diff options
Diffstat (limited to 'source3')
| -rw-r--r-- | source3/tdb/tdb.c | 338 | ||||
| -rw-r--r-- | source3/tdb/tdb.h | 3 |
2 files changed, 109 insertions, 232 deletions
diff --git a/source3/tdb/tdb.c b/source3/tdb/tdb.c index fc510e9561..aec546a310 100644 --- a/source3/tdb/tdb.c +++ b/source3/tdb/tdb.c @@ -78,19 +78,6 @@ struct list_struct { /* a null data record - useful for error returns */ static TDB_DATA null_data; -#if STANDALONE -/* like strdup but for memory */ -static char *memdup(char *d, int size) -{ - char *ret; - ret = (char *)malloc(size); - if (!ret) return NULL; - memcpy(ret, d, size); - return ret; -} -#endif - - /* a byte range locking function - return 0 on success this functions locks/unlocks 1 byte at the specified offset */ static int tdb_brlock(TDB_CONTEXT *tdb, tdb_off offset, @@ -109,10 +96,12 @@ static int tdb_brlock(TDB_CONTEXT *tdb, tdb_off offset, fl.l_len = 1; fl.l_pid = 0; - if (fcntl(tdb->fd, lck_type, &fl) != 0 && lck_type == F_SETLKW) { + if (fcntl(tdb->fd, lck_type, &fl) != 0) { #if TDB_DEBUG - printf("lock %d failed at %d (%s)\n", - set, offset, strerror(errno)); + if (lck_type == F_SETLKW) { + printf("lock %d failed at %d (%s)\n", + set, offset, strerror(errno)); + } #endif return -1; } @@ -489,6 +478,7 @@ static int tdb_new_database(TDB_CONTEXT *tdb, int hash_size) int i; /* create the header */ + strcpy(header.magic_food, TDB_MAGIC_FOOD); header.version = TDB_VERSION; header.hash_size = hash_size; lseek(tdb->fd, 0, SEEK_SET); @@ -509,138 +499,110 @@ static int tdb_new_database(TDB_CONTEXT *tdb, int hash_size) return 0; } - -/* 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 -*/ -int tdb_update(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf) +/* 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, unsigned int hash, + struct list_struct *rec) { - unsigned hash; tdb_off offset, rec_ptr; - struct list_struct rec; - char *data=NULL; - - /* find which hash bucket it is in */ - hash = tdb_hash(&key); - - tdb_lock(tdb, BUCKET(hash)); - + /* find the top of the hash chain */ offset = tdb_hash_top(tdb, hash); /* read in the hash top */ - if (ofs_read(tdb, offset, &rec_ptr) == -1) { - goto fail; - } + if (ofs_read(tdb, offset, &rec_ptr) == -1) + return 0; /* keep looking until we find the right record */ while (rec_ptr) { - if (rec_read(tdb, rec_ptr, &rec) == -1) { - goto fail; - } + if (rec_read(tdb, rec_ptr, rec) == -1) + return 0; - if (hash == rec.full_hash && key.dsize == rec.key_len) { - /* a very likely hit - read the full key */ - data = tdb_alloc_read(tdb, rec_ptr + sizeof(rec), - rec.key_len); - if (!data) goto fail; + if (hash == rec->full_hash && key.dsize == rec->key_len) { + char *k; + /* a very likely hit - read the key */ + k = tdb_alloc_read(tdb, rec_ptr + sizeof(*rec), + rec->key_len); - if (memcmp(key.dptr, data, key.dsize) == 0) { - /* definate hit */ - if (rec.rec_len < key.dsize + dbuf.dsize) { - /* the update won't fit! */ - goto fail; - } - if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len, - dbuf.dptr, dbuf.dsize) == -1) { - goto fail; - } - if (dbuf.dsize != rec.data_len) { - rec.data_len = dbuf.dsize; - if (rec_write(tdb, rec_ptr, &rec) == -1) { - goto fail; - } - } - free(data); - tdb_unlock(tdb, BUCKET(hash)); + if (!k) return 0; - } - /* a miss - drat */ - free(data); - data = NULL; + if (memcmp(key.dptr, k, key.dsize) == 0) { + free(k); + return rec_ptr; + } + free(k); } /* move to the next record */ - rec_ptr = rec.next; + rec_ptr = rec->next; } - - /* we didn't find it */ - fail: - tdb_unlock(tdb, BUCKET(hash)); - if (data) free(data); - return -1; + return 0; } - -/* find an entry in the database given a key */ -TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key) +/* 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 +*/ +int tdb_update(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf) { unsigned hash; - tdb_off offset, rec_ptr; struct list_struct rec; - char *data; - TDB_DATA ret; + tdb_off rec_ptr; + int ret = -1; /* find which hash bucket it is in */ hash = tdb_hash(&key); tdb_lock(tdb, BUCKET(hash)); + rec_ptr = tdb_find(tdb, key, hash, &rec); - /* find the top of the hash chain */ - offset = tdb_hash_top(tdb, hash); + if (!rec_ptr) + goto out; - /* read in the hash top */ - if (ofs_read(tdb, offset, &rec_ptr) == -1) { - goto fail; - } + /* must be long enough */ + if (rec.rec_len < key.dsize + dbuf.dsize) + goto out; - /* keep looking until we find the right record */ - while (rec_ptr) { - if (rec_read(tdb, rec_ptr, &rec) == -1) { - goto fail; - } + if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len, + dbuf.dptr, dbuf.dsize) == -1) + goto out; - if (hash == rec.full_hash && key.dsize == rec.key_len) { - /* a very likely hit - read the full record */ - data = tdb_alloc_read(tdb, rec_ptr + sizeof(rec), - rec.key_len + rec.data_len); - if (!data) { - goto fail; - } + if (dbuf.dsize != rec.data_len) { + /* update size */ + rec.data_len = dbuf.dsize; + ret = rec_write(tdb, rec_ptr, &rec); + } else + ret = 0; - if (memcmp(key.dptr, data, key.dsize) == 0) { - /* a definate match */ - ret.dptr = (char *)memdup(data + rec.key_len, rec.data_len); - ret.dsize = rec.data_len; - free(data); - tdb_unlock(tdb, BUCKET(hash)); - return ret; - } + out: + tdb_unlock(tdb, BUCKET(hash)); + return ret; +} - /* a miss - drat */ - free(data); - } +/* find an entry in the database given a key */ +TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key) +{ + unsigned hash; + tdb_off rec_ptr; + struct list_struct rec; + TDB_DATA ret = null_data; - /* move to the next record */ - rec_ptr = rec.next; - } + /* find which hash bucket it is in */ + hash = tdb_hash(&key); - /* we didn't find it */ - fail: + tdb_lock(tdb, BUCKET(hash)); + rec_ptr = tdb_find(tdb, key, hash, &rec); + + if (rec_ptr) { + ret.dptr = tdb_alloc_read(tdb, + rec_ptr + sizeof(rec) + rec.key_len, + rec.data_len); + ret.dsize = rec.data_len; + } + tdb_unlock(tdb, BUCKET(hash)); - return null_data; + return ret; } /* check if an entry in the database exists @@ -652,58 +614,18 @@ TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key) int tdb_exists(TDB_CONTEXT *tdb, TDB_DATA key) { unsigned hash; - tdb_off offset, rec_ptr; + tdb_off rec_ptr; struct list_struct rec; - char *data; - + /* find which hash bucket it is in */ hash = tdb_hash(&key); tdb_lock(tdb, BUCKET(hash)); - - /* find the top of the hash chain */ - offset = tdb_hash_top(tdb, hash); - - /* read in the hash top */ - if (ofs_read(tdb, offset, &rec_ptr) == -1) { - goto fail; - } - - /* keep looking until we find the right record */ - while (rec_ptr) { - if (rec_read(tdb, rec_ptr, &rec) == -1) { - goto fail; - } - - if (hash == rec.full_hash && key.dsize == rec.key_len) { - /* a very likely hit - read the full record */ - data = tdb_alloc_read(tdb, rec_ptr + sizeof(rec), - rec.key_len + rec.data_len); - if (!data) { - goto fail; - } - - if (memcmp(key.dptr, data, key.dsize) == 0) { - /* a definate match */ - free(data); - tdb_unlock(tdb, BUCKET(hash)); - return 1; - } - - /* a miss - drat */ - free(data); - } - - /* move to the next record */ - rec_ptr = rec.next; - } - - /* we didn't find it */ - fail: + rec_ptr = tdb_find(tdb, key, hash, &rec); tdb_unlock(tdb, BUCKET(hash)); - return 0; -} + return rec_ptr != 0; +} /* traverse the entire database - calling fn(tdb, key, data) on each element. return -1 on error or the record count traversed @@ -821,98 +743,49 @@ TDB_DATA tdb_firstkey(TDB_CONTEXT *tdb) /* find the next entry in the database, returning its key */ TDB_DATA tdb_nextkey(TDB_CONTEXT *tdb, TDB_DATA key) { - unsigned hash, h; - tdb_off offset, rec_ptr; + unsigned hash, hbucket; + tdb_off rec_ptr, offset; struct list_struct rec; - char *data; TDB_DATA ret; /* find which hash bucket it is in */ hash = tdb_hash(&key); - - tdb_lock(tdb, BUCKET(hash)); - - /* find the top of the hash chain */ - offset = tdb_hash_top(tdb, hash); - - /* read in the hash top */ - if (ofs_read(tdb, offset, &rec_ptr) == -1) { - goto fail; + hbucket = BUCKET(hash); + + tdb_lock(tdb, hbucket); + rec_ptr = tdb_find(tdb, key, hash, &rec); + if (rec_ptr) { + /* we want the next record after this one */ + rec_ptr = rec.next; } - /* look until we find the right record */ - while (rec_ptr) { - if (rec_read(tdb, rec_ptr, &rec) == -1) { - goto fail; - } + /* not found or last in hash: look for next non-empty hash chain */ + while (rec_ptr == 0) { + tdb_unlock(tdb, hbucket); - if (hash == rec.full_hash && key.dsize == rec.key_len) { - /* a very likely hit - read the full key */ - data = tdb_alloc_read(tdb, rec_ptr + sizeof(rec), - rec.key_len); - if (!data) { - goto fail; - } + if (++hbucket >= tdb->header.hash_size - 1) + return null_data; - if (memcmp(key.dptr, data, key.dsize) == 0) { - /* a definate match - we want the next - record after this one */ - rec_ptr = rec.next; - free(data); - if (rec_ptr == 0) goto next_hash; - goto found_record; - } - - /* a miss - drat */ - free(data); - } - - /* move to the next record */ - rec_ptr = rec.next; - } - - next_hash: - tdb_unlock(tdb, BUCKET(hash)); - - h = BUCKET(hash); - if (h == tdb->header.hash_size - 1) return null_data; - - /* look for a non-empty hash chain */ - for (hash = h+1, rec_ptr = 0; - hash < tdb->header.hash_size; - hash++) { - /* find the top of the hash chain */ - offset = tdb_hash_top(tdb, hash); - - tdb_lock(tdb, BUCKET(hash)); + offset = tdb_hash_top(tdb, hbucket); + tdb_lock(tdb, hbucket); /* read in the hash top */ if (ofs_read(tdb, offset, &rec_ptr) == -1) { - goto fail; + tdb_unlock(tdb, hbucket); + return null_data; } - - if (rec_ptr) break; - - tdb_unlock(tdb, BUCKET(hash)); } - if (rec_ptr == 0) return null_data; - - found_record: - - /* we've found a non-empty chain, now read the record */ - if (rec_read(tdb, rec_ptr, &rec) == -1) { - goto fail; + /* Read the record. */ + if (rec_read(tdb, rec_ptr, &rec) == 0) { + tdb_unlock(tdb, hbucket); + return null_data; } - - /* allocate and read the key space */ + /* allocate and read the key */ ret.dptr = tdb_alloc_read(tdb, rec_ptr + sizeof(rec), rec.key_len); ret.dsize = rec.key_len; - tdb_unlock(tdb, BUCKET(hash)); - return ret; + tdb_unlock(tdb, hbucket); - fail: - tdb_unlock(tdb, BUCKET(hash)); - return null_data; + return ret; } /* delete an entry in the database given a key */ @@ -953,7 +826,7 @@ int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key) } if (memcmp(key.dptr, data, key.dsize) == 0) { - /* a definate match - delete it */ + /* a definite match - delete it */ if (last_ptr == 0) { offset = tdb_hash_top(tdb, hash); if (ofs_write(tdb, offset, &rec.next) == -1) { @@ -1141,6 +1014,7 @@ TDB_CONTEXT *tdb_open(char *name, int hash_size, int tdb_flags, tdb_brlock(&tdb, ACTIVE_LOCK, LOCK_SET, F_RDLCK, F_SETLKW); 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) { /* its not a valid database - possibly initialise it */ if (!(open_flags & O_CREAT)) { diff --git a/source3/tdb/tdb.h b/source3/tdb/tdb.h index 9cb8f71a90..5ceb79ee4d 100644 --- a/source3/tdb/tdb.h +++ b/source3/tdb/tdb.h @@ -22,8 +22,11 @@ typedef unsigned tdb_len; typedef unsigned tdb_off; +#define TDB_MAGIC_FOOD "TDB file\n" + /* this is stored at the front of every database */ struct tdb_header { + char magic_food[32]; /* for /etc/magic */ unsigned version; /* version of the code */ unsigned hash_size; /* number of hash entries */ }; |