get(mc->mc_txn, pg, &omp, &level)) != 0)
6180 ovpages = omp->mp_pages;
6182 /* Is the ov page large enough? */
6183 if (ovpages >= dpages) {
6184 if (!(omp->mp_flags & P_DIRTY) &&
6185 (level || (env->me_flags & MDB_WRITEMAP)))
6187 rc = mdb_page_unspill(mc->mc_txn, omp, &omp);
6190 level = 0; /* dirty in this txn or clean */
6193 if (omp->mp_flags & P_DIRTY) {
6194 /* yes, overwrite it. Note in this case we don't
6195 * bother to try shrinking the page if the new data
6196 * is smaller than the overflow threshold.
6199 /* It is writable only in a parent txn */
6200 size_t sz = (size_t) env->me_psize * ovpages, off;
6201 MDB_page *np = mdb_page_malloc(mc->mc_txn, ovpages);
6207 rc2 = mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);
6208 mdb_cassert(mc, rc2 == 0);
6209 if (!(flags & MDB_RESERVE)) {
6210 /* Copy end of page, adjusting alignment so
6211 * compiler may copy words instead of bytes.
6213 off = (PAGEHDRSZ + data->mv_size) & -sizeof(size_t);
6214 memcpy((size_t *)((char *)np + off),
6215 (size_t *)((char *)omp + off), sz - off);
6218 memcpy(np, omp, sz); /* Copy beginning of page */
6221 SETDSZ(leaf, data->mv_size);
6222 if (F_ISSET(flags, MDB_RESERVE))
6223 data->mv_data = METADATA(omp);
6225 memcpy(METADATA(omp), data->mv_data, data->mv_size);
6229 if ((rc2 = mdb_ovpage_free(mc, omp)) != MDB_SUCCESS)
6231 } else if (data->mv_size == olddata.mv_size) {
6232 /* same size, just replace it. Note that we could
6233 * also reuse this node if the new data is smaller,
6234 * but instead we opt to shrink the node in that case.
6236 if (F_ISSET(flags, MDB_RESERVE))
6237 data->mv_data = olddata.mv_data;
6238 else if (!(mc->mc_flags & C_SUB))
6239 memcpy(olddata.mv_data, data->mv_data, data->mv_size);
6241 memcpy(NODEKEY(leaf), key->mv_data, key->mv_size);
6244 mdb_node_del(mc, 0);
6250 nflags = flags & NODE_ADD_FLAGS;
6251 nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(env, key, rdata);
6252 if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) {
6253 if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA )
6254 nflags &= ~MDB_APPEND; /* sub-page may need room to grow */
6256 nflags |= MDB_SPLIT_REPLACE;
6257 rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags);
6259 /* There is room already in this leaf page. */
6260 rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);
6261 if (rc == 0 && insert_key) {
6262 /* Adjust other cursors pointing to mp */
6263 MDB_cursor *m2, *m3;
6264 MDB_dbi dbi = mc->mc_dbi;
6265 unsigned i = mc->mc_top;
6266 MDB_page *mp = mc->mc_pg[i];
6268 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
6269 if (mc->mc_flags & C_SUB)
6270 m3 = &m2->mc_xcursor->mx_cursor;
6273 if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
6274 if (m3->mc_pg[i] == mp && m3->mc_ki[i] >= mc->mc_ki[i]) {
6281 if (rc == MDB_SUCCESS) {
6282 /* Now store the actual data in the child DB. Note that we're
6283 * storing the user data in the keys field, so there are strict
6284 * size limits on dupdata. The actual data fields of the child
6285 * DB are all zero size.
6293 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6294 if (flags & MDB_CURRENT) {
6295 xflags = MDB_CURRENT|MDB_NOSPILL;
6297 mdb_xcursor_init1(mc, leaf);
6298 xflags = (flags & MDB_NODUPDATA) ?
6299 MDB_NOOVERWRITE|MDB_NOSPILL : MDB_NOSPILL;
6301 /* converted, write the original data first */
6303 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);
6307 /* Adjust other cursors pointing to mp */
6309 unsigned i = mc->mc_top;
6310 MDB_page *mp = mc->mc_pg[i];
6312 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
6313 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
6314 if (!(m2->mc_flags & C_INITIALIZED)) continue;
6315 if (m2->mc_pg[i] == mp && m2->mc_ki[i] == mc->mc_ki[i]) {
6316 mdb_xcursor_init1(m2, leaf);
6320 /* we've done our job */
6323 ecount = mc->mc_xcursor->mx_db.md_entries;
6324 if (flags & MDB_APPENDDUP)
6325 xflags |= MDB_APPEND;
6326 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);
6327 if (flags & F_SUBDATA) {
6328 void *db = NODEDATA(leaf);
6329 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
6331 insert_data = mc->mc_xcursor->mx_db.md_entries - ecount;
6333 /* Increment count unless we just replaced an existing item. */
6335 mc->mc_db->md_entries++;
6337 /* Invalidate txn if we created an empty sub-DB */
6340 /* If we succeeded and the key didn't exist before,
6341 * make sure the cursor is marked valid.
6343 mc->mc_flags |= C_INITIALIZED;
6345 if (flags & MDB_MULTIPLE) {
6348 /* let caller know how many succeeded, if any */
6349 data[1].mv_size = mcount;
6350 if (mcount < dcount) {
6351 data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size;
6352 insert_key = insert_data = 0;
6359 if (rc == MDB_KEYEXIST) /* should not happen, we deleted that item */
6362 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
6367 mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
6373 if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
6374 return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
6376 if (!(mc->mc_flags & C_INITIALIZED))
6379 if (mc->mc_ki[mc->mc_top] >= NUMKEYS(mc->mc_pg[mc->mc_top]))
6380 return MDB_NOTFOUND;
6382 if (!(flags & MDB_NOSPILL) && (rc = mdb_page_spill(mc, NULL, NULL)))
6385 rc = mdb_cursor_touch(mc);
6389 mp = mc->mc_pg[mc->mc_top];
6392 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6394 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6395 if (flags & MDB_NODUPDATA) {
6396 /* mdb_cursor_del0() will subtract the final entry */
6397 mc->mc_db->md_entries -= mc->mc_xcursor->mx_db.md_entries - 1;
6399 if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
6400 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6402 rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, MDB_NOSPILL);
6405 /* If sub-DB still has entries, we're done */
6406 if (mc->mc_xcursor->mx_db.md_entries) {
6407 if (leaf->mn_flags & F_SUBDATA) {
6408 /* update subDB info */
6409 void *db = NODEDATA(leaf);
6410 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
6413 /* shrink fake page */
6414 mdb_node_shrink(mp, mc->mc_ki[mc->mc_top]);
6415 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6416 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6417 /* fix other sub-DB cursors pointed at this fake page */
6418 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
6419 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
6420 if (m2->mc_pg[mc->mc_top] == mp &&
6421 m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top])
6422 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6425 mc->mc_db->md_entries--;
6426 mc->mc_flags |= C_DEL;
6429 /* otherwise fall thru and delete the sub-DB */
6432 if (leaf->mn_flags & F_SUBDATA) {
6433 /* add all the child DB's pages to the free list */
6434 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
6440 /* add overflow pages to free list */
6441 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
6445 memcpy(&pg, NODEDATA(leaf), sizeof(pg));
6446 if ((rc = mdb_page_get(mc->mc_txn, pg, &omp, NULL)) ||
6447 (rc = mdb_ovpage_free(mc, omp)))
6452 return mdb_cursor_del0(mc);
6455 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
6459 /** Allocate and initialize new pages for a database.
6460 * @param[in] mc a cursor on the database being added to.
6461 * @param[in] flags flags defining what type of page is being allocated.
6462 * @param[in] num the number of pages to allocate. This is usually 1,
6463 * unless allocating overflow pages for a large record.
6464 * @param[out] mp Address of a page, or NULL on failure.
6465 * @return 0 on success, non-zero on failure.
6468 mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp)
6473 if ((rc = mdb_page_alloc(mc, num, &np)))
6475 DPRINTF(("allocated new mpage %"Z"u, page size %u",
6476 np->mp_pgno, mc->mc_txn->mt_env->me_psize));
6477 np->mp_flags = flags | P_DIRTY;
6478 np->mp_lower = (PAGEHDRSZ-PAGEBASE);
6479 np->mp_upper = mc->mc_txn->mt_env->me_psize - PAGEBASE;
6482 mc->mc_db->md_branch_pages++;
6483 else if (IS_LEAF(np))
6484 mc->mc_db->md_leaf_pages++;
6485 else if (IS_OVERFLOW(np)) {
6486 mc->mc_db->md_overflow_pages += num;
6494 /** Calculate the size of a leaf node.
6495 * The size depends on the environment's page size; if a data item
6496 * is too large it will be put onto an overflow page and the node
6497 * size will only include the key and not the data. Sizes are always
6498 * rounded up to an even number of bytes, to guarantee 2-byte alignment
6499 * of the #MDB_node headers.
6500 * @param[in] env The environment handle.
6501 * @param[in] key The key for the node.
6502 * @param[in] data The data for the node.
6503 * @return The number of bytes needed to store the node.
6506 mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data)
6510 sz = LEAFSIZE(key, data);
6511 if (sz > env->me_nodemax) {
6512 /* put on overflow page */
6513 sz -= data->mv_size - sizeof(pgno_t);
6516 return EVEN(sz + sizeof(indx_t));
6519 /** Calculate the size of a branch node.
6520 * The size should depend on the environment's page size but since
6521 * we currently don't support spilling large keys onto overflow
6522 * pages, it's simply the size of the #MDB_node header plus the
6523 * size of the key. Sizes are always rounded up to an even number
6524 * of bytes, to guarantee 2-byte alignment of the #MDB_node headers.
6525 * @param[in] env The environment handle.
6526 * @param[in] key The key for the node.
6527 * @return The number of bytes needed to store the node.
6530 mdb_branch_size(MDB_env *env, MDB_val *key)
6535 if (sz > env->me_nodemax) {
6536 /* put on overflow page */
6537 /* not implemented */
6538 /* sz -= key->size - sizeof(pgno_t); */
6541 return sz + sizeof(indx_t);
6544 /** Add a node to the page pointed to by the cursor.
6545 * @param[in] mc The cursor for this operation.
6546 * @param[in] indx The index on the page where the new node should be added.
6547 * @param[in] key The key for the new node.
6548 * @param[in] data The data for the new node, if any.
6549 * @param[in] pgno The page number, if adding a branch node.
6550 * @param[in] flags Flags for the node.
6551 * @return 0 on success, non-zero on failure. Possible errors are:
6553 * <li>ENOMEM - failed to allocate overflow pages for the node.
6554 * <li>MDB_PAGE_FULL - there is insufficient room in the page. This error
6555 * should never happen since all callers already calculate the
6556 * page's free space before calling this function.
6560 mdb_node_add(MDB_cursor *mc, indx_t indx,
6561 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags)
6564 size_t node_size = NODESIZE;
6568 MDB_page *mp = mc->mc_pg[mc->mc_top];
6569 MDB_page *ofp = NULL; /* overflow page */
6572 mdb_cassert(mc, mp->mp_upper >= mp->mp_lower);
6574 DPRINTF(("add to %s %spage %"Z"u index %i, data size %"Z"u key size %"Z"u [%s]",
6575 IS_LEAF(mp) ? "leaf" : "branch",
6576 IS_SUBP(mp) ? "sub-" : "",
6577 mdb_dbg_pgno(mp), indx, data ? data->mv_size : 0,
6578 key ? key->mv_size : 0, key ? DKEY(key) : "null"));
6581 /* Move higher keys up one slot. */
6582 int ksize = mc->mc_db->md_pad, dif;
6583 char *ptr = LEAF2KEY(mp, indx, ksize);
6584 dif = NUMKEYS(mp) - indx;
6586 memmove(ptr+ksize, ptr, dif*ksize);
6587 /* insert new key */
6588 memcpy(ptr, key->mv_data, ksize);
6590 /* Just using these for counting */
6591 mp->mp_lower += sizeof(indx_t);
6592 mp->mp_upper -= ksize - sizeof(indx_t);
6596 room = (ssize_t)SIZELEFT(mp) - (ssize_t)sizeof(indx_t);
6598 node_size += key->mv_size;
6600 mdb_cassert(mc, data);
6601 if (F_ISSET(flags, F_BIGDATA)) {
6602 /* Data already on overflow page. */
6603 node_size += sizeof(pgno_t);
6604 } else if (node_size + data->mv_size > mc->mc_txn->mt_env->me_nodemax) {
6605 int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
6607 /* Put data on overflow page. */
6608 DPRINTF(("data size is %"Z"u, node would be %"Z"u, put data on overflow page",
6609 data->mv_size, node_size+data->mv_size));
6610 node_size = EVEN(node_size + sizeof(pgno_t));
6611 if ((ssize_t)node_size > room)
6613 if ((rc = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp)))
6615 DPRINTF(("allocated overflow page %"Z"u", ofp->mp_pgno));
6619 node_size += data->mv_size;
6622 node_size = EVEN(node_size);
6623 if ((ssize_t)node_size > room)
6627 /* Move higher pointers up one slot. */
6628 for (i = NUMKEYS(mp); i > indx; i--)
6629 mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];
6631 /* Adjust free space offsets. */
6632 ofs = mp->mp_upper - node_size;
6633 mdb_cassert(mc, ofs >= mp->mp_lower + sizeof(indx_t));
6634 mp->mp_ptrs[indx] = ofs;
6636 mp->mp_lower += sizeof(indx_t);
6638 /* Write the node data. */
6639 node = NODEPTR(mp, indx);
6640 node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
6641 node->mn_flags = flags;
6643 SETDSZ(node,data->mv_size);
6648 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
6651 mdb_cassert(mc, key);
6653 if (F_ISSET(flags, F_BIGDATA))
6654 memcpy(node->mn_data + key->mv_size, data->mv_data,
6656 else if (F_ISSET(flags, MDB_RESERVE))
6657 data->mv_data = node->mn_data + key->mv_size;
6659 memcpy(node->mn_data + key->mv_size, data->mv_data,
6662 memcpy(node->mn_data + key->mv_size, &ofp->mp_pgno,
6664 if (F_ISSET(flags, MDB_RESERVE))
6665 data->mv_data = METADATA(ofp);
6667 memcpy(METADATA(ofp), data->mv_data, data->mv_size);
6674 DPRINTF(("not enough room in page %"Z"u, got %u ptrs",
6675 mdb_dbg_pgno(mp), NUMKEYS(mp)));
6676 DPRINTF(("upper-lower = %u - %u = %"Z"d", mp->mp_upper,mp->mp_lower,room));
6677 DPRINTF(("node size = %"Z"u", node_size));
6678 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
6679 return MDB_PAGE_FULL;
6682 /** Delete the specified node from a page.
6683 * @param[in] mc Cursor pointing to the node to delete.
6684 * @param[in] ksize The size of a node. Only used if the page is
6685 * part of a #MDB_DUPFIXED database.
6688 mdb_node_del(MDB_cursor *mc, int ksize)
6690 MDB_page *mp = mc->mc_pg[mc->mc_top];
6691 indx_t indx = mc->mc_ki[mc->mc_top];
6693 indx_t i, j, numkeys, ptr;
6697 DPRINTF(("delete node %u on %s page %"Z"u", indx,
6698 IS_LEAF(mp) ? "leaf" : "branch", mdb_dbg_pgno(mp)));
6699 numkeys = NUMKEYS(mp);
6700 mdb_cassert(mc, indx < numkeys);
6703 int x = numkeys - 1 - indx;
6704 base = LEAF2KEY(mp, indx, ksize);
6706 memmove(base, base + ksize, x * ksize);
6707 mp->mp_lower -= sizeof(indx_t);
6708 mp->mp_upper += ksize - sizeof(indx_t);
6712 node = NODEPTR(mp, indx);
6713 sz = NODESIZE + node->mn_ksize;
6715 if (F_ISSET(node->mn_flags, F_BIGDATA))
6716 sz += sizeof(pgno_t);
6718 sz += NODEDSZ(node);
6722 ptr = mp->mp_ptrs[indx];
6723 for (i = j = 0; i < numkeys; i++) {
6725 mp->mp_ptrs[j] = mp->mp_ptrs[i];
6726 if (mp->mp_ptrs[i] < ptr)
6727 mp->mp_ptrs[j] += sz;
6732 base = (char *)mp + mp->mp_upper + PAGEBASE;
6733 memmove(base + sz, base, ptr - mp->mp_upper);
6735 mp->mp_lower -= sizeof(indx_t);
6739 /** Compact the main page after deleting a node on a subpage.
6740 * @param[in] mp The main page to operate on.
6741 * @param[in] indx The index of the subpage on the main page.
6744 mdb_node_shrink(MDB_page *mp, indx_t indx)
6750 indx_t i, numkeys, ptr;
6752 node = NODEPTR(mp, indx);
6753 sp = (MDB_page *)NODEDATA(node);
6754 delta = SIZELEFT(sp);
6755 xp = (MDB_page *)((char *)sp + delta);
6757 /* shift subpage upward */
6759 nsize = NUMKEYS(sp) * sp->mp_pad;
6761 return; /* do not make the node uneven-sized */
6762 memmove(METADATA(xp), METADATA(sp), nsize);
6765 numkeys = NUMKEYS(sp);
6766 for (i=numkeys-1; i>=0; i--)
6767 xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta;
6769 xp->mp_upper = sp->mp_lower;
6770 xp->mp_lower = sp->mp_lower;
6771 xp->mp_flags = sp->mp_flags;
6772 xp->mp_pad = sp->mp_pad;
6773 COPY_PGNO(xp->mp_pgno, mp->mp_pgno);
6775 nsize = NODEDSZ(node) - delta;
6776 SETDSZ(node, nsize);
6778 /* shift lower nodes upward */
6779 ptr = mp->mp_ptrs[indx];
6780 numkeys = NUMKEYS(mp);
6781 for (i = 0; i < numkeys; i++) {
6782 if (mp->mp_ptrs[i] <= ptr)
6783 mp->mp_ptrs[i] += delta;
6786 base = (char *)mp + mp->mp_upper + PAGEBASE;
6787 memmove(base + delta, base, ptr - mp->mp_upper + NODESIZE + NODEKSZ(node));
6788 mp->mp_upper += delta;
6791 /** Initial setup of a sorted-dups cursor.
6792 * Sorted duplicates are implemented as a sub-database for the given key.
6793 * The duplicate data items are actually keys of the sub-database.
6794 * Operations on the duplicate data items are performed using a sub-cursor
6795 * initialized when the sub-database is first accessed. This function does
6796 * the preliminary setup of the sub-cursor, filling in the fields that
6797 * depend only on the parent DB.
6798 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
6801 mdb_xcursor_init0(MDB_cursor *mc)
6803 MDB_xcursor *mx = mc->mc_xcursor;
6805 mx->mx_cursor.mc_xcursor = NULL;
6806 mx->mx_cursor.mc_txn = mc->mc_txn;
6807 mx->mx_cursor.mc_db = &mx->mx_db;
6808 mx->mx_cursor.mc_dbx = &mx->mx_dbx;
6809 mx->mx_cursor.mc_dbi = mc->mc_dbi;
6810 mx->mx_cursor.mc_dbflag = &mx->mx_dbflag;
6811 mx->mx_cursor.mc_snum = 0;
6812 mx->mx_cursor.mc_top = 0;
6813 mx->mx_cursor.mc_flags = C_SUB;
6814 mx->mx_dbx.md_name.mv_size = 0;
6815 mx->mx_dbx.md_name.mv_data = NULL;
6816 mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp;
6817 mx->mx_dbx.md_dcmp = NULL;
6818 mx->mx_dbx.md_rel = mc->mc_dbx->md_rel;
6821 /** Final setup of a sorted-dups cursor.
6822 * Sets up the fields that depend on the data from the main cursor.
6823 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
6824 * @param[in] node The data containing the #MDB_db record for the
6825 * sorted-dup database.
6828 mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)
6830 MDB_xcursor *mx = mc->mc_xcursor;
6832 if (node->mn_flags & F_SUBDATA) {
6833 memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db));
6834 mx->mx_cursor.mc_pg[0] = 0;
6835 mx->mx_cursor.mc_snum = 0;
6836 mx->mx_cursor.mc_top = 0;
6837 mx->mx_cursor.mc_flags = C_SUB;
6839 MDB_page *fp = NODEDATA(node);
6840 mx->mx_db.md_pad = mc->mc_pg[mc->mc_top]->mp_pad;
6841 mx->mx_db.md_flags = 0;
6842 mx->mx_db.md_depth = 1;
6843 mx->mx_db.md_branch_pages = 0;
6844 mx->mx_db.md_leaf_pages = 1;
6845 mx->mx_db.md_overflow_pages = 0;
6846 mx->mx_db.md_entries = NUMKEYS(fp);
6847 COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno);
6848 mx->mx_cursor.mc_snum = 1;
6849 mx->mx_cursor.mc_top = 0;
6850 mx->mx_cursor.mc_flags = C_INITIALIZED|C_SUB;
6851 mx->mx_cursor.mc_pg[0] = fp;
6852 mx->mx_cursor.mc_ki[0] = 0;
6853 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
6854 mx->mx_db.md_flags = MDB_DUPFIXED;
6855 mx->mx_db.md_pad = fp->mp_pad;
6856 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
6857 mx->mx_db.md_flags |= MDB_INTEGERKEY;
6860 DPRINTF(("Sub-db -%u root page %"Z"u", mx->mx_cursor.mc_dbi,
6861 mx->mx_db.md_root));
6862 mx->mx_dbflag = DB_VALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
6863 #if UINT_MAX < SIZE_MAX
6864 if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(size_t))
6865 mx->mx_dbx.md_cmp = mdb_cmp_clong;
6869 /** Initialize a cursor for a given transaction and database. */
6871 mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
6874 mc->mc_backup = NULL;
6877 mc->mc_db = &txn->mt_dbs[dbi];
6878 mc->mc_dbx = &txn->mt_dbxs[dbi];
6879 mc->mc_dbflag = &txn->mt_dbflags[dbi];
6884 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
6885 mdb_tassert(txn, mx != NULL);
6886 mc->mc_xcursor = mx;
6887 mdb_xcursor_init0(mc);
6889 mc->mc_xcursor = NULL;
6891 if (*mc->mc_dbflag & DB_STALE) {
6892 mdb_page_search(mc, NULL, MDB_PS_ROOTONLY);
6897 mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
6900 size_t size = sizeof(MDB_cursor);
6902 if (!ret || !TXN_DBI_EXIST(txn, dbi))
6905 if (txn->mt_flags & MDB_TXN_ERROR)
6908 /* Allow read access to the freelist */
6909 if (!dbi && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
6912 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)
6913 size += sizeof(MDB_xcursor);
6915 if ((mc = malloc(size)) != NULL) {
6916 mdb_cursor_init(mc, txn, dbi, (MDB_xcursor *)(mc + 1));
6917 if (txn->mt_cursors) {
6918 mc->mc_next = txn->mt_cursors[dbi];
6919 txn->mt_cursors[dbi] = mc;
6920 mc->mc_flags |= C_UNTRACK;
6932 mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)
6934 if (!mc || !TXN_DBI_EXIST(txn, mc->mc_dbi))
6937 if ((mc->mc_flags & C_UNTRACK) || txn->mt_cursors)
6940 if (txn->mt_flags & MDB_TXN_ERROR)
6943 mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor);
6947 /* Return the count of duplicate data items for the current key */
6949 mdb_cursor_count(MDB_cursor *mc, size_t *countp)
6953 if (mc == NULL || countp == NULL)
6956 if (mc->mc_xcursor == NULL)
6957 return MDB_INCOMPATIBLE;
6959 if (mc->mc_txn->mt_flags & MDB_TXN_ERROR)
6962 if (!(mc->mc_flags & C_INITIALIZED))
6965 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6966 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6969 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
6972 *countp = mc->mc_xcursor->mx_db.md_entries;
6978 mdb_cursor_close(MDB_cursor *mc)
6980 if (mc && !mc->mc_backup) {
6981 /* remove from txn, if tracked */
6982 if ((mc->mc_flags & C_UNTRACK) && mc->mc_txn->mt_cursors) {
6983 MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi];
6984 while (*prev && *prev != mc) prev = &(*prev)->mc_next;
6986 *prev = mc->mc_next;
6993 mdb_cursor_txn(MDB_cursor *mc)
6995 if (!mc) return NULL;
7000 mdb_cursor_dbi(MDB_cursor *mc)
7005 /** Replace the key for a branch node with a new key.
7006 * @param[in] mc Cursor pointing to the node to operate on.
7007 * @param[in] key The new key to use.
7008 * @return 0 on success, non-zero on failure.
7011 mdb_update_key(MDB_cursor *mc, MDB_val *key)
7017 int delta, ksize, oksize;
7018 indx_t ptr, i, numkeys, indx;
7021 indx = mc->mc_ki[mc->mc_top];
7022 mp = mc->mc_pg[mc->mc_top];
7023 node = NODEPTR(mp, indx);
7024 ptr = mp->mp_ptrs[indx];
7028 char kbuf2[DKBUF_MAXKEYSIZE*2+1];
7029 k2.mv_data = NODEKEY(node);
7030 k2.mv_size = node->mn_ksize;
7031 DPRINTF(("update key %u (ofs %u) [%s] to [%s] on page %"Z"u",
7033 mdb_dkey(&k2, kbuf2),
7039 /* Sizes must be 2-byte aligned. */
7040 ksize = EVEN(key->mv_size);
7041 oksize = EVEN(node->mn_ksize);
7042 delta = ksize - oksize;
7044 /* Shift node contents if EVEN(key length) changed. */
7046 if (delta > 0 && SIZELEFT(mp) < delta) {
7048 /* not enough space left, do a delete and split */
7049 DPRINTF(("Not enough room, delta = %d, splitting...", delta));
7050 pgno = NODEPGNO(node);
7051 mdb_node_del(mc, 0);
7052 return mdb_page_split(mc, key, NULL, pgno, MDB_SPLIT_REPLACE);
7055 numkeys = NUMKEYS(mp);
7056 for (i = 0; i < numkeys; i++) {
7057 if (mp->mp_ptrs[i] <= ptr)
7058 mp->mp_ptrs[i] -= delta;
7061 base = (char *)mp + mp->mp_upper + PAGEBASE;
7062 len = ptr - mp->mp_upper + NODESIZE;
7063 memmove(base - delta, base, len);
7064 mp->mp_upper -= delta;
7066 node = NODEPTR(mp, indx);
7069 /* But even if no shift was needed, update ksize */
7070 if (node->mn_ksize != key->mv_size)
7071 node->mn_ksize = key->mv_size;
7074 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
7080 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst);
7082 /** Move a node from csrc to cdst.
7085 mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
7092 unsigned short flags;
7096 /* Mark src and dst as dirty. */
7097 if ((rc = mdb_page_touch(csrc)) ||
7098 (rc = mdb_page_touch(cdst)))
7101 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7102 key.mv_size = csrc->mc_db->md_pad;
7103 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
7105 data.mv_data = NULL;
7109 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]);
7110 mdb_cassert(csrc, !((size_t)srcnode & 1));
7111 srcpg = NODEPGNO(srcnode);
7112 flags = srcnode->mn_flags;
7113 if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
7114 unsigned int snum = csrc->mc_snum;
7116 /* must find the lowest key below src */
7117 rc = mdb_page_search_lowest(csrc);
7120 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7121 key.mv_size = csrc->mc_db->md_pad;
7122 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
7124 s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
7125 key.mv_size = NODEKSZ(s2);
7126 key.mv_data = NODEKEY(s2);
7128 csrc->mc_snum = snum--;
7129 csrc->mc_top = snum;
7131 key.mv_size = NODEKSZ(srcnode);
7132 key.mv_data = NODEKEY(srcnode);
7134 data.mv_size = NODEDSZ(srcnode);
7135 data.mv_data = NODEDATA(srcnode);
7137 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) {
7138 unsigned int snum = cdst->mc_snum;
7141 /* must find the lowest key below dst */
7142 mdb_cursor_copy(cdst, &mn);
7143 rc = mdb_page_search_lowest(&mn);
7146 if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {
7147 bkey.mv_size = mn.mc_db->md_pad;
7148 bkey.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, bkey.mv_size);
7150 s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);
7151 bkey.mv_size = NODEKSZ(s2);
7152 bkey.mv_data = NODEKEY(s2);
7154 mn.mc_snum = snum--;
7157 rc = mdb_update_key(&mn, &bkey);
7162 DPRINTF(("moving %s node %u [%s] on page %"Z"u to node %u on page %"Z"u",
7163 IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch",
7164 csrc->mc_ki[csrc->mc_top],
7166 csrc->mc_pg[csrc->mc_top]->mp_pgno,
7167 cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno));
7169 /* Add the node to the destination page.
7171 rc = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags);
7172 if (rc != MDB_SUCCESS)
7175 /* Delete the node from the source page.
7177 mdb_node_del(csrc, key.mv_size);
7180 /* Adjust other cursors pointing to mp */
7181 MDB_cursor *m2, *m3;
7182 MDB_dbi dbi = csrc->mc_dbi;
7183 MDB_page *mp = csrc->mc_pg[csrc->mc_top];
7185 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7186 if (csrc->mc_flags & C_SUB)
7187 m3 = &m2->mc_xcursor->mx_cursor;
7190 if (m3 == csrc) continue;
7191 if (m3->mc_pg[csrc->mc_top] == mp && m3->mc_ki[csrc->mc_top] ==
7192 csrc->mc_ki[csrc->mc_top]) {
7193 m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
7194 m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
7199 /* Update the parent separators.
7201 if (csrc->mc_ki[csrc->mc_top] == 0) {
7202 if (csrc->mc_ki[csrc->mc_top-1] != 0) {
7203 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7204 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
7206 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
7207 key.mv_size = NODEKSZ(srcnode);
7208 key.mv_data = NODEKEY(srcnode);
7210 DPRINTF(("update separator for source page %"Z"u to [%s]",
7211 csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key)));
7212 mdb_cursor_copy(csrc, &mn);
7215 if ((rc = mdb_update_key(&mn, &key)) != MDB_SUCCESS)
7218 if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
7220 indx_t ix = csrc->mc_ki[csrc->mc_top];
7221 nullkey.mv_size = 0;
7222 csrc->mc_ki[csrc->mc_top] = 0;
7223 rc = mdb_update_key(csrc, &nullkey);
7224 csrc->mc_ki[csrc->mc_top] = ix;
7225 mdb_cassert(csrc, rc == MDB_SUCCESS);
7229 if (cdst->mc_ki[cdst->mc_top] == 0) {
7230 if (cdst->mc_ki[cdst->mc_top-1] != 0) {
7231 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7232 key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size);
7234 srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
7235 key.mv_size = NODEKSZ(srcnode);
7236 key.mv_data = NODEKEY(srcnode);
7238 DPRINTF(("update separator for destination page %"Z"u to [%s]",
7239 cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key)));
7240 mdb_cursor_copy(cdst, &mn);
7243 if ((rc = mdb_update_key(&mn, &key)) != MDB_SUCCESS)
7246 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) {
7248 indx_t ix = cdst->mc_ki[cdst->mc_top];
7249 nullkey.mv_size = 0;
7250 cdst->mc_ki[cdst->mc_top] = 0;
7251 rc = mdb_update_key(cdst, &nullkey);
7252 cdst->mc_ki[cdst->mc_top] = ix;
7253 mdb_cassert(csrc, rc == MDB_SUCCESS);
7260 /** Merge one page into another.
7261 * The nodes from the page pointed to by \b csrc will
7262 * be copied to the page pointed to by \b cdst and then
7263 * the \b csrc page will be freed.
7264 * @param[in] csrc Cursor pointing to the source page.
7265 * @param[in] cdst Cursor pointing to the destination page.
7266 * @return 0 on success, non-zero on failure.
7269 mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
7271 MDB_page *psrc, *pdst;
7278 psrc = csrc->mc_pg[csrc->mc_top];
7279 pdst = cdst->mc_pg[cdst->mc_top];
7281 DPRINTF(("merging page %"Z"u into %"Z"u", psrc->mp_pgno, pdst->mp_pgno));
7283 mdb_cassert(csrc, csrc->mc_snum > 1); /* can't merge root page */
7284 mdb_cassert(csrc, cdst->mc_snum > 1);
7286 /* Mark dst as dirty. */
7287 if ((rc = mdb_page_touch(cdst)))
7290 /* Move all nodes from src to dst.
7292 j = nkeys = NUMKEYS(pdst);
7293 if (IS_LEAF2(psrc)) {
7294 key.mv_size = csrc->mc_db->md_pad;
7295 key.mv_data = METADATA(psrc);
7296 for (i = 0; i < NUMKEYS(psrc); i++, j++) {
7297 rc = mdb_node_add(cdst, j, &key, NULL, 0, 0);
7298 if (rc != MDB_SUCCESS)
7300 key.mv_data = (char *)key.mv_data + key.mv_size;
7303 for (i = 0; i < NUMKEYS(psrc); i++, j++) {
7304 srcnode = NODEPTR(psrc, i);
7305 if (i == 0 && IS_BRANCH(psrc)) {
7308 mdb_cursor_copy(csrc, &mn);
7309 /* must find the lowest key below src */
7310 rc = mdb_page_search_lowest(&mn);
7313 if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {
7314 key.mv_size = mn.mc_db->md_pad;
7315 key.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, key.mv_size);
7317 s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);
7318 key.mv_size = NODEKSZ(s2);
7319 key.mv_data = NODEKEY(s2);
7322 key.mv_size = srcnode->mn_ksize;
7323 key.mv_data = NODEKEY(srcnode);
7326 data.mv_size = NODEDSZ(srcnode);
7327 data.mv_data = NODEDATA(srcnode);
7328 rc = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags);
7329 if (rc != MDB_SUCCESS)
7334 DPRINTF(("dst page %"Z"u now has %u keys (%.1f%% filled)",
7335 pdst->mp_pgno, NUMKEYS(pdst),
7336 (float)PAGEFILL(cdst->mc_txn->mt_env, pdst) / 10));
7338 /* Unlink the src page from parent and add to free list.
7341 mdb_node_del(csrc, 0);
7342 if (csrc->mc_ki[csrc->mc_top] == 0) {
7344 rc = mdb_update_key(csrc, &key);
7352 psrc = csrc->mc_pg[csrc->mc_top];
7353 /* If not operating on FreeDB, allow this page to be reused
7354 * in this txn. Otherwise just add to free list.
7356 rc = mdb_page_loose(csrc, psrc);
7360 csrc->mc_db->md_leaf_pages--;
7362 csrc->mc_db->md_branch_pages--;
7364 /* Adjust other cursors pointing to mp */
7365 MDB_cursor *m2, *m3;
7366 MDB_dbi dbi = csrc->mc_dbi;
7368 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7369 if (csrc->mc_flags & C_SUB)
7370 m3 = &m2->mc_xcursor->mx_cursor;
7373 if (m3 == csrc) continue;
7374 if (m3->mc_snum < csrc->mc_snum) continue;
7375 if (m3->mc_pg[csrc->mc_top] == psrc) {
7376 m3->mc_pg[csrc->mc_top] = pdst;
7377 m3->mc_ki[csrc->mc_top] += nkeys;
7382 unsigned int snum = cdst->mc_snum;
7383 uint16_t depth = cdst->mc_db->md_depth;
7384 mdb_cursor_pop(cdst);
7385 rc = mdb_rebalance(cdst);
7386 /* Did the tree shrink? */
7387 if (depth > cdst->mc_db->md_depth)
7389 cdst->mc_snum = snum;
7390 cdst->mc_top = snum-1;
7395 /** Copy the contents of a cursor.
7396 * @param[in] csrc The cursor to copy from.
7397 * @param[out] cdst The cursor to copy to.
7400 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst)
7404 cdst->mc_txn = csrc->mc_txn;
7405 cdst->mc_dbi = csrc->mc_dbi;
7406 cdst->mc_db = csrc->mc_db;
7407 cdst->mc_dbx = csrc->mc_dbx;
7408 cdst->mc_snum = csrc->mc_snum;
7409 cdst->mc_top = csrc->mc_top;
7410 cdst->mc_flags = csrc->mc_flags;
7412 for (i=0; i<csrc->mc_snum; i++) {
7413 cdst->mc_pg[i] = csrc->mc_pg[i];
7414 cdst->mc_ki[i] = csrc->mc_ki[i];
7418 /** Rebalance the tree after a delete operation.
7419 * @param[in] mc Cursor pointing to the page where rebalancing
7421 * @return 0 on success, non-zero on failure.
7424 mdb_rebalance(MDB_cursor *mc)
7428 unsigned int ptop, minkeys;
7432 minkeys = 1 + (IS_BRANCH(mc->mc_pg[mc->mc_top]));
7433 DPRINTF(("rebalancing %s page %"Z"u (has %u keys, %.1f%% full)",
7434 IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",
7435 mdb_dbg_pgno(mc->mc_pg[mc->mc_top]), NUMKEYS(mc->mc_pg[mc->mc_top]),
7436 (float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10));
7438 if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= FILL_THRESHOLD &&
7439 NUMKEYS(mc->mc_pg[mc->mc_top]) >= minkeys) {
7440 DPRINTF(("no need to rebalance page %"Z"u, above fill threshold",
7441 mdb_dbg_pgno(mc->mc_pg[mc->mc_top])));
7445 if (mc->mc_snum < 2) {
7446 MDB_page *mp = mc->mc_pg[0];
7448 DPUTS("Can't rebalance a subpage, ignoring");
7451 if (NUMKEYS(mp) == 0) {
7452 DPUTS("tree is completely empty");
7453 mc->mc_db->md_root = P_INVALID;
7454 mc->mc_db->md_depth = 0;
7455 mc->mc_db->md_leaf_pages = 0;
7456 rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
7459 /* Adjust cursors pointing to mp */
7462 mc->mc_flags &= ~C_INITIALIZED;
7464 MDB_cursor *m2, *m3;
7465 MDB_dbi dbi = mc->mc_dbi;
7467 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7468 if (mc->mc_flags & C_SUB)
7469 m3 = &m2->mc_xcursor->mx_cursor;
7472 if (m3->mc_snum < mc->mc_snum) continue;
7473 if (m3->mc_pg[0] == mp) {
7476 m3->mc_flags &= ~C_INITIALIZED;
7480 } else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) {
7482 DPUTS("collapsing root page!");
7483 rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
7486 mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0));
7487 rc = mdb_page_get(mc->mc_txn,mc->mc_db->md_root,&mc->mc_pg[0],NULL);
7490 mc->mc_db->md_depth--;
7491 mc->mc_db->md_branch_pages--;
7492 mc->mc_ki[0] = mc->mc_ki[1];
7493 for (i = 1; i<mc->mc_db->md_depth; i++) {
7494 mc->mc_pg[i] = mc->mc_pg[i+1];
7495 mc->mc_ki[i] = mc->mc_ki[i+1];
7498 /* Adjust other cursors pointing to mp */
7499 MDB_cursor *m2, *m3;
7500 MDB_dbi dbi = mc->mc_dbi;
7502 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7503 if (mc->mc_flags & C_SUB)
7504 m3 = &m2->mc_xcursor->mx_cursor;
7507 if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
7508 if (m3->mc_pg[0] == mp) {
7511 for (i=0; i<m3->mc_snum; i++) {
7512 m3->mc_pg[i] = m3->mc_pg[i+1];
7513 m3->mc_ki[i] = m3->mc_ki[i+1];
7519 DPUTS("root page doesn't need rebalancing");
7523 /* The parent (branch page) must have at least 2 pointers,
7524 * otherwise the tree is invalid.
7526 ptop = mc->mc_top-1;
7527 mdb_cassert(mc, NUMKEYS(mc->mc_pg[ptop]) > 1);
7529 /* Leaf page fill factor is below the threshold.
7530 * Try to move keys from left or right neighbor, or
7531 * merge with a neighbor page.
7536 mdb_cursor_copy(mc, &mn);
7537 mn.mc_xcursor = NULL;
7539 oldki = mc->mc_ki[mc->mc_top];
7540 if (mc->mc_ki[ptop] == 0) {
7541 /* We're the leftmost leaf in our parent.
7543 DPUTS("reading right neighbor");
7545 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
7546 rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
7549 mn.mc_ki[mn.mc_top] = 0;
7550 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);
7552 /* There is at least one neighbor to the left.
7554 DPUTS("reading left neighbor");
7556 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
7557 rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
7560 mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;
7561 mc->mc_ki[mc->mc_top] = 0;
7564 DPRINTF(("found neighbor page %"Z"u (%u keys, %.1f%% full)",
7565 mn.mc_pg[mn.mc_top]->mp_pgno, NUMKEYS(mn.mc_pg[mn.mc_top]),
7566 (float)PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) / 10));
7568 /* If the neighbor page is above threshold and has enough keys,
7569 * move one key from it. Otherwise we should try to merge them.
7570 * (A branch page must never have less than 2 keys.)
7572 minkeys = 1 + (IS_BRANCH(mn.mc_pg[mn.mc_top]));
7573 if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= FILL_THRESHOLD && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) {
7574 rc = mdb_node_move(&mn, mc);
7575 if (mc->mc_ki[ptop]) {
7579 if (mc->mc_ki[ptop] == 0) {
7580 rc = mdb_page_merge(&mn, mc);
7582 oldki += NUMKEYS(mn.mc_pg[mn.mc_top]);
7583 mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1;
7584 rc = mdb_page_merge(mc, &mn);
7585 mdb_cursor_copy(&mn, mc);
7587 mc->mc_flags &= ~C_EOF;
7589 mc->mc_ki[mc->mc_top] = oldki;
7593 /** Complete a delete operation started by #mdb_cursor_del(). */
7595 mdb_cursor_del0(MDB_cursor *mc)
7602 ki = mc->mc_ki[mc->mc_top];
7603 mdb_node_del(mc, mc->mc_db->md_pad);
7604 mc->mc_db->md_entries--;
7605 rc = mdb_rebalance(mc);
7607 if (rc == MDB_SUCCESS) {
7608 MDB_cursor *m2, *m3;
7609 MDB_dbi dbi = mc->mc_dbi;
7611 mp = mc->mc_pg[mc->mc_top];
7612 nkeys = NUMKEYS(mp);
7614 /* if mc points past last node in page, find next sibling */
7615 if (mc->mc_ki[mc->mc_top] >= nkeys) {
7616 rc = mdb_cursor_sibling(mc, 1);
7617 if (rc == MDB_NOTFOUND) {
7618 mc->mc_flags |= C_EOF;
7623 /* Adjust other cursors pointing to mp */
7624 for (m2 = mc->mc_txn->mt_cursors[dbi]; !rc && m2; m2=m2->mc_next) {
7625 m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;
7626 if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))
7628 if (m3 == mc || m3->mc_snum < mc->mc_snum)
7630 if (m3->mc_pg[mc->mc_top] == mp) {
7631 if (m3->mc_ki[mc->mc_top] >= ki) {
7632 m3->mc_flags |= C_DEL;
7633 if (m3->mc_ki[mc->mc_top] > ki)
7634 m3->mc_ki[mc->mc_top]--;
7635 else if (mc->mc_db->md_flags & MDB_DUPSORT)
7636 m3->mc_xcursor->mx_cursor.mc_flags |= C_EOF;
7638 if (m3->mc_ki[mc->mc_top] >= nkeys) {
7639 rc = mdb_cursor_sibling(m3, 1);
7640 if (rc == MDB_NOTFOUND) {
7641 m3->mc_flags |= C_EOF;
7647 mc->mc_flags |= C_DEL;
7651 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
7656 mdb_del(MDB_txn *txn, MDB_dbi dbi,
7657 MDB_val *key, MDB_val *data)
7659 if (!key || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
7662 if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
7663 return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
7665 if (!F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
7666 /* must ignore any data */
7670 return mdb_del0(txn, dbi, key, data, 0);
7674 mdb_del0(MDB_txn *txn, MDB_dbi dbi,
7675 MDB_val *key, MDB_val *data, unsigned flags)
7680 MDB_val rdata, *xdata;
7684 DPRINTF(("====> delete db %u key [%s]", dbi, DKEY(key)));
7686 mdb_cursor_init(&mc, txn, dbi, &mx);
7695 flags |= MDB_NODUPDATA;
7697 rc = mdb_cursor_set(&mc, key, xdata, op, &exact);
7699 /* let mdb_page_split know about this cursor if needed:
7700 * delete will trigger a rebalance; if it needs to move
7701 * a node from one page to another, it will have to
7702 * update the parent's separator key(s). If the new sepkey
7703 * is larger than the current one, the parent page may
7704 * run out of space, triggering a split. We need this
7705 * cursor to be consistent until the end of the rebalance.
7707 mc.mc_flags |= C_UNTRACK;
7708 mc.mc_next = txn->mt_cursors[dbi];
7709 txn->mt_cursors[dbi] = &mc;
7710 rc = mdb_cursor_del(&mc, flags);
7711 txn->mt_cursors[dbi] = mc.mc_next;
7716 /** Split a page and insert a new node.
7717 * @param[in,out] mc Cursor pointing to the page and desired insertion index.
7718 * The cursor will be updated to point to the actual page and index where
7719 * the node got inserted after the split.
7720 * @param[in] newkey The key for the newly inserted node.
7721 * @param[in] newdata The data for the newly inserted node.
7722 * @param[in] newpgno The page number, if the new node is a branch node.
7723 * @param[in] nflags The #NODE_ADD_FLAGS for the new node.
7724 * @return 0 on success, non-zero on failure.
7727 mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno,
7728 unsigned int nflags)
7731 int rc = MDB_SUCCESS, new_root = 0, did_split = 0;
7734 int i, j, split_indx, nkeys, pmax;
7735 MDB_env *env = mc->mc_txn->mt_env;
7737 MDB_val sepkey, rkey, xdata, *rdata = &xdata;
7738 MDB_page *copy = NULL;
7739 MDB_page *mp, *rp, *pp;
7744 mp = mc->mc_pg[mc->mc_top];
7745 newindx = mc->mc_ki[mc->mc_top];
7746 nkeys = NUMKEYS(mp);
7748 DPRINTF(("-----> splitting %s page %"Z"u and adding [%s] at index %i/%i",
7749 IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno,
7750 DKEY(newkey), mc->mc_ki[mc->mc_top], nkeys));
7752 /* Create a right sibling. */
7753 if ((rc = mdb_page_new(mc, mp->mp_flags, 1, &rp)))
7755 DPRINTF(("new right sibling: page %"Z"u", rp->mp_pgno));
7757 if (mc->mc_snum < 2) {
7758 if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp)))
7760 /* shift current top to make room for new parent */
7761 mc->mc_pg[1] = mc->mc_pg[0];
7762 mc->mc_ki[1] = mc->mc_ki[0];
7765 mc->mc_db->md_root = pp->mp_pgno;
7766 DPRINTF(("root split! new root = %"Z"u", pp->mp_pgno));
7767 mc->mc_db->md_depth++;
7770 /* Add left (implicit) pointer. */
7771 if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) {
7772 /* undo the pre-push */
7773 mc->mc_pg[0] = mc->mc_pg[1];
7774 mc->mc_ki[0] = mc->mc_ki[1];
7775 mc->mc_db->md_root = mp->mp_pgno;
7776 mc->mc_db->md_depth--;
7783 ptop = mc->mc_top-1;
7784 DPRINTF(("parent branch page is %"Z"u", mc->mc_pg[ptop]->mp_pgno));
7787 mc->mc_flags |= C_SPLITTING;
7788 mdb_cursor_copy(mc, &mn);
7789 mn.mc_pg[mn.mc_top] = rp;
7790 mn.mc_ki[ptop] = mc->mc_ki[ptop]+1;
7792 if (nflags & MDB_APPEND) {
7793 mn.mc_ki[mn.mc_top] = 0;
7795 split_indx = newindx;
7799 split_indx = (nkeys+1) / 2;
7804 unsigned int lsize, rsize, ksize;
7805 /* Move half of the keys to the right sibling */
7806 x = mc->mc_ki[mc->mc_top] - split_indx;
7807 ksize = mc->mc_db->md_pad;
7808 split = LEAF2KEY(mp, split_indx, ksize);
7809 rsize = (nkeys - split_indx) * ksize;
7810 lsize = (nkeys - split_indx) * sizeof(indx_t);
7811 mp->mp_lower -= lsize;
7812 rp->mp_lower += lsize;
7813 mp->mp_upper += rsize - lsize;
7814 rp->mp_upper -= rsize - lsize;
7815 sepkey.mv_size = ksize;
7816 if (newindx == split_indx) {
7817 sepkey.mv_data = newkey->mv_data;
7819 sepkey.mv_data = split;
7822 ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize);
7823 memcpy(rp->mp_ptrs, split, rsize);
7824 sepkey.mv_data = rp->mp_ptrs;
7825 memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize);
7826 memcpy(ins, newkey->mv_data, ksize);
7827 mp->mp_lower += sizeof(indx_t);
7828 mp->mp_upper -= ksize - sizeof(indx_t);
7831 memcpy(rp->mp_ptrs, split, x * ksize);
7832 ins = LEAF2KEY(rp, x, ksize);
7833 memcpy(ins, newkey->mv_data, ksize);
7834 memcpy(ins+ksize, split + x * ksize, rsize - x * ksize);
7835 rp->mp_lower += sizeof(indx_t);
7836 rp->mp_upper -= ksize - sizeof(indx_t);
7837 mc->mc_ki[mc->mc_top] = x;
7838 mc->mc_pg[mc->mc_top] = rp;
7841 int psize, nsize, k;
7842 /* Maximum free space in an empty page */
7843 pmax = env->me_psize - PAGEHDRSZ;
7845 nsize = mdb_leaf_size(env, newkey, newdata);
7847 nsize = mdb_branch_size(env, newkey);
7848 nsize = EVEN(nsize);
7850 /* grab a page to hold a temporary copy */
7851 copy = mdb_page_malloc(mc->mc_txn, 1);
7856 copy->mp_pgno = mp->mp_pgno;
7857 copy->mp_flags = mp->mp_flags;
7858 copy->mp_lower = (PAGEHDRSZ-PAGEBASE);
7859 copy->mp_upper = env->me_psize - PAGEBASE;
7861 /* prepare to insert */
7862 for (i=0, j=0; i<nkeys; i++) {
7864 copy->mp_ptrs[j++] = 0;
7866 copy->mp_ptrs[j++] = mp->mp_ptrs[i];
7869 /* When items are relatively large the split point needs
7870 * to be checked, because being off-by-one will make the
7871 * difference between success or failure in mdb_node_add.
7873 * It's also relevant if a page happens to be laid out
7874 * such that one half of its nodes are all "small" and
7875 * the other half of its nodes are "large." If the new
7876 * item is also "large" and falls on the half with
7877 * "large" nodes, it also may not fit.
7879 * As a final tweak, if the new item goes on the last
7880 * spot on the page (and thus, onto the new page), bias
7881 * the split so the new page is emptier than the old page.
7882 * This yields better packing during sequential inserts.
7884 if (nkeys < 20 || nsize > pmax/16 || newindx >= nkeys) {
7885 /* Find split point */
7887 if (newindx <= split_indx || newindx >= nkeys) {
7889 k = newindx >= nkeys ? nkeys : split_indx+2;
7894 for (; i!=k; i+=j) {
7899 node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);
7900 psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
7902 if (F_ISSET(node->mn_flags, F_BIGDATA))
7903 psize += sizeof(pgno_t);
7905 psize += NODEDSZ(node);
7907 psize = EVEN(psize);
7909 if (psize > pmax || i == k-j) {
7910 split_indx = i + (j<0);
7915 if (split_indx == newindx) {
7916 sepkey.mv_size = newkey->mv_size;
7917 sepkey.mv_data = newkey->mv_data;
7919 node = (MDB_node *)((char *)mp + copy->mp_ptrs[split_indx] + PAGEBASE);
7920 sepkey.mv_size = node->mn_ksize;
7921 sepkey.mv_data = NODEKEY(node);
7926 DPRINTF(("separator is %d [%s]", split_indx, DKEY(&sepkey)));
7928 /* Copy separator key to the parent.
7930 if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(env, &sepkey)) {
7934 rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0);
7939 if (mn.mc_snum == mc->mc_snum) {
7940 mc->mc_pg[mc->mc_snum] = mc->mc_pg[mc->mc_top];
7941 mc->mc_ki[mc->mc_snum] = mc->mc_ki[mc->mc_top];
7942 mc->mc_pg[mc->mc_top] = mc->mc_pg[ptop];
7943 mc->mc_ki[mc->mc_top] = mc->mc_ki[ptop];
7948 /* Right page might now have changed parent.
7949 * Check if left page also changed parent.
7951 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
7952 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
7953 for (i=0; i<ptop; i++) {
7954 mc->mc_pg[i] = mn.mc_pg[i];
7955 mc->mc_ki[i] = mn.mc_ki[i];
7957 mc->mc_pg[ptop] = mn.mc_pg[ptop];
7958 if (mn.mc_ki[ptop]) {
7959 mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;
7961 /* find right page's left sibling */
7962 mc->mc_ki[ptop] = mn.mc_ki[ptop];
7963 mdb_cursor_sibling(mc, 0);
7968 rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);
7971 mc->mc_flags ^= C_SPLITTING;
7972 if (rc != MDB_SUCCESS) {
7975 if (nflags & MDB_APPEND) {
7976 mc->mc_pg[mc->mc_top] = rp;
7977 mc->mc_ki[mc->mc_top] = 0;
7978 rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags);
7981 for (i=0; i<mc->mc_top; i++)
7982 mc->mc_ki[i] = mn.mc_ki[i];
7983 } else if (!IS_LEAF2(mp)) {
7985 mc->mc_pg[mc->mc_top] = rp;
7990 rkey.mv_data = newkey->mv_data;
7991 rkey.mv_size = newkey->mv_size;
7997 /* Update index for the new key. */
7998 mc->mc_ki[mc->mc_top] = j;
8000 node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);
8001 rkey.mv_data = NODEKEY(node);
8002 rkey.mv_size = node->mn_ksize;
8004 xdata.mv_data = NODEDATA(node);
8005 xdata.mv_size = NODEDSZ(node);
8008 pgno = NODEPGNO(node);
8009 flags = node->mn_flags;
8012 if (!IS_LEAF(mp) && j == 0) {
8013 /* First branch index doesn't need key data. */
8017 rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags);
8023 mc->mc_pg[mc->mc_top] = copy;
8028 } while (i != split_indx);
8030 nkeys = NUMKEYS(copy);
8031 for (i=0; i<nkeys; i++)
8032 mp->mp_ptrs[i] = copy->mp_ptrs[i];
8033 mp->mp_lower = copy->mp_lower;
8034 mp->mp_upper = copy->mp_upper;
8035 memcpy(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1),
8036 env->me_psize - copy->mp_upper - PAGEBASE);
8038 /* reset back to original page */
8039 if (newindx < split_indx) {
8040 mc->mc_pg[mc->mc_top] = mp;
8041 if (nflags & MDB_RESERVE) {
8042 node = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
8043 if (!(node->mn_flags & F_BIGDATA))
8044 newdata->mv_data = NODEDATA(node);
8047 mc->mc_pg[mc->mc_top] = rp;
8049 /* Make sure mc_ki is still valid.
8051 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
8052 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
8053 for (i=0; i<=ptop; i++) {
8054 mc->mc_pg[i] = mn.mc_pg[i];
8055 mc->mc_ki[i] = mn.mc_ki[i];
8062 /* Adjust other cursors pointing to mp */
8063 MDB_cursor *m2, *m3;
8064 MDB_dbi dbi = mc->mc_dbi;
8065 int fixup = NUMKEYS(mp);
8067 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8068 if (mc->mc_flags & C_SUB)
8069 m3 = &m2->mc_xcursor->mx_cursor;
8074 if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED))
8076 if (m3->mc_flags & C_SPLITTING)
8081 for (k=m3->mc_top; k>=0; k--) {
8082 m3->mc_ki[k+1] = m3->mc_ki[k];
8083 m3->mc_pg[k+1] = m3->mc_pg[k];
8085 if (m3->mc_ki[0] >= split_indx) {
8090 m3->mc_pg[0] = mc->mc_pg[0];
8094 if (m3->mc_top >= mc->mc_top && m3->mc_pg[mc->mc_top] == mp) {
8095 if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE))
8096 m3->mc_ki[mc->mc_top]++;
8097 if (m3->mc_ki[mc->mc_top] >= fixup) {
8098 m3->mc_pg[mc->mc_top] = rp;
8099 m3->mc_ki[mc->mc_top] -= fixup;
8100 m3->mc_ki[ptop] = mn.mc_ki[ptop];
8102 } else if (!did_split && m3->mc_top >= ptop && m3->mc_pg[ptop] == mc->mc_pg[ptop] &&
8103 m3->mc_ki[ptop] >= mc->mc_ki[ptop]) {
8108 DPRINTF(("mp left: %d, rp left: %d", SIZELEFT(mp), SIZELEFT(rp)));
8111 if (copy) /* tmp page */
8112 mdb_page_free(env, copy);
8114 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
8119 mdb_put(MDB_txn *txn, MDB_dbi dbi,
8120 MDB_val *key, MDB_val *data, unsigned int flags)
8125 if (!key || !data || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
8128 if ((flags & (MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND|MDB_APPENDDUP)) != flags)
8131 mdb_cursor_init(&mc, txn, dbi, &mx);
8132 return mdb_cursor_put(&mc, key, data, flags);
8136 #define MDB_WBUF (1024*1024)
8139 /** State needed for a compacting copy. */
8140 typedef struct mdb_copy {
8141 pthread_mutex_t mc_mutex;
8142 pthread_cond_t mc_cond;
8149 pgno_t mc_next_pgno;
8152 volatile int mc_new;
8157 /** Dedicated writer thread for compacting copy. */
8158 static THREAD_RET ESECT
8159 mdb_env_copythr(void *arg)
8163 int toggle = 0, wsize, rc;
8166 #define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL)
8169 #define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0)
8172 pthread_mutex_lock(&my->mc_mutex);
8174 pthread_cond_signal(&my->mc_cond);
8177 pthread_cond_wait(&my->mc_cond, &my->mc_mutex);
8178 if (my->mc_new < 0) {
8183 wsize = my->mc_wlen[toggle];
8184 ptr = my->mc_wbuf[toggle];
8187 DO_WRITE(rc, my->mc_fd, ptr, wsize, len);
8191 } else if (len > 0) {
8205 /* If there's an overflow page tail, write it too */
8206 if (my->mc_olen[toggle]) {
8207 wsize = my->mc_olen[toggle];
8208 ptr = my->mc_over[toggle];
8209 my->mc_olen[toggle] = 0;
8212 my->mc_wlen[toggle] = 0;
8214 pthread_cond_signal(&my->mc_cond);
8216 pthread_cond_signal(&my->mc_cond);
8217 pthread_mutex_unlock(&my->mc_mutex);
8218 return (THREAD_RET)0;
8222 /** Tell the writer thread there's a buffer ready to write */
8224 mdb_env_cthr_toggle(mdb_copy *my, int st)
8226 int toggle = my->mc_toggle ^ 1;
8227 pthread_mutex_lock(&my->mc_mutex);
8228 if (my->mc_status) {
8229 pthread_mutex_unlock(&my->mc_mutex);
8230 return my->mc_status;
8232 while (my->mc_new == 1)
8233 pthread_cond_wait(&my->mc_cond, &my->mc_mutex);
8235 my->mc_toggle = toggle;
8236 pthread_cond_signal(&my->mc_cond);
8237 pthread_mutex_unlock(&my->mc_mutex);
8241 /** Depth-first tree traversal for compacting copy. */
8243 mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)
8246 MDB_txn *txn = my->mc_txn;
8248 MDB_page *mo, *mp, *leaf;
8253 /* Empty DB, nothing to do */
8254 if (*pg == P_INVALID)
8261 rc = mdb_page_get(my->mc_txn, *pg, &mc.mc_pg[0], NULL);
8264 rc = mdb_page_search_root(&mc, NULL, MDB_PS_FIRST);
8268 /* Make cursor pages writable */
8269 buf = ptr = malloc(my->mc_env->me_psize * mc.mc_snum);
8273 for (i=0; i<mc.mc_top; i++) {
8274 mdb_page_copy((MDB_page *)ptr, mc.mc_pg[i], my->mc_env->me_psize);
8275 mc.mc_pg[i] = (MDB_page *)ptr;
8276 ptr += my->mc_env->me_psize;
8279 /* This is writable space for a leaf page. Usually not needed. */
8280 leaf = (MDB_page *)ptr;
8282 toggle = my->mc_toggle;
8283 while (mc.mc_snum > 0) {
8285 mp = mc.mc_pg[mc.mc_top];
8289 if (!IS_LEAF2(mp) && !(flags & F_DUPDATA)) {
8290 for (i=0; i<n; i++) {
8291 ni = NODEPTR(mp, i);
8292 if (ni->mn_flags & F_BIGDATA) {
8296 /* Need writable leaf */
8298 mc.mc_pg[mc.mc_top] = leaf;
8299 mdb_page_copy(leaf, mp, my->mc_env->me_psize);
8301 ni = NODEPTR(mp, i);
8304 memcpy(&pg, NODEDATA(ni), sizeof(pg));
8305 rc = mdb_page_get(txn, pg, &omp, NULL);
8308 if (my->mc_wlen[toggle] >= MDB_WBUF) {
8309 rc = mdb_env_cthr_toggle(my, 1);
8312 toggle = my->mc_toggle;
8314 mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);
8315 memcpy(mo, omp, my->mc_env->me_psize);
8316 mo->mp_pgno = my->mc_next_pgno;
8317 my->mc_next_pgno += omp->mp_pages;
8318 my->mc_wlen[toggle] += my->mc_env->me_psize;
8319 if (omp->mp_pages > 1) {
8320 my->mc_olen[toggle] = my->mc_env->me_psize * (omp->mp_pages - 1);
8321 my->mc_over[toggle] = (char *)omp + my->mc_env->me_psize;
8322 rc = mdb_env_cthr_toggle(my, 1);
8325 toggle = my->mc_toggle;
8327 memcpy(NODEDATA(ni), &mo->mp_pgno, sizeof(pgno_t));
8328 } else if (ni->mn_flags & F_SUBDATA) {
8331 /* Need writable leaf */
8333 mc.mc_pg[mc.mc_top] = leaf;
8334 mdb_page_copy(leaf, mp, my->mc_env->me_psize);
8336 ni = NODEPTR(mp, i);
8339 memcpy(&db, NODEDATA(ni), sizeof(db));
8340 my->mc_toggle = toggle;
8341 rc = mdb_env_cwalk(my, &db.md_root, ni->mn_flags & F_DUPDATA);
8344 toggle = my->mc_toggle;
8345 memcpy(NODEDATA(ni), &db, sizeof(db));
8350 mc.mc_ki[mc.mc_top]++;
8351 if (mc.mc_ki[mc.mc_top] < n) {
8354 ni = NODEPTR(mp, mc.mc_ki[mc.mc_top]);
8356 rc = mdb_page_get(txn, pg, &mp, NULL);
8361 mc.mc_ki[mc.mc_top] = 0;
8362 if (IS_BRANCH(mp)) {
8363 /* Whenever we advance to a sibling branch page,
8364 * we must proceed all the way down to its first leaf.
8366 mdb_page_copy(mc.mc_pg[mc.mc_top], mp, my->mc_env->me_psize);
8369 mc.mc_pg[mc.mc_top] = mp;
8373 if (my->mc_wlen[toggle] >= MDB_WBUF) {
8374 rc = mdb_env_cthr_toggle(my, 1);
8377 toggle = my->mc_toggle;
8379 mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);
8380 mdb_page_copy(mo, mp, my->mc_env->me_psize);
8381 mo->mp_pgno = my->mc_next_pgno++;
8382 my->mc_wlen[toggle] += my->mc_env->me_psize;
8384 /* Update parent if there is one */
8385 ni = NODEPTR(mc.mc_pg[mc.mc_top-1], mc.mc_ki[mc.mc_top-1]);
8386 SETPGNO(ni, mo->mp_pgno);
8387 mdb_cursor_pop(&mc);
8389 /* Otherwise we're done */
8399 /** Copy environment with compaction. */
8401 mdb_env_copyfd1(MDB_env *env, HANDLE fd)
8406 MDB_txn *txn = NULL;
8411 my.mc_mutex = CreateMutex(NULL, FALSE, NULL);
8412 my.mc_cond = CreateEvent(NULL, FALSE, FALSE, NULL);
8413 my.mc_wbuf[0] = _aligned_malloc(MDB_WBUF*2, env->me_psize);
8414 if (my.mc_wbuf[0] == NULL)
8417 pthread_mutex_init(&my.mc_mutex, NULL);
8418 pthread_cond_init(&my.mc_cond, NULL);
8419 rc = posix_memalign((void **)&my.mc_wbuf[0], env->me_psize, MDB_WBUF*2);
8423 memset(my.mc_wbuf[0], 0, MDB_WBUF*2);
8424 my.mc_wbuf[1] = my.mc_wbuf[0] + MDB_WBUF;
8429 my.mc_next_pgno = 2;
8435 THREAD_CREATE(thr, mdb_env_copythr, &my);
8437 rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
8441 mp = (MDB_page *)my.mc_wbuf[0];
8442 memset(mp, 0, 2*env->me_psize);
8444 mp->mp_flags = P_META;
8445 mm = (MDB_meta *)METADATA(mp);
8446 mdb_env_init_meta0(env, mm);
8447 mm->mm_address = env->me_metas[0]->mm_address;
8449 mp = (MDB_page *)(my.mc_wbuf[0] + env->me_psize);
8451 mp->mp_flags = P_META;
8452 *(MDB_meta *)METADATA(mp) = *mm;
8453 mm = (MDB_meta *)METADATA(mp);
8455 /* Count the number of free pages, subtract from lastpg to find
8456 * number of active pages
8459 MDB_ID freecount = 0;
8462 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
8463 while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
8464 freecount += *(MDB_ID *)data.mv_data;
8465 freecount += txn->mt_dbs[0].md_branch_pages +
8466 txn->mt_dbs[0].md_leaf_pages +
8467 txn->mt_dbs[0].md_overflow_pages;
8469 /* Set metapage 1 */
8470 mm->mm_last_pg = txn->mt_next_pgno - freecount - 1;
8471 mm->mm_dbs[1] = txn->mt_dbs[1];
8472 mm->mm_dbs[1].md_root = mm->mm_last_pg;
8475 my.mc_wlen[0] = env->me_psize * 2;
8477 pthread_mutex_lock(&my.mc_mutex);
8479 pthread_cond_wait(&my.mc_cond, &my.mc_mutex);
8480 pthread_mutex_unlock(&my.mc_mutex);
8481 rc = mdb_env_cwalk(&my, &txn->mt_dbs[1].md_root, 0);
8482 if (rc == MDB_SUCCESS && my.mc_wlen[my.mc_toggle])
8483 rc = mdb_env_cthr_toggle(&my, 1);
8484 mdb_env_cthr_toggle(&my, -1);
8485 pthread_mutex_lock(&my.mc_mutex);
8487 pthread_cond_wait(&my.mc_cond, &my.mc_mutex);
8488 pthread_mutex_unlock(&my.mc_mutex);
8493 CloseHandle(my.mc_cond);
8494 CloseHandle(my.mc_mutex);
8495 _aligned_free(my.mc_wbuf[0]);
8497 pthread_cond_destroy(&my.mc_cond);
8498 pthread_mutex_destroy(&my.mc_mutex);
8499 free(my.mc_wbuf[0]);
8504 /** Copy environment as-is. */
8506 mdb_env_copyfd0(MDB_env *env, HANDLE fd)
8508 MDB_txn *txn = NULL;
8514 #define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL)
8518 #define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0)
8521 /* Do the lock/unlock of the reader mutex before starting the
8522 * write txn. Otherwise other read txns could block writers.
8524 rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
8529 /* We must start the actual read txn after blocking writers */
8530 mdb_txn_reset0(txn, "reset-stage1");
8532 /* Temporarily block writers until we snapshot the meta pages */
8535 rc = mdb_txn_renew0(txn);
8537 UNLOCK_MUTEX_W(env);
8542 wsize = env->me_psize * 2;
8546 DO_WRITE(rc, fd, ptr, w2, len);
8550 } else if (len > 0) {
8556 /* Non-blocking or async handles are not supported */
8562 UNLOCK_MUTEX_W(env);
8567 w2 = txn->mt_next_pgno * env->me_psize;
8570 LARGE_INTEGER fsize;
8571 GetFileSizeEx(env->me_fd, &fsize);
8572 if (w2 > fsize.QuadPart)
8573 w2 = fsize.QuadPart;
8578 fstat(env->me_fd, &st);
8579 if (w2 > (size_t)st.st_size)
8585 if (wsize > MAX_WRITE)
8589 DO_WRITE(rc, fd, ptr, w2, len);
8593 } else if (len > 0) {
8610 mdb_env_copyfd2(MDB_env *env, HANDLE fd, unsigned int flags)
8612 if (flags & MDB_CP_COMPACT)
8613 return mdb_env_copyfd1(env, fd);
8615 return mdb_env_copyfd0(env, fd);
8619 mdb_env_copyfd(MDB_env *env, HANDLE fd)
8621 return mdb_env_copyfd2(env, fd, 0);
8625 mdb_env_copy2(MDB_env *env, const char *path, unsigned int flags)
8629 HANDLE newfd = INVALID_HANDLE_VALUE;
8631 if (env->me_flags & MDB_NOSUBDIR) {
8632 lpath = (char *)path;
8635 len += sizeof(DATANAME);
8636 lpath = malloc(len);
8639 sprintf(lpath, "%s" DATANAME, path);
8642 /* The destination path must exist, but the destination file must not.
8643 * We don't want the OS to cache the writes, since the source data is
8644 * already in the OS cache.
8647 newfd = CreateFile(lpath, GENERIC_WRITE, 0, NULL, CREATE_NEW,
8648 FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL);
8650 newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL, 0666);
8652 if (newfd == INVALID_HANDLE_VALUE) {
8658 /* Set O_DIRECT if the file system supports it */
8659 if ((rc = fcntl(newfd, F_GETFL)) != -1)
8660 (void) fcntl(newfd, F_SETFL, rc | O_DIRECT);
8662 #ifdef F_NOCACHE /* __APPLE__ */
8663 rc = fcntl(newfd, F_NOCACHE, 1);
8670 rc = mdb_env_copyfd2(env, newfd, flags);
8673 if (!(env->me_flags & MDB_NOSUBDIR))
8675 if (newfd != INVALID_HANDLE_VALUE)
8676 if (close(newfd) < 0 && rc == MDB_SUCCESS)
8683 mdb_env_copy(MDB_env *env, const char *path)
8685 return mdb_env_copy2(env, path, 0);
8689 mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)
8691 if ((flag & CHANGEABLE) != flag)
8694 env->me_flags |= flag;
8696 env->me_flags &= ~flag;
8701 mdb_env_get_flags(MDB_env *env, unsigned int *arg)
8706 *arg = env->me_flags;
8711 mdb_env_set_userctx(MDB_env *env, void *ctx)
8715 env->me_userctx = ctx;
8720 mdb_env_get_userctx(MDB_env *env)
8722 return env ? env->me_userctx : NULL;
8726 mdb_env_set_assert(MDB_env *env, MDB_assert_func *func)
8731 env->me_assert_func = func;
8737 mdb_env_get_path(MDB_env *env, const char **arg)
8742 *arg = env->me_path;
8747 mdb_env_get_fd(MDB_env *env, mdb_filehandle_t *arg)
8756 /** Common code for #mdb_stat() and #mdb_env_stat().
8757 * @param[in] env the environment to operate in.
8758 * @param[in] db the #MDB_db record containing the stats to return.
8759 * @param[out] arg the address of an #MDB_stat structure to receive the stats.
8760 * @return 0, this function always succeeds.
8763 mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)
8765 arg->ms_psize = env->me_psize;
8766 arg->ms_depth = db->md_depth;
8767 arg->ms_branch_pages = db->md_branch_pages;
8768 arg->ms_leaf_pages = db->md_leaf_pages;
8769 arg->ms_overflow_pages = db->md_overflow_pages;
8770 arg->ms_entries = db->md_entries;
8776 mdb_env_stat(MDB_env *env, MDB_stat *arg)
8780 if (env == NULL || arg == NULL)
8783 toggle = mdb_env_pick_meta(env);
8785 return mdb_stat0(env, &env->me_metas[toggle]->mm_dbs[MAIN_DBI], arg);
8789 mdb_env_info(MDB_env *env, MDB_envinfo *arg)
8793 if (env == NULL || arg == NULL)
8796 toggle = mdb_env_pick_meta(env);
8797 arg->me_mapaddr = env->me_metas[toggle]->mm_address;
8798 arg->me_mapsize = env->me_mapsize;
8799 arg->me_maxreaders = env->me_maxreaders;
8801 /* me_numreaders may be zero if this process never used any readers. Use
8802 * the shared numreader count if it exists.
8804 arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : env->me_numreaders;
8806 arg->me_last_pgno = env->me_metas[toggle]->mm_last_pg;
8807 arg->me_last_txnid = env->me_metas[toggle]->mm_txnid;
8811 /** Set the default comparison functions for a database.
8812 * Called immediately after a database is opened to set the defaults.
8813 * The user can then override them with #mdb_set_compare() or
8814 * #mdb_set_dupsort().
8815 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
8816 * @param[in] dbi A database handle returned by #mdb_dbi_open()
8819 mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi)
8821 uint16_t f = txn->mt_dbs[dbi].md_flags;
8823 txn->mt_dbxs[dbi].md_cmp =
8824 (f & MDB_REVERSEKEY) ? mdb_cmp_memnr :
8825 (f & MDB_INTEGERKEY) ? mdb_cmp_cint : mdb_cmp_memn;
8827 txn->mt_dbxs[dbi].md_dcmp =
8828 !(f & MDB_DUPSORT) ? 0 :
8829 ((f & MDB_INTEGERDUP)
8830 ? ((f & MDB_DUPFIXED) ? mdb_cmp_int : mdb_cmp_cint)
8831 : ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn));
8834 int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
8839 int rc, dbflag, exact;
8840 unsigned int unused = 0, seq;
8843 if (txn->mt_dbxs[FREE_DBI].md_cmp == NULL) {
8844 mdb_default_cmp(txn, FREE_DBI);
8847 if ((flags & VALID_FLAGS) != flags)
8849 if (txn->mt_flags & MDB_TXN_ERROR)
8855 if (flags & PERSISTENT_FLAGS) {
8856 uint16_t f2 = flags & PERSISTENT_FLAGS;
8857 /* make sure flag changes get committed */
8858 if ((txn->mt_dbs[MAIN_DBI].md_flags | f2) != txn->mt_dbs[MAIN_DBI].md_flags) {
8859 txn->mt_dbs[MAIN_DBI].md_flags |= f2;
8860 txn->mt_flags |= MDB_TXN_DIRTY;
8863 mdb_default_cmp(txn, MAIN_DBI);
8867 if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {
8868 mdb_default_cmp(txn, MAIN_DBI);
8871 /* Is the DB already open? */
8873 for (i=2; i<txn->mt_numdbs; i++) {
8874 if (!txn->mt_dbxs[i].md_name.mv_size) {
8875 /* Remember this free slot */
8876 if (!unused) unused = i;
8879 if (len == txn->mt_dbxs[i].md_name.mv_size &&
8880 !strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) {
8886 /* If no free slot and max hit, fail */
8887 if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs)
8888 return MDB_DBS_FULL;
8890 /* Cannot mix named databases with some mainDB flags */
8891 if (txn->mt_dbs[MAIN_DBI].md_flags & (MDB_DUPSORT|MDB_INTEGERKEY))
8892 return (flags & MDB_CREATE) ? MDB_INCOMPATIBLE : MDB_NOTFOUND;
8894 /* Find the DB info */
8895 dbflag = DB_NEW|DB_VALID;
8898 key.mv_data = (void *)name;
8899 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
8900 rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact);
8901 if (rc == MDB_SUCCESS) {
8902 /* make sure this is actually a DB */
8903 MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]);
8904 if (!(node->mn_flags & F_SUBDATA))
8905 return MDB_INCOMPATIBLE;
8906 } else if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) {
8907 /* Create if requested */
8909 data.mv_size = sizeof(MDB_db);
8910 data.mv_data = &dummy;
8911 memset(&dummy, 0, sizeof(dummy));
8912 dummy.md_root = P_INVALID;
8913 dummy.md_flags = flags & PERSISTENT_FLAGS;
8914 rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA);
8918 /* OK, got info, add to table */
8919 if (rc == MDB_SUCCESS) {
8920 unsigned int slot = unused ? unused : txn->mt_numdbs;
8921 txn->mt_dbxs[slot].md_name.mv_data = strdup(name);
8922 txn->mt_dbxs[slot].md_name.mv_size = len;
8923 txn->mt_dbxs[slot].md_rel = NULL;
8924 txn->mt_dbflags[slot] = dbflag;
8925 /* txn-> and env-> are the same in read txns, use
8926 * tmp variable to avoid undefined assignment
8928 seq = ++txn->mt_env->me_dbiseqs[slot];
8929 txn->mt_dbiseqs[slot] = seq;
8931 memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db));
8933 mdb_default_cmp(txn, slot);
8942 int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
8944 if (!arg || !TXN_DBI_EXIST(txn, dbi))
8947 if (txn->mt_flags & MDB_TXN_ERROR)
8950 if (txn->mt_dbflags[dbi] & DB_STALE) {
8953 /* Stale, must read the DB's root. cursor_init does it for us. */
8954 mdb_cursor_init(&mc, txn, dbi, &mx);
8956 return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg);
8959 void mdb_dbi_close(MDB_env *env, MDB_dbi dbi)
8962 if (dbi <= MAIN_DBI || dbi >= env->me_maxdbs)
8964 ptr = env->me_dbxs[dbi].md_name.mv_data;
8965 /* If there was no name, this was already closed */
8967 env->me_dbxs[dbi].md_name.mv_data = NULL;
8968 env->me_dbxs[dbi].md_name.mv_size = 0;
8969 env->me_dbflags[dbi] = 0;
8970 env->me_dbiseqs[dbi]++;
8975 int mdb_dbi_flags(MDB_txn *txn, MDB_dbi dbi, unsigned int *flags)
8977 /* We could return the flags for the FREE_DBI too but what's the point? */
8978 if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
8980 *flags = txn->mt_dbs[dbi].md_flags & PERSISTENT_FLAGS;
8984 /** Add all the DB's pages to the free list.
8985 * @param[in] mc Cursor on the DB to free.
8986 * @param[in] subs non-Zero to check for sub-DBs in this DB.
8987 * @return 0 on success, non-zero on failure.
8990 mdb_drop0(MDB_cursor *mc, int subs)
8994 rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
8995 if (rc == MDB_SUCCESS) {
8996 MDB_txn *txn = mc->mc_txn;
9001 /* LEAF2 pages have no nodes, cannot have sub-DBs */
9002 if (IS_LEAF2(mc->mc_pg[mc->mc_top]))
9005 mdb_cursor_copy(mc, &mx);
9006 while (mc->mc_snum > 0) {
9007 MDB_page *mp = mc->mc_pg[mc->mc_top];
9008 unsigned n = NUMKEYS(mp);
9010 for (i=0; i<n; i++) {
9011 ni = NODEPTR(mp, i);
9012 if (ni->mn_flags & F_BIGDATA) {
9015 memcpy(&pg, NODEDATA(ni), sizeof(pg));
9016 rc = mdb_page_get(txn, pg, &omp, NULL);
9019 mdb_cassert(mc, IS_OVERFLOW(omp));
9020 rc = mdb_midl_append_range(&txn->mt_free_pgs,
9024 } else if (subs && (ni->mn_flags & F_SUBDATA)) {
9025 mdb_xcursor_init1(mc, ni);
9026 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
9032 if ((rc = mdb_midl_need(&txn->mt_free_pgs, n)) != 0)
9034 for (i=0; i<n; i++) {
9036 ni = NODEPTR(mp, i);
9039 mdb_midl_xappend(txn->mt_free_pgs, pg);
9044 mc->mc_ki[mc->mc_top] = i;
9045 rc = mdb_cursor_sibling(mc, 1);
9047 if (rc != MDB_NOTFOUND)
9049 /* no more siblings, go back to beginning
9050 * of previous level.
9054 for (i=1; i<mc->mc_snum; i++) {
9056 mc->mc_pg[i] = mx.mc_pg[i];
9061 rc = mdb_midl_append(&txn->mt_free_pgs, mc->mc_db->md_root);
9064 txn->mt_flags |= MDB_TXN_ERROR;
9065 } else if (rc == MDB_NOTFOUND) {
9071 int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)
9073 MDB_cursor *mc, *m2;
9076 if ((unsigned)del > 1 || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
9079 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
9082 if (dbi > MAIN_DBI && TXN_DBI_CHANGED(txn, dbi))
9085 rc = mdb_cursor_open(txn, dbi, &mc);
9089 rc = mdb_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT);
9090 /* Invalidate the dropped DB's cursors */
9091 for (m2 = txn->mt_cursors[dbi]; m2; m2 = m2->mc_next)
9092 m2->mc_flags &= ~(C_INITIALIZED|C_EOF);
9096 /* Can't delete the main DB */
9097 if (del && dbi > MAIN_DBI) {
9098 rc = mdb_del0(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL, 0);
9100 txn->mt_dbflags[dbi] = DB_STALE;
9101 mdb_dbi_close(txn->mt_env, dbi);
9103 txn->mt_flags |= MDB_TXN_ERROR;
9106 /* reset the DB record, mark it dirty */
9107 txn->mt_dbflags[dbi] |= DB_DIRTY;
9108 txn->mt_dbs[dbi].md_depth = 0;
9109 txn->mt_dbs[dbi].md_branch_pages = 0;
9110 txn->mt_dbs[dbi].md_leaf_pages = 0;
9111 txn->mt_dbs[dbi].md_overflow_pages = 0;
9112 txn->mt_dbs[dbi].md_entries = 0;
9113 txn->mt_dbs[dbi].md_root = P_INVALID;
9115 txn->mt_flags |= MDB_TXN_DIRTY;
9118 mdb_cursor_close(mc);
9122 int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
9124 if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
9127 txn->mt_dbxs[dbi].md_cmp = cmp;
9131 int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
9133 if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
9136 txn->mt_dbxs[dbi].md_dcmp = cmp;
9140 int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
9142 if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
9145 txn->mt_dbxs[dbi].md_rel = rel;
9149 int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx)
9151 if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
9154 txn->mt_dbxs[dbi].md_relctx = ctx;
9159 mdb_env_get_maxkeysize(MDB_env *env)
9161 return ENV_MAXKEY(env);
9165 mdb_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx)
9167 unsigned int i, rdrs;
9170 int rc = 0, first = 1;
9174 if (!env->me_txns) {
9175 return func("(no reader locks)\n", ctx);
9177 rdrs = env->me_txns->mti_numreaders;
9178 mr = env->me_txns->mti_readers;
9179 for (i=0; i<rdrs; i++) {
9181 txnid_t txnid = mr[i].mr_txnid;
9182 sprintf(buf, txnid == (txnid_t)-1 ?
9183 "%10d %"Z"x -\n" : "%10d %"Z"x %"Z"u\n",
9184 (int)mr[i].mr_pid, (size_t)mr[i].mr_tid, txnid);
9187 rc = func(" pid thread txnid\n", ctx);
9191 rc = func(buf, ctx);
9197 rc = func("(no active readers)\n", ctx);
9202 /** Insert pid into list if not already present.
9203 * return -1 if already present.
9206 mdb_pid_insert(MDB_PID_T *ids, MDB_PID_T pid)
9208 /* binary search of pid in list */
9210 unsigned cursor = 1;
9212 unsigned n = ids[0];
9215 unsigned pivot = n >> 1;
9216 cursor = base + pivot + 1;
9217 val = pid - ids[cursor];
9222 } else if ( val > 0 ) {
9227 /* found, so it's a duplicate */
9236 for (n = ids[0]; n > cursor; n--)
9243 mdb_reader_check(MDB_env *env, int *dead)
9245 unsigned int i, j, rdrs;
9247 MDB_PID_T *pids, pid;
9256 rdrs = env->me_txns->mti_numreaders;
9257 pids = malloc((rdrs+1) * sizeof(MDB_PID_T));
9261 mr = env->me_txns->mti_readers;
9262 for (i=0; i<rdrs; i++) {
9263 if (mr[i].mr_pid && mr[i].mr_pid != env->me_pid) {
9265 if (mdb_pid_insert(pids, pid) == 0) {
9266 if (!mdb_reader_pid(env, Pidcheck, pid)) {
9268 /* Recheck, a new process may have reused pid */
9269 if (!mdb_reader_pid(env, Pidcheck, pid)) {
9270 for (j=i; j<rdrs; j++)
9271 if (mr[j].mr_pid == pid) {
9272 DPRINTF(("clear stale reader pid %u txn %"Z"d",
9273 (unsigned) pid, mr[j].mr_txnid));
9278 UNLOCK_MUTEX_R(env);
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