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 2011-2012 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.
35 #include <sys/types.h>
37 #include <sys/param.h>
43 #ifdef HAVE_SYS_FILE_H
60 #if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER))
61 #include <resolv.h> /* defines BYTE_ORDER on HPUX and Solaris */
64 #if defined(__APPLE__) || defined (BSD)
65 # define MDB_USE_POSIX_SEM 1
66 # define MDB_FDATASYNC fsync
67 #elif defined(ANDROID)
68 # define MDB_FDATASYNC fsync
73 #ifdef MDB_USE_POSIX_SEM
74 #include <semaphore.h>
79 #include <valgrind/memcheck.h>
80 #define VGMEMP_CREATE(h,r,z) VALGRIND_CREATE_MEMPOOL(h,r,z)
81 #define VGMEMP_ALLOC(h,a,s) VALGRIND_MEMPOOL_ALLOC(h,a,s)
82 #define VGMEMP_FREE(h,a) VALGRIND_MEMPOOL_FREE(h,a)
83 #define VGMEMP_DESTROY(h) VALGRIND_DESTROY_MEMPOOL(h)
84 #define VGMEMP_DEFINED(a,s) VALGRIND_MAKE_MEM_DEFINED(a,s)
86 #define VGMEMP_CREATE(h,r,z)
87 #define VGMEMP_ALLOC(h,a,s)
88 #define VGMEMP_FREE(h,a)
89 #define VGMEMP_DESTROY(h)
90 #define VGMEMP_DEFINED(a,s)
94 # if (defined(_LITTLE_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN))
95 /* Solaris just defines one or the other */
96 # define LITTLE_ENDIAN 1234
97 # define BIG_ENDIAN 4321
98 # ifdef _LITTLE_ENDIAN
99 # define BYTE_ORDER LITTLE_ENDIAN
101 # define BYTE_ORDER BIG_ENDIAN
104 # define BYTE_ORDER __BYTE_ORDER
108 #ifndef LITTLE_ENDIAN
109 #define LITTLE_ENDIAN __LITTLE_ENDIAN
112 #define BIG_ENDIAN __BIG_ENDIAN
115 #if defined(__i386) || defined(__x86_64)
116 #define MISALIGNED_OK 1
122 #if (BYTE_ORDER == LITTLE_ENDIAN) == (BYTE_ORDER == BIG_ENDIAN)
123 # error "Unknown or unsupported endianness (BYTE_ORDER)"
124 #elif (-6 & 5) || CHAR_BIT != 8 || UINT_MAX < 0xffffffff || ULONG_MAX % 0xFFFF
125 # error "Two's complement, reasonably sized integer types, please"
128 /** @defgroup internal MDB Internals
131 /** @defgroup compat Windows Compatibility Macros
132 * A bunch of macros to minimize the amount of platform-specific ifdefs
133 * needed throughout the rest of the code. When the features this library
134 * needs are similar enough to POSIX to be hidden in a one-or-two line
135 * replacement, this macro approach is used.
139 #define pthread_t DWORD
140 #define pthread_mutex_t HANDLE
141 #define pthread_key_t DWORD
142 #define pthread_self() GetCurrentThreadId()
143 #define pthread_key_create(x,y) (*(x) = TlsAlloc())
144 #define pthread_key_delete(x) TlsFree(x)
145 #define pthread_getspecific(x) TlsGetValue(x)
146 #define pthread_setspecific(x,y) TlsSetValue(x,y)
147 #define pthread_mutex_unlock(x) ReleaseMutex(x)
148 #define pthread_mutex_lock(x) WaitForSingleObject(x, INFINITE)
149 #define LOCK_MUTEX_R(env) pthread_mutex_lock((env)->me_rmutex)
150 #define UNLOCK_MUTEX_R(env) pthread_mutex_unlock((env)->me_rmutex)
151 #define LOCK_MUTEX_W(env) pthread_mutex_lock((env)->me_wmutex)
152 #define UNLOCK_MUTEX_W(env) pthread_mutex_unlock((env)->me_wmutex)
153 #define getpid() GetCurrentProcessId()
154 #define MDB_FDATASYNC(fd) (!FlushFileBuffers(fd))
155 #define MDB_MSYNC(addr,len,flags) (!FlushViewOfFile(addr,len))
156 #define ErrCode() GetLastError()
157 #define GET_PAGESIZE(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;}
158 #define close(fd) CloseHandle(fd)
159 #define munmap(ptr,len) UnmapViewOfFile(ptr)
161 #ifdef MDB_USE_POSIX_SEM
162 #define LOCK_MUTEX_R(env) sem_wait((env)->me_rmutex)
163 #define UNLOCK_MUTEX_R(env) sem_post((env)->me_rmutex)
164 #define LOCK_MUTEX_W(env) sem_wait((env)->me_wmutex)
165 #define UNLOCK_MUTEX_W(env) sem_post((env)->me_wmutex)
167 /** Lock the reader mutex.
169 #define LOCK_MUTEX_R(env) pthread_mutex_lock(&(env)->me_txns->mti_mutex)
170 /** Unlock the reader mutex.
172 #define UNLOCK_MUTEX_R(env) pthread_mutex_unlock(&(env)->me_txns->mti_mutex)
174 /** Lock the writer mutex.
175 * Only a single write transaction is allowed at a time. Other writers
176 * will block waiting for this mutex.
178 #define LOCK_MUTEX_W(env) pthread_mutex_lock(&(env)->me_txns->mti_wmutex)
179 /** Unlock the writer mutex.
181 #define UNLOCK_MUTEX_W(env) pthread_mutex_unlock(&(env)->me_txns->mti_wmutex)
182 #endif /* MDB_USE_POSIX_SEM */
184 /** Get the error code for the last failed system function.
186 #define ErrCode() errno
188 /** An abstraction for a file handle.
189 * On POSIX systems file handles are small integers. On Windows
190 * they're opaque pointers.
194 /** A value for an invalid file handle.
195 * Mainly used to initialize file variables and signify that they are
198 #define INVALID_HANDLE_VALUE (-1)
200 /** Get the size of a memory page for the system.
201 * This is the basic size that the platform's memory manager uses, and is
202 * fundamental to the use of memory-mapped files.
204 #define GET_PAGESIZE(x) ((x) = sysconf(_SC_PAGE_SIZE))
207 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
210 #define MNAME_LEN (sizeof(pthread_mutex_t))
216 /** A flag for opening a file and requesting synchronous data writes.
217 * This is only used when writing a meta page. It's not strictly needed;
218 * we could just do a normal write and then immediately perform a flush.
219 * But if this flag is available it saves us an extra system call.
221 * @note If O_DSYNC is undefined but exists in /usr/include,
222 * preferably set some compiler flag to get the definition.
223 * Otherwise compile with the less efficient -DMDB_DSYNC=O_SYNC.
226 # define MDB_DSYNC O_DSYNC
230 /** Function for flushing the data of a file. Define this to fsync
231 * if fdatasync() is not supported.
233 #ifndef MDB_FDATASYNC
234 # define MDB_FDATASYNC fdatasync
238 # define MDB_MSYNC(addr,len,flags) msync(addr,len,flags)
249 /** A page number in the database.
250 * Note that 64 bit page numbers are overkill, since pages themselves
251 * already represent 12-13 bits of addressable memory, and the OS will
252 * always limit applications to a maximum of 63 bits of address space.
254 * @note In the #MDB_node structure, we only store 48 bits of this value,
255 * which thus limits us to only 60 bits of addressable data.
257 typedef MDB_ID pgno_t;
259 /** A transaction ID.
260 * See struct MDB_txn.mt_txnid for details.
262 typedef MDB_ID txnid_t;
264 /** @defgroup debug Debug Macros
268 /** Enable debug output.
269 * Set this to 1 for copious tracing. Set to 2 to add dumps of all IDLs
270 * read from and written to the database (used for free space management).
275 #if !(__STDC_VERSION__ >= 199901L || defined(__GNUC__))
276 # define DPRINTF (void) /* Vararg macros may be unsupported */
278 static int mdb_debug;
279 static txnid_t mdb_debug_start;
281 /** Print a debug message with printf formatting. */
282 # define DPRINTF(fmt, ...) /**< Requires 2 or more args */ \
283 ((void) ((mdb_debug) && \
284 fprintf(stderr, "%s:%d " fmt "\n", __func__, __LINE__, __VA_ARGS__)))
286 # define DPRINTF(fmt, ...) ((void) 0)
288 /** Print a debug string.
289 * The string is printed literally, with no format processing.
291 #define DPUTS(arg) DPRINTF("%s", arg)
294 /** A default memory page size.
295 * The actual size is platform-dependent, but we use this for
296 * boot-strapping. We probably should not be using this any more.
297 * The #GET_PAGESIZE() macro is used to get the actual size.
299 * Note that we don't currently support Huge pages. On Linux,
300 * regular data files cannot use Huge pages, and in general
301 * Huge pages aren't actually pageable. We rely on the OS
302 * demand-pager to read our data and page it out when memory
303 * pressure from other processes is high. So until OSs have
304 * actual paging support for Huge pages, they're not viable.
306 #define MDB_PAGESIZE 4096
308 /** The minimum number of keys required in a database page.
309 * Setting this to a larger value will place a smaller bound on the
310 * maximum size of a data item. Data items larger than this size will
311 * be pushed into overflow pages instead of being stored directly in
312 * the B-tree node. This value used to default to 4. With a page size
313 * of 4096 bytes that meant that any item larger than 1024 bytes would
314 * go into an overflow page. That also meant that on average 2-3KB of
315 * each overflow page was wasted space. The value cannot be lower than
316 * 2 because then there would no longer be a tree structure. With this
317 * value, items larger than 2KB will go into overflow pages, and on
318 * average only 1KB will be wasted.
320 #define MDB_MINKEYS 2
322 /** A stamp that identifies a file as an MDB file.
323 * There's nothing special about this value other than that it is easily
324 * recognizable, and it will reflect any byte order mismatches.
326 #define MDB_MAGIC 0xBEEFC0DE
328 /** The version number for a database's file format. */
329 #define MDB_VERSION 1
331 /** The maximum size of a key in the database.
332 * While data items have essentially unbounded size, we require that
333 * keys all fit onto a regular page. This limit could be raised a bit
334 * further if needed; to something just under #MDB_PAGESIZE / #MDB_MINKEYS.
336 #define MAXKEYSIZE 511
341 * This is used for printing a hex dump of a key's contents.
343 #define DKBUF char kbuf[(MAXKEYSIZE*2+1)]
344 /** Display a key in hex.
346 * Invoke a function to display a key in hex.
348 #define DKEY(x) mdb_dkey(x, kbuf)
350 #define DKBUF typedef int dummy_kbuf /* so we can put ';' after */
354 /** An invalid page number.
355 * Mainly used to denote an empty tree.
357 #define P_INVALID (~(pgno_t)0)
359 /** Test if a flag \b f is set in a flag word \b w. */
360 #define F_ISSET(w, f) (((w) & (f)) == (f))
362 /** Used for offsets within a single page.
363 * Since memory pages are typically 4 or 8KB in size, 12-13 bits,
366 typedef uint16_t indx_t;
368 /** Default size of memory map.
369 * This is certainly too small for any actual applications. Apps should always set
370 * the size explicitly using #mdb_env_set_mapsize().
372 #define DEFAULT_MAPSIZE 1048576
374 /** @defgroup readers Reader Lock Table
375 * Readers don't acquire any locks for their data access. Instead, they
376 * simply record their transaction ID in the reader table. The reader
377 * mutex is needed just to find an empty slot in the reader table. The
378 * slot's address is saved in thread-specific data so that subsequent read
379 * transactions started by the same thread need no further locking to proceed.
381 * Since the database uses multi-version concurrency control, readers don't
382 * actually need any locking. This table is used to keep track of which
383 * readers are using data from which old transactions, so that we'll know
384 * when a particular old transaction is no longer in use. Old transactions
385 * that have discarded any data pages can then have those pages reclaimed
386 * for use by a later write transaction.
388 * The lock table is constructed such that reader slots are aligned with the
389 * processor's cache line size. Any slot is only ever used by one thread.
390 * This alignment guarantees that there will be no contention or cache
391 * thrashing as threads update their own slot info, and also eliminates
392 * any need for locking when accessing a slot.
394 * A writer thread will scan every slot in the table to determine the oldest
395 * outstanding reader transaction. Any freed pages older than this will be
396 * reclaimed by the writer. The writer doesn't use any locks when scanning
397 * this table. This means that there's no guarantee that the writer will
398 * see the most up-to-date reader info, but that's not required for correct
399 * operation - all we need is to know the upper bound on the oldest reader,
400 * we don't care at all about the newest reader. So the only consequence of
401 * reading stale information here is that old pages might hang around a
402 * while longer before being reclaimed. That's actually good anyway, because
403 * the longer we delay reclaiming old pages, the more likely it is that a
404 * string of contiguous pages can be found after coalescing old pages from
405 * many old transactions together.
407 * @todo We don't actually do such coalescing yet, we grab pages from one
408 * old transaction at a time.
411 /** Number of slots in the reader table.
412 * This value was chosen somewhat arbitrarily. 126 readers plus a
413 * couple mutexes fit exactly into 8KB on my development machine.
414 * Applications should set the table size using #mdb_env_set_maxreaders().
416 #define DEFAULT_READERS 126
418 /** The size of a CPU cache line in bytes. We want our lock structures
419 * aligned to this size to avoid false cache line sharing in the
421 * This value works for most CPUs. For Itanium this should be 128.
427 /** The information we store in a single slot of the reader table.
428 * In addition to a transaction ID, we also record the process and
429 * thread ID that owns a slot, so that we can detect stale information,
430 * e.g. threads or processes that went away without cleaning up.
431 * @note We currently don't check for stale records. We simply re-init
432 * the table when we know that we're the only process opening the
435 typedef struct MDB_rxbody {
436 /** Current Transaction ID when this transaction began, or (txnid_t)-1.
437 * Multiple readers that start at the same time will probably have the
438 * same ID here. Again, it's not important to exclude them from
439 * anything; all we need to know is which version of the DB they
440 * started from so we can avoid overwriting any data used in that
441 * particular version.
444 /** The process ID of the process owning this reader txn. */
446 /** The thread ID of the thread owning this txn. */
450 /** The actual reader record, with cacheline padding. */
451 typedef struct MDB_reader {
454 /** shorthand for mrb_txnid */
455 #define mr_txnid mru.mrx.mrb_txnid
456 #define mr_pid mru.mrx.mrb_pid
457 #define mr_tid mru.mrx.mrb_tid
458 /** cache line alignment */
459 char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)];
463 /** The header for the reader table.
464 * The table resides in a memory-mapped file. (This is a different file
465 * than is used for the main database.)
467 * For POSIX the actual mutexes reside in the shared memory of this
468 * mapped file. On Windows, mutexes are named objects allocated by the
469 * kernel; we store the mutex names in this mapped file so that other
470 * processes can grab them. This same approach is also used on
471 * MacOSX/Darwin (using named semaphores) since MacOSX doesn't support
472 * process-shared POSIX mutexes. For these cases where a named object
473 * is used, the object name is derived from a 64 bit FNV hash of the
474 * environment pathname. As such, naming collisions are extremely
475 * unlikely. If a collision occurs, the results are unpredictable.
477 typedef struct MDB_txbody {
478 /** Stamp identifying this as an MDB file. It must be set
481 /** Version number of this lock file. Must be set to #MDB_VERSION. */
482 uint32_t mtb_version;
483 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
484 char mtb_rmname[MNAME_LEN];
486 /** Mutex protecting access to this table.
487 * This is the reader lock that #LOCK_MUTEX_R acquires.
489 pthread_mutex_t mtb_mutex;
491 /** The ID of the last transaction committed to the database.
492 * This is recorded here only for convenience; the value can always
493 * be determined by reading the main database meta pages.
496 /** The number of slots that have been used in the reader table.
497 * This always records the maximum count, it is not decremented
498 * when readers release their slots.
500 unsigned mtb_numreaders;
503 /** The actual reader table definition. */
504 typedef struct MDB_txninfo {
507 #define mti_magic mt1.mtb.mtb_magic
508 #define mti_version mt1.mtb.mtb_version
509 #define mti_mutex mt1.mtb.mtb_mutex
510 #define mti_rmname mt1.mtb.mtb_rmname
511 #define mti_txnid mt1.mtb.mtb_txnid
512 #define mti_numreaders mt1.mtb.mtb_numreaders
513 char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];
516 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
517 char mt2_wmname[MNAME_LEN];
518 #define mti_wmname mt2.mt2_wmname
520 pthread_mutex_t mt2_wmutex;
521 #define mti_wmutex mt2.mt2_wmutex
523 char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)];
525 MDB_reader mti_readers[1];
529 /** Common header for all page types.
530 * Overflow records occupy a number of contiguous pages with no
531 * headers on any page after the first.
533 typedef struct MDB_page {
534 #define mp_pgno mp_p.p_pgno
535 #define mp_next mp_p.p_next
537 pgno_t p_pgno; /**< page number */
538 void * p_next; /**< for in-memory list of freed structs */
541 /** @defgroup mdb_page Page Flags
543 * Flags for the page headers.
546 #define P_BRANCH 0x01 /**< branch page */
547 #define P_LEAF 0x02 /**< leaf page */
548 #define P_OVERFLOW 0x04 /**< overflow page */
549 #define P_META 0x08 /**< meta page */
550 #define P_DIRTY 0x10 /**< dirty page */
551 #define P_LEAF2 0x20 /**< for #MDB_DUPFIXED records */
552 #define P_SUBP 0x40 /**< for #MDB_DUPSORT sub-pages */
554 uint16_t mp_flags; /**< @ref mdb_page */
555 #define mp_lower mp_pb.pb.pb_lower
556 #define mp_upper mp_pb.pb.pb_upper
557 #define mp_pages mp_pb.pb_pages
560 indx_t pb_lower; /**< lower bound of free space */
561 indx_t pb_upper; /**< upper bound of free space */
563 uint32_t pb_pages; /**< number of overflow pages */
565 indx_t mp_ptrs[1]; /**< dynamic size */
568 /** Size of the page header, excluding dynamic data at the end */
569 #define PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs))
571 /** Address of first usable data byte in a page, after the header */
572 #define METADATA(p) ((void *)((char *)(p) + PAGEHDRSZ))
574 /** Number of nodes on a page */
575 #define NUMKEYS(p) (((p)->mp_lower - PAGEHDRSZ) >> 1)
577 /** The amount of space remaining in the page */
578 #define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower)
580 /** The percentage of space used in the page, in tenths of a percent. */
581 #define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \
582 ((env)->me_psize - PAGEHDRSZ))
583 /** The minimum page fill factor, in tenths of a percent.
584 * Pages emptier than this are candidates for merging.
586 #define FILL_THRESHOLD 250
588 /** Test if a page is a leaf page */
589 #define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF)
590 /** Test if a page is a LEAF2 page */
591 #define IS_LEAF2(p) F_ISSET((p)->mp_flags, P_LEAF2)
592 /** Test if a page is a branch page */
593 #define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH)
594 /** Test if a page is an overflow page */
595 #define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW)
596 /** Test if a page is a sub page */
597 #define IS_SUBP(p) F_ISSET((p)->mp_flags, P_SUBP)
599 /** The number of overflow pages needed to store the given size. */
600 #define OVPAGES(size, psize) ((PAGEHDRSZ-1 + (size)) / (psize) + 1)
602 /** Header for a single key/data pair within a page.
603 * We guarantee 2-byte alignment for nodes.
605 typedef struct MDB_node {
606 /** lo and hi are used for data size on leaf nodes and for
607 * child pgno on branch nodes. On 64 bit platforms, flags
608 * is also used for pgno. (Branch nodes have no flags).
609 * They are in host byte order in case that lets some
610 * accesses be optimized into a 32-bit word access.
612 #define mn_lo mn_offset[BYTE_ORDER!=LITTLE_ENDIAN]
613 #define mn_hi mn_offset[BYTE_ORDER==LITTLE_ENDIAN] /**< part of dsize or pgno */
614 unsigned short mn_offset[2]; /**< storage for #mn_lo and #mn_hi */
615 /** @defgroup mdb_node Node Flags
617 * Flags for node headers.
620 #define F_BIGDATA 0x01 /**< data put on overflow page */
621 #define F_SUBDATA 0x02 /**< data is a sub-database */
622 #define F_DUPDATA 0x04 /**< data has duplicates */
624 /** valid flags for #mdb_node_add() */
625 #define NODE_ADD_FLAGS (F_DUPDATA|F_SUBDATA|MDB_RESERVE|MDB_APPEND)
628 unsigned short mn_flags; /**< @ref mdb_node */
629 unsigned short mn_ksize; /**< key size */
630 char mn_data[1]; /**< key and data are appended here */
633 /** Size of the node header, excluding dynamic data at the end */
634 #define NODESIZE offsetof(MDB_node, mn_data)
636 /** Bit position of top word in page number, for shifting mn_flags */
637 #define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0)
639 /** Size of a node in a branch page with a given key.
640 * This is just the node header plus the key, there is no data.
642 #define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))
644 /** Size of a node in a leaf page with a given key and data.
645 * This is node header plus key plus data size.
647 #define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size)
649 /** Address of node \b i in page \b p */
650 #define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i]))
652 /** Address of the key for the node */
653 #define NODEKEY(node) (void *)((node)->mn_data)
655 /** Address of the data for a node */
656 #define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize)
658 /** Get the page number pointed to by a branch node */
659 #define NODEPGNO(node) \
660 ((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | \
661 (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0))
662 /** Set the page number in a branch node */
663 #define SETPGNO(node,pgno) do { \
664 (node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \
665 if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0)
667 /** Get the size of the data in a leaf node */
668 #define NODEDSZ(node) ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16))
669 /** Set the size of the data for a leaf node */
670 #define SETDSZ(node,size) do { \
671 (node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)
672 /** The size of a key in a node */
673 #define NODEKSZ(node) ((node)->mn_ksize)
675 /** Copy a page number from src to dst */
677 #define COPY_PGNO(dst,src) dst = src
679 #if SIZE_MAX > 4294967295UL
680 #define COPY_PGNO(dst,src) do { \
681 unsigned short *s, *d; \
682 s = (unsigned short *)&(src); \
683 d = (unsigned short *)&(dst); \
690 #define COPY_PGNO(dst,src) do { \
691 unsigned short *s, *d; \
692 s = (unsigned short *)&(src); \
693 d = (unsigned short *)&(dst); \
699 /** The address of a key in a LEAF2 page.
700 * LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate sub-DBs.
701 * There are no node headers, keys are stored contiguously.
703 #define LEAF2KEY(p, i, ks) ((char *)(p) + PAGEHDRSZ + ((i)*(ks)))
705 /** Set the \b node's key into \b key, if requested. */
706 #define MDB_GET_KEY(node, key) { if ((key) != NULL) { \
707 (key)->mv_size = NODEKSZ(node); (key)->mv_data = NODEKEY(node); } }
709 /** Information about a single database in the environment. */
710 typedef struct MDB_db {
711 uint32_t md_pad; /**< also ksize for LEAF2 pages */
712 uint16_t md_flags; /**< @ref mdb_open */
713 uint16_t md_depth; /**< depth of this tree */
714 pgno_t md_branch_pages; /**< number of internal pages */
715 pgno_t md_leaf_pages; /**< number of leaf pages */
716 pgno_t md_overflow_pages; /**< number of overflow pages */
717 size_t md_entries; /**< number of data items */
718 pgno_t md_root; /**< the root page of this tree */
721 /** Handle for the DB used to track free pages. */
723 /** Handle for the default DB. */
726 /** Meta page content. */
727 typedef struct MDB_meta {
728 /** Stamp identifying this as an MDB file. It must be set
731 /** Version number of this lock file. Must be set to #MDB_VERSION. */
733 void *mm_address; /**< address for fixed mapping */
734 size_t mm_mapsize; /**< size of mmap region */
735 MDB_db mm_dbs[2]; /**< first is free space, 2nd is main db */
736 /** The size of pages used in this DB */
737 #define mm_psize mm_dbs[0].md_pad
738 /** Any persistent environment flags. @ref mdb_env */
739 #define mm_flags mm_dbs[0].md_flags
740 pgno_t mm_last_pg; /**< last used page in file */
741 txnid_t mm_txnid; /**< txnid that committed this page */
744 /** Buffer for a stack-allocated dirty page.
745 * The members define size and alignment, and silence type
746 * aliasing warnings. They are not used directly; that could
747 * mean incorrectly using several union members in parallel.
749 typedef union MDB_pagebuf {
750 char mb_raw[MDB_PAGESIZE];
753 char mm_pad[PAGEHDRSZ];
758 /** Auxiliary DB info.
759 * The information here is mostly static/read-only. There is
760 * only a single copy of this record in the environment.
762 typedef struct MDB_dbx {
763 MDB_val md_name; /**< name of the database */
764 MDB_cmp_func *md_cmp; /**< function for comparing keys */
765 MDB_cmp_func *md_dcmp; /**< function for comparing data items */
766 MDB_rel_func *md_rel; /**< user relocate function */
767 void *md_relctx; /**< user-provided context for md_rel */
770 /** A database transaction.
771 * Every operation requires a transaction handle.
774 MDB_txn *mt_parent; /**< parent of a nested txn */
775 MDB_txn *mt_child; /**< nested txn under this txn */
776 pgno_t mt_next_pgno; /**< next unallocated page */
777 /** The ID of this transaction. IDs are integers incrementing from 1.
778 * Only committed write transactions increment the ID. If a transaction
779 * aborts, the ID may be re-used by the next writer.
782 MDB_env *mt_env; /**< the DB environment */
783 /** The list of pages that became unused during this transaction.
787 MDB_ID2L dirty_list; /**< modified pages */
788 MDB_reader *reader; /**< this thread's slot in the reader table */
790 /** Array of records for each DB known in the environment. */
792 /** Array of MDB_db records for each known DB */
794 /** @defgroup mt_dbflag Transaction DB Flags
798 #define DB_DIRTY 0x01 /**< DB was written in this txn */
799 #define DB_STALE 0x02 /**< DB record is older than txnID */
801 /** Array of cursors for each DB */
802 MDB_cursor **mt_cursors;
803 /** Array of flags for each DB */
804 unsigned char *mt_dbflags;
805 /** Number of DB records in use. This number only ever increments;
806 * we don't decrement it when individual DB handles are closed.
810 /** @defgroup mdb_txn Transaction Flags
814 #define MDB_TXN_RDONLY 0x01 /**< read-only transaction */
815 #define MDB_TXN_ERROR 0x02 /**< an error has occurred */
817 unsigned int mt_flags; /**< @ref mdb_txn */
818 /** Tracks which of the two meta pages was used at the start
819 * of this transaction.
821 unsigned int mt_toggle;
824 /** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty.
825 * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to
826 * raise this on a 64 bit machine.
828 #define CURSOR_STACK 32
832 /** Cursors are used for all DB operations */
834 /** Next cursor on this DB in this txn */
836 /** Original cursor if this is a shadow */
838 /** Context used for databases with #MDB_DUPSORT, otherwise NULL */
839 struct MDB_xcursor *mc_xcursor;
840 /** The transaction that owns this cursor */
842 /** The database handle this cursor operates on */
844 /** The database record for this cursor */
846 /** The database auxiliary record for this cursor */
848 /** The @ref mt_dbflag for this database */
849 unsigned char *mc_dbflag;
850 unsigned short mc_snum; /**< number of pushed pages */
851 unsigned short mc_top; /**< index of top page, normally mc_snum-1 */
852 /** @defgroup mdb_cursor Cursor Flags
854 * Cursor state flags.
857 #define C_INITIALIZED 0x01 /**< cursor has been initialized and is valid */
858 #define C_EOF 0x02 /**< No more data */
859 #define C_SUB 0x04 /**< Cursor is a sub-cursor */
860 #define C_SHADOW 0x08 /**< Cursor is a dup from a parent txn */
861 #define C_ALLOCD 0x10 /**< Cursor was malloc'd */
862 #define C_SPLITTING 0x20 /**< Cursor is in page_split */
864 unsigned int mc_flags; /**< @ref mdb_cursor */
865 MDB_page *mc_pg[CURSOR_STACK]; /**< stack of pushed pages */
866 indx_t mc_ki[CURSOR_STACK]; /**< stack of page indices */
869 /** Context for sorted-dup records.
870 * We could have gone to a fully recursive design, with arbitrarily
871 * deep nesting of sub-databases. But for now we only handle these
872 * levels - main DB, optional sub-DB, sorted-duplicate DB.
874 typedef struct MDB_xcursor {
875 /** A sub-cursor for traversing the Dup DB */
876 MDB_cursor mx_cursor;
877 /** The database record for this Dup DB */
879 /** The auxiliary DB record for this Dup DB */
881 /** The @ref mt_dbflag for this Dup DB */
882 unsigned char mx_dbflag;
885 /** A set of pages freed by an earlier transaction. */
886 typedef struct MDB_oldpages {
887 /** Usually we only read one record from the FREEDB at a time, but
888 * in case we read more, this will chain them together.
890 struct MDB_oldpages *mo_next;
891 /** The ID of the transaction in which these pages were freed. */
893 /** An #MDB_IDL of the pages */
894 pgno_t mo_pages[1]; /* dynamic */
897 /** The database environment. */
899 HANDLE me_fd; /**< The main data file */
900 HANDLE me_lfd; /**< The lock file */
901 HANDLE me_mfd; /**< just for writing the meta pages */
902 /** Failed to update the meta page. Probably an I/O error. */
903 #define MDB_FATAL_ERROR 0x80000000U
904 uint32_t me_flags; /**< @ref mdb_env */
905 unsigned int me_psize; /**< size of a page, from #GET_PAGESIZE */
906 unsigned int me_maxreaders; /**< size of the reader table */
907 unsigned int me_numreaders; /**< max numreaders set by this env */
908 MDB_dbi me_numdbs; /**< number of DBs opened */
909 MDB_dbi me_maxdbs; /**< size of the DB table */
910 pid_t me_pid; /**< process ID of this env */
911 char *me_path; /**< path to the DB files */
912 char *me_map; /**< the memory map of the data file */
913 MDB_txninfo *me_txns; /**< the memory map of the lock file */
914 MDB_meta *me_metas[2]; /**< pointers to the two meta pages */
915 MDB_txn *me_txn; /**< current write transaction */
916 size_t me_mapsize; /**< size of the data memory map */
917 off_t me_size; /**< current file size */
918 pgno_t me_maxpg; /**< me_mapsize / me_psize */
919 txnid_t me_pgfirst; /**< ID of first old page record we used */
920 txnid_t me_pglast; /**< ID of last old page record we used */
921 MDB_dbx *me_dbxs; /**< array of static DB info */
922 uint16_t *me_dbflags; /**< array of DB flags */
923 MDB_oldpages *me_pghead; /**< list of old page records */
924 MDB_oldpages *me_pgfree; /**< list of page records to free */
925 pthread_key_t me_txkey; /**< thread-key for readers */
926 MDB_page *me_dpages; /**< list of malloc'd blocks for re-use */
927 /** IDL of pages that became unused in a write txn */
929 /** ID2L of pages that were written during a write txn */
930 MDB_ID2 me_dirty_list[MDB_IDL_UM_SIZE];
932 HANDLE me_rmutex; /* Windows mutexes don't reside in shared mem */
934 #elif defined(MDB_USE_POSIX_SEM)
935 sem_t *me_rmutex; /* Shared mutexes are not supported */
939 /** max number of pages to commit in one writev() call */
940 #define MDB_COMMIT_PAGES 64
941 #if defined(IOV_MAX) && IOV_MAX < MDB_COMMIT_PAGES
942 #undef MDB_COMMIT_PAGES
943 #define MDB_COMMIT_PAGES IOV_MAX
946 static int mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp);
947 static int mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp);
948 static int mdb_page_touch(MDB_cursor *mc);
950 static int mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **mp);
951 static int mdb_page_search_root(MDB_cursor *mc,
952 MDB_val *key, int modify);
953 #define MDB_PS_MODIFY 1
954 #define MDB_PS_ROOTONLY 2
955 static int mdb_page_search(MDB_cursor *mc,
956 MDB_val *key, int flags);
957 static int mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst);
959 #define MDB_SPLIT_REPLACE MDB_APPENDDUP /**< newkey is not new */
960 static int mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,
961 pgno_t newpgno, unsigned int nflags);
963 static int mdb_env_read_header(MDB_env *env, MDB_meta *meta);
964 static int mdb_env_pick_meta(const MDB_env *env);
965 static int mdb_env_write_meta(MDB_txn *txn);
967 static MDB_node *mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp);
968 static int mdb_node_add(MDB_cursor *mc, indx_t indx,
969 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags);
970 static void mdb_node_del(MDB_page *mp, indx_t indx, int ksize);
971 static void mdb_node_shrink(MDB_page *mp, indx_t indx);
972 static int mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst);
973 static int mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data);
974 static size_t mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data);
975 static size_t mdb_branch_size(MDB_env *env, MDB_val *key);
977 static int mdb_rebalance(MDB_cursor *mc);
978 static int mdb_update_key(MDB_page *mp, indx_t indx, MDB_val *key);
980 static void mdb_cursor_pop(MDB_cursor *mc);
981 static int mdb_cursor_push(MDB_cursor *mc, MDB_page *mp);
983 static int mdb_cursor_del0(MDB_cursor *mc, MDB_node *leaf);
984 static int mdb_cursor_sibling(MDB_cursor *mc, int move_right);
985 static int mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
986 static int mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
987 static int mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op,
989 static int mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data);
990 static int mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data);
992 static void mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);
993 static void mdb_xcursor_init0(MDB_cursor *mc);
994 static void mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node);
996 static int mdb_drop0(MDB_cursor *mc, int subs);
997 static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi);
1000 static MDB_cmp_func mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long;
1004 static SECURITY_DESCRIPTOR mdb_null_sd;
1005 static SECURITY_ATTRIBUTES mdb_all_sa;
1006 static int mdb_sec_inited;
1009 /** Return the library version info. */
1011 mdb_version(int *major, int *minor, int *patch)
1013 if (major) *major = MDB_VERSION_MAJOR;
1014 if (minor) *minor = MDB_VERSION_MINOR;
1015 if (patch) *patch = MDB_VERSION_PATCH;
1016 return MDB_VERSION_STRING;
1019 /** Table of descriptions for MDB @ref errors */
1020 static char *const mdb_errstr[] = {
1021 "MDB_KEYEXIST: Key/data pair already exists",
1022 "MDB_NOTFOUND: No matching key/data pair found",
1023 "MDB_PAGE_NOTFOUND: Requested page not found",
1024 "MDB_CORRUPTED: Located page was wrong type",
1025 "MDB_PANIC: Update of meta page failed",
1026 "MDB_VERSION_MISMATCH: Database environment version mismatch",
1027 "MDB_INVALID: File is not an MDB file",
1028 "MDB_MAP_FULL: Environment mapsize limit reached",
1029 "MDB_DBS_FULL: Environment maxdbs limit reached",
1030 "MDB_READERS_FULL: Environment maxreaders limit reached",
1031 "MDB_TLS_FULL: Thread-local storage keys full - too many environments open",
1032 "MDB_TXN_FULL: Nested transaction has too many dirty pages - transaction too big",
1033 "MDB_CURSOR_FULL: Internal error - cursor stack limit reached",
1034 "MDB_PAGE_FULL: Internal error - page has no more space"
1038 mdb_strerror(int err)
1042 return ("Successful return: 0");
1044 if (err >= MDB_KEYEXIST && err <= MDB_LAST_ERRCODE) {
1045 i = err - MDB_KEYEXIST;
1046 return mdb_errstr[i];
1049 return strerror(err);
1053 /** Display a key in hexadecimal and return the address of the result.
1054 * @param[in] key the key to display
1055 * @param[in] buf the buffer to write into. Should always be #DKBUF.
1056 * @return The key in hexadecimal form.
1059 mdb_dkey(MDB_val *key, char *buf)
1062 unsigned char *c = key->mv_data;
1064 if (key->mv_size > MAXKEYSIZE)
1065 return "MAXKEYSIZE";
1066 /* may want to make this a dynamic check: if the key is mostly
1067 * printable characters, print it as-is instead of converting to hex.
1071 for (i=0; i<key->mv_size; i++)
1072 ptr += sprintf(ptr, "%02x", *c++);
1074 sprintf(buf, "%.*s", key->mv_size, key->mv_data);
1079 /** Display all the keys in the page. */
1081 mdb_page_list(MDB_page *mp)
1084 unsigned int i, nkeys, nsize;
1088 nkeys = NUMKEYS(mp);
1089 fprintf(stderr, "numkeys %d\n", nkeys);
1090 for (i=0; i<nkeys; i++) {
1091 node = NODEPTR(mp, i);
1092 key.mv_size = node->mn_ksize;
1093 key.mv_data = node->mn_data;
1094 nsize = NODESIZE + NODEKSZ(node) + sizeof(indx_t);
1095 if (F_ISSET(node->mn_flags, F_BIGDATA))
1096 nsize += sizeof(pgno_t);
1098 nsize += NODEDSZ(node);
1099 fprintf(stderr, "key %d: nsize %d, %s\n", i, nsize, DKEY(&key));
1104 mdb_cursor_chk(MDB_cursor *mc)
1110 if (!mc->mc_snum && !(mc->mc_flags & C_INITIALIZED)) return;
1111 for (i=0; i<mc->mc_top; i++) {
1113 node = NODEPTR(mp, mc->mc_ki[i]);
1114 if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno)
1117 if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i]))
1123 /** Count all the pages in each DB and in the freelist
1124 * and make sure it matches the actual number of pages
1127 static void mdb_audit(MDB_txn *txn)
1131 MDB_ID freecount, count;
1136 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
1137 while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
1138 freecount += *(MDB_ID *)data.mv_data;
1141 for (i = 0; i<txn->mt_numdbs; i++) {
1142 MDB_xcursor mx, *mxp;
1143 mxp = (txn->mt_dbs[i].md_flags & MDB_DUPSORT) ? &mx : NULL;
1144 mdb_cursor_init(&mc, txn, i, mxp);
1145 if (txn->mt_dbs[i].md_root == P_INVALID)
1147 count += txn->mt_dbs[i].md_branch_pages +
1148 txn->mt_dbs[i].md_leaf_pages +
1149 txn->mt_dbs[i].md_overflow_pages;
1150 if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) {
1151 mdb_page_search(&mc, NULL, 0);
1155 mp = mc.mc_pg[mc.mc_top];
1156 for (j=0; j<NUMKEYS(mp); j++) {
1157 MDB_node *leaf = NODEPTR(mp, j);
1158 if (leaf->mn_flags & F_SUBDATA) {
1160 memcpy(&db, NODEDATA(leaf), sizeof(db));
1161 count += db.md_branch_pages + db.md_leaf_pages +
1162 db.md_overflow_pages;
1166 while (mdb_cursor_sibling(&mc, 1) == 0);
1169 if (freecount + count + 2 /* metapages */ != txn->mt_next_pgno) {
1170 fprintf(stderr, "audit: %lu freecount: %lu count: %lu total: %lu next_pgno: %lu\n",
1171 txn->mt_txnid, freecount, count+2, freecount+count+2, txn->mt_next_pgno);
1177 mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1179 return txn->mt_dbxs[dbi].md_cmp(a, b);
1183 mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1185 if (txn->mt_dbxs[dbi].md_dcmp)
1186 return txn->mt_dbxs[dbi].md_dcmp(a, b);
1188 return EINVAL; /* too bad you can't distinguish this from a valid result */
1191 /** Allocate a single page.
1192 * Re-use old malloc'd pages first, otherwise just malloc.
1195 mdb_page_malloc(MDB_cursor *mc) {
1197 size_t sz = mc->mc_txn->mt_env->me_psize;
1198 if ((ret = mc->mc_txn->mt_env->me_dpages) != NULL) {
1199 VGMEMP_ALLOC(mc->mc_txn->mt_env, ret, sz);
1200 VGMEMP_DEFINED(ret, sizeof(ret->mp_next));
1201 mc->mc_txn->mt_env->me_dpages = ret->mp_next;
1202 } else if ((ret = malloc(sz)) != NULL) {
1203 VGMEMP_ALLOC(mc->mc_txn->mt_env, ret, sz);
1208 /** Allocate pages for writing.
1209 * If there are free pages available from older transactions, they
1210 * will be re-used first. Otherwise a new page will be allocated.
1211 * @param[in] mc cursor A cursor handle identifying the transaction and
1212 * database for which we are allocating.
1213 * @param[in] num the number of pages to allocate.
1214 * @param[out] mp Address of the allocated page(s). Requests for multiple pages
1215 * will always be satisfied by a single contiguous chunk of memory.
1216 * @return 0 on success, non-zero on failure.
1219 mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
1221 MDB_txn *txn = mc->mc_txn;
1223 pgno_t pgno = P_INVALID;
1228 /* The free list won't have any content at all until txn 2 has
1229 * committed. The pages freed by txn 2 will be unreferenced
1230 * after txn 3 commits, and so will be safe to re-use in txn 4.
1232 if (txn->mt_txnid > 3) {
1234 if (!txn->mt_env->me_pghead &&
1235 txn->mt_dbs[FREE_DBI].md_root != P_INVALID) {
1236 /* See if there's anything in the free DB */
1242 txnid_t *kptr, last;
1244 mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
1245 if (!txn->mt_env->me_pgfirst) {
1246 mdb_page_search(&m2, NULL, 0);
1247 leaf = NODEPTR(m2.mc_pg[m2.mc_top], 0);
1248 kptr = (txnid_t *)NODEKEY(leaf);
1255 last = txn->mt_env->me_pglast + 1;
1257 key.mv_data = &last;
1258 key.mv_size = sizeof(last);
1259 rc = mdb_cursor_set(&m2, &key, &data, MDB_SET, &exact);
1262 last = *(txnid_t *)key.mv_data;
1265 /* Unusable if referred by a meta page or reader... */
1267 if (last < txn->mt_txnid-1) {
1268 j = txn->mt_env->me_txns->mti_numreaders;
1269 r = txn->mt_env->me_txns->mti_readers + j;
1270 for (j = -j; j && (last<r[j].mr_txnid || !r[j].mr_pid); j++) ;
1274 /* It's usable, grab it.
1279 if (!txn->mt_env->me_pgfirst) {
1280 mdb_node_read(txn, leaf, &data);
1282 txn->mt_env->me_pglast = last;
1283 if (!txn->mt_env->me_pgfirst)
1284 txn->mt_env->me_pgfirst = last;
1285 idl = (MDB_ID *) data.mv_data;
1286 /* We might have a zero-length IDL due to freelist growth
1287 * during a prior commit
1289 if (!idl[0]) goto again;
1290 mop = malloc(sizeof(MDB_oldpages) + MDB_IDL_SIZEOF(idl) - sizeof(pgno_t));
1293 mop->mo_next = txn->mt_env->me_pghead;
1294 mop->mo_txnid = last;
1295 txn->mt_env->me_pghead = mop;
1296 memcpy(mop->mo_pages, idl, MDB_IDL_SIZEOF(idl));
1301 DPRINTF("IDL read txn %zu root %zu num %zu",
1302 mop->mo_txnid, txn->mt_dbs[FREE_DBI].md_root, idl[0]);
1303 for (i=0; i<idl[0]; i++) {
1304 DPRINTF("IDL %zu", idl[i+1]);
1311 if (txn->mt_env->me_pghead) {
1312 MDB_oldpages *mop = txn->mt_env->me_pghead;
1314 /* FIXME: For now, always use fresh pages. We
1315 * really ought to search the free list for a
1320 /* peel pages off tail, so we only have to truncate the list */
1321 pgno = MDB_IDL_LAST(mop->mo_pages);
1322 if (MDB_IDL_IS_RANGE(mop->mo_pages)) {
1324 if (mop->mo_pages[2] > mop->mo_pages[1])
1325 mop->mo_pages[0] = 0;
1329 if (MDB_IDL_IS_ZERO(mop->mo_pages)) {
1330 txn->mt_env->me_pghead = mop->mo_next;
1331 if (mc->mc_dbi == FREE_DBI) {
1332 mop->mo_next = txn->mt_env->me_pgfree;
1333 txn->mt_env->me_pgfree = mop;
1342 if (pgno == P_INVALID) {
1343 /* DB size is maxed out */
1344 if (txn->mt_next_pgno + num >= txn->mt_env->me_maxpg) {
1345 DPUTS("DB size maxed out");
1346 return MDB_MAP_FULL;
1349 if (txn->mt_env->me_flags & MDB_WRITEMAP) {
1350 if (pgno == P_INVALID) {
1351 pgno = txn->mt_next_pgno;
1352 txn->mt_next_pgno += num;
1354 np = (MDB_page *)(txn->mt_env->me_map + txn->mt_env->me_psize * pgno);
1357 if (txn->mt_env->me_dpages && num == 1) {
1358 np = txn->mt_env->me_dpages;
1359 VGMEMP_ALLOC(txn->mt_env, np, txn->mt_env->me_psize);
1360 VGMEMP_DEFINED(np, sizeof(np->mp_next));
1361 txn->mt_env->me_dpages = np->mp_next;
1363 size_t sz = txn->mt_env->me_psize * num;
1364 if ((np = malloc(sz)) == NULL)
1366 VGMEMP_ALLOC(txn->mt_env, np, sz);
1368 if (pgno == P_INVALID) {
1369 np->mp_pgno = txn->mt_next_pgno;
1370 txn->mt_next_pgno += num;
1375 mid.mid = np->mp_pgno;
1377 if (txn->mt_env->me_flags & MDB_WRITEMAP) {
1378 mdb_mid2l_append(txn->mt_u.dirty_list, &mid);
1380 mdb_mid2l_insert(txn->mt_u.dirty_list, &mid);
1387 /** Copy a page: avoid copying unused portions of the page.
1388 * @param[in] dst page to copy into
1389 * @param[in] src page to copy from
1392 mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize)
1394 dst->mp_flags = src->mp_flags | P_DIRTY;
1395 dst->mp_pages = src->mp_pages;
1397 if (IS_LEAF2(src)) {
1398 memcpy(dst->mp_ptrs, src->mp_ptrs, psize - PAGEHDRSZ - SIZELEFT(src));
1400 unsigned int i, nkeys = NUMKEYS(src);
1401 for (i=0; i<nkeys; i++)
1402 dst->mp_ptrs[i] = src->mp_ptrs[i];
1403 memcpy((char *)dst+src->mp_upper, (char *)src+src->mp_upper,
1404 psize - src->mp_upper);
1408 /** Touch a page: make it dirty and re-insert into tree with updated pgno.
1409 * @param[in] mc cursor pointing to the page to be touched
1410 * @return 0 on success, non-zero on failure.
1413 mdb_page_touch(MDB_cursor *mc)
1415 MDB_page *mp = mc->mc_pg[mc->mc_top];
1419 if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
1421 if ((rc = mdb_page_alloc(mc, 1, &np)))
1423 DPRINTF("touched db %u page %zu -> %zu", mc->mc_dbi, mp->mp_pgno, np->mp_pgno);
1424 assert(mp->mp_pgno != np->mp_pgno);
1425 mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
1427 /* If page isn't full, just copy the used portion */
1428 mdb_page_copy(np, mp, mc->mc_txn->mt_env->me_psize);
1431 memcpy(np, mp, mc->mc_txn->mt_env->me_psize);
1433 np->mp_flags |= P_DIRTY;
1438 /* Adjust other cursors pointing to mp */
1439 if (mc->mc_flags & C_SUB) {
1440 MDB_cursor *m2, *m3;
1441 MDB_dbi dbi = mc->mc_dbi-1;
1443 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
1444 if (m2 == mc) continue;
1445 m3 = &m2->mc_xcursor->mx_cursor;
1446 if (m3->mc_snum < mc->mc_snum) continue;
1447 if (m3->mc_pg[mc->mc_top] == mc->mc_pg[mc->mc_top]) {
1448 m3->mc_pg[mc->mc_top] = mp;
1454 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
1455 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
1456 if (m2->mc_pg[mc->mc_top] == mc->mc_pg[mc->mc_top]) {
1457 m2->mc_pg[mc->mc_top] = mp;
1461 mc->mc_pg[mc->mc_top] = mp;
1462 /** If this page has a parent, update the parent to point to
1466 SETPGNO(NODEPTR(mc->mc_pg[mc->mc_top-1], mc->mc_ki[mc->mc_top-1]), mp->mp_pgno);
1468 mc->mc_db->md_root = mp->mp_pgno;
1469 } else if (mc->mc_txn->mt_parent) {
1472 /* If txn has a parent, make sure the page is in our
1475 if (mc->mc_txn->mt_u.dirty_list[0].mid) {
1476 unsigned x = mdb_mid2l_search(mc->mc_txn->mt_u.dirty_list, mp->mp_pgno);
1477 if (x <= mc->mc_txn->mt_u.dirty_list[0].mid &&
1478 mc->mc_txn->mt_u.dirty_list[x].mid == mp->mp_pgno) {
1479 if (mc->mc_txn->mt_u.dirty_list[x].mptr != mp) {
1480 mp = mc->mc_txn->mt_u.dirty_list[x].mptr;
1481 mc->mc_pg[mc->mc_top] = mp;
1487 np = mdb_page_malloc(mc);
1490 memcpy(np, mp, mc->mc_txn->mt_env->me_psize);
1491 mid.mid = np->mp_pgno;
1493 mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &mid);
1501 mdb_env_sync(MDB_env *env, int force)
1504 if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) {
1505 if (env->me_flags & MDB_WRITEMAP) {
1506 int flags = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;
1507 if (MDB_MSYNC(env->me_map, env->me_mapsize, flags))
1510 else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd))
1514 if (MDB_FDATASYNC(env->me_fd))
1521 /** Make shadow copies of all of parent txn's cursors */
1523 mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst)
1525 MDB_cursor *mc, *m2;
1526 unsigned int i, j, size;
1528 for (i=0;i<src->mt_numdbs; i++) {
1529 if (src->mt_cursors[i]) {
1530 size = sizeof(MDB_cursor);
1531 if (src->mt_cursors[i]->mc_xcursor)
1532 size += sizeof(MDB_xcursor);
1533 for (m2 = src->mt_cursors[i]; m2; m2=m2->mc_next) {
1540 mc->mc_db = &dst->mt_dbs[i];
1541 mc->mc_dbx = m2->mc_dbx;
1542 mc->mc_dbflag = &dst->mt_dbflags[i];
1543 mc->mc_snum = m2->mc_snum;
1544 mc->mc_top = m2->mc_top;
1545 mc->mc_flags = m2->mc_flags | C_SHADOW;
1546 for (j=0; j<mc->mc_snum; j++) {
1547 mc->mc_pg[j] = m2->mc_pg[j];
1548 mc->mc_ki[j] = m2->mc_ki[j];
1550 if (m2->mc_xcursor) {
1551 MDB_xcursor *mx, *mx2;
1552 mx = (MDB_xcursor *)(mc+1);
1553 mc->mc_xcursor = mx;
1554 mx2 = m2->mc_xcursor;
1555 mx->mx_db = mx2->mx_db;
1556 mx->mx_dbx = mx2->mx_dbx;
1557 mx->mx_dbflag = mx2->mx_dbflag;
1558 mx->mx_cursor.mc_txn = dst;
1559 mx->mx_cursor.mc_dbi = mx2->mx_cursor.mc_dbi;
1560 mx->mx_cursor.mc_db = &mx->mx_db;
1561 mx->mx_cursor.mc_dbx = &mx->mx_dbx;
1562 mx->mx_cursor.mc_dbflag = &mx->mx_dbflag;
1563 mx->mx_cursor.mc_snum = mx2->mx_cursor.mc_snum;
1564 mx->mx_cursor.mc_top = mx2->mx_cursor.mc_top;
1565 mx->mx_cursor.mc_flags = mx2->mx_cursor.mc_flags | C_SHADOW;
1566 for (j=0; j<mx2->mx_cursor.mc_snum; j++) {
1567 mx->mx_cursor.mc_pg[j] = mx2->mx_cursor.mc_pg[j];
1568 mx->mx_cursor.mc_ki[j] = mx2->mx_cursor.mc_ki[j];
1571 mc->mc_xcursor = NULL;
1573 mc->mc_next = dst->mt_cursors[i];
1574 dst->mt_cursors[i] = mc;
1581 /** Merge shadow cursors back into parent's */
1583 mdb_cursor_merge(MDB_txn *txn)
1586 for (i=0; i<txn->mt_numdbs; i++) {
1587 if (txn->mt_cursors[i]) {
1589 while ((mc = txn->mt_cursors[i])) {
1590 txn->mt_cursors[i] = mc->mc_next;
1591 if (mc->mc_flags & C_SHADOW) {
1592 MDB_cursor *m2 = mc->mc_orig;
1594 m2->mc_snum = mc->mc_snum;
1595 m2->mc_top = mc->mc_top;
1596 for (j=0; j<mc->mc_snum; j++) {
1597 m2->mc_pg[j] = mc->mc_pg[j];
1598 m2->mc_ki[j] = mc->mc_ki[j];
1601 if (mc->mc_flags & C_ALLOCD)
1609 mdb_txn_reset0(MDB_txn *txn);
1611 /** Common code for #mdb_txn_begin() and #mdb_txn_renew().
1612 * @param[in] txn the transaction handle to initialize
1613 * @return 0 on success, non-zero on failure. This can only
1614 * fail for read-only transactions, and then only if the
1615 * reader table is full.
1618 mdb_txn_renew0(MDB_txn *txn)
1620 MDB_env *env = txn->mt_env;
1624 txn->mt_numdbs = env->me_numdbs;
1625 txn->mt_dbxs = env->me_dbxs; /* mostly static anyway */
1627 if (txn->mt_flags & MDB_TXN_RDONLY) {
1628 MDB_reader *r = pthread_getspecific(env->me_txkey);
1630 pid_t pid = env->me_pid;
1631 pthread_t tid = pthread_self();
1634 for (i=0; i<env->me_txns->mti_numreaders; i++)
1635 if (env->me_txns->mti_readers[i].mr_pid == 0)
1637 if (i == env->me_maxreaders) {
1638 UNLOCK_MUTEX_R(env);
1639 return MDB_READERS_FULL;
1641 env->me_txns->mti_readers[i].mr_pid = pid;
1642 env->me_txns->mti_readers[i].mr_tid = tid;
1643 if (i >= env->me_txns->mti_numreaders)
1644 env->me_txns->mti_numreaders = i+1;
1645 /* Save numreaders for un-mutexed mdb_env_close() */
1646 env->me_numreaders = env->me_txns->mti_numreaders;
1647 UNLOCK_MUTEX_R(env);
1648 r = &env->me_txns->mti_readers[i];
1649 pthread_setspecific(env->me_txkey, r);
1651 txn->mt_txnid = r->mr_txnid = env->me_txns->mti_txnid;
1652 txn->mt_toggle = txn->mt_txnid & 1;
1653 txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1;
1654 txn->mt_u.reader = r;
1658 txn->mt_txnid = env->me_txns->mti_txnid;
1659 txn->mt_toggle = txn->mt_txnid & 1;
1660 txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1;
1663 if (txn->mt_txnid == mdb_debug_start)
1666 txn->mt_u.dirty_list = env->me_dirty_list;
1667 txn->mt_u.dirty_list[0].mid = 0;
1668 txn->mt_free_pgs = env->me_free_pgs;
1669 txn->mt_free_pgs[0] = 0;
1673 /* Copy the DB info and flags */
1674 memcpy(txn->mt_dbs, env->me_metas[txn->mt_toggle]->mm_dbs, 2 * sizeof(MDB_db));
1675 for (i=2; i<txn->mt_numdbs; i++)
1676 txn->mt_dbs[i].md_flags = env->me_dbflags[i];
1677 txn->mt_dbflags[0] = txn->mt_dbflags[1] = 0;
1678 if (txn->mt_numdbs > 2)
1679 memset(txn->mt_dbflags+2, DB_STALE, txn->mt_numdbs-2);
1685 mdb_txn_renew(MDB_txn *txn)
1692 if (txn->mt_env->me_flags & MDB_FATAL_ERROR) {
1693 DPUTS("environment had fatal error, must shutdown!");
1697 rc = mdb_txn_renew0(txn);
1698 if (rc == MDB_SUCCESS) {
1699 DPRINTF("renew txn %zu%c %p on mdbenv %p, root page %zu",
1700 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
1701 (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root);
1707 mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
1712 if (env->me_flags & MDB_FATAL_ERROR) {
1713 DPUTS("environment had fatal error, must shutdown!");
1716 if ((env->me_flags & MDB_RDONLY) && !(flags & MDB_RDONLY))
1719 /* parent already has an active child txn */
1720 if (parent->mt_child) {
1723 /* nested TXNs not supported here */
1724 if (env->me_flags & MDB_WRITEMAP)
1727 size = sizeof(MDB_txn) + env->me_maxdbs * (sizeof(MDB_db)+1);
1728 if (!(flags & MDB_RDONLY))
1729 size += env->me_maxdbs * sizeof(MDB_cursor *);
1731 if ((txn = calloc(1, size)) == NULL) {
1732 DPRINTF("calloc: %s", strerror(ErrCode()));
1735 txn->mt_dbs = (MDB_db *)(txn+1);
1736 if (flags & MDB_RDONLY) {
1737 txn->mt_flags |= MDB_TXN_RDONLY;
1738 txn->mt_dbflags = (unsigned char *)(txn->mt_dbs + env->me_maxdbs);
1740 txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
1741 txn->mt_dbflags = (unsigned char *)(txn->mt_cursors + env->me_maxdbs);
1746 txn->mt_free_pgs = mdb_midl_alloc();
1747 if (!txn->mt_free_pgs) {
1751 txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE);
1752 if (!txn->mt_u.dirty_list) {
1753 free(txn->mt_free_pgs);
1757 txn->mt_txnid = parent->mt_txnid;
1758 txn->mt_toggle = parent->mt_toggle;
1759 txn->mt_u.dirty_list[0].mid = 0;
1760 txn->mt_free_pgs[0] = 0;
1761 txn->mt_next_pgno = parent->mt_next_pgno;
1762 parent->mt_child = txn;
1763 txn->mt_parent = parent;
1764 txn->mt_numdbs = parent->mt_numdbs;
1765 txn->mt_dbxs = parent->mt_dbxs;
1766 memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
1767 memcpy(txn->mt_dbflags, parent->mt_dbflags, txn->mt_numdbs);
1768 mdb_cursor_shadow(parent, txn);
1771 rc = mdb_txn_renew0(txn);
1777 DPRINTF("begin txn %zu%c %p on mdbenv %p, root page %zu",
1778 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
1779 (void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root);
1785 /** Common code for #mdb_txn_reset() and #mdb_txn_abort().
1786 * @param[in] txn the transaction handle to reset
1789 mdb_txn_reset0(MDB_txn *txn)
1791 MDB_env *env = txn->mt_env;
1793 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
1794 txn->mt_u.reader->mr_txnid = (txnid_t)-1;
1800 /* close(free) all cursors */
1801 for (i=0; i<txn->mt_numdbs; i++) {
1802 if (txn->mt_cursors[i]) {
1804 while ((mc = txn->mt_cursors[i])) {
1805 txn->mt_cursors[i] = mc->mc_next;
1806 if (mc->mc_flags & C_ALLOCD)
1812 if (!(env->me_flags & MDB_WRITEMAP)) {
1813 /* return all dirty pages to dpage list */
1814 for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++) {
1815 dp = txn->mt_u.dirty_list[i].mptr;
1816 if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
1817 dp->mp_next = txn->mt_env->me_dpages;
1818 VGMEMP_FREE(txn->mt_env, dp);
1819 txn->mt_env->me_dpages = dp;
1821 /* large pages just get freed directly */
1822 VGMEMP_FREE(txn->mt_env, dp);
1828 if (txn->mt_parent) {
1829 txn->mt_parent->mt_child = NULL;
1830 mdb_midl_free(txn->mt_free_pgs);
1831 free(txn->mt_u.dirty_list);
1834 if (mdb_midl_shrink(&txn->mt_free_pgs))
1835 env->me_free_pgs = txn->mt_free_pgs;
1838 while ((mop = txn->mt_env->me_pghead)) {
1839 txn->mt_env->me_pghead = mop->mo_next;
1842 txn->mt_env->me_pgfirst = 0;
1843 txn->mt_env->me_pglast = 0;
1846 /* The writer mutex was locked in mdb_txn_begin. */
1847 UNLOCK_MUTEX_W(env);
1852 mdb_txn_reset(MDB_txn *txn)
1857 DPRINTF("reset txn %zu%c %p on mdbenv %p, root page %zu",
1858 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
1859 (void *) txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root);
1861 mdb_txn_reset0(txn);
1865 mdb_txn_abort(MDB_txn *txn)
1870 DPRINTF("abort txn %zu%c %p on mdbenv %p, root page %zu",
1871 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
1872 (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root);
1875 mdb_txn_abort(txn->mt_child);
1877 mdb_txn_reset0(txn);
1882 mdb_txn_commit(MDB_txn *txn)
1890 pgno_t next, freecnt;
1893 assert(txn != NULL);
1894 assert(txn->mt_env != NULL);
1896 if (txn->mt_child) {
1897 mdb_txn_commit(txn->mt_child);
1898 txn->mt_child = NULL;
1903 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
1904 if (txn->mt_numdbs > env->me_numdbs) {
1905 /* update the DB flags */
1907 for (i = env->me_numdbs; i<txn->mt_numdbs; i++)
1908 env->me_dbflags[i] = txn->mt_dbs[i].md_flags;
1915 if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
1916 DPUTS("error flag is set, can't commit");
1918 txn->mt_parent->mt_flags |= MDB_TXN_ERROR;
1923 /* Merge (and close) our cursors with parent's */
1924 mdb_cursor_merge(txn);
1926 if (txn->mt_parent) {
1932 /* Update parent's DB table */
1933 ip = &txn->mt_parent->mt_dbs[2];
1934 jp = &txn->mt_dbs[2];
1935 for (i = 2; i < txn->mt_numdbs; i++) {
1936 if (ip->md_root != jp->md_root)
1940 txn->mt_parent->mt_numdbs = txn->mt_numdbs;
1942 /* Append our free list to parent's */
1943 mdb_midl_append_list(&txn->mt_parent->mt_free_pgs,
1945 mdb_midl_free(txn->mt_free_pgs);
1947 /* Merge our dirty list with parent's */
1948 dst = txn->mt_parent->mt_u.dirty_list;
1949 src = txn->mt_u.dirty_list;
1950 x = mdb_mid2l_search(dst, src[1].mid);
1951 for (y=1; y<=src[0].mid; y++) {
1952 while (x <= dst[0].mid && dst[x].mid != src[y].mid) x++;
1956 dst[x].mptr = src[y].mptr;
1959 for (; y<=src[0].mid; y++) {
1960 if (++x >= MDB_IDL_UM_MAX) {
1962 return MDB_TXN_FULL;
1967 free(txn->mt_u.dirty_list);
1968 txn->mt_parent->mt_child = NULL;
1973 if (txn != env->me_txn) {
1974 DPUTS("attempt to commit unknown transaction");
1979 if (!txn->mt_u.dirty_list[0].mid)
1982 DPRINTF("committing txn %zu %p on mdbenv %p, root page %zu",
1983 txn->mt_txnid, (void *)txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root);
1985 /* Update DB root pointers. Their pages have already been
1986 * touched so this is all in-place and cannot fail.
1988 if (txn->mt_numdbs > 2) {
1991 data.mv_size = sizeof(MDB_db);
1993 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
1994 for (i = 2; i < txn->mt_numdbs; i++) {
1995 if (txn->mt_dbflags[i] & DB_DIRTY) {
1996 data.mv_data = &txn->mt_dbs[i];
1997 mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data, 0);
2002 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
2004 /* should only be one record now */
2005 if (env->me_pghead) {
2006 /* make sure first page of freeDB is touched and on freelist */
2007 mdb_page_search(&mc, NULL, MDB_PS_MODIFY);
2010 /* Delete IDLs we used from the free list */
2011 if (env->me_pgfirst) {
2016 key.mv_size = sizeof(cur);
2017 for (cur = env->me_pgfirst; cur <= env->me_pglast; cur++) {
2020 mdb_cursor_set(&mc, &key, NULL, MDB_SET, &exact);
2021 rc = mdb_cursor_del(&mc, 0);
2027 env->me_pgfirst = 0;
2031 /* save to free list */
2033 freecnt = txn->mt_free_pgs[0];
2034 if (!MDB_IDL_IS_ZERO(txn->mt_free_pgs)) {
2037 /* make sure last page of freeDB is touched and on freelist */
2038 key.mv_size = MAXKEYSIZE+1;
2040 mdb_page_search(&mc, &key, MDB_PS_MODIFY);
2042 mdb_midl_sort(txn->mt_free_pgs);
2046 MDB_IDL idl = txn->mt_free_pgs;
2047 DPRINTF("IDL write txn %zu root %zu num %zu",
2048 txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, idl[0]);
2049 for (i=0; i<idl[0]; i++) {
2050 DPRINTF("IDL %zu", idl[i+1]);
2054 /* write to last page of freeDB */
2055 key.mv_size = sizeof(pgno_t);
2056 key.mv_data = &txn->mt_txnid;
2057 data.mv_data = txn->mt_free_pgs;
2058 /* The free list can still grow during this call,
2059 * despite the pre-emptive touches above. So check
2060 * and make sure the entire thing got written.
2063 freecnt = txn->mt_free_pgs[0];
2064 data.mv_size = MDB_IDL_SIZEOF(txn->mt_free_pgs);
2065 rc = mdb_cursor_put(&mc, &key, &data, 0);
2070 } while (freecnt != txn->mt_free_pgs[0]);
2072 /* should only be one record now */
2074 if (env->me_pghead) {
2080 mop = env->me_pghead;
2082 key.mv_size = sizeof(id);
2084 data.mv_size = MDB_IDL_SIZEOF(mop->mo_pages);
2085 data.mv_data = mop->mo_pages;
2086 orig = mop->mo_pages[0];
2087 /* These steps may grow the freelist again
2088 * due to freed overflow pages...
2090 mdb_cursor_put(&mc, &key, &data, 0);
2091 if (mop == env->me_pghead && env->me_pghead->mo_txnid == id) {
2092 /* could have been used again here */
2093 if (mop->mo_pages[0] != orig) {
2094 data.mv_size = MDB_IDL_SIZEOF(mop->mo_pages);
2095 data.mv_data = mop->mo_pages;
2097 mdb_cursor_put(&mc, &key, &data, 0);
2099 env->me_pghead = NULL;
2102 /* was completely used up */
2103 mdb_cursor_del(&mc, 0);
2107 env->me_pgfirst = 0;
2111 while (env->me_pgfree) {
2112 MDB_oldpages *mop = env->me_pgfree;
2113 env->me_pgfree = mop->mo_next;
2117 /* Check for growth of freelist again */
2118 if (freecnt != txn->mt_free_pgs[0])
2121 if (!MDB_IDL_IS_ZERO(txn->mt_free_pgs)) {
2122 if (mdb_midl_shrink(&txn->mt_free_pgs))
2123 env->me_free_pgs = txn->mt_free_pgs;
2130 if (env->me_flags & MDB_WRITEMAP) {
2131 for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++) {
2132 dp = txn->mt_u.dirty_list[i].mptr;
2133 /* clear dirty flag */
2134 dp->mp_flags &= ~P_DIRTY;
2135 txn->mt_u.dirty_list[i].mid = 0;
2137 txn->mt_u.dirty_list[0].mid = 0;
2141 /* Commit up to MDB_COMMIT_PAGES dirty pages to disk until done.
2147 /* Windows actually supports scatter/gather I/O, but only on
2148 * unbuffered file handles. Since we're relying on the OS page
2149 * cache for all our data, that's self-defeating. So we just
2150 * write pages one at a time. We use the ov structure to set
2151 * the write offset, to at least save the overhead of a Seek
2155 memset(&ov, 0, sizeof(ov));
2156 for (; i<=txn->mt_u.dirty_list[0].mid; i++) {
2158 dp = txn->mt_u.dirty_list[i].mptr;
2159 DPRINTF("committing page %zu", dp->mp_pgno);
2160 size = dp->mp_pgno * env->me_psize;
2161 ov.Offset = size & 0xffffffff;
2162 ov.OffsetHigh = size >> 16;
2163 ov.OffsetHigh >>= 16;
2164 /* clear dirty flag */
2165 dp->mp_flags &= ~P_DIRTY;
2166 wsize = env->me_psize;
2167 if (IS_OVERFLOW(dp)) wsize *= dp->mp_pages;
2168 rc = WriteFile(env->me_fd, dp, wsize, NULL, &ov);
2171 DPRINTF("WriteFile: %d", n);
2178 struct iovec iov[MDB_COMMIT_PAGES];
2182 for (; i<=txn->mt_u.dirty_list[0].mid; i++) {
2183 dp = txn->mt_u.dirty_list[i].mptr;
2184 if (dp->mp_pgno != next) {
2186 rc = writev(env->me_fd, iov, n);
2190 DPUTS("short write, filesystem full?");
2192 DPRINTF("writev: %s", strerror(n));
2199 lseek(env->me_fd, dp->mp_pgno * env->me_psize, SEEK_SET);
2202 DPRINTF("committing page %zu", dp->mp_pgno);
2203 iov[n].iov_len = env->me_psize;
2204 if (IS_OVERFLOW(dp)) iov[n].iov_len *= dp->mp_pages;
2205 iov[n].iov_base = (char *)dp;
2206 size += iov[n].iov_len;
2207 next = dp->mp_pgno + (IS_OVERFLOW(dp) ? dp->mp_pages : 1);
2208 /* clear dirty flag */
2209 dp->mp_flags &= ~P_DIRTY;
2210 if (++n >= MDB_COMMIT_PAGES) {
2220 rc = writev(env->me_fd, iov, n);
2224 DPUTS("short write, filesystem full?");
2226 DPRINTF("writev: %s", strerror(n));
2233 /* Drop the dirty pages.
2235 for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++) {
2236 dp = txn->mt_u.dirty_list[i].mptr;
2237 if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
2238 dp->mp_next = txn->mt_env->me_dpages;
2239 VGMEMP_FREE(txn->mt_env, dp);
2240 txn->mt_env->me_dpages = dp;
2242 VGMEMP_FREE(txn->mt_env, dp);
2245 txn->mt_u.dirty_list[i].mid = 0;
2247 txn->mt_u.dirty_list[0].mid = 0;
2250 if ((n = mdb_env_sync(env, 0)) != 0 ||
2251 (n = mdb_env_write_meta(txn)) != MDB_SUCCESS) {
2258 if (txn->mt_numdbs > env->me_numdbs) {
2259 /* update the DB flags */
2261 for (i = env->me_numdbs; i<txn->mt_numdbs; i++)
2262 env->me_dbflags[i] = txn->mt_dbs[i].md_flags;
2266 UNLOCK_MUTEX_W(env);
2272 /** Read the environment parameters of a DB environment before
2273 * mapping it into memory.
2274 * @param[in] env the environment handle
2275 * @param[out] meta address of where to store the meta information
2276 * @return 0 on success, non-zero on failure.
2279 mdb_env_read_header(MDB_env *env, MDB_meta *meta)
2286 /* We don't know the page size yet, so use a minimum value.
2290 if (!ReadFile(env->me_fd, &pbuf, MDB_PAGESIZE, (DWORD *)&rc, NULL) || rc == 0)
2292 if ((rc = read(env->me_fd, &pbuf, MDB_PAGESIZE)) == 0)
2297 else if (rc != MDB_PAGESIZE) {
2301 DPRINTF("read: %s", strerror(err));
2305 p = (MDB_page *)&pbuf;
2307 if (!F_ISSET(p->mp_flags, P_META)) {
2308 DPRINTF("page %zu not a meta page", p->mp_pgno);
2313 if (m->mm_magic != MDB_MAGIC) {
2314 DPUTS("meta has invalid magic");
2318 if (m->mm_version != MDB_VERSION) {
2319 DPRINTF("database is version %u, expected version %u",
2320 m->mm_version, MDB_VERSION);
2321 return MDB_VERSION_MISMATCH;
2324 memcpy(meta, m, sizeof(*m));
2328 /** Write the environment parameters of a freshly created DB environment.
2329 * @param[in] env the environment handle
2330 * @param[out] meta address of where to store the meta information
2331 * @return 0 on success, non-zero on failure.
2334 mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
2341 DPUTS("writing new meta page");
2343 GET_PAGESIZE(psize);
2345 meta->mm_magic = MDB_MAGIC;
2346 meta->mm_version = MDB_VERSION;
2347 meta->mm_psize = psize;
2348 meta->mm_last_pg = 1;
2349 meta->mm_flags = env->me_flags & 0xffff;
2350 meta->mm_flags |= MDB_INTEGERKEY;
2351 meta->mm_dbs[0].md_root = P_INVALID;
2352 meta->mm_dbs[1].md_root = P_INVALID;
2354 p = calloc(2, psize);
2356 p->mp_flags = P_META;
2359 memcpy(m, meta, sizeof(*meta));
2361 q = (MDB_page *)((char *)p + psize);
2364 q->mp_flags = P_META;
2367 memcpy(m, meta, sizeof(*meta));
2372 rc = WriteFile(env->me_fd, p, psize * 2, &len, NULL);
2373 rc = (len == psize * 2) ? MDB_SUCCESS : ErrCode();
2376 rc = write(env->me_fd, p, psize * 2);
2377 rc = (rc == (int)psize * 2) ? MDB_SUCCESS : ErrCode();
2383 /** Update the environment info to commit a transaction.
2384 * @param[in] txn the transaction that's being committed
2385 * @return 0 on success, non-zero on failure.
2388 mdb_env_write_meta(MDB_txn *txn)
2391 MDB_meta meta, metab;
2393 int rc, len, toggle;
2399 assert(txn != NULL);
2400 assert(txn->mt_env != NULL);
2402 toggle = !txn->mt_toggle;
2403 DPRINTF("writing meta page %d for root page %zu",
2404 toggle, txn->mt_dbs[MAIN_DBI].md_root);
2408 if (env->me_flags & MDB_WRITEMAP) {
2409 MDB_meta *mp = env->me_metas[toggle];
2410 mp->mm_dbs[0] = txn->mt_dbs[0];
2411 mp->mm_dbs[1] = txn->mt_dbs[1];
2412 mp->mm_last_pg = txn->mt_next_pgno - 1;
2413 mp->mm_txnid = txn->mt_txnid;
2414 if (!(env->me_flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {
2415 rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;
2418 ptr += env->me_psize;
2419 if (MDB_MSYNC(ptr, env->me_psize, rc)) {
2426 metab.mm_txnid = env->me_metas[toggle]->mm_txnid;
2427 metab.mm_last_pg = env->me_metas[toggle]->mm_last_pg;
2429 ptr = (char *)&meta;
2430 off = offsetof(MDB_meta, mm_dbs[0].md_depth);
2431 len = sizeof(MDB_meta) - off;
2434 meta.mm_dbs[0] = txn->mt_dbs[0];
2435 meta.mm_dbs[1] = txn->mt_dbs[1];
2436 meta.mm_last_pg = txn->mt_next_pgno - 1;
2437 meta.mm_txnid = txn->mt_txnid;
2440 off += env->me_psize;
2443 /* Write to the SYNC fd */
2446 memset(&ov, 0, sizeof(ov));
2448 WriteFile(env->me_mfd, ptr, len, (DWORD *)&rc, &ov);
2451 rc = pwrite(env->me_mfd, ptr, len, off);
2456 DPUTS("write failed, disk error?");
2457 /* On a failure, the pagecache still contains the new data.
2458 * Write some old data back, to prevent it from being used.
2459 * Use the non-SYNC fd; we know it will fail anyway.
2461 meta.mm_last_pg = metab.mm_last_pg;
2462 meta.mm_txnid = metab.mm_txnid;
2464 WriteFile(env->me_fd, ptr, len, NULL, &ov);
2466 r2 = pwrite(env->me_fd, ptr, len, off);
2469 env->me_flags |= MDB_FATAL_ERROR;
2473 /* Memory ordering issues are irrelevant; since the entire writer
2474 * is wrapped by wmutex, all of these changes will become visible
2475 * after the wmutex is unlocked. Since the DB is multi-version,
2476 * readers will get consistent data regardless of how fresh or
2477 * how stale their view of these values is.
2479 txn->mt_env->me_txns->mti_txnid = txn->mt_txnid;
2484 /** Check both meta pages to see which one is newer.
2485 * @param[in] env the environment handle
2486 * @return meta toggle (0 or 1).
2489 mdb_env_pick_meta(const MDB_env *env)
2491 return (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid);
2495 mdb_env_create(MDB_env **env)
2499 e = calloc(1, sizeof(MDB_env));
2503 e->me_free_pgs = mdb_midl_alloc();
2504 if (!e->me_free_pgs) {
2508 e->me_maxreaders = DEFAULT_READERS;
2510 e->me_fd = INVALID_HANDLE_VALUE;
2511 e->me_lfd = INVALID_HANDLE_VALUE;
2512 e->me_mfd = INVALID_HANDLE_VALUE;
2513 e->me_pid = getpid();
2514 VGMEMP_CREATE(e,0,0);
2520 mdb_env_set_mapsize(MDB_env *env, size_t size)
2524 env->me_mapsize = size;
2526 env->me_maxpg = env->me_mapsize / env->me_psize;
2531 mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs)
2535 env->me_maxdbs = dbs;
2540 mdb_env_set_maxreaders(MDB_env *env, unsigned int readers)
2542 if (env->me_map || readers < 1)
2544 env->me_maxreaders = readers;
2549 mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)
2551 if (!env || !readers)
2553 *readers = env->me_maxreaders;
2557 /** Further setup required for opening an MDB environment
2560 mdb_env_open2(MDB_env *env, unsigned int flags)
2562 int i, newenv = 0, prot;
2566 env->me_flags = flags;
2568 memset(&meta, 0, sizeof(meta));
2570 if ((i = mdb_env_read_header(env, &meta)) != 0) {
2573 DPUTS("new mdbenv");
2577 if (!env->me_mapsize) {
2578 env->me_mapsize = newenv ? DEFAULT_MAPSIZE : meta.mm_mapsize;
2584 LONG sizelo, sizehi;
2585 sizelo = env->me_mapsize & 0xffffffff;
2586 sizehi = env->me_mapsize >> 16; /* pointless on WIN32, only needed on W64 */
2588 /* Windows won't create mappings for zero length files.
2589 * Just allocate the maxsize right now.
2592 SetFilePointer(env->me_fd, sizelo, sizehi ? &sizehi : NULL, 0);
2593 if (!SetEndOfFile(env->me_fd))
2595 SetFilePointer(env->me_fd, 0, NULL, 0);
2597 mh = CreateFileMapping(env->me_fd, NULL, flags & MDB_WRITEMAP ?
2598 PAGE_READWRITE : PAGE_READONLY,
2599 sizehi, sizelo, NULL);
2602 env->me_map = MapViewOfFileEx(mh, flags & MDB_WRITEMAP ?
2603 FILE_MAP_WRITE : FILE_MAP_READ,
2604 0, 0, env->me_mapsize, meta.mm_address);
2611 if (meta.mm_address && (flags & MDB_FIXEDMAP))
2614 if (flags & MDB_WRITEMAP) {
2616 ftruncate(env->me_fd, env->me_mapsize);
2618 env->me_map = mmap(meta.mm_address, env->me_mapsize, prot, i,
2620 if (env->me_map == MAP_FAILED) {
2627 meta.mm_mapsize = env->me_mapsize;
2628 if (flags & MDB_FIXEDMAP)
2629 meta.mm_address = env->me_map;
2630 i = mdb_env_init_meta(env, &meta);
2631 if (i != MDB_SUCCESS) {
2632 munmap(env->me_map, env->me_mapsize);
2636 env->me_psize = meta.mm_psize;
2638 env->me_maxpg = env->me_mapsize / env->me_psize;
2640 p = (MDB_page *)env->me_map;
2641 env->me_metas[0] = METADATA(p);
2642 env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + meta.mm_psize);
2646 int toggle = mdb_env_pick_meta(env);
2647 MDB_db *db = &env->me_metas[toggle]->mm_dbs[MAIN_DBI];
2649 DPRINTF("opened database version %u, pagesize %u",
2650 env->me_metas[0]->mm_version, env->me_psize);
2651 DPRINTF("using meta page %d", toggle);
2652 DPRINTF("depth: %u", db->md_depth);
2653 DPRINTF("entries: %zu", db->md_entries);
2654 DPRINTF("branch pages: %zu", db->md_branch_pages);
2655 DPRINTF("leaf pages: %zu", db->md_leaf_pages);
2656 DPRINTF("overflow pages: %zu", db->md_overflow_pages);
2657 DPRINTF("root: %zu", db->md_root);
2665 /** Release a reader thread's slot in the reader lock table.
2666 * This function is called automatically when a thread exits.
2667 * @param[in] ptr This points to the slot in the reader lock table.
2670 mdb_env_reader_dest(void *ptr)
2672 MDB_reader *reader = ptr;
2678 /** Junk for arranging thread-specific callbacks on Windows. This is
2679 * necessarily platform and compiler-specific. Windows supports up
2680 * to 1088 keys. Let's assume nobody opens more than 64 environments
2681 * in a single process, for now. They can override this if needed.
2683 #ifndef MAX_TLS_KEYS
2684 #define MAX_TLS_KEYS 64
2686 static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS];
2687 static int mdb_tls_nkeys;
2689 static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr)
2693 case DLL_PROCESS_ATTACH: break;
2694 case DLL_THREAD_ATTACH: break;
2695 case DLL_THREAD_DETACH:
2696 for (i=0; i<mdb_tls_nkeys; i++) {
2697 MDB_reader *r = pthread_getspecific(mdb_tls_keys[i]);
2698 mdb_env_reader_dest(r);
2701 case DLL_PROCESS_DETACH: break;
2706 const PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
2708 PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
2712 /* Force some symbol references.
2713 * _tls_used forces the linker to create the TLS directory if not already done
2714 * mdb_tls_cbp prevents whole-program-optimizer from dropping the symbol.
2716 #pragma comment(linker, "/INCLUDE:_tls_used")
2717 #pragma comment(linker, "/INCLUDE:mdb_tls_cbp")
2718 #pragma const_seg(".CRT$XLB")
2719 extern const PIMAGE_TLS_CALLBACK mdb_tls_callback;
2720 const PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
2723 #pragma comment(linker, "/INCLUDE:__tls_used")
2724 #pragma comment(linker, "/INCLUDE:_mdb_tls_cbp")
2725 #pragma data_seg(".CRT$XLB")
2726 PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
2728 #endif /* WIN 32/64 */
2729 #endif /* !__GNUC__ */
2732 /** Downgrade the exclusive lock on the region back to shared */
2734 mdb_env_share_locks(MDB_env *env)
2736 int toggle = mdb_env_pick_meta(env);
2738 env->me_txns->mti_txnid = env->me_metas[toggle]->mm_txnid;
2743 /* First acquire a shared lock. The Unlock will
2744 * then release the existing exclusive lock.
2746 memset(&ov, 0, sizeof(ov));
2747 LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov);
2748 UnlockFile(env->me_lfd, 0, 0, 1, 0);
2752 struct flock lock_info;
2753 /* The shared lock replaces the existing lock */
2754 memset((void *)&lock_info, 0, sizeof(lock_info));
2755 lock_info.l_type = F_RDLCK;
2756 lock_info.l_whence = SEEK_SET;
2757 lock_info.l_start = 0;
2758 lock_info.l_len = 1;
2759 fcntl(env->me_lfd, F_SETLK, &lock_info);
2765 mdb_env_excl_lock(MDB_env *env, int *excl)
2768 if (LockFile(env->me_lfd, 0, 0, 1, 0)) {
2772 memset(&ov, 0, sizeof(ov));
2773 if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
2778 struct flock lock_info;
2779 memset((void *)&lock_info, 0, sizeof(lock_info));
2780 lock_info.l_type = F_WRLCK;
2781 lock_info.l_whence = SEEK_SET;
2782 lock_info.l_start = 0;
2783 lock_info.l_len = 1;
2784 if (!fcntl(env->me_lfd, F_SETLK, &lock_info)) {
2787 lock_info.l_type = F_RDLCK;
2788 if (fcntl(env->me_lfd, F_SETLKW, &lock_info)) {
2796 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
2798 * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code
2800 * @(#) $Revision: 5.1 $
2801 * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $
2802 * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $
2804 * http://www.isthe.com/chongo/tech/comp/fnv/index.html
2808 * Please do not copyright this code. This code is in the public domain.
2810 * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
2811 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
2812 * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
2813 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
2814 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
2815 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
2816 * PERFORMANCE OF THIS SOFTWARE.
2819 * chongo <Landon Curt Noll> /\oo/\
2820 * http://www.isthe.com/chongo/
2822 * Share and Enjoy! :-)
2825 typedef unsigned long long mdb_hash_t;
2826 #define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL)
2828 /** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer
2829 * @param[in] str string to hash
2830 * @param[in] hval initial value for hash
2831 * @return 64 bit hash
2833 * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the
2834 * hval arg on the first call.
2837 mdb_hash_val(MDB_val *val, mdb_hash_t hval)
2839 unsigned char *s = (unsigned char *)val->mv_data; /* unsigned string */
2840 unsigned char *end = s + val->mv_size;
2842 * FNV-1a hash each octet of the string
2845 /* xor the bottom with the current octet */
2846 hval ^= (mdb_hash_t)*s++;
2848 /* multiply by the 64 bit FNV magic prime mod 2^64 */
2849 hval += (hval << 1) + (hval << 4) + (hval << 5) +
2850 (hval << 7) + (hval << 8) + (hval << 40);
2852 /* return our new hash value */
2856 /** Hash the string and output the hash in hex.
2857 * @param[in] str string to hash
2858 * @param[out] hexbuf an array of 17 chars to hold the hash
2861 mdb_hash_hex(MDB_val *val, char *hexbuf)
2864 mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT);
2865 for (i=0; i<8; i++) {
2866 hexbuf += sprintf(hexbuf, "%02x", (unsigned int)h & 0xff);
2872 /** Open and/or initialize the lock region for the environment.
2873 * @param[in] env The MDB environment.
2874 * @param[in] lpath The pathname of the file used for the lock region.
2875 * @param[in] mode The Unix permissions for the file, if we create it.
2876 * @param[out] excl Set to true if we got an exclusive lock on the region.
2877 * @return 0 on success, non-zero on failure.
2880 mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
2888 if ((env->me_lfd = CreateFile(lpath, GENERIC_READ|GENERIC_WRITE,
2889 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
2890 FILE_ATTRIBUTE_NORMAL, NULL)) == INVALID_HANDLE_VALUE) {
2894 /* Try to get exclusive lock. If we succeed, then
2895 * nobody is using the lock region and we should initialize it.
2897 if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
2898 size = GetFileSize(env->me_lfd, NULL);
2904 if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT, mode)) == -1)
2906 /* Lose record locks when exec*() */
2907 if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0)
2908 fcntl(env->me_lfd, F_SETFD, fdflags);
2910 #else /* O_CLOEXEC on Linux: Open file and set FD_CLOEXEC atomically */
2911 if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT|O_CLOEXEC, mode)) == -1)
2915 /* Try to get exclusive lock. If we succeed, then
2916 * nobody is using the lock region and we should initialize it.
2918 if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
2920 size = lseek(env->me_lfd, 0, SEEK_END);
2922 rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
2923 if (size < rsize && *excl) {
2925 SetFilePointer(env->me_lfd, rsize, NULL, 0);
2926 if (!SetEndOfFile(env->me_lfd)) {
2931 if (ftruncate(env->me_lfd, rsize) != 0) {
2938 size = rsize - sizeof(MDB_txninfo);
2939 env->me_maxreaders = size/sizeof(MDB_reader) + 1;
2944 mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,
2950 env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL);
2952 if (!env->me_txns) {
2957 void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
2959 if (m == MAP_FAILED) {
2960 env->me_txns = NULL;
2969 BY_HANDLE_FILE_INFORMATION stbuf;
2978 if (!mdb_sec_inited) {
2979 InitializeSecurityDescriptor(&mdb_null_sd,
2980 SECURITY_DESCRIPTOR_REVISION);
2981 SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE);
2982 mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);
2983 mdb_all_sa.bInheritHandle = FALSE;
2984 mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;
2987 GetFileInformationByHandle(env->me_lfd, &stbuf);
2988 idbuf.volume = stbuf.dwVolumeSerialNumber;
2989 idbuf.nhigh = stbuf.nFileIndexHigh;
2990 idbuf.nlow = stbuf.nFileIndexLow;
2991 val.mv_data = &idbuf;
2992 val.mv_size = sizeof(idbuf);
2993 mdb_hash_hex(&val, hexbuf);
2994 sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", hexbuf);
2995 env->me_rmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
2996 if (!env->me_rmutex) {
3000 sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", hexbuf);
3001 env->me_wmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);
3002 if (!env->me_wmutex) {
3006 #elif defined(MDB_USE_POSIX_SEM)
3015 fstat(env->me_lfd, &stbuf);
3016 idbuf.dev = stbuf.st_dev;
3017 idbuf.ino = stbuf.st_ino;
3018 val.mv_data = &idbuf;
3019 val.mv_size = sizeof(idbuf);
3020 mdb_hash_hex(&val, hexbuf);
3021 sprintf(env->me_txns->mti_rmname, "/MDBr%s", hexbuf);
3022 if (sem_unlink(env->me_txns->mti_rmname)) {
3024 if (rc != ENOENT && rc != EINVAL)
3027 env->me_rmutex = sem_open(env->me_txns->mti_rmname, O_CREAT, mode, 1);
3028 if (env->me_rmutex == SEM_FAILED) {
3032 sprintf(env->me_txns->mti_wmname, "/MDBw%s", hexbuf);
3033 if (sem_unlink(env->me_txns->mti_wmname)) {
3035 if (rc != ENOENT && rc != EINVAL)
3038 env->me_wmutex = sem_open(env->me_txns->mti_wmname, O_CREAT, mode, 1);
3039 if (env->me_wmutex == SEM_FAILED) {
3043 #else /* MDB_USE_POSIX_SEM */
3044 pthread_mutexattr_t mattr;
3046 pthread_mutexattr_init(&mattr);
3047 rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED);
3051 pthread_mutex_init(&env->me_txns->mti_mutex, &mattr);
3052 pthread_mutex_init(&env->me_txns->mti_wmutex, &mattr);
3053 #endif /* _WIN32 || MDB_USE_POSIX_SEM */
3054 env->me_txns->mti_version = MDB_VERSION;
3055 env->me_txns->mti_magic = MDB_MAGIC;
3056 env->me_txns->mti_txnid = 0;
3057 env->me_txns->mti_numreaders = 0;
3060 if (env->me_txns->mti_magic != MDB_MAGIC) {
3061 DPUTS("lock region has invalid magic");
3065 if (env->me_txns->mti_version != MDB_VERSION) {
3066 DPRINTF("lock region is version %u, expected version %u",
3067 env->me_txns->mti_version, MDB_VERSION);
3068 rc = MDB_VERSION_MISMATCH;
3072 if (rc != EACCES && rc != EAGAIN) {
3076 env->me_rmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);
3077 if (!env->me_rmutex) {
3081 env->me_wmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
3082 if (!env->me_wmutex) {
3086 #elif defined(MDB_USE_POSIX_SEM)
3087 env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0);
3088 if (env->me_rmutex == SEM_FAILED) {
3092 env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0);
3093 if (env->me_wmutex == SEM_FAILED) {
3103 env->me_lfd = INVALID_HANDLE_VALUE;
3108 /** The name of the lock file in the DB environment */
3109 #define LOCKNAME "/lock.mdb"
3110 /** The name of the data file in the DB environment */
3111 #define DATANAME "/data.mdb"
3112 /** The suffix of the lock file when no subdir is used */
3113 #define LOCKSUFF "-lock"
3116 mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mode_t mode)
3118 int oflags, rc, len, excl;
3119 char *lpath, *dpath;
3122 if (flags & MDB_NOSUBDIR) {
3123 rc = len + sizeof(LOCKSUFF) + len + 1;
3125 rc = len + sizeof(LOCKNAME) + len + sizeof(DATANAME);
3130 if (flags & MDB_NOSUBDIR) {
3131 dpath = lpath + len + sizeof(LOCKSUFF);
3132 sprintf(lpath, "%s" LOCKSUFF, path);
3133 strcpy(dpath, path);
3135 dpath = lpath + len + sizeof(LOCKNAME);
3136 sprintf(lpath, "%s" LOCKNAME, path);
3137 sprintf(dpath, "%s" DATANAME, path);
3140 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
3145 if (F_ISSET(flags, MDB_RDONLY)) {
3146 oflags = GENERIC_READ;
3147 len = OPEN_EXISTING;
3149 oflags = GENERIC_READ|GENERIC_WRITE;
3152 mode = FILE_ATTRIBUTE_NORMAL;
3153 env->me_fd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
3154 NULL, len, mode, NULL);
3156 if (F_ISSET(flags, MDB_RDONLY))
3159 oflags = O_RDWR | O_CREAT;
3161 env->me_fd = open(dpath, oflags, mode);
3163 if (env->me_fd == INVALID_HANDLE_VALUE) {
3168 if ((rc = mdb_env_open2(env, flags)) == MDB_SUCCESS) {
3169 if (flags & (MDB_RDONLY|MDB_NOSYNC|MDB_NOMETASYNC|MDB_WRITEMAP)) {
3170 env->me_mfd = env->me_fd;
3172 /* synchronous fd for meta writes */
3174 env->me_mfd = CreateFile(dpath, oflags,
3175 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len,
3176 mode | FILE_FLAG_WRITE_THROUGH, NULL);
3178 env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode);
3180 if (env->me_mfd == INVALID_HANDLE_VALUE) {
3185 env->me_path = strdup(path);
3186 DPRINTF("opened dbenv %p", (void *) env);
3187 pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
3189 /* Windows TLS callbacks need help finding their TLS info. */
3190 if (mdb_tls_nkeys < MAX_TLS_KEYS)
3191 mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey;
3198 mdb_env_share_locks(env);
3200 env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx));
3201 env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t));
3202 if (!env->me_dbxs || !env->me_dbflags)
3208 if (env->me_fd != INVALID_HANDLE_VALUE) {
3210 env->me_fd = INVALID_HANDLE_VALUE;
3212 if (env->me_lfd != INVALID_HANDLE_VALUE) {
3214 env->me_lfd = INVALID_HANDLE_VALUE;
3222 mdb_env_close(MDB_env *env)
3229 VGMEMP_DESTROY(env);
3230 while (env->me_dpages) {
3231 dp = env->me_dpages;
3232 VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next));
3233 env->me_dpages = dp->mp_next;
3237 free(env->me_dbflags);
3241 pthread_key_delete(env->me_txkey);
3243 /* Delete our key from the global list */
3245 for (i=0; i<mdb_tls_nkeys; i++)
3246 if (mdb_tls_keys[i] == env->me_txkey) {
3247 mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1];
3255 munmap(env->me_map, env->me_mapsize);
3257 if (env->me_mfd != env->me_fd)
3261 pid_t pid = env->me_pid;
3263 for (i=0; i<env->me_numreaders; i++)
3264 if (env->me_txns->mti_readers[i].mr_pid == pid)
3265 env->me_txns->mti_readers[i].mr_pid = 0;
3267 CloseHandle(env->me_rmutex);
3268 CloseHandle(env->me_wmutex);
3269 /* Windows automatically destroys the mutexes when
3270 * the last handle closes.
3272 #elif defined(MDB_USE_POSIX_SEM)
3273 sem_close(env->me_rmutex);
3274 sem_close(env->me_wmutex);
3276 if (!mdb_env_excl_lock(env, &excl) && excl) {
3277 /* we are the only remaining user of the environment.
3278 clean up semaphores. */
3279 sem_unlink(env->me_txns->mti_rmname);
3280 sem_unlink(env->me_txns->mti_wmname);
3284 munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
3287 mdb_midl_free(env->me_free_pgs);
3291 /** Compare two items pointing at aligned size_t's */
3293 mdb_cmp_long(const MDB_val *a, const MDB_val *b)
3295 return (*(size_t *)a->mv_data < *(size_t *)b->mv_data) ? -1 :
3296 *(size_t *)a->mv_data > *(size_t *)b->mv_data;
3299 /** Compare two items pointing at aligned int's */
3301 mdb_cmp_int(const MDB_val *a, const MDB_val *b)
3303 return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 :
3304 *(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data;
3307 /** Compare two items pointing at ints of unknown alignment.
3308 * Nodes and keys are guaranteed to be 2-byte aligned.
3311 mdb_cmp_cint(const MDB_val *a, const MDB_val *b)
3313 #if BYTE_ORDER == LITTLE_ENDIAN
3314 unsigned short *u, *c;
3317 u = (unsigned short *) ((char *) a->mv_data + a->mv_size);
3318 c = (unsigned short *) ((char *) b->mv_data + a->mv_size);
3321 } while(!x && u > (unsigned short *)a->mv_data);
3324 return memcmp(a->mv_data, b->mv_data, a->mv_size);
3328 /** Compare two items lexically */
3330 mdb_cmp_memn(const MDB_val *a, const MDB_val *b)
3337 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
3343 diff = memcmp(a->mv_data, b->mv_data, len);
3344 return diff ? diff : len_diff<0 ? -1 : len_diff;
3347 /** Compare two items in reverse byte order */
3349 mdb_cmp_memnr(const MDB_val *a, const MDB_val *b)
3351 const unsigned char *p1, *p2, *p1_lim;
3355 p1_lim = (const unsigned char *)a->mv_data;
3356 p1 = (const unsigned char *)a->mv_data + a->mv_size;
3357 p2 = (const unsigned char *)b->mv_data + b->mv_size;
3359 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
3365 while (p1 > p1_lim) {
3366 diff = *--p1 - *--p2;
3370 return len_diff<0 ? -1 : len_diff;
3373 /** Search for key within a page, using binary search.
3374 * Returns the smallest entry larger or equal to the key.
3375 * If exactp is non-null, stores whether the found entry was an exact match
3376 * in *exactp (1 or 0).
3377 * Updates the cursor index with the index of the found entry.
3378 * If no entry larger or equal to the key is found, returns NULL.
3381 mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)
3383 unsigned int i = 0, nkeys;
3386 MDB_page *mp = mc->mc_pg[mc->mc_top];
3387 MDB_node *node = NULL;
3392 nkeys = NUMKEYS(mp);
3397 COPY_PGNO(pgno, mp->mp_pgno);
3398 DPRINTF("searching %u keys in %s %spage %zu",
3399 nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "",
3406 low = IS_LEAF(mp) ? 0 : 1;
3408 cmp = mc->mc_dbx->md_cmp;
3410 /* Branch pages have no data, so if using integer keys,
3411 * alignment is guaranteed. Use faster mdb_cmp_int.
3413 if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) {
3414 if (NODEPTR(mp, 1)->mn_ksize == sizeof(size_t))
3421 nodekey.mv_size = mc->mc_db->md_pad;
3422 node = NODEPTR(mp, 0); /* fake */
3423 while (low <= high) {
3424 i = (low + high) >> 1;
3425 nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size);
3426 rc = cmp(key, &nodekey);
3427 DPRINTF("found leaf index %u [%s], rc = %i",
3428 i, DKEY(&nodekey), rc);
3437 while (low <= high) {
3438 i = (low + high) >> 1;
3440 node = NODEPTR(mp, i);
3441 nodekey.mv_size = NODEKSZ(node);
3442 nodekey.mv_data = NODEKEY(node);
3444 rc = cmp(key, &nodekey);
3447 DPRINTF("found leaf index %u [%s], rc = %i",
3448 i, DKEY(&nodekey), rc);
3450 DPRINTF("found branch index %u [%s -> %zu], rc = %i",
3451 i, DKEY(&nodekey), NODEPGNO(node), rc);
3462 if (rc > 0) { /* Found entry is less than the key. */
3463 i++; /* Skip to get the smallest entry larger than key. */
3465 node = NODEPTR(mp, i);
3468 *exactp = (rc == 0);
3469 /* store the key index */
3470 mc->mc_ki[mc->mc_top] = i;
3472 /* There is no entry larger or equal to the key. */
3475 /* nodeptr is fake for LEAF2 */
3481 mdb_cursor_adjust(MDB_cursor *mc, func)
3485 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
3486 if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) {
3493 /** Pop a page off the top of the cursor's stack. */
3495 mdb_cursor_pop(MDB_cursor *mc)
3499 MDB_page *top = mc->mc_pg[mc->mc_top];
3505 DPRINTF("popped page %zu off db %u cursor %p", top->mp_pgno,
3506 mc->mc_dbi, (void *) mc);
3510 /** Push a page onto the top of the cursor's stack. */
3512 mdb_cursor_push(MDB_cursor *mc, MDB_page *mp)
3514 DPRINTF("pushing page %zu on db %u cursor %p", mp->mp_pgno,
3515 mc->mc_dbi, (void *) mc);
3517 if (mc->mc_snum >= CURSOR_STACK) {
3518 assert(mc->mc_snum < CURSOR_STACK);
3519 return MDB_CURSOR_FULL;
3522 mc->mc_top = mc->mc_snum++;
3523 mc->mc_pg[mc->mc_top] = mp;
3524 mc->mc_ki[mc->mc_top] = 0;
3529 /** Find the address of the page corresponding to a given page number.
3530 * @param[in] txn the transaction for this access.
3531 * @param[in] pgno the page number for the page to retrieve.
3532 * @param[out] ret address of a pointer where the page's address will be stored.
3533 * @return 0 on success, non-zero on failure.
3536 mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret)
3540 if (txn->mt_env->me_flags & MDB_WRITEMAP) {
3541 if (pgno < txn->mt_next_pgno)
3542 p = (MDB_page *)(txn->mt_env->me_map + txn->mt_env->me_psize * pgno);
3545 if (!F_ISSET(txn->mt_flags, MDB_TXN_RDONLY) && txn->mt_u.dirty_list[0].mid) {
3547 x = mdb_mid2l_search(txn->mt_u.dirty_list, pgno);
3548 if (x <= txn->mt_u.dirty_list[0].mid && txn->mt_u.dirty_list[x].mid == pgno) {
3549 p = txn->mt_u.dirty_list[x].mptr;
3553 if (pgno < txn->mt_next_pgno)
3554 p = (MDB_page *)(txn->mt_env->me_map + txn->mt_env->me_psize * pgno);
3559 DPRINTF("page %zu not found", pgno);
3562 return (p != NULL) ? MDB_SUCCESS : MDB_PAGE_NOTFOUND;
3565 /** Search for the page a given key should be in.
3566 * Pushes parent pages on the cursor stack. This function continues a
3567 * search on a cursor that has already been initialized. (Usually by
3568 * #mdb_page_search() but also by #mdb_node_move().)
3569 * @param[in,out] mc the cursor for this operation.
3570 * @param[in] key the key to search for. If NULL, search for the lowest
3571 * page. (This is used by #mdb_cursor_first().)
3572 * @param[in] flags If MDB_PS_MODIFY set, visited pages are updated with new page numbers.
3573 * If MDB_PS_ROOTONLY set, just fetch root node, no further lookups.
3574 * @return 0 on success, non-zero on failure.
3577 mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int modify)
3579 MDB_page *mp = mc->mc_pg[mc->mc_top];
3584 while (IS_BRANCH(mp)) {
3588 DPRINTF("branch page %zu has %u keys", mp->mp_pgno, NUMKEYS(mp));
3589 assert(NUMKEYS(mp) > 1);
3590 DPRINTF("found index 0 to page %zu", NODEPGNO(NODEPTR(mp, 0)));
3592 if (key == NULL) /* Initialize cursor to first page. */
3594 else if (key->mv_size > MAXKEYSIZE && key->mv_data == NULL) {
3595 /* cursor to last page */
3599 node = mdb_node_search(mc, key, &exact);
3601 i = NUMKEYS(mp) - 1;
3603 i = mc->mc_ki[mc->mc_top];
3612 DPRINTF("following index %u for key [%s]",
3614 assert(i < NUMKEYS(mp));
3615 node = NODEPTR(mp, i);
3617 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp)))
3620 mc->mc_ki[mc->mc_top] = i;
3621 if ((rc = mdb_cursor_push(mc, mp)))
3625 if ((rc = mdb_page_touch(mc)) != 0)
3627 mp = mc->mc_pg[mc->mc_top];
3632 DPRINTF("internal error, index points to a %02X page!?",
3634 return MDB_CORRUPTED;
3637 DPRINTF("found leaf page %zu for key [%s]", mp->mp_pgno,
3638 key ? DKEY(key) : NULL);
3643 /** Search for the page a given key should be in.
3644 * Pushes parent pages on the cursor stack. This function just sets up
3645 * the search; it finds the root page for \b mc's database and sets this
3646 * as the root of the cursor's stack. Then #mdb_page_search_root() is
3647 * called to complete the search.
3648 * @param[in,out] mc the cursor for this operation.
3649 * @param[in] key the key to search for. If NULL, search for the lowest
3650 * page. (This is used by #mdb_cursor_first().)
3651 * @param[in] modify If true, visited pages are updated with new page numbers.
3652 * @return 0 on success, non-zero on failure.
3655 mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)
3660 /* Make sure the txn is still viable, then find the root from
3661 * the txn's db table.
3663 if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_ERROR)) {
3664 DPUTS("transaction has failed, must abort");
3667 /* Make sure we're using an up-to-date root */
3668 if (mc->mc_dbi > MAIN_DBI) {
3669 if ((*mc->mc_dbflag & DB_STALE) ||
3670 ((flags & MDB_PS_MODIFY) && !(*mc->mc_dbflag & DB_DIRTY))) {
3672 unsigned char dbflag = 0;
3673 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);
3674 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, flags & MDB_PS_MODIFY);
3677 if (*mc->mc_dbflag & DB_STALE) {
3680 MDB_node *leaf = mdb_node_search(&mc2,
3681 &mc->mc_dbx->md_name, &exact);
3683 return MDB_NOTFOUND;
3684 mdb_node_read(mc->mc_txn, leaf, &data);
3685 memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db));
3687 if (flags & MDB_PS_MODIFY)
3689 *mc->mc_dbflag = dbflag;
3692 root = mc->mc_db->md_root;
3694 if (root == P_INVALID) { /* Tree is empty. */
3695 DPUTS("tree is empty");
3696 return MDB_NOTFOUND;
3701 if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root)
3702 if ((rc = mdb_page_get(mc->mc_txn, root, &mc->mc_pg[0])))
3708 DPRINTF("db %u root page %zu has flags 0x%X",
3709 mc->mc_dbi, root, mc->mc_pg[0]->mp_flags);
3711 if (flags & MDB_PS_MODIFY) {
3712 if ((rc = mdb_page_touch(mc)))
3716 if (flags & MDB_PS_ROOTONLY)
3719 return mdb_page_search_root(mc, key, flags);
3722 /** Return the data associated with a given node.
3723 * @param[in] txn The transaction for this operation.
3724 * @param[in] leaf The node being read.
3725 * @param[out] data Updated to point to the node's data.
3726 * @return 0 on success, non-zero on failure.
3729 mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data)
3731 MDB_page *omp; /* overflow page */
3735 if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
3736 data->mv_size = NODEDSZ(leaf);
3737 data->mv_data = NODEDATA(leaf);
3741 /* Read overflow data.
3743 data->mv_size = NODEDSZ(leaf);
3744 memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
3745 if ((rc = mdb_page_get(txn, pgno, &omp))) {
3746 DPRINTF("read overflow page %zu failed", pgno);
3749 data->mv_data = METADATA(omp);
3755 mdb_get(MDB_txn *txn, MDB_dbi dbi,
3756 MDB_val *key, MDB_val *data)
3765 DPRINTF("===> get db %u key [%s]", dbi, DKEY(key));
3767 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
3770 if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
3774 mdb_cursor_init(&mc, txn, dbi, &mx);
3775 return mdb_cursor_set(&mc, key, data, MDB_SET, &exact);
3778 /** Find a sibling for a page.
3779 * Replaces the page at the top of the cursor's stack with the
3780 * specified sibling, if one exists.
3781 * @param[in] mc The cursor for this operation.
3782 * @param[in] move_right Non-zero if the right sibling is requested,
3783 * otherwise the left sibling.
3784 * @return 0 on success, non-zero on failure.
3787 mdb_cursor_sibling(MDB_cursor *mc, int move_right)
3793 if (mc->mc_snum < 2) {
3794 return MDB_NOTFOUND; /* root has no siblings */
3798 DPRINTF("parent page is page %zu, index %u",
3799 mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]);
3801 if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top]))
3802 : (mc->mc_ki[mc->mc_top] == 0)) {
3803 DPRINTF("no more keys left, moving to %s sibling",
3804 move_right ? "right" : "left");
3805 if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS)
3809 mc->mc_ki[mc->mc_top]++;
3811 mc->mc_ki[mc->mc_top]--;
3812 DPRINTF("just moving to %s index key %u",
3813 move_right ? "right" : "left", mc->mc_ki[mc->mc_top]);
3815 assert(IS_BRANCH(mc->mc_pg[mc->mc_top]));
3817 indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
3818 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(indx), &mp)))
3821 mdb_cursor_push(mc, mp);
3826 /** Move the cursor to the next data item. */
3828 mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
3834 if (mc->mc_flags & C_EOF) {
3835 return MDB_NOTFOUND;
3838 assert(mc->mc_flags & C_INITIALIZED);
3840 mp = mc->mc_pg[mc->mc_top];
3842 if (mc->mc_db->md_flags & MDB_DUPSORT) {
3843 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
3844 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
3845 if (op == MDB_NEXT || op == MDB_NEXT_DUP) {
3846 rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);
3847 if (op != MDB_NEXT || rc == MDB_SUCCESS)
3851 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
3852 if (op == MDB_NEXT_DUP)
3853 return MDB_NOTFOUND;
3857 DPRINTF("cursor_next: top page is %zu in cursor %p", mp->mp_pgno, (void *) mc);
3859 if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) {
3860 DPUTS("=====> move to next sibling page");
3861 if (mdb_cursor_sibling(mc, 1) != MDB_SUCCESS) {
3862 mc->mc_flags |= C_EOF;
3863 mc->mc_flags &= ~C_INITIALIZED;
3864 return MDB_NOTFOUND;
3866 mp = mc->mc_pg[mc->mc_top];
3867 DPRINTF("next page is %zu, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]);
3869 mc->mc_ki[mc->mc_top]++;
3871 DPRINTF("==> cursor points to page %zu with %u keys, key index %u",
3872 mp->mp_pgno, NUMKEYS(mp), mc->mc_ki[mc->mc_top]);
3875 key->mv_size = mc->mc_db->md_pad;
3876 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
3880 assert(IS_LEAF(mp));
3881 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
3883 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
3884 mdb_xcursor_init1(mc, leaf);
3887 if ((rc = mdb_node_read(mc->mc_txn, leaf, data) != MDB_SUCCESS))
3890 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
3891 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
3892 if (rc != MDB_SUCCESS)
3897 MDB_GET_KEY(leaf, key);
3901 /** Move the cursor to the previous data item. */
3903 mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
3909 assert(mc->mc_flags & C_INITIALIZED);
3911 mp = mc->mc_pg[mc->mc_top];
3913 if (mc->mc_db->md_flags & MDB_DUPSORT) {
3914 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
3915 if (op == MDB_PREV || op == MDB_PREV_DUP) {
3916 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
3917 rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
3918 if (op != MDB_PREV || rc == MDB_SUCCESS)
3921 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
3922 if (op == MDB_PREV_DUP)
3923 return MDB_NOTFOUND;
3928 DPRINTF("cursor_prev: top page is %zu in cursor %p", mp->mp_pgno, (void *) mc);
3930 if (mc->mc_ki[mc->mc_top] == 0) {
3931 DPUTS("=====> move to prev sibling page");
3932 if (mdb_cursor_sibling(mc, 0) != MDB_SUCCESS) {
3933 mc->mc_flags &= ~C_INITIALIZED;
3934 return MDB_NOTFOUND;
3936 mp = mc->mc_pg[mc->mc_top];
3937 mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;
3938 DPRINTF("prev page is %zu, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]);
3940 mc->mc_ki[mc->mc_top]--;
3942 mc->mc_flags &= ~C_EOF;
3944 DPRINTF("==> cursor points to page %zu with %u keys, key index %u",
3945 mp->mp_pgno, NUMKEYS(mp), mc->mc_ki[mc->mc_top]);
3948 key->mv_size = mc->mc_db->md_pad;
3949 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
3953 assert(IS_LEAF(mp));
3954 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
3956 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
3957 mdb_xcursor_init1(mc, leaf);
3960 if ((rc = mdb_node_read(mc->mc_txn, leaf, data) != MDB_SUCCESS))
3963 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
3964 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
3965 if (rc != MDB_SUCCESS)
3970 MDB_GET_KEY(leaf, key);
3974 /** Set the cursor on a specific data item. */
3976 mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data,
3977 MDB_cursor_op op, int *exactp)
3981 MDB_node *leaf = NULL;
3986 assert(key->mv_size > 0);
3988 /* See if we're already on the right page */
3989 if (mc->mc_flags & C_INITIALIZED) {
3992 mp = mc->mc_pg[mc->mc_top];
3994 mc->mc_ki[mc->mc_top] = 0;
3995 return MDB_NOTFOUND;
3997 if (mp->mp_flags & P_LEAF2) {
3998 nodekey.mv_size = mc->mc_db->md_pad;
3999 nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size);
4001 leaf = NODEPTR(mp, 0);
4002 MDB_GET_KEY(leaf, &nodekey);
4004 rc = mc->mc_dbx->md_cmp(key, &nodekey);
4006 /* Probably happens rarely, but first node on the page
4007 * was the one we wanted.
4009 mc->mc_ki[mc->mc_top] = 0;
4016 unsigned int nkeys = NUMKEYS(mp);
4018 if (mp->mp_flags & P_LEAF2) {
4019 nodekey.mv_data = LEAF2KEY(mp,
4020 nkeys-1, nodekey.mv_size);
4022 leaf = NODEPTR(mp, nkeys-1);
4023 MDB_GET_KEY(leaf, &nodekey);
4025 rc = mc->mc_dbx->md_cmp(key, &nodekey);
4027 /* last node was the one we wanted */
4028 mc->mc_ki[mc->mc_top] = nkeys-1;
4034 if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) {
4035 /* This is definitely the right page, skip search_page */
4036 if (mp->mp_flags & P_LEAF2) {
4037 nodekey.mv_data = LEAF2KEY(mp,
4038 mc->mc_ki[mc->mc_top], nodekey.mv_size);
4040 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
4041 MDB_GET_KEY(leaf, &nodekey);
4043 rc = mc->mc_dbx->md_cmp(key, &nodekey);
4045 /* current node was the one we wanted */
4055 /* If any parents have right-sibs, search.
4056 * Otherwise, there's nothing further.
4058 for (i=0; i<mc->mc_top; i++)
4060 NUMKEYS(mc->mc_pg[i])-1)
4062 if (i == mc->mc_top) {
4063 /* There are no other pages */
4064 mc->mc_ki[mc->mc_top] = nkeys;
4065 return MDB_NOTFOUND;
4069 /* There are no other pages */
4070 mc->mc_ki[mc->mc_top] = 0;
4071 return MDB_NOTFOUND;
4075 rc = mdb_page_search(mc, key, 0);
4076 if (rc != MDB_SUCCESS)
4079 mp = mc->mc_pg[mc->mc_top];
4080 assert(IS_LEAF(mp));
4083 leaf = mdb_node_search(mc, key, exactp);
4084 if (exactp != NULL && !*exactp) {
4085 /* MDB_SET specified and not an exact match. */
4086 return MDB_NOTFOUND;
4090 DPUTS("===> inexact leaf not found, goto sibling");
4091 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS)
4092 return rc; /* no entries matched */
4093 mp = mc->mc_pg[mc->mc_top];
4094 assert(IS_LEAF(mp));
4095 leaf = NODEPTR(mp, 0);
4099 mc->mc_flags |= C_INITIALIZED;
4100 mc->mc_flags &= ~C_EOF;
4103 key->mv_size = mc->mc_db->md_pad;
4104 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
4108 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4109 mdb_xcursor_init1(mc, leaf);
4112 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4113 if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) {
4114 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
4117 if (op == MDB_GET_BOTH) {
4123 rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p);
4124 if (rc != MDB_SUCCESS)
4127 } else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {
4129 if ((rc = mdb_node_read(mc->mc_txn, leaf, &d2)) != MDB_SUCCESS)
4131 rc = mc->mc_dbx->md_dcmp(data, &d2);
4133 if (op == MDB_GET_BOTH || rc > 0)
4134 return MDB_NOTFOUND;
4139 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
4140 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
4145 /* The key already matches in all other cases */
4146 if (op == MDB_SET_RANGE || op == MDB_SET_KEY)
4147 MDB_GET_KEY(leaf, key);
4148 DPRINTF("==> cursor placed on key [%s]", DKEY(key));
4153 /** Move the cursor to the first item in the database. */
4155 mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data)
4160 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
4161 rc = mdb_page_search(mc, NULL, 0);
4162 if (rc != MDB_SUCCESS)
4165 assert(IS_LEAF(mc->mc_pg[mc->mc_top]));
4167 leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0);
4168 mc->mc_flags |= C_INITIALIZED;
4169 mc->mc_flags &= ~C_EOF;
4171 mc->mc_ki[mc->mc_top] = 0;
4173 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
4174 key->mv_size = mc->mc_db->md_pad;
4175 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size);
4180 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4181 mdb_xcursor_init1(mc, leaf);
4182 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
4187 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
4188 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
4192 MDB_GET_KEY(leaf, key);
4196 /** Move the cursor to the last item in the database. */
4198 mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)
4203 if (!(mc->mc_flags & C_EOF)) {
4205 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
4208 lkey.mv_size = MAXKEYSIZE+1;
4209 lkey.mv_data = NULL;
4210 rc = mdb_page_search(mc, &lkey, 0);
4211 if (rc != MDB_SUCCESS)
4214 assert(IS_LEAF(mc->mc_pg[mc->mc_top]));
4216 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;
4217 mc->mc_flags |= C_INITIALIZED|C_EOF;
4219 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
4221 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
4222 key->mv_size = mc->mc_db->md_pad;
4223 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size);
4228 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4229 mdb_xcursor_init1(mc, leaf);
4230 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
4235 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
4236 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
4241 MDB_GET_KEY(leaf, key);
4246 mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,
4256 case MDB_GET_BOTH_RANGE:
4257 if (data == NULL || mc->mc_xcursor == NULL) {
4265 if (key == NULL || key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
4267 } else if (op == MDB_SET_RANGE)
4268 rc = mdb_cursor_set(mc, key, data, op, NULL);
4270 rc = mdb_cursor_set(mc, key, data, op, &exact);
4272 case MDB_GET_MULTIPLE:
4274 !(mc->mc_db->md_flags & MDB_DUPFIXED) ||
4275 !(mc->mc_flags & C_INITIALIZED)) {
4280 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) ||
4281 (mc->mc_xcursor->mx_cursor.mc_flags & C_EOF))
4284 case MDB_NEXT_MULTIPLE:
4286 !(mc->mc_db->md_flags & MDB_DUPFIXED)) {
4290 if (!(mc->mc_flags & C_INITIALIZED))
4291 rc = mdb_cursor_first(mc, key, data);
4293 rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP);
4294 if (rc == MDB_SUCCESS) {
4295 if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
4298 mx = &mc->mc_xcursor->mx_cursor;
4299 data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) *
4301 data->mv_data = METADATA(mx->mc_pg[mx->mc_top]);
4302 mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1;
4310 case MDB_NEXT_NODUP:
4311 if (!(mc->mc_flags & C_INITIALIZED))
4312 rc = mdb_cursor_first(mc, key, data);
4314 rc = mdb_cursor_next(mc, key, data, op);
4318 case MDB_PREV_NODUP:
4319 if (!(mc->mc_flags & C_INITIALIZED) || (mc->mc_flags & C_EOF)) {
4320 rc = mdb_cursor_last(mc, key, data);
4321 mc->mc_flags &= ~C_EOF;
4323 rc = mdb_cursor_prev(mc, key, data, op);
4326 rc = mdb_cursor_first(mc, key, data);
4330 !(mc->mc_db->md_flags & MDB_DUPSORT) ||
4331 !(mc->mc_flags & C_INITIALIZED) ||
4332 !(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
4336 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
4339 rc = mdb_cursor_last(mc, key, data);
4343 !(mc->mc_db->md_flags & MDB_DUPSORT) ||
4344 !(mc->mc_flags & C_INITIALIZED) ||
4345 !(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
4349 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
4352 DPRINTF("unhandled/unimplemented cursor operation %u", op);
4360 /** Touch all the pages in the cursor stack.
4361 * Makes sure all the pages are writable, before attempting a write operation.
4362 * @param[in] mc The cursor to operate on.
4365 mdb_cursor_touch(MDB_cursor *mc)
4369 if (mc->mc_dbi > MAIN_DBI && !(*mc->mc_dbflag & DB_DIRTY)) {
4371 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);
4372 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY);
4375 *mc->mc_dbflag = DB_DIRTY;
4377 for (mc->mc_top = 0; mc->mc_top < mc->mc_snum; mc->mc_top++) {
4378 rc = mdb_page_touch(mc);
4382 mc->mc_top = mc->mc_snum-1;
4387 mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
4390 MDB_node *leaf = NULL;
4391 MDB_val xdata, *rdata, dkey;
4394 int do_sub = 0, insert = 0;
4395 unsigned int mcount = 0;
4399 char dbuf[MAXKEYSIZE+1];
4400 unsigned int nflags;
4403 if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_RDONLY))
4406 DPRINTF("==> put db %u key [%s], size %zu, data size %zu",
4407 mc->mc_dbi, DKEY(key), key ? key->mv_size:0, data->mv_size);
4411 if (flags == MDB_CURRENT) {
4412 if (!(mc->mc_flags & C_INITIALIZED))
4415 } else if (mc->mc_db->md_root == P_INVALID) {
4417 /* new database, write a root leaf page */
4418 DPUTS("allocating new root leaf page");
4419 if ((rc = mdb_page_new(mc, P_LEAF, 1, &np))) {
4423 mdb_cursor_push(mc, np);
4424 mc->mc_db->md_root = np->mp_pgno;
4425 mc->mc_db->md_depth++;
4426 *mc->mc_dbflag = DB_DIRTY;
4427 if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED))
4429 np->mp_flags |= P_LEAF2;
4430 mc->mc_flags |= C_INITIALIZED;
4436 if (flags & MDB_APPEND) {
4438 rc = mdb_cursor_last(mc, &k2, &d2);
4440 rc = mc->mc_dbx->md_cmp(key, &k2);
4443 mc->mc_ki[mc->mc_top]++;
4449 rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact);
4451 if ((flags & MDB_NOOVERWRITE) && rc == 0) {
4452 DPRINTF("duplicate key [%s]", DKEY(key));
4454 return MDB_KEYEXIST;
4456 if (rc && rc != MDB_NOTFOUND)
4460 /* Cursor is positioned, now make sure all pages are writable */
4461 rc2 = mdb_cursor_touch(mc);
4466 /* The key already exists */
4467 if (rc == MDB_SUCCESS) {
4468 /* there's only a key anyway, so this is a no-op */
4469 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
4470 unsigned int ksize = mc->mc_db->md_pad;
4471 if (key->mv_size != ksize)
4473 if (flags == MDB_CURRENT) {
4474 char *ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize);
4475 memcpy(ptr, key->mv_data, ksize);
4480 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
4483 if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) {
4484 /* Was a single item before, must convert now */
4486 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4487 /* Just overwrite the current item */
4488 if (flags == MDB_CURRENT)
4491 dkey.mv_size = NODEDSZ(leaf);
4492 dkey.mv_data = NODEDATA(leaf);
4493 #if UINT_MAX < SIZE_MAX
4494 if (mc->mc_dbx->md_dcmp == mdb_cmp_int && dkey.mv_size == sizeof(size_t))
4495 #ifdef MISALIGNED_OK
4496 mc->mc_dbx->md_dcmp = mdb_cmp_long;
4498 mc->mc_dbx->md_dcmp = mdb_cmp_cint;
4501 /* if data matches, ignore it */
4502 if (!mc->mc_dbx->md_dcmp(data, &dkey))
4503 return (flags == MDB_NODUPDATA) ? MDB_KEYEXIST : MDB_SUCCESS;
4505 /* create a fake page for the dup items */
4506 memcpy(dbuf, dkey.mv_data, dkey.mv_size);
4507 dkey.mv_data = dbuf;
4508 fp = (MDB_page *)&pbuf;
4509 fp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
4510 fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP;
4511 fp->mp_lower = PAGEHDRSZ;
4512 fp->mp_upper = PAGEHDRSZ + dkey.mv_size + data->mv_size;
4513 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
4514 fp->mp_flags |= P_LEAF2;
4515 fp->mp_pad = data->mv_size;
4516 fp->mp_upper += 2 * data->mv_size; /* leave space for 2 more */
4518 fp->mp_upper += 2 * sizeof(indx_t) + 2 * NODESIZE +
4519 (dkey.mv_size & 1) + (data->mv_size & 1);
4521 mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0);
4524 xdata.mv_size = fp->mp_upper;
4529 if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
4530 /* See if we need to convert from fake page to subDB */
4532 unsigned int offset;
4535 fp = NODEDATA(leaf);
4536 if (flags == MDB_CURRENT) {
4538 fp->mp_flags |= P_DIRTY;
4539 COPY_PGNO(fp->mp_pgno, mc->mc_pg[mc->mc_top]->mp_pgno);
4540 mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;
4544 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
4545 offset = fp->mp_pad;
4546 if (SIZELEFT(fp) >= offset)
4548 offset *= 4; /* space for 4 more */
4550 offset = NODESIZE + sizeof(indx_t) + data->mv_size;
4552 offset += offset & 1;
4553 if (NODESIZE + sizeof(indx_t) + NODEKSZ(leaf) + NODEDSZ(leaf) +
4554 offset >= (mc->mc_txn->mt_env->me_psize - PAGEHDRSZ) /
4556 /* yes, convert it */
4558 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
4559 dummy.md_pad = fp->mp_pad;
4560 dummy.md_flags = MDB_DUPFIXED;
4561 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
4562 dummy.md_flags |= MDB_INTEGERKEY;
4565 dummy.md_branch_pages = 0;
4566 dummy.md_leaf_pages = 1;
4567 dummy.md_overflow_pages = 0;
4568 dummy.md_entries = NUMKEYS(fp);
4570 xdata.mv_size = sizeof(MDB_db);
4571 xdata.mv_data = &dummy;
4572 if ((rc = mdb_page_alloc(mc, 1, &mp)))
4574 offset = mc->mc_txn->mt_env->me_psize - NODEDSZ(leaf);
4575 flags |= F_DUPDATA|F_SUBDATA;
4576 dummy.md_root = mp->mp_pgno;
4578 /* no, just grow it */
4580 xdata.mv_size = NODEDSZ(leaf) + offset;
4581 xdata.mv_data = &pbuf;
4582 mp = (MDB_page *)&pbuf;
4583 mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
4586 mp->mp_flags = fp->mp_flags | P_DIRTY;
4587 mp->mp_pad = fp->mp_pad;
4588 mp->mp_lower = fp->mp_lower;
4589 mp->mp_upper = fp->mp_upper + offset;
4591 memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad);
4593 nsize = NODEDSZ(leaf) - fp->mp_upper;
4594 memcpy((char *)mp + mp->mp_upper, (char *)fp + fp->mp_upper, nsize);
4595 for (i=0; i<NUMKEYS(fp); i++)
4596 mp->mp_ptrs[i] = fp->mp_ptrs[i] + offset;
4598 mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0);
4602 /* data is on sub-DB, just store it */
4603 flags |= F_DUPDATA|F_SUBDATA;
4607 /* overflow page overwrites need special handling */
4608 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
4611 int ovpages, dpages;
4613 ovpages = OVPAGES(NODEDSZ(leaf), mc->mc_txn->mt_env->me_psize);
4614 dpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
4615 memcpy(&pg, NODEDATA(leaf), sizeof(pg));
4616 mdb_page_get(mc->mc_txn, pg, &omp);
4617 /* Is the ov page writable and large enough? */
4618 if ((omp->mp_flags & P_DIRTY) && ovpages >= dpages) {
4619 /* yes, overwrite it. Note in this case we don't
4620 * bother to try shrinking the node if the new data
4621 * is smaller than the overflow threshold.
4623 if (F_ISSET(flags, MDB_RESERVE))
4624 data->mv_data = METADATA(omp);
4626 memcpy(METADATA(omp), data->mv_data, data->mv_size);
4629 /* no, free ovpages */
4631 mc->mc_db->md_overflow_pages -= ovpages;
4632 for (i=0; i<ovpages; i++) {
4633 DPRINTF("freed ov page %zu", pg);
4634 mdb_midl_append(&mc->mc_txn->mt_free_pgs, pg);
4638 } else if (NODEDSZ(leaf) == data->mv_size) {
4639 /* same size, just replace it. Note that we could
4640 * also reuse this node if the new data is smaller,
4641 * but instead we opt to shrink the node in that case.
4643 if (F_ISSET(flags, MDB_RESERVE))
4644 data->mv_data = NODEDATA(leaf);
4646 memcpy(NODEDATA(leaf), data->mv_data, data->mv_size);
4649 mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0);
4650 mc->mc_db->md_entries--;
4652 DPRINTF("inserting key at index %i", mc->mc_ki[mc->mc_top]);
4659 nflags = flags & NODE_ADD_FLAGS;
4660 nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(mc->mc_txn->mt_env, key, rdata);
4661 if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) {
4662 if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA )
4663 nflags &= ~MDB_APPEND;
4665 nflags |= MDB_SPLIT_REPLACE;
4666 rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags);
4668 /* There is room already in this leaf page. */
4669 rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);
4670 if (rc == 0 && !do_sub && insert) {
4671 /* Adjust other cursors pointing to mp */
4672 MDB_cursor *m2, *m3;
4673 MDB_dbi dbi = mc->mc_dbi;
4674 unsigned i = mc->mc_top;
4675 MDB_page *mp = mc->mc_pg[i];
4677 if (mc->mc_flags & C_SUB)
4680 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
4681 if (mc->mc_flags & C_SUB)
4682 m3 = &m2->mc_xcursor->mx_cursor;
4685 if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
4686 if (m3->mc_pg[i] == mp && m3->mc_ki[i] >= mc->mc_ki[i]) {
4693 if (rc != MDB_SUCCESS)
4694 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
4696 /* Now store the actual data in the child DB. Note that we're
4697 * storing the user data in the keys field, so there are strict
4698 * size limits on dupdata. The actual data fields of the child
4699 * DB are all zero size.
4706 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
4707 if (flags & MDB_CURRENT) {
4708 xflags = MDB_CURRENT;
4710 mdb_xcursor_init1(mc, leaf);
4711 xflags = (flags & MDB_NODUPDATA) ? MDB_NOOVERWRITE : 0;
4713 /* converted, write the original data first */
4715 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);
4719 /* Adjust other cursors pointing to mp */
4721 unsigned i = mc->mc_top;
4722 MDB_page *mp = mc->mc_pg[i];
4724 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
4725 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
4726 if (m2->mc_pg[i] == mp && m2->mc_ki[i] == mc->mc_ki[i]) {
4727 mdb_xcursor_init1(m2, leaf);
4732 if (flags & MDB_APPENDDUP)
4733 xflags |= MDB_APPEND;
4734 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);
4735 if (flags & F_SUBDATA) {
4736 void *db = NODEDATA(leaf);
4737 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
4740 /* sub-writes might have failed so check rc again.
4741 * Don't increment count if we just replaced an existing item.
4743 if (!rc && !(flags & MDB_CURRENT))
4744 mc->mc_db->md_entries++;
4745 if (flags & MDB_MULTIPLE) {
4747 if (mcount < data[1].mv_size) {
4748 data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size;
4749 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
4759 mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
4764 if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_RDONLY))
4767 if (!mc->mc_flags & C_INITIALIZED)
4770 rc = mdb_cursor_touch(mc);
4774 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
4776 if (!IS_LEAF2(mc->mc_pg[mc->mc_top]) && F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4777 if (flags != MDB_NODUPDATA) {
4778 if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
4779 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
4781 rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, 0);
4782 /* If sub-DB still has entries, we're done */
4783 if (mc->mc_xcursor->mx_db.md_entries) {
4784 if (leaf->mn_flags & F_SUBDATA) {
4785 /* update subDB info */
4786 void *db = NODEDATA(leaf);
4787 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
4789 /* shrink fake page */
4790 mdb_node_shrink(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
4792 mc->mc_db->md_entries--;
4795 /* otherwise fall thru and delete the sub-DB */
4798 if (leaf->mn_flags & F_SUBDATA) {
4799 /* add all the child DB's pages to the free list */
4800 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
4801 if (rc == MDB_SUCCESS) {
4802 mc->mc_db->md_entries -=
4803 mc->mc_xcursor->mx_db.md_entries;
4808 return mdb_cursor_del0(mc, leaf);
4811 /** Allocate and initialize new pages for a database.
4812 * @param[in] mc a cursor on the database being added to.
4813 * @param[in] flags flags defining what type of page is being allocated.
4814 * @param[in] num the number of pages to allocate. This is usually 1,
4815 * unless allocating overflow pages for a large record.
4816 * @param[out] mp Address of a page, or NULL on failure.
4817 * @return 0 on success, non-zero on failure.
4820 mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp)
4825 if ((rc = mdb_page_alloc(mc, num, &np)))
4827 DPRINTF("allocated new mpage %zu, page size %u",
4828 np->mp_pgno, mc->mc_txn->mt_env->me_psize);
4829 np->mp_flags = flags | P_DIRTY;
4830 np->mp_lower = PAGEHDRSZ;
4831 np->mp_upper = mc->mc_txn->mt_env->me_psize;
4834 mc->mc_db->md_branch_pages++;
4835 else if (IS_LEAF(np))
4836 mc->mc_db->md_leaf_pages++;
4837 else if (IS_OVERFLOW(np)) {
4838 mc->mc_db->md_overflow_pages += num;
4846 /** Calculate the size of a leaf node.
4847 * The size depends on the environment's page size; if a data item
4848 * is too large it will be put onto an overflow page and the node
4849 * size will only include the key and not the data. Sizes are always
4850 * rounded up to an even number of bytes, to guarantee 2-byte alignment
4851 * of the #MDB_node headers.
4852 * @param[in] env The environment handle.
4853 * @param[in] key The key for the node.
4854 * @param[in] data The data for the node.
4855 * @return The number of bytes needed to store the node.
4858 mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data)
4862 sz = LEAFSIZE(key, data);
4863 if (sz >= env->me_psize / MDB_MINKEYS) {
4864 /* put on overflow page */
4865 sz -= data->mv_size - sizeof(pgno_t);
4869 return sz + sizeof(indx_t);
4872 /** Calculate the size of a branch node.
4873 * The size should depend on the environment's page size but since
4874 * we currently don't support spilling large keys onto overflow
4875 * pages, it's simply the size of the #MDB_node header plus the
4876 * size of the key. Sizes are always rounded up to an even number
4877 * of bytes, to guarantee 2-byte alignment of the #MDB_node headers.
4878 * @param[in] env The environment handle.
4879 * @param[in] key The key for the node.
4880 * @return The number of bytes needed to store the node.
4883 mdb_branch_size(MDB_env *env, MDB_val *key)
4888 if (sz >= env->me_psize / MDB_MINKEYS) {
4889 /* put on overflow page */
4890 /* not implemented */
4891 /* sz -= key->size - sizeof(pgno_t); */
4894 return sz + sizeof(indx_t);
4897 /** Add a node to the page pointed to by the cursor.
4898 * @param[in] mc The cursor for this operation.
4899 * @param[in] indx The index on the page where the new node should be added.
4900 * @param[in] key The key for the new node.
4901 * @param[in] data The data for the new node, if any.
4902 * @param[in] pgno The page number, if adding a branch node.
4903 * @param[in] flags Flags for the node.
4904 * @return 0 on success, non-zero on failure. Possible errors are:
4906 * <li>ENOMEM - failed to allocate overflow pages for the node.
4907 * <li>MDB_PAGE_FULL - there is insufficient room in the page. This error
4908 * should never happen since all callers already calculate the
4909 * page's free space before calling this function.
4913 mdb_node_add(MDB_cursor *mc, indx_t indx,
4914 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags)
4917 size_t node_size = NODESIZE;
4920 MDB_page *mp = mc->mc_pg[mc->mc_top];
4921 MDB_page *ofp = NULL; /* overflow page */
4924 assert(mp->mp_upper >= mp->mp_lower);
4926 DPRINTF("add to %s %spage %zu index %i, data size %zu key size %zu [%s]",
4927 IS_LEAF(mp) ? "leaf" : "branch",
4928 IS_SUBP(mp) ? "sub-" : "",
4929 mp->mp_pgno, indx, data ? data->mv_size : 0,
4930 key ? key->mv_size : 0, key ? DKEY(key) : NULL);
4933 /* Move higher keys up one slot. */
4934 int ksize = mc->mc_db->md_pad, dif;
4935 char *ptr = LEAF2KEY(mp, indx, ksize);
4936 dif = NUMKEYS(mp) - indx;
4938 memmove(ptr+ksize, ptr, dif*ksize);
4939 /* insert new key */
4940 memcpy(ptr, key->mv_data, ksize);
4942 /* Just using these for counting */
4943 mp->mp_lower += sizeof(indx_t);
4944 mp->mp_upper -= ksize - sizeof(indx_t);
4949 node_size += key->mv_size;
4953 if (F_ISSET(flags, F_BIGDATA)) {
4954 /* Data already on overflow page. */
4955 node_size += sizeof(pgno_t);
4956 } else if (node_size + data->mv_size >= mc->mc_txn->mt_env->me_psize / MDB_MINKEYS) {
4957 int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
4959 /* Put data on overflow page. */
4960 DPRINTF("data size is %zu, node would be %zu, put data on overflow page",
4961 data->mv_size, node_size+data->mv_size);
4962 node_size += sizeof(pgno_t);
4963 if ((rc = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp)))
4965 DPRINTF("allocated overflow page %zu", ofp->mp_pgno);
4968 node_size += data->mv_size;
4971 node_size += node_size & 1;
4973 if (node_size + sizeof(indx_t) > SIZELEFT(mp)) {
4974 DPRINTF("not enough room in page %zu, got %u ptrs",
4975 mp->mp_pgno, NUMKEYS(mp));
4976 DPRINTF("upper - lower = %u - %u = %u", mp->mp_upper, mp->mp_lower,
4977 mp->mp_upper - mp->mp_lower);
4978 DPRINTF("node size = %zu", node_size);
4979 return MDB_PAGE_FULL;
4982 /* Move higher pointers up one slot. */
4983 for (i = NUMKEYS(mp); i > indx; i--)
4984 mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];
4986 /* Adjust free space offsets. */
4987 ofs = mp->mp_upper - node_size;
4988 assert(ofs >= mp->mp_lower + sizeof(indx_t));
4989 mp->mp_ptrs[indx] = ofs;
4991 mp->mp_lower += sizeof(indx_t);
4993 /* Write the node data. */
4994 node = NODEPTR(mp, indx);
4995 node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
4996 node->mn_flags = flags;
4998 SETDSZ(node,data->mv_size);
5003 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
5008 if (F_ISSET(flags, F_BIGDATA))
5009 memcpy(node->mn_data + key->mv_size, data->mv_data,
5011 else if (F_ISSET(flags, MDB_RESERVE))
5012 data->mv_data = node->mn_data + key->mv_size;
5014 memcpy(node->mn_data + key->mv_size, data->mv_data,
5017 memcpy(node->mn_data + key->mv_size, &ofp->mp_pgno,
5019 if (F_ISSET(flags, MDB_RESERVE))
5020 data->mv_data = METADATA(ofp);
5022 memcpy(METADATA(ofp), data->mv_data, data->mv_size);
5029 /** Delete the specified node from a page.
5030 * @param[in] mp The page to operate on.
5031 * @param[in] indx The index of the node to delete.
5032 * @param[in] ksize The size of a node. Only used if the page is
5033 * part of a #MDB_DUPFIXED database.
5036 mdb_node_del(MDB_page *mp, indx_t indx, int ksize)
5039 indx_t i, j, numkeys, ptr;
5046 COPY_PGNO(pgno, mp->mp_pgno);
5047 DPRINTF("delete node %u on %s page %zu", indx,
5048 IS_LEAF(mp) ? "leaf" : "branch", pgno);
5051 assert(indx < NUMKEYS(mp));
5054 int x = NUMKEYS(mp) - 1 - indx;
5055 base = LEAF2KEY(mp, indx, ksize);
5057 memmove(base, base + ksize, x * ksize);
5058 mp->mp_lower -= sizeof(indx_t);
5059 mp->mp_upper += ksize - sizeof(indx_t);
5063 node = NODEPTR(mp, indx);
5064 sz = NODESIZE + node->mn_ksize;
5066 if (F_ISSET(node->mn_flags, F_BIGDATA))
5067 sz += sizeof(pgno_t);
5069 sz += NODEDSZ(node);
5073 ptr = mp->mp_ptrs[indx];
5074 numkeys = NUMKEYS(mp);
5075 for (i = j = 0; i < numkeys; i++) {
5077 mp->mp_ptrs[j] = mp->mp_ptrs[i];
5078 if (mp->mp_ptrs[i] < ptr)
5079 mp->mp_ptrs[j] += sz;
5084 base = (char *)mp + mp->mp_upper;
5085 memmove(base + sz, base, ptr - mp->mp_upper);
5087 mp->mp_lower -= sizeof(indx_t);
5091 /** Compact the main page after deleting a node on a subpage.
5092 * @param[in] mp The main page to operate on.
5093 * @param[in] indx The index of the subpage on the main page.
5096 mdb_node_shrink(MDB_page *mp, indx_t indx)
5103 indx_t i, numkeys, ptr;
5105 node = NODEPTR(mp, indx);
5106 sp = (MDB_page *)NODEDATA(node);
5107 osize = NODEDSZ(node);
5109 delta = sp->mp_upper - sp->mp_lower;
5110 SETDSZ(node, osize - delta);
5111 xp = (MDB_page *)((char *)sp + delta);
5113 /* shift subpage upward */
5115 nsize = NUMKEYS(sp) * sp->mp_pad;
5116 memmove(METADATA(xp), METADATA(sp), nsize);
5119 nsize = osize - sp->mp_upper;
5120 numkeys = NUMKEYS(sp);
5121 for (i=numkeys-1; i>=0; i--)
5122 xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta;
5124 xp->mp_upper = sp->mp_lower;
5125 xp->mp_lower = sp->mp_lower;
5126 xp->mp_flags = sp->mp_flags;
5127 xp->mp_pad = sp->mp_pad;
5128 COPY_PGNO(xp->mp_pgno, mp->mp_pgno);
5130 /* shift lower nodes upward */
5131 ptr = mp->mp_ptrs[indx];
5132 numkeys = NUMKEYS(mp);
5133 for (i = 0; i < numkeys; i++) {
5134 if (mp->mp_ptrs[i] <= ptr)
5135 mp->mp_ptrs[i] += delta;
5138 base = (char *)mp + mp->mp_upper;
5139 memmove(base + delta, base, ptr - mp->mp_upper + NODESIZE + NODEKSZ(node));
5140 mp->mp_upper += delta;
5143 /** Initial setup of a sorted-dups cursor.
5144 * Sorted duplicates are implemented as a sub-database for the given key.
5145 * The duplicate data items are actually keys of the sub-database.
5146 * Operations on the duplicate data items are performed using a sub-cursor
5147 * initialized when the sub-database is first accessed. This function does
5148 * the preliminary setup of the sub-cursor, filling in the fields that
5149 * depend only on the parent DB.
5150 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
5153 mdb_xcursor_init0(MDB_cursor *mc)
5155 MDB_xcursor *mx = mc->mc_xcursor;
5157 mx->mx_cursor.mc_xcursor = NULL;
5158 mx->mx_cursor.mc_txn = mc->mc_txn;
5159 mx->mx_cursor.mc_db = &mx->mx_db;
5160 mx->mx_cursor.mc_dbx = &mx->mx_dbx;
5161 mx->mx_cursor.mc_dbi = mc->mc_dbi+1;
5162 mx->mx_cursor.mc_dbflag = &mx->mx_dbflag;
5163 mx->mx_cursor.mc_snum = 0;
5164 mx->mx_cursor.mc_top = 0;
5165 mx->mx_cursor.mc_flags = C_SUB;
5166 mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp;
5167 mx->mx_dbx.md_dcmp = NULL;
5168 mx->mx_dbx.md_rel = mc->mc_dbx->md_rel;
5171 /** Final setup of a sorted-dups cursor.
5172 * Sets up the fields that depend on the data from the main cursor.
5173 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
5174 * @param[in] node The data containing the #MDB_db record for the
5175 * sorted-dup database.
5178 mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)
5180 MDB_xcursor *mx = mc->mc_xcursor;
5182 if (node->mn_flags & F_SUBDATA) {
5183 memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db));
5184 mx->mx_cursor.mc_pg[0] = 0;
5185 mx->mx_cursor.mc_snum = 0;
5186 mx->mx_cursor.mc_flags = C_SUB;
5188 MDB_page *fp = NODEDATA(node);
5189 mx->mx_db.md_pad = mc->mc_pg[mc->mc_top]->mp_pad;
5190 mx->mx_db.md_flags = 0;
5191 mx->mx_db.md_depth = 1;
5192 mx->mx_db.md_branch_pages = 0;
5193 mx->mx_db.md_leaf_pages = 1;
5194 mx->mx_db.md_overflow_pages = 0;
5195 mx->mx_db.md_entries = NUMKEYS(fp);
5196 COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno);
5197 mx->mx_cursor.mc_snum = 1;
5198 mx->mx_cursor.mc_flags = C_INITIALIZED|C_SUB;
5199 mx->mx_cursor.mc_top = 0;
5200 mx->mx_cursor.mc_pg[0] = fp;
5201 mx->mx_cursor.mc_ki[0] = 0;
5202 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
5203 mx->mx_db.md_flags = MDB_DUPFIXED;
5204 mx->mx_db.md_pad = fp->mp_pad;
5205 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
5206 mx->mx_db.md_flags |= MDB_INTEGERKEY;
5209 DPRINTF("Sub-db %u for db %u root page %zu", mx->mx_cursor.mc_dbi, mc->mc_dbi,
5211 mx->mx_dbflag = (F_ISSET(mc->mc_pg[mc->mc_top]->mp_flags, P_DIRTY)) ?
5213 mx->mx_dbx.md_name.mv_data = NODEKEY(node);
5214 mx->mx_dbx.md_name.mv_size = node->mn_ksize;
5215 #if UINT_MAX < SIZE_MAX
5216 if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(size_t))
5217 #ifdef MISALIGNED_OK
5218 mx->mx_dbx.md_cmp = mdb_cmp_long;
5220 mx->mx_dbx.md_cmp = mdb_cmp_cint;
5225 /** Initialize a cursor for a given transaction and database. */
5227 mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
5232 mc->mc_db = &txn->mt_dbs[dbi];
5233 mc->mc_dbx = &txn->mt_dbxs[dbi];
5234 mc->mc_dbflag = &txn->mt_dbflags[dbi];
5239 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
5241 mc->mc_xcursor = mx;
5242 mdb_xcursor_init0(mc);
5244 mc->mc_xcursor = NULL;
5246 if (*mc->mc_dbflag & DB_STALE) {
5247 mdb_page_search(mc, NULL, MDB_PS_ROOTONLY);
5252 mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
5255 MDB_xcursor *mx = NULL;
5256 size_t size = sizeof(MDB_cursor);
5258 if (txn == NULL || ret == NULL || dbi >= txn->mt_numdbs)
5261 /* Allow read access to the freelist */
5262 if (!dbi && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
5265 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)
5266 size += sizeof(MDB_xcursor);
5268 if ((mc = malloc(size)) != NULL) {
5269 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
5270 mx = (MDB_xcursor *)(mc + 1);
5272 mdb_cursor_init(mc, txn, dbi, mx);
5273 if (txn->mt_cursors) {
5274 mc->mc_next = txn->mt_cursors[dbi];
5275 txn->mt_cursors[dbi] = mc;
5277 mc->mc_flags |= C_ALLOCD;
5288 mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)
5290 if (txn == NULL || mc == NULL || mc->mc_dbi >= txn->mt_numdbs)
5293 if (txn->mt_cursors)
5296 mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor);
5300 /* Return the count of duplicate data items for the current key */
5302 mdb_cursor_count(MDB_cursor *mc, size_t *countp)
5306 if (mc == NULL || countp == NULL)
5309 if (!(mc->mc_db->md_flags & MDB_DUPSORT))
5312 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5313 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5316 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
5319 *countp = mc->mc_xcursor->mx_db.md_entries;
5325 mdb_cursor_close(MDB_cursor *mc)
5328 /* remove from txn, if tracked */
5329 if (mc->mc_txn->mt_cursors) {
5330 MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi];
5331 while (*prev && *prev != mc) prev = &(*prev)->mc_next;
5333 *prev = mc->mc_next;
5335 if (mc->mc_flags & C_ALLOCD)
5341 mdb_cursor_txn(MDB_cursor *mc)
5343 if (!mc) return NULL;
5348 mdb_cursor_dbi(MDB_cursor *mc)
5354 /** Replace the key for a node with a new key.
5355 * @param[in] mp The page containing the node to operate on.
5356 * @param[in] indx The index of the node to operate on.
5357 * @param[in] key The new key to use.
5358 * @return 0 on success, non-zero on failure.
5361 mdb_update_key(MDB_page *mp, indx_t indx, MDB_val *key)
5367 indx_t ptr, i, numkeys;
5370 node = NODEPTR(mp, indx);
5371 ptr = mp->mp_ptrs[indx];
5375 char kbuf2[(MAXKEYSIZE*2+1)];
5376 k2.mv_data = NODEKEY(node);
5377 k2.mv_size = node->mn_ksize;
5378 DPRINTF("update key %u (ofs %u) [%s] to [%s] on page %zu",
5380 mdb_dkey(&k2, kbuf2),
5386 delta0 = delta = key->mv_size - node->mn_ksize;
5388 /* Must be 2-byte aligned. If new key is
5389 * shorter by 1, the shift will be skipped.
5391 delta += (delta & 1);
5393 if (delta > 0 && SIZELEFT(mp) < delta) {
5394 DPRINTF("OUCH! Not enough room, delta = %d", delta);
5395 return MDB_PAGE_FULL;
5398 numkeys = NUMKEYS(mp);
5399 for (i = 0; i < numkeys; i++) {
5400 if (mp->mp_ptrs[i] <= ptr)
5401 mp->mp_ptrs[i] -= delta;
5404 base = (char *)mp + mp->mp_upper;
5405 len = ptr - mp->mp_upper + NODESIZE;
5406 memmove(base - delta, base, len);
5407 mp->mp_upper -= delta;
5409 node = NODEPTR(mp, indx);
5412 /* But even if no shift was needed, update ksize */
5414 node->mn_ksize = key->mv_size;
5417 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
5422 /** Move a node from csrc to cdst.
5425 mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
5431 unsigned short flags;
5435 /* Mark src and dst as dirty. */
5436 if ((rc = mdb_page_touch(csrc)) ||
5437 (rc = mdb_page_touch(cdst)))
5440 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
5441 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0); /* fake */
5442 key.mv_size = csrc->mc_db->md_pad;
5443 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
5445 data.mv_data = NULL;
5449 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]);
5450 assert(!((long)srcnode&1));
5451 srcpg = NODEPGNO(srcnode);
5452 flags = srcnode->mn_flags;
5453 if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
5454 unsigned int snum = csrc->mc_snum;
5456 /* must find the lowest key below src */
5457 mdb_page_search_root(csrc, NULL, 0);
5458 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
5459 key.mv_size = csrc->mc_db->md_pad;
5460 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
5462 s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
5463 key.mv_size = NODEKSZ(s2);
5464 key.mv_data = NODEKEY(s2);
5466 csrc->mc_snum = snum--;
5467 csrc->mc_top = snum;
5469 key.mv_size = NODEKSZ(srcnode);
5470 key.mv_data = NODEKEY(srcnode);
5472 data.mv_size = NODEDSZ(srcnode);
5473 data.mv_data = NODEDATA(srcnode);
5475 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) {
5476 unsigned int snum = cdst->mc_snum;
5479 /* must find the lowest key below dst */
5480 mdb_page_search_root(cdst, NULL, 0);
5481 if (IS_LEAF2(cdst->mc_pg[cdst->mc_top])) {
5482 bkey.mv_size = cdst->mc_db->md_pad;
5483 bkey.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, bkey.mv_size);
5485 s2 = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
5486 bkey.mv_size = NODEKSZ(s2);
5487 bkey.mv_data = NODEKEY(s2);
5489 cdst->mc_snum = snum--;
5490 cdst->mc_top = snum;
5491 rc = mdb_update_key(cdst->mc_pg[cdst->mc_top], 0, &bkey);
5494 DPRINTF("moving %s node %u [%s] on page %zu to node %u on page %zu",
5495 IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch",
5496 csrc->mc_ki[csrc->mc_top],
5498 csrc->mc_pg[csrc->mc_top]->mp_pgno,
5499 cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno);
5501 /* Add the node to the destination page.
5503 rc = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags);
5504 if (rc != MDB_SUCCESS)
5507 /* Delete the node from the source page.
5509 mdb_node_del(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
5512 /* Adjust other cursors pointing to mp */
5513 MDB_cursor *m2, *m3;
5514 MDB_dbi dbi = csrc->mc_dbi;
5515 MDB_page *mp = csrc->mc_pg[csrc->mc_top];
5517 if (csrc->mc_flags & C_SUB)
5520 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
5521 if (m2 == csrc) continue;
5522 if (csrc->mc_flags & C_SUB)
5523 m3 = &m2->mc_xcursor->mx_cursor;
5526 if (m3->mc_pg[csrc->mc_top] == mp && m3->mc_ki[csrc->mc_top] ==
5527 csrc->mc_ki[csrc->mc_top]) {
5528 m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
5529 m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
5534 /* Update the parent separators.
5536 if (csrc->mc_ki[csrc->mc_top] == 0) {
5537 if (csrc->mc_ki[csrc->mc_top-1] != 0) {
5538 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
5539 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
5541 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
5542 key.mv_size = NODEKSZ(srcnode);
5543 key.mv_data = NODEKEY(srcnode);
5545 DPRINTF("update separator for source page %zu to [%s]",
5546 csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key));
5547 if ((rc = mdb_update_key(csrc->mc_pg[csrc->mc_top-1], csrc->mc_ki[csrc->mc_top-1],
5548 &key)) != MDB_SUCCESS)
5551 if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
5553 nullkey.mv_size = 0;
5554 rc = mdb_update_key(csrc->mc_pg[csrc->mc_top], 0, &nullkey);
5555 assert(rc == MDB_SUCCESS);
5559 if (cdst->mc_ki[cdst->mc_top] == 0) {
5560 if (cdst->mc_ki[cdst->mc_top-1] != 0) {
5561 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
5562 key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size);
5564 srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
5565 key.mv_size = NODEKSZ(srcnode);
5566 key.mv_data = NODEKEY(srcnode);
5568 DPRINTF("update separator for destination page %zu to [%s]",
5569 cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key));
5570 if ((rc = mdb_update_key(cdst->mc_pg[cdst->mc_top-1], cdst->mc_ki[cdst->mc_top-1],
5571 &key)) != MDB_SUCCESS)
5574 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) {
5576 nullkey.mv_size = 0;
5577 rc = mdb_update_key(cdst->mc_pg[cdst->mc_top], 0, &nullkey);
5578 assert(rc == MDB_SUCCESS);
5585 /** Merge one page into another.
5586 * The nodes from the page pointed to by \b csrc will
5587 * be copied to the page pointed to by \b cdst and then
5588 * the \b csrc page will be freed.
5589 * @param[in] csrc Cursor pointing to the source page.
5590 * @param[in] cdst Cursor pointing to the destination page.
5593 mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
5601 DPRINTF("merging page %zu into %zu", csrc->mc_pg[csrc->mc_top]->mp_pgno,
5602 cdst->mc_pg[cdst->mc_top]->mp_pgno);
5604 assert(csrc->mc_snum > 1); /* can't merge root page */
5605 assert(cdst->mc_snum > 1);
5607 /* Mark dst as dirty. */
5608 if ((rc = mdb_page_touch(cdst)))
5611 /* Move all nodes from src to dst.
5613 j = nkeys = NUMKEYS(cdst->mc_pg[cdst->mc_top]);
5614 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
5615 key.mv_size = csrc->mc_db->md_pad;
5616 key.mv_data = METADATA(csrc->mc_pg[csrc->mc_top]);
5617 for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) {
5618 rc = mdb_node_add(cdst, j, &key, NULL, 0, 0);
5619 if (rc != MDB_SUCCESS)
5621 key.mv_data = (char *)key.mv_data + key.mv_size;
5624 for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) {
5625 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], i);
5626 if (i == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
5627 unsigned int snum = csrc->mc_snum;
5629 /* must find the lowest key below src */
5630 mdb_page_search_root(csrc, NULL, 0);
5631 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
5632 key.mv_size = csrc->mc_db->md_pad;
5633 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
5635 s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
5636 key.mv_size = NODEKSZ(s2);
5637 key.mv_data = NODEKEY(s2);
5639 csrc->mc_snum = snum--;
5640 csrc->mc_top = snum;
5642 key.mv_size = srcnode->mn_ksize;
5643 key.mv_data = NODEKEY(srcnode);
5646 data.mv_size = NODEDSZ(srcnode);
5647 data.mv_data = NODEDATA(srcnode);
5648 rc = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags);
5649 if (rc != MDB_SUCCESS)
5654 DPRINTF("dst page %zu now has %u keys (%.1f%% filled)",
5655 cdst->mc_pg[cdst->mc_top]->mp_pgno, NUMKEYS(cdst->mc_pg[cdst->mc_top]), (float)PAGEFILL(cdst->mc_txn->mt_env, cdst->mc_pg[cdst->mc_top]) / 10);
5657 /* Unlink the src page from parent and add to free list.
5659 mdb_node_del(csrc->mc_pg[csrc->mc_top-1], csrc->mc_ki[csrc->mc_top-1], 0);
5660 if (csrc->mc_ki[csrc->mc_top-1] == 0) {
5662 if ((rc = mdb_update_key(csrc->mc_pg[csrc->mc_top-1], 0, &key)) != MDB_SUCCESS)
5666 mdb_midl_append(&csrc->mc_txn->mt_free_pgs, csrc->mc_pg[csrc->mc_top]->mp_pgno);
5667 if (IS_LEAF(csrc->mc_pg[csrc->mc_top]))
5668 csrc->mc_db->md_leaf_pages--;
5670 csrc->mc_db->md_branch_pages--;
5672 /* Adjust other cursors pointing to mp */
5673 MDB_cursor *m2, *m3;
5674 MDB_dbi dbi = csrc->mc_dbi;
5675 MDB_page *mp = cdst->mc_pg[cdst->mc_top];
5677 if (csrc->mc_flags & C_SUB)
5680 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
5681 if (csrc->mc_flags & C_SUB)
5682 m3 = &m2->mc_xcursor->mx_cursor;
5685 if (m3 == csrc) continue;
5686 if (m3->mc_snum < csrc->mc_snum) continue;
5687 if (m3->mc_pg[csrc->mc_top] == csrc->mc_pg[csrc->mc_top]) {
5688 m3->mc_pg[csrc->mc_top] = mp;
5689 m3->mc_ki[csrc->mc_top] += nkeys;
5693 mdb_cursor_pop(csrc);
5695 return mdb_rebalance(csrc);
5698 /** Copy the contents of a cursor.
5699 * @param[in] csrc The cursor to copy from.
5700 * @param[out] cdst The cursor to copy to.
5703 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst)
5707 cdst->mc_txn = csrc->mc_txn;
5708 cdst->mc_dbi = csrc->mc_dbi;
5709 cdst->mc_db = csrc->mc_db;
5710 cdst->mc_dbx = csrc->mc_dbx;
5711 cdst->mc_snum = csrc->mc_snum;
5712 cdst->mc_top = csrc->mc_top;
5713 cdst->mc_flags = csrc->mc_flags;
5715 for (i=0; i<csrc->mc_snum; i++) {
5716 cdst->mc_pg[i] = csrc->mc_pg[i];
5717 cdst->mc_ki[i] = csrc->mc_ki[i];
5721 /** Rebalance the tree after a delete operation.
5722 * @param[in] mc Cursor pointing to the page where rebalancing
5724 * @return 0 on success, non-zero on failure.
5727 mdb_rebalance(MDB_cursor *mc)
5737 COPY_PGNO(pgno, mc->mc_pg[mc->mc_top]->mp_pgno);
5738 DPRINTF("rebalancing %s page %zu (has %u keys, %.1f%% full)",
5739 IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",
5740 pgno, NUMKEYS(mc->mc_pg[mc->mc_top]), (float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10);
5744 if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= FILL_THRESHOLD) {
5747 COPY_PGNO(pgno, mc->mc_pg[mc->mc_top]->mp_pgno);
5748 DPRINTF("no need to rebalance page %zu, above fill threshold",
5754 if (mc->mc_snum < 2) {
5755 MDB_page *mp = mc->mc_pg[0];
5756 if (NUMKEYS(mp) == 0) {
5757 DPUTS("tree is completely empty");
5758 mc->mc_db->md_root = P_INVALID;
5759 mc->mc_db->md_depth = 0;
5760 mc->mc_db->md_leaf_pages = 0;
5761 mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
5765 /* Adjust other cursors pointing to mp */
5766 MDB_cursor *m2, *m3;
5767 MDB_dbi dbi = mc->mc_dbi;
5769 if (mc->mc_flags & C_SUB)
5772 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
5773 if (m2 == mc) continue;
5774 if (mc->mc_flags & C_SUB)
5775 m3 = &m2->mc_xcursor->mx_cursor;
5778 if (m3->mc_snum < mc->mc_snum) continue;
5779 if (m3->mc_pg[0] == mp) {
5785 } else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) {
5786 DPUTS("collapsing root page!");
5787 mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
5788 mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0));
5789 if ((rc = mdb_page_get(mc->mc_txn, mc->mc_db->md_root,
5792 mc->mc_db->md_depth--;
5793 mc->mc_db->md_branch_pages--;
5795 /* Adjust other cursors pointing to mp */
5796 MDB_cursor *m2, *m3;
5797 MDB_dbi dbi = mc->mc_dbi;
5799 if (mc->mc_flags & C_SUB)
5802 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
5803 if (m2 == mc) continue;
5804 if (mc->mc_flags & C_SUB)
5805 m3 = &m2->mc_xcursor->mx_cursor;
5808 if (m3->mc_snum < mc->mc_snum) continue;
5809 if (m3->mc_pg[0] == mp) {
5810 m3->mc_pg[0] = mc->mc_pg[0];
5815 DPUTS("root page doesn't need rebalancing");
5819 /* The parent (branch page) must have at least 2 pointers,
5820 * otherwise the tree is invalid.
5822 ptop = mc->mc_top-1;
5823 assert(NUMKEYS(mc->mc_pg[ptop]) > 1);
5825 /* Leaf page fill factor is below the threshold.
5826 * Try to move keys from left or right neighbor, or
5827 * merge with a neighbor page.
5832 mdb_cursor_copy(mc, &mn);
5833 mn.mc_xcursor = NULL;
5835 if (mc->mc_ki[ptop] == 0) {
5836 /* We're the leftmost leaf in our parent.
5838 DPUTS("reading right neighbor");
5840 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
5841 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mn.mc_pg[mn.mc_top])))
5843 mn.mc_ki[mn.mc_top] = 0;
5844 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);
5846 /* There is at least one neighbor to the left.
5848 DPUTS("reading left neighbor");
5850 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
5851 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mn.mc_pg[mn.mc_top])))
5853 mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;
5854 mc->mc_ki[mc->mc_top] = 0;
5857 DPRINTF("found neighbor page %zu (%u keys, %.1f%% full)",
5858 mn.mc_pg[mn.mc_top]->mp_pgno, NUMKEYS(mn.mc_pg[mn.mc_top]), (float)PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) / 10);
5860 /* If the neighbor page is above threshold and has at least two
5861 * keys, move one key from it.
5863 * Otherwise we should try to merge them.
5865 if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= FILL_THRESHOLD && NUMKEYS(mn.mc_pg[mn.mc_top]) >= 2)
5866 return mdb_node_move(&mn, mc);
5867 else { /* FIXME: if (has_enough_room()) */
5868 mc->mc_flags &= ~C_INITIALIZED;
5869 if (mc->mc_ki[ptop] == 0)
5870 return mdb_page_merge(&mn, mc);
5872 return mdb_page_merge(mc, &mn);
5876 /** Complete a delete operation started by #mdb_cursor_del(). */
5878 mdb_cursor_del0(MDB_cursor *mc, MDB_node *leaf)
5882 /* add overflow pages to free list */
5883 if (!IS_LEAF2(mc->mc_pg[mc->mc_top]) && F_ISSET(leaf->mn_flags, F_BIGDATA)) {
5887 memcpy(&pg, NODEDATA(leaf), sizeof(pg));
5888 ovpages = OVPAGES(NODEDSZ(leaf), mc->mc_txn->mt_env->me_psize);
5889 mc->mc_db->md_overflow_pages -= ovpages;
5890 for (i=0; i<ovpages; i++) {
5891 DPRINTF("freed ov page %zu", pg);
5892 mdb_midl_append(&mc->mc_txn->mt_free_pgs, pg);
5896 mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], mc->mc_db->md_pad);
5897 mc->mc_db->md_entries--;
5898 rc = mdb_rebalance(mc);
5899 if (rc != MDB_SUCCESS)
5900 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
5906 mdb_del(MDB_txn *txn, MDB_dbi dbi,
5907 MDB_val *key, MDB_val *data)
5912 MDB_val rdata, *xdata;
5916 assert(key != NULL);
5918 DPRINTF("====> delete db %u key [%s]", dbi, DKEY(key));
5920 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
5923 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
5927 if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
5931 mdb_cursor_init(&mc, txn, dbi, &mx);
5942 rc = mdb_cursor_set(&mc, key, xdata, op, &exact);
5944 rc = mdb_cursor_del(&mc, data ? 0 : MDB_NODUPDATA);
5948 /** Split a page and insert a new node.
5949 * @param[in,out] mc Cursor pointing to the page and desired insertion index.
5950 * The cursor will be updated to point to the actual page and index where
5951 * the node got inserted after the split.
5952 * @param[in] newkey The key for the newly inserted node.
5953 * @param[in] newdata The data for the newly inserted node.
5954 * @param[in] newpgno The page number, if the new node is a branch node.
5955 * @param[in] nflags The #NODE_ADD_FLAGS for the new node.
5956 * @return 0 on success, non-zero on failure.
5959 mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno,
5960 unsigned int nflags)
5963 int rc = MDB_SUCCESS, ins_new = 0, new_root = 0, newpos = 1, did_split = 0;
5966 unsigned int i, j, split_indx, nkeys, pmax;
5968 MDB_val sepkey, rkey, xdata, *rdata = &xdata;
5970 MDB_page *mp, *rp, *pp;
5975 mp = mc->mc_pg[mc->mc_top];
5976 newindx = mc->mc_ki[mc->mc_top];
5978 DPRINTF("-----> splitting %s page %zu and adding [%s] at index %i",
5979 IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno,
5980 DKEY(newkey), mc->mc_ki[mc->mc_top]);
5982 /* Create a right sibling. */
5983 if ((rc = mdb_page_new(mc, mp->mp_flags, 1, &rp)))
5985 DPRINTF("new right sibling: page %zu", rp->mp_pgno);
5987 if (mc->mc_snum < 2) {
5988 if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp)))
5990 /* shift current top to make room for new parent */
5991 mc->mc_pg[1] = mc->mc_pg[0];
5992 mc->mc_ki[1] = mc->mc_ki[0];
5995 mc->mc_db->md_root = pp->mp_pgno;
5996 DPRINTF("root split! new root = %zu", pp->mp_pgno);
5997 mc->mc_db->md_depth++;
6000 /* Add left (implicit) pointer. */
6001 if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) {
6002 /* undo the pre-push */
6003 mc->mc_pg[0] = mc->mc_pg[1];
6004 mc->mc_ki[0] = mc->mc_ki[1];
6005 mc->mc_db->md_root = mp->mp_pgno;
6006 mc->mc_db->md_depth--;
6013 ptop = mc->mc_top-1;
6014 DPRINTF("parent branch page is %zu", mc->mc_pg[ptop]->mp_pgno);
6017 mc->mc_flags |= C_SPLITTING;
6018 mdb_cursor_copy(mc, &mn);
6019 mn.mc_pg[mn.mc_top] = rp;
6020 mn.mc_ki[ptop] = mc->mc_ki[ptop]+1;
6022 if (nflags & MDB_APPEND) {
6023 mn.mc_ki[mn.mc_top] = 0;
6025 split_indx = newindx;
6030 nkeys = NUMKEYS(mp);
6031 split_indx = nkeys / 2;
6032 if (newindx < split_indx)
6038 unsigned int lsize, rsize, ksize;
6039 /* Move half of the keys to the right sibling */
6041 x = mc->mc_ki[mc->mc_top] - split_indx;
6042 ksize = mc->mc_db->md_pad;
6043 split = LEAF2KEY(mp, split_indx, ksize);
6044 rsize = (nkeys - split_indx) * ksize;
6045 lsize = (nkeys - split_indx) * sizeof(indx_t);
6046 mp->mp_lower -= lsize;
6047 rp->mp_lower += lsize;
6048 mp->mp_upper += rsize - lsize;
6049 rp->mp_upper -= rsize - lsize;
6050 sepkey.mv_size = ksize;
6051 if (newindx == split_indx) {
6052 sepkey.mv_data = newkey->mv_data;
6054 sepkey.mv_data = split;
6057 ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize);
6058 memcpy(rp->mp_ptrs, split, rsize);
6059 sepkey.mv_data = rp->mp_ptrs;
6060 memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize);
6061 memcpy(ins, newkey->mv_data, ksize);
6062 mp->mp_lower += sizeof(indx_t);
6063 mp->mp_upper -= ksize - sizeof(indx_t);
6066 memcpy(rp->mp_ptrs, split, x * ksize);
6067 ins = LEAF2KEY(rp, x, ksize);
6068 memcpy(ins, newkey->mv_data, ksize);
6069 memcpy(ins+ksize, split + x * ksize, rsize - x * ksize);
6070 rp->mp_lower += sizeof(indx_t);
6071 rp->mp_upper -= ksize - sizeof(indx_t);
6072 mc->mc_ki[mc->mc_top] = x;
6073 mc->mc_pg[mc->mc_top] = rp;
6078 /* For leaf pages, check the split point based on what
6079 * fits where, since otherwise mdb_node_add can fail.
6081 * This check is only needed when the data items are
6082 * relatively large, such that being off by one will
6083 * make the difference between success or failure.
6084 * When the size of the data items is much smaller than
6085 * one-half of a page, this check is irrelevant.
6088 unsigned int psize, nsize;
6089 /* Maximum free space in an empty page */
6090 pmax = mc->mc_txn->mt_env->me_psize - PAGEHDRSZ;
6091 nsize = mdb_leaf_size(mc->mc_txn->mt_env, newkey, newdata);
6092 if ((nkeys < 20) || (nsize > pmax/4)) {
6093 if (newindx <= split_indx) {
6096 for (i=0; i<split_indx; i++) {
6097 node = NODEPTR(mp, i);
6098 psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
6099 if (F_ISSET(node->mn_flags, F_BIGDATA))
6100 psize += sizeof(pgno_t);
6102 psize += NODEDSZ(node);
6106 split_indx = newindx;
6117 for (i=nkeys-1; i>=split_indx; i--) {
6118 node = NODEPTR(mp, i);
6119 psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
6120 if (F_ISSET(node->mn_flags, F_BIGDATA))
6121 psize += sizeof(pgno_t);
6123 psize += NODEDSZ(node);
6127 split_indx = newindx;
6137 /* First find the separating key between the split pages.
6138 * The case where newindx == split_indx is ambiguous; the
6139 * new item could go to the new page or stay on the original
6140 * page. If newpos == 1 it goes to the new page.
6142 if (newindx == split_indx && newpos) {
6143 sepkey.mv_size = newkey->mv_size;
6144 sepkey.mv_data = newkey->mv_data;
6146 node = NODEPTR(mp, split_indx);
6147 sepkey.mv_size = node->mn_ksize;
6148 sepkey.mv_data = NODEKEY(node);
6152 DPRINTF("separator is [%s]", DKEY(&sepkey));
6154 /* Copy separator key to the parent.
6156 if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(mc->mc_txn->mt_env, &sepkey)) {
6160 rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0);
6163 if (mn.mc_snum == mc->mc_snum) {
6164 mc->mc_pg[mc->mc_snum] = mc->mc_pg[mc->mc_top];
6165 mc->mc_ki[mc->mc_snum] = mc->mc_ki[mc->mc_top];
6166 mc->mc_pg[mc->mc_top] = mc->mc_pg[ptop];
6167 mc->mc_ki[mc->mc_top] = mc->mc_ki[ptop];
6172 /* Right page might now have changed parent.
6173 * Check if left page also changed parent.
6175 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
6176 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
6177 for (i=0; i<ptop; i++) {
6178 mc->mc_pg[i] = mn.mc_pg[i];
6179 mc->mc_ki[i] = mn.mc_ki[i];
6181 mc->mc_pg[ptop] = mn.mc_pg[ptop];
6182 mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;
6186 rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);
6189 mc->mc_flags ^= C_SPLITTING;
6190 if (rc != MDB_SUCCESS) {
6193 if (nflags & MDB_APPEND) {
6194 mc->mc_pg[mc->mc_top] = rp;
6195 mc->mc_ki[mc->mc_top] = 0;
6196 rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags);
6199 for (i=0; i<mc->mc_top; i++)
6200 mc->mc_ki[i] = mn.mc_ki[i];
6207 /* Move half of the keys to the right sibling. */
6209 /* grab a page to hold a temporary copy */
6210 copy = mdb_page_malloc(mc);
6214 copy->mp_pgno = mp->mp_pgno;
6215 copy->mp_flags = mp->mp_flags;
6216 copy->mp_lower = PAGEHDRSZ;
6217 copy->mp_upper = mc->mc_txn->mt_env->me_psize;
6218 mc->mc_pg[mc->mc_top] = copy;
6219 for (i = j = 0; i <= nkeys; j++) {
6220 if (i == split_indx) {
6221 /* Insert in right sibling. */
6222 /* Reset insert index for right sibling. */
6223 if (i != newindx || (newpos ^ ins_new)) {
6225 mc->mc_pg[mc->mc_top] = rp;
6229 if (i == newindx && !ins_new) {
6230 /* Insert the original entry that caused the split. */
6231 rkey.mv_data = newkey->mv_data;
6232 rkey.mv_size = newkey->mv_size;
6241 /* Update index for the new key. */
6242 mc->mc_ki[mc->mc_top] = j;
6243 } else if (i == nkeys) {
6246 node = NODEPTR(mp, i);
6247 rkey.mv_data = NODEKEY(node);
6248 rkey.mv_size = node->mn_ksize;
6250 xdata.mv_data = NODEDATA(node);
6251 xdata.mv_size = NODEDSZ(node);
6254 pgno = NODEPGNO(node);
6255 flags = node->mn_flags;
6260 if (!IS_LEAF(mp) && j == 0) {
6261 /* First branch index doesn't need key data. */
6265 rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags);
6269 nkeys = NUMKEYS(copy);
6270 for (i=0; i<nkeys; i++)
6271 mp->mp_ptrs[i] = copy->mp_ptrs[i];
6272 mp->mp_lower = copy->mp_lower;
6273 mp->mp_upper = copy->mp_upper;
6274 memcpy(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1),
6275 mc->mc_txn->mt_env->me_psize - copy->mp_upper);
6277 /* reset back to original page */
6278 if (newindx < split_indx || (!newpos && newindx == split_indx)) {
6279 mc->mc_pg[mc->mc_top] = mp;
6280 if (nflags & MDB_RESERVE) {
6281 node = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6282 if (!(node->mn_flags & F_BIGDATA))
6283 newdata->mv_data = NODEDATA(node);
6289 /* return tmp page to freelist */
6290 copy->mp_next = mc->mc_txn->mt_env->me_dpages;
6291 VGMEMP_FREE(mc->mc_txn->mt_env, copy);
6292 mc->mc_txn->mt_env->me_dpages = copy;
6295 /* Adjust other cursors pointing to mp */
6296 MDB_cursor *m2, *m3;
6297 MDB_dbi dbi = mc->mc_dbi;
6298 int fixup = NUMKEYS(mp);
6300 if (mc->mc_flags & C_SUB)
6303 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
6304 if (m2 == mc) continue;
6305 if (mc->mc_flags & C_SUB)
6306 m3 = &m2->mc_xcursor->mx_cursor;
6309 if (!(m3->mc_flags & C_INITIALIZED))
6311 if (m3->mc_flags & C_SPLITTING)
6316 for (k=m3->mc_top; k>=0; k--) {
6317 m3->mc_ki[k+1] = m3->mc_ki[k];
6318 m3->mc_pg[k+1] = m3->mc_pg[k];
6320 if (m3->mc_ki[0] >= split_indx) {
6325 m3->mc_pg[0] = mc->mc_pg[0];
6329 if (m3->mc_pg[mc->mc_top] == mp) {
6330 if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE))
6331 m3->mc_ki[mc->mc_top]++;
6332 if (m3->mc_ki[mc->mc_top] >= fixup) {
6333 m3->mc_pg[mc->mc_top] = rp;
6334 m3->mc_ki[mc->mc_top] -= fixup;
6335 m3->mc_ki[ptop] = mn.mc_ki[ptop];
6337 } else if (!did_split && m3->mc_pg[ptop] == mc->mc_pg[ptop] &&
6338 m3->mc_ki[ptop] >= mc->mc_ki[ptop]) {
6347 mdb_put(MDB_txn *txn, MDB_dbi dbi,
6348 MDB_val *key, MDB_val *data, unsigned int flags)
6353 assert(key != NULL);
6354 assert(data != NULL);
6356 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
6359 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
6363 if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
6367 if ((flags & (MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND)) != flags)
6370 mdb_cursor_init(&mc, txn, dbi, &mx);
6371 return mdb_cursor_put(&mc, key, data, flags);
6374 /** Only a subset of the @ref mdb_env flags can be changed
6375 * at runtime. Changing other flags requires closing the environment
6376 * and re-opening it with the new flags.
6378 #define CHANGEABLE (MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC)
6380 mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)
6382 if ((flag & CHANGEABLE) != flag)
6385 env->me_flags |= flag;
6387 env->me_flags &= ~flag;
6392 mdb_env_get_flags(MDB_env *env, unsigned int *arg)
6397 *arg = env->me_flags;
6402 mdb_env_get_path(MDB_env *env, const char **arg)
6407 *arg = env->me_path;
6411 /** Common code for #mdb_stat() and #mdb_env_stat().
6412 * @param[in] env the environment to operate in.
6413 * @param[in] db the #MDB_db record containing the stats to return.
6414 * @param[out] arg the address of an #MDB_stat structure to receive the stats.
6415 * @return 0, this function always succeeds.
6418 mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)
6420 arg->ms_psize = env->me_psize;
6421 arg->ms_depth = db->md_depth;
6422 arg->ms_branch_pages = db->md_branch_pages;
6423 arg->ms_leaf_pages = db->md_leaf_pages;
6424 arg->ms_overflow_pages = db->md_overflow_pages;
6425 arg->ms_entries = db->md_entries;
6430 mdb_env_stat(MDB_env *env, MDB_stat *arg)
6434 if (env == NULL || arg == NULL)
6437 toggle = mdb_env_pick_meta(env);
6439 return mdb_stat0(env, &env->me_metas[toggle]->mm_dbs[MAIN_DBI], arg);
6442 /** Set the default comparison functions for a database.
6443 * Called immediately after a database is opened to set the defaults.
6444 * The user can then override them with #mdb_set_compare() or
6445 * #mdb_set_dupsort().
6446 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
6447 * @param[in] dbi A database handle returned by #mdb_open()
6450 mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi)
6452 uint16_t f = txn->mt_dbs[dbi].md_flags;
6454 txn->mt_dbxs[dbi].md_cmp =
6455 (f & MDB_REVERSEKEY) ? mdb_cmp_memnr :
6456 (f & MDB_INTEGERKEY) ? mdb_cmp_cint : mdb_cmp_memn;
6458 txn->mt_dbxs[dbi].md_dcmp =
6459 !(f & MDB_DUPSORT) ? 0 :
6460 ((f & MDB_INTEGERDUP)
6461 ? ((f & MDB_DUPFIXED) ? mdb_cmp_int : mdb_cmp_cint)
6462 : ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn));
6465 int mdb_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
6470 int rc, dbflag, exact;
6471 unsigned int unused = 0;
6474 if (txn->mt_dbxs[FREE_DBI].md_cmp == NULL) {
6475 mdb_default_cmp(txn, FREE_DBI);
6481 if (flags & (MDB_DUPSORT|MDB_REVERSEKEY|MDB_INTEGERKEY))
6482 txn->mt_dbs[MAIN_DBI].md_flags |= (flags & (MDB_DUPSORT|MDB_REVERSEKEY|MDB_INTEGERKEY));
6483 mdb_default_cmp(txn, MAIN_DBI);
6487 if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {
6488 mdb_default_cmp(txn, MAIN_DBI);
6491 /* Is the DB already open? */
6493 for (i=2; i<txn->mt_numdbs; i++) {
6494 if (!txn->mt_dbxs[i].md_name.mv_size) {
6495 /* Remember this free slot */
6496 if (!unused) unused = i;
6499 if (len == txn->mt_dbxs[i].md_name.mv_size &&
6500 !strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) {
6506 /* If no free slot and max hit, fail */
6507 if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs - 1)
6508 return MDB_DBS_FULL;
6510 /* Find the DB info */
6514 key.mv_data = (void *)name;
6515 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
6516 rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact);
6517 if (rc == MDB_SUCCESS) {
6518 /* make sure this is actually a DB */
6519 MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]);
6520 if (!(node->mn_flags & F_SUBDATA))
6522 } else if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) {
6523 /* Create if requested */
6525 data.mv_size = sizeof(MDB_db);
6526 data.mv_data = &dummy;
6527 memset(&dummy, 0, sizeof(dummy));
6528 dummy.md_root = P_INVALID;
6529 dummy.md_flags = flags & 0xffff;
6530 rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA);
6534 /* OK, got info, add to table */
6535 if (rc == MDB_SUCCESS) {
6536 unsigned int slot = unused ? unused : txn->mt_numdbs;
6537 txn->mt_dbxs[slot].md_name.mv_data = strdup(name);
6538 txn->mt_dbxs[slot].md_name.mv_size = len;
6539 txn->mt_dbxs[slot].md_rel = NULL;
6540 txn->mt_dbflags[slot] = dbflag;
6541 memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db));
6543 txn->mt_env->me_dbflags[slot] = txn->mt_dbs[slot].md_flags;
6544 mdb_default_cmp(txn, slot);
6547 txn->mt_env->me_numdbs++;
6554 int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
6556 if (txn == NULL || arg == NULL || dbi >= txn->mt_numdbs)
6559 return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg);
6562 void mdb_close(MDB_env *env, MDB_dbi dbi)
6565 if (dbi <= MAIN_DBI || dbi >= env->me_numdbs)
6567 ptr = env->me_dbxs[dbi].md_name.mv_data;
6568 env->me_dbxs[dbi].md_name.mv_data = NULL;
6569 env->me_dbxs[dbi].md_name.mv_size = 0;
6573 /** Add all the DB's pages to the free list.
6574 * @param[in] mc Cursor on the DB to free.
6575 * @param[in] subs non-Zero to check for sub-DBs in this DB.
6576 * @return 0 on success, non-zero on failure.
6579 mdb_drop0(MDB_cursor *mc, int subs)
6583 rc = mdb_page_search(mc, NULL, 0);
6584 if (rc == MDB_SUCCESS) {
6589 /* LEAF2 pages have no nodes, cannot have sub-DBs */
6590 if (!subs || IS_LEAF2(mc->mc_pg[mc->mc_top]))
6593 mdb_cursor_copy(mc, &mx);
6594 while (mc->mc_snum > 0) {
6595 if (IS_LEAF(mc->mc_pg[mc->mc_top])) {
6596 for (i=0; i<NUMKEYS(mc->mc_pg[mc->mc_top]); i++) {
6597 ni = NODEPTR(mc->mc_pg[mc->mc_top], i);
6598 if (ni->mn_flags & F_SUBDATA) {
6599 mdb_xcursor_init1(mc, ni);
6600 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
6606 for (i=0; i<NUMKEYS(mc->mc_pg[mc->mc_top]); i++) {
6608 ni = NODEPTR(mc->mc_pg[mc->mc_top], i);
6611 mdb_midl_append(&mc->mc_txn->mt_free_pgs, pg);
6616 rc = mdb_cursor_sibling(mc, 1);
6618 /* no more siblings, go back to beginning
6619 * of previous level. (stack was already popped
6620 * by mdb_cursor_sibling)
6622 for (i=1; i<mc->mc_top; i++)
6623 mc->mc_pg[i] = mx.mc_pg[i];
6627 mdb_midl_append(&mc->mc_txn->mt_free_pgs,
6628 mc->mc_db->md_root);
6633 int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)
6638 if (!txn || !dbi || dbi >= txn->mt_numdbs)
6641 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
6644 rc = mdb_cursor_open(txn, dbi, &mc);
6648 rc = mdb_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT);
6652 /* Can't delete the main DB */
6653 if (del && dbi > MAIN_DBI) {
6654 rc = mdb_del(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL);
6656 mdb_close(txn->mt_env, dbi);
6658 txn->mt_dbflags[dbi] |= DB_DIRTY;
6659 txn->mt_dbs[dbi].md_depth = 0;
6660 txn->mt_dbs[dbi].md_branch_pages = 0;
6661 txn->mt_dbs[dbi].md_leaf_pages = 0;
6662 txn->mt_dbs[dbi].md_overflow_pages = 0;
6663 txn->mt_dbs[dbi].md_entries = 0;
6664 txn->mt_dbs[dbi].md_root = P_INVALID;
6667 mdb_cursor_close(mc);
6671 int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
6673 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
6676 txn->mt_dbxs[dbi].md_cmp = cmp;
6680 int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
6682 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
6685 txn->mt_dbxs[dbi].md_dcmp = cmp;
6689 int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
6691 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
6694 txn->mt_dbxs[dbi].md_rel = rel;
6698 int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx)
6700 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
6703 txn->mt_dbxs[dbi].md_relctx = ctx;
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