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>
40 #include <sys/param.h>
46 #ifdef HAVE_SYS_FILE_H
63 #if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER))
64 #include <netinet/in.h>
65 #include <resolv.h> /* defines BYTE_ORDER on HPUX and Solaris */
68 #if defined(__APPLE__) || defined (BSD)
69 # define MDB_USE_POSIX_SEM 1
70 # define MDB_FDATASYNC fsync
71 #elif defined(ANDROID)
72 # define MDB_FDATASYNC fsync
77 #ifdef MDB_USE_POSIX_SEM
78 #include <semaphore.h>
83 #include <valgrind/memcheck.h>
84 #define VGMEMP_CREATE(h,r,z) VALGRIND_CREATE_MEMPOOL(h,r,z)
85 #define VGMEMP_ALLOC(h,a,s) VALGRIND_MEMPOOL_ALLOC(h,a,s)
86 #define VGMEMP_FREE(h,a) VALGRIND_MEMPOOL_FREE(h,a)
87 #define VGMEMP_DESTROY(h) VALGRIND_DESTROY_MEMPOOL(h)
88 #define VGMEMP_DEFINED(a,s) VALGRIND_MAKE_MEM_DEFINED(a,s)
90 #define VGMEMP_CREATE(h,r,z)
91 #define VGMEMP_ALLOC(h,a,s)
92 #define VGMEMP_FREE(h,a)
93 #define VGMEMP_DESTROY(h)
94 #define VGMEMP_DEFINED(a,s)
98 # if (defined(_LITTLE_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN))
99 /* Solaris just defines one or the other */
100 # define LITTLE_ENDIAN 1234
101 # define BIG_ENDIAN 4321
102 # ifdef _LITTLE_ENDIAN
103 # define BYTE_ORDER LITTLE_ENDIAN
105 # define BYTE_ORDER BIG_ENDIAN
108 # define BYTE_ORDER __BYTE_ORDER
112 #ifndef LITTLE_ENDIAN
113 #define LITTLE_ENDIAN __LITTLE_ENDIAN
116 #define BIG_ENDIAN __BIG_ENDIAN
119 #if defined(__i386) || defined(__x86_64) || defined(_M_IX86)
120 #define MISALIGNED_OK 1
126 #if (BYTE_ORDER == LITTLE_ENDIAN) == (BYTE_ORDER == BIG_ENDIAN)
127 # error "Unknown or unsupported endianness (BYTE_ORDER)"
128 #elif (-6 & 5) || CHAR_BIT != 8 || UINT_MAX < 0xffffffff || ULONG_MAX % 0xFFFF
129 # error "Two's complement, reasonably sized integer types, please"
132 /** @defgroup internal MDB Internals
135 /** @defgroup compat Windows Compatibility Macros
136 * A bunch of macros to minimize the amount of platform-specific ifdefs
137 * needed throughout the rest of the code. When the features this library
138 * needs are similar enough to POSIX to be hidden in a one-or-two line
139 * replacement, this macro approach is used.
143 #define MDB_PIDLOCK 0
144 #define pthread_t DWORD
145 #define pthread_mutex_t HANDLE
146 #define pthread_key_t DWORD
147 #define pthread_self() GetCurrentThreadId()
148 #define pthread_key_create(x,y) \
149 ((*(x) = TlsAlloc()) == TLS_OUT_OF_INDEXES ? ErrCode() : 0)
150 #define pthread_key_delete(x) TlsFree(x)
151 #define pthread_getspecific(x) TlsGetValue(x)
152 #define pthread_setspecific(x,y) (TlsSetValue(x,y) ? 0 : ErrCode())
153 #define pthread_mutex_unlock(x) ReleaseMutex(x)
154 #define pthread_mutex_lock(x) WaitForSingleObject(x, INFINITE)
155 #define LOCK_MUTEX_R(env) pthread_mutex_lock((env)->me_rmutex)
156 #define UNLOCK_MUTEX_R(env) pthread_mutex_unlock((env)->me_rmutex)
157 #define LOCK_MUTEX_W(env) pthread_mutex_lock((env)->me_wmutex)
158 #define UNLOCK_MUTEX_W(env) pthread_mutex_unlock((env)->me_wmutex)
159 #define getpid() GetCurrentProcessId()
160 #define MDB_FDATASYNC(fd) (!FlushFileBuffers(fd))
161 #define MDB_MSYNC(addr,len,flags) (!FlushViewOfFile(addr,len))
162 #define ErrCode() GetLastError()
163 #define GET_PAGESIZE(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;}
164 #define close(fd) (CloseHandle(fd) ? 0 : -1)
165 #define munmap(ptr,len) UnmapViewOfFile(ptr)
166 #ifdef PROCESS_QUERY_LIMITED_INFORMATION
167 #define MDB_PROCESS_QUERY_LIMITED_INFORMATION PROCESS_QUERY_LIMITED_INFORMATION
169 #define MDB_PROCESS_QUERY_LIMITED_INFORMATION 0x1000
174 #define Z "z" /**< printf format modifier for size_t */
176 /** For MDB_LOCK_FORMAT: True if readers take a pid lock in the lockfile */
177 #define MDB_PIDLOCK 1
179 #ifdef MDB_USE_POSIX_SEM
181 #define LOCK_MUTEX_R(env) mdb_sem_wait((env)->me_rmutex)
182 #define UNLOCK_MUTEX_R(env) sem_post((env)->me_rmutex)
183 #define LOCK_MUTEX_W(env) mdb_sem_wait((env)->me_wmutex)
184 #define UNLOCK_MUTEX_W(env) sem_post((env)->me_wmutex)
187 mdb_sem_wait(sem_t *sem)
190 while ((rc = sem_wait(sem)) && (rc = errno) == EINTR) ;
195 /** Lock the reader mutex.
197 #define LOCK_MUTEX_R(env) pthread_mutex_lock(&(env)->me_txns->mti_mutex)
198 /** Unlock the reader mutex.
200 #define UNLOCK_MUTEX_R(env) pthread_mutex_unlock(&(env)->me_txns->mti_mutex)
202 /** Lock the writer mutex.
203 * Only a single write transaction is allowed at a time. Other writers
204 * will block waiting for this mutex.
206 #define LOCK_MUTEX_W(env) pthread_mutex_lock(&(env)->me_txns->mti_wmutex)
207 /** Unlock the writer mutex.
209 #define UNLOCK_MUTEX_W(env) pthread_mutex_unlock(&(env)->me_txns->mti_wmutex)
210 #endif /* MDB_USE_POSIX_SEM */
212 /** Get the error code for the last failed system function.
214 #define ErrCode() errno
216 /** An abstraction for a file handle.
217 * On POSIX systems file handles are small integers. On Windows
218 * they're opaque pointers.
222 /** A value for an invalid file handle.
223 * Mainly used to initialize file variables and signify that they are
226 #define INVALID_HANDLE_VALUE (-1)
228 /** Get the size of a memory page for the system.
229 * This is the basic size that the platform's memory manager uses, and is
230 * fundamental to the use of memory-mapped files.
232 #define GET_PAGESIZE(x) ((x) = sysconf(_SC_PAGE_SIZE))
235 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
238 #define MNAME_LEN (sizeof(pthread_mutex_t))
244 /** A flag for opening a file and requesting synchronous data writes.
245 * This is only used when writing a meta page. It's not strictly needed;
246 * we could just do a normal write and then immediately perform a flush.
247 * But if this flag is available it saves us an extra system call.
249 * @note If O_DSYNC is undefined but exists in /usr/include,
250 * preferably set some compiler flag to get the definition.
251 * Otherwise compile with the less efficient -DMDB_DSYNC=O_SYNC.
254 # define MDB_DSYNC O_DSYNC
258 /** Function for flushing the data of a file. Define this to fsync
259 * if fdatasync() is not supported.
261 #ifndef MDB_FDATASYNC
262 # define MDB_FDATASYNC fdatasync
266 # define MDB_MSYNC(addr,len,flags) msync(addr,len,flags)
277 /** A page number in the database.
278 * Note that 64 bit page numbers are overkill, since pages themselves
279 * already represent 12-13 bits of addressable memory, and the OS will
280 * always limit applications to a maximum of 63 bits of address space.
282 * @note In the #MDB_node structure, we only store 48 bits of this value,
283 * which thus limits us to only 60 bits of addressable data.
285 typedef MDB_ID pgno_t;
287 /** A transaction ID.
288 * See struct MDB_txn.mt_txnid for details.
290 typedef MDB_ID txnid_t;
292 /** @defgroup debug Debug Macros
296 /** Enable debug output. Needs variable argument macros (a C99 feature).
297 * Set this to 1 for copious tracing. Set to 2 to add dumps of all IDLs
298 * read from and written to the database (used for free space management).
304 static int mdb_debug;
305 static txnid_t mdb_debug_start;
307 /** Print a debug message with printf formatting.
308 * Requires double parenthesis around 2 or more args.
310 # define DPRINTF(args) ((void) ((mdb_debug) && DPRINTF0 args))
311 # define DPRINTF0(fmt, ...) \
312 fprintf(stderr, "%s:%d " fmt "\n", __func__, __LINE__, __VA_ARGS__)
314 # define DPRINTF(args) ((void) 0)
316 /** Print a debug string.
317 * The string is printed literally, with no format processing.
319 #define DPUTS(arg) DPRINTF(("%s", arg))
322 /** A default memory page size.
323 * The actual size is platform-dependent, but we use this for
324 * boot-strapping. We probably should not be using this any more.
325 * The #GET_PAGESIZE() macro is used to get the actual size.
327 * Note that we don't currently support Huge pages. On Linux,
328 * regular data files cannot use Huge pages, and in general
329 * Huge pages aren't actually pageable. We rely on the OS
330 * demand-pager to read our data and page it out when memory
331 * pressure from other processes is high. So until OSs have
332 * actual paging support for Huge pages, they're not viable.
334 #define MDB_PAGESIZE 4096
336 /** The minimum number of keys required in a database page.
337 * Setting this to a larger value will place a smaller bound on the
338 * maximum size of a data item. Data items larger than this size will
339 * be pushed into overflow pages instead of being stored directly in
340 * the B-tree node. This value used to default to 4. With a page size
341 * of 4096 bytes that meant that any item larger than 1024 bytes would
342 * go into an overflow page. That also meant that on average 2-3KB of
343 * each overflow page was wasted space. The value cannot be lower than
344 * 2 because then there would no longer be a tree structure. With this
345 * value, items larger than 2KB will go into overflow pages, and on
346 * average only 1KB will be wasted.
348 #define MDB_MINKEYS 2
350 /** A stamp that identifies a file as an MDB file.
351 * There's nothing special about this value other than that it is easily
352 * recognizable, and it will reflect any byte order mismatches.
354 #define MDB_MAGIC 0xBEEFC0DE
356 /** The version number for a database's datafile format. */
357 #define MDB_DATA_VERSION 1
358 /** The version number for a database's lockfile format. */
359 #define MDB_LOCK_VERSION 1
361 /** @brief The maximum size of a key in the database.
363 * The library rejects bigger keys, and cannot deal with records
364 * with bigger keys stored by a library with bigger max keysize.
366 * We require that keys all fit onto a regular page. This limit
367 * could be raised a bit further if needed; to something just
368 * under #MDB_PAGESIZE / #MDB_MINKEYS.
370 * Note that data items in an #MDB_DUPSORT database are actually keys
371 * of a subDB, so they're also limited to this size.
373 #ifndef MDB_MAXKEYSIZE
374 #define MDB_MAXKEYSIZE 511
377 /** @brief The maximum size of a data item.
379 * We only store a 32 bit value for node sizes.
381 #define MAXDATASIZE 0xffffffffUL
386 * This is used for printing a hex dump of a key's contents.
388 #define DKBUF char kbuf[(MDB_MAXKEYSIZE*2+1)]
389 /** Display a key in hex.
391 * Invoke a function to display a key in hex.
393 #define DKEY(x) mdb_dkey(x, kbuf)
399 /** An invalid page number.
400 * Mainly used to denote an empty tree.
402 #define P_INVALID (~(pgno_t)0)
404 /** Test if the flags \b f are set in a flag word \b w. */
405 #define F_ISSET(w, f) (((w) & (f)) == (f))
407 /** Used for offsets within a single page.
408 * Since memory pages are typically 4 or 8KB in size, 12-13 bits,
411 typedef uint16_t indx_t;
413 /** Default size of memory map.
414 * This is certainly too small for any actual applications. Apps should always set
415 * the size explicitly using #mdb_env_set_mapsize().
417 #define DEFAULT_MAPSIZE 1048576
419 /** @defgroup readers Reader Lock Table
420 * Readers don't acquire any locks for their data access. Instead, they
421 * simply record their transaction ID in the reader table. The reader
422 * mutex is needed just to find an empty slot in the reader table. The
423 * slot's address is saved in thread-specific data so that subsequent read
424 * transactions started by the same thread need no further locking to proceed.
426 * If #MDB_NOTLS is set, the slot address is not saved in thread-specific data.
428 * No reader table is used if the database is on a read-only filesystem.
430 * Since the database uses multi-version concurrency control, readers don't
431 * actually need any locking. This table is used to keep track of which
432 * readers are using data from which old transactions, so that we'll know
433 * when a particular old transaction is no longer in use. Old transactions
434 * that have discarded any data pages can then have those pages reclaimed
435 * for use by a later write transaction.
437 * The lock table is constructed such that reader slots are aligned with the
438 * processor's cache line size. Any slot is only ever used by one thread.
439 * This alignment guarantees that there will be no contention or cache
440 * thrashing as threads update their own slot info, and also eliminates
441 * any need for locking when accessing a slot.
443 * A writer thread will scan every slot in the table to determine the oldest
444 * outstanding reader transaction. Any freed pages older than this will be
445 * reclaimed by the writer. The writer doesn't use any locks when scanning
446 * this table. This means that there's no guarantee that the writer will
447 * see the most up-to-date reader info, but that's not required for correct
448 * operation - all we need is to know the upper bound on the oldest reader,
449 * we don't care at all about the newest reader. So the only consequence of
450 * reading stale information here is that old pages might hang around a
451 * while longer before being reclaimed. That's actually good anyway, because
452 * the longer we delay reclaiming old pages, the more likely it is that a
453 * string of contiguous pages can be found after coalescing old pages from
454 * many old transactions together.
457 /** Number of slots in the reader table.
458 * This value was chosen somewhat arbitrarily. 126 readers plus a
459 * couple mutexes fit exactly into 8KB on my development machine.
460 * Applications should set the table size using #mdb_env_set_maxreaders().
462 #define DEFAULT_READERS 126
464 /** The size of a CPU cache line in bytes. We want our lock structures
465 * aligned to this size to avoid false cache line sharing in the
467 * This value works for most CPUs. For Itanium this should be 128.
473 /** The information we store in a single slot of the reader table.
474 * In addition to a transaction ID, we also record the process and
475 * thread ID that owns a slot, so that we can detect stale information,
476 * e.g. threads or processes that went away without cleaning up.
477 * @note We currently don't check for stale records. We simply re-init
478 * the table when we know that we're the only process opening the
481 typedef struct MDB_rxbody {
482 /** Current Transaction ID when this transaction began, or (txnid_t)-1.
483 * Multiple readers that start at the same time will probably have the
484 * same ID here. Again, it's not important to exclude them from
485 * anything; all we need to know is which version of the DB they
486 * started from so we can avoid overwriting any data used in that
487 * particular version.
490 /** The process ID of the process owning this reader txn. */
492 /** The thread ID of the thread owning this txn. */
496 /** The actual reader record, with cacheline padding. */
497 typedef struct MDB_reader {
500 /** shorthand for mrb_txnid */
501 #define mr_txnid mru.mrx.mrb_txnid
502 #define mr_pid mru.mrx.mrb_pid
503 #define mr_tid mru.mrx.mrb_tid
504 /** cache line alignment */
505 char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)];
509 /** The header for the reader table.
510 * The table resides in a memory-mapped file. (This is a different file
511 * than is used for the main database.)
513 * For POSIX the actual mutexes reside in the shared memory of this
514 * mapped file. On Windows, mutexes are named objects allocated by the
515 * kernel; we store the mutex names in this mapped file so that other
516 * processes can grab them. This same approach is also used on
517 * MacOSX/Darwin (using named semaphores) since MacOSX doesn't support
518 * process-shared POSIX mutexes. For these cases where a named object
519 * is used, the object name is derived from a 64 bit FNV hash of the
520 * environment pathname. As such, naming collisions are extremely
521 * unlikely. If a collision occurs, the results are unpredictable.
523 typedef struct MDB_txbody {
524 /** Stamp identifying this as an MDB file. It must be set
527 /** Format of this lock file. Must be set to #MDB_LOCK_FORMAT. */
529 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
530 char mtb_rmname[MNAME_LEN];
532 /** Mutex protecting access to this table.
533 * This is the reader lock that #LOCK_MUTEX_R acquires.
535 pthread_mutex_t mtb_mutex;
537 /** The ID of the last transaction committed to the database.
538 * This is recorded here only for convenience; the value can always
539 * be determined by reading the main database meta pages.
542 /** The number of slots that have been used in the reader table.
543 * This always records the maximum count, it is not decremented
544 * when readers release their slots.
546 unsigned mtb_numreaders;
549 /** The actual reader table definition. */
550 typedef struct MDB_txninfo {
553 #define mti_magic mt1.mtb.mtb_magic
554 #define mti_format mt1.mtb.mtb_format
555 #define mti_mutex mt1.mtb.mtb_mutex
556 #define mti_rmname mt1.mtb.mtb_rmname
557 #define mti_txnid mt1.mtb.mtb_txnid
558 #define mti_numreaders mt1.mtb.mtb_numreaders
559 char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];
562 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
563 char mt2_wmname[MNAME_LEN];
564 #define mti_wmname mt2.mt2_wmname
566 pthread_mutex_t mt2_wmutex;
567 #define mti_wmutex mt2.mt2_wmutex
569 char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)];
571 MDB_reader mti_readers[1];
574 /** Lockfile format signature: version, features and field layout */
575 #define MDB_LOCK_FORMAT \
577 ((MDB_LOCK_VERSION) \
578 /* Flags which describe functionality */ \
579 + (((MDB_PIDLOCK) != 0) << 16)))
582 /** Common header for all page types.
583 * Overflow records occupy a number of contiguous pages with no
584 * headers on any page after the first.
586 typedef struct MDB_page {
587 #define mp_pgno mp_p.p_pgno
588 #define mp_next mp_p.p_next
590 pgno_t p_pgno; /**< page number */
591 void * p_next; /**< for in-memory list of freed structs */
594 /** @defgroup mdb_page Page Flags
596 * Flags for the page headers.
599 #define P_BRANCH 0x01 /**< branch page */
600 #define P_LEAF 0x02 /**< leaf page */
601 #define P_OVERFLOW 0x04 /**< overflow page */
602 #define P_META 0x08 /**< meta page */
603 #define P_DIRTY 0x10 /**< dirty page, also set for #P_SUBP pages */
604 #define P_LEAF2 0x20 /**< for #MDB_DUPFIXED records */
605 #define P_SUBP 0x40 /**< for #MDB_DUPSORT sub-pages */
606 #define P_KEEP 0x8000 /**< leave this page alone during spill */
608 uint16_t mp_flags; /**< @ref mdb_page */
609 #define mp_lower mp_pb.pb.pb_lower
610 #define mp_upper mp_pb.pb.pb_upper
611 #define mp_pages mp_pb.pb_pages
614 indx_t pb_lower; /**< lower bound of free space */
615 indx_t pb_upper; /**< upper bound of free space */
617 uint32_t pb_pages; /**< number of overflow pages */
619 indx_t mp_ptrs[1]; /**< dynamic size */
622 /** Size of the page header, excluding dynamic data at the end */
623 #define PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs))
625 /** Address of first usable data byte in a page, after the header */
626 #define METADATA(p) ((void *)((char *)(p) + PAGEHDRSZ))
628 /** Number of nodes on a page */
629 #define NUMKEYS(p) (((p)->mp_lower - PAGEHDRSZ) >> 1)
631 /** The amount of space remaining in the page */
632 #define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower)
634 /** The percentage of space used in the page, in tenths of a percent. */
635 #define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \
636 ((env)->me_psize - PAGEHDRSZ))
637 /** The minimum page fill factor, in tenths of a percent.
638 * Pages emptier than this are candidates for merging.
640 #define FILL_THRESHOLD 250
642 /** Test if a page is a leaf page */
643 #define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF)
644 /** Test if a page is a LEAF2 page */
645 #define IS_LEAF2(p) F_ISSET((p)->mp_flags, P_LEAF2)
646 /** Test if a page is a branch page */
647 #define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH)
648 /** Test if a page is an overflow page */
649 #define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW)
650 /** Test if a page is a sub page */
651 #define IS_SUBP(p) F_ISSET((p)->mp_flags, P_SUBP)
653 /** The number of overflow pages needed to store the given size. */
654 #define OVPAGES(size, psize) ((PAGEHDRSZ-1 + (size)) / (psize) + 1)
656 /** Header for a single key/data pair within a page.
657 * We guarantee 2-byte alignment for nodes.
659 typedef struct MDB_node {
660 /** lo and hi are used for data size on leaf nodes and for
661 * child pgno on branch nodes. On 64 bit platforms, flags
662 * is also used for pgno. (Branch nodes have no flags).
663 * They are in host byte order in case that lets some
664 * accesses be optimized into a 32-bit word access.
666 #define mn_lo mn_offset[BYTE_ORDER!=LITTLE_ENDIAN]
667 #define mn_hi mn_offset[BYTE_ORDER==LITTLE_ENDIAN] /**< part of dsize or pgno */
668 unsigned short mn_offset[2]; /**< storage for #mn_lo and #mn_hi */
669 /** @defgroup mdb_node Node Flags
671 * Flags for node headers.
674 #define F_BIGDATA 0x01 /**< data put on overflow page */
675 #define F_SUBDATA 0x02 /**< data is a sub-database */
676 #define F_DUPDATA 0x04 /**< data has duplicates */
678 /** valid flags for #mdb_node_add() */
679 #define NODE_ADD_FLAGS (F_DUPDATA|F_SUBDATA|MDB_RESERVE|MDB_APPEND)
682 unsigned short mn_flags; /**< @ref mdb_node */
683 unsigned short mn_ksize; /**< key size */
684 char mn_data[1]; /**< key and data are appended here */
687 /** Size of the node header, excluding dynamic data at the end */
688 #define NODESIZE offsetof(MDB_node, mn_data)
690 /** Bit position of top word in page number, for shifting mn_flags */
691 #define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0)
693 /** Size of a node in a branch page with a given key.
694 * This is just the node header plus the key, there is no data.
696 #define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))
698 /** Size of a node in a leaf page with a given key and data.
699 * This is node header plus key plus data size.
701 #define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size)
703 /** Address of node \b i in page \b p */
704 #define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i]))
706 /** Address of the key for the node */
707 #define NODEKEY(node) (void *)((node)->mn_data)
709 /** Address of the data for a node */
710 #define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize)
712 /** Get the page number pointed to by a branch node */
713 #define NODEPGNO(node) \
714 ((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | \
715 (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0))
716 /** Set the page number in a branch node */
717 #define SETPGNO(node,pgno) do { \
718 (node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \
719 if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0)
721 /** Get the size of the data in a leaf node */
722 #define NODEDSZ(node) ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16))
723 /** Set the size of the data for a leaf node */
724 #define SETDSZ(node,size) do { \
725 (node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)
726 /** The size of a key in a node */
727 #define NODEKSZ(node) ((node)->mn_ksize)
729 /** Copy a page number from src to dst */
731 #define COPY_PGNO(dst,src) dst = src
733 #if SIZE_MAX > 4294967295UL
734 #define COPY_PGNO(dst,src) do { \
735 unsigned short *s, *d; \
736 s = (unsigned short *)&(src); \
737 d = (unsigned short *)&(dst); \
744 #define COPY_PGNO(dst,src) do { \
745 unsigned short *s, *d; \
746 s = (unsigned short *)&(src); \
747 d = (unsigned short *)&(dst); \
753 /** The address of a key in a LEAF2 page.
754 * LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate sub-DBs.
755 * There are no node headers, keys are stored contiguously.
757 #define LEAF2KEY(p, i, ks) ((char *)(p) + PAGEHDRSZ + ((i)*(ks)))
759 /** Set the \b node's key into \b keyptr, if requested. */
760 #define MDB_GET_KEY(node, keyptr) { if ((keyptr) != NULL) { \
761 (keyptr)->mv_size = NODEKSZ(node); (keyptr)->mv_data = NODEKEY(node); } }
763 /** Set the \b node's key into \b key. */
764 #define MDB_GET_KEY2(node, key) { key.mv_size = NODEKSZ(node); key.mv_data = NODEKEY(node); }
766 /** Information about a single database in the environment. */
767 typedef struct MDB_db {
768 uint32_t md_pad; /**< also ksize for LEAF2 pages */
769 uint16_t md_flags; /**< @ref mdb_dbi_open */
770 uint16_t md_depth; /**< depth of this tree */
771 pgno_t md_branch_pages; /**< number of internal pages */
772 pgno_t md_leaf_pages; /**< number of leaf pages */
773 pgno_t md_overflow_pages; /**< number of overflow pages */
774 size_t md_entries; /**< number of data items */
775 pgno_t md_root; /**< the root page of this tree */
778 /** mdb_dbi_open flags */
779 #define MDB_VALID 0x8000 /**< DB handle is valid, for me_dbflags */
780 #define PERSISTENT_FLAGS (0xffff & ~(MDB_VALID))
781 #define VALID_FLAGS (MDB_REVERSEKEY|MDB_DUPSORT|MDB_INTEGERKEY|MDB_DUPFIXED|\
782 MDB_INTEGERDUP|MDB_REVERSEDUP|MDB_CREATE)
784 /** Handle for the DB used to track free pages. */
786 /** Handle for the default DB. */
789 /** Meta page content.
790 * A meta page is the start point for accessing a database snapshot.
791 * Pages 0-1 are meta pages. Transaction N writes meta page #(N % 2).
793 typedef struct MDB_meta {
794 /** Stamp identifying this as an MDB file. It must be set
797 /** Version number of this lock file. Must be set to #MDB_DATA_VERSION. */
799 void *mm_address; /**< address for fixed mapping */
800 size_t mm_mapsize; /**< size of mmap region */
801 MDB_db mm_dbs[2]; /**< first is free space, 2nd is main db */
802 /** The size of pages used in this DB */
803 #define mm_psize mm_dbs[0].md_pad
804 /** Any persistent environment flags. @ref mdb_env */
805 #define mm_flags mm_dbs[0].md_flags
806 pgno_t mm_last_pg; /**< last used page in file */
807 txnid_t mm_txnid; /**< txnid that committed this page */
810 /** Buffer for a stack-allocated dirty page.
811 * The members define size and alignment, and silence type
812 * aliasing warnings. They are not used directly; that could
813 * mean incorrectly using several union members in parallel.
815 typedef union MDB_pagebuf {
816 char mb_raw[MDB_PAGESIZE];
819 char mm_pad[PAGEHDRSZ];
824 /** Auxiliary DB info.
825 * The information here is mostly static/read-only. There is
826 * only a single copy of this record in the environment.
828 typedef struct MDB_dbx {
829 MDB_val md_name; /**< name of the database */
830 MDB_cmp_func *md_cmp; /**< function for comparing keys */
831 MDB_cmp_func *md_dcmp; /**< function for comparing data items */
832 MDB_rel_func *md_rel; /**< user relocate function */
833 void *md_relctx; /**< user-provided context for md_rel */
836 /** A database transaction.
837 * Every operation requires a transaction handle.
840 MDB_txn *mt_parent; /**< parent of a nested txn */
841 MDB_txn *mt_child; /**< nested txn under this txn */
842 pgno_t mt_next_pgno; /**< next unallocated page */
843 /** The ID of this transaction. IDs are integers incrementing from 1.
844 * Only committed write transactions increment the ID. If a transaction
845 * aborts, the ID may be re-used by the next writer.
848 MDB_env *mt_env; /**< the DB environment */
849 /** The list of pages that became unused during this transaction.
852 /** The sorted list of dirty pages we temporarily wrote to disk
853 * because the dirty list was full. page numbers in here are
854 * shifted left by 1, deleted slots have the LSB set.
856 MDB_IDL mt_spill_pgs;
858 /** For write txns: Modified pages. Sorted when not MDB_WRITEMAP. */
860 /** For read txns: This thread/txn's reader table slot, or NULL. */
863 /** Array of records for each DB known in the environment. */
865 /** Array of MDB_db records for each known DB */
867 /** @defgroup mt_dbflag Transaction DB Flags
871 #define DB_DIRTY 0x01 /**< DB was written in this txn */
872 #define DB_STALE 0x02 /**< Named-DB record is older than txnID */
873 #define DB_NEW 0x04 /**< Named-DB handle opened in this txn */
874 #define DB_VALID 0x08 /**< DB handle is valid, see also #MDB_VALID */
876 /** In write txns, array of cursors for each DB */
877 MDB_cursor **mt_cursors;
878 /** Array of flags for each DB */
879 unsigned char *mt_dbflags;
880 /** Number of DB records in use. This number only ever increments;
881 * we don't decrement it when individual DB handles are closed.
885 /** @defgroup mdb_txn Transaction Flags
889 #define MDB_TXN_RDONLY 0x01 /**< read-only transaction */
890 #define MDB_TXN_ERROR 0x02 /**< an error has occurred */
891 #define MDB_TXN_DIRTY 0x04 /**< must write, even if dirty list is empty */
892 #define MDB_TXN_SPILLS 0x08 /**< txn or a parent has spilled pages */
894 unsigned int mt_flags; /**< @ref mdb_txn */
895 /** dirty_list room: Array size - #dirty pages visible to this txn.
896 * Includes ancestor txns' dirty pages not hidden by other txns'
897 * dirty/spilled pages. Thus commit(nested txn) has room to merge
898 * dirty_list into mt_parent after freeing hidden mt_parent pages.
900 unsigned int mt_dirty_room;
901 /** Tracks which of the two meta pages was used at the start
902 * of this transaction.
904 unsigned int mt_toggle;
907 /** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty.
908 * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to
909 * raise this on a 64 bit machine.
911 #define CURSOR_STACK 32
915 /** Cursors are used for all DB operations.
916 * A cursor holds a path of (page pointer, key index) from the DB
917 * root to a position in the DB, plus other state. #MDB_DUPSORT
918 * cursors include an xcursor to the current data item. Write txns
919 * track their cursors and keep them up to date when data moves.
920 * Exception: An xcursor's pointer to a #P_SUBP page can be stale.
921 * (A node with #F_DUPDATA but no #F_SUBDATA contains a subpage).
924 /** Next cursor on this DB in this txn */
926 /** Backup of the original cursor if this cursor is a shadow */
927 MDB_cursor *mc_backup;
928 /** Context used for databases with #MDB_DUPSORT, otherwise NULL */
929 struct MDB_xcursor *mc_xcursor;
930 /** The transaction that owns this cursor */
932 /** The database handle this cursor operates on */
934 /** The database record for this cursor */
936 /** The database auxiliary record for this cursor */
938 /** The @ref mt_dbflag for this database */
939 unsigned char *mc_dbflag;
940 unsigned short mc_snum; /**< number of pushed pages */
941 unsigned short mc_top; /**< index of top page, normally mc_snum-1 */
942 /** @defgroup mdb_cursor Cursor Flags
944 * Cursor state flags.
947 #define C_INITIALIZED 0x01 /**< cursor has been initialized and is valid */
948 #define C_EOF 0x02 /**< No more data */
949 #define C_SUB 0x04 /**< Cursor is a sub-cursor */
950 #define C_DEL 0x08 /**< last op was a cursor_del */
951 #define C_SPLITTING 0x20 /**< Cursor is in page_split */
952 #define C_UNTRACK 0x40 /**< Un-track cursor when closing */
954 unsigned int mc_flags; /**< @ref mdb_cursor */
955 MDB_page *mc_pg[CURSOR_STACK]; /**< stack of pushed pages */
956 indx_t mc_ki[CURSOR_STACK]; /**< stack of page indices */
959 /** Context for sorted-dup records.
960 * We could have gone to a fully recursive design, with arbitrarily
961 * deep nesting of sub-databases. But for now we only handle these
962 * levels - main DB, optional sub-DB, sorted-duplicate DB.
964 typedef struct MDB_xcursor {
965 /** A sub-cursor for traversing the Dup DB */
966 MDB_cursor mx_cursor;
967 /** The database record for this Dup DB */
969 /** The auxiliary DB record for this Dup DB */
971 /** The @ref mt_dbflag for this Dup DB */
972 unsigned char mx_dbflag;
975 /** State of FreeDB old pages, stored in the MDB_env */
976 typedef struct MDB_pgstate {
977 pgno_t *mf_pghead; /**< Reclaimed freeDB pages, or NULL before use */
978 txnid_t mf_pglast; /**< ID of last used record, or 0 if !mf_pghead */
981 /** The database environment. */
983 HANDLE me_fd; /**< The main data file */
984 HANDLE me_lfd; /**< The lock file */
985 HANDLE me_mfd; /**< just for writing the meta pages */
986 /** Failed to update the meta page. Probably an I/O error. */
987 #define MDB_FATAL_ERROR 0x80000000U
988 /** Some fields are initialized. */
989 #define MDB_ENV_ACTIVE 0x20000000U
990 /** me_txkey is set */
991 #define MDB_ENV_TXKEY 0x10000000U
992 /** Have liveness lock in reader table */
993 #define MDB_LIVE_READER 0x08000000U
994 uint32_t me_flags; /**< @ref mdb_env */
995 unsigned int me_psize; /**< size of a page, from #GET_PAGESIZE */
996 unsigned int me_maxreaders; /**< size of the reader table */
997 unsigned int me_numreaders; /**< max numreaders set by this env */
998 MDB_dbi me_numdbs; /**< number of DBs opened */
999 MDB_dbi me_maxdbs; /**< size of the DB table */
1000 pid_t me_pid; /**< process ID of this env */
1001 char *me_path; /**< path to the DB files */
1002 char *me_map; /**< the memory map of the data file */
1003 MDB_txninfo *me_txns; /**< the memory map of the lock file or NULL */
1004 MDB_meta *me_metas[2]; /**< pointers to the two meta pages */
1005 MDB_txn *me_txn; /**< current write transaction */
1006 size_t me_mapsize; /**< size of the data memory map */
1007 off_t me_size; /**< current file size */
1008 pgno_t me_maxpg; /**< me_mapsize / me_psize */
1009 MDB_dbx *me_dbxs; /**< array of static DB info */
1010 uint16_t *me_dbflags; /**< array of flags from MDB_db.md_flags */
1011 pthread_key_t me_txkey; /**< thread-key for readers */
1012 MDB_pgstate me_pgstate; /**< state of old pages from freeDB */
1013 # define me_pglast me_pgstate.mf_pglast
1014 # define me_pghead me_pgstate.mf_pghead
1015 MDB_page *me_dpages; /**< list of malloc'd blocks for re-use */
1016 /** IDL of pages that became unused in a write txn */
1017 MDB_IDL me_free_pgs;
1018 /** ID2L of pages written during a write txn. Length MDB_IDL_UM_SIZE. */
1019 MDB_ID2L me_dirty_list;
1020 /** Max number of freelist items that can fit in a single overflow page */
1022 /** Max size of a node on a page */
1023 unsigned int me_nodemax;
1025 int me_pidquery; /**< Used in OpenProcess */
1026 HANDLE me_rmutex; /* Windows mutexes don't reside in shared mem */
1028 #elif defined(MDB_USE_POSIX_SEM)
1029 sem_t *me_rmutex; /* Shared mutexes are not supported */
1034 /** Nested transaction */
1035 typedef struct MDB_ntxn {
1036 MDB_txn mnt_txn; /**< the transaction */
1037 MDB_pgstate mnt_pgstate; /**< parent transaction's saved freestate */
1040 /** max number of pages to commit in one writev() call */
1041 #define MDB_COMMIT_PAGES 64
1042 #if defined(IOV_MAX) && IOV_MAX < MDB_COMMIT_PAGES
1043 #undef MDB_COMMIT_PAGES
1044 #define MDB_COMMIT_PAGES IOV_MAX
1047 /* max bytes to write in one call */
1048 #define MAX_WRITE (0x80000000U >> (sizeof(ssize_t) == 4))
1050 static int mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp);
1051 static int mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp);
1052 static int mdb_page_touch(MDB_cursor *mc);
1054 static int mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **mp, int *lvl);
1055 static int mdb_page_search_root(MDB_cursor *mc,
1056 MDB_val *key, int modify);
1057 #define MDB_PS_MODIFY 1
1058 #define MDB_PS_ROOTONLY 2
1059 #define MDB_PS_FIRST 4
1060 #define MDB_PS_LAST 8
1061 static int mdb_page_search(MDB_cursor *mc,
1062 MDB_val *key, int flags);
1063 static int mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst);
1065 #define MDB_SPLIT_REPLACE MDB_APPENDDUP /**< newkey is not new */
1066 static int mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,
1067 pgno_t newpgno, unsigned int nflags);
1069 static int mdb_env_read_header(MDB_env *env, MDB_meta *meta);
1070 static int mdb_env_pick_meta(const MDB_env *env);
1071 static int mdb_env_write_meta(MDB_txn *txn);
1072 #if !(defined(_WIN32) || defined(MDB_USE_POSIX_SEM)) /* Drop unused excl arg */
1073 # define mdb_env_close0(env, excl) mdb_env_close1(env)
1075 static void mdb_env_close0(MDB_env *env, int excl);
1077 static MDB_node *mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp);
1078 static int mdb_node_add(MDB_cursor *mc, indx_t indx,
1079 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags);
1080 static void mdb_node_del(MDB_page *mp, indx_t indx, int ksize);
1081 static void mdb_node_shrink(MDB_page *mp, indx_t indx);
1082 static int mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst);
1083 static int mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data);
1084 static size_t mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data);
1085 static size_t mdb_branch_size(MDB_env *env, MDB_val *key);
1087 static int mdb_rebalance(MDB_cursor *mc);
1088 static int mdb_update_key(MDB_cursor *mc, MDB_val *key);
1090 static void mdb_cursor_pop(MDB_cursor *mc);
1091 static int mdb_cursor_push(MDB_cursor *mc, MDB_page *mp);
1093 static int mdb_cursor_del0(MDB_cursor *mc, MDB_node *leaf);
1094 static int mdb_cursor_sibling(MDB_cursor *mc, int move_right);
1095 static int mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1096 static int mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1097 static int mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op,
1099 static int mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1100 static int mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1102 static void mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);
1103 static void mdb_xcursor_init0(MDB_cursor *mc);
1104 static void mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node);
1106 static int mdb_drop0(MDB_cursor *mc, int subs);
1107 static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi);
1110 static MDB_cmp_func mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long;
1114 static SECURITY_DESCRIPTOR mdb_null_sd;
1115 static SECURITY_ATTRIBUTES mdb_all_sa;
1116 static int mdb_sec_inited;
1119 /** Return the library version info. */
1121 mdb_version(int *major, int *minor, int *patch)
1123 if (major) *major = MDB_VERSION_MAJOR;
1124 if (minor) *minor = MDB_VERSION_MINOR;
1125 if (patch) *patch = MDB_VERSION_PATCH;
1126 return MDB_VERSION_STRING;
1129 /** Table of descriptions for MDB @ref errors */
1130 static char *const mdb_errstr[] = {
1131 "MDB_KEYEXIST: Key/data pair already exists",
1132 "MDB_NOTFOUND: No matching key/data pair found",
1133 "MDB_PAGE_NOTFOUND: Requested page not found",
1134 "MDB_CORRUPTED: Located page was wrong type",
1135 "MDB_PANIC: Update of meta page failed",
1136 "MDB_VERSION_MISMATCH: Database environment version mismatch",
1137 "MDB_INVALID: File is not an MDB file",
1138 "MDB_MAP_FULL: Environment mapsize limit reached",
1139 "MDB_DBS_FULL: Environment maxdbs limit reached",
1140 "MDB_READERS_FULL: Environment maxreaders limit reached",
1141 "MDB_TLS_FULL: Thread-local storage keys full - too many environments open",
1142 "MDB_TXN_FULL: Transaction has too many dirty pages - transaction too big",
1143 "MDB_CURSOR_FULL: Internal error - cursor stack limit reached",
1144 "MDB_PAGE_FULL: Internal error - page has no more space",
1145 "MDB_MAP_RESIZED: Database contents grew beyond environment mapsize",
1146 "MDB_INCOMPATIBLE: Operation and DB incompatible, or DB flags changed",
1147 "MDB_BAD_RSLOT: Invalid reuse of reader locktable slot",
1148 "MDB_BAD_TXN: Transaction cannot recover - it must be aborted",
1149 "MDB_BAD_VALSIZE: Too big key/data, key is empty, or wrong DUPFIXED size",
1153 mdb_strerror(int err)
1157 return ("Successful return: 0");
1159 if (err >= MDB_KEYEXIST && err <= MDB_LAST_ERRCODE) {
1160 i = err - MDB_KEYEXIST;
1161 return mdb_errstr[i];
1164 return strerror(err);
1168 /** Display a key in hexadecimal and return the address of the result.
1169 * @param[in] key the key to display
1170 * @param[in] buf the buffer to write into. Should always be #DKBUF.
1171 * @return The key in hexadecimal form.
1174 mdb_dkey(MDB_val *key, char *buf)
1177 unsigned char *c = key->mv_data;
1183 if (key->mv_size > MDB_MAXKEYSIZE)
1184 return "MDB_MAXKEYSIZE";
1185 /* may want to make this a dynamic check: if the key is mostly
1186 * printable characters, print it as-is instead of converting to hex.
1190 for (i=0; i<key->mv_size; i++)
1191 ptr += sprintf(ptr, "%02x", *c++);
1193 sprintf(buf, "%.*s", key->mv_size, key->mv_data);
1198 /** Display all the keys in the page. */
1200 mdb_page_list(MDB_page *mp)
1203 unsigned int i, nkeys, nsize;
1207 nkeys = NUMKEYS(mp);
1208 fprintf(stderr, "Page %"Z"u numkeys %d\n", mp->mp_pgno, nkeys);
1209 for (i=0; i<nkeys; i++) {
1210 node = NODEPTR(mp, i);
1211 key.mv_size = node->mn_ksize;
1212 key.mv_data = node->mn_data;
1213 nsize = NODESIZE + NODEKSZ(node) + sizeof(indx_t);
1214 if (IS_BRANCH(mp)) {
1215 fprintf(stderr, "key %d: page %"Z"u, %s\n", i, NODEPGNO(node),
1218 if (F_ISSET(node->mn_flags, F_BIGDATA))
1219 nsize += sizeof(pgno_t);
1221 nsize += NODEDSZ(node);
1222 fprintf(stderr, "key %d: nsize %d, %s\n", i, nsize, DKEY(&key));
1228 mdb_cursor_chk(MDB_cursor *mc)
1234 if (!mc->mc_snum && !(mc->mc_flags & C_INITIALIZED)) return;
1235 for (i=0; i<mc->mc_top; i++) {
1237 node = NODEPTR(mp, mc->mc_ki[i]);
1238 if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno)
1241 if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i]))
1247 /** Count all the pages in each DB and in the freelist
1248 * and make sure it matches the actual number of pages
1251 static void mdb_audit(MDB_txn *txn)
1255 MDB_ID freecount, count;
1260 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
1261 while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
1262 freecount += *(MDB_ID *)data.mv_data;
1265 for (i = 0; i<txn->mt_numdbs; i++) {
1267 mdb_cursor_init(&mc, txn, i, &mx);
1268 if (txn->mt_dbs[i].md_root == P_INVALID)
1270 count += txn->mt_dbs[i].md_branch_pages +
1271 txn->mt_dbs[i].md_leaf_pages +
1272 txn->mt_dbs[i].md_overflow_pages;
1273 if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) {
1274 mdb_page_search(&mc, NULL, MDB_PS_FIRST);
1278 mp = mc.mc_pg[mc.mc_top];
1279 for (j=0; j<NUMKEYS(mp); j++) {
1280 MDB_node *leaf = NODEPTR(mp, j);
1281 if (leaf->mn_flags & F_SUBDATA) {
1283 memcpy(&db, NODEDATA(leaf), sizeof(db));
1284 count += db.md_branch_pages + db.md_leaf_pages +
1285 db.md_overflow_pages;
1289 while (mdb_cursor_sibling(&mc, 1) == 0);
1292 if (freecount + count + 2 /* metapages */ != txn->mt_next_pgno) {
1293 fprintf(stderr, "audit: %lu freecount: %lu count: %lu total: %lu next_pgno: %lu\n",
1294 txn->mt_txnid, freecount, count+2, freecount+count+2, txn->mt_next_pgno);
1300 mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1302 return txn->mt_dbxs[dbi].md_cmp(a, b);
1306 mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1308 return txn->mt_dbxs[dbi].md_dcmp(a, b);
1311 /** Allocate memory for a page.
1312 * Re-use old malloc'd pages first for singletons, otherwise just malloc.
1315 mdb_page_malloc(MDB_txn *txn, unsigned num)
1317 MDB_env *env = txn->mt_env;
1318 MDB_page *ret = env->me_dpages;
1319 size_t sz = env->me_psize;
1322 VGMEMP_ALLOC(env, ret, sz);
1323 VGMEMP_DEFINED(ret, sizeof(ret->mp_next));
1324 env->me_dpages = ret->mp_next;
1330 if ((ret = malloc(sz)) != NULL) {
1331 VGMEMP_ALLOC(env, ret, sz);
1336 /** Free a single page.
1337 * Saves single pages to a list, for future reuse.
1338 * (This is not used for multi-page overflow pages.)
1341 mdb_page_free(MDB_env *env, MDB_page *mp)
1343 mp->mp_next = env->me_dpages;
1344 VGMEMP_FREE(env, mp);
1345 env->me_dpages = mp;
1348 /** Free a dirty page */
1350 mdb_dpage_free(MDB_env *env, MDB_page *dp)
1352 if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
1353 mdb_page_free(env, dp);
1355 /* large pages just get freed directly */
1356 VGMEMP_FREE(env, dp);
1361 /** Return all dirty pages to dpage list */
1363 mdb_dlist_free(MDB_txn *txn)
1365 MDB_env *env = txn->mt_env;
1366 MDB_ID2L dl = txn->mt_u.dirty_list;
1367 unsigned i, n = dl[0].mid;
1369 for (i = 1; i <= n; i++) {
1370 mdb_dpage_free(env, dl[i].mptr);
1375 /** Set or clear P_KEEP in dirty, non-overflow, non-sub pages watched by txn.
1376 * @param[in] mc A cursor handle for the current operation.
1377 * @param[in] pflags Flags of the pages to update:
1378 * P_DIRTY to set P_KEEP, P_DIRTY|P_KEEP to clear it.
1379 * @param[in] all No shortcuts. Needed except after a full #mdb_page_flush().
1380 * @return 0 on success, non-zero on failure.
1383 mdb_pages_xkeep(MDB_cursor *mc, unsigned pflags, int all)
1385 enum { Mask = P_SUBP|P_DIRTY|P_KEEP };
1386 MDB_txn *txn = mc->mc_txn;
1392 int rc = MDB_SUCCESS, level;
1394 /* Mark pages seen by cursors */
1395 if (mc->mc_flags & C_UNTRACK)
1396 mc = NULL; /* will find mc in mt_cursors */
1397 for (i = txn->mt_numdbs;; mc = txn->mt_cursors[--i]) {
1398 for (; mc; mc=mc->mc_next) {
1399 if (!(mc->mc_flags & C_INITIALIZED))
1401 for (m3 = mc;; m3 = &mx->mx_cursor) {
1403 for (j=0; j<m3->mc_snum; j++) {
1405 if ((mp->mp_flags & Mask) == pflags)
1406 mp->mp_flags ^= P_KEEP;
1408 mx = m3->mc_xcursor;
1409 /* Proceed to mx if it is at a sub-database */
1410 if (! (mx && (mx->mx_cursor.mc_flags & C_INITIALIZED)))
1412 if (! (mp && (mp->mp_flags & P_LEAF)))
1414 leaf = NODEPTR(mp, m3->mc_ki[j-1]);
1415 if (!(leaf->mn_flags & F_SUBDATA))
1424 /* Mark dirty root pages */
1425 for (i=0; i<txn->mt_numdbs; i++) {
1426 if (txn->mt_dbflags[i] & DB_DIRTY) {
1427 pgno_t pgno = txn->mt_dbs[i].md_root;
1428 if (pgno == P_INVALID)
1430 if ((rc = mdb_page_get(txn, pgno, &dp, &level)) != MDB_SUCCESS)
1432 if ((dp->mp_flags & Mask) == pflags && level <= 1)
1433 dp->mp_flags ^= P_KEEP;
1441 static int mdb_page_flush(MDB_txn *txn, int keep);
1443 /** Spill pages from the dirty list back to disk.
1444 * This is intended to prevent running into #MDB_TXN_FULL situations,
1445 * but note that they may still occur in a few cases:
1446 * 1) our estimate of the txn size could be too small. Currently this
1447 * seems unlikely, except with a large number of #MDB_MULTIPLE items.
1448 * 2) child txns may run out of space if their parents dirtied a
1449 * lot of pages and never spilled them. TODO: we probably should do
1450 * a preemptive spill during #mdb_txn_begin() of a child txn, if
1451 * the parent's dirty_room is below a given threshold.
1453 * Otherwise, if not using nested txns, it is expected that apps will
1454 * not run into #MDB_TXN_FULL any more. The pages are flushed to disk
1455 * the same way as for a txn commit, e.g. their P_DIRTY flag is cleared.
1456 * If the txn never references them again, they can be left alone.
1457 * If the txn only reads them, they can be used without any fuss.
1458 * If the txn writes them again, they can be dirtied immediately without
1459 * going thru all of the work of #mdb_page_touch(). Such references are
1460 * handled by #mdb_page_unspill().
1462 * Also note, we never spill DB root pages, nor pages of active cursors,
1463 * because we'll need these back again soon anyway. And in nested txns,
1464 * we can't spill a page in a child txn if it was already spilled in a
1465 * parent txn. That would alter the parent txns' data even though
1466 * the child hasn't committed yet, and we'd have no way to undo it if
1467 * the child aborted.
1469 * @param[in] m0 cursor A cursor handle identifying the transaction and
1470 * database for which we are checking space.
1471 * @param[in] key For a put operation, the key being stored.
1472 * @param[in] data For a put operation, the data being stored.
1473 * @return 0 on success, non-zero on failure.
1476 mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
1478 MDB_txn *txn = m0->mc_txn;
1480 MDB_ID2L dl = txn->mt_u.dirty_list;
1481 unsigned int i, j, need;
1484 if (m0->mc_flags & C_SUB)
1487 /* Estimate how much space this op will take */
1488 i = m0->mc_db->md_depth;
1489 /* Named DBs also dirty the main DB */
1490 if (m0->mc_dbi > MAIN_DBI)
1491 i += txn->mt_dbs[MAIN_DBI].md_depth;
1492 /* For puts, roughly factor in the key+data size */
1494 i += (LEAFSIZE(key, data) + txn->mt_env->me_psize) / txn->mt_env->me_psize;
1495 i += i; /* double it for good measure */
1498 if (txn->mt_dirty_room > i)
1501 if (!txn->mt_spill_pgs) {
1502 txn->mt_spill_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX);
1503 if (!txn->mt_spill_pgs)
1506 /* purge deleted slots */
1507 MDB_IDL sl = txn->mt_spill_pgs;
1508 unsigned int num = sl[0];
1510 for (i=1; i<=num; i++) {
1517 /* Preserve pages which may soon be dirtied again */
1518 if ((rc = mdb_pages_xkeep(m0, P_DIRTY, 1)) != MDB_SUCCESS)
1521 /* Less aggressive spill - we originally spilled the entire dirty list,
1522 * with a few exceptions for cursor pages and DB root pages. But this
1523 * turns out to be a lot of wasted effort because in a large txn many
1524 * of those pages will need to be used again. So now we spill only 1/8th
1525 * of the dirty pages. Testing revealed this to be a good tradeoff,
1526 * better than 1/2, 1/4, or 1/10.
1528 if (need < MDB_IDL_UM_MAX / 8)
1529 need = MDB_IDL_UM_MAX / 8;
1531 /* Save the page IDs of all the pages we're flushing */
1532 /* flush from the tail forward, this saves a lot of shifting later on. */
1533 for (i=dl[0].mid; i && need; i--) {
1534 MDB_ID pn = dl[i].mid << 1;
1536 if (dp->mp_flags & P_KEEP)
1538 /* Can't spill twice, make sure it's not already in a parent's
1541 if (txn->mt_parent) {
1543 for (tx2 = txn->mt_parent; tx2; tx2 = tx2->mt_parent) {
1544 if (tx2->mt_spill_pgs) {
1545 j = mdb_midl_search(tx2->mt_spill_pgs, pn);
1546 if (j <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[j] == pn) {
1547 dp->mp_flags |= P_KEEP;
1555 if ((rc = mdb_midl_append(&txn->mt_spill_pgs, pn)))
1559 mdb_midl_sort(txn->mt_spill_pgs);
1561 /* Flush the spilled part of dirty list */
1562 if ((rc = mdb_page_flush(txn, i)) != MDB_SUCCESS)
1565 /* Reset any dirty pages we kept that page_flush didn't see */
1566 rc = mdb_pages_xkeep(m0, P_DIRTY|P_KEEP, i);
1569 txn->mt_flags |= rc ? MDB_TXN_ERROR : MDB_TXN_SPILLS;
1573 /** Find oldest txnid still referenced. Expects txn->mt_txnid > 0. */
1575 mdb_find_oldest(MDB_txn *txn)
1578 txnid_t mr, oldest = txn->mt_txnid - 1;
1579 MDB_reader *r = txn->mt_env->me_txns->mti_readers;
1580 for (i = txn->mt_env->me_txns->mti_numreaders; --i >= 0; ) {
1590 /** Add a page to the txn's dirty list */
1592 mdb_page_dirty(MDB_txn *txn, MDB_page *mp)
1595 int (*insert)(MDB_ID2L, MDB_ID2 *);
1597 if (txn->mt_env->me_flags & MDB_WRITEMAP) {
1598 insert = mdb_mid2l_append;
1600 insert = mdb_mid2l_insert;
1602 mid.mid = mp->mp_pgno;
1604 insert(txn->mt_u.dirty_list, &mid);
1605 txn->mt_dirty_room--;
1608 /** Allocate page numbers and memory for writing. Maintain me_pglast,
1609 * me_pghead and mt_next_pgno.
1611 * If there are free pages available from older transactions, they
1612 * are re-used first. Otherwise allocate a new page at mt_next_pgno.
1613 * Do not modify the freedB, just merge freeDB records into me_pghead[]
1614 * and move me_pglast to say which records were consumed. Only this
1615 * function can create me_pghead and move me_pglast/mt_next_pgno.
1616 * @param[in] mc cursor A cursor handle identifying the transaction and
1617 * database for which we are allocating.
1618 * @param[in] num the number of pages to allocate.
1619 * @param[out] mp Address of the allocated page(s). Requests for multiple pages
1620 * will always be satisfied by a single contiguous chunk of memory.
1621 * @return 0 on success, non-zero on failure.
1624 mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
1626 #ifdef MDB_PARANOID /* Seems like we can ignore this now */
1627 /* Get at most <Max_retries> more freeDB records once me_pghead
1628 * has enough pages. If not enough, use new pages from the map.
1629 * If <Paranoid> and mc is updating the freeDB, only get new
1630 * records if me_pghead is empty. Then the freelist cannot play
1631 * catch-up with itself by growing while trying to save it.
1633 enum { Paranoid = 1, Max_retries = 500 };
1635 enum { Paranoid = 0, Max_retries = INT_MAX /*infinite*/ };
1637 int rc, n2 = num-1, retry = Max_retries;
1638 MDB_txn *txn = mc->mc_txn;
1639 MDB_env *env = txn->mt_env;
1640 pgno_t pgno, *mop = env->me_pghead;
1641 unsigned i, j, k, mop_len = mop ? mop[0] : 0;
1643 txnid_t oldest = 0, last;
1649 /* If our dirty list is already full, we can't do anything */
1650 if (txn->mt_dirty_room == 0)
1651 return MDB_TXN_FULL;
1653 for (op = MDB_FIRST;; op = MDB_NEXT) {
1656 pgno_t *idl, old_id, new_id;
1658 /* Seek a big enough contiguous page range. Prefer
1659 * pages at the tail, just truncating the list.
1661 if (mop_len >= (unsigned)num) {
1665 if (mop[i-n2] == pgno+n2)
1667 } while (--i >= (unsigned)num);
1668 if (Max_retries < INT_MAX && --retry < 0)
1672 if (op == MDB_FIRST) { /* 1st iteration */
1673 /* Prepare to fetch more and coalesce */
1674 oldest = mdb_find_oldest(txn);
1675 last = env->me_pglast;
1676 mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
1679 key.mv_data = &last; /* will look up last+1 */
1680 key.mv_size = sizeof(last);
1682 if (Paranoid && mc->mc_dbi == FREE_DBI)
1685 if (Paranoid && retry < 0 && mop_len)
1689 /* Do not fetch more if the record will be too recent */
1692 rc = mdb_cursor_get(&m2, &key, NULL, op);
1694 if (rc == MDB_NOTFOUND)
1698 last = *(txnid_t*)key.mv_data;
1701 np = m2.mc_pg[m2.mc_top];
1702 leaf = NODEPTR(np, m2.mc_ki[m2.mc_top]);
1703 if ((rc = mdb_node_read(txn, leaf, &data)) != MDB_SUCCESS)
1706 idl = (MDB_ID *) data.mv_data;
1709 if (!(env->me_pghead = mop = mdb_midl_alloc(i)))
1712 if ((rc = mdb_midl_need(&env->me_pghead, i)) != 0)
1714 mop = env->me_pghead;
1716 env->me_pglast = last;
1718 DPRINTF(("IDL read txn %"Z"u root %"Z"u num %u",
1719 last, txn->mt_dbs[FREE_DBI].md_root, i));
1721 DPRINTF(("IDL %"Z"u", idl[k]));
1723 /* Merge in descending sorted order */
1726 mop[0] = (pgno_t)-1;
1730 for (; old_id < new_id; old_id = mop[--j])
1737 /* Use new pages from the map when nothing suitable in the freeDB */
1739 pgno = txn->mt_next_pgno;
1740 if (pgno + num >= env->me_maxpg) {
1741 DPUTS("DB size maxed out");
1742 return MDB_MAP_FULL;
1746 if (env->me_flags & MDB_WRITEMAP) {
1747 np = (MDB_page *)(env->me_map + env->me_psize * pgno);
1749 if (!(np = mdb_page_malloc(txn, num)))
1753 mop[0] = mop_len -= num;
1754 /* Move any stragglers down */
1755 for (j = i-num; j < mop_len; )
1756 mop[++j] = mop[++i];
1758 txn->mt_next_pgno = pgno + num;
1761 mdb_page_dirty(txn, np);
1767 /** Copy the used portions of a non-overflow page.
1768 * @param[in] dst page to copy into
1769 * @param[in] src page to copy from
1770 * @param[in] psize size of a page
1773 mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize)
1775 enum { Align = sizeof(pgno_t) };
1776 indx_t upper = src->mp_upper, lower = src->mp_lower, unused = upper-lower;
1778 /* If page isn't full, just copy the used portion. Adjust
1779 * alignment so memcpy may copy words instead of bytes.
1781 if ((unused &= -Align) && !IS_LEAF2(src)) {
1783 memcpy(dst, src, (lower + (Align-1)) & -Align);
1784 memcpy((pgno_t *)((char *)dst+upper), (pgno_t *)((char *)src+upper),
1787 memcpy(dst, src, psize - unused);
1791 /** Pull a page off the txn's spill list, if present.
1792 * If a page being referenced was spilled to disk in this txn, bring
1793 * it back and make it dirty/writable again.
1794 * @param[in] txn the transaction handle.
1795 * @param[in] mp the page being referenced.
1796 * @param[out] ret the writable page, if any. ret is unchanged if
1797 * mp wasn't spilled.
1800 mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret)
1802 MDB_env *env = txn->mt_env;
1805 pgno_t pgno = mp->mp_pgno, pn = pgno << 1;
1807 for (tx2 = txn; tx2; tx2=tx2->mt_parent) {
1808 if (!tx2->mt_spill_pgs)
1810 x = mdb_midl_search(tx2->mt_spill_pgs, pn);
1811 if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
1814 if (txn->mt_dirty_room == 0)
1815 return MDB_TXN_FULL;
1816 if (IS_OVERFLOW(mp))
1820 if (env->me_flags & MDB_WRITEMAP) {
1823 np = mdb_page_malloc(txn, num);
1827 memcpy(np, mp, num * env->me_psize);
1829 mdb_page_copy(np, mp, env->me_psize);
1832 /* If in current txn, this page is no longer spilled.
1833 * If it happens to be the last page, truncate the spill list.
1834 * Otherwise mark it as deleted by setting the LSB.
1836 if (x == txn->mt_spill_pgs[0])
1837 txn->mt_spill_pgs[0]--;
1839 txn->mt_spill_pgs[x] |= 1;
1840 } /* otherwise, if belonging to a parent txn, the
1841 * page remains spilled until child commits
1844 mdb_page_dirty(txn, np);
1845 np->mp_flags |= P_DIRTY;
1853 /** Touch a page: make it dirty and re-insert into tree with updated pgno.
1854 * @param[in] mc cursor pointing to the page to be touched
1855 * @return 0 on success, non-zero on failure.
1858 mdb_page_touch(MDB_cursor *mc)
1860 MDB_page *mp = mc->mc_pg[mc->mc_top], *np;
1861 MDB_txn *txn = mc->mc_txn;
1862 MDB_cursor *m2, *m3;
1867 if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
1868 if (txn->mt_flags & MDB_TXN_SPILLS) {
1870 rc = mdb_page_unspill(txn, mp, &np);
1876 if ((rc = mdb_midl_need(&txn->mt_free_pgs, 1)) ||
1877 (rc = mdb_page_alloc(mc, 1, &np)))
1880 DPRINTF(("touched db %u page %"Z"u -> %"Z"u", mc->mc_dbi,mp->mp_pgno,pgno));
1881 assert(mp->mp_pgno != pgno);
1882 mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
1883 /* Update the parent page, if any, to point to the new page */
1885 MDB_page *parent = mc->mc_pg[mc->mc_top-1];
1886 MDB_node *node = NODEPTR(parent, mc->mc_ki[mc->mc_top-1]);
1887 SETPGNO(node, pgno);
1889 mc->mc_db->md_root = pgno;
1891 } else if (txn->mt_parent && !IS_SUBP(mp)) {
1892 MDB_ID2 mid, *dl = txn->mt_u.dirty_list;
1894 /* If txn has a parent, make sure the page is in our
1898 unsigned x = mdb_mid2l_search(dl, pgno);
1899 if (x <= dl[0].mid && dl[x].mid == pgno) {
1900 if (mp != dl[x].mptr) { /* bad cursor? */
1901 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
1902 return MDB_CORRUPTED;
1907 assert(dl[0].mid < MDB_IDL_UM_MAX);
1909 np = mdb_page_malloc(txn, 1);
1914 mdb_mid2l_insert(dl, &mid);
1919 mdb_page_copy(np, mp, txn->mt_env->me_psize);
1921 np->mp_flags |= P_DIRTY;
1924 /* Adjust cursors pointing to mp */
1925 mc->mc_pg[mc->mc_top] = np;
1927 if (mc->mc_flags & C_SUB) {
1929 for (m2 = txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
1930 m3 = &m2->mc_xcursor->mx_cursor;
1931 if (m3->mc_snum < mc->mc_snum) continue;
1932 if (m3->mc_pg[mc->mc_top] == mp)
1933 m3->mc_pg[mc->mc_top] = np;
1936 for (m2 = txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
1937 if (m2->mc_snum < mc->mc_snum) continue;
1938 if (m2->mc_pg[mc->mc_top] == mp) {
1939 m2->mc_pg[mc->mc_top] = np;
1940 if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
1941 m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top])
1943 MDB_node *leaf = NODEPTR(np, mc->mc_ki[mc->mc_top]);
1944 if (!(leaf->mn_flags & F_SUBDATA))
1945 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
1954 mdb_env_sync(MDB_env *env, int force)
1957 if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) {
1958 if (env->me_flags & MDB_WRITEMAP) {
1959 int flags = ((env->me_flags & MDB_MAPASYNC) && !force)
1960 ? MS_ASYNC : MS_SYNC;
1961 if (MDB_MSYNC(env->me_map, env->me_mapsize, flags))
1964 else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd))
1968 if (MDB_FDATASYNC(env->me_fd))
1975 /** Back up parent txn's cursors, then grab the originals for tracking */
1977 mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst)
1979 MDB_cursor *mc, *bk;
1984 for (i = src->mt_numdbs; --i >= 0; ) {
1985 if ((mc = src->mt_cursors[i]) != NULL) {
1986 size = sizeof(MDB_cursor);
1988 size += sizeof(MDB_xcursor);
1989 for (; mc; mc = bk->mc_next) {
1995 mc->mc_db = &dst->mt_dbs[i];
1996 /* Kill pointers into src - and dst to reduce abuse: The
1997 * user may not use mc until dst ends. Otherwise we'd...
1999 mc->mc_txn = NULL; /* ...set this to dst */
2000 mc->mc_dbflag = NULL; /* ...and &dst->mt_dbflags[i] */
2001 if ((mx = mc->mc_xcursor) != NULL) {
2002 *(MDB_xcursor *)(bk+1) = *mx;
2003 mx->mx_cursor.mc_txn = NULL; /* ...and dst. */
2005 mc->mc_next = dst->mt_cursors[i];
2006 dst->mt_cursors[i] = mc;
2013 /** Close this write txn's cursors, give parent txn's cursors back to parent.
2014 * @param[in] txn the transaction handle.
2015 * @param[in] merge true to keep changes to parent cursors, false to revert.
2016 * @return 0 on success, non-zero on failure.
2019 mdb_cursors_close(MDB_txn *txn, unsigned merge)
2021 MDB_cursor **cursors = txn->mt_cursors, *mc, *next, *bk;
2025 for (i = txn->mt_numdbs; --i >= 0; ) {
2026 for (mc = cursors[i]; mc; mc = next) {
2028 if ((bk = mc->mc_backup) != NULL) {
2030 /* Commit changes to parent txn */
2031 mc->mc_next = bk->mc_next;
2032 mc->mc_backup = bk->mc_backup;
2033 mc->mc_txn = bk->mc_txn;
2034 mc->mc_db = bk->mc_db;
2035 mc->mc_dbflag = bk->mc_dbflag;
2036 if ((mx = mc->mc_xcursor) != NULL)
2037 mx->mx_cursor.mc_txn = bk->mc_txn;
2039 /* Abort nested txn */
2041 if ((mx = mc->mc_xcursor) != NULL)
2042 *mx = *(MDB_xcursor *)(bk+1);
2046 /* Only malloced cursors are permanently tracked. */
2054 #define mdb_txn_reset0(txn, act) mdb_txn_reset0(txn)
2057 mdb_txn_reset0(MDB_txn *txn, const char *act);
2059 #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
2065 Pidset = F_SETLK, Pidcheck = F_GETLK
2069 /** Set or check a pid lock. Set returns 0 on success.
2070 * Check returns 0 if the process is certainly dead, nonzero if it may
2071 * be alive (the lock exists or an error happened so we do not know).
2073 * On Windows Pidset is a no-op, we merely check for the existence
2074 * of the process with the given pid. On POSIX we use a single byte
2075 * lock on the lockfile, set at an offset equal to the pid.
2078 mdb_reader_pid(MDB_env *env, enum Pidlock_op op, pid_t pid)
2080 #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
2083 if (op == Pidcheck) {
2084 h = OpenProcess(env->me_pidquery, FALSE, pid);
2085 /* No documented "no such process" code, but other program use this: */
2087 return ErrCode() != ERROR_INVALID_PARAMETER;
2088 /* A process exists until all handles to it close. Has it exited? */
2089 ret = WaitForSingleObject(h, 0) != 0;
2096 struct flock lock_info;
2097 memset(&lock_info, 0, sizeof(lock_info));
2098 lock_info.l_type = F_WRLCK;
2099 lock_info.l_whence = SEEK_SET;
2100 lock_info.l_start = pid;
2101 lock_info.l_len = 1;
2102 if ((rc = fcntl(env->me_lfd, op, &lock_info)) == 0) {
2103 if (op == F_GETLK && lock_info.l_type != F_UNLCK)
2105 } else if ((rc = ErrCode()) == EINTR) {
2113 /** Common code for #mdb_txn_begin() and #mdb_txn_renew().
2114 * @param[in] txn the transaction handle to initialize
2115 * @return 0 on success, non-zero on failure.
2118 mdb_txn_renew0(MDB_txn *txn)
2120 MDB_env *env = txn->mt_env;
2123 int rc, new_notls = 0;
2126 txn->mt_numdbs = env->me_numdbs;
2127 txn->mt_dbxs = env->me_dbxs; /* mostly static anyway */
2129 if (txn->mt_flags & MDB_TXN_RDONLY) {
2130 if (!env->me_txns) {
2131 i = mdb_env_pick_meta(env);
2132 txn->mt_txnid = env->me_metas[i]->mm_txnid;
2133 txn->mt_u.reader = NULL;
2135 MDB_reader *r = (env->me_flags & MDB_NOTLS) ? txn->mt_u.reader :
2136 pthread_getspecific(env->me_txkey);
2138 if (r->mr_pid != env->me_pid || r->mr_txnid != (txnid_t)-1)
2139 return MDB_BAD_RSLOT;
2141 pid_t pid = env->me_pid;
2142 pthread_t tid = pthread_self();
2144 if (!(env->me_flags & MDB_LIVE_READER)) {
2145 rc = mdb_reader_pid(env, Pidset, pid);
2147 UNLOCK_MUTEX_R(env);
2150 env->me_flags |= MDB_LIVE_READER;
2154 for (i=0; i<env->me_txns->mti_numreaders; i++)
2155 if (env->me_txns->mti_readers[i].mr_pid == 0)
2157 if (i == env->me_maxreaders) {
2158 UNLOCK_MUTEX_R(env);
2159 return MDB_READERS_FULL;
2161 env->me_txns->mti_readers[i].mr_pid = pid;
2162 env->me_txns->mti_readers[i].mr_tid = tid;
2163 if (i >= env->me_txns->mti_numreaders)
2164 env->me_txns->mti_numreaders = i+1;
2165 /* Save numreaders for un-mutexed mdb_env_close() */
2166 env->me_numreaders = env->me_txns->mti_numreaders;
2167 UNLOCK_MUTEX_R(env);
2168 r = &env->me_txns->mti_readers[i];
2169 new_notls = (env->me_flags & MDB_NOTLS);
2170 if (!new_notls && (rc=pthread_setspecific(env->me_txkey, r))) {
2175 txn->mt_txnid = r->mr_txnid = env->me_txns->mti_txnid;
2176 txn->mt_u.reader = r;
2178 txn->mt_toggle = txn->mt_txnid & 1;
2182 txn->mt_txnid = env->me_txns->mti_txnid;
2183 txn->mt_toggle = txn->mt_txnid & 1;
2186 if (txn->mt_txnid == mdb_debug_start)
2189 txn->mt_dirty_room = MDB_IDL_UM_MAX;
2190 txn->mt_u.dirty_list = env->me_dirty_list;
2191 txn->mt_u.dirty_list[0].mid = 0;
2192 txn->mt_free_pgs = env->me_free_pgs;
2193 txn->mt_free_pgs[0] = 0;
2194 txn->mt_spill_pgs = NULL;
2198 /* Copy the DB info and flags */
2199 memcpy(txn->mt_dbs, env->me_metas[txn->mt_toggle]->mm_dbs, 2 * sizeof(MDB_db));
2201 /* Moved to here to avoid a data race in read TXNs */
2202 txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1;
2204 for (i=2; i<txn->mt_numdbs; i++) {
2205 x = env->me_dbflags[i];
2206 txn->mt_dbs[i].md_flags = x & PERSISTENT_FLAGS;
2207 txn->mt_dbflags[i] = (x & MDB_VALID) ? DB_VALID|DB_STALE : 0;
2209 txn->mt_dbflags[0] = txn->mt_dbflags[1] = DB_VALID;
2211 if (env->me_maxpg < txn->mt_next_pgno) {
2212 mdb_txn_reset0(txn, "renew0-mapfail");
2214 txn->mt_u.reader->mr_pid = 0;
2215 txn->mt_u.reader = NULL;
2217 return MDB_MAP_RESIZED;
2224 mdb_txn_renew(MDB_txn *txn)
2228 if (!txn || txn->mt_dbxs) /* A reset txn has mt_dbxs==NULL */
2231 if (txn->mt_env->me_flags & MDB_FATAL_ERROR) {
2232 DPUTS("environment had fatal error, must shutdown!");
2236 rc = mdb_txn_renew0(txn);
2237 if (rc == MDB_SUCCESS) {
2238 DPRINTF(("renew txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2239 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2240 (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root));
2246 mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
2250 int rc, size, tsize = sizeof(MDB_txn);
2252 if (env->me_flags & MDB_FATAL_ERROR) {
2253 DPUTS("environment had fatal error, must shutdown!");
2256 if ((env->me_flags & MDB_RDONLY) && !(flags & MDB_RDONLY))
2259 /* Nested transactions: Max 1 child, write txns only, no writemap */
2260 if (parent->mt_child ||
2261 (flags & MDB_RDONLY) ||
2262 (parent->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR)) ||
2263 (env->me_flags & MDB_WRITEMAP))
2265 return (parent->mt_flags & MDB_TXN_RDONLY) ? EINVAL : MDB_BAD_TXN;
2267 tsize = sizeof(MDB_ntxn);
2269 size = tsize + env->me_maxdbs * (sizeof(MDB_db)+1);
2270 if (!(flags & MDB_RDONLY))
2271 size += env->me_maxdbs * sizeof(MDB_cursor *);
2273 if ((txn = calloc(1, size)) == NULL) {
2274 DPRINTF(("calloc: %s", strerror(ErrCode())));
2277 txn->mt_dbs = (MDB_db *) ((char *)txn + tsize);
2278 if (flags & MDB_RDONLY) {
2279 txn->mt_flags |= MDB_TXN_RDONLY;
2280 txn->mt_dbflags = (unsigned char *)(txn->mt_dbs + env->me_maxdbs);
2282 txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
2283 txn->mt_dbflags = (unsigned char *)(txn->mt_cursors + env->me_maxdbs);
2289 txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE);
2290 if (!txn->mt_u.dirty_list ||
2291 !(txn->mt_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)))
2293 free(txn->mt_u.dirty_list);
2297 txn->mt_txnid = parent->mt_txnid;
2298 txn->mt_toggle = parent->mt_toggle;
2299 txn->mt_dirty_room = parent->mt_dirty_room;
2300 txn->mt_u.dirty_list[0].mid = 0;
2301 txn->mt_spill_pgs = NULL;
2302 txn->mt_next_pgno = parent->mt_next_pgno;
2303 parent->mt_child = txn;
2304 txn->mt_parent = parent;
2305 txn->mt_numdbs = parent->mt_numdbs;
2306 txn->mt_flags = parent->mt_flags;
2307 txn->mt_dbxs = parent->mt_dbxs;
2308 memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
2309 /* Copy parent's mt_dbflags, but clear DB_NEW */
2310 for (i=0; i<txn->mt_numdbs; i++)
2311 txn->mt_dbflags[i] = parent->mt_dbflags[i] & ~DB_NEW;
2313 ntxn = (MDB_ntxn *)txn;
2314 ntxn->mnt_pgstate = env->me_pgstate; /* save parent me_pghead & co */
2315 if (env->me_pghead) {
2316 size = MDB_IDL_SIZEOF(env->me_pghead);
2317 env->me_pghead = mdb_midl_alloc(env->me_pghead[0]);
2319 memcpy(env->me_pghead, ntxn->mnt_pgstate.mf_pghead, size);
2324 rc = mdb_cursor_shadow(parent, txn);
2326 mdb_txn_reset0(txn, "beginchild-fail");
2328 rc = mdb_txn_renew0(txn);
2334 DPRINTF(("begin txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2335 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2336 (void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root));
2343 mdb_txn_env(MDB_txn *txn)
2345 if(!txn) return NULL;
2349 /** Export or close DBI handles opened in this txn. */
2351 mdb_dbis_update(MDB_txn *txn, int keep)
2354 MDB_dbi n = txn->mt_numdbs;
2355 MDB_env *env = txn->mt_env;
2356 unsigned char *tdbflags = txn->mt_dbflags;
2358 for (i = n; --i >= 2;) {
2359 if (tdbflags[i] & DB_NEW) {
2361 env->me_dbflags[i] = txn->mt_dbs[i].md_flags | MDB_VALID;
2363 char *ptr = env->me_dbxs[i].md_name.mv_data;
2364 env->me_dbxs[i].md_name.mv_data = NULL;
2365 env->me_dbxs[i].md_name.mv_size = 0;
2366 env->me_dbflags[i] = 0;
2371 if (keep && env->me_numdbs < n)
2375 /** Common code for #mdb_txn_reset() and #mdb_txn_abort().
2376 * May be called twice for readonly txns: First reset it, then abort.
2377 * @param[in] txn the transaction handle to reset
2378 * @param[in] act why the transaction is being reset
2381 mdb_txn_reset0(MDB_txn *txn, const char *act)
2383 MDB_env *env = txn->mt_env;
2385 /* Close any DBI handles opened in this txn */
2386 mdb_dbis_update(txn, 0);
2388 DPRINTF(("%s txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2389 act, txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2390 (void *) txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root));
2392 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
2393 if (txn->mt_u.reader) {
2394 txn->mt_u.reader->mr_txnid = (txnid_t)-1;
2395 if (!(env->me_flags & MDB_NOTLS))
2396 txn->mt_u.reader = NULL; /* txn does not own reader */
2398 txn->mt_numdbs = 0; /* close nothing if called again */
2399 txn->mt_dbxs = NULL; /* mark txn as reset */
2401 mdb_cursors_close(txn, 0);
2403 if (!(env->me_flags & MDB_WRITEMAP)) {
2404 mdb_dlist_free(txn);
2406 mdb_midl_free(env->me_pghead);
2408 if (txn->mt_parent) {
2409 txn->mt_parent->mt_child = NULL;
2410 env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate;
2411 mdb_midl_free(txn->mt_free_pgs);
2412 mdb_midl_free(txn->mt_spill_pgs);
2413 free(txn->mt_u.dirty_list);
2417 if (mdb_midl_shrink(&txn->mt_free_pgs))
2418 env->me_free_pgs = txn->mt_free_pgs;
2419 env->me_pghead = NULL;
2423 /* The writer mutex was locked in mdb_txn_begin. */
2424 UNLOCK_MUTEX_W(env);
2429 mdb_txn_reset(MDB_txn *txn)
2434 /* This call is only valid for read-only txns */
2435 if (!(txn->mt_flags & MDB_TXN_RDONLY))
2438 mdb_txn_reset0(txn, "reset");
2442 mdb_txn_abort(MDB_txn *txn)
2448 mdb_txn_abort(txn->mt_child);
2450 mdb_txn_reset0(txn, "abort");
2451 /* Free reader slot tied to this txn (if MDB_NOTLS && writable FS) */
2452 if ((txn->mt_flags & MDB_TXN_RDONLY) && txn->mt_u.reader)
2453 txn->mt_u.reader->mr_pid = 0;
2458 /** Save the freelist as of this transaction to the freeDB.
2459 * This changes the freelist. Keep trying until it stabilizes.
2462 mdb_freelist_save(MDB_txn *txn)
2464 /* env->me_pghead[] can grow and shrink during this call.
2465 * env->me_pglast and txn->mt_free_pgs[] can only grow.
2466 * Page numbers cannot disappear from txn->mt_free_pgs[].
2469 MDB_env *env = txn->mt_env;
2470 int rc, maxfree_1pg = env->me_maxfree_1pg, more = 1;
2471 txnid_t pglast = 0, head_id = 0;
2472 pgno_t freecnt = 0, *free_pgs, *mop;
2473 ssize_t head_room = 0, total_room = 0, mop_len;
2475 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
2477 if (env->me_pghead) {
2478 /* Make sure first page of freeDB is touched and on freelist */
2479 rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST|MDB_PS_MODIFY);
2480 if (rc && rc != MDB_NOTFOUND)
2485 /* Come back here after each Put() in case freelist changed */
2488 /* If using records from freeDB which we have not yet
2489 * deleted, delete them and any we reserved for me_pghead.
2491 while (pglast < env->me_pglast) {
2492 rc = mdb_cursor_first(&mc, &key, NULL);
2495 pglast = head_id = *(txnid_t *)key.mv_data;
2496 total_room = head_room = 0;
2497 assert(pglast <= env->me_pglast);
2498 rc = mdb_cursor_del(&mc, 0);
2503 /* Save the IDL of pages freed by this txn, to a single record */
2504 if (freecnt < txn->mt_free_pgs[0]) {
2506 /* Make sure last page of freeDB is touched and on freelist */
2507 rc = mdb_page_search(&mc, NULL, MDB_PS_LAST|MDB_PS_MODIFY);
2508 if (rc && rc != MDB_NOTFOUND)
2511 free_pgs = txn->mt_free_pgs;
2512 /* Write to last page of freeDB */
2513 key.mv_size = sizeof(txn->mt_txnid);
2514 key.mv_data = &txn->mt_txnid;
2516 freecnt = free_pgs[0];
2517 data.mv_size = MDB_IDL_SIZEOF(free_pgs);
2518 rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
2521 /* Retry if mt_free_pgs[] grew during the Put() */
2522 free_pgs = txn->mt_free_pgs;
2523 } while (freecnt < free_pgs[0]);
2524 mdb_midl_sort(free_pgs);
2525 memcpy(data.mv_data, free_pgs, data.mv_size);
2528 unsigned int i = free_pgs[0];
2529 DPRINTF(("IDL write txn %"Z"u root %"Z"u num %u",
2530 txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, i));
2532 DPRINTF(("IDL %"Z"u", free_pgs[i]));
2538 mop = env->me_pghead;
2539 mop_len = mop ? mop[0] : 0;
2541 /* Reserve records for me_pghead[]. Split it if multi-page,
2542 * to avoid searching freeDB for a page range. Use keys in
2543 * range [1,me_pglast]: Smaller than txnid of oldest reader.
2545 if (total_room >= mop_len) {
2546 if (total_room == mop_len || --more < 0)
2548 } else if (head_room >= maxfree_1pg && head_id > 1) {
2549 /* Keep current record (overflow page), add a new one */
2553 /* (Re)write {key = head_id, IDL length = head_room} */
2554 total_room -= head_room;
2555 head_room = mop_len - total_room;
2556 if (head_room > maxfree_1pg && head_id > 1) {
2557 /* Overflow multi-page for part of me_pghead */
2558 head_room /= head_id; /* amortize page sizes */
2559 head_room += maxfree_1pg - head_room % (maxfree_1pg + 1);
2560 } else if (head_room < 0) {
2561 /* Rare case, not bothering to delete this record */
2564 key.mv_size = sizeof(head_id);
2565 key.mv_data = &head_id;
2566 data.mv_size = (head_room + 1) * sizeof(pgno_t);
2567 rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
2570 *(MDB_ID *)data.mv_data = 0; /* IDL is initially empty */
2571 total_room += head_room;
2574 /* Fill in the reserved me_pghead records */
2580 rc = mdb_cursor_first(&mc, &key, &data);
2581 for (; !rc; rc = mdb_cursor_next(&mc, &key, &data, MDB_NEXT)) {
2582 unsigned flags = MDB_CURRENT;
2583 txnid_t id = *(txnid_t *)key.mv_data;
2584 ssize_t len = (ssize_t)(data.mv_size / sizeof(MDB_ID)) - 1;
2587 assert(len >= 0 && id <= env->me_pglast);
2589 if (len > mop_len) {
2591 data.mv_size = (len + 1) * sizeof(MDB_ID);
2594 data.mv_data = mop -= len;
2597 rc = mdb_cursor_put(&mc, &key, &data, flags);
2599 if (rc || !(mop_len -= len))
2606 /** Flush (some) dirty pages to the map, after clearing their dirty flag.
2607 * @param[in] txn the transaction that's being committed
2608 * @param[in] keep number of initial pages in dirty_list to keep dirty.
2609 * @return 0 on success, non-zero on failure.
2612 mdb_page_flush(MDB_txn *txn, int keep)
2614 MDB_env *env = txn->mt_env;
2615 MDB_ID2L dl = txn->mt_u.dirty_list;
2616 unsigned psize = env->me_psize, j;
2617 int i, pagecount = dl[0].mid, rc;
2618 size_t size = 0, pos = 0;
2620 MDB_page *dp = NULL;
2624 struct iovec iov[MDB_COMMIT_PAGES];
2625 ssize_t wpos = 0, wsize = 0, wres;
2626 size_t next_pos = 1; /* impossible pos, so pos != next_pos */
2632 if (env->me_flags & MDB_WRITEMAP) {
2633 /* Clear dirty flags */
2634 while (++i <= pagecount) {
2636 /* Don't flush this page yet */
2637 if (dp->mp_flags & P_KEEP) {
2638 dp->mp_flags ^= P_KEEP;
2642 dp->mp_flags &= ~P_DIRTY;
2647 /* Write the pages */
2649 if (++i <= pagecount) {
2651 /* Don't flush this page yet */
2652 if (dp->mp_flags & P_KEEP) {
2653 dp->mp_flags ^= P_KEEP;
2658 /* clear dirty flag */
2659 dp->mp_flags &= ~P_DIRTY;
2662 if (IS_OVERFLOW(dp)) size *= dp->mp_pages;
2667 /* Windows actually supports scatter/gather I/O, but only on
2668 * unbuffered file handles. Since we're relying on the OS page
2669 * cache for all our data, that's self-defeating. So we just
2670 * write pages one at a time. We use the ov structure to set
2671 * the write offset, to at least save the overhead of a Seek
2674 DPRINTF(("committing page %"Z"u", pgno));
2675 memset(&ov, 0, sizeof(ov));
2676 ov.Offset = pos & 0xffffffff;
2677 ov.OffsetHigh = pos >> 16 >> 16;
2678 if (!WriteFile(env->me_fd, dp, size, NULL, &ov)) {
2680 DPRINTF(("WriteFile: %d", rc));
2684 /* Write up to MDB_COMMIT_PAGES dirty pages at a time. */
2685 if (pos!=next_pos || n==MDB_COMMIT_PAGES || wsize+size>MAX_WRITE) {
2687 /* Write previous page(s) */
2688 #ifdef MDB_USE_PWRITEV
2689 wres = pwritev(env->me_fd, iov, n, wpos);
2692 wres = pwrite(env->me_fd, iov[0].iov_base, wsize, wpos);
2694 if (lseek(env->me_fd, wpos, SEEK_SET) == -1) {
2696 DPRINTF(("lseek: %s", strerror(rc)));
2699 wres = writev(env->me_fd, iov, n);
2702 if (wres != wsize) {
2705 DPRINTF(("Write error: %s", strerror(rc)));
2707 rc = EIO; /* TODO: Use which error code? */
2708 DPUTS("short write, filesystem full?");
2719 DPRINTF(("committing page %"Z"u", pgno));
2720 next_pos = pos + size;
2721 iov[n].iov_len = size;
2722 iov[n].iov_base = (char *)dp;
2728 for (i = keep; ++i <= pagecount; ) {
2730 /* This is a page we skipped above */
2733 dl[j].mid = dp->mp_pgno;
2736 mdb_dpage_free(env, dp);
2741 txn->mt_dirty_room += i - j;
2747 mdb_txn_commit(MDB_txn *txn)
2753 assert(txn != NULL);
2754 assert(txn->mt_env != NULL);
2756 if (txn->mt_child) {
2757 rc = mdb_txn_commit(txn->mt_child);
2758 txn->mt_child = NULL;
2765 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
2766 mdb_dbis_update(txn, 1);
2767 txn->mt_numdbs = 2; /* so txn_abort() doesn't close any new handles */
2772 if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
2773 DPUTS("error flag is set, can't commit");
2775 txn->mt_parent->mt_flags |= MDB_TXN_ERROR;
2780 if (txn->mt_parent) {
2781 MDB_txn *parent = txn->mt_parent;
2784 unsigned x, y, len, ps_len;
2786 /* Append our free list to parent's */
2787 rc = mdb_midl_append_list(&parent->mt_free_pgs, txn->mt_free_pgs);
2790 mdb_midl_free(txn->mt_free_pgs);
2791 /* Failures after this must either undo the changes
2792 * to the parent or set MDB_TXN_ERROR in the parent.
2795 parent->mt_next_pgno = txn->mt_next_pgno;
2796 parent->mt_flags = txn->mt_flags;
2798 /* Merge our cursors into parent's and close them */
2799 mdb_cursors_close(txn, 1);
2801 /* Update parent's DB table. */
2802 memcpy(parent->mt_dbs, txn->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
2803 parent->mt_numdbs = txn->mt_numdbs;
2804 parent->mt_dbflags[0] = txn->mt_dbflags[0];
2805 parent->mt_dbflags[1] = txn->mt_dbflags[1];
2806 for (i=2; i<txn->mt_numdbs; i++) {
2807 /* preserve parent's DB_NEW status */
2808 x = parent->mt_dbflags[i] & DB_NEW;
2809 parent->mt_dbflags[i] = txn->mt_dbflags[i] | x;
2812 dst = parent->mt_u.dirty_list;
2813 src = txn->mt_u.dirty_list;
2814 /* Remove anything in our dirty list from parent's spill list */
2815 if ((pspill = parent->mt_spill_pgs) && (ps_len = pspill[0])) {
2817 pspill[0] = (pgno_t)-1;
2818 /* Mark our dirty pages as deleted in parent spill list */
2819 for (i=0, len=src[0].mid; ++i <= len; ) {
2820 MDB_ID pn = src[i].mid << 1;
2821 while (pn > pspill[x])
2823 if (pn == pspill[x]) {
2828 /* Squash deleted pagenums if we deleted any */
2829 for (x=y; ++x <= ps_len; )
2830 if (!(pspill[x] & 1))
2831 pspill[++y] = pspill[x];
2835 /* Find len = length of merging our dirty list with parent's */
2837 dst[0].mid = 0; /* simplify loops */
2838 if (parent->mt_parent) {
2839 len = x + src[0].mid;
2840 y = mdb_mid2l_search(src, dst[x].mid + 1) - 1;
2841 for (i = x; y && i; y--) {
2842 pgno_t yp = src[y].mid;
2843 while (yp < dst[i].mid)
2845 if (yp == dst[i].mid) {
2850 } else { /* Simplify the above for single-ancestor case */
2851 len = MDB_IDL_UM_MAX - txn->mt_dirty_room;
2853 /* Merge our dirty list with parent's */
2855 for (i = len; y; dst[i--] = src[y--]) {
2856 pgno_t yp = src[y].mid;
2857 while (yp < dst[x].mid)
2858 dst[i--] = dst[x--];
2859 if (yp == dst[x].mid)
2860 free(dst[x--].mptr);
2864 free(txn->mt_u.dirty_list);
2865 parent->mt_dirty_room = txn->mt_dirty_room;
2866 if (txn->mt_spill_pgs) {
2867 if (parent->mt_spill_pgs) {
2868 /* TODO: Prevent failure here, so parent does not fail */
2869 rc = mdb_midl_append_list(&parent->mt_spill_pgs, txn->mt_spill_pgs);
2871 parent->mt_flags |= MDB_TXN_ERROR;
2872 mdb_midl_free(txn->mt_spill_pgs);
2873 mdb_midl_sort(parent->mt_spill_pgs);
2875 parent->mt_spill_pgs = txn->mt_spill_pgs;
2879 parent->mt_child = NULL;
2880 mdb_midl_free(((MDB_ntxn *)txn)->mnt_pgstate.mf_pghead);
2885 if (txn != env->me_txn) {
2886 DPUTS("attempt to commit unknown transaction");
2891 mdb_cursors_close(txn, 0);
2893 if (!txn->mt_u.dirty_list[0].mid &&
2894 !(txn->mt_flags & (MDB_TXN_DIRTY|MDB_TXN_SPILLS)))
2897 DPRINTF(("committing txn %"Z"u %p on mdbenv %p, root page %"Z"u",
2898 txn->mt_txnid, (void*)txn, (void*)env, txn->mt_dbs[MAIN_DBI].md_root));
2900 /* Update DB root pointers */
2901 if (txn->mt_numdbs > 2) {
2905 data.mv_size = sizeof(MDB_db);
2907 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
2908 for (i = 2; i < txn->mt_numdbs; i++) {
2909 if (txn->mt_dbflags[i] & DB_DIRTY) {
2910 data.mv_data = &txn->mt_dbs[i];
2911 rc = mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data, 0);
2918 rc = mdb_freelist_save(txn);
2922 mdb_midl_free(env->me_pghead);
2923 env->me_pghead = NULL;
2924 if (mdb_midl_shrink(&txn->mt_free_pgs))
2925 env->me_free_pgs = txn->mt_free_pgs;
2931 if ((rc = mdb_page_flush(txn, 0)) ||
2932 (rc = mdb_env_sync(env, 0)) ||
2933 (rc = mdb_env_write_meta(txn)))
2939 mdb_dbis_update(txn, 1);
2941 UNLOCK_MUTEX_W(env);
2951 /** Read the environment parameters of a DB environment before
2952 * mapping it into memory.
2953 * @param[in] env the environment handle
2954 * @param[out] meta address of where to store the meta information
2955 * @return 0 on success, non-zero on failure.
2958 mdb_env_read_header(MDB_env *env, MDB_meta *meta)
2965 /* We don't know the page size yet, so use a minimum value.
2966 * Read both meta pages so we can use the latest one.
2969 for (i=off=0; i<2; i++, off = meta->mm_psize) {
2973 memset(&ov, 0, sizeof(ov));
2975 rc = ReadFile(env->me_fd,&pbuf,MDB_PAGESIZE,&len,&ov) ? (int)len : -1;
2976 if (rc == -1 && ErrCode() == ERROR_HANDLE_EOF)
2979 rc = pread(env->me_fd, &pbuf, MDB_PAGESIZE, off);
2981 if (rc != MDB_PAGESIZE) {
2982 if (rc == 0 && off == 0)
2984 rc = rc < 0 ? (int) ErrCode() : MDB_INVALID;
2985 DPRINTF(("read: %s", mdb_strerror(rc)));
2989 p = (MDB_page *)&pbuf;
2991 if (!F_ISSET(p->mp_flags, P_META)) {
2992 DPRINTF(("page %"Z"u not a meta page", p->mp_pgno));
2997 if (m->mm_magic != MDB_MAGIC) {
2998 DPUTS("meta has invalid magic");
3002 if (m->mm_version != MDB_DATA_VERSION) {
3003 DPRINTF(("database is version %u, expected version %u",
3004 m->mm_version, MDB_DATA_VERSION));
3005 return MDB_VERSION_MISMATCH;
3008 if (off == 0 || m->mm_txnid > meta->mm_txnid)
3014 /** Write the environment parameters of a freshly created DB environment.
3015 * @param[in] env the environment handle
3016 * @param[out] meta address of where to store the meta information
3017 * @return 0 on success, non-zero on failure.
3020 mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
3028 memset(&ov, 0, sizeof(ov));
3029 #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
3031 rc = WriteFile(fd, ptr, size, &len, &ov); } while(0)
3034 #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
3035 len = pwrite(fd, ptr, size, pos); \
3036 rc = (len >= 0); } while(0)
3039 DPUTS("writing new meta page");
3041 psize = env->me_psize;
3043 meta->mm_magic = MDB_MAGIC;
3044 meta->mm_version = MDB_DATA_VERSION;
3045 meta->mm_mapsize = env->me_mapsize;
3046 meta->mm_psize = psize;
3047 meta->mm_last_pg = 1;
3048 meta->mm_flags = env->me_flags & 0xffff;
3049 meta->mm_flags |= MDB_INTEGERKEY;
3050 meta->mm_dbs[0].md_root = P_INVALID;
3051 meta->mm_dbs[1].md_root = P_INVALID;
3053 p = calloc(2, psize);
3055 p->mp_flags = P_META;
3056 *(MDB_meta *)METADATA(p) = *meta;
3058 q = (MDB_page *)((char *)p + psize);
3060 q->mp_flags = P_META;
3061 *(MDB_meta *)METADATA(q) = *meta;
3063 DO_PWRITE(rc, env->me_fd, p, psize * 2, len, 0);
3066 else if ((unsigned) len == psize * 2)
3074 /** Update the environment info to commit a transaction.
3075 * @param[in] txn the transaction that's being committed
3076 * @return 0 on success, non-zero on failure.
3079 mdb_env_write_meta(MDB_txn *txn)
3082 MDB_meta meta, metab, *mp;
3084 int rc, len, toggle;
3093 assert(txn != NULL);
3094 assert(txn->mt_env != NULL);
3096 toggle = !txn->mt_toggle;
3097 DPRINTF(("writing meta page %d for root page %"Z"u",
3098 toggle, txn->mt_dbs[MAIN_DBI].md_root));
3101 mp = env->me_metas[toggle];
3103 if (env->me_flags & MDB_WRITEMAP) {
3104 /* Persist any increases of mapsize config */
3105 if (env->me_mapsize > mp->mm_mapsize)
3106 mp->mm_mapsize = env->me_mapsize;
3107 mp->mm_dbs[0] = txn->mt_dbs[0];
3108 mp->mm_dbs[1] = txn->mt_dbs[1];
3109 mp->mm_last_pg = txn->mt_next_pgno - 1;
3110 mp->mm_txnid = txn->mt_txnid;
3111 if (!(env->me_flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {
3112 rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;
3115 ptr += env->me_psize;
3116 if (MDB_MSYNC(ptr, env->me_psize, rc)) {
3123 metab.mm_txnid = env->me_metas[toggle]->mm_txnid;
3124 metab.mm_last_pg = env->me_metas[toggle]->mm_last_pg;
3126 ptr = (char *)&meta;
3127 if (env->me_mapsize > mp->mm_mapsize) {
3128 /* Persist any increases of mapsize config */
3129 meta.mm_mapsize = env->me_mapsize;
3130 off = offsetof(MDB_meta, mm_mapsize);
3132 off = offsetof(MDB_meta, mm_dbs[0].md_depth);
3134 len = sizeof(MDB_meta) - off;
3137 meta.mm_dbs[0] = txn->mt_dbs[0];
3138 meta.mm_dbs[1] = txn->mt_dbs[1];
3139 meta.mm_last_pg = txn->mt_next_pgno - 1;
3140 meta.mm_txnid = txn->mt_txnid;
3143 off += env->me_psize;
3146 /* Write to the SYNC fd */
3147 mfd = env->me_flags & (MDB_NOSYNC|MDB_NOMETASYNC) ?
3148 env->me_fd : env->me_mfd;
3151 memset(&ov, 0, sizeof(ov));
3153 if (!WriteFile(mfd, ptr, len, (DWORD *)&rc, &ov))
3157 rc = pwrite(mfd, ptr, len, off);
3160 rc = rc < 0 ? ErrCode() : EIO;
3161 DPUTS("write failed, disk error?");
3162 /* On a failure, the pagecache still contains the new data.
3163 * Write some old data back, to prevent it from being used.
3164 * Use the non-SYNC fd; we know it will fail anyway.
3166 meta.mm_last_pg = metab.mm_last_pg;
3167 meta.mm_txnid = metab.mm_txnid;
3169 memset(&ov, 0, sizeof(ov));
3171 WriteFile(env->me_fd, ptr, len, NULL, &ov);
3173 r2 = pwrite(env->me_fd, ptr, len, off);
3174 (void)r2; /* Silence warnings. We don't care about pwrite's return value */
3177 env->me_flags |= MDB_FATAL_ERROR;
3181 /* Memory ordering issues are irrelevant; since the entire writer
3182 * is wrapped by wmutex, all of these changes will become visible
3183 * after the wmutex is unlocked. Since the DB is multi-version,
3184 * readers will get consistent data regardless of how fresh or
3185 * how stale their view of these values is.
3187 env->me_txns->mti_txnid = txn->mt_txnid;
3192 /** Check both meta pages to see which one is newer.
3193 * @param[in] env the environment handle
3194 * @return meta toggle (0 or 1).
3197 mdb_env_pick_meta(const MDB_env *env)
3199 return (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid);
3203 mdb_env_create(MDB_env **env)
3207 e = calloc(1, sizeof(MDB_env));
3211 e->me_maxreaders = DEFAULT_READERS;
3212 e->me_maxdbs = e->me_numdbs = 2;
3213 e->me_fd = INVALID_HANDLE_VALUE;
3214 e->me_lfd = INVALID_HANDLE_VALUE;
3215 e->me_mfd = INVALID_HANDLE_VALUE;
3216 #ifdef MDB_USE_POSIX_SEM
3217 e->me_rmutex = SEM_FAILED;
3218 e->me_wmutex = SEM_FAILED;
3220 e->me_pid = getpid();
3221 VGMEMP_CREATE(e,0,0);
3227 mdb_env_map(MDB_env *env, void *addr, int newsize)
3230 unsigned int flags = env->me_flags;
3234 LONG sizelo, sizehi;
3235 sizelo = env->me_mapsize & 0xffffffff;
3236 sizehi = env->me_mapsize >> 16 >> 16; /* only needed on Win64 */
3238 /* Windows won't create mappings for zero length files.
3239 * Just allocate the maxsize right now.
3242 if (SetFilePointer(env->me_fd, sizelo, &sizehi, 0) != (DWORD)sizelo
3243 || !SetEndOfFile(env->me_fd)
3244 || SetFilePointer(env->me_fd, 0, NULL, 0) != 0)
3247 mh = CreateFileMapping(env->me_fd, NULL, flags & MDB_WRITEMAP ?
3248 PAGE_READWRITE : PAGE_READONLY,
3249 sizehi, sizelo, NULL);
3252 env->me_map = MapViewOfFileEx(mh, flags & MDB_WRITEMAP ?
3253 FILE_MAP_WRITE : FILE_MAP_READ,
3254 0, 0, env->me_mapsize, addr);
3255 rc = env->me_map ? 0 : ErrCode();
3260 int prot = PROT_READ;
3261 if (flags & MDB_WRITEMAP) {
3263 if (newsize && ftruncate(env->me_fd, env->me_mapsize) < 0)
3266 env->me_map = mmap(addr, env->me_mapsize, prot, MAP_SHARED,
3268 if (env->me_map == MAP_FAILED) {
3272 /* Turn off readahead. It's harmful when the DB is larger than RAM. */
3274 madvise(env->me_map, env->me_mapsize, MADV_RANDOM);
3276 #ifdef POSIX_MADV_RANDOM
3277 posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM);
3278 #endif /* POSIX_MADV_RANDOM */
3279 #endif /* MADV_RANDOM */
3282 /* Can happen because the address argument to mmap() is just a
3283 * hint. mmap() can pick another, e.g. if the range is in use.
3284 * The MAP_FIXED flag would prevent that, but then mmap could
3285 * instead unmap existing pages to make room for the new map.
3287 if (addr && env->me_map != addr)
3288 return EBUSY; /* TODO: Make a new MDB_* error code? */
3290 p = (MDB_page *)env->me_map;
3291 env->me_metas[0] = METADATA(p);
3292 env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + env->me_psize);
3298 mdb_env_set_mapsize(MDB_env *env, size_t size)
3300 /* If env is already open, caller is responsible for making
3301 * sure there are no active txns.
3309 size = env->me_metas[mdb_env_pick_meta(env)]->mm_mapsize;
3310 munmap(env->me_map, env->me_mapsize);
3311 env->me_mapsize = size;
3312 old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL;
3313 rc = mdb_env_map(env, old, 1);
3317 env->me_mapsize = size;
3319 env->me_maxpg = env->me_mapsize / env->me_psize;
3324 mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs)
3328 env->me_maxdbs = dbs + 2; /* Named databases + main and free DB */
3333 mdb_env_set_maxreaders(MDB_env *env, unsigned int readers)
3335 if (env->me_map || readers < 1)
3337 env->me_maxreaders = readers;
3342 mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)
3344 if (!env || !readers)
3346 *readers = env->me_maxreaders;
3350 /** Further setup required for opening an MDB environment
3353 mdb_env_open2(MDB_env *env)
3355 unsigned int flags = env->me_flags;
3356 int i, newenv = 0, rc;
3360 /* See if we should use QueryLimited */
3362 if ((rc & 0xff) > 5)
3363 env->me_pidquery = MDB_PROCESS_QUERY_LIMITED_INFORMATION;
3365 env->me_pidquery = PROCESS_QUERY_INFORMATION;
3368 memset(&meta, 0, sizeof(meta));
3370 if ((i = mdb_env_read_header(env, &meta)) != 0) {
3373 DPUTS("new mdbenv");
3375 GET_PAGESIZE(env->me_psize);
3377 env->me_psize = meta.mm_psize;
3380 /* Was a mapsize configured? */
3381 if (!env->me_mapsize) {
3382 /* If this is a new environment, take the default,
3383 * else use the size recorded in the existing env.
3385 env->me_mapsize = newenv ? DEFAULT_MAPSIZE : meta.mm_mapsize;
3386 } else if (env->me_mapsize < meta.mm_mapsize) {
3387 /* If the configured size is smaller, make sure it's
3388 * still big enough. Silently round up to minimum if not.
3390 size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize;
3391 if (env->me_mapsize < minsize)
3392 env->me_mapsize = minsize;
3395 rc = mdb_env_map(env, meta.mm_address, newenv);
3400 if (flags & MDB_FIXEDMAP)
3401 meta.mm_address = env->me_map;
3402 i = mdb_env_init_meta(env, &meta);
3403 if (i != MDB_SUCCESS) {
3407 env->me_maxfree_1pg = (env->me_psize - PAGEHDRSZ) / sizeof(pgno_t) - 1;
3408 env->me_nodemax = (env->me_psize - PAGEHDRSZ) / MDB_MINKEYS;
3410 env->me_maxpg = env->me_mapsize / env->me_psize;
3413 int toggle = mdb_env_pick_meta(env);
3414 MDB_db *db = &env->me_metas[toggle]->mm_dbs[MAIN_DBI];
3416 DPRINTF(("opened database version %u, pagesize %u",
3417 env->me_metas[0]->mm_version, env->me_psize));
3418 DPRINTF(("using meta page %d", toggle));
3419 DPRINTF(("depth: %u", db->md_depth));
3420 DPRINTF(("entries: %"Z"u", db->md_entries));
3421 DPRINTF(("branch pages: %"Z"u", db->md_branch_pages));
3422 DPRINTF(("leaf pages: %"Z"u", db->md_leaf_pages));
3423 DPRINTF(("overflow pages: %"Z"u", db->md_overflow_pages));
3424 DPRINTF(("root: %"Z"u", db->md_root));
3432 /** Release a reader thread's slot in the reader lock table.
3433 * This function is called automatically when a thread exits.
3434 * @param[in] ptr This points to the slot in the reader lock table.
3437 mdb_env_reader_dest(void *ptr)
3439 MDB_reader *reader = ptr;
3445 /** Junk for arranging thread-specific callbacks on Windows. This is
3446 * necessarily platform and compiler-specific. Windows supports up
3447 * to 1088 keys. Let's assume nobody opens more than 64 environments
3448 * in a single process, for now. They can override this if needed.
3450 #ifndef MAX_TLS_KEYS
3451 #define MAX_TLS_KEYS 64
3453 static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS];
3454 static int mdb_tls_nkeys;
3456 static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr)
3460 case DLL_PROCESS_ATTACH: break;
3461 case DLL_THREAD_ATTACH: break;
3462 case DLL_THREAD_DETACH:
3463 for (i=0; i<mdb_tls_nkeys; i++) {
3464 MDB_reader *r = pthread_getspecific(mdb_tls_keys[i]);
3465 mdb_env_reader_dest(r);
3468 case DLL_PROCESS_DETACH: break;
3473 const PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
3475 PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
3479 /* Force some symbol references.
3480 * _tls_used forces the linker to create the TLS directory if not already done
3481 * mdb_tls_cbp prevents whole-program-optimizer from dropping the symbol.
3483 #pragma comment(linker, "/INCLUDE:_tls_used")
3484 #pragma comment(linker, "/INCLUDE:mdb_tls_cbp")
3485 #pragma const_seg(".CRT$XLB")
3486 extern const PIMAGE_TLS_CALLBACK mdb_tls_callback;
3487 const PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
3490 #pragma comment(linker, "/INCLUDE:__tls_used")
3491 #pragma comment(linker, "/INCLUDE:_mdb_tls_cbp")
3492 #pragma data_seg(".CRT$XLB")
3493 PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
3495 #endif /* WIN 32/64 */
3496 #endif /* !__GNUC__ */
3499 /** Downgrade the exclusive lock on the region back to shared */
3501 mdb_env_share_locks(MDB_env *env, int *excl)
3503 int rc = 0, toggle = mdb_env_pick_meta(env);
3505 env->me_txns->mti_txnid = env->me_metas[toggle]->mm_txnid;
3510 /* First acquire a shared lock. The Unlock will
3511 * then release the existing exclusive lock.
3513 memset(&ov, 0, sizeof(ov));
3514 if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
3517 UnlockFile(env->me_lfd, 0, 0, 1, 0);
3523 struct flock lock_info;
3524 /* The shared lock replaces the existing lock */
3525 memset((void *)&lock_info, 0, sizeof(lock_info));
3526 lock_info.l_type = F_RDLCK;
3527 lock_info.l_whence = SEEK_SET;
3528 lock_info.l_start = 0;
3529 lock_info.l_len = 1;
3530 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
3531 (rc = ErrCode()) == EINTR) ;
3532 *excl = rc ? -1 : 0; /* error may mean we lost the lock */
3539 /** Try to get exlusive lock, otherwise shared.
3540 * Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive.
3543 mdb_env_excl_lock(MDB_env *env, int *excl)
3547 if (LockFile(env->me_lfd, 0, 0, 1, 0)) {
3551 memset(&ov, 0, sizeof(ov));
3552 if (LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
3559 struct flock lock_info;
3560 memset((void *)&lock_info, 0, sizeof(lock_info));
3561 lock_info.l_type = F_WRLCK;
3562 lock_info.l_whence = SEEK_SET;
3563 lock_info.l_start = 0;
3564 lock_info.l_len = 1;
3565 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
3566 (rc = ErrCode()) == EINTR) ;
3570 # ifdef MDB_USE_POSIX_SEM
3571 if (*excl < 0) /* always true when !MDB_USE_POSIX_SEM */
3574 lock_info.l_type = F_RDLCK;
3575 while ((rc = fcntl(env->me_lfd, F_SETLKW, &lock_info)) &&
3576 (rc = ErrCode()) == EINTR) ;
3584 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
3586 * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code
3588 * @(#) $Revision: 5.1 $
3589 * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $
3590 * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $
3592 * http://www.isthe.com/chongo/tech/comp/fnv/index.html
3596 * Please do not copyright this code. This code is in the public domain.
3598 * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
3599 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
3600 * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
3601 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
3602 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
3603 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
3604 * PERFORMANCE OF THIS SOFTWARE.
3607 * chongo <Landon Curt Noll> /\oo/\
3608 * http://www.isthe.com/chongo/
3610 * Share and Enjoy! :-)
3613 typedef unsigned long long mdb_hash_t;
3614 #define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL)
3616 /** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer
3617 * @param[in] val value to hash
3618 * @param[in] hval initial value for hash
3619 * @return 64 bit hash
3621 * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the
3622 * hval arg on the first call.
3625 mdb_hash_val(MDB_val *val, mdb_hash_t hval)
3627 unsigned char *s = (unsigned char *)val->mv_data; /* unsigned string */
3628 unsigned char *end = s + val->mv_size;
3630 * FNV-1a hash each octet of the string
3633 /* xor the bottom with the current octet */
3634 hval ^= (mdb_hash_t)*s++;
3636 /* multiply by the 64 bit FNV magic prime mod 2^64 */
3637 hval += (hval << 1) + (hval << 4) + (hval << 5) +
3638 (hval << 7) + (hval << 8) + (hval << 40);
3640 /* return our new hash value */
3644 /** Hash the string and output the encoded hash.
3645 * This uses modified RFC1924 Ascii85 encoding to accommodate systems with
3646 * very short name limits. We don't care about the encoding being reversible,
3647 * we just want to preserve as many bits of the input as possible in a
3648 * small printable string.
3649 * @param[in] str string to hash
3650 * @param[out] encbuf an array of 11 chars to hold the hash
3652 static const char mdb_a85[]= "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";
3655 mdb_pack85(unsigned long l, char *out)
3659 for (i=0; i<5; i++) {
3660 *out++ = mdb_a85[l % 85];
3666 mdb_hash_enc(MDB_val *val, char *encbuf)
3668 mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT);
3670 mdb_pack85(h, encbuf);
3671 mdb_pack85(h>>32, encbuf+5);
3676 /** Open and/or initialize the lock region for the environment.
3677 * @param[in] env The MDB environment.
3678 * @param[in] lpath The pathname of the file used for the lock region.
3679 * @param[in] mode The Unix permissions for the file, if we create it.
3680 * @param[out] excl Resulting file lock type: -1 none, 0 shared, 1 exclusive
3681 * @param[in,out] excl In -1, out lock type: -1 none, 0 shared, 1 exclusive
3682 * @return 0 on success, non-zero on failure.
3685 mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
3688 # define MDB_ERRCODE_ROFS ERROR_WRITE_PROTECT
3690 # define MDB_ERRCODE_ROFS EROFS
3691 #ifdef O_CLOEXEC /* Linux: Open file and set FD_CLOEXEC atomically */
3692 # define MDB_CLOEXEC O_CLOEXEC
3695 # define MDB_CLOEXEC 0
3702 env->me_lfd = CreateFile(lpath, GENERIC_READ|GENERIC_WRITE,
3703 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
3704 FILE_ATTRIBUTE_NORMAL, NULL);
3706 env->me_lfd = open(lpath, O_RDWR|O_CREAT|MDB_CLOEXEC, mode);
3708 if (env->me_lfd == INVALID_HANDLE_VALUE) {
3710 if (rc == MDB_ERRCODE_ROFS && (env->me_flags & MDB_RDONLY)) {
3715 #if ! ((MDB_CLOEXEC) || defined(_WIN32))
3716 /* Lose record locks when exec*() */
3717 if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0)
3718 fcntl(env->me_lfd, F_SETFD, fdflags);
3721 if (!(env->me_flags & MDB_NOTLS)) {
3722 rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
3725 env->me_flags |= MDB_ENV_TXKEY;
3727 /* Windows TLS callbacks need help finding their TLS info. */
3728 if (mdb_tls_nkeys >= MAX_TLS_KEYS) {
3732 mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey;
3736 /* Try to get exclusive lock. If we succeed, then
3737 * nobody is using the lock region and we should initialize it.
3739 if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
3742 size = GetFileSize(env->me_lfd, NULL);
3744 size = lseek(env->me_lfd, 0, SEEK_END);
3745 if (size == -1) goto fail_errno;
3747 rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
3748 if (size < rsize && *excl > 0) {
3750 if (SetFilePointer(env->me_lfd, rsize, NULL, FILE_BEGIN) != rsize
3751 || !SetEndOfFile(env->me_lfd))
3754 if (ftruncate(env->me_lfd, rsize) != 0) goto fail_errno;
3758 size = rsize - sizeof(MDB_txninfo);
3759 env->me_maxreaders = size/sizeof(MDB_reader) + 1;
3764 mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,
3766 if (!mh) goto fail_errno;
3767 env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL);
3769 if (!env->me_txns) goto fail_errno;
3771 void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
3773 if (m == MAP_FAILED) goto fail_errno;
3779 BY_HANDLE_FILE_INFORMATION stbuf;
3788 if (!mdb_sec_inited) {
3789 InitializeSecurityDescriptor(&mdb_null_sd,
3790 SECURITY_DESCRIPTOR_REVISION);
3791 SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE);
3792 mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);
3793 mdb_all_sa.bInheritHandle = FALSE;
3794 mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;
3797 if (!GetFileInformationByHandle(env->me_lfd, &stbuf)) goto fail_errno;
3798 idbuf.volume = stbuf.dwVolumeSerialNumber;
3799 idbuf.nhigh = stbuf.nFileIndexHigh;
3800 idbuf.nlow = stbuf.nFileIndexLow;
3801 val.mv_data = &idbuf;
3802 val.mv_size = sizeof(idbuf);
3803 mdb_hash_enc(&val, encbuf);
3804 sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", encbuf);
3805 sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", encbuf);
3806 env->me_rmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
3807 if (!env->me_rmutex) goto fail_errno;
3808 env->me_wmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);
3809 if (!env->me_wmutex) goto fail_errno;
3810 #elif defined(MDB_USE_POSIX_SEM)
3819 #if defined(__NetBSD__)
3820 #define MDB_SHORT_SEMNAMES 1 /* limited to 14 chars */
3822 if (fstat(env->me_lfd, &stbuf)) goto fail_errno;
3823 idbuf.dev = stbuf.st_dev;
3824 idbuf.ino = stbuf.st_ino;
3825 val.mv_data = &idbuf;
3826 val.mv_size = sizeof(idbuf);
3827 mdb_hash_enc(&val, encbuf);
3828 #ifdef MDB_SHORT_SEMNAMES
3829 encbuf[9] = '\0'; /* drop name from 15 chars to 14 chars */
3831 sprintf(env->me_txns->mti_rmname, "/MDBr%s", encbuf);
3832 sprintf(env->me_txns->mti_wmname, "/MDBw%s", encbuf);
3833 /* Clean up after a previous run, if needed: Try to
3834 * remove both semaphores before doing anything else.
3836 sem_unlink(env->me_txns->mti_rmname);
3837 sem_unlink(env->me_txns->mti_wmname);
3838 env->me_rmutex = sem_open(env->me_txns->mti_rmname,
3839 O_CREAT|O_EXCL, mode, 1);
3840 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
3841 env->me_wmutex = sem_open(env->me_txns->mti_wmname,
3842 O_CREAT|O_EXCL, mode, 1);
3843 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
3844 #else /* MDB_USE_POSIX_SEM */
3845 pthread_mutexattr_t mattr;
3847 if ((rc = pthread_mutexattr_init(&mattr))
3848 || (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED))
3849 || (rc = pthread_mutex_init(&env->me_txns->mti_mutex, &mattr))
3850 || (rc = pthread_mutex_init(&env->me_txns->mti_wmutex, &mattr)))
3852 pthread_mutexattr_destroy(&mattr);
3853 #endif /* _WIN32 || MDB_USE_POSIX_SEM */
3855 env->me_txns->mti_magic = MDB_MAGIC;
3856 env->me_txns->mti_format = MDB_LOCK_FORMAT;
3857 env->me_txns->mti_txnid = 0;
3858 env->me_txns->mti_numreaders = 0;
3861 if (env->me_txns->mti_magic != MDB_MAGIC) {
3862 DPUTS("lock region has invalid magic");
3866 if (env->me_txns->mti_format != MDB_LOCK_FORMAT) {
3867 DPRINTF(("lock region has format+version 0x%x, expected 0x%x",
3868 env->me_txns->mti_format, MDB_LOCK_FORMAT));
3869 rc = MDB_VERSION_MISMATCH;
3873 if (rc && rc != EACCES && rc != EAGAIN) {
3877 env->me_rmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);
3878 if (!env->me_rmutex) goto fail_errno;
3879 env->me_wmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
3880 if (!env->me_wmutex) goto fail_errno;
3881 #elif defined(MDB_USE_POSIX_SEM)
3882 env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0);
3883 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
3884 env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0);
3885 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
3896 /** The name of the lock file in the DB environment */
3897 #define LOCKNAME "/lock.mdb"
3898 /** The name of the data file in the DB environment */
3899 #define DATANAME "/data.mdb"
3900 /** The suffix of the lock file when no subdir is used */
3901 #define LOCKSUFF "-lock"
3902 /** Only a subset of the @ref mdb_env flags can be changed
3903 * at runtime. Changing other flags requires closing the
3904 * environment and re-opening it with the new flags.
3906 #define CHANGEABLE (MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC)
3907 #define CHANGELESS (MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY|MDB_WRITEMAP|MDB_NOTLS)
3910 mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode)
3912 int oflags, rc, len, excl = -1;
3913 char *lpath, *dpath;
3915 if (env->me_fd!=INVALID_HANDLE_VALUE || (flags & ~(CHANGEABLE|CHANGELESS)))
3919 if (flags & MDB_NOSUBDIR) {
3920 rc = len + sizeof(LOCKSUFF) + len + 1;
3922 rc = len + sizeof(LOCKNAME) + len + sizeof(DATANAME);
3927 if (flags & MDB_NOSUBDIR) {
3928 dpath = lpath + len + sizeof(LOCKSUFF);
3929 sprintf(lpath, "%s" LOCKSUFF, path);
3930 strcpy(dpath, path);
3932 dpath = lpath + len + sizeof(LOCKNAME);
3933 sprintf(lpath, "%s" LOCKNAME, path);
3934 sprintf(dpath, "%s" DATANAME, path);
3938 flags |= env->me_flags;
3939 if (flags & MDB_RDONLY) {
3940 /* silently ignore WRITEMAP when we're only getting read access */
3941 flags &= ~MDB_WRITEMAP;
3943 if (!((env->me_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)) &&
3944 (env->me_dirty_list = calloc(MDB_IDL_UM_SIZE, sizeof(MDB_ID2)))))
3947 env->me_flags = flags |= MDB_ENV_ACTIVE;
3951 env->me_path = strdup(path);
3952 env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx));
3953 env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t));
3954 if (!(env->me_dbxs && env->me_path && env->me_dbflags)) {
3959 /* For RDONLY, get lockfile after we know datafile exists */
3960 if (!F_ISSET(flags, MDB_RDONLY)) {
3961 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
3967 if (F_ISSET(flags, MDB_RDONLY)) {
3968 oflags = GENERIC_READ;
3969 len = OPEN_EXISTING;
3971 oflags = GENERIC_READ|GENERIC_WRITE;
3974 mode = FILE_ATTRIBUTE_NORMAL;
3975 env->me_fd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
3976 NULL, len, mode, NULL);
3978 if (F_ISSET(flags, MDB_RDONLY))
3981 oflags = O_RDWR | O_CREAT;
3983 env->me_fd = open(dpath, oflags, mode);
3985 if (env->me_fd == INVALID_HANDLE_VALUE) {
3990 if (F_ISSET(flags, MDB_RDONLY)) {
3991 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
3996 if ((rc = mdb_env_open2(env)) == MDB_SUCCESS) {
3997 if (flags & (MDB_RDONLY|MDB_WRITEMAP)) {
3998 env->me_mfd = env->me_fd;
4000 /* Synchronous fd for meta writes. Needed even with
4001 * MDB_NOSYNC/MDB_NOMETASYNC, in case these get reset.
4004 len = OPEN_EXISTING;
4005 env->me_mfd = CreateFile(dpath, oflags,
4006 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len,
4007 mode | FILE_FLAG_WRITE_THROUGH, NULL);
4010 env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode);
4012 if (env->me_mfd == INVALID_HANDLE_VALUE) {
4017 DPRINTF(("opened dbenv %p", (void *) env));
4019 rc = mdb_env_share_locks(env, &excl);
4025 mdb_env_close0(env, excl);
4031 /** Destroy resources from mdb_env_open(), clear our readers & DBIs */
4033 mdb_env_close0(MDB_env *env, int excl)
4037 if (!(env->me_flags & MDB_ENV_ACTIVE))
4040 /* Doing this here since me_dbxs may not exist during mdb_env_close */
4041 for (i = env->me_maxdbs; --i > MAIN_DBI; )
4042 free(env->me_dbxs[i].md_name.mv_data);
4044 free(env->me_dbflags);
4047 free(env->me_dirty_list);
4048 mdb_midl_free(env->me_free_pgs);
4050 if (env->me_flags & MDB_ENV_TXKEY) {
4051 pthread_key_delete(env->me_txkey);
4053 /* Delete our key from the global list */
4054 for (i=0; i<mdb_tls_nkeys; i++)
4055 if (mdb_tls_keys[i] == env->me_txkey) {
4056 mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1];
4064 munmap(env->me_map, env->me_mapsize);
4066 if (env->me_mfd != env->me_fd && env->me_mfd != INVALID_HANDLE_VALUE)
4067 (void) close(env->me_mfd);
4068 if (env->me_fd != INVALID_HANDLE_VALUE)
4069 (void) close(env->me_fd);
4071 pid_t pid = env->me_pid;
4072 /* Clearing readers is done in this function because
4073 * me_txkey with its destructor must be disabled first.
4075 for (i = env->me_numreaders; --i >= 0; )
4076 if (env->me_txns->mti_readers[i].mr_pid == pid)
4077 env->me_txns->mti_readers[i].mr_pid = 0;
4079 if (env->me_rmutex) {
4080 CloseHandle(env->me_rmutex);
4081 if (env->me_wmutex) CloseHandle(env->me_wmutex);
4083 /* Windows automatically destroys the mutexes when
4084 * the last handle closes.
4086 #elif defined(MDB_USE_POSIX_SEM)
4087 if (env->me_rmutex != SEM_FAILED) {
4088 sem_close(env->me_rmutex);
4089 if (env->me_wmutex != SEM_FAILED)
4090 sem_close(env->me_wmutex);
4091 /* If we have the filelock: If we are the
4092 * only remaining user, clean up semaphores.
4095 mdb_env_excl_lock(env, &excl);
4097 sem_unlink(env->me_txns->mti_rmname);
4098 sem_unlink(env->me_txns->mti_wmname);
4102 munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
4104 if (env->me_lfd != INVALID_HANDLE_VALUE) {
4107 /* Unlock the lockfile. Windows would have unlocked it
4108 * after closing anyway, but not necessarily at once.
4110 UnlockFile(env->me_lfd, 0, 0, 1, 0);
4113 (void) close(env->me_lfd);
4116 env->me_flags &= ~(MDB_ENV_ACTIVE|MDB_ENV_TXKEY);
4120 mdb_env_copyfd(MDB_env *env, HANDLE fd)
4122 MDB_txn *txn = NULL;
4128 #define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL)
4132 #define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0)
4135 /* Do the lock/unlock of the reader mutex before starting the
4136 * write txn. Otherwise other read txns could block writers.
4138 rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
4143 /* We must start the actual read txn after blocking writers */
4144 mdb_txn_reset0(txn, "reset-stage1");
4146 /* Temporarily block writers until we snapshot the meta pages */
4149 rc = mdb_txn_renew0(txn);
4151 UNLOCK_MUTEX_W(env);
4156 wsize = env->me_psize * 2;
4160 DO_WRITE(rc, fd, ptr, w2, len);
4164 } else if (len > 0) {
4170 /* Non-blocking or async handles are not supported */
4176 UNLOCK_MUTEX_W(env);
4181 wsize = txn->mt_next_pgno * env->me_psize - wsize;
4183 if (wsize > MAX_WRITE)
4187 DO_WRITE(rc, fd, ptr, w2, len);
4191 } else if (len > 0) {
4208 mdb_env_copy(MDB_env *env, const char *path)
4212 HANDLE newfd = INVALID_HANDLE_VALUE;
4214 if (env->me_flags & MDB_NOSUBDIR) {
4215 lpath = (char *)path;
4218 len += sizeof(DATANAME);
4219 lpath = malloc(len);
4222 sprintf(lpath, "%s" DATANAME, path);
4225 /* The destination path must exist, but the destination file must not.
4226 * We don't want the OS to cache the writes, since the source data is
4227 * already in the OS cache.
4230 newfd = CreateFile(lpath, GENERIC_WRITE, 0, NULL, CREATE_NEW,
4231 FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL);
4233 newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL, 0666);
4235 if (newfd == INVALID_HANDLE_VALUE) {
4241 /* Set O_DIRECT if the file system supports it */
4242 if ((rc = fcntl(newfd, F_GETFL)) != -1)
4243 (void) fcntl(newfd, F_SETFL, rc | O_DIRECT);
4245 #ifdef F_NOCACHE /* __APPLE__ */
4246 rc = fcntl(newfd, F_NOCACHE, 1);
4253 rc = mdb_env_copyfd(env, newfd);
4256 if (!(env->me_flags & MDB_NOSUBDIR))
4258 if (newfd != INVALID_HANDLE_VALUE)
4259 if (close(newfd) < 0 && rc == MDB_SUCCESS)
4266 mdb_env_close(MDB_env *env)
4273 VGMEMP_DESTROY(env);
4274 while ((dp = env->me_dpages) != NULL) {
4275 VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next));
4276 env->me_dpages = dp->mp_next;
4280 mdb_env_close0(env, 0);
4284 /** Compare two items pointing at aligned size_t's */
4286 mdb_cmp_long(const MDB_val *a, const MDB_val *b)
4288 return (*(size_t *)a->mv_data < *(size_t *)b->mv_data) ? -1 :
4289 *(size_t *)a->mv_data > *(size_t *)b->mv_data;
4292 /** Compare two items pointing at aligned unsigned int's */
4294 mdb_cmp_int(const MDB_val *a, const MDB_val *b)
4296 return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 :
4297 *(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data;
4300 /** Compare two items pointing at unsigned ints of unknown alignment.
4301 * Nodes and keys are guaranteed to be 2-byte aligned.
4304 mdb_cmp_cint(const MDB_val *a, const MDB_val *b)
4306 #if BYTE_ORDER == LITTLE_ENDIAN
4307 unsigned short *u, *c;
4310 u = (unsigned short *) ((char *) a->mv_data + a->mv_size);
4311 c = (unsigned short *) ((char *) b->mv_data + a->mv_size);
4314 } while(!x && u > (unsigned short *)a->mv_data);
4317 return memcmp(a->mv_data, b->mv_data, a->mv_size);
4321 /** Compare two items lexically */
4323 mdb_cmp_memn(const MDB_val *a, const MDB_val *b)
4330 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
4336 diff = memcmp(a->mv_data, b->mv_data, len);
4337 return diff ? diff : len_diff<0 ? -1 : len_diff;
4340 /** Compare two items in reverse byte order */
4342 mdb_cmp_memnr(const MDB_val *a, const MDB_val *b)
4344 const unsigned char *p1, *p2, *p1_lim;
4348 p1_lim = (const unsigned char *)a->mv_data;
4349 p1 = (const unsigned char *)a->mv_data + a->mv_size;
4350 p2 = (const unsigned char *)b->mv_data + b->mv_size;
4352 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
4358 while (p1 > p1_lim) {
4359 diff = *--p1 - *--p2;
4363 return len_diff<0 ? -1 : len_diff;
4366 /** Search for key within a page, using binary search.
4367 * Returns the smallest entry larger or equal to the key.
4368 * If exactp is non-null, stores whether the found entry was an exact match
4369 * in *exactp (1 or 0).
4370 * Updates the cursor index with the index of the found entry.
4371 * If no entry larger or equal to the key is found, returns NULL.
4374 mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)
4376 unsigned int i = 0, nkeys;
4379 MDB_page *mp = mc->mc_pg[mc->mc_top];
4380 MDB_node *node = NULL;
4385 nkeys = NUMKEYS(mp);
4390 COPY_PGNO(pgno, mp->mp_pgno);
4391 DPRINTF(("searching %u keys in %s %spage %"Z"u",
4392 nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "",
4399 low = IS_LEAF(mp) ? 0 : 1;
4401 cmp = mc->mc_dbx->md_cmp;
4403 /* Branch pages have no data, so if using integer keys,
4404 * alignment is guaranteed. Use faster mdb_cmp_int.
4406 if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) {
4407 if (NODEPTR(mp, 1)->mn_ksize == sizeof(size_t))
4414 nodekey.mv_size = mc->mc_db->md_pad;
4415 node = NODEPTR(mp, 0); /* fake */
4416 while (low <= high) {
4417 i = (low + high) >> 1;
4418 nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size);
4419 rc = cmp(key, &nodekey);
4420 DPRINTF(("found leaf index %u [%s], rc = %i",
4421 i, DKEY(&nodekey), rc));
4430 while (low <= high) {
4431 i = (low + high) >> 1;
4433 node = NODEPTR(mp, i);
4434 nodekey.mv_size = NODEKSZ(node);
4435 nodekey.mv_data = NODEKEY(node);
4437 rc = cmp(key, &nodekey);
4440 DPRINTF(("found leaf index %u [%s], rc = %i",
4441 i, DKEY(&nodekey), rc));
4443 DPRINTF(("found branch index %u [%s -> %"Z"u], rc = %i",
4444 i, DKEY(&nodekey), NODEPGNO(node), rc));
4455 if (rc > 0) { /* Found entry is less than the key. */
4456 i++; /* Skip to get the smallest entry larger than key. */
4458 node = NODEPTR(mp, i);
4461 *exactp = (rc == 0);
4462 /* store the key index */
4463 mc->mc_ki[mc->mc_top] = i;
4465 /* There is no entry larger or equal to the key. */
4468 /* nodeptr is fake for LEAF2 */
4474 mdb_cursor_adjust(MDB_cursor *mc, func)
4478 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
4479 if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) {
4486 /** Pop a page off the top of the cursor's stack. */
4488 mdb_cursor_pop(MDB_cursor *mc)
4492 MDB_page *top = mc->mc_pg[mc->mc_top];
4498 DPRINTF(("popped page %"Z"u off db %u cursor %p", top->mp_pgno,
4499 mc->mc_dbi, (void *) mc));
4503 /** Push a page onto the top of the cursor's stack. */
4505 mdb_cursor_push(MDB_cursor *mc, MDB_page *mp)
4507 DPRINTF(("pushing page %"Z"u on db %u cursor %p", mp->mp_pgno,
4508 mc->mc_dbi, (void *) mc));
4510 if (mc->mc_snum >= CURSOR_STACK) {
4511 assert(mc->mc_snum < CURSOR_STACK);
4512 return MDB_CURSOR_FULL;
4515 mc->mc_top = mc->mc_snum++;
4516 mc->mc_pg[mc->mc_top] = mp;
4517 mc->mc_ki[mc->mc_top] = 0;
4522 /** Find the address of the page corresponding to a given page number.
4523 * @param[in] txn the transaction for this access.
4524 * @param[in] pgno the page number for the page to retrieve.
4525 * @param[out] ret address of a pointer where the page's address will be stored.
4526 * @param[out] lvl dirty_list inheritance level of found page. 1=current txn, 0=mapped page.
4527 * @return 0 on success, non-zero on failure.
4530 mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret, int *lvl)
4532 MDB_env *env = txn->mt_env;
4536 if (!((txn->mt_flags & MDB_TXN_RDONLY) | (env->me_flags & MDB_WRITEMAP))) {
4540 MDB_ID2L dl = tx2->mt_u.dirty_list;
4542 /* Spilled pages were dirtied in this txn and flushed
4543 * because the dirty list got full. Bring this page
4544 * back in from the map (but don't unspill it here,
4545 * leave that unless page_touch happens again).
4547 if (tx2->mt_spill_pgs) {
4548 MDB_ID pn = pgno << 1;
4549 x = mdb_midl_search(tx2->mt_spill_pgs, pn);
4550 if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
4551 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
4556 unsigned x = mdb_mid2l_search(dl, pgno);
4557 if (x <= dl[0].mid && dl[x].mid == pgno) {
4563 } while ((tx2 = tx2->mt_parent) != NULL);
4566 if (pgno < txn->mt_next_pgno) {
4568 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
4570 DPRINTF(("page %"Z"u not found", pgno));
4572 return MDB_PAGE_NOTFOUND;
4582 /** Finish #mdb_page_search() / #mdb_page_search_lowest().
4583 * The cursor is at the root page, set up the rest of it.
4586 mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags)
4588 MDB_page *mp = mc->mc_pg[mc->mc_top];
4592 while (IS_BRANCH(mp)) {
4596 DPRINTF(("branch page %"Z"u has %u keys", mp->mp_pgno, NUMKEYS(mp)));
4597 assert(NUMKEYS(mp) > 1);
4598 DPRINTF(("found index 0 to page %"Z"u", NODEPGNO(NODEPTR(mp, 0))));
4600 if (flags & (MDB_PS_FIRST|MDB_PS_LAST)) {
4602 if (flags & MDB_PS_LAST)
4603 i = NUMKEYS(mp) - 1;
4606 node = mdb_node_search(mc, key, &exact);
4608 i = NUMKEYS(mp) - 1;
4610 i = mc->mc_ki[mc->mc_top];
4616 DPRINTF(("following index %u for key [%s]", i, DKEY(key)));
4619 assert(i < NUMKEYS(mp));
4620 node = NODEPTR(mp, i);
4622 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
4625 mc->mc_ki[mc->mc_top] = i;
4626 if ((rc = mdb_cursor_push(mc, mp)))
4629 if (flags & MDB_PS_MODIFY) {
4630 if ((rc = mdb_page_touch(mc)) != 0)
4632 mp = mc->mc_pg[mc->mc_top];
4637 DPRINTF(("internal error, index points to a %02X page!?",
4639 return MDB_CORRUPTED;
4642 DPRINTF(("found leaf page %"Z"u for key [%s]", mp->mp_pgno,
4643 key ? DKEY(key) : "null"));
4644 mc->mc_flags |= C_INITIALIZED;
4645 mc->mc_flags &= ~C_EOF;
4650 /** Search for the lowest key under the current branch page.
4651 * This just bypasses a NUMKEYS check in the current page
4652 * before calling mdb_page_search_root(), because the callers
4653 * are all in situations where the current page is known to
4657 mdb_page_search_lowest(MDB_cursor *mc)
4659 MDB_page *mp = mc->mc_pg[mc->mc_top];
4660 MDB_node *node = NODEPTR(mp, 0);
4663 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
4666 mc->mc_ki[mc->mc_top] = 0;
4667 if ((rc = mdb_cursor_push(mc, mp)))
4669 return mdb_page_search_root(mc, NULL, MDB_PS_FIRST);
4672 /** Search for the page a given key should be in.
4673 * Push it and its parent pages on the cursor stack.
4674 * @param[in,out] mc the cursor for this operation.
4675 * @param[in] key the key to search for, or NULL for first/last page.
4676 * @param[in] flags If MDB_PS_MODIFY is set, visited pages in the DB
4677 * are touched (updated with new page numbers).
4678 * If MDB_PS_FIRST or MDB_PS_LAST is set, find first or last leaf.
4679 * This is used by #mdb_cursor_first() and #mdb_cursor_last().
4680 * If MDB_PS_ROOTONLY set, just fetch root node, no further lookups.
4681 * @return 0 on success, non-zero on failure.
4684 mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)
4689 /* Make sure the txn is still viable, then find the root from
4690 * the txn's db table and set it as the root of the cursor's stack.
4692 if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_ERROR)) {
4693 DPUTS("transaction has failed, must abort");
4696 /* Make sure we're using an up-to-date root */
4697 if (*mc->mc_dbflag & DB_STALE) {
4699 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);
4700 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, 0);
4707 MDB_node *leaf = mdb_node_search(&mc2,
4708 &mc->mc_dbx->md_name, &exact);
4710 return MDB_NOTFOUND;
4711 rc = mdb_node_read(mc->mc_txn, leaf, &data);
4714 memcpy(&flags, ((char *) data.mv_data + offsetof(MDB_db, md_flags)),
4716 /* The txn may not know this DBI, or another process may
4717 * have dropped and recreated the DB with other flags.
4719 if ((mc->mc_db->md_flags & PERSISTENT_FLAGS) != flags)
4720 return MDB_INCOMPATIBLE;
4721 memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db));
4723 *mc->mc_dbflag &= ~DB_STALE;
4725 root = mc->mc_db->md_root;
4727 if (root == P_INVALID) { /* Tree is empty. */
4728 DPUTS("tree is empty");
4729 return MDB_NOTFOUND;
4734 if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root)
4735 if ((rc = mdb_page_get(mc->mc_txn, root, &mc->mc_pg[0], NULL)) != 0)
4741 DPRINTF(("db %u root page %"Z"u has flags 0x%X",
4742 mc->mc_dbi, root, mc->mc_pg[0]->mp_flags));
4744 if (flags & MDB_PS_MODIFY) {
4745 if ((rc = mdb_page_touch(mc)))
4749 if (flags & MDB_PS_ROOTONLY)
4752 return mdb_page_search_root(mc, key, flags);
4756 mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
4758 MDB_txn *txn = mc->mc_txn;
4759 pgno_t pg = mp->mp_pgno;
4760 unsigned x = 0, ovpages = mp->mp_pages;
4761 MDB_env *env = txn->mt_env;
4762 MDB_IDL sl = txn->mt_spill_pgs;
4763 MDB_ID pn = pg << 1;
4766 DPRINTF(("free ov page %"Z"u (%d)", pg, ovpages));
4767 /* If the page is dirty or on the spill list we just acquired it,
4768 * so we should give it back to our current free list, if any.
4769 * Otherwise put it onto the list of pages we freed in this txn.
4771 * Won't create me_pghead: me_pglast must be inited along with it.
4772 * Unsupported in nested txns: They would need to hide the page
4773 * range in ancestor txns' dirty and spilled lists.
4775 if (env->me_pghead &&
4777 ((mp->mp_flags & P_DIRTY) ||
4778 (sl && (x = mdb_midl_search(sl, pn)) <= sl[0] && sl[x] == pn)))
4782 MDB_ID2 *dl, ix, iy;
4783 rc = mdb_midl_need(&env->me_pghead, ovpages);
4786 if (!(mp->mp_flags & P_DIRTY)) {
4787 /* This page is no longer spilled */
4794 /* Remove from dirty list */
4795 dl = txn->mt_u.dirty_list;
4797 for (ix = dl[x]; ix.mptr != mp; ix = iy) {
4805 dl[j] = ix; /* Unsorted. OK when MDB_TXN_ERROR. */
4806 txn->mt_flags |= MDB_TXN_ERROR;
4807 return MDB_CORRUPTED;
4810 if (!(env->me_flags & MDB_WRITEMAP))
4811 mdb_dpage_free(env, mp);
4813 /* Insert in me_pghead */
4814 mop = env->me_pghead;
4815 j = mop[0] + ovpages;
4816 for (i = mop[0]; i && mop[i] < pg; i--)
4822 rc = mdb_midl_append_range(&txn->mt_free_pgs, pg, ovpages);
4826 mc->mc_db->md_overflow_pages -= ovpages;
4830 /** Return the data associated with a given node.
4831 * @param[in] txn The transaction for this operation.
4832 * @param[in] leaf The node being read.
4833 * @param[out] data Updated to point to the node's data.
4834 * @return 0 on success, non-zero on failure.
4837 mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data)
4839 MDB_page *omp; /* overflow page */
4843 if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
4844 data->mv_size = NODEDSZ(leaf);
4845 data->mv_data = NODEDATA(leaf);
4849 /* Read overflow data.
4851 data->mv_size = NODEDSZ(leaf);
4852 memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
4853 if ((rc = mdb_page_get(txn, pgno, &omp, NULL)) != 0) {
4854 DPRINTF(("read overflow page %"Z"u failed", pgno));
4857 data->mv_data = METADATA(omp);
4863 mdb_get(MDB_txn *txn, MDB_dbi dbi,
4864 MDB_val *key, MDB_val *data)
4873 DPRINTF(("===> get db %u key [%s]", dbi, DKEY(key)));
4875 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs || !(txn->mt_dbflags[dbi] & DB_VALID))
4878 if (txn->mt_flags & MDB_TXN_ERROR)
4881 if (key->mv_size == 0 || key->mv_size > MDB_MAXKEYSIZE) {
4882 return MDB_BAD_VALSIZE;
4885 mdb_cursor_init(&mc, txn, dbi, &mx);
4886 return mdb_cursor_set(&mc, key, data, MDB_SET, &exact);
4889 /** Find a sibling for a page.
4890 * Replaces the page at the top of the cursor's stack with the
4891 * specified sibling, if one exists.
4892 * @param[in] mc The cursor for this operation.
4893 * @param[in] move_right Non-zero if the right sibling is requested,
4894 * otherwise the left sibling.
4895 * @return 0 on success, non-zero on failure.
4898 mdb_cursor_sibling(MDB_cursor *mc, int move_right)
4904 if (mc->mc_snum < 2) {
4905 return MDB_NOTFOUND; /* root has no siblings */
4909 DPRINTF(("parent page is page %"Z"u, index %u",
4910 mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]));
4912 if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top]))
4913 : (mc->mc_ki[mc->mc_top] == 0)) {
4914 DPRINTF(("no more keys left, moving to %s sibling",
4915 move_right ? "right" : "left"));
4916 if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) {
4917 /* undo cursor_pop before returning */
4924 mc->mc_ki[mc->mc_top]++;
4926 mc->mc_ki[mc->mc_top]--;
4927 DPRINTF(("just moving to %s index key %u",
4928 move_right ? "right" : "left", mc->mc_ki[mc->mc_top]));
4930 assert(IS_BRANCH(mc->mc_pg[mc->mc_top]));
4932 indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
4933 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(indx), &mp, NULL) != 0))
4936 mdb_cursor_push(mc, mp);
4938 mc->mc_ki[mc->mc_top] = NUMKEYS(mp)-1;
4943 /** Move the cursor to the next data item. */
4945 mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
4951 if (mc->mc_flags & C_EOF) {
4952 return MDB_NOTFOUND;
4955 assert(mc->mc_flags & C_INITIALIZED);
4957 mp = mc->mc_pg[mc->mc_top];
4959 if (mc->mc_db->md_flags & MDB_DUPSORT) {
4960 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
4961 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4962 if (op == MDB_NEXT || op == MDB_NEXT_DUP) {
4963 rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);
4964 if (op != MDB_NEXT || rc != MDB_NOTFOUND) {
4965 if (rc == MDB_SUCCESS)
4966 MDB_GET_KEY(leaf, key);
4971 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
4972 if (op == MDB_NEXT_DUP)
4973 return MDB_NOTFOUND;
4977 DPRINTF(("cursor_next: top page is %"Z"u in cursor %p", mp->mp_pgno, (void *) mc));
4978 if (mc->mc_flags & C_DEL)
4981 if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) {
4982 DPUTS("=====> move to next sibling page");
4983 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
4984 mc->mc_flags |= C_EOF;
4987 mp = mc->mc_pg[mc->mc_top];
4988 DPRINTF(("next page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
4990 mc->mc_ki[mc->mc_top]++;
4993 DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
4994 mp->mp_pgno, NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
4997 key->mv_size = mc->mc_db->md_pad;
4998 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5002 assert(IS_LEAF(mp));
5003 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5005 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5006 mdb_xcursor_init1(mc, leaf);
5009 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5012 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5013 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
5014 if (rc != MDB_SUCCESS)
5019 MDB_GET_KEY(leaf, key);
5023 /** Move the cursor to the previous data item. */
5025 mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
5031 assert(mc->mc_flags & C_INITIALIZED);
5033 mp = mc->mc_pg[mc->mc_top];
5035 if (mc->mc_db->md_flags & MDB_DUPSORT) {
5036 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5037 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5038 if (op == MDB_PREV || op == MDB_PREV_DUP) {
5039 rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
5040 if (op != MDB_PREV || rc != MDB_NOTFOUND) {
5041 if (rc == MDB_SUCCESS)
5042 MDB_GET_KEY(leaf, key);
5046 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5047 if (op == MDB_PREV_DUP)
5048 return MDB_NOTFOUND;
5053 DPRINTF(("cursor_prev: top page is %"Z"u in cursor %p", mp->mp_pgno, (void *) mc));
5055 if (mc->mc_ki[mc->mc_top] == 0) {
5056 DPUTS("=====> move to prev sibling page");
5057 if ((rc = mdb_cursor_sibling(mc, 0)) != MDB_SUCCESS) {
5060 mp = mc->mc_pg[mc->mc_top];
5061 mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;
5062 DPRINTF(("prev page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
5064 mc->mc_ki[mc->mc_top]--;
5066 mc->mc_flags &= ~C_EOF;
5068 DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
5069 mp->mp_pgno, NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
5072 key->mv_size = mc->mc_db->md_pad;
5073 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5077 assert(IS_LEAF(mp));
5078 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5080 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5081 mdb_xcursor_init1(mc, leaf);
5084 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5087 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5088 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
5089 if (rc != MDB_SUCCESS)
5094 MDB_GET_KEY(leaf, key);
5098 /** Set the cursor on a specific data item. */
5100 mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data,
5101 MDB_cursor_op op, int *exactp)
5105 MDB_node *leaf = NULL;
5110 assert(key->mv_size > 0);
5113 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5115 /* See if we're already on the right page */
5116 if (mc->mc_flags & C_INITIALIZED) {
5119 mp = mc->mc_pg[mc->mc_top];
5121 mc->mc_ki[mc->mc_top] = 0;
5122 return MDB_NOTFOUND;
5124 if (mp->mp_flags & P_LEAF2) {
5125 nodekey.mv_size = mc->mc_db->md_pad;
5126 nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size);
5128 leaf = NODEPTR(mp, 0);
5129 MDB_GET_KEY2(leaf, nodekey);
5131 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5133 /* Probably happens rarely, but first node on the page
5134 * was the one we wanted.
5136 mc->mc_ki[mc->mc_top] = 0;
5143 unsigned int nkeys = NUMKEYS(mp);
5145 if (mp->mp_flags & P_LEAF2) {
5146 nodekey.mv_data = LEAF2KEY(mp,
5147 nkeys-1, nodekey.mv_size);
5149 leaf = NODEPTR(mp, nkeys-1);
5150 MDB_GET_KEY2(leaf, nodekey);
5152 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5154 /* last node was the one we wanted */
5155 mc->mc_ki[mc->mc_top] = nkeys-1;
5161 if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) {
5162 /* This is definitely the right page, skip search_page */
5163 if (mp->mp_flags & P_LEAF2) {
5164 nodekey.mv_data = LEAF2KEY(mp,
5165 mc->mc_ki[mc->mc_top], nodekey.mv_size);
5167 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5168 MDB_GET_KEY2(leaf, nodekey);
5170 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5172 /* current node was the one we wanted */
5182 /* If any parents have right-sibs, search.
5183 * Otherwise, there's nothing further.
5185 for (i=0; i<mc->mc_top; i++)
5187 NUMKEYS(mc->mc_pg[i])-1)
5189 if (i == mc->mc_top) {
5190 /* There are no other pages */
5191 mc->mc_ki[mc->mc_top] = nkeys;
5192 return MDB_NOTFOUND;
5196 /* There are no other pages */
5197 mc->mc_ki[mc->mc_top] = 0;
5198 if (op == MDB_SET_RANGE) {
5202 return MDB_NOTFOUND;
5206 rc = mdb_page_search(mc, key, 0);
5207 if (rc != MDB_SUCCESS)
5210 mp = mc->mc_pg[mc->mc_top];
5211 assert(IS_LEAF(mp));
5214 leaf = mdb_node_search(mc, key, exactp);
5215 if (exactp != NULL && !*exactp) {
5216 /* MDB_SET specified and not an exact match. */
5217 return MDB_NOTFOUND;
5221 DPUTS("===> inexact leaf not found, goto sibling");
5222 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS)
5223 return rc; /* no entries matched */
5224 mp = mc->mc_pg[mc->mc_top];
5225 assert(IS_LEAF(mp));
5226 leaf = NODEPTR(mp, 0);
5230 mc->mc_flags |= C_INITIALIZED;
5231 mc->mc_flags &= ~C_EOF;
5234 key->mv_size = mc->mc_db->md_pad;
5235 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5239 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5240 mdb_xcursor_init1(mc, leaf);
5243 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5244 if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) {
5245 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
5248 if (op == MDB_GET_BOTH) {
5254 rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p);
5255 if (rc != MDB_SUCCESS)
5258 } else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {
5260 if ((rc = mdb_node_read(mc->mc_txn, leaf, &d2)) != MDB_SUCCESS)
5262 rc = mc->mc_dbx->md_dcmp(data, &d2);
5264 if (op == MDB_GET_BOTH || rc > 0)
5265 return MDB_NOTFOUND;
5271 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5272 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5277 /* The key already matches in all other cases */
5278 if (op == MDB_SET_RANGE || op == MDB_SET_KEY)
5279 MDB_GET_KEY(leaf, key);
5280 DPRINTF(("==> cursor placed on key [%s]", DKEY(key)));
5285 /** Move the cursor to the first item in the database. */
5287 mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data)
5293 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5295 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
5296 rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
5297 if (rc != MDB_SUCCESS)
5300 assert(IS_LEAF(mc->mc_pg[mc->mc_top]));
5302 leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0);
5303 mc->mc_flags |= C_INITIALIZED;
5304 mc->mc_flags &= ~C_EOF;
5306 mc->mc_ki[mc->mc_top] = 0;
5308 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
5309 key->mv_size = mc->mc_db->md_pad;
5310 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size);
5315 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5316 mdb_xcursor_init1(mc, leaf);
5317 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
5321 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5325 MDB_GET_KEY(leaf, key);
5329 /** Move the cursor to the last item in the database. */
5331 mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)
5337 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5339 if (!(mc->mc_flags & C_EOF)) {
5341 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
5342 rc = mdb_page_search(mc, NULL, MDB_PS_LAST);
5343 if (rc != MDB_SUCCESS)
5346 assert(IS_LEAF(mc->mc_pg[mc->mc_top]));
5349 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;
5350 mc->mc_flags |= C_INITIALIZED|C_EOF;
5351 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5353 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
5354 key->mv_size = mc->mc_db->md_pad;
5355 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size);
5360 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5361 mdb_xcursor_init1(mc, leaf);
5362 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
5366 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5371 MDB_GET_KEY(leaf, key);
5376 mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,
5381 int (*mfunc)(MDB_cursor *mc, MDB_val *key, MDB_val *data);
5385 if (mc->mc_txn->mt_flags & MDB_TXN_ERROR)
5389 case MDB_GET_CURRENT:
5390 if (!(mc->mc_flags & C_INITIALIZED)) {
5393 MDB_page *mp = mc->mc_pg[mc->mc_top];
5395 mc->mc_ki[mc->mc_top] = 0;
5401 key->mv_size = mc->mc_db->md_pad;
5402 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5404 MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5405 MDB_GET_KEY(leaf, key);
5407 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5408 if (mc->mc_flags & C_DEL)
5409 mdb_xcursor_init1(mc, leaf);
5410 rc = mdb_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT);
5412 rc = mdb_node_read(mc->mc_txn, leaf, data);
5419 case MDB_GET_BOTH_RANGE:
5424 if (mc->mc_xcursor == NULL) {
5425 rc = MDB_INCOMPATIBLE;
5434 } else if (key->mv_size == 0 || key->mv_size > MDB_MAXKEYSIZE) {
5435 rc = MDB_BAD_VALSIZE;
5436 } else if (op == MDB_SET_RANGE)
5437 rc = mdb_cursor_set(mc, key, data, op, NULL);
5439 rc = mdb_cursor_set(mc, key, data, op, &exact);
5441 case MDB_GET_MULTIPLE:
5442 if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
5446 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
5447 rc = MDB_INCOMPATIBLE;
5451 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) ||
5452 (mc->mc_xcursor->mx_cursor.mc_flags & C_EOF))
5455 case MDB_NEXT_MULTIPLE:
5460 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
5461 rc = MDB_INCOMPATIBLE;
5464 if (!(mc->mc_flags & C_INITIALIZED))
5465 rc = mdb_cursor_first(mc, key, data);
5467 rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP);
5468 if (rc == MDB_SUCCESS) {
5469 if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
5472 mx = &mc->mc_xcursor->mx_cursor;
5473 data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) *
5475 data->mv_data = METADATA(mx->mc_pg[mx->mc_top]);
5476 mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1;
5484 case MDB_NEXT_NODUP:
5485 if (!(mc->mc_flags & C_INITIALIZED))
5486 rc = mdb_cursor_first(mc, key, data);
5488 rc = mdb_cursor_next(mc, key, data, op);
5492 case MDB_PREV_NODUP:
5493 if (!(mc->mc_flags & C_INITIALIZED)) {
5494 rc = mdb_cursor_last(mc, key, data);
5497 mc->mc_flags |= C_INITIALIZED;
5498 mc->mc_ki[mc->mc_top]++;
5500 rc = mdb_cursor_prev(mc, key, data, op);
5503 rc = mdb_cursor_first(mc, key, data);
5506 mfunc = mdb_cursor_first;
5508 if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
5512 if (mc->mc_xcursor == NULL) {
5513 rc = MDB_INCOMPATIBLE;
5516 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
5520 rc = mfunc(&mc->mc_xcursor->mx_cursor, data, NULL);
5523 rc = mdb_cursor_last(mc, key, data);
5526 mfunc = mdb_cursor_last;
5529 DPRINTF(("unhandled/unimplemented cursor operation %u", op));
5534 if (mc->mc_flags & C_DEL)
5535 mc->mc_flags ^= C_DEL;
5540 /** Touch all the pages in the cursor stack.
5541 * Makes sure all the pages are writable, before attempting a write operation.
5542 * @param[in] mc The cursor to operate on.
5545 mdb_cursor_touch(MDB_cursor *mc)
5549 if (mc->mc_dbi > MAIN_DBI && !(*mc->mc_dbflag & DB_DIRTY)) {
5552 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, &mcx);
5553 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY);
5556 *mc->mc_dbflag |= DB_DIRTY;
5558 for (mc->mc_top = 0; mc->mc_top < mc->mc_snum; mc->mc_top++) {
5559 rc = mdb_page_touch(mc);
5563 mc->mc_top = mc->mc_snum-1;
5567 /** Do not spill pages to disk if txn is getting full, may fail instead */
5568 #define MDB_NOSPILL 0x8000
5571 mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
5574 enum { MDB_NO_ROOT = MDB_LAST_ERRCODE+10 }; /* internal code */
5575 MDB_node *leaf = NULL;
5576 MDB_val xdata, *rdata, dkey;
5579 int do_sub = 0, insert = 0;
5580 unsigned int mcount = 0, dcount = 0, nospill;
5584 char dbuf[MDB_MAXKEYSIZE+1];
5585 unsigned int nflags;
5588 /* Check this first so counter will always be zero on any
5591 if (flags & MDB_MULTIPLE) {
5592 dcount = data[1].mv_size;
5593 data[1].mv_size = 0;
5594 if (!F_ISSET(mc->mc_db->md_flags, MDB_DUPFIXED))
5595 return MDB_INCOMPATIBLE;
5598 nospill = flags & MDB_NOSPILL;
5599 flags &= ~MDB_NOSPILL;
5601 if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
5602 return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
5604 if (flags != MDB_CURRENT && (key->mv_size == 0 || key->mv_size > MDB_MAXKEYSIZE))
5605 return MDB_BAD_VALSIZE;
5607 if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT) && data->mv_size > MDB_MAXKEYSIZE)
5608 return MDB_BAD_VALSIZE;
5610 #if SIZE_MAX > MAXDATASIZE
5611 if (data->mv_size > MAXDATASIZE)
5612 return MDB_BAD_VALSIZE;
5615 DPRINTF(("==> put db %u key [%s], size %"Z"u, data size %"Z"u",
5616 mc->mc_dbi, DKEY(key), key ? key->mv_size:0, data->mv_size));
5620 if (flags == MDB_CURRENT) {
5621 if (!(mc->mc_flags & C_INITIALIZED))
5624 } else if (mc->mc_db->md_root == P_INVALID) {
5625 /* new database, cursor has nothing to point to */
5627 mc->mc_flags &= ~C_INITIALIZED;
5632 if (flags & MDB_APPEND) {
5634 rc = mdb_cursor_last(mc, &k2, &d2);
5636 rc = mc->mc_dbx->md_cmp(key, &k2);
5639 mc->mc_ki[mc->mc_top]++;
5641 /* new key is <= last key */
5646 rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact);
5648 if ((flags & MDB_NOOVERWRITE) && rc == 0) {
5649 DPRINTF(("duplicate key [%s]", DKEY(key)));
5651 return MDB_KEYEXIST;
5653 if (rc && rc != MDB_NOTFOUND)
5657 if (mc->mc_flags & C_DEL)
5658 mc->mc_flags ^= C_DEL;
5660 /* Cursor is positioned, check for room in the dirty list */
5662 if (flags & MDB_MULTIPLE) {
5664 xdata.mv_size = data->mv_size * dcount;
5668 if ((rc2 = mdb_page_spill(mc, key, rdata)))
5672 if (rc == MDB_NO_ROOT) {
5674 /* new database, write a root leaf page */
5675 DPUTS("allocating new root leaf page");
5676 if ((rc2 = mdb_page_new(mc, P_LEAF, 1, &np))) {
5679 mdb_cursor_push(mc, np);
5680 mc->mc_db->md_root = np->mp_pgno;
5681 mc->mc_db->md_depth++;
5682 *mc->mc_dbflag |= DB_DIRTY;
5683 if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED))
5685 np->mp_flags |= P_LEAF2;
5686 mc->mc_flags |= C_INITIALIZED;
5688 /* make sure all cursor pages are writable */
5689 rc2 = mdb_cursor_touch(mc);
5694 /* The key already exists */
5695 if (rc == MDB_SUCCESS) {
5696 /* there's only a key anyway, so this is a no-op */
5697 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
5698 unsigned int ksize = mc->mc_db->md_pad;
5699 if (key->mv_size != ksize)
5700 return MDB_BAD_VALSIZE;
5701 if (flags == MDB_CURRENT) {
5702 char *ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize);
5703 memcpy(ptr, key->mv_data, ksize);
5708 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5711 if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) {
5712 /* Was a single item before, must convert now */
5714 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5715 /* Just overwrite the current item */
5716 if (flags == MDB_CURRENT)
5719 dkey.mv_size = NODEDSZ(leaf);
5720 dkey.mv_data = NODEDATA(leaf);
5721 #if UINT_MAX < SIZE_MAX
5722 if (mc->mc_dbx->md_dcmp == mdb_cmp_int && dkey.mv_size == sizeof(size_t))
5723 #ifdef MISALIGNED_OK
5724 mc->mc_dbx->md_dcmp = mdb_cmp_long;
5726 mc->mc_dbx->md_dcmp = mdb_cmp_cint;
5729 /* if data matches, skip it */
5730 if (!mc->mc_dbx->md_dcmp(data, &dkey)) {
5731 if (flags & MDB_NODUPDATA)
5733 else if (flags & MDB_MULTIPLE)
5740 /* create a fake page for the dup items */
5741 memcpy(dbuf, dkey.mv_data, dkey.mv_size);
5742 dkey.mv_data = dbuf;
5743 fp = (MDB_page *)&pbuf;
5744 fp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
5745 fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP;
5746 fp->mp_lower = PAGEHDRSZ;
5747 fp->mp_upper = PAGEHDRSZ + dkey.mv_size + data->mv_size;
5748 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
5749 fp->mp_flags |= P_LEAF2;
5750 fp->mp_pad = data->mv_size;
5751 fp->mp_upper += 2 * data->mv_size; /* leave space for 2 more */
5753 fp->mp_upper += 2 * sizeof(indx_t) + 2 * NODESIZE +
5754 (dkey.mv_size & 1) + (data->mv_size & 1);
5756 mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0);
5759 xdata.mv_size = fp->mp_upper;
5764 if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
5765 /* See if we need to convert from fake page to subDB */
5767 unsigned int offset;
5771 fp = NODEDATA(leaf);
5772 if (flags == MDB_CURRENT) {
5774 fp->mp_flags |= P_DIRTY;
5775 COPY_PGNO(fp->mp_pgno, mc->mc_pg[mc->mc_top]->mp_pgno);
5776 mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;
5780 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
5781 offset = fp->mp_pad;
5782 if (SIZELEFT(fp) >= offset)
5784 offset *= 4; /* space for 4 more */
5786 offset = NODESIZE + sizeof(indx_t) + data->mv_size;
5788 offset += offset & 1;
5789 fp_flags = fp->mp_flags;
5790 if (NODESIZE + sizeof(indx_t) + NODEKSZ(leaf) + NODEDSZ(leaf) +
5791 offset >= mc->mc_txn->mt_env->me_nodemax) {
5792 /* yes, convert it */
5794 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
5795 dummy.md_pad = fp->mp_pad;
5796 dummy.md_flags = MDB_DUPFIXED;
5797 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
5798 dummy.md_flags |= MDB_INTEGERKEY;
5801 dummy.md_branch_pages = 0;
5802 dummy.md_leaf_pages = 1;
5803 dummy.md_overflow_pages = 0;
5804 dummy.md_entries = NUMKEYS(fp);
5806 xdata.mv_size = sizeof(MDB_db);
5807 xdata.mv_data = &dummy;
5808 if ((rc = mdb_page_alloc(mc, 1, &mp)))
5810 offset = mc->mc_txn->mt_env->me_psize - NODEDSZ(leaf);
5811 flags |= F_DUPDATA|F_SUBDATA;
5812 dummy.md_root = mp->mp_pgno;
5813 fp_flags &= ~P_SUBP;
5815 /* no, just grow it */
5817 xdata.mv_size = NODEDSZ(leaf) + offset;
5818 xdata.mv_data = &pbuf;
5819 mp = (MDB_page *)&pbuf;
5820 mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
5823 mp->mp_flags = fp_flags | P_DIRTY;
5824 mp->mp_pad = fp->mp_pad;
5825 mp->mp_lower = fp->mp_lower;
5826 mp->mp_upper = fp->mp_upper + offset;
5828 memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad);
5830 nsize = NODEDSZ(leaf) - fp->mp_upper;
5831 memcpy((char *)mp + mp->mp_upper, (char *)fp + fp->mp_upper, nsize);
5832 for (i=0; i<NUMKEYS(fp); i++)
5833 mp->mp_ptrs[i] = fp->mp_ptrs[i] + offset;
5835 mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0);
5839 /* data is on sub-DB, just store it */
5840 flags |= F_DUPDATA|F_SUBDATA;
5844 /* overflow page overwrites need special handling */
5845 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
5848 unsigned psize = mc->mc_txn->mt_env->me_psize;
5849 int level, ovpages, dpages = OVPAGES(data->mv_size, psize);
5851 memcpy(&pg, NODEDATA(leaf), sizeof(pg));
5852 if ((rc2 = mdb_page_get(mc->mc_txn, pg, &omp, &level)) != 0)
5854 ovpages = omp->mp_pages;
5856 /* Is the ov page large enough? */
5857 if (ovpages >= dpages) {
5858 if (!(omp->mp_flags & P_DIRTY) &&
5859 (level || (mc->mc_txn->mt_env->me_flags & MDB_WRITEMAP)))
5861 rc = mdb_page_unspill(mc->mc_txn, omp, &omp);
5864 level = 0; /* dirty in this txn or clean */
5867 if (omp->mp_flags & P_DIRTY) {
5868 /* yes, overwrite it. Note in this case we don't
5869 * bother to try shrinking the page if the new data
5870 * is smaller than the overflow threshold.
5873 /* It is writable only in a parent txn */
5874 size_t sz = (size_t) psize * ovpages, off;
5875 MDB_page *np = mdb_page_malloc(mc->mc_txn, ovpages);
5881 mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);
5882 if (!(flags & MDB_RESERVE)) {
5883 /* Copy end of page, adjusting alignment so
5884 * compiler may copy words instead of bytes.
5886 off = (PAGEHDRSZ + data->mv_size) & -sizeof(size_t);
5887 memcpy((size_t *)((char *)np + off),
5888 (size_t *)((char *)omp + off), sz - off);
5891 memcpy(np, omp, sz); /* Copy beginning of page */
5894 SETDSZ(leaf, data->mv_size);
5895 if (F_ISSET(flags, MDB_RESERVE))
5896 data->mv_data = METADATA(omp);
5898 memcpy(METADATA(omp), data->mv_data, data->mv_size);
5902 if ((rc2 = mdb_ovpage_free(mc, omp)) != MDB_SUCCESS)
5904 } else if (NODEDSZ(leaf) == data->mv_size) {
5905 /* same size, just replace it. Note that we could
5906 * also reuse this node if the new data is smaller,
5907 * but instead we opt to shrink the node in that case.
5909 if (F_ISSET(flags, MDB_RESERVE))
5910 data->mv_data = NODEDATA(leaf);
5911 else if (data->mv_size)
5912 memcpy(NODEDATA(leaf), data->mv_data, data->mv_size);
5914 memcpy(NODEKEY(leaf), key->mv_data, key->mv_size);
5917 mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0);
5918 mc->mc_db->md_entries--;
5920 DPRINTF(("inserting key at index %i", mc->mc_ki[mc->mc_top]));
5927 nflags = flags & NODE_ADD_FLAGS;
5928 nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(mc->mc_txn->mt_env, key, rdata);
5929 if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) {
5930 if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA )
5931 nflags &= ~MDB_APPEND;
5933 nflags |= MDB_SPLIT_REPLACE;
5934 rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags);
5936 /* There is room already in this leaf page. */
5937 rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);
5938 if (rc == 0 && !do_sub && insert) {
5939 /* Adjust other cursors pointing to mp */
5940 MDB_cursor *m2, *m3;
5941 MDB_dbi dbi = mc->mc_dbi;
5942 unsigned i = mc->mc_top;
5943 MDB_page *mp = mc->mc_pg[i];
5945 if (mc->mc_flags & C_SUB)
5948 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
5949 if (mc->mc_flags & C_SUB)
5950 m3 = &m2->mc_xcursor->mx_cursor;
5953 if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
5954 if (m3->mc_pg[i] == mp && m3->mc_ki[i] >= mc->mc_ki[i]) {
5961 if (rc != MDB_SUCCESS)
5962 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
5964 /* Now store the actual data in the child DB. Note that we're
5965 * storing the user data in the keys field, so there are strict
5966 * size limits on dupdata. The actual data fields of the child
5967 * DB are all zero size.
5974 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5975 if (flags & MDB_CURRENT) {
5976 xflags = MDB_CURRENT|MDB_NOSPILL;
5978 mdb_xcursor_init1(mc, leaf);
5979 xflags = (flags & MDB_NODUPDATA) ?
5980 MDB_NOOVERWRITE|MDB_NOSPILL : MDB_NOSPILL;
5982 /* converted, write the original data first */
5984 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);
5988 /* Adjust other cursors pointing to mp */
5990 unsigned i = mc->mc_top;
5991 MDB_page *mp = mc->mc_pg[i];
5993 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
5994 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
5995 if (!(m2->mc_flags & C_INITIALIZED)) continue;
5996 if (m2->mc_pg[i] == mp && m2->mc_ki[i] == mc->mc_ki[i]) {
5997 mdb_xcursor_init1(m2, leaf);
6001 /* we've done our job */
6004 if (flags & MDB_APPENDDUP)
6005 xflags |= MDB_APPEND;
6006 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);
6007 if (flags & F_SUBDATA) {
6008 void *db = NODEDATA(leaf);
6009 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
6012 /* sub-writes might have failed so check rc again.
6013 * Don't increment count if we just replaced an existing item.
6015 if (!rc && !(flags & MDB_CURRENT))
6016 mc->mc_db->md_entries++;
6017 if (flags & MDB_MULTIPLE) {
6021 /* let caller know how many succeeded, if any */
6022 data[1].mv_size = mcount;
6023 if (mcount < dcount) {
6024 data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size;
6025 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6032 /* If we succeeded and the key didn't exist before, make sure
6033 * the cursor is marked valid.
6036 mc->mc_flags |= C_INITIALIZED;
6041 mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
6046 if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
6047 return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
6049 if (!(mc->mc_flags & C_INITIALIZED))
6052 if (!(flags & MDB_NOSPILL) && (rc = mdb_page_spill(mc, NULL, NULL)))
6054 flags &= ~MDB_NOSPILL; /* TODO: Or change (flags != MDB_NODUPDATA) to ~(flags & MDB_NODUPDATA), not looking at the logic of that code just now */
6056 rc = mdb_cursor_touch(mc);
6060 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6062 if (!IS_LEAF2(mc->mc_pg[mc->mc_top]) && F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6063 if (!(flags & MDB_NODUPDATA)) {
6064 if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
6065 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6067 rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, MDB_NOSPILL);
6068 /* If sub-DB still has entries, we're done */
6069 if (mc->mc_xcursor->mx_db.md_entries) {
6070 if (leaf->mn_flags & F_SUBDATA) {
6071 /* update subDB info */
6072 void *db = NODEDATA(leaf);
6073 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
6076 /* shrink fake page */
6077 mdb_node_shrink(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6078 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6079 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6080 /* fix other sub-DB cursors pointed at this fake page */
6081 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
6082 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
6083 if (m2->mc_pg[mc->mc_top] == mc->mc_pg[mc->mc_top] &&
6084 m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top])
6085 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6088 mc->mc_db->md_entries--;
6089 mc->mc_flags |= C_DEL;
6092 /* otherwise fall thru and delete the sub-DB */
6095 if (leaf->mn_flags & F_SUBDATA) {
6096 /* add all the child DB's pages to the free list */
6097 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
6098 if (rc == MDB_SUCCESS) {
6099 mc->mc_db->md_entries -=
6100 mc->mc_xcursor->mx_db.md_entries;
6105 return mdb_cursor_del0(mc, leaf);
6108 /** Allocate and initialize new pages for a database.
6109 * @param[in] mc a cursor on the database being added to.
6110 * @param[in] flags flags defining what type of page is being allocated.
6111 * @param[in] num the number of pages to allocate. This is usually 1,
6112 * unless allocating overflow pages for a large record.
6113 * @param[out] mp Address of a page, or NULL on failure.
6114 * @return 0 on success, non-zero on failure.
6117 mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp)
6122 if ((rc = mdb_page_alloc(mc, num, &np)))
6124 DPRINTF(("allocated new mpage %"Z"u, page size %u",
6125 np->mp_pgno, mc->mc_txn->mt_env->me_psize));
6126 np->mp_flags = flags | P_DIRTY;
6127 np->mp_lower = PAGEHDRSZ;
6128 np->mp_upper = mc->mc_txn->mt_env->me_psize;
6131 mc->mc_db->md_branch_pages++;
6132 else if (IS_LEAF(np))
6133 mc->mc_db->md_leaf_pages++;
6134 else if (IS_OVERFLOW(np)) {
6135 mc->mc_db->md_overflow_pages += num;
6143 /** Calculate the size of a leaf node.
6144 * The size depends on the environment's page size; if a data item
6145 * is too large it will be put onto an overflow page and the node
6146 * size will only include the key and not the data. Sizes are always
6147 * rounded up to an even number of bytes, to guarantee 2-byte alignment
6148 * of the #MDB_node headers.
6149 * @param[in] env The environment handle.
6150 * @param[in] key The key for the node.
6151 * @param[in] data The data for the node.
6152 * @return The number of bytes needed to store the node.
6155 mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data)
6159 sz = LEAFSIZE(key, data);
6160 if (sz >= env->me_nodemax) {
6161 /* put on overflow page */
6162 sz -= data->mv_size - sizeof(pgno_t);
6166 return sz + sizeof(indx_t);
6169 /** Calculate the size of a branch node.
6170 * The size should depend on the environment's page size but since
6171 * we currently don't support spilling large keys onto overflow
6172 * pages, it's simply the size of the #MDB_node header plus the
6173 * size of the key. Sizes are always rounded up to an even number
6174 * of bytes, to guarantee 2-byte alignment of the #MDB_node headers.
6175 * @param[in] env The environment handle.
6176 * @param[in] key The key for the node.
6177 * @return The number of bytes needed to store the node.
6180 mdb_branch_size(MDB_env *env, MDB_val *key)
6185 if (sz >= env->me_nodemax) {
6186 /* put on overflow page */
6187 /* not implemented */
6188 /* sz -= key->size - sizeof(pgno_t); */
6191 return sz + sizeof(indx_t);
6194 /** Add a node to the page pointed to by the cursor.
6195 * @param[in] mc The cursor for this operation.
6196 * @param[in] indx The index on the page where the new node should be added.
6197 * @param[in] key The key for the new node.
6198 * @param[in] data The data for the new node, if any.
6199 * @param[in] pgno The page number, if adding a branch node.
6200 * @param[in] flags Flags for the node.
6201 * @return 0 on success, non-zero on failure. Possible errors are:
6203 * <li>ENOMEM - failed to allocate overflow pages for the node.
6204 * <li>MDB_PAGE_FULL - there is insufficient room in the page. This error
6205 * should never happen since all callers already calculate the
6206 * page's free space before calling this function.
6210 mdb_node_add(MDB_cursor *mc, indx_t indx,
6211 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags)
6214 size_t node_size = NODESIZE;
6217 MDB_page *mp = mc->mc_pg[mc->mc_top];
6218 MDB_page *ofp = NULL; /* overflow page */
6221 assert(mp->mp_upper >= mp->mp_lower);
6223 DPRINTF(("add to %s %spage %"Z"u index %i, data size %"Z"u key size %"Z"u [%s]",
6224 IS_LEAF(mp) ? "leaf" : "branch",
6225 IS_SUBP(mp) ? "sub-" : "",
6226 mp->mp_pgno, indx, data ? data->mv_size : 0,
6227 key ? key->mv_size : 0, key ? DKEY(key) : "null"));
6230 /* Move higher keys up one slot. */
6231 int ksize = mc->mc_db->md_pad, dif;
6232 char *ptr = LEAF2KEY(mp, indx, ksize);
6233 dif = NUMKEYS(mp) - indx;
6235 memmove(ptr+ksize, ptr, dif*ksize);
6236 /* insert new key */
6237 memcpy(ptr, key->mv_data, ksize);
6239 /* Just using these for counting */
6240 mp->mp_lower += sizeof(indx_t);
6241 mp->mp_upper -= ksize - sizeof(indx_t);
6246 node_size += key->mv_size;
6250 if (F_ISSET(flags, F_BIGDATA)) {
6251 /* Data already on overflow page. */
6252 node_size += sizeof(pgno_t);
6253 } else if (node_size + data->mv_size >= mc->mc_txn->mt_env->me_nodemax) {
6254 int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
6256 /* Put data on overflow page. */
6257 DPRINTF(("data size is %"Z"u, node would be %"Z"u, put data on overflow page",
6258 data->mv_size, node_size+data->mv_size));
6259 node_size += sizeof(pgno_t);
6260 if ((rc = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp)))
6262 DPRINTF(("allocated overflow page %"Z"u", ofp->mp_pgno));
6265 node_size += data->mv_size;
6268 node_size += node_size & 1;
6270 if (node_size + sizeof(indx_t) > SIZELEFT(mp)) {
6271 DPRINTF(("not enough room in page %"Z"u, got %u ptrs",
6272 mp->mp_pgno, NUMKEYS(mp)));
6273 DPRINTF(("upper - lower = %u - %u = %u", mp->mp_upper, mp->mp_lower,
6274 mp->mp_upper - mp->mp_lower));
6275 DPRINTF(("node size = %"Z"u", node_size));
6276 return MDB_PAGE_FULL;
6279 /* Move higher pointers up one slot. */
6280 for (i = NUMKEYS(mp); i > indx; i--)
6281 mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];
6283 /* Adjust free space offsets. */
6284 ofs = mp->mp_upper - node_size;
6285 assert(ofs >= mp->mp_lower + sizeof(indx_t));
6286 mp->mp_ptrs[indx] = ofs;
6288 mp->mp_lower += sizeof(indx_t);
6290 /* Write the node data. */
6291 node = NODEPTR(mp, indx);
6292 node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
6293 node->mn_flags = flags;
6295 SETDSZ(node,data->mv_size);
6300 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
6305 if (F_ISSET(flags, F_BIGDATA))
6306 memcpy(node->mn_data + key->mv_size, data->mv_data,
6308 else if (F_ISSET(flags, MDB_RESERVE))
6309 data->mv_data = node->mn_data + key->mv_size;
6311 memcpy(node->mn_data + key->mv_size, data->mv_data,
6314 memcpy(node->mn_data + key->mv_size, &ofp->mp_pgno,
6316 if (F_ISSET(flags, MDB_RESERVE))
6317 data->mv_data = METADATA(ofp);
6319 memcpy(METADATA(ofp), data->mv_data, data->mv_size);
6326 /** Delete the specified node from a page.
6327 * @param[in] mp The page to operate on.
6328 * @param[in] indx The index of the node to delete.
6329 * @param[in] ksize The size of a node. Only used if the page is
6330 * part of a #MDB_DUPFIXED database.
6333 mdb_node_del(MDB_page *mp, indx_t indx, int ksize)
6336 indx_t i, j, numkeys, ptr;
6343 COPY_PGNO(pgno, mp->mp_pgno);
6344 DPRINTF(("delete node %u on %s page %"Z"u", indx,
6345 IS_LEAF(mp) ? "leaf" : "branch", pgno));
6348 assert(indx < NUMKEYS(mp));
6351 int x = NUMKEYS(mp) - 1 - indx;
6352 base = LEAF2KEY(mp, indx, ksize);
6354 memmove(base, base + ksize, x * ksize);
6355 mp->mp_lower -= sizeof(indx_t);
6356 mp->mp_upper += ksize - sizeof(indx_t);
6360 node = NODEPTR(mp, indx);
6361 sz = NODESIZE + node->mn_ksize;
6363 if (F_ISSET(node->mn_flags, F_BIGDATA))
6364 sz += sizeof(pgno_t);
6366 sz += NODEDSZ(node);
6370 ptr = mp->mp_ptrs[indx];
6371 numkeys = NUMKEYS(mp);
6372 for (i = j = 0; i < numkeys; i++) {
6374 mp->mp_ptrs[j] = mp->mp_ptrs[i];
6375 if (mp->mp_ptrs[i] < ptr)
6376 mp->mp_ptrs[j] += sz;
6381 base = (char *)mp + mp->mp_upper;
6382 memmove(base + sz, base, ptr - mp->mp_upper);
6384 mp->mp_lower -= sizeof(indx_t);
6388 /** Compact the main page after deleting a node on a subpage.
6389 * @param[in] mp The main page to operate on.
6390 * @param[in] indx The index of the subpage on the main page.
6393 mdb_node_shrink(MDB_page *mp, indx_t indx)
6400 indx_t i, numkeys, ptr;
6402 node = NODEPTR(mp, indx);
6403 sp = (MDB_page *)NODEDATA(node);
6404 osize = NODEDSZ(node);
6406 delta = sp->mp_upper - sp->mp_lower;
6407 SETDSZ(node, osize - delta);
6408 xp = (MDB_page *)((char *)sp + delta);
6410 /* shift subpage upward */
6412 nsize = NUMKEYS(sp) * sp->mp_pad;
6413 memmove(METADATA(xp), METADATA(sp), nsize);
6416 nsize = osize - sp->mp_upper;
6417 numkeys = NUMKEYS(sp);
6418 for (i=numkeys-1; i>=0; i--)
6419 xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta;
6421 xp->mp_upper = sp->mp_lower;
6422 xp->mp_lower = sp->mp_lower;
6423 xp->mp_flags = sp->mp_flags;
6424 xp->mp_pad = sp->mp_pad;
6425 COPY_PGNO(xp->mp_pgno, mp->mp_pgno);
6427 /* shift lower nodes upward */
6428 ptr = mp->mp_ptrs[indx];
6429 numkeys = NUMKEYS(mp);
6430 for (i = 0; i < numkeys; i++) {
6431 if (mp->mp_ptrs[i] <= ptr)
6432 mp->mp_ptrs[i] += delta;
6435 base = (char *)mp + mp->mp_upper;
6436 memmove(base + delta, base, ptr - mp->mp_upper + NODESIZE + NODEKSZ(node));
6437 mp->mp_upper += delta;
6440 /** Initial setup of a sorted-dups cursor.
6441 * Sorted duplicates are implemented as a sub-database for the given key.
6442 * The duplicate data items are actually keys of the sub-database.
6443 * Operations on the duplicate data items are performed using a sub-cursor
6444 * initialized when the sub-database is first accessed. This function does
6445 * the preliminary setup of the sub-cursor, filling in the fields that
6446 * depend only on the parent DB.
6447 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
6450 mdb_xcursor_init0(MDB_cursor *mc)
6452 MDB_xcursor *mx = mc->mc_xcursor;
6454 mx->mx_cursor.mc_xcursor = NULL;
6455 mx->mx_cursor.mc_txn = mc->mc_txn;
6456 mx->mx_cursor.mc_db = &mx->mx_db;
6457 mx->mx_cursor.mc_dbx = &mx->mx_dbx;
6458 mx->mx_cursor.mc_dbi = mc->mc_dbi+1;
6459 mx->mx_cursor.mc_dbflag = &mx->mx_dbflag;
6460 mx->mx_cursor.mc_snum = 0;
6461 mx->mx_cursor.mc_top = 0;
6462 mx->mx_cursor.mc_flags = C_SUB;
6463 mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp;
6464 mx->mx_dbx.md_dcmp = NULL;
6465 mx->mx_dbx.md_rel = mc->mc_dbx->md_rel;
6468 /** Final setup of a sorted-dups cursor.
6469 * Sets up the fields that depend on the data from the main cursor.
6470 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
6471 * @param[in] node The data containing the #MDB_db record for the
6472 * sorted-dup database.
6475 mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)
6477 MDB_xcursor *mx = mc->mc_xcursor;
6479 if (node->mn_flags & F_SUBDATA) {
6480 memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db));
6481 mx->mx_cursor.mc_pg[0] = 0;
6482 mx->mx_cursor.mc_snum = 0;
6483 mx->mx_cursor.mc_flags = C_SUB;
6485 MDB_page *fp = NODEDATA(node);
6486 mx->mx_db.md_pad = mc->mc_pg[mc->mc_top]->mp_pad;
6487 mx->mx_db.md_flags = 0;
6488 mx->mx_db.md_depth = 1;
6489 mx->mx_db.md_branch_pages = 0;
6490 mx->mx_db.md_leaf_pages = 1;
6491 mx->mx_db.md_overflow_pages = 0;
6492 mx->mx_db.md_entries = NUMKEYS(fp);
6493 COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno);
6494 mx->mx_cursor.mc_snum = 1;
6495 mx->mx_cursor.mc_flags = C_INITIALIZED|C_SUB;
6496 mx->mx_cursor.mc_top = 0;
6497 mx->mx_cursor.mc_pg[0] = fp;
6498 mx->mx_cursor.mc_ki[0] = 0;
6499 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
6500 mx->mx_db.md_flags = MDB_DUPFIXED;
6501 mx->mx_db.md_pad = fp->mp_pad;
6502 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
6503 mx->mx_db.md_flags |= MDB_INTEGERKEY;
6506 DPRINTF(("Sub-db %u for db %u root page %"Z"u", mx->mx_cursor.mc_dbi, mc->mc_dbi,
6507 mx->mx_db.md_root));
6508 mx->mx_dbflag = DB_VALID | (F_ISSET(mc->mc_pg[mc->mc_top]->mp_flags, P_DIRTY) ?
6510 mx->mx_dbx.md_name.mv_data = NODEKEY(node);
6511 mx->mx_dbx.md_name.mv_size = node->mn_ksize;
6512 #if UINT_MAX < SIZE_MAX
6513 if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(size_t))
6514 #ifdef MISALIGNED_OK
6515 mx->mx_dbx.md_cmp = mdb_cmp_long;
6517 mx->mx_dbx.md_cmp = mdb_cmp_cint;
6522 /** Initialize a cursor for a given transaction and database. */
6524 mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
6527 mc->mc_backup = NULL;
6530 mc->mc_db = &txn->mt_dbs[dbi];
6531 mc->mc_dbx = &txn->mt_dbxs[dbi];
6532 mc->mc_dbflag = &txn->mt_dbflags[dbi];
6537 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
6539 mc->mc_xcursor = mx;
6540 mdb_xcursor_init0(mc);
6542 mc->mc_xcursor = NULL;
6544 if (*mc->mc_dbflag & DB_STALE) {
6545 mdb_page_search(mc, NULL, MDB_PS_ROOTONLY);
6550 mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
6553 size_t size = sizeof(MDB_cursor);
6555 if (txn == NULL || ret == NULL || dbi >= txn->mt_numdbs || !(txn->mt_dbflags[dbi] & DB_VALID))
6558 if (txn->mt_flags & MDB_TXN_ERROR)
6561 /* Allow read access to the freelist */
6562 if (!dbi && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
6565 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)
6566 size += sizeof(MDB_xcursor);
6568 if ((mc = malloc(size)) != NULL) {
6569 mdb_cursor_init(mc, txn, dbi, (MDB_xcursor *)(mc + 1));
6570 if (txn->mt_cursors) {
6571 mc->mc_next = txn->mt_cursors[dbi];
6572 txn->mt_cursors[dbi] = mc;
6573 mc->mc_flags |= C_UNTRACK;
6585 mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)
6587 if (txn == NULL || mc == NULL || mc->mc_dbi >= txn->mt_numdbs)
6590 if ((mc->mc_flags & C_UNTRACK) || txn->mt_cursors)
6593 mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor);
6597 /* Return the count of duplicate data items for the current key */
6599 mdb_cursor_count(MDB_cursor *mc, size_t *countp)
6603 if (mc == NULL || countp == NULL)
6606 if (mc->mc_xcursor == NULL)
6607 return MDB_INCOMPATIBLE;
6609 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6610 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6613 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
6616 *countp = mc->mc_xcursor->mx_db.md_entries;
6622 mdb_cursor_close(MDB_cursor *mc)
6624 if (mc && !mc->mc_backup) {
6625 /* remove from txn, if tracked */
6626 if ((mc->mc_flags & C_UNTRACK) && mc->mc_txn->mt_cursors) {
6627 MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi];
6628 while (*prev && *prev != mc) prev = &(*prev)->mc_next;
6630 *prev = mc->mc_next;
6637 mdb_cursor_txn(MDB_cursor *mc)
6639 if (!mc) return NULL;
6644 mdb_cursor_dbi(MDB_cursor *mc)
6650 /** Replace the key for a node with a new key.
6651 * @param[in] mc Cursor pointing to the node to operate on.
6652 * @param[in] key The new key to use.
6653 * @return 0 on success, non-zero on failure.
6656 mdb_update_key(MDB_cursor *mc, MDB_val *key)
6663 indx_t ptr, i, numkeys, indx;
6666 indx = mc->mc_ki[mc->mc_top];
6667 mp = mc->mc_pg[mc->mc_top];
6668 node = NODEPTR(mp, indx);
6669 ptr = mp->mp_ptrs[indx];
6673 char kbuf2[(MDB_MAXKEYSIZE*2+1)];
6674 k2.mv_data = NODEKEY(node);
6675 k2.mv_size = node->mn_ksize;
6676 DPRINTF(("update key %u (ofs %u) [%s] to [%s] on page %"Z"u",
6678 mdb_dkey(&k2, kbuf2),
6684 delta0 = delta = key->mv_size - node->mn_ksize;
6686 /* Must be 2-byte aligned. If new key is
6687 * shorter by 1, the shift will be skipped.
6689 delta += (delta & 1);
6691 if (delta > 0 && SIZELEFT(mp) < delta) {
6693 /* not enough space left, do a delete and split */
6694 DPRINTF(("Not enough room, delta = %d, splitting...", delta));
6695 pgno = NODEPGNO(node);
6696 mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0);
6697 return mdb_page_split(mc, key, NULL, pgno, MDB_SPLIT_REPLACE);
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 len = ptr - mp->mp_upper + NODESIZE;
6708 memmove(base - delta, base, len);
6709 mp->mp_upper -= delta;
6711 node = NODEPTR(mp, indx);
6714 /* But even if no shift was needed, update ksize */
6716 node->mn_ksize = key->mv_size;
6719 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
6725 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst);
6727 /** Move a node from csrc to cdst.
6730 mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
6737 unsigned short flags;
6741 /* Mark src and dst as dirty. */
6742 if ((rc = mdb_page_touch(csrc)) ||
6743 (rc = mdb_page_touch(cdst)))
6746 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
6747 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0); /* fake */
6748 key.mv_size = csrc->mc_db->md_pad;
6749 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
6751 data.mv_data = NULL;
6755 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]);
6756 assert(!((long)srcnode&1));
6757 srcpg = NODEPGNO(srcnode);
6758 flags = srcnode->mn_flags;
6759 if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
6760 unsigned int snum = csrc->mc_snum;
6762 /* must find the lowest key below src */
6763 mdb_page_search_lowest(csrc);
6764 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
6765 key.mv_size = csrc->mc_db->md_pad;
6766 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
6768 s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
6769 key.mv_size = NODEKSZ(s2);
6770 key.mv_data = NODEKEY(s2);
6772 csrc->mc_snum = snum--;
6773 csrc->mc_top = snum;
6775 key.mv_size = NODEKSZ(srcnode);
6776 key.mv_data = NODEKEY(srcnode);
6778 data.mv_size = NODEDSZ(srcnode);
6779 data.mv_data = NODEDATA(srcnode);
6781 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) {
6782 unsigned int snum = cdst->mc_snum;
6785 /* must find the lowest key below dst */
6786 mdb_page_search_lowest(cdst);
6787 if (IS_LEAF2(cdst->mc_pg[cdst->mc_top])) {
6788 bkey.mv_size = cdst->mc_db->md_pad;
6789 bkey.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, bkey.mv_size);
6791 s2 = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
6792 bkey.mv_size = NODEKSZ(s2);
6793 bkey.mv_data = NODEKEY(s2);
6795 cdst->mc_snum = snum--;
6796 cdst->mc_top = snum;
6797 mdb_cursor_copy(cdst, &mn);
6799 rc = mdb_update_key(&mn, &bkey);
6804 DPRINTF(("moving %s node %u [%s] on page %"Z"u to node %u on page %"Z"u",
6805 IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch",
6806 csrc->mc_ki[csrc->mc_top],
6808 csrc->mc_pg[csrc->mc_top]->mp_pgno,
6809 cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno));
6811 /* Add the node to the destination page.
6813 rc = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags);
6814 if (rc != MDB_SUCCESS)
6817 /* Delete the node from the source page.
6819 mdb_node_del(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
6822 /* Adjust other cursors pointing to mp */
6823 MDB_cursor *m2, *m3;
6824 MDB_dbi dbi = csrc->mc_dbi;
6825 MDB_page *mp = csrc->mc_pg[csrc->mc_top];
6827 if (csrc->mc_flags & C_SUB)
6830 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
6831 if (csrc->mc_flags & C_SUB)
6832 m3 = &m2->mc_xcursor->mx_cursor;
6835 if (m3 == csrc) continue;
6836 if (m3->mc_pg[csrc->mc_top] == mp && m3->mc_ki[csrc->mc_top] ==
6837 csrc->mc_ki[csrc->mc_top]) {
6838 m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
6839 m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
6844 /* Update the parent separators.
6846 if (csrc->mc_ki[csrc->mc_top] == 0) {
6847 if (csrc->mc_ki[csrc->mc_top-1] != 0) {
6848 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
6849 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
6851 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
6852 key.mv_size = NODEKSZ(srcnode);
6853 key.mv_data = NODEKEY(srcnode);
6855 DPRINTF(("update separator for source page %"Z"u to [%s]",
6856 csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key)));
6857 mdb_cursor_copy(csrc, &mn);
6860 if ((rc = mdb_update_key(&mn, &key)) != MDB_SUCCESS)
6863 if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
6865 indx_t ix = csrc->mc_ki[csrc->mc_top];
6866 nullkey.mv_size = 0;
6867 csrc->mc_ki[csrc->mc_top] = 0;
6868 rc = mdb_update_key(csrc, &nullkey);
6869 csrc->mc_ki[csrc->mc_top] = ix;
6870 assert(rc == MDB_SUCCESS);
6874 if (cdst->mc_ki[cdst->mc_top] == 0) {
6875 if (cdst->mc_ki[cdst->mc_top-1] != 0) {
6876 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
6877 key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size);
6879 srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
6880 key.mv_size = NODEKSZ(srcnode);
6881 key.mv_data = NODEKEY(srcnode);
6883 DPRINTF(("update separator for destination page %"Z"u to [%s]",
6884 cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key)));
6885 mdb_cursor_copy(cdst, &mn);
6888 if ((rc = mdb_update_key(&mn, &key)) != MDB_SUCCESS)
6891 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) {
6893 indx_t ix = cdst->mc_ki[cdst->mc_top];
6894 nullkey.mv_size = 0;
6895 cdst->mc_ki[cdst->mc_top] = 0;
6896 rc = mdb_update_key(cdst, &nullkey);
6897 cdst->mc_ki[cdst->mc_top] = ix;
6898 assert(rc == MDB_SUCCESS);
6905 /** Merge one page into another.
6906 * The nodes from the page pointed to by \b csrc will
6907 * be copied to the page pointed to by \b cdst and then
6908 * the \b csrc page will be freed.
6909 * @param[in] csrc Cursor pointing to the source page.
6910 * @param[in] cdst Cursor pointing to the destination page.
6913 mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
6921 DPRINTF(("merging page %"Z"u into %"Z"u", csrc->mc_pg[csrc->mc_top]->mp_pgno,
6922 cdst->mc_pg[cdst->mc_top]->mp_pgno));
6924 assert(csrc->mc_snum > 1); /* can't merge root page */
6925 assert(cdst->mc_snum > 1);
6927 /* Mark dst as dirty. */
6928 if ((rc = mdb_page_touch(cdst)))
6931 /* Move all nodes from src to dst.
6933 j = nkeys = NUMKEYS(cdst->mc_pg[cdst->mc_top]);
6934 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
6935 key.mv_size = csrc->mc_db->md_pad;
6936 key.mv_data = METADATA(csrc->mc_pg[csrc->mc_top]);
6937 for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) {
6938 rc = mdb_node_add(cdst, j, &key, NULL, 0, 0);
6939 if (rc != MDB_SUCCESS)
6941 key.mv_data = (char *)key.mv_data + key.mv_size;
6944 for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) {
6945 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], i);
6946 if (i == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
6947 unsigned int snum = csrc->mc_snum;
6949 /* must find the lowest key below src */
6950 mdb_page_search_lowest(csrc);
6951 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
6952 key.mv_size = csrc->mc_db->md_pad;
6953 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
6955 s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
6956 key.mv_size = NODEKSZ(s2);
6957 key.mv_data = NODEKEY(s2);
6959 csrc->mc_snum = snum--;
6960 csrc->mc_top = snum;
6962 key.mv_size = srcnode->mn_ksize;
6963 key.mv_data = NODEKEY(srcnode);
6966 data.mv_size = NODEDSZ(srcnode);
6967 data.mv_data = NODEDATA(srcnode);
6968 rc = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags);
6969 if (rc != MDB_SUCCESS)
6974 DPRINTF(("dst page %"Z"u now has %u keys (%.1f%% filled)",
6975 cdst->mc_pg[cdst->mc_top]->mp_pgno, NUMKEYS(cdst->mc_pg[cdst->mc_top]),
6976 (float)PAGEFILL(cdst->mc_txn->mt_env, cdst->mc_pg[cdst->mc_top]) / 10));
6978 /* Unlink the src page from parent and add to free list.
6980 mdb_node_del(csrc->mc_pg[csrc->mc_top-1], csrc->mc_ki[csrc->mc_top-1], 0);
6981 if (csrc->mc_ki[csrc->mc_top-1] == 0) {
6984 rc = mdb_update_key(csrc, &key);
6990 rc = mdb_midl_append(&csrc->mc_txn->mt_free_pgs,
6991 csrc->mc_pg[csrc->mc_top]->mp_pgno);
6994 if (IS_LEAF(csrc->mc_pg[csrc->mc_top]))
6995 csrc->mc_db->md_leaf_pages--;
6997 csrc->mc_db->md_branch_pages--;
6999 /* Adjust other cursors pointing to mp */
7000 MDB_cursor *m2, *m3;
7001 MDB_dbi dbi = csrc->mc_dbi;
7002 MDB_page *mp = cdst->mc_pg[cdst->mc_top];
7004 if (csrc->mc_flags & C_SUB)
7007 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7008 if (csrc->mc_flags & C_SUB)
7009 m3 = &m2->mc_xcursor->mx_cursor;
7012 if (m3 == csrc) continue;
7013 if (m3->mc_snum < csrc->mc_snum) continue;
7014 if (m3->mc_pg[csrc->mc_top] == csrc->mc_pg[csrc->mc_top]) {
7015 m3->mc_pg[csrc->mc_top] = mp;
7016 m3->mc_ki[csrc->mc_top] += nkeys;
7020 mdb_cursor_pop(csrc);
7022 return mdb_rebalance(csrc);
7025 /** Copy the contents of a cursor.
7026 * @param[in] csrc The cursor to copy from.
7027 * @param[out] cdst The cursor to copy to.
7030 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst)
7034 cdst->mc_txn = csrc->mc_txn;
7035 cdst->mc_dbi = csrc->mc_dbi;
7036 cdst->mc_db = csrc->mc_db;
7037 cdst->mc_dbx = csrc->mc_dbx;
7038 cdst->mc_snum = csrc->mc_snum;
7039 cdst->mc_top = csrc->mc_top;
7040 cdst->mc_flags = csrc->mc_flags;
7042 for (i=0; i<csrc->mc_snum; i++) {
7043 cdst->mc_pg[i] = csrc->mc_pg[i];
7044 cdst->mc_ki[i] = csrc->mc_ki[i];
7048 /** Rebalance the tree after a delete operation.
7049 * @param[in] mc Cursor pointing to the page where rebalancing
7051 * @return 0 on success, non-zero on failure.
7054 mdb_rebalance(MDB_cursor *mc)
7058 unsigned int ptop, minkeys;
7061 minkeys = 1 + (IS_BRANCH(mc->mc_pg[mc->mc_top]));
7065 COPY_PGNO(pgno, mc->mc_pg[mc->mc_top]->mp_pgno);
7066 DPRINTF(("rebalancing %s page %"Z"u (has %u keys, %.1f%% full)",
7067 IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",
7068 pgno, NUMKEYS(mc->mc_pg[mc->mc_top]),
7069 (float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10));
7073 if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= FILL_THRESHOLD &&
7074 NUMKEYS(mc->mc_pg[mc->mc_top]) >= minkeys) {
7077 COPY_PGNO(pgno, mc->mc_pg[mc->mc_top]->mp_pgno);
7078 DPRINTF(("no need to rebalance page %"Z"u, above fill threshold",
7084 if (mc->mc_snum < 2) {
7085 MDB_page *mp = mc->mc_pg[0];
7087 DPUTS("Can't rebalance a subpage, ignoring");
7090 if (NUMKEYS(mp) == 0) {
7091 DPUTS("tree is completely empty");
7092 mc->mc_db->md_root = P_INVALID;
7093 mc->mc_db->md_depth = 0;
7094 mc->mc_db->md_leaf_pages = 0;
7095 rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
7098 /* Adjust cursors pointing to mp */
7102 MDB_cursor *m2, *m3;
7103 MDB_dbi dbi = mc->mc_dbi;
7105 if (mc->mc_flags & C_SUB)
7108 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7109 if (mc->mc_flags & C_SUB)
7110 m3 = &m2->mc_xcursor->mx_cursor;
7113 if (m3->mc_snum < mc->mc_snum) continue;
7114 if (m3->mc_pg[0] == mp) {
7120 } else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) {
7121 DPUTS("collapsing root page!");
7122 rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
7125 mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0));
7126 rc = mdb_page_get(mc->mc_txn,mc->mc_db->md_root,&mc->mc_pg[0],NULL);
7129 mc->mc_db->md_depth--;
7130 mc->mc_db->md_branch_pages--;
7131 mc->mc_ki[0] = mc->mc_ki[1];
7133 /* Adjust other cursors pointing to mp */
7134 MDB_cursor *m2, *m3;
7135 MDB_dbi dbi = mc->mc_dbi;
7137 if (mc->mc_flags & C_SUB)
7140 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7141 if (mc->mc_flags & C_SUB)
7142 m3 = &m2->mc_xcursor->mx_cursor;
7145 if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
7146 if (m3->mc_pg[0] == mp) {
7147 m3->mc_pg[0] = mc->mc_pg[0];
7150 m3->mc_ki[0] = m3->mc_ki[1];
7155 DPUTS("root page doesn't need rebalancing");
7159 /* The parent (branch page) must have at least 2 pointers,
7160 * otherwise the tree is invalid.
7162 ptop = mc->mc_top-1;
7163 assert(NUMKEYS(mc->mc_pg[ptop]) > 1);
7165 /* Leaf page fill factor is below the threshold.
7166 * Try to move keys from left or right neighbor, or
7167 * merge with a neighbor page.
7172 mdb_cursor_copy(mc, &mn);
7173 mn.mc_xcursor = NULL;
7175 if (mc->mc_ki[ptop] == 0) {
7176 /* We're the leftmost leaf in our parent.
7178 DPUTS("reading right neighbor");
7180 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
7181 rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
7184 mn.mc_ki[mn.mc_top] = 0;
7185 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);
7187 /* There is at least one neighbor to the left.
7189 DPUTS("reading left neighbor");
7191 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
7192 rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
7195 mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;
7196 mc->mc_ki[mc->mc_top] = 0;
7199 DPRINTF(("found neighbor page %"Z"u (%u keys, %.1f%% full)",
7200 mn.mc_pg[mn.mc_top]->mp_pgno, NUMKEYS(mn.mc_pg[mn.mc_top]),
7201 (float)PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) / 10));
7203 /* If the neighbor page is above threshold and has enough keys,
7204 * move one key from it. Otherwise we should try to merge them.
7205 * (A branch page must never have less than 2 keys.)
7207 minkeys = 1 + (IS_BRANCH(mn.mc_pg[mn.mc_top]));
7208 if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= FILL_THRESHOLD && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys)
7209 return mdb_node_move(&mn, mc);
7211 if (mc->mc_ki[ptop] == 0)
7212 rc = mdb_page_merge(&mn, mc);
7214 mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1;
7215 rc = mdb_page_merge(mc, &mn);
7216 mdb_cursor_copy(&mn, mc);
7218 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
7223 /** Complete a delete operation started by #mdb_cursor_del(). */
7225 mdb_cursor_del0(MDB_cursor *mc, MDB_node *leaf)
7232 mp = mc->mc_pg[mc->mc_top];
7233 ki = mc->mc_ki[mc->mc_top];
7235 /* add overflow pages to free list */
7236 if (!IS_LEAF2(mp) && F_ISSET(leaf->mn_flags, F_BIGDATA)) {
7240 memcpy(&pg, NODEDATA(leaf), sizeof(pg));
7241 if ((rc = mdb_page_get(mc->mc_txn, pg, &omp, NULL)) ||
7242 (rc = mdb_ovpage_free(mc, omp)))
7245 mdb_node_del(mp, ki, mc->mc_db->md_pad);
7246 mc->mc_db->md_entries--;
7247 rc = mdb_rebalance(mc);
7248 if (rc != MDB_SUCCESS)
7249 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
7252 MDB_dbi dbi = mc->mc_dbi;
7254 mp = mc->mc_pg[mc->mc_top];
7255 nkeys = NUMKEYS(mp);
7257 /* if mc points past last node in page, find next sibling */
7258 if (mc->mc_ki[mc->mc_top] >= nkeys)
7259 mdb_cursor_sibling(mc, 1);
7261 /* Adjust other cursors pointing to mp */
7262 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7265 if (!(m2->mc_flags & C_INITIALIZED))
7267 if (m2->mc_pg[mc->mc_top] == mp) {
7268 if (m2->mc_ki[mc->mc_top] >= ki) {
7269 m2->mc_flags |= C_DEL;
7270 if (m2->mc_ki[mc->mc_top] > ki)
7271 m2->mc_ki[mc->mc_top]--;
7273 if (m2->mc_ki[mc->mc_top] >= nkeys)
7274 mdb_cursor_sibling(m2, 1);
7277 mc->mc_flags |= C_DEL;
7284 mdb_del(MDB_txn *txn, MDB_dbi dbi,
7285 MDB_val *key, MDB_val *data)
7290 MDB_val rdata, *xdata;
7294 assert(key != NULL);
7296 DPRINTF(("====> delete db %u key [%s]", dbi, DKEY(key)));
7298 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs || !(txn->mt_dbflags[dbi] & DB_VALID))
7301 if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
7302 return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
7304 if (key->mv_size == 0 || key->mv_size > MDB_MAXKEYSIZE) {
7305 return MDB_BAD_VALSIZE;
7308 mdb_cursor_init(&mc, txn, dbi, &mx);
7311 if (!F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
7312 /* must ignore any data */
7323 rc = mdb_cursor_set(&mc, key, xdata, op, &exact);
7325 /* let mdb_page_split know about this cursor if needed:
7326 * delete will trigger a rebalance; if it needs to move
7327 * a node from one page to another, it will have to
7328 * update the parent's separator key(s). If the new sepkey
7329 * is larger than the current one, the parent page may
7330 * run out of space, triggering a split. We need this
7331 * cursor to be consistent until the end of the rebalance.
7333 mc.mc_flags |= C_UNTRACK;
7334 mc.mc_next = txn->mt_cursors[dbi];
7335 txn->mt_cursors[dbi] = &mc;
7336 rc = mdb_cursor_del(&mc, data ? 0 : MDB_NODUPDATA);
7337 txn->mt_cursors[dbi] = mc.mc_next;
7342 /** Split a page and insert a new node.
7343 * @param[in,out] mc Cursor pointing to the page and desired insertion index.
7344 * The cursor will be updated to point to the actual page and index where
7345 * the node got inserted after the split.
7346 * @param[in] newkey The key for the newly inserted node.
7347 * @param[in] newdata The data for the newly inserted node.
7348 * @param[in] newpgno The page number, if the new node is a branch node.
7349 * @param[in] nflags The #NODE_ADD_FLAGS for the new node.
7350 * @return 0 on success, non-zero on failure.
7353 mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno,
7354 unsigned int nflags)
7357 int rc = MDB_SUCCESS, ins_new = 0, new_root = 0, newpos = 1, did_split = 0;
7360 unsigned int i, j, split_indx, nkeys, pmax;
7362 MDB_val sepkey, rkey, xdata, *rdata = &xdata;
7364 MDB_page *mp, *rp, *pp;
7369 mp = mc->mc_pg[mc->mc_top];
7370 newindx = mc->mc_ki[mc->mc_top];
7372 DPRINTF(("-----> splitting %s page %"Z"u and adding [%s] at index %i",
7373 IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno,
7374 DKEY(newkey), mc->mc_ki[mc->mc_top]));
7376 /* Create a right sibling. */
7377 if ((rc = mdb_page_new(mc, mp->mp_flags, 1, &rp)))
7379 DPRINTF(("new right sibling: page %"Z"u", rp->mp_pgno));
7381 if (mc->mc_snum < 2) {
7382 if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp)))
7384 /* shift current top to make room for new parent */
7385 mc->mc_pg[1] = mc->mc_pg[0];
7386 mc->mc_ki[1] = mc->mc_ki[0];
7389 mc->mc_db->md_root = pp->mp_pgno;
7390 DPRINTF(("root split! new root = %"Z"u", pp->mp_pgno));
7391 mc->mc_db->md_depth++;
7394 /* Add left (implicit) pointer. */
7395 if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) {
7396 /* undo the pre-push */
7397 mc->mc_pg[0] = mc->mc_pg[1];
7398 mc->mc_ki[0] = mc->mc_ki[1];
7399 mc->mc_db->md_root = mp->mp_pgno;
7400 mc->mc_db->md_depth--;
7407 ptop = mc->mc_top-1;
7408 DPRINTF(("parent branch page is %"Z"u", mc->mc_pg[ptop]->mp_pgno));
7411 mc->mc_flags |= C_SPLITTING;
7412 mdb_cursor_copy(mc, &mn);
7413 mn.mc_pg[mn.mc_top] = rp;
7414 mn.mc_ki[ptop] = mc->mc_ki[ptop]+1;
7416 if (nflags & MDB_APPEND) {
7417 mn.mc_ki[mn.mc_top] = 0;
7419 split_indx = newindx;
7424 nkeys = NUMKEYS(mp);
7425 split_indx = nkeys / 2;
7426 if (newindx < split_indx)
7432 unsigned int lsize, rsize, ksize;
7433 /* Move half of the keys to the right sibling */
7435 x = mc->mc_ki[mc->mc_top] - split_indx;
7436 ksize = mc->mc_db->md_pad;
7437 split = LEAF2KEY(mp, split_indx, ksize);
7438 rsize = (nkeys - split_indx) * ksize;
7439 lsize = (nkeys - split_indx) * sizeof(indx_t);
7440 mp->mp_lower -= lsize;
7441 rp->mp_lower += lsize;
7442 mp->mp_upper += rsize - lsize;
7443 rp->mp_upper -= rsize - lsize;
7444 sepkey.mv_size = ksize;
7445 if (newindx == split_indx) {
7446 sepkey.mv_data = newkey->mv_data;
7448 sepkey.mv_data = split;
7451 ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize);
7452 memcpy(rp->mp_ptrs, split, rsize);
7453 sepkey.mv_data = rp->mp_ptrs;
7454 memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize);
7455 memcpy(ins, newkey->mv_data, ksize);
7456 mp->mp_lower += sizeof(indx_t);
7457 mp->mp_upper -= ksize - sizeof(indx_t);
7460 memcpy(rp->mp_ptrs, split, x * ksize);
7461 ins = LEAF2KEY(rp, x, ksize);
7462 memcpy(ins, newkey->mv_data, ksize);
7463 memcpy(ins+ksize, split + x * ksize, rsize - x * ksize);
7464 rp->mp_lower += sizeof(indx_t);
7465 rp->mp_upper -= ksize - sizeof(indx_t);
7466 mc->mc_ki[mc->mc_top] = x;
7467 mc->mc_pg[mc->mc_top] = rp;
7472 /* For leaf pages, check the split point based on what
7473 * fits where, since otherwise mdb_node_add can fail.
7475 * This check is only needed when the data items are
7476 * relatively large, such that being off by one will
7477 * make the difference between success or failure.
7479 * It's also relevant if a page happens to be laid out
7480 * such that one half of its nodes are all "small" and
7481 * the other half of its nodes are "large." If the new
7482 * item is also "large" and falls on the half with
7483 * "large" nodes, it also may not fit.
7486 unsigned int psize, nsize;
7487 /* Maximum free space in an empty page */
7488 pmax = mc->mc_txn->mt_env->me_psize - PAGEHDRSZ;
7489 nsize = mdb_leaf_size(mc->mc_txn->mt_env, newkey, newdata);
7490 if ((nkeys < 20) || (nsize > pmax/16)) {
7491 if (newindx <= split_indx) {
7494 for (i=0; i<split_indx; i++) {
7495 node = NODEPTR(mp, i);
7496 psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
7497 if (F_ISSET(node->mn_flags, F_BIGDATA))
7498 psize += sizeof(pgno_t);
7500 psize += NODEDSZ(node);
7504 split_indx = newindx;
7515 for (i=nkeys-1; i>=split_indx; i--) {
7516 node = NODEPTR(mp, i);
7517 psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
7518 if (F_ISSET(node->mn_flags, F_BIGDATA))
7519 psize += sizeof(pgno_t);
7521 psize += NODEDSZ(node);
7525 split_indx = newindx;
7536 /* First find the separating key between the split pages.
7537 * The case where newindx == split_indx is ambiguous; the
7538 * new item could go to the new page or stay on the original
7539 * page. If newpos == 1 it goes to the new page.
7541 if (newindx == split_indx && newpos) {
7542 sepkey.mv_size = newkey->mv_size;
7543 sepkey.mv_data = newkey->mv_data;
7545 node = NODEPTR(mp, split_indx);
7546 sepkey.mv_size = node->mn_ksize;
7547 sepkey.mv_data = NODEKEY(node);
7551 DPRINTF(("separator is [%s]", DKEY(&sepkey)));
7553 /* Copy separator key to the parent.
7555 if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(mc->mc_txn->mt_env, &sepkey)) {
7559 rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0);
7562 if (mn.mc_snum == mc->mc_snum) {
7563 mc->mc_pg[mc->mc_snum] = mc->mc_pg[mc->mc_top];
7564 mc->mc_ki[mc->mc_snum] = mc->mc_ki[mc->mc_top];
7565 mc->mc_pg[mc->mc_top] = mc->mc_pg[ptop];
7566 mc->mc_ki[mc->mc_top] = mc->mc_ki[ptop];
7571 /* Right page might now have changed parent.
7572 * Check if left page also changed parent.
7574 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
7575 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
7576 for (i=0; i<ptop; i++) {
7577 mc->mc_pg[i] = mn.mc_pg[i];
7578 mc->mc_ki[i] = mn.mc_ki[i];
7580 mc->mc_pg[ptop] = mn.mc_pg[ptop];
7581 mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;
7585 rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);
7588 mc->mc_flags ^= C_SPLITTING;
7589 if (rc != MDB_SUCCESS) {
7592 if (nflags & MDB_APPEND) {
7593 mc->mc_pg[mc->mc_top] = rp;
7594 mc->mc_ki[mc->mc_top] = 0;
7595 rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags);
7598 for (i=0; i<mc->mc_top; i++)
7599 mc->mc_ki[i] = mn.mc_ki[i];
7606 /* Move half of the keys to the right sibling. */
7608 /* grab a page to hold a temporary copy */
7609 copy = mdb_page_malloc(mc->mc_txn, 1);
7613 copy->mp_pgno = mp->mp_pgno;
7614 copy->mp_flags = mp->mp_flags;
7615 copy->mp_lower = PAGEHDRSZ;
7616 copy->mp_upper = mc->mc_txn->mt_env->me_psize;
7617 mc->mc_pg[mc->mc_top] = copy;
7618 for (i = j = 0; i <= nkeys; j++) {
7619 if (i == split_indx) {
7620 /* Insert in right sibling. */
7621 /* Reset insert index for right sibling. */
7622 if (i != newindx || (newpos ^ ins_new)) {
7624 mc->mc_pg[mc->mc_top] = rp;
7628 if (i == newindx && !ins_new) {
7629 /* Insert the original entry that caused the split. */
7630 rkey.mv_data = newkey->mv_data;
7631 rkey.mv_size = newkey->mv_size;
7640 /* Update index for the new key. */
7641 mc->mc_ki[mc->mc_top] = j;
7642 } else if (i == nkeys) {
7645 node = NODEPTR(mp, i);
7646 rkey.mv_data = NODEKEY(node);
7647 rkey.mv_size = node->mn_ksize;
7649 xdata.mv_data = NODEDATA(node);
7650 xdata.mv_size = NODEDSZ(node);
7653 pgno = NODEPGNO(node);
7654 flags = node->mn_flags;
7659 if (!IS_LEAF(mp) && j == 0) {
7660 /* First branch index doesn't need key data. */
7664 rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags);
7668 nkeys = NUMKEYS(copy);
7669 for (i=0; i<nkeys; i++)
7670 mp->mp_ptrs[i] = copy->mp_ptrs[i];
7671 mp->mp_lower = copy->mp_lower;
7672 mp->mp_upper = copy->mp_upper;
7673 memcpy(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1),
7674 mc->mc_txn->mt_env->me_psize - copy->mp_upper);
7676 /* reset back to original page */
7677 if (newindx < split_indx || (!newpos && newindx == split_indx)) {
7678 mc->mc_pg[mc->mc_top] = mp;
7679 if (nflags & MDB_RESERVE) {
7680 node = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
7681 if (!(node->mn_flags & F_BIGDATA))
7682 newdata->mv_data = NODEDATA(node);
7686 /* Make sure mc_ki is still valid.
7688 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
7689 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
7690 for (i=0; i<ptop; i++) {
7691 mc->mc_pg[i] = mn.mc_pg[i];
7692 mc->mc_ki[i] = mn.mc_ki[i];
7694 mc->mc_pg[ptop] = mn.mc_pg[ptop];
7695 mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;
7699 /* return tmp page to freelist */
7700 mdb_page_free(mc->mc_txn->mt_env, copy);
7703 /* Adjust other cursors pointing to mp */
7704 MDB_cursor *m2, *m3;
7705 MDB_dbi dbi = mc->mc_dbi;
7706 int fixup = NUMKEYS(mp);
7708 if (mc->mc_flags & C_SUB)
7711 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7712 if (mc->mc_flags & C_SUB)
7713 m3 = &m2->mc_xcursor->mx_cursor;
7718 if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED))
7720 if (m3->mc_flags & C_SPLITTING)
7725 for (k=m3->mc_top; k>=0; k--) {
7726 m3->mc_ki[k+1] = m3->mc_ki[k];
7727 m3->mc_pg[k+1] = m3->mc_pg[k];
7729 if (m3->mc_ki[0] >= split_indx) {
7734 m3->mc_pg[0] = mc->mc_pg[0];
7738 if (m3->mc_top >= mc->mc_top && m3->mc_pg[mc->mc_top] == mp) {
7739 if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE))
7740 m3->mc_ki[mc->mc_top]++;
7741 if (m3->mc_ki[mc->mc_top] >= fixup) {
7742 m3->mc_pg[mc->mc_top] = rp;
7743 m3->mc_ki[mc->mc_top] -= fixup;
7744 m3->mc_ki[ptop] = mn.mc_ki[ptop];
7746 } else if (!did_split && m3->mc_top >= ptop && m3->mc_pg[ptop] == mc->mc_pg[ptop] &&
7747 m3->mc_ki[ptop] >= mc->mc_ki[ptop]) {
7756 mdb_put(MDB_txn *txn, MDB_dbi dbi,
7757 MDB_val *key, MDB_val *data, unsigned int flags)
7762 assert(key != NULL);
7763 assert(data != NULL);
7765 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs || !(txn->mt_dbflags[dbi] & DB_VALID))
7768 if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
7769 return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
7771 if (key->mv_size == 0 || key->mv_size > MDB_MAXKEYSIZE) {
7772 return MDB_BAD_VALSIZE;
7775 if ((flags & (MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND|MDB_APPENDDUP)) != flags)
7778 mdb_cursor_init(&mc, txn, dbi, &mx);
7779 return mdb_cursor_put(&mc, key, data, flags);
7783 mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)
7785 if ((flag & CHANGEABLE) != flag)
7788 env->me_flags |= flag;
7790 env->me_flags &= ~flag;
7795 mdb_env_get_flags(MDB_env *env, unsigned int *arg)
7800 *arg = env->me_flags;
7805 mdb_env_get_path(MDB_env *env, const char **arg)
7810 *arg = env->me_path;
7814 /** Common code for #mdb_stat() and #mdb_env_stat().
7815 * @param[in] env the environment to operate in.
7816 * @param[in] db the #MDB_db record containing the stats to return.
7817 * @param[out] arg the address of an #MDB_stat structure to receive the stats.
7818 * @return 0, this function always succeeds.
7821 mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)
7823 arg->ms_psize = env->me_psize;
7824 arg->ms_depth = db->md_depth;
7825 arg->ms_branch_pages = db->md_branch_pages;
7826 arg->ms_leaf_pages = db->md_leaf_pages;
7827 arg->ms_overflow_pages = db->md_overflow_pages;
7828 arg->ms_entries = db->md_entries;
7833 mdb_env_stat(MDB_env *env, MDB_stat *arg)
7837 if (env == NULL || arg == NULL)
7840 toggle = mdb_env_pick_meta(env);
7842 return mdb_stat0(env, &env->me_metas[toggle]->mm_dbs[MAIN_DBI], arg);
7846 mdb_env_info(MDB_env *env, MDB_envinfo *arg)
7850 if (env == NULL || arg == NULL)
7853 toggle = mdb_env_pick_meta(env);
7854 arg->me_mapaddr = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : 0;
7855 arg->me_mapsize = env->me_mapsize;
7856 arg->me_maxreaders = env->me_maxreaders;
7858 /* me_numreaders may be zero if this process never used any readers. Use
7859 * the shared numreader count if it exists.
7861 arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : env->me_numreaders;
7863 arg->me_last_pgno = env->me_metas[toggle]->mm_last_pg;
7864 arg->me_last_txnid = env->me_metas[toggle]->mm_txnid;
7868 /** Set the default comparison functions for a database.
7869 * Called immediately after a database is opened to set the defaults.
7870 * The user can then override them with #mdb_set_compare() or
7871 * #mdb_set_dupsort().
7872 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
7873 * @param[in] dbi A database handle returned by #mdb_dbi_open()
7876 mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi)
7878 uint16_t f = txn->mt_dbs[dbi].md_flags;
7880 txn->mt_dbxs[dbi].md_cmp =
7881 (f & MDB_REVERSEKEY) ? mdb_cmp_memnr :
7882 (f & MDB_INTEGERKEY) ? mdb_cmp_cint : mdb_cmp_memn;
7884 txn->mt_dbxs[dbi].md_dcmp =
7885 !(f & MDB_DUPSORT) ? 0 :
7886 ((f & MDB_INTEGERDUP)
7887 ? ((f & MDB_DUPFIXED) ? mdb_cmp_int : mdb_cmp_cint)
7888 : ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn));
7891 int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
7896 int rc, dbflag, exact;
7897 unsigned int unused = 0;
7900 if (txn->mt_dbxs[FREE_DBI].md_cmp == NULL) {
7901 mdb_default_cmp(txn, FREE_DBI);
7904 if ((flags & VALID_FLAGS) != flags)
7906 if (txn->mt_flags & MDB_TXN_ERROR)
7912 if (flags & PERSISTENT_FLAGS) {
7913 uint16_t f2 = flags & PERSISTENT_FLAGS;
7914 /* make sure flag changes get committed */
7915 if ((txn->mt_dbs[MAIN_DBI].md_flags | f2) != txn->mt_dbs[MAIN_DBI].md_flags) {
7916 txn->mt_dbs[MAIN_DBI].md_flags |= f2;
7917 txn->mt_flags |= MDB_TXN_DIRTY;
7920 mdb_default_cmp(txn, MAIN_DBI);
7924 if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {
7925 mdb_default_cmp(txn, MAIN_DBI);
7928 /* Is the DB already open? */
7930 for (i=2; i<txn->mt_numdbs; i++) {
7931 if (!txn->mt_dbxs[i].md_name.mv_size) {
7932 /* Remember this free slot */
7933 if (!unused) unused = i;
7936 if (len == txn->mt_dbxs[i].md_name.mv_size &&
7937 !strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) {
7943 /* If no free slot and max hit, fail */
7944 if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs)
7945 return MDB_DBS_FULL;
7947 /* Cannot mix named databases with some mainDB flags */
7948 if (txn->mt_dbs[MAIN_DBI].md_flags & (MDB_DUPSORT|MDB_INTEGERKEY))
7949 return (flags & MDB_CREATE) ? MDB_INCOMPATIBLE : MDB_NOTFOUND;
7951 /* Find the DB info */
7952 dbflag = DB_NEW|DB_VALID;
7955 key.mv_data = (void *)name;
7956 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
7957 rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact);
7958 if (rc == MDB_SUCCESS) {
7959 /* make sure this is actually a DB */
7960 MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]);
7961 if (!(node->mn_flags & F_SUBDATA))
7962 return MDB_INCOMPATIBLE;
7963 } else if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) {
7964 /* Create if requested */
7966 data.mv_size = sizeof(MDB_db);
7967 data.mv_data = &dummy;
7968 memset(&dummy, 0, sizeof(dummy));
7969 dummy.md_root = P_INVALID;
7970 dummy.md_flags = flags & PERSISTENT_FLAGS;
7971 rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA);
7975 /* OK, got info, add to table */
7976 if (rc == MDB_SUCCESS) {
7977 unsigned int slot = unused ? unused : txn->mt_numdbs;
7978 txn->mt_dbxs[slot].md_name.mv_data = strdup(name);
7979 txn->mt_dbxs[slot].md_name.mv_size = len;
7980 txn->mt_dbxs[slot].md_rel = NULL;
7981 txn->mt_dbflags[slot] = dbflag;
7982 memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db));
7984 mdb_default_cmp(txn, slot);
7993 int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
7995 if (txn == NULL || arg == NULL || dbi >= txn->mt_numdbs)
7998 if (txn->mt_dbflags[dbi] & DB_STALE) {
8001 /* Stale, must read the DB's root. cursor_init does it for us. */
8002 mdb_cursor_init(&mc, txn, dbi, &mx);
8004 return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg);
8007 void mdb_dbi_close(MDB_env *env, MDB_dbi dbi)
8010 if (dbi <= MAIN_DBI || dbi >= env->me_maxdbs)
8012 ptr = env->me_dbxs[dbi].md_name.mv_data;
8013 env->me_dbxs[dbi].md_name.mv_data = NULL;
8014 env->me_dbxs[dbi].md_name.mv_size = 0;
8015 env->me_dbflags[dbi] = 0;
8019 int mdb_dbi_flags(MDB_txn *txn, MDB_dbi dbi, unsigned int *flags)
8021 /* We could return the flags for the FREE_DBI too but what's the point? */
8022 if (txn == NULL || dbi < MAIN_DBI || dbi >= txn->mt_numdbs)
8024 *flags = txn->mt_dbs[dbi].md_flags & PERSISTENT_FLAGS;
8028 /** Add all the DB's pages to the free list.
8029 * @param[in] mc Cursor on the DB to free.
8030 * @param[in] subs non-Zero to check for sub-DBs in this DB.
8031 * @return 0 on success, non-zero on failure.
8034 mdb_drop0(MDB_cursor *mc, int subs)
8038 rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
8039 if (rc == MDB_SUCCESS) {
8040 MDB_txn *txn = mc->mc_txn;
8045 /* LEAF2 pages have no nodes, cannot have sub-DBs */
8046 if (IS_LEAF2(mc->mc_pg[mc->mc_top]))
8049 mdb_cursor_copy(mc, &mx);
8050 while (mc->mc_snum > 0) {
8051 MDB_page *mp = mc->mc_pg[mc->mc_top];
8052 unsigned n = NUMKEYS(mp);
8054 for (i=0; i<n; i++) {
8055 ni = NODEPTR(mp, i);
8056 if (ni->mn_flags & F_BIGDATA) {
8059 memcpy(&pg, NODEDATA(ni), sizeof(pg));
8060 rc = mdb_page_get(txn, pg, &omp, NULL);
8063 assert(IS_OVERFLOW(omp));
8064 rc = mdb_midl_append_range(&txn->mt_free_pgs,
8068 } else if (subs && (ni->mn_flags & F_SUBDATA)) {
8069 mdb_xcursor_init1(mc, ni);
8070 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
8076 if ((rc = mdb_midl_need(&txn->mt_free_pgs, n)) != 0)
8078 for (i=0; i<n; i++) {
8080 ni = NODEPTR(mp, i);
8083 mdb_midl_xappend(txn->mt_free_pgs, pg);
8088 mc->mc_ki[mc->mc_top] = i;
8089 rc = mdb_cursor_sibling(mc, 1);
8091 /* no more siblings, go back to beginning
8092 * of previous level.
8096 for (i=1; i<mc->mc_snum; i++) {
8098 mc->mc_pg[i] = mx.mc_pg[i];
8103 rc = mdb_midl_append(&txn->mt_free_pgs, mc->mc_db->md_root);
8104 } else if (rc == MDB_NOTFOUND) {
8110 int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)
8112 MDB_cursor *mc, *m2;
8115 if (!txn || !dbi || dbi >= txn->mt_numdbs || (unsigned)del > 1 || !(txn->mt_dbflags[dbi] & DB_VALID))
8118 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
8121 rc = mdb_cursor_open(txn, dbi, &mc);
8125 rc = mdb_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT);
8126 /* Invalidate the dropped DB's cursors */
8127 for (m2 = txn->mt_cursors[dbi]; m2; m2 = m2->mc_next)
8128 m2->mc_flags &= ~(C_INITIALIZED|C_EOF);
8132 /* Can't delete the main DB */
8133 if (del && dbi > MAIN_DBI) {
8134 rc = mdb_del(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL);
8136 txn->mt_dbflags[dbi] = DB_STALE;
8137 mdb_dbi_close(txn->mt_env, dbi);
8140 /* reset the DB record, mark it dirty */
8141 txn->mt_dbflags[dbi] |= DB_DIRTY;
8142 txn->mt_dbs[dbi].md_depth = 0;
8143 txn->mt_dbs[dbi].md_branch_pages = 0;
8144 txn->mt_dbs[dbi].md_leaf_pages = 0;
8145 txn->mt_dbs[dbi].md_overflow_pages = 0;
8146 txn->mt_dbs[dbi].md_entries = 0;
8147 txn->mt_dbs[dbi].md_root = P_INVALID;
8149 txn->mt_flags |= MDB_TXN_DIRTY;
8152 mdb_cursor_close(mc);
8156 int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
8158 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs || !(txn->mt_dbflags[dbi] & DB_VALID))
8161 txn->mt_dbxs[dbi].md_cmp = cmp;
8165 int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
8167 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs || !(txn->mt_dbflags[dbi] & DB_VALID))
8170 txn->mt_dbxs[dbi].md_dcmp = cmp;
8174 int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
8176 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs || !(txn->mt_dbflags[dbi] & DB_VALID))
8179 txn->mt_dbxs[dbi].md_rel = rel;
8183 int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx)
8185 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs || !(txn->mt_dbflags[dbi] & DB_VALID))
8188 txn->mt_dbxs[dbi].md_relctx = ctx;
8192 int mdb_env_get_maxkeysize(MDB_env *env)
8194 return MDB_MAXKEYSIZE;
8197 int mdb_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx)
8199 unsigned int i, rdrs;
8206 if (!env->me_txns) {
8207 return func("(no reader locks)\n", ctx);
8209 rdrs = env->me_txns->mti_numreaders;
8210 mr = env->me_txns->mti_readers;
8211 for (i=0; i<rdrs; i++) {
8216 if (mr[i].mr_txnid == (txnid_t)-1) {
8217 sprintf(buf, "%10d %"Z"x -\n", mr[i].mr_pid, tid);
8219 sprintf(buf, "%10d %"Z"x %"Z"u\n", mr[i].mr_pid, tid, mr[i].mr_txnid);
8223 func(" pid thread txnid\n", ctx);
8225 rc = func(buf, ctx);
8231 func("(no active readers)\n", ctx);
8236 /** Insert pid into list if not already present.
8237 * return -1 if already present.
8239 static int mdb_pid_insert(pid_t *ids, pid_t pid)
8241 /* binary search of pid in list */
8243 unsigned cursor = 1;
8245 unsigned n = ids[0];
8248 unsigned pivot = n >> 1;
8249 cursor = base + pivot + 1;
8250 val = pid - ids[cursor];
8255 } else if ( val > 0 ) {
8260 /* found, so it's a duplicate */
8269 for (n = ids[0]; n > cursor; n--)
8275 int mdb_reader_check(MDB_env *env, int *dead)
8277 unsigned int i, j, rdrs;
8288 rdrs = env->me_txns->mti_numreaders;
8289 pids = malloc((rdrs+1) * sizeof(pid_t));
8293 mr = env->me_txns->mti_readers;
8295 for (i=0; i<rdrs; i++) {
8296 if (mr[i].mr_pid && mr[i].mr_pid != env->me_pid) {
8298 if (mdb_pid_insert(pids, pid) == 0) {
8299 if (!mdb_reader_pid(env, Pidcheck, pid)) {
8301 /* Recheck, a new process may have reused pid */
8302 if (!mdb_reader_pid(env, Pidcheck, pid)) {
8303 for (j=i; j<rdrs; j++)
8304 if (mr[j].mr_pid == pid) {
8305 DPRINTF(("clear stale reader pid %u txn %"Z"d",
8306 (unsigned) pid, mr[j].mr_txnid));
8311 UNLOCK_MUTEX_R(env);
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