/** @file mdb.c * @brief Lightning memory-mapped database library * * A Btree-based database management library modeled loosely on the * BerkeleyDB API, but much simplified. */ /* * Copyright 2011-2014 Howard Chu, Symas Corp. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted only as authorized by the OpenLDAP * Public License. * * A copy of this license is available in the file LICENSE in the * top-level directory of the distribution or, alternatively, at * . * * This code is derived from btree.c written by Martin Hedenfalk. * * Copyright (c) 2009, 2010 Martin Hedenfalk * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #ifndef _GNU_SOURCE #define _GNU_SOURCE 1 #endif #ifdef _WIN32 #include #include /** getpid() returns int; MinGW defines pid_t but MinGW64 typedefs it * as int64 which is wrong. MSVC doesn't define it at all, so just * don't use it. */ #define MDB_PID_T int #define MDB_THR_T DWORD #include #include #ifdef __GNUC__ # include #else # define LITTLE_ENDIAN 1234 # define BIG_ENDIAN 4321 # define BYTE_ORDER LITTLE_ENDIAN # ifndef SSIZE_MAX # define SSIZE_MAX INT_MAX # endif #endif #else #include #include #define MDB_PID_T pid_t #define MDB_THR_T pthread_t #include #include #include #ifdef HAVE_SYS_FILE_H #include #endif #include #endif #if defined(__mips) && defined(__linux) /* MIPS has cache coherency issues, requires explicit cache control */ #include extern int cacheflush(char *addr, int nbytes, int cache); #define CACHEFLUSH(addr, bytes, cache) cacheflush(addr, bytes, cache) #else #define CACHEFLUSH(addr, bytes, cache) #endif #include #include #include #include #include #include #include #include #include #if defined(__sun) || defined(ANDROID) /* Most platforms have posix_memalign, older may only have memalign */ #define HAVE_MEMALIGN 1 #include #endif #if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER)) #include #include /* defines BYTE_ORDER on HPUX and Solaris */ #endif #if defined(__APPLE__) || defined (BSD) # define MDB_USE_SYSV_SEM 1 # define MDB_FDATASYNC fsync #elif defined(ANDROID) # define MDB_FDATASYNC fsync #endif #ifndef _WIN32 #include #ifdef MDB_USE_SYSV_SEM #include #include #ifdef _SEM_SEMUN_UNDEFINED union semun { int val; struct semid_ds *buf; unsigned short *array; }; #endif /* _SEM_SEMUN_UNDEFINED */ #endif /* MDB_USE_SYSV_SEM */ #endif /* !_WIN32 */ #ifdef USE_VALGRIND #include #define VGMEMP_CREATE(h,r,z) VALGRIND_CREATE_MEMPOOL(h,r,z) #define VGMEMP_ALLOC(h,a,s) VALGRIND_MEMPOOL_ALLOC(h,a,s) #define VGMEMP_FREE(h,a) VALGRIND_MEMPOOL_FREE(h,a) #define VGMEMP_DESTROY(h) VALGRIND_DESTROY_MEMPOOL(h) #define VGMEMP_DEFINED(a,s) VALGRIND_MAKE_MEM_DEFINED(a,s) #else #define VGMEMP_CREATE(h,r,z) #define VGMEMP_ALLOC(h,a,s) #define VGMEMP_FREE(h,a) #define VGMEMP_DESTROY(h) #define VGMEMP_DEFINED(a,s) #endif #ifndef BYTE_ORDER # if (defined(_LITTLE_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN)) /* Solaris just defines one or the other */ # define LITTLE_ENDIAN 1234 # define BIG_ENDIAN 4321 # ifdef _LITTLE_ENDIAN # define BYTE_ORDER LITTLE_ENDIAN # else # define BYTE_ORDER BIG_ENDIAN # endif # else # define BYTE_ORDER __BYTE_ORDER # endif #endif #ifndef LITTLE_ENDIAN #define LITTLE_ENDIAN __LITTLE_ENDIAN #endif #ifndef BIG_ENDIAN #define BIG_ENDIAN __BIG_ENDIAN #endif #if defined(__i386) || defined(__x86_64) || defined(_M_IX86) #define MISALIGNED_OK 1 #endif #include "lmdb.h" #include "midl.h" #if (BYTE_ORDER == LITTLE_ENDIAN) == (BYTE_ORDER == BIG_ENDIAN) # error "Unknown or unsupported endianness (BYTE_ORDER)" #elif (-6 & 5) || CHAR_BIT != 8 || UINT_MAX < 0xffffffff || ULONG_MAX % 0xFFFF # error "Two's complement, reasonably sized integer types, please" #endif #ifdef __GNUC__ /** Put infrequently used env functions in separate section */ # ifdef __APPLE__ # define ESECT __attribute__ ((section("__TEXT,text_env"))) # else # define ESECT __attribute__ ((section("text_env"))) # endif #else #define ESECT #endif /** @defgroup internal LMDB Internals * @{ */ /** @defgroup compat Compatibility Macros * A bunch of macros to minimize the amount of platform-specific ifdefs * needed throughout the rest of the code. When the features this library * needs are similar enough to POSIX to be hidden in a one-or-two line * replacement, this macro approach is used. * @{ */ /** Features under development */ #ifndef MDB_DEVEL #define MDB_DEVEL 0 #endif #if defined(_WIN32) || (defined(EOWNERDEAD) && !defined(MDB_USE_SYSV_SEM)) #define MDB_ROBUST_SUPPORTED 1 #endif /** Wrapper around __func__, which is a C99 feature */ #if __STDC_VERSION__ >= 199901L # define mdb_func_ __func__ #elif __GNUC__ >= 2 || _MSC_VER >= 1300 # define mdb_func_ __FUNCTION__ #else /* If a debug message says (), update the #if statements above */ # define mdb_func_ "" #endif #ifdef _WIN32 #define MDB_USE_HASH 1 #define MDB_PIDLOCK 0 #define THREAD_RET DWORD #define pthread_t HANDLE #define pthread_mutex_t HANDLE #define pthread_cond_t HANDLE typedef HANDLE mdb_mutex_t; #define pthread_key_t DWORD #define pthread_self() GetCurrentThreadId() #define pthread_key_create(x,y) \ ((*(x) = TlsAlloc()) == TLS_OUT_OF_INDEXES ? ErrCode() : 0) #define pthread_key_delete(x) TlsFree(x) #define pthread_getspecific(x) TlsGetValue(x) #define pthread_setspecific(x,y) (TlsSetValue(x,y) ? 0 : ErrCode()) #define pthread_mutex_consistent(mutex) 0 #define pthread_mutex_unlock(x) ReleaseMutex(*x) #define pthread_mutex_lock(x) WaitForSingleObject(*x, INFINITE) #define pthread_cond_signal(x) SetEvent(*x) #define pthread_cond_wait(cond,mutex) do{SignalObjectAndWait(*mutex, *cond, INFINITE, FALSE); WaitForSingleObject(*mutex, INFINITE);}while(0) #define THREAD_CREATE(thr,start,arg) thr=CreateThread(NULL,0,start,arg,0,NULL) #define THREAD_FINISH(thr) WaitForSingleObject(thr, INFINITE) #define MDB_MUTEX(env, rw) ((env)->me_##rw##mutex) #define LOCK_MUTEX0(mutex) WaitForSingleObject(mutex, INFINITE) #define UNLOCK_MUTEX(mutex) ReleaseMutex(mutex) #define getpid() GetCurrentProcessId() #define MDB_FDATASYNC(fd) (!FlushFileBuffers(fd)) #define MDB_MSYNC(addr,len,flags) (!FlushViewOfFile(addr,len)) #define ErrCode() GetLastError() #define GET_PAGESIZE(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;} #define close(fd) (CloseHandle(fd) ? 0 : -1) #define munmap(ptr,len) UnmapViewOfFile(ptr) #ifdef PROCESS_QUERY_LIMITED_INFORMATION #define MDB_PROCESS_QUERY_LIMITED_INFORMATION PROCESS_QUERY_LIMITED_INFORMATION #else #define MDB_PROCESS_QUERY_LIMITED_INFORMATION 0x1000 #endif #define Z "I" #else #define THREAD_RET void * #define THREAD_CREATE(thr,start,arg) pthread_create(&thr,NULL,start,arg) #define THREAD_FINISH(thr) pthread_join(thr,NULL) #define Z "z" /**< printf format modifier for size_t */ /** For MDB_LOCK_FORMAT: True if readers take a pid lock in the lockfile */ #define MDB_PIDLOCK 1 #ifdef MDB_USE_SYSV_SEM typedef struct mdb_mutex { int semid; int semnum; } mdb_mutex_t; #define MDB_MUTEX(env, rw) (&(env)->me_##rw##mutex) #define LOCK_MUTEX0(mutex) mdb_sem_wait(mutex) #define UNLOCK_MUTEX(mutex) do { \ struct sembuf sb = { 0, 1, SEM_UNDO }; \ sb.sem_num = (mutex)->semnum; \ semop((mutex)->semid, &sb, 1); \ } while(0) static int mdb_sem_wait(mdb_mutex_t *sem) { int rc; struct sembuf sb = { 0, -1, SEM_UNDO }; sb.sem_num = sem->semnum; while ((rc = semop(sem->semid, &sb, 1)) && (rc = errno) == EINTR) ; return rc; } #else /** Pointer/HANDLE type of shared mutex/semaphore. */ typedef pthread_mutex_t mdb_mutex_t; /** Mutex for the reader table (rw = r) or write transaction (rw = w). */ #define MDB_MUTEX(env, rw) (&(env)->me_txns->mti_##rw##mutex) /** Lock the reader or writer mutex. * Returns 0 or a code to give #mdb_mutex_failed(), as in #LOCK_MUTEX(). */ #define LOCK_MUTEX0(mutex) pthread_mutex_lock(mutex) /** Unlock the reader or writer mutex. */ #define UNLOCK_MUTEX(mutex) pthread_mutex_unlock(mutex) #endif /* MDB_USE_SYSV_SEM */ /** Get the error code for the last failed system function. */ #define ErrCode() errno /** An abstraction for a file handle. * On POSIX systems file handles are small integers. On Windows * they're opaque pointers. */ #define HANDLE int /** A value for an invalid file handle. * Mainly used to initialize file variables and signify that they are * unused. */ #define INVALID_HANDLE_VALUE (-1) /** Get the size of a memory page for the system. * This is the basic size that the platform's memory manager uses, and is * fundamental to the use of memory-mapped files. */ #define GET_PAGESIZE(x) ((x) = sysconf(_SC_PAGE_SIZE)) #endif #if defined(_WIN32) #define MNAME_LEN 32 #elif defined(MDB_USE_SYSV_SEM) #define MNAME_LEN 0 #else #define MNAME_LEN (sizeof(pthread_mutex_t)) #endif /** @} */ #ifdef MDB_ROBUST_SUPPORTED /** Lock mutex, handle any error, set rc = result. * Return 0 on success, nonzero (not rc) on error. */ #define LOCK_MUTEX(rc, env, mutex) \ (((rc) = LOCK_MUTEX0(mutex)) && \ ((rc) = mdb_mutex_failed(env, mutex, rc))) static int mdb_mutex_failed(MDB_env *env, mdb_mutex_t *mutex, int rc); #else #define LOCK_MUTEX(rc, env, mutex) ((rc) = LOCK_MUTEX0(mutex)) #define mdb_mutex_failed(env, mutex, rc) (rc) #endif #ifndef _WIN32 /** A flag for opening a file and requesting synchronous data writes. * This is only used when writing a meta page. It's not strictly needed; * we could just do a normal write and then immediately perform a flush. * But if this flag is available it saves us an extra system call. * * @note If O_DSYNC is undefined but exists in /usr/include, * preferably set some compiler flag to get the definition. * Otherwise compile with the less efficient -DMDB_DSYNC=O_SYNC. */ #ifndef MDB_DSYNC # define MDB_DSYNC O_DSYNC #endif #endif /** Function for flushing the data of a file. Define this to fsync * if fdatasync() is not supported. */ #ifndef MDB_FDATASYNC # define MDB_FDATASYNC fdatasync #endif #ifndef MDB_MSYNC # define MDB_MSYNC(addr,len,flags) msync(addr,len,flags) #endif #ifndef MS_SYNC #define MS_SYNC 1 #endif #ifndef MS_ASYNC #define MS_ASYNC 0 #endif /** A page number in the database. * Note that 64 bit page numbers are overkill, since pages themselves * already represent 12-13 bits of addressable memory, and the OS will * always limit applications to a maximum of 63 bits of address space. * * @note In the #MDB_node structure, we only store 48 bits of this value, * which thus limits us to only 60 bits of addressable data. */ typedef MDB_ID pgno_t; /** A transaction ID. * See struct MDB_txn.mt_txnid for details. */ typedef MDB_ID txnid_t; /** @defgroup debug Debug Macros * @{ */ #ifndef MDB_DEBUG /** Enable debug output. Needs variable argument macros (a C99 feature). * Set this to 1 for copious tracing. Set to 2 to add dumps of all IDLs * read from and written to the database (used for free space management). */ #define MDB_DEBUG 0 #endif #if MDB_DEBUG static int mdb_debug; static txnid_t mdb_debug_start; /** Print a debug message with printf formatting. * Requires double parenthesis around 2 or more args. */ # define DPRINTF(args) ((void) ((mdb_debug) && DPRINTF0 args)) # define DPRINTF0(fmt, ...) \ fprintf(stderr, "%s:%d " fmt "\n", mdb_func_, __LINE__, __VA_ARGS__) #else # define DPRINTF(args) ((void) 0) #endif /** Print a debug string. * The string is printed literally, with no format processing. */ #define DPUTS(arg) DPRINTF(("%s", arg)) /** Debuging output value of a cursor DBI: Negative in a sub-cursor. */ #define DDBI(mc) \ (((mc)->mc_flags & C_SUB) ? -(int)(mc)->mc_dbi : (int)(mc)->mc_dbi) /** @} */ /** @brief The maximum size of a database page. * * It is 32k or 64k, since value-PAGEBASE must fit in * #MDB_page.%mp_upper. * * LMDB will use database pages < OS pages if needed. * That causes more I/O in write transactions: The OS must * know (read) the whole page before writing a partial page. * * Note that we don't currently support Huge pages. On Linux, * regular data files cannot use Huge pages, and in general * Huge pages aren't actually pageable. We rely on the OS * demand-pager to read our data and page it out when memory * pressure from other processes is high. So until OSs have * actual paging support for Huge pages, they're not viable. */ #define MAX_PAGESIZE (PAGEBASE ? 0x10000 : 0x8000) /** The minimum number of keys required in a database page. * Setting this to a larger value will place a smaller bound on the * maximum size of a data item. Data items larger than this size will * be pushed into overflow pages instead of being stored directly in * the B-tree node. This value used to default to 4. With a page size * of 4096 bytes that meant that any item larger than 1024 bytes would * go into an overflow page. That also meant that on average 2-3KB of * each overflow page was wasted space. The value cannot be lower than * 2 because then there would no longer be a tree structure. With this * value, items larger than 2KB will go into overflow pages, and on * average only 1KB will be wasted. */ #define MDB_MINKEYS 2 /** A stamp that identifies a file as an LMDB file. * There's nothing special about this value other than that it is easily * recognizable, and it will reflect any byte order mismatches. */ #define MDB_MAGIC 0xBEEFC0DE /** The version number for a database's datafile format. */ #define MDB_DATA_VERSION ((MDB_DEVEL) ? 999 : 1) /** The version number for a database's lockfile format. */ #define MDB_LOCK_VERSION ((MDB_DEVEL) ? 999 : 1) /** @brief The max size of a key we can write, or 0 for dynamic max. * * Define this as 0 to compute the max from the page size. 511 * is default for backwards compat: liblmdb <= 0.9.10 can break * when modifying a DB with keys/dupsort data bigger than its max. * #MDB_DEVEL sets the default to 0. * * Data items in an #MDB_DUPSORT database are also limited to * this size, since they're actually keys of a sub-DB. Keys and * #MDB_DUPSORT data items must fit on a node in a regular page. */ #ifndef MDB_MAXKEYSIZE #define MDB_MAXKEYSIZE ((MDB_DEVEL) ? 0 : 511) #endif /** The maximum size of a key we can write to the environment. */ #if MDB_MAXKEYSIZE #define ENV_MAXKEY(env) (MDB_MAXKEYSIZE) #else #define ENV_MAXKEY(env) ((env)->me_maxkey) #endif /** @brief The maximum size of a data item. * * We only store a 32 bit value for node sizes. */ #define MAXDATASIZE 0xffffffffUL #if MDB_DEBUG /** Key size which fits in a #DKBUF. * @ingroup debug */ #define DKBUF_MAXKEYSIZE ((MDB_MAXKEYSIZE) > 0 ? (MDB_MAXKEYSIZE) : 511) /** A key buffer. * @ingroup debug * This is used for printing a hex dump of a key's contents. */ #define DKBUF char kbuf[DKBUF_MAXKEYSIZE*2+1] /** Display a key in hex. * @ingroup debug * Invoke a function to display a key in hex. */ #define DKEY(x) mdb_dkey(x, kbuf) #else #define DKBUF #define DKEY(x) 0 #endif /** An invalid page number. * Mainly used to denote an empty tree. */ #define P_INVALID (~(pgno_t)0) /** Test if the flags \b f are set in a flag word \b w. */ #define F_ISSET(w, f) (((w) & (f)) == (f)) /** Round \b n up to an even number. */ #define EVEN(n) (((n) + 1U) & -2) /* sign-extending -2 to match n+1U */ /** Used for offsets within a single page. * Since memory pages are typically 4 or 8KB in size, 12-13 bits, * this is plenty. */ typedef uint16_t indx_t; /** Default size of memory map. * This is certainly too small for any actual applications. Apps should always set * the size explicitly using #mdb_env_set_mapsize(). */ #define DEFAULT_MAPSIZE 1048576 /** @defgroup readers Reader Lock Table * Readers don't acquire any locks for their data access. Instead, they * simply record their transaction ID in the reader table. The reader * mutex is needed just to find an empty slot in the reader table. The * slot's address is saved in thread-specific data so that subsequent read * transactions started by the same thread need no further locking to proceed. * * If #MDB_NOTLS is set, the slot address is not saved in thread-specific data. * * No reader table is used if the database is on a read-only filesystem, or * if #MDB_NOLOCK is set. * * Since the database uses multi-version concurrency control, readers don't * actually need any locking. This table is used to keep track of which * readers are using data from which old transactions, so that we'll know * when a particular old transaction is no longer in use. Old transactions * that have discarded any data pages can then have those pages reclaimed * for use by a later write transaction. * * The lock table is constructed such that reader slots are aligned with the * processor's cache line size. Any slot is only ever used by one thread. * This alignment guarantees that there will be no contention or cache * thrashing as threads update their own slot info, and also eliminates * any need for locking when accessing a slot. * * A writer thread will scan every slot in the table to determine the oldest * outstanding reader transaction. Any freed pages older than this will be * reclaimed by the writer. The writer doesn't use any locks when scanning * this table. This means that there's no guarantee that the writer will * see the most up-to-date reader info, but that's not required for correct * operation - all we need is to know the upper bound on the oldest reader, * we don't care at all about the newest reader. So the only consequence of * reading stale information here is that old pages might hang around a * while longer before being reclaimed. That's actually good anyway, because * the longer we delay reclaiming old pages, the more likely it is that a * string of contiguous pages can be found after coalescing old pages from * many old transactions together. * @{ */ /** Number of slots in the reader table. * This value was chosen somewhat arbitrarily. 126 readers plus a * couple mutexes fit exactly into 8KB on my development machine. * Applications should set the table size using #mdb_env_set_maxreaders(). */ #define DEFAULT_READERS 126 /** The size of a CPU cache line in bytes. We want our lock structures * aligned to this size to avoid false cache line sharing in the * lock table. * This value works for most CPUs. For Itanium this should be 128. */ #ifndef CACHELINE #define CACHELINE 64 #endif /** The information we store in a single slot of the reader table. * In addition to a transaction ID, we also record the process and * thread ID that owns a slot, so that we can detect stale information, * e.g. threads or processes that went away without cleaning up. * @note We currently don't check for stale records. We simply re-init * the table when we know that we're the only process opening the * lock file. */ typedef struct MDB_rxbody { /** Current Transaction ID when this transaction began, or (txnid_t)-1. * Multiple readers that start at the same time will probably have the * same ID here. Again, it's not important to exclude them from * anything; all we need to know is which version of the DB they * started from so we can avoid overwriting any data used in that * particular version. */ volatile txnid_t mrb_txnid; /** The process ID of the process owning this reader txn. */ volatile MDB_PID_T mrb_pid; /** The thread ID of the thread owning this txn. */ volatile MDB_THR_T mrb_tid; } MDB_rxbody; /** The actual reader record, with cacheline padding. */ typedef struct MDB_reader { union { MDB_rxbody mrx; /** shorthand for mrb_txnid */ #define mr_txnid mru.mrx.mrb_txnid #define mr_pid mru.mrx.mrb_pid #define mr_tid mru.mrx.mrb_tid /** cache line alignment */ char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)]; } mru; } MDB_reader; /** The header for the reader table. * The table resides in a memory-mapped file. (This is a different file * than is used for the main database.) * * For POSIX the actual mutexes reside in the shared memory of this * mapped file. On Windows, mutexes are named objects allocated by the * kernel; we store the mutex names in this mapped file so that other * processes can grab them. This same approach is also used on * MacOSX/Darwin (using named semaphores) since MacOSX doesn't support * process-shared POSIX mutexes. For these cases where a named object * is used, the object name is derived from a 64 bit FNV hash of the * environment pathname. As such, naming collisions are extremely * unlikely. If a collision occurs, the results are unpredictable. */ typedef struct MDB_txbody { /** Stamp identifying this as an LMDB file. It must be set * to #MDB_MAGIC. */ uint32_t mtb_magic; /** Format of this lock file. Must be set to #MDB_LOCK_FORMAT. */ uint32_t mtb_format; #if defined(_WIN32) char mtb_rmname[MNAME_LEN]; #elif defined(MDB_USE_SYSV_SEM) int mtb_semid; #else /** Mutex protecting access to this table. * This is the #MDB_MUTEX(env,r) reader table lock. */ pthread_mutex_t mtb_rmutex; #endif /** The ID of the last transaction committed to the database. * This is recorded here only for convenience; the value can always * be determined by reading the main database meta pages. */ volatile txnid_t mtb_txnid; /** The number of slots that have been used in the reader table. * This always records the maximum count, it is not decremented * when readers release their slots. */ volatile unsigned mtb_numreaders; } MDB_txbody; /** The actual reader table definition. */ typedef struct MDB_txninfo { union { MDB_txbody mtb; #define mti_magic mt1.mtb.mtb_magic #define mti_format mt1.mtb.mtb_format #define mti_rmutex mt1.mtb.mtb_rmutex #define mti_rmname mt1.mtb.mtb_rmname #define mti_txnid mt1.mtb.mtb_txnid #define mti_numreaders mt1.mtb.mtb_numreaders char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)]; } mt1; #ifdef MDB_USE_SYSV_SEM #define mti_semid mt1.mtb.mtb_semid #else union { #if defined(_WIN32) char mt2_wmname[MNAME_LEN]; #define mti_wmname mt2.mt2_wmname #else pthread_mutex_t mt2_wmutex; #define mti_wmutex mt2.mt2_wmutex #endif char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)]; } mt2; #endif MDB_reader mti_readers[1]; } MDB_txninfo; /** Lockfile format signature: version, features and field layout */ #define MDB_LOCK_FORMAT \ ((uint32_t) \ ((MDB_LOCK_VERSION) \ /* Flags which describe functionality */ \ + (((MNAME_LEN) == 0) << 18) /* MDB_USE_SYSV_SEM */ \ + (((MDB_PIDLOCK) != 0) << 16))) /** @} */ /** Common header for all page types. * Overflow records occupy a number of contiguous pages with no * headers on any page after the first. */ typedef struct MDB_page { #define mp_pgno mp_p.p_pgno #define mp_next mp_p.p_next union { pgno_t p_pgno; /**< page number */ struct MDB_page *p_next; /**< for in-memory list of freed pages */ } mp_p; uint16_t mp_pad; /** @defgroup mdb_page Page Flags * @ingroup internal * Flags for the page headers. * @{ */ #define P_BRANCH 0x01 /**< branch page */ #define P_LEAF 0x02 /**< leaf page */ #define P_OVERFLOW 0x04 /**< overflow page */ #define P_META 0x08 /**< meta page */ #define P_DIRTY 0x10 /**< dirty page, also set for #P_SUBP pages */ #define P_LEAF2 0x20 /**< for #MDB_DUPFIXED records */ #define P_SUBP 0x40 /**< for #MDB_DUPSORT sub-pages */ #define P_LOOSE 0x4000 /**< page was dirtied then freed, can be reused */ #define P_KEEP 0x8000 /**< leave this page alone during spill */ /** @} */ uint16_t mp_flags; /**< @ref mdb_page */ #define mp_lower mp_pb.pb.pb_lower #define mp_upper mp_pb.pb.pb_upper #define mp_pages mp_pb.pb_pages union { struct { indx_t pb_lower; /**< lower bound of free space */ indx_t pb_upper; /**< upper bound of free space */ } pb; uint32_t pb_pages; /**< number of overflow pages */ } mp_pb; indx_t mp_ptrs[1]; /**< dynamic size */ } MDB_page; /** Size of the page header, excluding dynamic data at the end */ #define PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs)) /** Address of first usable data byte in a page, after the header */ #define METADATA(p) ((void *)((char *)(p) + PAGEHDRSZ)) /** ITS#7713, change PAGEBASE to handle 65536 byte pages */ #define PAGEBASE ((MDB_DEVEL) ? PAGEHDRSZ : 0) /** Number of nodes on a page */ #define NUMKEYS(p) (((p)->mp_lower - (PAGEHDRSZ-PAGEBASE)) >> 1) /** The amount of space remaining in the page */ #define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower) /** The percentage of space used in the page, in tenths of a percent. */ #define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \ ((env)->me_psize - PAGEHDRSZ)) /** The minimum page fill factor, in tenths of a percent. * Pages emptier than this are candidates for merging. */ #define FILL_THRESHOLD 250 /** Test if a page is a leaf page */ #define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF) /** Test if a page is a LEAF2 page */ #define IS_LEAF2(p) F_ISSET((p)->mp_flags, P_LEAF2) /** Test if a page is a branch page */ #define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH) /** Test if a page is an overflow page */ #define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW) /** Test if a page is a sub page */ #define IS_SUBP(p) F_ISSET((p)->mp_flags, P_SUBP) /** The number of overflow pages needed to store the given size. */ #define OVPAGES(size, psize) ((PAGEHDRSZ-1 + (size)) / (psize) + 1) /** Link in #MDB_txn.%mt_loose_pgs list */ #define NEXT_LOOSE_PAGE(p) (*(MDB_page **)((p) + 2)) /** Header for a single key/data pair within a page. * Used in pages of type #P_BRANCH and #P_LEAF without #P_LEAF2. * We guarantee 2-byte alignment for 'MDB_node's. */ typedef struct MDB_node { /** lo and hi are used for data size on leaf nodes and for * child pgno on branch nodes. On 64 bit platforms, flags * is also used for pgno. (Branch nodes have no flags). * They are in host byte order in case that lets some * accesses be optimized into a 32-bit word access. */ #if BYTE_ORDER == LITTLE_ENDIAN unsigned short mn_lo, mn_hi; /**< part of data size or pgno */ #else unsigned short mn_hi, mn_lo; #endif /** @defgroup mdb_node Node Flags * @ingroup internal * Flags for node headers. * @{ */ #define F_BIGDATA 0x01 /**< data put on overflow page */ #define F_SUBDATA 0x02 /**< data is a sub-database */ #define F_DUPDATA 0x04 /**< data has duplicates */ /** valid flags for #mdb_node_add() */ #define NODE_ADD_FLAGS (F_DUPDATA|F_SUBDATA|MDB_RESERVE|MDB_APPEND) /** @} */ unsigned short mn_flags; /**< @ref mdb_node */ unsigned short mn_ksize; /**< key size */ char mn_data[1]; /**< key and data are appended here */ } MDB_node; /** Size of the node header, excluding dynamic data at the end */ #define NODESIZE offsetof(MDB_node, mn_data) /** Bit position of top word in page number, for shifting mn_flags */ #define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0) /** Size of a node in a branch page with a given key. * This is just the node header plus the key, there is no data. */ #define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size)) /** Size of a node in a leaf page with a given key and data. * This is node header plus key plus data size. */ #define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size) /** Address of node \b i in page \b p */ #define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i] + PAGEBASE)) /** Address of the key for the node */ #define NODEKEY(node) (void *)((node)->mn_data) /** Address of the data for a node */ #define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize) /** Get the page number pointed to by a branch node */ #define NODEPGNO(node) \ ((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | \ (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0)) /** Set the page number in a branch node */ #define SETPGNO(node,pgno) do { \ (node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \ if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0) /** Get the size of the data in a leaf node */ #define NODEDSZ(node) ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16)) /** Set the size of the data for a leaf node */ #define SETDSZ(node,size) do { \ (node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0) /** The size of a key in a node */ #define NODEKSZ(node) ((node)->mn_ksize) /** Copy a page number from src to dst */ #ifdef MISALIGNED_OK #define COPY_PGNO(dst,src) dst = src #else #if SIZE_MAX > 4294967295UL #define COPY_PGNO(dst,src) do { \ unsigned short *s, *d; \ s = (unsigned short *)&(src); \ d = (unsigned short *)&(dst); \ *d++ = *s++; \ *d++ = *s++; \ *d++ = *s++; \ *d = *s; \ } while (0) #else #define COPY_PGNO(dst,src) do { \ unsigned short *s, *d; \ s = (unsigned short *)&(src); \ d = (unsigned short *)&(dst); \ *d++ = *s++; \ *d = *s; \ } while (0) #endif #endif /** The address of a key in a LEAF2 page. * LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate sub-DBs. * There are no node headers, keys are stored contiguously. */ #define LEAF2KEY(p, i, ks) ((char *)(p) + PAGEHDRSZ + ((i)*(ks))) /** Set the \b node's key into \b keyptr, if requested. */ #define MDB_GET_KEY(node, keyptr) { if ((keyptr) != NULL) { \ (keyptr)->mv_size = NODEKSZ(node); (keyptr)->mv_data = NODEKEY(node); } } /** Set the \b node's key into \b key. */ #define MDB_GET_KEY2(node, key) { key.mv_size = NODEKSZ(node); key.mv_data = NODEKEY(node); } /** Information about a single database in the environment. */ typedef struct MDB_db { uint32_t md_pad; /**< also ksize for LEAF2 pages */ uint16_t md_flags; /**< @ref mdb_dbi_open */ uint16_t md_depth; /**< depth of this tree */ pgno_t md_branch_pages; /**< number of internal pages */ pgno_t md_leaf_pages; /**< number of leaf pages */ pgno_t md_overflow_pages; /**< number of overflow pages */ size_t md_entries; /**< number of data items */ pgno_t md_root; /**< the root page of this tree */ } MDB_db; /** mdb_dbi_open flags */ #define MDB_VALID 0x8000 /**< DB handle is valid, for me_dbflags */ #define PERSISTENT_FLAGS (0xffff & ~(MDB_VALID)) #define VALID_FLAGS (MDB_REVERSEKEY|MDB_DUPSORT|MDB_INTEGERKEY|MDB_DUPFIXED|\ MDB_INTEGERDUP|MDB_REVERSEDUP|MDB_CREATE) /** Handle for the DB used to track free pages. */ #define FREE_DBI 0 /** Handle for the default DB. */ #define MAIN_DBI 1 /** Meta page content. * A meta page is the start point for accessing a database snapshot. * Pages 0-1 are meta pages. Transaction N writes meta page #(N % 2). */ typedef struct MDB_meta { /** Stamp identifying this as an LMDB file. It must be set * to #MDB_MAGIC. */ uint32_t mm_magic; /** Version number of this file. Must be set to #MDB_DATA_VERSION. */ uint32_t mm_version; void *mm_address; /**< address for fixed mapping */ size_t mm_mapsize; /**< size of mmap region */ MDB_db mm_dbs[2]; /**< first is free space, 2nd is main db */ /** The size of pages used in this DB */ #define mm_psize mm_dbs[0].md_pad /** Any persistent environment flags. @ref mdb_env */ #define mm_flags mm_dbs[0].md_flags pgno_t mm_last_pg; /**< last used page in file */ volatile txnid_t mm_txnid; /**< txnid that committed this page */ } MDB_meta; /** Buffer for a stack-allocated meta page. * The members define size and alignment, and silence type * aliasing warnings. They are not used directly; that could * mean incorrectly using several union members in parallel. */ typedef union MDB_metabuf { MDB_page mb_page; struct { char mm_pad[PAGEHDRSZ]; MDB_meta mm_meta; } mb_metabuf; } MDB_metabuf; /** Auxiliary DB info. * The information here is mostly static/read-only. There is * only a single copy of this record in the environment. */ typedef struct MDB_dbx { MDB_val md_name; /**< name of the database */ MDB_cmp_func *md_cmp; /**< function for comparing keys */ MDB_cmp_func *md_dcmp; /**< function for comparing data items */ MDB_rel_func *md_rel; /**< user relocate function */ void *md_relctx; /**< user-provided context for md_rel */ } MDB_dbx; /** A database transaction. * Every operation requires a transaction handle. */ struct MDB_txn { MDB_txn *mt_parent; /**< parent of a nested txn */ MDB_txn *mt_child; /**< nested txn under this txn */ pgno_t mt_next_pgno; /**< next unallocated page */ /** The ID of this transaction. IDs are integers incrementing from 1. * Only committed write transactions increment the ID. If a transaction * aborts, the ID may be re-used by the next writer. */ txnid_t mt_txnid; MDB_env *mt_env; /**< the DB environment */ /** The list of pages that became unused during this transaction. */ MDB_IDL mt_free_pgs; /** The list of loose pages that became unused and may be reused * in this transaction, linked through #NEXT_LOOSE_PAGE(page). */ MDB_page *mt_loose_pgs; /* #Number of loose pages (#mt_loose_pgs) */ int mt_loose_count; /** The sorted list of dirty pages we temporarily wrote to disk * because the dirty list was full. page numbers in here are * shifted left by 1, deleted slots have the LSB set. */ MDB_IDL mt_spill_pgs; union { /** For write txns: Modified pages. Sorted when not MDB_WRITEMAP. */ MDB_ID2L dirty_list; /** For read txns: This thread/txn's reader table slot, or NULL. */ MDB_reader *reader; } mt_u; /** Array of records for each DB known in the environment. */ MDB_dbx *mt_dbxs; /** Array of MDB_db records for each known DB */ MDB_db *mt_dbs; /** Array of sequence numbers for each DB handle */ unsigned int *mt_dbiseqs; /** @defgroup mt_dbflag Transaction DB Flags * @ingroup internal * @{ */ #define DB_DIRTY 0x01 /**< DB was modified or is DUPSORT data */ #define DB_STALE 0x02 /**< Named-DB record is older than txnID */ #define DB_NEW 0x04 /**< Named-DB handle opened in this txn */ #define DB_VALID 0x08 /**< DB handle is valid, see also #MDB_VALID */ /** @} */ /** In write txns, array of cursors for each DB */ MDB_cursor **mt_cursors; /** Array of flags for each DB */ unsigned char *mt_dbflags; /** Number of DB records in use. This number only ever increments; * we don't decrement it when individual DB handles are closed. */ MDB_dbi mt_numdbs; /** @defgroup mdb_txn Transaction Flags * @ingroup internal * @{ */ #define MDB_TXN_RDONLY 0x01 /**< read-only transaction */ #define MDB_TXN_ERROR 0x02 /**< txn is unusable after an error */ #define MDB_TXN_DIRTY 0x04 /**< must write, even if dirty list is empty */ #define MDB_TXN_SPILLS 0x08 /**< txn or a parent has spilled pages */ /** @} */ unsigned int mt_flags; /**< @ref mdb_txn */ /** #dirty_list room: Array size - \#dirty pages visible to this txn. * Includes ancestor txns' dirty pages not hidden by other txns' * dirty/spilled pages. Thus commit(nested txn) has room to merge * dirty_list into mt_parent after freeing hidden mt_parent pages. */ unsigned int mt_dirty_room; }; /** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty. * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to * raise this on a 64 bit machine. */ #define CURSOR_STACK 32 struct MDB_xcursor; /** Cursors are used for all DB operations. * A cursor holds a path of (page pointer, key index) from the DB * root to a position in the DB, plus other state. #MDB_DUPSORT * cursors include an xcursor to the current data item. Write txns * track their cursors and keep them up to date when data moves. * Exception: An xcursor's pointer to a #P_SUBP page can be stale. * (A node with #F_DUPDATA but no #F_SUBDATA contains a subpage). */ struct MDB_cursor { /** Next cursor on this DB in this txn */ MDB_cursor *mc_next; /** Backup of the original cursor if this cursor is a shadow */ MDB_cursor *mc_backup; /** Context used for databases with #MDB_DUPSORT, otherwise NULL */ struct MDB_xcursor *mc_xcursor; /** The transaction that owns this cursor */ MDB_txn *mc_txn; /** The database handle this cursor operates on */ MDB_dbi mc_dbi; /** The database record for this cursor */ MDB_db *mc_db; /** The database auxiliary record for this cursor */ MDB_dbx *mc_dbx; /** The @ref mt_dbflag for this database */ unsigned char *mc_dbflag; unsigned short mc_snum; /**< number of pushed pages */ unsigned short mc_top; /**< index of top page, normally mc_snum-1 */ /** @defgroup mdb_cursor Cursor Flags * @ingroup internal * Cursor state flags. * @{ */ #define C_INITIALIZED 0x01 /**< cursor has been initialized and is valid */ #define C_EOF 0x02 /**< No more data */ #define C_SUB 0x04 /**< Cursor is a sub-cursor */ #define C_DEL 0x08 /**< last op was a cursor_del */ #define C_SPLITTING 0x20 /**< Cursor is in page_split */ #define C_UNTRACK 0x40 /**< Un-track cursor when closing */ /** @} */ unsigned int mc_flags; /**< @ref mdb_cursor */ MDB_page *mc_pg[CURSOR_STACK]; /**< stack of pushed pages */ indx_t mc_ki[CURSOR_STACK]; /**< stack of page indices */ }; /** Context for sorted-dup records. * We could have gone to a fully recursive design, with arbitrarily * deep nesting of sub-databases. But for now we only handle these * levels - main DB, optional sub-DB, sorted-duplicate DB. */ typedef struct MDB_xcursor { /** A sub-cursor for traversing the Dup DB */ MDB_cursor mx_cursor; /** The database record for this Dup DB */ MDB_db mx_db; /** The auxiliary DB record for this Dup DB */ MDB_dbx mx_dbx; /** The @ref mt_dbflag for this Dup DB */ unsigned char mx_dbflag; } MDB_xcursor; /** State of FreeDB old pages, stored in the MDB_env */ typedef struct MDB_pgstate { pgno_t *mf_pghead; /**< Reclaimed freeDB pages, or NULL before use */ txnid_t mf_pglast; /**< ID of last used record, or 0 if !mf_pghead */ } MDB_pgstate; /** The database environment. */ struct MDB_env { HANDLE me_fd; /**< The main data file */ HANDLE me_lfd; /**< The lock file */ HANDLE me_mfd; /**< just for writing the meta pages */ /** Failed to update the meta page. Probably an I/O error. */ #define MDB_FATAL_ERROR 0x80000000U /** Some fields are initialized. */ #define MDB_ENV_ACTIVE 0x20000000U /** me_txkey is set */ #define MDB_ENV_TXKEY 0x10000000U uint32_t me_flags; /**< @ref mdb_env */ unsigned int me_psize; /**< DB page size, inited from me_os_psize */ unsigned int me_os_psize; /**< OS page size, from #GET_PAGESIZE */ unsigned int me_maxreaders; /**< size of the reader table */ unsigned int me_numreaders; /**< max numreaders set by this env */ MDB_dbi me_numdbs; /**< number of DBs opened */ MDB_dbi me_maxdbs; /**< size of the DB table */ MDB_PID_T me_pid; /**< process ID of this env */ char *me_path; /**< path to the DB files */ char *me_map; /**< the memory map of the data file */ MDB_txninfo *me_txns; /**< the memory map of the lock file or NULL */ MDB_meta *me_metas[2]; /**< pointers to the two meta pages */ void *me_pbuf; /**< scratch area for DUPSORT put() */ MDB_txn *me_txn; /**< current write transaction */ MDB_txn *me_txn0; /**< prealloc'd write transaction */ size_t me_mapsize; /**< size of the data memory map */ off_t me_size; /**< current file size */ pgno_t me_maxpg; /**< me_mapsize / me_psize */ MDB_dbx *me_dbxs; /**< array of static DB info */ uint16_t *me_dbflags; /**< array of flags from MDB_db.md_flags */ unsigned int *me_dbiseqs; /**< array of dbi sequence numbers */ pthread_key_t me_txkey; /**< thread-key for readers */ txnid_t me_pgoldest; /**< ID of oldest reader last time we looked */ MDB_pgstate me_pgstate; /**< state of old pages from freeDB */ # define me_pglast me_pgstate.mf_pglast # define me_pghead me_pgstate.mf_pghead MDB_page *me_dpages; /**< list of malloc'd blocks for re-use */ /** IDL of pages that became unused in a write txn */ MDB_IDL me_free_pgs; /** ID2L of pages written during a write txn. Length MDB_IDL_UM_SIZE. */ MDB_ID2L me_dirty_list; /** Max number of freelist items that can fit in a single overflow page */ int me_maxfree_1pg; /** Max size of a node on a page */ unsigned int me_nodemax; #if !(MDB_MAXKEYSIZE) unsigned int me_maxkey; /**< max size of a key */ #endif int me_live_reader; /**< have liveness lock in reader table */ #ifdef _WIN32 int me_pidquery; /**< Used in OpenProcess */ #endif #ifdef __linux int me_fsynconly; /**< fdatasync is unreliable */ #endif #if defined(_WIN32) || defined(MDB_USE_SYSV_SEM) /* Windows mutexes/SysV semaphores do not reside in shared mem */ mdb_mutex_t me_rmutex; mdb_mutex_t me_wmutex; #endif void *me_userctx; /**< User-settable context */ MDB_assert_func *me_assert_func; /**< Callback for assertion failures */ }; /** Nested transaction */ typedef struct MDB_ntxn { MDB_txn mnt_txn; /**< the transaction */ MDB_pgstate mnt_pgstate; /**< parent transaction's saved freestate */ } MDB_ntxn; /** max number of pages to commit in one writev() call */ #define MDB_COMMIT_PAGES 64 #if defined(IOV_MAX) && IOV_MAX < MDB_COMMIT_PAGES #undef MDB_COMMIT_PAGES #define MDB_COMMIT_PAGES IOV_MAX #endif /** max bytes to write in one call */ #define MAX_WRITE (0x80000000U >> (sizeof(ssize_t) == 4)) /** Check \b txn and \b dbi arguments to a function */ #define TXN_DBI_EXIST(txn, dbi) \ ((txn) && (dbi) < (txn)->mt_numdbs && ((txn)->mt_dbflags[dbi] & DB_VALID)) /** Check for misused \b dbi handles */ #define TXN_DBI_CHANGED(txn, dbi) \ ((txn)->mt_dbiseqs[dbi] != (txn)->mt_env->me_dbiseqs[dbi]) static int mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp); static int mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp); static int mdb_page_touch(MDB_cursor *mc); static int mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **mp, int *lvl); static int mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int modify); #define MDB_PS_MODIFY 1 #define MDB_PS_ROOTONLY 2 #define MDB_PS_FIRST 4 #define MDB_PS_LAST 8 static int mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags); static int mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst); #define MDB_SPLIT_REPLACE MDB_APPENDDUP /**< newkey is not new */ static int mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno, unsigned int nflags); static int mdb_env_read_header(MDB_env *env, MDB_meta *meta); static int mdb_env_pick_meta(const MDB_env *env); static int mdb_env_write_meta(MDB_txn *txn); #if !(defined(_WIN32) || defined(MDB_USE_SYSV_SEM)) /* Drop unused excl arg */ # define mdb_env_close0(env, excl) mdb_env_close1(env) #endif static void mdb_env_close0(MDB_env *env, int excl); static MDB_node *mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp); static int mdb_node_add(MDB_cursor *mc, indx_t indx, MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags); static void mdb_node_del(MDB_cursor *mc, int ksize); static void mdb_node_shrink(MDB_page *mp, indx_t indx); static int mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst); static int mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data); static size_t mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data); static size_t mdb_branch_size(MDB_env *env, MDB_val *key); static int mdb_rebalance(MDB_cursor *mc); static int mdb_update_key(MDB_cursor *mc, MDB_val *key); static void mdb_cursor_pop(MDB_cursor *mc); static int mdb_cursor_push(MDB_cursor *mc, MDB_page *mp); static int mdb_cursor_del0(MDB_cursor *mc); static int mdb_del0(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned flags); static int mdb_cursor_sibling(MDB_cursor *mc, int move_right); static int mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op); static int mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op); static int mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op, int *exactp); static int mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data); static int mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data); static void mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx); static void mdb_xcursor_init0(MDB_cursor *mc); static void mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node); static int mdb_drop0(MDB_cursor *mc, int subs); static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi); static int mdb_reader_check0(MDB_env *env, int rlocked, int *dead); /** @cond */ static MDB_cmp_func mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long; /** @endcond */ #ifdef _WIN32 static SECURITY_DESCRIPTOR mdb_null_sd; static SECURITY_ATTRIBUTES mdb_all_sa; static int mdb_sec_inited; #endif /** Return the library version info. */ char * mdb_version(int *major, int *minor, int *patch) { if (major) *major = MDB_VERSION_MAJOR; if (minor) *minor = MDB_VERSION_MINOR; if (patch) *patch = MDB_VERSION_PATCH; return MDB_VERSION_STRING; } /** Table of descriptions for LMDB @ref errors */ static char *const mdb_errstr[] = { "MDB_KEYEXIST: Key/data pair already exists", "MDB_NOTFOUND: No matching key/data pair found", "MDB_PAGE_NOTFOUND: Requested page not found", "MDB_CORRUPTED: Located page was wrong type", "MDB_PANIC: Update of meta page failed or environment had fatal error", "MDB_VERSION_MISMATCH: Database environment version mismatch", "MDB_INVALID: File is not an LMDB file", "MDB_MAP_FULL: Environment mapsize limit reached", "MDB_DBS_FULL: Environment maxdbs limit reached", "MDB_READERS_FULL: Environment maxreaders limit reached", "MDB_TLS_FULL: Thread-local storage keys full - too many environments open", "MDB_TXN_FULL: Transaction has too many dirty pages - transaction too big", "MDB_CURSOR_FULL: Internal error - cursor stack limit reached", "MDB_PAGE_FULL: Internal error - page has no more space", "MDB_MAP_RESIZED: Database contents grew beyond environment mapsize", "MDB_INCOMPATIBLE: Operation and DB incompatible, or DB flags changed", "MDB_BAD_RSLOT: Invalid reuse of reader locktable slot", "MDB_BAD_TXN: Transaction cannot recover - it must be aborted", "MDB_BAD_VALSIZE: Unsupported size of key/DB name/data, or wrong DUPFIXED size", "MDB_BAD_DBI: The specified DBI handle was closed/changed unexpectedly", }; char * mdb_strerror(int err) { #ifdef _WIN32 /** HACK: pad 4KB on stack over the buf. Return system msgs in buf. * This works as long as no function between the call to mdb_strerror * and the actual use of the message uses more than 4K of stack. */ char pad[4096]; char buf[1024], *ptr = buf; #endif int i; if (!err) return ("Successful return: 0"); if (err >= MDB_KEYEXIST && err <= MDB_LAST_ERRCODE) { i = err - MDB_KEYEXIST; return mdb_errstr[i]; } #ifdef _WIN32 /* These are the C-runtime error codes we use. The comment indicates * their numeric value, and the Win32 error they would correspond to * if the error actually came from a Win32 API. A major mess, we should * have used LMDB-specific error codes for everything. */ switch(err) { case ENOENT: /* 2, FILE_NOT_FOUND */ case EIO: /* 5, ACCESS_DENIED */ case ENOMEM: /* 12, INVALID_ACCESS */ case EACCES: /* 13, INVALID_DATA */ case EBUSY: /* 16, CURRENT_DIRECTORY */ case EINVAL: /* 22, BAD_COMMAND */ case ENOSPC: /* 28, OUT_OF_PAPER */ return strerror(err); default: ; } buf[0] = 0; FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, err, 0, ptr, sizeof(buf), (va_list *)pad); return ptr; #else return strerror(err); #endif } /** assert(3) variant in cursor context */ #define mdb_cassert(mc, expr) mdb_assert0((mc)->mc_txn->mt_env, expr, #expr) /** assert(3) variant in transaction context */ #define mdb_tassert(mc, expr) mdb_assert0((txn)->mt_env, expr, #expr) /** assert(3) variant in environment context */ #define mdb_eassert(env, expr) mdb_assert0(env, expr, #expr) #ifndef NDEBUG # define mdb_assert0(env, expr, expr_txt) ((expr) ? (void)0 : \ mdb_assert_fail(env, expr_txt, mdb_func_, __FILE__, __LINE__)) static void mdb_assert_fail(MDB_env *env, const char *expr_txt, const char *func, const char *file, int line) { char buf[400]; sprintf(buf, "%.100s:%d: Assertion '%.200s' failed in %.40s()", file, line, expr_txt, func); if (env->me_assert_func) env->me_assert_func(env, buf); fprintf(stderr, "%s\n", buf); abort(); } #else # define mdb_assert0(env, expr, expr_txt) ((void) 0) #endif /* NDEBUG */ #if MDB_DEBUG /** Return the page number of \b mp which may be sub-page, for debug output */ static pgno_t mdb_dbg_pgno(MDB_page *mp) { pgno_t ret; COPY_PGNO(ret, mp->mp_pgno); return ret; } /** Display a key in hexadecimal and return the address of the result. * @param[in] key the key to display * @param[in] buf the buffer to write into. Should always be #DKBUF. * @return The key in hexadecimal form. */ char * mdb_dkey(MDB_val *key, char *buf) { char *ptr = buf; unsigned char *c = key->mv_data; unsigned int i; if (!key) return ""; if (key->mv_size > DKBUF_MAXKEYSIZE) return "MDB_MAXKEYSIZE"; /* may want to make this a dynamic check: if the key is mostly * printable characters, print it as-is instead of converting to hex. */ #if 1 buf[0] = '\0'; for (i=0; imv_size; i++) ptr += sprintf(ptr, "%02x", *c++); #else sprintf(buf, "%.*s", key->mv_size, key->mv_data); #endif return buf; } static const char * mdb_leafnode_type(MDB_node *n) { static char *const tp[2][2] = {{"", ": DB"}, {": sub-page", ": sub-DB"}}; return F_ISSET(n->mn_flags, F_BIGDATA) ? ": overflow page" : tp[F_ISSET(n->mn_flags, F_DUPDATA)][F_ISSET(n->mn_flags, F_SUBDATA)]; } /** Display all the keys in the page. */ void mdb_page_list(MDB_page *mp) { pgno_t pgno = mdb_dbg_pgno(mp); const char *type, *state = (mp->mp_flags & P_DIRTY) ? ", dirty" : ""; MDB_node *node; unsigned int i, nkeys, nsize, total = 0; MDB_val key; DKBUF; switch (mp->mp_flags & (P_BRANCH|P_LEAF|P_LEAF2|P_META|P_OVERFLOW|P_SUBP)) { case P_BRANCH: type = "Branch page"; break; case P_LEAF: type = "Leaf page"; break; case P_LEAF|P_SUBP: type = "Sub-page"; break; case P_LEAF|P_LEAF2: type = "LEAF2 page"; break; case P_LEAF|P_LEAF2|P_SUBP: type = "LEAF2 sub-page"; break; case P_OVERFLOW: fprintf(stderr, "Overflow page %"Z"u pages %u%s\n", pgno, mp->mp_pages, state); return; case P_META: fprintf(stderr, "Meta-page %"Z"u txnid %"Z"u\n", pgno, ((MDB_meta *)METADATA(mp))->mm_txnid); return; default: fprintf(stderr, "Bad page %"Z"u flags 0x%u\n", pgno, mp->mp_flags); return; } nkeys = NUMKEYS(mp); fprintf(stderr, "%s %"Z"u numkeys %d%s\n", type, pgno, nkeys, state); for (i=0; imp_pad; key.mv_data = LEAF2KEY(mp, i, nsize); total += nsize; fprintf(stderr, "key %d: nsize %d, %s\n", i, nsize, DKEY(&key)); continue; } node = NODEPTR(mp, i); key.mv_size = node->mn_ksize; key.mv_data = node->mn_data; nsize = NODESIZE + key.mv_size; if (IS_BRANCH(mp)) { fprintf(stderr, "key %d: page %"Z"u, %s\n", i, NODEPGNO(node), DKEY(&key)); total += nsize; } else { if (F_ISSET(node->mn_flags, F_BIGDATA)) nsize += sizeof(pgno_t); else nsize += NODEDSZ(node); total += nsize; nsize += sizeof(indx_t); fprintf(stderr, "key %d: nsize %d, %s%s\n", i, nsize, DKEY(&key), mdb_leafnode_type(node)); } total = EVEN(total); } fprintf(stderr, "Total: header %d + contents %d + unused %d\n", IS_LEAF2(mp) ? PAGEHDRSZ : PAGEBASE + mp->mp_lower, total, SIZELEFT(mp)); } void mdb_cursor_chk(MDB_cursor *mc) { unsigned int i; MDB_node *node; MDB_page *mp; if (!mc->mc_snum && !(mc->mc_flags & C_INITIALIZED)) return; for (i=0; imc_top; i++) { mp = mc->mc_pg[i]; node = NODEPTR(mp, mc->mc_ki[i]); if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno) printf("oops!\n"); } if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i])) printf("ack!\n"); } #endif #if (MDB_DEBUG) > 2 /** Count all the pages in each DB and in the freelist * and make sure it matches the actual number of pages * being used. * All named DBs must be open for a correct count. */ static void mdb_audit(MDB_txn *txn) { MDB_cursor mc; MDB_val key, data; MDB_ID freecount, count; MDB_dbi i; int rc; freecount = 0; mdb_cursor_init(&mc, txn, FREE_DBI, NULL); while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0) freecount += *(MDB_ID *)data.mv_data; mdb_tassert(txn, rc == MDB_NOTFOUND); count = 0; for (i = 0; imt_numdbs; i++) { MDB_xcursor mx; if (!(txn->mt_dbflags[i] & DB_VALID)) continue; mdb_cursor_init(&mc, txn, i, &mx); if (txn->mt_dbs[i].md_root == P_INVALID) continue; count += txn->mt_dbs[i].md_branch_pages + txn->mt_dbs[i].md_leaf_pages + txn->mt_dbs[i].md_overflow_pages; if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) { rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST); for (; rc == MDB_SUCCESS; rc = mdb_cursor_sibling(&mc, 1)) { unsigned j; MDB_page *mp; mp = mc.mc_pg[mc.mc_top]; for (j=0; jmn_flags & F_SUBDATA) { MDB_db db; memcpy(&db, NODEDATA(leaf), sizeof(db)); count += db.md_branch_pages + db.md_leaf_pages + db.md_overflow_pages; } } } mdb_tassert(txn, rc == MDB_NOTFOUND); } } if (freecount + count + 2 /* metapages */ != txn->mt_next_pgno) { fprintf(stderr, "audit: %lu freecount: %lu count: %lu total: %lu next_pgno: %lu\n", txn->mt_txnid, freecount, count+2, freecount+count+2, txn->mt_next_pgno); } } #endif int mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b) { return txn->mt_dbxs[dbi].md_cmp(a, b); } int mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b) { return txn->mt_dbxs[dbi].md_dcmp(a, b); } /** Allocate memory for a page. * Re-use old malloc'd pages first for singletons, otherwise just malloc. */ static MDB_page * mdb_page_malloc(MDB_txn *txn, unsigned num) { MDB_env *env = txn->mt_env; MDB_page *ret = env->me_dpages; size_t psize = env->me_psize, sz = psize, off; /* For ! #MDB_NOMEMINIT, psize counts how much to init. * For a single page alloc, we init everything after the page header. * For multi-page, we init the final page; if the caller needed that * many pages they will be filling in at least up to the last page. */ if (num == 1) { if (ret) { VGMEMP_ALLOC(env, ret, sz); VGMEMP_DEFINED(ret, sizeof(ret->mp_next)); env->me_dpages = ret->mp_next; return ret; } psize -= off = PAGEHDRSZ; } else { sz *= num; off = sz - psize; } if ((ret = malloc(sz)) != NULL) { VGMEMP_ALLOC(env, ret, sz); if (!(env->me_flags & MDB_NOMEMINIT)) { memset((char *)ret + off, 0, psize); ret->mp_pad = 0; } } else { txn->mt_flags |= MDB_TXN_ERROR; } return ret; } /** Free a single page. * Saves single pages to a list, for future reuse. * (This is not used for multi-page overflow pages.) */ static void mdb_page_free(MDB_env *env, MDB_page *mp) { mp->mp_next = env->me_dpages; VGMEMP_FREE(env, mp); env->me_dpages = mp; } /** Free a dirty page */ static void mdb_dpage_free(MDB_env *env, MDB_page *dp) { if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) { mdb_page_free(env, dp); } else { /* large pages just get freed directly */ VGMEMP_FREE(env, dp); free(dp); } } /** Return all dirty pages to dpage list */ static void mdb_dlist_free(MDB_txn *txn) { MDB_env *env = txn->mt_env; MDB_ID2L dl = txn->mt_u.dirty_list; unsigned i, n = dl[0].mid; for (i = 1; i <= n; i++) { mdb_dpage_free(env, dl[i].mptr); } dl[0].mid = 0; } /** Loosen or free a single page. * Saves single pages to a list for future reuse * in this same txn. It has been pulled from the freeDB * and already resides on the dirty list, but has been * deleted. Use these pages first before pulling again * from the freeDB. * * If the page wasn't dirtied in this txn, just add it * to this txn's free list. */ static int mdb_page_loose(MDB_cursor *mc, MDB_page *mp) { int loose = 0; pgno_t pgno = mp->mp_pgno; MDB_txn *txn = mc->mc_txn; if ((mp->mp_flags & P_DIRTY) && mc->mc_dbi != FREE_DBI) { if (txn->mt_parent) { MDB_ID2 *dl = txn->mt_u.dirty_list; /* If txn has a parent, make sure the page is in our * dirty list. */ if (dl[0].mid) { unsigned x = mdb_mid2l_search(dl, pgno); if (x <= dl[0].mid && dl[x].mid == pgno) { if (mp != dl[x].mptr) { /* bad cursor? */ mc->mc_flags &= ~(C_INITIALIZED|C_EOF); txn->mt_flags |= MDB_TXN_ERROR; return MDB_CORRUPTED; } /* ok, it's ours */ loose = 1; } } } else { /* no parent txn, so it's just ours */ loose = 1; } } if (loose) { DPRINTF(("loosen db %d page %"Z"u", DDBI(mc), mp->mp_pgno)); NEXT_LOOSE_PAGE(mp) = txn->mt_loose_pgs; txn->mt_loose_pgs = mp; txn->mt_loose_count++; mp->mp_flags |= P_LOOSE; } else { int rc = mdb_midl_append(&txn->mt_free_pgs, pgno); if (rc) return rc; } return MDB_SUCCESS; } /** Set or clear P_KEEP in dirty, non-overflow, non-sub pages watched by txn. * @param[in] mc A cursor handle for the current operation. * @param[in] pflags Flags of the pages to update: * P_DIRTY to set P_KEEP, P_DIRTY|P_KEEP to clear it. * @param[in] all No shortcuts. Needed except after a full #mdb_page_flush(). * @return 0 on success, non-zero on failure. */ static int mdb_pages_xkeep(MDB_cursor *mc, unsigned pflags, int all) { enum { Mask = P_SUBP|P_DIRTY|P_LOOSE|P_KEEP }; MDB_txn *txn = mc->mc_txn; MDB_cursor *m3; MDB_xcursor *mx; MDB_page *dp, *mp; MDB_node *leaf; unsigned i, j; int rc = MDB_SUCCESS, level; /* Mark pages seen by cursors */ if (mc->mc_flags & C_UNTRACK) mc = NULL; /* will find mc in mt_cursors */ for (i = txn->mt_numdbs;; mc = txn->mt_cursors[--i]) { for (; mc; mc=mc->mc_next) { if (!(mc->mc_flags & C_INITIALIZED)) continue; for (m3 = mc;; m3 = &mx->mx_cursor) { mp = NULL; for (j=0; jmc_snum; j++) { mp = m3->mc_pg[j]; if ((mp->mp_flags & Mask) == pflags) mp->mp_flags ^= P_KEEP; } mx = m3->mc_xcursor; /* Proceed to mx if it is at a sub-database */ if (! (mx && (mx->mx_cursor.mc_flags & C_INITIALIZED))) break; if (! (mp && (mp->mp_flags & P_LEAF))) break; leaf = NODEPTR(mp, m3->mc_ki[j-1]); if (!(leaf->mn_flags & F_SUBDATA)) break; } } if (i == 0) break; } if (all) { /* Mark dirty root pages */ for (i=0; imt_numdbs; i++) { if (txn->mt_dbflags[i] & DB_DIRTY) { pgno_t pgno = txn->mt_dbs[i].md_root; if (pgno == P_INVALID) continue; if ((rc = mdb_page_get(txn, pgno, &dp, &level)) != MDB_SUCCESS) break; if ((dp->mp_flags & Mask) == pflags && level <= 1) dp->mp_flags ^= P_KEEP; } } } return rc; } static int mdb_page_flush(MDB_txn *txn, int keep); /** Spill pages from the dirty list back to disk. * This is intended to prevent running into #MDB_TXN_FULL situations, * but note that they may still occur in a few cases: * 1) our estimate of the txn size could be too small. Currently this * seems unlikely, except with a large number of #MDB_MULTIPLE items. * 2) child txns may run out of space if their parents dirtied a * lot of pages and never spilled them. TODO: we probably should do * a preemptive spill during #mdb_txn_begin() of a child txn, if * the parent's dirty_room is below a given threshold. * * Otherwise, if not using nested txns, it is expected that apps will * not run into #MDB_TXN_FULL any more. The pages are flushed to disk * the same way as for a txn commit, e.g. their P_DIRTY flag is cleared. * If the txn never references them again, they can be left alone. * If the txn only reads them, they can be used without any fuss. * If the txn writes them again, they can be dirtied immediately without * going thru all of the work of #mdb_page_touch(). Such references are * handled by #mdb_page_unspill(). * * Also note, we never spill DB root pages, nor pages of active cursors, * because we'll need these back again soon anyway. And in nested txns, * we can't spill a page in a child txn if it was already spilled in a * parent txn. That would alter the parent txns' data even though * the child hasn't committed yet, and we'd have no way to undo it if * the child aborted. * * @param[in] m0 cursor A cursor handle identifying the transaction and * database for which we are checking space. * @param[in] key For a put operation, the key being stored. * @param[in] data For a put operation, the data being stored. * @return 0 on success, non-zero on failure. */ static int mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data) { MDB_txn *txn = m0->mc_txn; MDB_page *dp; MDB_ID2L dl = txn->mt_u.dirty_list; unsigned int i, j, need; int rc; if (m0->mc_flags & C_SUB) return MDB_SUCCESS; /* Estimate how much space this op will take */ i = m0->mc_db->md_depth; /* Named DBs also dirty the main DB */ if (m0->mc_dbi > MAIN_DBI) i += txn->mt_dbs[MAIN_DBI].md_depth; /* For puts, roughly factor in the key+data size */ if (key) i += (LEAFSIZE(key, data) + txn->mt_env->me_psize) / txn->mt_env->me_psize; i += i; /* double it for good measure */ need = i; if (txn->mt_dirty_room > i) return MDB_SUCCESS; if (!txn->mt_spill_pgs) { txn->mt_spill_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX); if (!txn->mt_spill_pgs) return ENOMEM; } else { /* purge deleted slots */ MDB_IDL sl = txn->mt_spill_pgs; unsigned int num = sl[0]; j=0; for (i=1; i<=num; i++) { if (!(sl[i] & 1)) sl[++j] = sl[i]; } sl[0] = j; } /* Preserve pages which may soon be dirtied again */ if ((rc = mdb_pages_xkeep(m0, P_DIRTY, 1)) != MDB_SUCCESS) goto done; /* Less aggressive spill - we originally spilled the entire dirty list, * with a few exceptions for cursor pages and DB root pages. But this * turns out to be a lot of wasted effort because in a large txn many * of those pages will need to be used again. So now we spill only 1/8th * of the dirty pages. Testing revealed this to be a good tradeoff, * better than 1/2, 1/4, or 1/10. */ if (need < MDB_IDL_UM_MAX / 8) need = MDB_IDL_UM_MAX / 8; /* Save the page IDs of all the pages we're flushing */ /* flush from the tail forward, this saves a lot of shifting later on. */ for (i=dl[0].mid; i && need; i--) { MDB_ID pn = dl[i].mid << 1; dp = dl[i].mptr; if (dp->mp_flags & (P_LOOSE|P_KEEP)) continue; /* Can't spill twice, make sure it's not already in a parent's * spill list. */ if (txn->mt_parent) { MDB_txn *tx2; for (tx2 = txn->mt_parent; tx2; tx2 = tx2->mt_parent) { if (tx2->mt_spill_pgs) { j = mdb_midl_search(tx2->mt_spill_pgs, pn); if (j <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[j] == pn) { dp->mp_flags |= P_KEEP; break; } } } if (tx2) continue; } if ((rc = mdb_midl_append(&txn->mt_spill_pgs, pn))) goto done; need--; } mdb_midl_sort(txn->mt_spill_pgs); /* Flush the spilled part of dirty list */ if ((rc = mdb_page_flush(txn, i)) != MDB_SUCCESS) goto done; /* Reset any dirty pages we kept that page_flush didn't see */ rc = mdb_pages_xkeep(m0, P_DIRTY|P_KEEP, i); done: txn->mt_flags |= rc ? MDB_TXN_ERROR : MDB_TXN_SPILLS; return rc; } /** Find oldest txnid still referenced. Expects txn->mt_txnid > 0. */ static txnid_t mdb_find_oldest(MDB_txn *txn) { int i; txnid_t mr, oldest = txn->mt_txnid - 1; if (txn->mt_env->me_txns) { MDB_reader *r = txn->mt_env->me_txns->mti_readers; for (i = txn->mt_env->me_txns->mti_numreaders; --i >= 0; ) { if (r[i].mr_pid) { mr = r[i].mr_txnid; if (oldest > mr) oldest = mr; } } } return oldest; } /** Add a page to the txn's dirty list */ static void mdb_page_dirty(MDB_txn *txn, MDB_page *mp) { MDB_ID2 mid; int rc, (*insert)(MDB_ID2L, MDB_ID2 *); if (txn->mt_env->me_flags & MDB_WRITEMAP) { insert = mdb_mid2l_append; } else { insert = mdb_mid2l_insert; } mid.mid = mp->mp_pgno; mid.mptr = mp; rc = insert(txn->mt_u.dirty_list, &mid); mdb_tassert(txn, rc == 0); txn->mt_dirty_room--; } /** Allocate page numbers and memory for writing. Maintain me_pglast, * me_pghead and mt_next_pgno. * * If there are free pages available from older transactions, they * are re-used first. Otherwise allocate a new page at mt_next_pgno. * Do not modify the freedB, just merge freeDB records into me_pghead[] * and move me_pglast to say which records were consumed. Only this * function can create me_pghead and move me_pglast/mt_next_pgno. * @param[in] mc cursor A cursor handle identifying the transaction and * database for which we are allocating. * @param[in] num the number of pages to allocate. * @param[out] mp Address of the allocated page(s). Requests for multiple pages * will always be satisfied by a single contiguous chunk of memory. * @return 0 on success, non-zero on failure. */ static int mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp) { #ifdef MDB_PARANOID /* Seems like we can ignore this now */ /* Get at most more freeDB records once me_pghead * has enough pages. If not enough, use new pages from the map. * If and mc is updating the freeDB, only get new * records if me_pghead is empty. Then the freelist cannot play * catch-up with itself by growing while trying to save it. */ enum { Paranoid = 1, Max_retries = 500 }; #else enum { Paranoid = 0, Max_retries = INT_MAX /*infinite*/ }; #endif int rc, retry = num * 60; MDB_txn *txn = mc->mc_txn; MDB_env *env = txn->mt_env; pgno_t pgno, *mop = env->me_pghead; unsigned i, j, mop_len = mop ? mop[0] : 0, n2 = num-1; MDB_page *np; txnid_t oldest = 0, last; MDB_cursor_op op; MDB_cursor m2; int found_old = 0; /* If there are any loose pages, just use them */ if (num == 1 && txn->mt_loose_pgs) { np = txn->mt_loose_pgs; txn->mt_loose_pgs = NEXT_LOOSE_PAGE(np); txn->mt_loose_count--; DPRINTF(("db %d use loose page %"Z"u", DDBI(mc), np->mp_pgno)); *mp = np; return MDB_SUCCESS; } *mp = NULL; /* If our dirty list is already full, we can't do anything */ if (txn->mt_dirty_room == 0) { rc = MDB_TXN_FULL; goto fail; } for (op = MDB_FIRST;; op = MDB_NEXT) { MDB_val key, data; MDB_node *leaf; pgno_t *idl; /* Seek a big enough contiguous page range. Prefer * pages at the tail, just truncating the list. */ if (mop_len > n2) { i = mop_len; do { pgno = mop[i]; if (mop[i-n2] == pgno+n2) goto search_done; } while (--i > n2); if (--retry < 0) break; } if (op == MDB_FIRST) { /* 1st iteration */ /* Prepare to fetch more and coalesce */ last = env->me_pglast; oldest = env->me_pgoldest; mdb_cursor_init(&m2, txn, FREE_DBI, NULL); if (last) { op = MDB_SET_RANGE; key.mv_data = &last; /* will look up last+1 */ key.mv_size = sizeof(last); } if (Paranoid && mc->mc_dbi == FREE_DBI) retry = -1; } if (Paranoid && retry < 0 && mop_len) break; last++; /* Do not fetch more if the record will be too recent */ if (oldest <= last) { if (!found_old) { oldest = mdb_find_oldest(txn); env->me_pgoldest = oldest; found_old = 1; } if (oldest <= last) break; } rc = mdb_cursor_get(&m2, &key, NULL, op); if (rc) { if (rc == MDB_NOTFOUND) break; goto fail; } last = *(txnid_t*)key.mv_data; if (oldest <= last) { if (!found_old) { oldest = mdb_find_oldest(txn); env->me_pgoldest = oldest; found_old = 1; } if (oldest <= last) break; } np = m2.mc_pg[m2.mc_top]; leaf = NODEPTR(np, m2.mc_ki[m2.mc_top]); if ((rc = mdb_node_read(txn, leaf, &data)) != MDB_SUCCESS) return rc; idl = (MDB_ID *) data.mv_data; i = idl[0]; if (!mop) { if (!(env->me_pghead = mop = mdb_midl_alloc(i))) { rc = ENOMEM; goto fail; } } else { if ((rc = mdb_midl_need(&env->me_pghead, i)) != 0) goto fail; mop = env->me_pghead; } env->me_pglast = last; #if (MDB_DEBUG) > 1 DPRINTF(("IDL read txn %"Z"u root %"Z"u num %u", last, txn->mt_dbs[FREE_DBI].md_root, i)); for (j = i; j; j--) DPRINTF(("IDL %"Z"u", idl[j])); #endif /* Merge in descending sorted order */ mdb_midl_xmerge(mop, idl); mop_len = mop[0]; } /* Use new pages from the map when nothing suitable in the freeDB */ i = 0; pgno = txn->mt_next_pgno; if (pgno + num >= env->me_maxpg) { DPUTS("DB size maxed out"); rc = MDB_MAP_FULL; goto fail; } search_done: if (env->me_flags & MDB_WRITEMAP) { np = (MDB_page *)(env->me_map + env->me_psize * pgno); } else { if (!(np = mdb_page_malloc(txn, num))) { rc = ENOMEM; goto fail; } } if (i) { mop[0] = mop_len -= num; /* Move any stragglers down */ for (j = i-num; j < mop_len; ) mop[++j] = mop[++i]; } else { txn->mt_next_pgno = pgno + num; } np->mp_pgno = pgno; mdb_page_dirty(txn, np); *mp = np; return MDB_SUCCESS; fail: txn->mt_flags |= MDB_TXN_ERROR; return rc; } /** Copy the used portions of a non-overflow page. * @param[in] dst page to copy into * @param[in] src page to copy from * @param[in] psize size of a page */ static void mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize) { enum { Align = sizeof(pgno_t) }; indx_t upper = src->mp_upper, lower = src->mp_lower, unused = upper-lower; /* If page isn't full, just copy the used portion. Adjust * alignment so memcpy may copy words instead of bytes. */ if ((unused &= -Align) && !IS_LEAF2(src)) { upper = (upper + PAGEBASE) & -Align; memcpy(dst, src, (lower + PAGEBASE + (Align-1)) & -Align); memcpy((pgno_t *)((char *)dst+upper), (pgno_t *)((char *)src+upper), psize - upper); } else { memcpy(dst, src, psize - unused); } } /** Pull a page off the txn's spill list, if present. * If a page being referenced was spilled to disk in this txn, bring * it back and make it dirty/writable again. * @param[in] txn the transaction handle. * @param[in] mp the page being referenced. It must not be dirty. * @param[out] ret the writable page, if any. ret is unchanged if * mp wasn't spilled. */ static int mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret) { MDB_env *env = txn->mt_env; const MDB_txn *tx2; unsigned x; pgno_t pgno = mp->mp_pgno, pn = pgno << 1; for (tx2 = txn; tx2; tx2=tx2->mt_parent) { if (!tx2->mt_spill_pgs) continue; x = mdb_midl_search(tx2->mt_spill_pgs, pn); if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) { MDB_page *np; int num; if (txn->mt_dirty_room == 0) return MDB_TXN_FULL; if (IS_OVERFLOW(mp)) num = mp->mp_pages; else num = 1; if (env->me_flags & MDB_WRITEMAP) { np = mp; } else { np = mdb_page_malloc(txn, num); if (!np) return ENOMEM; if (num > 1) memcpy(np, mp, num * env->me_psize); else mdb_page_copy(np, mp, env->me_psize); } if (tx2 == txn) { /* If in current txn, this page is no longer spilled. * If it happens to be the last page, truncate the spill list. * Otherwise mark it as deleted by setting the LSB. */ if (x == txn->mt_spill_pgs[0]) txn->mt_spill_pgs[0]--; else txn->mt_spill_pgs[x] |= 1; } /* otherwise, if belonging to a parent txn, the * page remains spilled until child commits */ mdb_page_dirty(txn, np); np->mp_flags |= P_DIRTY; *ret = np; break; } } return MDB_SUCCESS; } /** Touch a page: make it dirty and re-insert into tree with updated pgno. * @param[in] mc cursor pointing to the page to be touched * @return 0 on success, non-zero on failure. */ static int mdb_page_touch(MDB_cursor *mc) { MDB_page *mp = mc->mc_pg[mc->mc_top], *np; MDB_txn *txn = mc->mc_txn; MDB_cursor *m2, *m3; pgno_t pgno; int rc; if (!F_ISSET(mp->mp_flags, P_DIRTY)) { if (txn->mt_flags & MDB_TXN_SPILLS) { np = NULL; rc = mdb_page_unspill(txn, mp, &np); if (rc) goto fail; if (np) goto done; } if ((rc = mdb_midl_need(&txn->mt_free_pgs, 1)) || (rc = mdb_page_alloc(mc, 1, &np))) goto fail; pgno = np->mp_pgno; DPRINTF(("touched db %d page %"Z"u -> %"Z"u", DDBI(mc), mp->mp_pgno, pgno)); mdb_cassert(mc, mp->mp_pgno != pgno); mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno); /* Update the parent page, if any, to point to the new page */ if (mc->mc_top) { MDB_page *parent = mc->mc_pg[mc->mc_top-1]; MDB_node *node = NODEPTR(parent, mc->mc_ki[mc->mc_top-1]); SETPGNO(node, pgno); } else { mc->mc_db->md_root = pgno; } } else if (txn->mt_parent && !IS_SUBP(mp)) { MDB_ID2 mid, *dl = txn->mt_u.dirty_list; pgno = mp->mp_pgno; /* If txn has a parent, make sure the page is in our * dirty list. */ if (dl[0].mid) { unsigned x = mdb_mid2l_search(dl, pgno); if (x <= dl[0].mid && dl[x].mid == pgno) { if (mp != dl[x].mptr) { /* bad cursor? */ mc->mc_flags &= ~(C_INITIALIZED|C_EOF); txn->mt_flags |= MDB_TXN_ERROR; return MDB_CORRUPTED; } return 0; } } mdb_cassert(mc, dl[0].mid < MDB_IDL_UM_MAX); /* No - copy it */ np = mdb_page_malloc(txn, 1); if (!np) return ENOMEM; mid.mid = pgno; mid.mptr = np; rc = mdb_mid2l_insert(dl, &mid); mdb_cassert(mc, rc == 0); } else { return 0; } mdb_page_copy(np, mp, txn->mt_env->me_psize); np->mp_pgno = pgno; np->mp_flags |= P_DIRTY; done: /* Adjust cursors pointing to mp */ mc->mc_pg[mc->mc_top] = np; m2 = txn->mt_cursors[mc->mc_dbi]; if (mc->mc_flags & C_SUB) { for (; m2; m2=m2->mc_next) { m3 = &m2->mc_xcursor->mx_cursor; if (m3->mc_snum < mc->mc_snum) continue; if (m3->mc_pg[mc->mc_top] == mp) m3->mc_pg[mc->mc_top] = np; } } else { for (; m2; m2=m2->mc_next) { if (m2->mc_snum < mc->mc_snum) continue; if (m2->mc_pg[mc->mc_top] == mp) { m2->mc_pg[mc->mc_top] = np; if ((mc->mc_db->md_flags & MDB_DUPSORT) && IS_LEAF(np) && m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top]) { MDB_node *leaf = NODEPTR(np, mc->mc_ki[mc->mc_top]); if (!(leaf->mn_flags & F_SUBDATA)) m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf); } } } } return 0; fail: txn->mt_flags |= MDB_TXN_ERROR; return rc; } int mdb_env_sync(MDB_env *env, int force) { int rc = 0; if (env->me_flags & MDB_RDONLY) return EACCES; if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) { if (env->me_flags & MDB_WRITEMAP) { int flags = ((env->me_flags & MDB_MAPASYNC) && !force) ? MS_ASYNC : MS_SYNC; if (MDB_MSYNC(env->me_map, env->me_mapsize, flags)) rc = ErrCode(); #ifdef _WIN32 else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd)) rc = ErrCode(); #endif } else { #ifdef __linux if (env->me_fsynconly) { if (fsync(env->me_fd)) rc = ErrCode(); } else #endif if (MDB_FDATASYNC(env->me_fd)) rc = ErrCode(); } } return rc; } /** Back up parent txn's cursors, then grab the originals for tracking */ static int mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst) { MDB_cursor *mc, *bk; MDB_xcursor *mx; size_t size; int i; for (i = src->mt_numdbs; --i >= 0; ) { if ((mc = src->mt_cursors[i]) != NULL) { size = sizeof(MDB_cursor); if (mc->mc_xcursor) size += sizeof(MDB_xcursor); for (; mc; mc = bk->mc_next) { bk = malloc(size); if (!bk) return ENOMEM; *bk = *mc; mc->mc_backup = bk; mc->mc_db = &dst->mt_dbs[i]; /* Kill pointers into src - and dst to reduce abuse: The * user may not use mc until dst ends. Otherwise we'd... */ mc->mc_txn = NULL; /* ...set this to dst */ mc->mc_dbflag = NULL; /* ...and &dst->mt_dbflags[i] */ if ((mx = mc->mc_xcursor) != NULL) { *(MDB_xcursor *)(bk+1) = *mx; mx->mx_cursor.mc_txn = NULL; /* ...and dst. */ } mc->mc_next = dst->mt_cursors[i]; dst->mt_cursors[i] = mc; } } } return MDB_SUCCESS; } /** Close this write txn's cursors, give parent txn's cursors back to parent. * @param[in] txn the transaction handle. * @param[in] merge true to keep changes to parent cursors, false to revert. * @return 0 on success, non-zero on failure. */ static void mdb_cursors_close(MDB_txn *txn, unsigned merge) { MDB_cursor **cursors = txn->mt_cursors, *mc, *next, *bk; MDB_xcursor *mx; int i; for (i = txn->mt_numdbs; --i >= 0; ) { for (mc = cursors[i]; mc; mc = next) { next = mc->mc_next; if ((bk = mc->mc_backup) != NULL) { if (merge) { /* Commit changes to parent txn */ mc->mc_next = bk->mc_next; mc->mc_backup = bk->mc_backup; mc->mc_txn = bk->mc_txn; mc->mc_db = bk->mc_db; mc->mc_dbflag = bk->mc_dbflag; if ((mx = mc->mc_xcursor) != NULL) mx->mx_cursor.mc_txn = bk->mc_txn; } else { /* Abort nested txn */ *mc = *bk; if ((mx = mc->mc_xcursor) != NULL) *mx = *(MDB_xcursor *)(bk+1); } mc = bk; } /* Only malloced cursors are permanently tracked. */ free(mc); } cursors[i] = NULL; } } #if !(MDB_DEBUG) #define mdb_txn_reset0(txn, act) mdb_txn_reset0(txn) #endif static void mdb_txn_reset0(MDB_txn *txn, const char *act); #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */ enum Pidlock_op { Pidset, Pidcheck }; #else enum Pidlock_op { Pidset = F_SETLK, Pidcheck = F_GETLK }; #endif /** Set or check a pid lock. Set returns 0 on success. * Check returns 0 if the process is certainly dead, nonzero if it may * be alive (the lock exists or an error happened so we do not know). * * On Windows Pidset is a no-op, we merely check for the existence * of the process with the given pid. On POSIX we use a single byte * lock on the lockfile, set at an offset equal to the pid. */ static int mdb_reader_pid(MDB_env *env, enum Pidlock_op op, MDB_PID_T pid) { #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */ int ret = 0; HANDLE h; if (op == Pidcheck) { h = OpenProcess(env->me_pidquery, FALSE, pid); /* No documented "no such process" code, but other program use this: */ if (!h) return ErrCode() != ERROR_INVALID_PARAMETER; /* A process exists until all handles to it close. Has it exited? */ ret = WaitForSingleObject(h, 0) != 0; CloseHandle(h); } return ret; #else for (;;) { int rc; struct flock lock_info; memset(&lock_info, 0, sizeof(lock_info)); lock_info.l_type = F_WRLCK; lock_info.l_whence = SEEK_SET; lock_info.l_start = pid; lock_info.l_len = 1; if ((rc = fcntl(env->me_lfd, op, &lock_info)) == 0) { if (op == F_GETLK && lock_info.l_type != F_UNLCK) rc = -1; } else if ((rc = ErrCode()) == EINTR) { continue; } return rc; } #endif } /** Common code for #mdb_txn_begin() and #mdb_txn_renew(). * @param[in] txn the transaction handle to initialize * @return 0 on success, non-zero on failure. */ static int mdb_txn_renew0(MDB_txn *txn) { MDB_env *env = txn->mt_env; MDB_txninfo *ti = env->me_txns; MDB_meta *meta; unsigned int i, nr; uint16_t x; int rc, new_notls = 0; if (txn->mt_flags & MDB_TXN_RDONLY) { /* Setup db info */ txn->mt_numdbs = env->me_numdbs; txn->mt_dbxs = env->me_dbxs; /* mostly static anyway */ if (!ti) { meta = env->me_metas[ mdb_env_pick_meta(env) ]; txn->mt_txnid = meta->mm_txnid; txn->mt_u.reader = NULL; } else { MDB_reader *r = (env->me_flags & MDB_NOTLS) ? txn->mt_u.reader : pthread_getspecific(env->me_txkey); if (r) { if (r->mr_pid != env->me_pid || r->mr_txnid != (txnid_t)-1) return MDB_BAD_RSLOT; } else { MDB_PID_T pid = env->me_pid; MDB_THR_T tid = pthread_self(); mdb_mutex_t *rmutex = MDB_MUTEX(env, r); if (!env->me_live_reader) { rc = mdb_reader_pid(env, Pidset, pid); if (rc) return rc; env->me_live_reader = 1; } if (LOCK_MUTEX(rc, env, rmutex)) return rc; nr = ti->mti_numreaders; for (i=0; imti_readers[i].mr_pid == 0) break; if (i == env->me_maxreaders) { UNLOCK_MUTEX(rmutex); return MDB_READERS_FULL; } r = &ti->mti_readers[i]; r->mr_txnid = (txnid_t)-1; r->mr_tid = tid; r->mr_pid = pid; /* should be written last, see ITS#7971. */ if (i == nr) ti->mti_numreaders = ++nr; /* Save numreaders for un-mutexed mdb_env_close() */ env->me_numreaders = nr; UNLOCK_MUTEX(rmutex); new_notls = (env->me_flags & MDB_NOTLS); if (!new_notls && (rc=pthread_setspecific(env->me_txkey, r))) { r->mr_pid = 0; return rc; } } do /* LY: Retry on a race, ITS#7970. */ r->mr_txnid = ti->mti_txnid; while(r->mr_txnid != ti->mti_txnid); txn->mt_txnid = r->mr_txnid; txn->mt_u.reader = r; meta = env->me_metas[txn->mt_txnid & 1]; } } else { if (ti) { if (LOCK_MUTEX(rc, env, MDB_MUTEX(env, w))) return rc; #ifdef MDB_USE_SYSV_SEM meta = env->me_metas[ mdb_env_pick_meta(env) ]; txn->mt_txnid = meta->mm_txnid; /* Update mti_txnid like mdb_mutex_failed() would, * in case last writer crashed before updating it. */ ti->mti_txnid = txn->mt_txnid; #else txn->mt_txnid = ti->mti_txnid; meta = env->me_metas[txn->mt_txnid & 1]; #endif } else { meta = env->me_metas[ mdb_env_pick_meta(env) ]; txn->mt_txnid = meta->mm_txnid; } /* Setup db info */ txn->mt_numdbs = env->me_numdbs; txn->mt_txnid++; #if MDB_DEBUG if (txn->mt_txnid == mdb_debug_start) mdb_debug = 1; #endif txn->mt_flags = 0; txn->mt_child = NULL; txn->mt_loose_pgs = NULL; txn->mt_loose_count = 0; txn->mt_dirty_room = MDB_IDL_UM_MAX; txn->mt_u.dirty_list = env->me_dirty_list; txn->mt_u.dirty_list[0].mid = 0; txn->mt_free_pgs = env->me_free_pgs; txn->mt_free_pgs[0] = 0; txn->mt_spill_pgs = NULL; env->me_txn = txn; memcpy(txn->mt_dbiseqs, env->me_dbiseqs, env->me_maxdbs * sizeof(unsigned int)); } /* Copy the DB info and flags */ memcpy(txn->mt_dbs, meta->mm_dbs, 2 * sizeof(MDB_db)); /* Moved to here to avoid a data race in read TXNs */ txn->mt_next_pgno = meta->mm_last_pg+1; for (i=2; imt_numdbs; i++) { x = env->me_dbflags[i]; txn->mt_dbs[i].md_flags = x & PERSISTENT_FLAGS; txn->mt_dbflags[i] = (x & MDB_VALID) ? DB_VALID|DB_STALE : 0; } txn->mt_dbflags[0] = txn->mt_dbflags[1] = DB_VALID; if (env->me_maxpg < txn->mt_next_pgno) { mdb_txn_reset0(txn, "renew0-mapfail"); if (new_notls) { txn->mt_u.reader->mr_pid = 0; txn->mt_u.reader = NULL; } return MDB_MAP_RESIZED; } return MDB_SUCCESS; } int mdb_txn_renew(MDB_txn *txn) { int rc; if (!txn || txn->mt_dbxs) /* A reset txn has mt_dbxs==NULL */ return EINVAL; if (txn->mt_env->me_flags & MDB_FATAL_ERROR) { DPUTS("environment had fatal error, must shutdown!"); return MDB_PANIC; } rc = mdb_txn_renew0(txn); if (rc == MDB_SUCCESS) { DPRINTF(("renew txn %"Z"u%c %p on mdbenv %p, root page %"Z"u", txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root)); } return rc; } int mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret) { MDB_txn *txn; MDB_ntxn *ntxn; int rc, size, tsize = sizeof(MDB_txn); if (env->me_flags & MDB_FATAL_ERROR) { DPUTS("environment had fatal error, must shutdown!"); return MDB_PANIC; } if ((env->me_flags & MDB_RDONLY) && !(flags & MDB_RDONLY)) return EACCES; if (parent) { /* Nested transactions: Max 1 child, write txns only, no writemap */ if (parent->mt_child || (flags & MDB_RDONLY) || (parent->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR)) || (env->me_flags & MDB_WRITEMAP)) { return (parent->mt_flags & MDB_TXN_RDONLY) ? EINVAL : MDB_BAD_TXN; } tsize = sizeof(MDB_ntxn); } size = tsize; if (!(flags & MDB_RDONLY)) { if (!parent) { txn = env->me_txn0; /* just reuse preallocated write txn */ goto ok; } /* child txns use own copy of cursors */ size += env->me_maxdbs * sizeof(MDB_cursor *); } size += env->me_maxdbs * (sizeof(MDB_db)+1); if ((txn = calloc(1, size)) == NULL) { DPRINTF(("calloc: %s", strerror(errno))); return ENOMEM; } txn->mt_dbs = (MDB_db *) ((char *)txn + tsize); if (flags & MDB_RDONLY) { txn->mt_flags |= MDB_TXN_RDONLY; txn->mt_dbflags = (unsigned char *)(txn->mt_dbs + env->me_maxdbs); txn->mt_dbiseqs = env->me_dbiseqs; } else { txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs); if (parent) { txn->mt_dbiseqs = parent->mt_dbiseqs; txn->mt_dbflags = (unsigned char *)(txn->mt_cursors + env->me_maxdbs); } else { txn->mt_dbiseqs = (unsigned int *)(txn->mt_cursors + env->me_maxdbs); txn->mt_dbflags = (unsigned char *)(txn->mt_dbiseqs + env->me_maxdbs); } } txn->mt_env = env; ok: if (parent) { unsigned int i; txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE); if (!txn->mt_u.dirty_list || !(txn->mt_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX))) { free(txn->mt_u.dirty_list); free(txn); return ENOMEM; } txn->mt_txnid = parent->mt_txnid; txn->mt_dirty_room = parent->mt_dirty_room; txn->mt_u.dirty_list[0].mid = 0; txn->mt_spill_pgs = NULL; txn->mt_next_pgno = parent->mt_next_pgno; parent->mt_child = txn; txn->mt_parent = parent; txn->mt_numdbs = parent->mt_numdbs; txn->mt_flags = parent->mt_flags; txn->mt_dbxs = parent->mt_dbxs; memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db)); /* Copy parent's mt_dbflags, but clear DB_NEW */ for (i=0; imt_numdbs; i++) txn->mt_dbflags[i] = parent->mt_dbflags[i] & ~DB_NEW; rc = 0; ntxn = (MDB_ntxn *)txn; ntxn->mnt_pgstate = env->me_pgstate; /* save parent me_pghead & co */ if (env->me_pghead) { size = MDB_IDL_SIZEOF(env->me_pghead); env->me_pghead = mdb_midl_alloc(env->me_pghead[0]); if (env->me_pghead) memcpy(env->me_pghead, ntxn->mnt_pgstate.mf_pghead, size); else rc = ENOMEM; } if (!rc) rc = mdb_cursor_shadow(parent, txn); if (rc) mdb_txn_reset0(txn, "beginchild-fail"); } else { rc = mdb_txn_renew0(txn); } if (rc) { if (txn != env->me_txn0) free(txn); } else { *ret = txn; DPRINTF(("begin txn %"Z"u%c %p on mdbenv %p, root page %"Z"u", txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', (void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root)); } return rc; } MDB_env * mdb_txn_env(MDB_txn *txn) { if(!txn) return NULL; return txn->mt_env; } size_t mdb_txn_id(MDB_txn *txn) { if(!txn) return 0; return txn->mt_txnid; } /** Export or close DBI handles opened in this txn. */ static void mdb_dbis_update(MDB_txn *txn, int keep) { int i; MDB_dbi n = txn->mt_numdbs; MDB_env *env = txn->mt_env; unsigned char *tdbflags = txn->mt_dbflags; for (i = n; --i >= 2;) { if (tdbflags[i] & DB_NEW) { if (keep) { env->me_dbflags[i] = txn->mt_dbs[i].md_flags | MDB_VALID; } else { char *ptr = env->me_dbxs[i].md_name.mv_data; if (ptr) { env->me_dbxs[i].md_name.mv_data = NULL; env->me_dbxs[i].md_name.mv_size = 0; env->me_dbflags[i] = 0; env->me_dbiseqs[i]++; free(ptr); } } } } if (keep && env->me_numdbs < n) env->me_numdbs = n; } /** Common code for #mdb_txn_reset() and #mdb_txn_abort(). * May be called twice for readonly txns: First reset it, then abort. * @param[in] txn the transaction handle to reset * @param[in] act why the transaction is being reset */ static void mdb_txn_reset0(MDB_txn *txn, const char *act) { MDB_env *env = txn->mt_env; /* Close any DBI handles opened in this txn */ mdb_dbis_update(txn, 0); DPRINTF(("%s txn %"Z"u%c %p on mdbenv %p, root page %"Z"u", act, txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', (void *) txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root)); if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) { if (txn->mt_u.reader) { txn->mt_u.reader->mr_txnid = (txnid_t)-1; if (!(env->me_flags & MDB_NOTLS)) txn->mt_u.reader = NULL; /* txn does not own reader */ } txn->mt_numdbs = 0; /* close nothing if called again */ txn->mt_dbxs = NULL; /* mark txn as reset */ } else { pgno_t *pghead = env->me_pghead; mdb_cursors_close(txn, 0); if (!(env->me_flags & MDB_WRITEMAP)) { mdb_dlist_free(txn); } if (!txn->mt_parent) { if (mdb_midl_shrink(&txn->mt_free_pgs)) env->me_free_pgs = txn->mt_free_pgs; /* me_pgstate: */ env->me_pghead = NULL; env->me_pglast = 0; env->me_txn = NULL; /* The writer mutex was locked in mdb_txn_begin. */ if (env->me_txns) UNLOCK_MUTEX(MDB_MUTEX(env, w)); } else { txn->mt_parent->mt_child = NULL; env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate; mdb_midl_free(txn->mt_free_pgs); mdb_midl_free(txn->mt_spill_pgs); free(txn->mt_u.dirty_list); } mdb_midl_free(pghead); } } void mdb_txn_reset(MDB_txn *txn) { if (txn == NULL) return; /* This call is only valid for read-only txns */ if (!(txn->mt_flags & MDB_TXN_RDONLY)) return; mdb_txn_reset0(txn, "reset"); } void mdb_txn_abort(MDB_txn *txn) { if (txn == NULL) return; if (txn->mt_child) mdb_txn_abort(txn->mt_child); mdb_txn_reset0(txn, "abort"); /* Free reader slot tied to this txn (if MDB_NOTLS && writable FS) */ if ((txn->mt_flags & MDB_TXN_RDONLY) && txn->mt_u.reader) txn->mt_u.reader->mr_pid = 0; if (txn != txn->mt_env->me_txn0) free(txn); } /** Save the freelist as of this transaction to the freeDB. * This changes the freelist. Keep trying until it stabilizes. */ static int mdb_freelist_save(MDB_txn *txn) { /* env->me_pghead[] can grow and shrink during this call. * env->me_pglast and txn->mt_free_pgs[] can only grow. * Page numbers cannot disappear from txn->mt_free_pgs[]. */ MDB_cursor mc; MDB_env *env = txn->mt_env; int rc, maxfree_1pg = env->me_maxfree_1pg, more = 1; txnid_t pglast = 0, head_id = 0; pgno_t freecnt = 0, *free_pgs, *mop; ssize_t head_room = 0, total_room = 0, mop_len, clean_limit; mdb_cursor_init(&mc, txn, FREE_DBI, NULL); if (env->me_pghead) { /* Make sure first page of freeDB is touched and on freelist */ rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST|MDB_PS_MODIFY); if (rc && rc != MDB_NOTFOUND) return rc; } if (!env->me_pghead && txn->mt_loose_pgs) { /* Put loose page numbers in mt_free_pgs, since * we may be unable to return them to me_pghead. */ MDB_page *mp = txn->mt_loose_pgs; if ((rc = mdb_midl_need(&txn->mt_free_pgs, txn->mt_loose_count)) != 0) return rc; for (; mp; mp = NEXT_LOOSE_PAGE(mp)) mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno); txn->mt_loose_pgs = NULL; txn->mt_loose_count = 0; } /* MDB_RESERVE cancels meminit in ovpage malloc (when no WRITEMAP) */ clean_limit = (env->me_flags & (MDB_NOMEMINIT|MDB_WRITEMAP)) ? SSIZE_MAX : maxfree_1pg; for (;;) { /* Come back here after each Put() in case freelist changed */ MDB_val key, data; pgno_t *pgs; ssize_t j; /* If using records from freeDB which we have not yet * deleted, delete them and any we reserved for me_pghead. */ while (pglast < env->me_pglast) { rc = mdb_cursor_first(&mc, &key, NULL); if (rc) return rc; pglast = head_id = *(txnid_t *)key.mv_data; total_room = head_room = 0; mdb_tassert(txn, pglast <= env->me_pglast); rc = mdb_cursor_del(&mc, 0); if (rc) return rc; } /* Save the IDL of pages freed by this txn, to a single record */ if (freecnt < txn->mt_free_pgs[0]) { if (!freecnt) { /* Make sure last page of freeDB is touched and on freelist */ rc = mdb_page_search(&mc, NULL, MDB_PS_LAST|MDB_PS_MODIFY); if (rc && rc != MDB_NOTFOUND) return rc; } free_pgs = txn->mt_free_pgs; /* Write to last page of freeDB */ key.mv_size = sizeof(txn->mt_txnid); key.mv_data = &txn->mt_txnid; do { freecnt = free_pgs[0]; data.mv_size = MDB_IDL_SIZEOF(free_pgs); rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE); if (rc) return rc; /* Retry if mt_free_pgs[] grew during the Put() */ free_pgs = txn->mt_free_pgs; } while (freecnt < free_pgs[0]); mdb_midl_sort(free_pgs); memcpy(data.mv_data, free_pgs, data.mv_size); #if (MDB_DEBUG) > 1 { unsigned int i = free_pgs[0]; DPRINTF(("IDL write txn %"Z"u root %"Z"u num %u", txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, i)); for (; i; i--) DPRINTF(("IDL %"Z"u", free_pgs[i])); } #endif continue; } mop = env->me_pghead; mop_len = (mop ? mop[0] : 0) + txn->mt_loose_count; /* Reserve records for me_pghead[]. Split it if multi-page, * to avoid searching freeDB for a page range. Use keys in * range [1,me_pglast]: Smaller than txnid of oldest reader. */ if (total_room >= mop_len) { if (total_room == mop_len || --more < 0) break; } else if (head_room >= maxfree_1pg && head_id > 1) { /* Keep current record (overflow page), add a new one */ head_id--; head_room = 0; } /* (Re)write {key = head_id, IDL length = head_room} */ total_room -= head_room; head_room = mop_len - total_room; if (head_room > maxfree_1pg && head_id > 1) { /* Overflow multi-page for part of me_pghead */ head_room /= head_id; /* amortize page sizes */ head_room += maxfree_1pg - head_room % (maxfree_1pg + 1); } else if (head_room < 0) { /* Rare case, not bothering to delete this record */ head_room = 0; } key.mv_size = sizeof(head_id); key.mv_data = &head_id; data.mv_size = (head_room + 1) * sizeof(pgno_t); rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE); if (rc) return rc; /* IDL is initially empty, zero out at least the length */ pgs = (pgno_t *)data.mv_data; j = head_room > clean_limit ? head_room : 0; do { pgs[j] = 0; } while (--j >= 0); total_room += head_room; } /* Return loose page numbers to me_pghead, though usually none are * left at this point. The pages themselves remain in dirty_list. */ if (txn->mt_loose_pgs) { MDB_page *mp = txn->mt_loose_pgs; unsigned count = txn->mt_loose_count; MDB_IDL loose; /* Room for loose pages + temp IDL with same */ if ((rc = mdb_midl_need(&env->me_pghead, 2*count+1)) != 0) return rc; mop = env->me_pghead; loose = mop + MDB_IDL_ALLOCLEN(mop) - count; for (count = 0; mp; mp = NEXT_LOOSE_PAGE(mp)) loose[ ++count ] = mp->mp_pgno; loose[0] = count; mdb_midl_sort(loose); mdb_midl_xmerge(mop, loose); txn->mt_loose_pgs = NULL; txn->mt_loose_count = 0; mop_len = mop[0]; } /* Fill in the reserved me_pghead records */ rc = MDB_SUCCESS; if (mop_len) { MDB_val key, data; mop += mop_len; rc = mdb_cursor_first(&mc, &key, &data); for (; !rc; rc = mdb_cursor_next(&mc, &key, &data, MDB_NEXT)) { txnid_t id = *(txnid_t *)key.mv_data; ssize_t len = (ssize_t)(data.mv_size / sizeof(MDB_ID)) - 1; MDB_ID save; mdb_tassert(txn, len >= 0 && id <= env->me_pglast); key.mv_data = &id; if (len > mop_len) { len = mop_len; data.mv_size = (len + 1) * sizeof(MDB_ID); } data.mv_data = mop -= len; save = mop[0]; mop[0] = len; rc = mdb_cursor_put(&mc, &key, &data, MDB_CURRENT); mop[0] = save; if (rc || !(mop_len -= len)) break; } } return rc; } /** Flush (some) dirty pages to the map, after clearing their dirty flag. * @param[in] txn the transaction that's being committed * @param[in] keep number of initial pages in dirty_list to keep dirty. * @return 0 on success, non-zero on failure. */ static int mdb_page_flush(MDB_txn *txn, int keep) { MDB_env *env = txn->mt_env; MDB_ID2L dl = txn->mt_u.dirty_list; unsigned psize = env->me_psize, j; int i, pagecount = dl[0].mid, rc; size_t size = 0, pos = 0; pgno_t pgno = 0; MDB_page *dp = NULL; #ifdef _WIN32 OVERLAPPED ov; #else struct iovec iov[MDB_COMMIT_PAGES]; ssize_t wpos = 0, wsize = 0, wres; size_t next_pos = 1; /* impossible pos, so pos != next_pos */ int n = 0; #endif j = i = keep; if (env->me_flags & MDB_WRITEMAP) { /* Clear dirty flags */ while (++i <= pagecount) { dp = dl[i].mptr; /* Don't flush this page yet */ if (dp->mp_flags & (P_LOOSE|P_KEEP)) { dp->mp_flags &= ~P_KEEP; dl[++j] = dl[i]; continue; } dp->mp_flags &= ~P_DIRTY; } goto done; } /* Write the pages */ for (;;) { if (++i <= pagecount) { dp = dl[i].mptr; /* Don't flush this page yet */ if (dp->mp_flags & (P_LOOSE|P_KEEP)) { dp->mp_flags &= ~P_KEEP; dl[i].mid = 0; continue; } pgno = dl[i].mid; /* clear dirty flag */ dp->mp_flags &= ~P_DIRTY; pos = pgno * psize; size = psize; if (IS_OVERFLOW(dp)) size *= dp->mp_pages; } #ifdef _WIN32 else break; /* Windows actually supports scatter/gather I/O, but only on * unbuffered file handles. Since we're relying on the OS page * cache for all our data, that's self-defeating. So we just * write pages one at a time. We use the ov structure to set * the write offset, to at least save the overhead of a Seek * system call. */ DPRINTF(("committing page %"Z"u", pgno)); memset(&ov, 0, sizeof(ov)); ov.Offset = pos & 0xffffffff; ov.OffsetHigh = pos >> 16 >> 16; if (!WriteFile(env->me_fd, dp, size, NULL, &ov)) { rc = ErrCode(); DPRINTF(("WriteFile: %d", rc)); return rc; } #else /* Write up to MDB_COMMIT_PAGES dirty pages at a time. */ if (pos!=next_pos || n==MDB_COMMIT_PAGES || wsize+size>MAX_WRITE) { if (n) { /* Write previous page(s) */ #ifdef MDB_USE_PWRITEV wres = pwritev(env->me_fd, iov, n, wpos); #else if (n == 1) { wres = pwrite(env->me_fd, iov[0].iov_base, wsize, wpos); } else { if (lseek(env->me_fd, wpos, SEEK_SET) == -1) { rc = ErrCode(); DPRINTF(("lseek: %s", strerror(rc))); return rc; } wres = writev(env->me_fd, iov, n); } #endif if (wres != wsize) { if (wres < 0) { rc = ErrCode(); DPRINTF(("Write error: %s", strerror(rc))); } else { rc = EIO; /* TODO: Use which error code? */ DPUTS("short write, filesystem full?"); } return rc; } n = 0; } if (i > pagecount) break; wpos = pos; wsize = 0; } DPRINTF(("committing page %"Z"u", pgno)); next_pos = pos + size; iov[n].iov_len = size; iov[n].iov_base = (char *)dp; wsize += size; n++; #endif /* _WIN32 */ } /* MIPS has cache coherency issues, this is a no-op everywhere else * Note: for any size >= on-chip cache size, entire on-chip cache is * flushed. */ CACHEFLUSH(env->me_map, txn->mt_next_pgno * env->me_psize, DCACHE); for (i = keep; ++i <= pagecount; ) { dp = dl[i].mptr; /* This is a page we skipped above */ if (!dl[i].mid) { dl[++j] = dl[i]; dl[j].mid = dp->mp_pgno; continue; } mdb_dpage_free(env, dp); } done: i--; txn->mt_dirty_room += i - j; dl[0].mid = j; return MDB_SUCCESS; } int mdb_txn_commit(MDB_txn *txn) { int rc; unsigned int i; MDB_env *env; if (txn == NULL || txn->mt_env == NULL) return EINVAL; if (txn->mt_child) { rc = mdb_txn_commit(txn->mt_child); txn->mt_child = NULL; if (rc) goto fail; } env = txn->mt_env; if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) { mdb_dbis_update(txn, 1); txn->mt_numdbs = 2; /* so txn_abort() doesn't close any new handles */ mdb_txn_abort(txn); return MDB_SUCCESS; } if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) { DPUTS("error flag is set, can't commit"); if (txn->mt_parent) txn->mt_parent->mt_flags |= MDB_TXN_ERROR; rc = MDB_BAD_TXN; goto fail; } if (txn->mt_parent) { MDB_txn *parent = txn->mt_parent; MDB_page **lp; MDB_ID2L dst, src; MDB_IDL pspill; unsigned x, y, len, ps_len; /* Append our free list to parent's */ rc = mdb_midl_append_list(&parent->mt_free_pgs, txn->mt_free_pgs); if (rc) goto fail; mdb_midl_free(txn->mt_free_pgs); /* Failures after this must either undo the changes * to the parent or set MDB_TXN_ERROR in the parent. */ parent->mt_next_pgno = txn->mt_next_pgno; parent->mt_flags = txn->mt_flags; /* Merge our cursors into parent's and close them */ mdb_cursors_close(txn, 1); /* Update parent's DB table. */ memcpy(parent->mt_dbs, txn->mt_dbs, txn->mt_numdbs * sizeof(MDB_db)); parent->mt_numdbs = txn->mt_numdbs; parent->mt_dbflags[0] = txn->mt_dbflags[0]; parent->mt_dbflags[1] = txn->mt_dbflags[1]; for (i=2; imt_numdbs; i++) { /* preserve parent's DB_NEW status */ x = parent->mt_dbflags[i] & DB_NEW; parent->mt_dbflags[i] = txn->mt_dbflags[i] | x; } dst = parent->mt_u.dirty_list; src = txn->mt_u.dirty_list; /* Remove anything in our dirty list from parent's spill list */ if ((pspill = parent->mt_spill_pgs) && (ps_len = pspill[0])) { x = y = ps_len; pspill[0] = (pgno_t)-1; /* Mark our dirty pages as deleted in parent spill list */ for (i=0, len=src[0].mid; ++i <= len; ) { MDB_ID pn = src[i].mid << 1; while (pn > pspill[x]) x--; if (pn == pspill[x]) { pspill[x] = 1; y = --x; } } /* Squash deleted pagenums if we deleted any */ for (x=y; ++x <= ps_len; ) if (!(pspill[x] & 1)) pspill[++y] = pspill[x]; pspill[0] = y; } /* Find len = length of merging our dirty list with parent's */ x = dst[0].mid; dst[0].mid = 0; /* simplify loops */ if (parent->mt_parent) { len = x + src[0].mid; y = mdb_mid2l_search(src, dst[x].mid + 1) - 1; for (i = x; y && i; y--) { pgno_t yp = src[y].mid; while (yp < dst[i].mid) i--; if (yp == dst[i].mid) { i--; len--; } } } else { /* Simplify the above for single-ancestor case */ len = MDB_IDL_UM_MAX - txn->mt_dirty_room; } /* Merge our dirty list with parent's */ y = src[0].mid; for (i = len; y; dst[i--] = src[y--]) { pgno_t yp = src[y].mid; while (yp < dst[x].mid) dst[i--] = dst[x--]; if (yp == dst[x].mid) free(dst[x--].mptr); } mdb_tassert(txn, i == x); dst[0].mid = len; free(txn->mt_u.dirty_list); parent->mt_dirty_room = txn->mt_dirty_room; if (txn->mt_spill_pgs) { if (parent->mt_spill_pgs) { /* TODO: Prevent failure here, so parent does not fail */ rc = mdb_midl_append_list(&parent->mt_spill_pgs, txn->mt_spill_pgs); if (rc) parent->mt_flags |= MDB_TXN_ERROR; mdb_midl_free(txn->mt_spill_pgs); mdb_midl_sort(parent->mt_spill_pgs); } else { parent->mt_spill_pgs = txn->mt_spill_pgs; } } /* Append our loose page list to parent's */ for (lp = &parent->mt_loose_pgs; *lp; lp = &NEXT_LOOSE_PAGE(lp)) ; *lp = txn->mt_loose_pgs; parent->mt_loose_count += txn->mt_loose_count; parent->mt_child = NULL; mdb_midl_free(((MDB_ntxn *)txn)->mnt_pgstate.mf_pghead); free(txn); return rc; } if (txn != env->me_txn) { DPUTS("attempt to commit unknown transaction"); rc = EINVAL; goto fail; } mdb_cursors_close(txn, 0); if (!txn->mt_u.dirty_list[0].mid && !(txn->mt_flags & (MDB_TXN_DIRTY|MDB_TXN_SPILLS))) goto done; DPRINTF(("committing txn %"Z"u %p on mdbenv %p, root page %"Z"u", txn->mt_txnid, (void*)txn, (void*)env, txn->mt_dbs[MAIN_DBI].md_root)); /* Update DB root pointers */ if (txn->mt_numdbs > 2) { MDB_cursor mc; MDB_dbi i; MDB_val data; data.mv_size = sizeof(MDB_db); mdb_cursor_init(&mc, txn, MAIN_DBI, NULL); for (i = 2; i < txn->mt_numdbs; i++) { if (txn->mt_dbflags[i] & DB_DIRTY) { if (TXN_DBI_CHANGED(txn, i)) { rc = MDB_BAD_DBI; goto fail; } data.mv_data = &txn->mt_dbs[i]; rc = mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data, 0); if (rc) goto fail; } } } rc = mdb_freelist_save(txn); if (rc) goto fail; mdb_midl_free(env->me_pghead); env->me_pghead = NULL; if (mdb_midl_shrink(&txn->mt_free_pgs)) env->me_free_pgs = txn->mt_free_pgs; #if (MDB_DEBUG) > 2 mdb_audit(txn); #endif if ((rc = mdb_page_flush(txn, 0)) || (rc = mdb_env_sync(env, 0)) || (rc = mdb_env_write_meta(txn))) goto fail; /* Free P_LOOSE pages left behind in dirty_list */ if (!(env->me_flags & MDB_WRITEMAP)) mdb_dlist_free(txn); done: env->me_pglast = 0; env->me_txn = NULL; mdb_dbis_update(txn, 1); if (env->me_txns) UNLOCK_MUTEX(MDB_MUTEX(env, w)); if (txn != env->me_txn0) free(txn); return MDB_SUCCESS; fail: mdb_txn_abort(txn); return rc; } /** Read the environment parameters of a DB environment before * mapping it into memory. * @param[in] env the environment handle * @param[out] meta address of where to store the meta information * @return 0 on success, non-zero on failure. */ static int ESECT mdb_env_read_header(MDB_env *env, MDB_meta *meta) { MDB_metabuf pbuf; MDB_page *p; MDB_meta *m; int i, rc, off; enum { Size = sizeof(pbuf) }; /* We don't know the page size yet, so use a minimum value. * Read both meta pages so we can use the latest one. */ for (i=off=0; i<2; i++, off = meta->mm_psize) { #ifdef _WIN32 DWORD len; OVERLAPPED ov; memset(&ov, 0, sizeof(ov)); ov.Offset = off; rc = ReadFile(env->me_fd, &pbuf, Size, &len, &ov) ? (int)len : -1; if (rc == -1 && ErrCode() == ERROR_HANDLE_EOF) rc = 0; #else rc = pread(env->me_fd, &pbuf, Size, off); #endif if (rc != Size) { if (rc == 0 && off == 0) return ENOENT; rc = rc < 0 ? (int) ErrCode() : MDB_INVALID; DPRINTF(("read: %s", mdb_strerror(rc))); return rc; } p = (MDB_page *)&pbuf; if (!F_ISSET(p->mp_flags, P_META)) { DPRINTF(("page %"Z"u not a meta page", p->mp_pgno)); return MDB_INVALID; } m = METADATA(p); if (m->mm_magic != MDB_MAGIC) { DPUTS("meta has invalid magic"); return MDB_INVALID; } if (m->mm_version != MDB_DATA_VERSION) { DPRINTF(("database is version %u, expected version %u", m->mm_version, MDB_DATA_VERSION)); return MDB_VERSION_MISMATCH; } if (off == 0 || m->mm_txnid > meta->mm_txnid) *meta = *m; } return 0; } /** Fill in most of the zeroed #MDB_meta for an empty database environment */ static void ESECT mdb_env_init_meta0(MDB_env *env, MDB_meta *meta) { meta->mm_magic = MDB_MAGIC; meta->mm_version = MDB_DATA_VERSION; meta->mm_mapsize = env->me_mapsize; meta->mm_psize = env->me_psize; meta->mm_last_pg = 1; meta->mm_flags = env->me_flags & 0xffff; meta->mm_flags |= MDB_INTEGERKEY; meta->mm_dbs[0].md_root = P_INVALID; meta->mm_dbs[1].md_root = P_INVALID; } /** Write the environment parameters of a freshly created DB environment. * @param[in] env the environment handle * @param[in] meta the #MDB_meta to write * @return 0 on success, non-zero on failure. */ static int ESECT mdb_env_init_meta(MDB_env *env, MDB_meta *meta) { MDB_page *p, *q; int rc; unsigned int psize; #ifdef _WIN32 DWORD len; OVERLAPPED ov; memset(&ov, 0, sizeof(ov)); #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \ ov.Offset = pos; \ rc = WriteFile(fd, ptr, size, &len, &ov); } while(0) #else int len; #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \ len = pwrite(fd, ptr, size, pos); \ rc = (len >= 0); } while(0) #endif DPUTS("writing new meta page"); psize = env->me_psize; p = calloc(2, psize); p->mp_pgno = 0; p->mp_flags = P_META; *(MDB_meta *)METADATA(p) = *meta; q = (MDB_page *)((char *)p + psize); q->mp_pgno = 1; q->mp_flags = P_META; *(MDB_meta *)METADATA(q) = *meta; DO_PWRITE(rc, env->me_fd, p, psize * 2, len, 0); if (!rc) rc = ErrCode(); else if ((unsigned) len == psize * 2) rc = MDB_SUCCESS; else rc = ENOSPC; free(p); return rc; } /** Update the environment info to commit a transaction. * @param[in] txn the transaction that's being committed * @return 0 on success, non-zero on failure. */ static int mdb_env_write_meta(MDB_txn *txn) { MDB_env *env; MDB_meta meta, metab, *mp; size_t mapsize; off_t off; int rc, len, toggle; char *ptr; HANDLE mfd; #ifdef _WIN32 OVERLAPPED ov; #else int r2; #endif toggle = txn->mt_txnid & 1; DPRINTF(("writing meta page %d for root page %"Z"u", toggle, txn->mt_dbs[MAIN_DBI].md_root)); env = txn->mt_env; mp = env->me_metas[toggle]; mapsize = env->me_metas[toggle ^ 1]->mm_mapsize; /* Persist any increases of mapsize config */ if (mapsize < env->me_mapsize) mapsize = env->me_mapsize; if (env->me_flags & MDB_WRITEMAP) { mp->mm_mapsize = mapsize; mp->mm_dbs[0] = txn->mt_dbs[0]; mp->mm_dbs[1] = txn->mt_dbs[1]; mp->mm_last_pg = txn->mt_next_pgno - 1; #if !(defined(_MSC_VER) || defined(__i386__) || defined(__x86_64__)) /* LY: issue a memory barrier, if not x86. ITS#7969 */ __sync_synchronize(); #endif mp->mm_txnid = txn->mt_txnid; if (!(env->me_flags & (MDB_NOMETASYNC|MDB_NOSYNC))) { unsigned meta_size = env->me_psize; rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC; ptr = env->me_map; if (toggle) { #ifndef _WIN32 /* POSIX msync() requires ptr = start of OS page */ if (meta_size < env->me_os_psize) meta_size += meta_size; else #endif ptr += meta_size; } if (MDB_MSYNC(ptr, meta_size, rc)) { rc = ErrCode(); goto fail; } } goto done; } metab.mm_txnid = env->me_metas[toggle]->mm_txnid; metab.mm_last_pg = env->me_metas[toggle]->mm_last_pg; meta.mm_mapsize = mapsize; meta.mm_dbs[0] = txn->mt_dbs[0]; meta.mm_dbs[1] = txn->mt_dbs[1]; meta.mm_last_pg = txn->mt_next_pgno - 1; meta.mm_txnid = txn->mt_txnid; off = offsetof(MDB_meta, mm_mapsize); ptr = (char *)&meta + off; len = sizeof(MDB_meta) - off; if (toggle) off += env->me_psize; off += PAGEHDRSZ; /* Write to the SYNC fd */ mfd = env->me_flags & (MDB_NOSYNC|MDB_NOMETASYNC) ? env->me_fd : env->me_mfd; #ifdef _WIN32 { memset(&ov, 0, sizeof(ov)); ov.Offset = off; if (!WriteFile(mfd, ptr, len, (DWORD *)&rc, &ov)) rc = -1; } #else rc = pwrite(mfd, ptr, len, off); #endif if (rc != len) { rc = rc < 0 ? ErrCode() : EIO; DPUTS("write failed, disk error?"); /* On a failure, the pagecache still contains the new data. * Write some old data back, to prevent it from being used. * Use the non-SYNC fd; we know it will fail anyway. */ meta.mm_last_pg = metab.mm_last_pg; meta.mm_txnid = metab.mm_txnid; #ifdef _WIN32 memset(&ov, 0, sizeof(ov)); ov.Offset = off; WriteFile(env->me_fd, ptr, len, NULL, &ov); #else r2 = pwrite(env->me_fd, ptr, len, off); (void)r2; /* Silence warnings. We don't care about pwrite's return value */ #endif fail: env->me_flags |= MDB_FATAL_ERROR; return rc; } /* MIPS has cache coherency issues, this is a no-op everywhere else */ CACHEFLUSH(env->me_map + off, len, DCACHE); done: /* Memory ordering issues are irrelevant; since the entire writer * is wrapped by wmutex, all of these changes will become visible * after the wmutex is unlocked. Since the DB is multi-version, * readers will get consistent data regardless of how fresh or * how stale their view of these values is. */ if (env->me_txns) env->me_txns->mti_txnid = txn->mt_txnid; return MDB_SUCCESS; } /** Check both meta pages to see which one is newer. * @param[in] env the environment handle * @return meta toggle (0 or 1). */ static int mdb_env_pick_meta(const MDB_env *env) { return (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid); } int ESECT mdb_env_create(MDB_env **env) { MDB_env *e; e = calloc(1, sizeof(MDB_env)); if (!e) return ENOMEM; e->me_maxreaders = DEFAULT_READERS; e->me_maxdbs = e->me_numdbs = 2; e->me_fd = INVALID_HANDLE_VALUE; e->me_lfd = INVALID_HANDLE_VALUE; e->me_mfd = INVALID_HANDLE_VALUE; #ifdef MDB_USE_SYSV_SEM e->me_rmutex.semid = -1; e->me_wmutex.semid = -1; #endif e->me_pid = getpid(); GET_PAGESIZE(e->me_os_psize); VGMEMP_CREATE(e,0,0); *env = e; return MDB_SUCCESS; } static int ESECT mdb_env_map(MDB_env *env, void *addr) { MDB_page *p; unsigned int flags = env->me_flags; #ifdef _WIN32 int rc; HANDLE mh; LONG sizelo, sizehi; size_t msize; if (flags & MDB_RDONLY) { /* Don't set explicit map size, use whatever exists */ msize = 0; sizelo = 0; sizehi = 0; } else { msize = env->me_mapsize; sizelo = msize & 0xffffffff; sizehi = msize >> 16 >> 16; /* only needed on Win64 */ /* Windows won't create mappings for zero length files. * and won't map more than the file size. * Just set the maxsize right now. */ if (SetFilePointer(env->me_fd, sizelo, &sizehi, 0) != (DWORD)sizelo || !SetEndOfFile(env->me_fd) || SetFilePointer(env->me_fd, 0, NULL, 0) != 0) return ErrCode(); } mh = CreateFileMapping(env->me_fd, NULL, flags & MDB_WRITEMAP ? PAGE_READWRITE : PAGE_READONLY, sizehi, sizelo, NULL); if (!mh) return ErrCode(); env->me_map = MapViewOfFileEx(mh, flags & MDB_WRITEMAP ? FILE_MAP_WRITE : FILE_MAP_READ, 0, 0, msize, addr); rc = env->me_map ? 0 : ErrCode(); CloseHandle(mh); if (rc) return rc; #else int prot = PROT_READ; if (flags & MDB_WRITEMAP) { prot |= PROT_WRITE; if (ftruncate(env->me_fd, env->me_mapsize) < 0) return ErrCode(); } env->me_map = mmap(addr, env->me_mapsize, prot, MAP_SHARED, env->me_fd, 0); if (env->me_map == MAP_FAILED) { env->me_map = NULL; return ErrCode(); } if (flags & MDB_NORDAHEAD) { /* Turn off readahead. It's harmful when the DB is larger than RAM. */ #ifdef MADV_RANDOM madvise(env->me_map, env->me_mapsize, MADV_RANDOM); #else #ifdef POSIX_MADV_RANDOM posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM); #endif /* POSIX_MADV_RANDOM */ #endif /* MADV_RANDOM */ } #endif /* _WIN32 */ /* Can happen because the address argument to mmap() is just a * hint. mmap() can pick another, e.g. if the range is in use. * The MAP_FIXED flag would prevent that, but then mmap could * instead unmap existing pages to make room for the new map. */ if (addr && env->me_map != addr) return EBUSY; /* TODO: Make a new MDB_* error code? */ p = (MDB_page *)env->me_map; env->me_metas[0] = METADATA(p); env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + env->me_psize); return MDB_SUCCESS; } int ESECT mdb_env_set_mapsize(MDB_env *env, size_t size) { /* If env is already open, caller is responsible for making * sure there are no active txns. */ if (env->me_map) { int rc; MDB_meta *meta; void *old; if (env->me_txn) return EINVAL; meta = env->me_metas[mdb_env_pick_meta(env)]; if (!size) size = meta->mm_mapsize; { /* Silently round up to minimum if the size is too small */ size_t minsize = (meta->mm_last_pg + 1) * env->me_psize; if (size < minsize) size = minsize; } munmap(env->me_map, env->me_mapsize); env->me_mapsize = size; old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL; rc = mdb_env_map(env, old); if (rc) return rc; } env->me_mapsize = size; if (env->me_psize) env->me_maxpg = env->me_mapsize / env->me_psize; return MDB_SUCCESS; } int ESECT mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs) { if (env->me_map) return EINVAL; env->me_maxdbs = dbs + 2; /* Named databases + main and free DB */ return MDB_SUCCESS; } int ESECT mdb_env_set_maxreaders(MDB_env *env, unsigned int readers) { if (env->me_map || readers < 1) return EINVAL; env->me_maxreaders = readers; return MDB_SUCCESS; } int ESECT mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers) { if (!env || !readers) return EINVAL; *readers = env->me_maxreaders; return MDB_SUCCESS; } static int ESECT mdb_fsize(HANDLE fd, size_t *size) { #ifdef _WIN32 LARGE_INTEGER fsize; if (!GetFileSizeEx(fd, &fsize)) return ErrCode(); *size = fsize.QuadPart; #else struct stat st; if (fstat(fd, &st)) return ErrCode(); *size = st.st_size; #endif return MDB_SUCCESS; } #ifdef __linux #include #include #endif /** Further setup required for opening an LMDB environment */ static int ESECT mdb_env_open2(MDB_env *env) { unsigned int flags = env->me_flags; int i, newenv = 0, rc; MDB_meta meta; #ifdef _WIN32 /* See if we should use QueryLimited */ rc = GetVersion(); if ((rc & 0xff) > 5) env->me_pidquery = MDB_PROCESS_QUERY_LIMITED_INFORMATION; else env->me_pidquery = PROCESS_QUERY_INFORMATION; #endif /* _WIN32 */ #ifdef __linux /* ext3/ext4 fdatasync is broken on some older Linux kernels. * https://lkml.org/lkml/2012/9/3/83 * Kernels after 3.6-rc6 are known good. * https://lkml.org/lkml/2012/9/10/556 * See if the DB is on ext3/ext4, then check for new enough kernel * Kernels 2.6.32.60, 2.6.34.15, 3.2.30, and 3.5.4 are also known * to be patched. */ { struct statfs st; fstatfs(env->me_fd, &st); while (st.f_type == 0xEF53) { struct utsname uts; int i; uname(&uts); if (uts.release[0] < '3') { if (!strncmp(uts.release, "2.6.32.", 7)) { i = atoi(uts.release+7); if (i >= 60) break; /* 2.6.32.60 and newer is OK */ } else if (!strncmp(uts.release, "2.6.34.", 7)) { i = atoi(uts.release+7); if (i >= 15) break; /* 2.6.34.15 and newer is OK */ } } else if (uts.release[0] == '3') { i = atoi(uts.release+2); if (i > 5) break; /* 3.6 and newer is OK */ if (i == 5) { i = atoi(uts.release+4); if (i >= 4) break; /* 3.5.4 and newer is OK */ } else if (i == 2) { i = atoi(uts.release+4); if (i >= 30) break; /* 3.2.30 and newer is OK */ } } else { /* 4.x and newer is OK */ break; } env->me_fsynconly = 1; break; } } #endif if ((i = mdb_env_read_header(env, &meta)) != 0) { if (i != ENOENT) return i; DPUTS("new mdbenv"); newenv = 1; env->me_psize = env->me_os_psize; if (env->me_psize > MAX_PAGESIZE) env->me_psize = MAX_PAGESIZE; memset(&meta, 0, sizeof(meta)); mdb_env_init_meta0(env, &meta); meta.mm_mapsize = DEFAULT_MAPSIZE; } else { env->me_psize = meta.mm_psize; } /* Was a mapsize configured? */ if (!env->me_mapsize) { env->me_mapsize = meta.mm_mapsize; } { /* Make sure mapsize >= committed data size. Even when using * mm_mapsize, which could be broken in old files (ITS#7789). */ size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize; if (env->me_mapsize < minsize) env->me_mapsize = minsize; } meta.mm_mapsize = env->me_mapsize; if (newenv && !(flags & MDB_FIXEDMAP)) { /* mdb_env_map() may grow the datafile. Write the metapages * first, so the file will be valid if initialization fails. * Except with FIXEDMAP, since we do not yet know mm_address. * We could fill in mm_address later, but then a different * program might end up doing that - one with a memory layout * and map address which does not suit the main program. */ rc = mdb_env_init_meta(env, &meta); if (rc) return rc; newenv = 0; } rc = mdb_env_map(env, (flags & MDB_FIXEDMAP) ? meta.mm_address : NULL); if (rc) return rc; if (newenv) { if (flags & MDB_FIXEDMAP) meta.mm_address = env->me_map; i = mdb_env_init_meta(env, &meta); if (i != MDB_SUCCESS) { return i; } } env->me_maxfree_1pg = (env->me_psize - PAGEHDRSZ) / sizeof(pgno_t) - 1; env->me_nodemax = (((env->me_psize - PAGEHDRSZ) / MDB_MINKEYS) & -2) - sizeof(indx_t); #if !(MDB_MAXKEYSIZE) env->me_maxkey = env->me_nodemax - (NODESIZE + sizeof(MDB_db)); #endif env->me_maxpg = env->me_mapsize / env->me_psize; #if MDB_DEBUG { int toggle = mdb_env_pick_meta(env); MDB_db *db = &env->me_metas[toggle]->mm_dbs[MAIN_DBI]; DPRINTF(("opened database version %u, pagesize %u", env->me_metas[0]->mm_version, env->me_psize)); DPRINTF(("using meta page %d", toggle)); DPRINTF(("depth: %u", db->md_depth)); DPRINTF(("entries: %"Z"u", db->md_entries)); DPRINTF(("branch pages: %"Z"u", db->md_branch_pages)); DPRINTF(("leaf pages: %"Z"u", db->md_leaf_pages)); DPRINTF(("overflow pages: %"Z"u", db->md_overflow_pages)); DPRINTF(("root: %"Z"u", db->md_root)); } #endif return MDB_SUCCESS; } /** Release a reader thread's slot in the reader lock table. * This function is called automatically when a thread exits. * @param[in] ptr This points to the slot in the reader lock table. */ static void mdb_env_reader_dest(void *ptr) { MDB_reader *reader = ptr; reader->mr_pid = 0; } #ifdef _WIN32 /** Junk for arranging thread-specific callbacks on Windows. This is * necessarily platform and compiler-specific. Windows supports up * to 1088 keys. Let's assume nobody opens more than 64 environments * in a single process, for now. They can override this if needed. */ #ifndef MAX_TLS_KEYS #define MAX_TLS_KEYS 64 #endif static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS]; static int mdb_tls_nkeys; static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr) { int i; switch(reason) { case DLL_PROCESS_ATTACH: break; case DLL_THREAD_ATTACH: break; case DLL_THREAD_DETACH: for (i=0; ime_txns->mti_txnid = env->me_metas[toggle]->mm_txnid; #ifdef _WIN32 { OVERLAPPED ov; /* First acquire a shared lock. The Unlock will * then release the existing exclusive lock. */ memset(&ov, 0, sizeof(ov)); if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) { rc = ErrCode(); } else { UnlockFile(env->me_lfd, 0, 0, 1, 0); *excl = 0; } } #else { struct flock lock_info; /* The shared lock replaces the existing lock */ memset((void *)&lock_info, 0, sizeof(lock_info)); lock_info.l_type = F_RDLCK; lock_info.l_whence = SEEK_SET; lock_info.l_start = 0; lock_info.l_len = 1; while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) && (rc = ErrCode()) == EINTR) ; *excl = rc ? -1 : 0; /* error may mean we lost the lock */ } #endif return rc; } /** Try to get exclusive lock, otherwise shared. * Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive. */ static int ESECT mdb_env_excl_lock(MDB_env *env, int *excl) { int rc = 0; #ifdef _WIN32 if (LockFile(env->me_lfd, 0, 0, 1, 0)) { *excl = 1; } else { OVERLAPPED ov; memset(&ov, 0, sizeof(ov)); if (LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) { *excl = 0; } else { rc = ErrCode(); } } #else struct flock lock_info; memset((void *)&lock_info, 0, sizeof(lock_info)); lock_info.l_type = F_WRLCK; lock_info.l_whence = SEEK_SET; lock_info.l_start = 0; lock_info.l_len = 1; while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) && (rc = ErrCode()) == EINTR) ; if (!rc) { *excl = 1; } else # ifdef MDB_USE_SYSV_SEM if (*excl < 0) /* always true when !MDB_USE_SYSV_SEM */ # endif { lock_info.l_type = F_RDLCK; while ((rc = fcntl(env->me_lfd, F_SETLKW, &lock_info)) && (rc = ErrCode()) == EINTR) ; if (rc == 0) *excl = 0; } #endif return rc; } #ifdef MDB_USE_HASH /* * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code * * @(#) $Revision: 5.1 $ * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $ * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $ * * http://www.isthe.com/chongo/tech/comp/fnv/index.html * *** * * Please do not copyright this code. This code is in the public domain. * * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR * PERFORMANCE OF THIS SOFTWARE. * * By: * chongo /\oo/\ * http://www.isthe.com/chongo/ * * Share and Enjoy! :-) */ typedef unsigned long long mdb_hash_t; #define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL) /** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer * @param[in] val value to hash * @param[in] hval initial value for hash * @return 64 bit hash * * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the * hval arg on the first call. */ static mdb_hash_t mdb_hash_val(MDB_val *val, mdb_hash_t hval) { unsigned char *s = (unsigned char *)val->mv_data; /* unsigned string */ unsigned char *end = s + val->mv_size; /* * FNV-1a hash each octet of the string */ while (s < end) { /* xor the bottom with the current octet */ hval ^= (mdb_hash_t)*s++; /* multiply by the 64 bit FNV magic prime mod 2^64 */ hval += (hval << 1) + (hval << 4) + (hval << 5) + (hval << 7) + (hval << 8) + (hval << 40); } /* return our new hash value */ return hval; } /** Hash the string and output the encoded hash. * This uses modified RFC1924 Ascii85 encoding to accommodate systems with * very short name limits. We don't care about the encoding being reversible, * we just want to preserve as many bits of the input as possible in a * small printable string. * @param[in] str string to hash * @param[out] encbuf an array of 11 chars to hold the hash */ static const char mdb_a85[]= "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~"; static void mdb_pack85(unsigned long l, char *out) { int i; for (i=0; i<5; i++) { *out++ = mdb_a85[l % 85]; l /= 85; } } static void mdb_hash_enc(MDB_val *val, char *encbuf) { mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT); mdb_pack85(h, encbuf); mdb_pack85(h>>32, encbuf+5); encbuf[10] = '\0'; } #endif /** Open and/or initialize the lock region for the environment. * @param[in] env The LMDB environment. * @param[in] lpath The pathname of the file used for the lock region. * @param[in] mode The Unix permissions for the file, if we create it. * @param[in,out] excl In -1, out lock type: -1 none, 0 shared, 1 exclusive * @return 0 on success, non-zero on failure. */ static int ESECT mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl) { #ifdef _WIN32 # define MDB_ERRCODE_ROFS ERROR_WRITE_PROTECT #else # define MDB_ERRCODE_ROFS EROFS #ifdef O_CLOEXEC /* Linux: Open file and set FD_CLOEXEC atomically */ # define MDB_CLOEXEC O_CLOEXEC #else int fdflags; # define MDB_CLOEXEC 0 #endif #endif int rc; off_t size, rsize; #ifdef _WIN32 env->me_lfd = CreateFile(lpath, GENERIC_READ|GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL); #else env->me_lfd = open(lpath, O_RDWR|O_CREAT|MDB_CLOEXEC, mode); #endif if (env->me_lfd == INVALID_HANDLE_VALUE) { rc = ErrCode(); if (rc == MDB_ERRCODE_ROFS && (env->me_flags & MDB_RDONLY)) { return MDB_SUCCESS; } goto fail_errno; } #if ! ((MDB_CLOEXEC) || defined(_WIN32)) /* Lose record locks when exec*() */ if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0) fcntl(env->me_lfd, F_SETFD, fdflags); #endif if (!(env->me_flags & MDB_NOTLS)) { rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest); if (rc) goto fail; env->me_flags |= MDB_ENV_TXKEY; #ifdef _WIN32 /* Windows TLS callbacks need help finding their TLS info. */ if (mdb_tls_nkeys >= MAX_TLS_KEYS) { rc = MDB_TLS_FULL; goto fail; } mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey; #endif } /* Try to get exclusive lock. If we succeed, then * nobody is using the lock region and we should initialize it. */ if ((rc = mdb_env_excl_lock(env, excl))) goto fail; #ifdef _WIN32 size = GetFileSize(env->me_lfd, NULL); #else size = lseek(env->me_lfd, 0, SEEK_END); if (size == -1) goto fail_errno; #endif rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo); if (size < rsize && *excl > 0) { #ifdef _WIN32 if (SetFilePointer(env->me_lfd, rsize, NULL, FILE_BEGIN) != (DWORD)rsize || !SetEndOfFile(env->me_lfd)) goto fail_errno; #else if (ftruncate(env->me_lfd, rsize) != 0) goto fail_errno; #endif } else { rsize = size; size = rsize - sizeof(MDB_txninfo); env->me_maxreaders = size/sizeof(MDB_reader) + 1; } { #ifdef _WIN32 HANDLE mh; mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE, 0, 0, NULL); if (!mh) goto fail_errno; env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL); CloseHandle(mh); if (!env->me_txns) goto fail_errno; #else void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED, env->me_lfd, 0); if (m == MAP_FAILED) goto fail_errno; env->me_txns = m; #endif } if (*excl > 0) { #ifdef _WIN32 BY_HANDLE_FILE_INFORMATION stbuf; struct { DWORD volume; DWORD nhigh; DWORD nlow; } idbuf; MDB_val val; char encbuf[11]; if (!mdb_sec_inited) { InitializeSecurityDescriptor(&mdb_null_sd, SECURITY_DESCRIPTOR_REVISION); SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE); mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES); mdb_all_sa.bInheritHandle = FALSE; mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd; mdb_sec_inited = 1; } if (!GetFileInformationByHandle(env->me_lfd, &stbuf)) goto fail_errno; idbuf.volume = stbuf.dwVolumeSerialNumber; idbuf.nhigh = stbuf.nFileIndexHigh; idbuf.nlow = stbuf.nFileIndexLow; val.mv_data = &idbuf; val.mv_size = sizeof(idbuf); mdb_hash_enc(&val, encbuf); sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", encbuf); sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", encbuf); env->me_rmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_rmname); if (!env->me_rmutex) goto fail_errno; env->me_wmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_wmname); if (!env->me_wmutex) goto fail_errno; #elif defined(MDB_USE_SYSV_SEM) union semun semu; unsigned short vals[2] = {1, 1}; int semid = semget(IPC_PRIVATE, 2, mode); if (semid < 0) goto fail_errno; env->me_rmutex.semid = semid; env->me_wmutex.semid = semid; env->me_rmutex.semnum = 0; env->me_wmutex.semnum = 1; semu.array = vals; if (semctl(semid, 0, SETALL, semu) < 0) goto fail_errno; env->me_txns->mti_semid = semid; #else /* MDB_USE_SYSV_SEM */ pthread_mutexattr_t mattr; if ((rc = pthread_mutexattr_init(&mattr)) || (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED)) #ifdef MDB_ROBUST_SUPPORTED || (rc = pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST)) #endif || (rc = pthread_mutex_init(&env->me_txns->mti_rmutex, &mattr)) || (rc = pthread_mutex_init(&env->me_txns->mti_wmutex, &mattr))) goto fail; pthread_mutexattr_destroy(&mattr); #endif /* _WIN32 || MDB_USE_SYSV_SEM */ env->me_txns->mti_magic = MDB_MAGIC; env->me_txns->mti_format = MDB_LOCK_FORMAT; env->me_txns->mti_txnid = 0; env->me_txns->mti_numreaders = 0; } else { #ifdef MDB_USE_SYSV_SEM struct semid_ds buf; union semun semu; int semid; #endif if (env->me_txns->mti_magic != MDB_MAGIC) { DPUTS("lock region has invalid magic"); rc = MDB_INVALID; goto fail; } if (env->me_txns->mti_format != MDB_LOCK_FORMAT) { DPRINTF(("lock region has format+version 0x%x, expected 0x%x", env->me_txns->mti_format, MDB_LOCK_FORMAT)); rc = MDB_VERSION_MISMATCH; goto fail; } rc = ErrCode(); if (rc && rc != EACCES && rc != EAGAIN) { goto fail; } #ifdef _WIN32 env->me_rmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname); if (!env->me_rmutex) goto fail_errno; env->me_wmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname); if (!env->me_wmutex) goto fail_errno; #elif defined(MDB_USE_SYSV_SEM) semid = env->me_txns->mti_semid; semu.buf = &buf; /* check for read access */ if (semctl(semid, 0, IPC_STAT, semu) < 0) goto fail_errno; /* check for write access */ if (semctl(semid, 0, IPC_SET, semu) < 0) goto fail_errno; env->me_rmutex.semid = semid; env->me_wmutex.semid = semid; env->me_rmutex.semnum = 0; env->me_wmutex.semnum = 1; #endif } return MDB_SUCCESS; fail_errno: rc = ErrCode(); fail: return rc; } /** The name of the lock file in the DB environment */ #define LOCKNAME "/lock.mdb" /** The name of the data file in the DB environment */ #define DATANAME "/data.mdb" /** The suffix of the lock file when no subdir is used */ #define LOCKSUFF "-lock" /** Only a subset of the @ref mdb_env flags can be changed * at runtime. Changing other flags requires closing the * environment and re-opening it with the new flags. */ #define CHANGEABLE (MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC|MDB_NOMEMINIT) #define CHANGELESS (MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY| \ MDB_WRITEMAP|MDB_NOTLS|MDB_NOLOCK|MDB_NORDAHEAD) #if VALID_FLAGS & PERSISTENT_FLAGS & (CHANGEABLE|CHANGELESS) # error "Persistent DB flags & env flags overlap, but both go in mm_flags" #endif int ESECT mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode) { int oflags, rc, len, excl = -1; char *lpath, *dpath; if (env->me_fd!=INVALID_HANDLE_VALUE || (flags & ~(CHANGEABLE|CHANGELESS))) return EINVAL; len = strlen(path); if (flags & MDB_NOSUBDIR) { rc = len + sizeof(LOCKSUFF) + len + 1; } else { rc = len + sizeof(LOCKNAME) + len + sizeof(DATANAME); } lpath = malloc(rc); if (!lpath) return ENOMEM; if (flags & MDB_NOSUBDIR) { dpath = lpath + len + sizeof(LOCKSUFF); sprintf(lpath, "%s" LOCKSUFF, path); strcpy(dpath, path); } else { dpath = lpath + len + sizeof(LOCKNAME); sprintf(lpath, "%s" LOCKNAME, path); sprintf(dpath, "%s" DATANAME, path); } rc = MDB_SUCCESS; flags |= env->me_flags; if (flags & MDB_RDONLY) { /* silently ignore WRITEMAP when we're only getting read access */ flags &= ~MDB_WRITEMAP; } else { if (!((env->me_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)) && (env->me_dirty_list = calloc(MDB_IDL_UM_SIZE, sizeof(MDB_ID2))))) rc = ENOMEM; } env->me_flags = flags |= MDB_ENV_ACTIVE; if (rc) goto leave; env->me_path = strdup(path); env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx)); env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t)); env->me_dbiseqs = calloc(env->me_maxdbs, sizeof(unsigned int)); if (!(env->me_dbxs && env->me_path && env->me_dbflags && env->me_dbiseqs)) { rc = ENOMEM; goto leave; } /* For RDONLY, get lockfile after we know datafile exists */ if (!(flags & (MDB_RDONLY|MDB_NOLOCK))) { rc = mdb_env_setup_locks(env, lpath, mode, &excl); if (rc) goto leave; } #ifdef _WIN32 if (F_ISSET(flags, MDB_RDONLY)) { oflags = GENERIC_READ; len = OPEN_EXISTING; } else { oflags = GENERIC_READ|GENERIC_WRITE; len = OPEN_ALWAYS; } mode = FILE_ATTRIBUTE_NORMAL; env->me_fd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len, mode, NULL); #else if (F_ISSET(flags, MDB_RDONLY)) oflags = O_RDONLY; else oflags = O_RDWR | O_CREAT; env->me_fd = open(dpath, oflags, mode); #endif if (env->me_fd == INVALID_HANDLE_VALUE) { rc = ErrCode(); goto leave; } if ((flags & (MDB_RDONLY|MDB_NOLOCK)) == MDB_RDONLY) { rc = mdb_env_setup_locks(env, lpath, mode, &excl); if (rc) goto leave; } if ((rc = mdb_env_open2(env)) == MDB_SUCCESS) { if (flags & (MDB_RDONLY|MDB_WRITEMAP)) { env->me_mfd = env->me_fd; } else { /* Synchronous fd for meta writes. Needed even with * MDB_NOSYNC/MDB_NOMETASYNC, in case these get reset. */ #ifdef _WIN32 len = OPEN_EXISTING; env->me_mfd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len, mode | FILE_FLAG_WRITE_THROUGH, NULL); #else oflags &= ~O_CREAT; env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode); #endif if (env->me_mfd == INVALID_HANDLE_VALUE) { rc = ErrCode(); goto leave; } } DPRINTF(("opened dbenv %p", (void *) env)); if (excl > 0) { rc = mdb_env_share_locks(env, &excl); if (rc) goto leave; } if (!((flags & MDB_RDONLY) || (env->me_pbuf = calloc(1, env->me_psize)))) rc = ENOMEM; if (!(flags & MDB_RDONLY)) { MDB_txn *txn; int tsize = sizeof(MDB_txn), size = tsize + env->me_maxdbs * (sizeof(MDB_db)+sizeof(MDB_cursor *)+sizeof(unsigned int)+1); txn = calloc(1, size); if (txn) { txn->mt_dbs = (MDB_db *)((char *)txn + tsize); txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs); txn->mt_dbiseqs = (unsigned int *)(txn->mt_cursors + env->me_maxdbs); txn->mt_dbflags = (unsigned char *)(txn->mt_dbiseqs + env->me_maxdbs); txn->mt_env = env; txn->mt_dbxs = env->me_dbxs; env->me_txn0 = txn; } else { rc = ENOMEM; } } } leave: if (rc) { mdb_env_close0(env, excl); } free(lpath); return rc; } /** Destroy resources from mdb_env_open(), clear our readers & DBIs */ static void ESECT mdb_env_close0(MDB_env *env, int excl) { int i; if (!(env->me_flags & MDB_ENV_ACTIVE)) return; /* Doing this here since me_dbxs may not exist during mdb_env_close */ for (i = env->me_maxdbs; --i > MAIN_DBI; ) free(env->me_dbxs[i].md_name.mv_data); free(env->me_pbuf); free(env->me_dbiseqs); free(env->me_dbflags); free(env->me_dbxs); free(env->me_path); free(env->me_dirty_list); free(env->me_txn0); mdb_midl_free(env->me_free_pgs); if (env->me_flags & MDB_ENV_TXKEY) { pthread_key_delete(env->me_txkey); #ifdef _WIN32 /* Delete our key from the global list */ for (i=0; ime_txkey) { mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1]; mdb_tls_nkeys--; break; } #endif } if (env->me_map) { munmap(env->me_map, env->me_mapsize); } if (env->me_mfd != env->me_fd && env->me_mfd != INVALID_HANDLE_VALUE) (void) close(env->me_mfd); if (env->me_fd != INVALID_HANDLE_VALUE) (void) close(env->me_fd); if (env->me_txns) { MDB_PID_T pid = env->me_pid; /* Clearing readers is done in this function because * me_txkey with its destructor must be disabled first. */ for (i = env->me_numreaders; --i >= 0; ) if (env->me_txns->mti_readers[i].mr_pid == pid) env->me_txns->mti_readers[i].mr_pid = 0; #ifdef _WIN32 if (env->me_rmutex) { CloseHandle(env->me_rmutex); if (env->me_wmutex) CloseHandle(env->me_wmutex); } /* Windows automatically destroys the mutexes when * the last handle closes. */ #elif defined(MDB_USE_SYSV_SEM) if (env->me_rmutex.semid != -1) { /* If we have the filelock: If we are the * only remaining user, clean up semaphores. */ if (excl == 0) mdb_env_excl_lock(env, &excl); if (excl > 0) semctl(env->me_rmutex.semid, 0, IPC_RMID); } #endif munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo)); } if (env->me_lfd != INVALID_HANDLE_VALUE) { #ifdef _WIN32 if (excl >= 0) { /* Unlock the lockfile. Windows would have unlocked it * after closing anyway, but not necessarily at once. */ UnlockFile(env->me_lfd, 0, 0, 1, 0); } #endif (void) close(env->me_lfd); } env->me_flags &= ~(MDB_ENV_ACTIVE|MDB_ENV_TXKEY); } void ESECT mdb_env_close(MDB_env *env) { MDB_page *dp; if (env == NULL) return; VGMEMP_DESTROY(env); while ((dp = env->me_dpages) != NULL) { VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next)); env->me_dpages = dp->mp_next; free(dp); } mdb_env_close0(env, 0); free(env); } /** Compare two items pointing at aligned size_t's */ static int mdb_cmp_long(const MDB_val *a, const MDB_val *b) { return (*(size_t *)a->mv_data < *(size_t *)b->mv_data) ? -1 : *(size_t *)a->mv_data > *(size_t *)b->mv_data; } /** Compare two items pointing at aligned unsigned int's */ static int mdb_cmp_int(const MDB_val *a, const MDB_val *b) { return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 : *(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data; } /** Compare two items pointing at unsigned ints of unknown alignment. * Nodes and keys are guaranteed to be 2-byte aligned. */ static int mdb_cmp_cint(const MDB_val *a, const MDB_val *b) { #if BYTE_ORDER == LITTLE_ENDIAN unsigned short *u, *c; int x; u = (unsigned short *) ((char *) a->mv_data + a->mv_size); c = (unsigned short *) ((char *) b->mv_data + a->mv_size); do { x = *--u - *--c; } while(!x && u > (unsigned short *)a->mv_data); return x; #else unsigned short *u, *c, *end; int x; end = (unsigned short *) ((char *) a->mv_data + a->mv_size); u = (unsigned short *)a->mv_data; c = (unsigned short *)b->mv_data; do { x = *u++ - *c++; } while(!x && u < end); return x; #endif } /** Compare two items pointing at size_t's of unknown alignment. */ #ifdef MISALIGNED_OK # define mdb_cmp_clong mdb_cmp_long #else # define mdb_cmp_clong mdb_cmp_cint #endif /** Compare two items lexically */ static int mdb_cmp_memn(const MDB_val *a, const MDB_val *b) { int diff; ssize_t len_diff; unsigned int len; len = a->mv_size; len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size; if (len_diff > 0) { len = b->mv_size; len_diff = 1; } diff = memcmp(a->mv_data, b->mv_data, len); return diff ? diff : len_diff<0 ? -1 : len_diff; } /** Compare two items in reverse byte order */ static int mdb_cmp_memnr(const MDB_val *a, const MDB_val *b) { const unsigned char *p1, *p2, *p1_lim; ssize_t len_diff; int diff; p1_lim = (const unsigned char *)a->mv_data; p1 = (const unsigned char *)a->mv_data + a->mv_size; p2 = (const unsigned char *)b->mv_data + b->mv_size; len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size; if (len_diff > 0) { p1_lim += len_diff; len_diff = 1; } while (p1 > p1_lim) { diff = *--p1 - *--p2; if (diff) return diff; } return len_diff<0 ? -1 : len_diff; } /** Search for key within a page, using binary search. * Returns the smallest entry larger or equal to the key. * If exactp is non-null, stores whether the found entry was an exact match * in *exactp (1 or 0). * Updates the cursor index with the index of the found entry. * If no entry larger or equal to the key is found, returns NULL. */ static MDB_node * mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp) { unsigned int i = 0, nkeys; int low, high; int rc = 0; MDB_page *mp = mc->mc_pg[mc->mc_top]; MDB_node *node = NULL; MDB_val nodekey; MDB_cmp_func *cmp; DKBUF; nkeys = NUMKEYS(mp); DPRINTF(("searching %u keys in %s %spage %"Z"u", nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "", mdb_dbg_pgno(mp))); low = IS_LEAF(mp) ? 0 : 1; high = nkeys - 1; cmp = mc->mc_dbx->md_cmp; /* Branch pages have no data, so if using integer keys, * alignment is guaranteed. Use faster mdb_cmp_int. */ if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) { if (NODEPTR(mp, 1)->mn_ksize == sizeof(size_t)) cmp = mdb_cmp_long; else cmp = mdb_cmp_int; } if (IS_LEAF2(mp)) { nodekey.mv_size = mc->mc_db->md_pad; node = NODEPTR(mp, 0); /* fake */ while (low <= high) { i = (low + high) >> 1; nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size); rc = cmp(key, &nodekey); DPRINTF(("found leaf index %u [%s], rc = %i", i, DKEY(&nodekey), rc)); if (rc == 0) break; if (rc > 0) low = i + 1; else high = i - 1; } } else { while (low <= high) { i = (low + high) >> 1; node = NODEPTR(mp, i); nodekey.mv_size = NODEKSZ(node); nodekey.mv_data = NODEKEY(node); rc = cmp(key, &nodekey); #if MDB_DEBUG if (IS_LEAF(mp)) DPRINTF(("found leaf index %u [%s], rc = %i", i, DKEY(&nodekey), rc)); else DPRINTF(("found branch index %u [%s -> %"Z"u], rc = %i", i, DKEY(&nodekey), NODEPGNO(node), rc)); #endif if (rc == 0) break; if (rc > 0) low = i + 1; else high = i - 1; } } if (rc > 0) { /* Found entry is less than the key. */ i++; /* Skip to get the smallest entry larger than key. */ if (!IS_LEAF2(mp)) node = NODEPTR(mp, i); } if (exactp) *exactp = (rc == 0 && nkeys > 0); /* store the key index */ mc->mc_ki[mc->mc_top] = i; if (i >= nkeys) /* There is no entry larger or equal to the key. */ return NULL; /* nodeptr is fake for LEAF2 */ return node; } #if 0 static void mdb_cursor_adjust(MDB_cursor *mc, func) { MDB_cursor *m2; for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) { if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) { func(mc, m2); } } } #endif /** Pop a page off the top of the cursor's stack. */ static void mdb_cursor_pop(MDB_cursor *mc) { if (mc->mc_snum) { #if MDB_DEBUG MDB_page *top = mc->mc_pg[mc->mc_top]; #endif mc->mc_snum--; if (mc->mc_snum) mc->mc_top--; DPRINTF(("popped page %"Z"u off db %d cursor %p", top->mp_pgno, DDBI(mc), (void *) mc)); } } /** Push a page onto the top of the cursor's stack. */ static int mdb_cursor_push(MDB_cursor *mc, MDB_page *mp) { DPRINTF(("pushing page %"Z"u on db %d cursor %p", mp->mp_pgno, DDBI(mc), (void *) mc)); if (mc->mc_snum >= CURSOR_STACK) { mc->mc_txn->mt_flags |= MDB_TXN_ERROR; return MDB_CURSOR_FULL; } mc->mc_top = mc->mc_snum++; mc->mc_pg[mc->mc_top] = mp; mc->mc_ki[mc->mc_top] = 0; return MDB_SUCCESS; } /** Find the address of the page corresponding to a given page number. * @param[in] txn the transaction for this access. * @param[in] pgno the page number for the page to retrieve. * @param[out] ret address of a pointer where the page's address will be stored. * @param[out] lvl dirty_list inheritance level of found page. 1=current txn, 0=mapped page. * @return 0 on success, non-zero on failure. */ static int mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret, int *lvl) { MDB_env *env = txn->mt_env; MDB_page *p = NULL; int level; if (!((txn->mt_flags & MDB_TXN_RDONLY) | (env->me_flags & MDB_WRITEMAP))) { MDB_txn *tx2 = txn; level = 1; do { MDB_ID2L dl = tx2->mt_u.dirty_list; unsigned x; /* Spilled pages were dirtied in this txn and flushed * because the dirty list got full. Bring this page * back in from the map (but don't unspill it here, * leave that unless page_touch happens again). */ if (tx2->mt_spill_pgs) { MDB_ID pn = pgno << 1; x = mdb_midl_search(tx2->mt_spill_pgs, pn); if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) { p = (MDB_page *)(env->me_map + env->me_psize * pgno); goto done; } } if (dl[0].mid) { unsigned x = mdb_mid2l_search(dl, pgno); if (x <= dl[0].mid && dl[x].mid == pgno) { p = dl[x].mptr; goto done; } } level++; } while ((tx2 = tx2->mt_parent) != NULL); } if (pgno < txn->mt_next_pgno) { level = 0; p = (MDB_page *)(env->me_map + env->me_psize * pgno); } else { DPRINTF(("page %"Z"u not found", pgno)); txn->mt_flags |= MDB_TXN_ERROR; return MDB_PAGE_NOTFOUND; } done: *ret = p; if (lvl) *lvl = level; return MDB_SUCCESS; } /** Finish #mdb_page_search() / #mdb_page_search_lowest(). * The cursor is at the root page, set up the rest of it. */ static int mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags) { MDB_page *mp = mc->mc_pg[mc->mc_top]; int rc; DKBUF; while (IS_BRANCH(mp)) { MDB_node *node; indx_t i; DPRINTF(("branch page %"Z"u has %u keys", mp->mp_pgno, NUMKEYS(mp))); mdb_cassert(mc, NUMKEYS(mp) > 1); DPRINTF(("found index 0 to page %"Z"u", NODEPGNO(NODEPTR(mp, 0)))); if (flags & (MDB_PS_FIRST|MDB_PS_LAST)) { i = 0; if (flags & MDB_PS_LAST) i = NUMKEYS(mp) - 1; } else { int exact; node = mdb_node_search(mc, key, &exact); if (node == NULL) i = NUMKEYS(mp) - 1; else { i = mc->mc_ki[mc->mc_top]; if (!exact) { mdb_cassert(mc, i > 0); i--; } } DPRINTF(("following index %u for key [%s]", i, DKEY(key))); } mdb_cassert(mc, i < NUMKEYS(mp)); node = NODEPTR(mp, i); if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0) return rc; mc->mc_ki[mc->mc_top] = i; if ((rc = mdb_cursor_push(mc, mp))) return rc; if (flags & MDB_PS_MODIFY) { if ((rc = mdb_page_touch(mc)) != 0) return rc; mp = mc->mc_pg[mc->mc_top]; } } if (!IS_LEAF(mp)) { DPRINTF(("internal error, index points to a %02X page!?", mp->mp_flags)); mc->mc_txn->mt_flags |= MDB_TXN_ERROR; return MDB_CORRUPTED; } DPRINTF(("found leaf page %"Z"u for key [%s]", mp->mp_pgno, key ? DKEY(key) : "null")); mc->mc_flags |= C_INITIALIZED; mc->mc_flags &= ~C_EOF; return MDB_SUCCESS; } /** Search for the lowest key under the current branch page. * This just bypasses a NUMKEYS check in the current page * before calling mdb_page_search_root(), because the callers * are all in situations where the current page is known to * be underfilled. */ static int mdb_page_search_lowest(MDB_cursor *mc) { MDB_page *mp = mc->mc_pg[mc->mc_top]; MDB_node *node = NODEPTR(mp, 0); int rc; if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0) return rc; mc->mc_ki[mc->mc_top] = 0; if ((rc = mdb_cursor_push(mc, mp))) return rc; return mdb_page_search_root(mc, NULL, MDB_PS_FIRST); } /** Search for the page a given key should be in. * Push it and its parent pages on the cursor stack. * @param[in,out] mc the cursor for this operation. * @param[in] key the key to search for, or NULL for first/last page. * @param[in] flags If MDB_PS_MODIFY is set, visited pages in the DB * are touched (updated with new page numbers). * If MDB_PS_FIRST or MDB_PS_LAST is set, find first or last leaf. * This is used by #mdb_cursor_first() and #mdb_cursor_last(). * If MDB_PS_ROOTONLY set, just fetch root node, no further lookups. * @return 0 on success, non-zero on failure. */ static int mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags) { int rc; pgno_t root; /* Make sure the txn is still viable, then find the root from * the txn's db table and set it as the root of the cursor's stack. */ if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_ERROR)) { DPUTS("transaction has failed, must abort"); return MDB_BAD_TXN; } else { /* Make sure we're using an up-to-date root */ if (*mc->mc_dbflag & DB_STALE) { MDB_cursor mc2; if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi)) return MDB_BAD_DBI; mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL); rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, 0); if (rc) return rc; { MDB_val data; int exact = 0; uint16_t flags; MDB_node *leaf = mdb_node_search(&mc2, &mc->mc_dbx->md_name, &exact); if (!exact) return MDB_NOTFOUND; rc = mdb_node_read(mc->mc_txn, leaf, &data); if (rc) return rc; memcpy(&flags, ((char *) data.mv_data + offsetof(MDB_db, md_flags)), sizeof(uint16_t)); /* The txn may not know this DBI, or another process may * have dropped and recreated the DB with other flags. */ if ((mc->mc_db->md_flags & PERSISTENT_FLAGS) != flags) return MDB_INCOMPATIBLE; memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db)); } *mc->mc_dbflag &= ~DB_STALE; } root = mc->mc_db->md_root; if (root == P_INVALID) { /* Tree is empty. */ DPUTS("tree is empty"); return MDB_NOTFOUND; } } mdb_cassert(mc, root > 1); if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root) if ((rc = mdb_page_get(mc->mc_txn, root, &mc->mc_pg[0], NULL)) != 0) return rc; mc->mc_snum = 1; mc->mc_top = 0; DPRINTF(("db %d root page %"Z"u has flags 0x%X", DDBI(mc), root, mc->mc_pg[0]->mp_flags)); if (flags & MDB_PS_MODIFY) { if ((rc = mdb_page_touch(mc))) return rc; } if (flags & MDB_PS_ROOTONLY) return MDB_SUCCESS; return mdb_page_search_root(mc, key, flags); } static int mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp) { MDB_txn *txn = mc->mc_txn; pgno_t pg = mp->mp_pgno; unsigned x = 0, ovpages = mp->mp_pages; MDB_env *env = txn->mt_env; MDB_IDL sl = txn->mt_spill_pgs; MDB_ID pn = pg << 1; int rc; DPRINTF(("free ov page %"Z"u (%d)", pg, ovpages)); /* If the page is dirty or on the spill list we just acquired it, * so we should give it back to our current free list, if any. * Otherwise put it onto the list of pages we freed in this txn. * * Won't create me_pghead: me_pglast must be inited along with it. * Unsupported in nested txns: They would need to hide the page * range in ancestor txns' dirty and spilled lists. */ if (env->me_pghead && !txn->mt_parent && ((mp->mp_flags & P_DIRTY) || (sl && (x = mdb_midl_search(sl, pn)) <= sl[0] && sl[x] == pn))) { unsigned i, j; pgno_t *mop; MDB_ID2 *dl, ix, iy; rc = mdb_midl_need(&env->me_pghead, ovpages); if (rc) return rc; if (!(mp->mp_flags & P_DIRTY)) { /* This page is no longer spilled */ if (x == sl[0]) sl[0]--; else sl[x] |= 1; goto release; } /* Remove from dirty list */ dl = txn->mt_u.dirty_list; x = dl[0].mid--; for (ix = dl[x]; ix.mptr != mp; ix = iy) { if (x > 1) { x--; iy = dl[x]; dl[x] = ix; } else { mdb_cassert(mc, x > 1); j = ++(dl[0].mid); dl[j] = ix; /* Unsorted. OK when MDB_TXN_ERROR. */ txn->mt_flags |= MDB_TXN_ERROR; return MDB_CORRUPTED; } } if (!(env->me_flags & MDB_WRITEMAP)) mdb_dpage_free(env, mp); release: /* Insert in me_pghead */ mop = env->me_pghead; j = mop[0] + ovpages; for (i = mop[0]; i && mop[i] < pg; i--) mop[j--] = mop[i]; while (j>i) mop[j--] = pg++; mop[0] += ovpages; } else { rc = mdb_midl_append_range(&txn->mt_free_pgs, pg, ovpages); if (rc) return rc; } mc->mc_db->md_overflow_pages -= ovpages; return 0; } /** Return the data associated with a given node. * @param[in] txn The transaction for this operation. * @param[in] leaf The node being read. * @param[out] data Updated to point to the node's data. * @return 0 on success, non-zero on failure. */ static int mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data) { MDB_page *omp; /* overflow page */ pgno_t pgno; int rc; if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) { data->mv_size = NODEDSZ(leaf); data->mv_data = NODEDATA(leaf); return MDB_SUCCESS; } /* Read overflow data. */ data->mv_size = NODEDSZ(leaf); memcpy(&pgno, NODEDATA(leaf), sizeof(pgno)); if ((rc = mdb_page_get(txn, pgno, &omp, NULL)) != 0) { DPRINTF(("read overflow page %"Z"u failed", pgno)); return rc; } data->mv_data = METADATA(omp); return MDB_SUCCESS; } int mdb_get(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data) { MDB_cursor mc; MDB_xcursor mx; int exact = 0; DKBUF; DPRINTF(("===> get db %u key [%s]", dbi, DKEY(key))); if (!key || !data || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi)) return EINVAL; if (txn->mt_flags & MDB_TXN_ERROR) return MDB_BAD_TXN; mdb_cursor_init(&mc, txn, dbi, &mx); return mdb_cursor_set(&mc, key, data, MDB_SET, &exact); } /** Find a sibling for a page. * Replaces the page at the top of the cursor's stack with the * specified sibling, if one exists. * @param[in] mc The cursor for this operation. * @param[in] move_right Non-zero if the right sibling is requested, * otherwise the left sibling. * @return 0 on success, non-zero on failure. */ static int mdb_cursor_sibling(MDB_cursor *mc, int move_right) { int rc; MDB_node *indx; MDB_page *mp; if (mc->mc_snum < 2) { return MDB_NOTFOUND; /* root has no siblings */ } mdb_cursor_pop(mc); DPRINTF(("parent page is page %"Z"u, index %u", mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top])); if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top])) : (mc->mc_ki[mc->mc_top] == 0)) { DPRINTF(("no more keys left, moving to %s sibling", move_right ? "right" : "left")); if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) { /* undo cursor_pop before returning */ mc->mc_top++; mc->mc_snum++; return rc; } } else { if (move_right) mc->mc_ki[mc->mc_top]++; else mc->mc_ki[mc->mc_top]--; DPRINTF(("just moving to %s index key %u", move_right ? "right" : "left", mc->mc_ki[mc->mc_top])); } mdb_cassert(mc, IS_BRANCH(mc->mc_pg[mc->mc_top])); indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(indx), &mp, NULL)) != 0) { /* mc will be inconsistent if caller does mc_snum++ as above */ mc->mc_flags &= ~(C_INITIALIZED|C_EOF); return rc; } mdb_cursor_push(mc, mp); if (!move_right) mc->mc_ki[mc->mc_top] = NUMKEYS(mp)-1; return MDB_SUCCESS; } /** Move the cursor to the next data item. */ static int mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op) { MDB_page *mp; MDB_node *leaf; int rc; if (mc->mc_flags & C_EOF) { return MDB_NOTFOUND; } mdb_cassert(mc, mc->mc_flags & C_INITIALIZED); mp = mc->mc_pg[mc->mc_top]; if (mc->mc_db->md_flags & MDB_DUPSORT) { leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { if (op == MDB_NEXT || op == MDB_NEXT_DUP) { rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT); if (op != MDB_NEXT || rc != MDB_NOTFOUND) { if (rc == MDB_SUCCESS) MDB_GET_KEY(leaf, key); return rc; } } } else { mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF); if (op == MDB_NEXT_DUP) return MDB_NOTFOUND; } } DPRINTF(("cursor_next: top page is %"Z"u in cursor %p", mdb_dbg_pgno(mp), (void *) mc)); if (mc->mc_flags & C_DEL) goto skip; if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) { DPUTS("=====> move to next sibling page"); if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) { mc->mc_flags |= C_EOF; return rc; } mp = mc->mc_pg[mc->mc_top]; DPRINTF(("next page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top])); } else mc->mc_ki[mc->mc_top]++; skip: DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u", mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top])); if (IS_LEAF2(mp)) { key->mv_size = mc->mc_db->md_pad; key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size); return MDB_SUCCESS; } mdb_cassert(mc, IS_LEAF(mp)); leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdb_xcursor_init1(mc, leaf); } if (data) { if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS) return rc; if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL); if (rc != MDB_SUCCESS) return rc; } } MDB_GET_KEY(leaf, key); return MDB_SUCCESS; } /** Move the cursor to the previous data item. */ static int mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op) { MDB_page *mp; MDB_node *leaf; int rc; mdb_cassert(mc, mc->mc_flags & C_INITIALIZED); mp = mc->mc_pg[mc->mc_top]; if (mc->mc_db->md_flags & MDB_DUPSORT) { leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { if (op == MDB_PREV || op == MDB_PREV_DUP) { rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV); if (op != MDB_PREV || rc != MDB_NOTFOUND) { if (rc == MDB_SUCCESS) { MDB_GET_KEY(leaf, key); mc->mc_flags &= ~C_EOF; } return rc; } } } else { mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF); if (op == MDB_PREV_DUP) return MDB_NOTFOUND; } } DPRINTF(("cursor_prev: top page is %"Z"u in cursor %p", mdb_dbg_pgno(mp), (void *) mc)); if (mc->mc_ki[mc->mc_top] == 0) { DPUTS("=====> move to prev sibling page"); if ((rc = mdb_cursor_sibling(mc, 0)) != MDB_SUCCESS) { return rc; } mp = mc->mc_pg[mc->mc_top]; mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1; DPRINTF(("prev page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top])); } else mc->mc_ki[mc->mc_top]--; mc->mc_flags &= ~C_EOF; DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u", mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top])); if (IS_LEAF2(mp)) { key->mv_size = mc->mc_db->md_pad; key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size); return MDB_SUCCESS; } mdb_cassert(mc, IS_LEAF(mp)); leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdb_xcursor_init1(mc, leaf); } if (data) { if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS) return rc; if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL); if (rc != MDB_SUCCESS) return rc; } } MDB_GET_KEY(leaf, key); return MDB_SUCCESS; } /** Set the cursor on a specific data item. */ static int mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op, int *exactp) { int rc; MDB_page *mp; MDB_node *leaf = NULL; DKBUF; if (key->mv_size == 0) return MDB_BAD_VALSIZE; if (mc->mc_xcursor) mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF); /* See if we're already on the right page */ if (mc->mc_flags & C_INITIALIZED) { MDB_val nodekey; mp = mc->mc_pg[mc->mc_top]; if (!NUMKEYS(mp)) { mc->mc_ki[mc->mc_top] = 0; return MDB_NOTFOUND; } if (mp->mp_flags & P_LEAF2) { nodekey.mv_size = mc->mc_db->md_pad; nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size); } else { leaf = NODEPTR(mp, 0); MDB_GET_KEY2(leaf, nodekey); } rc = mc->mc_dbx->md_cmp(key, &nodekey); if (rc == 0) { /* Probably happens rarely, but first node on the page * was the one we wanted. */ mc->mc_ki[mc->mc_top] = 0; if (exactp) *exactp = 1; goto set1; } if (rc > 0) { unsigned int i; unsigned int nkeys = NUMKEYS(mp); if (nkeys > 1) { if (mp->mp_flags & P_LEAF2) { nodekey.mv_data = LEAF2KEY(mp, nkeys-1, nodekey.mv_size); } else { leaf = NODEPTR(mp, nkeys-1); MDB_GET_KEY2(leaf, nodekey); } rc = mc->mc_dbx->md_cmp(key, &nodekey); if (rc == 0) { /* last node was the one we wanted */ mc->mc_ki[mc->mc_top] = nkeys-1; if (exactp) *exactp = 1; goto set1; } if (rc < 0) { if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) { /* This is definitely the right page, skip search_page */ if (mp->mp_flags & P_LEAF2) { nodekey.mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], nodekey.mv_size); } else { leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); MDB_GET_KEY2(leaf, nodekey); } rc = mc->mc_dbx->md_cmp(key, &nodekey); if (rc == 0) { /* current node was the one we wanted */ if (exactp) *exactp = 1; goto set1; } } rc = 0; goto set2; } } /* If any parents have right-sibs, search. * Otherwise, there's nothing further. */ for (i=0; imc_top; i++) if (mc->mc_ki[i] < NUMKEYS(mc->mc_pg[i])-1) break; if (i == mc->mc_top) { /* There are no other pages */ mc->mc_ki[mc->mc_top] = nkeys; return MDB_NOTFOUND; } } if (!mc->mc_top) { /* There are no other pages */ mc->mc_ki[mc->mc_top] = 0; if (op == MDB_SET_RANGE && !exactp) { rc = 0; goto set1; } else return MDB_NOTFOUND; } } rc = mdb_page_search(mc, key, 0); if (rc != MDB_SUCCESS) return rc; mp = mc->mc_pg[mc->mc_top]; mdb_cassert(mc, IS_LEAF(mp)); set2: leaf = mdb_node_search(mc, key, exactp); if (exactp != NULL && !*exactp) { /* MDB_SET specified and not an exact match. */ return MDB_NOTFOUND; } if (leaf == NULL) { DPUTS("===> inexact leaf not found, goto sibling"); if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) return rc; /* no entries matched */ mp = mc->mc_pg[mc->mc_top]; mdb_cassert(mc, IS_LEAF(mp)); leaf = NODEPTR(mp, 0); } set1: mc->mc_flags |= C_INITIALIZED; mc->mc_flags &= ~C_EOF; if (IS_LEAF2(mp)) { if (op == MDB_SET_RANGE || op == MDB_SET_KEY) { key->mv_size = mc->mc_db->md_pad; key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size); } return MDB_SUCCESS; } if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdb_xcursor_init1(mc, leaf); } if (data) { if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) { rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL); } else { int ex2, *ex2p; if (op == MDB_GET_BOTH) { ex2p = &ex2; ex2 = 0; } else { ex2p = NULL; } rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p); if (rc != MDB_SUCCESS) return rc; } } else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) { MDB_val d2; if ((rc = mdb_node_read(mc->mc_txn, leaf, &d2)) != MDB_SUCCESS) return rc; rc = mc->mc_dbx->md_dcmp(data, &d2); if (rc) { if (op == MDB_GET_BOTH || rc > 0) return MDB_NOTFOUND; rc = 0; *data = d2; } } else { if (mc->mc_xcursor) mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF); if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS) return rc; } } /* The key already matches in all other cases */ if (op == MDB_SET_RANGE || op == MDB_SET_KEY) MDB_GET_KEY(leaf, key); DPRINTF(("==> cursor placed on key [%s]", DKEY(key))); return rc; } /** Move the cursor to the first item in the database. */ static int mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data) { int rc; MDB_node *leaf; if (mc->mc_xcursor) mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF); if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) { rc = mdb_page_search(mc, NULL, MDB_PS_FIRST); if (rc != MDB_SUCCESS) return rc; } mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top])); leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0); mc->mc_flags |= C_INITIALIZED; mc->mc_flags &= ~C_EOF; mc->mc_ki[mc->mc_top] = 0; if (IS_LEAF2(mc->mc_pg[mc->mc_top])) { key->mv_size = mc->mc_db->md_pad; key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size); return MDB_SUCCESS; } if (data) { if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdb_xcursor_init1(mc, leaf); rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL); if (rc) return rc; } else { if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS) return rc; } } MDB_GET_KEY(leaf, key); return MDB_SUCCESS; } /** Move the cursor to the last item in the database. */ static int mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data) { int rc; MDB_node *leaf; if (mc->mc_xcursor) mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF); if (!(mc->mc_flags & C_EOF)) { if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) { rc = mdb_page_search(mc, NULL, MDB_PS_LAST); if (rc != MDB_SUCCESS) return rc; } mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top])); } mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1; mc->mc_flags |= C_INITIALIZED|C_EOF; leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); if (IS_LEAF2(mc->mc_pg[mc->mc_top])) { key->mv_size = mc->mc_db->md_pad; key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size); return MDB_SUCCESS; } if (data) { if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdb_xcursor_init1(mc, leaf); rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL); if (rc) return rc; } else { if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS) return rc; } } MDB_GET_KEY(leaf, key); return MDB_SUCCESS; } int mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op) { int rc; int exact = 0; int (*mfunc)(MDB_cursor *mc, MDB_val *key, MDB_val *data); if (mc == NULL) return EINVAL; if (mc->mc_txn->mt_flags & MDB_TXN_ERROR) return MDB_BAD_TXN; switch (op) { case MDB_GET_CURRENT: if (!(mc->mc_flags & C_INITIALIZED)) { rc = EINVAL; } else { MDB_page *mp = mc->mc_pg[mc->mc_top]; int nkeys = NUMKEYS(mp); if (!nkeys || mc->mc_ki[mc->mc_top] >= nkeys) { mc->mc_ki[mc->mc_top] = nkeys; rc = MDB_NOTFOUND; break; } rc = MDB_SUCCESS; if (IS_LEAF2(mp)) { key->mv_size = mc->mc_db->md_pad; key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size); } else { MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); MDB_GET_KEY(leaf, key); if (data) { if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { if (mc->mc_flags & C_DEL) mdb_xcursor_init1(mc, leaf); rc = mdb_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT); } else { rc = mdb_node_read(mc->mc_txn, leaf, data); } } } } break; case MDB_GET_BOTH: case MDB_GET_BOTH_RANGE: if (data == NULL) { rc = EINVAL; break; } if (mc->mc_xcursor == NULL) { rc = MDB_INCOMPATIBLE; break; } /* FALLTHRU */ case MDB_SET: case MDB_SET_KEY: case MDB_SET_RANGE: if (key == NULL) { rc = EINVAL; } else { rc = mdb_cursor_set(mc, key, data, op, op == MDB_SET_RANGE ? NULL : &exact); } break; case MDB_GET_MULTIPLE: if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) { rc = EINVAL; break; } if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) { rc = MDB_INCOMPATIBLE; break; } rc = MDB_SUCCESS; if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) || (mc->mc_xcursor->mx_cursor.mc_flags & C_EOF)) break; goto fetchm; case MDB_NEXT_MULTIPLE: if (data == NULL) { rc = EINVAL; break; } if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) { rc = MDB_INCOMPATIBLE; break; } if (!(mc->mc_flags & C_INITIALIZED)) rc = mdb_cursor_first(mc, key, data); else rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP); if (rc == MDB_SUCCESS) { if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) { MDB_cursor *mx; fetchm: mx = &mc->mc_xcursor->mx_cursor; data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) * mx->mc_db->md_pad; data->mv_data = METADATA(mx->mc_pg[mx->mc_top]); mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1; } else { rc = MDB_NOTFOUND; } } break; case MDB_NEXT: case MDB_NEXT_DUP: case MDB_NEXT_NODUP: if (!(mc->mc_flags & C_INITIALIZED)) rc = mdb_cursor_first(mc, key, data); else rc = mdb_cursor_next(mc, key, data, op); break; case MDB_PREV: case MDB_PREV_DUP: case MDB_PREV_NODUP: if (!(mc->mc_flags & C_INITIALIZED)) { rc = mdb_cursor_last(mc, key, data); if (rc) break; mc->mc_flags |= C_INITIALIZED; mc->mc_ki[mc->mc_top]++; } rc = mdb_cursor_prev(mc, key, data, op); break; case MDB_FIRST: rc = mdb_cursor_first(mc, key, data); break; case MDB_FIRST_DUP: mfunc = mdb_cursor_first; mmove: if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) { rc = EINVAL; break; } if (mc->mc_xcursor == NULL) { rc = MDB_INCOMPATIBLE; break; } { MDB_node *leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) { MDB_GET_KEY(leaf, key); rc = mdb_node_read(mc->mc_txn, leaf, data); break; } } if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) { rc = EINVAL; break; } rc = mfunc(&mc->mc_xcursor->mx_cursor, data, NULL); break; case MDB_LAST: rc = mdb_cursor_last(mc, key, data); break; case MDB_LAST_DUP: mfunc = mdb_cursor_last; goto mmove; default: DPRINTF(("unhandled/unimplemented cursor operation %u", op)); rc = EINVAL; break; } if (mc->mc_flags & C_DEL) mc->mc_flags ^= C_DEL; return rc; } /** Touch all the pages in the cursor stack. Set mc_top. * Makes sure all the pages are writable, before attempting a write operation. * @param[in] mc The cursor to operate on. */ static int mdb_cursor_touch(MDB_cursor *mc) { int rc = MDB_SUCCESS; if (mc->mc_dbi > MAIN_DBI && !(*mc->mc_dbflag & DB_DIRTY)) { MDB_cursor mc2; MDB_xcursor mcx; if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi)) return MDB_BAD_DBI; mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, &mcx); rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY); if (rc) return rc; *mc->mc_dbflag |= DB_DIRTY; } mc->mc_top = 0; if (mc->mc_snum) { do { rc = mdb_page_touch(mc); } while (!rc && ++(mc->mc_top) < mc->mc_snum); mc->mc_top = mc->mc_snum-1; } return rc; } /** Do not spill pages to disk if txn is getting full, may fail instead */ #define MDB_NOSPILL 0x8000 int mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data, unsigned int flags) { enum { MDB_NO_ROOT = MDB_LAST_ERRCODE+10 }; /* internal code */ MDB_env *env; MDB_node *leaf = NULL; MDB_page *fp, *mp; uint16_t fp_flags; MDB_val xdata, *rdata, dkey, olddata; MDB_db dummy; int do_sub = 0, insert_key, insert_data; unsigned int mcount = 0, dcount = 0, nospill; size_t nsize; int rc, rc2; unsigned int nflags; DKBUF; if (mc == NULL || key == NULL) return EINVAL; env = mc->mc_txn->mt_env; /* Check this first so counter will always be zero on any * early failures. */ if (flags & MDB_MULTIPLE) { dcount = data[1].mv_size; data[1].mv_size = 0; if (!F_ISSET(mc->mc_db->md_flags, MDB_DUPFIXED)) return MDB_INCOMPATIBLE; } nospill = flags & MDB_NOSPILL; flags &= ~MDB_NOSPILL; if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR)) return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN; if (key->mv_size-1 >= ENV_MAXKEY(env)) return MDB_BAD_VALSIZE; #if SIZE_MAX > MAXDATASIZE if (data->mv_size > ((mc->mc_db->md_flags & MDB_DUPSORT) ? ENV_MAXKEY(env) : MAXDATASIZE)) return MDB_BAD_VALSIZE; #else if ((mc->mc_db->md_flags & MDB_DUPSORT) && data->mv_size > ENV_MAXKEY(env)) return MDB_BAD_VALSIZE; #endif DPRINTF(("==> put db %d key [%s], size %"Z"u, data size %"Z"u", DDBI(mc), DKEY(key), key ? key->mv_size : 0, data->mv_size)); dkey.mv_size = 0; if (flags == MDB_CURRENT) { if (!(mc->mc_flags & C_INITIALIZED)) return EINVAL; rc = MDB_SUCCESS; } else if (mc->mc_db->md_root == P_INVALID) { /* new database, cursor has nothing to point to */ mc->mc_snum = 0; mc->mc_top = 0; mc->mc_flags &= ~C_INITIALIZED; rc = MDB_NO_ROOT; } else { int exact = 0; MDB_val d2; if (flags & MDB_APPEND) { MDB_val k2; rc = mdb_cursor_last(mc, &k2, &d2); if (rc == 0) { rc = mc->mc_dbx->md_cmp(key, &k2); if (rc > 0) { rc = MDB_NOTFOUND; mc->mc_ki[mc->mc_top]++; } else { /* new key is <= last key */ rc = MDB_KEYEXIST; } } } else { rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact); } if ((flags & MDB_NOOVERWRITE) && rc == 0) { DPRINTF(("duplicate key [%s]", DKEY(key))); *data = d2; return MDB_KEYEXIST; } if (rc && rc != MDB_NOTFOUND) return rc; } if (mc->mc_flags & C_DEL) mc->mc_flags ^= C_DEL; /* Cursor is positioned, check for room in the dirty list */ if (!nospill) { if (flags & MDB_MULTIPLE) { rdata = &xdata; xdata.mv_size = data->mv_size * dcount; } else { rdata = data; } if ((rc2 = mdb_page_spill(mc, key, rdata))) return rc2; } if (rc == MDB_NO_ROOT) { MDB_page *np; /* new database, write a root leaf page */ DPUTS("allocating new root leaf page"); if ((rc2 = mdb_page_new(mc, P_LEAF, 1, &np))) { return rc2; } mdb_cursor_push(mc, np); mc->mc_db->md_root = np->mp_pgno; mc->mc_db->md_depth++; *mc->mc_dbflag |= DB_DIRTY; if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED)) == MDB_DUPFIXED) np->mp_flags |= P_LEAF2; mc->mc_flags |= C_INITIALIZED; } else { /* make sure all cursor pages are writable */ rc2 = mdb_cursor_touch(mc); if (rc2) return rc2; } insert_key = insert_data = rc; if (insert_key) { /* The key does not exist */ DPRINTF(("inserting key at index %i", mc->mc_ki[mc->mc_top])); if ((mc->mc_db->md_flags & MDB_DUPSORT) && LEAFSIZE(key, data) > env->me_nodemax) { /* Too big for a node, insert in sub-DB. Set up an empty * "old sub-page" for prep_subDB to expand to a full page. */ fp_flags = P_LEAF|P_DIRTY; fp = env->me_pbuf; fp->mp_pad = data->mv_size; /* used if MDB_DUPFIXED */ fp->mp_lower = fp->mp_upper = (PAGEHDRSZ-PAGEBASE); olddata.mv_size = PAGEHDRSZ; goto prep_subDB; } } else { /* there's only a key anyway, so this is a no-op */ if (IS_LEAF2(mc->mc_pg[mc->mc_top])) { char *ptr; unsigned int ksize = mc->mc_db->md_pad; if (key->mv_size != ksize) return MDB_BAD_VALSIZE; ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize); memcpy(ptr, key->mv_data, ksize); fix_parent: /* if overwriting slot 0 of leaf, need to * update branch key if there is a parent page */ if (mc->mc_top && !mc->mc_ki[mc->mc_top]) { unsigned short top = mc->mc_top; mc->mc_top--; /* slot 0 is always an empty key, find real slot */ while (mc->mc_top && !mc->mc_ki[mc->mc_top]) mc->mc_top--; if (mc->mc_ki[mc->mc_top]) rc2 = mdb_update_key(mc, key); else rc2 = MDB_SUCCESS; mc->mc_top = top; if (rc2) return rc2; } return MDB_SUCCESS; } more: leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); olddata.mv_size = NODEDSZ(leaf); olddata.mv_data = NODEDATA(leaf); /* DB has dups? */ if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) { /* Prepare (sub-)page/sub-DB to accept the new item, * if needed. fp: old sub-page or a header faking * it. mp: new (sub-)page. offset: growth in page * size. xdata: node data with new page or DB. */ unsigned i, offset = 0; mp = fp = xdata.mv_data = env->me_pbuf; mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno; /* Was a single item before, must convert now */ if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) { /* Just overwrite the current item */ if (flags == MDB_CURRENT) goto current; #if UINT_MAX < SIZE_MAX if (mc->mc_dbx->md_dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t)) mc->mc_dbx->md_dcmp = mdb_cmp_clong; #endif /* does data match? */ if (!mc->mc_dbx->md_dcmp(data, &olddata)) { if (flags & MDB_NODUPDATA) return MDB_KEYEXIST; /* overwrite it */ goto current; } /* Back up original data item */ dkey.mv_size = olddata.mv_size; dkey.mv_data = memcpy(fp+1, olddata.mv_data, olddata.mv_size); /* Make sub-page header for the dup items, with dummy body */ fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP; fp->mp_lower = (PAGEHDRSZ-PAGEBASE); xdata.mv_size = PAGEHDRSZ + dkey.mv_size + data->mv_size; if (mc->mc_db->md_flags & MDB_DUPFIXED) { fp->mp_flags |= P_LEAF2; fp->mp_pad = data->mv_size; xdata.mv_size += 2 * data->mv_size; /* leave space for 2 more */ } else { xdata.mv_size += 2 * (sizeof(indx_t) + NODESIZE) + (dkey.mv_size & 1) + (data->mv_size & 1); } fp->mp_upper = xdata.mv_size - PAGEBASE; olddata.mv_size = xdata.mv_size; /* pretend olddata is fp */ } else if (leaf->mn_flags & F_SUBDATA) { /* Data is on sub-DB, just store it */ flags |= F_DUPDATA|F_SUBDATA; goto put_sub; } else { /* Data is on sub-page */ fp = olddata.mv_data; switch (flags) { default: if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) { offset = EVEN(NODESIZE + sizeof(indx_t) + data->mv_size); break; } offset = fp->mp_pad; if (SIZELEFT(fp) < offset) { offset *= 4; /* space for 4 more */ break; } /* FALLTHRU: Big enough MDB_DUPFIXED sub-page */ case MDB_CURRENT: fp->mp_flags |= P_DIRTY; COPY_PGNO(fp->mp_pgno, mp->mp_pgno); mc->mc_xcursor->mx_cursor.mc_pg[0] = fp; flags |= F_DUPDATA; goto put_sub; } xdata.mv_size = olddata.mv_size + offset; } fp_flags = fp->mp_flags; if (NODESIZE + NODEKSZ(leaf) + xdata.mv_size > env->me_nodemax) { /* Too big for a sub-page, convert to sub-DB */ fp_flags &= ~P_SUBP; prep_subDB: if (mc->mc_db->md_flags & MDB_DUPFIXED) { fp_flags |= P_LEAF2; dummy.md_pad = fp->mp_pad; dummy.md_flags = MDB_DUPFIXED; if (mc->mc_db->md_flags & MDB_INTEGERDUP) dummy.md_flags |= MDB_INTEGERKEY; } else { dummy.md_pad = 0; dummy.md_flags = 0; } dummy.md_depth = 1; dummy.md_branch_pages = 0; dummy.md_leaf_pages = 1; dummy.md_overflow_pages = 0; dummy.md_entries = NUMKEYS(fp); xdata.mv_size = sizeof(MDB_db); xdata.mv_data = &dummy; if ((rc = mdb_page_alloc(mc, 1, &mp))) return rc; offset = env->me_psize - olddata.mv_size; flags |= F_DUPDATA|F_SUBDATA; dummy.md_root = mp->mp_pgno; } if (mp != fp) { mp->mp_flags = fp_flags | P_DIRTY; mp->mp_pad = fp->mp_pad; mp->mp_lower = fp->mp_lower; mp->mp_upper = fp->mp_upper + offset; if (fp_flags & P_LEAF2) { memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad); } else { memcpy((char *)mp + mp->mp_upper + PAGEBASE, (char *)fp + fp->mp_upper + PAGEBASE, olddata.mv_size - fp->mp_upper - PAGEBASE); for (i=0; imp_ptrs[i] = fp->mp_ptrs[i] + offset; } } rdata = &xdata; flags |= F_DUPDATA; do_sub = 1; if (!insert_key) mdb_node_del(mc, 0); goto new_sub; } current: /* overflow page overwrites need special handling */ if (F_ISSET(leaf->mn_flags, F_BIGDATA)) { MDB_page *omp; pgno_t pg; int level, ovpages, dpages = OVPAGES(data->mv_size, env->me_psize); memcpy(&pg, olddata.mv_data, sizeof(pg)); if ((rc2 = mdb_page_get(mc->mc_txn, pg, &omp, &level)) != 0) return rc2; ovpages = omp->mp_pages; /* Is the ov page large enough? */ if (ovpages >= dpages) { if (!(omp->mp_flags & P_DIRTY) && (level || (env->me_flags & MDB_WRITEMAP))) { rc = mdb_page_unspill(mc->mc_txn, omp, &omp); if (rc) return rc; level = 0; /* dirty in this txn or clean */ } /* Is it dirty? */ if (omp->mp_flags & P_DIRTY) { /* yes, overwrite it. Note in this case we don't * bother to try shrinking the page if the new data * is smaller than the overflow threshold. */ if (level > 1) { /* It is writable only in a parent txn */ size_t sz = (size_t) env->me_psize * ovpages, off; MDB_page *np = mdb_page_malloc(mc->mc_txn, ovpages); MDB_ID2 id2; if (!np) return ENOMEM; id2.mid = pg; id2.mptr = np; rc2 = mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2); mdb_cassert(mc, rc2 == 0); if (!(flags & MDB_RESERVE)) { /* Copy end of page, adjusting alignment so * compiler may copy words instead of bytes. */ off = (PAGEHDRSZ + data->mv_size) & -sizeof(size_t); memcpy((size_t *)((char *)np + off), (size_t *)((char *)omp + off), sz - off); sz = PAGEHDRSZ; } memcpy(np, omp, sz); /* Copy beginning of page */ omp = np; } SETDSZ(leaf, data->mv_size); if (F_ISSET(flags, MDB_RESERVE)) data->mv_data = METADATA(omp); else memcpy(METADATA(omp), data->mv_data, data->mv_size); return MDB_SUCCESS; } } if ((rc2 = mdb_ovpage_free(mc, omp)) != MDB_SUCCESS) return rc2; } else if (data->mv_size == olddata.mv_size) { /* same size, just replace it. Note that we could * also reuse this node if the new data is smaller, * but instead we opt to shrink the node in that case. */ if (F_ISSET(flags, MDB_RESERVE)) data->mv_data = olddata.mv_data; else if (!(mc->mc_flags & C_SUB)) memcpy(olddata.mv_data, data->mv_data, data->mv_size); else { memcpy(NODEKEY(leaf), key->mv_data, key->mv_size); goto fix_parent; } return MDB_SUCCESS; } mdb_node_del(mc, 0); } rdata = data; new_sub: nflags = flags & NODE_ADD_FLAGS; nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(env, key, rdata); if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) { if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA ) nflags &= ~MDB_APPEND; /* sub-page may need room to grow */ if (!insert_key) nflags |= MDB_SPLIT_REPLACE; rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags); } else { /* There is room already in this leaf page. */ rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags); if (rc == 0 && insert_key) { /* Adjust other cursors pointing to mp */ MDB_cursor *m2, *m3; MDB_dbi dbi = mc->mc_dbi; unsigned i = mc->mc_top; MDB_page *mp = mc->mc_pg[i]; for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { if (mc->mc_flags & C_SUB) m3 = &m2->mc_xcursor->mx_cursor; else m3 = m2; if (m3 == mc || m3->mc_snum < mc->mc_snum) continue; if (m3->mc_pg[i] == mp && m3->mc_ki[i] >= mc->mc_ki[i]) { m3->mc_ki[i]++; } } } } if (rc == MDB_SUCCESS) { /* Now store the actual data in the child DB. Note that we're * storing the user data in the keys field, so there are strict * size limits on dupdata. The actual data fields of the child * DB are all zero size. */ if (do_sub) { int xflags; size_t ecount; put_sub: xdata.mv_size = 0; xdata.mv_data = ""; leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); if (flags & MDB_CURRENT) { xflags = MDB_CURRENT|MDB_NOSPILL; } else { mdb_xcursor_init1(mc, leaf); xflags = (flags & MDB_NODUPDATA) ? MDB_NOOVERWRITE|MDB_NOSPILL : MDB_NOSPILL; } /* converted, write the original data first */ if (dkey.mv_size) { rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags); if (rc) goto bad_sub; { /* Adjust other cursors pointing to mp */ MDB_cursor *m2; unsigned i = mc->mc_top; MDB_page *mp = mc->mc_pg[i]; for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) { if (m2 == mc || m2->mc_snum < mc->mc_snum) continue; if (!(m2->mc_flags & C_INITIALIZED)) continue; if (m2->mc_pg[i] == mp && m2->mc_ki[i] == mc->mc_ki[i]) { mdb_xcursor_init1(m2, leaf); } } } /* we've done our job */ dkey.mv_size = 0; } ecount = mc->mc_xcursor->mx_db.md_entries; if (flags & MDB_APPENDDUP) xflags |= MDB_APPEND; rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags); if (flags & F_SUBDATA) { void *db = NODEDATA(leaf); memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db)); } insert_data = mc->mc_xcursor->mx_db.md_entries - ecount; } /* Increment count unless we just replaced an existing item. */ if (insert_data) mc->mc_db->md_entries++; if (insert_key) { /* Invalidate txn if we created an empty sub-DB */ if (rc) goto bad_sub; /* If we succeeded and the key didn't exist before, * make sure the cursor is marked valid. */ mc->mc_flags |= C_INITIALIZED; } if (flags & MDB_MULTIPLE) { if (!rc) { mcount++; /* let caller know how many succeeded, if any */ data[1].mv_size = mcount; if (mcount < dcount) { data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size; insert_key = insert_data = 0; goto more; } } } return rc; bad_sub: if (rc == MDB_KEYEXIST) /* should not happen, we deleted that item */ rc = MDB_CORRUPTED; } mc->mc_txn->mt_flags |= MDB_TXN_ERROR; return rc; } int mdb_cursor_del(MDB_cursor *mc, unsigned int flags) { MDB_node *leaf; MDB_page *mp; int rc; if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR)) return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN; if (!(mc->mc_flags & C_INITIALIZED)) return EINVAL; if (mc->mc_ki[mc->mc_top] >= NUMKEYS(mc->mc_pg[mc->mc_top])) return MDB_NOTFOUND; if (!(flags & MDB_NOSPILL) && (rc = mdb_page_spill(mc, NULL, NULL))) return rc; rc = mdb_cursor_touch(mc); if (rc) return rc; mp = mc->mc_pg[mc->mc_top]; if (IS_LEAF2(mp)) goto del_key; leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { if (flags & MDB_NODUPDATA) { /* mdb_cursor_del0() will subtract the final entry */ mc->mc_db->md_entries -= mc->mc_xcursor->mx_db.md_entries - 1; } else { if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) { mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf); } rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, MDB_NOSPILL); if (rc) return rc; /* If sub-DB still has entries, we're done */ if (mc->mc_xcursor->mx_db.md_entries) { if (leaf->mn_flags & F_SUBDATA) { /* update subDB info */ void *db = NODEDATA(leaf); memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db)); } else { MDB_cursor *m2; /* shrink fake page */ mdb_node_shrink(mp, mc->mc_ki[mc->mc_top]); leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf); /* fix other sub-DB cursors pointed at this fake page */ for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) { if (m2 == mc || m2->mc_snum < mc->mc_snum) continue; if (m2->mc_pg[mc->mc_top] == mp && m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top]) m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf); } } mc->mc_db->md_entries--; mc->mc_flags |= C_DEL; return rc; } /* otherwise fall thru and delete the sub-DB */ } if (leaf->mn_flags & F_SUBDATA) { /* add all the child DB's pages to the free list */ rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0); if (rc) goto fail; } } /* add overflow pages to free list */ if (F_ISSET(leaf->mn_flags, F_BIGDATA)) { MDB_page *omp; pgno_t pg; memcpy(&pg, NODEDATA(leaf), sizeof(pg)); if ((rc = mdb_page_get(mc->mc_txn, pg, &omp, NULL)) || (rc = mdb_ovpage_free(mc, omp))) goto fail; } del_key: return mdb_cursor_del0(mc); fail: mc->mc_txn->mt_flags |= MDB_TXN_ERROR; return rc; } /** Allocate and initialize new pages for a database. * @param[in] mc a cursor on the database being added to. * @param[in] flags flags defining what type of page is being allocated. * @param[in] num the number of pages to allocate. This is usually 1, * unless allocating overflow pages for a large record. * @param[out] mp Address of a page, or NULL on failure. * @return 0 on success, non-zero on failure. */ static int mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp) { MDB_page *np; int rc; if ((rc = mdb_page_alloc(mc, num, &np))) return rc; DPRINTF(("allocated new mpage %"Z"u, page size %u", np->mp_pgno, mc->mc_txn->mt_env->me_psize)); np->mp_flags = flags | P_DIRTY; np->mp_lower = (PAGEHDRSZ-PAGEBASE); np->mp_upper = mc->mc_txn->mt_env->me_psize - PAGEBASE; if (IS_BRANCH(np)) mc->mc_db->md_branch_pages++; else if (IS_LEAF(np)) mc->mc_db->md_leaf_pages++; else if (IS_OVERFLOW(np)) { mc->mc_db->md_overflow_pages += num; np->mp_pages = num; } *mp = np; return 0; } /** Calculate the size of a leaf node. * The size depends on the environment's page size; if a data item * is too large it will be put onto an overflow page and the node * size will only include the key and not the data. Sizes are always * rounded up to an even number of bytes, to guarantee 2-byte alignment * of the #MDB_node headers. * @param[in] env The environment handle. * @param[in] key The key for the node. * @param[in] data The data for the node. * @return The number of bytes needed to store the node. */ static size_t mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data) { size_t sz; sz = LEAFSIZE(key, data); if (sz > env->me_nodemax) { /* put on overflow page */ sz -= data->mv_size - sizeof(pgno_t); } return EVEN(sz + sizeof(indx_t)); } /** Calculate the size of a branch node. * The size should depend on the environment's page size but since * we currently don't support spilling large keys onto overflow * pages, it's simply the size of the #MDB_node header plus the * size of the key. Sizes are always rounded up to an even number * of bytes, to guarantee 2-byte alignment of the #MDB_node headers. * @param[in] env The environment handle. * @param[in] key The key for the node. * @return The number of bytes needed to store the node. */ static size_t mdb_branch_size(MDB_env *env, MDB_val *key) { size_t sz; sz = INDXSIZE(key); if (sz > env->me_nodemax) { /* put on overflow page */ /* not implemented */ /* sz -= key->size - sizeof(pgno_t); */ } return sz + sizeof(indx_t); } /** Add a node to the page pointed to by the cursor. * @param[in] mc The cursor for this operation. * @param[in] indx The index on the page where the new node should be added. * @param[in] key The key for the new node. * @param[in] data The data for the new node, if any. * @param[in] pgno The page number, if adding a branch node. * @param[in] flags Flags for the node. * @return 0 on success, non-zero on failure. Possible errors are: *
    *
  • ENOMEM - failed to allocate overflow pages for the node. *
  • MDB_PAGE_FULL - there is insufficient room in the page. This error * should never happen since all callers already calculate the * page's free space before calling this function. *
*/ static int mdb_node_add(MDB_cursor *mc, indx_t indx, MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags) { unsigned int i; size_t node_size = NODESIZE; ssize_t room; indx_t ofs; MDB_node *node; MDB_page *mp = mc->mc_pg[mc->mc_top]; MDB_page *ofp = NULL; /* overflow page */ DKBUF; mdb_cassert(mc, mp->mp_upper >= mp->mp_lower); DPRINTF(("add to %s %spage %"Z"u index %i, data size %"Z"u key size %"Z"u [%s]", IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "", mdb_dbg_pgno(mp), indx, data ? data->mv_size : 0, key ? key->mv_size : 0, key ? DKEY(key) : "null")); if (IS_LEAF2(mp)) { /* Move higher keys up one slot. */ int ksize = mc->mc_db->md_pad, dif; char *ptr = LEAF2KEY(mp, indx, ksize); dif = NUMKEYS(mp) - indx; if (dif > 0) memmove(ptr+ksize, ptr, dif*ksize); /* insert new key */ memcpy(ptr, key->mv_data, ksize); /* Just using these for counting */ mp->mp_lower += sizeof(indx_t); mp->mp_upper -= ksize - sizeof(indx_t); return MDB_SUCCESS; } room = (ssize_t)SIZELEFT(mp) - (ssize_t)sizeof(indx_t); if (key != NULL) node_size += key->mv_size; if (IS_LEAF(mp)) { mdb_cassert(mc, data); if (F_ISSET(flags, F_BIGDATA)) { /* Data already on overflow page. */ node_size += sizeof(pgno_t); } else if (node_size + data->mv_size > mc->mc_txn->mt_env->me_nodemax) { int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize); int rc; /* Put data on overflow page. */ DPRINTF(("data size is %"Z"u, node would be %"Z"u, put data on overflow page", data->mv_size, node_size+data->mv_size)); node_size = EVEN(node_size + sizeof(pgno_t)); if ((ssize_t)node_size > room) goto full; if ((rc = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp))) return rc; DPRINTF(("allocated overflow page %"Z"u", ofp->mp_pgno)); flags |= F_BIGDATA; goto update; } else { node_size += data->mv_size; } } node_size = EVEN(node_size); if ((ssize_t)node_size > room) goto full; update: /* Move higher pointers up one slot. */ for (i = NUMKEYS(mp); i > indx; i--) mp->mp_ptrs[i] = mp->mp_ptrs[i - 1]; /* Adjust free space offsets. */ ofs = mp->mp_upper - node_size; mdb_cassert(mc, ofs >= mp->mp_lower + sizeof(indx_t)); mp->mp_ptrs[indx] = ofs; mp->mp_upper = ofs; mp->mp_lower += sizeof(indx_t); /* Write the node data. */ node = NODEPTR(mp, indx); node->mn_ksize = (key == NULL) ? 0 : key->mv_size; node->mn_flags = flags; if (IS_LEAF(mp)) SETDSZ(node,data->mv_size); else SETPGNO(node,pgno); if (key) memcpy(NODEKEY(node), key->mv_data, key->mv_size); if (IS_LEAF(mp)) { mdb_cassert(mc, key); if (ofp == NULL) { if (F_ISSET(flags, F_BIGDATA)) memcpy(node->mn_data + key->mv_size, data->mv_data, sizeof(pgno_t)); else if (F_ISSET(flags, MDB_RESERVE)) data->mv_data = node->mn_data + key->mv_size; else memcpy(node->mn_data + key->mv_size, data->mv_data, data->mv_size); } else { memcpy(node->mn_data + key->mv_size, &ofp->mp_pgno, sizeof(pgno_t)); if (F_ISSET(flags, MDB_RESERVE)) data->mv_data = METADATA(ofp); else memcpy(METADATA(ofp), data->mv_data, data->mv_size); } } return MDB_SUCCESS; full: DPRINTF(("not enough room in page %"Z"u, got %u ptrs", mdb_dbg_pgno(mp), NUMKEYS(mp))); DPRINTF(("upper-lower = %u - %u = %"Z"d", mp->mp_upper,mp->mp_lower,room)); DPRINTF(("node size = %"Z"u", node_size)); mc->mc_txn->mt_flags |= MDB_TXN_ERROR; return MDB_PAGE_FULL; } /** Delete the specified node from a page. * @param[in] mc Cursor pointing to the node to delete. * @param[in] ksize The size of a node. Only used if the page is * part of a #MDB_DUPFIXED database. */ static void mdb_node_del(MDB_cursor *mc, int ksize) { MDB_page *mp = mc->mc_pg[mc->mc_top]; indx_t indx = mc->mc_ki[mc->mc_top]; unsigned int sz; indx_t i, j, numkeys, ptr; MDB_node *node; char *base; DPRINTF(("delete node %u on %s page %"Z"u", indx, IS_LEAF(mp) ? "leaf" : "branch", mdb_dbg_pgno(mp))); numkeys = NUMKEYS(mp); mdb_cassert(mc, indx < numkeys); if (IS_LEAF2(mp)) { int x = numkeys - 1 - indx; base = LEAF2KEY(mp, indx, ksize); if (x) memmove(base, base + ksize, x * ksize); mp->mp_lower -= sizeof(indx_t); mp->mp_upper += ksize - sizeof(indx_t); return; } node = NODEPTR(mp, indx); sz = NODESIZE + node->mn_ksize; if (IS_LEAF(mp)) { if (F_ISSET(node->mn_flags, F_BIGDATA)) sz += sizeof(pgno_t); else sz += NODEDSZ(node); } sz = EVEN(sz); ptr = mp->mp_ptrs[indx]; for (i = j = 0; i < numkeys; i++) { if (i != indx) { mp->mp_ptrs[j] = mp->mp_ptrs[i]; if (mp->mp_ptrs[i] < ptr) mp->mp_ptrs[j] += sz; j++; } } base = (char *)mp + mp->mp_upper + PAGEBASE; memmove(base + sz, base, ptr - mp->mp_upper); mp->mp_lower -= sizeof(indx_t); mp->mp_upper += sz; } /** Compact the main page after deleting a node on a subpage. * @param[in] mp The main page to operate on. * @param[in] indx The index of the subpage on the main page. */ static void mdb_node_shrink(MDB_page *mp, indx_t indx) { MDB_node *node; MDB_page *sp, *xp; char *base; int nsize, delta; indx_t i, numkeys, ptr; node = NODEPTR(mp, indx); sp = (MDB_page *)NODEDATA(node); delta = SIZELEFT(sp); xp = (MDB_page *)((char *)sp + delta); /* shift subpage upward */ if (IS_LEAF2(sp)) { nsize = NUMKEYS(sp) * sp->mp_pad; if (nsize & 1) return; /* do not make the node uneven-sized */ memmove(METADATA(xp), METADATA(sp), nsize); } else { int i; numkeys = NUMKEYS(sp); for (i=numkeys-1; i>=0; i--) xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta; } xp->mp_upper = sp->mp_lower; xp->mp_lower = sp->mp_lower; xp->mp_flags = sp->mp_flags; xp->mp_pad = sp->mp_pad; COPY_PGNO(xp->mp_pgno, mp->mp_pgno); nsize = NODEDSZ(node) - delta; SETDSZ(node, nsize); /* shift lower nodes upward */ ptr = mp->mp_ptrs[indx]; numkeys = NUMKEYS(mp); for (i = 0; i < numkeys; i++) { if (mp->mp_ptrs[i] <= ptr) mp->mp_ptrs[i] += delta; } base = (char *)mp + mp->mp_upper + PAGEBASE; memmove(base + delta, base, ptr - mp->mp_upper + NODESIZE + NODEKSZ(node)); mp->mp_upper += delta; } /** Initial setup of a sorted-dups cursor. * Sorted duplicates are implemented as a sub-database for the given key. * The duplicate data items are actually keys of the sub-database. * Operations on the duplicate data items are performed using a sub-cursor * initialized when the sub-database is first accessed. This function does * the preliminary setup of the sub-cursor, filling in the fields that * depend only on the parent DB. * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized. */ static void mdb_xcursor_init0(MDB_cursor *mc) { MDB_xcursor *mx = mc->mc_xcursor; mx->mx_cursor.mc_xcursor = NULL; mx->mx_cursor.mc_txn = mc->mc_txn; mx->mx_cursor.mc_db = &mx->mx_db; mx->mx_cursor.mc_dbx = &mx->mx_dbx; mx->mx_cursor.mc_dbi = mc->mc_dbi; mx->mx_cursor.mc_dbflag = &mx->mx_dbflag; mx->mx_cursor.mc_snum = 0; mx->mx_cursor.mc_top = 0; mx->mx_cursor.mc_flags = C_SUB; mx->mx_dbx.md_name.mv_size = 0; mx->mx_dbx.md_name.mv_data = NULL; mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp; mx->mx_dbx.md_dcmp = NULL; mx->mx_dbx.md_rel = mc->mc_dbx->md_rel; } /** Final setup of a sorted-dups cursor. * Sets up the fields that depend on the data from the main cursor. * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized. * @param[in] node The data containing the #MDB_db record for the * sorted-dup database. */ static void mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node) { MDB_xcursor *mx = mc->mc_xcursor; if (node->mn_flags & F_SUBDATA) { memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db)); mx->mx_cursor.mc_pg[0] = 0; mx->mx_cursor.mc_snum = 0; mx->mx_cursor.mc_top = 0; mx->mx_cursor.mc_flags = C_SUB; } else { MDB_page *fp = NODEDATA(node); mx->mx_db.md_pad = mc->mc_pg[mc->mc_top]->mp_pad; mx->mx_db.md_flags = 0; mx->mx_db.md_depth = 1; mx->mx_db.md_branch_pages = 0; mx->mx_db.md_leaf_pages = 1; mx->mx_db.md_overflow_pages = 0; mx->mx_db.md_entries = NUMKEYS(fp); COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno); mx->mx_cursor.mc_snum = 1; mx->mx_cursor.mc_top = 0; mx->mx_cursor.mc_flags = C_INITIALIZED|C_SUB; mx->mx_cursor.mc_pg[0] = fp; mx->mx_cursor.mc_ki[0] = 0; if (mc->mc_db->md_flags & MDB_DUPFIXED) { mx->mx_db.md_flags = MDB_DUPFIXED; mx->mx_db.md_pad = fp->mp_pad; if (mc->mc_db->md_flags & MDB_INTEGERDUP) mx->mx_db.md_flags |= MDB_INTEGERKEY; } } DPRINTF(("Sub-db -%u root page %"Z"u", mx->mx_cursor.mc_dbi, mx->mx_db.md_root)); mx->mx_dbflag = DB_VALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */ #if UINT_MAX < SIZE_MAX if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(size_t)) mx->mx_dbx.md_cmp = mdb_cmp_clong; #endif } /** Initialize a cursor for a given transaction and database. */ static void mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx) { mc->mc_next = NULL; mc->mc_backup = NULL; mc->mc_dbi = dbi; mc->mc_txn = txn; mc->mc_db = &txn->mt_dbs[dbi]; mc->mc_dbx = &txn->mt_dbxs[dbi]; mc->mc_dbflag = &txn->mt_dbflags[dbi]; mc->mc_snum = 0; mc->mc_top = 0; mc->mc_pg[0] = 0; mc->mc_flags = 0; if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) { mdb_tassert(txn, mx != NULL); mc->mc_xcursor = mx; mdb_xcursor_init0(mc); } else { mc->mc_xcursor = NULL; } if (*mc->mc_dbflag & DB_STALE) { mdb_page_search(mc, NULL, MDB_PS_ROOTONLY); } } int mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret) { MDB_cursor *mc; size_t size = sizeof(MDB_cursor); if (!ret || !TXN_DBI_EXIST(txn, dbi)) return EINVAL; if (txn->mt_flags & MDB_TXN_ERROR) return MDB_BAD_TXN; /* Allow read access to the freelist */ if (!dbi && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) return EINVAL; if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) size += sizeof(MDB_xcursor); if ((mc = malloc(size)) != NULL) { mdb_cursor_init(mc, txn, dbi, (MDB_xcursor *)(mc + 1)); if (txn->mt_cursors) { mc->mc_next = txn->mt_cursors[dbi]; txn->mt_cursors[dbi] = mc; mc->mc_flags |= C_UNTRACK; } } else { return ENOMEM; } *ret = mc; return MDB_SUCCESS; } int mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc) { if (!mc || !TXN_DBI_EXIST(txn, mc->mc_dbi)) return EINVAL; if ((mc->mc_flags & C_UNTRACK) || txn->mt_cursors) return EINVAL; if (txn->mt_flags & MDB_TXN_ERROR) return MDB_BAD_TXN; mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor); return MDB_SUCCESS; } /* Return the count of duplicate data items for the current key */ int mdb_cursor_count(MDB_cursor *mc, size_t *countp) { MDB_node *leaf; if (mc == NULL || countp == NULL) return EINVAL; if (mc->mc_xcursor == NULL) return MDB_INCOMPATIBLE; if (mc->mc_txn->mt_flags & MDB_TXN_ERROR) return MDB_BAD_TXN; if (!(mc->mc_flags & C_INITIALIZED)) return EINVAL; if (!mc->mc_snum || (mc->mc_flags & C_EOF)) return MDB_NOTFOUND; leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) { *countp = 1; } else { if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) return EINVAL; *countp = mc->mc_xcursor->mx_db.md_entries; } return MDB_SUCCESS; } void mdb_cursor_close(MDB_cursor *mc) { if (mc && !mc->mc_backup) { /* remove from txn, if tracked */ if ((mc->mc_flags & C_UNTRACK) && mc->mc_txn->mt_cursors) { MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi]; while (*prev && *prev != mc) prev = &(*prev)->mc_next; if (*prev == mc) *prev = mc->mc_next; } free(mc); } } MDB_txn * mdb_cursor_txn(MDB_cursor *mc) { if (!mc) return NULL; return mc->mc_txn; } MDB_dbi mdb_cursor_dbi(MDB_cursor *mc) { return mc->mc_dbi; } /** Replace the key for a branch node with a new key. * @param[in] mc Cursor pointing to the node to operate on. * @param[in] key The new key to use. * @return 0 on success, non-zero on failure. */ static int mdb_update_key(MDB_cursor *mc, MDB_val *key) { MDB_page *mp; MDB_node *node; char *base; size_t len; int delta, ksize, oksize; indx_t ptr, i, numkeys, indx; DKBUF; indx = mc->mc_ki[mc->mc_top]; mp = mc->mc_pg[mc->mc_top]; node = NODEPTR(mp, indx); ptr = mp->mp_ptrs[indx]; #if MDB_DEBUG { MDB_val k2; char kbuf2[DKBUF_MAXKEYSIZE*2+1]; k2.mv_data = NODEKEY(node); k2.mv_size = node->mn_ksize; DPRINTF(("update key %u (ofs %u) [%s] to [%s] on page %"Z"u", indx, ptr, mdb_dkey(&k2, kbuf2), DKEY(key), mp->mp_pgno)); } #endif /* Sizes must be 2-byte aligned. */ ksize = EVEN(key->mv_size); oksize = EVEN(node->mn_ksize); delta = ksize - oksize; /* Shift node contents if EVEN(key length) changed. */ if (delta) { if (delta > 0 && SIZELEFT(mp) < delta) { pgno_t pgno; /* not enough space left, do a delete and split */ DPRINTF(("Not enough room, delta = %d, splitting...", delta)); pgno = NODEPGNO(node); mdb_node_del(mc, 0); return mdb_page_split(mc, key, NULL, pgno, MDB_SPLIT_REPLACE); } numkeys = NUMKEYS(mp); for (i = 0; i < numkeys; i++) { if (mp->mp_ptrs[i] <= ptr) mp->mp_ptrs[i] -= delta; } base = (char *)mp + mp->mp_upper + PAGEBASE; len = ptr - mp->mp_upper + NODESIZE; memmove(base - delta, base, len); mp->mp_upper -= delta; node = NODEPTR(mp, indx); } /* But even if no shift was needed, update ksize */ if (node->mn_ksize != key->mv_size) node->mn_ksize = key->mv_size; if (key->mv_size) memcpy(NODEKEY(node), key->mv_data, key->mv_size); return MDB_SUCCESS; } static void mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst); /** Move a node from csrc to cdst. */ static int mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst) { MDB_node *srcnode; MDB_val key, data; pgno_t srcpg; MDB_cursor mn; int rc; unsigned short flags; DKBUF; /* Mark src and dst as dirty. */ if ((rc = mdb_page_touch(csrc)) || (rc = mdb_page_touch(cdst))) return rc; if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { key.mv_size = csrc->mc_db->md_pad; key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size); data.mv_size = 0; data.mv_data = NULL; srcpg = 0; flags = 0; } else { srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]); mdb_cassert(csrc, !((size_t)srcnode & 1)); srcpg = NODEPGNO(srcnode); flags = srcnode->mn_flags; if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) { unsigned int snum = csrc->mc_snum; MDB_node *s2; /* must find the lowest key below src */ rc = mdb_page_search_lowest(csrc); if (rc) return rc; if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { key.mv_size = csrc->mc_db->md_pad; key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size); } else { s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0); key.mv_size = NODEKSZ(s2); key.mv_data = NODEKEY(s2); } csrc->mc_snum = snum--; csrc->mc_top = snum; } else { key.mv_size = NODEKSZ(srcnode); key.mv_data = NODEKEY(srcnode); } data.mv_size = NODEDSZ(srcnode); data.mv_data = NODEDATA(srcnode); } if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) { unsigned int snum = cdst->mc_snum; MDB_node *s2; MDB_val bkey; /* must find the lowest key below dst */ mdb_cursor_copy(cdst, &mn); rc = mdb_page_search_lowest(&mn); if (rc) return rc; if (IS_LEAF2(mn.mc_pg[mn.mc_top])) { bkey.mv_size = mn.mc_db->md_pad; bkey.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, bkey.mv_size); } else { s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0); bkey.mv_size = NODEKSZ(s2); bkey.mv_data = NODEKEY(s2); } mn.mc_snum = snum--; mn.mc_top = snum; mn.mc_ki[snum] = 0; rc = mdb_update_key(&mn, &bkey); if (rc) return rc; } DPRINTF(("moving %s node %u [%s] on page %"Z"u to node %u on page %"Z"u", IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch", csrc->mc_ki[csrc->mc_top], DKEY(&key), csrc->mc_pg[csrc->mc_top]->mp_pgno, cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno)); /* Add the node to the destination page. */ rc = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags); if (rc != MDB_SUCCESS) return rc; /* Delete the node from the source page. */ mdb_node_del(csrc, key.mv_size); { /* Adjust other cursors pointing to mp */ MDB_cursor *m2, *m3; MDB_dbi dbi = csrc->mc_dbi; MDB_page *mp = csrc->mc_pg[csrc->mc_top]; for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { if (csrc->mc_flags & C_SUB) m3 = &m2->mc_xcursor->mx_cursor; else m3 = m2; if (m3 == csrc) continue; if (m3->mc_pg[csrc->mc_top] == mp && m3->mc_ki[csrc->mc_top] == csrc->mc_ki[csrc->mc_top]) { m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top]; m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top]; } } } /* Update the parent separators. */ if (csrc->mc_ki[csrc->mc_top] == 0) { if (csrc->mc_ki[csrc->mc_top-1] != 0) { if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size); } else { srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0); key.mv_size = NODEKSZ(srcnode); key.mv_data = NODEKEY(srcnode); } DPRINTF(("update separator for source page %"Z"u to [%s]", csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key))); mdb_cursor_copy(csrc, &mn); mn.mc_snum--; mn.mc_top--; if ((rc = mdb_update_key(&mn, &key)) != MDB_SUCCESS) return rc; } if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) { MDB_val nullkey; indx_t ix = csrc->mc_ki[csrc->mc_top]; nullkey.mv_size = 0; csrc->mc_ki[csrc->mc_top] = 0; rc = mdb_update_key(csrc, &nullkey); csrc->mc_ki[csrc->mc_top] = ix; mdb_cassert(csrc, rc == MDB_SUCCESS); } } if (cdst->mc_ki[cdst->mc_top] == 0) { if (cdst->mc_ki[cdst->mc_top-1] != 0) { if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size); } else { srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0); key.mv_size = NODEKSZ(srcnode); key.mv_data = NODEKEY(srcnode); } DPRINTF(("update separator for destination page %"Z"u to [%s]", cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key))); mdb_cursor_copy(cdst, &mn); mn.mc_snum--; mn.mc_top--; if ((rc = mdb_update_key(&mn, &key)) != MDB_SUCCESS) return rc; } if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) { MDB_val nullkey; indx_t ix = cdst->mc_ki[cdst->mc_top]; nullkey.mv_size = 0; cdst->mc_ki[cdst->mc_top] = 0; rc = mdb_update_key(cdst, &nullkey); cdst->mc_ki[cdst->mc_top] = ix; mdb_cassert(csrc, rc == MDB_SUCCESS); } } return MDB_SUCCESS; } /** Merge one page into another. * The nodes from the page pointed to by \b csrc will * be copied to the page pointed to by \b cdst and then * the \b csrc page will be freed. * @param[in] csrc Cursor pointing to the source page. * @param[in] cdst Cursor pointing to the destination page. * @return 0 on success, non-zero on failure. */ static int mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst) { MDB_page *psrc, *pdst; MDB_node *srcnode; MDB_val key, data; unsigned nkeys; int rc; indx_t i, j; psrc = csrc->mc_pg[csrc->mc_top]; pdst = cdst->mc_pg[cdst->mc_top]; DPRINTF(("merging page %"Z"u into %"Z"u", psrc->mp_pgno, pdst->mp_pgno)); mdb_cassert(csrc, csrc->mc_snum > 1); /* can't merge root page */ mdb_cassert(csrc, cdst->mc_snum > 1); /* Mark dst as dirty. */ if ((rc = mdb_page_touch(cdst))) return rc; /* Move all nodes from src to dst. */ j = nkeys = NUMKEYS(pdst); if (IS_LEAF2(psrc)) { key.mv_size = csrc->mc_db->md_pad; key.mv_data = METADATA(psrc); for (i = 0; i < NUMKEYS(psrc); i++, j++) { rc = mdb_node_add(cdst, j, &key, NULL, 0, 0); if (rc != MDB_SUCCESS) return rc; key.mv_data = (char *)key.mv_data + key.mv_size; } } else { for (i = 0; i < NUMKEYS(psrc); i++, j++) { srcnode = NODEPTR(psrc, i); if (i == 0 && IS_BRANCH(psrc)) { MDB_cursor mn; MDB_node *s2; mdb_cursor_copy(csrc, &mn); /* must find the lowest key below src */ rc = mdb_page_search_lowest(&mn); if (rc) return rc; if (IS_LEAF2(mn.mc_pg[mn.mc_top])) { key.mv_size = mn.mc_db->md_pad; key.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, key.mv_size); } else { s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0); key.mv_size = NODEKSZ(s2); key.mv_data = NODEKEY(s2); } } else { key.mv_size = srcnode->mn_ksize; key.mv_data = NODEKEY(srcnode); } data.mv_size = NODEDSZ(srcnode); data.mv_data = NODEDATA(srcnode); rc = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags); if (rc != MDB_SUCCESS) return rc; } } DPRINTF(("dst page %"Z"u now has %u keys (%.1f%% filled)", pdst->mp_pgno, NUMKEYS(pdst), (float)PAGEFILL(cdst->mc_txn->mt_env, pdst) / 10)); /* Unlink the src page from parent and add to free list. */ csrc->mc_top--; mdb_node_del(csrc, 0); if (csrc->mc_ki[csrc->mc_top] == 0) { key.mv_size = 0; rc = mdb_update_key(csrc, &key); if (rc) { csrc->mc_top++; return rc; } } csrc->mc_top++; psrc = csrc->mc_pg[csrc->mc_top]; /* If not operating on FreeDB, allow this page to be reused * in this txn. Otherwise just add to free list. */ rc = mdb_page_loose(csrc, psrc); if (rc) return rc; if (IS_LEAF(psrc)) csrc->mc_db->md_leaf_pages--; else csrc->mc_db->md_branch_pages--; { /* Adjust other cursors pointing to mp */ MDB_cursor *m2, *m3; MDB_dbi dbi = csrc->mc_dbi; for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { if (csrc->mc_flags & C_SUB) m3 = &m2->mc_xcursor->mx_cursor; else m3 = m2; if (m3 == csrc) continue; if (m3->mc_snum < csrc->mc_snum) continue; if (m3->mc_pg[csrc->mc_top] == psrc) { m3->mc_pg[csrc->mc_top] = pdst; m3->mc_ki[csrc->mc_top] += nkeys; } } } { unsigned int snum = cdst->mc_snum; uint16_t depth = cdst->mc_db->md_depth; mdb_cursor_pop(cdst); rc = mdb_rebalance(cdst); /* Did the tree shrink? */ if (depth > cdst->mc_db->md_depth) snum--; cdst->mc_snum = snum; cdst->mc_top = snum-1; } return rc; } /** Copy the contents of a cursor. * @param[in] csrc The cursor to copy from. * @param[out] cdst The cursor to copy to. */ static void mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst) { unsigned int i; cdst->mc_txn = csrc->mc_txn; cdst->mc_dbi = csrc->mc_dbi; cdst->mc_db = csrc->mc_db; cdst->mc_dbx = csrc->mc_dbx; cdst->mc_snum = csrc->mc_snum; cdst->mc_top = csrc->mc_top; cdst->mc_flags = csrc->mc_flags; for (i=0; imc_snum; i++) { cdst->mc_pg[i] = csrc->mc_pg[i]; cdst->mc_ki[i] = csrc->mc_ki[i]; } } /** Rebalance the tree after a delete operation. * @param[in] mc Cursor pointing to the page where rebalancing * should begin. * @return 0 on success, non-zero on failure. */ static int mdb_rebalance(MDB_cursor *mc) { MDB_node *node; int rc; unsigned int ptop, minkeys; MDB_cursor mn; indx_t oldki; minkeys = 1 + (IS_BRANCH(mc->mc_pg[mc->mc_top])); DPRINTF(("rebalancing %s page %"Z"u (has %u keys, %.1f%% full)", IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch", mdb_dbg_pgno(mc->mc_pg[mc->mc_top]), NUMKEYS(mc->mc_pg[mc->mc_top]), (float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10)); if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= FILL_THRESHOLD && NUMKEYS(mc->mc_pg[mc->mc_top]) >= minkeys) { DPRINTF(("no need to rebalance page %"Z"u, above fill threshold", mdb_dbg_pgno(mc->mc_pg[mc->mc_top]))); return MDB_SUCCESS; } if (mc->mc_snum < 2) { MDB_page *mp = mc->mc_pg[0]; if (IS_SUBP(mp)) { DPUTS("Can't rebalance a subpage, ignoring"); return MDB_SUCCESS; } if (NUMKEYS(mp) == 0) { DPUTS("tree is completely empty"); mc->mc_db->md_root = P_INVALID; mc->mc_db->md_depth = 0; mc->mc_db->md_leaf_pages = 0; rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno); if (rc) return rc; /* Adjust cursors pointing to mp */ mc->mc_snum = 0; mc->mc_top = 0; mc->mc_flags &= ~C_INITIALIZED; { MDB_cursor *m2, *m3; MDB_dbi dbi = mc->mc_dbi; for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { if (mc->mc_flags & C_SUB) m3 = &m2->mc_xcursor->mx_cursor; else m3 = m2; if (m3->mc_snum < mc->mc_snum) continue; if (m3->mc_pg[0] == mp) { m3->mc_snum = 0; m3->mc_top = 0; m3->mc_flags &= ~C_INITIALIZED; } } } } else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) { int i; DPUTS("collapsing root page!"); rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno); if (rc) return rc; mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0)); rc = mdb_page_get(mc->mc_txn,mc->mc_db->md_root,&mc->mc_pg[0],NULL); if (rc) return rc; mc->mc_db->md_depth--; mc->mc_db->md_branch_pages--; mc->mc_ki[0] = mc->mc_ki[1]; for (i = 1; imc_db->md_depth; i++) { mc->mc_pg[i] = mc->mc_pg[i+1]; mc->mc_ki[i] = mc->mc_ki[i+1]; } { /* Adjust other cursors pointing to mp */ MDB_cursor *m2, *m3; MDB_dbi dbi = mc->mc_dbi; for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { if (mc->mc_flags & C_SUB) m3 = &m2->mc_xcursor->mx_cursor; else m3 = m2; if (m3 == mc || m3->mc_snum < mc->mc_snum) continue; if (m3->mc_pg[0] == mp) { m3->mc_snum--; m3->mc_top--; for (i=0; imc_snum; i++) { m3->mc_pg[i] = m3->mc_pg[i+1]; m3->mc_ki[i] = m3->mc_ki[i+1]; } } } } } else DPUTS("root page doesn't need rebalancing"); return MDB_SUCCESS; } /* The parent (branch page) must have at least 2 pointers, * otherwise the tree is invalid. */ ptop = mc->mc_top-1; mdb_cassert(mc, NUMKEYS(mc->mc_pg[ptop]) > 1); /* Leaf page fill factor is below the threshold. * Try to move keys from left or right neighbor, or * merge with a neighbor page. */ /* Find neighbors. */ mdb_cursor_copy(mc, &mn); mn.mc_xcursor = NULL; oldki = mc->mc_ki[mc->mc_top]; if (mc->mc_ki[ptop] == 0) { /* We're the leftmost leaf in our parent. */ DPUTS("reading right neighbor"); mn.mc_ki[ptop]++; node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]); rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL); if (rc) return rc; mn.mc_ki[mn.mc_top] = 0; mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]); } else { /* There is at least one neighbor to the left. */ DPUTS("reading left neighbor"); mn.mc_ki[ptop]--; node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]); rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL); if (rc) return rc; mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1; mc->mc_ki[mc->mc_top] = 0; } DPRINTF(("found neighbor page %"Z"u (%u keys, %.1f%% full)", 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)); /* If the neighbor page is above threshold and has enough keys, * move one key from it. Otherwise we should try to merge them. * (A branch page must never have less than 2 keys.) */ minkeys = 1 + (IS_BRANCH(mn.mc_pg[mn.mc_top])); if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= FILL_THRESHOLD && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) { rc = mdb_node_move(&mn, mc); if (mc->mc_ki[ptop]) { oldki++; } } else { if (mc->mc_ki[ptop] == 0) { rc = mdb_page_merge(&mn, mc); } else { oldki += NUMKEYS(mn.mc_pg[mn.mc_top]); mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1; rc = mdb_page_merge(mc, &mn); mdb_cursor_copy(&mn, mc); } mc->mc_flags &= ~C_EOF; } mc->mc_ki[mc->mc_top] = oldki; return rc; } /** Complete a delete operation started by #mdb_cursor_del(). */ static int mdb_cursor_del0(MDB_cursor *mc) { int rc; MDB_page *mp; indx_t ki; unsigned int nkeys; ki = mc->mc_ki[mc->mc_top]; mdb_node_del(mc, mc->mc_db->md_pad); mc->mc_db->md_entries--; rc = mdb_rebalance(mc); if (rc == MDB_SUCCESS) { MDB_cursor *m2, *m3; MDB_dbi dbi = mc->mc_dbi; mp = mc->mc_pg[mc->mc_top]; nkeys = NUMKEYS(mp); /* if mc points past last node in page, find next sibling */ if (mc->mc_ki[mc->mc_top] >= nkeys) { rc = mdb_cursor_sibling(mc, 1); if (rc == MDB_NOTFOUND) { mc->mc_flags |= C_EOF; rc = MDB_SUCCESS; } } /* Adjust other cursors pointing to mp */ for (m2 = mc->mc_txn->mt_cursors[dbi]; !rc && m2; m2=m2->mc_next) { m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2; if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED)) continue; if (m3 == mc || m3->mc_snum < mc->mc_snum) continue; if (m3->mc_pg[mc->mc_top] == mp) { if (m3->mc_ki[mc->mc_top] >= ki) { m3->mc_flags |= C_DEL; if (m3->mc_ki[mc->mc_top] > ki) m3->mc_ki[mc->mc_top]--; else if (mc->mc_db->md_flags & MDB_DUPSORT) m3->mc_xcursor->mx_cursor.mc_flags |= C_EOF; } if (m3->mc_ki[mc->mc_top] >= nkeys) { rc = mdb_cursor_sibling(m3, 1); if (rc == MDB_NOTFOUND) { m3->mc_flags |= C_EOF; rc = MDB_SUCCESS; } } } } mc->mc_flags |= C_DEL; } if (rc) mc->mc_txn->mt_flags |= MDB_TXN_ERROR; return rc; } int mdb_del(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data) { if (!key || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi)) return EINVAL; if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR)) return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN; if (!F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) { /* must ignore any data */ data = NULL; } return mdb_del0(txn, dbi, key, data, 0); } static int mdb_del0(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned flags) { MDB_cursor mc; MDB_xcursor mx; MDB_cursor_op op; MDB_val rdata, *xdata; int rc, exact = 0; DKBUF; DPRINTF(("====> delete db %u key [%s]", dbi, DKEY(key))); mdb_cursor_init(&mc, txn, dbi, &mx); if (data) { op = MDB_GET_BOTH; rdata = *data; xdata = &rdata; } else { op = MDB_SET; xdata = NULL; flags |= MDB_NODUPDATA; } rc = mdb_cursor_set(&mc, key, xdata, op, &exact); if (rc == 0) { /* let mdb_page_split know about this cursor if needed: * delete will trigger a rebalance; if it needs to move * a node from one page to another, it will have to * update the parent's separator key(s). If the new sepkey * is larger than the current one, the parent page may * run out of space, triggering a split. We need this * cursor to be consistent until the end of the rebalance. */ mc.mc_flags |= C_UNTRACK; mc.mc_next = txn->mt_cursors[dbi]; txn->mt_cursors[dbi] = &mc; rc = mdb_cursor_del(&mc, flags); txn->mt_cursors[dbi] = mc.mc_next; } return rc; } /** Split a page and insert a new node. * @param[in,out] mc Cursor pointing to the page and desired insertion index. * The cursor will be updated to point to the actual page and index where * the node got inserted after the split. * @param[in] newkey The key for the newly inserted node. * @param[in] newdata The data for the newly inserted node. * @param[in] newpgno The page number, if the new node is a branch node. * @param[in] nflags The #NODE_ADD_FLAGS for the new node. * @return 0 on success, non-zero on failure. */ static int mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno, unsigned int nflags) { unsigned int flags; int rc = MDB_SUCCESS, new_root = 0, did_split = 0; indx_t newindx; pgno_t pgno = 0; int i, j, split_indx, nkeys, pmax; MDB_env *env = mc->mc_txn->mt_env; MDB_node *node; MDB_val sepkey, rkey, xdata, *rdata = &xdata; MDB_page *copy = NULL; MDB_page *mp, *rp, *pp; int ptop; MDB_cursor mn; DKBUF; mp = mc->mc_pg[mc->mc_top]; newindx = mc->mc_ki[mc->mc_top]; nkeys = NUMKEYS(mp); DPRINTF(("-----> splitting %s page %"Z"u and adding [%s] at index %i/%i", IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno, DKEY(newkey), mc->mc_ki[mc->mc_top], nkeys)); /* Create a right sibling. */ if ((rc = mdb_page_new(mc, mp->mp_flags, 1, &rp))) return rc; DPRINTF(("new right sibling: page %"Z"u", rp->mp_pgno)); if (mc->mc_snum < 2) { if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp))) goto done; /* shift current top to make room for new parent */ mc->mc_pg[1] = mc->mc_pg[0]; mc->mc_ki[1] = mc->mc_ki[0]; mc->mc_pg[0] = pp; mc->mc_ki[0] = 0; mc->mc_db->md_root = pp->mp_pgno; DPRINTF(("root split! new root = %"Z"u", pp->mp_pgno)); mc->mc_db->md_depth++; new_root = 1; /* Add left (implicit) pointer. */ if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) { /* undo the pre-push */ mc->mc_pg[0] = mc->mc_pg[1]; mc->mc_ki[0] = mc->mc_ki[1]; mc->mc_db->md_root = mp->mp_pgno; mc->mc_db->md_depth--; goto done; } mc->mc_snum = 2; mc->mc_top = 1; ptop = 0; } else { ptop = mc->mc_top-1; DPRINTF(("parent branch page is %"Z"u", mc->mc_pg[ptop]->mp_pgno)); } mc->mc_flags |= C_SPLITTING; mdb_cursor_copy(mc, &mn); mn.mc_pg[mn.mc_top] = rp; mn.mc_ki[ptop] = mc->mc_ki[ptop]+1; if (nflags & MDB_APPEND) { mn.mc_ki[mn.mc_top] = 0; sepkey = *newkey; split_indx = newindx; nkeys = 0; } else { split_indx = (nkeys+1) / 2; if (IS_LEAF2(rp)) { char *split, *ins; int x; unsigned int lsize, rsize, ksize; /* Move half of the keys to the right sibling */ x = mc->mc_ki[mc->mc_top] - split_indx; ksize = mc->mc_db->md_pad; split = LEAF2KEY(mp, split_indx, ksize); rsize = (nkeys - split_indx) * ksize; lsize = (nkeys - split_indx) * sizeof(indx_t); mp->mp_lower -= lsize; rp->mp_lower += lsize; mp->mp_upper += rsize - lsize; rp->mp_upper -= rsize - lsize; sepkey.mv_size = ksize; if (newindx == split_indx) { sepkey.mv_data = newkey->mv_data; } else { sepkey.mv_data = split; } if (x<0) { ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize); memcpy(rp->mp_ptrs, split, rsize); sepkey.mv_data = rp->mp_ptrs; memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize); memcpy(ins, newkey->mv_data, ksize); mp->mp_lower += sizeof(indx_t); mp->mp_upper -= ksize - sizeof(indx_t); } else { if (x) memcpy(rp->mp_ptrs, split, x * ksize); ins = LEAF2KEY(rp, x, ksize); memcpy(ins, newkey->mv_data, ksize); memcpy(ins+ksize, split + x * ksize, rsize - x * ksize); rp->mp_lower += sizeof(indx_t); rp->mp_upper -= ksize - sizeof(indx_t); mc->mc_ki[mc->mc_top] = x; mc->mc_pg[mc->mc_top] = rp; } } else { int psize, nsize, k; /* Maximum free space in an empty page */ pmax = env->me_psize - PAGEHDRSZ; if (IS_LEAF(mp)) nsize = mdb_leaf_size(env, newkey, newdata); else nsize = mdb_branch_size(env, newkey); nsize = EVEN(nsize); /* grab a page to hold a temporary copy */ copy = mdb_page_malloc(mc->mc_txn, 1); if (copy == NULL) { rc = ENOMEM; goto done; } copy->mp_pgno = mp->mp_pgno; copy->mp_flags = mp->mp_flags; copy->mp_lower = (PAGEHDRSZ-PAGEBASE); copy->mp_upper = env->me_psize - PAGEBASE; /* prepare to insert */ for (i=0, j=0; imp_ptrs[j++] = 0; } copy->mp_ptrs[j++] = mp->mp_ptrs[i]; } /* When items are relatively large the split point needs * to be checked, because being off-by-one will make the * difference between success or failure in mdb_node_add. * * It's also relevant if a page happens to be laid out * such that one half of its nodes are all "small" and * the other half of its nodes are "large." If the new * item is also "large" and falls on the half with * "large" nodes, it also may not fit. * * As a final tweak, if the new item goes on the last * spot on the page (and thus, onto the new page), bias * the split so the new page is emptier than the old page. * This yields better packing during sequential inserts. */ if (nkeys < 20 || nsize > pmax/16 || newindx >= nkeys) { /* Find split point */ psize = 0; if (newindx <= split_indx || newindx >= nkeys) { i = 0; j = 1; k = newindx >= nkeys ? nkeys : split_indx+2; } else { i = nkeys; j = -1; k = split_indx-1; } for (; i!=k; i+=j) { if (i == newindx) { psize += nsize; node = NULL; } else { node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE); psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t); if (IS_LEAF(mp)) { if (F_ISSET(node->mn_flags, F_BIGDATA)) psize += sizeof(pgno_t); else psize += NODEDSZ(node); } psize = EVEN(psize); } if (psize > pmax || i == k-j) { split_indx = i + (j<0); break; } } } if (split_indx == newindx) { sepkey.mv_size = newkey->mv_size; sepkey.mv_data = newkey->mv_data; } else { node = (MDB_node *)((char *)mp + copy->mp_ptrs[split_indx] + PAGEBASE); sepkey.mv_size = node->mn_ksize; sepkey.mv_data = NODEKEY(node); } } } DPRINTF(("separator is %d [%s]", split_indx, DKEY(&sepkey))); /* Copy separator key to the parent. */ if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(env, &sepkey)) { mn.mc_snum--; mn.mc_top--; did_split = 1; rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0); if (rc) goto done; /* root split? */ if (mn.mc_snum == mc->mc_snum) { mc->mc_pg[mc->mc_snum] = mc->mc_pg[mc->mc_top]; mc->mc_ki[mc->mc_snum] = mc->mc_ki[mc->mc_top]; mc->mc_pg[mc->mc_top] = mc->mc_pg[ptop]; mc->mc_ki[mc->mc_top] = mc->mc_ki[ptop]; mc->mc_snum++; mc->mc_top++; ptop++; } /* Right page might now have changed parent. * Check if left page also changed parent. */ if (mn.mc_pg[ptop] != mc->mc_pg[ptop] && mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) { for (i=0; imc_pg[i] = mn.mc_pg[i]; mc->mc_ki[i] = mn.mc_ki[i]; } mc->mc_pg[ptop] = mn.mc_pg[ptop]; if (mn.mc_ki[ptop]) { mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1; } else { /* find right page's left sibling */ mc->mc_ki[ptop] = mn.mc_ki[ptop]; mdb_cursor_sibling(mc, 0); } } } else { mn.mc_top--; rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0); mn.mc_top++; } mc->mc_flags ^= C_SPLITTING; if (rc != MDB_SUCCESS) { goto done; } if (nflags & MDB_APPEND) { mc->mc_pg[mc->mc_top] = rp; mc->mc_ki[mc->mc_top] = 0; rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags); if (rc) goto done; for (i=0; imc_top; i++) mc->mc_ki[i] = mn.mc_ki[i]; } else if (!IS_LEAF2(mp)) { /* Move nodes */ mc->mc_pg[mc->mc_top] = rp; i = split_indx; j = 0; do { if (i == newindx) { rkey.mv_data = newkey->mv_data; rkey.mv_size = newkey->mv_size; if (IS_LEAF(mp)) { rdata = newdata; } else pgno = newpgno; flags = nflags; /* Update index for the new key. */ mc->mc_ki[mc->mc_top] = j; } else { node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE); rkey.mv_data = NODEKEY(node); rkey.mv_size = node->mn_ksize; if (IS_LEAF(mp)) { xdata.mv_data = NODEDATA(node); xdata.mv_size = NODEDSZ(node); rdata = &xdata; } else pgno = NODEPGNO(node); flags = node->mn_flags; } if (!IS_LEAF(mp) && j == 0) { /* First branch index doesn't need key data. */ rkey.mv_size = 0; } rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags); if (rc) goto done; if (i == nkeys) { i = 0; j = 0; mc->mc_pg[mc->mc_top] = copy; } else { i++; j++; } } while (i != split_indx); nkeys = NUMKEYS(copy); for (i=0; imp_ptrs[i] = copy->mp_ptrs[i]; mp->mp_lower = copy->mp_lower; mp->mp_upper = copy->mp_upper; memcpy(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1), env->me_psize - copy->mp_upper - PAGEBASE); /* reset back to original page */ if (newindx < split_indx) { mc->mc_pg[mc->mc_top] = mp; if (nflags & MDB_RESERVE) { node = NODEPTR(mp, mc->mc_ki[mc->mc_top]); if (!(node->mn_flags & F_BIGDATA)) newdata->mv_data = NODEDATA(node); } } else { mc->mc_pg[mc->mc_top] = rp; mc->mc_ki[ptop]++; /* Make sure mc_ki is still valid. */ if (mn.mc_pg[ptop] != mc->mc_pg[ptop] && mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) { for (i=0; i<=ptop; i++) { mc->mc_pg[i] = mn.mc_pg[i]; mc->mc_ki[i] = mn.mc_ki[i]; } } } } { /* Adjust other cursors pointing to mp */ MDB_cursor *m2, *m3; MDB_dbi dbi = mc->mc_dbi; int fixup = NUMKEYS(mp); for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { if (mc->mc_flags & C_SUB) m3 = &m2->mc_xcursor->mx_cursor; else m3 = m2; if (m3 == mc) continue; if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED)) continue; if (m3->mc_flags & C_SPLITTING) continue; if (new_root) { int k; /* root split */ for (k=m3->mc_top; k>=0; k--) { m3->mc_ki[k+1] = m3->mc_ki[k]; m3->mc_pg[k+1] = m3->mc_pg[k]; } if (m3->mc_ki[0] >= split_indx) { m3->mc_ki[0] = 1; } else { m3->mc_ki[0] = 0; } m3->mc_pg[0] = mc->mc_pg[0]; m3->mc_snum++; m3->mc_top++; } if (m3->mc_top >= mc->mc_top && m3->mc_pg[mc->mc_top] == mp) { if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE)) m3->mc_ki[mc->mc_top]++; if (m3->mc_ki[mc->mc_top] >= fixup) { m3->mc_pg[mc->mc_top] = rp; m3->mc_ki[mc->mc_top] -= fixup; m3->mc_ki[ptop] = mn.mc_ki[ptop]; } } else if (!did_split && m3->mc_top >= ptop && m3->mc_pg[ptop] == mc->mc_pg[ptop] && m3->mc_ki[ptop] >= mc->mc_ki[ptop]) { m3->mc_ki[ptop]++; } } } DPRINTF(("mp left: %d, rp left: %d", SIZELEFT(mp), SIZELEFT(rp))); done: if (copy) /* tmp page */ mdb_page_free(env, copy); if (rc) mc->mc_txn->mt_flags |= MDB_TXN_ERROR; return rc; } int mdb_put(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned int flags) { MDB_cursor mc; MDB_xcursor mx; if (!key || !data || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi)) return EINVAL; if ((flags & (MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND|MDB_APPENDDUP)) != flags) return EINVAL; mdb_cursor_init(&mc, txn, dbi, &mx); return mdb_cursor_put(&mc, key, data, flags); } #ifndef MDB_WBUF #define MDB_WBUF (1024*1024) #endif /** State needed for a compacting copy. */ typedef struct mdb_copy { pthread_mutex_t mc_mutex; pthread_cond_t mc_cond; char *mc_wbuf[2]; char *mc_over[2]; MDB_env *mc_env; MDB_txn *mc_txn; int mc_wlen[2]; int mc_olen[2]; pgno_t mc_next_pgno; HANDLE mc_fd; int mc_status; volatile int mc_new; int mc_toggle; } mdb_copy; /** Dedicated writer thread for compacting copy. */ static THREAD_RET ESECT mdb_env_copythr(void *arg) { mdb_copy *my = arg; char *ptr; int toggle = 0, wsize, rc; #ifdef _WIN32 DWORD len; #define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL) #else int len; #define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0) #endif pthread_mutex_lock(&my->mc_mutex); my->mc_new = 0; pthread_cond_signal(&my->mc_cond); for(;;) { while (!my->mc_new) pthread_cond_wait(&my->mc_cond, &my->mc_mutex); if (my->mc_new < 0) { my->mc_new = 0; break; } my->mc_new = 0; wsize = my->mc_wlen[toggle]; ptr = my->mc_wbuf[toggle]; again: while (wsize > 0) { DO_WRITE(rc, my->mc_fd, ptr, wsize, len); if (!rc) { rc = ErrCode(); break; } else if (len > 0) { rc = MDB_SUCCESS; ptr += len; wsize -= len; continue; } else { rc = EIO; break; } } if (rc) { my->mc_status = rc; break; } /* If there's an overflow page tail, write it too */ if (my->mc_olen[toggle]) { wsize = my->mc_olen[toggle]; ptr = my->mc_over[toggle]; my->mc_olen[toggle] = 0; goto again; } my->mc_wlen[toggle] = 0; toggle ^= 1; pthread_cond_signal(&my->mc_cond); } pthread_cond_signal(&my->mc_cond); pthread_mutex_unlock(&my->mc_mutex); return (THREAD_RET)0; #undef DO_WRITE } /** Tell the writer thread there's a buffer ready to write */ static int ESECT mdb_env_cthr_toggle(mdb_copy *my, int st) { int toggle = my->mc_toggle ^ 1; pthread_mutex_lock(&my->mc_mutex); if (my->mc_status) { pthread_mutex_unlock(&my->mc_mutex); return my->mc_status; } while (my->mc_new == 1) pthread_cond_wait(&my->mc_cond, &my->mc_mutex); my->mc_new = st; my->mc_toggle = toggle; pthread_cond_signal(&my->mc_cond); pthread_mutex_unlock(&my->mc_mutex); return 0; } /** Depth-first tree traversal for compacting copy. */ static int ESECT mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags) { MDB_cursor mc; MDB_txn *txn = my->mc_txn; MDB_node *ni; MDB_page *mo, *mp, *leaf; char *buf, *ptr; int rc, toggle; unsigned int i; /* Empty DB, nothing to do */ if (*pg == P_INVALID) return MDB_SUCCESS; mc.mc_snum = 1; mc.mc_top = 0; mc.mc_txn = txn; rc = mdb_page_get(my->mc_txn, *pg, &mc.mc_pg[0], NULL); if (rc) return rc; rc = mdb_page_search_root(&mc, NULL, MDB_PS_FIRST); if (rc) return rc; /* Make cursor pages writable */ buf = ptr = malloc(my->mc_env->me_psize * mc.mc_snum); if (buf == NULL) return ENOMEM; for (i=0; imc_env->me_psize); mc.mc_pg[i] = (MDB_page *)ptr; ptr += my->mc_env->me_psize; } /* This is writable space for a leaf page. Usually not needed. */ leaf = (MDB_page *)ptr; toggle = my->mc_toggle; while (mc.mc_snum > 0) { unsigned n; mp = mc.mc_pg[mc.mc_top]; n = NUMKEYS(mp); if (IS_LEAF(mp)) { if (!IS_LEAF2(mp) && !(flags & F_DUPDATA)) { for (i=0; imn_flags & F_BIGDATA) { MDB_page *omp; pgno_t pg; /* Need writable leaf */ if (mp != leaf) { mc.mc_pg[mc.mc_top] = leaf; mdb_page_copy(leaf, mp, my->mc_env->me_psize); mp = leaf; ni = NODEPTR(mp, i); } memcpy(&pg, NODEDATA(ni), sizeof(pg)); rc = mdb_page_get(txn, pg, &omp, NULL); if (rc) goto done; if (my->mc_wlen[toggle] >= MDB_WBUF) { rc = mdb_env_cthr_toggle(my, 1); if (rc) goto done; toggle = my->mc_toggle; } mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]); memcpy(mo, omp, my->mc_env->me_psize); mo->mp_pgno = my->mc_next_pgno; my->mc_next_pgno += omp->mp_pages; my->mc_wlen[toggle] += my->mc_env->me_psize; if (omp->mp_pages > 1) { my->mc_olen[toggle] = my->mc_env->me_psize * (omp->mp_pages - 1); my->mc_over[toggle] = (char *)omp + my->mc_env->me_psize; rc = mdb_env_cthr_toggle(my, 1); if (rc) goto done; toggle = my->mc_toggle; } memcpy(NODEDATA(ni), &mo->mp_pgno, sizeof(pgno_t)); } else if (ni->mn_flags & F_SUBDATA) { MDB_db db; /* Need writable leaf */ if (mp != leaf) { mc.mc_pg[mc.mc_top] = leaf; mdb_page_copy(leaf, mp, my->mc_env->me_psize); mp = leaf; ni = NODEPTR(mp, i); } memcpy(&db, NODEDATA(ni), sizeof(db)); my->mc_toggle = toggle; rc = mdb_env_cwalk(my, &db.md_root, ni->mn_flags & F_DUPDATA); if (rc) goto done; toggle = my->mc_toggle; memcpy(NODEDATA(ni), &db, sizeof(db)); } } } } else { mc.mc_ki[mc.mc_top]++; if (mc.mc_ki[mc.mc_top] < n) { pgno_t pg; again: ni = NODEPTR(mp, mc.mc_ki[mc.mc_top]); pg = NODEPGNO(ni); rc = mdb_page_get(txn, pg, &mp, NULL); if (rc) goto done; mc.mc_top++; mc.mc_snum++; mc.mc_ki[mc.mc_top] = 0; if (IS_BRANCH(mp)) { /* Whenever we advance to a sibling branch page, * we must proceed all the way down to its first leaf. */ mdb_page_copy(mc.mc_pg[mc.mc_top], mp, my->mc_env->me_psize); goto again; } else mc.mc_pg[mc.mc_top] = mp; continue; } } if (my->mc_wlen[toggle] >= MDB_WBUF) { rc = mdb_env_cthr_toggle(my, 1); if (rc) goto done; toggle = my->mc_toggle; } mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]); mdb_page_copy(mo, mp, my->mc_env->me_psize); mo->mp_pgno = my->mc_next_pgno++; my->mc_wlen[toggle] += my->mc_env->me_psize; if (mc.mc_top) { /* Update parent if there is one */ ni = NODEPTR(mc.mc_pg[mc.mc_top-1], mc.mc_ki[mc.mc_top-1]); SETPGNO(ni, mo->mp_pgno); mdb_cursor_pop(&mc); } else { /* Otherwise we're done */ *pg = mo->mp_pgno; break; } } done: free(buf); return rc; } /** Copy environment with compaction. */ static int ESECT mdb_env_copyfd1(MDB_env *env, HANDLE fd) { MDB_meta *mm; MDB_page *mp; mdb_copy my; MDB_txn *txn = NULL; pthread_t thr; int rc; #ifdef _WIN32 my.mc_mutex = CreateMutex(NULL, FALSE, NULL); my.mc_cond = CreateEvent(NULL, FALSE, FALSE, NULL); my.mc_wbuf[0] = _aligned_malloc(MDB_WBUF*2, env->me_os_psize); if (my.mc_wbuf[0] == NULL) return errno; #else pthread_mutex_init(&my.mc_mutex, NULL); pthread_cond_init(&my.mc_cond, NULL); #ifdef HAVE_MEMALIGN my.mc_wbuf[0] = memalign(env->me_os_psize, MDB_WBUF*2); if (my.mc_wbuf[0] == NULL) return errno; #else rc = posix_memalign((void **)&my.mc_wbuf[0], env->me_os_psize, MDB_WBUF*2); if (rc) return rc; #endif #endif memset(my.mc_wbuf[0], 0, MDB_WBUF*2); my.mc_wbuf[1] = my.mc_wbuf[0] + MDB_WBUF; my.mc_wlen[0] = 0; my.mc_wlen[1] = 0; my.mc_olen[0] = 0; my.mc_olen[1] = 0; my.mc_next_pgno = 2; my.mc_status = 0; my.mc_new = 1; my.mc_toggle = 0; my.mc_env = env; my.mc_fd = fd; THREAD_CREATE(thr, mdb_env_copythr, &my); rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn); if (rc) return rc; mp = (MDB_page *)my.mc_wbuf[0]; memset(mp, 0, 2*env->me_psize); mp->mp_pgno = 0; mp->mp_flags = P_META; mm = (MDB_meta *)METADATA(mp); mdb_env_init_meta0(env, mm); mm->mm_address = env->me_metas[0]->mm_address; mp = (MDB_page *)(my.mc_wbuf[0] + env->me_psize); mp->mp_pgno = 1; mp->mp_flags = P_META; *(MDB_meta *)METADATA(mp) = *mm; mm = (MDB_meta *)METADATA(mp); /* Count the number of free pages, subtract from lastpg to find * number of active pages */ { MDB_ID freecount = 0; MDB_cursor mc; MDB_val key, data; mdb_cursor_init(&mc, txn, FREE_DBI, NULL); while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0) freecount += *(MDB_ID *)data.mv_data; freecount += txn->mt_dbs[0].md_branch_pages + txn->mt_dbs[0].md_leaf_pages + txn->mt_dbs[0].md_overflow_pages; /* Set metapage 1 */ mm->mm_last_pg = txn->mt_next_pgno - freecount - 1; mm->mm_dbs[1] = txn->mt_dbs[1]; if (mm->mm_last_pg > 1) { mm->mm_dbs[1].md_root = mm->mm_last_pg; mm->mm_txnid = 1; } else { mm->mm_dbs[1].md_root = P_INVALID; } } my.mc_wlen[0] = env->me_psize * 2; my.mc_txn = txn; pthread_mutex_lock(&my.mc_mutex); while(my.mc_new) pthread_cond_wait(&my.mc_cond, &my.mc_mutex); pthread_mutex_unlock(&my.mc_mutex); rc = mdb_env_cwalk(&my, &txn->mt_dbs[1].md_root, 0); if (rc == MDB_SUCCESS && my.mc_wlen[my.mc_toggle]) rc = mdb_env_cthr_toggle(&my, 1); mdb_env_cthr_toggle(&my, -1); pthread_mutex_lock(&my.mc_mutex); while(my.mc_new) pthread_cond_wait(&my.mc_cond, &my.mc_mutex); pthread_mutex_unlock(&my.mc_mutex); THREAD_FINISH(thr); mdb_txn_abort(txn); #ifdef _WIN32 CloseHandle(my.mc_cond); CloseHandle(my.mc_mutex); _aligned_free(my.mc_wbuf[0]); #else pthread_cond_destroy(&my.mc_cond); pthread_mutex_destroy(&my.mc_mutex); free(my.mc_wbuf[0]); #endif return rc; } /** Copy environment as-is. */ static int ESECT mdb_env_copyfd0(MDB_env *env, HANDLE fd) { MDB_txn *txn = NULL; mdb_mutex_t *wmutex = NULL; int rc; size_t wsize; char *ptr; #ifdef _WIN32 DWORD len, w2; #define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL) #else ssize_t len; size_t w2; #define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0) #endif /* Do the lock/unlock of the reader mutex before starting the * write txn. Otherwise other read txns could block writers. */ rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn); if (rc) return rc; if (env->me_txns) { /* We must start the actual read txn after blocking writers */ mdb_txn_reset0(txn, "reset-stage1"); /* Temporarily block writers until we snapshot the meta pages */ wmutex = MDB_MUTEX(env, w); if (LOCK_MUTEX(rc, env, wmutex)) goto leave; rc = mdb_txn_renew0(txn); if (rc) { UNLOCK_MUTEX(wmutex); goto leave; } } wsize = env->me_psize * 2; ptr = env->me_map; w2 = wsize; while (w2 > 0) { DO_WRITE(rc, fd, ptr, w2, len); if (!rc) { rc = ErrCode(); break; } else if (len > 0) { rc = MDB_SUCCESS; ptr += len; w2 -= len; continue; } else { /* Non-blocking or async handles are not supported */ rc = EIO; break; } } if (wmutex) UNLOCK_MUTEX(wmutex); if (rc) goto leave; w2 = txn->mt_next_pgno * env->me_psize; { size_t fsize = 0; if ((rc = mdb_fsize(env->me_fd, &fsize))) goto leave; if (w2 > fsize) w2 = fsize; } wsize = w2 - wsize; while (wsize > 0) { if (wsize > MAX_WRITE) w2 = MAX_WRITE; else w2 = wsize; DO_WRITE(rc, fd, ptr, w2, len); if (!rc) { rc = ErrCode(); break; } else if (len > 0) { rc = MDB_SUCCESS; ptr += len; wsize -= len; continue; } else { rc = EIO; break; } } leave: mdb_txn_abort(txn); return rc; } int ESECT mdb_env_copyfd2(MDB_env *env, HANDLE fd, unsigned int flags) { if (flags & MDB_CP_COMPACT) return mdb_env_copyfd1(env, fd); else return mdb_env_copyfd0(env, fd); } int ESECT mdb_env_copyfd(MDB_env *env, HANDLE fd) { return mdb_env_copyfd2(env, fd, 0); } int ESECT mdb_env_copy2(MDB_env *env, const char *path, unsigned int flags) { int rc, len; char *lpath; HANDLE newfd = INVALID_HANDLE_VALUE; if (env->me_flags & MDB_NOSUBDIR) { lpath = (char *)path; } else { len = strlen(path); len += sizeof(DATANAME); lpath = malloc(len); if (!lpath) return ENOMEM; sprintf(lpath, "%s" DATANAME, path); } /* The destination path must exist, but the destination file must not. * We don't want the OS to cache the writes, since the source data is * already in the OS cache. */ #ifdef _WIN32 newfd = CreateFile(lpath, GENERIC_WRITE, 0, NULL, CREATE_NEW, FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL); #else newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL, 0666); #endif if (newfd == INVALID_HANDLE_VALUE) { rc = ErrCode(); goto leave; } if (env->me_psize >= env->me_os_psize) { #ifdef O_DIRECT /* Set O_DIRECT if the file system supports it */ if ((rc = fcntl(newfd, F_GETFL)) != -1) (void) fcntl(newfd, F_SETFL, rc | O_DIRECT); #endif #ifdef F_NOCACHE /* __APPLE__ */ rc = fcntl(newfd, F_NOCACHE, 1); if (rc) { rc = ErrCode(); goto leave; } #endif } rc = mdb_env_copyfd2(env, newfd, flags); leave: if (!(env->me_flags & MDB_NOSUBDIR)) free(lpath); if (newfd != INVALID_HANDLE_VALUE) if (close(newfd) < 0 && rc == MDB_SUCCESS) rc = ErrCode(); return rc; } int ESECT mdb_env_copy(MDB_env *env, const char *path) { return mdb_env_copy2(env, path, 0); } int ESECT mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff) { if (flag & (env->me_map ? ~CHANGEABLE : ~(CHANGEABLE|CHANGELESS))) return EINVAL; if (onoff) env->me_flags |= flag; else env->me_flags &= ~flag; return MDB_SUCCESS; } int ESECT mdb_env_get_flags(MDB_env *env, unsigned int *arg) { if (!env || !arg) return EINVAL; *arg = env->me_flags; return MDB_SUCCESS; } int ESECT mdb_env_set_userctx(MDB_env *env, void *ctx) { if (!env) return EINVAL; env->me_userctx = ctx; return MDB_SUCCESS; } void * ESECT mdb_env_get_userctx(MDB_env *env) { return env ? env->me_userctx : NULL; } int ESECT mdb_env_set_assert(MDB_env *env, MDB_assert_func *func) { if (!env) return EINVAL; #ifndef NDEBUG env->me_assert_func = func; #endif return MDB_SUCCESS; } int ESECT mdb_env_get_path(MDB_env *env, const char **arg) { if (!env || !arg) return EINVAL; *arg = env->me_path; return MDB_SUCCESS; } int ESECT mdb_env_get_fd(MDB_env *env, mdb_filehandle_t *arg) { if (!env || !arg) return EINVAL; *arg = env->me_fd; return MDB_SUCCESS; } /** Common code for #mdb_stat() and #mdb_env_stat(). * @param[in] env the environment to operate in. * @param[in] db the #MDB_db record containing the stats to return. * @param[out] arg the address of an #MDB_stat structure to receive the stats. * @return 0, this function always succeeds. */ static int ESECT mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg) { arg->ms_psize = env->me_psize; arg->ms_depth = db->md_depth; arg->ms_branch_pages = db->md_branch_pages; arg->ms_leaf_pages = db->md_leaf_pages; arg->ms_overflow_pages = db->md_overflow_pages; arg->ms_entries = db->md_entries; return MDB_SUCCESS; } int ESECT mdb_env_stat(MDB_env *env, MDB_stat *arg) { int toggle; if (env == NULL || arg == NULL) return EINVAL; toggle = mdb_env_pick_meta(env); return mdb_stat0(env, &env->me_metas[toggle]->mm_dbs[MAIN_DBI], arg); } int ESECT mdb_env_info(MDB_env *env, MDB_envinfo *arg) { int toggle; if (env == NULL || arg == NULL) return EINVAL; toggle = mdb_env_pick_meta(env); arg->me_mapaddr = env->me_metas[toggle]->mm_address; arg->me_mapsize = env->me_mapsize; arg->me_maxreaders = env->me_maxreaders; /* me_numreaders may be zero if this process never used any readers. Use * the shared numreader count if it exists. */ arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : env->me_numreaders; arg->me_last_pgno = env->me_metas[toggle]->mm_last_pg; arg->me_last_txnid = env->me_metas[toggle]->mm_txnid; return MDB_SUCCESS; } /** Set the default comparison functions for a database. * Called immediately after a database is opened to set the defaults. * The user can then override them with #mdb_set_compare() or * #mdb_set_dupsort(). * @param[in] txn A transaction handle returned by #mdb_txn_begin() * @param[in] dbi A database handle returned by #mdb_dbi_open() */ static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi) { uint16_t f = txn->mt_dbs[dbi].md_flags; txn->mt_dbxs[dbi].md_cmp = (f & MDB_REVERSEKEY) ? mdb_cmp_memnr : (f & MDB_INTEGERKEY) ? mdb_cmp_cint : mdb_cmp_memn; txn->mt_dbxs[dbi].md_dcmp = !(f & MDB_DUPSORT) ? 0 : ((f & MDB_INTEGERDUP) ? ((f & MDB_DUPFIXED) ? mdb_cmp_int : mdb_cmp_cint) : ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn)); } int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi) { MDB_val key, data; MDB_dbi i; MDB_cursor mc; MDB_db dummy; int rc, dbflag, exact; unsigned int unused = 0, seq; size_t len; if (txn->mt_dbxs[FREE_DBI].md_cmp == NULL) { mdb_default_cmp(txn, FREE_DBI); } if ((flags & VALID_FLAGS) != flags) return EINVAL; if (txn->mt_flags & MDB_TXN_ERROR) return MDB_BAD_TXN; /* main DB? */ if (!name) { *dbi = MAIN_DBI; if (flags & PERSISTENT_FLAGS) { uint16_t f2 = flags & PERSISTENT_FLAGS; /* make sure flag changes get committed */ if ((txn->mt_dbs[MAIN_DBI].md_flags | f2) != txn->mt_dbs[MAIN_DBI].md_flags) { txn->mt_dbs[MAIN_DBI].md_flags |= f2; txn->mt_flags |= MDB_TXN_DIRTY; } } mdb_default_cmp(txn, MAIN_DBI); return MDB_SUCCESS; } if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) { mdb_default_cmp(txn, MAIN_DBI); } /* Is the DB already open? */ len = strlen(name); for (i=2; imt_numdbs; i++) { if (!txn->mt_dbxs[i].md_name.mv_size) { /* Remember this free slot */ if (!unused) unused = i; continue; } if (len == txn->mt_dbxs[i].md_name.mv_size && !strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) { *dbi = i; return MDB_SUCCESS; } } /* If no free slot and max hit, fail */ if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs) return MDB_DBS_FULL; /* Cannot mix named databases with some mainDB flags */ if (txn->mt_dbs[MAIN_DBI].md_flags & (MDB_DUPSORT|MDB_INTEGERKEY)) return (flags & MDB_CREATE) ? MDB_INCOMPATIBLE : MDB_NOTFOUND; /* Find the DB info */ dbflag = DB_NEW|DB_VALID; exact = 0; key.mv_size = len; key.mv_data = (void *)name; mdb_cursor_init(&mc, txn, MAIN_DBI, NULL); rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact); if (rc == MDB_SUCCESS) { /* make sure this is actually a DB */ MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]); if (!(node->mn_flags & F_SUBDATA)) return MDB_INCOMPATIBLE; } else if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) { /* Create if requested */ data.mv_size = sizeof(MDB_db); data.mv_data = &dummy; memset(&dummy, 0, sizeof(dummy)); dummy.md_root = P_INVALID; dummy.md_flags = flags & PERSISTENT_FLAGS; rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA); dbflag |= DB_DIRTY; } /* OK, got info, add to table */ if (rc == MDB_SUCCESS) { unsigned int slot = unused ? unused : txn->mt_numdbs; txn->mt_dbxs[slot].md_name.mv_data = strdup(name); txn->mt_dbxs[slot].md_name.mv_size = len; txn->mt_dbxs[slot].md_rel = NULL; txn->mt_dbflags[slot] = dbflag; /* txn-> and env-> are the same in read txns, use * tmp variable to avoid undefined assignment */ seq = ++txn->mt_env->me_dbiseqs[slot]; txn->mt_dbiseqs[slot] = seq; memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db)); *dbi = slot; mdb_default_cmp(txn, slot); if (!unused) { txn->mt_numdbs++; } } return rc; } int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg) { if (!arg || !TXN_DBI_EXIST(txn, dbi)) return EINVAL; if (txn->mt_flags & MDB_TXN_ERROR) return MDB_BAD_TXN; if (txn->mt_dbflags[dbi] & DB_STALE) { MDB_cursor mc; MDB_xcursor mx; /* Stale, must read the DB's root. cursor_init does it for us. */ mdb_cursor_init(&mc, txn, dbi, &mx); } return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg); } void mdb_dbi_close(MDB_env *env, MDB_dbi dbi) { char *ptr; if (dbi <= MAIN_DBI || dbi >= env->me_maxdbs) return; ptr = env->me_dbxs[dbi].md_name.mv_data; /* If there was no name, this was already closed */ if (ptr) { env->me_dbxs[dbi].md_name.mv_data = NULL; env->me_dbxs[dbi].md_name.mv_size = 0; env->me_dbflags[dbi] = 0; env->me_dbiseqs[dbi]++; free(ptr); } } int mdb_dbi_flags(MDB_txn *txn, MDB_dbi dbi, unsigned int *flags) { /* We could return the flags for the FREE_DBI too but what's the point? */ if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi)) return EINVAL; *flags = txn->mt_dbs[dbi].md_flags & PERSISTENT_FLAGS; return MDB_SUCCESS; } /** Add all the DB's pages to the free list. * @param[in] mc Cursor on the DB to free. * @param[in] subs non-Zero to check for sub-DBs in this DB. * @return 0 on success, non-zero on failure. */ static int mdb_drop0(MDB_cursor *mc, int subs) { int rc; rc = mdb_page_search(mc, NULL, MDB_PS_FIRST); if (rc == MDB_SUCCESS) { MDB_txn *txn = mc->mc_txn; MDB_node *ni; MDB_cursor mx; unsigned int i; /* LEAF2 pages have no nodes, cannot have sub-DBs */ if (IS_LEAF2(mc->mc_pg[mc->mc_top])) mdb_cursor_pop(mc); mdb_cursor_copy(mc, &mx); while (mc->mc_snum > 0) { MDB_page *mp = mc->mc_pg[mc->mc_top]; unsigned n = NUMKEYS(mp); if (IS_LEAF(mp)) { for (i=0; imn_flags & F_BIGDATA) { MDB_page *omp; pgno_t pg; memcpy(&pg, NODEDATA(ni), sizeof(pg)); rc = mdb_page_get(txn, pg, &omp, NULL); if (rc != 0) goto done; mdb_cassert(mc, IS_OVERFLOW(omp)); rc = mdb_midl_append_range(&txn->mt_free_pgs, pg, omp->mp_pages); if (rc) goto done; } else if (subs && (ni->mn_flags & F_SUBDATA)) { mdb_xcursor_init1(mc, ni); rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0); if (rc) goto done; } } } else { if ((rc = mdb_midl_need(&txn->mt_free_pgs, n)) != 0) goto done; for (i=0; imt_free_pgs, pg); } } if (!mc->mc_top) break; mc->mc_ki[mc->mc_top] = i; rc = mdb_cursor_sibling(mc, 1); if (rc) { if (rc != MDB_NOTFOUND) goto done; /* no more siblings, go back to beginning * of previous level. */ mdb_cursor_pop(mc); mc->mc_ki[0] = 0; for (i=1; imc_snum; i++) { mc->mc_ki[i] = 0; mc->mc_pg[i] = mx.mc_pg[i]; } } } /* free it */ rc = mdb_midl_append(&txn->mt_free_pgs, mc->mc_db->md_root); done: if (rc) txn->mt_flags |= MDB_TXN_ERROR; } else if (rc == MDB_NOTFOUND) { rc = MDB_SUCCESS; } return rc; } int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del) { MDB_cursor *mc, *m2; int rc; if ((unsigned)del > 1 || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi)) return EINVAL; if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) return EACCES; if (dbi > MAIN_DBI && TXN_DBI_CHANGED(txn, dbi)) return MDB_BAD_DBI; rc = mdb_cursor_open(txn, dbi, &mc); if (rc) return rc; rc = mdb_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT); /* Invalidate the dropped DB's cursors */ for (m2 = txn->mt_cursors[dbi]; m2; m2 = m2->mc_next) m2->mc_flags &= ~(C_INITIALIZED|C_EOF); if (rc) goto leave; /* Can't delete the main DB */ if (del && dbi > MAIN_DBI) { rc = mdb_del0(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL, 0); if (!rc) { txn->mt_dbflags[dbi] = DB_STALE; mdb_dbi_close(txn->mt_env, dbi); } else { txn->mt_flags |= MDB_TXN_ERROR; } } else { /* reset the DB record, mark it dirty */ txn->mt_dbflags[dbi] |= DB_DIRTY; txn->mt_dbs[dbi].md_depth = 0; txn->mt_dbs[dbi].md_branch_pages = 0; txn->mt_dbs[dbi].md_leaf_pages = 0; txn->mt_dbs[dbi].md_overflow_pages = 0; txn->mt_dbs[dbi].md_entries = 0; txn->mt_dbs[dbi].md_root = P_INVALID; txn->mt_flags |= MDB_TXN_DIRTY; } leave: mdb_cursor_close(mc); return rc; } int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp) { if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi)) return EINVAL; txn->mt_dbxs[dbi].md_cmp = cmp; return MDB_SUCCESS; } int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp) { if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi)) return EINVAL; txn->mt_dbxs[dbi].md_dcmp = cmp; return MDB_SUCCESS; } int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel) { if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi)) return EINVAL; txn->mt_dbxs[dbi].md_rel = rel; return MDB_SUCCESS; } int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx) { if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi)) return EINVAL; txn->mt_dbxs[dbi].md_relctx = ctx; return MDB_SUCCESS; } int ESECT mdb_env_get_maxkeysize(MDB_env *env) { return ENV_MAXKEY(env); } int ESECT mdb_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx) { unsigned int i, rdrs; MDB_reader *mr; char buf[64]; int rc = 0, first = 1; if (!env || !func) return -1; if (!env->me_txns) { return func("(no reader locks)\n", ctx); } rdrs = env->me_txns->mti_numreaders; mr = env->me_txns->mti_readers; for (i=0; i> 1; cursor = base + pivot + 1; val = pid - ids[cursor]; if( val < 0 ) { n = pivot; } else if ( val > 0 ) { base = cursor; n -= pivot + 1; } else { /* found, so it's a duplicate */ return -1; } } if( val > 0 ) { ++cursor; } ids[0]++; for (n = ids[0]; n > cursor; n--) ids[n] = ids[n-1]; ids[n] = pid; return 0; } int ESECT mdb_reader_check(MDB_env *env, int *dead) { if (!env) return EINVAL; if (dead) *dead = 0; return env->me_txns ? mdb_reader_check0(env, 0, dead) : MDB_SUCCESS; } /** As #mdb_reader_check(). rlocked = . */ static int mdb_reader_check0(MDB_env *env, int rlocked, int *dead) { mdb_mutex_t *rmutex = rlocked ? NULL : MDB_MUTEX(env, r); unsigned int i, j, rdrs; MDB_reader *mr; MDB_PID_T *pids, pid; int rc = MDB_SUCCESS, count = 0; rdrs = env->me_txns->mti_numreaders; pids = malloc((rdrs+1) * sizeof(MDB_PID_T)); if (!pids) return ENOMEM; pids[0] = 0; mr = env->me_txns->mti_readers; for (i=0; ime_pid) { if (mdb_pid_insert(pids, pid) == 0) { if (!mdb_reader_pid(env, Pidcheck, pid)) { /* Stale reader found */ j = i; if (rmutex) { if ((rc = LOCK_MUTEX0(rmutex)) != 0) { if ((rc = mdb_mutex_failed(env, rmutex, rc))) break; rdrs = 0; /* the above checked all readers */ } else { /* Recheck, a new process may have reused pid */ if (mdb_reader_pid(env, Pidcheck, pid)) j = rdrs; } } for (; jme_txns->mti_txnid = env->me_metas[toggle]->mm_txnid; /* env is hosed if the dead thread was ours */ if (env->me_txn) { env->me_flags |= MDB_FATAL_ERROR; env->me_txn = NULL; rc = MDB_PANIC; } } DPRINTF(("%cmutex owner died, %s", (rlocked ? 'r' : 'w'), (rc ? "this process' env is hosed" : "recovering"))); rc2 = mdb_reader_check0(env, rlocked, NULL); if (rc2 == 0) rc2 = pthread_mutex_consistent(mutex); if (rc || (rc = rc2)) { DPRINTF(("LOCK_MUTEX recovery failed, %s", mdb_strerror(rc))); UNLOCK_MUTEX(mutex); } } else { #ifdef _WIN32 rc = ErrCode(); #endif DPRINTF(("LOCK_MUTEX failed, %s", mdb_strerror(rc))); } return rc; } #endif /* MDB_ROBUST_SUPPORTED */ /** @} */