trivial database library
- Copyright (C) Andrew Tridgell 1999-2004
+ Copyright (C) Andrew Tridgell 1999-2005
Copyright (C) Paul `Rusty' Russell 2000
Copyright (C) Jeremy Allison 2000-2003
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
+#include "tdb_private.h"
-/* NOTE: If you use tdbs under valgrind, and in particular if you run
- * tdbtorture, you may get spurious "uninitialized value" warnings. I
- * think this is because valgrind doesn't understand that the mmap'd
- * area may be written to by other processes. Memory can, from the
- * point of view of the grinded process, spontaneously become
- * initialized.
- *
- * I can think of a few solutions. [mbp 20030311]
- *
- * 1 - Write suppressions for Valgrind so that it doesn't complain
- * about this. Probably the most reasonable but people need to
- * remember to use them.
- *
- * 2 - Use IO not mmap when running under valgrind. Not so nice.
- *
- * 3 - Use the special valgrind macros to mark memory as valid at the
- * right time. Probably too hard -- the process just doesn't know.
- */
-
-#ifndef _SAMBA_BUILD_
-#if HAVE_CONFIG_H
-#include <config.h>
-#endif
-
-#include <stdlib.h>
-#include <stdio.h>
-#include <stdint.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <string.h>
-#include <fcntl.h>
-#include <errno.h>
-#include <sys/mman.h>
-#include <sys/stat.h>
-#include "tdb.h"
-#else
-#include "includes.h"
-#include "lib/tdb/include/tdb.h"
-#include "system/time.h"
-#include "system/shmem.h"
-#include "system/filesys.h"
-#endif
-
-#define TDB_MAGIC_FOOD "TDB file\n"
-#define TDB_VERSION (0x26011967 + 6)
-#define TDB_MAGIC (0x26011999U)
-#define TDB_FREE_MAGIC (~TDB_MAGIC)
-#define TDB_DEAD_MAGIC (0xFEE1DEAD)
-#define TDB_ALIGNMENT 4
-#define MIN_REC_SIZE (2*sizeof(struct list_struct) + TDB_ALIGNMENT)
-#define DEFAULT_HASH_SIZE 131
-#define TDB_PAGE_SIZE 0x2000
-#define FREELIST_TOP (sizeof(struct tdb_header))
-#define TDB_ALIGN(x,a) (((x) + (a)-1) & ~((a)-1))
-#define TDB_BYTEREV(x) (((((x)&0xff)<<24)|((x)&0xFF00)<<8)|(((x)>>8)&0xFF00)|((x)>>24))
-#define TDB_DEAD(r) ((r)->magic == TDB_DEAD_MAGIC)
-#define TDB_BAD_MAGIC(r) ((r)->magic != TDB_MAGIC && !TDB_DEAD(r))
-#define TDB_HASH_TOP(hash) (FREELIST_TOP + (BUCKET(hash)+1)*sizeof(tdb_off))
-#define TDB_DATA_START(hash_size) (TDB_HASH_TOP(hash_size-1) + TDB_SPINLOCK_SIZE(hash_size))
-
-
-/* NB assumes there is a local variable called "tdb" that is the
- * current context, also takes doubly-parenthesized print-style
- * argument. */
-#define TDB_LOG(x) tdb->log_fn x
-
-/* lock offsets */
-#define GLOBAL_LOCK 0
-#define ACTIVE_LOCK 4
-
-#ifndef MAP_FILE
-#define MAP_FILE 0
-#endif
-
-#ifndef MAP_FAILED
-#define MAP_FAILED ((void *)-1)
-#endif
-
-#ifndef discard_const_p
-# if defined(__intptr_t_defined) || defined(HAVE_INTPTR_T)
-# define discard_const(ptr) ((void *)((intptr_t)(ptr)))
-# else
-# define discard_const(ptr) ((void *)(ptr))
-# endif
-# define discard_const_p(type, ptr) ((type *)discard_const(ptr))
-#endif
-
-/* free memory if the pointer is valid and zero the pointer */
-#ifndef SAFE_FREE
-#define SAFE_FREE(x) do { if ((x) != NULL) {free(discard_const_p(void *, (x))); (x)=NULL;} } while(0)
-#endif
-
-#define BUCKET(hash) ((hash) % tdb->header.hash_size)
TDB_DATA tdb_null;
-/* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
-static TDB_CONTEXT *tdbs = NULL;
-
-static int tdb_munmap(TDB_CONTEXT *tdb)
-{
- if (tdb->flags & TDB_INTERNAL)
- return 0;
-
-#ifdef HAVE_MMAP
- if (tdb->map_ptr) {
- int ret = munmap(tdb->map_ptr, tdb->map_size);
- if (ret != 0)
- return ret;
- }
-#endif
- tdb->map_ptr = NULL;
- return 0;
-}
-
-static void tdb_mmap(TDB_CONTEXT *tdb)
-{
- if (tdb->flags & TDB_INTERNAL)
- return;
-
-#ifdef HAVE_MMAP
- if (!(tdb->flags & TDB_NOMMAP)) {
- tdb->map_ptr = mmap(NULL, tdb->map_size,
- PROT_READ|(tdb->read_only? 0:PROT_WRITE),
- MAP_SHARED|MAP_FILE, tdb->fd, 0);
-
- /*
- * NB. When mmap fails it returns MAP_FAILED *NOT* NULL !!!!
- */
-
- if (tdb->map_ptr == MAP_FAILED) {
- tdb->map_ptr = NULL;
- TDB_LOG((tdb, 2, "tdb_mmap failed for size %d (%s)\n",
- tdb->map_size, strerror(errno)));
- }
- } else {
- tdb->map_ptr = NULL;
- }
-#else
- tdb->map_ptr = NULL;
-#endif
-}
-
-/* Endian conversion: we only ever deal with 4 byte quantities */
-static void *convert(void *buf, u32 size)
-{
- u32 i, *p = buf;
- for (i = 0; i < size / 4; i++)
- p[i] = TDB_BYTEREV(p[i]);
- return buf;
-}
-#define DOCONV() (tdb->flags & TDB_CONVERT)
-#define CONVERT(x) (DOCONV() ? convert(&x, sizeof(x)) : &x)
-
-/* the body of the database is made of one list_struct for the free space
- plus a separate data list for each hash value */
-struct list_struct {
- tdb_off next; /* offset of the next record in the list */
- tdb_len rec_len; /* total byte length of record */
- tdb_len key_len; /* byte length of key */
- tdb_len data_len; /* byte length of data */
- u32 full_hash; /* the full 32 bit hash of the key */
- u32 magic; /* try to catch errors */
- /* the following union is implied:
- union {
- char record[rec_len];
- struct {
- char key[key_len];
- char data[data_len];
- }
- u32 totalsize; (tailer)
- }
- */
-};
-
-/* a byte range locking function - return 0 on success
- this functions locks/unlocks 1 byte at the specified offset.
-
- On error, errno is also set so that errors are passed back properly
- through tdb_open(). */
-static int tdb_brlock(TDB_CONTEXT *tdb, tdb_off offset,
- int rw_type, int lck_type, int probe)
-{
- struct flock fl;
- int ret;
-
- if (tdb->flags & TDB_NOLOCK)
- return 0;
- if ((rw_type == F_WRLCK) && (tdb->read_only)) {
- errno = EACCES;
- return -1;
- }
-
- fl.l_type = rw_type;
- fl.l_whence = SEEK_SET;
- fl.l_start = offset;
- fl.l_len = 1;
- fl.l_pid = 0;
-
- do {
- ret = fcntl(tdb->fd,lck_type,&fl);
- } while (ret == -1 && errno == EINTR);
-
- if (ret == -1) {
- if (!probe && lck_type != F_SETLK) {
- /* Ensure error code is set for log fun to examine. */
- tdb->ecode = TDB_ERR_LOCK;
- TDB_LOG((tdb, 5,"tdb_brlock failed (fd=%d) at offset %d rw_type=%d lck_type=%d\n",
- tdb->fd, offset, rw_type, lck_type));
- }
- /* Generic lock error. errno set by fcntl.
- * EAGAIN is an expected return from non-blocking
- * locks. */
- if (errno != EAGAIN) {
- TDB_LOG((tdb, 5, "tdb_brlock failed (fd=%d) at offset %d rw_type=%d lck_type=%d: %s\n",
- tdb->fd, offset, rw_type, lck_type,
- strerror(errno)));
- }
- return TDB_ERRCODE(TDB_ERR_LOCK, -1);
- }
- return 0;
-}
-
-/* lock a list in the database. list -1 is the alloc list */
-static int tdb_lock(TDB_CONTEXT *tdb, int list, int ltype)
-{
- if (list < -1 || list >= (int)tdb->header.hash_size) {
- TDB_LOG((tdb, 0,"tdb_lock: invalid list %d for ltype=%d\n",
- list, ltype));
- return -1;
- }
- if (tdb->flags & TDB_NOLOCK)
- return 0;
-
- /* Since fcntl locks don't nest, we do a lock for the first one,
- and simply bump the count for future ones */
- if (tdb->locked[list+1].count == 0) {
- if (!tdb->read_only && tdb->header.rwlocks) {
- if (tdb_spinlock(tdb, list, ltype)) {
- TDB_LOG((tdb, 0, "tdb_lock spinlock failed on list %d ltype=%d\n",
- list, ltype));
- return -1;
- }
- } else if (tdb_brlock(tdb,FREELIST_TOP+4*list,ltype,F_SETLKW, 0)) {
- TDB_LOG((tdb, 0,"tdb_lock failed on list %d ltype=%d (%s)\n",
- list, ltype, strerror(errno)));
- return -1;
- }
- tdb->locked[list+1].ltype = ltype;
- }
- tdb->locked[list+1].count++;
- return 0;
-}
-
-/* unlock the database: returns void because it's too late for errors. */
- /* changed to return int it may be interesting to know there
- has been an error --simo */
-static int tdb_unlock(TDB_CONTEXT *tdb, int list, int ltype)
-{
- int ret = -1;
-
- if (tdb->flags & TDB_NOLOCK)
- return 0;
-
- /* Sanity checks */
- if (list < -1 || list >= (int)tdb->header.hash_size) {
- TDB_LOG((tdb, 0, "tdb_unlock: list %d invalid (%d)\n", list, tdb->header.hash_size));
- return ret;
- }
-
- if (tdb->locked[list+1].count==0) {
- TDB_LOG((tdb, 0, "tdb_unlock: count is 0\n"));
- return ret;
- }
-
- if (tdb->locked[list+1].count == 1) {
- /* Down to last nested lock: unlock underneath */
- if (!tdb->read_only && tdb->header.rwlocks) {
- ret = tdb_spinunlock(tdb, list, ltype);
- } else {
- ret = tdb_brlock(tdb, FREELIST_TOP+4*list, F_UNLCK, F_SETLKW, 0);
- }
- } else {
- ret = 0;
- }
- tdb->locked[list+1].count--;
-
- if (ret)
- TDB_LOG((tdb, 0,"tdb_unlock: An error occurred unlocking!\n"));
- return ret;
-}
-
-/* This is based on the hash algorithm from gdbm */
-static u32 default_tdb_hash(TDB_DATA *key)
-{
- u32 value; /* Used to compute the hash value. */
- u32 i; /* Used to cycle through random values. */
-
- /* Set the initial value from the key size. */
- for (value = 0x238F13AF * key->dsize, i=0; i < key->dsize; i++)
- value = (value + (key->dptr[i] << (i*5 % 24)));
-
- return (1103515243 * value + 12345);
-}
-
-/* check for an out of bounds access - if it is out of bounds then
- see if the database has been expanded by someone else and expand
- if necessary
- note that "len" is the minimum length needed for the db
+/*
+ increment the tdb sequence number if the tdb has been opened using
+ the TDB_SEQNUM flag
*/
-static int tdb_oob(TDB_CONTEXT *tdb, tdb_off len, int probe)
-{
- struct stat st;
- if (len <= tdb->map_size)
- return 0;
- if (tdb->flags & TDB_INTERNAL) {
- if (!probe) {
- /* Ensure ecode is set for log fn. */
- tdb->ecode = TDB_ERR_IO;
- TDB_LOG((tdb, 0,"tdb_oob len %d beyond internal malloc size %d\n",
- (int)len, (int)tdb->map_size));
- }
- return TDB_ERRCODE(TDB_ERR_IO, -1);
- }
-
- if (fstat(tdb->fd, &st) == -1)
- return TDB_ERRCODE(TDB_ERR_IO, -1);
-
- if (st.st_size < (size_t)len) {
- if (!probe) {
- /* Ensure ecode is set for log fn. */
- tdb->ecode = TDB_ERR_IO;
- TDB_LOG((tdb, 0,"tdb_oob len %d beyond eof at %d\n",
- (int)len, (int)st.st_size));
- }
- return TDB_ERRCODE(TDB_ERR_IO, -1);
- }
-
- /* Unmap, update size, remap */
- if (tdb_munmap(tdb) == -1)
- return TDB_ERRCODE(TDB_ERR_IO, -1);
- tdb->map_size = st.st_size;
- tdb_mmap(tdb);
- return 0;
-}
-
-/* write a lump of data at a specified offset */
-static int tdb_write(TDB_CONTEXT *tdb, tdb_off off, void *buf, tdb_len len)
-{
- if (tdb_oob(tdb, off + len, 0) != 0)
- return -1;
-
- if (tdb->map_ptr)
- memcpy(off + (char *)tdb->map_ptr, buf, len);
-#ifdef HAVE_PWRITE
- else if (pwrite(tdb->fd, buf, len, off) != (ssize_t)len) {
-#else
- else if (lseek(tdb->fd, off, SEEK_SET) != off
- || write(tdb->fd, buf, len) != (ssize_t)len) {
-#endif
- /* Ensure ecode is set for log fn. */
- tdb->ecode = TDB_ERR_IO;
- TDB_LOG((tdb, 0,"tdb_write failed at %d len=%d (%s)\n",
- off, len, strerror(errno)));
- return TDB_ERRCODE(TDB_ERR_IO, -1);
- }
- return 0;
-}
-
-/* read a lump of data at a specified offset, maybe convert */
-static int tdb_read(TDB_CONTEXT *tdb,tdb_off off,void *buf,tdb_len len,int cv)
-{
- if (tdb_oob(tdb, off + len, 0) != 0)
- return -1;
-
- if (tdb->map_ptr)
- memcpy(buf, off + (char *)tdb->map_ptr, len);
-#ifdef HAVE_PREAD
- else if (pread(tdb->fd, buf, len, off) != (ssize_t)len) {
-#else
- else if (lseek(tdb->fd, off, SEEK_SET) != off
- || read(tdb->fd, buf, len) != (ssize_t)len) {
-#endif
- /* Ensure ecode is set for log fn. */
- tdb->ecode = TDB_ERR_IO;
- TDB_LOG((tdb, 0,"tdb_read failed at %d len=%d (%s)\n",
- off, len, strerror(errno)));
- return TDB_ERRCODE(TDB_ERR_IO, -1);
- }
- if (cv)
- convert(buf, len);
- return 0;
-}
-
-/* read a lump of data, allocating the space for it */
-static char *tdb_alloc_read(TDB_CONTEXT *tdb, tdb_off offset, tdb_len len)
-{
- char *buf;
-
- if (!(buf = malloc(len))) {
- /* Ensure ecode is set for log fn. */
- tdb->ecode = TDB_ERR_OOM;
- TDB_LOG((tdb, 0,"tdb_alloc_read malloc failed len=%d (%s)\n",
- len, strerror(errno)));
- return TDB_ERRCODE(TDB_ERR_OOM, buf);
- }
- if (tdb_read(tdb, offset, buf, len, 0) == -1) {
- SAFE_FREE(buf);
- return NULL;
- }
- return buf;
-}
-
-/* read/write a tdb_off */
-static int ofs_read(TDB_CONTEXT *tdb, tdb_off offset, tdb_off *d)
-{
- return tdb_read(tdb, offset, (char*)d, sizeof(*d), DOCONV());
-}
-static int ofs_write(TDB_CONTEXT *tdb, tdb_off offset, tdb_off *d)
-{
- tdb_off off = *d;
- return tdb_write(tdb, offset, CONVERT(off), sizeof(*d));
-}
-
-/* read/write a record */
-static int rec_read(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec)
-{
- if (tdb_read(tdb, offset, rec, sizeof(*rec),DOCONV()) == -1)
- return -1;
- if (TDB_BAD_MAGIC(rec)) {
- /* Ensure ecode is set for log fn. */
- tdb->ecode = TDB_ERR_CORRUPT;
- TDB_LOG((tdb, 0,"rec_read bad magic 0x%x at offset=%d\n", rec->magic, offset));
- return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
- }
- return tdb_oob(tdb, rec->next+sizeof(*rec), 0);
-}
-static int rec_write(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec)
-{
- struct list_struct r = *rec;
- return tdb_write(tdb, offset, CONVERT(r), sizeof(r));
-}
-
-/* read a freelist record and check for simple errors */
-static int rec_free_read(TDB_CONTEXT *tdb, tdb_off off, struct list_struct *rec)
-{
- if (tdb_read(tdb, off, rec, sizeof(*rec),DOCONV()) == -1)
- return -1;
-
- if (rec->magic == TDB_MAGIC) {
- /* this happens when a app is showdown while deleting a record - we should
- not completely fail when this happens */
- TDB_LOG((tdb, 0,"rec_free_read non-free magic 0x%x at offset=%d - fixing\n",
- rec->magic, off));
- rec->magic = TDB_FREE_MAGIC;
- if (tdb_write(tdb, off, rec, sizeof(*rec)) == -1)
- return -1;
- }
-
- if (rec->magic != TDB_FREE_MAGIC) {
- /* Ensure ecode is set for log fn. */
- tdb->ecode = TDB_ERR_CORRUPT;
- TDB_LOG((tdb, 0,"rec_free_read bad magic 0x%x at offset=%d\n",
- rec->magic, off));
- return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
- }
- if (tdb_oob(tdb, rec->next+sizeof(*rec), 0) != 0)
- return -1;
- return 0;
-}
-
-/* update a record tailer (must hold allocation lock) */
-static int update_tailer(TDB_CONTEXT *tdb, tdb_off offset,
- const struct list_struct *rec)
-{
- tdb_off totalsize;
-
- /* Offset of tailer from record header */
- totalsize = sizeof(*rec) + rec->rec_len;
- return ofs_write(tdb, offset + totalsize - sizeof(tdb_off),
- &totalsize);
-}
-
-static tdb_off tdb_dump_record(TDB_CONTEXT *tdb, tdb_off offset)
-{
- struct list_struct rec;
- tdb_off tailer_ofs, tailer;
-
- if (tdb_read(tdb, offset, (char *)&rec, sizeof(rec), DOCONV()) == -1) {
- printf("ERROR: failed to read record at %u\n", offset);
- return 0;
- }
-
- printf(" rec: offset=0x%08x next=0x%08x rec_len=%d key_len=%d data_len=%d full_hash=0x%x magic=0x%x\n",
- offset, rec.next, rec.rec_len, rec.key_len, rec.data_len, rec.full_hash, rec.magic);
-
- tailer_ofs = offset + sizeof(rec) + rec.rec_len - sizeof(tdb_off);
- if (ofs_read(tdb, tailer_ofs, &tailer) == -1) {
- printf("ERROR: failed to read tailer at %u\n", tailer_ofs);
- return rec.next;
- }
-
- if (tailer != rec.rec_len + sizeof(rec)) {
- printf("ERROR: tailer does not match record! tailer=%u totalsize=%u\n",
- (unsigned int)tailer, (unsigned int)(rec.rec_len + sizeof(rec)));
- }
- return rec.next;
-}
-
-static int tdb_dump_chain(TDB_CONTEXT *tdb, int i)
-{
- tdb_off rec_ptr, top;
-
- top = TDB_HASH_TOP(i);
-
- if (tdb_lock(tdb, i, F_WRLCK) != 0)
- return -1;
-
- if (ofs_read(tdb, top, &rec_ptr) == -1)
- return tdb_unlock(tdb, i, F_WRLCK);
-
- if (rec_ptr)
- printf("hash=%d\n", i);
-
- while (rec_ptr) {
- rec_ptr = tdb_dump_record(tdb, rec_ptr);
- }
-
- return tdb_unlock(tdb, i, F_WRLCK);
-}
-
-void tdb_dump_all(TDB_CONTEXT *tdb)
-{
- int i;
- for (i=0;i<tdb->header.hash_size;i++) {
- tdb_dump_chain(tdb, i);
- }
- printf("freelist:\n");
- tdb_dump_chain(tdb, -1);
-}
-
-int tdb_printfreelist(TDB_CONTEXT *tdb)
-{
- int ret;
- long total_free = 0;
- tdb_off offset, rec_ptr;
- struct list_struct rec;
-
- if ((ret = tdb_lock(tdb, -1, F_WRLCK)) != 0)
- return ret;
-
- offset = FREELIST_TOP;
-
- /* read in the freelist top */
- if (ofs_read(tdb, offset, &rec_ptr) == -1) {
- tdb_unlock(tdb, -1, F_WRLCK);
- return 0;
- }
-
- printf("freelist top=[0x%08x]\n", rec_ptr );
- while (rec_ptr) {
- if (tdb_read(tdb, rec_ptr, (char *)&rec, sizeof(rec), DOCONV()) == -1) {
- tdb_unlock(tdb, -1, F_WRLCK);
- return -1;
- }
-
- if (rec.magic != TDB_FREE_MAGIC) {
- printf("bad magic 0x%08x in free list\n", rec.magic);
- tdb_unlock(tdb, -1, F_WRLCK);
- return -1;
- }
-
- printf("entry offset=[0x%08x], rec.rec_len = [0x%08x (%d)] (end = 0x%08x)\n",
- rec_ptr, rec.rec_len, rec.rec_len, rec_ptr + rec.rec_len);
- total_free += rec.rec_len;
-
- /* move to the next record */
- rec_ptr = rec.next;
- }
- printf("total rec_len = [0x%08x (%d)]\n", (int)total_free,
- (int)total_free);
-
- return tdb_unlock(tdb, -1, F_WRLCK);
-}
-
-/* Remove an element from the freelist. Must have alloc lock. */
-static int remove_from_freelist(TDB_CONTEXT *tdb, tdb_off off, tdb_off next)
-{
- tdb_off last_ptr, i;
-
- /* read in the freelist top */
- last_ptr = FREELIST_TOP;
- while (ofs_read(tdb, last_ptr, &i) != -1 && i != 0) {
- if (i == off) {
- /* We've found it! */
- return ofs_write(tdb, last_ptr, &next);
- }
- /* Follow chain (next offset is at start of record) */
- last_ptr = i;
- }
- TDB_LOG((tdb, 0,"remove_from_freelist: not on list at off=%d\n", off));
- return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
-}
-
-/* Add an element into the freelist. Merge adjacent records if
- neccessary. */
-static int tdb_free(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec)
-{
- tdb_off right, left;
-
- /* Allocation and tailer lock */
- if (tdb_lock(tdb, -1, F_WRLCK) != 0)
- return -1;
-
- /* set an initial tailer, so if we fail we don't leave a bogus record */
- if (update_tailer(tdb, offset, rec) != 0) {
- TDB_LOG((tdb, 0, "tdb_free: upfate_tailer failed!\n"));
- goto fail;
- }
-
- /* Look right first (I'm an Australian, dammit) */
- right = offset + sizeof(*rec) + rec->rec_len;
- if (right + sizeof(*rec) <= tdb->map_size) {
- struct list_struct r;
-
- if (tdb_read(tdb, right, &r, sizeof(r), DOCONV()) == -1) {
- TDB_LOG((tdb, 0, "tdb_free: right read failed at %u\n", right));
- goto left;
- }
-
- /* If it's free, expand to include it. */
- if (r.magic == TDB_FREE_MAGIC) {
- if (remove_from_freelist(tdb, right, r.next) == -1) {
- TDB_LOG((tdb, 0, "tdb_free: right free failed at %u\n", right));
- goto left;
- }
- rec->rec_len += sizeof(r) + r.rec_len;
- }
- }
-
-left:
- /* Look left */
- left = offset - sizeof(tdb_off);
- if (left > TDB_DATA_START(tdb->header.hash_size)) {
- struct list_struct l;
- tdb_off leftsize;
-
- /* Read in tailer and jump back to header */
- if (ofs_read(tdb, left, &leftsize) == -1) {
- TDB_LOG((tdb, 0, "tdb_free: left offset read failed at %u\n", left));
- goto update;
- }
- left = offset - leftsize;
-
- /* Now read in record */
- if (tdb_read(tdb, left, &l, sizeof(l), DOCONV()) == -1) {
- TDB_LOG((tdb, 0, "tdb_free: left read failed at %u (%u)\n", left, leftsize));
- goto update;
- }
-
- /* If it's free, expand to include it. */
- if (l.magic == TDB_FREE_MAGIC) {
- if (remove_from_freelist(tdb, left, l.next) == -1) {
- TDB_LOG((tdb, 0, "tdb_free: left free failed at %u\n", left));
- goto update;
- } else {
- offset = left;
- rec->rec_len += leftsize;
- }
- }
- }
-
-update:
- if (update_tailer(tdb, offset, rec) == -1) {
- TDB_LOG((tdb, 0, "tdb_free: update_tailer failed at %u\n", offset));
- goto fail;
- }
-
- /* Now, prepend to free list */
- rec->magic = TDB_FREE_MAGIC;
-
- if (ofs_read(tdb, FREELIST_TOP, &rec->next) == -1 ||
- rec_write(tdb, offset, rec) == -1 ||
- ofs_write(tdb, FREELIST_TOP, &offset) == -1) {
- TDB_LOG((tdb, 0, "tdb_free record write failed at offset=%d\n", offset));
- goto fail;
- }
-
- /* And we're done. */
- tdb_unlock(tdb, -1, F_WRLCK);
- return 0;
-
- fail:
- tdb_unlock(tdb, -1, F_WRLCK);
- return -1;
-}
-
-
-/* expand a file. we prefer to use ftruncate, as that is what posix
- says to use for mmap expansion */
-static int expand_file(TDB_CONTEXT *tdb, tdb_off size, tdb_off addition)
-{
- char buf[1024];
-#if HAVE_FTRUNCATE_EXTEND
- if (ftruncate(tdb->fd, size+addition) != 0) {
- TDB_LOG((tdb, 0, "expand_file ftruncate to %d failed (%s)\n",
- size+addition, strerror(errno)));
- return -1;
- }
-#else
- char b = 0;
-
-#ifdef HAVE_PWRITE
- if (pwrite(tdb->fd, &b, 1, (size+addition) - 1) != 1) {
-#else
- if (lseek(tdb->fd, (size+addition) - 1, SEEK_SET) != (size+addition) - 1 ||
- write(tdb->fd, &b, 1) != 1) {
-#endif
- TDB_LOG((tdb, 0, "expand_file to %d failed (%s)\n",
- size+addition, strerror(errno)));
- return -1;
- }
-#endif
-
- /* now fill the file with something. This ensures that the file isn't sparse, which would be
- very bad if we ran out of disk. This must be done with write, not via mmap */
- memset(buf, 0x42, sizeof(buf));
- while (addition) {
- int n = addition>sizeof(buf)?sizeof(buf):addition;
-#ifdef HAVE_PWRITE
- int ret = pwrite(tdb->fd, buf, n, size);
-#else
- int ret;
- if (lseek(tdb->fd, size, SEEK_SET) != size)
- return -1;
- ret = write(tdb->fd, buf, n);
-#endif
- if (ret != n) {
- TDB_LOG((tdb, 0, "expand_file write of %d failed (%s)\n",
- n, strerror(errno)));
- return -1;
- }
- addition -= n;
- size += n;
- }
- return 0;
-}
-
-
-/* expand the database at least size bytes by expanding the underlying
- file and doing the mmap again if necessary */
-static int tdb_expand(TDB_CONTEXT *tdb, tdb_off size)
-{
- struct list_struct rec;
- tdb_off offset;
-
- if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
- TDB_LOG((tdb, 0, "lock failed in tdb_expand\n"));
- return -1;
- }
-
- /* must know about any previous expansions by another process */
- tdb_oob(tdb, tdb->map_size + 1, 1);
-
- /* always make room for at least 10 more records, and round
- the database up to a multiple of TDB_PAGE_SIZE */
- size = TDB_ALIGN(tdb->map_size + size*10, TDB_PAGE_SIZE) - tdb->map_size;
-
- if (!(tdb->flags & TDB_INTERNAL))
- tdb_munmap(tdb);
-
- /*
- * We must ensure the file is unmapped before doing this
- * to ensure consistency with systems like OpenBSD where
- * writes and mmaps are not consistent.
- */
-
- /* expand the file itself */
- if (!(tdb->flags & TDB_INTERNAL)) {
- if (expand_file(tdb, tdb->map_size, size) != 0)
- goto fail;
- }
-
- tdb->map_size += size;
-
- if (tdb->flags & TDB_INTERNAL) {
- char *new_map_ptr = realloc(tdb->map_ptr, tdb->map_size);
- if (!new_map_ptr) {
- tdb->map_size -= size;
- goto fail;
- }
- tdb->map_ptr = new_map_ptr;
- } else {
- /*
- * We must ensure the file is remapped before adding the space
- * to ensure consistency with systems like OpenBSD where
- * writes and mmaps are not consistent.
- */
-
- /* We're ok if the mmap fails as we'll fallback to read/write */
- tdb_mmap(tdb);
- }
-
- /* form a new freelist record */
- memset(&rec,'\0',sizeof(rec));
- rec.rec_len = size - sizeof(rec);
-
- /* link it into the free list */
- offset = tdb->map_size - size;
- if (tdb_free(tdb, offset, &rec) == -1)
- goto fail;
-
- tdb_unlock(tdb, -1, F_WRLCK);
- return 0;
- fail:
- tdb_unlock(tdb, -1, F_WRLCK);
- return -1;
-}
-
-
-/*
- the core of tdb_allocate - called when we have decided which
- free list entry to use
- */
-static tdb_off tdb_allocate_ofs(TDB_CONTEXT *tdb, tdb_len length, tdb_off rec_ptr,
- struct list_struct *rec, tdb_off last_ptr)
+static void tdb_increment_seqnum(struct tdb_context *tdb)
{
- struct list_struct newrec;
- tdb_off newrec_ptr;
-
- memset(&newrec, '\0', sizeof(newrec));
-
- /* found it - now possibly split it up */
- if (rec->rec_len > length + MIN_REC_SIZE) {
- /* Length of left piece */
- length = TDB_ALIGN(length, TDB_ALIGNMENT);
-
- /* Right piece to go on free list */
- newrec.rec_len = rec->rec_len - (sizeof(*rec) + length);
- newrec_ptr = rec_ptr + sizeof(*rec) + length;
-
- /* And left record is shortened */
- rec->rec_len = length;
- } else {
- newrec_ptr = 0;
- }
+ tdb_off_t seqnum=0;
- /* Remove allocated record from the free list */
- if (ofs_write(tdb, last_ptr, &rec->next) == -1) {
- return 0;
- }
-
- /* Update header: do this before we drop alloc
- lock, otherwise tdb_free() might try to
- merge with us, thinking we're free.
- (Thanks Jeremy Allison). */
- rec->magic = TDB_MAGIC;
- if (rec_write(tdb, rec_ptr, rec) == -1) {
- return 0;
- }
-
- /* Did we create new block? */
- if (newrec_ptr) {
- /* Update allocated record tailer (we
- shortened it). */
- if (update_tailer(tdb, rec_ptr, rec) == -1) {
- return 0;
- }
-
- /* Free new record */
- if (tdb_free(tdb, newrec_ptr, &newrec) == -1) {
- return 0;
- }
+ if (!(tdb->flags & TDB_SEQNUM)) {
+ return;
}
-
- /* all done - return the new record offset */
- return rec_ptr;
-}
-
-/* allocate some space from the free list. The offset returned points
- to a unconnected list_struct within the database with room for at
- least length bytes of total data
-
- 0 is returned if the space could not be allocated
- */
-static tdb_off tdb_allocate(TDB_CONTEXT *tdb, tdb_len length,
- struct list_struct *rec)
-{
- tdb_off rec_ptr, last_ptr, newrec_ptr;
- struct {
- tdb_off rec_ptr, last_ptr;
- tdb_len rec_len;
- } bestfit;
- if (tdb_lock(tdb, -1, F_WRLCK) == -1)
- return 0;
-
- /* Extra bytes required for tailer */
- length += sizeof(tdb_off);
-
- again:
- last_ptr = FREELIST_TOP;
-
- /* read in the freelist top */
- if (ofs_read(tdb, FREELIST_TOP, &rec_ptr) == -1)
- goto fail;
-
- bestfit.rec_ptr = 0;
-
- /*
- this is a best fit allocation strategy. Originally we used
- a first fit strategy, but it suffered from massive fragmentation
- issues when faced with a slowly increasing record size.
- */
- while (rec_ptr) {
- if (rec_free_read(tdb, rec_ptr, rec) == -1) {
- goto fail;
- }
-
- if (rec->rec_len >= length) {
- if (bestfit.rec_ptr == 0 ||
- rec->rec_len < bestfit.rec_len) {
- bestfit.rec_len = rec->rec_len;
- bestfit.rec_ptr = rec_ptr;
- bestfit.last_ptr = last_ptr;
- /* consider a fit to be good enough if we aren't wasting more than half the space */
- if (bestfit.rec_len < 2*length) {
- break;
- }
- }
- }
-
- /* move to the next record */
- last_ptr = rec_ptr;
- rec_ptr = rec->next;
+ if (tdb_brlock(tdb, TDB_SEQNUM_OFS, F_WRLCK, F_SETLKW, 1, 1) != 0) {
+ return;
}
- if (bestfit.rec_ptr != 0) {
- if (rec_free_read(tdb, bestfit.rec_ptr, rec) == -1) {
- goto fail;
- }
-
- newrec_ptr = tdb_allocate_ofs(tdb, length, bestfit.rec_ptr, rec, bestfit.last_ptr);
- tdb_unlock(tdb, -1, F_WRLCK);
- return newrec_ptr;
- }
+ /* we ignore errors from this, as we have no sane way of
+ dealing with them.
+ */
+ tdb_ofs_read(tdb, TDB_SEQNUM_OFS, &seqnum);
+ seqnum++;
+ tdb_ofs_write(tdb, TDB_SEQNUM_OFS, &seqnum);
- /* we didn't find enough space. See if we can expand the
- database and if we can then try again */
- if (tdb_expand(tdb, length + sizeof(*rec)) == 0)
- goto again;
- fail:
- tdb_unlock(tdb, -1, F_WRLCK);
- return 0;
+ tdb_brlock(tdb, TDB_SEQNUM_OFS, F_UNLCK, F_SETLKW, 1, 1);
}
-/* initialise a new database with a specified hash size */
-static int tdb_new_database(TDB_CONTEXT *tdb, int hash_size)
-{
- struct tdb_header *newdb;
- int size, ret = -1;
-
- /* We make it up in memory, then write it out if not internal */
- size = sizeof(struct tdb_header) + (hash_size+1)*sizeof(tdb_off);
- if (!(newdb = calloc(size, 1)))
- return TDB_ERRCODE(TDB_ERR_OOM, -1);
-
- /* Fill in the header */
- newdb->version = TDB_VERSION;
- newdb->hash_size = hash_size;
-#ifdef USE_SPINLOCKS
- newdb->rwlocks = size;
-#endif
- if (tdb->flags & TDB_INTERNAL) {
- tdb->map_size = size;
- tdb->map_ptr = (char *)newdb;
- memcpy(&tdb->header, newdb, sizeof(tdb->header));
- /* Convert the `ondisk' version if asked. */
- CONVERT(*newdb);
- return 0;
- }
- if (lseek(tdb->fd, 0, SEEK_SET) == -1)
- goto fail;
-
- if (ftruncate(tdb->fd, 0) == -1)
- goto fail;
-
- /* This creates an endian-converted header, as if read from disk */
- CONVERT(*newdb);
- memcpy(&tdb->header, newdb, sizeof(tdb->header));
- /* Don't endian-convert the magic food! */
- memcpy(newdb->magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1);
- if (write(tdb->fd, newdb, size) != size)
- ret = -1;
- else
- ret = tdb_create_rwlocks(tdb->fd, hash_size);
-
- fail:
- SAFE_FREE(newdb);
- return ret;
-}
/* Returns 0 on fail. On success, return offset of record, and fills
in rec */
-static tdb_off tdb_find(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash,
+static tdb_off_t tdb_find(struct tdb_context *tdb, TDB_DATA key, u32 hash,
struct list_struct *r)
{
- tdb_off rec_ptr;
+ tdb_off_t rec_ptr;
/* read in the hash top */
- if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1)
+ if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1)
return 0;
/* keep looking until we find the right record */
while (rec_ptr) {
- if (rec_read(tdb, rec_ptr, r) == -1)
+ if (tdb_rec_read(tdb, rec_ptr, r) == -1)
return 0;
if (!TDB_DEAD(r) && hash==r->full_hash && key.dsize==r->key_len) {
- char *k;
+ unsigned char *k;
/* a very likely hit - read the key */
k = tdb_alloc_read(tdb, rec_ptr + sizeof(*r),
r->key_len);
}
/* As tdb_find, but if you succeed, keep the lock */
-static tdb_off tdb_find_lock_hash(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash, int locktype,
- struct list_struct *rec)
+tdb_off_t tdb_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, u32 hash, int locktype,
+ struct list_struct *rec)
{
u32 rec_ptr;
return rec_ptr;
}
-enum TDB_ERROR tdb_error(TDB_CONTEXT *tdb)
-{
- return tdb->ecode;
-}
-
-static struct tdb_errname {
- enum TDB_ERROR ecode; const char *estring;
-} emap[] = { {TDB_SUCCESS, "Success"},
- {TDB_ERR_CORRUPT, "Corrupt database"},
- {TDB_ERR_IO, "IO Error"},
- {TDB_ERR_LOCK, "Locking error"},
- {TDB_ERR_OOM, "Out of memory"},
- {TDB_ERR_EXISTS, "Record exists"},
- {TDB_ERR_NOLOCK, "Lock exists on other keys"},
- {TDB_ERR_NOEXIST, "Record does not exist"} };
-
-/* Error string for the last tdb error */
-const char *tdb_errorstr(TDB_CONTEXT *tdb)
-{
- u32 i;
- for (i = 0; i < sizeof(emap) / sizeof(struct tdb_errname); i++)
- if (tdb->ecode == emap[i].ecode)
- return emap[i].estring;
- return "Invalid error code";
-}
/* update an entry in place - this only works if the new data size
is <= the old data size and the key exists.
on failure return -1.
*/
-
-static int tdb_update_hash(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash, TDB_DATA dbuf)
+static int tdb_update_hash(struct tdb_context *tdb, TDB_DATA key, u32 hash, TDB_DATA dbuf)
{
struct list_struct rec;
- tdb_off rec_ptr;
+ tdb_off_t rec_ptr;
/* find entry */
if (!(rec_ptr = tdb_find(tdb, key, hash, &rec)))
return -1;
/* must be long enough key, data and tailer */
- if (rec.rec_len < key.dsize + dbuf.dsize + sizeof(tdb_off)) {
+ if (rec.rec_len < key.dsize + dbuf.dsize + sizeof(tdb_off_t)) {
tdb->ecode = TDB_SUCCESS; /* Not really an error */
return -1;
}
- if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len,
+ if (tdb->methods->tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len,
dbuf.dptr, dbuf.dsize) == -1)
return -1;
if (dbuf.dsize != rec.data_len) {
/* update size */
rec.data_len = dbuf.dsize;
- return rec_write(tdb, rec_ptr, &rec);
+ return tdb_rec_write(tdb, rec_ptr, &rec);
}
return 0;
* then the TDB_DATA will have zero length but
* a non-zero pointer
*/
-
-TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key)
+TDB_DATA tdb_fetch(struct tdb_context *tdb, TDB_DATA key)
{
- tdb_off rec_ptr;
+ tdb_off_t rec_ptr;
struct list_struct rec;
TDB_DATA ret;
u32 hash;
/* check if an entry in the database exists
note that 1 is returned if the key is found and 0 is returned if not found
- this doesn't match the conventions in the rest of this module, but is
- compatible with gdbm
-*/
-static int tdb_exists_hash(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash)
-{
- struct list_struct rec;
-
- if (tdb_find_lock_hash(tdb, key, hash, F_RDLCK, &rec) == 0)
- return 0;
- tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK);
- return 1;
-}
-
-int tdb_exists(TDB_CONTEXT *tdb, TDB_DATA key)
-{
- u32 hash = tdb->hash_fn(&key);
- return tdb_exists_hash(tdb, key, hash);
-}
-
-/* record lock stops delete underneath */
-static int lock_record(TDB_CONTEXT *tdb, tdb_off off)
-{
- return off ? tdb_brlock(tdb, off, F_RDLCK, F_SETLKW, 0) : 0;
-}
-/*
- Write locks override our own fcntl readlocks, so check it here.
- Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not
- an error to fail to get the lock here.
-*/
-
-static int write_lock_record(TDB_CONTEXT *tdb, tdb_off off)
-{
- struct tdb_traverse_lock *i;
- for (i = &tdb->travlocks; i; i = i->next)
- if (i->off == off)
- return -1;
- return tdb_brlock(tdb, off, F_WRLCK, F_SETLK, 1);
-}
-
-/*
- Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not
- an error to fail to get the lock here.
+ this doesn't match the conventions in the rest of this module, but is
+ compatible with gdbm
*/
-
-static int write_unlock_record(TDB_CONTEXT *tdb, tdb_off off)
+static int tdb_exists_hash(struct tdb_context *tdb, TDB_DATA key, u32 hash)
{
- return tdb_brlock(tdb, off, F_UNLCK, F_SETLK, 0);
+ struct list_struct rec;
+
+ if (tdb_find_lock_hash(tdb, key, hash, F_RDLCK, &rec) == 0)
+ return 0;
+ tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK);
+ return 1;
}
-/* fcntl locks don't stack: avoid unlocking someone else's */
-static int unlock_record(TDB_CONTEXT *tdb, tdb_off off)
-{
- struct tdb_traverse_lock *i;
- u32 count = 0;
- if (off == 0)
- return 0;
- for (i = &tdb->travlocks; i; i = i->next)
- if (i->off == off)
- count++;
- return (count == 1 ? tdb_brlock(tdb, off, F_UNLCK, F_SETLKW, 0) : 0);
+int tdb_exists(struct tdb_context *tdb, TDB_DATA key)
+{
+ u32 hash = tdb->hash_fn(&key);
+ return tdb_exists_hash(tdb, key, hash);
}
/* actually delete an entry in the database given the offset */
-static int do_delete(TDB_CONTEXT *tdb, tdb_off rec_ptr, struct list_struct*rec)
+int tdb_do_delete(struct tdb_context *tdb, tdb_off_t rec_ptr, struct list_struct*rec)
{
- tdb_off last_ptr, i;
+ tdb_off_t last_ptr, i;
struct list_struct lastrec;
- if (tdb->read_only) return -1;
+ if (tdb->read_only || tdb->traverse_read) return -1;
- if (write_lock_record(tdb, rec_ptr) == -1) {
+ if (tdb_write_lock_record(tdb, rec_ptr) == -1) {
/* Someone traversing here: mark it as dead */
rec->magic = TDB_DEAD_MAGIC;
- return rec_write(tdb, rec_ptr, rec);
+ return tdb_rec_write(tdb, rec_ptr, rec);
}
- if (write_unlock_record(tdb, rec_ptr) != 0)
+ if (tdb_write_unlock_record(tdb, rec_ptr) != 0)
return -1;
/* find previous record in hash chain */
- if (ofs_read(tdb, TDB_HASH_TOP(rec->full_hash), &i) == -1)
+ if (tdb_ofs_read(tdb, TDB_HASH_TOP(rec->full_hash), &i) == -1)
return -1;
for (last_ptr = 0; i != rec_ptr; last_ptr = i, i = lastrec.next)
- if (rec_read(tdb, i, &lastrec) == -1)
+ if (tdb_rec_read(tdb, i, &lastrec) == -1)
return -1;
/* unlink it: next ptr is at start of record. */
if (last_ptr == 0)
last_ptr = TDB_HASH_TOP(rec->full_hash);
- if (ofs_write(tdb, last_ptr, &rec->next) == -1)
+ if (tdb_ofs_write(tdb, last_ptr, &rec->next) == -1)
return -1;
/* recover the space */
return 0;
}
-/* Uses traverse lock: 0 = finish, -1 = error, other = record offset */
-static int tdb_next_lock(TDB_CONTEXT *tdb, struct tdb_traverse_lock *tlock,
- struct list_struct *rec)
-{
- int want_next = (tlock->off != 0);
-
- /* Lock each chain from the start one. */
- for (; tlock->hash < tdb->header.hash_size; tlock->hash++) {
- if (tdb_lock(tdb, tlock->hash, F_WRLCK) == -1)
- return -1;
-
- /* No previous record? Start at top of chain. */
- if (!tlock->off) {
- if (ofs_read(tdb, TDB_HASH_TOP(tlock->hash),
- &tlock->off) == -1)
- goto fail;
- } else {
- /* Otherwise unlock the previous record. */
- if (unlock_record(tdb, tlock->off) != 0)
- goto fail;
- }
-
- if (want_next) {
- /* We have offset of old record: grab next */
- if (rec_read(tdb, tlock->off, rec) == -1)
- goto fail;
- tlock->off = rec->next;
- }
-
- /* Iterate through chain */
- while( tlock->off) {
- tdb_off current;
- if (rec_read(tdb, tlock->off, rec) == -1)
- goto fail;
- if (!TDB_DEAD(rec)) {
- /* Woohoo: we found one! */
- if (lock_record(tdb, tlock->off) != 0)
- goto fail;
- return tlock->off;
- }
-
- /* Detect infinite loops. From "Shlomi Yaakobovich" <Shlomi@exanet.com>. */
- if (tlock->off == rec->next) {
- TDB_LOG((tdb, 0, "tdb_next_lock: loop detected.\n"));
- goto fail;
- }
-
- /* Try to clean dead ones from old traverses */
- current = tlock->off;
- tlock->off = rec->next;
- if (!tdb->read_only &&
- do_delete(tdb, current, rec) != 0)
- goto fail;
- }
- tdb_unlock(tdb, tlock->hash, F_WRLCK);
- want_next = 0;
- }
- /* We finished iteration without finding anything */
- return TDB_ERRCODE(TDB_SUCCESS, 0);
-
- fail:
- tlock->off = 0;
- if (tdb_unlock(tdb, tlock->hash, F_WRLCK) != 0)
- TDB_LOG((tdb, 0, "tdb_next_lock: On error unlock failed!\n"));
- return -1;
-}
-
-/* traverse the entire database - calling fn(tdb, key, data) on each element.
- return -1 on error or the record count traversed
- if fn is NULL then it is not called
- a non-zero return value from fn() indicates that the traversal should stop
- */
-int tdb_traverse(TDB_CONTEXT *tdb, tdb_traverse_func fn, void *private)
-{
- TDB_DATA key, dbuf;
- struct list_struct rec;
- struct tdb_traverse_lock tl = { NULL, 0, 0 };
- int ret, count = 0;
-
- /* This was in the initializaton, above, but the IRIX compiler
- * did not like it. crh
- */
- tl.next = tdb->travlocks.next;
-
- /* fcntl locks don't stack: beware traverse inside traverse */
- tdb->travlocks.next = &tl;
-
- /* tdb_next_lock places locks on the record returned, and its chain */
- while ((ret = tdb_next_lock(tdb, &tl, &rec)) > 0) {
- count++;
- /* now read the full record */
- key.dptr = tdb_alloc_read(tdb, tl.off + sizeof(rec),
- rec.key_len + rec.data_len);
- if (!key.dptr) {
- ret = -1;
- if (tdb_unlock(tdb, tl.hash, F_WRLCK) != 0)
- goto out;
- if (unlock_record(tdb, tl.off) != 0)
- TDB_LOG((tdb, 0, "tdb_traverse: key.dptr == NULL and unlock_record failed!\n"));
- goto out;
- }
- key.dsize = rec.key_len;
- dbuf.dptr = key.dptr + rec.key_len;
- dbuf.dsize = rec.data_len;
-
- /* Drop chain lock, call out */
- if (tdb_unlock(tdb, tl.hash, F_WRLCK) != 0) {
- ret = -1;
- goto out;
- }
- if (fn && fn(tdb, key, dbuf, private)) {
- /* They want us to terminate traversal */
- ret = count;
- if (unlock_record(tdb, tl.off) != 0) {
- TDB_LOG((tdb, 0, "tdb_traverse: unlock_record failed!\n"));;
- ret = -1;
- }
- tdb->travlocks.next = tl.next;
- SAFE_FREE(key.dptr);
- return count;
- }
- SAFE_FREE(key.dptr);
- }
-out:
- tdb->travlocks.next = tl.next;
- if (ret < 0)
- return -1;
- else
- return count;
-}
-
-/* find the first entry in the database and return its key */
-TDB_DATA tdb_firstkey(TDB_CONTEXT *tdb)
-{
- TDB_DATA key;
- struct list_struct rec;
-
- /* release any old lock */
- if (unlock_record(tdb, tdb->travlocks.off) != 0)
- return tdb_null;
- tdb->travlocks.off = tdb->travlocks.hash = 0;
-
- if (tdb_next_lock(tdb, &tdb->travlocks, &rec) <= 0)
- return tdb_null;
- /* now read the key */
- key.dsize = rec.key_len;
- key.dptr =tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec),key.dsize);
- if (tdb_unlock(tdb, BUCKET(tdb->travlocks.hash), F_WRLCK) != 0)
- TDB_LOG((tdb, 0, "tdb_firstkey: error occurred while tdb_unlocking!\n"));
- return key;
-}
-
-/* find the next entry in the database, returning its key */
-TDB_DATA tdb_nextkey(TDB_CONTEXT *tdb, TDB_DATA oldkey)
-{
- u32 oldhash;
- TDB_DATA key = tdb_null;
- struct list_struct rec;
- char *k = NULL;
-
- /* Is locked key the old key? If so, traverse will be reliable. */
- if (tdb->travlocks.off) {
- if (tdb_lock(tdb,tdb->travlocks.hash,F_WRLCK))
- return tdb_null;
- if (rec_read(tdb, tdb->travlocks.off, &rec) == -1
- || !(k = tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec),
- rec.key_len))
- || memcmp(k, oldkey.dptr, oldkey.dsize) != 0) {
- /* No, it wasn't: unlock it and start from scratch */
- if (unlock_record(tdb, tdb->travlocks.off) != 0)
- return tdb_null;
- if (tdb_unlock(tdb, tdb->travlocks.hash, F_WRLCK) != 0)
- return tdb_null;
- tdb->travlocks.off = 0;
- }
-
- SAFE_FREE(k);
- }
-
- if (!tdb->travlocks.off) {
- /* No previous element: do normal find, and lock record */
- tdb->travlocks.off = tdb_find_lock_hash(tdb, oldkey, tdb->hash_fn(&oldkey), F_WRLCK, &rec);
- if (!tdb->travlocks.off)
- return tdb_null;
- tdb->travlocks.hash = BUCKET(rec.full_hash);
- if (lock_record(tdb, tdb->travlocks.off) != 0) {
- TDB_LOG((tdb, 0, "tdb_nextkey: lock_record failed (%s)!\n", strerror(errno)));
- return tdb_null;
- }
- }
- oldhash = tdb->travlocks.hash;
-
- /* Grab next record: locks chain and returned record,
- unlocks old record */
- if (tdb_next_lock(tdb, &tdb->travlocks, &rec) > 0) {
- key.dsize = rec.key_len;
- key.dptr = tdb_alloc_read(tdb, tdb->travlocks.off+sizeof(rec),
- key.dsize);
- /* Unlock the chain of this new record */
- if (tdb_unlock(tdb, tdb->travlocks.hash, F_WRLCK) != 0)
- TDB_LOG((tdb, 0, "tdb_nextkey: WARNING tdb_unlock failed!\n"));
- }
- /* Unlock the chain of old record */
- if (tdb_unlock(tdb, BUCKET(oldhash), F_WRLCK) != 0)
- TDB_LOG((tdb, 0, "tdb_nextkey: WARNING tdb_unlock failed!\n"));
- return key;
-}
-
/* delete an entry in the database given a key */
-static int tdb_delete_hash(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash)
+static int tdb_delete_hash(struct tdb_context *tdb, TDB_DATA key, u32 hash)
{
- tdb_off rec_ptr;
+ tdb_off_t rec_ptr;
struct list_struct rec;
int ret;
if (!(rec_ptr = tdb_find_lock_hash(tdb, key, hash, F_WRLCK, &rec)))
return -1;
- ret = do_delete(tdb, rec_ptr, &rec);
+ ret = tdb_do_delete(tdb, rec_ptr, &rec);
+
+ if (ret == 0) {
+ tdb_increment_seqnum(tdb);
+ }
+
if (tdb_unlock(tdb, BUCKET(rec.full_hash), F_WRLCK) != 0)
- TDB_LOG((tdb, 0, "tdb_delete: WARNING tdb_unlock failed!\n"));
+ TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_delete: WARNING tdb_unlock failed!\n"));
return ret;
}
-int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key)
+int tdb_delete(struct tdb_context *tdb, TDB_DATA key)
{
u32 hash = tdb->hash_fn(&key);
return tdb_delete_hash(tdb, key, hash);
return 0 on success, -1 on failure
*/
-int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag)
+int tdb_store(struct tdb_context *tdb, TDB_DATA key, TDB_DATA dbuf, int flag)
{
struct list_struct rec;
u32 hash;
- tdb_off rec_ptr;
+ tdb_off_t rec_ptr;
char *p = NULL;
int ret = 0;
+ if (tdb->read_only || tdb->traverse_read) {
+ tdb->ecode = TDB_ERR_RDONLY;
+ return -1;
+ }
+
/* find which hash bucket it is in */
hash = tdb->hash_fn(&key);
if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1)
goto fail;
/* Read hash top into next ptr */
- if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1)
+ if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1)
goto fail;
rec.key_len = key.dsize;
rec.magic = TDB_MAGIC;
/* write out and point the top of the hash chain at it */
- if (rec_write(tdb, rec_ptr, &rec) == -1
- || tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+dbuf.dsize)==-1
- || ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) {
+ if (tdb_rec_write(tdb, rec_ptr, &rec) == -1
+ || tdb->methods->tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+dbuf.dsize)==-1
+ || tdb_ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) {
/* Need to tdb_unallocate() here */
goto fail;
}
+
+ tdb_increment_seqnum(tdb);
+
out:
SAFE_FREE(p);
tdb_unlock(tdb, BUCKET(hash), F_WRLCK);
goto out;
}
-/* Attempt to append data to an entry in place - this only works if the new data size
- is <= the old data size and the key exists.
- on failure return -1. Record must be locked before calling.
-*/
-static int tdb_append_inplace(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash, TDB_DATA new_dbuf)
-{
- struct list_struct rec;
- tdb_off rec_ptr;
-
- /* find entry */
- if (!(rec_ptr = tdb_find(tdb, key, hash, &rec)))
- return -1;
-
- /* Append of 0 is always ok. */
- if (new_dbuf.dsize == 0)
- return 0;
-
- /* must be long enough for key, old data + new data and tailer */
- if (rec.rec_len < key.dsize + rec.data_len + new_dbuf.dsize + sizeof(tdb_off)) {
- /* No room. */
- tdb->ecode = TDB_SUCCESS; /* Not really an error */
- return -1;
- }
-
- if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len + rec.data_len,
- new_dbuf.dptr, new_dbuf.dsize) == -1)
- return -1;
-
- /* update size */
- rec.data_len += new_dbuf.dsize;
- return rec_write(tdb, rec_ptr, &rec);
-}
/* Append to an entry. Create if not exist. */
-
-int tdb_append(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA new_dbuf)
+int tdb_append(struct tdb_context *tdb, TDB_DATA key, TDB_DATA new_dbuf)
{
- struct list_struct rec;
u32 hash;
- tdb_off rec_ptr;
- char *p = NULL;
- int ret = 0;
- size_t new_data_size = 0;
+ TDB_DATA dbuf;
+ int ret = -1;
/* find which hash bucket it is in */
hash = tdb->hash_fn(&key);
if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1)
return -1;
- /* first try in-place. */
- if (tdb_append_inplace(tdb, key, hash, new_dbuf) == 0)
- goto out;
-
- /* reset the error code potentially set by the tdb_append_inplace() */
- tdb->ecode = TDB_SUCCESS;
-
- /* find entry */
- if (!(rec_ptr = tdb_find(tdb, key, hash, &rec))) {
- if (tdb->ecode != TDB_ERR_NOEXIST)
- goto fail;
+ dbuf = tdb_fetch(tdb, key);
- /* Not found - create. */
-
- ret = tdb_store(tdb, key, new_dbuf, TDB_INSERT);
- goto out;
+ if (dbuf.dptr == NULL) {
+ dbuf.dptr = malloc(new_dbuf.dsize);
+ } else {
+ dbuf.dptr = realloc(dbuf.dptr, dbuf.dsize + new_dbuf.dsize);
}
- new_data_size = rec.data_len + new_dbuf.dsize;
-
- /* Copy key+old_value+value *before* allocating free space in case malloc
- fails and we are left with a dead spot in the tdb. */
-
- if (!(p = (char *)malloc(key.dsize + new_data_size))) {
+ if (dbuf.dptr == NULL) {
tdb->ecode = TDB_ERR_OOM;
- goto fail;
- }
-
- /* Copy the key in place. */
- memcpy(p, key.dptr, key.dsize);
-
- /* Now read the old data into place. */
- if (rec.data_len &&
- tdb_read(tdb, rec_ptr + sizeof(rec) + rec.key_len, p + key.dsize, rec.data_len, 0) == -1)
- goto fail;
-
- /* Finally append the new data. */
- if (new_dbuf.dsize)
- memcpy(p+key.dsize+rec.data_len, new_dbuf.dptr, new_dbuf.dsize);
-
- /* delete any existing record - if it doesn't exist we don't
- care. Doing this first reduces fragmentation, and avoids
- coalescing with `allocated' block before it's updated. */
-
- tdb_delete_hash(tdb, key, hash);
-
- if (!(rec_ptr = tdb_allocate(tdb, key.dsize + new_data_size, &rec)))
- goto fail;
-
- /* Read hash top into next ptr */
- if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1)
- goto fail;
-
- rec.key_len = key.dsize;
- rec.data_len = new_data_size;
- rec.full_hash = hash;
- rec.magic = TDB_MAGIC;
-
- /* write out and point the top of the hash chain at it */
- if (rec_write(tdb, rec_ptr, &rec) == -1
- || tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+new_data_size)==-1
- || ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) {
- /* Need to tdb_unallocate() here */
- goto fail;
+ goto failed;
}
- out:
- SAFE_FREE(p);
- tdb_unlock(tdb, BUCKET(hash), F_WRLCK);
- return ret;
-
-fail:
- ret = -1;
- goto out;
-}
-
-static int tdb_already_open(dev_t device,
- ino_t ino)
-{
- TDB_CONTEXT *i;
-
- for (i = tdbs; i; i = i->next) {
- if (i->device == device && i->inode == ino) {
- return 1;
- }
- }
-
- return 0;
-}
-
-/* open the database, creating it if necessary
-
- The open_flags and mode are passed straight to the open call on the
- database file. A flags value of O_WRONLY is invalid. The hash size
- is advisory, use zero for a default value.
-
- Return is NULL on error, in which case errno is also set. Don't
- try to call tdb_error or tdb_errname, just do strerror(errno).
-
- @param name may be NULL for internal databases. */
-TDB_CONTEXT *tdb_open(const char *name, int hash_size, int tdb_flags,
- int open_flags, mode_t mode)
-{
- return tdb_open_ex(name, hash_size, tdb_flags, open_flags, mode, NULL, NULL);
-}
-
-/* a default logging function */
-static void null_log_fn(TDB_CONTEXT *tdb, int level, const char *fmt, ...)
-{
-}
-
-
-TDB_CONTEXT *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
- int open_flags, mode_t mode,
- tdb_log_func log_fn,
- tdb_hash_func hash_fn)
-{
- TDB_CONTEXT *tdb;
- struct stat st;
- int rev = 0, locked = 0;
- uint8_t *vp;
- u32 vertest;
-
- if (!(tdb = calloc(1, sizeof *tdb))) {
- /* Can't log this */
- errno = ENOMEM;
- goto fail;
- }
- tdb->fd = -1;
- tdb->name = NULL;
- tdb->map_ptr = NULL;
- tdb->flags = tdb_flags;
- tdb->open_flags = open_flags;
- tdb->log_fn = log_fn?log_fn:null_log_fn;
- tdb->hash_fn = hash_fn ? hash_fn : default_tdb_hash;
-
- if ((open_flags & O_ACCMODE) == O_WRONLY) {
- TDB_LOG((tdb, 0, "tdb_open_ex: can't open tdb %s write-only\n",
- name));
- errno = EINVAL;
- goto fail;
- }
-
- if (hash_size == 0)
- hash_size = DEFAULT_HASH_SIZE;
- if ((open_flags & O_ACCMODE) == O_RDONLY) {
- tdb->read_only = 1;
- /* read only databases don't do locking or clear if first */
- tdb->flags |= TDB_NOLOCK;
- tdb->flags &= ~TDB_CLEAR_IF_FIRST;
- }
-
- /* internal databases don't mmap or lock, and start off cleared */
- if (tdb->flags & TDB_INTERNAL) {
- tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
- tdb->flags &= ~TDB_CLEAR_IF_FIRST;
- if (tdb_new_database(tdb, hash_size) != 0) {
- TDB_LOG((tdb, 0, "tdb_open_ex: tdb_new_database failed!"));
- goto fail;
- }
- goto internal;
- }
-
- if ((tdb->fd = open(name, open_flags, mode)) == -1) {
- TDB_LOG((tdb, 5, "tdb_open_ex: could not open file %s: %s\n",
- name, strerror(errno)));
- goto fail; /* errno set by open(2) */
- }
-
- /* ensure there is only one process initialising at once */
- if (tdb_brlock(tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW, 0) == -1) {
- TDB_LOG((tdb, 0, "tdb_open_ex: failed to get global lock on %s: %s\n",
- name, strerror(errno)));
- goto fail; /* errno set by tdb_brlock */
- }
-
- /* we need to zero database if we are the only one with it open */
- if ((tdb_flags & TDB_CLEAR_IF_FIRST) &&
- (locked = (tdb_brlock(tdb, ACTIVE_LOCK, F_WRLCK, F_SETLK, 0) == 0))) {
- open_flags |= O_CREAT;
- if (ftruncate(tdb->fd, 0) == -1) {
- TDB_LOG((tdb, 0, "tdb_open_ex: "
- "failed to truncate %s: %s\n",
- name, strerror(errno)));
- goto fail; /* errno set by ftruncate */
- }
- }
-
- if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header)
- || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0
- || (tdb->header.version != TDB_VERSION
- && !(rev = (tdb->header.version==TDB_BYTEREV(TDB_VERSION))))) {
- /* its not a valid database - possibly initialise it */
- if (!(open_flags & O_CREAT) || tdb_new_database(tdb, hash_size) == -1) {
- errno = EIO; /* ie bad format or something */
- goto fail;
- }
- rev = (tdb->flags & TDB_CONVERT);
- }
- vp = (uint8_t *)&tdb->header.version;
- vertest = (((u32)vp[0]) << 24) | (((u32)vp[1]) << 16) |
- (((u32)vp[2]) << 8) | (u32)vp[3];
- tdb->flags |= (vertest==TDB_VERSION) ? TDB_BIGENDIAN : 0;
- if (!rev)
- tdb->flags &= ~TDB_CONVERT;
- else {
- tdb->flags |= TDB_CONVERT;
- convert(&tdb->header, sizeof(tdb->header));
- }
- if (fstat(tdb->fd, &st) == -1)
- goto fail;
-
- /* Is it already in the open list? If so, fail. */
- if (tdb_already_open(st.st_dev, st.st_ino)) {
- TDB_LOG((tdb, 2, "tdb_open_ex: "
- "%s (%d,%d) is already open in this process\n",
- name, (int)st.st_dev, (int)st.st_ino));
- errno = EBUSY;
- goto fail;
- }
-
- if (!(tdb->name = (char *)strdup(name))) {
- errno = ENOMEM;
- goto fail;
- }
-
- tdb->map_size = st.st_size;
- tdb->device = st.st_dev;
- tdb->inode = st.st_ino;
- tdb->locked = calloc(tdb->header.hash_size+1, sizeof(tdb->locked[0]));
- if (!tdb->locked) {
- TDB_LOG((tdb, 2, "tdb_open_ex: "
- "failed to allocate lock structure for %s\n",
- name));
- errno = ENOMEM;
- goto fail;
- }
- tdb_mmap(tdb);
- if (locked) {
- if (!tdb->read_only)
- if (tdb_clear_spinlocks(tdb) != 0) {
- TDB_LOG((tdb, 0, "tdb_open_ex: "
- "failed to clear spinlock\n"));
- goto fail;
- }
- if (tdb_brlock(tdb, ACTIVE_LOCK, F_UNLCK, F_SETLK, 0) == -1) {
- TDB_LOG((tdb, 0, "tdb_open_ex: "
- "failed to take ACTIVE_LOCK on %s: %s\n",
- name, strerror(errno)));
- goto fail;
- }
+ memcpy(dbuf.dptr + dbuf.dsize, new_dbuf.dptr, new_dbuf.dsize);
+ dbuf.dsize += new_dbuf.dsize;
- }
-
- /* We always need to do this if the CLEAR_IF_FIRST flag is set, even if
- we didn't get the initial exclusive lock as we need to let all other
- users know we're using it. */
-
- if (tdb_flags & TDB_CLEAR_IF_FIRST) {
- /* leave this lock in place to indicate it's in use */
- if (tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -1)
- goto fail;
- }
-
-
- internal:
- /* Internal (memory-only) databases skip all the code above to
- * do with disk files, and resume here by releasing their
- * global lock and hooking into the active list. */
- if (tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0) == -1)
- goto fail;
- tdb->next = tdbs;
- tdbs = tdb;
- return tdb;
-
- fail:
- { int save_errno = errno;
-
- if (!tdb)
- return NULL;
+ ret = tdb_store(tdb, key, dbuf, 0);
- if (tdb->map_ptr) {
- if (tdb->flags & TDB_INTERNAL)
- SAFE_FREE(tdb->map_ptr);
- else
- tdb_munmap(tdb);
- }
- SAFE_FREE(tdb->name);
- if (tdb->fd != -1)
- if (close(tdb->fd) != 0)
- TDB_LOG((tdb, 5, "tdb_open_ex: failed to close tdb->fd on error!\n"));
- SAFE_FREE(tdb->locked);
- SAFE_FREE(tdb);
- errno = save_errno;
- return NULL;
- }
-}
-
-/**
- * Close a database.
- *
- * @returns -1 for error; 0 for success.
- **/
-int tdb_close(TDB_CONTEXT *tdb)
-{
- TDB_CONTEXT **i;
- int ret = 0;
-
- if (tdb->map_ptr) {
- if (tdb->flags & TDB_INTERNAL)
- SAFE_FREE(tdb->map_ptr);
- else
- tdb_munmap(tdb);
- }
- SAFE_FREE(tdb->name);
- if (tdb->fd != -1)
- ret = close(tdb->fd);
- SAFE_FREE(tdb->locked);
-
- /* Remove from contexts list */
- for (i = &tdbs; *i; i = &(*i)->next) {
- if (*i == tdb) {
- *i = tdb->next;
- break;
- }
- }
-
- memset(tdb, 0, sizeof(*tdb));
- SAFE_FREE(tdb);
-
+failed:
+ tdb_unlock(tdb, BUCKET(hash), F_WRLCK);
+ SAFE_FREE(dbuf.dptr);
return ret;
}
-/* lock/unlock entire database */
-int tdb_lockall(TDB_CONTEXT *tdb)
-{
- u32 i;
-
- /* There are no locks on read-only dbs */
- if (tdb->read_only)
- return TDB_ERRCODE(TDB_ERR_LOCK, -1);
- for (i = 0; i < tdb->header.hash_size; i++)
- if (tdb_lock(tdb, i, F_WRLCK))
- break;
-
- /* If error, release locks we have... */
- if (i < tdb->header.hash_size) {
- u32 j;
-
- for ( j = 0; j < i; j++)
- tdb_unlock(tdb, j, F_WRLCK);
- return TDB_ERRCODE(TDB_ERR_NOLOCK, -1);
- }
-
- return 0;
-}
-void tdb_unlockall(TDB_CONTEXT *tdb)
-{
- u32 i;
- for (i=0; i < tdb->header.hash_size; i++)
- tdb_unlock(tdb, i, F_WRLCK);
-}
-
-/* lock/unlock one hash chain. This is meant to be used to reduce
- contention - it cannot guarantee how many records will be locked */
-int tdb_chainlock(TDB_CONTEXT *tdb, TDB_DATA key)
-{
- return tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK);
-}
-
-int tdb_chainunlock(TDB_CONTEXT *tdb, TDB_DATA key)
-{
- return tdb_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK);
-}
-int tdb_chainlock_read(TDB_CONTEXT *tdb, TDB_DATA key)
+/*
+ return the name of the current tdb file
+ useful for external logging functions
+*/
+const char *tdb_name(struct tdb_context *tdb)
{
- return tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_RDLCK);
+ return tdb->name;
}
-int tdb_chainunlock_read(TDB_CONTEXT *tdb, TDB_DATA key)
+/*
+ return the underlying file descriptor being used by tdb, or -1
+ useful for external routines that want to check the device/inode
+ of the fd
+*/
+int tdb_fd(struct tdb_context *tdb)
{
- return tdb_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_RDLCK);
+ return tdb->fd;
}
-
-/* register a loging function */
-void tdb_logging_function(TDB_CONTEXT *tdb, void (*fn)(TDB_CONTEXT *, int , const char *, ...))
+/*
+ return the current logging function
+ useful for external tdb routines that wish to log tdb errors
+*/
+tdb_log_func tdb_log_fn(struct tdb_context *tdb)
{
- tdb->log_fn = fn?fn:null_log_fn;
+ return tdb->log.log_fn;
}
-/* reopen a tdb - this can be used after a fork to ensure that we have an independent
- seek pointer from our parent and to re-establish locks */
-int tdb_reopen(TDB_CONTEXT *tdb)
+/*
+ get the tdb sequence number. Only makes sense if the writers opened
+ with TDB_SEQNUM set. Note that this sequence number will wrap quite
+ quickly, so it should only be used for a 'has something changed'
+ test, not for code that relies on the count of the number of changes
+ made. If you want a counter then use a tdb record.
+
+ The aim of this sequence number is to allow for a very lightweight
+ test of a possible tdb change.
+*/
+int tdb_get_seqnum(struct tdb_context *tdb)
{
- struct stat st;
-
- if (tdb->flags & TDB_INTERNAL)
- return 0; /* Nothing to do. */
- if (tdb_munmap(tdb) != 0) {
- TDB_LOG((tdb, 0, "tdb_reopen: munmap failed (%s)\n", strerror(errno)));
- goto fail;
- }
- if (close(tdb->fd) != 0)
- TDB_LOG((tdb, 0, "tdb_reopen: WARNING closing tdb->fd failed!\n"));
- tdb->fd = open(tdb->name, tdb->open_flags & ~(O_CREAT|O_TRUNC), 0);
- if (tdb->fd == -1) {
- TDB_LOG((tdb, 0, "tdb_reopen: open failed (%s)\n", strerror(errno)));
- goto fail;
- }
- if (fstat(tdb->fd, &st) != 0) {
- TDB_LOG((tdb, 0, "tdb_reopen: fstat failed (%s)\n", strerror(errno)));
- goto fail;
- }
- if (st.st_ino != tdb->inode || st.st_dev != tdb->device) {
- TDB_LOG((tdb, 0, "tdb_reopen: file dev/inode has changed!\n"));
- goto fail;
- }
- tdb_mmap(tdb);
- if ((tdb->flags & TDB_CLEAR_IF_FIRST) && (tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -1)) {
- TDB_LOG((tdb, 0, "tdb_reopen: failed to obtain active lock\n"));
- goto fail;
- }
+ tdb_off_t seqnum=0;
- return 0;
-
-fail:
- tdb_close(tdb);
- return -1;
+ tdb_ofs_read(tdb, TDB_SEQNUM_OFS, &seqnum);
+ return seqnum;
}
-/* reopen all tdb's */
-int tdb_reopen_all(void)
+int tdb_hash_size(struct tdb_context *tdb)
{
- TDB_CONTEXT *tdb;
-
- for (tdb=tdbs; tdb; tdb = tdb->next) {
- /* Ensure no clear-if-first. */
- tdb->flags &= ~TDB_CLEAR_IF_FIRST;
- if (tdb_reopen(tdb) != 0)
- return -1;
- }
-
- return 0;
+ return tdb->header.hash_size;
}
git.samba.org / ira / wip.git / blobdiff