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-rw-r--r--source3/tdb/tdb.c338
-rw-r--r--source3/tdb/tdb.h3
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 */
};
generated by cgit (git 2.34.1) at 2024-12-14 19:19:32 +0000