2 * @brief memory-mapped database library
4 * A Btree-based database management library modeled loosely on the
5 * BerkeleyDB API, but much simplified.
8 * Copyright 2011-2013 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.
38 #include <sys/types.h>
42 /** getpid() returns int; MinGW defines pid_t but MinGW64 typedefs it
43 * as int64 which is wrong. MSVC doesn't define it at all, so just
48 # include <sys/param.h>
50 # define LITTLE_ENDIAN 1234
51 # define BIG_ENDIAN 4321
52 # define BYTE_ORDER LITTLE_ENDIAN
54 # define SSIZE_MAX INT_MAX
58 #define MDB_PID_T pid_t
59 #include <sys/param.h>
62 #ifdef HAVE_SYS_FILE_H
78 #if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER))
79 #include <netinet/in.h>
80 #include <resolv.h> /* defines BYTE_ORDER on HPUX and Solaris */
83 #if defined(__APPLE__) || defined (BSD)
84 # define MDB_USE_POSIX_SEM 1
85 # define MDB_FDATASYNC fsync
86 #elif defined(ANDROID)
87 # define MDB_FDATASYNC fsync
92 #ifdef MDB_USE_POSIX_SEM
93 # define MDB_USE_HASH 1
94 #include <semaphore.h>
99 #include <valgrind/memcheck.h>
100 #define VGMEMP_CREATE(h,r,z) VALGRIND_CREATE_MEMPOOL(h,r,z)
101 #define VGMEMP_ALLOC(h,a,s) VALGRIND_MEMPOOL_ALLOC(h,a,s)
102 #define VGMEMP_FREE(h,a) VALGRIND_MEMPOOL_FREE(h,a)
103 #define VGMEMP_DESTROY(h) VALGRIND_DESTROY_MEMPOOL(h)
104 #define VGMEMP_DEFINED(a,s) VALGRIND_MAKE_MEM_DEFINED(a,s)
106 #define VGMEMP_CREATE(h,r,z)
107 #define VGMEMP_ALLOC(h,a,s)
108 #define VGMEMP_FREE(h,a)
109 #define VGMEMP_DESTROY(h)
110 #define VGMEMP_DEFINED(a,s)
114 # if (defined(_LITTLE_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN))
115 /* Solaris just defines one or the other */
116 # define LITTLE_ENDIAN 1234
117 # define BIG_ENDIAN 4321
118 # ifdef _LITTLE_ENDIAN
119 # define BYTE_ORDER LITTLE_ENDIAN
121 # define BYTE_ORDER BIG_ENDIAN
124 # define BYTE_ORDER __BYTE_ORDER
128 #ifndef LITTLE_ENDIAN
129 #define LITTLE_ENDIAN __LITTLE_ENDIAN
132 #define BIG_ENDIAN __BIG_ENDIAN
135 #if defined(__i386) || defined(__x86_64) || defined(_M_IX86)
136 #define MISALIGNED_OK 1
142 #if (BYTE_ORDER == LITTLE_ENDIAN) == (BYTE_ORDER == BIG_ENDIAN)
143 # error "Unknown or unsupported endianness (BYTE_ORDER)"
144 #elif (-6 & 5) || CHAR_BIT != 8 || UINT_MAX < 0xffffffff || ULONG_MAX % 0xFFFF
145 # error "Two's complement, reasonably sized integer types, please"
148 /** @defgroup internal MDB Internals
151 /** @defgroup compat Compatibility Macros
152 * A bunch of macros to minimize the amount of platform-specific ifdefs
153 * needed throughout the rest of the code. When the features this library
154 * needs are similar enough to POSIX to be hidden in a one-or-two line
155 * replacement, this macro approach is used.
159 /** Wrapper around __func__, which is a C99 feature */
160 #if __STDC_VERSION__ >= 199901L
161 # define mdb_func_ __func__
162 #elif __GNUC__ >= 2 || _MSC_VER >= 1300
163 # define mdb_func_ __FUNCTION__
165 /* If a debug message says <mdb_unknown>(), update the #if statements above */
166 # define mdb_func_ "<mdb_unknown>"
170 #define MDB_USE_HASH 1
171 #define MDB_PIDLOCK 0
172 #define pthread_t DWORD
173 #define pthread_mutex_t HANDLE
174 #define pthread_key_t DWORD
175 #define pthread_self() GetCurrentThreadId()
176 #define pthread_key_create(x,y) \
177 ((*(x) = TlsAlloc()) == TLS_OUT_OF_INDEXES ? ErrCode() : 0)
178 #define pthread_key_delete(x) TlsFree(x)
179 #define pthread_getspecific(x) TlsGetValue(x)
180 #define pthread_setspecific(x,y) (TlsSetValue(x,y) ? 0 : ErrCode())
181 #define pthread_mutex_unlock(x) ReleaseMutex(x)
182 #define pthread_mutex_lock(x) WaitForSingleObject(x, INFINITE)
183 #define LOCK_MUTEX_R(env) pthread_mutex_lock((env)->me_rmutex)
184 #define UNLOCK_MUTEX_R(env) pthread_mutex_unlock((env)->me_rmutex)
185 #define LOCK_MUTEX_W(env) pthread_mutex_lock((env)->me_wmutex)
186 #define UNLOCK_MUTEX_W(env) pthread_mutex_unlock((env)->me_wmutex)
187 #define getpid() GetCurrentProcessId()
188 #define MDB_FDATASYNC(fd) (!FlushFileBuffers(fd))
189 #define MDB_MSYNC(addr,len,flags) (!FlushViewOfFile(addr,len))
190 #define ErrCode() GetLastError()
191 #define GET_PAGESIZE(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;}
192 #define close(fd) (CloseHandle(fd) ? 0 : -1)
193 #define munmap(ptr,len) UnmapViewOfFile(ptr)
194 #ifdef PROCESS_QUERY_LIMITED_INFORMATION
195 #define MDB_PROCESS_QUERY_LIMITED_INFORMATION PROCESS_QUERY_LIMITED_INFORMATION
197 #define MDB_PROCESS_QUERY_LIMITED_INFORMATION 0x1000
202 #define Z "z" /**< printf format modifier for size_t */
204 /** For MDB_LOCK_FORMAT: True if readers take a pid lock in the lockfile */
205 #define MDB_PIDLOCK 1
207 #ifdef MDB_USE_POSIX_SEM
209 #define LOCK_MUTEX_R(env) mdb_sem_wait((env)->me_rmutex)
210 #define UNLOCK_MUTEX_R(env) sem_post((env)->me_rmutex)
211 #define LOCK_MUTEX_W(env) mdb_sem_wait((env)->me_wmutex)
212 #define UNLOCK_MUTEX_W(env) sem_post((env)->me_wmutex)
215 mdb_sem_wait(sem_t *sem)
218 while ((rc = sem_wait(sem)) && (rc = errno) == EINTR) ;
223 /** Lock the reader mutex.
225 #define LOCK_MUTEX_R(env) pthread_mutex_lock(&(env)->me_txns->mti_mutex)
226 /** Unlock the reader mutex.
228 #define UNLOCK_MUTEX_R(env) pthread_mutex_unlock(&(env)->me_txns->mti_mutex)
230 /** Lock the writer mutex.
231 * Only a single write transaction is allowed at a time. Other writers
232 * will block waiting for this mutex.
234 #define LOCK_MUTEX_W(env) pthread_mutex_lock(&(env)->me_txns->mti_wmutex)
235 /** Unlock the writer mutex.
237 #define UNLOCK_MUTEX_W(env) pthread_mutex_unlock(&(env)->me_txns->mti_wmutex)
238 #endif /* MDB_USE_POSIX_SEM */
240 /** Get the error code for the last failed system function.
242 #define ErrCode() errno
244 /** An abstraction for a file handle.
245 * On POSIX systems file handles are small integers. On Windows
246 * they're opaque pointers.
250 /** A value for an invalid file handle.
251 * Mainly used to initialize file variables and signify that they are
254 #define INVALID_HANDLE_VALUE (-1)
256 /** Get the size of a memory page for the system.
257 * This is the basic size that the platform's memory manager uses, and is
258 * fundamental to the use of memory-mapped files.
260 #define GET_PAGESIZE(x) ((x) = sysconf(_SC_PAGE_SIZE))
263 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
266 #define MNAME_LEN (sizeof(pthread_mutex_t))
272 /** A flag for opening a file and requesting synchronous data writes.
273 * This is only used when writing a meta page. It's not strictly needed;
274 * we could just do a normal write and then immediately perform a flush.
275 * But if this flag is available it saves us an extra system call.
277 * @note If O_DSYNC is undefined but exists in /usr/include,
278 * preferably set some compiler flag to get the definition.
279 * Otherwise compile with the less efficient -DMDB_DSYNC=O_SYNC.
282 # define MDB_DSYNC O_DSYNC
286 /** Function for flushing the data of a file. Define this to fsync
287 * if fdatasync() is not supported.
289 #ifndef MDB_FDATASYNC
290 # define MDB_FDATASYNC fdatasync
294 # define MDB_MSYNC(addr,len,flags) msync(addr,len,flags)
305 /** A page number in the database.
306 * Note that 64 bit page numbers are overkill, since pages themselves
307 * already represent 12-13 bits of addressable memory, and the OS will
308 * always limit applications to a maximum of 63 bits of address space.
310 * @note In the #MDB_node structure, we only store 48 bits of this value,
311 * which thus limits us to only 60 bits of addressable data.
313 typedef MDB_ID pgno_t;
315 /** A transaction ID.
316 * See struct MDB_txn.mt_txnid for details.
318 typedef MDB_ID txnid_t;
320 /** @defgroup debug Debug Macros
324 /** Enable debug output. Needs variable argument macros (a C99 feature).
325 * Set this to 1 for copious tracing. Set to 2 to add dumps of all IDLs
326 * read from and written to the database (used for free space management).
332 static int mdb_debug;
333 static txnid_t mdb_debug_start;
335 /** Print a debug message with printf formatting.
336 * Requires double parenthesis around 2 or more args.
338 # define DPRINTF(args) ((void) ((mdb_debug) && DPRINTF0 args))
339 # define DPRINTF0(fmt, ...) \
340 fprintf(stderr, "%s:%d " fmt "\n", mdb_func_, __LINE__, __VA_ARGS__)
342 # define DPRINTF(args) ((void) 0)
344 /** Print a debug string.
345 * The string is printed literally, with no format processing.
347 #define DPUTS(arg) DPRINTF(("%s", arg))
348 /** Debuging output value of a cursor DBI: Negative in a sub-cursor. */
350 (((mc)->mc_flags & C_SUB) ? -(int)(mc)->mc_dbi : (int)(mc)->mc_dbi)
353 /** @brief The maximum size of a database page.
355 * This is 32k, since it must fit in #MDB_page.%mp_upper.
357 * LMDB will use database pages < OS pages if needed.
358 * That causes more I/O in write transactions: The OS must
359 * know (read) the whole page before writing a partial page.
361 * Note that we don't currently support Huge pages. On Linux,
362 * regular data files cannot use Huge pages, and in general
363 * Huge pages aren't actually pageable. We rely on the OS
364 * demand-pager to read our data and page it out when memory
365 * pressure from other processes is high. So until OSs have
366 * actual paging support for Huge pages, they're not viable.
368 #define MAX_PAGESIZE 0x8000
370 /** The minimum number of keys required in a database page.
371 * Setting this to a larger value will place a smaller bound on the
372 * maximum size of a data item. Data items larger than this size will
373 * be pushed into overflow pages instead of being stored directly in
374 * the B-tree node. This value used to default to 4. With a page size
375 * of 4096 bytes that meant that any item larger than 1024 bytes would
376 * go into an overflow page. That also meant that on average 2-3KB of
377 * each overflow page was wasted space. The value cannot be lower than
378 * 2 because then there would no longer be a tree structure. With this
379 * value, items larger than 2KB will go into overflow pages, and on
380 * average only 1KB will be wasted.
382 #define MDB_MINKEYS 2
384 /** A stamp that identifies a file as an MDB file.
385 * There's nothing special about this value other than that it is easily
386 * recognizable, and it will reflect any byte order mismatches.
388 #define MDB_MAGIC 0xBEEFC0DE
390 /** The version number for a database's datafile format. */
391 #define MDB_DATA_VERSION 1
392 /** The version number for a database's lockfile format. */
393 #define MDB_LOCK_VERSION 1
395 /** @brief The max size of a key we can write, or 0 for dynamic max.
397 * Define this as 0 to compute the max from the page size. 511
398 * is default for backwards compat: liblmdb <= 0.9.10 can break
399 * when modifying a DB with keys/dupsort data bigger than its max.
401 * Data items in an #MDB_DUPSORT database are also limited to
402 * this size, since they're actually keys of a sub-DB. Keys and
403 * #MDB_DUPSORT data items must fit on a node in a regular page.
405 #ifndef MDB_MAXKEYSIZE
406 #define MDB_MAXKEYSIZE 511
409 /** The maximum size of a key we can write to the environment. */
411 #define ENV_MAXKEY(env) (MDB_MAXKEYSIZE)
413 #define ENV_MAXKEY(env) ((env)->me_maxkey)
416 /** @brief The maximum size of a data item.
418 * We only store a 32 bit value for node sizes.
420 #define MAXDATASIZE 0xffffffffUL
423 /** Key size which fits in a #DKBUF.
426 #define DKBUF_MAXKEYSIZE ((MDB_MAXKEYSIZE) > 0 ? (MDB_MAXKEYSIZE) : 511)
429 * This is used for printing a hex dump of a key's contents.
431 #define DKBUF char kbuf[DKBUF_MAXKEYSIZE*2+1]
432 /** Display a key in hex.
434 * Invoke a function to display a key in hex.
436 #define DKEY(x) mdb_dkey(x, kbuf)
442 /** An invalid page number.
443 * Mainly used to denote an empty tree.
445 #define P_INVALID (~(pgno_t)0)
447 /** Test if the flags \b f are set in a flag word \b w. */
448 #define F_ISSET(w, f) (((w) & (f)) == (f))
450 /** Round \b n up to an even number. */
451 #define EVEN(n) (((n) + 1U) & -2) /* sign-extending -2 to match n+1U */
453 /** Used for offsets within a single page.
454 * Since memory pages are typically 4 or 8KB in size, 12-13 bits,
457 typedef uint16_t indx_t;
459 /** Default size of memory map.
460 * This is certainly too small for any actual applications. Apps should always set
461 * the size explicitly using #mdb_env_set_mapsize().
463 #define DEFAULT_MAPSIZE 1048576
465 /** @defgroup readers Reader Lock Table
466 * Readers don't acquire any locks for their data access. Instead, they
467 * simply record their transaction ID in the reader table. The reader
468 * mutex is needed just to find an empty slot in the reader table. The
469 * slot's address is saved in thread-specific data so that subsequent read
470 * transactions started by the same thread need no further locking to proceed.
472 * If #MDB_NOTLS is set, the slot address is not saved in thread-specific data.
474 * No reader table is used if the database is on a read-only filesystem, or
475 * if #MDB_NOLOCK is set.
477 * Since the database uses multi-version concurrency control, readers don't
478 * actually need any locking. This table is used to keep track of which
479 * readers are using data from which old transactions, so that we'll know
480 * when a particular old transaction is no longer in use. Old transactions
481 * that have discarded any data pages can then have those pages reclaimed
482 * for use by a later write transaction.
484 * The lock table is constructed such that reader slots are aligned with the
485 * processor's cache line size. Any slot is only ever used by one thread.
486 * This alignment guarantees that there will be no contention or cache
487 * thrashing as threads update their own slot info, and also eliminates
488 * any need for locking when accessing a slot.
490 * A writer thread will scan every slot in the table to determine the oldest
491 * outstanding reader transaction. Any freed pages older than this will be
492 * reclaimed by the writer. The writer doesn't use any locks when scanning
493 * this table. This means that there's no guarantee that the writer will
494 * see the most up-to-date reader info, but that's not required for correct
495 * operation - all we need is to know the upper bound on the oldest reader,
496 * we don't care at all about the newest reader. So the only consequence of
497 * reading stale information here is that old pages might hang around a
498 * while longer before being reclaimed. That's actually good anyway, because
499 * the longer we delay reclaiming old pages, the more likely it is that a
500 * string of contiguous pages can be found after coalescing old pages from
501 * many old transactions together.
504 /** Number of slots in the reader table.
505 * This value was chosen somewhat arbitrarily. 126 readers plus a
506 * couple mutexes fit exactly into 8KB on my development machine.
507 * Applications should set the table size using #mdb_env_set_maxreaders().
509 #define DEFAULT_READERS 126
511 /** The size of a CPU cache line in bytes. We want our lock structures
512 * aligned to this size to avoid false cache line sharing in the
514 * This value works for most CPUs. For Itanium this should be 128.
520 /** The information we store in a single slot of the reader table.
521 * In addition to a transaction ID, we also record the process and
522 * thread ID that owns a slot, so that we can detect stale information,
523 * e.g. threads or processes that went away without cleaning up.
524 * @note We currently don't check for stale records. We simply re-init
525 * the table when we know that we're the only process opening the
528 typedef struct MDB_rxbody {
529 /** Current Transaction ID when this transaction began, or (txnid_t)-1.
530 * Multiple readers that start at the same time will probably have the
531 * same ID here. Again, it's not important to exclude them from
532 * anything; all we need to know is which version of the DB they
533 * started from so we can avoid overwriting any data used in that
534 * particular version.
537 /** The process ID of the process owning this reader txn. */
539 /** The thread ID of the thread owning this txn. */
543 /** The actual reader record, with cacheline padding. */
544 typedef struct MDB_reader {
547 /** shorthand for mrb_txnid */
548 #define mr_txnid mru.mrx.mrb_txnid
549 #define mr_pid mru.mrx.mrb_pid
550 #define mr_tid mru.mrx.mrb_tid
551 /** cache line alignment */
552 char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)];
556 /** The header for the reader table.
557 * The table resides in a memory-mapped file. (This is a different file
558 * than is used for the main database.)
560 * For POSIX the actual mutexes reside in the shared memory of this
561 * mapped file. On Windows, mutexes are named objects allocated by the
562 * kernel; we store the mutex names in this mapped file so that other
563 * processes can grab them. This same approach is also used on
564 * MacOSX/Darwin (using named semaphores) since MacOSX doesn't support
565 * process-shared POSIX mutexes. For these cases where a named object
566 * is used, the object name is derived from a 64 bit FNV hash of the
567 * environment pathname. As such, naming collisions are extremely
568 * unlikely. If a collision occurs, the results are unpredictable.
570 typedef struct MDB_txbody {
571 /** Stamp identifying this as an MDB file. It must be set
574 /** Format of this lock file. Must be set to #MDB_LOCK_FORMAT. */
576 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
577 char mtb_rmname[MNAME_LEN];
579 /** Mutex protecting access to this table.
580 * This is the reader lock that #LOCK_MUTEX_R acquires.
582 pthread_mutex_t mtb_mutex;
584 /** The ID of the last transaction committed to the database.
585 * This is recorded here only for convenience; the value can always
586 * be determined by reading the main database meta pages.
589 /** The number of slots that have been used in the reader table.
590 * This always records the maximum count, it is not decremented
591 * when readers release their slots.
593 unsigned mtb_numreaders;
596 /** The actual reader table definition. */
597 typedef struct MDB_txninfo {
600 #define mti_magic mt1.mtb.mtb_magic
601 #define mti_format mt1.mtb.mtb_format
602 #define mti_mutex mt1.mtb.mtb_mutex
603 #define mti_rmname mt1.mtb.mtb_rmname
604 #define mti_txnid mt1.mtb.mtb_txnid
605 #define mti_numreaders mt1.mtb.mtb_numreaders
606 char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];
609 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
610 char mt2_wmname[MNAME_LEN];
611 #define mti_wmname mt2.mt2_wmname
613 pthread_mutex_t mt2_wmutex;
614 #define mti_wmutex mt2.mt2_wmutex
616 char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)];
618 MDB_reader mti_readers[1];
621 /** Lockfile format signature: version, features and field layout */
622 #define MDB_LOCK_FORMAT \
624 ((MDB_LOCK_VERSION) \
625 /* Flags which describe functionality */ \
626 + (((MDB_PIDLOCK) != 0) << 16)))
629 /** Common header for all page types.
630 * Overflow records occupy a number of contiguous pages with no
631 * headers on any page after the first.
633 typedef struct MDB_page {
634 #define mp_pgno mp_p.p_pgno
635 #define mp_next mp_p.p_next
637 pgno_t p_pgno; /**< page number */
638 void * p_next; /**< for in-memory list of freed structs */
641 /** @defgroup mdb_page Page Flags
643 * Flags for the page headers.
646 #define P_BRANCH 0x01 /**< branch page */
647 #define P_LEAF 0x02 /**< leaf page */
648 #define P_OVERFLOW 0x04 /**< overflow page */
649 #define P_META 0x08 /**< meta page */
650 #define P_DIRTY 0x10 /**< dirty page, also set for #P_SUBP pages */
651 #define P_LEAF2 0x20 /**< for #MDB_DUPFIXED records */
652 #define P_SUBP 0x40 /**< for #MDB_DUPSORT sub-pages */
653 #define P_KEEP 0x8000 /**< leave this page alone during spill */
655 uint16_t mp_flags; /**< @ref mdb_page */
656 #define mp_lower mp_pb.pb.pb_lower
657 #define mp_upper mp_pb.pb.pb_upper
658 #define mp_pages mp_pb.pb_pages
661 indx_t pb_lower; /**< lower bound of free space */
662 indx_t pb_upper; /**< upper bound of free space */
664 uint32_t pb_pages; /**< number of overflow pages */
666 indx_t mp_ptrs[1]; /**< dynamic size */
669 /** Size of the page header, excluding dynamic data at the end */
670 #define PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs))
672 /** Address of first usable data byte in a page, after the header */
673 #define METADATA(p) ((void *)((char *)(p) + PAGEHDRSZ))
675 /** Number of nodes on a page */
676 #define NUMKEYS(p) (((p)->mp_lower - PAGEHDRSZ) >> 1)
678 /** The amount of space remaining in the page */
679 #define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower)
681 /** The percentage of space used in the page, in tenths of a percent. */
682 #define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \
683 ((env)->me_psize - PAGEHDRSZ))
684 /** The minimum page fill factor, in tenths of a percent.
685 * Pages emptier than this are candidates for merging.
687 #define FILL_THRESHOLD 250
689 /** Test if a page is a leaf page */
690 #define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF)
691 /** Test if a page is a LEAF2 page */
692 #define IS_LEAF2(p) F_ISSET((p)->mp_flags, P_LEAF2)
693 /** Test if a page is a branch page */
694 #define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH)
695 /** Test if a page is an overflow page */
696 #define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW)
697 /** Test if a page is a sub page */
698 #define IS_SUBP(p) F_ISSET((p)->mp_flags, P_SUBP)
700 /** The number of overflow pages needed to store the given size. */
701 #define OVPAGES(size, psize) ((PAGEHDRSZ-1 + (size)) / (psize) + 1)
703 /** Header for a single key/data pair within a page.
704 * Used in pages of type #P_BRANCH and #P_LEAF without #P_LEAF2.
705 * We guarantee 2-byte alignment for 'MDB_node's.
707 typedef struct MDB_node {
708 /** lo and hi are used for data size on leaf nodes and for
709 * child pgno on branch nodes. On 64 bit platforms, flags
710 * is also used for pgno. (Branch nodes have no flags).
711 * They are in host byte order in case that lets some
712 * accesses be optimized into a 32-bit word access.
714 #if BYTE_ORDER == LITTLE_ENDIAN
715 unsigned short mn_lo, mn_hi; /**< part of data size or pgno */
717 unsigned short mn_hi, mn_lo;
719 /** @defgroup mdb_node Node Flags
721 * Flags for node headers.
724 #define F_BIGDATA 0x01 /**< data put on overflow page */
725 #define F_SUBDATA 0x02 /**< data is a sub-database */
726 #define F_DUPDATA 0x04 /**< data has duplicates */
728 /** valid flags for #mdb_node_add() */
729 #define NODE_ADD_FLAGS (F_DUPDATA|F_SUBDATA|MDB_RESERVE|MDB_APPEND)
732 unsigned short mn_flags; /**< @ref mdb_node */
733 unsigned short mn_ksize; /**< key size */
734 char mn_data[1]; /**< key and data are appended here */
737 /** Size of the node header, excluding dynamic data at the end */
738 #define NODESIZE offsetof(MDB_node, mn_data)
740 /** Bit position of top word in page number, for shifting mn_flags */
741 #define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0)
743 /** Size of a node in a branch page with a given key.
744 * This is just the node header plus the key, there is no data.
746 #define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))
748 /** Size of a node in a leaf page with a given key and data.
749 * This is node header plus key plus data size.
751 #define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size)
753 /** Address of node \b i in page \b p */
754 #define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i]))
756 /** Address of the key for the node */
757 #define NODEKEY(node) (void *)((node)->mn_data)
759 /** Address of the data for a node */
760 #define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize)
762 /** Get the page number pointed to by a branch node */
763 #define NODEPGNO(node) \
764 ((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | \
765 (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0))
766 /** Set the page number in a branch node */
767 #define SETPGNO(node,pgno) do { \
768 (node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \
769 if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0)
771 /** Get the size of the data in a leaf node */
772 #define NODEDSZ(node) ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16))
773 /** Set the size of the data for a leaf node */
774 #define SETDSZ(node,size) do { \
775 (node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)
776 /** The size of a key in a node */
777 #define NODEKSZ(node) ((node)->mn_ksize)
779 /** Copy a page number from src to dst */
781 #define COPY_PGNO(dst,src) dst = src
783 #if SIZE_MAX > 4294967295UL
784 #define COPY_PGNO(dst,src) do { \
785 unsigned short *s, *d; \
786 s = (unsigned short *)&(src); \
787 d = (unsigned short *)&(dst); \
794 #define COPY_PGNO(dst,src) do { \
795 unsigned short *s, *d; \
796 s = (unsigned short *)&(src); \
797 d = (unsigned short *)&(dst); \
803 /** The address of a key in a LEAF2 page.
804 * LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate sub-DBs.
805 * There are no node headers, keys are stored contiguously.
807 #define LEAF2KEY(p, i, ks) ((char *)(p) + PAGEHDRSZ + ((i)*(ks)))
809 /** Set the \b node's key into \b keyptr, if requested. */
810 #define MDB_GET_KEY(node, keyptr) { if ((keyptr) != NULL) { \
811 (keyptr)->mv_size = NODEKSZ(node); (keyptr)->mv_data = NODEKEY(node); } }
813 /** Set the \b node's key into \b key. */
814 #define MDB_GET_KEY2(node, key) { key.mv_size = NODEKSZ(node); key.mv_data = NODEKEY(node); }
816 /** Information about a single database in the environment. */
817 typedef struct MDB_db {
818 uint32_t md_pad; /**< also ksize for LEAF2 pages */
819 uint16_t md_flags; /**< @ref mdb_dbi_open */
820 uint16_t md_depth; /**< depth of this tree */
821 pgno_t md_branch_pages; /**< number of internal pages */
822 pgno_t md_leaf_pages; /**< number of leaf pages */
823 pgno_t md_overflow_pages; /**< number of overflow pages */
824 size_t md_entries; /**< number of data items */
825 pgno_t md_root; /**< the root page of this tree */
828 /** mdb_dbi_open flags */
829 #define MDB_VALID 0x8000 /**< DB handle is valid, for me_dbflags */
830 #define PERSISTENT_FLAGS (0xffff & ~(MDB_VALID))
831 #define VALID_FLAGS (MDB_REVERSEKEY|MDB_DUPSORT|MDB_INTEGERKEY|MDB_DUPFIXED|\
832 MDB_INTEGERDUP|MDB_REVERSEDUP|MDB_CREATE)
834 /** Handle for the DB used to track free pages. */
836 /** Handle for the default DB. */
839 /** Meta page content.
840 * A meta page is the start point for accessing a database snapshot.
841 * Pages 0-1 are meta pages. Transaction N writes meta page #(N % 2).
843 typedef struct MDB_meta {
844 /** Stamp identifying this as an MDB file. It must be set
847 /** Version number of this lock file. Must be set to #MDB_DATA_VERSION. */
849 void *mm_address; /**< address for fixed mapping */
850 size_t mm_mapsize; /**< size of mmap region */
851 MDB_db mm_dbs[2]; /**< first is free space, 2nd is main db */
852 /** The size of pages used in this DB */
853 #define mm_psize mm_dbs[0].md_pad
854 /** Any persistent environment flags. @ref mdb_env */
855 #define mm_flags mm_dbs[0].md_flags
856 pgno_t mm_last_pg; /**< last used page in file */
857 txnid_t mm_txnid; /**< txnid that committed this page */
860 /** Buffer for a stack-allocated meta page.
861 * The members define size and alignment, and silence type
862 * aliasing warnings. They are not used directly; that could
863 * mean incorrectly using several union members in parallel.
865 typedef union MDB_metabuf {
868 char mm_pad[PAGEHDRSZ];
873 /** Auxiliary DB info.
874 * The information here is mostly static/read-only. There is
875 * only a single copy of this record in the environment.
877 typedef struct MDB_dbx {
878 MDB_val md_name; /**< name of the database */
879 MDB_cmp_func *md_cmp; /**< function for comparing keys */
880 MDB_cmp_func *md_dcmp; /**< function for comparing data items */
881 MDB_rel_func *md_rel; /**< user relocate function */
882 void *md_relctx; /**< user-provided context for md_rel */
885 /** A database transaction.
886 * Every operation requires a transaction handle.
889 MDB_txn *mt_parent; /**< parent of a nested txn */
890 MDB_txn *mt_child; /**< nested txn under this txn */
891 pgno_t mt_next_pgno; /**< next unallocated page */
892 /** The ID of this transaction. IDs are integers incrementing from 1.
893 * Only committed write transactions increment the ID. If a transaction
894 * aborts, the ID may be re-used by the next writer.
897 MDB_env *mt_env; /**< the DB environment */
898 /** The list of pages that became unused during this transaction.
901 /** The sorted list of dirty pages we temporarily wrote to disk
902 * because the dirty list was full. page numbers in here are
903 * shifted left by 1, deleted slots have the LSB set.
905 MDB_IDL mt_spill_pgs;
907 /** For write txns: Modified pages. Sorted when not MDB_WRITEMAP. */
909 /** For read txns: This thread/txn's reader table slot, or NULL. */
912 /** Array of records for each DB known in the environment. */
914 /** Array of MDB_db records for each known DB */
916 /** @defgroup mt_dbflag Transaction DB Flags
920 #define DB_DIRTY 0x01 /**< DB was modified or is DUPSORT data */
921 #define DB_STALE 0x02 /**< Named-DB record is older than txnID */
922 #define DB_NEW 0x04 /**< Named-DB handle opened in this txn */
923 #define DB_VALID 0x08 /**< DB handle is valid, see also #MDB_VALID */
925 /** In write txns, array of cursors for each DB */
926 MDB_cursor **mt_cursors;
927 /** Array of flags for each DB */
928 unsigned char *mt_dbflags;
929 /** Number of DB records in use. This number only ever increments;
930 * we don't decrement it when individual DB handles are closed.
934 /** @defgroup mdb_txn Transaction Flags
938 #define MDB_TXN_RDONLY 0x01 /**< read-only transaction */
939 #define MDB_TXN_ERROR 0x02 /**< txn is unusable after an error */
940 #define MDB_TXN_DIRTY 0x04 /**< must write, even if dirty list is empty */
941 #define MDB_TXN_SPILLS 0x08 /**< txn or a parent has spilled pages */
943 unsigned int mt_flags; /**< @ref mdb_txn */
944 /** #dirty_list room: Array size - \#dirty pages visible to this txn.
945 * Includes ancestor txns' dirty pages not hidden by other txns'
946 * dirty/spilled pages. Thus commit(nested txn) has room to merge
947 * dirty_list into mt_parent after freeing hidden mt_parent pages.
949 unsigned int mt_dirty_room;
952 /** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty.
953 * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to
954 * raise this on a 64 bit machine.
956 #define CURSOR_STACK 32
960 /** Cursors are used for all DB operations.
961 * A cursor holds a path of (page pointer, key index) from the DB
962 * root to a position in the DB, plus other state. #MDB_DUPSORT
963 * cursors include an xcursor to the current data item. Write txns
964 * track their cursors and keep them up to date when data moves.
965 * Exception: An xcursor's pointer to a #P_SUBP page can be stale.
966 * (A node with #F_DUPDATA but no #F_SUBDATA contains a subpage).
969 /** Next cursor on this DB in this txn */
971 /** Backup of the original cursor if this cursor is a shadow */
972 MDB_cursor *mc_backup;
973 /** Context used for databases with #MDB_DUPSORT, otherwise NULL */
974 struct MDB_xcursor *mc_xcursor;
975 /** The transaction that owns this cursor */
977 /** The database handle this cursor operates on */
979 /** The database record for this cursor */
981 /** The database auxiliary record for this cursor */
983 /** The @ref mt_dbflag for this database */
984 unsigned char *mc_dbflag;
985 unsigned short mc_snum; /**< number of pushed pages */
986 unsigned short mc_top; /**< index of top page, normally mc_snum-1 */
987 /** @defgroup mdb_cursor Cursor Flags
989 * Cursor state flags.
992 #define C_INITIALIZED 0x01 /**< cursor has been initialized and is valid */
993 #define C_EOF 0x02 /**< No more data */
994 #define C_SUB 0x04 /**< Cursor is a sub-cursor */
995 #define C_DEL 0x08 /**< last op was a cursor_del */
996 #define C_SPLITTING 0x20 /**< Cursor is in page_split */
997 #define C_UNTRACK 0x40 /**< Un-track cursor when closing */
999 unsigned int mc_flags; /**< @ref mdb_cursor */
1000 MDB_page *mc_pg[CURSOR_STACK]; /**< stack of pushed pages */
1001 indx_t mc_ki[CURSOR_STACK]; /**< stack of page indices */
1004 /** Context for sorted-dup records.
1005 * We could have gone to a fully recursive design, with arbitrarily
1006 * deep nesting of sub-databases. But for now we only handle these
1007 * levels - main DB, optional sub-DB, sorted-duplicate DB.
1009 typedef struct MDB_xcursor {
1010 /** A sub-cursor for traversing the Dup DB */
1011 MDB_cursor mx_cursor;
1012 /** The database record for this Dup DB */
1014 /** The auxiliary DB record for this Dup DB */
1016 /** The @ref mt_dbflag for this Dup DB */
1017 unsigned char mx_dbflag;
1020 /** State of FreeDB old pages, stored in the MDB_env */
1021 typedef struct MDB_pgstate {
1022 pgno_t *mf_pghead; /**< Reclaimed freeDB pages, or NULL before use */
1023 txnid_t mf_pglast; /**< ID of last used record, or 0 if !mf_pghead */
1026 /** The database environment. */
1028 HANDLE me_fd; /**< The main data file */
1029 HANDLE me_lfd; /**< The lock file */
1030 HANDLE me_mfd; /**< just for writing the meta pages */
1031 /** Failed to update the meta page. Probably an I/O error. */
1032 #define MDB_FATAL_ERROR 0x80000000U
1033 /** Some fields are initialized. */
1034 #define MDB_ENV_ACTIVE 0x20000000U
1035 /** me_txkey is set */
1036 #define MDB_ENV_TXKEY 0x10000000U
1037 uint32_t me_flags; /**< @ref mdb_env */
1038 unsigned int me_psize; /**< DB page size, inited from me_os_psize */
1039 unsigned int me_os_psize; /**< OS page size, from #GET_PAGESIZE */
1040 unsigned int me_maxreaders; /**< size of the reader table */
1041 unsigned int me_numreaders; /**< max numreaders set by this env */
1042 MDB_dbi me_numdbs; /**< number of DBs opened */
1043 MDB_dbi me_maxdbs; /**< size of the DB table */
1044 MDB_PID_T me_pid; /**< process ID of this env */
1045 char *me_path; /**< path to the DB files */
1046 char *me_map; /**< the memory map of the data file */
1047 MDB_txninfo *me_txns; /**< the memory map of the lock file or NULL */
1048 MDB_meta *me_metas[2]; /**< pointers to the two meta pages */
1049 void *me_pbuf; /**< scratch area for DUPSORT put() */
1050 MDB_txn *me_txn; /**< current write transaction */
1051 size_t me_mapsize; /**< size of the data memory map */
1052 off_t me_size; /**< current file size */
1053 pgno_t me_maxpg; /**< me_mapsize / me_psize */
1054 MDB_dbx *me_dbxs; /**< array of static DB info */
1055 uint16_t *me_dbflags; /**< array of flags from MDB_db.md_flags */
1056 pthread_key_t me_txkey; /**< thread-key for readers */
1057 MDB_pgstate me_pgstate; /**< state of old pages from freeDB */
1058 # define me_pglast me_pgstate.mf_pglast
1059 # define me_pghead me_pgstate.mf_pghead
1060 MDB_page *me_dpages; /**< list of malloc'd blocks for re-use */
1061 /** IDL of pages that became unused in a write txn */
1062 MDB_IDL me_free_pgs;
1063 /** ID2L of pages written during a write txn. Length MDB_IDL_UM_SIZE. */
1064 MDB_ID2L me_dirty_list;
1065 /** Max number of freelist items that can fit in a single overflow page */
1067 /** Max size of a node on a page */
1068 unsigned int me_nodemax;
1069 #if !(MDB_MAXKEYSIZE)
1070 unsigned int me_maxkey; /**< max size of a key */
1072 int me_live_reader; /**< have liveness lock in reader table */
1074 int me_pidquery; /**< Used in OpenProcess */
1075 HANDLE me_rmutex; /* Windows mutexes don't reside in shared mem */
1077 #elif defined(MDB_USE_POSIX_SEM)
1078 sem_t *me_rmutex; /* Shared mutexes are not supported */
1081 void *me_userctx; /**< User-settable context */
1082 MDB_assert_func *me_assert_func; /**< Callback for assertion failures */
1085 /** Nested transaction */
1086 typedef struct MDB_ntxn {
1087 MDB_txn mnt_txn; /**< the transaction */
1088 MDB_pgstate mnt_pgstate; /**< parent transaction's saved freestate */
1091 /** max number of pages to commit in one writev() call */
1092 #define MDB_COMMIT_PAGES 64
1093 #if defined(IOV_MAX) && IOV_MAX < MDB_COMMIT_PAGES
1094 #undef MDB_COMMIT_PAGES
1095 #define MDB_COMMIT_PAGES IOV_MAX
1098 /** max bytes to write in one call */
1099 #define MAX_WRITE (0x80000000U >> (sizeof(ssize_t) == 4))
1101 /** Check \b txn and \b dbi arguments to a function */
1102 #define TXN_DBI_EXIST(txn, dbi) \
1103 ((txn) && (dbi) < (txn)->mt_numdbs && ((txn)->mt_dbflags[dbi] & DB_VALID))
1105 static int mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp);
1106 static int mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp);
1107 static int mdb_page_touch(MDB_cursor *mc);
1109 static int mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **mp, int *lvl);
1110 static int mdb_page_search_root(MDB_cursor *mc,
1111 MDB_val *key, int modify);
1112 #define MDB_PS_MODIFY 1
1113 #define MDB_PS_ROOTONLY 2
1114 #define MDB_PS_FIRST 4
1115 #define MDB_PS_LAST 8
1116 static int mdb_page_search(MDB_cursor *mc,
1117 MDB_val *key, int flags);
1118 static int mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst);
1120 #define MDB_SPLIT_REPLACE MDB_APPENDDUP /**< newkey is not new */
1121 static int mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,
1122 pgno_t newpgno, unsigned int nflags);
1124 static int mdb_env_read_header(MDB_env *env, MDB_meta *meta);
1125 static int mdb_env_pick_meta(const MDB_env *env);
1126 static int mdb_env_write_meta(MDB_txn *txn);
1127 #if !(defined(_WIN32) || defined(MDB_USE_POSIX_SEM)) /* Drop unused excl arg */
1128 # define mdb_env_close0(env, excl) mdb_env_close1(env)
1130 static void mdb_env_close0(MDB_env *env, int excl);
1132 static MDB_node *mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp);
1133 static int mdb_node_add(MDB_cursor *mc, indx_t indx,
1134 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags);
1135 static void mdb_node_del(MDB_cursor *mc, int ksize);
1136 static void mdb_node_shrink(MDB_page *mp, indx_t indx);
1137 static int mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst);
1138 static int mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data);
1139 static size_t mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data);
1140 static size_t mdb_branch_size(MDB_env *env, MDB_val *key);
1142 static int mdb_rebalance(MDB_cursor *mc);
1143 static int mdb_update_key(MDB_cursor *mc, MDB_val *key);
1145 static void mdb_cursor_pop(MDB_cursor *mc);
1146 static int mdb_cursor_push(MDB_cursor *mc, MDB_page *mp);
1148 static int mdb_cursor_del0(MDB_cursor *mc);
1149 static int mdb_del0(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned flags);
1150 static int mdb_cursor_sibling(MDB_cursor *mc, int move_right);
1151 static int mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1152 static int mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1153 static int mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op,
1155 static int mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1156 static int mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1158 static void mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);
1159 static void mdb_xcursor_init0(MDB_cursor *mc);
1160 static void mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node);
1162 static int mdb_drop0(MDB_cursor *mc, int subs);
1163 static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi);
1166 static MDB_cmp_func mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long;
1170 static SECURITY_DESCRIPTOR mdb_null_sd;
1171 static SECURITY_ATTRIBUTES mdb_all_sa;
1172 static int mdb_sec_inited;
1175 /** Return the library version info. */
1177 mdb_version(int *major, int *minor, int *patch)
1179 if (major) *major = MDB_VERSION_MAJOR;
1180 if (minor) *minor = MDB_VERSION_MINOR;
1181 if (patch) *patch = MDB_VERSION_PATCH;
1182 return MDB_VERSION_STRING;
1185 /** Table of descriptions for MDB @ref errors */
1186 static char *const mdb_errstr[] = {
1187 "MDB_KEYEXIST: Key/data pair already exists",
1188 "MDB_NOTFOUND: No matching key/data pair found",
1189 "MDB_PAGE_NOTFOUND: Requested page not found",
1190 "MDB_CORRUPTED: Located page was wrong type",
1191 "MDB_PANIC: Update of meta page failed",
1192 "MDB_VERSION_MISMATCH: Database environment version mismatch",
1193 "MDB_INVALID: File is not an MDB file",
1194 "MDB_MAP_FULL: Environment mapsize limit reached",
1195 "MDB_DBS_FULL: Environment maxdbs limit reached",
1196 "MDB_READERS_FULL: Environment maxreaders limit reached",
1197 "MDB_TLS_FULL: Thread-local storage keys full - too many environments open",
1198 "MDB_TXN_FULL: Transaction has too many dirty pages - transaction too big",
1199 "MDB_CURSOR_FULL: Internal error - cursor stack limit reached",
1200 "MDB_PAGE_FULL: Internal error - page has no more space",
1201 "MDB_MAP_RESIZED: Database contents grew beyond environment mapsize",
1202 "MDB_INCOMPATIBLE: Operation and DB incompatible, or DB flags changed",
1203 "MDB_BAD_RSLOT: Invalid reuse of reader locktable slot",
1204 "MDB_BAD_TXN: Transaction cannot recover - it must be aborted",
1205 "MDB_BAD_VALSIZE: Too big key/data, key is empty, or wrong DUPFIXED size",
1209 mdb_strerror(int err)
1213 return ("Successful return: 0");
1215 if (err >= MDB_KEYEXIST && err <= MDB_LAST_ERRCODE) {
1216 i = err - MDB_KEYEXIST;
1217 return mdb_errstr[i];
1220 return strerror(err);
1223 /** assert(3) variant in cursor context */
1224 #define mdb_cassert(mc, expr) mdb_assert0((mc)->mc_txn->mt_env, expr, #expr)
1225 /** assert(3) variant in transaction context */
1226 #define mdb_tassert(mc, expr) mdb_assert0((txn)->mt_env, expr, #expr)
1227 /** assert(3) variant in environment context */
1228 #define mdb_eassert(env, expr) mdb_assert0(env, expr, #expr)
1231 # define mdb_assert0(env, expr, expr_txt) ((expr) ? (void)0 : \
1232 mdb_assert_fail(env, expr_txt, mdb_func_, __FILE__, __LINE__))
1235 mdb_assert_fail(MDB_env *env, const char *expr_txt,
1236 const char *func, const char *file, int line)
1239 sprintf(buf, "%.100s:%d: Assertion '%.200s' failed in %.40s()",
1240 file, line, expr_txt, func);
1241 if (env->me_assert_func)
1242 env->me_assert_func(env, buf);
1243 fprintf(stderr, "%s\n", buf);
1247 # define mdb_assert0(env, expr, expr_txt) ((void) 0)
1251 /** Return the page number of \b mp which may be sub-page, for debug output */
1253 mdb_dbg_pgno(MDB_page *mp)
1256 COPY_PGNO(ret, mp->mp_pgno);
1260 /** Display a key in hexadecimal and return the address of the result.
1261 * @param[in] key the key to display
1262 * @param[in] buf the buffer to write into. Should always be #DKBUF.
1263 * @return The key in hexadecimal form.
1266 mdb_dkey(MDB_val *key, char *buf)
1269 unsigned char *c = key->mv_data;
1275 if (key->mv_size > DKBUF_MAXKEYSIZE)
1276 return "MDB_MAXKEYSIZE";
1277 /* may want to make this a dynamic check: if the key is mostly
1278 * printable characters, print it as-is instead of converting to hex.
1282 for (i=0; i<key->mv_size; i++)
1283 ptr += sprintf(ptr, "%02x", *c++);
1285 sprintf(buf, "%.*s", key->mv_size, key->mv_data);
1291 mdb_leafnode_type(MDB_node *n)
1293 static char *const tp[2][2] = {{"", ": DB"}, {": sub-page", ": sub-DB"}};
1294 return F_ISSET(n->mn_flags, F_BIGDATA) ? ": overflow page" :
1295 tp[F_ISSET(n->mn_flags, F_DUPDATA)][F_ISSET(n->mn_flags, F_SUBDATA)];
1298 /** Display all the keys in the page. */
1300 mdb_page_list(MDB_page *mp)
1302 pgno_t pgno = mdb_dbg_pgno(mp);
1303 const char *type, *state = (mp->mp_flags & P_DIRTY) ? ", dirty" : "";
1305 unsigned int i, nkeys, nsize, total = 0;
1309 switch (mp->mp_flags & (P_BRANCH|P_LEAF|P_LEAF2|P_META|P_OVERFLOW|P_SUBP)) {
1310 case P_BRANCH: type = "Branch page"; break;
1311 case P_LEAF: type = "Leaf page"; break;
1312 case P_LEAF|P_SUBP: type = "Sub-page"; break;
1313 case P_LEAF|P_LEAF2: type = "LEAF2 page"; break;
1314 case P_LEAF|P_LEAF2|P_SUBP: type = "LEAF2 sub-page"; break;
1316 fprintf(stderr, "Overflow page %"Z"u pages %u%s\n",
1317 pgno, mp->mp_pages, state);
1320 fprintf(stderr, "Meta-page %"Z"u txnid %"Z"u\n",
1321 pgno, ((MDB_meta *)METADATA(mp))->mm_txnid);
1324 fprintf(stderr, "Bad page %"Z"u flags 0x%u\n", pgno, mp->mp_flags);
1328 nkeys = NUMKEYS(mp);
1329 fprintf(stderr, "%s %"Z"u numkeys %d%s\n", type, pgno, nkeys, state);
1331 for (i=0; i<nkeys; i++) {
1332 if (IS_LEAF2(mp)) { /* LEAF2 pages have no mp_ptrs[] or node headers */
1333 key.mv_size = nsize = mp->mp_pad;
1334 key.mv_data = LEAF2KEY(mp, i, nsize);
1336 fprintf(stderr, "key %d: nsize %d, %s\n", i, nsize, DKEY(&key));
1339 node = NODEPTR(mp, i);
1340 key.mv_size = node->mn_ksize;
1341 key.mv_data = node->mn_data;
1342 nsize = NODESIZE + key.mv_size;
1343 if (IS_BRANCH(mp)) {
1344 fprintf(stderr, "key %d: page %"Z"u, %s\n", i, NODEPGNO(node),
1348 if (F_ISSET(node->mn_flags, F_BIGDATA))
1349 nsize += sizeof(pgno_t);
1351 nsize += NODEDSZ(node);
1353 nsize += sizeof(indx_t);
1354 fprintf(stderr, "key %d: nsize %d, %s%s\n",
1355 i, nsize, DKEY(&key), mdb_leafnode_type(node));
1357 total = EVEN(total);
1359 fprintf(stderr, "Total: header %d + contents %d + unused %d\n",
1360 IS_LEAF2(mp) ? PAGEHDRSZ : mp->mp_lower, total, SIZELEFT(mp));
1364 mdb_cursor_chk(MDB_cursor *mc)
1370 if (!mc->mc_snum && !(mc->mc_flags & C_INITIALIZED)) return;
1371 for (i=0; i<mc->mc_top; i++) {
1373 node = NODEPTR(mp, mc->mc_ki[i]);
1374 if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno)
1377 if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i]))
1383 /** Count all the pages in each DB and in the freelist
1384 * and make sure it matches the actual number of pages
1386 * All named DBs must be open for a correct count.
1388 static void mdb_audit(MDB_txn *txn)
1392 MDB_ID freecount, count;
1397 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
1398 while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
1399 freecount += *(MDB_ID *)data.mv_data;
1400 mdb_tassert(txn, rc == MDB_NOTFOUND);
1403 for (i = 0; i<txn->mt_numdbs; i++) {
1405 if (!(txn->mt_dbflags[i] & DB_VALID))
1407 mdb_cursor_init(&mc, txn, i, &mx);
1408 if (txn->mt_dbs[i].md_root == P_INVALID)
1410 count += txn->mt_dbs[i].md_branch_pages +
1411 txn->mt_dbs[i].md_leaf_pages +
1412 txn->mt_dbs[i].md_overflow_pages;
1413 if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) {
1414 rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST);
1415 for (; rc == MDB_SUCCESS; rc = mdb_cursor_sibling(&mc, 1)) {
1418 mp = mc.mc_pg[mc.mc_top];
1419 for (j=0; j<NUMKEYS(mp); j++) {
1420 MDB_node *leaf = NODEPTR(mp, j);
1421 if (leaf->mn_flags & F_SUBDATA) {
1423 memcpy(&db, NODEDATA(leaf), sizeof(db));
1424 count += db.md_branch_pages + db.md_leaf_pages +
1425 db.md_overflow_pages;
1429 mdb_tassert(txn, rc == MDB_NOTFOUND);
1432 if (freecount + count + 2 /* metapages */ != txn->mt_next_pgno) {
1433 fprintf(stderr, "audit: %lu freecount: %lu count: %lu total: %lu next_pgno: %lu\n",
1434 txn->mt_txnid, freecount, count+2, freecount+count+2, txn->mt_next_pgno);
1440 mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1442 return txn->mt_dbxs[dbi].md_cmp(a, b);
1446 mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1448 return txn->mt_dbxs[dbi].md_dcmp(a, b);
1451 /** Allocate memory for a page.
1452 * Re-use old malloc'd pages first for singletons, otherwise just malloc.
1455 mdb_page_malloc(MDB_txn *txn, unsigned num)
1457 MDB_env *env = txn->mt_env;
1458 MDB_page *ret = env->me_dpages;
1459 size_t psize = env->me_psize, sz = psize, off;
1460 /* For ! #MDB_NOMEMINIT, psize counts how much to init.
1461 * For a single page alloc, we init everything after the page header.
1462 * For multi-page, we init the final page; if the caller needed that
1463 * many pages they will be filling in at least up to the last page.
1467 VGMEMP_ALLOC(env, ret, sz);
1468 VGMEMP_DEFINED(ret, sizeof(ret->mp_next));
1469 env->me_dpages = ret->mp_next;
1472 psize -= off = PAGEHDRSZ;
1477 if ((ret = malloc(sz)) != NULL) {
1478 VGMEMP_ALLOC(env, ret, sz);
1479 if (!(env->me_flags & MDB_NOMEMINIT)) {
1480 memset((char *)ret + off, 0, psize);
1484 txn->mt_flags |= MDB_TXN_ERROR;
1489 /** Free a single page.
1490 * Saves single pages to a list, for future reuse.
1491 * (This is not used for multi-page overflow pages.)
1494 mdb_page_free(MDB_env *env, MDB_page *mp)
1496 mp->mp_next = env->me_dpages;
1497 VGMEMP_FREE(env, mp);
1498 env->me_dpages = mp;
1501 /** Free a dirty page */
1503 mdb_dpage_free(MDB_env *env, MDB_page *dp)
1505 if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
1506 mdb_page_free(env, dp);
1508 /* large pages just get freed directly */
1509 VGMEMP_FREE(env, dp);
1514 /** Return all dirty pages to dpage list */
1516 mdb_dlist_free(MDB_txn *txn)
1518 MDB_env *env = txn->mt_env;
1519 MDB_ID2L dl = txn->mt_u.dirty_list;
1520 unsigned i, n = dl[0].mid;
1522 for (i = 1; i <= n; i++) {
1523 mdb_dpage_free(env, dl[i].mptr);
1528 /** Set or clear P_KEEP in dirty, non-overflow, non-sub pages watched by txn.
1529 * @param[in] mc A cursor handle for the current operation.
1530 * @param[in] pflags Flags of the pages to update:
1531 * P_DIRTY to set P_KEEP, P_DIRTY|P_KEEP to clear it.
1532 * @param[in] all No shortcuts. Needed except after a full #mdb_page_flush().
1533 * @return 0 on success, non-zero on failure.
1536 mdb_pages_xkeep(MDB_cursor *mc, unsigned pflags, int all)
1538 enum { Mask = P_SUBP|P_DIRTY|P_KEEP };
1539 MDB_txn *txn = mc->mc_txn;
1545 int rc = MDB_SUCCESS, level;
1547 /* Mark pages seen by cursors */
1548 if (mc->mc_flags & C_UNTRACK)
1549 mc = NULL; /* will find mc in mt_cursors */
1550 for (i = txn->mt_numdbs;; mc = txn->mt_cursors[--i]) {
1551 for (; mc; mc=mc->mc_next) {
1552 if (!(mc->mc_flags & C_INITIALIZED))
1554 for (m3 = mc;; m3 = &mx->mx_cursor) {
1556 for (j=0; j<m3->mc_snum; j++) {
1558 if ((mp->mp_flags & Mask) == pflags)
1559 mp->mp_flags ^= P_KEEP;
1561 mx = m3->mc_xcursor;
1562 /* Proceed to mx if it is at a sub-database */
1563 if (! (mx && (mx->mx_cursor.mc_flags & C_INITIALIZED)))
1565 if (! (mp && (mp->mp_flags & P_LEAF)))
1567 leaf = NODEPTR(mp, m3->mc_ki[j-1]);
1568 if (!(leaf->mn_flags & F_SUBDATA))
1577 /* Mark dirty root pages */
1578 for (i=0; i<txn->mt_numdbs; i++) {
1579 if (txn->mt_dbflags[i] & DB_DIRTY) {
1580 pgno_t pgno = txn->mt_dbs[i].md_root;
1581 if (pgno == P_INVALID)
1583 if ((rc = mdb_page_get(txn, pgno, &dp, &level)) != MDB_SUCCESS)
1585 if ((dp->mp_flags & Mask) == pflags && level <= 1)
1586 dp->mp_flags ^= P_KEEP;
1594 static int mdb_page_flush(MDB_txn *txn, int keep);
1596 /** Spill pages from the dirty list back to disk.
1597 * This is intended to prevent running into #MDB_TXN_FULL situations,
1598 * but note that they may still occur in a few cases:
1599 * 1) our estimate of the txn size could be too small. Currently this
1600 * seems unlikely, except with a large number of #MDB_MULTIPLE items.
1601 * 2) child txns may run out of space if their parents dirtied a
1602 * lot of pages and never spilled them. TODO: we probably should do
1603 * a preemptive spill during #mdb_txn_begin() of a child txn, if
1604 * the parent's dirty_room is below a given threshold.
1606 * Otherwise, if not using nested txns, it is expected that apps will
1607 * not run into #MDB_TXN_FULL any more. The pages are flushed to disk
1608 * the same way as for a txn commit, e.g. their P_DIRTY flag is cleared.
1609 * If the txn never references them again, they can be left alone.
1610 * If the txn only reads them, they can be used without any fuss.
1611 * If the txn writes them again, they can be dirtied immediately without
1612 * going thru all of the work of #mdb_page_touch(). Such references are
1613 * handled by #mdb_page_unspill().
1615 * Also note, we never spill DB root pages, nor pages of active cursors,
1616 * because we'll need these back again soon anyway. And in nested txns,
1617 * we can't spill a page in a child txn if it was already spilled in a
1618 * parent txn. That would alter the parent txns' data even though
1619 * the child hasn't committed yet, and we'd have no way to undo it if
1620 * the child aborted.
1622 * @param[in] m0 cursor A cursor handle identifying the transaction and
1623 * database for which we are checking space.
1624 * @param[in] key For a put operation, the key being stored.
1625 * @param[in] data For a put operation, the data being stored.
1626 * @return 0 on success, non-zero on failure.
1629 mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
1631 MDB_txn *txn = m0->mc_txn;
1633 MDB_ID2L dl = txn->mt_u.dirty_list;
1634 unsigned int i, j, need;
1637 if (m0->mc_flags & C_SUB)
1640 /* Estimate how much space this op will take */
1641 i = m0->mc_db->md_depth;
1642 /* Named DBs also dirty the main DB */
1643 if (m0->mc_dbi > MAIN_DBI)
1644 i += txn->mt_dbs[MAIN_DBI].md_depth;
1645 /* For puts, roughly factor in the key+data size */
1647 i += (LEAFSIZE(key, data) + txn->mt_env->me_psize) / txn->mt_env->me_psize;
1648 i += i; /* double it for good measure */
1651 if (txn->mt_dirty_room > i)
1654 if (!txn->mt_spill_pgs) {
1655 txn->mt_spill_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX);
1656 if (!txn->mt_spill_pgs)
1659 /* purge deleted slots */
1660 MDB_IDL sl = txn->mt_spill_pgs;
1661 unsigned int num = sl[0];
1663 for (i=1; i<=num; i++) {
1670 /* Preserve pages which may soon be dirtied again */
1671 if ((rc = mdb_pages_xkeep(m0, P_DIRTY, 1)) != MDB_SUCCESS)
1674 /* Less aggressive spill - we originally spilled the entire dirty list,
1675 * with a few exceptions for cursor pages and DB root pages. But this
1676 * turns out to be a lot of wasted effort because in a large txn many
1677 * of those pages will need to be used again. So now we spill only 1/8th
1678 * of the dirty pages. Testing revealed this to be a good tradeoff,
1679 * better than 1/2, 1/4, or 1/10.
1681 if (need < MDB_IDL_UM_MAX / 8)
1682 need = MDB_IDL_UM_MAX / 8;
1684 /* Save the page IDs of all the pages we're flushing */
1685 /* flush from the tail forward, this saves a lot of shifting later on. */
1686 for (i=dl[0].mid; i && need; i--) {
1687 MDB_ID pn = dl[i].mid << 1;
1689 if (dp->mp_flags & P_KEEP)
1691 /* Can't spill twice, make sure it's not already in a parent's
1694 if (txn->mt_parent) {
1696 for (tx2 = txn->mt_parent; tx2; tx2 = tx2->mt_parent) {
1697 if (tx2->mt_spill_pgs) {
1698 j = mdb_midl_search(tx2->mt_spill_pgs, pn);
1699 if (j <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[j] == pn) {
1700 dp->mp_flags |= P_KEEP;
1708 if ((rc = mdb_midl_append(&txn->mt_spill_pgs, pn)))
1712 mdb_midl_sort(txn->mt_spill_pgs);
1714 /* Flush the spilled part of dirty list */
1715 if ((rc = mdb_page_flush(txn, i)) != MDB_SUCCESS)
1718 /* Reset any dirty pages we kept that page_flush didn't see */
1719 rc = mdb_pages_xkeep(m0, P_DIRTY|P_KEEP, i);
1722 txn->mt_flags |= rc ? MDB_TXN_ERROR : MDB_TXN_SPILLS;
1726 /** Find oldest txnid still referenced. Expects txn->mt_txnid > 0. */
1728 mdb_find_oldest(MDB_txn *txn)
1731 txnid_t mr, oldest = txn->mt_txnid - 1;
1732 if (txn->mt_env->me_txns) {
1733 MDB_reader *r = txn->mt_env->me_txns->mti_readers;
1734 for (i = txn->mt_env->me_txns->mti_numreaders; --i >= 0; ) {
1745 /** Add a page to the txn's dirty list */
1747 mdb_page_dirty(MDB_txn *txn, MDB_page *mp)
1750 int rc, (*insert)(MDB_ID2L, MDB_ID2 *);
1752 if (txn->mt_env->me_flags & MDB_WRITEMAP) {
1753 insert = mdb_mid2l_append;
1755 insert = mdb_mid2l_insert;
1757 mid.mid = mp->mp_pgno;
1759 rc = insert(txn->mt_u.dirty_list, &mid);
1760 mdb_tassert(txn, rc == 0);
1761 txn->mt_dirty_room--;
1764 /** Allocate page numbers and memory for writing. Maintain me_pglast,
1765 * me_pghead and mt_next_pgno.
1767 * If there are free pages available from older transactions, they
1768 * are re-used first. Otherwise allocate a new page at mt_next_pgno.
1769 * Do not modify the freedB, just merge freeDB records into me_pghead[]
1770 * and move me_pglast to say which records were consumed. Only this
1771 * function can create me_pghead and move me_pglast/mt_next_pgno.
1772 * @param[in] mc cursor A cursor handle identifying the transaction and
1773 * database for which we are allocating.
1774 * @param[in] num the number of pages to allocate.
1775 * @param[out] mp Address of the allocated page(s). Requests for multiple pages
1776 * will always be satisfied by a single contiguous chunk of memory.
1777 * @return 0 on success, non-zero on failure.
1780 mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
1782 #ifdef MDB_PARANOID /* Seems like we can ignore this now */
1783 /* Get at most <Max_retries> more freeDB records once me_pghead
1784 * has enough pages. If not enough, use new pages from the map.
1785 * If <Paranoid> and mc is updating the freeDB, only get new
1786 * records if me_pghead is empty. Then the freelist cannot play
1787 * catch-up with itself by growing while trying to save it.
1789 enum { Paranoid = 1, Max_retries = 500 };
1791 enum { Paranoid = 0, Max_retries = INT_MAX /*infinite*/ };
1793 int rc, retry = Max_retries;
1794 MDB_txn *txn = mc->mc_txn;
1795 MDB_env *env = txn->mt_env;
1796 pgno_t pgno, *mop = env->me_pghead;
1797 unsigned i, j, k, mop_len = mop ? mop[0] : 0, n2 = num-1;
1799 txnid_t oldest = 0, last;
1805 /* If our dirty list is already full, we can't do anything */
1806 if (txn->mt_dirty_room == 0) {
1811 for (op = MDB_FIRST;; op = MDB_NEXT) {
1814 pgno_t *idl, old_id, new_id;
1816 /* Seek a big enough contiguous page range. Prefer
1817 * pages at the tail, just truncating the list.
1823 if (mop[i-n2] == pgno+n2)
1826 if (Max_retries < INT_MAX && --retry < 0)
1830 if (op == MDB_FIRST) { /* 1st iteration */
1831 /* Prepare to fetch more and coalesce */
1832 oldest = mdb_find_oldest(txn);
1833 last = env->me_pglast;
1834 mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
1837 key.mv_data = &last; /* will look up last+1 */
1838 key.mv_size = sizeof(last);
1840 if (Paranoid && mc->mc_dbi == FREE_DBI)
1843 if (Paranoid && retry < 0 && mop_len)
1847 /* Do not fetch more if the record will be too recent */
1850 rc = mdb_cursor_get(&m2, &key, NULL, op);
1852 if (rc == MDB_NOTFOUND)
1856 last = *(txnid_t*)key.mv_data;
1859 np = m2.mc_pg[m2.mc_top];
1860 leaf = NODEPTR(np, m2.mc_ki[m2.mc_top]);
1861 if ((rc = mdb_node_read(txn, leaf, &data)) != MDB_SUCCESS)
1864 idl = (MDB_ID *) data.mv_data;
1867 if (!(env->me_pghead = mop = mdb_midl_alloc(i))) {
1872 if ((rc = mdb_midl_need(&env->me_pghead, i)) != 0)
1874 mop = env->me_pghead;
1876 env->me_pglast = last;
1878 DPRINTF(("IDL read txn %"Z"u root %"Z"u num %u",
1879 last, txn->mt_dbs[FREE_DBI].md_root, i));
1881 DPRINTF(("IDL %"Z"u", idl[k]));
1883 /* Merge in descending sorted order */
1886 mop[0] = (pgno_t)-1;
1890 for (; old_id < new_id; old_id = mop[--j])
1897 /* Use new pages from the map when nothing suitable in the freeDB */
1899 pgno = txn->mt_next_pgno;
1900 if (pgno + num >= env->me_maxpg) {
1901 DPUTS("DB size maxed out");
1907 if (env->me_flags & MDB_WRITEMAP) {
1908 np = (MDB_page *)(env->me_map + env->me_psize * pgno);
1910 if (!(np = mdb_page_malloc(txn, num))) {
1916 mop[0] = mop_len -= num;
1917 /* Move any stragglers down */
1918 for (j = i-num; j < mop_len; )
1919 mop[++j] = mop[++i];
1921 txn->mt_next_pgno = pgno + num;
1924 mdb_page_dirty(txn, np);
1930 txn->mt_flags |= MDB_TXN_ERROR;
1934 /** Copy the used portions of a non-overflow page.
1935 * @param[in] dst page to copy into
1936 * @param[in] src page to copy from
1937 * @param[in] psize size of a page
1940 mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize)
1942 enum { Align = sizeof(pgno_t) };
1943 indx_t upper = src->mp_upper, lower = src->mp_lower, unused = upper-lower;
1945 /* If page isn't full, just copy the used portion. Adjust
1946 * alignment so memcpy may copy words instead of bytes.
1948 if ((unused &= -Align) && !IS_LEAF2(src)) {
1950 memcpy(dst, src, (lower + (Align-1)) & -Align);
1951 memcpy((pgno_t *)((char *)dst+upper), (pgno_t *)((char *)src+upper),
1954 memcpy(dst, src, psize - unused);
1958 /** Pull a page off the txn's spill list, if present.
1959 * If a page being referenced was spilled to disk in this txn, bring
1960 * it back and make it dirty/writable again.
1961 * @param[in] txn the transaction handle.
1962 * @param[in] mp the page being referenced. It must not be dirty.
1963 * @param[out] ret the writable page, if any. ret is unchanged if
1964 * mp wasn't spilled.
1967 mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret)
1969 MDB_env *env = txn->mt_env;
1972 pgno_t pgno = mp->mp_pgno, pn = pgno << 1;
1974 for (tx2 = txn; tx2; tx2=tx2->mt_parent) {
1975 if (!tx2->mt_spill_pgs)
1977 x = mdb_midl_search(tx2->mt_spill_pgs, pn);
1978 if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
1981 if (txn->mt_dirty_room == 0)
1982 return MDB_TXN_FULL;
1983 if (IS_OVERFLOW(mp))
1987 if (env->me_flags & MDB_WRITEMAP) {
1990 np = mdb_page_malloc(txn, num);
1994 memcpy(np, mp, num * env->me_psize);
1996 mdb_page_copy(np, mp, env->me_psize);
1999 /* If in current txn, this page is no longer spilled.
2000 * If it happens to be the last page, truncate the spill list.
2001 * Otherwise mark it as deleted by setting the LSB.
2003 if (x == txn->mt_spill_pgs[0])
2004 txn->mt_spill_pgs[0]--;
2006 txn->mt_spill_pgs[x] |= 1;
2007 } /* otherwise, if belonging to a parent txn, the
2008 * page remains spilled until child commits
2011 mdb_page_dirty(txn, np);
2012 np->mp_flags |= P_DIRTY;
2020 /** Touch a page: make it dirty and re-insert into tree with updated pgno.
2021 * @param[in] mc cursor pointing to the page to be touched
2022 * @return 0 on success, non-zero on failure.
2025 mdb_page_touch(MDB_cursor *mc)
2027 MDB_page *mp = mc->mc_pg[mc->mc_top], *np;
2028 MDB_txn *txn = mc->mc_txn;
2029 MDB_cursor *m2, *m3;
2033 if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
2034 if (txn->mt_flags & MDB_TXN_SPILLS) {
2036 rc = mdb_page_unspill(txn, mp, &np);
2042 if ((rc = mdb_midl_need(&txn->mt_free_pgs, 1)) ||
2043 (rc = mdb_page_alloc(mc, 1, &np)))
2046 DPRINTF(("touched db %d page %"Z"u -> %"Z"u", DDBI(mc),
2047 mp->mp_pgno, pgno));
2048 mdb_cassert(mc, mp->mp_pgno != pgno);
2049 mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
2050 /* Update the parent page, if any, to point to the new page */
2052 MDB_page *parent = mc->mc_pg[mc->mc_top-1];
2053 MDB_node *node = NODEPTR(parent, mc->mc_ki[mc->mc_top-1]);
2054 SETPGNO(node, pgno);
2056 mc->mc_db->md_root = pgno;
2058 } else if (txn->mt_parent && !IS_SUBP(mp)) {
2059 MDB_ID2 mid, *dl = txn->mt_u.dirty_list;
2061 /* If txn has a parent, make sure the page is in our
2065 unsigned x = mdb_mid2l_search(dl, pgno);
2066 if (x <= dl[0].mid && dl[x].mid == pgno) {
2067 if (mp != dl[x].mptr) { /* bad cursor? */
2068 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
2069 txn->mt_flags |= MDB_TXN_ERROR;
2070 return MDB_CORRUPTED;
2075 mdb_cassert(mc, dl[0].mid < MDB_IDL_UM_MAX);
2077 np = mdb_page_malloc(txn, 1);
2082 rc = mdb_mid2l_insert(dl, &mid);
2083 mdb_cassert(mc, rc == 0);
2088 mdb_page_copy(np, mp, txn->mt_env->me_psize);
2090 np->mp_flags |= P_DIRTY;
2093 /* Adjust cursors pointing to mp */
2094 mc->mc_pg[mc->mc_top] = np;
2095 m2 = txn->mt_cursors[mc->mc_dbi];
2096 if (mc->mc_flags & C_SUB) {
2097 for (; m2; m2=m2->mc_next) {
2098 m3 = &m2->mc_xcursor->mx_cursor;
2099 if (m3->mc_snum < mc->mc_snum) continue;
2100 if (m3->mc_pg[mc->mc_top] == mp)
2101 m3->mc_pg[mc->mc_top] = np;
2104 for (; m2; m2=m2->mc_next) {
2105 if (m2->mc_snum < mc->mc_snum) continue;
2106 if (m2->mc_pg[mc->mc_top] == mp) {
2107 m2->mc_pg[mc->mc_top] = np;
2108 if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
2110 m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top])
2112 MDB_node *leaf = NODEPTR(np, mc->mc_ki[mc->mc_top]);
2113 if (!(leaf->mn_flags & F_SUBDATA))
2114 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
2122 txn->mt_flags |= MDB_TXN_ERROR;
2127 mdb_env_sync(MDB_env *env, int force)
2130 if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) {
2131 if (env->me_flags & MDB_WRITEMAP) {
2132 int flags = ((env->me_flags & MDB_MAPASYNC) && !force)
2133 ? MS_ASYNC : MS_SYNC;
2134 if (MDB_MSYNC(env->me_map, env->me_mapsize, flags))
2137 else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd))
2141 if (MDB_FDATASYNC(env->me_fd))
2148 /** Back up parent txn's cursors, then grab the originals for tracking */
2150 mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst)
2152 MDB_cursor *mc, *bk;
2157 for (i = src->mt_numdbs; --i >= 0; ) {
2158 if ((mc = src->mt_cursors[i]) != NULL) {
2159 size = sizeof(MDB_cursor);
2161 size += sizeof(MDB_xcursor);
2162 for (; mc; mc = bk->mc_next) {
2168 mc->mc_db = &dst->mt_dbs[i];
2169 /* Kill pointers into src - and dst to reduce abuse: The
2170 * user may not use mc until dst ends. Otherwise we'd...
2172 mc->mc_txn = NULL; /* ...set this to dst */
2173 mc->mc_dbflag = NULL; /* ...and &dst->mt_dbflags[i] */
2174 if ((mx = mc->mc_xcursor) != NULL) {
2175 *(MDB_xcursor *)(bk+1) = *mx;
2176 mx->mx_cursor.mc_txn = NULL; /* ...and dst. */
2178 mc->mc_next = dst->mt_cursors[i];
2179 dst->mt_cursors[i] = mc;
2186 /** Close this write txn's cursors, give parent txn's cursors back to parent.
2187 * @param[in] txn the transaction handle.
2188 * @param[in] merge true to keep changes to parent cursors, false to revert.
2189 * @return 0 on success, non-zero on failure.
2192 mdb_cursors_close(MDB_txn *txn, unsigned merge)
2194 MDB_cursor **cursors = txn->mt_cursors, *mc, *next, *bk;
2198 for (i = txn->mt_numdbs; --i >= 0; ) {
2199 for (mc = cursors[i]; mc; mc = next) {
2201 if ((bk = mc->mc_backup) != NULL) {
2203 /* Commit changes to parent txn */
2204 mc->mc_next = bk->mc_next;
2205 mc->mc_backup = bk->mc_backup;
2206 mc->mc_txn = bk->mc_txn;
2207 mc->mc_db = bk->mc_db;
2208 mc->mc_dbflag = bk->mc_dbflag;
2209 if ((mx = mc->mc_xcursor) != NULL)
2210 mx->mx_cursor.mc_txn = bk->mc_txn;
2212 /* Abort nested txn */
2214 if ((mx = mc->mc_xcursor) != NULL)
2215 *mx = *(MDB_xcursor *)(bk+1);
2219 /* Only malloced cursors are permanently tracked. */
2227 #define mdb_txn_reset0(txn, act) mdb_txn_reset0(txn)
2230 mdb_txn_reset0(MDB_txn *txn, const char *act);
2232 #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
2238 Pidset = F_SETLK, Pidcheck = F_GETLK
2242 /** Set or check a pid lock. Set returns 0 on success.
2243 * Check returns 0 if the process is certainly dead, nonzero if it may
2244 * be alive (the lock exists or an error happened so we do not know).
2246 * On Windows Pidset is a no-op, we merely check for the existence
2247 * of the process with the given pid. On POSIX we use a single byte
2248 * lock on the lockfile, set at an offset equal to the pid.
2251 mdb_reader_pid(MDB_env *env, enum Pidlock_op op, MDB_PID_T pid)
2253 #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
2256 if (op == Pidcheck) {
2257 h = OpenProcess(env->me_pidquery, FALSE, pid);
2258 /* No documented "no such process" code, but other program use this: */
2260 return ErrCode() != ERROR_INVALID_PARAMETER;
2261 /* A process exists until all handles to it close. Has it exited? */
2262 ret = WaitForSingleObject(h, 0) != 0;
2269 struct flock lock_info;
2270 memset(&lock_info, 0, sizeof(lock_info));
2271 lock_info.l_type = F_WRLCK;
2272 lock_info.l_whence = SEEK_SET;
2273 lock_info.l_start = pid;
2274 lock_info.l_len = 1;
2275 if ((rc = fcntl(env->me_lfd, op, &lock_info)) == 0) {
2276 if (op == F_GETLK && lock_info.l_type != F_UNLCK)
2278 } else if ((rc = ErrCode()) == EINTR) {
2286 /** Common code for #mdb_txn_begin() and #mdb_txn_renew().
2287 * @param[in] txn the transaction handle to initialize
2288 * @return 0 on success, non-zero on failure.
2291 mdb_txn_renew0(MDB_txn *txn)
2293 MDB_env *env = txn->mt_env;
2294 MDB_txninfo *ti = env->me_txns;
2298 int rc, new_notls = 0;
2301 txn->mt_numdbs = env->me_numdbs;
2302 txn->mt_dbxs = env->me_dbxs; /* mostly static anyway */
2304 if (txn->mt_flags & MDB_TXN_RDONLY) {
2306 meta = env->me_metas[ mdb_env_pick_meta(env) ];
2307 txn->mt_txnid = meta->mm_txnid;
2308 txn->mt_u.reader = NULL;
2310 MDB_reader *r = (env->me_flags & MDB_NOTLS) ? txn->mt_u.reader :
2311 pthread_getspecific(env->me_txkey);
2313 if (r->mr_pid != env->me_pid || r->mr_txnid != (txnid_t)-1)
2314 return MDB_BAD_RSLOT;
2316 MDB_PID_T pid = env->me_pid;
2317 pthread_t tid = pthread_self();
2319 if (!env->me_live_reader) {
2320 rc = mdb_reader_pid(env, Pidset, pid);
2323 env->me_live_reader = 1;
2327 nr = ti->mti_numreaders;
2328 for (i=0; i<nr; i++)
2329 if (ti->mti_readers[i].mr_pid == 0)
2331 if (i == env->me_maxreaders) {
2332 UNLOCK_MUTEX_R(env);
2333 return MDB_READERS_FULL;
2335 ti->mti_readers[i].mr_pid = pid;
2336 ti->mti_readers[i].mr_tid = tid;
2338 ti->mti_numreaders = ++nr;
2339 /* Save numreaders for un-mutexed mdb_env_close() */
2340 env->me_numreaders = nr;
2341 UNLOCK_MUTEX_R(env);
2343 r = &ti->mti_readers[i];
2344 new_notls = (env->me_flags & MDB_NOTLS);
2345 if (!new_notls && (rc=pthread_setspecific(env->me_txkey, r))) {
2350 txn->mt_txnid = r->mr_txnid = ti->mti_txnid;
2351 txn->mt_u.reader = r;
2352 meta = env->me_metas[txn->mt_txnid & 1];
2358 txn->mt_txnid = ti->mti_txnid;
2359 meta = env->me_metas[txn->mt_txnid & 1];
2361 meta = env->me_metas[ mdb_env_pick_meta(env) ];
2362 txn->mt_txnid = meta->mm_txnid;
2366 if (txn->mt_txnid == mdb_debug_start)
2369 txn->mt_dirty_room = MDB_IDL_UM_MAX;
2370 txn->mt_u.dirty_list = env->me_dirty_list;
2371 txn->mt_u.dirty_list[0].mid = 0;
2372 txn->mt_free_pgs = env->me_free_pgs;
2373 txn->mt_free_pgs[0] = 0;
2374 txn->mt_spill_pgs = NULL;
2378 /* Copy the DB info and flags */
2379 memcpy(txn->mt_dbs, meta->mm_dbs, 2 * sizeof(MDB_db));
2381 /* Moved to here to avoid a data race in read TXNs */
2382 txn->mt_next_pgno = meta->mm_last_pg+1;
2384 for (i=2; i<txn->mt_numdbs; i++) {
2385 x = env->me_dbflags[i];
2386 txn->mt_dbs[i].md_flags = x & PERSISTENT_FLAGS;
2387 txn->mt_dbflags[i] = (x & MDB_VALID) ? DB_VALID|DB_STALE : 0;
2389 txn->mt_dbflags[0] = txn->mt_dbflags[1] = DB_VALID;
2391 if (env->me_maxpg < txn->mt_next_pgno) {
2392 mdb_txn_reset0(txn, "renew0-mapfail");
2394 txn->mt_u.reader->mr_pid = 0;
2395 txn->mt_u.reader = NULL;
2397 return MDB_MAP_RESIZED;
2404 mdb_txn_renew(MDB_txn *txn)
2408 if (!txn || txn->mt_dbxs) /* A reset txn has mt_dbxs==NULL */
2411 if (txn->mt_env->me_flags & MDB_FATAL_ERROR) {
2412 DPUTS("environment had fatal error, must shutdown!");
2416 rc = mdb_txn_renew0(txn);
2417 if (rc == MDB_SUCCESS) {
2418 DPRINTF(("renew txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2419 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2420 (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root));
2426 mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
2430 int rc, size, tsize = sizeof(MDB_txn);
2432 if (env->me_flags & MDB_FATAL_ERROR) {
2433 DPUTS("environment had fatal error, must shutdown!");
2436 if ((env->me_flags & MDB_RDONLY) && !(flags & MDB_RDONLY))
2439 /* Nested transactions: Max 1 child, write txns only, no writemap */
2440 if (parent->mt_child ||
2441 (flags & MDB_RDONLY) ||
2442 (parent->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR)) ||
2443 (env->me_flags & MDB_WRITEMAP))
2445 return (parent->mt_flags & MDB_TXN_RDONLY) ? EINVAL : MDB_BAD_TXN;
2447 tsize = sizeof(MDB_ntxn);
2449 size = tsize + env->me_maxdbs * (sizeof(MDB_db)+1);
2450 if (!(flags & MDB_RDONLY))
2451 size += env->me_maxdbs * sizeof(MDB_cursor *);
2453 if ((txn = calloc(1, size)) == NULL) {
2454 DPRINTF(("calloc: %s", strerror(ErrCode())));
2457 txn->mt_dbs = (MDB_db *) ((char *)txn + tsize);
2458 if (flags & MDB_RDONLY) {
2459 txn->mt_flags |= MDB_TXN_RDONLY;
2460 txn->mt_dbflags = (unsigned char *)(txn->mt_dbs + env->me_maxdbs);
2462 txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
2463 txn->mt_dbflags = (unsigned char *)(txn->mt_cursors + env->me_maxdbs);
2469 txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE);
2470 if (!txn->mt_u.dirty_list ||
2471 !(txn->mt_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)))
2473 free(txn->mt_u.dirty_list);
2477 txn->mt_txnid = parent->mt_txnid;
2478 txn->mt_dirty_room = parent->mt_dirty_room;
2479 txn->mt_u.dirty_list[0].mid = 0;
2480 txn->mt_spill_pgs = NULL;
2481 txn->mt_next_pgno = parent->mt_next_pgno;
2482 parent->mt_child = txn;
2483 txn->mt_parent = parent;
2484 txn->mt_numdbs = parent->mt_numdbs;
2485 txn->mt_flags = parent->mt_flags;
2486 txn->mt_dbxs = parent->mt_dbxs;
2487 memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
2488 /* Copy parent's mt_dbflags, but clear DB_NEW */
2489 for (i=0; i<txn->mt_numdbs; i++)
2490 txn->mt_dbflags[i] = parent->mt_dbflags[i] & ~DB_NEW;
2492 ntxn = (MDB_ntxn *)txn;
2493 ntxn->mnt_pgstate = env->me_pgstate; /* save parent me_pghead & co */
2494 if (env->me_pghead) {
2495 size = MDB_IDL_SIZEOF(env->me_pghead);
2496 env->me_pghead = mdb_midl_alloc(env->me_pghead[0]);
2498 memcpy(env->me_pghead, ntxn->mnt_pgstate.mf_pghead, size);
2503 rc = mdb_cursor_shadow(parent, txn);
2505 mdb_txn_reset0(txn, "beginchild-fail");
2507 rc = mdb_txn_renew0(txn);
2513 DPRINTF(("begin txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2514 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2515 (void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root));
2522 mdb_txn_env(MDB_txn *txn)
2524 if(!txn) return NULL;
2528 /** Export or close DBI handles opened in this txn. */
2530 mdb_dbis_update(MDB_txn *txn, int keep)
2533 MDB_dbi n = txn->mt_numdbs;
2534 MDB_env *env = txn->mt_env;
2535 unsigned char *tdbflags = txn->mt_dbflags;
2537 for (i = n; --i >= 2;) {
2538 if (tdbflags[i] & DB_NEW) {
2540 env->me_dbflags[i] = txn->mt_dbs[i].md_flags | MDB_VALID;
2542 char *ptr = env->me_dbxs[i].md_name.mv_data;
2543 env->me_dbxs[i].md_name.mv_data = NULL;
2544 env->me_dbxs[i].md_name.mv_size = 0;
2545 env->me_dbflags[i] = 0;
2550 if (keep && env->me_numdbs < n)
2554 /** Common code for #mdb_txn_reset() and #mdb_txn_abort().
2555 * May be called twice for readonly txns: First reset it, then abort.
2556 * @param[in] txn the transaction handle to reset
2557 * @param[in] act why the transaction is being reset
2560 mdb_txn_reset0(MDB_txn *txn, const char *act)
2562 MDB_env *env = txn->mt_env;
2564 /* Close any DBI handles opened in this txn */
2565 mdb_dbis_update(txn, 0);
2567 DPRINTF(("%s txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2568 act, txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2569 (void *) txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root));
2571 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
2572 if (txn->mt_u.reader) {
2573 txn->mt_u.reader->mr_txnid = (txnid_t)-1;
2574 if (!(env->me_flags & MDB_NOTLS))
2575 txn->mt_u.reader = NULL; /* txn does not own reader */
2577 txn->mt_numdbs = 0; /* close nothing if called again */
2578 txn->mt_dbxs = NULL; /* mark txn as reset */
2580 mdb_cursors_close(txn, 0);
2582 if (!(env->me_flags & MDB_WRITEMAP)) {
2583 mdb_dlist_free(txn);
2585 mdb_midl_free(env->me_pghead);
2587 if (txn->mt_parent) {
2588 txn->mt_parent->mt_child = NULL;
2589 env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate;
2590 mdb_midl_free(txn->mt_free_pgs);
2591 mdb_midl_free(txn->mt_spill_pgs);
2592 free(txn->mt_u.dirty_list);
2596 if (mdb_midl_shrink(&txn->mt_free_pgs))
2597 env->me_free_pgs = txn->mt_free_pgs;
2598 env->me_pghead = NULL;
2602 /* The writer mutex was locked in mdb_txn_begin. */
2604 UNLOCK_MUTEX_W(env);
2609 mdb_txn_reset(MDB_txn *txn)
2614 /* This call is only valid for read-only txns */
2615 if (!(txn->mt_flags & MDB_TXN_RDONLY))
2618 mdb_txn_reset0(txn, "reset");
2622 mdb_txn_abort(MDB_txn *txn)
2628 mdb_txn_abort(txn->mt_child);
2630 mdb_txn_reset0(txn, "abort");
2631 /* Free reader slot tied to this txn (if MDB_NOTLS && writable FS) */
2632 if ((txn->mt_flags & MDB_TXN_RDONLY) && txn->mt_u.reader)
2633 txn->mt_u.reader->mr_pid = 0;
2638 /** Save the freelist as of this transaction to the freeDB.
2639 * This changes the freelist. Keep trying until it stabilizes.
2642 mdb_freelist_save(MDB_txn *txn)
2644 /* env->me_pghead[] can grow and shrink during this call.
2645 * env->me_pglast and txn->mt_free_pgs[] can only grow.
2646 * Page numbers cannot disappear from txn->mt_free_pgs[].
2649 MDB_env *env = txn->mt_env;
2650 int rc, maxfree_1pg = env->me_maxfree_1pg, more = 1;
2651 txnid_t pglast = 0, head_id = 0;
2652 pgno_t freecnt = 0, *free_pgs, *mop;
2653 ssize_t head_room = 0, total_room = 0, mop_len, clean_limit;
2655 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
2657 if (env->me_pghead) {
2658 /* Make sure first page of freeDB is touched and on freelist */
2659 rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST|MDB_PS_MODIFY);
2660 if (rc && rc != MDB_NOTFOUND)
2664 /* MDB_RESERVE cancels meminit in ovpage malloc (when no WRITEMAP) */
2665 clean_limit = (env->me_flags & (MDB_NOMEMINIT|MDB_WRITEMAP))
2666 ? SSIZE_MAX : maxfree_1pg;
2669 /* Come back here after each Put() in case freelist changed */
2674 /* If using records from freeDB which we have not yet
2675 * deleted, delete them and any we reserved for me_pghead.
2677 while (pglast < env->me_pglast) {
2678 rc = mdb_cursor_first(&mc, &key, NULL);
2681 pglast = head_id = *(txnid_t *)key.mv_data;
2682 total_room = head_room = 0;
2683 mdb_tassert(txn, pglast <= env->me_pglast);
2684 rc = mdb_cursor_del(&mc, 0);
2689 /* Save the IDL of pages freed by this txn, to a single record */
2690 if (freecnt < txn->mt_free_pgs[0]) {
2692 /* Make sure last page of freeDB is touched and on freelist */
2693 rc = mdb_page_search(&mc, NULL, MDB_PS_LAST|MDB_PS_MODIFY);
2694 if (rc && rc != MDB_NOTFOUND)
2697 free_pgs = txn->mt_free_pgs;
2698 /* Write to last page of freeDB */
2699 key.mv_size = sizeof(txn->mt_txnid);
2700 key.mv_data = &txn->mt_txnid;
2702 freecnt = free_pgs[0];
2703 data.mv_size = MDB_IDL_SIZEOF(free_pgs);
2704 rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
2707 /* Retry if mt_free_pgs[] grew during the Put() */
2708 free_pgs = txn->mt_free_pgs;
2709 } while (freecnt < free_pgs[0]);
2710 mdb_midl_sort(free_pgs);
2711 memcpy(data.mv_data, free_pgs, data.mv_size);
2714 unsigned int i = free_pgs[0];
2715 DPRINTF(("IDL write txn %"Z"u root %"Z"u num %u",
2716 txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, i));
2718 DPRINTF(("IDL %"Z"u", free_pgs[i]));
2724 mop = env->me_pghead;
2725 mop_len = mop ? mop[0] : 0;
2727 /* Reserve records for me_pghead[]. Split it if multi-page,
2728 * to avoid searching freeDB for a page range. Use keys in
2729 * range [1,me_pglast]: Smaller than txnid of oldest reader.
2731 if (total_room >= mop_len) {
2732 if (total_room == mop_len || --more < 0)
2734 } else if (head_room >= maxfree_1pg && head_id > 1) {
2735 /* Keep current record (overflow page), add a new one */
2739 /* (Re)write {key = head_id, IDL length = head_room} */
2740 total_room -= head_room;
2741 head_room = mop_len - total_room;
2742 if (head_room > maxfree_1pg && head_id > 1) {
2743 /* Overflow multi-page for part of me_pghead */
2744 head_room /= head_id; /* amortize page sizes */
2745 head_room += maxfree_1pg - head_room % (maxfree_1pg + 1);
2746 } else if (head_room < 0) {
2747 /* Rare case, not bothering to delete this record */
2750 key.mv_size = sizeof(head_id);
2751 key.mv_data = &head_id;
2752 data.mv_size = (head_room + 1) * sizeof(pgno_t);
2753 rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
2756 /* IDL is initially empty, zero out at least the length */
2757 pgs = (pgno_t *)data.mv_data;
2758 j = head_room > clean_limit ? head_room : 0;
2762 total_room += head_room;
2765 /* Fill in the reserved me_pghead records */
2771 rc = mdb_cursor_first(&mc, &key, &data);
2772 for (; !rc; rc = mdb_cursor_next(&mc, &key, &data, MDB_NEXT)) {
2773 unsigned flags = MDB_CURRENT;
2774 txnid_t id = *(txnid_t *)key.mv_data;
2775 ssize_t len = (ssize_t)(data.mv_size / sizeof(MDB_ID)) - 1;
2778 mdb_tassert(txn, len >= 0 && id <= env->me_pglast);
2779 if (len > mop_len) {
2781 data.mv_size = (len + 1) * sizeof(MDB_ID);
2782 /* Drop MDB_CURRENT when changing the data size */
2786 data.mv_data = mop -= len;
2789 rc = mdb_cursor_put(&mc, &key, &data, flags);
2791 if (rc || !(mop_len -= len))
2798 /** Flush (some) dirty pages to the map, after clearing their dirty flag.
2799 * @param[in] txn the transaction that's being committed
2800 * @param[in] keep number of initial pages in dirty_list to keep dirty.
2801 * @return 0 on success, non-zero on failure.
2804 mdb_page_flush(MDB_txn *txn, int keep)
2806 MDB_env *env = txn->mt_env;
2807 MDB_ID2L dl = txn->mt_u.dirty_list;
2808 unsigned psize = env->me_psize, j;
2809 int i, pagecount = dl[0].mid, rc;
2810 size_t size = 0, pos = 0;
2812 MDB_page *dp = NULL;
2816 struct iovec iov[MDB_COMMIT_PAGES];
2817 ssize_t wpos = 0, wsize = 0, wres;
2818 size_t next_pos = 1; /* impossible pos, so pos != next_pos */
2824 if (env->me_flags & MDB_WRITEMAP) {
2825 /* Clear dirty flags */
2826 while (++i <= pagecount) {
2828 /* Don't flush this page yet */
2829 if (dp->mp_flags & P_KEEP) {
2830 dp->mp_flags ^= P_KEEP;
2834 dp->mp_flags &= ~P_DIRTY;
2839 /* Write the pages */
2841 if (++i <= pagecount) {
2843 /* Don't flush this page yet */
2844 if (dp->mp_flags & P_KEEP) {
2845 dp->mp_flags ^= P_KEEP;
2850 /* clear dirty flag */
2851 dp->mp_flags &= ~P_DIRTY;
2854 if (IS_OVERFLOW(dp)) size *= dp->mp_pages;
2859 /* Windows actually supports scatter/gather I/O, but only on
2860 * unbuffered file handles. Since we're relying on the OS page
2861 * cache for all our data, that's self-defeating. So we just
2862 * write pages one at a time. We use the ov structure to set
2863 * the write offset, to at least save the overhead of a Seek
2866 DPRINTF(("committing page %"Z"u", pgno));
2867 memset(&ov, 0, sizeof(ov));
2868 ov.Offset = pos & 0xffffffff;
2869 ov.OffsetHigh = pos >> 16 >> 16;
2870 if (!WriteFile(env->me_fd, dp, size, NULL, &ov)) {
2872 DPRINTF(("WriteFile: %d", rc));
2876 /* Write up to MDB_COMMIT_PAGES dirty pages at a time. */
2877 if (pos!=next_pos || n==MDB_COMMIT_PAGES || wsize+size>MAX_WRITE) {
2879 /* Write previous page(s) */
2880 #ifdef MDB_USE_PWRITEV
2881 wres = pwritev(env->me_fd, iov, n, wpos);
2884 wres = pwrite(env->me_fd, iov[0].iov_base, wsize, wpos);
2886 if (lseek(env->me_fd, wpos, SEEK_SET) == -1) {
2888 DPRINTF(("lseek: %s", strerror(rc)));
2891 wres = writev(env->me_fd, iov, n);
2894 if (wres != wsize) {
2897 DPRINTF(("Write error: %s", strerror(rc)));
2899 rc = EIO; /* TODO: Use which error code? */
2900 DPUTS("short write, filesystem full?");
2911 DPRINTF(("committing page %"Z"u", pgno));
2912 next_pos = pos + size;
2913 iov[n].iov_len = size;
2914 iov[n].iov_base = (char *)dp;
2920 for (i = keep; ++i <= pagecount; ) {
2922 /* This is a page we skipped above */
2925 dl[j].mid = dp->mp_pgno;
2928 mdb_dpage_free(env, dp);
2933 txn->mt_dirty_room += i - j;
2939 mdb_txn_commit(MDB_txn *txn)
2945 if (txn == NULL || txn->mt_env == NULL)
2948 if (txn->mt_child) {
2949 rc = mdb_txn_commit(txn->mt_child);
2950 txn->mt_child = NULL;
2957 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
2958 mdb_dbis_update(txn, 1);
2959 txn->mt_numdbs = 2; /* so txn_abort() doesn't close any new handles */
2964 if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
2965 DPUTS("error flag is set, can't commit");
2967 txn->mt_parent->mt_flags |= MDB_TXN_ERROR;
2972 if (txn->mt_parent) {
2973 MDB_txn *parent = txn->mt_parent;
2976 unsigned x, y, len, ps_len;
2978 /* Append our free list to parent's */
2979 rc = mdb_midl_append_list(&parent->mt_free_pgs, txn->mt_free_pgs);
2982 mdb_midl_free(txn->mt_free_pgs);
2983 /* Failures after this must either undo the changes
2984 * to the parent or set MDB_TXN_ERROR in the parent.
2987 parent->mt_next_pgno = txn->mt_next_pgno;
2988 parent->mt_flags = txn->mt_flags;
2990 /* Merge our cursors into parent's and close them */
2991 mdb_cursors_close(txn, 1);
2993 /* Update parent's DB table. */
2994 memcpy(parent->mt_dbs, txn->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
2995 parent->mt_numdbs = txn->mt_numdbs;
2996 parent->mt_dbflags[0] = txn->mt_dbflags[0];
2997 parent->mt_dbflags[1] = txn->mt_dbflags[1];
2998 for (i=2; i<txn->mt_numdbs; i++) {
2999 /* preserve parent's DB_NEW status */
3000 x = parent->mt_dbflags[i] & DB_NEW;
3001 parent->mt_dbflags[i] = txn->mt_dbflags[i] | x;
3004 dst = parent->mt_u.dirty_list;
3005 src = txn->mt_u.dirty_list;
3006 /* Remove anything in our dirty list from parent's spill list */
3007 if ((pspill = parent->mt_spill_pgs) && (ps_len = pspill[0])) {
3009 pspill[0] = (pgno_t)-1;
3010 /* Mark our dirty pages as deleted in parent spill list */
3011 for (i=0, len=src[0].mid; ++i <= len; ) {
3012 MDB_ID pn = src[i].mid << 1;
3013 while (pn > pspill[x])
3015 if (pn == pspill[x]) {
3020 /* Squash deleted pagenums if we deleted any */
3021 for (x=y; ++x <= ps_len; )
3022 if (!(pspill[x] & 1))
3023 pspill[++y] = pspill[x];
3027 /* Find len = length of merging our dirty list with parent's */
3029 dst[0].mid = 0; /* simplify loops */
3030 if (parent->mt_parent) {
3031 len = x + src[0].mid;
3032 y = mdb_mid2l_search(src, dst[x].mid + 1) - 1;
3033 for (i = x; y && i; y--) {
3034 pgno_t yp = src[y].mid;
3035 while (yp < dst[i].mid)
3037 if (yp == dst[i].mid) {
3042 } else { /* Simplify the above for single-ancestor case */
3043 len = MDB_IDL_UM_MAX - txn->mt_dirty_room;
3045 /* Merge our dirty list with parent's */
3047 for (i = len; y; dst[i--] = src[y--]) {
3048 pgno_t yp = src[y].mid;
3049 while (yp < dst[x].mid)
3050 dst[i--] = dst[x--];
3051 if (yp == dst[x].mid)
3052 free(dst[x--].mptr);
3054 mdb_tassert(txn, i == x);
3056 free(txn->mt_u.dirty_list);
3057 parent->mt_dirty_room = txn->mt_dirty_room;
3058 if (txn->mt_spill_pgs) {
3059 if (parent->mt_spill_pgs) {
3060 /* TODO: Prevent failure here, so parent does not fail */
3061 rc = mdb_midl_append_list(&parent->mt_spill_pgs, txn->mt_spill_pgs);
3063 parent->mt_flags |= MDB_TXN_ERROR;
3064 mdb_midl_free(txn->mt_spill_pgs);
3065 mdb_midl_sort(parent->mt_spill_pgs);
3067 parent->mt_spill_pgs = txn->mt_spill_pgs;
3071 parent->mt_child = NULL;
3072 mdb_midl_free(((MDB_ntxn *)txn)->mnt_pgstate.mf_pghead);
3077 if (txn != env->me_txn) {
3078 DPUTS("attempt to commit unknown transaction");
3083 mdb_cursors_close(txn, 0);
3085 if (!txn->mt_u.dirty_list[0].mid &&
3086 !(txn->mt_flags & (MDB_TXN_DIRTY|MDB_TXN_SPILLS)))
3089 DPRINTF(("committing txn %"Z"u %p on mdbenv %p, root page %"Z"u",
3090 txn->mt_txnid, (void*)txn, (void*)env, txn->mt_dbs[MAIN_DBI].md_root));
3092 /* Update DB root pointers */
3093 if (txn->mt_numdbs > 2) {
3097 data.mv_size = sizeof(MDB_db);
3099 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
3100 for (i = 2; i < txn->mt_numdbs; i++) {
3101 if (txn->mt_dbflags[i] & DB_DIRTY) {
3102 data.mv_data = &txn->mt_dbs[i];
3103 rc = mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data, 0);
3110 rc = mdb_freelist_save(txn);
3114 mdb_midl_free(env->me_pghead);
3115 env->me_pghead = NULL;
3116 if (mdb_midl_shrink(&txn->mt_free_pgs))
3117 env->me_free_pgs = txn->mt_free_pgs;
3123 if ((rc = mdb_page_flush(txn, 0)) ||
3124 (rc = mdb_env_sync(env, 0)) ||
3125 (rc = mdb_env_write_meta(txn)))
3131 mdb_dbis_update(txn, 1);
3134 UNLOCK_MUTEX_W(env);
3144 /** Read the environment parameters of a DB environment before
3145 * mapping it into memory.
3146 * @param[in] env the environment handle
3147 * @param[out] meta address of where to store the meta information
3148 * @return 0 on success, non-zero on failure.
3151 mdb_env_read_header(MDB_env *env, MDB_meta *meta)
3157 enum { Size = sizeof(pbuf) };
3159 /* We don't know the page size yet, so use a minimum value.
3160 * Read both meta pages so we can use the latest one.
3163 for (i=off=0; i<2; i++, off = meta->mm_psize) {
3167 memset(&ov, 0, sizeof(ov));
3169 rc = ReadFile(env->me_fd, &pbuf, Size, &len, &ov) ? (int)len : -1;
3170 if (rc == -1 && ErrCode() == ERROR_HANDLE_EOF)
3173 rc = pread(env->me_fd, &pbuf, Size, off);
3176 if (rc == 0 && off == 0)
3178 rc = rc < 0 ? (int) ErrCode() : MDB_INVALID;
3179 DPRINTF(("read: %s", mdb_strerror(rc)));
3183 p = (MDB_page *)&pbuf;
3185 if (!F_ISSET(p->mp_flags, P_META)) {
3186 DPRINTF(("page %"Z"u not a meta page", p->mp_pgno));
3191 if (m->mm_magic != MDB_MAGIC) {
3192 DPUTS("meta has invalid magic");
3196 if (m->mm_version != MDB_DATA_VERSION) {
3197 DPRINTF(("database is version %u, expected version %u",
3198 m->mm_version, MDB_DATA_VERSION));
3199 return MDB_VERSION_MISMATCH;
3202 if (off == 0 || m->mm_txnid > meta->mm_txnid)
3208 /** Write the environment parameters of a freshly created DB environment.
3209 * @param[in] env the environment handle
3210 * @param[out] meta address of where to store the meta information
3211 * @return 0 on success, non-zero on failure.
3214 mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
3222 memset(&ov, 0, sizeof(ov));
3223 #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
3225 rc = WriteFile(fd, ptr, size, &len, &ov); } while(0)
3228 #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
3229 len = pwrite(fd, ptr, size, pos); \
3230 rc = (len >= 0); } while(0)
3233 DPUTS("writing new meta page");
3235 psize = env->me_psize;
3237 meta->mm_magic = MDB_MAGIC;
3238 meta->mm_version = MDB_DATA_VERSION;
3239 meta->mm_mapsize = env->me_mapsize;
3240 meta->mm_psize = psize;
3241 meta->mm_last_pg = 1;
3242 meta->mm_flags = env->me_flags & 0xffff;
3243 meta->mm_flags |= MDB_INTEGERKEY;
3244 meta->mm_dbs[0].md_root = P_INVALID;
3245 meta->mm_dbs[1].md_root = P_INVALID;
3247 p = calloc(2, psize);
3249 p->mp_flags = P_META;
3250 *(MDB_meta *)METADATA(p) = *meta;
3252 q = (MDB_page *)((char *)p + psize);
3254 q->mp_flags = P_META;
3255 *(MDB_meta *)METADATA(q) = *meta;
3257 DO_PWRITE(rc, env->me_fd, p, psize * 2, len, 0);
3260 else if ((unsigned) len == psize * 2)
3268 /** Update the environment info to commit a transaction.
3269 * @param[in] txn the transaction that's being committed
3270 * @return 0 on success, non-zero on failure.
3273 mdb_env_write_meta(MDB_txn *txn)
3276 MDB_meta meta, metab, *mp;
3278 int rc, len, toggle;
3287 toggle = txn->mt_txnid & 1;
3288 DPRINTF(("writing meta page %d for root page %"Z"u",
3289 toggle, txn->mt_dbs[MAIN_DBI].md_root));
3292 mp = env->me_metas[toggle];
3294 if (env->me_flags & MDB_WRITEMAP) {
3295 /* Persist any increases of mapsize config */
3296 if (env->me_mapsize > mp->mm_mapsize)
3297 mp->mm_mapsize = env->me_mapsize;
3298 mp->mm_dbs[0] = txn->mt_dbs[0];
3299 mp->mm_dbs[1] = txn->mt_dbs[1];
3300 mp->mm_last_pg = txn->mt_next_pgno - 1;
3301 mp->mm_txnid = txn->mt_txnid;
3302 if (!(env->me_flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {
3303 unsigned meta_size = env->me_psize;
3304 rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;
3307 #ifndef _WIN32 /* POSIX msync() requires ptr = start of OS page */
3308 if (meta_size < env->me_os_psize)
3309 meta_size += meta_size;
3314 if (MDB_MSYNC(ptr, meta_size, rc)) {
3321 metab.mm_txnid = env->me_metas[toggle]->mm_txnid;
3322 metab.mm_last_pg = env->me_metas[toggle]->mm_last_pg;
3324 ptr = (char *)&meta;
3325 if (env->me_mapsize > mp->mm_mapsize) {
3326 /* Persist any increases of mapsize config */
3327 meta.mm_mapsize = env->me_mapsize;
3328 off = offsetof(MDB_meta, mm_mapsize);
3330 off = offsetof(MDB_meta, mm_dbs[0].md_depth);
3332 len = sizeof(MDB_meta) - off;
3335 meta.mm_dbs[0] = txn->mt_dbs[0];
3336 meta.mm_dbs[1] = txn->mt_dbs[1];
3337 meta.mm_last_pg = txn->mt_next_pgno - 1;
3338 meta.mm_txnid = txn->mt_txnid;
3341 off += env->me_psize;
3344 /* Write to the SYNC fd */
3345 mfd = env->me_flags & (MDB_NOSYNC|MDB_NOMETASYNC) ?
3346 env->me_fd : env->me_mfd;
3349 memset(&ov, 0, sizeof(ov));
3351 if (!WriteFile(mfd, ptr, len, (DWORD *)&rc, &ov))
3355 rc = pwrite(mfd, ptr, len, off);
3358 rc = rc < 0 ? ErrCode() : EIO;
3359 DPUTS("write failed, disk error?");
3360 /* On a failure, the pagecache still contains the new data.
3361 * Write some old data back, to prevent it from being used.
3362 * Use the non-SYNC fd; we know it will fail anyway.
3364 meta.mm_last_pg = metab.mm_last_pg;
3365 meta.mm_txnid = metab.mm_txnid;
3367 memset(&ov, 0, sizeof(ov));
3369 WriteFile(env->me_fd, ptr, len, NULL, &ov);
3371 r2 = pwrite(env->me_fd, ptr, len, off);
3372 (void)r2; /* Silence warnings. We don't care about pwrite's return value */
3375 env->me_flags |= MDB_FATAL_ERROR;
3379 /* Memory ordering issues are irrelevant; since the entire writer
3380 * is wrapped by wmutex, all of these changes will become visible
3381 * after the wmutex is unlocked. Since the DB is multi-version,
3382 * readers will get consistent data regardless of how fresh or
3383 * how stale their view of these values is.
3386 env->me_txns->mti_txnid = txn->mt_txnid;
3391 /** Check both meta pages to see which one is newer.
3392 * @param[in] env the environment handle
3393 * @return meta toggle (0 or 1).
3396 mdb_env_pick_meta(const MDB_env *env)
3398 return (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid);
3402 mdb_env_create(MDB_env **env)
3406 e = calloc(1, sizeof(MDB_env));
3410 e->me_maxreaders = DEFAULT_READERS;
3411 e->me_maxdbs = e->me_numdbs = 2;
3412 e->me_fd = INVALID_HANDLE_VALUE;
3413 e->me_lfd = INVALID_HANDLE_VALUE;
3414 e->me_mfd = INVALID_HANDLE_VALUE;
3415 #ifdef MDB_USE_POSIX_SEM
3416 e->me_rmutex = SEM_FAILED;
3417 e->me_wmutex = SEM_FAILED;
3419 e->me_pid = getpid();
3420 GET_PAGESIZE(e->me_os_psize);
3421 VGMEMP_CREATE(e,0,0);
3427 mdb_env_map(MDB_env *env, void *addr, int newsize)
3430 unsigned int flags = env->me_flags;
3434 LONG sizelo, sizehi;
3435 sizelo = env->me_mapsize & 0xffffffff;
3436 sizehi = env->me_mapsize >> 16 >> 16; /* only needed on Win64 */
3438 /* Windows won't create mappings for zero length files.
3439 * Just allocate the maxsize right now.
3442 if (SetFilePointer(env->me_fd, sizelo, &sizehi, 0) != (DWORD)sizelo
3443 || !SetEndOfFile(env->me_fd)
3444 || SetFilePointer(env->me_fd, 0, NULL, 0) != 0)
3447 mh = CreateFileMapping(env->me_fd, NULL, flags & MDB_WRITEMAP ?
3448 PAGE_READWRITE : PAGE_READONLY,
3449 sizehi, sizelo, NULL);
3452 env->me_map = MapViewOfFileEx(mh, flags & MDB_WRITEMAP ?
3453 FILE_MAP_WRITE : FILE_MAP_READ,
3454 0, 0, env->me_mapsize, addr);
3455 rc = env->me_map ? 0 : ErrCode();
3460 int prot = PROT_READ;
3461 if (flags & MDB_WRITEMAP) {
3463 if (ftruncate(env->me_fd, env->me_mapsize) < 0)
3466 env->me_map = mmap(addr, env->me_mapsize, prot, MAP_SHARED,
3468 if (env->me_map == MAP_FAILED) {
3473 if (flags & MDB_NORDAHEAD) {
3474 /* Turn off readahead. It's harmful when the DB is larger than RAM. */
3476 madvise(env->me_map, env->me_mapsize, MADV_RANDOM);
3478 #ifdef POSIX_MADV_RANDOM
3479 posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM);
3480 #endif /* POSIX_MADV_RANDOM */
3481 #endif /* MADV_RANDOM */
3485 /* Can happen because the address argument to mmap() is just a
3486 * hint. mmap() can pick another, e.g. if the range is in use.
3487 * The MAP_FIXED flag would prevent that, but then mmap could
3488 * instead unmap existing pages to make room for the new map.
3490 if (addr && env->me_map != addr)
3491 return EBUSY; /* TODO: Make a new MDB_* error code? */
3493 p = (MDB_page *)env->me_map;
3494 env->me_metas[0] = METADATA(p);
3495 env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + env->me_psize);
3501 mdb_env_set_mapsize(MDB_env *env, size_t size)
3503 /* If env is already open, caller is responsible for making
3504 * sure there are no active txns.
3512 size = env->me_metas[mdb_env_pick_meta(env)]->mm_mapsize;
3513 else if (size < env->me_mapsize) {
3514 /* If the configured size is smaller, make sure it's
3515 * still big enough. Silently round up to minimum if not.
3517 size_t minsize = (env->me_metas[mdb_env_pick_meta(env)]->mm_last_pg + 1) * env->me_psize;
3521 munmap(env->me_map, env->me_mapsize);
3522 env->me_mapsize = size;
3523 old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL;
3524 rc = mdb_env_map(env, old, 1);
3528 env->me_mapsize = size;
3530 env->me_maxpg = env->me_mapsize / env->me_psize;
3535 mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs)
3539 env->me_maxdbs = dbs + 2; /* Named databases + main and free DB */
3544 mdb_env_set_maxreaders(MDB_env *env, unsigned int readers)
3546 if (env->me_map || readers < 1)
3548 env->me_maxreaders = readers;
3553 mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)
3555 if (!env || !readers)
3557 *readers = env->me_maxreaders;
3561 /** Further setup required for opening an MDB environment
3564 mdb_env_open2(MDB_env *env)
3566 unsigned int flags = env->me_flags;
3567 int i, newenv = 0, rc;
3571 /* See if we should use QueryLimited */
3573 if ((rc & 0xff) > 5)
3574 env->me_pidquery = MDB_PROCESS_QUERY_LIMITED_INFORMATION;
3576 env->me_pidquery = PROCESS_QUERY_INFORMATION;
3579 memset(&meta, 0, sizeof(meta));
3581 if ((i = mdb_env_read_header(env, &meta)) != 0) {
3584 DPUTS("new mdbenv");
3586 env->me_psize = env->me_os_psize;
3587 if (env->me_psize > MAX_PAGESIZE)
3588 env->me_psize = MAX_PAGESIZE;
3590 env->me_psize = meta.mm_psize;
3593 /* Was a mapsize configured? */
3594 if (!env->me_mapsize) {
3595 /* If this is a new environment, take the default,
3596 * else use the size recorded in the existing env.
3598 env->me_mapsize = newenv ? DEFAULT_MAPSIZE : meta.mm_mapsize;
3599 } else if (env->me_mapsize < meta.mm_mapsize) {
3600 /* If the configured size is smaller, make sure it's
3601 * still big enough. Silently round up to minimum if not.
3603 size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize;
3604 if (env->me_mapsize < minsize)
3605 env->me_mapsize = minsize;
3608 rc = mdb_env_map(env, meta.mm_address, newenv || env->me_mapsize != meta.mm_mapsize);
3613 if (flags & MDB_FIXEDMAP)
3614 meta.mm_address = env->me_map;
3615 i = mdb_env_init_meta(env, &meta);
3616 if (i != MDB_SUCCESS) {
3621 env->me_maxfree_1pg = (env->me_psize - PAGEHDRSZ) / sizeof(pgno_t) - 1;
3622 env->me_nodemax = (((env->me_psize - PAGEHDRSZ) / MDB_MINKEYS) & -2)
3624 #if !(MDB_MAXKEYSIZE)
3625 env->me_maxkey = env->me_nodemax - (NODESIZE + sizeof(MDB_db));
3627 env->me_maxpg = env->me_mapsize / env->me_psize;
3631 int toggle = mdb_env_pick_meta(env);
3632 MDB_db *db = &env->me_metas[toggle]->mm_dbs[MAIN_DBI];
3634 DPRINTF(("opened database version %u, pagesize %u",
3635 env->me_metas[0]->mm_version, env->me_psize));
3636 DPRINTF(("using meta page %d", toggle));
3637 DPRINTF(("depth: %u", db->md_depth));
3638 DPRINTF(("entries: %"Z"u", db->md_entries));
3639 DPRINTF(("branch pages: %"Z"u", db->md_branch_pages));
3640 DPRINTF(("leaf pages: %"Z"u", db->md_leaf_pages));
3641 DPRINTF(("overflow pages: %"Z"u", db->md_overflow_pages));
3642 DPRINTF(("root: %"Z"u", db->md_root));
3650 /** Release a reader thread's slot in the reader lock table.
3651 * This function is called automatically when a thread exits.
3652 * @param[in] ptr This points to the slot in the reader lock table.
3655 mdb_env_reader_dest(void *ptr)
3657 MDB_reader *reader = ptr;
3663 /** Junk for arranging thread-specific callbacks on Windows. This is
3664 * necessarily platform and compiler-specific. Windows supports up
3665 * to 1088 keys. Let's assume nobody opens more than 64 environments
3666 * in a single process, for now. They can override this if needed.
3668 #ifndef MAX_TLS_KEYS
3669 #define MAX_TLS_KEYS 64
3671 static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS];
3672 static int mdb_tls_nkeys;
3674 static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr)
3678 case DLL_PROCESS_ATTACH: break;
3679 case DLL_THREAD_ATTACH: break;
3680 case DLL_THREAD_DETACH:
3681 for (i=0; i<mdb_tls_nkeys; i++) {
3682 MDB_reader *r = pthread_getspecific(mdb_tls_keys[i]);
3683 mdb_env_reader_dest(r);
3686 case DLL_PROCESS_DETACH: break;
3691 const PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
3693 PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
3697 /* Force some symbol references.
3698 * _tls_used forces the linker to create the TLS directory if not already done
3699 * mdb_tls_cbp prevents whole-program-optimizer from dropping the symbol.
3701 #pragma comment(linker, "/INCLUDE:_tls_used")
3702 #pragma comment(linker, "/INCLUDE:mdb_tls_cbp")
3703 #pragma const_seg(".CRT$XLB")
3704 extern const PIMAGE_TLS_CALLBACK mdb_tls_cbp;
3705 const PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
3708 #pragma comment(linker, "/INCLUDE:__tls_used")
3709 #pragma comment(linker, "/INCLUDE:_mdb_tls_cbp")
3710 #pragma data_seg(".CRT$XLB")
3711 PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
3713 #endif /* WIN 32/64 */
3714 #endif /* !__GNUC__ */
3717 /** Downgrade the exclusive lock on the region back to shared */
3719 mdb_env_share_locks(MDB_env *env, int *excl)
3721 int rc = 0, toggle = mdb_env_pick_meta(env);
3723 env->me_txns->mti_txnid = env->me_metas[toggle]->mm_txnid;
3728 /* First acquire a shared lock. The Unlock will
3729 * then release the existing exclusive lock.
3731 memset(&ov, 0, sizeof(ov));
3732 if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
3735 UnlockFile(env->me_lfd, 0, 0, 1, 0);
3741 struct flock lock_info;
3742 /* The shared lock replaces the existing lock */
3743 memset((void *)&lock_info, 0, sizeof(lock_info));
3744 lock_info.l_type = F_RDLCK;
3745 lock_info.l_whence = SEEK_SET;
3746 lock_info.l_start = 0;
3747 lock_info.l_len = 1;
3748 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
3749 (rc = ErrCode()) == EINTR) ;
3750 *excl = rc ? -1 : 0; /* error may mean we lost the lock */
3757 /** Try to get exlusive lock, otherwise shared.
3758 * Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive.
3761 mdb_env_excl_lock(MDB_env *env, int *excl)
3765 if (LockFile(env->me_lfd, 0, 0, 1, 0)) {
3769 memset(&ov, 0, sizeof(ov));
3770 if (LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
3777 struct flock lock_info;
3778 memset((void *)&lock_info, 0, sizeof(lock_info));
3779 lock_info.l_type = F_WRLCK;
3780 lock_info.l_whence = SEEK_SET;
3781 lock_info.l_start = 0;
3782 lock_info.l_len = 1;
3783 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
3784 (rc = ErrCode()) == EINTR) ;
3788 # ifdef MDB_USE_POSIX_SEM
3789 if (*excl < 0) /* always true when !MDB_USE_POSIX_SEM */
3792 lock_info.l_type = F_RDLCK;
3793 while ((rc = fcntl(env->me_lfd, F_SETLKW, &lock_info)) &&
3794 (rc = ErrCode()) == EINTR) ;
3804 * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code
3806 * @(#) $Revision: 5.1 $
3807 * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $
3808 * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $
3810 * http://www.isthe.com/chongo/tech/comp/fnv/index.html
3814 * Please do not copyright this code. This code is in the public domain.
3816 * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
3817 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
3818 * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
3819 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
3820 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
3821 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
3822 * PERFORMANCE OF THIS SOFTWARE.
3825 * chongo <Landon Curt Noll> /\oo/\
3826 * http://www.isthe.com/chongo/
3828 * Share and Enjoy! :-)
3831 typedef unsigned long long mdb_hash_t;
3832 #define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL)
3834 /** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer
3835 * @param[in] val value to hash
3836 * @param[in] hval initial value for hash
3837 * @return 64 bit hash
3839 * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the
3840 * hval arg on the first call.
3843 mdb_hash_val(MDB_val *val, mdb_hash_t hval)
3845 unsigned char *s = (unsigned char *)val->mv_data; /* unsigned string */
3846 unsigned char *end = s + val->mv_size;
3848 * FNV-1a hash each octet of the string
3851 /* xor the bottom with the current octet */
3852 hval ^= (mdb_hash_t)*s++;
3854 /* multiply by the 64 bit FNV magic prime mod 2^64 */
3855 hval += (hval << 1) + (hval << 4) + (hval << 5) +
3856 (hval << 7) + (hval << 8) + (hval << 40);
3858 /* return our new hash value */
3862 /** Hash the string and output the encoded hash.
3863 * This uses modified RFC1924 Ascii85 encoding to accommodate systems with
3864 * very short name limits. We don't care about the encoding being reversible,
3865 * we just want to preserve as many bits of the input as possible in a
3866 * small printable string.
3867 * @param[in] str string to hash
3868 * @param[out] encbuf an array of 11 chars to hold the hash
3870 static const char mdb_a85[]= "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";
3873 mdb_pack85(unsigned long l, char *out)
3877 for (i=0; i<5; i++) {
3878 *out++ = mdb_a85[l % 85];
3884 mdb_hash_enc(MDB_val *val, char *encbuf)
3886 mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT);
3888 mdb_pack85(h, encbuf);
3889 mdb_pack85(h>>32, encbuf+5);
3894 /** Open and/or initialize the lock region for the environment.
3895 * @param[in] env The MDB environment.
3896 * @param[in] lpath The pathname of the file used for the lock region.
3897 * @param[in] mode The Unix permissions for the file, if we create it.
3898 * @param[out] excl Resulting file lock type: -1 none, 0 shared, 1 exclusive
3899 * @param[in,out] excl In -1, out lock type: -1 none, 0 shared, 1 exclusive
3900 * @return 0 on success, non-zero on failure.
3903 mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
3906 # define MDB_ERRCODE_ROFS ERROR_WRITE_PROTECT
3908 # define MDB_ERRCODE_ROFS EROFS
3909 #ifdef O_CLOEXEC /* Linux: Open file and set FD_CLOEXEC atomically */
3910 # define MDB_CLOEXEC O_CLOEXEC
3913 # define MDB_CLOEXEC 0
3920 env->me_lfd = CreateFile(lpath, GENERIC_READ|GENERIC_WRITE,
3921 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
3922 FILE_ATTRIBUTE_NORMAL, NULL);
3924 env->me_lfd = open(lpath, O_RDWR|O_CREAT|MDB_CLOEXEC, mode);
3926 if (env->me_lfd == INVALID_HANDLE_VALUE) {
3928 if (rc == MDB_ERRCODE_ROFS && (env->me_flags & MDB_RDONLY)) {
3933 #if ! ((MDB_CLOEXEC) || defined(_WIN32))
3934 /* Lose record locks when exec*() */
3935 if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0)
3936 fcntl(env->me_lfd, F_SETFD, fdflags);
3939 if (!(env->me_flags & MDB_NOTLS)) {
3940 rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
3943 env->me_flags |= MDB_ENV_TXKEY;
3945 /* Windows TLS callbacks need help finding their TLS info. */
3946 if (mdb_tls_nkeys >= MAX_TLS_KEYS) {
3950 mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey;
3954 /* Try to get exclusive lock. If we succeed, then
3955 * nobody is using the lock region and we should initialize it.
3957 if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
3960 size = GetFileSize(env->me_lfd, NULL);
3962 size = lseek(env->me_lfd, 0, SEEK_END);
3963 if (size == -1) goto fail_errno;
3965 rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
3966 if (size < rsize && *excl > 0) {
3968 if (SetFilePointer(env->me_lfd, rsize, NULL, FILE_BEGIN) != (DWORD)rsize
3969 || !SetEndOfFile(env->me_lfd))
3972 if (ftruncate(env->me_lfd, rsize) != 0) goto fail_errno;
3976 size = rsize - sizeof(MDB_txninfo);
3977 env->me_maxreaders = size/sizeof(MDB_reader) + 1;
3982 mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,
3984 if (!mh) goto fail_errno;
3985 env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL);
3987 if (!env->me_txns) goto fail_errno;
3989 void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
3991 if (m == MAP_FAILED) goto fail_errno;
3997 BY_HANDLE_FILE_INFORMATION stbuf;
4006 if (!mdb_sec_inited) {
4007 InitializeSecurityDescriptor(&mdb_null_sd,
4008 SECURITY_DESCRIPTOR_REVISION);
4009 SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE);
4010 mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);
4011 mdb_all_sa.bInheritHandle = FALSE;
4012 mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;
4015 if (!GetFileInformationByHandle(env->me_lfd, &stbuf)) goto fail_errno;
4016 idbuf.volume = stbuf.dwVolumeSerialNumber;
4017 idbuf.nhigh = stbuf.nFileIndexHigh;
4018 idbuf.nlow = stbuf.nFileIndexLow;
4019 val.mv_data = &idbuf;
4020 val.mv_size = sizeof(idbuf);
4021 mdb_hash_enc(&val, encbuf);
4022 sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", encbuf);
4023 sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", encbuf);
4024 env->me_rmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
4025 if (!env->me_rmutex) goto fail_errno;
4026 env->me_wmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);
4027 if (!env->me_wmutex) goto fail_errno;
4028 #elif defined(MDB_USE_POSIX_SEM)
4037 #if defined(__NetBSD__)
4038 #define MDB_SHORT_SEMNAMES 1 /* limited to 14 chars */
4040 if (fstat(env->me_lfd, &stbuf)) goto fail_errno;
4041 idbuf.dev = stbuf.st_dev;
4042 idbuf.ino = stbuf.st_ino;
4043 val.mv_data = &idbuf;
4044 val.mv_size = sizeof(idbuf);
4045 mdb_hash_enc(&val, encbuf);
4046 #ifdef MDB_SHORT_SEMNAMES
4047 encbuf[9] = '\0'; /* drop name from 15 chars to 14 chars */
4049 sprintf(env->me_txns->mti_rmname, "/MDBr%s", encbuf);
4050 sprintf(env->me_txns->mti_wmname, "/MDBw%s", encbuf);
4051 /* Clean up after a previous run, if needed: Try to
4052 * remove both semaphores before doing anything else.
4054 sem_unlink(env->me_txns->mti_rmname);
4055 sem_unlink(env->me_txns->mti_wmname);
4056 env->me_rmutex = sem_open(env->me_txns->mti_rmname,
4057 O_CREAT|O_EXCL, mode, 1);
4058 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
4059 env->me_wmutex = sem_open(env->me_txns->mti_wmname,
4060 O_CREAT|O_EXCL, mode, 1);
4061 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
4062 #else /* MDB_USE_POSIX_SEM */
4063 pthread_mutexattr_t mattr;
4065 if ((rc = pthread_mutexattr_init(&mattr))
4066 || (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED))
4067 || (rc = pthread_mutex_init(&env->me_txns->mti_mutex, &mattr))
4068 || (rc = pthread_mutex_init(&env->me_txns->mti_wmutex, &mattr)))
4070 pthread_mutexattr_destroy(&mattr);
4071 #endif /* _WIN32 || MDB_USE_POSIX_SEM */
4073 env->me_txns->mti_magic = MDB_MAGIC;
4074 env->me_txns->mti_format = MDB_LOCK_FORMAT;
4075 env->me_txns->mti_txnid = 0;
4076 env->me_txns->mti_numreaders = 0;
4079 if (env->me_txns->mti_magic != MDB_MAGIC) {
4080 DPUTS("lock region has invalid magic");
4084 if (env->me_txns->mti_format != MDB_LOCK_FORMAT) {
4085 DPRINTF(("lock region has format+version 0x%x, expected 0x%x",
4086 env->me_txns->mti_format, MDB_LOCK_FORMAT));
4087 rc = MDB_VERSION_MISMATCH;
4091 if (rc && rc != EACCES && rc != EAGAIN) {
4095 env->me_rmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);
4096 if (!env->me_rmutex) goto fail_errno;
4097 env->me_wmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
4098 if (!env->me_wmutex) goto fail_errno;
4099 #elif defined(MDB_USE_POSIX_SEM)
4100 env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0);
4101 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
4102 env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0);
4103 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
4114 /** The name of the lock file in the DB environment */
4115 #define LOCKNAME "/lock.mdb"
4116 /** The name of the data file in the DB environment */
4117 #define DATANAME "/data.mdb"
4118 /** The suffix of the lock file when no subdir is used */
4119 #define LOCKSUFF "-lock"
4120 /** Only a subset of the @ref mdb_env flags can be changed
4121 * at runtime. Changing other flags requires closing the
4122 * environment and re-opening it with the new flags.
4124 #define CHANGEABLE (MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC|MDB_NOMEMINIT)
4125 #define CHANGELESS (MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY|MDB_WRITEMAP| \
4126 MDB_NOTLS|MDB_NOLOCK|MDB_NORDAHEAD)
4128 #if VALID_FLAGS & PERSISTENT_FLAGS & (CHANGEABLE|CHANGELESS)
4129 # error "Persistent DB flags & env flags overlap, but both go in mm_flags"
4133 mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode)
4135 int oflags, rc, len, excl = -1;
4136 char *lpath, *dpath;
4138 if (env->me_fd!=INVALID_HANDLE_VALUE || (flags & ~(CHANGEABLE|CHANGELESS)))
4142 if (flags & MDB_NOSUBDIR) {
4143 rc = len + sizeof(LOCKSUFF) + len + 1;
4145 rc = len + sizeof(LOCKNAME) + len + sizeof(DATANAME);
4150 if (flags & MDB_NOSUBDIR) {
4151 dpath = lpath + len + sizeof(LOCKSUFF);
4152 sprintf(lpath, "%s" LOCKSUFF, path);
4153 strcpy(dpath, path);
4155 dpath = lpath + len + sizeof(LOCKNAME);
4156 sprintf(lpath, "%s" LOCKNAME, path);
4157 sprintf(dpath, "%s" DATANAME, path);
4161 flags |= env->me_flags;
4162 if (flags & MDB_RDONLY) {
4163 /* silently ignore WRITEMAP when we're only getting read access */
4164 flags &= ~MDB_WRITEMAP;
4166 if (!((env->me_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)) &&
4167 (env->me_dirty_list = calloc(MDB_IDL_UM_SIZE, sizeof(MDB_ID2)))))
4170 env->me_flags = flags |= MDB_ENV_ACTIVE;
4174 env->me_path = strdup(path);
4175 env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx));
4176 env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t));
4177 if (!(env->me_dbxs && env->me_path && env->me_dbflags)) {
4182 /* For RDONLY, get lockfile after we know datafile exists */
4183 if (!(flags & (MDB_RDONLY|MDB_NOLOCK))) {
4184 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
4190 if (F_ISSET(flags, MDB_RDONLY)) {
4191 oflags = GENERIC_READ;
4192 len = OPEN_EXISTING;
4194 oflags = GENERIC_READ|GENERIC_WRITE;
4197 mode = FILE_ATTRIBUTE_NORMAL;
4198 env->me_fd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
4199 NULL, len, mode, NULL);
4201 if (F_ISSET(flags, MDB_RDONLY))
4204 oflags = O_RDWR | O_CREAT;
4206 env->me_fd = open(dpath, oflags, mode);
4208 if (env->me_fd == INVALID_HANDLE_VALUE) {
4213 if ((flags & (MDB_RDONLY|MDB_NOLOCK)) == MDB_RDONLY) {
4214 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
4219 if ((rc = mdb_env_open2(env)) == MDB_SUCCESS) {
4220 if (flags & (MDB_RDONLY|MDB_WRITEMAP)) {
4221 env->me_mfd = env->me_fd;
4223 /* Synchronous fd for meta writes. Needed even with
4224 * MDB_NOSYNC/MDB_NOMETASYNC, in case these get reset.
4227 len = OPEN_EXISTING;
4228 env->me_mfd = CreateFile(dpath, oflags,
4229 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len,
4230 mode | FILE_FLAG_WRITE_THROUGH, NULL);
4233 env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode);
4235 if (env->me_mfd == INVALID_HANDLE_VALUE) {
4240 DPRINTF(("opened dbenv %p", (void *) env));
4242 rc = mdb_env_share_locks(env, &excl);
4246 if (!((flags & MDB_RDONLY) ||
4247 (env->me_pbuf = calloc(1, env->me_psize))))
4253 mdb_env_close0(env, excl);
4259 /** Destroy resources from mdb_env_open(), clear our readers & DBIs */
4261 mdb_env_close0(MDB_env *env, int excl)
4265 if (!(env->me_flags & MDB_ENV_ACTIVE))
4268 /* Doing this here since me_dbxs may not exist during mdb_env_close */
4269 for (i = env->me_maxdbs; --i > MAIN_DBI; )
4270 free(env->me_dbxs[i].md_name.mv_data);
4273 free(env->me_dbflags);
4276 free(env->me_dirty_list);
4277 mdb_midl_free(env->me_free_pgs);
4279 if (env->me_flags & MDB_ENV_TXKEY) {
4280 pthread_key_delete(env->me_txkey);
4282 /* Delete our key from the global list */
4283 for (i=0; i<mdb_tls_nkeys; i++)
4284 if (mdb_tls_keys[i] == env->me_txkey) {
4285 mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1];
4293 munmap(env->me_map, env->me_mapsize);
4295 if (env->me_mfd != env->me_fd && env->me_mfd != INVALID_HANDLE_VALUE)
4296 (void) close(env->me_mfd);
4297 if (env->me_fd != INVALID_HANDLE_VALUE)
4298 (void) close(env->me_fd);
4300 MDB_PID_T pid = env->me_pid;
4301 /* Clearing readers is done in this function because
4302 * me_txkey with its destructor must be disabled first.
4304 for (i = env->me_numreaders; --i >= 0; )
4305 if (env->me_txns->mti_readers[i].mr_pid == pid)
4306 env->me_txns->mti_readers[i].mr_pid = 0;
4308 if (env->me_rmutex) {
4309 CloseHandle(env->me_rmutex);
4310 if (env->me_wmutex) CloseHandle(env->me_wmutex);
4312 /* Windows automatically destroys the mutexes when
4313 * the last handle closes.
4315 #elif defined(MDB_USE_POSIX_SEM)
4316 if (env->me_rmutex != SEM_FAILED) {
4317 sem_close(env->me_rmutex);
4318 if (env->me_wmutex != SEM_FAILED)
4319 sem_close(env->me_wmutex);
4320 /* If we have the filelock: If we are the
4321 * only remaining user, clean up semaphores.
4324 mdb_env_excl_lock(env, &excl);
4326 sem_unlink(env->me_txns->mti_rmname);
4327 sem_unlink(env->me_txns->mti_wmname);
4331 munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
4333 if (env->me_lfd != INVALID_HANDLE_VALUE) {
4336 /* Unlock the lockfile. Windows would have unlocked it
4337 * after closing anyway, but not necessarily at once.
4339 UnlockFile(env->me_lfd, 0, 0, 1, 0);
4342 (void) close(env->me_lfd);
4345 env->me_flags &= ~(MDB_ENV_ACTIVE|MDB_ENV_TXKEY);
4349 mdb_env_copyfd(MDB_env *env, HANDLE fd)
4351 MDB_txn *txn = NULL;
4357 #define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL)
4361 #define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0)
4364 /* Do the lock/unlock of the reader mutex before starting the
4365 * write txn. Otherwise other read txns could block writers.
4367 rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
4372 /* We must start the actual read txn after blocking writers */
4373 mdb_txn_reset0(txn, "reset-stage1");
4375 /* Temporarily block writers until we snapshot the meta pages */
4378 rc = mdb_txn_renew0(txn);
4380 UNLOCK_MUTEX_W(env);
4385 wsize = env->me_psize * 2;
4389 DO_WRITE(rc, fd, ptr, w2, len);
4393 } else if (len > 0) {
4399 /* Non-blocking or async handles are not supported */
4405 UNLOCK_MUTEX_W(env);
4410 wsize = txn->mt_next_pgno * env->me_psize - wsize;
4412 if (wsize > MAX_WRITE)
4416 DO_WRITE(rc, fd, ptr, w2, len);
4420 } else if (len > 0) {
4437 mdb_env_copy(MDB_env *env, const char *path)
4441 HANDLE newfd = INVALID_HANDLE_VALUE;
4443 if (env->me_flags & MDB_NOSUBDIR) {
4444 lpath = (char *)path;
4447 len += sizeof(DATANAME);
4448 lpath = malloc(len);
4451 sprintf(lpath, "%s" DATANAME, path);
4454 /* The destination path must exist, but the destination file must not.
4455 * We don't want the OS to cache the writes, since the source data is
4456 * already in the OS cache.
4459 newfd = CreateFile(lpath, GENERIC_WRITE, 0, NULL, CREATE_NEW,
4460 FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL);
4462 newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL, 0666);
4464 if (newfd == INVALID_HANDLE_VALUE) {
4470 /* Set O_DIRECT if the file system supports it */
4471 if ((rc = fcntl(newfd, F_GETFL)) != -1)
4472 (void) fcntl(newfd, F_SETFL, rc | O_DIRECT);
4474 #ifdef F_NOCACHE /* __APPLE__ */
4475 rc = fcntl(newfd, F_NOCACHE, 1);
4482 rc = mdb_env_copyfd(env, newfd);
4485 if (!(env->me_flags & MDB_NOSUBDIR))
4487 if (newfd != INVALID_HANDLE_VALUE)
4488 if (close(newfd) < 0 && rc == MDB_SUCCESS)
4495 mdb_env_close(MDB_env *env)
4502 VGMEMP_DESTROY(env);
4503 while ((dp = env->me_dpages) != NULL) {
4504 VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next));
4505 env->me_dpages = dp->mp_next;
4509 mdb_env_close0(env, 0);
4513 /** Compare two items pointing at aligned size_t's */
4515 mdb_cmp_long(const MDB_val *a, const MDB_val *b)
4517 return (*(size_t *)a->mv_data < *(size_t *)b->mv_data) ? -1 :
4518 *(size_t *)a->mv_data > *(size_t *)b->mv_data;
4521 /** Compare two items pointing at aligned unsigned int's */
4523 mdb_cmp_int(const MDB_val *a, const MDB_val *b)
4525 return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 :
4526 *(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data;
4529 /** Compare two items pointing at unsigned ints of unknown alignment.
4530 * Nodes and keys are guaranteed to be 2-byte aligned.
4533 mdb_cmp_cint(const MDB_val *a, const MDB_val *b)
4535 #if BYTE_ORDER == LITTLE_ENDIAN
4536 unsigned short *u, *c;
4539 u = (unsigned short *) ((char *) a->mv_data + a->mv_size);
4540 c = (unsigned short *) ((char *) b->mv_data + a->mv_size);
4543 } while(!x && u > (unsigned short *)a->mv_data);
4546 return memcmp(a->mv_data, b->mv_data, a->mv_size);
4550 /** Compare two items lexically */
4552 mdb_cmp_memn(const MDB_val *a, const MDB_val *b)
4559 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
4565 diff = memcmp(a->mv_data, b->mv_data, len);
4566 return diff ? diff : len_diff<0 ? -1 : len_diff;
4569 /** Compare two items in reverse byte order */
4571 mdb_cmp_memnr(const MDB_val *a, const MDB_val *b)
4573 const unsigned char *p1, *p2, *p1_lim;
4577 p1_lim = (const unsigned char *)a->mv_data;
4578 p1 = (const unsigned char *)a->mv_data + a->mv_size;
4579 p2 = (const unsigned char *)b->mv_data + b->mv_size;
4581 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
4587 while (p1 > p1_lim) {
4588 diff = *--p1 - *--p2;
4592 return len_diff<0 ? -1 : len_diff;
4595 /** Search for key within a page, using binary search.
4596 * Returns the smallest entry larger or equal to the key.
4597 * If exactp is non-null, stores whether the found entry was an exact match
4598 * in *exactp (1 or 0).
4599 * Updates the cursor index with the index of the found entry.
4600 * If no entry larger or equal to the key is found, returns NULL.
4603 mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)
4605 unsigned int i = 0, nkeys;
4608 MDB_page *mp = mc->mc_pg[mc->mc_top];
4609 MDB_node *node = NULL;
4614 nkeys = NUMKEYS(mp);
4616 DPRINTF(("searching %u keys in %s %spage %"Z"u",
4617 nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "",
4620 low = IS_LEAF(mp) ? 0 : 1;
4622 cmp = mc->mc_dbx->md_cmp;
4624 /* Branch pages have no data, so if using integer keys,
4625 * alignment is guaranteed. Use faster mdb_cmp_int.
4627 if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) {
4628 if (NODEPTR(mp, 1)->mn_ksize == sizeof(size_t))
4635 nodekey.mv_size = mc->mc_db->md_pad;
4636 node = NODEPTR(mp, 0); /* fake */
4637 while (low <= high) {
4638 i = (low + high) >> 1;
4639 nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size);
4640 rc = cmp(key, &nodekey);
4641 DPRINTF(("found leaf index %u [%s], rc = %i",
4642 i, DKEY(&nodekey), rc));
4651 while (low <= high) {
4652 i = (low + high) >> 1;
4654 node = NODEPTR(mp, i);
4655 nodekey.mv_size = NODEKSZ(node);
4656 nodekey.mv_data = NODEKEY(node);
4658 rc = cmp(key, &nodekey);
4661 DPRINTF(("found leaf index %u [%s], rc = %i",
4662 i, DKEY(&nodekey), rc));
4664 DPRINTF(("found branch index %u [%s -> %"Z"u], rc = %i",
4665 i, DKEY(&nodekey), NODEPGNO(node), rc));
4676 if (rc > 0) { /* Found entry is less than the key. */
4677 i++; /* Skip to get the smallest entry larger than key. */
4679 node = NODEPTR(mp, i);
4682 *exactp = (rc == 0 && nkeys > 0);
4683 /* store the key index */
4684 mc->mc_ki[mc->mc_top] = i;
4686 /* There is no entry larger or equal to the key. */
4689 /* nodeptr is fake for LEAF2 */
4695 mdb_cursor_adjust(MDB_cursor *mc, func)
4699 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
4700 if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) {
4707 /** Pop a page off the top of the cursor's stack. */
4709 mdb_cursor_pop(MDB_cursor *mc)
4713 MDB_page *top = mc->mc_pg[mc->mc_top];
4719 DPRINTF(("popped page %"Z"u off db %d cursor %p", top->mp_pgno,
4720 DDBI(mc), (void *) mc));
4724 /** Push a page onto the top of the cursor's stack. */
4726 mdb_cursor_push(MDB_cursor *mc, MDB_page *mp)
4728 DPRINTF(("pushing page %"Z"u on db %d cursor %p", mp->mp_pgno,
4729 DDBI(mc), (void *) mc));
4731 if (mc->mc_snum >= CURSOR_STACK) {
4732 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
4733 return MDB_CURSOR_FULL;
4736 mc->mc_top = mc->mc_snum++;
4737 mc->mc_pg[mc->mc_top] = mp;
4738 mc->mc_ki[mc->mc_top] = 0;
4743 /** Find the address of the page corresponding to a given page number.
4744 * @param[in] txn the transaction for this access.
4745 * @param[in] pgno the page number for the page to retrieve.
4746 * @param[out] ret address of a pointer where the page's address will be stored.
4747 * @param[out] lvl dirty_list inheritance level of found page. 1=current txn, 0=mapped page.
4748 * @return 0 on success, non-zero on failure.
4751 mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret, int *lvl)
4753 MDB_env *env = txn->mt_env;
4757 if (!((txn->mt_flags & MDB_TXN_RDONLY) | (env->me_flags & MDB_WRITEMAP))) {
4761 MDB_ID2L dl = tx2->mt_u.dirty_list;
4763 /* Spilled pages were dirtied in this txn and flushed
4764 * because the dirty list got full. Bring this page
4765 * back in from the map (but don't unspill it here,
4766 * leave that unless page_touch happens again).
4768 if (tx2->mt_spill_pgs) {
4769 MDB_ID pn = pgno << 1;
4770 x = mdb_midl_search(tx2->mt_spill_pgs, pn);
4771 if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
4772 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
4777 unsigned x = mdb_mid2l_search(dl, pgno);
4778 if (x <= dl[0].mid && dl[x].mid == pgno) {
4784 } while ((tx2 = tx2->mt_parent) != NULL);
4787 if (pgno < txn->mt_next_pgno) {
4789 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
4791 DPRINTF(("page %"Z"u not found", pgno));
4792 txn->mt_flags |= MDB_TXN_ERROR;
4793 return MDB_PAGE_NOTFOUND;
4803 /** Finish #mdb_page_search() / #mdb_page_search_lowest().
4804 * The cursor is at the root page, set up the rest of it.
4807 mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags)
4809 MDB_page *mp = mc->mc_pg[mc->mc_top];
4813 while (IS_BRANCH(mp)) {
4817 DPRINTF(("branch page %"Z"u has %u keys", mp->mp_pgno, NUMKEYS(mp)));
4818 mdb_cassert(mc, NUMKEYS(mp) > 1);
4819 DPRINTF(("found index 0 to page %"Z"u", NODEPGNO(NODEPTR(mp, 0))));
4821 if (flags & (MDB_PS_FIRST|MDB_PS_LAST)) {
4823 if (flags & MDB_PS_LAST)
4824 i = NUMKEYS(mp) - 1;
4827 node = mdb_node_search(mc, key, &exact);
4829 i = NUMKEYS(mp) - 1;
4831 i = mc->mc_ki[mc->mc_top];
4833 mdb_cassert(mc, i > 0);
4837 DPRINTF(("following index %u for key [%s]", i, DKEY(key)));
4840 mdb_cassert(mc, i < NUMKEYS(mp));
4841 node = NODEPTR(mp, i);
4843 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
4846 mc->mc_ki[mc->mc_top] = i;
4847 if ((rc = mdb_cursor_push(mc, mp)))
4850 if (flags & MDB_PS_MODIFY) {
4851 if ((rc = mdb_page_touch(mc)) != 0)
4853 mp = mc->mc_pg[mc->mc_top];
4858 DPRINTF(("internal error, index points to a %02X page!?",
4860 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
4861 return MDB_CORRUPTED;
4864 DPRINTF(("found leaf page %"Z"u for key [%s]", mp->mp_pgno,
4865 key ? DKEY(key) : "null"));
4866 mc->mc_flags |= C_INITIALIZED;
4867 mc->mc_flags &= ~C_EOF;
4872 /** Search for the lowest key under the current branch page.
4873 * This just bypasses a NUMKEYS check in the current page
4874 * before calling mdb_page_search_root(), because the callers
4875 * are all in situations where the current page is known to
4879 mdb_page_search_lowest(MDB_cursor *mc)
4881 MDB_page *mp = mc->mc_pg[mc->mc_top];
4882 MDB_node *node = NODEPTR(mp, 0);
4885 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
4888 mc->mc_ki[mc->mc_top] = 0;
4889 if ((rc = mdb_cursor_push(mc, mp)))
4891 return mdb_page_search_root(mc, NULL, MDB_PS_FIRST);
4894 /** Search for the page a given key should be in.
4895 * Push it and its parent pages on the cursor stack.
4896 * @param[in,out] mc the cursor for this operation.
4897 * @param[in] key the key to search for, or NULL for first/last page.
4898 * @param[in] flags If MDB_PS_MODIFY is set, visited pages in the DB
4899 * are touched (updated with new page numbers).
4900 * If MDB_PS_FIRST or MDB_PS_LAST is set, find first or last leaf.
4901 * This is used by #mdb_cursor_first() and #mdb_cursor_last().
4902 * If MDB_PS_ROOTONLY set, just fetch root node, no further lookups.
4903 * @return 0 on success, non-zero on failure.
4906 mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)
4911 /* Make sure the txn is still viable, then find the root from
4912 * the txn's db table and set it as the root of the cursor's stack.
4914 if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_ERROR)) {
4915 DPUTS("transaction has failed, must abort");
4918 /* Make sure we're using an up-to-date root */
4919 if (*mc->mc_dbflag & DB_STALE) {
4921 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);
4922 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, 0);
4929 MDB_node *leaf = mdb_node_search(&mc2,
4930 &mc->mc_dbx->md_name, &exact);
4932 return MDB_NOTFOUND;
4933 rc = mdb_node_read(mc->mc_txn, leaf, &data);
4936 memcpy(&flags, ((char *) data.mv_data + offsetof(MDB_db, md_flags)),
4938 /* The txn may not know this DBI, or another process may
4939 * have dropped and recreated the DB with other flags.
4941 if ((mc->mc_db->md_flags & PERSISTENT_FLAGS) != flags)
4942 return MDB_INCOMPATIBLE;
4943 memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db));
4945 *mc->mc_dbflag &= ~DB_STALE;
4947 root = mc->mc_db->md_root;
4949 if (root == P_INVALID) { /* Tree is empty. */
4950 DPUTS("tree is empty");
4951 return MDB_NOTFOUND;
4955 mdb_cassert(mc, root > 1);
4956 if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root)
4957 if ((rc = mdb_page_get(mc->mc_txn, root, &mc->mc_pg[0], NULL)) != 0)
4963 DPRINTF(("db %d root page %"Z"u has flags 0x%X",
4964 DDBI(mc), root, mc->mc_pg[0]->mp_flags));
4966 if (flags & MDB_PS_MODIFY) {
4967 if ((rc = mdb_page_touch(mc)))
4971 if (flags & MDB_PS_ROOTONLY)
4974 return mdb_page_search_root(mc, key, flags);
4978 mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
4980 MDB_txn *txn = mc->mc_txn;
4981 pgno_t pg = mp->mp_pgno;
4982 unsigned x = 0, ovpages = mp->mp_pages;
4983 MDB_env *env = txn->mt_env;
4984 MDB_IDL sl = txn->mt_spill_pgs;
4985 MDB_ID pn = pg << 1;
4988 DPRINTF(("free ov page %"Z"u (%d)", pg, ovpages));
4989 /* If the page is dirty or on the spill list we just acquired it,
4990 * so we should give it back to our current free list, if any.
4991 * Otherwise put it onto the list of pages we freed in this txn.
4993 * Won't create me_pghead: me_pglast must be inited along with it.
4994 * Unsupported in nested txns: They would need to hide the page
4995 * range in ancestor txns' dirty and spilled lists.
4997 if (env->me_pghead &&
4999 ((mp->mp_flags & P_DIRTY) ||
5000 (sl && (x = mdb_midl_search(sl, pn)) <= sl[0] && sl[x] == pn)))
5004 MDB_ID2 *dl, ix, iy;
5005 rc = mdb_midl_need(&env->me_pghead, ovpages);
5008 if (!(mp->mp_flags & P_DIRTY)) {
5009 /* This page is no longer spilled */
5016 /* Remove from dirty list */
5017 dl = txn->mt_u.dirty_list;
5019 for (ix = dl[x]; ix.mptr != mp; ix = iy) {
5025 mdb_cassert(mc, x > 1);
5027 dl[j] = ix; /* Unsorted. OK when MDB_TXN_ERROR. */
5028 txn->mt_flags |= MDB_TXN_ERROR;
5029 return MDB_CORRUPTED;
5032 if (!(env->me_flags & MDB_WRITEMAP))
5033 mdb_dpage_free(env, mp);
5035 /* Insert in me_pghead */
5036 mop = env->me_pghead;
5037 j = mop[0] + ovpages;
5038 for (i = mop[0]; i && mop[i] < pg; i--)
5044 rc = mdb_midl_append_range(&txn->mt_free_pgs, pg, ovpages);
5048 mc->mc_db->md_overflow_pages -= ovpages;
5052 /** Return the data associated with a given node.
5053 * @param[in] txn The transaction for this operation.
5054 * @param[in] leaf The node being read.
5055 * @param[out] data Updated to point to the node's data.
5056 * @return 0 on success, non-zero on failure.
5059 mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data)
5061 MDB_page *omp; /* overflow page */
5065 if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
5066 data->mv_size = NODEDSZ(leaf);
5067 data->mv_data = NODEDATA(leaf);
5071 /* Read overflow data.
5073 data->mv_size = NODEDSZ(leaf);
5074 memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
5075 if ((rc = mdb_page_get(txn, pgno, &omp, NULL)) != 0) {
5076 DPRINTF(("read overflow page %"Z"u failed", pgno));
5079 data->mv_data = METADATA(omp);
5085 mdb_get(MDB_txn *txn, MDB_dbi dbi,
5086 MDB_val *key, MDB_val *data)
5093 DPRINTF(("===> get db %u key [%s]", dbi, DKEY(key)));
5095 if (!key || !data || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
5098 if (txn->mt_flags & MDB_TXN_ERROR)
5101 mdb_cursor_init(&mc, txn, dbi, &mx);
5102 return mdb_cursor_set(&mc, key, data, MDB_SET, &exact);
5105 /** Find a sibling for a page.
5106 * Replaces the page at the top of the cursor's stack with the
5107 * specified sibling, if one exists.
5108 * @param[in] mc The cursor for this operation.
5109 * @param[in] move_right Non-zero if the right sibling is requested,
5110 * otherwise the left sibling.
5111 * @return 0 on success, non-zero on failure.
5114 mdb_cursor_sibling(MDB_cursor *mc, int move_right)
5120 if (mc->mc_snum < 2) {
5121 return MDB_NOTFOUND; /* root has no siblings */
5125 DPRINTF(("parent page is page %"Z"u, index %u",
5126 mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]));
5128 if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top]))
5129 : (mc->mc_ki[mc->mc_top] == 0)) {
5130 DPRINTF(("no more keys left, moving to %s sibling",
5131 move_right ? "right" : "left"));
5132 if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) {
5133 /* undo cursor_pop before returning */
5140 mc->mc_ki[mc->mc_top]++;
5142 mc->mc_ki[mc->mc_top]--;
5143 DPRINTF(("just moving to %s index key %u",
5144 move_right ? "right" : "left", mc->mc_ki[mc->mc_top]));
5146 mdb_cassert(mc, IS_BRANCH(mc->mc_pg[mc->mc_top]));
5148 indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5149 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(indx), &mp, NULL)) != 0) {
5150 /* mc will be inconsistent if caller does mc_snum++ as above */
5151 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
5155 mdb_cursor_push(mc, mp);
5157 mc->mc_ki[mc->mc_top] = NUMKEYS(mp)-1;
5162 /** Move the cursor to the next data item. */
5164 mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
5170 if (mc->mc_flags & C_EOF) {
5171 return MDB_NOTFOUND;
5174 mdb_cassert(mc, mc->mc_flags & C_INITIALIZED);
5176 mp = mc->mc_pg[mc->mc_top];
5178 if (mc->mc_db->md_flags & MDB_DUPSORT) {
5179 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5180 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5181 if (op == MDB_NEXT || op == MDB_NEXT_DUP) {
5182 rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);
5183 if (op != MDB_NEXT || rc != MDB_NOTFOUND) {
5184 if (rc == MDB_SUCCESS)
5185 MDB_GET_KEY(leaf, key);
5190 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5191 if (op == MDB_NEXT_DUP)
5192 return MDB_NOTFOUND;
5196 DPRINTF(("cursor_next: top page is %"Z"u in cursor %p",
5197 mdb_dbg_pgno(mp), (void *) mc));
5198 if (mc->mc_flags & C_DEL)
5201 if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) {
5202 DPUTS("=====> move to next sibling page");
5203 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
5204 mc->mc_flags |= C_EOF;
5207 mp = mc->mc_pg[mc->mc_top];
5208 DPRINTF(("next page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
5210 mc->mc_ki[mc->mc_top]++;
5213 DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
5214 mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
5217 key->mv_size = mc->mc_db->md_pad;
5218 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5222 mdb_cassert(mc, IS_LEAF(mp));
5223 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5225 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5226 mdb_xcursor_init1(mc, leaf);
5229 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5232 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5233 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
5234 if (rc != MDB_SUCCESS)
5239 MDB_GET_KEY(leaf, key);
5243 /** Move the cursor to the previous data item. */
5245 mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
5251 mdb_cassert(mc, mc->mc_flags & C_INITIALIZED);
5253 mp = mc->mc_pg[mc->mc_top];
5255 if (mc->mc_db->md_flags & MDB_DUPSORT) {
5256 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5257 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5258 if (op == MDB_PREV || op == MDB_PREV_DUP) {
5259 rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
5260 if (op != MDB_PREV || rc != MDB_NOTFOUND) {
5261 if (rc == MDB_SUCCESS)
5262 MDB_GET_KEY(leaf, key);
5266 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5267 if (op == MDB_PREV_DUP)
5268 return MDB_NOTFOUND;
5273 DPRINTF(("cursor_prev: top page is %"Z"u in cursor %p",
5274 mdb_dbg_pgno(mp), (void *) mc));
5276 if (mc->mc_ki[mc->mc_top] == 0) {
5277 DPUTS("=====> move to prev sibling page");
5278 if ((rc = mdb_cursor_sibling(mc, 0)) != MDB_SUCCESS) {
5281 mp = mc->mc_pg[mc->mc_top];
5282 mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;
5283 DPRINTF(("prev page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
5285 mc->mc_ki[mc->mc_top]--;
5287 mc->mc_flags &= ~C_EOF;
5289 DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
5290 mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
5293 key->mv_size = mc->mc_db->md_pad;
5294 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5298 mdb_cassert(mc, IS_LEAF(mp));
5299 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5301 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5302 mdb_xcursor_init1(mc, leaf);
5305 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5308 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5309 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
5310 if (rc != MDB_SUCCESS)
5315 MDB_GET_KEY(leaf, key);
5319 /** Set the cursor on a specific data item. */
5321 mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data,
5322 MDB_cursor_op op, int *exactp)
5326 MDB_node *leaf = NULL;
5329 if (key->mv_size == 0)
5330 return MDB_BAD_VALSIZE;
5333 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5335 /* See if we're already on the right page */
5336 if (mc->mc_flags & C_INITIALIZED) {
5339 mp = mc->mc_pg[mc->mc_top];
5341 mc->mc_ki[mc->mc_top] = 0;
5342 return MDB_NOTFOUND;
5344 if (mp->mp_flags & P_LEAF2) {
5345 nodekey.mv_size = mc->mc_db->md_pad;
5346 nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size);
5348 leaf = NODEPTR(mp, 0);
5349 MDB_GET_KEY2(leaf, nodekey);
5351 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5353 /* Probably happens rarely, but first node on the page
5354 * was the one we wanted.
5356 mc->mc_ki[mc->mc_top] = 0;
5363 unsigned int nkeys = NUMKEYS(mp);
5365 if (mp->mp_flags & P_LEAF2) {
5366 nodekey.mv_data = LEAF2KEY(mp,
5367 nkeys-1, nodekey.mv_size);
5369 leaf = NODEPTR(mp, nkeys-1);
5370 MDB_GET_KEY2(leaf, nodekey);
5372 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5374 /* last node was the one we wanted */
5375 mc->mc_ki[mc->mc_top] = nkeys-1;
5381 if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) {
5382 /* This is definitely the right page, skip search_page */
5383 if (mp->mp_flags & P_LEAF2) {
5384 nodekey.mv_data = LEAF2KEY(mp,
5385 mc->mc_ki[mc->mc_top], nodekey.mv_size);
5387 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5388 MDB_GET_KEY2(leaf, nodekey);
5390 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5392 /* current node was the one we wanted */
5402 /* If any parents have right-sibs, search.
5403 * Otherwise, there's nothing further.
5405 for (i=0; i<mc->mc_top; i++)
5407 NUMKEYS(mc->mc_pg[i])-1)
5409 if (i == mc->mc_top) {
5410 /* There are no other pages */
5411 mc->mc_ki[mc->mc_top] = nkeys;
5412 return MDB_NOTFOUND;
5416 /* There are no other pages */
5417 mc->mc_ki[mc->mc_top] = 0;
5418 if (op == MDB_SET_RANGE) {
5422 return MDB_NOTFOUND;
5426 rc = mdb_page_search(mc, key, 0);
5427 if (rc != MDB_SUCCESS)
5430 mp = mc->mc_pg[mc->mc_top];
5431 mdb_cassert(mc, IS_LEAF(mp));
5434 leaf = mdb_node_search(mc, key, exactp);
5435 if (exactp != NULL && !*exactp) {
5436 /* MDB_SET specified and not an exact match. */
5437 return MDB_NOTFOUND;
5441 DPUTS("===> inexact leaf not found, goto sibling");
5442 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS)
5443 return rc; /* no entries matched */
5444 mp = mc->mc_pg[mc->mc_top];
5445 mdb_cassert(mc, IS_LEAF(mp));
5446 leaf = NODEPTR(mp, 0);
5450 mc->mc_flags |= C_INITIALIZED;
5451 mc->mc_flags &= ~C_EOF;
5454 key->mv_size = mc->mc_db->md_pad;
5455 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5459 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5460 mdb_xcursor_init1(mc, leaf);
5463 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5464 if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) {
5465 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
5468 if (op == MDB_GET_BOTH) {
5474 rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p);
5475 if (rc != MDB_SUCCESS)
5478 } else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {
5480 if ((rc = mdb_node_read(mc->mc_txn, leaf, &d2)) != MDB_SUCCESS)
5482 rc = mc->mc_dbx->md_dcmp(data, &d2);
5484 if (op == MDB_GET_BOTH || rc > 0)
5485 return MDB_NOTFOUND;
5492 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5493 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5498 /* The key already matches in all other cases */
5499 if (op == MDB_SET_RANGE || op == MDB_SET_KEY)
5500 MDB_GET_KEY(leaf, key);
5501 DPRINTF(("==> cursor placed on key [%s]", DKEY(key)));
5506 /** Move the cursor to the first item in the database. */
5508 mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data)
5514 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5516 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
5517 rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
5518 if (rc != MDB_SUCCESS)
5521 mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
5523 leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0);
5524 mc->mc_flags |= C_INITIALIZED;
5525 mc->mc_flags &= ~C_EOF;
5527 mc->mc_ki[mc->mc_top] = 0;
5529 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
5530 key->mv_size = mc->mc_db->md_pad;
5531 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size);
5536 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5537 mdb_xcursor_init1(mc, leaf);
5538 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
5542 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5546 MDB_GET_KEY(leaf, key);
5550 /** Move the cursor to the last item in the database. */
5552 mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)
5558 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5560 if (!(mc->mc_flags & C_EOF)) {
5562 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
5563 rc = mdb_page_search(mc, NULL, MDB_PS_LAST);
5564 if (rc != MDB_SUCCESS)
5567 mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
5570 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;
5571 mc->mc_flags |= C_INITIALIZED|C_EOF;
5572 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5574 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
5575 key->mv_size = mc->mc_db->md_pad;
5576 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size);
5581 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5582 mdb_xcursor_init1(mc, leaf);
5583 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
5587 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5592 MDB_GET_KEY(leaf, key);
5597 mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,
5602 int (*mfunc)(MDB_cursor *mc, MDB_val *key, MDB_val *data);
5607 if (mc->mc_txn->mt_flags & MDB_TXN_ERROR)
5611 case MDB_GET_CURRENT:
5612 if (!(mc->mc_flags & C_INITIALIZED)) {
5615 MDB_page *mp = mc->mc_pg[mc->mc_top];
5616 int nkeys = NUMKEYS(mp);
5617 if (!nkeys || mc->mc_ki[mc->mc_top] >= nkeys) {
5618 mc->mc_ki[mc->mc_top] = nkeys;
5624 key->mv_size = mc->mc_db->md_pad;
5625 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5627 MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5628 MDB_GET_KEY(leaf, key);
5630 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5631 if (mc->mc_flags & C_DEL)
5632 mdb_xcursor_init1(mc, leaf);
5633 rc = mdb_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT);
5635 rc = mdb_node_read(mc->mc_txn, leaf, data);
5642 case MDB_GET_BOTH_RANGE:
5647 if (mc->mc_xcursor == NULL) {
5648 rc = MDB_INCOMPATIBLE;
5658 rc = mdb_cursor_set(mc, key, data, op,
5659 op == MDB_SET_RANGE ? NULL : &exact);
5662 case MDB_GET_MULTIPLE:
5663 if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
5667 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
5668 rc = MDB_INCOMPATIBLE;
5672 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) ||
5673 (mc->mc_xcursor->mx_cursor.mc_flags & C_EOF))
5676 case MDB_NEXT_MULTIPLE:
5681 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
5682 rc = MDB_INCOMPATIBLE;
5685 if (!(mc->mc_flags & C_INITIALIZED))
5686 rc = mdb_cursor_first(mc, key, data);
5688 rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP);
5689 if (rc == MDB_SUCCESS) {
5690 if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
5693 mx = &mc->mc_xcursor->mx_cursor;
5694 data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) *
5696 data->mv_data = METADATA(mx->mc_pg[mx->mc_top]);
5697 mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1;
5705 case MDB_NEXT_NODUP:
5706 if (!(mc->mc_flags & C_INITIALIZED))
5707 rc = mdb_cursor_first(mc, key, data);
5709 rc = mdb_cursor_next(mc, key, data, op);
5713 case MDB_PREV_NODUP:
5714 if (!(mc->mc_flags & C_INITIALIZED)) {
5715 rc = mdb_cursor_last(mc, key, data);
5718 mc->mc_flags |= C_INITIALIZED;
5719 mc->mc_ki[mc->mc_top]++;
5721 rc = mdb_cursor_prev(mc, key, data, op);
5724 rc = mdb_cursor_first(mc, key, data);
5727 mfunc = mdb_cursor_first;
5729 if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
5733 if (mc->mc_xcursor == NULL) {
5734 rc = MDB_INCOMPATIBLE;
5737 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
5741 rc = mfunc(&mc->mc_xcursor->mx_cursor, data, NULL);
5744 rc = mdb_cursor_last(mc, key, data);
5747 mfunc = mdb_cursor_last;
5750 DPRINTF(("unhandled/unimplemented cursor operation %u", op));
5755 if (mc->mc_flags & C_DEL)
5756 mc->mc_flags ^= C_DEL;
5761 /** Touch all the pages in the cursor stack. Set mc_top.
5762 * Makes sure all the pages are writable, before attempting a write operation.
5763 * @param[in] mc The cursor to operate on.
5766 mdb_cursor_touch(MDB_cursor *mc)
5768 int rc = MDB_SUCCESS;
5770 if (mc->mc_dbi > MAIN_DBI && !(*mc->mc_dbflag & DB_DIRTY)) {
5773 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, &mcx);
5774 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY);
5777 *mc->mc_dbflag |= DB_DIRTY;
5782 rc = mdb_page_touch(mc);
5783 } while (!rc && ++(mc->mc_top) < mc->mc_snum);
5784 mc->mc_top = mc->mc_snum-1;
5789 /** Do not spill pages to disk if txn is getting full, may fail instead */
5790 #define MDB_NOSPILL 0x8000
5793 mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
5796 enum { MDB_NO_ROOT = MDB_LAST_ERRCODE+10 }; /* internal code */
5798 MDB_node *leaf = NULL;
5801 MDB_val xdata, *rdata, dkey, olddata;
5803 int do_sub = 0, insert;
5804 unsigned int mcount = 0, dcount = 0, nospill;
5807 unsigned int nflags;
5813 env = mc->mc_txn->mt_env;
5815 /* Check this first so counter will always be zero on any
5818 if (flags & MDB_MULTIPLE) {
5819 dcount = data[1].mv_size;
5820 data[1].mv_size = 0;
5821 if (!F_ISSET(mc->mc_db->md_flags, MDB_DUPFIXED))
5822 return MDB_INCOMPATIBLE;
5825 nospill = flags & MDB_NOSPILL;
5826 flags &= ~MDB_NOSPILL;
5828 if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
5829 return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
5831 if (flags != MDB_CURRENT) {
5834 if (key->mv_size-1 >= ENV_MAXKEY(env))
5835 return MDB_BAD_VALSIZE;
5837 /* Ignore key except in sub-cursor, where key holds the data */
5838 if (!(mc->mc_flags & C_SUB))
5842 #if SIZE_MAX > MAXDATASIZE
5843 if (data->mv_size > ((mc->mc_db->md_flags & MDB_DUPSORT) ? ENV_MAXKEY(env) : MAXDATASIZE))
5844 return MDB_BAD_VALSIZE;
5846 if ((mc->mc_db->md_flags & MDB_DUPSORT) && data->mv_size > ENV_MAXKEY(env))
5847 return MDB_BAD_VALSIZE;
5850 DPRINTF(("==> put db %d key [%s], size %"Z"u, data size %"Z"u",
5851 DDBI(mc), DKEY(key), key ? key->mv_size : 0, data->mv_size));
5855 if (flags == MDB_CURRENT) {
5856 if (!(mc->mc_flags & C_INITIALIZED))
5859 } else if (mc->mc_db->md_root == P_INVALID) {
5860 /* new database, cursor has nothing to point to */
5863 mc->mc_flags &= ~C_INITIALIZED;
5868 if (flags & MDB_APPEND) {
5870 rc = mdb_cursor_last(mc, &k2, &d2);
5872 rc = mc->mc_dbx->md_cmp(key, &k2);
5875 mc->mc_ki[mc->mc_top]++;
5877 /* new key is <= last key */
5882 rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact);
5884 if ((flags & MDB_NOOVERWRITE) && rc == 0) {
5885 DPRINTF(("duplicate key [%s]", DKEY(key)));
5887 return MDB_KEYEXIST;
5889 if (rc && rc != MDB_NOTFOUND)
5893 if (mc->mc_flags & C_DEL)
5894 mc->mc_flags ^= C_DEL;
5896 /* Cursor is positioned, check for room in the dirty list */
5898 if (flags & MDB_MULTIPLE) {
5900 xdata.mv_size = data->mv_size * dcount;
5904 if ((rc2 = mdb_page_spill(mc, key, rdata)))
5908 if (rc == MDB_NO_ROOT) {
5910 /* new database, write a root leaf page */
5911 DPUTS("allocating new root leaf page");
5912 if ((rc2 = mdb_page_new(mc, P_LEAF, 1, &np))) {
5915 mdb_cursor_push(mc, np);
5916 mc->mc_db->md_root = np->mp_pgno;
5917 mc->mc_db->md_depth++;
5918 *mc->mc_dbflag |= DB_DIRTY;
5919 if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED))
5921 np->mp_flags |= P_LEAF2;
5922 mc->mc_flags |= C_INITIALIZED;
5924 /* make sure all cursor pages are writable */
5925 rc2 = mdb_cursor_touch(mc);
5932 /* The key does not exist */
5933 DPRINTF(("inserting key at index %i", mc->mc_ki[mc->mc_top]));
5934 if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
5935 LEAFSIZE(key, data) > env->me_nodemax)
5937 /* Too big for a node, insert in sub-DB */
5938 fp_flags = P_LEAF|P_DIRTY;
5940 fp->mp_pad = data->mv_size; /* used if MDB_DUPFIXED */
5941 fp->mp_lower = fp->mp_upper = olddata.mv_size = PAGEHDRSZ;
5945 /* there's only a key anyway, so this is a no-op */
5946 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
5947 unsigned int ksize = mc->mc_db->md_pad;
5948 if (key->mv_size != ksize)
5949 return MDB_BAD_VALSIZE;
5950 if (flags == MDB_CURRENT) {
5951 char *ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize);
5952 memcpy(ptr, key->mv_data, ksize);
5958 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5959 olddata.mv_size = NODEDSZ(leaf);
5960 olddata.mv_data = NODEDATA(leaf);
5963 if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) {
5964 /* Prepare (sub-)page/sub-DB to accept the new item,
5965 * if needed. fp: old sub-page or a header faking
5966 * it. mp: new (sub-)page. offset: growth in page
5967 * size. xdata: node data with new page or DB.
5969 unsigned i, offset = 0;
5970 mp = fp = xdata.mv_data = env->me_pbuf;
5971 mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
5973 /* Was a single item before, must convert now */
5974 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5975 /* Just overwrite the current item */
5976 if (flags == MDB_CURRENT)
5979 #if UINT_MAX < SIZE_MAX
5980 if (mc->mc_dbx->md_dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
5981 #ifdef MISALIGNED_OK
5982 mc->mc_dbx->md_dcmp = mdb_cmp_long;
5984 mc->mc_dbx->md_dcmp = mdb_cmp_cint;
5987 /* if data matches, skip it */
5988 if (!mc->mc_dbx->md_dcmp(data, &olddata)) {
5989 if (flags & MDB_NODUPDATA)
5991 else if (flags & MDB_MULTIPLE)
5998 /* Back up original data item */
5999 dkey.mv_size = olddata.mv_size;
6000 dkey.mv_data = memcpy(fp+1, olddata.mv_data, olddata.mv_size);
6002 /* Make sub-page header for the dup items, with dummy body */
6003 fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP;
6004 fp->mp_lower = PAGEHDRSZ;
6005 xdata.mv_size = PAGEHDRSZ + dkey.mv_size + data->mv_size;
6006 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
6007 fp->mp_flags |= P_LEAF2;
6008 fp->mp_pad = data->mv_size;
6009 xdata.mv_size += 2 * data->mv_size; /* leave space for 2 more */
6011 xdata.mv_size += 2 * (sizeof(indx_t) + NODESIZE) +
6012 (dkey.mv_size & 1) + (data->mv_size & 1);
6014 fp->mp_upper = xdata.mv_size;
6015 olddata.mv_size = fp->mp_upper; /* pretend olddata is fp */
6016 } else if (leaf->mn_flags & F_SUBDATA) {
6017 /* Data is on sub-DB, just store it */
6018 flags |= F_DUPDATA|F_SUBDATA;
6021 /* Data is on sub-page */
6022 fp = olddata.mv_data;
6025 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
6026 offset = EVEN(NODESIZE + sizeof(indx_t) +
6030 offset = fp->mp_pad;
6031 if (SIZELEFT(fp) < offset) {
6032 offset *= 4; /* space for 4 more */
6035 /* FALLTHRU: Big enough MDB_DUPFIXED sub-page */
6037 fp->mp_flags |= P_DIRTY;
6038 COPY_PGNO(fp->mp_pgno, mp->mp_pgno);
6039 mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;
6043 xdata.mv_size = olddata.mv_size + offset;
6046 fp_flags = fp->mp_flags;
6047 if (NODESIZE + NODEKSZ(leaf) + xdata.mv_size > env->me_nodemax) {
6048 /* Too big for a sub-page, convert to sub-DB */
6049 fp_flags &= ~P_SUBP;
6051 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
6052 fp_flags |= P_LEAF2;
6053 dummy.md_pad = fp->mp_pad;
6054 dummy.md_flags = MDB_DUPFIXED;
6055 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
6056 dummy.md_flags |= MDB_INTEGERKEY;
6062 dummy.md_branch_pages = 0;
6063 dummy.md_leaf_pages = 1;
6064 dummy.md_overflow_pages = 0;
6065 dummy.md_entries = NUMKEYS(fp);
6066 xdata.mv_size = sizeof(MDB_db);
6067 xdata.mv_data = &dummy;
6068 if ((rc = mdb_page_alloc(mc, 1, &mp)))
6070 offset = env->me_psize - olddata.mv_size;
6071 flags |= F_DUPDATA|F_SUBDATA;
6072 dummy.md_root = mp->mp_pgno;
6075 mp->mp_flags = fp_flags | P_DIRTY;
6076 mp->mp_pad = fp->mp_pad;
6077 mp->mp_lower = fp->mp_lower;
6078 mp->mp_upper = fp->mp_upper + offset;
6079 if (fp_flags & P_LEAF2) {
6080 memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad);
6082 memcpy((char *)mp + mp->mp_upper, (char *)fp + fp->mp_upper,
6083 olddata.mv_size - fp->mp_upper);
6084 for (i=0; i<NUMKEYS(fp); i++)
6085 mp->mp_ptrs[i] = fp->mp_ptrs[i] + offset;
6093 mdb_node_del(mc, 0);
6097 /* overflow page overwrites need special handling */
6098 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
6101 int level, ovpages, dpages = OVPAGES(data->mv_size, env->me_psize);
6103 memcpy(&pg, olddata.mv_data, sizeof(pg));
6104 if ((rc2 = mdb_page_get(mc->mc_txn, pg, &omp, &level)) != 0)
6106 ovpages = omp->mp_pages;
6108 /* Is the ov page large enough? */
6109 if (ovpages >= dpages) {
6110 if (!(omp->mp_flags & P_DIRTY) &&
6111 (level || (env->me_flags & MDB_WRITEMAP)))
6113 rc = mdb_page_unspill(mc->mc_txn, omp, &omp);
6116 level = 0; /* dirty in this txn or clean */
6119 if (omp->mp_flags & P_DIRTY) {
6120 /* yes, overwrite it. Note in this case we don't
6121 * bother to try shrinking the page if the new data
6122 * is smaller than the overflow threshold.
6125 /* It is writable only in a parent txn */
6126 size_t sz = (size_t) env->me_psize * ovpages, off;
6127 MDB_page *np = mdb_page_malloc(mc->mc_txn, ovpages);
6133 rc = mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);
6134 mdb_cassert(mc, rc == 0);
6135 if (!(flags & MDB_RESERVE)) {
6136 /* Copy end of page, adjusting alignment so
6137 * compiler may copy words instead of bytes.
6139 off = (PAGEHDRSZ + data->mv_size) & -sizeof(size_t);
6140 memcpy((size_t *)((char *)np + off),
6141 (size_t *)((char *)omp + off), sz - off);
6144 memcpy(np, omp, sz); /* Copy beginning of page */
6147 SETDSZ(leaf, data->mv_size);
6148 if (F_ISSET(flags, MDB_RESERVE))
6149 data->mv_data = METADATA(omp);
6151 memcpy(METADATA(omp), data->mv_data, data->mv_size);
6155 if ((rc2 = mdb_ovpage_free(mc, omp)) != MDB_SUCCESS)
6157 } else if (data->mv_size == olddata.mv_size) {
6158 /* same size, just replace it. Note that we could
6159 * also reuse this node if the new data is smaller,
6160 * but instead we opt to shrink the node in that case.
6162 if (F_ISSET(flags, MDB_RESERVE))
6163 data->mv_data = olddata.mv_data;
6164 else if (!(mc->mc_flags & C_SUB))
6165 memcpy(olddata.mv_data, data->mv_data, data->mv_size);
6167 memcpy(NODEKEY(leaf), key->mv_data, key->mv_size);
6170 mdb_node_del(mc, 0);
6171 mc->mc_db->md_entries--;
6177 nflags = flags & NODE_ADD_FLAGS;
6178 nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(env, key, rdata);
6179 if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) {
6180 if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA )
6181 nflags &= ~MDB_APPEND;
6183 nflags |= MDB_SPLIT_REPLACE;
6184 rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags);
6186 /* There is room already in this leaf page. */
6187 rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);
6188 if (rc == 0 && !do_sub && insert) {
6189 /* Adjust other cursors pointing to mp */
6190 MDB_cursor *m2, *m3;
6191 MDB_dbi dbi = mc->mc_dbi;
6192 unsigned i = mc->mc_top;
6193 MDB_page *mp = mc->mc_pg[i];
6195 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
6196 if (mc->mc_flags & C_SUB)
6197 m3 = &m2->mc_xcursor->mx_cursor;
6200 if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
6201 if (m3->mc_pg[i] == mp && m3->mc_ki[i] >= mc->mc_ki[i]) {
6208 if (rc != MDB_SUCCESS)
6209 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
6211 /* Now store the actual data in the child DB. Note that we're
6212 * storing the user data in the keys field, so there are strict
6213 * size limits on dupdata. The actual data fields of the child
6214 * DB are all zero size.
6221 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6222 if (flags & MDB_CURRENT) {
6223 xflags = MDB_CURRENT|MDB_NOSPILL;
6225 mdb_xcursor_init1(mc, leaf);
6226 xflags = (flags & MDB_NODUPDATA) ?
6227 MDB_NOOVERWRITE|MDB_NOSPILL : MDB_NOSPILL;
6229 /* converted, write the original data first */
6231 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);
6233 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
6234 return rc == MDB_KEYEXIST ? MDB_CORRUPTED : rc;
6237 /* Adjust other cursors pointing to mp */
6239 unsigned i = mc->mc_top;
6240 MDB_page *mp = mc->mc_pg[i];
6242 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
6243 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
6244 if (!(m2->mc_flags & C_INITIALIZED)) continue;
6245 if (m2->mc_pg[i] == mp && m2->mc_ki[i] == mc->mc_ki[i]) {
6246 mdb_xcursor_init1(m2, leaf);
6250 /* we've done our job */
6253 if (flags & MDB_APPENDDUP)
6254 xflags |= MDB_APPEND;
6255 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);
6256 if (flags & F_SUBDATA) {
6257 void *db = NODEDATA(leaf);
6258 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
6261 /* sub-writes might have failed so check rc again.
6262 * Don't increment count if we just replaced an existing item.
6264 if (!rc && !(flags & MDB_CURRENT))
6265 mc->mc_db->md_entries++;
6266 if (flags & MDB_MULTIPLE) {
6270 /* let caller know how many succeeded, if any */
6271 data[1].mv_size = mcount;
6272 if (mcount < dcount) {
6273 data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size;
6280 /* If we succeeded and the key didn't exist before, make sure
6281 * the cursor is marked valid.
6284 mc->mc_flags |= C_INITIALIZED;
6289 mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
6295 if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
6296 return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
6298 if (!(mc->mc_flags & C_INITIALIZED))
6301 if (mc->mc_ki[mc->mc_top] >= NUMKEYS(mc->mc_pg[mc->mc_top]))
6302 return MDB_NOTFOUND;
6304 if (!(flags & MDB_NOSPILL) && (rc = mdb_page_spill(mc, NULL, NULL)))
6307 rc = mdb_cursor_touch(mc);
6311 mp = mc->mc_pg[mc->mc_top];
6314 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6316 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6317 if (!(flags & MDB_NODUPDATA)) {
6318 if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
6319 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6321 rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, MDB_NOSPILL);
6324 /* If sub-DB still has entries, we're done */
6325 if (mc->mc_xcursor->mx_db.md_entries) {
6326 if (leaf->mn_flags & F_SUBDATA) {
6327 /* update subDB info */
6328 void *db = NODEDATA(leaf);
6329 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
6332 /* shrink fake page */
6333 mdb_node_shrink(mp, mc->mc_ki[mc->mc_top]);
6334 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6335 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6336 /* fix other sub-DB cursors pointed at this fake page */
6337 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
6338 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
6339 if (m2->mc_pg[mc->mc_top] == mp &&
6340 m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top])
6341 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6344 mc->mc_db->md_entries--;
6345 mc->mc_flags |= C_DEL;
6348 /* otherwise fall thru and delete the sub-DB */
6351 if (leaf->mn_flags & F_SUBDATA) {
6352 /* add all the child DB's pages to the free list */
6353 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
6356 mc->mc_db->md_entries -= mc->mc_xcursor->mx_db.md_entries;
6360 /* add overflow pages to free list */
6361 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
6365 memcpy(&pg, NODEDATA(leaf), sizeof(pg));
6366 if ((rc = mdb_page_get(mc->mc_txn, pg, &omp, NULL)) ||
6367 (rc = mdb_ovpage_free(mc, omp)))
6372 return mdb_cursor_del0(mc);
6375 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
6379 /** Allocate and initialize new pages for a database.
6380 * @param[in] mc a cursor on the database being added to.
6381 * @param[in] flags flags defining what type of page is being allocated.
6382 * @param[in] num the number of pages to allocate. This is usually 1,
6383 * unless allocating overflow pages for a large record.
6384 * @param[out] mp Address of a page, or NULL on failure.
6385 * @return 0 on success, non-zero on failure.
6388 mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp)
6393 if ((rc = mdb_page_alloc(mc, num, &np)))
6395 DPRINTF(("allocated new mpage %"Z"u, page size %u",
6396 np->mp_pgno, mc->mc_txn->mt_env->me_psize));
6397 np->mp_flags = flags | P_DIRTY;
6398 np->mp_lower = PAGEHDRSZ;
6399 np->mp_upper = mc->mc_txn->mt_env->me_psize;
6402 mc->mc_db->md_branch_pages++;
6403 else if (IS_LEAF(np))
6404 mc->mc_db->md_leaf_pages++;
6405 else if (IS_OVERFLOW(np)) {
6406 mc->mc_db->md_overflow_pages += num;
6414 /** Calculate the size of a leaf node.
6415 * The size depends on the environment's page size; if a data item
6416 * is too large it will be put onto an overflow page and the node
6417 * size will only include the key and not the data. Sizes are always
6418 * rounded up to an even number of bytes, to guarantee 2-byte alignment
6419 * of the #MDB_node headers.
6420 * @param[in] env The environment handle.
6421 * @param[in] key The key for the node.
6422 * @param[in] data The data for the node.
6423 * @return The number of bytes needed to store the node.
6426 mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data)
6430 sz = LEAFSIZE(key, data);
6431 if (sz > env->me_nodemax) {
6432 /* put on overflow page */
6433 sz -= data->mv_size - sizeof(pgno_t);
6436 return EVEN(sz + sizeof(indx_t));
6439 /** Calculate the size of a branch node.
6440 * The size should depend on the environment's page size but since
6441 * we currently don't support spilling large keys onto overflow
6442 * pages, it's simply the size of the #MDB_node header plus the
6443 * size of the key. Sizes are always rounded up to an even number
6444 * of bytes, to guarantee 2-byte alignment of the #MDB_node headers.
6445 * @param[in] env The environment handle.
6446 * @param[in] key The key for the node.
6447 * @return The number of bytes needed to store the node.
6450 mdb_branch_size(MDB_env *env, MDB_val *key)
6455 if (sz > env->me_nodemax) {
6456 /* put on overflow page */
6457 /* not implemented */
6458 /* sz -= key->size - sizeof(pgno_t); */
6461 return sz + sizeof(indx_t);
6464 /** Add a node to the page pointed to by the cursor.
6465 * @param[in] mc The cursor for this operation.
6466 * @param[in] indx The index on the page where the new node should be added.
6467 * @param[in] key The key for the new node.
6468 * @param[in] data The data for the new node, if any.
6469 * @param[in] pgno The page number, if adding a branch node.
6470 * @param[in] flags Flags for the node.
6471 * @return 0 on success, non-zero on failure. Possible errors are:
6473 * <li>ENOMEM - failed to allocate overflow pages for the node.
6474 * <li>MDB_PAGE_FULL - there is insufficient room in the page. This error
6475 * should never happen since all callers already calculate the
6476 * page's free space before calling this function.
6480 mdb_node_add(MDB_cursor *mc, indx_t indx,
6481 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags)
6484 size_t node_size = NODESIZE;
6488 MDB_page *mp = mc->mc_pg[mc->mc_top];
6489 MDB_page *ofp = NULL; /* overflow page */
6492 mdb_cassert(mc, mp->mp_upper >= mp->mp_lower);
6494 DPRINTF(("add to %s %spage %"Z"u index %i, data size %"Z"u key size %"Z"u [%s]",
6495 IS_LEAF(mp) ? "leaf" : "branch",
6496 IS_SUBP(mp) ? "sub-" : "",
6497 mdb_dbg_pgno(mp), indx, data ? data->mv_size : 0,
6498 key ? key->mv_size : 0, key ? DKEY(key) : "null"));
6501 /* Move higher keys up one slot. */
6502 int ksize = mc->mc_db->md_pad, dif;
6503 char *ptr = LEAF2KEY(mp, indx, ksize);
6504 dif = NUMKEYS(mp) - indx;
6506 memmove(ptr+ksize, ptr, dif*ksize);
6507 /* insert new key */
6508 memcpy(ptr, key->mv_data, ksize);
6510 /* Just using these for counting */
6511 mp->mp_lower += sizeof(indx_t);
6512 mp->mp_upper -= ksize - sizeof(indx_t);
6516 room = (ssize_t)SIZELEFT(mp) - (ssize_t)sizeof(indx_t);
6518 node_size += key->mv_size;
6520 mdb_cassert(mc, data);
6521 if (F_ISSET(flags, F_BIGDATA)) {
6522 /* Data already on overflow page. */
6523 node_size += sizeof(pgno_t);
6524 } else if (node_size + data->mv_size > mc->mc_txn->mt_env->me_nodemax) {
6525 int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
6527 /* Put data on overflow page. */
6528 DPRINTF(("data size is %"Z"u, node would be %"Z"u, put data on overflow page",
6529 data->mv_size, node_size+data->mv_size));
6530 node_size = EVEN(node_size + sizeof(pgno_t));
6531 if ((ssize_t)node_size > room)
6533 if ((rc = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp)))
6535 DPRINTF(("allocated overflow page %"Z"u", ofp->mp_pgno));
6539 node_size += data->mv_size;
6542 node_size = EVEN(node_size);
6543 if ((ssize_t)node_size > room)
6547 /* Move higher pointers up one slot. */
6548 for (i = NUMKEYS(mp); i > indx; i--)
6549 mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];
6551 /* Adjust free space offsets. */
6552 ofs = mp->mp_upper - node_size;
6553 mdb_cassert(mc, ofs >= mp->mp_lower + sizeof(indx_t));
6554 mp->mp_ptrs[indx] = ofs;
6556 mp->mp_lower += sizeof(indx_t);
6558 /* Write the node data. */
6559 node = NODEPTR(mp, indx);
6560 node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
6561 node->mn_flags = flags;
6563 SETDSZ(node,data->mv_size);
6568 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
6571 mdb_cassert(mc, key);
6573 if (F_ISSET(flags, F_BIGDATA))
6574 memcpy(node->mn_data + key->mv_size, data->mv_data,
6576 else if (F_ISSET(flags, MDB_RESERVE))
6577 data->mv_data = node->mn_data + key->mv_size;
6579 memcpy(node->mn_data + key->mv_size, data->mv_data,
6582 memcpy(node->mn_data + key->mv_size, &ofp->mp_pgno,
6584 if (F_ISSET(flags, MDB_RESERVE))
6585 data->mv_data = METADATA(ofp);
6587 memcpy(METADATA(ofp), data->mv_data, data->mv_size);
6594 DPRINTF(("not enough room in page %"Z"u, got %u ptrs",
6595 mdb_dbg_pgno(mp), NUMKEYS(mp)));
6596 DPRINTF(("upper-lower = %u - %u = %"Z"d", mp->mp_upper,mp->mp_lower,room));
6597 DPRINTF(("node size = %"Z"u", node_size));
6598 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
6599 return MDB_PAGE_FULL;
6602 /** Delete the specified node from a page.
6603 * @param[in] mc Cursor pointing to the node to delete.
6604 * @param[in] ksize The size of a node. Only used if the page is
6605 * part of a #MDB_DUPFIXED database.
6608 mdb_node_del(MDB_cursor *mc, int ksize)
6610 MDB_page *mp = mc->mc_pg[mc->mc_top];
6611 indx_t indx = mc->mc_ki[mc->mc_top];
6613 indx_t i, j, numkeys, ptr;
6617 DPRINTF(("delete node %u on %s page %"Z"u", indx,
6618 IS_LEAF(mp) ? "leaf" : "branch", mdb_dbg_pgno(mp)));
6619 numkeys = NUMKEYS(mp);
6620 mdb_cassert(mc, indx < numkeys);
6623 int x = numkeys - 1 - indx;
6624 base = LEAF2KEY(mp, indx, ksize);
6626 memmove(base, base + ksize, x * ksize);
6627 mp->mp_lower -= sizeof(indx_t);
6628 mp->mp_upper += ksize - sizeof(indx_t);
6632 node = NODEPTR(mp, indx);
6633 sz = NODESIZE + node->mn_ksize;
6635 if (F_ISSET(node->mn_flags, F_BIGDATA))
6636 sz += sizeof(pgno_t);
6638 sz += NODEDSZ(node);
6642 ptr = mp->mp_ptrs[indx];
6643 for (i = j = 0; i < numkeys; i++) {
6645 mp->mp_ptrs[j] = mp->mp_ptrs[i];
6646 if (mp->mp_ptrs[i] < ptr)
6647 mp->mp_ptrs[j] += sz;
6652 base = (char *)mp + mp->mp_upper;
6653 memmove(base + sz, base, ptr - mp->mp_upper);
6655 mp->mp_lower -= sizeof(indx_t);
6659 /** Compact the main page after deleting a node on a subpage.
6660 * @param[in] mp The main page to operate on.
6661 * @param[in] indx The index of the subpage on the main page.
6664 mdb_node_shrink(MDB_page *mp, indx_t indx)
6670 indx_t i, numkeys, ptr;
6672 node = NODEPTR(mp, indx);
6673 sp = (MDB_page *)NODEDATA(node);
6674 delta = SIZELEFT(sp);
6675 xp = (MDB_page *)((char *)sp + delta);
6677 /* shift subpage upward */
6679 nsize = NUMKEYS(sp) * sp->mp_pad;
6681 return; /* do not make the node uneven-sized */
6682 memmove(METADATA(xp), METADATA(sp), nsize);
6685 numkeys = NUMKEYS(sp);
6686 for (i=numkeys-1; i>=0; i--)
6687 xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta;
6689 xp->mp_upper = sp->mp_lower;
6690 xp->mp_lower = sp->mp_lower;
6691 xp->mp_flags = sp->mp_flags;
6692 xp->mp_pad = sp->mp_pad;
6693 COPY_PGNO(xp->mp_pgno, mp->mp_pgno);
6695 nsize = NODEDSZ(node) - delta;
6696 SETDSZ(node, nsize);
6698 /* shift lower nodes upward */
6699 ptr = mp->mp_ptrs[indx];
6700 numkeys = NUMKEYS(mp);
6701 for (i = 0; i < numkeys; i++) {
6702 if (mp->mp_ptrs[i] <= ptr)
6703 mp->mp_ptrs[i] += delta;
6706 base = (char *)mp + mp->mp_upper;
6707 memmove(base + delta, base, ptr - mp->mp_upper + NODESIZE + NODEKSZ(node));
6708 mp->mp_upper += delta;
6711 /** Initial setup of a sorted-dups cursor.
6712 * Sorted duplicates are implemented as a sub-database for the given key.
6713 * The duplicate data items are actually keys of the sub-database.
6714 * Operations on the duplicate data items are performed using a sub-cursor
6715 * initialized when the sub-database is first accessed. This function does
6716 * the preliminary setup of the sub-cursor, filling in the fields that
6717 * depend only on the parent DB.
6718 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
6721 mdb_xcursor_init0(MDB_cursor *mc)
6723 MDB_xcursor *mx = mc->mc_xcursor;
6725 mx->mx_cursor.mc_xcursor = NULL;
6726 mx->mx_cursor.mc_txn = mc->mc_txn;
6727 mx->mx_cursor.mc_db = &mx->mx_db;
6728 mx->mx_cursor.mc_dbx = &mx->mx_dbx;
6729 mx->mx_cursor.mc_dbi = mc->mc_dbi;
6730 mx->mx_cursor.mc_dbflag = &mx->mx_dbflag;
6731 mx->mx_cursor.mc_snum = 0;
6732 mx->mx_cursor.mc_top = 0;
6733 mx->mx_cursor.mc_flags = C_SUB;
6734 mx->mx_dbx.md_name.mv_size = 0;
6735 mx->mx_dbx.md_name.mv_data = NULL;
6736 mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp;
6737 mx->mx_dbx.md_dcmp = NULL;
6738 mx->mx_dbx.md_rel = mc->mc_dbx->md_rel;
6741 /** Final setup of a sorted-dups cursor.
6742 * Sets up the fields that depend on the data from the main cursor.
6743 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
6744 * @param[in] node The data containing the #MDB_db record for the
6745 * sorted-dup database.
6748 mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)
6750 MDB_xcursor *mx = mc->mc_xcursor;
6752 if (node->mn_flags & F_SUBDATA) {
6753 memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db));
6754 mx->mx_cursor.mc_pg[0] = 0;
6755 mx->mx_cursor.mc_snum = 0;
6756 mx->mx_cursor.mc_top = 0;
6757 mx->mx_cursor.mc_flags = C_SUB;
6759 MDB_page *fp = NODEDATA(node);
6760 mx->mx_db.md_pad = mc->mc_pg[mc->mc_top]->mp_pad;
6761 mx->mx_db.md_flags = 0;
6762 mx->mx_db.md_depth = 1;
6763 mx->mx_db.md_branch_pages = 0;
6764 mx->mx_db.md_leaf_pages = 1;
6765 mx->mx_db.md_overflow_pages = 0;
6766 mx->mx_db.md_entries = NUMKEYS(fp);
6767 COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno);
6768 mx->mx_cursor.mc_snum = 1;
6769 mx->mx_cursor.mc_top = 0;
6770 mx->mx_cursor.mc_flags = C_INITIALIZED|C_SUB;
6771 mx->mx_cursor.mc_pg[0] = fp;
6772 mx->mx_cursor.mc_ki[0] = 0;
6773 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
6774 mx->mx_db.md_flags = MDB_DUPFIXED;
6775 mx->mx_db.md_pad = fp->mp_pad;
6776 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
6777 mx->mx_db.md_flags |= MDB_INTEGERKEY;
6780 DPRINTF(("Sub-db -%u root page %"Z"u", mx->mx_cursor.mc_dbi,
6781 mx->mx_db.md_root));
6782 mx->mx_dbflag = DB_VALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
6783 #if UINT_MAX < SIZE_MAX
6784 if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(size_t))
6785 #ifdef MISALIGNED_OK
6786 mx->mx_dbx.md_cmp = mdb_cmp_long;
6788 mx->mx_dbx.md_cmp = mdb_cmp_cint;
6793 /** Initialize a cursor for a given transaction and database. */
6795 mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
6798 mc->mc_backup = NULL;
6801 mc->mc_db = &txn->mt_dbs[dbi];
6802 mc->mc_dbx = &txn->mt_dbxs[dbi];
6803 mc->mc_dbflag = &txn->mt_dbflags[dbi];
6808 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
6809 mdb_tassert(txn, mx != NULL);
6810 mc->mc_xcursor = mx;
6811 mdb_xcursor_init0(mc);
6813 mc->mc_xcursor = NULL;
6815 if (*mc->mc_dbflag & DB_STALE) {
6816 mdb_page_search(mc, NULL, MDB_PS_ROOTONLY);
6821 mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
6824 size_t size = sizeof(MDB_cursor);
6826 if (!ret || !TXN_DBI_EXIST(txn, dbi))
6829 if (txn->mt_flags & MDB_TXN_ERROR)
6832 /* Allow read access to the freelist */
6833 if (!dbi && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
6836 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)
6837 size += sizeof(MDB_xcursor);
6839 if ((mc = malloc(size)) != NULL) {
6840 mdb_cursor_init(mc, txn, dbi, (MDB_xcursor *)(mc + 1));
6841 if (txn->mt_cursors) {
6842 mc->mc_next = txn->mt_cursors[dbi];
6843 txn->mt_cursors[dbi] = mc;
6844 mc->mc_flags |= C_UNTRACK;
6856 mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)
6858 if (!mc || !TXN_DBI_EXIST(txn, mc->mc_dbi))
6861 if ((mc->mc_flags & C_UNTRACK) || txn->mt_cursors)
6864 if (txn->mt_flags & MDB_TXN_ERROR)
6867 mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor);
6871 /* Return the count of duplicate data items for the current key */
6873 mdb_cursor_count(MDB_cursor *mc, size_t *countp)
6877 if (mc == NULL || countp == NULL)
6880 if (mc->mc_xcursor == NULL)
6881 return MDB_INCOMPATIBLE;
6883 if (mc->mc_txn->mt_flags & MDB_TXN_ERROR)
6886 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6887 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6890 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
6893 *countp = mc->mc_xcursor->mx_db.md_entries;
6899 mdb_cursor_close(MDB_cursor *mc)
6901 if (mc && !mc->mc_backup) {
6902 /* remove from txn, if tracked */
6903 if ((mc->mc_flags & C_UNTRACK) && mc->mc_txn->mt_cursors) {
6904 MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi];
6905 while (*prev && *prev != mc) prev = &(*prev)->mc_next;
6907 *prev = mc->mc_next;
6914 mdb_cursor_txn(MDB_cursor *mc)
6916 if (!mc) return NULL;
6921 mdb_cursor_dbi(MDB_cursor *mc)
6926 /** Replace the key for a branch node with a new key.
6927 * @param[in] mc Cursor pointing to the node to operate on.
6928 * @param[in] key The new key to use.
6929 * @return 0 on success, non-zero on failure.
6932 mdb_update_key(MDB_cursor *mc, MDB_val *key)
6938 int delta, ksize, oksize;
6939 indx_t ptr, i, numkeys, indx;
6942 indx = mc->mc_ki[mc->mc_top];
6943 mp = mc->mc_pg[mc->mc_top];
6944 node = NODEPTR(mp, indx);
6945 ptr = mp->mp_ptrs[indx];
6949 char kbuf2[DKBUF_MAXKEYSIZE*2+1];
6950 k2.mv_data = NODEKEY(node);
6951 k2.mv_size = node->mn_ksize;
6952 DPRINTF(("update key %u (ofs %u) [%s] to [%s] on page %"Z"u",
6954 mdb_dkey(&k2, kbuf2),
6960 /* Sizes must be 2-byte aligned. */
6961 ksize = EVEN(key->mv_size);
6962 oksize = EVEN(node->mn_ksize);
6963 delta = ksize - oksize;
6965 /* Shift node contents if EVEN(key length) changed. */
6967 if (delta > 0 && SIZELEFT(mp) < delta) {
6969 /* not enough space left, do a delete and split */
6970 DPRINTF(("Not enough room, delta = %d, splitting...", delta));
6971 pgno = NODEPGNO(node);
6972 mdb_node_del(mc, 0);
6973 return mdb_page_split(mc, key, NULL, pgno, MDB_SPLIT_REPLACE);
6976 numkeys = NUMKEYS(mp);
6977 for (i = 0; i < numkeys; i++) {
6978 if (mp->mp_ptrs[i] <= ptr)
6979 mp->mp_ptrs[i] -= delta;
6982 base = (char *)mp + mp->mp_upper;
6983 len = ptr - mp->mp_upper + NODESIZE;
6984 memmove(base - delta, base, len);
6985 mp->mp_upper -= delta;
6987 node = NODEPTR(mp, indx);
6990 /* But even if no shift was needed, update ksize */
6991 if (node->mn_ksize != key->mv_size)
6992 node->mn_ksize = key->mv_size;
6995 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
7001 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst);
7003 /** Move a node from csrc to cdst.
7006 mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
7013 unsigned short flags;
7017 /* Mark src and dst as dirty. */
7018 if ((rc = mdb_page_touch(csrc)) ||
7019 (rc = mdb_page_touch(cdst)))
7022 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7023 key.mv_size = csrc->mc_db->md_pad;
7024 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
7026 data.mv_data = NULL;
7030 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]);
7031 mdb_cassert(csrc, !((size_t)srcnode & 1));
7032 srcpg = NODEPGNO(srcnode);
7033 flags = srcnode->mn_flags;
7034 if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
7035 unsigned int snum = csrc->mc_snum;
7037 /* must find the lowest key below src */
7038 rc = mdb_page_search_lowest(csrc);
7041 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7042 key.mv_size = csrc->mc_db->md_pad;
7043 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
7045 s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
7046 key.mv_size = NODEKSZ(s2);
7047 key.mv_data = NODEKEY(s2);
7049 csrc->mc_snum = snum--;
7050 csrc->mc_top = snum;
7052 key.mv_size = NODEKSZ(srcnode);
7053 key.mv_data = NODEKEY(srcnode);
7055 data.mv_size = NODEDSZ(srcnode);
7056 data.mv_data = NODEDATA(srcnode);
7058 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) {
7059 unsigned int snum = cdst->mc_snum;
7062 /* must find the lowest key below dst */
7063 rc = mdb_page_search_lowest(cdst);
7066 if (IS_LEAF2(cdst->mc_pg[cdst->mc_top])) {
7067 bkey.mv_size = cdst->mc_db->md_pad;
7068 bkey.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, bkey.mv_size);
7070 s2 = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
7071 bkey.mv_size = NODEKSZ(s2);
7072 bkey.mv_data = NODEKEY(s2);
7074 cdst->mc_snum = snum--;
7075 cdst->mc_top = snum;
7076 mdb_cursor_copy(cdst, &mn);
7078 rc = mdb_update_key(&mn, &bkey);
7083 DPRINTF(("moving %s node %u [%s] on page %"Z"u to node %u on page %"Z"u",
7084 IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch",
7085 csrc->mc_ki[csrc->mc_top],
7087 csrc->mc_pg[csrc->mc_top]->mp_pgno,
7088 cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno));
7090 /* Add the node to the destination page.
7092 rc = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags);
7093 if (rc != MDB_SUCCESS)
7096 /* Delete the node from the source page.
7098 mdb_node_del(csrc, key.mv_size);
7101 /* Adjust other cursors pointing to mp */
7102 MDB_cursor *m2, *m3;
7103 MDB_dbi dbi = csrc->mc_dbi;
7104 MDB_page *mp = csrc->mc_pg[csrc->mc_top];
7106 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7107 if (csrc->mc_flags & C_SUB)
7108 m3 = &m2->mc_xcursor->mx_cursor;
7111 if (m3 == csrc) continue;
7112 if (m3->mc_pg[csrc->mc_top] == mp && m3->mc_ki[csrc->mc_top] ==
7113 csrc->mc_ki[csrc->mc_top]) {
7114 m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
7115 m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
7120 /* Update the parent separators.
7122 if (csrc->mc_ki[csrc->mc_top] == 0) {
7123 if (csrc->mc_ki[csrc->mc_top-1] != 0) {
7124 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7125 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
7127 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
7128 key.mv_size = NODEKSZ(srcnode);
7129 key.mv_data = NODEKEY(srcnode);
7131 DPRINTF(("update separator for source page %"Z"u to [%s]",
7132 csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key)));
7133 mdb_cursor_copy(csrc, &mn);
7136 if ((rc = mdb_update_key(&mn, &key)) != MDB_SUCCESS)
7139 if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
7141 indx_t ix = csrc->mc_ki[csrc->mc_top];
7142 nullkey.mv_size = 0;
7143 csrc->mc_ki[csrc->mc_top] = 0;
7144 rc = mdb_update_key(csrc, &nullkey);
7145 csrc->mc_ki[csrc->mc_top] = ix;
7146 mdb_cassert(csrc, rc == MDB_SUCCESS);
7150 if (cdst->mc_ki[cdst->mc_top] == 0) {
7151 if (cdst->mc_ki[cdst->mc_top-1] != 0) {
7152 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7153 key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size);
7155 srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
7156 key.mv_size = NODEKSZ(srcnode);
7157 key.mv_data = NODEKEY(srcnode);
7159 DPRINTF(("update separator for destination page %"Z"u to [%s]",
7160 cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key)));
7161 mdb_cursor_copy(cdst, &mn);
7164 if ((rc = mdb_update_key(&mn, &key)) != MDB_SUCCESS)
7167 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) {
7169 indx_t ix = cdst->mc_ki[cdst->mc_top];
7170 nullkey.mv_size = 0;
7171 cdst->mc_ki[cdst->mc_top] = 0;
7172 rc = mdb_update_key(cdst, &nullkey);
7173 cdst->mc_ki[cdst->mc_top] = ix;
7174 mdb_cassert(csrc, rc == MDB_SUCCESS);
7181 /** Merge one page into another.
7182 * The nodes from the page pointed to by \b csrc will
7183 * be copied to the page pointed to by \b cdst and then
7184 * the \b csrc page will be freed.
7185 * @param[in] csrc Cursor pointing to the source page.
7186 * @param[in] cdst Cursor pointing to the destination page.
7187 * @return 0 on success, non-zero on failure.
7190 mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
7198 DPRINTF(("merging page %"Z"u into %"Z"u", csrc->mc_pg[csrc->mc_top]->mp_pgno,
7199 cdst->mc_pg[cdst->mc_top]->mp_pgno));
7201 mdb_cassert(csrc, csrc->mc_snum > 1); /* can't merge root page */
7202 mdb_cassert(csrc, cdst->mc_snum > 1);
7204 /* Mark dst as dirty. */
7205 if ((rc = mdb_page_touch(cdst)))
7208 /* Move all nodes from src to dst.
7210 j = nkeys = NUMKEYS(cdst->mc_pg[cdst->mc_top]);
7211 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7212 key.mv_size = csrc->mc_db->md_pad;
7213 key.mv_data = METADATA(csrc->mc_pg[csrc->mc_top]);
7214 for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) {
7215 rc = mdb_node_add(cdst, j, &key, NULL, 0, 0);
7216 if (rc != MDB_SUCCESS)
7218 key.mv_data = (char *)key.mv_data + key.mv_size;
7221 for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) {
7222 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], i);
7223 if (i == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
7224 unsigned int snum = csrc->mc_snum;
7226 /* must find the lowest key below src */
7227 rc = mdb_page_search_lowest(csrc);
7230 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7231 key.mv_size = csrc->mc_db->md_pad;
7232 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
7234 s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
7235 key.mv_size = NODEKSZ(s2);
7236 key.mv_data = NODEKEY(s2);
7238 csrc->mc_snum = snum--;
7239 csrc->mc_top = snum;
7241 key.mv_size = srcnode->mn_ksize;
7242 key.mv_data = NODEKEY(srcnode);
7245 data.mv_size = NODEDSZ(srcnode);
7246 data.mv_data = NODEDATA(srcnode);
7247 rc = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags);
7248 if (rc != MDB_SUCCESS)
7253 DPRINTF(("dst page %"Z"u now has %u keys (%.1f%% filled)",
7254 cdst->mc_pg[cdst->mc_top]->mp_pgno, NUMKEYS(cdst->mc_pg[cdst->mc_top]),
7255 (float)PAGEFILL(cdst->mc_txn->mt_env, cdst->mc_pg[cdst->mc_top]) / 10));
7257 /* Unlink the src page from parent and add to free list.
7260 mdb_node_del(csrc, 0);
7261 if (csrc->mc_ki[csrc->mc_top] == 0) {
7263 rc = mdb_update_key(csrc, &key);
7271 rc = mdb_midl_append(&csrc->mc_txn->mt_free_pgs,
7272 csrc->mc_pg[csrc->mc_top]->mp_pgno);
7275 if (IS_LEAF(csrc->mc_pg[csrc->mc_top]))
7276 csrc->mc_db->md_leaf_pages--;
7278 csrc->mc_db->md_branch_pages--;
7280 /* Adjust other cursors pointing to mp */
7281 MDB_cursor *m2, *m3;
7282 MDB_dbi dbi = csrc->mc_dbi;
7283 MDB_page *mp = cdst->mc_pg[cdst->mc_top];
7285 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7286 if (csrc->mc_flags & C_SUB)
7287 m3 = &m2->mc_xcursor->mx_cursor;
7290 if (m3 == csrc) continue;
7291 if (m3->mc_snum < csrc->mc_snum) continue;
7292 if (m3->mc_pg[csrc->mc_top] == csrc->mc_pg[csrc->mc_top]) {
7293 m3->mc_pg[csrc->mc_top] = mp;
7294 m3->mc_ki[csrc->mc_top] += nkeys;
7298 mdb_cursor_pop(csrc);
7300 return mdb_rebalance(csrc);
7303 /** Copy the contents of a cursor.
7304 * @param[in] csrc The cursor to copy from.
7305 * @param[out] cdst The cursor to copy to.
7308 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst)
7312 cdst->mc_txn = csrc->mc_txn;
7313 cdst->mc_dbi = csrc->mc_dbi;
7314 cdst->mc_db = csrc->mc_db;
7315 cdst->mc_dbx = csrc->mc_dbx;
7316 cdst->mc_snum = csrc->mc_snum;
7317 cdst->mc_top = csrc->mc_top;
7318 cdst->mc_flags = csrc->mc_flags;
7320 for (i=0; i<csrc->mc_snum; i++) {
7321 cdst->mc_pg[i] = csrc->mc_pg[i];
7322 cdst->mc_ki[i] = csrc->mc_ki[i];
7326 /** Rebalance the tree after a delete operation.
7327 * @param[in] mc Cursor pointing to the page where rebalancing
7329 * @return 0 on success, non-zero on failure.
7332 mdb_rebalance(MDB_cursor *mc)
7336 unsigned int ptop, minkeys;
7339 minkeys = 1 + (IS_BRANCH(mc->mc_pg[mc->mc_top]));
7340 DPRINTF(("rebalancing %s page %"Z"u (has %u keys, %.1f%% full)",
7341 IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",
7342 mdb_dbg_pgno(mc->mc_pg[mc->mc_top]), NUMKEYS(mc->mc_pg[mc->mc_top]),
7343 (float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10));
7345 if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= FILL_THRESHOLD &&
7346 NUMKEYS(mc->mc_pg[mc->mc_top]) >= minkeys) {
7347 DPRINTF(("no need to rebalance page %"Z"u, above fill threshold",
7348 mdb_dbg_pgno(mc->mc_pg[mc->mc_top])));
7352 if (mc->mc_snum < 2) {
7353 MDB_page *mp = mc->mc_pg[0];
7355 DPUTS("Can't rebalance a subpage, ignoring");
7358 if (NUMKEYS(mp) == 0) {
7359 DPUTS("tree is completely empty");
7360 mc->mc_db->md_root = P_INVALID;
7361 mc->mc_db->md_depth = 0;
7362 mc->mc_db->md_leaf_pages = 0;
7363 rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
7366 /* Adjust cursors pointing to mp */
7369 mc->mc_flags &= ~C_INITIALIZED;
7371 MDB_cursor *m2, *m3;
7372 MDB_dbi dbi = mc->mc_dbi;
7374 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7375 if (mc->mc_flags & C_SUB)
7376 m3 = &m2->mc_xcursor->mx_cursor;
7379 if (m3->mc_snum < mc->mc_snum) continue;
7380 if (m3->mc_pg[0] == mp) {
7383 m3->mc_flags &= ~C_INITIALIZED;
7387 } else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) {
7388 DPUTS("collapsing root page!");
7389 rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
7392 mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0));
7393 rc = mdb_page_get(mc->mc_txn,mc->mc_db->md_root,&mc->mc_pg[0],NULL);
7396 mc->mc_db->md_depth--;
7397 mc->mc_db->md_branch_pages--;
7398 mc->mc_ki[0] = mc->mc_ki[1];
7400 /* Adjust other cursors pointing to mp */
7401 MDB_cursor *m2, *m3;
7402 MDB_dbi dbi = mc->mc_dbi;
7404 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7405 if (mc->mc_flags & C_SUB)
7406 m3 = &m2->mc_xcursor->mx_cursor;
7409 if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
7410 if (m3->mc_pg[0] == mp) {
7414 for (i=0; i<m3->mc_snum; i++) {
7415 m3->mc_pg[i] = m3->mc_pg[i+1];
7416 m3->mc_ki[i] = m3->mc_ki[i+1];
7422 DPUTS("root page doesn't need rebalancing");
7426 /* The parent (branch page) must have at least 2 pointers,
7427 * otherwise the tree is invalid.
7429 ptop = mc->mc_top-1;
7430 mdb_cassert(mc, NUMKEYS(mc->mc_pg[ptop]) > 1);
7432 /* Leaf page fill factor is below the threshold.
7433 * Try to move keys from left or right neighbor, or
7434 * merge with a neighbor page.
7439 mdb_cursor_copy(mc, &mn);
7440 mn.mc_xcursor = NULL;
7442 if (mc->mc_ki[ptop] == 0) {
7443 /* We're the leftmost leaf in our parent.
7445 DPUTS("reading right neighbor");
7447 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
7448 rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
7451 mn.mc_ki[mn.mc_top] = 0;
7452 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);
7454 /* There is at least one neighbor to the left.
7456 DPUTS("reading left neighbor");
7458 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
7459 rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
7462 mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;
7463 mc->mc_ki[mc->mc_top] = 0;
7466 DPRINTF(("found neighbor page %"Z"u (%u keys, %.1f%% full)",
7467 mn.mc_pg[mn.mc_top]->mp_pgno, NUMKEYS(mn.mc_pg[mn.mc_top]),
7468 (float)PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) / 10));
7470 /* If the neighbor page is above threshold and has enough keys,
7471 * move one key from it. Otherwise we should try to merge them.
7472 * (A branch page must never have less than 2 keys.)
7474 minkeys = 1 + (IS_BRANCH(mn.mc_pg[mn.mc_top]));
7475 if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= FILL_THRESHOLD && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys)
7476 return mdb_node_move(&mn, mc);
7478 if (mc->mc_ki[ptop] == 0)
7479 rc = mdb_page_merge(&mn, mc);
7481 mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1;
7482 rc = mdb_page_merge(mc, &mn);
7483 mdb_cursor_copy(&mn, mc);
7485 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
7490 /** Complete a delete operation started by #mdb_cursor_del(). */
7492 mdb_cursor_del0(MDB_cursor *mc)
7499 ki = mc->mc_ki[mc->mc_top];
7500 mdb_node_del(mc, mc->mc_db->md_pad);
7501 mc->mc_db->md_entries--;
7502 rc = mdb_rebalance(mc);
7504 if (rc == MDB_SUCCESS) {
7505 MDB_cursor *m2, *m3;
7506 MDB_dbi dbi = mc->mc_dbi;
7508 mp = mc->mc_pg[mc->mc_top];
7509 nkeys = NUMKEYS(mp);
7511 /* if mc points past last node in page, find next sibling */
7512 if (mc->mc_ki[mc->mc_top] >= nkeys) {
7513 rc = mdb_cursor_sibling(mc, 1);
7514 if (rc == MDB_NOTFOUND)
7518 /* Adjust other cursors pointing to mp */
7519 for (m2 = mc->mc_txn->mt_cursors[dbi]; !rc && m2; m2=m2->mc_next) {
7520 m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;
7521 if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))
7523 if (m3 == mc || m3->mc_snum < mc->mc_snum)
7525 if (m3->mc_pg[mc->mc_top] == mp) {
7526 if (m3->mc_ki[mc->mc_top] >= ki) {
7527 m3->mc_flags |= C_DEL;
7528 if (m3->mc_ki[mc->mc_top] > ki)
7529 m3->mc_ki[mc->mc_top]--;
7531 if (m3->mc_ki[mc->mc_top] >= nkeys) {
7532 rc = mdb_cursor_sibling(m3, 1);
7533 if (rc == MDB_NOTFOUND)
7538 mc->mc_flags |= C_DEL;
7542 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
7547 mdb_del(MDB_txn *txn, MDB_dbi dbi,
7548 MDB_val *key, MDB_val *data)
7550 if (!key || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
7553 if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
7554 return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
7556 if (!F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
7557 /* must ignore any data */
7561 return mdb_del0(txn, dbi, key, data, 0);
7565 mdb_del0(MDB_txn *txn, MDB_dbi dbi,
7566 MDB_val *key, MDB_val *data, unsigned flags)
7571 MDB_val rdata, *xdata;
7575 DPRINTF(("====> delete db %u key [%s]", dbi, DKEY(key)));
7577 mdb_cursor_init(&mc, txn, dbi, &mx);
7586 flags |= MDB_NODUPDATA;
7588 rc = mdb_cursor_set(&mc, key, xdata, op, &exact);
7590 /* let mdb_page_split know about this cursor if needed:
7591 * delete will trigger a rebalance; if it needs to move
7592 * a node from one page to another, it will have to
7593 * update the parent's separator key(s). If the new sepkey
7594 * is larger than the current one, the parent page may
7595 * run out of space, triggering a split. We need this
7596 * cursor to be consistent until the end of the rebalance.
7598 mc.mc_flags |= C_UNTRACK;
7599 mc.mc_next = txn->mt_cursors[dbi];
7600 txn->mt_cursors[dbi] = &mc;
7601 rc = mdb_cursor_del(&mc, flags);
7602 txn->mt_cursors[dbi] = mc.mc_next;
7607 /** Split a page and insert a new node.
7608 * @param[in,out] mc Cursor pointing to the page and desired insertion index.
7609 * The cursor will be updated to point to the actual page and index where
7610 * the node got inserted after the split.
7611 * @param[in] newkey The key for the newly inserted node.
7612 * @param[in] newdata The data for the newly inserted node.
7613 * @param[in] newpgno The page number, if the new node is a branch node.
7614 * @param[in] nflags The #NODE_ADD_FLAGS for the new node.
7615 * @return 0 on success, non-zero on failure.
7618 mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno,
7619 unsigned int nflags)
7622 int rc = MDB_SUCCESS, new_root = 0, did_split = 0;
7625 int i, j, split_indx, nkeys, pmax;
7626 MDB_env *env = mc->mc_txn->mt_env;
7628 MDB_val sepkey, rkey, xdata, *rdata = &xdata;
7629 MDB_page *copy = NULL;
7630 MDB_page *mp, *rp, *pp;
7635 mp = mc->mc_pg[mc->mc_top];
7636 newindx = mc->mc_ki[mc->mc_top];
7637 nkeys = NUMKEYS(mp);
7639 DPRINTF(("-----> splitting %s page %"Z"u and adding [%s] at index %i/%i",
7640 IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno,
7641 DKEY(newkey), mc->mc_ki[mc->mc_top], nkeys));
7643 /* Create a right sibling. */
7644 if ((rc = mdb_page_new(mc, mp->mp_flags, 1, &rp)))
7646 DPRINTF(("new right sibling: page %"Z"u", rp->mp_pgno));
7648 if (mc->mc_snum < 2) {
7649 if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp)))
7651 /* shift current top to make room for new parent */
7652 mc->mc_pg[1] = mc->mc_pg[0];
7653 mc->mc_ki[1] = mc->mc_ki[0];
7656 mc->mc_db->md_root = pp->mp_pgno;
7657 DPRINTF(("root split! new root = %"Z"u", pp->mp_pgno));
7658 mc->mc_db->md_depth++;
7661 /* Add left (implicit) pointer. */
7662 if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) {
7663 /* undo the pre-push */
7664 mc->mc_pg[0] = mc->mc_pg[1];
7665 mc->mc_ki[0] = mc->mc_ki[1];
7666 mc->mc_db->md_root = mp->mp_pgno;
7667 mc->mc_db->md_depth--;
7674 ptop = mc->mc_top-1;
7675 DPRINTF(("parent branch page is %"Z"u", mc->mc_pg[ptop]->mp_pgno));
7678 mc->mc_flags |= C_SPLITTING;
7679 mdb_cursor_copy(mc, &mn);
7680 mn.mc_pg[mn.mc_top] = rp;
7681 mn.mc_ki[ptop] = mc->mc_ki[ptop]+1;
7683 if (nflags & MDB_APPEND) {
7684 mn.mc_ki[mn.mc_top] = 0;
7686 split_indx = newindx;
7690 split_indx = (nkeys+1) / 2;
7695 unsigned int lsize, rsize, ksize;
7696 /* Move half of the keys to the right sibling */
7697 x = mc->mc_ki[mc->mc_top] - split_indx;
7698 ksize = mc->mc_db->md_pad;
7699 split = LEAF2KEY(mp, split_indx, ksize);
7700 rsize = (nkeys - split_indx) * ksize;
7701 lsize = (nkeys - split_indx) * sizeof(indx_t);
7702 mp->mp_lower -= lsize;
7703 rp->mp_lower += lsize;
7704 mp->mp_upper += rsize - lsize;
7705 rp->mp_upper -= rsize - lsize;
7706 sepkey.mv_size = ksize;
7707 if (newindx == split_indx) {
7708 sepkey.mv_data = newkey->mv_data;
7710 sepkey.mv_data = split;
7713 ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize);
7714 memcpy(rp->mp_ptrs, split, rsize);
7715 sepkey.mv_data = rp->mp_ptrs;
7716 memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize);
7717 memcpy(ins, newkey->mv_data, ksize);
7718 mp->mp_lower += sizeof(indx_t);
7719 mp->mp_upper -= ksize - sizeof(indx_t);
7722 memcpy(rp->mp_ptrs, split, x * ksize);
7723 ins = LEAF2KEY(rp, x, ksize);
7724 memcpy(ins, newkey->mv_data, ksize);
7725 memcpy(ins+ksize, split + x * ksize, rsize - x * ksize);
7726 rp->mp_lower += sizeof(indx_t);
7727 rp->mp_upper -= ksize - sizeof(indx_t);
7728 mc->mc_ki[mc->mc_top] = x;
7729 mc->mc_pg[mc->mc_top] = rp;
7732 int psize, nsize, k;
7733 /* Maximum free space in an empty page */
7734 pmax = env->me_psize - PAGEHDRSZ;
7736 nsize = mdb_leaf_size(env, newkey, newdata);
7738 nsize = mdb_branch_size(env, newkey);
7739 nsize = EVEN(nsize);
7741 /* grab a page to hold a temporary copy */
7742 copy = mdb_page_malloc(mc->mc_txn, 1);
7747 copy->mp_pgno = mp->mp_pgno;
7748 copy->mp_flags = mp->mp_flags;
7749 copy->mp_lower = PAGEHDRSZ;
7750 copy->mp_upper = env->me_psize;
7752 /* prepare to insert */
7753 for (i=0, j=0; i<nkeys; i++) {
7755 copy->mp_ptrs[j++] = 0;
7757 copy->mp_ptrs[j++] = mp->mp_ptrs[i];
7760 /* When items are relatively large the split point needs
7761 * to be checked, because being off-by-one will make the
7762 * difference between success or failure in mdb_node_add.
7764 * It's also relevant if a page happens to be laid out
7765 * such that one half of its nodes are all "small" and
7766 * the other half of its nodes are "large." If the new
7767 * item is also "large" and falls on the half with
7768 * "large" nodes, it also may not fit.
7770 * As a final tweak, if the new item goes on the last
7771 * spot on the page (and thus, onto the new page), bias
7772 * the split so the new page is emptier than the old page.
7773 * This yields better packing during sequential inserts.
7775 if (nkeys < 20 || nsize > pmax/16 || newindx >= nkeys) {
7776 /* Find split point */
7778 if (newindx <= split_indx || newindx >= nkeys) {
7780 k = newindx >= nkeys ? nkeys : split_indx+2;
7785 for (; i!=k; i+=j) {
7790 node = (MDB_node *)((char *)mp + copy->mp_ptrs[i]);
7791 psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
7793 if (F_ISSET(node->mn_flags, F_BIGDATA))
7794 psize += sizeof(pgno_t);
7796 psize += NODEDSZ(node);
7798 psize = EVEN(psize);
7800 if (psize > pmax || i == k-j) {
7801 split_indx = i + (j<0);
7806 if (split_indx == newindx) {
7807 sepkey.mv_size = newkey->mv_size;
7808 sepkey.mv_data = newkey->mv_data;
7810 node = (MDB_node *)((char *)mp + copy->mp_ptrs[split_indx]);
7811 sepkey.mv_size = node->mn_ksize;
7812 sepkey.mv_data = NODEKEY(node);
7817 DPRINTF(("separator is %d [%s]", split_indx, DKEY(&sepkey)));
7819 /* Copy separator key to the parent.
7821 if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(env, &sepkey)) {
7825 rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0);
7830 if (mn.mc_snum == mc->mc_snum) {
7831 mc->mc_pg[mc->mc_snum] = mc->mc_pg[mc->mc_top];
7832 mc->mc_ki[mc->mc_snum] = mc->mc_ki[mc->mc_top];
7833 mc->mc_pg[mc->mc_top] = mc->mc_pg[ptop];
7834 mc->mc_ki[mc->mc_top] = mc->mc_ki[ptop];
7839 /* Right page might now have changed parent.
7840 * Check if left page also changed parent.
7842 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
7843 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
7844 for (i=0; i<ptop; i++) {
7845 mc->mc_pg[i] = mn.mc_pg[i];
7846 mc->mc_ki[i] = mn.mc_ki[i];
7848 mc->mc_pg[ptop] = mn.mc_pg[ptop];
7849 if (mn.mc_ki[ptop]) {
7850 mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;
7852 /* find right page's left sibling */
7853 mc->mc_ki[ptop] = mn.mc_ki[ptop];
7854 mdb_cursor_sibling(mc, 0);
7859 rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);
7862 mc->mc_flags ^= C_SPLITTING;
7863 if (rc != MDB_SUCCESS) {
7866 if (nflags & MDB_APPEND) {
7867 mc->mc_pg[mc->mc_top] = rp;
7868 mc->mc_ki[mc->mc_top] = 0;
7869 rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags);
7872 for (i=0; i<mc->mc_top; i++)
7873 mc->mc_ki[i] = mn.mc_ki[i];
7874 } else if (!IS_LEAF2(mp)) {
7876 mc->mc_pg[mc->mc_top] = rp;
7881 rkey.mv_data = newkey->mv_data;
7882 rkey.mv_size = newkey->mv_size;
7888 /* Update index for the new key. */
7889 mc->mc_ki[mc->mc_top] = j;
7891 node = (MDB_node *)((char *)mp + copy->mp_ptrs[i]);
7892 rkey.mv_data = NODEKEY(node);
7893 rkey.mv_size = node->mn_ksize;
7895 xdata.mv_data = NODEDATA(node);
7896 xdata.mv_size = NODEDSZ(node);
7899 pgno = NODEPGNO(node);
7900 flags = node->mn_flags;
7903 if (!IS_LEAF(mp) && j == 0) {
7904 /* First branch index doesn't need key data. */
7908 rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags);
7914 mc->mc_pg[mc->mc_top] = copy;
7919 } while (i != split_indx);
7921 nkeys = NUMKEYS(copy);
7922 for (i=0; i<nkeys; i++)
7923 mp->mp_ptrs[i] = copy->mp_ptrs[i];
7924 mp->mp_lower = copy->mp_lower;
7925 mp->mp_upper = copy->mp_upper;
7926 memcpy(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1),
7927 env->me_psize - copy->mp_upper);
7929 /* reset back to original page */
7930 if (newindx < split_indx) {
7931 mc->mc_pg[mc->mc_top] = mp;
7932 if (nflags & MDB_RESERVE) {
7933 node = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
7934 if (!(node->mn_flags & F_BIGDATA))
7935 newdata->mv_data = NODEDATA(node);
7938 mc->mc_pg[mc->mc_top] = rp;
7940 /* Make sure mc_ki is still valid.
7942 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
7943 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
7944 for (i=0; i<=ptop; i++) {
7945 mc->mc_pg[i] = mn.mc_pg[i];
7946 mc->mc_ki[i] = mn.mc_ki[i];
7953 /* Adjust other cursors pointing to mp */
7954 MDB_cursor *m2, *m3;
7955 MDB_dbi dbi = mc->mc_dbi;
7956 int fixup = NUMKEYS(mp);
7958 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7959 if (mc->mc_flags & C_SUB)
7960 m3 = &m2->mc_xcursor->mx_cursor;
7965 if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED))
7967 if (m3->mc_flags & C_SPLITTING)
7972 for (k=m3->mc_top; k>=0; k--) {
7973 m3->mc_ki[k+1] = m3->mc_ki[k];
7974 m3->mc_pg[k+1] = m3->mc_pg[k];
7976 if (m3->mc_ki[0] >= split_indx) {
7981 m3->mc_pg[0] = mc->mc_pg[0];
7985 if (m3->mc_top >= mc->mc_top && m3->mc_pg[mc->mc_top] == mp) {
7986 if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE))
7987 m3->mc_ki[mc->mc_top]++;
7988 if (m3->mc_ki[mc->mc_top] >= fixup) {
7989 m3->mc_pg[mc->mc_top] = rp;
7990 m3->mc_ki[mc->mc_top] -= fixup;
7991 m3->mc_ki[ptop] = mn.mc_ki[ptop];
7993 } else if (!did_split && m3->mc_top >= ptop && m3->mc_pg[ptop] == mc->mc_pg[ptop] &&
7994 m3->mc_ki[ptop] >= mc->mc_ki[ptop]) {
7999 DPRINTF(("mp left: %d, rp left: %d", SIZELEFT(mp), SIZELEFT(rp)));
8002 if (copy) /* tmp page */
8003 mdb_page_free(env, copy);
8005 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
8010 mdb_put(MDB_txn *txn, MDB_dbi dbi,
8011 MDB_val *key, MDB_val *data, unsigned int flags)
8016 if (!key || !data || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
8019 if ((flags & (MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND|MDB_APPENDDUP)) != flags)
8022 mdb_cursor_init(&mc, txn, dbi, &mx);
8023 return mdb_cursor_put(&mc, key, data, flags);
8027 mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)
8029 if ((flag & CHANGEABLE) != flag)
8032 env->me_flags |= flag;
8034 env->me_flags &= ~flag;
8039 mdb_env_get_flags(MDB_env *env, unsigned int *arg)
8044 *arg = env->me_flags;
8049 mdb_env_set_userctx(MDB_env *env, void *ctx)
8053 env->me_userctx = ctx;
8058 mdb_env_get_userctx(MDB_env *env)
8060 return env ? env->me_userctx : NULL;
8064 mdb_env_set_assert(MDB_env *env, MDB_assert_func *func)
8069 env->me_assert_func = func;
8075 mdb_env_get_path(MDB_env *env, const char **arg)
8080 *arg = env->me_path;
8085 mdb_env_get_fd(MDB_env *env, mdb_filehandle_t *arg)
8094 /** Common code for #mdb_stat() and #mdb_env_stat().
8095 * @param[in] env the environment to operate in.
8096 * @param[in] db the #MDB_db record containing the stats to return.
8097 * @param[out] arg the address of an #MDB_stat structure to receive the stats.
8098 * @return 0, this function always succeeds.
8101 mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)
8103 arg->ms_psize = env->me_psize;
8104 arg->ms_depth = db->md_depth;
8105 arg->ms_branch_pages = db->md_branch_pages;
8106 arg->ms_leaf_pages = db->md_leaf_pages;
8107 arg->ms_overflow_pages = db->md_overflow_pages;
8108 arg->ms_entries = db->md_entries;
8113 mdb_env_stat(MDB_env *env, MDB_stat *arg)
8117 if (env == NULL || arg == NULL)
8120 toggle = mdb_env_pick_meta(env);
8122 return mdb_stat0(env, &env->me_metas[toggle]->mm_dbs[MAIN_DBI], arg);
8126 mdb_env_info(MDB_env *env, MDB_envinfo *arg)
8130 if (env == NULL || arg == NULL)
8133 toggle = mdb_env_pick_meta(env);
8134 arg->me_mapaddr = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : 0;
8135 arg->me_mapsize = env->me_mapsize;
8136 arg->me_maxreaders = env->me_maxreaders;
8138 /* me_numreaders may be zero if this process never used any readers. Use
8139 * the shared numreader count if it exists.
8141 arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : env->me_numreaders;
8143 arg->me_last_pgno = env->me_metas[toggle]->mm_last_pg;
8144 arg->me_last_txnid = env->me_metas[toggle]->mm_txnid;
8148 /** Set the default comparison functions for a database.
8149 * Called immediately after a database is opened to set the defaults.
8150 * The user can then override them with #mdb_set_compare() or
8151 * #mdb_set_dupsort().
8152 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
8153 * @param[in] dbi A database handle returned by #mdb_dbi_open()
8156 mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi)
8158 uint16_t f = txn->mt_dbs[dbi].md_flags;
8160 txn->mt_dbxs[dbi].md_cmp =
8161 (f & MDB_REVERSEKEY) ? mdb_cmp_memnr :
8162 (f & MDB_INTEGERKEY) ? mdb_cmp_cint : mdb_cmp_memn;
8164 txn->mt_dbxs[dbi].md_dcmp =
8165 !(f & MDB_DUPSORT) ? 0 :
8166 ((f & MDB_INTEGERDUP)
8167 ? ((f & MDB_DUPFIXED) ? mdb_cmp_int : mdb_cmp_cint)
8168 : ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn));
8171 int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
8176 int rc, dbflag, exact;
8177 unsigned int unused = 0;
8180 if (txn->mt_dbxs[FREE_DBI].md_cmp == NULL) {
8181 mdb_default_cmp(txn, FREE_DBI);
8184 if ((flags & VALID_FLAGS) != flags)
8186 if (txn->mt_flags & MDB_TXN_ERROR)
8192 if (flags & PERSISTENT_FLAGS) {
8193 uint16_t f2 = flags & PERSISTENT_FLAGS;
8194 /* make sure flag changes get committed */
8195 if ((txn->mt_dbs[MAIN_DBI].md_flags | f2) != txn->mt_dbs[MAIN_DBI].md_flags) {
8196 txn->mt_dbs[MAIN_DBI].md_flags |= f2;
8197 txn->mt_flags |= MDB_TXN_DIRTY;
8200 mdb_default_cmp(txn, MAIN_DBI);
8204 if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {
8205 mdb_default_cmp(txn, MAIN_DBI);
8208 /* Is the DB already open? */
8210 for (i=2; i<txn->mt_numdbs; i++) {
8211 if (!txn->mt_dbxs[i].md_name.mv_size) {
8212 /* Remember this free slot */
8213 if (!unused) unused = i;
8216 if (len == txn->mt_dbxs[i].md_name.mv_size &&
8217 !strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) {
8223 /* If no free slot and max hit, fail */
8224 if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs)
8225 return MDB_DBS_FULL;
8227 /* Cannot mix named databases with some mainDB flags */
8228 if (txn->mt_dbs[MAIN_DBI].md_flags & (MDB_DUPSORT|MDB_INTEGERKEY))
8229 return (flags & MDB_CREATE) ? MDB_INCOMPATIBLE : MDB_NOTFOUND;
8231 /* Find the DB info */
8232 dbflag = DB_NEW|DB_VALID;
8235 key.mv_data = (void *)name;
8236 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
8237 rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact);
8238 if (rc == MDB_SUCCESS) {
8239 /* make sure this is actually a DB */
8240 MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]);
8241 if (!(node->mn_flags & F_SUBDATA))
8242 return MDB_INCOMPATIBLE;
8243 } else if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) {
8244 /* Create if requested */
8246 data.mv_size = sizeof(MDB_db);
8247 data.mv_data = &dummy;
8248 memset(&dummy, 0, sizeof(dummy));
8249 dummy.md_root = P_INVALID;
8250 dummy.md_flags = flags & PERSISTENT_FLAGS;
8251 rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA);
8255 /* OK, got info, add to table */
8256 if (rc == MDB_SUCCESS) {
8257 unsigned int slot = unused ? unused : txn->mt_numdbs;
8258 txn->mt_dbxs[slot].md_name.mv_data = strdup(name);
8259 txn->mt_dbxs[slot].md_name.mv_size = len;
8260 txn->mt_dbxs[slot].md_rel = NULL;
8261 txn->mt_dbflags[slot] = dbflag;
8262 memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db));
8264 mdb_default_cmp(txn, slot);
8273 int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
8275 if (!arg || !TXN_DBI_EXIST(txn, dbi))
8278 if (txn->mt_flags & MDB_TXN_ERROR)
8281 if (txn->mt_dbflags[dbi] & DB_STALE) {
8284 /* Stale, must read the DB's root. cursor_init does it for us. */
8285 mdb_cursor_init(&mc, txn, dbi, &mx);
8287 return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg);
8290 void mdb_dbi_close(MDB_env *env, MDB_dbi dbi)
8293 if (dbi <= MAIN_DBI || dbi >= env->me_maxdbs)
8295 ptr = env->me_dbxs[dbi].md_name.mv_data;
8296 env->me_dbxs[dbi].md_name.mv_data = NULL;
8297 env->me_dbxs[dbi].md_name.mv_size = 0;
8298 env->me_dbflags[dbi] = 0;
8302 int mdb_dbi_flags(MDB_txn *txn, MDB_dbi dbi, unsigned int *flags)
8304 /* We could return the flags for the FREE_DBI too but what's the point? */
8305 if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
8307 *flags = txn->mt_dbs[dbi].md_flags & PERSISTENT_FLAGS;
8311 /** Add all the DB's pages to the free list.
8312 * @param[in] mc Cursor on the DB to free.
8313 * @param[in] subs non-Zero to check for sub-DBs in this DB.
8314 * @return 0 on success, non-zero on failure.
8317 mdb_drop0(MDB_cursor *mc, int subs)
8321 rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
8322 if (rc == MDB_SUCCESS) {
8323 MDB_txn *txn = mc->mc_txn;
8328 /* LEAF2 pages have no nodes, cannot have sub-DBs */
8329 if (IS_LEAF2(mc->mc_pg[mc->mc_top]))
8332 mdb_cursor_copy(mc, &mx);
8333 while (mc->mc_snum > 0) {
8334 MDB_page *mp = mc->mc_pg[mc->mc_top];
8335 unsigned n = NUMKEYS(mp);
8337 for (i=0; i<n; i++) {
8338 ni = NODEPTR(mp, i);
8339 if (ni->mn_flags & F_BIGDATA) {
8342 memcpy(&pg, NODEDATA(ni), sizeof(pg));
8343 rc = mdb_page_get(txn, pg, &omp, NULL);
8346 mdb_cassert(mc, IS_OVERFLOW(omp));
8347 rc = mdb_midl_append_range(&txn->mt_free_pgs,
8351 } else if (subs && (ni->mn_flags & F_SUBDATA)) {
8352 mdb_xcursor_init1(mc, ni);
8353 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
8359 if ((rc = mdb_midl_need(&txn->mt_free_pgs, n)) != 0)
8361 for (i=0; i<n; i++) {
8363 ni = NODEPTR(mp, i);
8366 mdb_midl_xappend(txn->mt_free_pgs, pg);
8371 mc->mc_ki[mc->mc_top] = i;
8372 rc = mdb_cursor_sibling(mc, 1);
8374 if (rc != MDB_NOTFOUND)
8376 /* no more siblings, go back to beginning
8377 * of previous level.
8381 for (i=1; i<mc->mc_snum; i++) {
8383 mc->mc_pg[i] = mx.mc_pg[i];
8388 rc = mdb_midl_append(&txn->mt_free_pgs, mc->mc_db->md_root);
8391 txn->mt_flags |= MDB_TXN_ERROR;
8392 } else if (rc == MDB_NOTFOUND) {
8398 int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)
8400 MDB_cursor *mc, *m2;
8403 if ((unsigned)del > 1 || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
8406 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
8409 rc = mdb_cursor_open(txn, dbi, &mc);
8413 rc = mdb_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT);
8414 /* Invalidate the dropped DB's cursors */
8415 for (m2 = txn->mt_cursors[dbi]; m2; m2 = m2->mc_next)
8416 m2->mc_flags &= ~(C_INITIALIZED|C_EOF);
8420 /* Can't delete the main DB */
8421 if (del && dbi > MAIN_DBI) {
8422 rc = mdb_del0(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL, 0);
8424 txn->mt_dbflags[dbi] = DB_STALE;
8425 mdb_dbi_close(txn->mt_env, dbi);
8427 txn->mt_flags |= MDB_TXN_ERROR;
8430 /* reset the DB record, mark it dirty */
8431 txn->mt_dbflags[dbi] |= DB_DIRTY;
8432 txn->mt_dbs[dbi].md_depth = 0;
8433 txn->mt_dbs[dbi].md_branch_pages = 0;
8434 txn->mt_dbs[dbi].md_leaf_pages = 0;
8435 txn->mt_dbs[dbi].md_overflow_pages = 0;
8436 txn->mt_dbs[dbi].md_entries = 0;
8437 txn->mt_dbs[dbi].md_root = P_INVALID;
8439 txn->mt_flags |= MDB_TXN_DIRTY;
8442 mdb_cursor_close(mc);
8446 int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
8448 if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
8451 txn->mt_dbxs[dbi].md_cmp = cmp;
8455 int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
8457 if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
8460 txn->mt_dbxs[dbi].md_dcmp = cmp;
8464 int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
8466 if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
8469 txn->mt_dbxs[dbi].md_rel = rel;
8473 int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx)
8475 if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
8478 txn->mt_dbxs[dbi].md_relctx = ctx;
8482 int mdb_env_get_maxkeysize(MDB_env *env)
8484 return ENV_MAXKEY(env);
8487 int mdb_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx)
8489 unsigned int i, rdrs;
8492 int rc = 0, first = 1;
8496 if (!env->me_txns) {
8497 return func("(no reader locks)\n", ctx);
8499 rdrs = env->me_txns->mti_numreaders;
8500 mr = env->me_txns->mti_readers;
8501 for (i=0; i<rdrs; i++) {
8503 txnid_t txnid = mr[i].mr_txnid;
8504 sprintf(buf, txnid == (txnid_t)-1 ?
8505 "%10d %"Z"x -\n" : "%10d %"Z"x %"Z"u\n",
8506 (int)mr[i].mr_pid, (size_t)mr[i].mr_tid, txnid);
8509 rc = func(" pid thread txnid\n", ctx);
8513 rc = func(buf, ctx);
8519 rc = func("(no active readers)\n", ctx);
8524 /** Insert pid into list if not already present.
8525 * return -1 if already present.
8527 static int mdb_pid_insert(MDB_PID_T *ids, MDB_PID_T pid)
8529 /* binary search of pid in list */
8531 unsigned cursor = 1;
8533 unsigned n = ids[0];
8536 unsigned pivot = n >> 1;
8537 cursor = base + pivot + 1;
8538 val = pid - ids[cursor];
8543 } else if ( val > 0 ) {
8548 /* found, so it's a duplicate */
8557 for (n = ids[0]; n > cursor; n--)
8563 int mdb_reader_check(MDB_env *env, int *dead)
8565 unsigned int i, j, rdrs;
8567 MDB_PID_T *pids, pid;
8576 rdrs = env->me_txns->mti_numreaders;
8577 pids = malloc((rdrs+1) * sizeof(MDB_PID_T));
8581 mr = env->me_txns->mti_readers;
8582 for (i=0; i<rdrs; i++) {
8583 if (mr[i].mr_pid && mr[i].mr_pid != env->me_pid) {
8585 if (mdb_pid_insert(pids, pid) == 0) {
8586 if (!mdb_reader_pid(env, Pidcheck, pid)) {
8588 /* Recheck, a new process may have reused pid */
8589 if (!mdb_reader_pid(env, Pidcheck, pid)) {
8590 for (j=i; j<rdrs; j++)
8591 if (mr[j].mr_pid == pid) {
8592 DPRINTF(("clear stale reader pid %u txn %"Z"d",
8593 (unsigned) pid, mr[j].mr_txnid));
8598 UNLOCK_MUTEX_R(env);
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