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.
36 #include <sys/types.h>
38 #include <sys/param.h>
44 #ifdef HAVE_SYS_FILE_H
61 #if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER))
62 #include <resolv.h> /* defines BYTE_ORDER on HPUX and Solaris */
65 #if defined(__APPLE__) || defined (BSD)
66 # define MDB_USE_POSIX_SEM 1
67 # define MDB_FDATASYNC fsync
68 #elif defined(ANDROID)
69 # define MDB_FDATASYNC fsync
74 #ifdef MDB_USE_POSIX_SEM
75 #include <semaphore.h>
80 #include <valgrind/memcheck.h>
81 #define VGMEMP_CREATE(h,r,z) VALGRIND_CREATE_MEMPOOL(h,r,z)
82 #define VGMEMP_ALLOC(h,a,s) VALGRIND_MEMPOOL_ALLOC(h,a,s)
83 #define VGMEMP_FREE(h,a) VALGRIND_MEMPOOL_FREE(h,a)
84 #define VGMEMP_DESTROY(h) VALGRIND_DESTROY_MEMPOOL(h)
85 #define VGMEMP_DEFINED(a,s) VALGRIND_MAKE_MEM_DEFINED(a,s)
87 #define VGMEMP_CREATE(h,r,z)
88 #define VGMEMP_ALLOC(h,a,s)
89 #define VGMEMP_FREE(h,a)
90 #define VGMEMP_DESTROY(h)
91 #define VGMEMP_DEFINED(a,s)
95 # if (defined(_LITTLE_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN))
96 /* Solaris just defines one or the other */
97 # define LITTLE_ENDIAN 1234
98 # define BIG_ENDIAN 4321
99 # ifdef _LITTLE_ENDIAN
100 # define BYTE_ORDER LITTLE_ENDIAN
102 # define BYTE_ORDER BIG_ENDIAN
105 # define BYTE_ORDER __BYTE_ORDER
109 #ifndef LITTLE_ENDIAN
110 #define LITTLE_ENDIAN __LITTLE_ENDIAN
113 #define BIG_ENDIAN __BIG_ENDIAN
116 #if defined(__i386) || defined(__x86_64)
117 #define MISALIGNED_OK 1
123 #if (BYTE_ORDER == LITTLE_ENDIAN) == (BYTE_ORDER == BIG_ENDIAN)
124 # error "Unknown or unsupported endianness (BYTE_ORDER)"
125 #elif (-6 & 5) || CHAR_BIT != 8 || UINT_MAX < 0xffffffff || ULONG_MAX % 0xFFFF
126 # error "Two's complement, reasonably sized integer types, please"
129 /** @defgroup internal MDB Internals
132 /** @defgroup compat Windows Compatibility Macros
133 * A bunch of macros to minimize the amount of platform-specific ifdefs
134 * needed throughout the rest of the code. When the features this library
135 * needs are similar enough to POSIX to be hidden in a one-or-two line
136 * replacement, this macro approach is used.
140 #define pthread_t DWORD
141 #define pthread_mutex_t HANDLE
142 #define pthread_key_t DWORD
143 #define pthread_self() GetCurrentThreadId()
144 #define pthread_key_create(x,y) \
145 ((*(x) = TlsAlloc()) == TLS_OUT_OF_INDEXES ? ErrCode() : 0)
146 #define pthread_key_delete(x) TlsFree(x)
147 #define pthread_getspecific(x) TlsGetValue(x)
148 #define pthread_setspecific(x,y) (TlsSetValue(x,y) ? 0 : ErrCode())
149 #define pthread_mutex_unlock(x) ReleaseMutex(x)
150 #define pthread_mutex_lock(x) WaitForSingleObject(x, INFINITE)
151 #define LOCK_MUTEX_R(env) pthread_mutex_lock((env)->me_rmutex)
152 #define UNLOCK_MUTEX_R(env) pthread_mutex_unlock((env)->me_rmutex)
153 #define LOCK_MUTEX_W(env) pthread_mutex_lock((env)->me_wmutex)
154 #define UNLOCK_MUTEX_W(env) pthread_mutex_unlock((env)->me_wmutex)
155 #define getpid() GetCurrentProcessId()
156 #define MDB_FDATASYNC(fd) (!FlushFileBuffers(fd))
157 #define MDB_MSYNC(addr,len,flags) (!FlushViewOfFile(addr,len))
158 #define ErrCode() GetLastError()
159 #define GET_PAGESIZE(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;}
160 #define close(fd) CloseHandle(fd)
161 #define munmap(ptr,len) UnmapViewOfFile(ptr)
164 #ifdef MDB_USE_POSIX_SEM
166 #define LOCK_MUTEX_R(env) mdb_sem_wait((env)->me_rmutex)
167 #define UNLOCK_MUTEX_R(env) sem_post((env)->me_rmutex)
168 #define LOCK_MUTEX_W(env) mdb_sem_wait((env)->me_wmutex)
169 #define UNLOCK_MUTEX_W(env) sem_post((env)->me_wmutex)
172 mdb_sem_wait(sem_t *sem)
175 while ((rc = sem_wait(sem)) && (rc = errno) == EINTR) ;
180 /** Lock the reader mutex.
182 #define LOCK_MUTEX_R(env) pthread_mutex_lock(&(env)->me_txns->mti_mutex)
183 /** Unlock the reader mutex.
185 #define UNLOCK_MUTEX_R(env) pthread_mutex_unlock(&(env)->me_txns->mti_mutex)
187 /** Lock the writer mutex.
188 * Only a single write transaction is allowed at a time. Other writers
189 * will block waiting for this mutex.
191 #define LOCK_MUTEX_W(env) pthread_mutex_lock(&(env)->me_txns->mti_wmutex)
192 /** Unlock the writer mutex.
194 #define UNLOCK_MUTEX_W(env) pthread_mutex_unlock(&(env)->me_txns->mti_wmutex)
195 #endif /* MDB_USE_POSIX_SEM */
197 /** Get the error code for the last failed system function.
199 #define ErrCode() errno
201 /** An abstraction for a file handle.
202 * On POSIX systems file handles are small integers. On Windows
203 * they're opaque pointers.
207 /** A value for an invalid file handle.
208 * Mainly used to initialize file variables and signify that they are
211 #define INVALID_HANDLE_VALUE (-1)
213 /** Get the size of a memory page for the system.
214 * This is the basic size that the platform's memory manager uses, and is
215 * fundamental to the use of memory-mapped files.
217 #define GET_PAGESIZE(x) ((x) = sysconf(_SC_PAGE_SIZE))
220 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
223 #define MNAME_LEN (sizeof(pthread_mutex_t))
229 /** A flag for opening a file and requesting synchronous data writes.
230 * This is only used when writing a meta page. It's not strictly needed;
231 * we could just do a normal write and then immediately perform a flush.
232 * But if this flag is available it saves us an extra system call.
234 * @note If O_DSYNC is undefined but exists in /usr/include,
235 * preferably set some compiler flag to get the definition.
236 * Otherwise compile with the less efficient -DMDB_DSYNC=O_SYNC.
239 # define MDB_DSYNC O_DSYNC
243 /** Function for flushing the data of a file. Define this to fsync
244 * if fdatasync() is not supported.
246 #ifndef MDB_FDATASYNC
247 # define MDB_FDATASYNC fdatasync
251 # define MDB_MSYNC(addr,len,flags) msync(addr,len,flags)
262 /** A page number in the database.
263 * Note that 64 bit page numbers are overkill, since pages themselves
264 * already represent 12-13 bits of addressable memory, and the OS will
265 * always limit applications to a maximum of 63 bits of address space.
267 * @note In the #MDB_node structure, we only store 48 bits of this value,
268 * which thus limits us to only 60 bits of addressable data.
270 typedef MDB_ID pgno_t;
272 /** A transaction ID.
273 * See struct MDB_txn.mt_txnid for details.
275 typedef MDB_ID txnid_t;
277 /** @defgroup debug Debug Macros
281 /** Enable debug output.
282 * Set this to 1 for copious tracing. Set to 2 to add dumps of all IDLs
283 * read from and written to the database (used for free space management).
288 #if !(__STDC_VERSION__ >= 199901L || defined(__GNUC__))
289 # define DPRINTF (void) /* Vararg macros may be unsupported */
291 static int mdb_debug;
292 static txnid_t mdb_debug_start;
294 /** Print a debug message with printf formatting. */
295 # define DPRINTF(fmt, ...) /**< Requires 2 or more args */ \
296 ((void) ((mdb_debug) && \
297 fprintf(stderr, "%s:%d " fmt "\n", __func__, __LINE__, __VA_ARGS__)))
299 # define DPRINTF(fmt, ...) ((void) 0)
301 /** Print a debug string.
302 * The string is printed literally, with no format processing.
304 #define DPUTS(arg) DPRINTF("%s", arg)
307 /** A default memory page size.
308 * The actual size is platform-dependent, but we use this for
309 * boot-strapping. We probably should not be using this any more.
310 * The #GET_PAGESIZE() macro is used to get the actual size.
312 * Note that we don't currently support Huge pages. On Linux,
313 * regular data files cannot use Huge pages, and in general
314 * Huge pages aren't actually pageable. We rely on the OS
315 * demand-pager to read our data and page it out when memory
316 * pressure from other processes is high. So until OSs have
317 * actual paging support for Huge pages, they're not viable.
319 #define MDB_PAGESIZE 4096
321 /** The minimum number of keys required in a database page.
322 * Setting this to a larger value will place a smaller bound on the
323 * maximum size of a data item. Data items larger than this size will
324 * be pushed into overflow pages instead of being stored directly in
325 * the B-tree node. This value used to default to 4. With a page size
326 * of 4096 bytes that meant that any item larger than 1024 bytes would
327 * go into an overflow page. That also meant that on average 2-3KB of
328 * each overflow page was wasted space. The value cannot be lower than
329 * 2 because then there would no longer be a tree structure. With this
330 * value, items larger than 2KB will go into overflow pages, and on
331 * average only 1KB will be wasted.
333 #define MDB_MINKEYS 2
335 /** A stamp that identifies a file as an MDB file.
336 * There's nothing special about this value other than that it is easily
337 * recognizable, and it will reflect any byte order mismatches.
339 #define MDB_MAGIC 0xBEEFC0DE
341 /** The version number for a database's file format. */
342 #define MDB_VERSION 1
344 /** The maximum size of a key in the database.
345 * While data items have essentially unbounded size, we require that
346 * keys all fit onto a regular page. This limit could be raised a bit
347 * further if needed; to something just under #MDB_PAGESIZE / #MDB_MINKEYS.
349 #define MAXKEYSIZE 511
354 * This is used for printing a hex dump of a key's contents.
356 #define DKBUF char kbuf[(MAXKEYSIZE*2+1)]
357 /** Display a key in hex.
359 * Invoke a function to display a key in hex.
361 #define DKEY(x) mdb_dkey(x, kbuf)
363 #define DKBUF typedef int dummy_kbuf /* so we can put ';' after */
367 /** An invalid page number.
368 * Mainly used to denote an empty tree.
370 #define P_INVALID (~(pgno_t)0)
372 /** Test if a flag \b f is set in a flag word \b w. */
373 #define F_ISSET(w, f) (((w) & (f)) == (f))
375 /** Used for offsets within a single page.
376 * Since memory pages are typically 4 or 8KB in size, 12-13 bits,
379 typedef uint16_t indx_t;
381 /** Default size of memory map.
382 * This is certainly too small for any actual applications. Apps should always set
383 * the size explicitly using #mdb_env_set_mapsize().
385 #define DEFAULT_MAPSIZE 1048576
387 /** @defgroup readers Reader Lock Table
388 * Readers don't acquire any locks for their data access. Instead, they
389 * simply record their transaction ID in the reader table. The reader
390 * mutex is needed just to find an empty slot in the reader table. The
391 * slot's address is saved in thread-specific data so that subsequent read
392 * transactions started by the same thread need no further locking to proceed.
394 * Since the database uses multi-version concurrency control, readers don't
395 * actually need any locking. This table is used to keep track of which
396 * readers are using data from which old transactions, so that we'll know
397 * when a particular old transaction is no longer in use. Old transactions
398 * that have discarded any data pages can then have those pages reclaimed
399 * for use by a later write transaction.
401 * The lock table is constructed such that reader slots are aligned with the
402 * processor's cache line size. Any slot is only ever used by one thread.
403 * This alignment guarantees that there will be no contention or cache
404 * thrashing as threads update their own slot info, and also eliminates
405 * any need for locking when accessing a slot.
407 * A writer thread will scan every slot in the table to determine the oldest
408 * outstanding reader transaction. Any freed pages older than this will be
409 * reclaimed by the writer. The writer doesn't use any locks when scanning
410 * this table. This means that there's no guarantee that the writer will
411 * see the most up-to-date reader info, but that's not required for correct
412 * operation - all we need is to know the upper bound on the oldest reader,
413 * we don't care at all about the newest reader. So the only consequence of
414 * reading stale information here is that old pages might hang around a
415 * while longer before being reclaimed. That's actually good anyway, because
416 * the longer we delay reclaiming old pages, the more likely it is that a
417 * string of contiguous pages can be found after coalescing old pages from
418 * many old transactions together.
420 * @todo We don't actually do such coalescing yet, we grab pages from one
421 * old transaction at a time.
424 /** Number of slots in the reader table.
425 * This value was chosen somewhat arbitrarily. 126 readers plus a
426 * couple mutexes fit exactly into 8KB on my development machine.
427 * Applications should set the table size using #mdb_env_set_maxreaders().
429 #define DEFAULT_READERS 126
431 /** The size of a CPU cache line in bytes. We want our lock structures
432 * aligned to this size to avoid false cache line sharing in the
434 * This value works for most CPUs. For Itanium this should be 128.
440 /** The information we store in a single slot of the reader table.
441 * In addition to a transaction ID, we also record the process and
442 * thread ID that owns a slot, so that we can detect stale information,
443 * e.g. threads or processes that went away without cleaning up.
444 * @note We currently don't check for stale records. We simply re-init
445 * the table when we know that we're the only process opening the
448 typedef struct MDB_rxbody {
449 /** Current Transaction ID when this transaction began, or (txnid_t)-1.
450 * Multiple readers that start at the same time will probably have the
451 * same ID here. Again, it's not important to exclude them from
452 * anything; all we need to know is which version of the DB they
453 * started from so we can avoid overwriting any data used in that
454 * particular version.
457 /** The process ID of the process owning this reader txn. */
459 /** The thread ID of the thread owning this txn. */
463 /** The actual reader record, with cacheline padding. */
464 typedef struct MDB_reader {
467 /** shorthand for mrb_txnid */
468 #define mr_txnid mru.mrx.mrb_txnid
469 #define mr_pid mru.mrx.mrb_pid
470 #define mr_tid mru.mrx.mrb_tid
471 /** cache line alignment */
472 char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)];
476 /** The header for the reader table.
477 * The table resides in a memory-mapped file. (This is a different file
478 * than is used for the main database.)
480 * For POSIX the actual mutexes reside in the shared memory of this
481 * mapped file. On Windows, mutexes are named objects allocated by the
482 * kernel; we store the mutex names in this mapped file so that other
483 * processes can grab them. This same approach is also used on
484 * MacOSX/Darwin (using named semaphores) since MacOSX doesn't support
485 * process-shared POSIX mutexes. For these cases where a named object
486 * is used, the object name is derived from a 64 bit FNV hash of the
487 * environment pathname. As such, naming collisions are extremely
488 * unlikely. If a collision occurs, the results are unpredictable.
490 typedef struct MDB_txbody {
491 /** Stamp identifying this as an MDB file. It must be set
494 /** Version number of this lock file. Must be set to #MDB_VERSION. */
495 uint32_t mtb_version;
496 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
497 char mtb_rmname[MNAME_LEN];
499 /** Mutex protecting access to this table.
500 * This is the reader lock that #LOCK_MUTEX_R acquires.
502 pthread_mutex_t mtb_mutex;
504 /** The ID of the last transaction committed to the database.
505 * This is recorded here only for convenience; the value can always
506 * be determined by reading the main database meta pages.
509 /** The number of slots that have been used in the reader table.
510 * This always records the maximum count, it is not decremented
511 * when readers release their slots.
513 unsigned mtb_numreaders;
516 /** The actual reader table definition. */
517 typedef struct MDB_txninfo {
520 #define mti_magic mt1.mtb.mtb_magic
521 #define mti_version mt1.mtb.mtb_version
522 #define mti_mutex mt1.mtb.mtb_mutex
523 #define mti_rmname mt1.mtb.mtb_rmname
524 #define mti_txnid mt1.mtb.mtb_txnid
525 #define mti_numreaders mt1.mtb.mtb_numreaders
526 char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];
529 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
530 char mt2_wmname[MNAME_LEN];
531 #define mti_wmname mt2.mt2_wmname
533 pthread_mutex_t mt2_wmutex;
534 #define mti_wmutex mt2.mt2_wmutex
536 char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)];
538 MDB_reader mti_readers[1];
542 /** Common header for all page types.
543 * Overflow records occupy a number of contiguous pages with no
544 * headers on any page after the first.
546 typedef struct MDB_page {
547 #define mp_pgno mp_p.p_pgno
548 #define mp_next mp_p.p_next
550 pgno_t p_pgno; /**< page number */
551 void * p_next; /**< for in-memory list of freed structs */
554 /** @defgroup mdb_page Page Flags
556 * Flags for the page headers.
559 #define P_BRANCH 0x01 /**< branch page */
560 #define P_LEAF 0x02 /**< leaf page */
561 #define P_OVERFLOW 0x04 /**< overflow page */
562 #define P_META 0x08 /**< meta page */
563 #define P_DIRTY 0x10 /**< dirty page */
564 #define P_LEAF2 0x20 /**< for #MDB_DUPFIXED records */
565 #define P_SUBP 0x40 /**< for #MDB_DUPSORT sub-pages */
567 uint16_t mp_flags; /**< @ref mdb_page */
568 #define mp_lower mp_pb.pb.pb_lower
569 #define mp_upper mp_pb.pb.pb_upper
570 #define mp_pages mp_pb.pb_pages
573 indx_t pb_lower; /**< lower bound of free space */
574 indx_t pb_upper; /**< upper bound of free space */
576 uint32_t pb_pages; /**< number of overflow pages */
578 indx_t mp_ptrs[1]; /**< dynamic size */
581 /** Size of the page header, excluding dynamic data at the end */
582 #define PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs))
584 /** Address of first usable data byte in a page, after the header */
585 #define METADATA(p) ((void *)((char *)(p) + PAGEHDRSZ))
587 /** Number of nodes on a page */
588 #define NUMKEYS(p) (((p)->mp_lower - PAGEHDRSZ) >> 1)
590 /** The amount of space remaining in the page */
591 #define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower)
593 /** The percentage of space used in the page, in tenths of a percent. */
594 #define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \
595 ((env)->me_psize - PAGEHDRSZ))
596 /** The minimum page fill factor, in tenths of a percent.
597 * Pages emptier than this are candidates for merging.
599 #define FILL_THRESHOLD 250
601 /** Test if a page is a leaf page */
602 #define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF)
603 /** Test if a page is a LEAF2 page */
604 #define IS_LEAF2(p) F_ISSET((p)->mp_flags, P_LEAF2)
605 /** Test if a page is a branch page */
606 #define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH)
607 /** Test if a page is an overflow page */
608 #define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW)
609 /** Test if a page is a sub page */
610 #define IS_SUBP(p) F_ISSET((p)->mp_flags, P_SUBP)
612 /** The number of overflow pages needed to store the given size. */
613 #define OVPAGES(size, psize) ((PAGEHDRSZ-1 + (size)) / (psize) + 1)
615 /** Header for a single key/data pair within a page.
616 * We guarantee 2-byte alignment for nodes.
618 typedef struct MDB_node {
619 /** lo and hi are used for data size on leaf nodes and for
620 * child pgno on branch nodes. On 64 bit platforms, flags
621 * is also used for pgno. (Branch nodes have no flags).
622 * They are in host byte order in case that lets some
623 * accesses be optimized into a 32-bit word access.
625 #define mn_lo mn_offset[BYTE_ORDER!=LITTLE_ENDIAN]
626 #define mn_hi mn_offset[BYTE_ORDER==LITTLE_ENDIAN] /**< part of dsize or pgno */
627 unsigned short mn_offset[2]; /**< storage for #mn_lo and #mn_hi */
628 /** @defgroup mdb_node Node Flags
630 * Flags for node headers.
633 #define F_BIGDATA 0x01 /**< data put on overflow page */
634 #define F_SUBDATA 0x02 /**< data is a sub-database */
635 #define F_DUPDATA 0x04 /**< data has duplicates */
637 /** valid flags for #mdb_node_add() */
638 #define NODE_ADD_FLAGS (F_DUPDATA|F_SUBDATA|MDB_RESERVE|MDB_APPEND)
641 unsigned short mn_flags; /**< @ref mdb_node */
642 unsigned short mn_ksize; /**< key size */
643 char mn_data[1]; /**< key and data are appended here */
646 /** Size of the node header, excluding dynamic data at the end */
647 #define NODESIZE offsetof(MDB_node, mn_data)
649 /** Bit position of top word in page number, for shifting mn_flags */
650 #define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0)
652 /** Size of a node in a branch page with a given key.
653 * This is just the node header plus the key, there is no data.
655 #define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))
657 /** Size of a node in a leaf page with a given key and data.
658 * This is node header plus key plus data size.
660 #define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size)
662 /** Address of node \b i in page \b p */
663 #define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i]))
665 /** Address of the key for the node */
666 #define NODEKEY(node) (void *)((node)->mn_data)
668 /** Address of the data for a node */
669 #define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize)
671 /** Get the page number pointed to by a branch node */
672 #define NODEPGNO(node) \
673 ((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | \
674 (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0))
675 /** Set the page number in a branch node */
676 #define SETPGNO(node,pgno) do { \
677 (node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \
678 if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0)
680 /** Get the size of the data in a leaf node */
681 #define NODEDSZ(node) ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16))
682 /** Set the size of the data for a leaf node */
683 #define SETDSZ(node,size) do { \
684 (node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)
685 /** The size of a key in a node */
686 #define NODEKSZ(node) ((node)->mn_ksize)
688 /** Copy a page number from src to dst */
690 #define COPY_PGNO(dst,src) dst = src
692 #if SIZE_MAX > 4294967295UL
693 #define COPY_PGNO(dst,src) do { \
694 unsigned short *s, *d; \
695 s = (unsigned short *)&(src); \
696 d = (unsigned short *)&(dst); \
703 #define COPY_PGNO(dst,src) do { \
704 unsigned short *s, *d; \
705 s = (unsigned short *)&(src); \
706 d = (unsigned short *)&(dst); \
712 /** The address of a key in a LEAF2 page.
713 * LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate sub-DBs.
714 * There are no node headers, keys are stored contiguously.
716 #define LEAF2KEY(p, i, ks) ((char *)(p) + PAGEHDRSZ + ((i)*(ks)))
718 /** Set the \b node's key into \b key, if requested. */
719 #define MDB_GET_KEY(node, key) { if ((key) != NULL) { \
720 (key)->mv_size = NODEKSZ(node); (key)->mv_data = NODEKEY(node); } }
722 /** Information about a single database in the environment. */
723 typedef struct MDB_db {
724 uint32_t md_pad; /**< also ksize for LEAF2 pages */
725 uint16_t md_flags; /**< @ref mdb_open */
726 uint16_t md_depth; /**< depth of this tree */
727 pgno_t md_branch_pages; /**< number of internal pages */
728 pgno_t md_leaf_pages; /**< number of leaf pages */
729 pgno_t md_overflow_pages; /**< number of overflow pages */
730 size_t md_entries; /**< number of data items */
731 pgno_t md_root; /**< the root page of this tree */
734 /** Handle for the DB used to track free pages. */
736 /** Handle for the default DB. */
739 /** Meta page content. */
740 typedef struct MDB_meta {
741 /** Stamp identifying this as an MDB file. It must be set
744 /** Version number of this lock file. Must be set to #MDB_VERSION. */
746 void *mm_address; /**< address for fixed mapping */
747 size_t mm_mapsize; /**< size of mmap region */
748 MDB_db mm_dbs[2]; /**< first is free space, 2nd is main db */
749 /** The size of pages used in this DB */
750 #define mm_psize mm_dbs[0].md_pad
751 /** Any persistent environment flags. @ref mdb_env */
752 #define mm_flags mm_dbs[0].md_flags
753 pgno_t mm_last_pg; /**< last used page in file */
754 txnid_t mm_txnid; /**< txnid that committed this page */
757 /** Buffer for a stack-allocated dirty page.
758 * The members define size and alignment, and silence type
759 * aliasing warnings. They are not used directly; that could
760 * mean incorrectly using several union members in parallel.
762 typedef union MDB_pagebuf {
763 char mb_raw[MDB_PAGESIZE];
766 char mm_pad[PAGEHDRSZ];
771 /** Auxiliary DB info.
772 * The information here is mostly static/read-only. There is
773 * only a single copy of this record in the environment.
775 typedef struct MDB_dbx {
776 MDB_val md_name; /**< name of the database */
777 MDB_cmp_func *md_cmp; /**< function for comparing keys */
778 MDB_cmp_func *md_dcmp; /**< function for comparing data items */
779 MDB_rel_func *md_rel; /**< user relocate function */
780 void *md_relctx; /**< user-provided context for md_rel */
783 /** A database transaction.
784 * Every operation requires a transaction handle.
787 MDB_txn *mt_parent; /**< parent of a nested txn */
788 MDB_txn *mt_child; /**< nested txn under this txn */
789 pgno_t mt_next_pgno; /**< next unallocated page */
790 /** The ID of this transaction. IDs are integers incrementing from 1.
791 * Only committed write transactions increment the ID. If a transaction
792 * aborts, the ID may be re-used by the next writer.
795 MDB_env *mt_env; /**< the DB environment */
796 /** The list of pages that became unused during this transaction.
800 MDB_ID2L dirty_list; /**< modified pages */
801 MDB_reader *reader; /**< this thread's slot in the reader table */
803 /** Array of records for each DB known in the environment. */
805 /** Array of MDB_db records for each known DB */
807 /** @defgroup mt_dbflag Transaction DB Flags
811 #define DB_DIRTY 0x01 /**< DB was written in this txn */
812 #define DB_STALE 0x02 /**< DB record is older than txnID */
814 /** Array of cursors for each DB */
815 MDB_cursor **mt_cursors;
816 /** Array of flags for each DB */
817 unsigned char *mt_dbflags;
818 /** Number of DB records in use. This number only ever increments;
819 * we don't decrement it when individual DB handles are closed.
823 /** @defgroup mdb_txn Transaction Flags
827 #define MDB_TXN_RDONLY 0x01 /**< read-only transaction */
828 #define MDB_TXN_ERROR 0x02 /**< an error has occurred */
830 unsigned int mt_flags; /**< @ref mdb_txn */
831 /** Tracks which of the two meta pages was used at the start
832 * of this transaction.
834 unsigned int mt_toggle;
837 /** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty.
838 * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to
839 * raise this on a 64 bit machine.
841 #define CURSOR_STACK 32
845 /** Cursors are used for all DB operations */
847 /** Next cursor on this DB in this txn */
849 /** Original cursor if this is a shadow */
851 /** Context used for databases with #MDB_DUPSORT, otherwise NULL */
852 struct MDB_xcursor *mc_xcursor;
853 /** The transaction that owns this cursor */
855 /** The database handle this cursor operates on */
857 /** The database record for this cursor */
859 /** The database auxiliary record for this cursor */
861 /** The @ref mt_dbflag for this database */
862 unsigned char *mc_dbflag;
863 unsigned short mc_snum; /**< number of pushed pages */
864 unsigned short mc_top; /**< index of top page, normally mc_snum-1 */
865 /** @defgroup mdb_cursor Cursor Flags
867 * Cursor state flags.
870 #define C_INITIALIZED 0x01 /**< cursor has been initialized and is valid */
871 #define C_EOF 0x02 /**< No more data */
872 #define C_SUB 0x04 /**< Cursor is a sub-cursor */
873 #define C_SHADOW 0x08 /**< Cursor is a dup from a parent txn */
874 #define C_ALLOCD 0x10 /**< Cursor was malloc'd */
875 #define C_SPLITTING 0x20 /**< Cursor is in page_split */
877 unsigned int mc_flags; /**< @ref mdb_cursor */
878 MDB_page *mc_pg[CURSOR_STACK]; /**< stack of pushed pages */
879 indx_t mc_ki[CURSOR_STACK]; /**< stack of page indices */
882 /** Context for sorted-dup records.
883 * We could have gone to a fully recursive design, with arbitrarily
884 * deep nesting of sub-databases. But for now we only handle these
885 * levels - main DB, optional sub-DB, sorted-duplicate DB.
887 typedef struct MDB_xcursor {
888 /** A sub-cursor for traversing the Dup DB */
889 MDB_cursor mx_cursor;
890 /** The database record for this Dup DB */
892 /** The auxiliary DB record for this Dup DB */
894 /** The @ref mt_dbflag for this Dup DB */
895 unsigned char mx_dbflag;
898 /** A set of pages freed by an earlier transaction. */
899 typedef struct MDB_oldpages {
900 /** Usually we only read one record from the FREEDB at a time, but
901 * in case we read more, this will chain them together.
903 struct MDB_oldpages *mo_next;
904 /** The ID of the transaction in which these pages were freed. */
906 /** An #MDB_IDL of the pages */
907 pgno_t mo_pages[1]; /* dynamic */
910 /** The database environment. */
912 HANDLE me_fd; /**< The main data file */
913 HANDLE me_lfd; /**< The lock file */
914 HANDLE me_mfd; /**< just for writing the meta pages */
915 /** Failed to update the meta page. Probably an I/O error. */
916 #define MDB_FATAL_ERROR 0x80000000U
917 /** Read-only Filesystem. Allow read access, no locking. */
918 #define MDB_ROFS 0x40000000U
919 /** Some fields are initialized. */
920 #define MDB_ENV_ACTIVE 0x20000000U
921 uint32_t me_flags; /**< @ref mdb_env */
922 unsigned int me_psize; /**< size of a page, from #GET_PAGESIZE */
923 unsigned int me_maxreaders; /**< size of the reader table */
924 unsigned int me_numreaders; /**< max numreaders set by this env */
925 MDB_dbi me_numdbs; /**< number of DBs opened */
926 MDB_dbi me_maxdbs; /**< size of the DB table */
927 pid_t me_pid; /**< process ID of this env */
928 char *me_path; /**< path to the DB files */
929 char *me_map; /**< the memory map of the data file */
930 MDB_txninfo *me_txns; /**< the memory map of the lock file */
931 MDB_meta *me_metas[2]; /**< pointers to the two meta pages */
932 MDB_txn *me_txn; /**< current write transaction */
933 size_t me_mapsize; /**< size of the data memory map */
934 off_t me_size; /**< current file size */
935 pgno_t me_maxpg; /**< me_mapsize / me_psize */
936 txnid_t me_pgfirst; /**< ID of first old page record we used */
937 txnid_t me_pglast; /**< ID of last old page record we used */
938 MDB_dbx *me_dbxs; /**< array of static DB info */
939 uint16_t *me_dbflags; /**< array of DB flags */
940 MDB_oldpages *me_pghead; /**< list of old page records */
941 MDB_oldpages *me_pgfree; /**< list of page records to free */
942 pthread_key_t me_txkey; /**< thread-key for readers */
943 MDB_page *me_dpages; /**< list of malloc'd blocks for re-use */
944 /** IDL of pages that became unused in a write txn */
946 /** ID2L of pages that were written during a write txn */
947 MDB_ID2 me_dirty_list[MDB_IDL_UM_SIZE];
949 HANDLE me_rmutex; /* Windows mutexes don't reside in shared mem */
951 #elif defined(MDB_USE_POSIX_SEM)
952 sem_t *me_rmutex; /* Shared mutexes are not supported */
956 /** max number of pages to commit in one writev() call */
957 #define MDB_COMMIT_PAGES 64
958 #if defined(IOV_MAX) && IOV_MAX < MDB_COMMIT_PAGES
959 #undef MDB_COMMIT_PAGES
960 #define MDB_COMMIT_PAGES IOV_MAX
963 static int mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp);
964 static int mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp);
965 static int mdb_page_touch(MDB_cursor *mc);
967 static int mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **mp);
968 static int mdb_page_search_root(MDB_cursor *mc,
969 MDB_val *key, int modify);
970 #define MDB_PS_MODIFY 1
971 #define MDB_PS_ROOTONLY 2
972 static int mdb_page_search(MDB_cursor *mc,
973 MDB_val *key, int flags);
974 static int mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst);
976 #define MDB_SPLIT_REPLACE MDB_APPENDDUP /**< newkey is not new */
977 static int mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,
978 pgno_t newpgno, unsigned int nflags);
980 static int mdb_env_read_header(MDB_env *env, MDB_meta *meta);
981 static int mdb_env_pick_meta(const MDB_env *env);
982 static int mdb_env_write_meta(MDB_txn *txn);
983 static void mdb_env_close0(MDB_env *env, int excl);
985 static MDB_node *mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp);
986 static int mdb_node_add(MDB_cursor *mc, indx_t indx,
987 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags);
988 static void mdb_node_del(MDB_page *mp, indx_t indx, int ksize);
989 static void mdb_node_shrink(MDB_page *mp, indx_t indx);
990 static int mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst);
991 static int mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data);
992 static size_t mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data);
993 static size_t mdb_branch_size(MDB_env *env, MDB_val *key);
995 static int mdb_rebalance(MDB_cursor *mc);
996 static int mdb_update_key(MDB_page *mp, indx_t indx, MDB_val *key);
998 static void mdb_cursor_pop(MDB_cursor *mc);
999 static int mdb_cursor_push(MDB_cursor *mc, MDB_page *mp);
1001 static int mdb_cursor_del0(MDB_cursor *mc, MDB_node *leaf);
1002 static int mdb_cursor_sibling(MDB_cursor *mc, int move_right);
1003 static int mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1004 static int mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1005 static int mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op,
1007 static int mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1008 static int mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1010 static void mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);
1011 static void mdb_xcursor_init0(MDB_cursor *mc);
1012 static void mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node);
1014 static int mdb_drop0(MDB_cursor *mc, int subs);
1015 static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi);
1018 static MDB_cmp_func mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long;
1022 static SECURITY_DESCRIPTOR mdb_null_sd;
1023 static SECURITY_ATTRIBUTES mdb_all_sa;
1024 static int mdb_sec_inited;
1027 /** Return the library version info. */
1029 mdb_version(int *major, int *minor, int *patch)
1031 if (major) *major = MDB_VERSION_MAJOR;
1032 if (minor) *minor = MDB_VERSION_MINOR;
1033 if (patch) *patch = MDB_VERSION_PATCH;
1034 return MDB_VERSION_STRING;
1037 /** Table of descriptions for MDB @ref errors */
1038 static char *const mdb_errstr[] = {
1039 "MDB_KEYEXIST: Key/data pair already exists",
1040 "MDB_NOTFOUND: No matching key/data pair found",
1041 "MDB_PAGE_NOTFOUND: Requested page not found",
1042 "MDB_CORRUPTED: Located page was wrong type",
1043 "MDB_PANIC: Update of meta page failed",
1044 "MDB_VERSION_MISMATCH: Database environment version mismatch",
1045 "MDB_INVALID: File is not an MDB file",
1046 "MDB_MAP_FULL: Environment mapsize limit reached",
1047 "MDB_DBS_FULL: Environment maxdbs limit reached",
1048 "MDB_READERS_FULL: Environment maxreaders limit reached",
1049 "MDB_TLS_FULL: Thread-local storage keys full - too many environments open",
1050 "MDB_TXN_FULL: Nested transaction has too many dirty pages - transaction too big",
1051 "MDB_CURSOR_FULL: Internal error - cursor stack limit reached",
1052 "MDB_PAGE_FULL: Internal error - page has no more space"
1056 mdb_strerror(int err)
1060 return ("Successful return: 0");
1062 if (err >= MDB_KEYEXIST && err <= MDB_LAST_ERRCODE) {
1063 i = err - MDB_KEYEXIST;
1064 return mdb_errstr[i];
1067 return strerror(err);
1071 /** Display a key in hexadecimal and return the address of the result.
1072 * @param[in] key the key to display
1073 * @param[in] buf the buffer to write into. Should always be #DKBUF.
1074 * @return The key in hexadecimal form.
1077 mdb_dkey(MDB_val *key, char *buf)
1080 unsigned char *c = key->mv_data;
1082 if (key->mv_size > MAXKEYSIZE)
1083 return "MAXKEYSIZE";
1084 /* may want to make this a dynamic check: if the key is mostly
1085 * printable characters, print it as-is instead of converting to hex.
1089 for (i=0; i<key->mv_size; i++)
1090 ptr += sprintf(ptr, "%02x", *c++);
1092 sprintf(buf, "%.*s", key->mv_size, key->mv_data);
1097 /** Display all the keys in the page. */
1099 mdb_page_list(MDB_page *mp)
1102 unsigned int i, nkeys, nsize;
1106 nkeys = NUMKEYS(mp);
1107 fprintf(stderr, "numkeys %d\n", nkeys);
1108 for (i=0; i<nkeys; i++) {
1109 node = NODEPTR(mp, i);
1110 key.mv_size = node->mn_ksize;
1111 key.mv_data = node->mn_data;
1112 nsize = NODESIZE + NODEKSZ(node) + sizeof(indx_t);
1113 if (F_ISSET(node->mn_flags, F_BIGDATA))
1114 nsize += sizeof(pgno_t);
1116 nsize += NODEDSZ(node);
1117 fprintf(stderr, "key %d: nsize %d, %s\n", i, nsize, DKEY(&key));
1122 mdb_cursor_chk(MDB_cursor *mc)
1128 if (!mc->mc_snum && !(mc->mc_flags & C_INITIALIZED)) return;
1129 for (i=0; i<mc->mc_top; i++) {
1131 node = NODEPTR(mp, mc->mc_ki[i]);
1132 if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno)
1135 if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i]))
1141 /** Count all the pages in each DB and in the freelist
1142 * and make sure it matches the actual number of pages
1145 static void mdb_audit(MDB_txn *txn)
1149 MDB_ID freecount, count;
1154 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
1155 while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
1156 freecount += *(MDB_ID *)data.mv_data;
1159 for (i = 0; i<txn->mt_numdbs; i++) {
1160 MDB_xcursor mx, *mxp;
1161 mxp = (txn->mt_dbs[i].md_flags & MDB_DUPSORT) ? &mx : NULL;
1162 mdb_cursor_init(&mc, txn, i, mxp);
1163 if (txn->mt_dbs[i].md_root == P_INVALID)
1165 count += txn->mt_dbs[i].md_branch_pages +
1166 txn->mt_dbs[i].md_leaf_pages +
1167 txn->mt_dbs[i].md_overflow_pages;
1168 if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) {
1169 mdb_page_search(&mc, NULL, 0);
1173 mp = mc.mc_pg[mc.mc_top];
1174 for (j=0; j<NUMKEYS(mp); j++) {
1175 MDB_node *leaf = NODEPTR(mp, j);
1176 if (leaf->mn_flags & F_SUBDATA) {
1178 memcpy(&db, NODEDATA(leaf), sizeof(db));
1179 count += db.md_branch_pages + db.md_leaf_pages +
1180 db.md_overflow_pages;
1184 while (mdb_cursor_sibling(&mc, 1) == 0);
1187 if (freecount + count + 2 /* metapages */ != txn->mt_next_pgno) {
1188 fprintf(stderr, "audit: %lu freecount: %lu count: %lu total: %lu next_pgno: %lu\n",
1189 txn->mt_txnid, freecount, count+2, freecount+count+2, txn->mt_next_pgno);
1195 mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1197 return txn->mt_dbxs[dbi].md_cmp(a, b);
1201 mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1203 if (txn->mt_dbxs[dbi].md_dcmp)
1204 return txn->mt_dbxs[dbi].md_dcmp(a, b);
1206 return EINVAL; /* too bad you can't distinguish this from a valid result */
1209 /** Allocate a single page.
1210 * Re-use old malloc'd pages first, otherwise just malloc.
1213 mdb_page_malloc(MDB_cursor *mc) {
1215 size_t sz = mc->mc_txn->mt_env->me_psize;
1216 if ((ret = mc->mc_txn->mt_env->me_dpages) != NULL) {
1217 VGMEMP_ALLOC(mc->mc_txn->mt_env, ret, sz);
1218 VGMEMP_DEFINED(ret, sizeof(ret->mp_next));
1219 mc->mc_txn->mt_env->me_dpages = ret->mp_next;
1220 } else if ((ret = malloc(sz)) != NULL) {
1221 VGMEMP_ALLOC(mc->mc_txn->mt_env, ret, sz);
1226 /** Allocate pages for writing.
1227 * If there are free pages available from older transactions, they
1228 * will be re-used first. Otherwise a new page will be allocated.
1229 * @param[in] mc cursor A cursor handle identifying the transaction and
1230 * database for which we are allocating.
1231 * @param[in] num the number of pages to allocate.
1232 * @param[out] mp Address of the allocated page(s). Requests for multiple pages
1233 * will always be satisfied by a single contiguous chunk of memory.
1234 * @return 0 on success, non-zero on failure.
1237 mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
1239 MDB_txn *txn = mc->mc_txn;
1241 pgno_t pgno = P_INVALID;
1246 /* The free list won't have any content at all until txn 2 has
1247 * committed. The pages freed by txn 2 will be unreferenced
1248 * after txn 3 commits, and so will be safe to re-use in txn 4.
1250 if (txn->mt_txnid > 3) {
1252 if (!txn->mt_env->me_pghead &&
1253 txn->mt_dbs[FREE_DBI].md_root != P_INVALID) {
1254 /* See if there's anything in the free DB */
1260 txnid_t *kptr, last;
1262 mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
1263 if (!txn->mt_env->me_pgfirst) {
1264 mdb_page_search(&m2, NULL, 0);
1265 leaf = NODEPTR(m2.mc_pg[m2.mc_top], 0);
1266 kptr = (txnid_t *)NODEKEY(leaf);
1273 last = txn->mt_env->me_pglast + 1;
1275 key.mv_data = &last;
1276 key.mv_size = sizeof(last);
1277 rc = mdb_cursor_set(&m2, &key, &data, MDB_SET, &exact);
1280 last = *(txnid_t *)key.mv_data;
1283 /* Unusable if referred by a meta page or reader... */
1285 if (last < txn->mt_txnid-1) {
1286 j = txn->mt_env->me_txns->mti_numreaders;
1287 r = txn->mt_env->me_txns->mti_readers + j;
1288 for (j = -j; j && (last<r[j].mr_txnid || !r[j].mr_pid); j++) ;
1292 /* It's usable, grab it.
1297 if (!txn->mt_env->me_pgfirst) {
1298 mdb_node_read(txn, leaf, &data);
1300 txn->mt_env->me_pglast = last;
1301 if (!txn->mt_env->me_pgfirst)
1302 txn->mt_env->me_pgfirst = last;
1303 idl = (MDB_ID *) data.mv_data;
1304 /* We might have a zero-length IDL due to freelist growth
1305 * during a prior commit
1307 if (!idl[0]) goto again;
1308 mop = malloc(sizeof(MDB_oldpages) + MDB_IDL_SIZEOF(idl) - sizeof(pgno_t));
1311 mop->mo_next = txn->mt_env->me_pghead;
1312 mop->mo_txnid = last;
1313 txn->mt_env->me_pghead = mop;
1314 memcpy(mop->mo_pages, idl, MDB_IDL_SIZEOF(idl));
1319 DPRINTF("IDL read txn %zu root %zu num %zu",
1320 mop->mo_txnid, txn->mt_dbs[FREE_DBI].md_root, idl[0]);
1321 for (i=0; i<idl[0]; i++) {
1322 DPRINTF("IDL %zu", idl[i+1]);
1329 if (txn->mt_env->me_pghead) {
1330 MDB_oldpages *mop = txn->mt_env->me_pghead;
1332 /* FIXME: For now, always use fresh pages. We
1333 * really ought to search the free list for a
1338 /* peel pages off tail, so we only have to truncate the list */
1339 pgno = MDB_IDL_LAST(mop->mo_pages);
1340 if (MDB_IDL_IS_RANGE(mop->mo_pages)) {
1342 if (mop->mo_pages[2] > mop->mo_pages[1])
1343 mop->mo_pages[0] = 0;
1347 if (MDB_IDL_IS_ZERO(mop->mo_pages)) {
1348 txn->mt_env->me_pghead = mop->mo_next;
1349 if (mc->mc_dbi == FREE_DBI) {
1350 mop->mo_next = txn->mt_env->me_pgfree;
1351 txn->mt_env->me_pgfree = mop;
1360 if (pgno == P_INVALID) {
1361 /* DB size is maxed out */
1362 if (txn->mt_next_pgno + num >= txn->mt_env->me_maxpg) {
1363 DPUTS("DB size maxed out");
1364 return MDB_MAP_FULL;
1367 if (txn->mt_env->me_flags & MDB_WRITEMAP) {
1368 if (pgno == P_INVALID) {
1369 pgno = txn->mt_next_pgno;
1370 txn->mt_next_pgno += num;
1372 np = (MDB_page *)(txn->mt_env->me_map + txn->mt_env->me_psize * pgno);
1375 if (txn->mt_env->me_dpages && num == 1) {
1376 np = txn->mt_env->me_dpages;
1377 VGMEMP_ALLOC(txn->mt_env, np, txn->mt_env->me_psize);
1378 VGMEMP_DEFINED(np, sizeof(np->mp_next));
1379 txn->mt_env->me_dpages = np->mp_next;
1381 size_t sz = txn->mt_env->me_psize * num;
1382 if ((np = malloc(sz)) == NULL)
1384 VGMEMP_ALLOC(txn->mt_env, np, sz);
1386 if (pgno == P_INVALID) {
1387 np->mp_pgno = txn->mt_next_pgno;
1388 txn->mt_next_pgno += num;
1393 mid.mid = np->mp_pgno;
1395 if (txn->mt_env->me_flags & MDB_WRITEMAP) {
1396 mdb_mid2l_append(txn->mt_u.dirty_list, &mid);
1398 mdb_mid2l_insert(txn->mt_u.dirty_list, &mid);
1405 /** Copy a page: avoid copying unused portions of the page.
1406 * @param[in] dst page to copy into
1407 * @param[in] src page to copy from
1410 mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize)
1412 dst->mp_flags = src->mp_flags | P_DIRTY;
1413 dst->mp_pages = src->mp_pages;
1415 if (IS_LEAF2(src)) {
1416 memcpy(dst->mp_ptrs, src->mp_ptrs, psize - PAGEHDRSZ - SIZELEFT(src));
1418 unsigned int i, nkeys = NUMKEYS(src);
1419 for (i=0; i<nkeys; i++)
1420 dst->mp_ptrs[i] = src->mp_ptrs[i];
1421 memcpy((char *)dst+src->mp_upper, (char *)src+src->mp_upper,
1422 psize - src->mp_upper);
1426 /** Touch a page: make it dirty and re-insert into tree with updated pgno.
1427 * @param[in] mc cursor pointing to the page to be touched
1428 * @return 0 on success, non-zero on failure.
1431 mdb_page_touch(MDB_cursor *mc)
1433 MDB_page *mp = mc->mc_pg[mc->mc_top];
1437 if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
1439 if ((rc = mdb_page_alloc(mc, 1, &np)))
1441 DPRINTF("touched db %u page %zu -> %zu", mc->mc_dbi, mp->mp_pgno, np->mp_pgno);
1442 assert(mp->mp_pgno != np->mp_pgno);
1443 mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
1445 /* If page isn't full, just copy the used portion */
1446 mdb_page_copy(np, mp, mc->mc_txn->mt_env->me_psize);
1449 memcpy(np, mp, mc->mc_txn->mt_env->me_psize);
1451 np->mp_flags |= P_DIRTY;
1456 /* Adjust other cursors pointing to mp */
1457 if (mc->mc_flags & C_SUB) {
1458 MDB_cursor *m2, *m3;
1459 MDB_dbi dbi = mc->mc_dbi-1;
1461 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
1462 if (m2 == mc) continue;
1463 m3 = &m2->mc_xcursor->mx_cursor;
1464 if (m3->mc_snum < mc->mc_snum) continue;
1465 if (m3->mc_pg[mc->mc_top] == mc->mc_pg[mc->mc_top]) {
1466 m3->mc_pg[mc->mc_top] = mp;
1472 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
1473 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
1474 if (m2->mc_pg[mc->mc_top] == mc->mc_pg[mc->mc_top]) {
1475 m2->mc_pg[mc->mc_top] = mp;
1479 mc->mc_pg[mc->mc_top] = mp;
1480 /** If this page has a parent, update the parent to point to
1484 SETPGNO(NODEPTR(mc->mc_pg[mc->mc_top-1], mc->mc_ki[mc->mc_top-1]), mp->mp_pgno);
1486 mc->mc_db->md_root = mp->mp_pgno;
1487 } else if (mc->mc_txn->mt_parent) {
1490 /* If txn has a parent, make sure the page is in our
1493 if (mc->mc_txn->mt_u.dirty_list[0].mid) {
1494 unsigned x = mdb_mid2l_search(mc->mc_txn->mt_u.dirty_list, mp->mp_pgno);
1495 if (x <= mc->mc_txn->mt_u.dirty_list[0].mid &&
1496 mc->mc_txn->mt_u.dirty_list[x].mid == mp->mp_pgno) {
1497 if (mc->mc_txn->mt_u.dirty_list[x].mptr != mp) {
1498 mp = mc->mc_txn->mt_u.dirty_list[x].mptr;
1499 mc->mc_pg[mc->mc_top] = mp;
1505 np = mdb_page_malloc(mc);
1508 memcpy(np, mp, mc->mc_txn->mt_env->me_psize);
1509 mid.mid = np->mp_pgno;
1511 mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &mid);
1519 mdb_env_sync(MDB_env *env, int force)
1522 if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) {
1523 if (env->me_flags & MDB_WRITEMAP) {
1524 int flags = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;
1525 if (MDB_MSYNC(env->me_map, env->me_mapsize, flags))
1528 else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd))
1532 if (MDB_FDATASYNC(env->me_fd))
1539 /** Make shadow copies of all of parent txn's cursors */
1541 mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst)
1543 MDB_cursor *mc, *m2;
1544 unsigned int i, j, size;
1546 for (i=0;i<src->mt_numdbs; i++) {
1547 if (src->mt_cursors[i]) {
1548 size = sizeof(MDB_cursor);
1549 if (src->mt_cursors[i]->mc_xcursor)
1550 size += sizeof(MDB_xcursor);
1551 for (m2 = src->mt_cursors[i]; m2; m2=m2->mc_next) {
1558 mc->mc_db = &dst->mt_dbs[i];
1559 mc->mc_dbx = m2->mc_dbx;
1560 mc->mc_dbflag = &dst->mt_dbflags[i];
1561 mc->mc_snum = m2->mc_snum;
1562 mc->mc_top = m2->mc_top;
1563 mc->mc_flags = m2->mc_flags | C_SHADOW;
1564 for (j=0; j<mc->mc_snum; j++) {
1565 mc->mc_pg[j] = m2->mc_pg[j];
1566 mc->mc_ki[j] = m2->mc_ki[j];
1568 if (m2->mc_xcursor) {
1569 MDB_xcursor *mx, *mx2;
1570 mx = (MDB_xcursor *)(mc+1);
1571 mc->mc_xcursor = mx;
1572 mx2 = m2->mc_xcursor;
1573 mx->mx_db = mx2->mx_db;
1574 mx->mx_dbx = mx2->mx_dbx;
1575 mx->mx_dbflag = mx2->mx_dbflag;
1576 mx->mx_cursor.mc_txn = dst;
1577 mx->mx_cursor.mc_dbi = mx2->mx_cursor.mc_dbi;
1578 mx->mx_cursor.mc_db = &mx->mx_db;
1579 mx->mx_cursor.mc_dbx = &mx->mx_dbx;
1580 mx->mx_cursor.mc_dbflag = &mx->mx_dbflag;
1581 mx->mx_cursor.mc_snum = mx2->mx_cursor.mc_snum;
1582 mx->mx_cursor.mc_top = mx2->mx_cursor.mc_top;
1583 mx->mx_cursor.mc_flags = mx2->mx_cursor.mc_flags | C_SHADOW;
1584 for (j=0; j<mx2->mx_cursor.mc_snum; j++) {
1585 mx->mx_cursor.mc_pg[j] = mx2->mx_cursor.mc_pg[j];
1586 mx->mx_cursor.mc_ki[j] = mx2->mx_cursor.mc_ki[j];
1589 mc->mc_xcursor = NULL;
1591 mc->mc_next = dst->mt_cursors[i];
1592 dst->mt_cursors[i] = mc;
1599 /** Merge shadow cursors back into parent's */
1601 mdb_cursor_merge(MDB_txn *txn)
1604 for (i=0; i<txn->mt_numdbs; i++) {
1605 if (txn->mt_cursors[i]) {
1607 while ((mc = txn->mt_cursors[i])) {
1608 txn->mt_cursors[i] = mc->mc_next;
1609 if (mc->mc_flags & C_SHADOW) {
1610 MDB_cursor *m2 = mc->mc_orig;
1612 m2->mc_snum = mc->mc_snum;
1613 m2->mc_top = mc->mc_top;
1614 for (j=0; j<mc->mc_snum; j++) {
1615 m2->mc_pg[j] = mc->mc_pg[j];
1616 m2->mc_ki[j] = mc->mc_ki[j];
1619 if (mc->mc_flags & C_ALLOCD)
1627 mdb_txn_reset0(MDB_txn *txn);
1629 /** Common code for #mdb_txn_begin() and #mdb_txn_renew().
1630 * @param[in] txn the transaction handle to initialize
1631 * @return 0 on success, non-zero on failure. This can only
1632 * fail for read-only transactions, and then only if the
1633 * reader table is full.
1636 mdb_txn_renew0(MDB_txn *txn)
1638 MDB_env *env = txn->mt_env;
1643 txn->mt_numdbs = env->me_numdbs;
1644 txn->mt_dbxs = env->me_dbxs; /* mostly static anyway */
1646 if (txn->mt_flags & MDB_TXN_RDONLY) {
1647 if (env->me_flags & MDB_ROFS) {
1648 i = mdb_env_pick_meta(env);
1649 txn->mt_txnid = env->me_metas[i]->mm_txnid;
1650 txn->mt_u.reader = NULL;
1652 MDB_reader *r = pthread_getspecific(env->me_txkey);
1654 pid_t pid = env->me_pid;
1655 pthread_t tid = pthread_self();
1658 for (i=0; i<env->me_txns->mti_numreaders; i++)
1659 if (env->me_txns->mti_readers[i].mr_pid == 0)
1661 if (i == env->me_maxreaders) {
1662 UNLOCK_MUTEX_R(env);
1663 return MDB_READERS_FULL;
1665 env->me_txns->mti_readers[i].mr_pid = pid;
1666 env->me_txns->mti_readers[i].mr_tid = tid;
1667 if (i >= env->me_txns->mti_numreaders)
1668 env->me_txns->mti_numreaders = i+1;
1669 /* Save numreaders for un-mutexed mdb_env_close() */
1670 env->me_numreaders = env->me_txns->mti_numreaders;
1671 UNLOCK_MUTEX_R(env);
1672 r = &env->me_txns->mti_readers[i];
1673 if ((rc = pthread_setspecific(env->me_txkey, r)) != 0) {
1674 env->me_txns->mti_readers[i].mr_pid = 0;
1678 txn->mt_txnid = r->mr_txnid = env->me_txns->mti_txnid;
1679 txn->mt_u.reader = r;
1681 txn->mt_toggle = txn->mt_txnid & 1;
1682 txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1;
1686 txn->mt_txnid = env->me_txns->mti_txnid;
1687 txn->mt_toggle = txn->mt_txnid & 1;
1688 txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1;
1691 if (txn->mt_txnid == mdb_debug_start)
1694 txn->mt_u.dirty_list = env->me_dirty_list;
1695 txn->mt_u.dirty_list[0].mid = 0;
1696 txn->mt_free_pgs = env->me_free_pgs;
1697 txn->mt_free_pgs[0] = 0;
1701 /* Copy the DB info and flags */
1702 memcpy(txn->mt_dbs, env->me_metas[txn->mt_toggle]->mm_dbs, 2 * sizeof(MDB_db));
1703 for (i=2; i<txn->mt_numdbs; i++)
1704 txn->mt_dbs[i].md_flags = env->me_dbflags[i];
1705 txn->mt_dbflags[0] = txn->mt_dbflags[1] = 0;
1706 if (txn->mt_numdbs > 2)
1707 memset(txn->mt_dbflags+2, DB_STALE, txn->mt_numdbs-2);
1713 mdb_txn_renew(MDB_txn *txn)
1717 if (! (txn && txn->mt_flags & MDB_TXN_RDONLY))
1720 if (txn->mt_env->me_flags & MDB_FATAL_ERROR) {
1721 DPUTS("environment had fatal error, must shutdown!");
1725 rc = mdb_txn_renew0(txn);
1726 if (rc == MDB_SUCCESS) {
1727 DPRINTF("renew txn %zu%c %p on mdbenv %p, root page %zu",
1728 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
1729 (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root);
1735 mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
1740 if (env->me_flags & MDB_FATAL_ERROR) {
1741 DPUTS("environment had fatal error, must shutdown!");
1744 if ((env->me_flags & MDB_RDONLY) && !(flags & MDB_RDONLY))
1747 /* Nested transactions: Max 1 child, write txns only, no writemap */
1748 if (parent->mt_child ||
1749 (flags & MDB_RDONLY) || (parent->mt_flags & MDB_TXN_RDONLY) ||
1750 (env->me_flags & MDB_WRITEMAP))
1755 size = sizeof(MDB_txn) + env->me_maxdbs * (sizeof(MDB_db)+1);
1756 if (!(flags & MDB_RDONLY))
1757 size += env->me_maxdbs * sizeof(MDB_cursor *);
1759 if ((txn = calloc(1, size)) == NULL) {
1760 DPRINTF("calloc: %s", strerror(ErrCode()));
1763 txn->mt_dbs = (MDB_db *)(txn+1);
1764 if (flags & MDB_RDONLY) {
1765 txn->mt_flags |= MDB_TXN_RDONLY;
1766 txn->mt_dbflags = (unsigned char *)(txn->mt_dbs + env->me_maxdbs);
1768 txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
1769 txn->mt_dbflags = (unsigned char *)(txn->mt_cursors + env->me_maxdbs);
1774 txn->mt_free_pgs = mdb_midl_alloc();
1775 if (!txn->mt_free_pgs) {
1779 txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE);
1780 if (!txn->mt_u.dirty_list) {
1781 free(txn->mt_free_pgs);
1785 txn->mt_txnid = parent->mt_txnid;
1786 txn->mt_toggle = parent->mt_toggle;
1787 txn->mt_u.dirty_list[0].mid = 0;
1788 txn->mt_free_pgs[0] = 0;
1789 txn->mt_next_pgno = parent->mt_next_pgno;
1790 parent->mt_child = txn;
1791 txn->mt_parent = parent;
1792 txn->mt_numdbs = parent->mt_numdbs;
1793 txn->mt_dbxs = parent->mt_dbxs;
1794 memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
1795 memcpy(txn->mt_dbflags, parent->mt_dbflags, txn->mt_numdbs);
1796 mdb_cursor_shadow(parent, txn);
1799 rc = mdb_txn_renew0(txn);
1805 DPRINTF("begin txn %zu%c %p on mdbenv %p, root page %zu",
1806 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
1807 (void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root);
1813 /** Common code for #mdb_txn_reset() and #mdb_txn_abort().
1814 * @param[in] txn the transaction handle to reset
1817 mdb_txn_reset0(MDB_txn *txn)
1819 MDB_env *env = txn->mt_env;
1821 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
1822 if (!(env->me_flags & MDB_ROFS))
1823 txn->mt_u.reader->mr_txnid = (txnid_t)-1;
1829 /* close(free) all cursors */
1830 for (i=0; i<txn->mt_numdbs; i++) {
1831 if (txn->mt_cursors[i]) {
1833 while ((mc = txn->mt_cursors[i])) {
1834 txn->mt_cursors[i] = mc->mc_next;
1835 if (mc->mc_flags & C_ALLOCD)
1841 if (!(env->me_flags & MDB_WRITEMAP)) {
1842 /* return all dirty pages to dpage list */
1843 for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++) {
1844 dp = txn->mt_u.dirty_list[i].mptr;
1845 if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
1846 dp->mp_next = txn->mt_env->me_dpages;
1847 VGMEMP_FREE(txn->mt_env, dp);
1848 txn->mt_env->me_dpages = dp;
1850 /* large pages just get freed directly */
1851 VGMEMP_FREE(txn->mt_env, dp);
1857 if (txn->mt_parent) {
1858 txn->mt_parent->mt_child = NULL;
1859 mdb_midl_free(txn->mt_free_pgs);
1860 free(txn->mt_u.dirty_list);
1863 if (mdb_midl_shrink(&txn->mt_free_pgs))
1864 env->me_free_pgs = txn->mt_free_pgs;
1867 while ((mop = txn->mt_env->me_pghead)) {
1868 txn->mt_env->me_pghead = mop->mo_next;
1871 txn->mt_env->me_pgfirst = 0;
1872 txn->mt_env->me_pglast = 0;
1875 /* The writer mutex was locked in mdb_txn_begin. */
1876 UNLOCK_MUTEX_W(env);
1881 mdb_txn_reset(MDB_txn *txn)
1886 DPRINTF("reset txn %zu%c %p on mdbenv %p, root page %zu",
1887 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
1888 (void *) txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root);
1890 mdb_txn_reset0(txn);
1894 mdb_txn_abort(MDB_txn *txn)
1899 DPRINTF("abort txn %zu%c %p on mdbenv %p, root page %zu",
1900 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
1901 (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root);
1904 mdb_txn_abort(txn->mt_child);
1906 mdb_txn_reset0(txn);
1911 mdb_txn_commit(MDB_txn *txn)
1919 pgno_t next, freecnt;
1922 assert(txn != NULL);
1923 assert(txn->mt_env != NULL);
1925 if (txn->mt_child) {
1926 mdb_txn_commit(txn->mt_child);
1927 txn->mt_child = NULL;
1932 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
1933 if (txn->mt_numdbs > env->me_numdbs) {
1934 /* update the DB flags */
1936 for (i = env->me_numdbs; i<txn->mt_numdbs; i++)
1937 env->me_dbflags[i] = txn->mt_dbs[i].md_flags;
1944 if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
1945 DPUTS("error flag is set, can't commit");
1947 txn->mt_parent->mt_flags |= MDB_TXN_ERROR;
1952 /* Merge (and close) our cursors with parent's */
1953 mdb_cursor_merge(txn);
1955 if (txn->mt_parent) {
1961 /* Update parent's DB table */
1962 ip = &txn->mt_parent->mt_dbs[2];
1963 jp = &txn->mt_dbs[2];
1964 for (i = 2; i < txn->mt_numdbs; i++) {
1965 if (ip->md_root != jp->md_root)
1969 txn->mt_parent->mt_numdbs = txn->mt_numdbs;
1971 /* Append our free list to parent's */
1972 mdb_midl_append_list(&txn->mt_parent->mt_free_pgs,
1974 mdb_midl_free(txn->mt_free_pgs);
1976 /* Merge our dirty list with parent's */
1977 dst = txn->mt_parent->mt_u.dirty_list;
1978 src = txn->mt_u.dirty_list;
1979 x = mdb_mid2l_search(dst, src[1].mid);
1980 for (y=1; y<=src[0].mid; y++) {
1981 while (x <= dst[0].mid && dst[x].mid != src[y].mid) x++;
1985 dst[x].mptr = src[y].mptr;
1988 for (; y<=src[0].mid; y++) {
1989 if (++x >= MDB_IDL_UM_MAX) {
1991 return MDB_TXN_FULL;
1996 free(txn->mt_u.dirty_list);
1997 txn->mt_parent->mt_child = NULL;
2002 if (txn != env->me_txn) {
2003 DPUTS("attempt to commit unknown transaction");
2008 if (!txn->mt_u.dirty_list[0].mid)
2011 DPRINTF("committing txn %zu %p on mdbenv %p, root page %zu",
2012 txn->mt_txnid, (void *)txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root);
2014 /* Update DB root pointers. Their pages have already been
2015 * touched so this is all in-place and cannot fail.
2017 if (txn->mt_numdbs > 2) {
2020 data.mv_size = sizeof(MDB_db);
2022 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
2023 for (i = 2; i < txn->mt_numdbs; i++) {
2024 if (txn->mt_dbflags[i] & DB_DIRTY) {
2025 data.mv_data = &txn->mt_dbs[i];
2026 mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data, 0);
2031 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
2033 /* should only be one record now */
2034 if (env->me_pghead) {
2035 /* make sure first page of freeDB is touched and on freelist */
2036 mdb_page_search(&mc, NULL, MDB_PS_MODIFY);
2039 /* Delete IDLs we used from the free list */
2040 if (env->me_pgfirst) {
2045 key.mv_size = sizeof(cur);
2046 for (cur = env->me_pgfirst; cur <= env->me_pglast; cur++) {
2049 mdb_cursor_set(&mc, &key, NULL, MDB_SET, &exact);
2050 rc = mdb_cursor_del(&mc, 0);
2056 env->me_pgfirst = 0;
2060 /* save to free list */
2062 freecnt = txn->mt_free_pgs[0];
2063 if (!MDB_IDL_IS_ZERO(txn->mt_free_pgs)) {
2066 /* make sure last page of freeDB is touched and on freelist */
2067 key.mv_size = MAXKEYSIZE+1;
2069 mdb_page_search(&mc, &key, MDB_PS_MODIFY);
2071 mdb_midl_sort(txn->mt_free_pgs);
2075 MDB_IDL idl = txn->mt_free_pgs;
2076 DPRINTF("IDL write txn %zu root %zu num %zu",
2077 txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, idl[0]);
2078 for (i=0; i<idl[0]; i++) {
2079 DPRINTF("IDL %zu", idl[i+1]);
2083 /* write to last page of freeDB */
2084 key.mv_size = sizeof(pgno_t);
2085 key.mv_data = &txn->mt_txnid;
2086 data.mv_data = txn->mt_free_pgs;
2087 /* The free list can still grow during this call,
2088 * despite the pre-emptive touches above. So check
2089 * and make sure the entire thing got written.
2092 freecnt = txn->mt_free_pgs[0];
2093 data.mv_size = MDB_IDL_SIZEOF(txn->mt_free_pgs);
2094 rc = mdb_cursor_put(&mc, &key, &data, 0);
2099 } while (freecnt != txn->mt_free_pgs[0]);
2101 /* should only be one record now */
2103 if (env->me_pghead) {
2109 mop = env->me_pghead;
2111 key.mv_size = sizeof(id);
2113 data.mv_size = MDB_IDL_SIZEOF(mop->mo_pages);
2114 data.mv_data = mop->mo_pages;
2115 orig = mop->mo_pages[0];
2116 /* These steps may grow the freelist again
2117 * due to freed overflow pages...
2119 mdb_cursor_put(&mc, &key, &data, 0);
2120 if (mop == env->me_pghead && env->me_pghead->mo_txnid == id) {
2121 /* could have been used again here */
2122 if (mop->mo_pages[0] != orig) {
2123 data.mv_size = MDB_IDL_SIZEOF(mop->mo_pages);
2124 data.mv_data = mop->mo_pages;
2126 mdb_cursor_put(&mc, &key, &data, 0);
2128 env->me_pghead = NULL;
2131 /* was completely used up */
2132 mdb_cursor_del(&mc, 0);
2136 env->me_pgfirst = 0;
2140 while (env->me_pgfree) {
2141 MDB_oldpages *mop = env->me_pgfree;
2142 env->me_pgfree = mop->mo_next;
2146 /* Check for growth of freelist again */
2147 if (freecnt != txn->mt_free_pgs[0])
2150 if (!MDB_IDL_IS_ZERO(txn->mt_free_pgs)) {
2151 if (mdb_midl_shrink(&txn->mt_free_pgs))
2152 env->me_free_pgs = txn->mt_free_pgs;
2159 if (env->me_flags & MDB_WRITEMAP) {
2160 for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++) {
2161 dp = txn->mt_u.dirty_list[i].mptr;
2162 /* clear dirty flag */
2163 dp->mp_flags &= ~P_DIRTY;
2164 txn->mt_u.dirty_list[i].mid = 0;
2166 txn->mt_u.dirty_list[0].mid = 0;
2170 /* Commit up to MDB_COMMIT_PAGES dirty pages to disk until done.
2176 /* Windows actually supports scatter/gather I/O, but only on
2177 * unbuffered file handles. Since we're relying on the OS page
2178 * cache for all our data, that's self-defeating. So we just
2179 * write pages one at a time. We use the ov structure to set
2180 * the write offset, to at least save the overhead of a Seek
2184 memset(&ov, 0, sizeof(ov));
2185 for (; i<=txn->mt_u.dirty_list[0].mid; i++) {
2187 dp = txn->mt_u.dirty_list[i].mptr;
2188 DPRINTF("committing page %zu", dp->mp_pgno);
2189 size = dp->mp_pgno * env->me_psize;
2190 ov.Offset = size & 0xffffffff;
2191 ov.OffsetHigh = size >> 16;
2192 ov.OffsetHigh >>= 16;
2193 /* clear dirty flag */
2194 dp->mp_flags &= ~P_DIRTY;
2195 wsize = env->me_psize;
2196 if (IS_OVERFLOW(dp)) wsize *= dp->mp_pages;
2197 rc = WriteFile(env->me_fd, dp, wsize, NULL, &ov);
2200 DPRINTF("WriteFile: %d", n);
2207 struct iovec iov[MDB_COMMIT_PAGES];
2211 for (; i<=txn->mt_u.dirty_list[0].mid; i++) {
2212 dp = txn->mt_u.dirty_list[i].mptr;
2213 if (dp->mp_pgno != next) {
2215 rc = writev(env->me_fd, iov, n);
2219 DPUTS("short write, filesystem full?");
2221 DPRINTF("writev: %s", strerror(n));
2228 lseek(env->me_fd, dp->mp_pgno * env->me_psize, SEEK_SET);
2231 DPRINTF("committing page %zu", dp->mp_pgno);
2232 iov[n].iov_len = env->me_psize;
2233 if (IS_OVERFLOW(dp)) iov[n].iov_len *= dp->mp_pages;
2234 iov[n].iov_base = (char *)dp;
2235 size += iov[n].iov_len;
2236 next = dp->mp_pgno + (IS_OVERFLOW(dp) ? dp->mp_pages : 1);
2237 /* clear dirty flag */
2238 dp->mp_flags &= ~P_DIRTY;
2239 if (++n >= MDB_COMMIT_PAGES) {
2249 rc = writev(env->me_fd, iov, n);
2253 DPUTS("short write, filesystem full?");
2255 DPRINTF("writev: %s", strerror(n));
2262 /* Drop the dirty pages.
2264 for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++) {
2265 dp = txn->mt_u.dirty_list[i].mptr;
2266 if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
2267 dp->mp_next = txn->mt_env->me_dpages;
2268 VGMEMP_FREE(txn->mt_env, dp);
2269 txn->mt_env->me_dpages = dp;
2271 VGMEMP_FREE(txn->mt_env, dp);
2274 txn->mt_u.dirty_list[i].mid = 0;
2276 txn->mt_u.dirty_list[0].mid = 0;
2279 if ((n = mdb_env_sync(env, 0)) != 0 ||
2280 (n = mdb_env_write_meta(txn)) != MDB_SUCCESS) {
2287 if (txn->mt_numdbs > env->me_numdbs) {
2288 /* update the DB flags */
2290 for (i = env->me_numdbs; i<txn->mt_numdbs; i++)
2291 env->me_dbflags[i] = txn->mt_dbs[i].md_flags;
2295 UNLOCK_MUTEX_W(env);
2301 /** Read the environment parameters of a DB environment before
2302 * mapping it into memory.
2303 * @param[in] env the environment handle
2304 * @param[out] meta address of where to store the meta information
2305 * @return 0 on success, non-zero on failure.
2308 mdb_env_read_header(MDB_env *env, MDB_meta *meta)
2315 /* We don't know the page size yet, so use a minimum value.
2319 if (!ReadFile(env->me_fd, &pbuf, MDB_PAGESIZE, (DWORD *)&rc, NULL) || rc == 0)
2321 if ((rc = read(env->me_fd, &pbuf, MDB_PAGESIZE)) == 0)
2326 else if (rc != MDB_PAGESIZE) {
2330 DPRINTF("read: %s", strerror(err));
2334 p = (MDB_page *)&pbuf;
2336 if (!F_ISSET(p->mp_flags, P_META)) {
2337 DPRINTF("page %zu not a meta page", p->mp_pgno);
2342 if (m->mm_magic != MDB_MAGIC) {
2343 DPUTS("meta has invalid magic");
2347 if (m->mm_version != MDB_VERSION) {
2348 DPRINTF("database is version %u, expected version %u",
2349 m->mm_version, MDB_VERSION);
2350 return MDB_VERSION_MISMATCH;
2353 memcpy(meta, m, sizeof(*m));
2357 /** Write the environment parameters of a freshly created DB environment.
2358 * @param[in] env the environment handle
2359 * @param[out] meta address of where to store the meta information
2360 * @return 0 on success, non-zero on failure.
2363 mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
2370 DPUTS("writing new meta page");
2372 GET_PAGESIZE(psize);
2374 meta->mm_magic = MDB_MAGIC;
2375 meta->mm_version = MDB_VERSION;
2376 meta->mm_psize = psize;
2377 meta->mm_last_pg = 1;
2378 meta->mm_flags = env->me_flags & 0xffff;
2379 meta->mm_flags |= MDB_INTEGERKEY;
2380 meta->mm_dbs[0].md_root = P_INVALID;
2381 meta->mm_dbs[1].md_root = P_INVALID;
2383 p = calloc(2, psize);
2385 p->mp_flags = P_META;
2388 memcpy(m, meta, sizeof(*meta));
2390 q = (MDB_page *)((char *)p + psize);
2393 q->mp_flags = P_META;
2396 memcpy(m, meta, sizeof(*meta));
2401 rc = WriteFile(env->me_fd, p, psize * 2, &len, NULL);
2402 rc = (len == psize * 2) ? MDB_SUCCESS : ErrCode();
2405 rc = write(env->me_fd, p, psize * 2);
2406 rc = (rc == (int)psize * 2) ? MDB_SUCCESS : ErrCode();
2412 /** Update the environment info to commit a transaction.
2413 * @param[in] txn the transaction that's being committed
2414 * @return 0 on success, non-zero on failure.
2417 mdb_env_write_meta(MDB_txn *txn)
2420 MDB_meta meta, metab, *mp;
2422 int rc, len, toggle;
2428 assert(txn != NULL);
2429 assert(txn->mt_env != NULL);
2431 toggle = !txn->mt_toggle;
2432 DPRINTF("writing meta page %d for root page %zu",
2433 toggle, txn->mt_dbs[MAIN_DBI].md_root);
2436 mp = env->me_metas[toggle];
2438 if (env->me_flags & MDB_WRITEMAP) {
2439 /* Persist any increases of mapsize config */
2440 if (env->me_mapsize > mp->mm_mapsize)
2441 mp->mm_mapsize = env->me_mapsize;
2442 mp->mm_dbs[0] = txn->mt_dbs[0];
2443 mp->mm_dbs[1] = txn->mt_dbs[1];
2444 mp->mm_last_pg = txn->mt_next_pgno - 1;
2445 mp->mm_txnid = txn->mt_txnid;
2446 if (!(env->me_flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {
2447 rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;
2450 ptr += env->me_psize;
2451 if (MDB_MSYNC(ptr, env->me_psize, rc)) {
2458 metab.mm_txnid = env->me_metas[toggle]->mm_txnid;
2459 metab.mm_last_pg = env->me_metas[toggle]->mm_last_pg;
2461 ptr = (char *)&meta;
2462 if (env->me_mapsize > mp->mm_mapsize) {
2463 /* Persist any increases of mapsize config */
2464 meta.mm_mapsize = env->me_mapsize;
2465 off = offsetof(MDB_meta, mm_mapsize);
2467 off = offsetof(MDB_meta, mm_dbs[0].md_depth);
2469 len = sizeof(MDB_meta) - off;
2472 meta.mm_dbs[0] = txn->mt_dbs[0];
2473 meta.mm_dbs[1] = txn->mt_dbs[1];
2474 meta.mm_last_pg = txn->mt_next_pgno - 1;
2475 meta.mm_txnid = txn->mt_txnid;
2478 off += env->me_psize;
2481 /* Write to the SYNC fd */
2484 memset(&ov, 0, sizeof(ov));
2486 WriteFile(env->me_mfd, ptr, len, (DWORD *)&rc, &ov);
2489 rc = pwrite(env->me_mfd, ptr, len, off);
2494 DPUTS("write failed, disk error?");
2495 /* On a failure, the pagecache still contains the new data.
2496 * Write some old data back, to prevent it from being used.
2497 * Use the non-SYNC fd; we know it will fail anyway.
2499 meta.mm_last_pg = metab.mm_last_pg;
2500 meta.mm_txnid = metab.mm_txnid;
2502 WriteFile(env->me_fd, ptr, len, NULL, &ov);
2504 r2 = pwrite(env->me_fd, ptr, len, off);
2507 env->me_flags |= MDB_FATAL_ERROR;
2511 /* Memory ordering issues are irrelevant; since the entire writer
2512 * is wrapped by wmutex, all of these changes will become visible
2513 * after the wmutex is unlocked. Since the DB is multi-version,
2514 * readers will get consistent data regardless of how fresh or
2515 * how stale their view of these values is.
2517 txn->mt_env->me_txns->mti_txnid = txn->mt_txnid;
2522 /** Check both meta pages to see which one is newer.
2523 * @param[in] env the environment handle
2524 * @return meta toggle (0 or 1).
2527 mdb_env_pick_meta(const MDB_env *env)
2529 return (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid);
2533 mdb_env_create(MDB_env **env)
2537 e = calloc(1, sizeof(MDB_env));
2541 e->me_free_pgs = mdb_midl_alloc();
2542 if (!e->me_free_pgs) {
2546 e->me_maxreaders = DEFAULT_READERS;
2548 e->me_fd = INVALID_HANDLE_VALUE;
2549 e->me_lfd = INVALID_HANDLE_VALUE;
2550 e->me_mfd = INVALID_HANDLE_VALUE;
2551 #ifdef MDB_USE_POSIX_SEM
2552 e->me_rmutex = SEM_FAILED;
2553 e->me_wmutex = SEM_FAILED;
2555 e->me_pid = getpid();
2556 VGMEMP_CREATE(e,0,0);
2562 mdb_env_set_mapsize(MDB_env *env, size_t size)
2566 env->me_mapsize = size;
2568 env->me_maxpg = env->me_mapsize / env->me_psize;
2573 mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs)
2577 env->me_maxdbs = dbs;
2582 mdb_env_set_maxreaders(MDB_env *env, unsigned int readers)
2584 if (env->me_map || readers < 1)
2586 env->me_maxreaders = readers;
2591 mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)
2593 if (!env || !readers)
2595 *readers = env->me_maxreaders;
2599 /** Further setup required for opening an MDB environment
2602 mdb_env_open2(MDB_env *env)
2604 unsigned int flags = env->me_flags;
2605 int i, newenv = 0, prot;
2609 memset(&meta, 0, sizeof(meta));
2611 if ((i = mdb_env_read_header(env, &meta)) != 0) {
2614 DPUTS("new mdbenv");
2616 meta.mm_mapsize = env->me_mapsize > DEFAULT_MAPSIZE ? env->me_mapsize : DEFAULT_MAPSIZE;
2619 if (env->me_mapsize < meta.mm_mapsize)
2620 env->me_mapsize = meta.mm_mapsize;
2625 LONG sizelo, sizehi;
2626 sizelo = env->me_mapsize & 0xffffffff;
2627 sizehi = env->me_mapsize >> 16; /* pointless on WIN32, only needed on W64 */
2629 /* Windows won't create mappings for zero length files.
2630 * Just allocate the maxsize right now.
2633 SetFilePointer(env->me_fd, sizelo, sizehi ? &sizehi : NULL, 0);
2634 if (!SetEndOfFile(env->me_fd))
2636 SetFilePointer(env->me_fd, 0, NULL, 0);
2638 mh = CreateFileMapping(env->me_fd, NULL, flags & MDB_WRITEMAP ?
2639 PAGE_READWRITE : PAGE_READONLY,
2640 sizehi, sizelo, NULL);
2643 env->me_map = MapViewOfFileEx(mh, flags & MDB_WRITEMAP ?
2644 FILE_MAP_WRITE : FILE_MAP_READ,
2645 0, 0, env->me_mapsize, meta.mm_address);
2652 if (meta.mm_address && (flags & MDB_FIXEDMAP))
2655 if (flags & MDB_WRITEMAP) {
2657 if (ftruncate(env->me_fd, env->me_mapsize) < 0)
2660 env->me_map = mmap(meta.mm_address, env->me_mapsize, prot, i,
2662 if (env->me_map == MAP_FAILED) {
2669 if (flags & MDB_FIXEDMAP)
2670 meta.mm_address = env->me_map;
2671 i = mdb_env_init_meta(env, &meta);
2672 if (i != MDB_SUCCESS) {
2676 env->me_psize = meta.mm_psize;
2678 env->me_maxpg = env->me_mapsize / env->me_psize;
2680 p = (MDB_page *)env->me_map;
2681 env->me_metas[0] = METADATA(p);
2682 env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + meta.mm_psize);
2686 int toggle = mdb_env_pick_meta(env);
2687 MDB_db *db = &env->me_metas[toggle]->mm_dbs[MAIN_DBI];
2689 DPRINTF("opened database version %u, pagesize %u",
2690 env->me_metas[0]->mm_version, env->me_psize);
2691 DPRINTF("using meta page %d", toggle);
2692 DPRINTF("depth: %u", db->md_depth);
2693 DPRINTF("entries: %zu", db->md_entries);
2694 DPRINTF("branch pages: %zu", db->md_branch_pages);
2695 DPRINTF("leaf pages: %zu", db->md_leaf_pages);
2696 DPRINTF("overflow pages: %zu", db->md_overflow_pages);
2697 DPRINTF("root: %zu", db->md_root);
2705 /** Release a reader thread's slot in the reader lock table.
2706 * This function is called automatically when a thread exits.
2707 * @param[in] ptr This points to the slot in the reader lock table.
2710 mdb_env_reader_dest(void *ptr)
2712 MDB_reader *reader = ptr;
2718 /** Junk for arranging thread-specific callbacks on Windows. This is
2719 * necessarily platform and compiler-specific. Windows supports up
2720 * to 1088 keys. Let's assume nobody opens more than 64 environments
2721 * in a single process, for now. They can override this if needed.
2723 #ifndef MAX_TLS_KEYS
2724 #define MAX_TLS_KEYS 64
2726 static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS];
2727 static int mdb_tls_nkeys;
2729 static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr)
2733 case DLL_PROCESS_ATTACH: break;
2734 case DLL_THREAD_ATTACH: break;
2735 case DLL_THREAD_DETACH:
2736 for (i=0; i<mdb_tls_nkeys; i++) {
2737 MDB_reader *r = pthread_getspecific(mdb_tls_keys[i]);
2738 mdb_env_reader_dest(r);
2741 case DLL_PROCESS_DETACH: break;
2746 const PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
2748 PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
2752 /* Force some symbol references.
2753 * _tls_used forces the linker to create the TLS directory if not already done
2754 * mdb_tls_cbp prevents whole-program-optimizer from dropping the symbol.
2756 #pragma comment(linker, "/INCLUDE:_tls_used")
2757 #pragma comment(linker, "/INCLUDE:mdb_tls_cbp")
2758 #pragma const_seg(".CRT$XLB")
2759 extern const PIMAGE_TLS_CALLBACK mdb_tls_callback;
2760 const PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
2763 #pragma comment(linker, "/INCLUDE:__tls_used")
2764 #pragma comment(linker, "/INCLUDE:_mdb_tls_cbp")
2765 #pragma data_seg(".CRT$XLB")
2766 PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
2768 #endif /* WIN 32/64 */
2769 #endif /* !__GNUC__ */
2772 /** Downgrade the exclusive lock on the region back to shared */
2774 mdb_env_share_locks(MDB_env *env, int *excl)
2776 int rc = 0, toggle = mdb_env_pick_meta(env);
2778 env->me_txns->mti_txnid = env->me_metas[toggle]->mm_txnid;
2783 /* First acquire a shared lock. The Unlock will
2784 * then release the existing exclusive lock.
2786 memset(&ov, 0, sizeof(ov));
2787 if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
2790 UnlockFile(env->me_lfd, 0, 0, 1, 0);
2796 struct flock lock_info;
2797 /* The shared lock replaces the existing lock */
2798 memset((void *)&lock_info, 0, sizeof(lock_info));
2799 lock_info.l_type = F_RDLCK;
2800 lock_info.l_whence = SEEK_SET;
2801 lock_info.l_start = 0;
2802 lock_info.l_len = 1;
2803 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
2804 (rc = ErrCode()) == EINTR) ;
2805 *excl = rc ? -1 : 0; /* error may mean we lost the lock */
2812 /** Try to get exlusive lock, otherwise shared.
2813 * Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive.
2816 mdb_env_excl_lock(MDB_env *env, int *excl)
2820 if (LockFile(env->me_lfd, 0, 0, 1, 0)) {
2824 memset(&ov, 0, sizeof(ov));
2825 if (LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
2832 struct flock lock_info;
2833 memset((void *)&lock_info, 0, sizeof(lock_info));
2834 lock_info.l_type = F_WRLCK;
2835 lock_info.l_whence = SEEK_SET;
2836 lock_info.l_start = 0;
2837 lock_info.l_len = 1;
2838 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
2839 (rc = ErrCode()) == EINTR) ;
2843 # ifdef MDB_USE_POSIX_SEM
2844 if (*excl < 0) /* always true when !MDB_USE_POSIX_SEM */
2847 lock_info.l_type = F_RDLCK;
2848 while ((rc = fcntl(env->me_lfd, F_SETLKW, &lock_info)) &&
2849 (rc = ErrCode()) == EINTR) ;
2857 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
2859 * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code
2861 * @(#) $Revision: 5.1 $
2862 * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $
2863 * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $
2865 * http://www.isthe.com/chongo/tech/comp/fnv/index.html
2869 * Please do not copyright this code. This code is in the public domain.
2871 * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
2872 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
2873 * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
2874 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
2875 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
2876 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
2877 * PERFORMANCE OF THIS SOFTWARE.
2880 * chongo <Landon Curt Noll> /\oo/\
2881 * http://www.isthe.com/chongo/
2883 * Share and Enjoy! :-)
2886 typedef unsigned long long mdb_hash_t;
2887 #define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL)
2889 /** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer
2890 * @param[in] str string to hash
2891 * @param[in] hval initial value for hash
2892 * @return 64 bit hash
2894 * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the
2895 * hval arg on the first call.
2898 mdb_hash_val(MDB_val *val, mdb_hash_t hval)
2900 unsigned char *s = (unsigned char *)val->mv_data; /* unsigned string */
2901 unsigned char *end = s + val->mv_size;
2903 * FNV-1a hash each octet of the string
2906 /* xor the bottom with the current octet */
2907 hval ^= (mdb_hash_t)*s++;
2909 /* multiply by the 64 bit FNV magic prime mod 2^64 */
2910 hval += (hval << 1) + (hval << 4) + (hval << 5) +
2911 (hval << 7) + (hval << 8) + (hval << 40);
2913 /* return our new hash value */
2917 /** Hash the string and output the hash in hex.
2918 * @param[in] str string to hash
2919 * @param[out] hexbuf an array of 17 chars to hold the hash
2922 mdb_hash_hex(MDB_val *val, char *hexbuf)
2925 mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT);
2926 for (i=0; i<8; i++) {
2927 hexbuf += sprintf(hexbuf, "%02x", (unsigned int)h & 0xff);
2933 /** Open and/or initialize the lock region for the environment.
2934 * @param[in] env The MDB environment.
2935 * @param[in] lpath The pathname of the file used for the lock region.
2936 * @param[in] mode The Unix permissions for the file, if we create it.
2937 * @param[out] excl Resulting file lock type: -1 none, 0 shared, 1 exclusive
2938 * @return 0 on success, non-zero on failure.
2941 mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
2949 if ((env->me_lfd = CreateFile(lpath, GENERIC_READ|GENERIC_WRITE,
2950 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
2951 FILE_ATTRIBUTE_NORMAL, NULL)) == INVALID_HANDLE_VALUE) {
2953 if (rc == ERROR_WRITE_PROTECT && (env->me_flags & MDB_RDONLY)) {
2954 env->me_flags |= MDB_ROFS;
2959 /* Try to get exclusive lock. If we succeed, then
2960 * nobody is using the lock region and we should initialize it.
2962 if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
2963 size = GetFileSize(env->me_lfd, NULL);
2969 if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT, mode)) == -1) {
2971 if (rc == EROFS && (env->me_flags & MDB_RDONLY)) {
2972 env->me_flags |= MDB_ROFS;
2977 /* Lose record locks when exec*() */
2978 if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0)
2979 fcntl(env->me_lfd, F_SETFD, fdflags);
2981 #else /* O_CLOEXEC on Linux: Open file and set FD_CLOEXEC atomically */
2982 if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT|O_CLOEXEC, mode)) == -1) {
2984 if (rc == EROFS && (env->me_flags & MDB_RDONLY)) {
2985 env->me_flags |= MDB_ROFS;
2992 /* Try to get exclusive lock. If we succeed, then
2993 * nobody is using the lock region and we should initialize it.
2995 if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
2997 size = lseek(env->me_lfd, 0, SEEK_END);
2999 rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
3000 if (size < rsize && *excl > 0) {
3002 SetFilePointer(env->me_lfd, rsize, NULL, 0);
3003 if (!SetEndOfFile(env->me_lfd)) goto fail_errno;
3005 if (ftruncate(env->me_lfd, rsize) != 0) goto fail_errno;
3009 size = rsize - sizeof(MDB_txninfo);
3010 env->me_maxreaders = size/sizeof(MDB_reader) + 1;
3015 mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,
3017 if (!mh) goto fail_errno;
3018 env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL);
3020 if (!env->me_txns) goto fail_errno;
3022 void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
3024 if (m == MAP_FAILED) goto fail_errno;
3030 BY_HANDLE_FILE_INFORMATION stbuf;
3039 if (!mdb_sec_inited) {
3040 InitializeSecurityDescriptor(&mdb_null_sd,
3041 SECURITY_DESCRIPTOR_REVISION);
3042 SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE);
3043 mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);
3044 mdb_all_sa.bInheritHandle = FALSE;
3045 mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;
3048 if (!GetFileInformationByHandle(env->me_lfd, &stbuf)) goto fail_errno;
3049 idbuf.volume = stbuf.dwVolumeSerialNumber;
3050 idbuf.nhigh = stbuf.nFileIndexHigh;
3051 idbuf.nlow = stbuf.nFileIndexLow;
3052 val.mv_data = &idbuf;
3053 val.mv_size = sizeof(idbuf);
3054 mdb_hash_hex(&val, hexbuf);
3055 sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", hexbuf);
3056 sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", hexbuf);
3057 env->me_rmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
3058 if (!env->me_rmutex) goto fail_errno;
3059 env->me_wmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);
3060 if (!env->me_wmutex) goto fail_errno;
3061 #elif defined(MDB_USE_POSIX_SEM)
3070 if (fstat(env->me_lfd, &stbuf)) goto fail_errno;
3071 idbuf.dev = stbuf.st_dev;
3072 idbuf.ino = stbuf.st_ino;
3073 val.mv_data = &idbuf;
3074 val.mv_size = sizeof(idbuf);
3075 mdb_hash_hex(&val, hexbuf);
3076 sprintf(env->me_txns->mti_rmname, "/MDBr%s", hexbuf);
3077 sprintf(env->me_txns->mti_wmname, "/MDBw%s", hexbuf);
3078 /* Clean up after a previous run, if needed: Try to
3079 * remove both semaphores before doing anything else.
3081 sem_unlink(env->me_txns->mti_rmname);
3082 sem_unlink(env->me_txns->mti_wmname);
3083 env->me_rmutex = sem_open(env->me_txns->mti_rmname,
3084 O_CREAT|O_EXCL, mode, 1);
3085 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
3086 env->me_wmutex = sem_open(env->me_txns->mti_wmname,
3087 O_CREAT|O_EXCL, mode, 1);
3088 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
3089 #else /* MDB_USE_POSIX_SEM */
3090 pthread_mutexattr_t mattr;
3092 if ((rc = pthread_mutexattr_init(&mattr))
3093 || (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED))
3094 || (rc = pthread_mutex_init(&env->me_txns->mti_mutex, &mattr))
3095 || (rc = pthread_mutex_init(&env->me_txns->mti_wmutex, &mattr)))
3097 pthread_mutexattr_destroy(&mattr);
3098 #endif /* _WIN32 || MDB_USE_POSIX_SEM */
3100 env->me_txns->mti_version = MDB_VERSION;
3101 env->me_txns->mti_magic = MDB_MAGIC;
3102 env->me_txns->mti_txnid = 0;
3103 env->me_txns->mti_numreaders = 0;
3106 if (env->me_txns->mti_magic != MDB_MAGIC) {
3107 DPUTS("lock region has invalid magic");
3111 if (env->me_txns->mti_version != MDB_VERSION) {
3112 DPRINTF("lock region is version %u, expected version %u",
3113 env->me_txns->mti_version, MDB_VERSION);
3114 rc = MDB_VERSION_MISMATCH;
3118 if (rc != EACCES && rc != EAGAIN) {
3122 env->me_rmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);
3123 if (!env->me_rmutex) goto fail_errno;
3124 env->me_wmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
3125 if (!env->me_wmutex) goto fail_errno;
3126 #elif defined(MDB_USE_POSIX_SEM)
3127 env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0);
3128 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
3129 env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0);
3130 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
3141 /** The name of the lock file in the DB environment */
3142 #define LOCKNAME "/lock.mdb"
3143 /** The name of the data file in the DB environment */
3144 #define DATANAME "/data.mdb"
3145 /** The suffix of the lock file when no subdir is used */
3146 #define LOCKSUFF "-lock"
3149 mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mode_t mode)
3151 int oflags, rc, len, excl;
3152 char *lpath, *dpath;
3154 if (env->me_fd != INVALID_HANDLE_VALUE)
3158 if (flags & MDB_NOSUBDIR) {
3159 rc = len + sizeof(LOCKSUFF) + len + 1;
3161 rc = len + sizeof(LOCKNAME) + len + sizeof(DATANAME);
3166 if (flags & MDB_NOSUBDIR) {
3167 dpath = lpath + len + sizeof(LOCKSUFF);
3168 sprintf(lpath, "%s" LOCKSUFF, path);
3169 strcpy(dpath, path);
3171 dpath = lpath + len + sizeof(LOCKNAME);
3172 sprintf(lpath, "%s" LOCKNAME, path);
3173 sprintf(dpath, "%s" DATANAME, path);
3176 flags |= env->me_flags;
3177 /* silently ignore WRITEMAP if we're only getting read access */
3178 if (F_ISSET(flags, MDB_RDONLY|MDB_WRITEMAP))
3179 flags ^= MDB_WRITEMAP;
3180 env->me_flags = flags |= MDB_ENV_ACTIVE;
3182 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
3187 if (F_ISSET(flags, MDB_RDONLY)) {
3188 oflags = GENERIC_READ;
3189 len = OPEN_EXISTING;
3191 oflags = GENERIC_READ|GENERIC_WRITE;
3194 mode = FILE_ATTRIBUTE_NORMAL;
3195 env->me_fd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
3196 NULL, len, mode, NULL);
3198 if (F_ISSET(flags, MDB_RDONLY))
3201 oflags = O_RDWR | O_CREAT;
3203 env->me_fd = open(dpath, oflags, mode);
3205 if (env->me_fd == INVALID_HANDLE_VALUE) {
3210 if ((rc = mdb_env_open2(env)) == MDB_SUCCESS) {
3211 if (flags & (MDB_RDONLY|MDB_NOSYNC|MDB_NOMETASYNC|MDB_WRITEMAP)) {
3212 env->me_mfd = env->me_fd;
3214 /* synchronous fd for meta writes */
3216 env->me_mfd = CreateFile(dpath, oflags,
3217 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len,
3218 mode | FILE_FLAG_WRITE_THROUGH, NULL);
3220 env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode);
3222 if (env->me_mfd == INVALID_HANDLE_VALUE) {
3227 DPRINTF("opened dbenv %p", (void *) env);
3228 rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
3231 env->me_numdbs = 2; /* this notes that me_txkey was set */
3233 /* Windows TLS callbacks need help finding their TLS info. */
3234 if (mdb_tls_nkeys < MAX_TLS_KEYS)
3235 mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey;
3242 rc = mdb_env_share_locks(env, &excl);
3246 env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx));
3247 env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t));
3248 env->me_path = strdup(path);
3249 if (!env->me_dbxs || !env->me_dbflags || !env->me_path)
3255 mdb_env_close0(env, excl);
3261 /** Destroy resources from mdb_env_open() and clear our readers */
3263 mdb_env_close0(MDB_env *env, int excl)
3267 if (!(env->me_flags & MDB_ENV_ACTIVE))
3270 free(env->me_dbflags);
3274 if (env->me_numdbs) {
3275 pthread_key_delete(env->me_txkey);
3277 /* Delete our key from the global list */
3278 for (i=0; i<mdb_tls_nkeys; i++)
3279 if (mdb_tls_keys[i] == env->me_txkey) {
3280 mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1];
3288 munmap(env->me_map, env->me_mapsize);
3290 if (env->me_mfd != env->me_fd && env->me_mfd != INVALID_HANDLE_VALUE)
3292 if (env->me_fd != INVALID_HANDLE_VALUE)
3295 pid_t pid = env->me_pid;
3296 /* Clearing readers is done in this function because
3297 * me_txkey with its destructor must be disabled first.
3299 for (i = env->me_numreaders; --i >= 0; )
3300 if (env->me_txns->mti_readers[i].mr_pid == pid)
3301 env->me_txns->mti_readers[i].mr_pid = 0;
3303 if (env->me_rmutex) {
3304 CloseHandle(env->me_rmutex);
3305 if (env->me_wmutex) CloseHandle(env->me_wmutex);
3307 /* Windows automatically destroys the mutexes when
3308 * the last handle closes.
3310 #elif defined(MDB_USE_POSIX_SEM)
3311 if (env->me_rmutex != SEM_FAILED) {
3312 sem_close(env->me_rmutex);
3313 if (env->me_wmutex != SEM_FAILED)
3314 sem_close(env->me_wmutex);
3315 /* If we have the filelock: If we are the
3316 * only remaining user, clean up semaphores.
3319 mdb_env_excl_lock(env, &excl);
3321 sem_unlink(env->me_txns->mti_rmname);
3322 sem_unlink(env->me_txns->mti_wmname);
3326 munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
3328 if (env->me_lfd != INVALID_HANDLE_VALUE) {
3331 /* Unlock the lockfile. Windows would have unlocked it
3332 * after closing anyway, but not necessarily at once.
3334 UnlockFile(env->me_lfd, 0, 0, 1, 0);
3340 env->me_flags &= ~MDB_ENV_ACTIVE;
3344 mdb_env_copy(MDB_env *env, const char *path)
3346 MDB_txn *txn = NULL;
3350 HANDLE newfd = INVALID_HANDLE_VALUE;
3352 if (env->me_flags & MDB_NOSUBDIR) {
3353 lpath = (char *)path;
3356 len += sizeof(DATANAME);
3357 lpath = malloc(len);
3360 sprintf(lpath, "%s" DATANAME, path);
3363 /* The destination path must exist, but the destination file must not.
3364 * We don't want the OS to cache the writes, since the source data is
3365 * already in the OS cache.
3368 newfd = CreateFile(lpath, GENERIC_WRITE, 0, NULL, CREATE_NEW,
3369 FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL);
3371 newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL
3377 if (!(env->me_flags & MDB_NOSUBDIR))
3379 if (newfd == INVALID_HANDLE_VALUE) {
3384 #ifdef F_NOCACHE /* __APPLE__ */
3385 rc = fcntl(newfd, F_NOCACHE, 1);
3392 /* Do the lock/unlock of the reader mutex before starting the
3393 * write txn. Otherwise other read txns could block writers.
3395 rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
3399 if (!(env->me_flags & MDB_ROFS)) {
3400 /* We must start the actual read txn after blocking writers */
3401 mdb_txn_reset0(txn);
3403 /* Temporarily block writers until we snapshot the meta pages */
3406 rc = mdb_txn_renew0(txn);
3408 UNLOCK_MUTEX_W(env);
3413 wsize = env->me_psize * 2;
3417 rc = WriteFile(newfd, env->me_map, wsize, &len, NULL);
3418 rc = (len == wsize) ? MDB_SUCCESS : ErrCode();
3421 rc = write(newfd, env->me_map, wsize);
3422 rc = (rc == (int)wsize) ? MDB_SUCCESS : ErrCode();
3424 if (! (env->me_flags & MDB_ROFS))
3425 UNLOCK_MUTEX_W(env);
3430 ptr = env->me_map + wsize;
3431 wsize = txn->mt_next_pgno * env->me_psize - wsize;
3435 rc = WriteFile(newfd, ptr, wsize, &len, NULL);
3436 rc = (len == wsize) ? MDB_SUCCESS : ErrCode();
3439 rc = write(newfd, ptr, wsize);
3440 rc = (rc == (int)wsize) ? MDB_SUCCESS : ErrCode();
3445 if (newfd != INVALID_HANDLE_VALUE)
3452 mdb_env_close(MDB_env *env)
3459 VGMEMP_DESTROY(env);
3460 while ((dp = env->me_dpages) != NULL) {
3461 VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next));
3462 env->me_dpages = dp->mp_next;
3466 mdb_env_close0(env, 0);
3467 mdb_midl_free(env->me_free_pgs);
3471 /** Compare two items pointing at aligned size_t's */
3473 mdb_cmp_long(const MDB_val *a, const MDB_val *b)
3475 return (*(size_t *)a->mv_data < *(size_t *)b->mv_data) ? -1 :
3476 *(size_t *)a->mv_data > *(size_t *)b->mv_data;
3479 /** Compare two items pointing at aligned int's */
3481 mdb_cmp_int(const MDB_val *a, const MDB_val *b)
3483 return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 :
3484 *(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data;
3487 /** Compare two items pointing at ints of unknown alignment.
3488 * Nodes and keys are guaranteed to be 2-byte aligned.
3491 mdb_cmp_cint(const MDB_val *a, const MDB_val *b)
3493 #if BYTE_ORDER == LITTLE_ENDIAN
3494 unsigned short *u, *c;
3497 u = (unsigned short *) ((char *) a->mv_data + a->mv_size);
3498 c = (unsigned short *) ((char *) b->mv_data + a->mv_size);
3501 } while(!x && u > (unsigned short *)a->mv_data);
3504 return memcmp(a->mv_data, b->mv_data, a->mv_size);
3508 /** Compare two items lexically */
3510 mdb_cmp_memn(const MDB_val *a, const MDB_val *b)
3517 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
3523 diff = memcmp(a->mv_data, b->mv_data, len);
3524 return diff ? diff : len_diff<0 ? -1 : len_diff;
3527 /** Compare two items in reverse byte order */
3529 mdb_cmp_memnr(const MDB_val *a, const MDB_val *b)
3531 const unsigned char *p1, *p2, *p1_lim;
3535 p1_lim = (const unsigned char *)a->mv_data;
3536 p1 = (const unsigned char *)a->mv_data + a->mv_size;
3537 p2 = (const unsigned char *)b->mv_data + b->mv_size;
3539 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
3545 while (p1 > p1_lim) {
3546 diff = *--p1 - *--p2;
3550 return len_diff<0 ? -1 : len_diff;
3553 /** Search for key within a page, using binary search.
3554 * Returns the smallest entry larger or equal to the key.
3555 * If exactp is non-null, stores whether the found entry was an exact match
3556 * in *exactp (1 or 0).
3557 * Updates the cursor index with the index of the found entry.
3558 * If no entry larger or equal to the key is found, returns NULL.
3561 mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)
3563 unsigned int i = 0, nkeys;
3566 MDB_page *mp = mc->mc_pg[mc->mc_top];
3567 MDB_node *node = NULL;
3572 nkeys = NUMKEYS(mp);
3577 COPY_PGNO(pgno, mp->mp_pgno);
3578 DPRINTF("searching %u keys in %s %spage %zu",
3579 nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "",
3586 low = IS_LEAF(mp) ? 0 : 1;
3588 cmp = mc->mc_dbx->md_cmp;
3590 /* Branch pages have no data, so if using integer keys,
3591 * alignment is guaranteed. Use faster mdb_cmp_int.
3593 if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) {
3594 if (NODEPTR(mp, 1)->mn_ksize == sizeof(size_t))
3601 nodekey.mv_size = mc->mc_db->md_pad;
3602 node = NODEPTR(mp, 0); /* fake */
3603 while (low <= high) {
3604 i = (low + high) >> 1;
3605 nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size);
3606 rc = cmp(key, &nodekey);
3607 DPRINTF("found leaf index %u [%s], rc = %i",
3608 i, DKEY(&nodekey), rc);
3617 while (low <= high) {
3618 i = (low + high) >> 1;
3620 node = NODEPTR(mp, i);
3621 nodekey.mv_size = NODEKSZ(node);
3622 nodekey.mv_data = NODEKEY(node);
3624 rc = cmp(key, &nodekey);
3627 DPRINTF("found leaf index %u [%s], rc = %i",
3628 i, DKEY(&nodekey), rc);
3630 DPRINTF("found branch index %u [%s -> %zu], rc = %i",
3631 i, DKEY(&nodekey), NODEPGNO(node), rc);
3642 if (rc > 0) { /* Found entry is less than the key. */
3643 i++; /* Skip to get the smallest entry larger than key. */
3645 node = NODEPTR(mp, i);
3648 *exactp = (rc == 0);
3649 /* store the key index */
3650 mc->mc_ki[mc->mc_top] = i;
3652 /* There is no entry larger or equal to the key. */
3655 /* nodeptr is fake for LEAF2 */
3661 mdb_cursor_adjust(MDB_cursor *mc, func)
3665 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
3666 if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) {
3673 /** Pop a page off the top of the cursor's stack. */
3675 mdb_cursor_pop(MDB_cursor *mc)
3679 MDB_page *top = mc->mc_pg[mc->mc_top];
3685 DPRINTF("popped page %zu off db %u cursor %p", top->mp_pgno,
3686 mc->mc_dbi, (void *) mc);
3690 /** Push a page onto the top of the cursor's stack. */
3692 mdb_cursor_push(MDB_cursor *mc, MDB_page *mp)
3694 DPRINTF("pushing page %zu on db %u cursor %p", mp->mp_pgno,
3695 mc->mc_dbi, (void *) mc);
3697 if (mc->mc_snum >= CURSOR_STACK) {
3698 assert(mc->mc_snum < CURSOR_STACK);
3699 return MDB_CURSOR_FULL;
3702 mc->mc_top = mc->mc_snum++;
3703 mc->mc_pg[mc->mc_top] = mp;
3704 mc->mc_ki[mc->mc_top] = 0;
3709 /** Find the address of the page corresponding to a given page number.
3710 * @param[in] txn the transaction for this access.
3711 * @param[in] pgno the page number for the page to retrieve.
3712 * @param[out] ret address of a pointer where the page's address will be stored.
3713 * @return 0 on success, non-zero on failure.
3716 mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret)
3720 if (txn->mt_env->me_flags & MDB_WRITEMAP) {
3721 if (pgno < txn->mt_next_pgno)
3722 p = (MDB_page *)(txn->mt_env->me_map + txn->mt_env->me_psize * pgno);
3725 if (!F_ISSET(txn->mt_flags, MDB_TXN_RDONLY) && txn->mt_u.dirty_list[0].mid) {
3727 x = mdb_mid2l_search(txn->mt_u.dirty_list, pgno);
3728 if (x <= txn->mt_u.dirty_list[0].mid && txn->mt_u.dirty_list[x].mid == pgno) {
3729 p = txn->mt_u.dirty_list[x].mptr;
3733 if (pgno < txn->mt_next_pgno)
3734 p = (MDB_page *)(txn->mt_env->me_map + txn->mt_env->me_psize * pgno);
3739 DPRINTF("page %zu not found", pgno);
3742 return (p != NULL) ? MDB_SUCCESS : MDB_PAGE_NOTFOUND;
3745 /** Search for the page a given key should be in.
3746 * Pushes parent pages on the cursor stack. This function continues a
3747 * search on a cursor that has already been initialized. (Usually by
3748 * #mdb_page_search() but also by #mdb_node_move().)
3749 * @param[in,out] mc the cursor for this operation.
3750 * @param[in] key the key to search for. If NULL, search for the lowest
3751 * page. (This is used by #mdb_cursor_first().)
3752 * @param[in] flags If MDB_PS_MODIFY set, visited pages are updated with new page numbers.
3753 * If MDB_PS_ROOTONLY set, just fetch root node, no further lookups.
3754 * @return 0 on success, non-zero on failure.
3757 mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int modify)
3759 MDB_page *mp = mc->mc_pg[mc->mc_top];
3764 while (IS_BRANCH(mp)) {
3768 DPRINTF("branch page %zu has %u keys", mp->mp_pgno, NUMKEYS(mp));
3769 assert(NUMKEYS(mp) > 1);
3770 DPRINTF("found index 0 to page %zu", NODEPGNO(NODEPTR(mp, 0)));
3772 if (key == NULL) /* Initialize cursor to first page. */
3774 else if (key->mv_size > MAXKEYSIZE && key->mv_data == NULL) {
3775 /* cursor to last page */
3779 node = mdb_node_search(mc, key, &exact);
3781 i = NUMKEYS(mp) - 1;
3783 i = mc->mc_ki[mc->mc_top];
3792 DPRINTF("following index %u for key [%s]",
3794 assert(i < NUMKEYS(mp));
3795 node = NODEPTR(mp, i);
3797 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp)))
3800 mc->mc_ki[mc->mc_top] = i;
3801 if ((rc = mdb_cursor_push(mc, mp)))
3805 if ((rc = mdb_page_touch(mc)) != 0)
3807 mp = mc->mc_pg[mc->mc_top];
3812 DPRINTF("internal error, index points to a %02X page!?",
3814 return MDB_CORRUPTED;
3817 DPRINTF("found leaf page %zu for key [%s]", mp->mp_pgno,
3818 key ? DKEY(key) : NULL);
3823 /** Search for the page a given key should be in.
3824 * Pushes parent pages on the cursor stack. This function just sets up
3825 * the search; it finds the root page for \b mc's database and sets this
3826 * as the root of the cursor's stack. Then #mdb_page_search_root() is
3827 * called to complete the search.
3828 * @param[in,out] mc the cursor for this operation.
3829 * @param[in] key the key to search for. If NULL, search for the lowest
3830 * page. (This is used by #mdb_cursor_first().)
3831 * @param[in] modify If true, visited pages are updated with new page numbers.
3832 * @return 0 on success, non-zero on failure.
3835 mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)
3840 /* Make sure the txn is still viable, then find the root from
3841 * the txn's db table.
3843 if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_ERROR)) {
3844 DPUTS("transaction has failed, must abort");
3847 /* Make sure we're using an up-to-date root */
3848 if (mc->mc_dbi > MAIN_DBI) {
3849 if ((*mc->mc_dbflag & DB_STALE) ||
3850 ((flags & MDB_PS_MODIFY) && !(*mc->mc_dbflag & DB_DIRTY))) {
3852 unsigned char dbflag = 0;
3853 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);
3854 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, flags & MDB_PS_MODIFY);
3857 if (*mc->mc_dbflag & DB_STALE) {
3860 MDB_node *leaf = mdb_node_search(&mc2,
3861 &mc->mc_dbx->md_name, &exact);
3863 return MDB_NOTFOUND;
3864 mdb_node_read(mc->mc_txn, leaf, &data);
3865 memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db));
3867 if (flags & MDB_PS_MODIFY)
3869 *mc->mc_dbflag = dbflag;
3872 root = mc->mc_db->md_root;
3874 if (root == P_INVALID) { /* Tree is empty. */
3875 DPUTS("tree is empty");
3876 return MDB_NOTFOUND;
3881 if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root)
3882 if ((rc = mdb_page_get(mc->mc_txn, root, &mc->mc_pg[0])))
3888 DPRINTF("db %u root page %zu has flags 0x%X",
3889 mc->mc_dbi, root, mc->mc_pg[0]->mp_flags);
3891 if (flags & MDB_PS_MODIFY) {
3892 if ((rc = mdb_page_touch(mc)))
3896 if (flags & MDB_PS_ROOTONLY)
3899 return mdb_page_search_root(mc, key, flags);
3902 /** Return the data associated with a given node.
3903 * @param[in] txn The transaction for this operation.
3904 * @param[in] leaf The node being read.
3905 * @param[out] data Updated to point to the node's data.
3906 * @return 0 on success, non-zero on failure.
3909 mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data)
3911 MDB_page *omp; /* overflow page */
3915 if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
3916 data->mv_size = NODEDSZ(leaf);
3917 data->mv_data = NODEDATA(leaf);
3921 /* Read overflow data.
3923 data->mv_size = NODEDSZ(leaf);
3924 memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
3925 if ((rc = mdb_page_get(txn, pgno, &omp))) {
3926 DPRINTF("read overflow page %zu failed", pgno);
3929 data->mv_data = METADATA(omp);
3935 mdb_get(MDB_txn *txn, MDB_dbi dbi,
3936 MDB_val *key, MDB_val *data)
3945 DPRINTF("===> get db %u key [%s]", dbi, DKEY(key));
3947 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
3950 if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
3954 mdb_cursor_init(&mc, txn, dbi, &mx);
3955 return mdb_cursor_set(&mc, key, data, MDB_SET, &exact);
3958 /** Find a sibling for a page.
3959 * Replaces the page at the top of the cursor's stack with the
3960 * specified sibling, if one exists.
3961 * @param[in] mc The cursor for this operation.
3962 * @param[in] move_right Non-zero if the right sibling is requested,
3963 * otherwise the left sibling.
3964 * @return 0 on success, non-zero on failure.
3967 mdb_cursor_sibling(MDB_cursor *mc, int move_right)
3973 if (mc->mc_snum < 2) {
3974 return MDB_NOTFOUND; /* root has no siblings */
3978 DPRINTF("parent page is page %zu, index %u",
3979 mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]);
3981 if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top]))
3982 : (mc->mc_ki[mc->mc_top] == 0)) {
3983 DPRINTF("no more keys left, moving to %s sibling",
3984 move_right ? "right" : "left");
3985 if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS)
3989 mc->mc_ki[mc->mc_top]++;
3991 mc->mc_ki[mc->mc_top]--;
3992 DPRINTF("just moving to %s index key %u",
3993 move_right ? "right" : "left", mc->mc_ki[mc->mc_top]);
3995 assert(IS_BRANCH(mc->mc_pg[mc->mc_top]));
3997 indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
3998 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(indx), &mp)))
4001 mdb_cursor_push(mc, mp);
4006 /** Move the cursor to the next data item. */
4008 mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
4014 if (mc->mc_flags & C_EOF) {
4015 return MDB_NOTFOUND;
4018 assert(mc->mc_flags & C_INITIALIZED);
4020 mp = mc->mc_pg[mc->mc_top];
4022 if (mc->mc_db->md_flags & MDB_DUPSORT) {
4023 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
4024 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4025 if (op == MDB_NEXT || op == MDB_NEXT_DUP) {
4026 rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);
4027 if (op != MDB_NEXT || rc == MDB_SUCCESS)
4031 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
4032 if (op == MDB_NEXT_DUP)
4033 return MDB_NOTFOUND;
4037 DPRINTF("cursor_next: top page is %zu in cursor %p", mp->mp_pgno, (void *) mc);
4039 if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) {
4040 DPUTS("=====> move to next sibling page");
4041 if (mdb_cursor_sibling(mc, 1) != MDB_SUCCESS) {
4042 mc->mc_flags |= C_EOF;
4043 mc->mc_flags &= ~C_INITIALIZED;
4044 return MDB_NOTFOUND;
4046 mp = mc->mc_pg[mc->mc_top];
4047 DPRINTF("next page is %zu, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]);
4049 mc->mc_ki[mc->mc_top]++;
4051 DPRINTF("==> cursor points to page %zu with %u keys, key index %u",
4052 mp->mp_pgno, NUMKEYS(mp), mc->mc_ki[mc->mc_top]);
4055 key->mv_size = mc->mc_db->md_pad;
4056 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
4060 assert(IS_LEAF(mp));
4061 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
4063 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4064 mdb_xcursor_init1(mc, leaf);
4067 if ((rc = mdb_node_read(mc->mc_txn, leaf, data) != MDB_SUCCESS))
4070 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4071 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
4072 if (rc != MDB_SUCCESS)
4077 MDB_GET_KEY(leaf, key);
4081 /** Move the cursor to the previous data item. */
4083 mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
4089 assert(mc->mc_flags & C_INITIALIZED);
4091 mp = mc->mc_pg[mc->mc_top];
4093 if (mc->mc_db->md_flags & MDB_DUPSORT) {
4094 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
4095 if (op == MDB_PREV || op == MDB_PREV_DUP) {
4096 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4097 rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
4098 if (op != MDB_PREV || rc == MDB_SUCCESS)
4101 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
4102 if (op == MDB_PREV_DUP)
4103 return MDB_NOTFOUND;
4108 DPRINTF("cursor_prev: top page is %zu in cursor %p", mp->mp_pgno, (void *) mc);
4110 if (mc->mc_ki[mc->mc_top] == 0) {
4111 DPUTS("=====> move to prev sibling page");
4112 if (mdb_cursor_sibling(mc, 0) != MDB_SUCCESS) {
4113 mc->mc_flags &= ~C_INITIALIZED;
4114 return MDB_NOTFOUND;
4116 mp = mc->mc_pg[mc->mc_top];
4117 mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;
4118 DPRINTF("prev page is %zu, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]);
4120 mc->mc_ki[mc->mc_top]--;
4122 mc->mc_flags &= ~C_EOF;
4124 DPRINTF("==> cursor points to page %zu with %u keys, key index %u",
4125 mp->mp_pgno, NUMKEYS(mp), mc->mc_ki[mc->mc_top]);
4128 key->mv_size = mc->mc_db->md_pad;
4129 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
4133 assert(IS_LEAF(mp));
4134 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
4136 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4137 mdb_xcursor_init1(mc, leaf);
4140 if ((rc = mdb_node_read(mc->mc_txn, leaf, data) != MDB_SUCCESS))
4143 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4144 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
4145 if (rc != MDB_SUCCESS)
4150 MDB_GET_KEY(leaf, key);
4154 /** Set the cursor on a specific data item. */
4156 mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data,
4157 MDB_cursor_op op, int *exactp)
4161 MDB_node *leaf = NULL;
4166 assert(key->mv_size > 0);
4168 /* See if we're already on the right page */
4169 if (mc->mc_flags & C_INITIALIZED) {
4172 mp = mc->mc_pg[mc->mc_top];
4174 mc->mc_ki[mc->mc_top] = 0;
4175 return MDB_NOTFOUND;
4177 if (mp->mp_flags & P_LEAF2) {
4178 nodekey.mv_size = mc->mc_db->md_pad;
4179 nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size);
4181 leaf = NODEPTR(mp, 0);
4182 MDB_GET_KEY(leaf, &nodekey);
4184 rc = mc->mc_dbx->md_cmp(key, &nodekey);
4186 /* Probably happens rarely, but first node on the page
4187 * was the one we wanted.
4189 mc->mc_ki[mc->mc_top] = 0;
4196 unsigned int nkeys = NUMKEYS(mp);
4198 if (mp->mp_flags & P_LEAF2) {
4199 nodekey.mv_data = LEAF2KEY(mp,
4200 nkeys-1, nodekey.mv_size);
4202 leaf = NODEPTR(mp, nkeys-1);
4203 MDB_GET_KEY(leaf, &nodekey);
4205 rc = mc->mc_dbx->md_cmp(key, &nodekey);
4207 /* last node was the one we wanted */
4208 mc->mc_ki[mc->mc_top] = nkeys-1;
4214 if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) {
4215 /* This is definitely the right page, skip search_page */
4216 if (mp->mp_flags & P_LEAF2) {
4217 nodekey.mv_data = LEAF2KEY(mp,
4218 mc->mc_ki[mc->mc_top], nodekey.mv_size);
4220 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
4221 MDB_GET_KEY(leaf, &nodekey);
4223 rc = mc->mc_dbx->md_cmp(key, &nodekey);
4225 /* current node was the one we wanted */
4235 /* If any parents have right-sibs, search.
4236 * Otherwise, there's nothing further.
4238 for (i=0; i<mc->mc_top; i++)
4240 NUMKEYS(mc->mc_pg[i])-1)
4242 if (i == mc->mc_top) {
4243 /* There are no other pages */
4244 mc->mc_ki[mc->mc_top] = nkeys;
4245 return MDB_NOTFOUND;
4249 /* There are no other pages */
4250 mc->mc_ki[mc->mc_top] = 0;
4251 return MDB_NOTFOUND;
4255 rc = mdb_page_search(mc, key, 0);
4256 if (rc != MDB_SUCCESS)
4259 mp = mc->mc_pg[mc->mc_top];
4260 assert(IS_LEAF(mp));
4263 leaf = mdb_node_search(mc, key, exactp);
4264 if (exactp != NULL && !*exactp) {
4265 /* MDB_SET specified and not an exact match. */
4266 return MDB_NOTFOUND;
4270 DPUTS("===> inexact leaf not found, goto sibling");
4271 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS)
4272 return rc; /* no entries matched */
4273 mp = mc->mc_pg[mc->mc_top];
4274 assert(IS_LEAF(mp));
4275 leaf = NODEPTR(mp, 0);
4279 mc->mc_flags |= C_INITIALIZED;
4280 mc->mc_flags &= ~C_EOF;
4283 key->mv_size = mc->mc_db->md_pad;
4284 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
4288 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4289 mdb_xcursor_init1(mc, leaf);
4292 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4293 if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) {
4294 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
4297 if (op == MDB_GET_BOTH) {
4303 rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p);
4304 if (rc != MDB_SUCCESS)
4307 } else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {
4309 if ((rc = mdb_node_read(mc->mc_txn, leaf, &d2)) != MDB_SUCCESS)
4311 rc = mc->mc_dbx->md_dcmp(data, &d2);
4313 if (op == MDB_GET_BOTH || rc > 0)
4314 return MDB_NOTFOUND;
4319 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
4320 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
4325 /* The key already matches in all other cases */
4326 if (op == MDB_SET_RANGE || op == MDB_SET_KEY)
4327 MDB_GET_KEY(leaf, key);
4328 DPRINTF("==> cursor placed on key [%s]", DKEY(key));
4333 /** Move the cursor to the first item in the database. */
4335 mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data)
4340 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
4341 rc = mdb_page_search(mc, NULL, 0);
4342 if (rc != MDB_SUCCESS)
4345 assert(IS_LEAF(mc->mc_pg[mc->mc_top]));
4347 leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0);
4348 mc->mc_flags |= C_INITIALIZED;
4349 mc->mc_flags &= ~C_EOF;
4351 mc->mc_ki[mc->mc_top] = 0;
4353 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
4354 key->mv_size = mc->mc_db->md_pad;
4355 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size);
4360 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4361 mdb_xcursor_init1(mc, leaf);
4362 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
4367 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
4368 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
4372 MDB_GET_KEY(leaf, key);
4376 /** Move the cursor to the last item in the database. */
4378 mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)
4383 if (!(mc->mc_flags & C_EOF)) {
4385 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
4388 lkey.mv_size = MAXKEYSIZE+1;
4389 lkey.mv_data = NULL;
4390 rc = mdb_page_search(mc, &lkey, 0);
4391 if (rc != MDB_SUCCESS)
4394 assert(IS_LEAF(mc->mc_pg[mc->mc_top]));
4396 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;
4397 mc->mc_flags |= C_INITIALIZED|C_EOF;
4399 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
4401 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
4402 key->mv_size = mc->mc_db->md_pad;
4403 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size);
4408 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4409 mdb_xcursor_init1(mc, leaf);
4410 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
4415 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
4416 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
4421 MDB_GET_KEY(leaf, key);
4426 mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,
4435 case MDB_GET_CURRENT:
4436 if (!mc->mc_flags & C_INITIALIZED) {
4439 MDB_page *mp = mc->mc_pg[mc->mc_top];
4441 mc->mc_ki[mc->mc_top] = 0;
4447 key->mv_size = mc->mc_db->md_pad;
4448 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
4450 MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
4451 MDB_GET_KEY(leaf, key);
4453 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4454 rc = mdb_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT);
4456 rc = mdb_node_read(mc->mc_txn, leaf, data);
4463 case MDB_GET_BOTH_RANGE:
4464 if (data == NULL || mc->mc_xcursor == NULL) {
4472 if (key == NULL || key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
4474 } else if (op == MDB_SET_RANGE)
4475 rc = mdb_cursor_set(mc, key, data, op, NULL);
4477 rc = mdb_cursor_set(mc, key, data, op, &exact);
4479 case MDB_GET_MULTIPLE:
4481 !(mc->mc_db->md_flags & MDB_DUPFIXED) ||
4482 !(mc->mc_flags & C_INITIALIZED)) {
4487 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) ||
4488 (mc->mc_xcursor->mx_cursor.mc_flags & C_EOF))
4491 case MDB_NEXT_MULTIPLE:
4493 !(mc->mc_db->md_flags & MDB_DUPFIXED)) {
4497 if (!(mc->mc_flags & C_INITIALIZED))
4498 rc = mdb_cursor_first(mc, key, data);
4500 rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP);
4501 if (rc == MDB_SUCCESS) {
4502 if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
4505 mx = &mc->mc_xcursor->mx_cursor;
4506 data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) *
4508 data->mv_data = METADATA(mx->mc_pg[mx->mc_top]);
4509 mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1;
4517 case MDB_NEXT_NODUP:
4518 if (!(mc->mc_flags & C_INITIALIZED))
4519 rc = mdb_cursor_first(mc, key, data);
4521 rc = mdb_cursor_next(mc, key, data, op);
4525 case MDB_PREV_NODUP:
4526 if (!(mc->mc_flags & C_INITIALIZED) || (mc->mc_flags & C_EOF)) {
4527 rc = mdb_cursor_last(mc, key, data);
4528 mc->mc_flags &= ~C_EOF;
4530 rc = mdb_cursor_prev(mc, key, data, op);
4533 rc = mdb_cursor_first(mc, key, data);
4537 !(mc->mc_db->md_flags & MDB_DUPSORT) ||
4538 !(mc->mc_flags & C_INITIALIZED) ||
4539 !(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
4543 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
4546 rc = mdb_cursor_last(mc, key, data);
4550 !(mc->mc_db->md_flags & MDB_DUPSORT) ||
4551 !(mc->mc_flags & C_INITIALIZED) ||
4552 !(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
4556 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
4559 DPRINTF("unhandled/unimplemented cursor operation %u", op);
4567 /** Touch all the pages in the cursor stack.
4568 * Makes sure all the pages are writable, before attempting a write operation.
4569 * @param[in] mc The cursor to operate on.
4572 mdb_cursor_touch(MDB_cursor *mc)
4576 if (mc->mc_dbi > MAIN_DBI && !(*mc->mc_dbflag & DB_DIRTY)) {
4578 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);
4579 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY);
4582 *mc->mc_dbflag = DB_DIRTY;
4584 for (mc->mc_top = 0; mc->mc_top < mc->mc_snum; mc->mc_top++) {
4585 rc = mdb_page_touch(mc);
4589 mc->mc_top = mc->mc_snum-1;
4594 mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
4597 MDB_node *leaf = NULL;
4598 MDB_val xdata, *rdata, dkey;
4601 int do_sub = 0, insert = 0;
4602 unsigned int mcount = 0;
4606 char dbuf[MAXKEYSIZE+1];
4607 unsigned int nflags;
4610 if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_RDONLY))
4613 DPRINTF("==> put db %u key [%s], size %zu, data size %zu",
4614 mc->mc_dbi, DKEY(key), key ? key->mv_size:0, data->mv_size);
4618 if (flags == MDB_CURRENT) {
4619 if (!(mc->mc_flags & C_INITIALIZED))
4622 } else if (mc->mc_db->md_root == P_INVALID) {
4624 /* new database, write a root leaf page */
4625 DPUTS("allocating new root leaf page");
4626 if ((rc = mdb_page_new(mc, P_LEAF, 1, &np))) {
4630 mdb_cursor_push(mc, np);
4631 mc->mc_db->md_root = np->mp_pgno;
4632 mc->mc_db->md_depth++;
4633 *mc->mc_dbflag = DB_DIRTY;
4634 if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED))
4636 np->mp_flags |= P_LEAF2;
4637 mc->mc_flags |= C_INITIALIZED;
4643 if (flags & MDB_APPEND) {
4645 rc = mdb_cursor_last(mc, &k2, &d2);
4647 rc = mc->mc_dbx->md_cmp(key, &k2);
4650 mc->mc_ki[mc->mc_top]++;
4656 rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact);
4658 if ((flags & MDB_NOOVERWRITE) && rc == 0) {
4659 DPRINTF("duplicate key [%s]", DKEY(key));
4661 return MDB_KEYEXIST;
4663 if (rc && rc != MDB_NOTFOUND)
4667 /* Cursor is positioned, now make sure all pages are writable */
4668 rc2 = mdb_cursor_touch(mc);
4673 /* The key already exists */
4674 if (rc == MDB_SUCCESS) {
4675 /* there's only a key anyway, so this is a no-op */
4676 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
4677 unsigned int ksize = mc->mc_db->md_pad;
4678 if (key->mv_size != ksize)
4680 if (flags == MDB_CURRENT) {
4681 char *ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize);
4682 memcpy(ptr, key->mv_data, ksize);
4687 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
4690 if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) {
4691 /* Was a single item before, must convert now */
4693 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4694 /* Just overwrite the current item */
4695 if (flags == MDB_CURRENT)
4698 dkey.mv_size = NODEDSZ(leaf);
4699 dkey.mv_data = NODEDATA(leaf);
4700 #if UINT_MAX < SIZE_MAX
4701 if (mc->mc_dbx->md_dcmp == mdb_cmp_int && dkey.mv_size == sizeof(size_t))
4702 #ifdef MISALIGNED_OK
4703 mc->mc_dbx->md_dcmp = mdb_cmp_long;
4705 mc->mc_dbx->md_dcmp = mdb_cmp_cint;
4708 /* if data matches, ignore it */
4709 if (!mc->mc_dbx->md_dcmp(data, &dkey))
4710 return (flags == MDB_NODUPDATA) ? MDB_KEYEXIST : MDB_SUCCESS;
4712 /* create a fake page for the dup items */
4713 memcpy(dbuf, dkey.mv_data, dkey.mv_size);
4714 dkey.mv_data = dbuf;
4715 fp = (MDB_page *)&pbuf;
4716 fp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
4717 fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP;
4718 fp->mp_lower = PAGEHDRSZ;
4719 fp->mp_upper = PAGEHDRSZ + dkey.mv_size + data->mv_size;
4720 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
4721 fp->mp_flags |= P_LEAF2;
4722 fp->mp_pad = data->mv_size;
4723 fp->mp_upper += 2 * data->mv_size; /* leave space for 2 more */
4725 fp->mp_upper += 2 * sizeof(indx_t) + 2 * NODESIZE +
4726 (dkey.mv_size & 1) + (data->mv_size & 1);
4728 mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0);
4731 xdata.mv_size = fp->mp_upper;
4736 if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
4737 /* See if we need to convert from fake page to subDB */
4739 unsigned int offset;
4742 fp = NODEDATA(leaf);
4743 if (flags == MDB_CURRENT) {
4745 fp->mp_flags |= P_DIRTY;
4746 COPY_PGNO(fp->mp_pgno, mc->mc_pg[mc->mc_top]->mp_pgno);
4747 mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;
4751 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
4752 offset = fp->mp_pad;
4753 if (SIZELEFT(fp) >= offset)
4755 offset *= 4; /* space for 4 more */
4757 offset = NODESIZE + sizeof(indx_t) + data->mv_size;
4759 offset += offset & 1;
4760 if (NODESIZE + sizeof(indx_t) + NODEKSZ(leaf) + NODEDSZ(leaf) +
4761 offset >= (mc->mc_txn->mt_env->me_psize - PAGEHDRSZ) /
4763 /* yes, convert it */
4765 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
4766 dummy.md_pad = fp->mp_pad;
4767 dummy.md_flags = MDB_DUPFIXED;
4768 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
4769 dummy.md_flags |= MDB_INTEGERKEY;
4772 dummy.md_branch_pages = 0;
4773 dummy.md_leaf_pages = 1;
4774 dummy.md_overflow_pages = 0;
4775 dummy.md_entries = NUMKEYS(fp);
4777 xdata.mv_size = sizeof(MDB_db);
4778 xdata.mv_data = &dummy;
4779 if ((rc = mdb_page_alloc(mc, 1, &mp)))
4781 offset = mc->mc_txn->mt_env->me_psize - NODEDSZ(leaf);
4782 flags |= F_DUPDATA|F_SUBDATA;
4783 dummy.md_root = mp->mp_pgno;
4785 /* no, just grow it */
4787 xdata.mv_size = NODEDSZ(leaf) + offset;
4788 xdata.mv_data = &pbuf;
4789 mp = (MDB_page *)&pbuf;
4790 mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
4793 mp->mp_flags = fp->mp_flags | P_DIRTY;
4794 mp->mp_pad = fp->mp_pad;
4795 mp->mp_lower = fp->mp_lower;
4796 mp->mp_upper = fp->mp_upper + offset;
4798 memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad);
4800 nsize = NODEDSZ(leaf) - fp->mp_upper;
4801 memcpy((char *)mp + mp->mp_upper, (char *)fp + fp->mp_upper, nsize);
4802 for (i=0; i<NUMKEYS(fp); i++)
4803 mp->mp_ptrs[i] = fp->mp_ptrs[i] + offset;
4805 mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0);
4809 /* data is on sub-DB, just store it */
4810 flags |= F_DUPDATA|F_SUBDATA;
4814 /* overflow page overwrites need special handling */
4815 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
4818 int ovpages, dpages;
4820 ovpages = OVPAGES(NODEDSZ(leaf), mc->mc_txn->mt_env->me_psize);
4821 dpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
4822 memcpy(&pg, NODEDATA(leaf), sizeof(pg));
4823 mdb_page_get(mc->mc_txn, pg, &omp);
4824 /* Is the ov page writable and large enough? */
4825 if ((omp->mp_flags & P_DIRTY) && ovpages >= dpages) {
4826 /* yes, overwrite it. Note in this case we don't
4827 * bother to try shrinking the node if the new data
4828 * is smaller than the overflow threshold.
4830 if (F_ISSET(flags, MDB_RESERVE))
4831 data->mv_data = METADATA(omp);
4833 memcpy(METADATA(omp), data->mv_data, data->mv_size);
4836 /* no, free ovpages */
4838 mc->mc_db->md_overflow_pages -= ovpages;
4839 for (i=0; i<ovpages; i++) {
4840 DPRINTF("freed ov page %zu", pg);
4841 mdb_midl_append(&mc->mc_txn->mt_free_pgs, pg);
4845 } else if (NODEDSZ(leaf) == data->mv_size) {
4846 /* same size, just replace it. Note that we could
4847 * also reuse this node if the new data is smaller,
4848 * but instead we opt to shrink the node in that case.
4850 if (F_ISSET(flags, MDB_RESERVE))
4851 data->mv_data = NODEDATA(leaf);
4853 memcpy(NODEDATA(leaf), data->mv_data, data->mv_size);
4856 mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0);
4857 mc->mc_db->md_entries--;
4859 DPRINTF("inserting key at index %i", mc->mc_ki[mc->mc_top]);
4866 nflags = flags & NODE_ADD_FLAGS;
4867 nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(mc->mc_txn->mt_env, key, rdata);
4868 if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) {
4869 if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA )
4870 nflags &= ~MDB_APPEND;
4872 nflags |= MDB_SPLIT_REPLACE;
4873 rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags);
4875 /* There is room already in this leaf page. */
4876 rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);
4877 if (rc == 0 && !do_sub && insert) {
4878 /* Adjust other cursors pointing to mp */
4879 MDB_cursor *m2, *m3;
4880 MDB_dbi dbi = mc->mc_dbi;
4881 unsigned i = mc->mc_top;
4882 MDB_page *mp = mc->mc_pg[i];
4884 if (mc->mc_flags & C_SUB)
4887 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
4888 if (mc->mc_flags & C_SUB)
4889 m3 = &m2->mc_xcursor->mx_cursor;
4892 if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
4893 if (m3->mc_pg[i] == mp && m3->mc_ki[i] >= mc->mc_ki[i]) {
4900 if (rc != MDB_SUCCESS)
4901 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
4903 /* Now store the actual data in the child DB. Note that we're
4904 * storing the user data in the keys field, so there are strict
4905 * size limits on dupdata. The actual data fields of the child
4906 * DB are all zero size.
4913 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
4914 if (flags & MDB_CURRENT) {
4915 xflags = MDB_CURRENT;
4917 mdb_xcursor_init1(mc, leaf);
4918 xflags = (flags & MDB_NODUPDATA) ? MDB_NOOVERWRITE : 0;
4920 /* converted, write the original data first */
4922 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);
4926 /* Adjust other cursors pointing to mp */
4928 unsigned i = mc->mc_top;
4929 MDB_page *mp = mc->mc_pg[i];
4931 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
4932 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
4933 if (m2->mc_pg[i] == mp && m2->mc_ki[i] == mc->mc_ki[i]) {
4934 mdb_xcursor_init1(m2, leaf);
4939 if (flags & MDB_APPENDDUP)
4940 xflags |= MDB_APPEND;
4941 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);
4942 if (flags & F_SUBDATA) {
4943 void *db = NODEDATA(leaf);
4944 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
4947 /* sub-writes might have failed so check rc again.
4948 * Don't increment count if we just replaced an existing item.
4950 if (!rc && !(flags & MDB_CURRENT))
4951 mc->mc_db->md_entries++;
4952 if (flags & MDB_MULTIPLE) {
4954 if (mcount < data[1].mv_size) {
4955 data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size;
4956 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
4966 mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
4971 if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_RDONLY))
4974 if (!mc->mc_flags & C_INITIALIZED)
4977 rc = mdb_cursor_touch(mc);
4981 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
4983 if (!IS_LEAF2(mc->mc_pg[mc->mc_top]) && F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4984 if (flags != MDB_NODUPDATA) {
4985 if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
4986 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
4988 rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, 0);
4989 /* If sub-DB still has entries, we're done */
4990 if (mc->mc_xcursor->mx_db.md_entries) {
4991 if (leaf->mn_flags & F_SUBDATA) {
4992 /* update subDB info */
4993 void *db = NODEDATA(leaf);
4994 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
4996 /* shrink fake page */
4997 mdb_node_shrink(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
4999 mc->mc_db->md_entries--;
5002 /* otherwise fall thru and delete the sub-DB */
5005 if (leaf->mn_flags & F_SUBDATA) {
5006 /* add all the child DB's pages to the free list */
5007 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
5008 if (rc == MDB_SUCCESS) {
5009 mc->mc_db->md_entries -=
5010 mc->mc_xcursor->mx_db.md_entries;
5015 return mdb_cursor_del0(mc, leaf);
5018 /** Allocate and initialize new pages for a database.
5019 * @param[in] mc a cursor on the database being added to.
5020 * @param[in] flags flags defining what type of page is being allocated.
5021 * @param[in] num the number of pages to allocate. This is usually 1,
5022 * unless allocating overflow pages for a large record.
5023 * @param[out] mp Address of a page, or NULL on failure.
5024 * @return 0 on success, non-zero on failure.
5027 mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp)
5032 if ((rc = mdb_page_alloc(mc, num, &np)))
5034 DPRINTF("allocated new mpage %zu, page size %u",
5035 np->mp_pgno, mc->mc_txn->mt_env->me_psize);
5036 np->mp_flags = flags | P_DIRTY;
5037 np->mp_lower = PAGEHDRSZ;
5038 np->mp_upper = mc->mc_txn->mt_env->me_psize;
5041 mc->mc_db->md_branch_pages++;
5042 else if (IS_LEAF(np))
5043 mc->mc_db->md_leaf_pages++;
5044 else if (IS_OVERFLOW(np)) {
5045 mc->mc_db->md_overflow_pages += num;
5053 /** Calculate the size of a leaf node.
5054 * The size depends on the environment's page size; if a data item
5055 * is too large it will be put onto an overflow page and the node
5056 * size will only include the key and not the data. Sizes are always
5057 * rounded up to an even number of bytes, to guarantee 2-byte alignment
5058 * of the #MDB_node headers.
5059 * @param[in] env The environment handle.
5060 * @param[in] key The key for the node.
5061 * @param[in] data The data for the node.
5062 * @return The number of bytes needed to store the node.
5065 mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data)
5069 sz = LEAFSIZE(key, data);
5070 if (sz >= env->me_psize / MDB_MINKEYS) {
5071 /* put on overflow page */
5072 sz -= data->mv_size - sizeof(pgno_t);
5076 return sz + sizeof(indx_t);
5079 /** Calculate the size of a branch node.
5080 * The size should depend on the environment's page size but since
5081 * we currently don't support spilling large keys onto overflow
5082 * pages, it's simply the size of the #MDB_node header plus the
5083 * size of the key. Sizes are always rounded up to an even number
5084 * of bytes, to guarantee 2-byte alignment of the #MDB_node headers.
5085 * @param[in] env The environment handle.
5086 * @param[in] key The key for the node.
5087 * @return The number of bytes needed to store the node.
5090 mdb_branch_size(MDB_env *env, MDB_val *key)
5095 if (sz >= env->me_psize / MDB_MINKEYS) {
5096 /* put on overflow page */
5097 /* not implemented */
5098 /* sz -= key->size - sizeof(pgno_t); */
5101 return sz + sizeof(indx_t);
5104 /** Add a node to the page pointed to by the cursor.
5105 * @param[in] mc The cursor for this operation.
5106 * @param[in] indx The index on the page where the new node should be added.
5107 * @param[in] key The key for the new node.
5108 * @param[in] data The data for the new node, if any.
5109 * @param[in] pgno The page number, if adding a branch node.
5110 * @param[in] flags Flags for the node.
5111 * @return 0 on success, non-zero on failure. Possible errors are:
5113 * <li>ENOMEM - failed to allocate overflow pages for the node.
5114 * <li>MDB_PAGE_FULL - there is insufficient room in the page. This error
5115 * should never happen since all callers already calculate the
5116 * page's free space before calling this function.
5120 mdb_node_add(MDB_cursor *mc, indx_t indx,
5121 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags)
5124 size_t node_size = NODESIZE;
5127 MDB_page *mp = mc->mc_pg[mc->mc_top];
5128 MDB_page *ofp = NULL; /* overflow page */
5131 assert(mp->mp_upper >= mp->mp_lower);
5133 DPRINTF("add to %s %spage %zu index %i, data size %zu key size %zu [%s]",
5134 IS_LEAF(mp) ? "leaf" : "branch",
5135 IS_SUBP(mp) ? "sub-" : "",
5136 mp->mp_pgno, indx, data ? data->mv_size : 0,
5137 key ? key->mv_size : 0, key ? DKEY(key) : NULL);
5140 /* Move higher keys up one slot. */
5141 int ksize = mc->mc_db->md_pad, dif;
5142 char *ptr = LEAF2KEY(mp, indx, ksize);
5143 dif = NUMKEYS(mp) - indx;
5145 memmove(ptr+ksize, ptr, dif*ksize);
5146 /* insert new key */
5147 memcpy(ptr, key->mv_data, ksize);
5149 /* Just using these for counting */
5150 mp->mp_lower += sizeof(indx_t);
5151 mp->mp_upper -= ksize - sizeof(indx_t);
5156 node_size += key->mv_size;
5160 if (F_ISSET(flags, F_BIGDATA)) {
5161 /* Data already on overflow page. */
5162 node_size += sizeof(pgno_t);
5163 } else if (node_size + data->mv_size >= mc->mc_txn->mt_env->me_psize / MDB_MINKEYS) {
5164 int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
5166 /* Put data on overflow page. */
5167 DPRINTF("data size is %zu, node would be %zu, put data on overflow page",
5168 data->mv_size, node_size+data->mv_size);
5169 node_size += sizeof(pgno_t);
5170 if ((rc = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp)))
5172 DPRINTF("allocated overflow page %zu", ofp->mp_pgno);
5175 node_size += data->mv_size;
5178 node_size += node_size & 1;
5180 if (node_size + sizeof(indx_t) > SIZELEFT(mp)) {
5181 DPRINTF("not enough room in page %zu, got %u ptrs",
5182 mp->mp_pgno, NUMKEYS(mp));
5183 DPRINTF("upper - lower = %u - %u = %u", mp->mp_upper, mp->mp_lower,
5184 mp->mp_upper - mp->mp_lower);
5185 DPRINTF("node size = %zu", node_size);
5186 return MDB_PAGE_FULL;
5189 /* Move higher pointers up one slot. */
5190 for (i = NUMKEYS(mp); i > indx; i--)
5191 mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];
5193 /* Adjust free space offsets. */
5194 ofs = mp->mp_upper - node_size;
5195 assert(ofs >= mp->mp_lower + sizeof(indx_t));
5196 mp->mp_ptrs[indx] = ofs;
5198 mp->mp_lower += sizeof(indx_t);
5200 /* Write the node data. */
5201 node = NODEPTR(mp, indx);
5202 node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
5203 node->mn_flags = flags;
5205 SETDSZ(node,data->mv_size);
5210 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
5215 if (F_ISSET(flags, F_BIGDATA))
5216 memcpy(node->mn_data + key->mv_size, data->mv_data,
5218 else if (F_ISSET(flags, MDB_RESERVE))
5219 data->mv_data = node->mn_data + key->mv_size;
5221 memcpy(node->mn_data + key->mv_size, data->mv_data,
5224 memcpy(node->mn_data + key->mv_size, &ofp->mp_pgno,
5226 if (F_ISSET(flags, MDB_RESERVE))
5227 data->mv_data = METADATA(ofp);
5229 memcpy(METADATA(ofp), data->mv_data, data->mv_size);
5236 /** Delete the specified node from a page.
5237 * @param[in] mp The page to operate on.
5238 * @param[in] indx The index of the node to delete.
5239 * @param[in] ksize The size of a node. Only used if the page is
5240 * part of a #MDB_DUPFIXED database.
5243 mdb_node_del(MDB_page *mp, indx_t indx, int ksize)
5246 indx_t i, j, numkeys, ptr;
5253 COPY_PGNO(pgno, mp->mp_pgno);
5254 DPRINTF("delete node %u on %s page %zu", indx,
5255 IS_LEAF(mp) ? "leaf" : "branch", pgno);
5258 assert(indx < NUMKEYS(mp));
5261 int x = NUMKEYS(mp) - 1 - indx;
5262 base = LEAF2KEY(mp, indx, ksize);
5264 memmove(base, base + ksize, x * ksize);
5265 mp->mp_lower -= sizeof(indx_t);
5266 mp->mp_upper += ksize - sizeof(indx_t);
5270 node = NODEPTR(mp, indx);
5271 sz = NODESIZE + node->mn_ksize;
5273 if (F_ISSET(node->mn_flags, F_BIGDATA))
5274 sz += sizeof(pgno_t);
5276 sz += NODEDSZ(node);
5280 ptr = mp->mp_ptrs[indx];
5281 numkeys = NUMKEYS(mp);
5282 for (i = j = 0; i < numkeys; i++) {
5284 mp->mp_ptrs[j] = mp->mp_ptrs[i];
5285 if (mp->mp_ptrs[i] < ptr)
5286 mp->mp_ptrs[j] += sz;
5291 base = (char *)mp + mp->mp_upper;
5292 memmove(base + sz, base, ptr - mp->mp_upper);
5294 mp->mp_lower -= sizeof(indx_t);
5298 /** Compact the main page after deleting a node on a subpage.
5299 * @param[in] mp The main page to operate on.
5300 * @param[in] indx The index of the subpage on the main page.
5303 mdb_node_shrink(MDB_page *mp, indx_t indx)
5310 indx_t i, numkeys, ptr;
5312 node = NODEPTR(mp, indx);
5313 sp = (MDB_page *)NODEDATA(node);
5314 osize = NODEDSZ(node);
5316 delta = sp->mp_upper - sp->mp_lower;
5317 SETDSZ(node, osize - delta);
5318 xp = (MDB_page *)((char *)sp + delta);
5320 /* shift subpage upward */
5322 nsize = NUMKEYS(sp) * sp->mp_pad;
5323 memmove(METADATA(xp), METADATA(sp), nsize);
5326 nsize = osize - sp->mp_upper;
5327 numkeys = NUMKEYS(sp);
5328 for (i=numkeys-1; i>=0; i--)
5329 xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta;
5331 xp->mp_upper = sp->mp_lower;
5332 xp->mp_lower = sp->mp_lower;
5333 xp->mp_flags = sp->mp_flags;
5334 xp->mp_pad = sp->mp_pad;
5335 COPY_PGNO(xp->mp_pgno, mp->mp_pgno);
5337 /* shift lower nodes upward */
5338 ptr = mp->mp_ptrs[indx];
5339 numkeys = NUMKEYS(mp);
5340 for (i = 0; i < numkeys; i++) {
5341 if (mp->mp_ptrs[i] <= ptr)
5342 mp->mp_ptrs[i] += delta;
5345 base = (char *)mp + mp->mp_upper;
5346 memmove(base + delta, base, ptr - mp->mp_upper + NODESIZE + NODEKSZ(node));
5347 mp->mp_upper += delta;
5350 /** Initial setup of a sorted-dups cursor.
5351 * Sorted duplicates are implemented as a sub-database for the given key.
5352 * The duplicate data items are actually keys of the sub-database.
5353 * Operations on the duplicate data items are performed using a sub-cursor
5354 * initialized when the sub-database is first accessed. This function does
5355 * the preliminary setup of the sub-cursor, filling in the fields that
5356 * depend only on the parent DB.
5357 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
5360 mdb_xcursor_init0(MDB_cursor *mc)
5362 MDB_xcursor *mx = mc->mc_xcursor;
5364 mx->mx_cursor.mc_xcursor = NULL;
5365 mx->mx_cursor.mc_txn = mc->mc_txn;
5366 mx->mx_cursor.mc_db = &mx->mx_db;
5367 mx->mx_cursor.mc_dbx = &mx->mx_dbx;
5368 mx->mx_cursor.mc_dbi = mc->mc_dbi+1;
5369 mx->mx_cursor.mc_dbflag = &mx->mx_dbflag;
5370 mx->mx_cursor.mc_snum = 0;
5371 mx->mx_cursor.mc_top = 0;
5372 mx->mx_cursor.mc_flags = C_SUB;
5373 mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp;
5374 mx->mx_dbx.md_dcmp = NULL;
5375 mx->mx_dbx.md_rel = mc->mc_dbx->md_rel;
5378 /** Final setup of a sorted-dups cursor.
5379 * Sets up the fields that depend on the data from the main cursor.
5380 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
5381 * @param[in] node The data containing the #MDB_db record for the
5382 * sorted-dup database.
5385 mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)
5387 MDB_xcursor *mx = mc->mc_xcursor;
5389 if (node->mn_flags & F_SUBDATA) {
5390 memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db));
5391 mx->mx_cursor.mc_pg[0] = 0;
5392 mx->mx_cursor.mc_snum = 0;
5393 mx->mx_cursor.mc_flags = C_SUB;
5395 MDB_page *fp = NODEDATA(node);
5396 mx->mx_db.md_pad = mc->mc_pg[mc->mc_top]->mp_pad;
5397 mx->mx_db.md_flags = 0;
5398 mx->mx_db.md_depth = 1;
5399 mx->mx_db.md_branch_pages = 0;
5400 mx->mx_db.md_leaf_pages = 1;
5401 mx->mx_db.md_overflow_pages = 0;
5402 mx->mx_db.md_entries = NUMKEYS(fp);
5403 COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno);
5404 mx->mx_cursor.mc_snum = 1;
5405 mx->mx_cursor.mc_flags = C_INITIALIZED|C_SUB;
5406 mx->mx_cursor.mc_top = 0;
5407 mx->mx_cursor.mc_pg[0] = fp;
5408 mx->mx_cursor.mc_ki[0] = 0;
5409 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
5410 mx->mx_db.md_flags = MDB_DUPFIXED;
5411 mx->mx_db.md_pad = fp->mp_pad;
5412 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
5413 mx->mx_db.md_flags |= MDB_INTEGERKEY;
5416 DPRINTF("Sub-db %u for db %u root page %zu", mx->mx_cursor.mc_dbi, mc->mc_dbi,
5418 mx->mx_dbflag = (F_ISSET(mc->mc_pg[mc->mc_top]->mp_flags, P_DIRTY)) ?
5420 mx->mx_dbx.md_name.mv_data = NODEKEY(node);
5421 mx->mx_dbx.md_name.mv_size = node->mn_ksize;
5422 #if UINT_MAX < SIZE_MAX
5423 if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(size_t))
5424 #ifdef MISALIGNED_OK
5425 mx->mx_dbx.md_cmp = mdb_cmp_long;
5427 mx->mx_dbx.md_cmp = mdb_cmp_cint;
5432 /** Initialize a cursor for a given transaction and database. */
5434 mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
5439 mc->mc_db = &txn->mt_dbs[dbi];
5440 mc->mc_dbx = &txn->mt_dbxs[dbi];
5441 mc->mc_dbflag = &txn->mt_dbflags[dbi];
5446 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
5448 mc->mc_xcursor = mx;
5449 mdb_xcursor_init0(mc);
5451 mc->mc_xcursor = NULL;
5453 if (*mc->mc_dbflag & DB_STALE) {
5454 mdb_page_search(mc, NULL, MDB_PS_ROOTONLY);
5459 mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
5462 MDB_xcursor *mx = NULL;
5463 size_t size = sizeof(MDB_cursor);
5465 if (txn == NULL || ret == NULL || dbi >= txn->mt_numdbs)
5468 /* Allow read access to the freelist */
5469 if (!dbi && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
5472 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)
5473 size += sizeof(MDB_xcursor);
5475 if ((mc = malloc(size)) != NULL) {
5476 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
5477 mx = (MDB_xcursor *)(mc + 1);
5479 mdb_cursor_init(mc, txn, dbi, mx);
5480 if (txn->mt_cursors) {
5481 mc->mc_next = txn->mt_cursors[dbi];
5482 txn->mt_cursors[dbi] = mc;
5484 mc->mc_flags |= C_ALLOCD;
5495 mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)
5497 if (txn == NULL || mc == NULL || mc->mc_dbi >= txn->mt_numdbs)
5500 if (txn->mt_cursors)
5503 mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor);
5507 /* Return the count of duplicate data items for the current key */
5509 mdb_cursor_count(MDB_cursor *mc, size_t *countp)
5513 if (mc == NULL || countp == NULL)
5516 if (!(mc->mc_db->md_flags & MDB_DUPSORT))
5519 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5520 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5523 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
5526 *countp = mc->mc_xcursor->mx_db.md_entries;
5532 mdb_cursor_close(MDB_cursor *mc)
5535 /* remove from txn, if tracked */
5536 if (mc->mc_txn->mt_cursors) {
5537 MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi];
5538 while (*prev && *prev != mc) prev = &(*prev)->mc_next;
5540 *prev = mc->mc_next;
5542 if (mc->mc_flags & C_ALLOCD)
5548 mdb_cursor_txn(MDB_cursor *mc)
5550 if (!mc) return NULL;
5555 mdb_cursor_dbi(MDB_cursor *mc)
5561 /** Replace the key for a node with a new key.
5562 * @param[in] mp The page containing the node to operate on.
5563 * @param[in] indx The index of the node to operate on.
5564 * @param[in] key The new key to use.
5565 * @return 0 on success, non-zero on failure.
5568 mdb_update_key(MDB_page *mp, indx_t indx, MDB_val *key)
5574 indx_t ptr, i, numkeys;
5577 node = NODEPTR(mp, indx);
5578 ptr = mp->mp_ptrs[indx];
5582 char kbuf2[(MAXKEYSIZE*2+1)];
5583 k2.mv_data = NODEKEY(node);
5584 k2.mv_size = node->mn_ksize;
5585 DPRINTF("update key %u (ofs %u) [%s] to [%s] on page %zu",
5587 mdb_dkey(&k2, kbuf2),
5593 delta0 = delta = key->mv_size - node->mn_ksize;
5595 /* Must be 2-byte aligned. If new key is
5596 * shorter by 1, the shift will be skipped.
5598 delta += (delta & 1);
5600 if (delta > 0 && SIZELEFT(mp) < delta) {
5601 DPRINTF("OUCH! Not enough room, delta = %d", delta);
5602 return MDB_PAGE_FULL;
5605 numkeys = NUMKEYS(mp);
5606 for (i = 0; i < numkeys; i++) {
5607 if (mp->mp_ptrs[i] <= ptr)
5608 mp->mp_ptrs[i] -= delta;
5611 base = (char *)mp + mp->mp_upper;
5612 len = ptr - mp->mp_upper + NODESIZE;
5613 memmove(base - delta, base, len);
5614 mp->mp_upper -= delta;
5616 node = NODEPTR(mp, indx);
5619 /* But even if no shift was needed, update ksize */
5621 node->mn_ksize = key->mv_size;
5624 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
5629 /** Move a node from csrc to cdst.
5632 mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
5638 unsigned short flags;
5642 /* Mark src and dst as dirty. */
5643 if ((rc = mdb_page_touch(csrc)) ||
5644 (rc = mdb_page_touch(cdst)))
5647 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
5648 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0); /* fake */
5649 key.mv_size = csrc->mc_db->md_pad;
5650 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
5652 data.mv_data = NULL;
5656 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]);
5657 assert(!((long)srcnode&1));
5658 srcpg = NODEPGNO(srcnode);
5659 flags = srcnode->mn_flags;
5660 if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
5661 unsigned int snum = csrc->mc_snum;
5663 /* must find the lowest key below src */
5664 mdb_page_search_root(csrc, NULL, 0);
5665 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
5666 key.mv_size = csrc->mc_db->md_pad;
5667 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
5669 s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
5670 key.mv_size = NODEKSZ(s2);
5671 key.mv_data = NODEKEY(s2);
5673 csrc->mc_snum = snum--;
5674 csrc->mc_top = snum;
5676 key.mv_size = NODEKSZ(srcnode);
5677 key.mv_data = NODEKEY(srcnode);
5679 data.mv_size = NODEDSZ(srcnode);
5680 data.mv_data = NODEDATA(srcnode);
5682 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) {
5683 unsigned int snum = cdst->mc_snum;
5686 /* must find the lowest key below dst */
5687 mdb_page_search_root(cdst, NULL, 0);
5688 if (IS_LEAF2(cdst->mc_pg[cdst->mc_top])) {
5689 bkey.mv_size = cdst->mc_db->md_pad;
5690 bkey.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, bkey.mv_size);
5692 s2 = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
5693 bkey.mv_size = NODEKSZ(s2);
5694 bkey.mv_data = NODEKEY(s2);
5696 cdst->mc_snum = snum--;
5697 cdst->mc_top = snum;
5698 rc = mdb_update_key(cdst->mc_pg[cdst->mc_top], 0, &bkey);
5701 DPRINTF("moving %s node %u [%s] on page %zu to node %u on page %zu",
5702 IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch",
5703 csrc->mc_ki[csrc->mc_top],
5705 csrc->mc_pg[csrc->mc_top]->mp_pgno,
5706 cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno);
5708 /* Add the node to the destination page.
5710 rc = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags);
5711 if (rc != MDB_SUCCESS)
5714 /* Delete the node from the source page.
5716 mdb_node_del(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
5719 /* Adjust other cursors pointing to mp */
5720 MDB_cursor *m2, *m3;
5721 MDB_dbi dbi = csrc->mc_dbi;
5722 MDB_page *mp = csrc->mc_pg[csrc->mc_top];
5724 if (csrc->mc_flags & C_SUB)
5727 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
5728 if (m2 == csrc) continue;
5729 if (csrc->mc_flags & C_SUB)
5730 m3 = &m2->mc_xcursor->mx_cursor;
5733 if (m3->mc_pg[csrc->mc_top] == mp && m3->mc_ki[csrc->mc_top] ==
5734 csrc->mc_ki[csrc->mc_top]) {
5735 m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
5736 m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
5741 /* Update the parent separators.
5743 if (csrc->mc_ki[csrc->mc_top] == 0) {
5744 if (csrc->mc_ki[csrc->mc_top-1] != 0) {
5745 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
5746 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
5748 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
5749 key.mv_size = NODEKSZ(srcnode);
5750 key.mv_data = NODEKEY(srcnode);
5752 DPRINTF("update separator for source page %zu to [%s]",
5753 csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key));
5754 if ((rc = mdb_update_key(csrc->mc_pg[csrc->mc_top-1], csrc->mc_ki[csrc->mc_top-1],
5755 &key)) != MDB_SUCCESS)
5758 if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
5760 nullkey.mv_size = 0;
5761 rc = mdb_update_key(csrc->mc_pg[csrc->mc_top], 0, &nullkey);
5762 assert(rc == MDB_SUCCESS);
5766 if (cdst->mc_ki[cdst->mc_top] == 0) {
5767 if (cdst->mc_ki[cdst->mc_top-1] != 0) {
5768 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
5769 key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size);
5771 srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
5772 key.mv_size = NODEKSZ(srcnode);
5773 key.mv_data = NODEKEY(srcnode);
5775 DPRINTF("update separator for destination page %zu to [%s]",
5776 cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key));
5777 if ((rc = mdb_update_key(cdst->mc_pg[cdst->mc_top-1], cdst->mc_ki[cdst->mc_top-1],
5778 &key)) != MDB_SUCCESS)
5781 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) {
5783 nullkey.mv_size = 0;
5784 rc = mdb_update_key(cdst->mc_pg[cdst->mc_top], 0, &nullkey);
5785 assert(rc == MDB_SUCCESS);
5792 /** Merge one page into another.
5793 * The nodes from the page pointed to by \b csrc will
5794 * be copied to the page pointed to by \b cdst and then
5795 * the \b csrc page will be freed.
5796 * @param[in] csrc Cursor pointing to the source page.
5797 * @param[in] cdst Cursor pointing to the destination page.
5800 mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
5808 DPRINTF("merging page %zu into %zu", csrc->mc_pg[csrc->mc_top]->mp_pgno,
5809 cdst->mc_pg[cdst->mc_top]->mp_pgno);
5811 assert(csrc->mc_snum > 1); /* can't merge root page */
5812 assert(cdst->mc_snum > 1);
5814 /* Mark dst as dirty. */
5815 if ((rc = mdb_page_touch(cdst)))
5818 /* Move all nodes from src to dst.
5820 j = nkeys = NUMKEYS(cdst->mc_pg[cdst->mc_top]);
5821 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
5822 key.mv_size = csrc->mc_db->md_pad;
5823 key.mv_data = METADATA(csrc->mc_pg[csrc->mc_top]);
5824 for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) {
5825 rc = mdb_node_add(cdst, j, &key, NULL, 0, 0);
5826 if (rc != MDB_SUCCESS)
5828 key.mv_data = (char *)key.mv_data + key.mv_size;
5831 for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) {
5832 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], i);
5833 if (i == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
5834 unsigned int snum = csrc->mc_snum;
5836 /* must find the lowest key below src */
5837 mdb_page_search_root(csrc, NULL, 0);
5838 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
5839 key.mv_size = csrc->mc_db->md_pad;
5840 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
5842 s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
5843 key.mv_size = NODEKSZ(s2);
5844 key.mv_data = NODEKEY(s2);
5846 csrc->mc_snum = snum--;
5847 csrc->mc_top = snum;
5849 key.mv_size = srcnode->mn_ksize;
5850 key.mv_data = NODEKEY(srcnode);
5853 data.mv_size = NODEDSZ(srcnode);
5854 data.mv_data = NODEDATA(srcnode);
5855 rc = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags);
5856 if (rc != MDB_SUCCESS)
5861 DPRINTF("dst page %zu now has %u keys (%.1f%% filled)",
5862 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);
5864 /* Unlink the src page from parent and add to free list.
5866 mdb_node_del(csrc->mc_pg[csrc->mc_top-1], csrc->mc_ki[csrc->mc_top-1], 0);
5867 if (csrc->mc_ki[csrc->mc_top-1] == 0) {
5869 if ((rc = mdb_update_key(csrc->mc_pg[csrc->mc_top-1], 0, &key)) != MDB_SUCCESS)
5873 mdb_midl_append(&csrc->mc_txn->mt_free_pgs, csrc->mc_pg[csrc->mc_top]->mp_pgno);
5874 if (IS_LEAF(csrc->mc_pg[csrc->mc_top]))
5875 csrc->mc_db->md_leaf_pages--;
5877 csrc->mc_db->md_branch_pages--;
5879 /* Adjust other cursors pointing to mp */
5880 MDB_cursor *m2, *m3;
5881 MDB_dbi dbi = csrc->mc_dbi;
5882 MDB_page *mp = cdst->mc_pg[cdst->mc_top];
5884 if (csrc->mc_flags & C_SUB)
5887 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
5888 if (csrc->mc_flags & C_SUB)
5889 m3 = &m2->mc_xcursor->mx_cursor;
5892 if (m3 == csrc) continue;
5893 if (m3->mc_snum < csrc->mc_snum) continue;
5894 if (m3->mc_pg[csrc->mc_top] == csrc->mc_pg[csrc->mc_top]) {
5895 m3->mc_pg[csrc->mc_top] = mp;
5896 m3->mc_ki[csrc->mc_top] += nkeys;
5900 mdb_cursor_pop(csrc);
5902 return mdb_rebalance(csrc);
5905 /** Copy the contents of a cursor.
5906 * @param[in] csrc The cursor to copy from.
5907 * @param[out] cdst The cursor to copy to.
5910 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst)
5914 cdst->mc_txn = csrc->mc_txn;
5915 cdst->mc_dbi = csrc->mc_dbi;
5916 cdst->mc_db = csrc->mc_db;
5917 cdst->mc_dbx = csrc->mc_dbx;
5918 cdst->mc_snum = csrc->mc_snum;
5919 cdst->mc_top = csrc->mc_top;
5920 cdst->mc_flags = csrc->mc_flags;
5922 for (i=0; i<csrc->mc_snum; i++) {
5923 cdst->mc_pg[i] = csrc->mc_pg[i];
5924 cdst->mc_ki[i] = csrc->mc_ki[i];
5928 /** Rebalance the tree after a delete operation.
5929 * @param[in] mc Cursor pointing to the page where rebalancing
5931 * @return 0 on success, non-zero on failure.
5934 mdb_rebalance(MDB_cursor *mc)
5944 COPY_PGNO(pgno, mc->mc_pg[mc->mc_top]->mp_pgno);
5945 DPRINTF("rebalancing %s page %zu (has %u keys, %.1f%% full)",
5946 IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",
5947 pgno, NUMKEYS(mc->mc_pg[mc->mc_top]), (float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10);
5951 if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= FILL_THRESHOLD) {
5954 COPY_PGNO(pgno, mc->mc_pg[mc->mc_top]->mp_pgno);
5955 DPRINTF("no need to rebalance page %zu, above fill threshold",
5961 if (mc->mc_snum < 2) {
5962 MDB_page *mp = mc->mc_pg[0];
5963 if (NUMKEYS(mp) == 0) {
5964 DPUTS("tree is completely empty");
5965 mc->mc_db->md_root = P_INVALID;
5966 mc->mc_db->md_depth = 0;
5967 mc->mc_db->md_leaf_pages = 0;
5968 mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
5972 /* Adjust other cursors pointing to mp */
5973 MDB_cursor *m2, *m3;
5974 MDB_dbi dbi = mc->mc_dbi;
5976 if (mc->mc_flags & C_SUB)
5979 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
5980 if (m2 == mc) continue;
5981 if (mc->mc_flags & C_SUB)
5982 m3 = &m2->mc_xcursor->mx_cursor;
5985 if (m3->mc_snum < mc->mc_snum) continue;
5986 if (m3->mc_pg[0] == mp) {
5992 } else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) {
5993 DPUTS("collapsing root page!");
5994 mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
5995 mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0));
5996 if ((rc = mdb_page_get(mc->mc_txn, mc->mc_db->md_root,
5999 mc->mc_db->md_depth--;
6000 mc->mc_db->md_branch_pages--;
6002 /* Adjust other cursors pointing to mp */
6003 MDB_cursor *m2, *m3;
6004 MDB_dbi dbi = mc->mc_dbi;
6006 if (mc->mc_flags & C_SUB)
6009 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
6010 if (m2 == mc) continue;
6011 if (mc->mc_flags & C_SUB)
6012 m3 = &m2->mc_xcursor->mx_cursor;
6015 if (m3->mc_snum < mc->mc_snum) continue;
6016 if (m3->mc_pg[0] == mp) {
6017 m3->mc_pg[0] = mc->mc_pg[0];
6022 DPUTS("root page doesn't need rebalancing");
6026 /* The parent (branch page) must have at least 2 pointers,
6027 * otherwise the tree is invalid.
6029 ptop = mc->mc_top-1;
6030 assert(NUMKEYS(mc->mc_pg[ptop]) > 1);
6032 /* Leaf page fill factor is below the threshold.
6033 * Try to move keys from left or right neighbor, or
6034 * merge with a neighbor page.
6039 mdb_cursor_copy(mc, &mn);
6040 mn.mc_xcursor = NULL;
6042 if (mc->mc_ki[ptop] == 0) {
6043 /* We're the leftmost leaf in our parent.
6045 DPUTS("reading right neighbor");
6047 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
6048 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mn.mc_pg[mn.mc_top])))
6050 mn.mc_ki[mn.mc_top] = 0;
6051 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);
6053 /* There is at least one neighbor to the left.
6055 DPUTS("reading left neighbor");
6057 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
6058 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mn.mc_pg[mn.mc_top])))
6060 mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;
6061 mc->mc_ki[mc->mc_top] = 0;
6064 DPRINTF("found neighbor page %zu (%u keys, %.1f%% full)",
6065 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);
6067 /* If the neighbor page is above threshold and has at least two
6068 * keys, move one key from it.
6070 * Otherwise we should try to merge them.
6072 if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= FILL_THRESHOLD && NUMKEYS(mn.mc_pg[mn.mc_top]) >= 2)
6073 return mdb_node_move(&mn, mc);
6074 else { /* FIXME: if (has_enough_room()) */
6075 mc->mc_flags &= ~C_INITIALIZED;
6076 if (mc->mc_ki[ptop] == 0)
6077 return mdb_page_merge(&mn, mc);
6079 return mdb_page_merge(mc, &mn);
6083 /** Complete a delete operation started by #mdb_cursor_del(). */
6085 mdb_cursor_del0(MDB_cursor *mc, MDB_node *leaf)
6089 /* add overflow pages to free list */
6090 if (!IS_LEAF2(mc->mc_pg[mc->mc_top]) && F_ISSET(leaf->mn_flags, F_BIGDATA)) {
6094 memcpy(&pg, NODEDATA(leaf), sizeof(pg));
6095 ovpages = OVPAGES(NODEDSZ(leaf), mc->mc_txn->mt_env->me_psize);
6096 mc->mc_db->md_overflow_pages -= ovpages;
6097 for (i=0; i<ovpages; i++) {
6098 DPRINTF("freed ov page %zu", pg);
6099 mdb_midl_append(&mc->mc_txn->mt_free_pgs, pg);
6103 mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], mc->mc_db->md_pad);
6104 mc->mc_db->md_entries--;
6105 rc = mdb_rebalance(mc);
6106 if (rc != MDB_SUCCESS)
6107 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
6113 mdb_del(MDB_txn *txn, MDB_dbi dbi,
6114 MDB_val *key, MDB_val *data)
6119 MDB_val rdata, *xdata;
6123 assert(key != NULL);
6125 DPRINTF("====> delete db %u key [%s]", dbi, DKEY(key));
6127 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
6130 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
6134 if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
6138 mdb_cursor_init(&mc, txn, dbi, &mx);
6149 rc = mdb_cursor_set(&mc, key, xdata, op, &exact);
6151 rc = mdb_cursor_del(&mc, data ? 0 : MDB_NODUPDATA);
6155 /** Split a page and insert a new node.
6156 * @param[in,out] mc Cursor pointing to the page and desired insertion index.
6157 * The cursor will be updated to point to the actual page and index where
6158 * the node got inserted after the split.
6159 * @param[in] newkey The key for the newly inserted node.
6160 * @param[in] newdata The data for the newly inserted node.
6161 * @param[in] newpgno The page number, if the new node is a branch node.
6162 * @param[in] nflags The #NODE_ADD_FLAGS for the new node.
6163 * @return 0 on success, non-zero on failure.
6166 mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno,
6167 unsigned int nflags)
6170 int rc = MDB_SUCCESS, ins_new = 0, new_root = 0, newpos = 1, did_split = 0;
6173 unsigned int i, j, split_indx, nkeys, pmax;
6175 MDB_val sepkey, rkey, xdata, *rdata = &xdata;
6177 MDB_page *mp, *rp, *pp;
6182 mp = mc->mc_pg[mc->mc_top];
6183 newindx = mc->mc_ki[mc->mc_top];
6185 DPRINTF("-----> splitting %s page %zu and adding [%s] at index %i",
6186 IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno,
6187 DKEY(newkey), mc->mc_ki[mc->mc_top]);
6189 /* Create a right sibling. */
6190 if ((rc = mdb_page_new(mc, mp->mp_flags, 1, &rp)))
6192 DPRINTF("new right sibling: page %zu", rp->mp_pgno);
6194 if (mc->mc_snum < 2) {
6195 if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp)))
6197 /* shift current top to make room for new parent */
6198 mc->mc_pg[1] = mc->mc_pg[0];
6199 mc->mc_ki[1] = mc->mc_ki[0];
6202 mc->mc_db->md_root = pp->mp_pgno;
6203 DPRINTF("root split! new root = %zu", pp->mp_pgno);
6204 mc->mc_db->md_depth++;
6207 /* Add left (implicit) pointer. */
6208 if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) {
6209 /* undo the pre-push */
6210 mc->mc_pg[0] = mc->mc_pg[1];
6211 mc->mc_ki[0] = mc->mc_ki[1];
6212 mc->mc_db->md_root = mp->mp_pgno;
6213 mc->mc_db->md_depth--;
6220 ptop = mc->mc_top-1;
6221 DPRINTF("parent branch page is %zu", mc->mc_pg[ptop]->mp_pgno);
6224 mc->mc_flags |= C_SPLITTING;
6225 mdb_cursor_copy(mc, &mn);
6226 mn.mc_pg[mn.mc_top] = rp;
6227 mn.mc_ki[ptop] = mc->mc_ki[ptop]+1;
6229 if (nflags & MDB_APPEND) {
6230 mn.mc_ki[mn.mc_top] = 0;
6232 split_indx = newindx;
6237 nkeys = NUMKEYS(mp);
6238 split_indx = nkeys / 2;
6239 if (newindx < split_indx)
6245 unsigned int lsize, rsize, ksize;
6246 /* Move half of the keys to the right sibling */
6248 x = mc->mc_ki[mc->mc_top] - split_indx;
6249 ksize = mc->mc_db->md_pad;
6250 split = LEAF2KEY(mp, split_indx, ksize);
6251 rsize = (nkeys - split_indx) * ksize;
6252 lsize = (nkeys - split_indx) * sizeof(indx_t);
6253 mp->mp_lower -= lsize;
6254 rp->mp_lower += lsize;
6255 mp->mp_upper += rsize - lsize;
6256 rp->mp_upper -= rsize - lsize;
6257 sepkey.mv_size = ksize;
6258 if (newindx == split_indx) {
6259 sepkey.mv_data = newkey->mv_data;
6261 sepkey.mv_data = split;
6264 ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize);
6265 memcpy(rp->mp_ptrs, split, rsize);
6266 sepkey.mv_data = rp->mp_ptrs;
6267 memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize);
6268 memcpy(ins, newkey->mv_data, ksize);
6269 mp->mp_lower += sizeof(indx_t);
6270 mp->mp_upper -= ksize - sizeof(indx_t);
6273 memcpy(rp->mp_ptrs, split, x * ksize);
6274 ins = LEAF2KEY(rp, x, ksize);
6275 memcpy(ins, newkey->mv_data, ksize);
6276 memcpy(ins+ksize, split + x * ksize, rsize - x * ksize);
6277 rp->mp_lower += sizeof(indx_t);
6278 rp->mp_upper -= ksize - sizeof(indx_t);
6279 mc->mc_ki[mc->mc_top] = x;
6280 mc->mc_pg[mc->mc_top] = rp;
6285 /* For leaf pages, check the split point based on what
6286 * fits where, since otherwise mdb_node_add can fail.
6288 * This check is only needed when the data items are
6289 * relatively large, such that being off by one will
6290 * make the difference between success or failure.
6292 * It's also relevant if a page happens to be laid out
6293 * such that one half of its nodes are all "small" and
6294 * the other half of its nodes are "large." If the new
6295 * item is also "large" and falls on the half with
6296 * "large" nodes, it also may not fit.
6299 unsigned int psize, nsize;
6300 /* Maximum free space in an empty page */
6301 pmax = mc->mc_txn->mt_env->me_psize - PAGEHDRSZ;
6302 nsize = mdb_leaf_size(mc->mc_txn->mt_env, newkey, newdata);
6303 if ((nkeys < 20) || (nsize > pmax/16)) {
6304 if (newindx <= split_indx) {
6307 for (i=0; i<split_indx; i++) {
6308 node = NODEPTR(mp, i);
6309 psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
6310 if (F_ISSET(node->mn_flags, F_BIGDATA))
6311 psize += sizeof(pgno_t);
6313 psize += NODEDSZ(node);
6317 split_indx = newindx;
6328 for (i=nkeys-1; i>=split_indx; i--) {
6329 node = NODEPTR(mp, i);
6330 psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
6331 if (F_ISSET(node->mn_flags, F_BIGDATA))
6332 psize += sizeof(pgno_t);
6334 psize += NODEDSZ(node);
6338 split_indx = newindx;
6349 /* First find the separating key between the split pages.
6350 * The case where newindx == split_indx is ambiguous; the
6351 * new item could go to the new page or stay on the original
6352 * page. If newpos == 1 it goes to the new page.
6354 if (newindx == split_indx && newpos) {
6355 sepkey.mv_size = newkey->mv_size;
6356 sepkey.mv_data = newkey->mv_data;
6358 node = NODEPTR(mp, split_indx);
6359 sepkey.mv_size = node->mn_ksize;
6360 sepkey.mv_data = NODEKEY(node);
6364 DPRINTF("separator is [%s]", DKEY(&sepkey));
6366 /* Copy separator key to the parent.
6368 if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(mc->mc_txn->mt_env, &sepkey)) {
6372 rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0);
6375 if (mn.mc_snum == mc->mc_snum) {
6376 mc->mc_pg[mc->mc_snum] = mc->mc_pg[mc->mc_top];
6377 mc->mc_ki[mc->mc_snum] = mc->mc_ki[mc->mc_top];
6378 mc->mc_pg[mc->mc_top] = mc->mc_pg[ptop];
6379 mc->mc_ki[mc->mc_top] = mc->mc_ki[ptop];
6384 /* Right page might now have changed parent.
6385 * Check if left page also changed parent.
6387 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
6388 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
6389 for (i=0; i<ptop; i++) {
6390 mc->mc_pg[i] = mn.mc_pg[i];
6391 mc->mc_ki[i] = mn.mc_ki[i];
6393 mc->mc_pg[ptop] = mn.mc_pg[ptop];
6394 mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;
6398 rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);
6401 mc->mc_flags ^= C_SPLITTING;
6402 if (rc != MDB_SUCCESS) {
6405 if (nflags & MDB_APPEND) {
6406 mc->mc_pg[mc->mc_top] = rp;
6407 mc->mc_ki[mc->mc_top] = 0;
6408 rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags);
6411 for (i=0; i<mc->mc_top; i++)
6412 mc->mc_ki[i] = mn.mc_ki[i];
6419 /* Move half of the keys to the right sibling. */
6421 /* grab a page to hold a temporary copy */
6422 copy = mdb_page_malloc(mc);
6426 copy->mp_pgno = mp->mp_pgno;
6427 copy->mp_flags = mp->mp_flags;
6428 copy->mp_lower = PAGEHDRSZ;
6429 copy->mp_upper = mc->mc_txn->mt_env->me_psize;
6430 mc->mc_pg[mc->mc_top] = copy;
6431 for (i = j = 0; i <= nkeys; j++) {
6432 if (i == split_indx) {
6433 /* Insert in right sibling. */
6434 /* Reset insert index for right sibling. */
6435 if (i != newindx || (newpos ^ ins_new)) {
6437 mc->mc_pg[mc->mc_top] = rp;
6441 if (i == newindx && !ins_new) {
6442 /* Insert the original entry that caused the split. */
6443 rkey.mv_data = newkey->mv_data;
6444 rkey.mv_size = newkey->mv_size;
6453 /* Update index for the new key. */
6454 mc->mc_ki[mc->mc_top] = j;
6455 } else if (i == nkeys) {
6458 node = NODEPTR(mp, i);
6459 rkey.mv_data = NODEKEY(node);
6460 rkey.mv_size = node->mn_ksize;
6462 xdata.mv_data = NODEDATA(node);
6463 xdata.mv_size = NODEDSZ(node);
6466 pgno = NODEPGNO(node);
6467 flags = node->mn_flags;
6472 if (!IS_LEAF(mp) && j == 0) {
6473 /* First branch index doesn't need key data. */
6477 rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags);
6481 nkeys = NUMKEYS(copy);
6482 for (i=0; i<nkeys; i++)
6483 mp->mp_ptrs[i] = copy->mp_ptrs[i];
6484 mp->mp_lower = copy->mp_lower;
6485 mp->mp_upper = copy->mp_upper;
6486 memcpy(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1),
6487 mc->mc_txn->mt_env->me_psize - copy->mp_upper);
6489 /* reset back to original page */
6490 if (newindx < split_indx || (!newpos && newindx == split_indx)) {
6491 mc->mc_pg[mc->mc_top] = mp;
6492 if (nflags & MDB_RESERVE) {
6493 node = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6494 if (!(node->mn_flags & F_BIGDATA))
6495 newdata->mv_data = NODEDATA(node);
6501 /* return tmp page to freelist */
6502 copy->mp_next = mc->mc_txn->mt_env->me_dpages;
6503 VGMEMP_FREE(mc->mc_txn->mt_env, copy);
6504 mc->mc_txn->mt_env->me_dpages = copy;
6507 /* Adjust other cursors pointing to mp */
6508 MDB_cursor *m2, *m3;
6509 MDB_dbi dbi = mc->mc_dbi;
6510 int fixup = NUMKEYS(mp);
6512 if (mc->mc_flags & C_SUB)
6515 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
6516 if (m2 == mc) continue;
6517 if (mc->mc_flags & C_SUB)
6518 m3 = &m2->mc_xcursor->mx_cursor;
6521 if (!(m3->mc_flags & C_INITIALIZED))
6523 if (m3->mc_flags & C_SPLITTING)
6528 for (k=m3->mc_top; k>=0; k--) {
6529 m3->mc_ki[k+1] = m3->mc_ki[k];
6530 m3->mc_pg[k+1] = m3->mc_pg[k];
6532 if (m3->mc_ki[0] >= split_indx) {
6537 m3->mc_pg[0] = mc->mc_pg[0];
6541 if (m3->mc_pg[mc->mc_top] == mp) {
6542 if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE))
6543 m3->mc_ki[mc->mc_top]++;
6544 if (m3->mc_ki[mc->mc_top] >= fixup) {
6545 m3->mc_pg[mc->mc_top] = rp;
6546 m3->mc_ki[mc->mc_top] -= fixup;
6547 m3->mc_ki[ptop] = mn.mc_ki[ptop];
6549 } else if (!did_split && m3->mc_pg[ptop] == mc->mc_pg[ptop] &&
6550 m3->mc_ki[ptop] >= mc->mc_ki[ptop]) {
6559 mdb_put(MDB_txn *txn, MDB_dbi dbi,
6560 MDB_val *key, MDB_val *data, unsigned int flags)
6565 assert(key != NULL);
6566 assert(data != NULL);
6568 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
6571 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
6575 if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
6579 if ((flags & (MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND)) != flags)
6582 mdb_cursor_init(&mc, txn, dbi, &mx);
6583 return mdb_cursor_put(&mc, key, data, flags);
6586 /** Only a subset of the @ref mdb_env flags can be changed
6587 * at runtime. Changing other flags requires closing the environment
6588 * and re-opening it with the new flags.
6590 #define CHANGEABLE (MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC)
6592 mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)
6594 if ((flag & CHANGEABLE) != flag)
6597 env->me_flags |= flag;
6599 env->me_flags &= ~flag;
6604 mdb_env_get_flags(MDB_env *env, unsigned int *arg)
6609 *arg = env->me_flags;
6614 mdb_env_get_path(MDB_env *env, const char **arg)
6619 *arg = env->me_path;
6623 /** Common code for #mdb_stat() and #mdb_env_stat().
6624 * @param[in] env the environment to operate in.
6625 * @param[in] db the #MDB_db record containing the stats to return.
6626 * @param[out] arg the address of an #MDB_stat structure to receive the stats.
6627 * @return 0, this function always succeeds.
6630 mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)
6632 arg->ms_psize = env->me_psize;
6633 arg->ms_depth = db->md_depth;
6634 arg->ms_branch_pages = db->md_branch_pages;
6635 arg->ms_leaf_pages = db->md_leaf_pages;
6636 arg->ms_overflow_pages = db->md_overflow_pages;
6637 arg->ms_entries = db->md_entries;
6642 mdb_env_stat(MDB_env *env, MDB_stat *arg)
6646 if (env == NULL || arg == NULL)
6649 toggle = mdb_env_pick_meta(env);
6651 return mdb_stat0(env, &env->me_metas[toggle]->mm_dbs[MAIN_DBI], arg);
6655 mdb_env_info(MDB_env *env, MDB_envinfo *arg)
6659 if (env == NULL || arg == NULL)
6662 toggle = mdb_env_pick_meta(env);
6663 arg->me_mapsize = env->me_mapsize;
6664 arg->me_maxreaders = env->me_maxreaders;
6665 arg->me_numreaders = env->me_numreaders;
6666 arg->me_last_txnid = env->me_metas[toggle]->mm_txnid;
6667 arg->me_last_pgno = env->me_metas[toggle]->mm_last_pg;
6671 /** Set the default comparison functions for a database.
6672 * Called immediately after a database is opened to set the defaults.
6673 * The user can then override them with #mdb_set_compare() or
6674 * #mdb_set_dupsort().
6675 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
6676 * @param[in] dbi A database handle returned by #mdb_open()
6679 mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi)
6681 uint16_t f = txn->mt_dbs[dbi].md_flags;
6683 txn->mt_dbxs[dbi].md_cmp =
6684 (f & MDB_REVERSEKEY) ? mdb_cmp_memnr :
6685 (f & MDB_INTEGERKEY) ? mdb_cmp_cint : mdb_cmp_memn;
6687 txn->mt_dbxs[dbi].md_dcmp =
6688 !(f & MDB_DUPSORT) ? 0 :
6689 ((f & MDB_INTEGERDUP)
6690 ? ((f & MDB_DUPFIXED) ? mdb_cmp_int : mdb_cmp_cint)
6691 : ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn));
6694 int mdb_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
6699 int rc, dbflag, exact;
6700 unsigned int unused = 0;
6703 if (txn->mt_dbxs[FREE_DBI].md_cmp == NULL) {
6704 mdb_default_cmp(txn, FREE_DBI);
6710 if (flags & (MDB_DUPSORT|MDB_REVERSEKEY|MDB_INTEGERKEY))
6711 txn->mt_dbs[MAIN_DBI].md_flags |= (flags & (MDB_DUPSORT|MDB_REVERSEKEY|MDB_INTEGERKEY));
6712 mdb_default_cmp(txn, MAIN_DBI);
6716 if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {
6717 mdb_default_cmp(txn, MAIN_DBI);
6720 /* Is the DB already open? */
6722 for (i=2; i<txn->mt_numdbs; i++) {
6723 if (!txn->mt_dbxs[i].md_name.mv_size) {
6724 /* Remember this free slot */
6725 if (!unused) unused = i;
6728 if (len == txn->mt_dbxs[i].md_name.mv_size &&
6729 !strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) {
6735 /* If no free slot and max hit, fail */
6736 if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs)
6737 return MDB_DBS_FULL;
6739 /* Find the DB info */
6743 key.mv_data = (void *)name;
6744 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
6745 rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact);
6746 if (rc == MDB_SUCCESS) {
6747 /* make sure this is actually a DB */
6748 MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]);
6749 if (!(node->mn_flags & F_SUBDATA))
6751 } else if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) {
6752 /* Create if requested */
6754 data.mv_size = sizeof(MDB_db);
6755 data.mv_data = &dummy;
6756 memset(&dummy, 0, sizeof(dummy));
6757 dummy.md_root = P_INVALID;
6758 dummy.md_flags = flags & 0xffff;
6759 rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA);
6763 /* OK, got info, add to table */
6764 if (rc == MDB_SUCCESS) {
6765 unsigned int slot = unused ? unused : txn->mt_numdbs;
6766 txn->mt_dbxs[slot].md_name.mv_data = strdup(name);
6767 txn->mt_dbxs[slot].md_name.mv_size = len;
6768 txn->mt_dbxs[slot].md_rel = NULL;
6769 txn->mt_dbflags[slot] = dbflag;
6770 memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db));
6772 txn->mt_env->me_dbflags[slot] = txn->mt_dbs[slot].md_flags;
6773 mdb_default_cmp(txn, slot);
6776 txn->mt_env->me_numdbs++;
6783 int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
6785 if (txn == NULL || arg == NULL || dbi >= txn->mt_numdbs)
6788 return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg);
6791 void mdb_close(MDB_env *env, MDB_dbi dbi)
6794 if (dbi <= MAIN_DBI || dbi >= env->me_numdbs)
6796 ptr = env->me_dbxs[dbi].md_name.mv_data;
6797 env->me_dbxs[dbi].md_name.mv_data = NULL;
6798 env->me_dbxs[dbi].md_name.mv_size = 0;
6802 /** Add all the DB's pages to the free list.
6803 * @param[in] mc Cursor on the DB to free.
6804 * @param[in] subs non-Zero to check for sub-DBs in this DB.
6805 * @return 0 on success, non-zero on failure.
6808 mdb_drop0(MDB_cursor *mc, int subs)
6812 rc = mdb_page_search(mc, NULL, 0);
6813 if (rc == MDB_SUCCESS) {
6818 /* LEAF2 pages have no nodes, cannot have sub-DBs */
6819 if (!subs || IS_LEAF2(mc->mc_pg[mc->mc_top]))
6822 mdb_cursor_copy(mc, &mx);
6823 while (mc->mc_snum > 0) {
6824 if (IS_LEAF(mc->mc_pg[mc->mc_top])) {
6825 for (i=0; i<NUMKEYS(mc->mc_pg[mc->mc_top]); i++) {
6826 ni = NODEPTR(mc->mc_pg[mc->mc_top], i);
6827 if (ni->mn_flags & F_SUBDATA) {
6828 mdb_xcursor_init1(mc, ni);
6829 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
6835 for (i=0; i<NUMKEYS(mc->mc_pg[mc->mc_top]); i++) {
6837 ni = NODEPTR(mc->mc_pg[mc->mc_top], i);
6840 mdb_midl_append(&mc->mc_txn->mt_free_pgs, pg);
6845 rc = mdb_cursor_sibling(mc, 1);
6847 /* no more siblings, go back to beginning
6848 * of previous level. (stack was already popped
6849 * by mdb_cursor_sibling)
6851 for (i=1; i<mc->mc_top; i++)
6852 mc->mc_pg[i] = mx.mc_pg[i];
6856 mdb_midl_append(&mc->mc_txn->mt_free_pgs,
6857 mc->mc_db->md_root);
6862 int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)
6867 if (!txn || !dbi || dbi >= txn->mt_numdbs)
6870 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
6873 rc = mdb_cursor_open(txn, dbi, &mc);
6877 rc = mdb_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT);
6881 /* Can't delete the main DB */
6882 if (del && dbi > MAIN_DBI) {
6883 rc = mdb_del(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL);
6885 mdb_close(txn->mt_env, dbi);
6887 /* reset the DB record, mark it dirty */
6888 txn->mt_dbflags[dbi] |= DB_DIRTY;
6889 txn->mt_dbs[dbi].md_depth = 0;
6890 txn->mt_dbs[dbi].md_branch_pages = 0;
6891 txn->mt_dbs[dbi].md_leaf_pages = 0;
6892 txn->mt_dbs[dbi].md_overflow_pages = 0;
6893 txn->mt_dbs[dbi].md_entries = 0;
6894 txn->mt_dbs[dbi].md_root = P_INVALID;
6896 if (!txn->mt_u.dirty_list[0].mid) {
6899 /* make sure we have at least one dirty page in this txn
6900 * otherwise these changes will be ignored.
6902 key.mv_size = sizeof(txnid_t);
6903 key.mv_data = &txn->mt_txnid;
6904 data.mv_size = sizeof(MDB_ID);
6905 data.mv_data = txn->mt_free_pgs;
6906 mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
6907 rc = mdb_cursor_put(&m2, &key, &data, 0);
6911 mdb_cursor_close(mc);
6915 int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
6917 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
6920 txn->mt_dbxs[dbi].md_cmp = cmp;
6924 int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
6926 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
6929 txn->mt_dbxs[dbi].md_dcmp = cmp;
6933 int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
6935 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
6938 txn->mt_dbxs[dbi].md_rel = rel;
6942 int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx)
6944 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
6947 txn->mt_dbxs[dbi].md_relctx = ctx;
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