2 * @brief memory-mapped database library
4 * A Btree-based database management library modeled loosely on the
5 * BerkeleyDB API, but much simplified.
8 * Copyright 2011-2013 Howard Chu, Symas Corp.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted only as authorized by the OpenLDAP
15 * A copy of this license is available in the file LICENSE in the
16 * top-level directory of the distribution or, alternatively, at
17 * <http://www.OpenLDAP.org/license.html>.
19 * This code is derived from btree.c written by Martin Hedenfalk.
21 * Copyright (c) 2009, 2010 Martin Hedenfalk <martin@bzero.se>
23 * Permission to use, copy, modify, and distribute this software for any
24 * purpose with or without fee is hereby granted, provided that the above
25 * copyright notice and this permission notice appear in all copies.
27 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
28 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
29 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
30 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
31 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
32 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
33 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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)
300 # define MDB_DEBUG_SKIP
302 /** Print a debug string.
303 * The string is printed literally, with no format processing.
305 #define DPUTS(arg) DPRINTF("%s", arg)
308 /** A default memory page size.
309 * The actual size is platform-dependent, but we use this for
310 * boot-strapping. We probably should not be using this any more.
311 * The #GET_PAGESIZE() macro is used to get the actual size.
313 * Note that we don't currently support Huge pages. On Linux,
314 * regular data files cannot use Huge pages, and in general
315 * Huge pages aren't actually pageable. We rely on the OS
316 * demand-pager to read our data and page it out when memory
317 * pressure from other processes is high. So until OSs have
318 * actual paging support for Huge pages, they're not viable.
320 #define MDB_PAGESIZE 4096
322 /** The minimum number of keys required in a database page.
323 * Setting this to a larger value will place a smaller bound on the
324 * maximum size of a data item. Data items larger than this size will
325 * be pushed into overflow pages instead of being stored directly in
326 * the B-tree node. This value used to default to 4. With a page size
327 * of 4096 bytes that meant that any item larger than 1024 bytes would
328 * go into an overflow page. That also meant that on average 2-3KB of
329 * each overflow page was wasted space. The value cannot be lower than
330 * 2 because then there would no longer be a tree structure. With this
331 * value, items larger than 2KB will go into overflow pages, and on
332 * average only 1KB will be wasted.
334 #define MDB_MINKEYS 2
336 /** A stamp that identifies a file as an MDB file.
337 * There's nothing special about this value other than that it is easily
338 * recognizable, and it will reflect any byte order mismatches.
340 #define MDB_MAGIC 0xBEEFC0DE
342 /** The version number for a database's file format. */
343 #define MDB_VERSION 1
345 /** @brief The maximum size of a key in the database.
347 * We require that keys all fit onto a regular page. This limit
348 * could be raised a bit further if needed; to something just
349 * under #MDB_PAGESIZE / #MDB_MINKEYS.
351 * Note that data items in an #MDB_DUPSORT database are actually keys
352 * of a subDB, so they're also limited to this size.
354 #ifndef MDB_MAXKEYSIZE
355 #define MDB_MAXKEYSIZE 511
358 /** @brief The maximum size of a data item.
360 * We only store a 32 bit value for node sizes.
362 #define MAXDATASIZE 0xffffffffUL
367 * This is used for printing a hex dump of a key's contents.
369 #define DKBUF char kbuf[(MDB_MAXKEYSIZE*2+1)]
370 /** Display a key in hex.
372 * Invoke a function to display a key in hex.
374 #define DKEY(x) mdb_dkey(x, kbuf)
376 #define DKBUF typedef int dummy_kbuf /* so we can put ';' after */
380 /** An invalid page number.
381 * Mainly used to denote an empty tree.
383 #define P_INVALID (~(pgno_t)0)
385 /** Test if the flags \b f are set in a flag word \b w. */
386 #define F_ISSET(w, f) (((w) & (f)) == (f))
388 /** Used for offsets within a single page.
389 * Since memory pages are typically 4 or 8KB in size, 12-13 bits,
392 typedef uint16_t indx_t;
394 /** Default size of memory map.
395 * This is certainly too small for any actual applications. Apps should always set
396 * the size explicitly using #mdb_env_set_mapsize().
398 #define DEFAULT_MAPSIZE 1048576
400 /** @defgroup readers Reader Lock Table
401 * Readers don't acquire any locks for their data access. Instead, they
402 * simply record their transaction ID in the reader table. The reader
403 * mutex is needed just to find an empty slot in the reader table. The
404 * slot's address is saved in thread-specific data so that subsequent read
405 * transactions started by the same thread need no further locking to proceed.
407 * No reader table is used if the database is on a read-only filesystem.
409 * Since the database uses multi-version concurrency control, readers don't
410 * actually need any locking. This table is used to keep track of which
411 * readers are using data from which old transactions, so that we'll know
412 * when a particular old transaction is no longer in use. Old transactions
413 * that have discarded any data pages can then have those pages reclaimed
414 * for use by a later write transaction.
416 * The lock table is constructed such that reader slots are aligned with the
417 * processor's cache line size. Any slot is only ever used by one thread.
418 * This alignment guarantees that there will be no contention or cache
419 * thrashing as threads update their own slot info, and also eliminates
420 * any need for locking when accessing a slot.
422 * A writer thread will scan every slot in the table to determine the oldest
423 * outstanding reader transaction. Any freed pages older than this will be
424 * reclaimed by the writer. The writer doesn't use any locks when scanning
425 * this table. This means that there's no guarantee that the writer will
426 * see the most up-to-date reader info, but that's not required for correct
427 * operation - all we need is to know the upper bound on the oldest reader,
428 * we don't care at all about the newest reader. So the only consequence of
429 * reading stale information here is that old pages might hang around a
430 * while longer before being reclaimed. That's actually good anyway, because
431 * the longer we delay reclaiming old pages, the more likely it is that a
432 * string of contiguous pages can be found after coalescing old pages from
433 * many old transactions together.
435 * @todo We don't actually do such coalescing yet, we grab pages from one
436 * old transaction at a time.
439 /** Number of slots in the reader table.
440 * This value was chosen somewhat arbitrarily. 126 readers plus a
441 * couple mutexes fit exactly into 8KB on my development machine.
442 * Applications should set the table size using #mdb_env_set_maxreaders().
444 #define DEFAULT_READERS 126
446 /** The size of a CPU cache line in bytes. We want our lock structures
447 * aligned to this size to avoid false cache line sharing in the
449 * This value works for most CPUs. For Itanium this should be 128.
455 /** The information we store in a single slot of the reader table.
456 * In addition to a transaction ID, we also record the process and
457 * thread ID that owns a slot, so that we can detect stale information,
458 * e.g. threads or processes that went away without cleaning up.
459 * @note We currently don't check for stale records. We simply re-init
460 * the table when we know that we're the only process opening the
463 typedef struct MDB_rxbody {
464 /** Current Transaction ID when this transaction began, or (txnid_t)-1.
465 * Multiple readers that start at the same time will probably have the
466 * same ID here. Again, it's not important to exclude them from
467 * anything; all we need to know is which version of the DB they
468 * started from so we can avoid overwriting any data used in that
469 * particular version.
472 /** The process ID of the process owning this reader txn. */
474 /** The thread ID of the thread owning this txn. */
478 /** The actual reader record, with cacheline padding. */
479 typedef struct MDB_reader {
482 /** shorthand for mrb_txnid */
483 #define mr_txnid mru.mrx.mrb_txnid
484 #define mr_pid mru.mrx.mrb_pid
485 #define mr_tid mru.mrx.mrb_tid
486 /** cache line alignment */
487 char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)];
491 /** The header for the reader table.
492 * The table resides in a memory-mapped file. (This is a different file
493 * than is used for the main database.)
495 * For POSIX the actual mutexes reside in the shared memory of this
496 * mapped file. On Windows, mutexes are named objects allocated by the
497 * kernel; we store the mutex names in this mapped file so that other
498 * processes can grab them. This same approach is also used on
499 * MacOSX/Darwin (using named semaphores) since MacOSX doesn't support
500 * process-shared POSIX mutexes. For these cases where a named object
501 * is used, the object name is derived from a 64 bit FNV hash of the
502 * environment pathname. As such, naming collisions are extremely
503 * unlikely. If a collision occurs, the results are unpredictable.
505 typedef struct MDB_txbody {
506 /** Stamp identifying this as an MDB file. It must be set
509 /** Version number of this lock file. Must be set to #MDB_VERSION. */
510 uint32_t mtb_version;
511 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
512 char mtb_rmname[MNAME_LEN];
514 /** Mutex protecting access to this table.
515 * This is the reader lock that #LOCK_MUTEX_R acquires.
517 pthread_mutex_t mtb_mutex;
519 /** The ID of the last transaction committed to the database.
520 * This is recorded here only for convenience; the value can always
521 * be determined by reading the main database meta pages.
524 /** The number of slots that have been used in the reader table.
525 * This always records the maximum count, it is not decremented
526 * when readers release their slots.
528 unsigned mtb_numreaders;
531 /** The actual reader table definition. */
532 typedef struct MDB_txninfo {
535 #define mti_magic mt1.mtb.mtb_magic
536 #define mti_version mt1.mtb.mtb_version
537 #define mti_mutex mt1.mtb.mtb_mutex
538 #define mti_rmname mt1.mtb.mtb_rmname
539 #define mti_txnid mt1.mtb.mtb_txnid
540 #define mti_numreaders mt1.mtb.mtb_numreaders
541 char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];
544 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
545 char mt2_wmname[MNAME_LEN];
546 #define mti_wmname mt2.mt2_wmname
548 pthread_mutex_t mt2_wmutex;
549 #define mti_wmutex mt2.mt2_wmutex
551 char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)];
553 MDB_reader mti_readers[1];
557 /** Common header for all page types.
558 * Overflow records occupy a number of contiguous pages with no
559 * headers on any page after the first.
561 typedef struct MDB_page {
562 #define mp_pgno mp_p.p_pgno
563 #define mp_next mp_p.p_next
565 pgno_t p_pgno; /**< page number */
566 void * p_next; /**< for in-memory list of freed structs */
569 /** @defgroup mdb_page Page Flags
571 * Flags for the page headers.
574 #define P_BRANCH 0x01 /**< branch page */
575 #define P_LEAF 0x02 /**< leaf page */
576 #define P_OVERFLOW 0x04 /**< overflow page */
577 #define P_META 0x08 /**< meta page */
578 #define P_DIRTY 0x10 /**< dirty page */
579 #define P_LEAF2 0x20 /**< for #MDB_DUPFIXED records */
580 #define P_SUBP 0x40 /**< for #MDB_DUPSORT sub-pages */
582 uint16_t mp_flags; /**< @ref mdb_page */
583 #define mp_lower mp_pb.pb.pb_lower
584 #define mp_upper mp_pb.pb.pb_upper
585 #define mp_pages mp_pb.pb_pages
588 indx_t pb_lower; /**< lower bound of free space */
589 indx_t pb_upper; /**< upper bound of free space */
591 uint32_t pb_pages; /**< number of overflow pages */
593 indx_t mp_ptrs[1]; /**< dynamic size */
596 /** Size of the page header, excluding dynamic data at the end */
597 #define PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs))
599 /** Address of first usable data byte in a page, after the header */
600 #define METADATA(p) ((void *)((char *)(p) + PAGEHDRSZ))
602 /** Number of nodes on a page */
603 #define NUMKEYS(p) (((p)->mp_lower - PAGEHDRSZ) >> 1)
605 /** The amount of space remaining in the page */
606 #define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower)
608 /** The percentage of space used in the page, in tenths of a percent. */
609 #define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \
610 ((env)->me_psize - PAGEHDRSZ))
611 /** The minimum page fill factor, in tenths of a percent.
612 * Pages emptier than this are candidates for merging.
614 #define FILL_THRESHOLD 250
616 /** Test if a page is a leaf page */
617 #define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF)
618 /** Test if a page is a LEAF2 page */
619 #define IS_LEAF2(p) F_ISSET((p)->mp_flags, P_LEAF2)
620 /** Test if a page is a branch page */
621 #define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH)
622 /** Test if a page is an overflow page */
623 #define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW)
624 /** Test if a page is a sub page */
625 #define IS_SUBP(p) F_ISSET((p)->mp_flags, P_SUBP)
627 /** The number of overflow pages needed to store the given size. */
628 #define OVPAGES(size, psize) ((PAGEHDRSZ-1 + (size)) / (psize) + 1)
630 /** Header for a single key/data pair within a page.
631 * We guarantee 2-byte alignment for nodes.
633 typedef struct MDB_node {
634 /** lo and hi are used for data size on leaf nodes and for
635 * child pgno on branch nodes. On 64 bit platforms, flags
636 * is also used for pgno. (Branch nodes have no flags).
637 * They are in host byte order in case that lets some
638 * accesses be optimized into a 32-bit word access.
640 #define mn_lo mn_offset[BYTE_ORDER!=LITTLE_ENDIAN]
641 #define mn_hi mn_offset[BYTE_ORDER==LITTLE_ENDIAN] /**< part of dsize or pgno */
642 unsigned short mn_offset[2]; /**< storage for #mn_lo and #mn_hi */
643 /** @defgroup mdb_node Node Flags
645 * Flags for node headers.
648 #define F_BIGDATA 0x01 /**< data put on overflow page */
649 #define F_SUBDATA 0x02 /**< data is a sub-database */
650 #define F_DUPDATA 0x04 /**< data has duplicates */
652 /** valid flags for #mdb_node_add() */
653 #define NODE_ADD_FLAGS (F_DUPDATA|F_SUBDATA|MDB_RESERVE|MDB_APPEND)
656 unsigned short mn_flags; /**< @ref mdb_node */
657 unsigned short mn_ksize; /**< key size */
658 char mn_data[1]; /**< key and data are appended here */
661 /** Size of the node header, excluding dynamic data at the end */
662 #define NODESIZE offsetof(MDB_node, mn_data)
664 /** Bit position of top word in page number, for shifting mn_flags */
665 #define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0)
667 /** Size of a node in a branch page with a given key.
668 * This is just the node header plus the key, there is no data.
670 #define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))
672 /** Size of a node in a leaf page with a given key and data.
673 * This is node header plus key plus data size.
675 #define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size)
677 /** Address of node \b i in page \b p */
678 #define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i]))
680 /** Address of the key for the node */
681 #define NODEKEY(node) (void *)((node)->mn_data)
683 /** Address of the data for a node */
684 #define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize)
686 /** Get the page number pointed to by a branch node */
687 #define NODEPGNO(node) \
688 ((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | \
689 (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0))
690 /** Set the page number in a branch node */
691 #define SETPGNO(node,pgno) do { \
692 (node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \
693 if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0)
695 /** Get the size of the data in a leaf node */
696 #define NODEDSZ(node) ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16))
697 /** Set the size of the data for a leaf node */
698 #define SETDSZ(node,size) do { \
699 (node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)
700 /** The size of a key in a node */
701 #define NODEKSZ(node) ((node)->mn_ksize)
703 /** Copy a page number from src to dst */
705 #define COPY_PGNO(dst,src) dst = src
707 #if SIZE_MAX > 4294967295UL
708 #define COPY_PGNO(dst,src) do { \
709 unsigned short *s, *d; \
710 s = (unsigned short *)&(src); \
711 d = (unsigned short *)&(dst); \
718 #define COPY_PGNO(dst,src) do { \
719 unsigned short *s, *d; \
720 s = (unsigned short *)&(src); \
721 d = (unsigned short *)&(dst); \
727 /** The address of a key in a LEAF2 page.
728 * LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate sub-DBs.
729 * There are no node headers, keys are stored contiguously.
731 #define LEAF2KEY(p, i, ks) ((char *)(p) + PAGEHDRSZ + ((i)*(ks)))
733 /** Set the \b node's key into \b key, if requested. */
734 #define MDB_GET_KEY(node, key) { if ((key) != NULL) { \
735 (key)->mv_size = NODEKSZ(node); (key)->mv_data = NODEKEY(node); } }
737 /** Information about a single database in the environment. */
738 typedef struct MDB_db {
739 uint32_t md_pad; /**< also ksize for LEAF2 pages */
740 uint16_t md_flags; /**< @ref mdb_dbi_open */
741 uint16_t md_depth; /**< depth of this tree */
742 pgno_t md_branch_pages; /**< number of internal pages */
743 pgno_t md_leaf_pages; /**< number of leaf pages */
744 pgno_t md_overflow_pages; /**< number of overflow pages */
745 size_t md_entries; /**< number of data items */
746 pgno_t md_root; /**< the root page of this tree */
749 /** Handle for the DB used to track free pages. */
751 /** Handle for the default DB. */
754 /** Meta page content. */
755 typedef struct MDB_meta {
756 /** Stamp identifying this as an MDB file. It must be set
759 /** Version number of this lock file. Must be set to #MDB_VERSION. */
761 void *mm_address; /**< address for fixed mapping */
762 size_t mm_mapsize; /**< size of mmap region */
763 MDB_db mm_dbs[2]; /**< first is free space, 2nd is main db */
764 /** The size of pages used in this DB */
765 #define mm_psize mm_dbs[0].md_pad
766 /** Any persistent environment flags. @ref mdb_env */
767 #define mm_flags mm_dbs[0].md_flags
768 pgno_t mm_last_pg; /**< last used page in file */
769 txnid_t mm_txnid; /**< txnid that committed this page */
772 /** Buffer for a stack-allocated dirty page.
773 * The members define size and alignment, and silence type
774 * aliasing warnings. They are not used directly; that could
775 * mean incorrectly using several union members in parallel.
777 typedef union MDB_pagebuf {
778 char mb_raw[MDB_PAGESIZE];
781 char mm_pad[PAGEHDRSZ];
786 /** Auxiliary DB info.
787 * The information here is mostly static/read-only. There is
788 * only a single copy of this record in the environment.
790 typedef struct MDB_dbx {
791 MDB_val md_name; /**< name of the database */
792 MDB_cmp_func *md_cmp; /**< function for comparing keys */
793 MDB_cmp_func *md_dcmp; /**< function for comparing data items */
794 MDB_rel_func *md_rel; /**< user relocate function */
795 void *md_relctx; /**< user-provided context for md_rel */
798 /** A database transaction.
799 * Every operation requires a transaction handle.
802 MDB_txn *mt_parent; /**< parent of a nested txn */
803 MDB_txn *mt_child; /**< nested txn under this txn */
804 pgno_t mt_next_pgno; /**< next unallocated page */
805 /** The ID of this transaction. IDs are integers incrementing from 1.
806 * Only committed write transactions increment the ID. If a transaction
807 * aborts, the ID may be re-used by the next writer.
810 MDB_env *mt_env; /**< the DB environment */
811 /** The list of pages that became unused during this transaction.
815 MDB_ID2L dirty_list; /**< for write txns: modified pages */
816 MDB_reader *reader; /**< this thread's reader table slot or NULL */
818 /** Array of records for each DB known in the environment. */
820 /** Array of MDB_db records for each known DB */
822 /** @defgroup mt_dbflag Transaction DB Flags
826 #define DB_DIRTY 0x01 /**< DB was written in this txn */
827 #define DB_STALE 0x02 /**< DB record is older than txnID */
829 /** In write txns, array of cursors for each DB */
830 MDB_cursor **mt_cursors;
831 /** Array of flags for each DB */
832 unsigned char *mt_dbflags;
833 /** Number of DB records in use. This number only ever increments;
834 * we don't decrement it when individual DB handles are closed.
838 /** @defgroup mdb_txn Transaction Flags
842 #define MDB_TXN_RDONLY 0x01 /**< read-only transaction */
843 #define MDB_TXN_ERROR 0x02 /**< an error has occurred */
844 #define MDB_TXN_DIRTY 0x04 /**< must write, even if dirty list is empty */
846 unsigned int mt_flags; /**< @ref mdb_txn */
847 /** Tracks which of the two meta pages was used at the start
848 * of this transaction.
850 unsigned int mt_toggle;
853 /** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty.
854 * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to
855 * raise this on a 64 bit machine.
857 #define CURSOR_STACK 32
861 /** Cursors are used for all DB operations */
863 /** Next cursor on this DB in this txn */
865 /** Original cursor if this is a shadow */
867 /** Context used for databases with #MDB_DUPSORT, otherwise NULL */
868 struct MDB_xcursor *mc_xcursor;
869 /** The transaction that owns this cursor */
871 /** The database handle this cursor operates on */
873 /** The database record for this cursor */
875 /** The database auxiliary record for this cursor */
877 /** The @ref mt_dbflag for this database */
878 unsigned char *mc_dbflag;
879 unsigned short mc_snum; /**< number of pushed pages */
880 unsigned short mc_top; /**< index of top page, normally mc_snum-1 */
881 /** @defgroup mdb_cursor Cursor Flags
883 * Cursor state flags.
886 #define C_INITIALIZED 0x01 /**< cursor has been initialized and is valid */
887 #define C_EOF 0x02 /**< No more data */
888 #define C_SUB 0x04 /**< Cursor is a sub-cursor */
889 #define C_SHADOW 0x08 /**< Cursor is a dup from a parent txn */
890 #define C_ALLOCD 0x10 /**< Cursor was malloc'd */
891 #define C_SPLITTING 0x20 /**< Cursor is in page_split */
893 unsigned int mc_flags; /**< @ref mdb_cursor */
894 MDB_page *mc_pg[CURSOR_STACK]; /**< stack of pushed pages */
895 indx_t mc_ki[CURSOR_STACK]; /**< stack of page indices */
898 /** Context for sorted-dup records.
899 * We could have gone to a fully recursive design, with arbitrarily
900 * deep nesting of sub-databases. But for now we only handle these
901 * levels - main DB, optional sub-DB, sorted-duplicate DB.
903 typedef struct MDB_xcursor {
904 /** A sub-cursor for traversing the Dup DB */
905 MDB_cursor mx_cursor;
906 /** The database record for this Dup DB */
908 /** The auxiliary DB record for this Dup DB */
910 /** The @ref mt_dbflag for this Dup DB */
911 unsigned char mx_dbflag;
914 /** A set of pages freed by an earlier transaction. */
915 typedef struct MDB_oldpages {
916 /** Usually we only read one record from the FREEDB at a time, but
917 * in case we read more, this will chain them together.
919 struct MDB_oldpages *mo_next;
920 /** The ID of the transaction in which these pages were freed. */
922 /** An #MDB_IDL of the pages */
923 pgno_t mo_pages[1]; /* dynamic */
926 /** The database environment. */
928 HANDLE me_fd; /**< The main data file */
929 HANDLE me_lfd; /**< The lock file */
930 HANDLE me_mfd; /**< just for writing the meta pages */
931 /** Failed to update the meta page. Probably an I/O error. */
932 #define MDB_FATAL_ERROR 0x80000000U
933 /** Read-only Filesystem. Allow read access, no locking. */
934 #define MDB_ROFS 0x40000000U
935 /** Some fields are initialized. */
936 #define MDB_ENV_ACTIVE 0x20000000U
937 uint32_t me_flags; /**< @ref mdb_env */
938 unsigned int me_psize; /**< size of a page, from #GET_PAGESIZE */
939 unsigned int me_maxreaders; /**< size of the reader table */
940 unsigned int me_numreaders; /**< max numreaders set by this env */
941 MDB_dbi me_numdbs; /**< number of DBs opened */
942 MDB_dbi me_maxdbs; /**< size of the DB table */
943 pid_t me_pid; /**< process ID of this env */
944 char *me_path; /**< path to the DB files */
945 char *me_map; /**< the memory map of the data file */
946 MDB_txninfo *me_txns; /**< the memory map of the lock file or NULL */
947 MDB_meta *me_metas[2]; /**< pointers to the two meta pages */
948 MDB_txn *me_txn; /**< current write transaction */
949 size_t me_mapsize; /**< size of the data memory map */
950 off_t me_size; /**< current file size */
951 pgno_t me_maxpg; /**< me_mapsize / me_psize */
952 txnid_t me_pgfirst; /**< ID of first old page record we used */
953 txnid_t me_pglast; /**< ID of last old page record we used */
954 MDB_dbx *me_dbxs; /**< array of static DB info */
955 uint16_t *me_dbflags; /**< array of flags from MDB_db.md_flags */
956 MDB_oldpages *me_pghead; /**< list of old page records */
957 MDB_oldpages *me_pgfree; /**< list of page records to free */
958 pthread_key_t me_txkey; /**< thread-key for readers */
959 MDB_page *me_dpages; /**< list of malloc'd blocks for re-use */
960 /** IDL of pages that became unused in a write txn */
962 /** ID2L of pages that were written during a write txn */
963 MDB_ID2 me_dirty_list[MDB_IDL_UM_SIZE];
965 HANDLE me_rmutex; /* Windows mutexes don't reside in shared mem */
967 #elif defined(MDB_USE_POSIX_SEM)
968 sem_t *me_rmutex; /* Shared mutexes are not supported */
972 /** max number of pages to commit in one writev() call */
973 #define MDB_COMMIT_PAGES 64
974 #if defined(IOV_MAX) && IOV_MAX < MDB_COMMIT_PAGES
975 #undef MDB_COMMIT_PAGES
976 #define MDB_COMMIT_PAGES IOV_MAX
979 static int mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp);
980 static int mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp);
981 static int mdb_page_touch(MDB_cursor *mc);
983 static int mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **mp);
984 static int mdb_page_search_root(MDB_cursor *mc,
985 MDB_val *key, int modify);
986 #define MDB_PS_MODIFY 1
987 #define MDB_PS_ROOTONLY 2
988 static int mdb_page_search(MDB_cursor *mc,
989 MDB_val *key, int flags);
990 static int mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst);
992 #define MDB_SPLIT_REPLACE MDB_APPENDDUP /**< newkey is not new */
993 static int mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,
994 pgno_t newpgno, unsigned int nflags);
996 static int mdb_env_read_header(MDB_env *env, MDB_meta *meta);
997 static int mdb_env_pick_meta(const MDB_env *env);
998 static int mdb_env_write_meta(MDB_txn *txn);
999 static void mdb_env_close0(MDB_env *env, int excl);
1001 static MDB_node *mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp);
1002 static int mdb_node_add(MDB_cursor *mc, indx_t indx,
1003 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags);
1004 static void mdb_node_del(MDB_page *mp, indx_t indx, int ksize);
1005 static void mdb_node_shrink(MDB_page *mp, indx_t indx);
1006 static int mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst);
1007 static int mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data);
1008 static size_t mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data);
1009 static size_t mdb_branch_size(MDB_env *env, MDB_val *key);
1011 static int mdb_rebalance(MDB_cursor *mc);
1012 static int mdb_update_key(MDB_page *mp, indx_t indx, MDB_val *key);
1014 static void mdb_cursor_pop(MDB_cursor *mc);
1015 static int mdb_cursor_push(MDB_cursor *mc, MDB_page *mp);
1017 static int mdb_cursor_del0(MDB_cursor *mc, MDB_node *leaf);
1018 static int mdb_cursor_sibling(MDB_cursor *mc, int move_right);
1019 static int mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1020 static int mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1021 static int mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op,
1023 static int mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1024 static int mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1026 static void mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);
1027 static void mdb_xcursor_init0(MDB_cursor *mc);
1028 static void mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node);
1030 static int mdb_drop0(MDB_cursor *mc, int subs);
1031 static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi);
1034 static MDB_cmp_func mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long;
1038 static SECURITY_DESCRIPTOR mdb_null_sd;
1039 static SECURITY_ATTRIBUTES mdb_all_sa;
1040 static int mdb_sec_inited;
1043 /** Return the library version info. */
1045 mdb_version(int *major, int *minor, int *patch)
1047 if (major) *major = MDB_VERSION_MAJOR;
1048 if (minor) *minor = MDB_VERSION_MINOR;
1049 if (patch) *patch = MDB_VERSION_PATCH;
1050 return MDB_VERSION_STRING;
1053 /** Table of descriptions for MDB @ref errors */
1054 static char *const mdb_errstr[] = {
1055 "MDB_KEYEXIST: Key/data pair already exists",
1056 "MDB_NOTFOUND: No matching key/data pair found",
1057 "MDB_PAGE_NOTFOUND: Requested page not found",
1058 "MDB_CORRUPTED: Located page was wrong type",
1059 "MDB_PANIC: Update of meta page failed",
1060 "MDB_VERSION_MISMATCH: Database environment version mismatch",
1061 "MDB_INVALID: File is not an MDB file",
1062 "MDB_MAP_FULL: Environment mapsize limit reached",
1063 "MDB_DBS_FULL: Environment maxdbs limit reached",
1064 "MDB_READERS_FULL: Environment maxreaders limit reached",
1065 "MDB_TLS_FULL: Thread-local storage keys full - too many environments open",
1066 "MDB_TXN_FULL: Transaction has too many dirty pages - transaction too big",
1067 "MDB_CURSOR_FULL: Internal error - cursor stack limit reached",
1068 "MDB_PAGE_FULL: Internal error - page has no more space"
1072 mdb_strerror(int err)
1076 return ("Successful return: 0");
1078 if (err >= MDB_KEYEXIST && err <= MDB_LAST_ERRCODE) {
1079 i = err - MDB_KEYEXIST;
1080 return mdb_errstr[i];
1083 return strerror(err);
1087 /** Display a key in hexadecimal and return the address of the result.
1088 * @param[in] key the key to display
1089 * @param[in] buf the buffer to write into. Should always be #DKBUF.
1090 * @return The key in hexadecimal form.
1093 mdb_dkey(MDB_val *key, char *buf)
1096 unsigned char *c = key->mv_data;
1098 if (key->mv_size > MDB_MAXKEYSIZE)
1099 return "MDB_MAXKEYSIZE";
1100 /* may want to make this a dynamic check: if the key is mostly
1101 * printable characters, print it as-is instead of converting to hex.
1105 for (i=0; i<key->mv_size; i++)
1106 ptr += sprintf(ptr, "%02x", *c++);
1108 sprintf(buf, "%.*s", key->mv_size, key->mv_data);
1113 /** Display all the keys in the page. */
1115 mdb_page_list(MDB_page *mp)
1118 unsigned int i, nkeys, nsize;
1122 nkeys = NUMKEYS(mp);
1123 fprintf(stderr, "numkeys %d\n", nkeys);
1124 for (i=0; i<nkeys; i++) {
1125 node = NODEPTR(mp, i);
1126 key.mv_size = node->mn_ksize;
1127 key.mv_data = node->mn_data;
1128 nsize = NODESIZE + NODEKSZ(node) + sizeof(indx_t);
1129 if (F_ISSET(node->mn_flags, F_BIGDATA))
1130 nsize += sizeof(pgno_t);
1132 nsize += NODEDSZ(node);
1133 fprintf(stderr, "key %d: nsize %d, %s\n", i, nsize, DKEY(&key));
1138 mdb_cursor_chk(MDB_cursor *mc)
1144 if (!mc->mc_snum && !(mc->mc_flags & C_INITIALIZED)) return;
1145 for (i=0; i<mc->mc_top; i++) {
1147 node = NODEPTR(mp, mc->mc_ki[i]);
1148 if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno)
1151 if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i]))
1157 /** Count all the pages in each DB and in the freelist
1158 * and make sure it matches the actual number of pages
1161 static void mdb_audit(MDB_txn *txn)
1165 MDB_ID freecount, count;
1170 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
1171 while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
1172 freecount += *(MDB_ID *)data.mv_data;
1175 for (i = 0; i<txn->mt_numdbs; i++) {
1176 MDB_xcursor mx, *mxp;
1177 mxp = (txn->mt_dbs[i].md_flags & MDB_DUPSORT) ? &mx : NULL;
1178 mdb_cursor_init(&mc, txn, i, mxp);
1179 if (txn->mt_dbs[i].md_root == P_INVALID)
1181 count += txn->mt_dbs[i].md_branch_pages +
1182 txn->mt_dbs[i].md_leaf_pages +
1183 txn->mt_dbs[i].md_overflow_pages;
1184 if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) {
1185 mdb_page_search(&mc, NULL, 0);
1189 mp = mc.mc_pg[mc.mc_top];
1190 for (j=0; j<NUMKEYS(mp); j++) {
1191 MDB_node *leaf = NODEPTR(mp, j);
1192 if (leaf->mn_flags & F_SUBDATA) {
1194 memcpy(&db, NODEDATA(leaf), sizeof(db));
1195 count += db.md_branch_pages + db.md_leaf_pages +
1196 db.md_overflow_pages;
1200 while (mdb_cursor_sibling(&mc, 1) == 0);
1203 if (freecount + count + 2 /* metapages */ != txn->mt_next_pgno) {
1204 fprintf(stderr, "audit: %lu freecount: %lu count: %lu total: %lu next_pgno: %lu\n",
1205 txn->mt_txnid, freecount, count+2, freecount+count+2, txn->mt_next_pgno);
1211 mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1213 return txn->mt_dbxs[dbi].md_cmp(a, b);
1217 mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1219 if (txn->mt_dbxs[dbi].md_dcmp)
1220 return txn->mt_dbxs[dbi].md_dcmp(a, b);
1222 return EINVAL; /* too bad you can't distinguish this from a valid result */
1225 /** Allocate a single page.
1226 * Re-use old malloc'd pages first, otherwise just malloc.
1229 mdb_page_malloc(MDB_cursor *mc) {
1231 size_t sz = mc->mc_txn->mt_env->me_psize;
1232 if ((ret = mc->mc_txn->mt_env->me_dpages) != NULL) {
1233 VGMEMP_ALLOC(mc->mc_txn->mt_env, ret, sz);
1234 VGMEMP_DEFINED(ret, sizeof(ret->mp_next));
1235 mc->mc_txn->mt_env->me_dpages = ret->mp_next;
1236 } else if ((ret = malloc(sz)) != NULL) {
1237 VGMEMP_ALLOC(mc->mc_txn->mt_env, ret, sz);
1243 mdb_page_free(MDB_env *env, MDB_page *mp)
1245 mp->mp_next = env->me_dpages;
1246 VGMEMP_FREE(env, mp);
1247 env->me_dpages = mp;
1250 /** Allocate pages for writing.
1251 * If there are free pages available from older transactions, they
1252 * will be re-used first. Otherwise a new page will be allocated.
1253 * @param[in] mc cursor A cursor handle identifying the transaction and
1254 * database for which we are allocating.
1255 * @param[in] num the number of pages to allocate.
1256 * @param[out] mp Address of the allocated page(s). Requests for multiple pages
1257 * will always be satisfied by a single contiguous chunk of memory.
1258 * @return 0 on success, non-zero on failure.
1261 mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
1263 MDB_txn *txn = mc->mc_txn;
1265 pgno_t pgno = P_INVALID;
1267 txnid_t oldest = 0, last;
1272 /* If our dirty list is already full, we can't do anything */
1273 if (txn->mt_u.dirty_list[0].mid >= MDB_IDL_UM_MAX)
1274 return MDB_TXN_FULL;
1276 /* The free list won't have any content at all until txn 2 has
1277 * committed. The pages freed by txn 2 will be unreferenced
1278 * after txn 3 commits, and so will be safe to re-use in txn 4.
1280 if (txn->mt_txnid > 3) {
1282 if (!txn->mt_env->me_pghead &&
1283 txn->mt_dbs[FREE_DBI].md_root != P_INVALID) {
1284 /* See if there's anything in the free DB */
1291 mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
1292 if (!txn->mt_env->me_pgfirst) {
1293 mdb_page_search(&m2, NULL, 0);
1294 leaf = NODEPTR(m2.mc_pg[m2.mc_top], 0);
1295 kptr = (txnid_t *)NODEKEY(leaf);
1302 last = txn->mt_env->me_pglast + 1;
1304 key.mv_data = &last;
1305 key.mv_size = sizeof(last);
1306 rc = mdb_cursor_set(&m2, &key, &data, MDB_SET, &exact);
1309 last = *(txnid_t *)key.mv_data;
1315 oldest = txn->mt_txnid - 1;
1316 nr = txn->mt_env->me_txns->mti_numreaders;
1317 r = txn->mt_env->me_txns->mti_readers;
1318 for (i=0; i<nr; i++) {
1319 if (!r[i].mr_pid) continue;
1326 if (oldest > last) {
1327 /* It's usable, grab it.
1332 if (!txn->mt_env->me_pgfirst) {
1333 mdb_node_read(txn, leaf, &data);
1335 txn->mt_env->me_pglast = last;
1336 if (!txn->mt_env->me_pgfirst)
1337 txn->mt_env->me_pgfirst = last;
1338 idl = (MDB_ID *) data.mv_data;
1339 /* We might have a zero-length IDL due to freelist growth
1340 * during a prior commit
1342 if (!idl[0]) goto again;
1343 mop = malloc(sizeof(MDB_oldpages) + MDB_IDL_SIZEOF(idl) - sizeof(pgno_t));
1346 mop->mo_next = txn->mt_env->me_pghead;
1347 mop->mo_txnid = last;
1348 txn->mt_env->me_pghead = mop;
1349 memcpy(mop->mo_pages, idl, MDB_IDL_SIZEOF(idl));
1354 DPRINTF("IDL read txn %zu root %zu num %zu",
1355 mop->mo_txnid, txn->mt_dbs[FREE_DBI].md_root, idl[0]);
1356 for (i=0; i<idl[0]; i++) {
1357 DPRINTF("IDL %zu", idl[i+1]);
1364 if (txn->mt_env->me_pghead) {
1365 MDB_oldpages *mop = txn->mt_env->me_pghead;
1368 int retry = 500, readit = 0, n2 = num-1;
1369 unsigned int i, j, k;
1371 /* If current list is too short, must fetch more and coalesce */
1372 if (mop->mo_pages[0] < (unsigned)num)
1375 mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
1377 /* If on freelist, don't try to read more. If what we have
1378 * right now isn't enough just use new pages.
1379 * TODO: get all of this working. Many circular dependencies...
1381 if (mc->mc_dbi == FREE_DBI) {
1391 last = mop->mo_txnid + 1;
1393 /* We haven't hit the readers list yet? */
1399 oldest = txn->mt_txnid - 1;
1400 nr = txn->mt_env->me_txns->mti_numreaders;
1401 r = txn->mt_env->me_txns->mti_readers;
1402 for (i=0; i<nr; i++) {
1403 if (!r[i].mr_pid) continue;
1410 /* There's nothing we can use on the freelist */
1411 if (oldest - last < 1)
1415 key.mv_data = &last;
1416 key.mv_size = sizeof(last);
1417 rc = mdb_cursor_set(&m2, &key, &data, MDB_SET, &exact);
1420 idl = (MDB_ID *) data.mv_data;
1421 mop2 = malloc(sizeof(MDB_oldpages) + MDB_IDL_SIZEOF(idl) - 2*sizeof(pgno_t) + MDB_IDL_SIZEOF(mop->mo_pages));
1424 /* merge in sorted order */
1425 i = idl[0]; j = mop->mo_pages[0]; mop2->mo_pages[0] = k = i+j;
1426 mop->mo_pages[0] = P_INVALID;
1427 while (i>0 || j>0) {
1428 if (i && idl[i] < mop->mo_pages[j])
1429 mop2->mo_pages[k--] = idl[i--];
1431 mop2->mo_pages[k--] = mop->mo_pages[j--];
1433 txn->mt_env->me_pglast = last;
1434 mop2->mo_txnid = last;
1435 mop2->mo_next = mop->mo_next;
1436 txn->mt_env->me_pghead = mop2;
1439 /* Keep trying to read until we have enough */
1440 if (mop->mo_pages[0] < (unsigned)num) {
1445 /* current list has enough pages, but are they contiguous? */
1446 for (i=mop->mo_pages[0]; i>=(unsigned)num; i--) {
1447 if (mop->mo_pages[i-n2] == mop->mo_pages[i] + n2) {
1448 pgno = mop->mo_pages[i];
1450 /* move any stragglers down */
1451 for (j=i+num; j<=mop->mo_pages[0]; j++)
1452 mop->mo_pages[i++] = mop->mo_pages[j];
1453 mop->mo_pages[0] -= num;
1458 /* Stop if we succeeded, or no more retries */
1459 if (!retry || pgno != P_INVALID)
1466 /* peel pages off tail, so we only have to truncate the list */
1467 pgno = MDB_IDL_LAST(mop->mo_pages);
1470 if (MDB_IDL_IS_ZERO(mop->mo_pages)) {
1471 txn->mt_env->me_pghead = mop->mo_next;
1472 if (mc->mc_dbi == FREE_DBI) {
1473 mop->mo_next = txn->mt_env->me_pgfree;
1474 txn->mt_env->me_pgfree = mop;
1482 if (pgno == P_INVALID) {
1483 /* DB size is maxed out */
1484 if (txn->mt_next_pgno + num >= txn->mt_env->me_maxpg) {
1485 DPUTS("DB size maxed out");
1486 return MDB_MAP_FULL;
1489 if (txn->mt_env->me_flags & MDB_WRITEMAP) {
1490 if (pgno == P_INVALID) {
1491 pgno = txn->mt_next_pgno;
1492 txn->mt_next_pgno += num;
1494 np = (MDB_page *)(txn->mt_env->me_map + txn->mt_env->me_psize * pgno);
1497 if (txn->mt_env->me_dpages && num == 1) {
1498 np = txn->mt_env->me_dpages;
1499 VGMEMP_ALLOC(txn->mt_env, np, txn->mt_env->me_psize);
1500 VGMEMP_DEFINED(np, sizeof(np->mp_next));
1501 txn->mt_env->me_dpages = np->mp_next;
1503 size_t sz = txn->mt_env->me_psize * num;
1504 if ((np = malloc(sz)) == NULL)
1506 VGMEMP_ALLOC(txn->mt_env, np, sz);
1508 if (pgno == P_INVALID) {
1509 np->mp_pgno = txn->mt_next_pgno;
1510 txn->mt_next_pgno += num;
1515 mid.mid = np->mp_pgno;
1517 if (txn->mt_env->me_flags & MDB_WRITEMAP) {
1518 mdb_mid2l_append(txn->mt_u.dirty_list, &mid);
1520 mdb_mid2l_insert(txn->mt_u.dirty_list, &mid);
1527 /** Copy a page: avoid copying unused portions of the page.
1528 * @param[in] dst page to copy into
1529 * @param[in] src page to copy from
1532 mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize)
1534 dst->mp_flags = src->mp_flags | P_DIRTY;
1535 dst->mp_pages = src->mp_pages;
1537 if (IS_LEAF2(src)) {
1538 memcpy(dst->mp_ptrs, src->mp_ptrs, psize - PAGEHDRSZ - SIZELEFT(src));
1540 unsigned int i, nkeys = NUMKEYS(src);
1541 for (i=0; i<nkeys; i++)
1542 dst->mp_ptrs[i] = src->mp_ptrs[i];
1543 memcpy((char *)dst+src->mp_upper, (char *)src+src->mp_upper,
1544 psize - src->mp_upper);
1548 /** Touch a page: make it dirty and re-insert into tree with updated pgno.
1549 * @param[in] mc cursor pointing to the page to be touched
1550 * @return 0 on success, non-zero on failure.
1553 mdb_page_touch(MDB_cursor *mc)
1555 MDB_page *mp = mc->mc_pg[mc->mc_top];
1559 if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
1561 if ((rc = mdb_page_alloc(mc, 1, &np)))
1563 DPRINTF("touched db %u page %zu -> %zu", mc->mc_dbi, mp->mp_pgno, np->mp_pgno);
1564 assert(mp->mp_pgno != np->mp_pgno);
1565 mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
1567 /* If page isn't full, just copy the used portion */
1568 mdb_page_copy(np, mp, mc->mc_txn->mt_env->me_psize);
1571 memcpy(np, mp, mc->mc_txn->mt_env->me_psize);
1573 np->mp_flags |= P_DIRTY;
1578 /* Adjust other cursors pointing to mp */
1579 if (mc->mc_flags & C_SUB) {
1580 MDB_cursor *m2, *m3;
1581 MDB_dbi dbi = mc->mc_dbi-1;
1583 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
1584 if (m2 == mc) continue;
1585 m3 = &m2->mc_xcursor->mx_cursor;
1586 if (m3->mc_snum < mc->mc_snum) continue;
1587 if (m3->mc_pg[mc->mc_top] == mc->mc_pg[mc->mc_top]) {
1588 m3->mc_pg[mc->mc_top] = mp;
1594 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
1595 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
1596 if (m2->mc_pg[mc->mc_top] == mc->mc_pg[mc->mc_top]) {
1597 m2->mc_pg[mc->mc_top] = mp;
1601 mc->mc_pg[mc->mc_top] = mp;
1602 /** If this page has a parent, update the parent to point to
1606 SETPGNO(NODEPTR(mc->mc_pg[mc->mc_top-1], mc->mc_ki[mc->mc_top-1]), mp->mp_pgno);
1608 mc->mc_db->md_root = mp->mp_pgno;
1609 } else if (mc->mc_txn->mt_parent) {
1612 /* If txn has a parent, make sure the page is in our
1615 if (mc->mc_txn->mt_u.dirty_list[0].mid) {
1616 unsigned x = mdb_mid2l_search(mc->mc_txn->mt_u.dirty_list, mp->mp_pgno);
1617 if (x <= mc->mc_txn->mt_u.dirty_list[0].mid &&
1618 mc->mc_txn->mt_u.dirty_list[x].mid == mp->mp_pgno) {
1619 if (mc->mc_txn->mt_u.dirty_list[x].mptr != mp) {
1620 mp = mc->mc_txn->mt_u.dirty_list[x].mptr;
1621 mc->mc_pg[mc->mc_top] = mp;
1626 if (mc->mc_txn->mt_u.dirty_list[0].mid >= MDB_IDL_UM_MAX)
1627 return MDB_TXN_FULL;
1629 np = mdb_page_malloc(mc);
1632 memcpy(np, mp, mc->mc_txn->mt_env->me_psize);
1633 mid.mid = np->mp_pgno;
1635 mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &mid);
1643 mdb_env_sync(MDB_env *env, int force)
1646 if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) {
1647 if (env->me_flags & MDB_WRITEMAP) {
1648 int flags = ((env->me_flags & MDB_MAPASYNC) && !force)
1649 ? MS_ASYNC : MS_SYNC;
1650 if (MDB_MSYNC(env->me_map, env->me_mapsize, flags))
1653 else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd))
1657 if (MDB_FDATASYNC(env->me_fd))
1664 /** Make shadow copies of all of parent txn's cursors */
1666 mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst)
1668 MDB_cursor *mc, *m2;
1669 unsigned int i, j, size;
1671 for (i=0;i<src->mt_numdbs; i++) {
1672 if (src->mt_cursors[i]) {
1673 size = sizeof(MDB_cursor);
1674 if (src->mt_cursors[i]->mc_xcursor)
1675 size += sizeof(MDB_xcursor);
1676 for (m2 = src->mt_cursors[i]; m2; m2=m2->mc_next) {
1683 mc->mc_db = &dst->mt_dbs[i];
1684 mc->mc_dbx = m2->mc_dbx;
1685 mc->mc_dbflag = &dst->mt_dbflags[i];
1686 mc->mc_snum = m2->mc_snum;
1687 mc->mc_top = m2->mc_top;
1688 mc->mc_flags = m2->mc_flags | C_SHADOW;
1689 for (j=0; j<mc->mc_snum; j++) {
1690 mc->mc_pg[j] = m2->mc_pg[j];
1691 mc->mc_ki[j] = m2->mc_ki[j];
1693 if (m2->mc_xcursor) {
1694 MDB_xcursor *mx, *mx2;
1695 mx = (MDB_xcursor *)(mc+1);
1696 mc->mc_xcursor = mx;
1697 mx2 = m2->mc_xcursor;
1698 mx->mx_db = mx2->mx_db;
1699 mx->mx_dbx = mx2->mx_dbx;
1700 mx->mx_dbflag = mx2->mx_dbflag;
1701 mx->mx_cursor.mc_txn = dst;
1702 mx->mx_cursor.mc_dbi = mx2->mx_cursor.mc_dbi;
1703 mx->mx_cursor.mc_db = &mx->mx_db;
1704 mx->mx_cursor.mc_dbx = &mx->mx_dbx;
1705 mx->mx_cursor.mc_dbflag = &mx->mx_dbflag;
1706 mx->mx_cursor.mc_snum = mx2->mx_cursor.mc_snum;
1707 mx->mx_cursor.mc_top = mx2->mx_cursor.mc_top;
1708 mx->mx_cursor.mc_flags = mx2->mx_cursor.mc_flags | C_SHADOW;
1709 for (j=0; j<mx2->mx_cursor.mc_snum; j++) {
1710 mx->mx_cursor.mc_pg[j] = mx2->mx_cursor.mc_pg[j];
1711 mx->mx_cursor.mc_ki[j] = mx2->mx_cursor.mc_ki[j];
1714 mc->mc_xcursor = NULL;
1716 mc->mc_next = dst->mt_cursors[i];
1717 dst->mt_cursors[i] = mc;
1724 /** Merge shadow cursors back into parent's */
1726 mdb_cursor_merge(MDB_txn *txn)
1729 for (i=0; i<txn->mt_numdbs; i++) {
1730 if (txn->mt_cursors[i]) {
1732 while ((mc = txn->mt_cursors[i])) {
1733 txn->mt_cursors[i] = mc->mc_next;
1734 if (mc->mc_flags & C_SHADOW) {
1735 MDB_cursor *m2 = mc->mc_orig;
1737 m2->mc_snum = mc->mc_snum;
1738 m2->mc_top = mc->mc_top;
1739 for (j=0; j<mc->mc_snum; j++) {
1740 m2->mc_pg[j] = mc->mc_pg[j];
1741 m2->mc_ki[j] = mc->mc_ki[j];
1744 if (mc->mc_flags & C_ALLOCD)
1752 mdb_txn_reset0(MDB_txn *txn);
1754 /** Common code for #mdb_txn_begin() and #mdb_txn_renew().
1755 * @param[in] txn the transaction handle to initialize
1756 * @return 0 on success, non-zero on failure. This can only
1757 * fail for read-only transactions, and then only if the
1758 * reader table is full.
1761 mdb_txn_renew0(MDB_txn *txn)
1763 MDB_env *env = txn->mt_env;
1768 txn->mt_numdbs = env->me_numdbs;
1769 txn->mt_dbxs = env->me_dbxs; /* mostly static anyway */
1771 if (txn->mt_flags & MDB_TXN_RDONLY) {
1772 if (env->me_flags & MDB_ROFS) {
1773 i = mdb_env_pick_meta(env);
1774 txn->mt_txnid = env->me_metas[i]->mm_txnid;
1775 txn->mt_u.reader = NULL;
1777 MDB_reader *r = pthread_getspecific(env->me_txkey);
1779 pid_t pid = env->me_pid;
1780 pthread_t tid = pthread_self();
1783 for (i=0; i<env->me_txns->mti_numreaders; i++)
1784 if (env->me_txns->mti_readers[i].mr_pid == 0)
1786 if (i == env->me_maxreaders) {
1787 UNLOCK_MUTEX_R(env);
1788 return MDB_READERS_FULL;
1790 env->me_txns->mti_readers[i].mr_pid = pid;
1791 env->me_txns->mti_readers[i].mr_tid = tid;
1792 if (i >= env->me_txns->mti_numreaders)
1793 env->me_txns->mti_numreaders = i+1;
1794 /* Save numreaders for un-mutexed mdb_env_close() */
1795 env->me_numreaders = env->me_txns->mti_numreaders;
1796 UNLOCK_MUTEX_R(env);
1797 r = &env->me_txns->mti_readers[i];
1798 if ((rc = pthread_setspecific(env->me_txkey, r)) != 0) {
1799 env->me_txns->mti_readers[i].mr_pid = 0;
1803 txn->mt_txnid = r->mr_txnid = env->me_txns->mti_txnid;
1804 txn->mt_u.reader = r;
1806 txn->mt_toggle = txn->mt_txnid & 1;
1807 txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1;
1811 txn->mt_txnid = env->me_txns->mti_txnid;
1812 txn->mt_toggle = txn->mt_txnid & 1;
1813 txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1;
1816 if (txn->mt_txnid == mdb_debug_start)
1819 txn->mt_u.dirty_list = env->me_dirty_list;
1820 txn->mt_u.dirty_list[0].mid = 0;
1821 txn->mt_free_pgs = env->me_free_pgs;
1822 txn->mt_free_pgs[0] = 0;
1826 /* Copy the DB info and flags */
1827 memcpy(txn->mt_dbs, env->me_metas[txn->mt_toggle]->mm_dbs, 2 * sizeof(MDB_db));
1828 for (i=2; i<txn->mt_numdbs; i++)
1829 txn->mt_dbs[i].md_flags = env->me_dbflags[i];
1830 txn->mt_dbflags[0] = txn->mt_dbflags[1] = 0;
1831 if (txn->mt_numdbs > 2)
1832 memset(txn->mt_dbflags+2, DB_STALE, txn->mt_numdbs-2);
1838 mdb_txn_renew(MDB_txn *txn)
1842 if (! (txn && txn->mt_flags & MDB_TXN_RDONLY))
1845 if (txn->mt_env->me_flags & MDB_FATAL_ERROR) {
1846 DPUTS("environment had fatal error, must shutdown!");
1850 rc = mdb_txn_renew0(txn);
1851 if (rc == MDB_SUCCESS) {
1852 DPRINTF("renew txn %zu%c %p on mdbenv %p, root page %zu",
1853 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
1854 (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root);
1860 mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
1865 if (env->me_flags & MDB_FATAL_ERROR) {
1866 DPUTS("environment had fatal error, must shutdown!");
1869 if ((env->me_flags & MDB_RDONLY) && !(flags & MDB_RDONLY))
1872 /* Nested transactions: Max 1 child, write txns only, no writemap */
1873 if (parent->mt_child ||
1874 (flags & MDB_RDONLY) || (parent->mt_flags & MDB_TXN_RDONLY) ||
1875 (env->me_flags & MDB_WRITEMAP))
1880 size = sizeof(MDB_txn) + env->me_maxdbs * (sizeof(MDB_db)+1);
1881 if (!(flags & MDB_RDONLY))
1882 size += env->me_maxdbs * sizeof(MDB_cursor *);
1884 if ((txn = calloc(1, size)) == NULL) {
1885 DPRINTF("calloc: %s", strerror(ErrCode()));
1888 txn->mt_dbs = (MDB_db *)(txn+1);
1889 if (flags & MDB_RDONLY) {
1890 txn->mt_flags |= MDB_TXN_RDONLY;
1891 txn->mt_dbflags = (unsigned char *)(txn->mt_dbs + env->me_maxdbs);
1893 txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
1894 txn->mt_dbflags = (unsigned char *)(txn->mt_cursors + env->me_maxdbs);
1899 txn->mt_free_pgs = mdb_midl_alloc();
1900 if (!txn->mt_free_pgs) {
1904 txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE);
1905 if (!txn->mt_u.dirty_list) {
1906 free(txn->mt_free_pgs);
1910 txn->mt_txnid = parent->mt_txnid;
1911 txn->mt_toggle = parent->mt_toggle;
1912 txn->mt_u.dirty_list[0].mid = 0;
1913 txn->mt_free_pgs[0] = 0;
1914 txn->mt_next_pgno = parent->mt_next_pgno;
1915 parent->mt_child = txn;
1916 txn->mt_parent = parent;
1917 txn->mt_numdbs = parent->mt_numdbs;
1918 txn->mt_dbxs = parent->mt_dbxs;
1919 memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
1920 memcpy(txn->mt_dbflags, parent->mt_dbflags, txn->mt_numdbs);
1921 mdb_cursor_shadow(parent, txn);
1924 rc = mdb_txn_renew0(txn);
1930 DPRINTF("begin txn %zu%c %p on mdbenv %p, root page %zu",
1931 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
1932 (void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root);
1938 /** Common code for #mdb_txn_reset() and #mdb_txn_abort().
1939 * @param[in] txn the transaction handle to reset
1942 mdb_txn_reset0(MDB_txn *txn)
1944 MDB_env *env = txn->mt_env;
1946 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
1947 if (!(env->me_flags & MDB_ROFS))
1948 txn->mt_u.reader->mr_txnid = (txnid_t)-1;
1954 /* close(free) all cursors */
1955 for (i=0; i<txn->mt_numdbs; i++) {
1956 if (txn->mt_cursors[i]) {
1958 while ((mc = txn->mt_cursors[i])) {
1959 txn->mt_cursors[i] = mc->mc_next;
1960 if (mc->mc_flags & C_ALLOCD)
1966 if (!(env->me_flags & MDB_WRITEMAP)) {
1967 /* return all dirty pages to dpage list */
1968 for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++) {
1969 dp = txn->mt_u.dirty_list[i].mptr;
1970 if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
1971 mdb_page_free(txn->mt_env, dp);
1973 /* large pages just get freed directly */
1974 VGMEMP_FREE(txn->mt_env, dp);
1980 if (txn->mt_parent) {
1981 txn->mt_parent->mt_child = NULL;
1982 mdb_midl_free(txn->mt_free_pgs);
1983 free(txn->mt_u.dirty_list);
1986 if (mdb_midl_shrink(&txn->mt_free_pgs))
1987 env->me_free_pgs = txn->mt_free_pgs;
1990 while ((mop = txn->mt_env->me_pghead)) {
1991 txn->mt_env->me_pghead = mop->mo_next;
1994 txn->mt_env->me_pgfirst = 0;
1995 txn->mt_env->me_pglast = 0;
1998 /* The writer mutex was locked in mdb_txn_begin. */
1999 UNLOCK_MUTEX_W(env);
2004 mdb_txn_reset(MDB_txn *txn)
2009 DPRINTF("reset txn %zu%c %p on mdbenv %p, root page %zu",
2010 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2011 (void *) txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root);
2013 mdb_txn_reset0(txn);
2017 mdb_txn_abort(MDB_txn *txn)
2022 DPRINTF("abort txn %zu%c %p on mdbenv %p, root page %zu",
2023 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2024 (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root);
2027 mdb_txn_abort(txn->mt_child);
2029 mdb_txn_reset0(txn);
2034 mdb_txn_commit(MDB_txn *txn)
2042 pgno_t next, freecnt;
2045 assert(txn != NULL);
2046 assert(txn->mt_env != NULL);
2048 if (txn->mt_child) {
2049 mdb_txn_commit(txn->mt_child);
2050 txn->mt_child = NULL;
2055 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
2056 if (txn->mt_numdbs > env->me_numdbs) {
2057 /* update the DB flags */
2059 for (i = env->me_numdbs; i<txn->mt_numdbs; i++)
2060 env->me_dbflags[i] = txn->mt_dbs[i].md_flags;
2067 if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
2068 DPUTS("error flag is set, can't commit");
2070 txn->mt_parent->mt_flags |= MDB_TXN_ERROR;
2075 if (txn->mt_parent) {
2081 /* Merge (and close) our cursors with parent's */
2082 mdb_cursor_merge(txn);
2084 /* Update parent's DB table */
2085 ip = &txn->mt_parent->mt_dbs[2];
2086 jp = &txn->mt_dbs[2];
2087 for (i = 2; i < txn->mt_numdbs; i++) {
2088 if (ip->md_root != jp->md_root)
2092 txn->mt_parent->mt_numdbs = txn->mt_numdbs;
2094 /* Append our free list to parent's */
2095 mdb_midl_append_list(&txn->mt_parent->mt_free_pgs,
2097 mdb_midl_free(txn->mt_free_pgs);
2099 /* Merge our dirty list with parent's */
2100 dst = txn->mt_parent->mt_u.dirty_list;
2101 src = txn->mt_u.dirty_list;
2102 x = mdb_mid2l_search(dst, src[1].mid);
2103 for (y=1; y<=src[0].mid; y++) {
2104 while (x <= dst[0].mid && dst[x].mid != src[y].mid) x++;
2108 dst[x].mptr = src[y].mptr;
2111 for (; y<=src[0].mid; y++) {
2112 if (++x >= MDB_IDL_UM_MAX) {
2114 return MDB_TXN_FULL;
2119 free(txn->mt_u.dirty_list);
2120 txn->mt_parent->mt_child = NULL;
2125 if (txn != env->me_txn) {
2126 DPUTS("attempt to commit unknown transaction");
2131 if (!txn->mt_u.dirty_list[0].mid && !(txn->mt_flags & MDB_TXN_DIRTY))
2134 DPRINTF("committing txn %zu %p on mdbenv %p, root page %zu",
2135 txn->mt_txnid, (void *)txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root);
2137 /* Update DB root pointers. Their pages have already been
2138 * touched so this is all in-place and cannot fail.
2140 if (txn->mt_numdbs > 2) {
2143 data.mv_size = sizeof(MDB_db);
2145 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
2146 for (i = 2; i < txn->mt_numdbs; i++) {
2147 if (txn->mt_dbflags[i] & DB_DIRTY) {
2148 data.mv_data = &txn->mt_dbs[i];
2149 mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data, 0);
2154 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
2156 /* should only be one record now */
2157 if (env->me_pghead || env->me_pgfirst) {
2158 /* make sure first page of freeDB is touched and on freelist */
2159 rc = mdb_page_search(&mc, NULL, MDB_PS_MODIFY);
2160 if (rc && rc != MDB_NOTFOUND) {
2167 /* Delete IDLs we used from the free list */
2168 if (env->me_pgfirst) {
2173 key.mv_size = sizeof(cur);
2174 for (cur = env->me_pgfirst; cur <= env->me_pglast; cur++) {
2177 mdb_cursor_set(&mc, &key, NULL, MDB_SET, &exact);
2178 rc = mdb_cursor_del(&mc, 0);
2182 env->me_pgfirst = 0;
2186 /* save to free list */
2188 freecnt = txn->mt_free_pgs[0];
2189 if (!MDB_IDL_IS_ZERO(txn->mt_free_pgs)) {
2192 /* make sure last page of freeDB is touched and on freelist */
2193 key.mv_size = MDB_MAXKEYSIZE+1;
2195 rc = mdb_page_search(&mc, &key, MDB_PS_MODIFY);
2196 if (rc && rc != MDB_NOTFOUND)
2202 MDB_IDL idl = txn->mt_free_pgs;
2203 mdb_midl_sort(txn->mt_free_pgs);
2204 DPRINTF("IDL write txn %zu root %zu num %zu",
2205 txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, idl[0]);
2206 for (i=1; i<=idl[0]; i++) {
2207 DPRINTF("IDL %zu", idl[i]);
2211 /* write to last page of freeDB */
2212 key.mv_size = sizeof(pgno_t);
2213 key.mv_data = &txn->mt_txnid;
2214 data.mv_data = txn->mt_free_pgs;
2215 /* The free list can still grow during this call,
2216 * despite the pre-emptive touches above. So check
2217 * and make sure the entire thing got written.
2220 freecnt = txn->mt_free_pgs[0];
2221 data.mv_size = MDB_IDL_SIZEOF(txn->mt_free_pgs);
2222 mdb_midl_sort(txn->mt_free_pgs);
2223 rc = mdb_cursor_put(&mc, &key, &data, 0);
2226 } while (freecnt != txn->mt_free_pgs[0]);
2228 /* should only be one record now */
2230 if (env->me_pghead) {
2236 mop = env->me_pghead;
2238 key.mv_size = sizeof(id);
2240 data.mv_size = MDB_IDL_SIZEOF(mop->mo_pages);
2241 data.mv_data = mop->mo_pages;
2242 orig = mop->mo_pages[0];
2243 /* These steps may grow the freelist again
2244 * due to freed overflow pages...
2246 rc = mdb_cursor_put(&mc, &key, &data, 0);
2249 if (mop == env->me_pghead && env->me_pghead->mo_txnid == id) {
2250 /* could have been used again here */
2251 if (mop->mo_pages[0] != orig) {
2252 data.mv_size = MDB_IDL_SIZEOF(mop->mo_pages);
2253 data.mv_data = mop->mo_pages;
2255 rc = mdb_cursor_put(&mc, &key, &data, 0);
2260 /* was completely used up */
2261 rc = mdb_cursor_del(&mc, 0);
2267 env->me_pgfirst = 0;
2271 /* Check for growth of freelist again */
2272 if (freecnt != txn->mt_free_pgs[0])
2275 if (env->me_pghead) {
2276 free(env->me_pghead);
2277 env->me_pghead = NULL;
2280 while (env->me_pgfree) {
2281 MDB_oldpages *mop = env->me_pgfree;
2282 env->me_pgfree = mop->mo_next;
2286 if (!MDB_IDL_IS_ZERO(txn->mt_free_pgs)) {
2287 if (mdb_midl_shrink(&txn->mt_free_pgs))
2288 env->me_free_pgs = txn->mt_free_pgs;
2295 if (env->me_flags & MDB_WRITEMAP) {
2296 for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++) {
2297 dp = txn->mt_u.dirty_list[i].mptr;
2298 /* clear dirty flag */
2299 dp->mp_flags &= ~P_DIRTY;
2300 txn->mt_u.dirty_list[i].mid = 0;
2302 txn->mt_u.dirty_list[0].mid = 0;
2306 /* Commit up to MDB_COMMIT_PAGES dirty pages to disk until done.
2312 /* Windows actually supports scatter/gather I/O, but only on
2313 * unbuffered file handles. Since we're relying on the OS page
2314 * cache for all our data, that's self-defeating. So we just
2315 * write pages one at a time. We use the ov structure to set
2316 * the write offset, to at least save the overhead of a Seek
2320 memset(&ov, 0, sizeof(ov));
2321 for (; i<=txn->mt_u.dirty_list[0].mid; i++) {
2323 dp = txn->mt_u.dirty_list[i].mptr;
2324 DPRINTF("committing page %zu", dp->mp_pgno);
2325 size = dp->mp_pgno * env->me_psize;
2326 ov.Offset = size & 0xffffffff;
2327 ov.OffsetHigh = size >> 16;
2328 ov.OffsetHigh >>= 16;
2329 /* clear dirty flag */
2330 dp->mp_flags &= ~P_DIRTY;
2331 wsize = env->me_psize;
2332 if (IS_OVERFLOW(dp)) wsize *= dp->mp_pages;
2333 rc = WriteFile(env->me_fd, dp, wsize, NULL, &ov);
2336 DPRINTF("WriteFile: %d", n);
2343 struct iovec iov[MDB_COMMIT_PAGES];
2347 for (; i<=txn->mt_u.dirty_list[0].mid; i++) {
2348 dp = txn->mt_u.dirty_list[i].mptr;
2349 if (dp->mp_pgno != next) {
2351 rc = writev(env->me_fd, iov, n);
2355 DPUTS("short write, filesystem full?");
2357 DPRINTF("writev: %s", strerror(n));
2364 lseek(env->me_fd, dp->mp_pgno * env->me_psize, SEEK_SET);
2367 DPRINTF("committing page %zu", dp->mp_pgno);
2368 iov[n].iov_len = env->me_psize;
2369 if (IS_OVERFLOW(dp)) iov[n].iov_len *= dp->mp_pages;
2370 iov[n].iov_base = (char *)dp;
2371 size += iov[n].iov_len;
2372 next = dp->mp_pgno + (IS_OVERFLOW(dp) ? dp->mp_pages : 1);
2373 /* clear dirty flag */
2374 dp->mp_flags &= ~P_DIRTY;
2375 if (++n >= MDB_COMMIT_PAGES) {
2385 rc = writev(env->me_fd, iov, n);
2389 DPUTS("short write, filesystem full?");
2391 DPRINTF("writev: %s", strerror(n));
2398 /* Drop the dirty pages.
2400 for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++) {
2401 dp = txn->mt_u.dirty_list[i].mptr;
2402 if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
2403 mdb_page_free(txn->mt_env, dp);
2405 VGMEMP_FREE(txn->mt_env, dp);
2408 txn->mt_u.dirty_list[i].mid = 0;
2410 txn->mt_u.dirty_list[0].mid = 0;
2413 if ((n = mdb_env_sync(env, 0)) != 0 ||
2414 (n = mdb_env_write_meta(txn)) != MDB_SUCCESS) {
2421 if (txn->mt_numdbs > env->me_numdbs) {
2422 /* update the DB flags */
2424 for (i = env->me_numdbs; i<txn->mt_numdbs; i++)
2425 env->me_dbflags[i] = txn->mt_dbs[i].md_flags;
2429 UNLOCK_MUTEX_W(env);
2435 /** Read the environment parameters of a DB environment before
2436 * mapping it into memory.
2437 * @param[in] env the environment handle
2438 * @param[out] meta address of where to store the meta information
2439 * @return 0 on success, non-zero on failure.
2442 mdb_env_read_header(MDB_env *env, MDB_meta *meta)
2449 /* We don't know the page size yet, so use a minimum value.
2450 * Read both meta pages so we can use the latest one.
2453 for (i=0; i<2; i++) {
2455 if (!ReadFile(env->me_fd, &pbuf, MDB_PAGESIZE, (DWORD *)&rc, NULL) || rc == 0)
2457 if ((rc = read(env->me_fd, &pbuf, MDB_PAGESIZE)) == 0)
2462 else if (rc != MDB_PAGESIZE) {
2466 DPRINTF("read: %s", strerror(err));
2470 p = (MDB_page *)&pbuf;
2472 if (!F_ISSET(p->mp_flags, P_META)) {
2473 DPRINTF("page %zu not a meta page", p->mp_pgno);
2478 if (m->mm_magic != MDB_MAGIC) {
2479 DPUTS("meta has invalid magic");
2483 if (m->mm_version != MDB_VERSION) {
2484 DPRINTF("database is version %u, expected version %u",
2485 m->mm_version, MDB_VERSION);
2486 return MDB_VERSION_MISMATCH;
2490 if (m->mm_txnid > meta->mm_txnid)
2491 memcpy(meta, m, sizeof(*m));
2493 memcpy(meta, m, sizeof(*m));
2495 if (SetFilePointer(env->me_fd, meta->mm_psize, NULL, FILE_BEGIN) != meta->mm_psize)
2497 if (lseek(env->me_fd, meta->mm_psize, SEEK_SET) != meta->mm_psize)
2505 /** Write the environment parameters of a freshly created DB environment.
2506 * @param[in] env the environment handle
2507 * @param[out] meta address of where to store the meta information
2508 * @return 0 on success, non-zero on failure.
2511 mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
2518 DPUTS("writing new meta page");
2520 GET_PAGESIZE(psize);
2522 meta->mm_magic = MDB_MAGIC;
2523 meta->mm_version = MDB_VERSION;
2524 meta->mm_mapsize = env->me_mapsize;
2525 meta->mm_psize = psize;
2526 meta->mm_last_pg = 1;
2527 meta->mm_flags = env->me_flags & 0xffff;
2528 meta->mm_flags |= MDB_INTEGERKEY;
2529 meta->mm_dbs[0].md_root = P_INVALID;
2530 meta->mm_dbs[1].md_root = P_INVALID;
2532 p = calloc(2, psize);
2534 p->mp_flags = P_META;
2537 memcpy(m, meta, sizeof(*meta));
2539 q = (MDB_page *)((char *)p + psize);
2542 q->mp_flags = P_META;
2545 memcpy(m, meta, sizeof(*meta));
2550 SetFilePointer(env->me_fd, 0, NULL, FILE_BEGIN);
2551 rc = WriteFile(env->me_fd, p, psize * 2, &len, NULL);
2552 rc = (len == psize * 2) ? MDB_SUCCESS : ErrCode();
2555 lseek(env->me_fd, 0, SEEK_SET);
2556 rc = write(env->me_fd, p, psize * 2);
2557 rc = (rc == (int)psize * 2) ? MDB_SUCCESS : ErrCode();
2563 /** Update the environment info to commit a transaction.
2564 * @param[in] txn the transaction that's being committed
2565 * @return 0 on success, non-zero on failure.
2568 mdb_env_write_meta(MDB_txn *txn)
2571 MDB_meta meta, metab, *mp;
2573 int rc, len, toggle;
2580 assert(txn != NULL);
2581 assert(txn->mt_env != NULL);
2583 toggle = !txn->mt_toggle;
2584 DPRINTF("writing meta page %d for root page %zu",
2585 toggle, txn->mt_dbs[MAIN_DBI].md_root);
2588 mp = env->me_metas[toggle];
2590 if (env->me_flags & MDB_WRITEMAP) {
2591 /* Persist any increases of mapsize config */
2592 if (env->me_mapsize > mp->mm_mapsize)
2593 mp->mm_mapsize = env->me_mapsize;
2594 mp->mm_dbs[0] = txn->mt_dbs[0];
2595 mp->mm_dbs[1] = txn->mt_dbs[1];
2596 mp->mm_last_pg = txn->mt_next_pgno - 1;
2597 mp->mm_txnid = txn->mt_txnid;
2598 if (!(env->me_flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {
2599 rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;
2602 ptr += env->me_psize;
2603 if (MDB_MSYNC(ptr, env->me_psize, rc)) {
2610 metab.mm_txnid = env->me_metas[toggle]->mm_txnid;
2611 metab.mm_last_pg = env->me_metas[toggle]->mm_last_pg;
2613 ptr = (char *)&meta;
2614 if (env->me_mapsize > mp->mm_mapsize) {
2615 /* Persist any increases of mapsize config */
2616 meta.mm_mapsize = env->me_mapsize;
2617 off = offsetof(MDB_meta, mm_mapsize);
2619 off = offsetof(MDB_meta, mm_dbs[0].md_depth);
2621 len = sizeof(MDB_meta) - off;
2624 meta.mm_dbs[0] = txn->mt_dbs[0];
2625 meta.mm_dbs[1] = txn->mt_dbs[1];
2626 meta.mm_last_pg = txn->mt_next_pgno - 1;
2627 meta.mm_txnid = txn->mt_txnid;
2630 off += env->me_psize;
2633 /* Write to the SYNC fd */
2634 mfd = env->me_flags & (MDB_NOSYNC|MDB_NOMETASYNC) ?
2635 env->me_fd : env->me_mfd;
2638 memset(&ov, 0, sizeof(ov));
2640 WriteFile(mfd, ptr, len, (DWORD *)&rc, &ov);
2643 rc = pwrite(mfd, ptr, len, off);
2648 DPUTS("write failed, disk error?");
2649 /* On a failure, the pagecache still contains the new data.
2650 * Write some old data back, to prevent it from being used.
2651 * Use the non-SYNC fd; we know it will fail anyway.
2653 meta.mm_last_pg = metab.mm_last_pg;
2654 meta.mm_txnid = metab.mm_txnid;
2656 WriteFile(env->me_fd, ptr, len, NULL, &ov);
2658 r2 = pwrite(env->me_fd, ptr, len, off);
2661 env->me_flags |= MDB_FATAL_ERROR;
2665 /* Memory ordering issues are irrelevant; since the entire writer
2666 * is wrapped by wmutex, all of these changes will become visible
2667 * after the wmutex is unlocked. Since the DB is multi-version,
2668 * readers will get consistent data regardless of how fresh or
2669 * how stale their view of these values is.
2671 txn->mt_env->me_txns->mti_txnid = txn->mt_txnid;
2676 /** Check both meta pages to see which one is newer.
2677 * @param[in] env the environment handle
2678 * @return meta toggle (0 or 1).
2681 mdb_env_pick_meta(const MDB_env *env)
2683 return (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid);
2687 mdb_env_create(MDB_env **env)
2691 e = calloc(1, sizeof(MDB_env));
2695 e->me_free_pgs = mdb_midl_alloc();
2696 if (!e->me_free_pgs) {
2700 e->me_maxreaders = DEFAULT_READERS;
2702 e->me_fd = INVALID_HANDLE_VALUE;
2703 e->me_lfd = INVALID_HANDLE_VALUE;
2704 e->me_mfd = INVALID_HANDLE_VALUE;
2705 #ifdef MDB_USE_POSIX_SEM
2706 e->me_rmutex = SEM_FAILED;
2707 e->me_wmutex = SEM_FAILED;
2709 e->me_pid = getpid();
2710 VGMEMP_CREATE(e,0,0);
2716 mdb_env_set_mapsize(MDB_env *env, size_t size)
2720 env->me_mapsize = size;
2722 env->me_maxpg = env->me_mapsize / env->me_psize;
2727 mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs)
2731 env->me_maxdbs = dbs + 2; /* Named databases + main and free DB */
2736 mdb_env_set_maxreaders(MDB_env *env, unsigned int readers)
2738 if (env->me_map || readers < 1)
2740 env->me_maxreaders = readers;
2745 mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)
2747 if (!env || !readers)
2749 *readers = env->me_maxreaders;
2753 /** Further setup required for opening an MDB environment
2756 mdb_env_open2(MDB_env *env)
2758 unsigned int flags = env->me_flags;
2759 int i, newenv = 0, prot;
2763 memset(&meta, 0, sizeof(meta));
2765 if ((i = mdb_env_read_header(env, &meta)) != 0) {
2768 DPUTS("new mdbenv");
2772 /* Was a mapsize configured? */
2773 if (!env->me_mapsize) {
2774 /* If this is a new environment, take the default,
2775 * else use the size recorded in the existing env.
2777 env->me_mapsize = newenv ? DEFAULT_MAPSIZE : meta.mm_mapsize;
2778 } else if (env->me_mapsize < meta.mm_mapsize) {
2779 /* If the configured size is smaller, make sure it's
2780 * still big enough. Silently round up to minimum if not.
2782 size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize;
2783 if (env->me_mapsize < minsize)
2784 env->me_mapsize = minsize;
2790 LONG sizelo, sizehi;
2791 sizelo = env->me_mapsize & 0xffffffff;
2792 sizehi = env->me_mapsize >> 16; /* pointless on WIN32, only needed on W64 */
2794 /* Windows won't create mappings for zero length files.
2795 * Just allocate the maxsize right now.
2798 SetFilePointer(env->me_fd, sizelo, sizehi ? &sizehi : NULL, 0);
2799 if (!SetEndOfFile(env->me_fd))
2801 SetFilePointer(env->me_fd, 0, NULL, 0);
2803 mh = CreateFileMapping(env->me_fd, NULL, flags & MDB_WRITEMAP ?
2804 PAGE_READWRITE : PAGE_READONLY,
2805 sizehi, sizelo, NULL);
2808 env->me_map = MapViewOfFileEx(mh, flags & MDB_WRITEMAP ?
2809 FILE_MAP_WRITE : FILE_MAP_READ,
2810 0, 0, env->me_mapsize, meta.mm_address);
2818 if (flags & MDB_WRITEMAP) {
2820 if (ftruncate(env->me_fd, env->me_mapsize) < 0)
2823 env->me_map = mmap(meta.mm_address, env->me_mapsize, prot, i,
2825 if (env->me_map == MAP_FAILED) {
2832 if (flags & MDB_FIXEDMAP)
2833 meta.mm_address = env->me_map;
2834 i = mdb_env_init_meta(env, &meta);
2835 if (i != MDB_SUCCESS) {
2838 } else if (meta.mm_address && env->me_map != meta.mm_address) {
2839 /* Can happen because the address argument to mmap() is just a
2840 * hint. mmap() can pick another, e.g. if the range is in use.
2841 * The MAP_FIXED flag would prevent that, but then mmap could
2842 * instead unmap existing pages to make room for the new map.
2844 return EBUSY; /* TODO: Make a new MDB_* error code? */
2846 env->me_psize = meta.mm_psize;
2848 env->me_maxpg = env->me_mapsize / env->me_psize;
2850 p = (MDB_page *)env->me_map;
2851 env->me_metas[0] = METADATA(p);
2852 env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + meta.mm_psize);
2856 int toggle = mdb_env_pick_meta(env);
2857 MDB_db *db = &env->me_metas[toggle]->mm_dbs[MAIN_DBI];
2859 DPRINTF("opened database version %u, pagesize %u",
2860 env->me_metas[0]->mm_version, env->me_psize);
2861 DPRINTF("using meta page %d", toggle);
2862 DPRINTF("depth: %u", db->md_depth);
2863 DPRINTF("entries: %zu", db->md_entries);
2864 DPRINTF("branch pages: %zu", db->md_branch_pages);
2865 DPRINTF("leaf pages: %zu", db->md_leaf_pages);
2866 DPRINTF("overflow pages: %zu", db->md_overflow_pages);
2867 DPRINTF("root: %zu", db->md_root);
2875 /** Release a reader thread's slot in the reader lock table.
2876 * This function is called automatically when a thread exits.
2877 * @param[in] ptr This points to the slot in the reader lock table.
2880 mdb_env_reader_dest(void *ptr)
2882 MDB_reader *reader = ptr;
2888 /** Junk for arranging thread-specific callbacks on Windows. This is
2889 * necessarily platform and compiler-specific. Windows supports up
2890 * to 1088 keys. Let's assume nobody opens more than 64 environments
2891 * in a single process, for now. They can override this if needed.
2893 #ifndef MAX_TLS_KEYS
2894 #define MAX_TLS_KEYS 64
2896 static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS];
2897 static int mdb_tls_nkeys;
2899 static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr)
2903 case DLL_PROCESS_ATTACH: break;
2904 case DLL_THREAD_ATTACH: break;
2905 case DLL_THREAD_DETACH:
2906 for (i=0; i<mdb_tls_nkeys; i++) {
2907 MDB_reader *r = pthread_getspecific(mdb_tls_keys[i]);
2908 mdb_env_reader_dest(r);
2911 case DLL_PROCESS_DETACH: break;
2916 const PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
2918 PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
2922 /* Force some symbol references.
2923 * _tls_used forces the linker to create the TLS directory if not already done
2924 * mdb_tls_cbp prevents whole-program-optimizer from dropping the symbol.
2926 #pragma comment(linker, "/INCLUDE:_tls_used")
2927 #pragma comment(linker, "/INCLUDE:mdb_tls_cbp")
2928 #pragma const_seg(".CRT$XLB")
2929 extern const PIMAGE_TLS_CALLBACK mdb_tls_callback;
2930 const PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
2933 #pragma comment(linker, "/INCLUDE:__tls_used")
2934 #pragma comment(linker, "/INCLUDE:_mdb_tls_cbp")
2935 #pragma data_seg(".CRT$XLB")
2936 PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
2938 #endif /* WIN 32/64 */
2939 #endif /* !__GNUC__ */
2942 /** Downgrade the exclusive lock on the region back to shared */
2944 mdb_env_share_locks(MDB_env *env, int *excl)
2946 int rc = 0, toggle = mdb_env_pick_meta(env);
2948 env->me_txns->mti_txnid = env->me_metas[toggle]->mm_txnid;
2953 /* First acquire a shared lock. The Unlock will
2954 * then release the existing exclusive lock.
2956 memset(&ov, 0, sizeof(ov));
2957 if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
2960 UnlockFile(env->me_lfd, 0, 0, 1, 0);
2966 struct flock lock_info;
2967 /* The shared lock replaces the existing lock */
2968 memset((void *)&lock_info, 0, sizeof(lock_info));
2969 lock_info.l_type = F_RDLCK;
2970 lock_info.l_whence = SEEK_SET;
2971 lock_info.l_start = 0;
2972 lock_info.l_len = 1;
2973 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
2974 (rc = ErrCode()) == EINTR) ;
2975 *excl = rc ? -1 : 0; /* error may mean we lost the lock */
2982 /** Try to get exlusive lock, otherwise shared.
2983 * Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive.
2986 mdb_env_excl_lock(MDB_env *env, int *excl)
2990 if (LockFile(env->me_lfd, 0, 0, 1, 0)) {
2994 memset(&ov, 0, sizeof(ov));
2995 if (LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
3002 struct flock lock_info;
3003 memset((void *)&lock_info, 0, sizeof(lock_info));
3004 lock_info.l_type = F_WRLCK;
3005 lock_info.l_whence = SEEK_SET;
3006 lock_info.l_start = 0;
3007 lock_info.l_len = 1;
3008 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
3009 (rc = ErrCode()) == EINTR) ;
3013 # ifdef MDB_USE_POSIX_SEM
3014 if (*excl < 0) /* always true when !MDB_USE_POSIX_SEM */
3017 lock_info.l_type = F_RDLCK;
3018 while ((rc = fcntl(env->me_lfd, F_SETLKW, &lock_info)) &&
3019 (rc = ErrCode()) == EINTR) ;
3027 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
3029 * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code
3031 * @(#) $Revision: 5.1 $
3032 * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $
3033 * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $
3035 * http://www.isthe.com/chongo/tech/comp/fnv/index.html
3039 * Please do not copyright this code. This code is in the public domain.
3041 * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
3042 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
3043 * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
3044 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
3045 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
3046 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
3047 * PERFORMANCE OF THIS SOFTWARE.
3050 * chongo <Landon Curt Noll> /\oo/\
3051 * http://www.isthe.com/chongo/
3053 * Share and Enjoy! :-)
3056 typedef unsigned long long mdb_hash_t;
3057 #define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL)
3059 /** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer
3060 * @param[in] str string to hash
3061 * @param[in] hval initial value for hash
3062 * @return 64 bit hash
3064 * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the
3065 * hval arg on the first call.
3068 mdb_hash_val(MDB_val *val, mdb_hash_t hval)
3070 unsigned char *s = (unsigned char *)val->mv_data; /* unsigned string */
3071 unsigned char *end = s + val->mv_size;
3073 * FNV-1a hash each octet of the string
3076 /* xor the bottom with the current octet */
3077 hval ^= (mdb_hash_t)*s++;
3079 /* multiply by the 64 bit FNV magic prime mod 2^64 */
3080 hval += (hval << 1) + (hval << 4) + (hval << 5) +
3081 (hval << 7) + (hval << 8) + (hval << 40);
3083 /* return our new hash value */
3087 /** Hash the string and output the hash in hex.
3088 * @param[in] str string to hash
3089 * @param[out] hexbuf an array of 17 chars to hold the hash
3092 mdb_hash_hex(MDB_val *val, char *hexbuf)
3095 mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT);
3096 for (i=0; i<8; i++) {
3097 hexbuf += sprintf(hexbuf, "%02x", (unsigned int)h & 0xff);
3103 /** Open and/or initialize the lock region for the environment.
3104 * @param[in] env The MDB environment.
3105 * @param[in] lpath The pathname of the file used for the lock region.
3106 * @param[in] mode The Unix permissions for the file, if we create it.
3107 * @param[out] excl Resulting file lock type: -1 none, 0 shared, 1 exclusive
3108 * @return 0 on success, non-zero on failure.
3111 mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
3119 if ((env->me_lfd = CreateFile(lpath, GENERIC_READ|GENERIC_WRITE,
3120 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
3121 FILE_ATTRIBUTE_NORMAL, NULL)) == INVALID_HANDLE_VALUE) {
3123 if (rc == ERROR_WRITE_PROTECT && (env->me_flags & MDB_RDONLY)) {
3124 env->me_flags |= MDB_ROFS;
3129 /* Try to get exclusive lock. If we succeed, then
3130 * nobody is using the lock region and we should initialize it.
3132 if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
3133 size = GetFileSize(env->me_lfd, NULL);
3139 if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT, mode)) == -1) {
3141 if (rc == EROFS && (env->me_flags & MDB_RDONLY)) {
3142 env->me_flags |= MDB_ROFS;
3147 /* Lose record locks when exec*() */
3148 if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0)
3149 fcntl(env->me_lfd, F_SETFD, fdflags);
3151 #else /* O_CLOEXEC on Linux: Open file and set FD_CLOEXEC atomically */
3152 if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT|O_CLOEXEC, mode)) == -1) {
3154 if (rc == EROFS && (env->me_flags & MDB_RDONLY)) {
3155 env->me_flags |= MDB_ROFS;
3162 /* Try to get exclusive lock. If we succeed, then
3163 * nobody is using the lock region and we should initialize it.
3165 if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
3167 size = lseek(env->me_lfd, 0, SEEK_END);
3169 rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
3170 if (size < rsize && *excl > 0) {
3172 SetFilePointer(env->me_lfd, rsize, NULL, 0);
3173 if (!SetEndOfFile(env->me_lfd)) goto fail_errno;
3175 if (ftruncate(env->me_lfd, rsize) != 0) goto fail_errno;
3179 size = rsize - sizeof(MDB_txninfo);
3180 env->me_maxreaders = size/sizeof(MDB_reader) + 1;
3185 mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,
3187 if (!mh) goto fail_errno;
3188 env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL);
3190 if (!env->me_txns) goto fail_errno;
3192 void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
3194 if (m == MAP_FAILED) goto fail_errno;
3200 BY_HANDLE_FILE_INFORMATION stbuf;
3209 if (!mdb_sec_inited) {
3210 InitializeSecurityDescriptor(&mdb_null_sd,
3211 SECURITY_DESCRIPTOR_REVISION);
3212 SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE);
3213 mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);
3214 mdb_all_sa.bInheritHandle = FALSE;
3215 mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;
3218 if (!GetFileInformationByHandle(env->me_lfd, &stbuf)) goto fail_errno;
3219 idbuf.volume = stbuf.dwVolumeSerialNumber;
3220 idbuf.nhigh = stbuf.nFileIndexHigh;
3221 idbuf.nlow = stbuf.nFileIndexLow;
3222 val.mv_data = &idbuf;
3223 val.mv_size = sizeof(idbuf);
3224 mdb_hash_hex(&val, hexbuf);
3225 sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", hexbuf);
3226 sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", hexbuf);
3227 env->me_rmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
3228 if (!env->me_rmutex) goto fail_errno;
3229 env->me_wmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);
3230 if (!env->me_wmutex) goto fail_errno;
3231 #elif defined(MDB_USE_POSIX_SEM)
3240 if (fstat(env->me_lfd, &stbuf)) goto fail_errno;
3241 idbuf.dev = stbuf.st_dev;
3242 idbuf.ino = stbuf.st_ino;
3243 val.mv_data = &idbuf;
3244 val.mv_size = sizeof(idbuf);
3245 mdb_hash_hex(&val, hexbuf);
3246 sprintf(env->me_txns->mti_rmname, "/MDBr%s", hexbuf);
3247 sprintf(env->me_txns->mti_wmname, "/MDBw%s", hexbuf);
3248 /* Clean up after a previous run, if needed: Try to
3249 * remove both semaphores before doing anything else.
3251 sem_unlink(env->me_txns->mti_rmname);
3252 sem_unlink(env->me_txns->mti_wmname);
3253 env->me_rmutex = sem_open(env->me_txns->mti_rmname,
3254 O_CREAT|O_EXCL, mode, 1);
3255 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
3256 env->me_wmutex = sem_open(env->me_txns->mti_wmname,
3257 O_CREAT|O_EXCL, mode, 1);
3258 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
3259 #else /* MDB_USE_POSIX_SEM */
3260 pthread_mutexattr_t mattr;
3262 if ((rc = pthread_mutexattr_init(&mattr))
3263 || (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED))
3264 || (rc = pthread_mutex_init(&env->me_txns->mti_mutex, &mattr))
3265 || (rc = pthread_mutex_init(&env->me_txns->mti_wmutex, &mattr)))
3267 pthread_mutexattr_destroy(&mattr);
3268 #endif /* _WIN32 || MDB_USE_POSIX_SEM */
3270 env->me_txns->mti_version = MDB_VERSION;
3271 env->me_txns->mti_magic = MDB_MAGIC;
3272 env->me_txns->mti_txnid = 0;
3273 env->me_txns->mti_numreaders = 0;
3276 if (env->me_txns->mti_magic != MDB_MAGIC) {
3277 DPUTS("lock region has invalid magic");
3281 if (env->me_txns->mti_version != MDB_VERSION) {
3282 DPRINTF("lock region is version %u, expected version %u",
3283 env->me_txns->mti_version, MDB_VERSION);
3284 rc = MDB_VERSION_MISMATCH;
3288 if (rc != EACCES && rc != EAGAIN) {
3292 env->me_rmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);
3293 if (!env->me_rmutex) goto fail_errno;
3294 env->me_wmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
3295 if (!env->me_wmutex) goto fail_errno;
3296 #elif defined(MDB_USE_POSIX_SEM)
3297 env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0);
3298 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
3299 env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0);
3300 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
3311 /** The name of the lock file in the DB environment */
3312 #define LOCKNAME "/lock.mdb"
3313 /** The name of the data file in the DB environment */
3314 #define DATANAME "/data.mdb"
3315 /** The suffix of the lock file when no subdir is used */
3316 #define LOCKSUFF "-lock"
3317 /** Only a subset of the @ref mdb_env flags can be changed
3318 * at runtime. Changing other flags requires closing the
3319 * environment and re-opening it with the new flags.
3321 #define CHANGEABLE (MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC)
3322 #define CHANGELESS (MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY|MDB_WRITEMAP)
3325 mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mode_t mode)
3327 int oflags, rc, len, excl;
3328 char *lpath, *dpath;
3330 if (env->me_fd!=INVALID_HANDLE_VALUE || (flags & ~(CHANGEABLE|CHANGELESS)))
3334 if (flags & MDB_NOSUBDIR) {
3335 rc = len + sizeof(LOCKSUFF) + len + 1;
3337 rc = len + sizeof(LOCKNAME) + len + sizeof(DATANAME);
3342 if (flags & MDB_NOSUBDIR) {
3343 dpath = lpath + len + sizeof(LOCKSUFF);
3344 sprintf(lpath, "%s" LOCKSUFF, path);
3345 strcpy(dpath, path);
3347 dpath = lpath + len + sizeof(LOCKNAME);
3348 sprintf(lpath, "%s" LOCKNAME, path);
3349 sprintf(dpath, "%s" DATANAME, path);
3352 flags |= env->me_flags;
3353 /* silently ignore WRITEMAP if we're only getting read access */
3354 if (F_ISSET(flags, MDB_RDONLY|MDB_WRITEMAP))
3355 flags ^= MDB_WRITEMAP;
3356 env->me_flags = flags |= MDB_ENV_ACTIVE;
3358 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
3363 if (F_ISSET(flags, MDB_RDONLY)) {
3364 oflags = GENERIC_READ;
3365 len = OPEN_EXISTING;
3367 oflags = GENERIC_READ|GENERIC_WRITE;
3370 mode = FILE_ATTRIBUTE_NORMAL;
3371 env->me_fd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
3372 NULL, len, mode, NULL);
3374 if (F_ISSET(flags, MDB_RDONLY))
3377 oflags = O_RDWR | O_CREAT;
3379 env->me_fd = open(dpath, oflags, mode);
3381 if (env->me_fd == INVALID_HANDLE_VALUE) {
3386 if ((rc = mdb_env_open2(env)) == MDB_SUCCESS) {
3387 if (flags & (MDB_RDONLY|MDB_WRITEMAP)) {
3388 env->me_mfd = env->me_fd;
3390 /* Synchronous fd for meta writes. Needed even with
3391 * MDB_NOSYNC/MDB_NOMETASYNC, in case these get reset.
3394 env->me_mfd = CreateFile(dpath, oflags,
3395 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len,
3396 mode | FILE_FLAG_WRITE_THROUGH, NULL);
3398 env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode);
3400 if (env->me_mfd == INVALID_HANDLE_VALUE) {
3405 DPRINTF("opened dbenv %p", (void *) env);
3406 rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
3409 env->me_numdbs = 2; /* this notes that me_txkey was set */
3411 /* Windows TLS callbacks need help finding their TLS info. */
3412 if (mdb_tls_nkeys < MAX_TLS_KEYS)
3413 mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey;
3420 rc = mdb_env_share_locks(env, &excl);
3424 env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx));
3425 env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t));
3426 env->me_path = strdup(path);
3427 if (!env->me_dbxs || !env->me_dbflags || !env->me_path)
3433 mdb_env_close0(env, excl);
3439 /** Destroy resources from mdb_env_open() and clear our readers */
3441 mdb_env_close0(MDB_env *env, int excl)
3445 if (!(env->me_flags & MDB_ENV_ACTIVE))
3448 free(env->me_dbflags);
3452 if (env->me_numdbs) {
3453 pthread_key_delete(env->me_txkey);
3455 /* Delete our key from the global list */
3456 for (i=0; i<mdb_tls_nkeys; i++)
3457 if (mdb_tls_keys[i] == env->me_txkey) {
3458 mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1];
3466 munmap(env->me_map, env->me_mapsize);
3468 if (env->me_mfd != env->me_fd && env->me_mfd != INVALID_HANDLE_VALUE)
3470 if (env->me_fd != INVALID_HANDLE_VALUE)
3473 pid_t pid = env->me_pid;
3474 /* Clearing readers is done in this function because
3475 * me_txkey with its destructor must be disabled first.
3477 for (i = env->me_numreaders; --i >= 0; )
3478 if (env->me_txns->mti_readers[i].mr_pid == pid)
3479 env->me_txns->mti_readers[i].mr_pid = 0;
3481 if (env->me_rmutex) {
3482 CloseHandle(env->me_rmutex);
3483 if (env->me_wmutex) CloseHandle(env->me_wmutex);
3485 /* Windows automatically destroys the mutexes when
3486 * the last handle closes.
3488 #elif defined(MDB_USE_POSIX_SEM)
3489 if (env->me_rmutex != SEM_FAILED) {
3490 sem_close(env->me_rmutex);
3491 if (env->me_wmutex != SEM_FAILED)
3492 sem_close(env->me_wmutex);
3493 /* If we have the filelock: If we are the
3494 * only remaining user, clean up semaphores.
3497 mdb_env_excl_lock(env, &excl);
3499 sem_unlink(env->me_txns->mti_rmname);
3500 sem_unlink(env->me_txns->mti_wmname);
3504 munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
3506 if (env->me_lfd != INVALID_HANDLE_VALUE) {
3509 /* Unlock the lockfile. Windows would have unlocked it
3510 * after closing anyway, but not necessarily at once.
3512 UnlockFile(env->me_lfd, 0, 0, 1, 0);
3518 env->me_flags &= ~MDB_ENV_ACTIVE;
3522 mdb_env_copy(MDB_env *env, const char *path)
3524 MDB_txn *txn = NULL;
3528 HANDLE newfd = INVALID_HANDLE_VALUE;
3530 if (env->me_flags & MDB_NOSUBDIR) {
3531 lpath = (char *)path;
3534 len += sizeof(DATANAME);
3535 lpath = malloc(len);
3538 sprintf(lpath, "%s" DATANAME, path);
3541 /* The destination path must exist, but the destination file must not.
3542 * We don't want the OS to cache the writes, since the source data is
3543 * already in the OS cache.
3546 newfd = CreateFile(lpath, GENERIC_WRITE, 0, NULL, CREATE_NEW,
3547 FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL);
3549 newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL
3555 if (!(env->me_flags & MDB_NOSUBDIR))
3557 if (newfd == INVALID_HANDLE_VALUE) {
3562 #ifdef F_NOCACHE /* __APPLE__ */
3563 rc = fcntl(newfd, F_NOCACHE, 1);
3570 /* Do the lock/unlock of the reader mutex before starting the
3571 * write txn. Otherwise other read txns could block writers.
3573 rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
3577 if (!(env->me_flags & MDB_ROFS)) {
3578 /* We must start the actual read txn after blocking writers */
3579 mdb_txn_reset0(txn);
3581 /* Temporarily block writers until we snapshot the meta pages */
3584 rc = mdb_txn_renew0(txn);
3586 UNLOCK_MUTEX_W(env);
3591 wsize = env->me_psize * 2;
3595 rc = WriteFile(newfd, env->me_map, wsize, &len, NULL);
3596 rc = (len == wsize) ? MDB_SUCCESS : ErrCode();
3599 rc = write(newfd, env->me_map, wsize);
3600 rc = (rc == (int)wsize) ? MDB_SUCCESS : ErrCode();
3602 if (! (env->me_flags & MDB_ROFS))
3603 UNLOCK_MUTEX_W(env);
3608 ptr = env->me_map + wsize;
3609 wsize = txn->mt_next_pgno * env->me_psize - wsize;
3610 #define MAX_WRITE 2147483648U
3614 if (wsize > MAX_WRITE)
3618 rc = WriteFile(newfd, ptr, w2, &len, NULL);
3619 rc = (len == w2) ? MDB_SUCCESS : ErrCode();
3628 if (wsize > MAX_WRITE)
3632 wres = write(newfd, ptr, w2);
3633 rc = (wres > 0) ? MDB_SUCCESS : ErrCode();
3642 if (newfd != INVALID_HANDLE_VALUE)
3649 mdb_env_close(MDB_env *env)
3656 VGMEMP_DESTROY(env);
3657 while ((dp = env->me_dpages) != NULL) {
3658 VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next));
3659 env->me_dpages = dp->mp_next;
3663 mdb_env_close0(env, 0);
3664 mdb_midl_free(env->me_free_pgs);
3668 /** Compare two items pointing at aligned size_t's */
3670 mdb_cmp_long(const MDB_val *a, const MDB_val *b)
3672 return (*(size_t *)a->mv_data < *(size_t *)b->mv_data) ? -1 :
3673 *(size_t *)a->mv_data > *(size_t *)b->mv_data;
3676 /** Compare two items pointing at aligned int's */
3678 mdb_cmp_int(const MDB_val *a, const MDB_val *b)
3680 return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 :
3681 *(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data;
3684 /** Compare two items pointing at ints of unknown alignment.
3685 * Nodes and keys are guaranteed to be 2-byte aligned.
3688 mdb_cmp_cint(const MDB_val *a, const MDB_val *b)
3690 #if BYTE_ORDER == LITTLE_ENDIAN
3691 unsigned short *u, *c;
3694 u = (unsigned short *) ((char *) a->mv_data + a->mv_size);
3695 c = (unsigned short *) ((char *) b->mv_data + a->mv_size);
3698 } while(!x && u > (unsigned short *)a->mv_data);
3701 return memcmp(a->mv_data, b->mv_data, a->mv_size);
3705 /** Compare two items lexically */
3707 mdb_cmp_memn(const MDB_val *a, const MDB_val *b)
3714 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
3720 diff = memcmp(a->mv_data, b->mv_data, len);
3721 return diff ? diff : len_diff<0 ? -1 : len_diff;
3724 /** Compare two items in reverse byte order */
3726 mdb_cmp_memnr(const MDB_val *a, const MDB_val *b)
3728 const unsigned char *p1, *p2, *p1_lim;
3732 p1_lim = (const unsigned char *)a->mv_data;
3733 p1 = (const unsigned char *)a->mv_data + a->mv_size;
3734 p2 = (const unsigned char *)b->mv_data + b->mv_size;
3736 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
3742 while (p1 > p1_lim) {
3743 diff = *--p1 - *--p2;
3747 return len_diff<0 ? -1 : len_diff;
3750 /** Search for key within a page, using binary search.
3751 * Returns the smallest entry larger or equal to the key.
3752 * If exactp is non-null, stores whether the found entry was an exact match
3753 * in *exactp (1 or 0).
3754 * Updates the cursor index with the index of the found entry.
3755 * If no entry larger or equal to the key is found, returns NULL.
3758 mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)
3760 unsigned int i = 0, nkeys;
3763 MDB_page *mp = mc->mc_pg[mc->mc_top];
3764 MDB_node *node = NULL;
3769 nkeys = NUMKEYS(mp);
3774 COPY_PGNO(pgno, mp->mp_pgno);
3775 DPRINTF("searching %u keys in %s %spage %zu",
3776 nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "",
3783 low = IS_LEAF(mp) ? 0 : 1;
3785 cmp = mc->mc_dbx->md_cmp;
3787 /* Branch pages have no data, so if using integer keys,
3788 * alignment is guaranteed. Use faster mdb_cmp_int.
3790 if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) {
3791 if (NODEPTR(mp, 1)->mn_ksize == sizeof(size_t))
3798 nodekey.mv_size = mc->mc_db->md_pad;
3799 node = NODEPTR(mp, 0); /* fake */
3800 while (low <= high) {
3801 i = (low + high) >> 1;
3802 nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size);
3803 rc = cmp(key, &nodekey);
3804 DPRINTF("found leaf index %u [%s], rc = %i",
3805 i, DKEY(&nodekey), rc);
3814 while (low <= high) {
3815 i = (low + high) >> 1;
3817 node = NODEPTR(mp, i);
3818 nodekey.mv_size = NODEKSZ(node);
3819 nodekey.mv_data = NODEKEY(node);
3821 rc = cmp(key, &nodekey);
3824 DPRINTF("found leaf index %u [%s], rc = %i",
3825 i, DKEY(&nodekey), rc);
3827 DPRINTF("found branch index %u [%s -> %zu], rc = %i",
3828 i, DKEY(&nodekey), NODEPGNO(node), rc);
3839 if (rc > 0) { /* Found entry is less than the key. */
3840 i++; /* Skip to get the smallest entry larger than key. */
3842 node = NODEPTR(mp, i);
3845 *exactp = (rc == 0);
3846 /* store the key index */
3847 mc->mc_ki[mc->mc_top] = i;
3849 /* There is no entry larger or equal to the key. */
3852 /* nodeptr is fake for LEAF2 */
3858 mdb_cursor_adjust(MDB_cursor *mc, func)
3862 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
3863 if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) {
3870 /** Pop a page off the top of the cursor's stack. */
3872 mdb_cursor_pop(MDB_cursor *mc)
3875 #ifndef MDB_DEBUG_SKIP
3876 MDB_page *top = mc->mc_pg[mc->mc_top];
3882 DPRINTF("popped page %zu off db %u cursor %p", top->mp_pgno,
3883 mc->mc_dbi, (void *) mc);
3887 /** Push a page onto the top of the cursor's stack. */
3889 mdb_cursor_push(MDB_cursor *mc, MDB_page *mp)
3891 DPRINTF("pushing page %zu on db %u cursor %p", mp->mp_pgno,
3892 mc->mc_dbi, (void *) mc);
3894 if (mc->mc_snum >= CURSOR_STACK) {
3895 assert(mc->mc_snum < CURSOR_STACK);
3896 return MDB_CURSOR_FULL;
3899 mc->mc_top = mc->mc_snum++;
3900 mc->mc_pg[mc->mc_top] = mp;
3901 mc->mc_ki[mc->mc_top] = 0;
3906 /** Find the address of the page corresponding to a given page number.
3907 * @param[in] txn the transaction for this access.
3908 * @param[in] pgno the page number for the page to retrieve.
3909 * @param[out] ret address of a pointer where the page's address will be stored.
3910 * @return 0 on success, non-zero on failure.
3913 mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret)
3917 if (txn->mt_env->me_flags & MDB_WRITEMAP) {
3918 if (pgno < txn->mt_next_pgno)
3919 p = (MDB_page *)(txn->mt_env->me_map + txn->mt_env->me_psize * pgno);
3922 if (!F_ISSET(txn->mt_flags, MDB_TXN_RDONLY) && txn->mt_u.dirty_list[0].mid) {
3924 x = mdb_mid2l_search(txn->mt_u.dirty_list, pgno);
3925 if (x <= txn->mt_u.dirty_list[0].mid && txn->mt_u.dirty_list[x].mid == pgno) {
3926 p = txn->mt_u.dirty_list[x].mptr;
3930 if (pgno < txn->mt_next_pgno)
3931 p = (MDB_page *)(txn->mt_env->me_map + txn->mt_env->me_psize * pgno);
3936 DPRINTF("page %zu not found", pgno);
3939 return (p != NULL) ? MDB_SUCCESS : MDB_PAGE_NOTFOUND;
3942 /** Search for the page a given key should be in.
3943 * Pushes parent pages on the cursor stack. This function continues a
3944 * search on a cursor that has already been initialized. (Usually by
3945 * #mdb_page_search() but also by #mdb_node_move().)
3946 * @param[in,out] mc the cursor for this operation.
3947 * @param[in] key the key to search for. If NULL, search for the lowest
3948 * page. (This is used by #mdb_cursor_first().)
3949 * @param[in] flags If MDB_PS_MODIFY set, visited pages are updated with new page numbers.
3950 * If MDB_PS_ROOTONLY set, just fetch root node, no further lookups.
3951 * @return 0 on success, non-zero on failure.
3954 mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int modify)
3956 MDB_page *mp = mc->mc_pg[mc->mc_top];
3961 while (IS_BRANCH(mp)) {
3965 DPRINTF("branch page %zu has %u keys", mp->mp_pgno, NUMKEYS(mp));
3966 assert(NUMKEYS(mp) > 1);
3967 DPRINTF("found index 0 to page %zu", NODEPGNO(NODEPTR(mp, 0)));
3969 if (key == NULL) /* Initialize cursor to first page. */
3971 else if (key->mv_size > MDB_MAXKEYSIZE && key->mv_data == NULL) {
3972 /* cursor to last page */
3976 node = mdb_node_search(mc, key, &exact);
3978 i = NUMKEYS(mp) - 1;
3980 i = mc->mc_ki[mc->mc_top];
3989 DPRINTF("following index %u for key [%s]",
3991 assert(i < NUMKEYS(mp));
3992 node = NODEPTR(mp, i);
3994 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp)))
3997 mc->mc_ki[mc->mc_top] = i;
3998 if ((rc = mdb_cursor_push(mc, mp)))
4002 if ((rc = mdb_page_touch(mc)) != 0)
4004 mp = mc->mc_pg[mc->mc_top];
4009 DPRINTF("internal error, index points to a %02X page!?",
4011 return MDB_CORRUPTED;
4014 DPRINTF("found leaf page %zu for key [%s]", mp->mp_pgno,
4015 key ? DKEY(key) : NULL);
4020 /** Search for the page a given key should be in.
4021 * Pushes parent pages on the cursor stack. This function just sets up
4022 * the search; it finds the root page for \b mc's database and sets this
4023 * as the root of the cursor's stack. Then #mdb_page_search_root() is
4024 * called to complete the search.
4025 * @param[in,out] mc the cursor for this operation.
4026 * @param[in] key the key to search for. If NULL, search for the lowest
4027 * page. (This is used by #mdb_cursor_first().)
4028 * @param[in] modify If true, visited pages are updated with new page numbers.
4029 * @return 0 on success, non-zero on failure.
4032 mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)
4037 /* Make sure the txn is still viable, then find the root from
4038 * the txn's db table.
4040 if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_ERROR)) {
4041 DPUTS("transaction has failed, must abort");
4044 /* Make sure we're using an up-to-date root */
4045 if (mc->mc_dbi > MAIN_DBI) {
4046 if ((*mc->mc_dbflag & DB_STALE) ||
4047 ((flags & MDB_PS_MODIFY) && !(*mc->mc_dbflag & DB_DIRTY))) {
4049 unsigned char dbflag = 0;
4050 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);
4051 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, flags & MDB_PS_MODIFY);
4054 if (*mc->mc_dbflag & DB_STALE) {
4057 MDB_node *leaf = mdb_node_search(&mc2,
4058 &mc->mc_dbx->md_name, &exact);
4060 return MDB_NOTFOUND;
4061 mdb_node_read(mc->mc_txn, leaf, &data);
4062 memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db));
4064 if (flags & MDB_PS_MODIFY)
4066 *mc->mc_dbflag = dbflag;
4069 root = mc->mc_db->md_root;
4071 if (root == P_INVALID) { /* Tree is empty. */
4072 DPUTS("tree is empty");
4073 return MDB_NOTFOUND;
4078 if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root)
4079 if ((rc = mdb_page_get(mc->mc_txn, root, &mc->mc_pg[0])))
4085 DPRINTF("db %u root page %zu has flags 0x%X",
4086 mc->mc_dbi, root, mc->mc_pg[0]->mp_flags);
4088 if (flags & MDB_PS_MODIFY) {
4089 if ((rc = mdb_page_touch(mc)))
4093 if (flags & MDB_PS_ROOTONLY)
4096 return mdb_page_search_root(mc, key, flags);
4099 /** Return the data associated with a given node.
4100 * @param[in] txn The transaction for this operation.
4101 * @param[in] leaf The node being read.
4102 * @param[out] data Updated to point to the node's data.
4103 * @return 0 on success, non-zero on failure.
4106 mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data)
4108 MDB_page *omp; /* overflow page */
4112 if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
4113 data->mv_size = NODEDSZ(leaf);
4114 data->mv_data = NODEDATA(leaf);
4118 /* Read overflow data.
4120 data->mv_size = NODEDSZ(leaf);
4121 memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
4122 if ((rc = mdb_page_get(txn, pgno, &omp))) {
4123 DPRINTF("read overflow page %zu failed", pgno);
4126 data->mv_data = METADATA(omp);
4132 mdb_get(MDB_txn *txn, MDB_dbi dbi,
4133 MDB_val *key, MDB_val *data)
4142 DPRINTF("===> get db %u key [%s]", dbi, DKEY(key));
4144 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
4147 if (key->mv_size == 0 || key->mv_size > MDB_MAXKEYSIZE) {
4151 mdb_cursor_init(&mc, txn, dbi, &mx);
4152 return mdb_cursor_set(&mc, key, data, MDB_SET, &exact);
4155 /** Find a sibling for a page.
4156 * Replaces the page at the top of the cursor's stack with the
4157 * specified sibling, if one exists.
4158 * @param[in] mc The cursor for this operation.
4159 * @param[in] move_right Non-zero if the right sibling is requested,
4160 * otherwise the left sibling.
4161 * @return 0 on success, non-zero on failure.
4164 mdb_cursor_sibling(MDB_cursor *mc, int move_right)
4170 if (mc->mc_snum < 2) {
4171 return MDB_NOTFOUND; /* root has no siblings */
4175 DPRINTF("parent page is page %zu, index %u",
4176 mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]);
4178 if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top]))
4179 : (mc->mc_ki[mc->mc_top] == 0)) {
4180 DPRINTF("no more keys left, moving to %s sibling",
4181 move_right ? "right" : "left");
4182 if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) {
4183 /* undo cursor_pop before returning */
4190 mc->mc_ki[mc->mc_top]++;
4192 mc->mc_ki[mc->mc_top]--;
4193 DPRINTF("just moving to %s index key %u",
4194 move_right ? "right" : "left", mc->mc_ki[mc->mc_top]);
4196 assert(IS_BRANCH(mc->mc_pg[mc->mc_top]));
4198 indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
4199 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(indx), &mp)))
4202 mdb_cursor_push(mc, mp);
4207 /** Move the cursor to the next data item. */
4209 mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
4215 if (mc->mc_flags & C_EOF) {
4216 return MDB_NOTFOUND;
4219 assert(mc->mc_flags & C_INITIALIZED);
4221 mp = mc->mc_pg[mc->mc_top];
4223 if (mc->mc_db->md_flags & MDB_DUPSORT) {
4224 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
4225 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4226 if (op == MDB_NEXT || op == MDB_NEXT_DUP) {
4227 rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);
4228 if (op != MDB_NEXT || rc == MDB_SUCCESS)
4232 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
4233 if (op == MDB_NEXT_DUP)
4234 return MDB_NOTFOUND;
4238 DPRINTF("cursor_next: top page is %zu in cursor %p", mp->mp_pgno, (void *) mc);
4240 if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) {
4241 DPUTS("=====> move to next sibling page");
4242 if (mdb_cursor_sibling(mc, 1) != MDB_SUCCESS) {
4243 mc->mc_flags |= C_EOF;
4244 mc->mc_flags &= ~C_INITIALIZED;
4245 return MDB_NOTFOUND;
4247 mp = mc->mc_pg[mc->mc_top];
4248 DPRINTF("next page is %zu, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]);
4250 mc->mc_ki[mc->mc_top]++;
4252 DPRINTF("==> cursor points to page %zu with %u keys, key index %u",
4253 mp->mp_pgno, NUMKEYS(mp), mc->mc_ki[mc->mc_top]);
4256 key->mv_size = mc->mc_db->md_pad;
4257 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
4261 assert(IS_LEAF(mp));
4262 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
4264 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4265 mdb_xcursor_init1(mc, leaf);
4268 if ((rc = mdb_node_read(mc->mc_txn, leaf, data) != MDB_SUCCESS))
4271 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4272 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
4273 if (rc != MDB_SUCCESS)
4278 MDB_GET_KEY(leaf, key);
4282 /** Move the cursor to the previous data item. */
4284 mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
4290 assert(mc->mc_flags & C_INITIALIZED);
4292 mp = mc->mc_pg[mc->mc_top];
4294 if (mc->mc_db->md_flags & MDB_DUPSORT) {
4295 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
4296 if (op == MDB_PREV || op == MDB_PREV_DUP) {
4297 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4298 rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
4299 if (op != MDB_PREV || rc == MDB_SUCCESS)
4302 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
4303 if (op == MDB_PREV_DUP)
4304 return MDB_NOTFOUND;
4309 DPRINTF("cursor_prev: top page is %zu in cursor %p", mp->mp_pgno, (void *) mc);
4311 if (mc->mc_ki[mc->mc_top] == 0) {
4312 DPUTS("=====> move to prev sibling page");
4313 if (mdb_cursor_sibling(mc, 0) != MDB_SUCCESS) {
4314 mc->mc_flags &= ~C_INITIALIZED;
4315 return MDB_NOTFOUND;
4317 mp = mc->mc_pg[mc->mc_top];
4318 mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;
4319 DPRINTF("prev page is %zu, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]);
4321 mc->mc_ki[mc->mc_top]--;
4323 mc->mc_flags &= ~C_EOF;
4325 DPRINTF("==> cursor points to page %zu with %u keys, key index %u",
4326 mp->mp_pgno, NUMKEYS(mp), mc->mc_ki[mc->mc_top]);
4329 key->mv_size = mc->mc_db->md_pad;
4330 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
4334 assert(IS_LEAF(mp));
4335 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
4337 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4338 mdb_xcursor_init1(mc, leaf);
4341 if ((rc = mdb_node_read(mc->mc_txn, leaf, data) != MDB_SUCCESS))
4344 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4345 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
4346 if (rc != MDB_SUCCESS)
4351 MDB_GET_KEY(leaf, key);
4355 /** Set the cursor on a specific data item. */
4357 mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data,
4358 MDB_cursor_op op, int *exactp)
4362 MDB_node *leaf = NULL;
4367 assert(key->mv_size > 0);
4369 /* See if we're already on the right page */
4370 if (mc->mc_flags & C_INITIALIZED) {
4373 mp = mc->mc_pg[mc->mc_top];
4375 mc->mc_ki[mc->mc_top] = 0;
4376 return MDB_NOTFOUND;
4378 if (mp->mp_flags & P_LEAF2) {
4379 nodekey.mv_size = mc->mc_db->md_pad;
4380 nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size);
4382 leaf = NODEPTR(mp, 0);
4383 MDB_GET_KEY(leaf, &nodekey);
4385 rc = mc->mc_dbx->md_cmp(key, &nodekey);
4387 /* Probably happens rarely, but first node on the page
4388 * was the one we wanted.
4390 mc->mc_ki[mc->mc_top] = 0;
4397 unsigned int nkeys = NUMKEYS(mp);
4399 if (mp->mp_flags & P_LEAF2) {
4400 nodekey.mv_data = LEAF2KEY(mp,
4401 nkeys-1, nodekey.mv_size);
4403 leaf = NODEPTR(mp, nkeys-1);
4404 MDB_GET_KEY(leaf, &nodekey);
4406 rc = mc->mc_dbx->md_cmp(key, &nodekey);
4408 /* last node was the one we wanted */
4409 mc->mc_ki[mc->mc_top] = nkeys-1;
4415 if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) {
4416 /* This is definitely the right page, skip search_page */
4417 if (mp->mp_flags & P_LEAF2) {
4418 nodekey.mv_data = LEAF2KEY(mp,
4419 mc->mc_ki[mc->mc_top], nodekey.mv_size);
4421 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
4422 MDB_GET_KEY(leaf, &nodekey);
4424 rc = mc->mc_dbx->md_cmp(key, &nodekey);
4426 /* current node was the one we wanted */
4436 /* If any parents have right-sibs, search.
4437 * Otherwise, there's nothing further.
4439 for (i=0; i<mc->mc_top; i++)
4441 NUMKEYS(mc->mc_pg[i])-1)
4443 if (i == mc->mc_top) {
4444 /* There are no other pages */
4445 mc->mc_ki[mc->mc_top] = nkeys;
4446 return MDB_NOTFOUND;
4450 /* There are no other pages */
4451 mc->mc_ki[mc->mc_top] = 0;
4452 return MDB_NOTFOUND;
4456 rc = mdb_page_search(mc, key, 0);
4457 if (rc != MDB_SUCCESS)
4460 mp = mc->mc_pg[mc->mc_top];
4461 assert(IS_LEAF(mp));
4464 leaf = mdb_node_search(mc, key, exactp);
4465 if (exactp != NULL && !*exactp) {
4466 /* MDB_SET specified and not an exact match. */
4467 return MDB_NOTFOUND;
4471 DPUTS("===> inexact leaf not found, goto sibling");
4472 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS)
4473 return rc; /* no entries matched */
4474 mp = mc->mc_pg[mc->mc_top];
4475 assert(IS_LEAF(mp));
4476 leaf = NODEPTR(mp, 0);
4480 mc->mc_flags |= C_INITIALIZED;
4481 mc->mc_flags &= ~C_EOF;
4484 key->mv_size = mc->mc_db->md_pad;
4485 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
4489 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4490 mdb_xcursor_init1(mc, leaf);
4493 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4494 if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) {
4495 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
4498 if (op == MDB_GET_BOTH) {
4504 rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p);
4505 if (rc != MDB_SUCCESS)
4508 } else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {
4510 if ((rc = mdb_node_read(mc->mc_txn, leaf, &d2)) != MDB_SUCCESS)
4512 rc = mc->mc_dbx->md_dcmp(data, &d2);
4514 if (op == MDB_GET_BOTH || rc > 0)
4515 return MDB_NOTFOUND;
4520 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
4521 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
4526 /* The key already matches in all other cases */
4527 if (op == MDB_SET_RANGE || op == MDB_SET_KEY)
4528 MDB_GET_KEY(leaf, key);
4529 DPRINTF("==> cursor placed on key [%s]", DKEY(key));
4534 /** Move the cursor to the first item in the database. */
4536 mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data)
4541 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
4542 rc = mdb_page_search(mc, NULL, 0);
4543 if (rc != MDB_SUCCESS)
4546 assert(IS_LEAF(mc->mc_pg[mc->mc_top]));
4548 leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0);
4549 mc->mc_flags |= C_INITIALIZED;
4550 mc->mc_flags &= ~C_EOF;
4552 mc->mc_ki[mc->mc_top] = 0;
4554 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
4555 key->mv_size = mc->mc_db->md_pad;
4556 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size);
4561 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4562 mdb_xcursor_init1(mc, leaf);
4563 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
4568 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
4569 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
4573 MDB_GET_KEY(leaf, key);
4577 /** Move the cursor to the last item in the database. */
4579 mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)
4584 if (!(mc->mc_flags & C_EOF)) {
4586 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
4589 lkey.mv_size = MDB_MAXKEYSIZE+1;
4590 lkey.mv_data = NULL;
4591 rc = mdb_page_search(mc, &lkey, 0);
4592 if (rc != MDB_SUCCESS)
4595 assert(IS_LEAF(mc->mc_pg[mc->mc_top]));
4597 mc->mc_flags |= C_INITIALIZED|C_EOF;
4598 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;
4600 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
4602 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
4603 key->mv_size = mc->mc_db->md_pad;
4604 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size);
4609 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4610 mdb_xcursor_init1(mc, leaf);
4611 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
4616 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
4617 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
4622 MDB_GET_KEY(leaf, key);
4627 mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,
4636 case MDB_GET_CURRENT:
4637 if (!mc->mc_flags & C_INITIALIZED) {
4640 MDB_page *mp = mc->mc_pg[mc->mc_top];
4642 mc->mc_ki[mc->mc_top] = 0;
4648 key->mv_size = mc->mc_db->md_pad;
4649 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
4651 MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
4652 MDB_GET_KEY(leaf, key);
4654 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4655 rc = mdb_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT);
4657 rc = mdb_node_read(mc->mc_txn, leaf, data);
4664 case MDB_GET_BOTH_RANGE:
4665 if (data == NULL || mc->mc_xcursor == NULL) {
4673 if (key == NULL || key->mv_size == 0 || key->mv_size > MDB_MAXKEYSIZE) {
4675 } else if (op == MDB_SET_RANGE)
4676 rc = mdb_cursor_set(mc, key, data, op, NULL);
4678 rc = mdb_cursor_set(mc, key, data, op, &exact);
4680 case MDB_GET_MULTIPLE:
4682 !(mc->mc_db->md_flags & MDB_DUPFIXED) ||
4683 !(mc->mc_flags & C_INITIALIZED)) {
4688 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) ||
4689 (mc->mc_xcursor->mx_cursor.mc_flags & C_EOF))
4692 case MDB_NEXT_MULTIPLE:
4694 !(mc->mc_db->md_flags & MDB_DUPFIXED)) {
4698 if (!(mc->mc_flags & C_INITIALIZED))
4699 rc = mdb_cursor_first(mc, key, data);
4701 rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP);
4702 if (rc == MDB_SUCCESS) {
4703 if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
4706 mx = &mc->mc_xcursor->mx_cursor;
4707 data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) *
4709 data->mv_data = METADATA(mx->mc_pg[mx->mc_top]);
4710 mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1;
4718 case MDB_NEXT_NODUP:
4719 if (!(mc->mc_flags & C_INITIALIZED))
4720 rc = mdb_cursor_first(mc, key, data);
4722 rc = mdb_cursor_next(mc, key, data, op);
4726 case MDB_PREV_NODUP:
4727 if (!(mc->mc_flags & C_INITIALIZED) || (mc->mc_flags & C_EOF)) {
4728 rc = mdb_cursor_last(mc, key, data);
4729 mc->mc_flags |= C_INITIALIZED;
4730 mc->mc_ki[mc->mc_top]++;
4732 rc = mdb_cursor_prev(mc, key, data, op);
4735 rc = mdb_cursor_first(mc, key, data);
4739 !(mc->mc_db->md_flags & MDB_DUPSORT) ||
4740 !(mc->mc_flags & C_INITIALIZED) ||
4741 !(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
4745 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
4748 rc = mdb_cursor_last(mc, key, data);
4752 !(mc->mc_db->md_flags & MDB_DUPSORT) ||
4753 !(mc->mc_flags & C_INITIALIZED) ||
4754 !(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
4758 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
4761 DPRINTF("unhandled/unimplemented cursor operation %u", op);
4769 /** Touch all the pages in the cursor stack.
4770 * Makes sure all the pages are writable, before attempting a write operation.
4771 * @param[in] mc The cursor to operate on.
4774 mdb_cursor_touch(MDB_cursor *mc)
4778 if (mc->mc_dbi > MAIN_DBI && !(*mc->mc_dbflag & DB_DIRTY)) {
4781 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI,
4782 mc->mc_txn->mt_dbs[MAIN_DBI].md_flags & MDB_DUPSORT ? &mcx : NULL);
4783 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY);
4786 *mc->mc_dbflag = DB_DIRTY;
4788 for (mc->mc_top = 0; mc->mc_top < mc->mc_snum; mc->mc_top++) {
4789 rc = mdb_page_touch(mc);
4793 mc->mc_top = mc->mc_snum-1;
4798 mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
4801 MDB_node *leaf = NULL;
4802 MDB_val xdata, *rdata, dkey;
4805 int do_sub = 0, insert = 0;
4806 unsigned int mcount = 0;
4810 char dbuf[MDB_MAXKEYSIZE+1];
4811 unsigned int nflags;
4814 if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_RDONLY))
4817 if (key->mv_size == 0 || key->mv_size > MDB_MAXKEYSIZE)
4820 if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT) && data->mv_size > MDB_MAXKEYSIZE)
4823 #if SIZE_MAX > MAXDATASIZE
4824 if (data->mv_size > MAXDATASIZE)
4828 DPRINTF("==> put db %u key [%s], size %zu, data size %zu",
4829 mc->mc_dbi, DKEY(key), key ? key->mv_size:0, data->mv_size);
4833 if (flags == MDB_CURRENT) {
4834 if (!(mc->mc_flags & C_INITIALIZED))
4837 } else if (mc->mc_db->md_root == P_INVALID) {
4839 /* new database, write a root leaf page */
4840 DPUTS("allocating new root leaf page");
4841 if ((rc = mdb_page_new(mc, P_LEAF, 1, &np))) {
4845 mdb_cursor_push(mc, np);
4846 mc->mc_db->md_root = np->mp_pgno;
4847 mc->mc_db->md_depth++;
4848 *mc->mc_dbflag = DB_DIRTY;
4849 if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED))
4851 np->mp_flags |= P_LEAF2;
4852 mc->mc_flags |= C_INITIALIZED;
4858 if (flags & MDB_APPEND) {
4860 rc = mdb_cursor_last(mc, &k2, &d2);
4862 rc = mc->mc_dbx->md_cmp(key, &k2);
4865 mc->mc_ki[mc->mc_top]++;
4871 rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact);
4873 if ((flags & MDB_NOOVERWRITE) && rc == 0) {
4874 DPRINTF("duplicate key [%s]", DKEY(key));
4876 return MDB_KEYEXIST;
4878 if (rc && rc != MDB_NOTFOUND)
4882 /* Cursor is positioned, now make sure all pages are writable */
4883 rc2 = mdb_cursor_touch(mc);
4888 /* The key already exists */
4889 if (rc == MDB_SUCCESS) {
4890 /* there's only a key anyway, so this is a no-op */
4891 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
4892 unsigned int ksize = mc->mc_db->md_pad;
4893 if (key->mv_size != ksize)
4895 if (flags == MDB_CURRENT) {
4896 char *ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize);
4897 memcpy(ptr, key->mv_data, ksize);
4902 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
4905 if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) {
4906 /* Was a single item before, must convert now */
4908 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
4909 /* Just overwrite the current item */
4910 if (flags == MDB_CURRENT)
4913 dkey.mv_size = NODEDSZ(leaf);
4914 dkey.mv_data = NODEDATA(leaf);
4915 #if UINT_MAX < SIZE_MAX
4916 if (mc->mc_dbx->md_dcmp == mdb_cmp_int && dkey.mv_size == sizeof(size_t))
4917 #ifdef MISALIGNED_OK
4918 mc->mc_dbx->md_dcmp = mdb_cmp_long;
4920 mc->mc_dbx->md_dcmp = mdb_cmp_cint;
4923 /* if data matches, ignore it */
4924 if (!mc->mc_dbx->md_dcmp(data, &dkey))
4925 return (flags == MDB_NODUPDATA) ? MDB_KEYEXIST : MDB_SUCCESS;
4927 /* create a fake page for the dup items */
4928 memcpy(dbuf, dkey.mv_data, dkey.mv_size);
4929 dkey.mv_data = dbuf;
4930 fp = (MDB_page *)&pbuf;
4931 fp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
4932 fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP;
4933 fp->mp_lower = PAGEHDRSZ;
4934 fp->mp_upper = PAGEHDRSZ + dkey.mv_size + data->mv_size;
4935 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
4936 fp->mp_flags |= P_LEAF2;
4937 fp->mp_pad = data->mv_size;
4938 fp->mp_upper += 2 * data->mv_size; /* leave space for 2 more */
4940 fp->mp_upper += 2 * sizeof(indx_t) + 2 * NODESIZE +
4941 (dkey.mv_size & 1) + (data->mv_size & 1);
4943 mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0);
4946 xdata.mv_size = fp->mp_upper;
4951 if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
4952 /* See if we need to convert from fake page to subDB */
4954 unsigned int offset;
4957 fp = NODEDATA(leaf);
4958 if (flags == MDB_CURRENT) {
4960 fp->mp_flags |= P_DIRTY;
4961 COPY_PGNO(fp->mp_pgno, mc->mc_pg[mc->mc_top]->mp_pgno);
4962 mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;
4966 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
4967 offset = fp->mp_pad;
4968 if (SIZELEFT(fp) >= offset)
4970 offset *= 4; /* space for 4 more */
4972 offset = NODESIZE + sizeof(indx_t) + data->mv_size;
4974 offset += offset & 1;
4975 if (NODESIZE + sizeof(indx_t) + NODEKSZ(leaf) + NODEDSZ(leaf) +
4976 offset >= (mc->mc_txn->mt_env->me_psize - PAGEHDRSZ) /
4978 /* yes, convert it */
4980 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
4981 dummy.md_pad = fp->mp_pad;
4982 dummy.md_flags = MDB_DUPFIXED;
4983 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
4984 dummy.md_flags |= MDB_INTEGERKEY;
4987 dummy.md_branch_pages = 0;
4988 dummy.md_leaf_pages = 1;
4989 dummy.md_overflow_pages = 0;
4990 dummy.md_entries = NUMKEYS(fp);
4992 xdata.mv_size = sizeof(MDB_db);
4993 xdata.mv_data = &dummy;
4994 if ((rc = mdb_page_alloc(mc, 1, &mp)))
4996 offset = mc->mc_txn->mt_env->me_psize - NODEDSZ(leaf);
4997 flags |= F_DUPDATA|F_SUBDATA;
4998 dummy.md_root = mp->mp_pgno;
5000 /* no, just grow it */
5002 xdata.mv_size = NODEDSZ(leaf) + offset;
5003 xdata.mv_data = &pbuf;
5004 mp = (MDB_page *)&pbuf;
5005 mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
5008 mp->mp_flags = fp->mp_flags | P_DIRTY;
5009 mp->mp_pad = fp->mp_pad;
5010 mp->mp_lower = fp->mp_lower;
5011 mp->mp_upper = fp->mp_upper + offset;
5013 memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad);
5015 nsize = NODEDSZ(leaf) - fp->mp_upper;
5016 memcpy((char *)mp + mp->mp_upper, (char *)fp + fp->mp_upper, nsize);
5017 for (i=0; i<NUMKEYS(fp); i++)
5018 mp->mp_ptrs[i] = fp->mp_ptrs[i] + offset;
5020 mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0);
5024 /* data is on sub-DB, just store it */
5025 flags |= F_DUPDATA|F_SUBDATA;
5029 /* overflow page overwrites need special handling */
5030 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
5033 int ovpages, dpages;
5035 ovpages = OVPAGES(NODEDSZ(leaf), mc->mc_txn->mt_env->me_psize);
5036 dpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
5037 memcpy(&pg, NODEDATA(leaf), sizeof(pg));
5038 mdb_page_get(mc->mc_txn, pg, &omp);
5039 /* Is the ov page writable and large enough? */
5040 if ((omp->mp_flags & P_DIRTY) && ovpages >= dpages) {
5041 /* yes, overwrite it. Note in this case we don't
5042 * bother to try shrinking the node if the new data
5043 * is smaller than the overflow threshold.
5045 if (F_ISSET(flags, MDB_RESERVE))
5046 data->mv_data = METADATA(omp);
5048 memcpy(METADATA(omp), data->mv_data, data->mv_size);
5051 /* no, free ovpages */
5053 mc->mc_db->md_overflow_pages -= ovpages;
5054 for (i=0; i<ovpages; i++) {
5055 DPRINTF("freed ov page %zu", pg);
5056 mdb_midl_append(&mc->mc_txn->mt_free_pgs, pg);
5060 } else if (NODEDSZ(leaf) == data->mv_size) {
5061 /* same size, just replace it. Note that we could
5062 * also reuse this node if the new data is smaller,
5063 * but instead we opt to shrink the node in that case.
5065 if (F_ISSET(flags, MDB_RESERVE))
5066 data->mv_data = NODEDATA(leaf);
5067 else if (data->mv_size)
5068 memcpy(NODEDATA(leaf), data->mv_data, data->mv_size);
5070 memcpy(NODEKEY(leaf), key->mv_data, key->mv_size);
5073 mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0);
5074 mc->mc_db->md_entries--;
5076 DPRINTF("inserting key at index %i", mc->mc_ki[mc->mc_top]);
5083 nflags = flags & NODE_ADD_FLAGS;
5084 nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(mc->mc_txn->mt_env, key, rdata);
5085 if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) {
5086 if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA )
5087 nflags &= ~MDB_APPEND;
5089 nflags |= MDB_SPLIT_REPLACE;
5090 rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags);
5092 /* There is room already in this leaf page. */
5093 rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);
5094 if (rc == 0 && !do_sub && insert) {
5095 /* Adjust other cursors pointing to mp */
5096 MDB_cursor *m2, *m3;
5097 MDB_dbi dbi = mc->mc_dbi;
5098 unsigned i = mc->mc_top;
5099 MDB_page *mp = mc->mc_pg[i];
5101 if (mc->mc_flags & C_SUB)
5104 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
5105 if (mc->mc_flags & C_SUB)
5106 m3 = &m2->mc_xcursor->mx_cursor;
5109 if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
5110 if (m3->mc_pg[i] == mp && m3->mc_ki[i] >= mc->mc_ki[i]) {
5117 if (rc != MDB_SUCCESS)
5118 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
5120 /* Now store the actual data in the child DB. Note that we're
5121 * storing the user data in the keys field, so there are strict
5122 * size limits on dupdata. The actual data fields of the child
5123 * DB are all zero size.
5130 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5131 if (flags & MDB_CURRENT) {
5132 xflags = MDB_CURRENT;
5134 mdb_xcursor_init1(mc, leaf);
5135 xflags = (flags & MDB_NODUPDATA) ? MDB_NOOVERWRITE : 0;
5137 /* converted, write the original data first */
5139 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);
5143 /* Adjust other cursors pointing to mp */
5145 unsigned i = mc->mc_top;
5146 MDB_page *mp = mc->mc_pg[i];
5148 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
5149 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
5150 if (m2->mc_pg[i] == mp && m2->mc_ki[i] == mc->mc_ki[i]) {
5151 mdb_xcursor_init1(m2, leaf);
5156 if (flags & MDB_APPENDDUP)
5157 xflags |= MDB_APPEND;
5158 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);
5159 if (flags & F_SUBDATA) {
5160 void *db = NODEDATA(leaf);
5161 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
5164 /* sub-writes might have failed so check rc again.
5165 * Don't increment count if we just replaced an existing item.
5167 if (!rc && !(flags & MDB_CURRENT))
5168 mc->mc_db->md_entries++;
5169 if (flags & MDB_MULTIPLE) {
5171 if (mcount < data[1].mv_size) {
5172 data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size;
5173 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5183 mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
5188 if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_RDONLY))
5191 if (!mc->mc_flags & C_INITIALIZED)
5194 rc = mdb_cursor_touch(mc);
5198 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5200 if (!IS_LEAF2(mc->mc_pg[mc->mc_top]) && F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5201 if (flags != MDB_NODUPDATA) {
5202 if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
5203 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
5205 rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, 0);
5206 /* If sub-DB still has entries, we're done */
5207 if (mc->mc_xcursor->mx_db.md_entries) {
5208 if (leaf->mn_flags & F_SUBDATA) {
5209 /* update subDB info */
5210 void *db = NODEDATA(leaf);
5211 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
5213 /* shrink fake page */
5214 mdb_node_shrink(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5216 mc->mc_db->md_entries--;
5219 /* otherwise fall thru and delete the sub-DB */
5222 if (leaf->mn_flags & F_SUBDATA) {
5223 /* add all the child DB's pages to the free list */
5224 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
5225 if (rc == MDB_SUCCESS) {
5226 mc->mc_db->md_entries -=
5227 mc->mc_xcursor->mx_db.md_entries;
5232 return mdb_cursor_del0(mc, leaf);
5235 /** Allocate and initialize new pages for a database.
5236 * @param[in] mc a cursor on the database being added to.
5237 * @param[in] flags flags defining what type of page is being allocated.
5238 * @param[in] num the number of pages to allocate. This is usually 1,
5239 * unless allocating overflow pages for a large record.
5240 * @param[out] mp Address of a page, or NULL on failure.
5241 * @return 0 on success, non-zero on failure.
5244 mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp)
5249 if ((rc = mdb_page_alloc(mc, num, &np)))
5251 DPRINTF("allocated new mpage %zu, page size %u",
5252 np->mp_pgno, mc->mc_txn->mt_env->me_psize);
5253 np->mp_flags = flags | P_DIRTY;
5254 np->mp_lower = PAGEHDRSZ;
5255 np->mp_upper = mc->mc_txn->mt_env->me_psize;
5258 mc->mc_db->md_branch_pages++;
5259 else if (IS_LEAF(np))
5260 mc->mc_db->md_leaf_pages++;
5261 else if (IS_OVERFLOW(np)) {
5262 mc->mc_db->md_overflow_pages += num;
5270 /** Calculate the size of a leaf node.
5271 * The size depends on the environment's page size; if a data item
5272 * is too large it will be put onto an overflow page and the node
5273 * size will only include the key and not the data. Sizes are always
5274 * rounded up to an even number of bytes, to guarantee 2-byte alignment
5275 * of the #MDB_node headers.
5276 * @param[in] env The environment handle.
5277 * @param[in] key The key for the node.
5278 * @param[in] data The data for the node.
5279 * @return The number of bytes needed to store the node.
5282 mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data)
5286 sz = LEAFSIZE(key, data);
5287 if (sz >= env->me_psize / MDB_MINKEYS) {
5288 /* put on overflow page */
5289 sz -= data->mv_size - sizeof(pgno_t);
5293 return sz + sizeof(indx_t);
5296 /** Calculate the size of a branch node.
5297 * The size should depend on the environment's page size but since
5298 * we currently don't support spilling large keys onto overflow
5299 * pages, it's simply the size of the #MDB_node header plus the
5300 * size of the key. Sizes are always rounded up to an even number
5301 * of bytes, to guarantee 2-byte alignment of the #MDB_node headers.
5302 * @param[in] env The environment handle.
5303 * @param[in] key The key for the node.
5304 * @return The number of bytes needed to store the node.
5307 mdb_branch_size(MDB_env *env, MDB_val *key)
5312 if (sz >= env->me_psize / MDB_MINKEYS) {
5313 /* put on overflow page */
5314 /* not implemented */
5315 /* sz -= key->size - sizeof(pgno_t); */
5318 return sz + sizeof(indx_t);
5321 /** Add a node to the page pointed to by the cursor.
5322 * @param[in] mc The cursor for this operation.
5323 * @param[in] indx The index on the page where the new node should be added.
5324 * @param[in] key The key for the new node.
5325 * @param[in] data The data for the new node, if any.
5326 * @param[in] pgno The page number, if adding a branch node.
5327 * @param[in] flags Flags for the node.
5328 * @return 0 on success, non-zero on failure. Possible errors are:
5330 * <li>ENOMEM - failed to allocate overflow pages for the node.
5331 * <li>MDB_PAGE_FULL - there is insufficient room in the page. This error
5332 * should never happen since all callers already calculate the
5333 * page's free space before calling this function.
5337 mdb_node_add(MDB_cursor *mc, indx_t indx,
5338 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags)
5341 size_t node_size = NODESIZE;
5344 MDB_page *mp = mc->mc_pg[mc->mc_top];
5345 MDB_page *ofp = NULL; /* overflow page */
5348 assert(mp->mp_upper >= mp->mp_lower);
5350 DPRINTF("add to %s %spage %zu index %i, data size %zu key size %zu [%s]",
5351 IS_LEAF(mp) ? "leaf" : "branch",
5352 IS_SUBP(mp) ? "sub-" : "",
5353 mp->mp_pgno, indx, data ? data->mv_size : 0,
5354 key ? key->mv_size : 0, key ? DKEY(key) : NULL);
5357 /* Move higher keys up one slot. */
5358 int ksize = mc->mc_db->md_pad, dif;
5359 char *ptr = LEAF2KEY(mp, indx, ksize);
5360 dif = NUMKEYS(mp) - indx;
5362 memmove(ptr+ksize, ptr, dif*ksize);
5363 /* insert new key */
5364 memcpy(ptr, key->mv_data, ksize);
5366 /* Just using these for counting */
5367 mp->mp_lower += sizeof(indx_t);
5368 mp->mp_upper -= ksize - sizeof(indx_t);
5373 node_size += key->mv_size;
5377 if (F_ISSET(flags, F_BIGDATA)) {
5378 /* Data already on overflow page. */
5379 node_size += sizeof(pgno_t);
5380 } else if (node_size + data->mv_size >= mc->mc_txn->mt_env->me_psize / MDB_MINKEYS) {
5381 int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
5383 /* Put data on overflow page. */
5384 DPRINTF("data size is %zu, node would be %zu, put data on overflow page",
5385 data->mv_size, node_size+data->mv_size);
5386 node_size += sizeof(pgno_t);
5387 if ((rc = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp)))
5389 DPRINTF("allocated overflow page %zu", ofp->mp_pgno);
5392 node_size += data->mv_size;
5395 node_size += node_size & 1;
5397 if (node_size + sizeof(indx_t) > SIZELEFT(mp)) {
5398 DPRINTF("not enough room in page %zu, got %u ptrs",
5399 mp->mp_pgno, NUMKEYS(mp));
5400 DPRINTF("upper - lower = %u - %u = %u", mp->mp_upper, mp->mp_lower,
5401 mp->mp_upper - mp->mp_lower);
5402 DPRINTF("node size = %zu", node_size);
5403 return MDB_PAGE_FULL;
5406 /* Move higher pointers up one slot. */
5407 for (i = NUMKEYS(mp); i > indx; i--)
5408 mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];
5410 /* Adjust free space offsets. */
5411 ofs = mp->mp_upper - node_size;
5412 assert(ofs >= mp->mp_lower + sizeof(indx_t));
5413 mp->mp_ptrs[indx] = ofs;
5415 mp->mp_lower += sizeof(indx_t);
5417 /* Write the node data. */
5418 node = NODEPTR(mp, indx);
5419 node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
5420 node->mn_flags = flags;
5422 SETDSZ(node,data->mv_size);
5427 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
5432 if (F_ISSET(flags, F_BIGDATA))
5433 memcpy(node->mn_data + key->mv_size, data->mv_data,
5435 else if (F_ISSET(flags, MDB_RESERVE))
5436 data->mv_data = node->mn_data + key->mv_size;
5438 memcpy(node->mn_data + key->mv_size, data->mv_data,
5441 memcpy(node->mn_data + key->mv_size, &ofp->mp_pgno,
5443 if (F_ISSET(flags, MDB_RESERVE))
5444 data->mv_data = METADATA(ofp);
5446 memcpy(METADATA(ofp), data->mv_data, data->mv_size);
5453 /** Delete the specified node from a page.
5454 * @param[in] mp The page to operate on.
5455 * @param[in] indx The index of the node to delete.
5456 * @param[in] ksize The size of a node. Only used if the page is
5457 * part of a #MDB_DUPFIXED database.
5460 mdb_node_del(MDB_page *mp, indx_t indx, int ksize)
5463 indx_t i, j, numkeys, ptr;
5470 COPY_PGNO(pgno, mp->mp_pgno);
5471 DPRINTF("delete node %u on %s page %zu", indx,
5472 IS_LEAF(mp) ? "leaf" : "branch", pgno);
5475 assert(indx < NUMKEYS(mp));
5478 int x = NUMKEYS(mp) - 1 - indx;
5479 base = LEAF2KEY(mp, indx, ksize);
5481 memmove(base, base + ksize, x * ksize);
5482 mp->mp_lower -= sizeof(indx_t);
5483 mp->mp_upper += ksize - sizeof(indx_t);
5487 node = NODEPTR(mp, indx);
5488 sz = NODESIZE + node->mn_ksize;
5490 if (F_ISSET(node->mn_flags, F_BIGDATA))
5491 sz += sizeof(pgno_t);
5493 sz += NODEDSZ(node);
5497 ptr = mp->mp_ptrs[indx];
5498 numkeys = NUMKEYS(mp);
5499 for (i = j = 0; i < numkeys; i++) {
5501 mp->mp_ptrs[j] = mp->mp_ptrs[i];
5502 if (mp->mp_ptrs[i] < ptr)
5503 mp->mp_ptrs[j] += sz;
5508 base = (char *)mp + mp->mp_upper;
5509 memmove(base + sz, base, ptr - mp->mp_upper);
5511 mp->mp_lower -= sizeof(indx_t);
5515 /** Compact the main page after deleting a node on a subpage.
5516 * @param[in] mp The main page to operate on.
5517 * @param[in] indx The index of the subpage on the main page.
5520 mdb_node_shrink(MDB_page *mp, indx_t indx)
5527 indx_t i, numkeys, ptr;
5529 node = NODEPTR(mp, indx);
5530 sp = (MDB_page *)NODEDATA(node);
5531 osize = NODEDSZ(node);
5533 delta = sp->mp_upper - sp->mp_lower;
5534 SETDSZ(node, osize - delta);
5535 xp = (MDB_page *)((char *)sp + delta);
5537 /* shift subpage upward */
5539 nsize = NUMKEYS(sp) * sp->mp_pad;
5540 memmove(METADATA(xp), METADATA(sp), nsize);
5543 nsize = osize - sp->mp_upper;
5544 numkeys = NUMKEYS(sp);
5545 for (i=numkeys-1; i>=0; i--)
5546 xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta;
5548 xp->mp_upper = sp->mp_lower;
5549 xp->mp_lower = sp->mp_lower;
5550 xp->mp_flags = sp->mp_flags;
5551 xp->mp_pad = sp->mp_pad;
5552 COPY_PGNO(xp->mp_pgno, mp->mp_pgno);
5554 /* shift lower nodes upward */
5555 ptr = mp->mp_ptrs[indx];
5556 numkeys = NUMKEYS(mp);
5557 for (i = 0; i < numkeys; i++) {
5558 if (mp->mp_ptrs[i] <= ptr)
5559 mp->mp_ptrs[i] += delta;
5562 base = (char *)mp + mp->mp_upper;
5563 memmove(base + delta, base, ptr - mp->mp_upper + NODESIZE + NODEKSZ(node));
5564 mp->mp_upper += delta;
5567 /** Initial setup of a sorted-dups cursor.
5568 * Sorted duplicates are implemented as a sub-database for the given key.
5569 * The duplicate data items are actually keys of the sub-database.
5570 * Operations on the duplicate data items are performed using a sub-cursor
5571 * initialized when the sub-database is first accessed. This function does
5572 * the preliminary setup of the sub-cursor, filling in the fields that
5573 * depend only on the parent DB.
5574 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
5577 mdb_xcursor_init0(MDB_cursor *mc)
5579 MDB_xcursor *mx = mc->mc_xcursor;
5581 mx->mx_cursor.mc_xcursor = NULL;
5582 mx->mx_cursor.mc_txn = mc->mc_txn;
5583 mx->mx_cursor.mc_db = &mx->mx_db;
5584 mx->mx_cursor.mc_dbx = &mx->mx_dbx;
5585 mx->mx_cursor.mc_dbi = mc->mc_dbi+1;
5586 mx->mx_cursor.mc_dbflag = &mx->mx_dbflag;
5587 mx->mx_cursor.mc_snum = 0;
5588 mx->mx_cursor.mc_top = 0;
5589 mx->mx_cursor.mc_flags = C_SUB;
5590 mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp;
5591 mx->mx_dbx.md_dcmp = NULL;
5592 mx->mx_dbx.md_rel = mc->mc_dbx->md_rel;
5595 /** Final setup of a sorted-dups cursor.
5596 * Sets up the fields that depend on the data from the main cursor.
5597 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
5598 * @param[in] node The data containing the #MDB_db record for the
5599 * sorted-dup database.
5602 mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)
5604 MDB_xcursor *mx = mc->mc_xcursor;
5606 if (node->mn_flags & F_SUBDATA) {
5607 memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db));
5608 mx->mx_cursor.mc_pg[0] = 0;
5609 mx->mx_cursor.mc_snum = 0;
5610 mx->mx_cursor.mc_flags = C_SUB;
5612 MDB_page *fp = NODEDATA(node);
5613 mx->mx_db.md_pad = mc->mc_pg[mc->mc_top]->mp_pad;
5614 mx->mx_db.md_flags = 0;
5615 mx->mx_db.md_depth = 1;
5616 mx->mx_db.md_branch_pages = 0;
5617 mx->mx_db.md_leaf_pages = 1;
5618 mx->mx_db.md_overflow_pages = 0;
5619 mx->mx_db.md_entries = NUMKEYS(fp);
5620 COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno);
5621 mx->mx_cursor.mc_snum = 1;
5622 mx->mx_cursor.mc_flags = C_INITIALIZED|C_SUB;
5623 mx->mx_cursor.mc_top = 0;
5624 mx->mx_cursor.mc_pg[0] = fp;
5625 mx->mx_cursor.mc_ki[0] = 0;
5626 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
5627 mx->mx_db.md_flags = MDB_DUPFIXED;
5628 mx->mx_db.md_pad = fp->mp_pad;
5629 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
5630 mx->mx_db.md_flags |= MDB_INTEGERKEY;
5633 DPRINTF("Sub-db %u for db %u root page %zu", mx->mx_cursor.mc_dbi, mc->mc_dbi,
5635 mx->mx_dbflag = (F_ISSET(mc->mc_pg[mc->mc_top]->mp_flags, P_DIRTY)) ?
5637 mx->mx_dbx.md_name.mv_data = NODEKEY(node);
5638 mx->mx_dbx.md_name.mv_size = node->mn_ksize;
5639 #if UINT_MAX < SIZE_MAX
5640 if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(size_t))
5641 #ifdef MISALIGNED_OK
5642 mx->mx_dbx.md_cmp = mdb_cmp_long;
5644 mx->mx_dbx.md_cmp = mdb_cmp_cint;
5649 /** Initialize a cursor for a given transaction and database. */
5651 mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
5656 mc->mc_db = &txn->mt_dbs[dbi];
5657 mc->mc_dbx = &txn->mt_dbxs[dbi];
5658 mc->mc_dbflag = &txn->mt_dbflags[dbi];
5663 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
5665 mc->mc_xcursor = mx;
5666 mdb_xcursor_init0(mc);
5668 mc->mc_xcursor = NULL;
5670 if (*mc->mc_dbflag & DB_STALE) {
5671 mdb_page_search(mc, NULL, MDB_PS_ROOTONLY);
5676 mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
5679 MDB_xcursor *mx = NULL;
5680 size_t size = sizeof(MDB_cursor);
5682 if (txn == NULL || ret == NULL || dbi >= txn->mt_numdbs)
5685 /* Allow read access to the freelist */
5686 if (!dbi && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
5689 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)
5690 size += sizeof(MDB_xcursor);
5692 if ((mc = malloc(size)) != NULL) {
5693 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
5694 mx = (MDB_xcursor *)(mc + 1);
5696 mdb_cursor_init(mc, txn, dbi, mx);
5697 if (txn->mt_cursors) {
5698 mc->mc_next = txn->mt_cursors[dbi];
5699 txn->mt_cursors[dbi] = mc;
5701 mc->mc_flags |= C_ALLOCD;
5712 mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)
5714 if (txn == NULL || mc == NULL || mc->mc_dbi >= txn->mt_numdbs)
5717 if (txn->mt_cursors)
5720 mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor);
5724 /* Return the count of duplicate data items for the current key */
5726 mdb_cursor_count(MDB_cursor *mc, size_t *countp)
5730 if (mc == NULL || countp == NULL)
5733 if (!(mc->mc_db->md_flags & MDB_DUPSORT))
5736 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5737 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5740 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
5743 *countp = mc->mc_xcursor->mx_db.md_entries;
5749 mdb_cursor_close(MDB_cursor *mc)
5752 /* remove from txn, if tracked */
5753 if (mc->mc_txn->mt_cursors) {
5754 MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi];
5755 while (*prev && *prev != mc) prev = &(*prev)->mc_next;
5757 *prev = mc->mc_next;
5759 if (mc->mc_flags & C_ALLOCD)
5765 mdb_cursor_txn(MDB_cursor *mc)
5767 if (!mc) return NULL;
5772 mdb_cursor_dbi(MDB_cursor *mc)
5778 /** Replace the key for a node with a new key.
5779 * @param[in] mp The page containing the node to operate on.
5780 * @param[in] indx The index of the node to operate on.
5781 * @param[in] key The new key to use.
5782 * @return 0 on success, non-zero on failure.
5785 mdb_update_key(MDB_page *mp, indx_t indx, MDB_val *key)
5791 indx_t ptr, i, numkeys;
5794 node = NODEPTR(mp, indx);
5795 ptr = mp->mp_ptrs[indx];
5799 char kbuf2[(MDB_MAXKEYSIZE*2+1)];
5800 k2.mv_data = NODEKEY(node);
5801 k2.mv_size = node->mn_ksize;
5802 DPRINTF("update key %u (ofs %u) [%s] to [%s] on page %zu",
5804 mdb_dkey(&k2, kbuf2),
5810 delta0 = delta = key->mv_size - node->mn_ksize;
5812 /* Must be 2-byte aligned. If new key is
5813 * shorter by 1, the shift will be skipped.
5815 delta += (delta & 1);
5817 if (delta > 0 && SIZELEFT(mp) < delta) {
5818 DPRINTF("OUCH! Not enough room, delta = %d", delta);
5819 return MDB_PAGE_FULL;
5822 numkeys = NUMKEYS(mp);
5823 for (i = 0; i < numkeys; i++) {
5824 if (mp->mp_ptrs[i] <= ptr)
5825 mp->mp_ptrs[i] -= delta;
5828 base = (char *)mp + mp->mp_upper;
5829 len = ptr - mp->mp_upper + NODESIZE;
5830 memmove(base - delta, base, len);
5831 mp->mp_upper -= delta;
5833 node = NODEPTR(mp, indx);
5836 /* But even if no shift was needed, update ksize */
5838 node->mn_ksize = key->mv_size;
5841 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
5846 /** Move a node from csrc to cdst.
5849 mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
5855 unsigned short flags;
5859 /* Mark src and dst as dirty. */
5860 if ((rc = mdb_page_touch(csrc)) ||
5861 (rc = mdb_page_touch(cdst)))
5864 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
5865 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0); /* fake */
5866 key.mv_size = csrc->mc_db->md_pad;
5867 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
5869 data.mv_data = NULL;
5873 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]);
5874 assert(!((long)srcnode&1));
5875 srcpg = NODEPGNO(srcnode);
5876 flags = srcnode->mn_flags;
5877 if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
5878 unsigned int snum = csrc->mc_snum;
5880 /* must find the lowest key below src */
5881 mdb_page_search_root(csrc, NULL, 0);
5882 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
5883 key.mv_size = csrc->mc_db->md_pad;
5884 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
5886 s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
5887 key.mv_size = NODEKSZ(s2);
5888 key.mv_data = NODEKEY(s2);
5890 csrc->mc_snum = snum--;
5891 csrc->mc_top = snum;
5893 key.mv_size = NODEKSZ(srcnode);
5894 key.mv_data = NODEKEY(srcnode);
5896 data.mv_size = NODEDSZ(srcnode);
5897 data.mv_data = NODEDATA(srcnode);
5899 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) {
5900 unsigned int snum = cdst->mc_snum;
5903 /* must find the lowest key below dst */
5904 mdb_page_search_root(cdst, NULL, 0);
5905 if (IS_LEAF2(cdst->mc_pg[cdst->mc_top])) {
5906 bkey.mv_size = cdst->mc_db->md_pad;
5907 bkey.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, bkey.mv_size);
5909 s2 = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
5910 bkey.mv_size = NODEKSZ(s2);
5911 bkey.mv_data = NODEKEY(s2);
5913 cdst->mc_snum = snum--;
5914 cdst->mc_top = snum;
5915 rc = mdb_update_key(cdst->mc_pg[cdst->mc_top], 0, &bkey);
5918 DPRINTF("moving %s node %u [%s] on page %zu to node %u on page %zu",
5919 IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch",
5920 csrc->mc_ki[csrc->mc_top],
5922 csrc->mc_pg[csrc->mc_top]->mp_pgno,
5923 cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno);
5925 /* Add the node to the destination page.
5927 rc = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags);
5928 if (rc != MDB_SUCCESS)
5931 /* Delete the node from the source page.
5933 mdb_node_del(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
5936 /* Adjust other cursors pointing to mp */
5937 MDB_cursor *m2, *m3;
5938 MDB_dbi dbi = csrc->mc_dbi;
5939 MDB_page *mp = csrc->mc_pg[csrc->mc_top];
5941 if (csrc->mc_flags & C_SUB)
5944 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
5945 if (m2 == csrc) continue;
5946 if (csrc->mc_flags & C_SUB)
5947 m3 = &m2->mc_xcursor->mx_cursor;
5950 if (m3->mc_pg[csrc->mc_top] == mp && m3->mc_ki[csrc->mc_top] ==
5951 csrc->mc_ki[csrc->mc_top]) {
5952 m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
5953 m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
5958 /* Update the parent separators.
5960 if (csrc->mc_ki[csrc->mc_top] == 0) {
5961 if (csrc->mc_ki[csrc->mc_top-1] != 0) {
5962 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
5963 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
5965 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
5966 key.mv_size = NODEKSZ(srcnode);
5967 key.mv_data = NODEKEY(srcnode);
5969 DPRINTF("update separator for source page %zu to [%s]",
5970 csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key));
5971 if ((rc = mdb_update_key(csrc->mc_pg[csrc->mc_top-1], csrc->mc_ki[csrc->mc_top-1],
5972 &key)) != MDB_SUCCESS)
5975 if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
5977 nullkey.mv_size = 0;
5978 rc = mdb_update_key(csrc->mc_pg[csrc->mc_top], 0, &nullkey);
5979 assert(rc == MDB_SUCCESS);
5983 if (cdst->mc_ki[cdst->mc_top] == 0) {
5984 if (cdst->mc_ki[cdst->mc_top-1] != 0) {
5985 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
5986 key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size);
5988 srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
5989 key.mv_size = NODEKSZ(srcnode);
5990 key.mv_data = NODEKEY(srcnode);
5992 DPRINTF("update separator for destination page %zu to [%s]",
5993 cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key));
5994 if ((rc = mdb_update_key(cdst->mc_pg[cdst->mc_top-1], cdst->mc_ki[cdst->mc_top-1],
5995 &key)) != MDB_SUCCESS)
5998 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) {
6000 nullkey.mv_size = 0;
6001 rc = mdb_update_key(cdst->mc_pg[cdst->mc_top], 0, &nullkey);
6002 assert(rc == MDB_SUCCESS);
6009 /** Merge one page into another.
6010 * The nodes from the page pointed to by \b csrc will
6011 * be copied to the page pointed to by \b cdst and then
6012 * the \b csrc page will be freed.
6013 * @param[in] csrc Cursor pointing to the source page.
6014 * @param[in] cdst Cursor pointing to the destination page.
6017 mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
6025 DPRINTF("merging page %zu into %zu", csrc->mc_pg[csrc->mc_top]->mp_pgno,
6026 cdst->mc_pg[cdst->mc_top]->mp_pgno);
6028 assert(csrc->mc_snum > 1); /* can't merge root page */
6029 assert(cdst->mc_snum > 1);
6031 /* Mark dst as dirty. */
6032 if ((rc = mdb_page_touch(cdst)))
6035 /* Move all nodes from src to dst.
6037 j = nkeys = NUMKEYS(cdst->mc_pg[cdst->mc_top]);
6038 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
6039 key.mv_size = csrc->mc_db->md_pad;
6040 key.mv_data = METADATA(csrc->mc_pg[csrc->mc_top]);
6041 for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) {
6042 rc = mdb_node_add(cdst, j, &key, NULL, 0, 0);
6043 if (rc != MDB_SUCCESS)
6045 key.mv_data = (char *)key.mv_data + key.mv_size;
6048 for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) {
6049 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], i);
6050 if (i == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
6051 unsigned int snum = csrc->mc_snum;
6053 /* must find the lowest key below src */
6054 mdb_page_search_root(csrc, NULL, 0);
6055 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
6056 key.mv_size = csrc->mc_db->md_pad;
6057 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
6059 s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
6060 key.mv_size = NODEKSZ(s2);
6061 key.mv_data = NODEKEY(s2);
6063 csrc->mc_snum = snum--;
6064 csrc->mc_top = snum;
6066 key.mv_size = srcnode->mn_ksize;
6067 key.mv_data = NODEKEY(srcnode);
6070 data.mv_size = NODEDSZ(srcnode);
6071 data.mv_data = NODEDATA(srcnode);
6072 rc = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags);
6073 if (rc != MDB_SUCCESS)
6078 DPRINTF("dst page %zu now has %u keys (%.1f%% filled)",
6079 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);
6081 /* Unlink the src page from parent and add to free list.
6083 mdb_node_del(csrc->mc_pg[csrc->mc_top-1], csrc->mc_ki[csrc->mc_top-1], 0);
6084 if (csrc->mc_ki[csrc->mc_top-1] == 0) {
6086 if ((rc = mdb_update_key(csrc->mc_pg[csrc->mc_top-1], 0, &key)) != MDB_SUCCESS)
6090 mdb_midl_append(&csrc->mc_txn->mt_free_pgs, csrc->mc_pg[csrc->mc_top]->mp_pgno);
6091 if (IS_LEAF(csrc->mc_pg[csrc->mc_top]))
6092 csrc->mc_db->md_leaf_pages--;
6094 csrc->mc_db->md_branch_pages--;
6096 /* Adjust other cursors pointing to mp */
6097 MDB_cursor *m2, *m3;
6098 MDB_dbi dbi = csrc->mc_dbi;
6099 MDB_page *mp = cdst->mc_pg[cdst->mc_top];
6101 if (csrc->mc_flags & C_SUB)
6104 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
6105 if (csrc->mc_flags & C_SUB)
6106 m3 = &m2->mc_xcursor->mx_cursor;
6109 if (m3 == csrc) continue;
6110 if (m3->mc_snum < csrc->mc_snum) continue;
6111 if (m3->mc_pg[csrc->mc_top] == csrc->mc_pg[csrc->mc_top]) {
6112 m3->mc_pg[csrc->mc_top] = mp;
6113 m3->mc_ki[csrc->mc_top] += nkeys;
6117 mdb_cursor_pop(csrc);
6119 return mdb_rebalance(csrc);
6122 /** Copy the contents of a cursor.
6123 * @param[in] csrc The cursor to copy from.
6124 * @param[out] cdst The cursor to copy to.
6127 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst)
6131 cdst->mc_txn = csrc->mc_txn;
6132 cdst->mc_dbi = csrc->mc_dbi;
6133 cdst->mc_db = csrc->mc_db;
6134 cdst->mc_dbx = csrc->mc_dbx;
6135 cdst->mc_snum = csrc->mc_snum;
6136 cdst->mc_top = csrc->mc_top;
6137 cdst->mc_flags = csrc->mc_flags;
6139 for (i=0; i<csrc->mc_snum; i++) {
6140 cdst->mc_pg[i] = csrc->mc_pg[i];
6141 cdst->mc_ki[i] = csrc->mc_ki[i];
6145 /** Rebalance the tree after a delete operation.
6146 * @param[in] mc Cursor pointing to the page where rebalancing
6148 * @return 0 on success, non-zero on failure.
6151 mdb_rebalance(MDB_cursor *mc)
6161 COPY_PGNO(pgno, mc->mc_pg[mc->mc_top]->mp_pgno);
6162 DPRINTF("rebalancing %s page %zu (has %u keys, %.1f%% full)",
6163 IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",
6164 pgno, NUMKEYS(mc->mc_pg[mc->mc_top]), (float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10);
6168 if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= FILL_THRESHOLD) {
6171 COPY_PGNO(pgno, mc->mc_pg[mc->mc_top]->mp_pgno);
6172 DPRINTF("no need to rebalance page %zu, above fill threshold",
6178 if (mc->mc_snum < 2) {
6179 MDB_page *mp = mc->mc_pg[0];
6180 if (NUMKEYS(mp) == 0) {
6181 DPUTS("tree is completely empty");
6182 mc->mc_db->md_root = P_INVALID;
6183 mc->mc_db->md_depth = 0;
6184 mc->mc_db->md_leaf_pages = 0;
6185 mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
6189 /* Adjust other cursors pointing to mp */
6190 MDB_cursor *m2, *m3;
6191 MDB_dbi dbi = mc->mc_dbi;
6193 if (mc->mc_flags & C_SUB)
6196 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
6197 if (m2 == mc) continue;
6198 if (mc->mc_flags & C_SUB)
6199 m3 = &m2->mc_xcursor->mx_cursor;
6202 if (m3->mc_snum < mc->mc_snum) continue;
6203 if (m3->mc_pg[0] == mp) {
6209 } else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) {
6210 DPUTS("collapsing root page!");
6211 mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
6212 mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0));
6213 if ((rc = mdb_page_get(mc->mc_txn, mc->mc_db->md_root,
6216 mc->mc_db->md_depth--;
6217 mc->mc_db->md_branch_pages--;
6219 /* Adjust other cursors pointing to mp */
6220 MDB_cursor *m2, *m3;
6221 MDB_dbi dbi = mc->mc_dbi;
6223 if (mc->mc_flags & C_SUB)
6226 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
6227 if (m2 == mc) continue;
6228 if (mc->mc_flags & C_SUB)
6229 m3 = &m2->mc_xcursor->mx_cursor;
6232 if (m3->mc_snum < mc->mc_snum) continue;
6233 if (m3->mc_pg[0] == mp) {
6234 m3->mc_pg[0] = mc->mc_pg[0];
6239 DPUTS("root page doesn't need rebalancing");
6243 /* The parent (branch page) must have at least 2 pointers,
6244 * otherwise the tree is invalid.
6246 ptop = mc->mc_top-1;
6247 assert(NUMKEYS(mc->mc_pg[ptop]) > 1);
6249 /* Leaf page fill factor is below the threshold.
6250 * Try to move keys from left or right neighbor, or
6251 * merge with a neighbor page.
6256 mdb_cursor_copy(mc, &mn);
6257 mn.mc_xcursor = NULL;
6259 if (mc->mc_ki[ptop] == 0) {
6260 /* We're the leftmost leaf in our parent.
6262 DPUTS("reading right neighbor");
6264 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
6265 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mn.mc_pg[mn.mc_top])))
6267 mn.mc_ki[mn.mc_top] = 0;
6268 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);
6270 /* There is at least one neighbor to the left.
6272 DPUTS("reading left neighbor");
6274 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
6275 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mn.mc_pg[mn.mc_top])))
6277 mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;
6278 mc->mc_ki[mc->mc_top] = 0;
6281 DPRINTF("found neighbor page %zu (%u keys, %.1f%% full)",
6282 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);
6284 /* If the neighbor page is above threshold and has at least two
6285 * keys, move one key from it.
6287 * Otherwise we should try to merge them.
6289 if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= FILL_THRESHOLD && NUMKEYS(mn.mc_pg[mn.mc_top]) >= 2)
6290 return mdb_node_move(&mn, mc);
6291 else { /* FIXME: if (has_enough_room()) */
6292 mc->mc_flags &= ~C_INITIALIZED;
6293 if (mc->mc_ki[ptop] == 0)
6294 return mdb_page_merge(&mn, mc);
6296 return mdb_page_merge(mc, &mn);
6300 /** Complete a delete operation started by #mdb_cursor_del(). */
6302 mdb_cursor_del0(MDB_cursor *mc, MDB_node *leaf)
6306 /* add overflow pages to free list */
6307 if (!IS_LEAF2(mc->mc_pg[mc->mc_top]) && F_ISSET(leaf->mn_flags, F_BIGDATA)) {
6311 memcpy(&pg, NODEDATA(leaf), sizeof(pg));
6312 ovpages = OVPAGES(NODEDSZ(leaf), mc->mc_txn->mt_env->me_psize);
6313 mc->mc_db->md_overflow_pages -= ovpages;
6314 for (i=0; i<ovpages; i++) {
6315 DPRINTF("freed ov page %zu", pg);
6316 mdb_midl_append(&mc->mc_txn->mt_free_pgs, pg);
6320 mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], mc->mc_db->md_pad);
6321 mc->mc_db->md_entries--;
6322 rc = mdb_rebalance(mc);
6323 if (rc != MDB_SUCCESS)
6324 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
6330 mdb_del(MDB_txn *txn, MDB_dbi dbi,
6331 MDB_val *key, MDB_val *data)
6336 MDB_val rdata, *xdata;
6340 assert(key != NULL);
6342 DPRINTF("====> delete db %u key [%s]", dbi, DKEY(key));
6344 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
6347 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
6351 if (key->mv_size == 0 || key->mv_size > MDB_MAXKEYSIZE) {
6355 mdb_cursor_init(&mc, txn, dbi, &mx);
6366 rc = mdb_cursor_set(&mc, key, xdata, op, &exact);
6368 rc = mdb_cursor_del(&mc, data ? 0 : MDB_NODUPDATA);
6372 /** Split a page and insert a new node.
6373 * @param[in,out] mc Cursor pointing to the page and desired insertion index.
6374 * The cursor will be updated to point to the actual page and index where
6375 * the node got inserted after the split.
6376 * @param[in] newkey The key for the newly inserted node.
6377 * @param[in] newdata The data for the newly inserted node.
6378 * @param[in] newpgno The page number, if the new node is a branch node.
6379 * @param[in] nflags The #NODE_ADD_FLAGS for the new node.
6380 * @return 0 on success, non-zero on failure.
6383 mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno,
6384 unsigned int nflags)
6387 int rc = MDB_SUCCESS, ins_new = 0, new_root = 0, newpos = 1, did_split = 0;
6390 unsigned int i, j, split_indx, nkeys, pmax;
6392 MDB_val sepkey, rkey, xdata, *rdata = &xdata;
6394 MDB_page *mp, *rp, *pp;
6399 mp = mc->mc_pg[mc->mc_top];
6400 newindx = mc->mc_ki[mc->mc_top];
6402 DPRINTF("-----> splitting %s page %zu and adding [%s] at index %i",
6403 IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno,
6404 DKEY(newkey), mc->mc_ki[mc->mc_top]);
6406 /* Create a right sibling. */
6407 if ((rc = mdb_page_new(mc, mp->mp_flags, 1, &rp)))
6409 DPRINTF("new right sibling: page %zu", rp->mp_pgno);
6411 if (mc->mc_snum < 2) {
6412 if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp)))
6414 /* shift current top to make room for new parent */
6415 mc->mc_pg[1] = mc->mc_pg[0];
6416 mc->mc_ki[1] = mc->mc_ki[0];
6419 mc->mc_db->md_root = pp->mp_pgno;
6420 DPRINTF("root split! new root = %zu", pp->mp_pgno);
6421 mc->mc_db->md_depth++;
6424 /* Add left (implicit) pointer. */
6425 if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) {
6426 /* undo the pre-push */
6427 mc->mc_pg[0] = mc->mc_pg[1];
6428 mc->mc_ki[0] = mc->mc_ki[1];
6429 mc->mc_db->md_root = mp->mp_pgno;
6430 mc->mc_db->md_depth--;
6437 ptop = mc->mc_top-1;
6438 DPRINTF("parent branch page is %zu", mc->mc_pg[ptop]->mp_pgno);
6441 mc->mc_flags |= C_SPLITTING;
6442 mdb_cursor_copy(mc, &mn);
6443 mn.mc_pg[mn.mc_top] = rp;
6444 mn.mc_ki[ptop] = mc->mc_ki[ptop]+1;
6446 if (nflags & MDB_APPEND) {
6447 mn.mc_ki[mn.mc_top] = 0;
6449 split_indx = newindx;
6454 nkeys = NUMKEYS(mp);
6455 split_indx = nkeys / 2;
6456 if (newindx < split_indx)
6462 unsigned int lsize, rsize, ksize;
6463 /* Move half of the keys to the right sibling */
6465 x = mc->mc_ki[mc->mc_top] - split_indx;
6466 ksize = mc->mc_db->md_pad;
6467 split = LEAF2KEY(mp, split_indx, ksize);
6468 rsize = (nkeys - split_indx) * ksize;
6469 lsize = (nkeys - split_indx) * sizeof(indx_t);
6470 mp->mp_lower -= lsize;
6471 rp->mp_lower += lsize;
6472 mp->mp_upper += rsize - lsize;
6473 rp->mp_upper -= rsize - lsize;
6474 sepkey.mv_size = ksize;
6475 if (newindx == split_indx) {
6476 sepkey.mv_data = newkey->mv_data;
6478 sepkey.mv_data = split;
6481 ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize);
6482 memcpy(rp->mp_ptrs, split, rsize);
6483 sepkey.mv_data = rp->mp_ptrs;
6484 memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize);
6485 memcpy(ins, newkey->mv_data, ksize);
6486 mp->mp_lower += sizeof(indx_t);
6487 mp->mp_upper -= ksize - sizeof(indx_t);
6490 memcpy(rp->mp_ptrs, split, x * ksize);
6491 ins = LEAF2KEY(rp, x, ksize);
6492 memcpy(ins, newkey->mv_data, ksize);
6493 memcpy(ins+ksize, split + x * ksize, rsize - x * ksize);
6494 rp->mp_lower += sizeof(indx_t);
6495 rp->mp_upper -= ksize - sizeof(indx_t);
6496 mc->mc_ki[mc->mc_top] = x;
6497 mc->mc_pg[mc->mc_top] = rp;
6502 /* For leaf pages, check the split point based on what
6503 * fits where, since otherwise mdb_node_add can fail.
6505 * This check is only needed when the data items are
6506 * relatively large, such that being off by one will
6507 * make the difference between success or failure.
6509 * It's also relevant if a page happens to be laid out
6510 * such that one half of its nodes are all "small" and
6511 * the other half of its nodes are "large." If the new
6512 * item is also "large" and falls on the half with
6513 * "large" nodes, it also may not fit.
6516 unsigned int psize, nsize;
6517 /* Maximum free space in an empty page */
6518 pmax = mc->mc_txn->mt_env->me_psize - PAGEHDRSZ;
6519 nsize = mdb_leaf_size(mc->mc_txn->mt_env, newkey, newdata);
6520 if ((nkeys < 20) || (nsize > pmax/16)) {
6521 if (newindx <= split_indx) {
6524 for (i=0; i<split_indx; i++) {
6525 node = NODEPTR(mp, i);
6526 psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
6527 if (F_ISSET(node->mn_flags, F_BIGDATA))
6528 psize += sizeof(pgno_t);
6530 psize += NODEDSZ(node);
6534 split_indx = newindx;
6545 for (i=nkeys-1; i>=split_indx; i--) {
6546 node = NODEPTR(mp, i);
6547 psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
6548 if (F_ISSET(node->mn_flags, F_BIGDATA))
6549 psize += sizeof(pgno_t);
6551 psize += NODEDSZ(node);
6555 split_indx = newindx;
6566 /* First find the separating key between the split pages.
6567 * The case where newindx == split_indx is ambiguous; the
6568 * new item could go to the new page or stay on the original
6569 * page. If newpos == 1 it goes to the new page.
6571 if (newindx == split_indx && newpos) {
6572 sepkey.mv_size = newkey->mv_size;
6573 sepkey.mv_data = newkey->mv_data;
6575 node = NODEPTR(mp, split_indx);
6576 sepkey.mv_size = node->mn_ksize;
6577 sepkey.mv_data = NODEKEY(node);
6581 DPRINTF("separator is [%s]", DKEY(&sepkey));
6583 /* Copy separator key to the parent.
6585 if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(mc->mc_txn->mt_env, &sepkey)) {
6589 rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0);
6592 if (mn.mc_snum == mc->mc_snum) {
6593 mc->mc_pg[mc->mc_snum] = mc->mc_pg[mc->mc_top];
6594 mc->mc_ki[mc->mc_snum] = mc->mc_ki[mc->mc_top];
6595 mc->mc_pg[mc->mc_top] = mc->mc_pg[ptop];
6596 mc->mc_ki[mc->mc_top] = mc->mc_ki[ptop];
6601 /* Right page might now have changed parent.
6602 * Check if left page also changed parent.
6604 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
6605 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
6606 for (i=0; i<ptop; i++) {
6607 mc->mc_pg[i] = mn.mc_pg[i];
6608 mc->mc_ki[i] = mn.mc_ki[i];
6610 mc->mc_pg[ptop] = mn.mc_pg[ptop];
6611 mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;
6615 rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);
6618 mc->mc_flags ^= C_SPLITTING;
6619 if (rc != MDB_SUCCESS) {
6622 if (nflags & MDB_APPEND) {
6623 mc->mc_pg[mc->mc_top] = rp;
6624 mc->mc_ki[mc->mc_top] = 0;
6625 rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags);
6628 for (i=0; i<mc->mc_top; i++)
6629 mc->mc_ki[i] = mn.mc_ki[i];
6636 /* Move half of the keys to the right sibling. */
6638 /* grab a page to hold a temporary copy */
6639 copy = mdb_page_malloc(mc);
6643 copy->mp_pgno = mp->mp_pgno;
6644 copy->mp_flags = mp->mp_flags;
6645 copy->mp_lower = PAGEHDRSZ;
6646 copy->mp_upper = mc->mc_txn->mt_env->me_psize;
6647 mc->mc_pg[mc->mc_top] = copy;
6648 for (i = j = 0; i <= nkeys; j++) {
6649 if (i == split_indx) {
6650 /* Insert in right sibling. */
6651 /* Reset insert index for right sibling. */
6652 if (i != newindx || (newpos ^ ins_new)) {
6654 mc->mc_pg[mc->mc_top] = rp;
6658 if (i == newindx && !ins_new) {
6659 /* Insert the original entry that caused the split. */
6660 rkey.mv_data = newkey->mv_data;
6661 rkey.mv_size = newkey->mv_size;
6670 /* Update index for the new key. */
6671 mc->mc_ki[mc->mc_top] = j;
6672 } else if (i == nkeys) {
6675 node = NODEPTR(mp, i);
6676 rkey.mv_data = NODEKEY(node);
6677 rkey.mv_size = node->mn_ksize;
6679 xdata.mv_data = NODEDATA(node);
6680 xdata.mv_size = NODEDSZ(node);
6683 pgno = NODEPGNO(node);
6684 flags = node->mn_flags;
6689 if (!IS_LEAF(mp) && j == 0) {
6690 /* First branch index doesn't need key data. */
6694 rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags);
6698 nkeys = NUMKEYS(copy);
6699 for (i=0; i<nkeys; i++)
6700 mp->mp_ptrs[i] = copy->mp_ptrs[i];
6701 mp->mp_lower = copy->mp_lower;
6702 mp->mp_upper = copy->mp_upper;
6703 memcpy(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1),
6704 mc->mc_txn->mt_env->me_psize - copy->mp_upper);
6706 /* reset back to original page */
6707 if (newindx < split_indx || (!newpos && newindx == split_indx)) {
6708 mc->mc_pg[mc->mc_top] = mp;
6709 if (nflags & MDB_RESERVE) {
6710 node = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6711 if (!(node->mn_flags & F_BIGDATA))
6712 newdata->mv_data = NODEDATA(node);
6718 /* return tmp page to freelist */
6719 mdb_page_free(mc->mc_txn->mt_env, copy);
6722 /* Adjust other cursors pointing to mp */
6723 MDB_cursor *m2, *m3;
6724 MDB_dbi dbi = mc->mc_dbi;
6725 int fixup = NUMKEYS(mp);
6727 if (mc->mc_flags & C_SUB)
6730 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
6731 if (m2 == mc) continue;
6732 if (mc->mc_flags & C_SUB)
6733 m3 = &m2->mc_xcursor->mx_cursor;
6736 if (!(m3->mc_flags & C_INITIALIZED))
6738 if (m3->mc_flags & C_SPLITTING)
6743 for (k=m3->mc_top; k>=0; k--) {
6744 m3->mc_ki[k+1] = m3->mc_ki[k];
6745 m3->mc_pg[k+1] = m3->mc_pg[k];
6747 if (m3->mc_ki[0] >= split_indx) {
6752 m3->mc_pg[0] = mc->mc_pg[0];
6756 if (m3->mc_pg[mc->mc_top] == mp) {
6757 if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE))
6758 m3->mc_ki[mc->mc_top]++;
6759 if (m3->mc_ki[mc->mc_top] >= fixup) {
6760 m3->mc_pg[mc->mc_top] = rp;
6761 m3->mc_ki[mc->mc_top] -= fixup;
6762 m3->mc_ki[ptop] = mn.mc_ki[ptop];
6764 } else if (!did_split && m3->mc_pg[ptop] == mc->mc_pg[ptop] &&
6765 m3->mc_ki[ptop] >= mc->mc_ki[ptop]) {
6774 mdb_put(MDB_txn *txn, MDB_dbi dbi,
6775 MDB_val *key, MDB_val *data, unsigned int flags)
6780 assert(key != NULL);
6781 assert(data != NULL);
6783 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
6786 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
6790 if (key->mv_size == 0 || key->mv_size > MDB_MAXKEYSIZE) {
6794 if ((flags & (MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND)) != flags)
6797 mdb_cursor_init(&mc, txn, dbi, &mx);
6798 return mdb_cursor_put(&mc, key, data, flags);
6802 mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)
6804 if ((flag & CHANGEABLE) != flag)
6807 env->me_flags |= flag;
6809 env->me_flags &= ~flag;
6814 mdb_env_get_flags(MDB_env *env, unsigned int *arg)
6819 *arg = env->me_flags;
6824 mdb_env_get_path(MDB_env *env, const char **arg)
6829 *arg = env->me_path;
6833 /** Common code for #mdb_stat() and #mdb_env_stat().
6834 * @param[in] env the environment to operate in.
6835 * @param[in] db the #MDB_db record containing the stats to return.
6836 * @param[out] arg the address of an #MDB_stat structure to receive the stats.
6837 * @return 0, this function always succeeds.
6840 mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)
6842 arg->ms_psize = env->me_psize;
6843 arg->ms_depth = db->md_depth;
6844 arg->ms_branch_pages = db->md_branch_pages;
6845 arg->ms_leaf_pages = db->md_leaf_pages;
6846 arg->ms_overflow_pages = db->md_overflow_pages;
6847 arg->ms_entries = db->md_entries;
6852 mdb_env_stat(MDB_env *env, MDB_stat *arg)
6856 if (env == NULL || arg == NULL)
6859 toggle = mdb_env_pick_meta(env);
6861 return mdb_stat0(env, &env->me_metas[toggle]->mm_dbs[MAIN_DBI], arg);
6865 mdb_env_info(MDB_env *env, MDB_envinfo *arg)
6869 if (env == NULL || arg == NULL)
6872 toggle = mdb_env_pick_meta(env);
6873 arg->me_mapaddr = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : 0;
6874 arg->me_mapsize = env->me_mapsize;
6875 arg->me_maxreaders = env->me_maxreaders;
6876 arg->me_numreaders = env->me_numreaders;
6877 arg->me_last_pgno = env->me_metas[toggle]->mm_last_pg;
6878 arg->me_last_txnid = env->me_metas[toggle]->mm_txnid;
6882 /** Set the default comparison functions for a database.
6883 * Called immediately after a database is opened to set the defaults.
6884 * The user can then override them with #mdb_set_compare() or
6885 * #mdb_set_dupsort().
6886 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
6887 * @param[in] dbi A database handle returned by #mdb_dbi_open()
6890 mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi)
6892 uint16_t f = txn->mt_dbs[dbi].md_flags;
6894 txn->mt_dbxs[dbi].md_cmp =
6895 (f & MDB_REVERSEKEY) ? mdb_cmp_memnr :
6896 (f & MDB_INTEGERKEY) ? mdb_cmp_cint : mdb_cmp_memn;
6898 txn->mt_dbxs[dbi].md_dcmp =
6899 !(f & MDB_DUPSORT) ? 0 :
6900 ((f & MDB_INTEGERDUP)
6901 ? ((f & MDB_DUPFIXED) ? mdb_cmp_int : mdb_cmp_cint)
6902 : ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn));
6905 #define PERSISTENT_FLAGS 0xffff
6906 #define VALID_FLAGS (MDB_REVERSEKEY|MDB_DUPSORT|MDB_INTEGERKEY|MDB_DUPFIXED|\
6907 MDB_INTEGERDUP|MDB_REVERSEDUP|MDB_CREATE)
6908 int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
6913 int rc, dbflag, exact;
6914 unsigned int unused = 0;
6917 if (txn->mt_dbxs[FREE_DBI].md_cmp == NULL) {
6918 mdb_default_cmp(txn, FREE_DBI);
6921 if ((flags & VALID_FLAGS) != flags)
6927 if (flags & PERSISTENT_FLAGS) {
6928 uint16_t f2 = flags & PERSISTENT_FLAGS;
6929 /* make sure flag changes get committed */
6930 if ((txn->mt_dbs[MAIN_DBI].md_flags | f2) != txn->mt_dbs[MAIN_DBI].md_flags) {
6931 txn->mt_dbs[MAIN_DBI].md_flags |= f2;
6932 txn->mt_flags |= MDB_TXN_DIRTY;
6935 mdb_default_cmp(txn, MAIN_DBI);
6939 if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {
6940 mdb_default_cmp(txn, MAIN_DBI);
6943 /* Is the DB already open? */
6945 for (i=2; i<txn->mt_numdbs; i++) {
6946 if (!txn->mt_dbxs[i].md_name.mv_size) {
6947 /* Remember this free slot */
6948 if (!unused) unused = i;
6951 if (len == txn->mt_dbxs[i].md_name.mv_size &&
6952 !strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) {
6958 /* If no free slot and max hit, fail */
6959 if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs)
6960 return MDB_DBS_FULL;
6962 /* Find the DB info */
6966 key.mv_data = (void *)name;
6967 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
6968 rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact);
6969 if (rc == MDB_SUCCESS) {
6970 /* make sure this is actually a DB */
6971 MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]);
6972 if (!(node->mn_flags & F_SUBDATA))
6974 } else if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) {
6975 /* Create if requested */
6977 data.mv_size = sizeof(MDB_db);
6978 data.mv_data = &dummy;
6979 memset(&dummy, 0, sizeof(dummy));
6980 dummy.md_root = P_INVALID;
6981 dummy.md_flags = flags & PERSISTENT_FLAGS;
6982 rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA);
6986 /* OK, got info, add to table */
6987 if (rc == MDB_SUCCESS) {
6988 unsigned int slot = unused ? unused : txn->mt_numdbs;
6989 txn->mt_dbxs[slot].md_name.mv_data = strdup(name);
6990 txn->mt_dbxs[slot].md_name.mv_size = len;
6991 txn->mt_dbxs[slot].md_rel = NULL;
6992 txn->mt_dbflags[slot] = dbflag;
6993 memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db));
6995 txn->mt_env->me_dbflags[slot] = txn->mt_dbs[slot].md_flags;
6996 mdb_default_cmp(txn, slot);
6999 txn->mt_env->me_numdbs++;
7006 int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
7008 if (txn == NULL || arg == NULL || dbi >= txn->mt_numdbs)
7011 return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg);
7014 void mdb_dbi_close(MDB_env *env, MDB_dbi dbi)
7017 if (dbi <= MAIN_DBI || dbi >= env->me_numdbs)
7019 ptr = env->me_dbxs[dbi].md_name.mv_data;
7020 env->me_dbxs[dbi].md_name.mv_data = NULL;
7021 env->me_dbxs[dbi].md_name.mv_size = 0;
7025 /** Add all the DB's pages to the free list.
7026 * @param[in] mc Cursor on the DB to free.
7027 * @param[in] subs non-Zero to check for sub-DBs in this DB.
7028 * @return 0 on success, non-zero on failure.
7031 mdb_drop0(MDB_cursor *mc, int subs)
7035 rc = mdb_page_search(mc, NULL, 0);
7036 if (rc == MDB_SUCCESS) {
7041 /* LEAF2 pages have no nodes, cannot have sub-DBs */
7042 if (!subs || IS_LEAF2(mc->mc_pg[mc->mc_top]))
7045 mdb_cursor_copy(mc, &mx);
7046 while (mc->mc_snum > 0) {
7047 if (IS_LEAF(mc->mc_pg[mc->mc_top])) {
7048 for (i=0; i<NUMKEYS(mc->mc_pg[mc->mc_top]); i++) {
7049 ni = NODEPTR(mc->mc_pg[mc->mc_top], i);
7050 if (ni->mn_flags & F_SUBDATA) {
7051 mdb_xcursor_init1(mc, ni);
7052 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
7058 for (i=0; i<NUMKEYS(mc->mc_pg[mc->mc_top]); i++) {
7060 ni = NODEPTR(mc->mc_pg[mc->mc_top], i);
7063 mdb_midl_append(&mc->mc_txn->mt_free_pgs, pg);
7068 rc = mdb_cursor_sibling(mc, 1);
7070 /* no more siblings, go back to beginning
7071 * of previous level.
7074 for (i=1; i<mc->mc_top; i++)
7075 mc->mc_pg[i] = mx.mc_pg[i];
7079 mdb_midl_append(&mc->mc_txn->mt_free_pgs,
7080 mc->mc_db->md_root);
7085 int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)
7090 if (!txn || !dbi || dbi >= txn->mt_numdbs || (unsigned)del > 1)
7093 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
7096 rc = mdb_cursor_open(txn, dbi, &mc);
7100 rc = mdb_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT);
7104 /* Can't delete the main DB */
7105 if (del && dbi > MAIN_DBI) {
7106 rc = mdb_del(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL);
7108 mdb_dbi_close(txn->mt_env, dbi);
7110 /* reset the DB record, mark it dirty */
7111 txn->mt_dbflags[dbi] |= DB_DIRTY;
7112 txn->mt_dbs[dbi].md_depth = 0;
7113 txn->mt_dbs[dbi].md_branch_pages = 0;
7114 txn->mt_dbs[dbi].md_leaf_pages = 0;
7115 txn->mt_dbs[dbi].md_overflow_pages = 0;
7116 txn->mt_dbs[dbi].md_entries = 0;
7117 txn->mt_dbs[dbi].md_root = P_INVALID;
7119 if (!txn->mt_u.dirty_list[0].mid) {
7122 /* make sure we have at least one dirty page in this txn
7123 * otherwise these changes will be ignored.
7125 key.mv_size = sizeof(txnid_t);
7126 key.mv_data = &txn->mt_txnid;
7127 data.mv_size = sizeof(MDB_ID);
7128 data.mv_data = txn->mt_free_pgs;
7129 mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
7130 rc = mdb_cursor_put(&m2, &key, &data, 0);
7134 mdb_cursor_close(mc);
7138 int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
7140 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
7143 txn->mt_dbxs[dbi].md_cmp = cmp;
7147 int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
7149 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
7152 txn->mt_dbxs[dbi].md_dcmp = cmp;
7156 int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
7158 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
7161 txn->mt_dbxs[dbi].md_rel = rel;
7165 int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx)
7167 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
7170 txn->mt_dbxs[dbi].md_relctx = ctx;
projects / openldap / blob