tdb2: unify tdb1_firstkey/tdb1_nextkey into tdb_firstkey/tdb_nextkey.

Switch on the TDB_VERSION1 flag.

ccan/tdb2/private.h

@@ -685,6 +685,10 @@ int tdb1_transaction_start(struct tdb_context *tdb);
 int tdb1_transaction_prepare_commit(struct tdb_context *tdb);
 int tdb1_transaction_commit(struct tdb_context *tdb);
 
+/* tdb1_traverse.c: */
+TDB_DATA tdb1_firstkey(struct tdb_context *tdb);
+TDB_DATA tdb1_nextkey(struct tdb_context *tdb, TDB_DATA key);
+
 /* tdb.c: */
 enum TDB_ERROR COLD tdb_logerr(struct tdb_context *tdb,
 			       enum TDB_ERROR ecode,

ccan/tdb2/tdb1.h

@@ -38,10 +38,6 @@
 
 void tdb1_set_max_dead(struct tdb_context *tdb, int max_dead);
 
-TDB_DATA tdb1_firstkey(struct tdb_context *tdb);
-
-TDB_DATA tdb1_nextkey(struct tdb_context *tdb, TDB_DATA key);
-
 int tdb1_get_seqnum(struct tdb_context *tdb);
 
 void tdb1_increment_seqnum_nonblock(struct tdb_context *tdb);

ccan/tdb2/traverse.c

@@ -61,6 +61,16 @@ enum TDB_ERROR tdb_firstkey(struct tdb_context *tdb, struct tdb_data *key)
 {
 	struct traverse_info tinfo;
 
+	if (tdb->flags & TDB_VERSION1) {
+		tdb->last_error = TDB_SUCCESS;
+		*key = tdb1_firstkey(tdb);
+		/* TDB1 didn't set error for last key. */
+		if (!key->dptr && tdb->last_error == TDB_SUCCESS) {
+			tdb->last_error = TDB_ERR_NOEXIST;
+		}
+		return tdb->last_error;
+	}
+
 	return tdb->last_error = first_in_hash(tdb, &tinfo, key, NULL);
 }
 
@@ -71,6 +81,18 @@ enum TDB_ERROR tdb_nextkey(struct tdb_context *tdb, struct tdb_data *key)
 	struct hash_info h;
 	struct tdb_used_record rec;
 
+	if (tdb->flags & TDB_VERSION1) {
+		struct tdb_data last_key = *key;
+		tdb->last_error = TDB_SUCCESS;
+		*key = tdb1_nextkey(tdb, last_key);
+		free(last_key.dptr);
+		/* TDB1 didn't set error for last key. */
+		if (!key->dptr && tdb->last_error == TDB_SUCCESS) {
+			tdb->last_error = TDB_ERR_NOEXIST;
+		}
+		return tdb->last_error;
+	}
+
 	tinfo.prev = find_and_lock(tdb, *key, F_RDLCK, &h, &rec, &tinfo);
 	free(key->dptr);
 	if (TDB_OFF_IS_ERR(tinfo.prev)) {