X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb%2Ftdb.c;h=cb0b88519d961ea292bcfd7d2b8db2772f50ad37;hp=cb2af49f8f9f7b8bb29c4f86d0624712579543ea;hb=9d045ca09a0b052d968e11d98540f63a8a0aa412;hpb=bcf7916c5d694858766869dfd570e525127154a6

diff --git a/ccan/tdb/tdb.c b/ccan/tdb/tdb.c
index cb2af49f..cb0b8851 100644
--- a/ccan/tdb/tdb.c
+++ b/ccan/tdb/tdb.c
@@ -59,13 +59,14 @@ static void tdb_increment_seqnum(struct tdb_context *tdb)
 		return;
 	}
 
-	if (tdb_brlock(tdb, TDB_SEQNUM_OFS, F_WRLCK, F_SETLKW, 1, 1) != 0) {
+	if (tdb_brlock(tdb, F_WRLCK, TDB_SEQNUM_OFS, 1,
+		       TDB_LOCK_WAIT|TDB_LOCK_PROBE) != 0) {
 		return;
 	}
 
 	tdb_increment_seqnum_nonblock(tdb);
 
-	tdb_brlock(tdb, TDB_SEQNUM_OFS, F_UNLCK, F_SETLKW, 1, 1);
+	tdb_brunlock(tdb, F_WRLCK, TDB_SEQNUM_OFS, 1);
 }
 
 static int tdb_key_compare(TDB_DATA key, TDB_DATA data, void *private_data)
@@ -76,7 +77,7 @@ static int tdb_key_compare(TDB_DATA key, TDB_DATA data, void *private_data)
 /* Returns 0 on fail.  On success, return offset of record, and fills
    in rec */
 static tdb_off_t tdb_find(struct tdb_context *tdb, TDB_DATA key, uint32_t hash,
-			struct list_struct *r)
+			struct tdb_record *r)
 {
 	tdb_off_t rec_ptr;
 	
@@ -110,7 +111,7 @@ static tdb_off_t tdb_find(struct tdb_context *tdb, TDB_DATA key, uint32_t hash,
 
 /* As tdb_find, but if you succeed, keep the lock */
 tdb_off_t tdb_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash, int locktype,
-			   struct list_struct *rec)
+			   struct tdb_record *rec)
 {
 	uint32_t rec_ptr;
 
@@ -121,6 +122,7 @@ tdb_off_t tdb_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t has
 	return rec_ptr;
 }
 
+static TDB_DATA _tdb_fetch(struct 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.
@@ -128,13 +130,32 @@ tdb_off_t tdb_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t has
 */
 static int tdb_update_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash, TDB_DATA dbuf)
 {
-	struct list_struct rec;
+	struct tdb_record rec;
 	tdb_off_t rec_ptr;
 
 	/* find entry */
 	if (!(rec_ptr = tdb_find(tdb, key, hash, &rec)))
 		return -1;
 
+	/* it could be an exact duplicate of what is there - this is
+	 * surprisingly common (eg. with a ldb re-index). */
+	if (rec.key_len == key.dsize && 
+	    rec.data_len == dbuf.dsize &&
+	    rec.full_hash == hash) {
+		TDB_DATA data = _tdb_fetch(tdb, key);
+		if (data.dsize == dbuf.dsize &&
+		    memcmp(data.dptr, dbuf.dptr, data.dsize) == 0) {
+			if (data.dptr) {
+				free(data.dptr);
+			}
+			return 0;
+		}
+		if (data.dptr) {
+			free(data.dptr);
+		}
+	}
+	 
+
 	/* must be long enough key, data and tailer */
 	if (rec.rec_len < key.dsize + dbuf.dsize + sizeof(tdb_off_t)) {
 		tdb->ecode = TDB_SUCCESS; /* Not really an error */
@@ -160,10 +181,10 @@ static int tdb_update_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash,
  * then the TDB_DATA will have zero length but
  * a non-zero pointer
  */
-static TDB_DATA do_tdb_fetch(struct tdb_context *tdb, TDB_DATA key)
+static TDB_DATA _tdb_fetch(struct tdb_context *tdb, TDB_DATA key)
 {
 	tdb_off_t rec_ptr;
-	struct list_struct rec;
+	struct tdb_record rec;
 	TDB_DATA ret;
 	uint32_t hash;
 
@@ -181,7 +202,7 @@ static TDB_DATA do_tdb_fetch(struct tdb_context *tdb, TDB_DATA key)
 
 TDB_DATA tdb_fetch(struct tdb_context *tdb, TDB_DATA key)
 {
-	TDB_DATA ret = do_tdb_fetch(tdb, key);
+	TDB_DATA ret = _tdb_fetch(tdb, key);
 
 	tdb_trace_1rec_retrec(tdb, "tdb_fetch", key, ret);
 	return ret;
@@ -209,7 +230,7 @@ int tdb_parse_record(struct tdb_context *tdb, TDB_DATA key,
 		     void *private_data)
 {
 	tdb_off_t rec_ptr;
-	struct list_struct rec;
+	struct tdb_record rec;
 	int ret;
 	uint32_t hash;
 
@@ -240,7 +261,7 @@ int tdb_parse_record(struct tdb_context *tdb, TDB_DATA key,
 */
 static int tdb_exists_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash)
 {
-	struct list_struct rec;
+	struct tdb_record rec;
 	
 	if (tdb_find_lock_hash(tdb, key, hash, F_RDLCK, &rec) == 0)
 		return 0;
@@ -259,10 +280,10 @@ int tdb_exists(struct tdb_context *tdb, TDB_DATA key)
 }
 
 /* actually delete an entry in the database given the offset */
-int tdb_do_delete(struct tdb_context *tdb, tdb_off_t rec_ptr, struct list_struct *rec)
+int tdb_do_delete(struct tdb_context *tdb, tdb_off_t rec_ptr, struct tdb_record *rec)
 {
 	tdb_off_t last_ptr, i;
-	struct list_struct lastrec;
+	struct tdb_record lastrec;
 
 	if (tdb->read_only || tdb->traverse_read) return -1;
 
@@ -298,7 +319,7 @@ static int tdb_count_dead(struct tdb_context *tdb, uint32_t hash)
 {
 	int res = 0;
 	tdb_off_t rec_ptr;
-	struct list_struct rec;
+	struct tdb_record rec;
 	
 	/* read in the hash top */
 	if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1)
@@ -322,7 +343,7 @@ static int tdb_count_dead(struct tdb_context *tdb, uint32_t hash)
 static int tdb_purge_dead(struct tdb_context *tdb, uint32_t hash)
 {
 	int res = -1;
-	struct list_struct rec;
+	struct tdb_record rec;
 	tdb_off_t rec_ptr;
 
 	if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
@@ -358,7 +379,7 @@ static int tdb_purge_dead(struct tdb_context *tdb, uint32_t hash)
 static int tdb_delete_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash)
 {
 	tdb_off_t rec_ptr;
-	struct list_struct rec;
+	struct tdb_record rec;
 	int ret;
 
 	if (tdb->max_dead_records != 0) {
@@ -421,7 +442,7 @@ int tdb_delete(struct tdb_context *tdb, TDB_DATA key)
  * See if we have a dead record around with enough space
  */
 static tdb_off_t tdb_find_dead(struct tdb_context *tdb, uint32_t hash,
-			       struct list_struct *r, tdb_len_t length)
+			       struct tdb_record *r, tdb_len_t length)
 {
 	tdb_off_t rec_ptr;
 	
@@ -446,10 +467,10 @@ static tdb_off_t tdb_find_dead(struct tdb_context *tdb, uint32_t hash,
 	return 0;
 }
 
-static int _tdb_store(struct tdb_context *tdb, TDB_DATA key, TDB_DATA dbuf,
-		      int flag, uint32_t hash)
+static int _tdb_store(struct tdb_context *tdb, TDB_DATA key,
+		      TDB_DATA dbuf, int flag, uint32_t hash)
 {
-	struct list_struct rec;
+	struct tdb_record rec;
 	tdb_off_t rec_ptr;
 	char *p = NULL;
 	int ret = -1;
@@ -613,7 +634,7 @@ int tdb_append(struct tdb_context *tdb, TDB_DATA key, TDB_DATA new_dbuf)
 	if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1)
 		return -1;
 
-	dbuf = do_tdb_fetch(tdb, key);
+	dbuf = _tdb_fetch(tdb, key);
 
 	if (dbuf.dptr == NULL) {
 		dbuf.dptr = (unsigned char *)malloc(new_dbuf.dsize);
@@ -714,11 +735,41 @@ int tdb_get_flags(struct tdb_context *tdb)
 
 void tdb_add_flags(struct tdb_context *tdb, unsigned flags)
 {
+	if ((flags & TDB_ALLOW_NESTING) &&
+	    (flags & TDB_DISALLOW_NESTING)) {
+		tdb->ecode = TDB_ERR_NESTING;
+		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_add_flags: "
+			"allow_nesting and disallow_nesting are not allowed together!"));
+		return;
+	}
+
+	if (flags & TDB_ALLOW_NESTING) {
+		tdb->flags &= ~TDB_DISALLOW_NESTING;
+	}
+	if (flags & TDB_DISALLOW_NESTING) {
+		tdb->flags &= ~TDB_ALLOW_NESTING;
+	}
+
 	tdb->flags |= flags;
 }
 
 void tdb_remove_flags(struct tdb_context *tdb, unsigned flags)
 {
+	if ((flags & TDB_ALLOW_NESTING) &&
+	    (flags & TDB_DISALLOW_NESTING)) {
+		tdb->ecode = TDB_ERR_NESTING;
+		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_remove_flags: "
+			"allow_nesting and disallow_nesting are not allowed together!"));
+		return;
+	}
+
+	if (flags & TDB_ALLOW_NESTING) {
+		tdb->flags |= TDB_DISALLOW_NESTING;
+	}
+	if (flags & TDB_DISALLOW_NESTING) {
+		tdb->flags |= TDB_ALLOW_NESTING;
+	}
+
 	tdb->flags &= ~flags;
 }
 
@@ -738,7 +789,7 @@ void tdb_enable_seqnum(struct tdb_context *tdb)
  */
 static int tdb_free_region(struct tdb_context *tdb, tdb_off_t offset, ssize_t length)
 {
-	struct list_struct rec;
+	struct tdb_record rec;
 	if (length <= sizeof(rec)) {
 		/* the region is not worth adding */
 		return 0;
@@ -787,7 +838,7 @@ int tdb_wipe_all(struct tdb_context *tdb)
 	}
 
 	if (recovery_head != 0) {
-		struct list_struct rec;
+		struct tdb_record rec;
 		if (tdb->methods->tdb_read(tdb, recovery_head, &rec, sizeof(rec), DOCONV()) == -1) {
 			TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_wipe_all: failed to read recovery record\n"));
 			return -1;