storage: speed up replication by not getting object next_serial for nothing

neo/storage/database/manager.py

@@ -435,6 +435,20 @@ class DatabaseManager(object):
                 compression, checksum, data,
                 None if data_serial is None else util.p64(data_serial))
 
+    @fallback
+    def _fetchObject(self, oid, tid):
+        r = self._getObject(oid, tid)
+        if r:
+            return r[:1] + r[2:]
+
+    def fetchObject(self, oid, tid):
+        u64 = util.u64
+        r = self._fetchObject(u64(oid), u64(tid))
+        if r:
+            serial, compression, checksum, data, data_serial = r
+            return (util.p64(serial), compression, checksum, data,
+                None if data_serial is None else util.p64(data_serial))
+
     @contextmanager
     def replicated(self, offset):
         readable_set = self._readable_set

neo/storage/database/mysqldb.py

@@ -698,6 +698,21 @@ class MySQLDatabaseManager(DatabaseManager):
         if r:
             return [(p64(tid), length or 0) for tid, length in r]
 
+    def _fetchObject(self, oid, tid):
+        r = self.query(
+            'SELECT tid, compression, data.hash, value, value_tid'
+            ' FROM obj FORCE INDEX(`partition`)'
+            ' LEFT JOIN data ON (obj.data_id = data.id)'
+            ' WHERE `partition` = %d AND oid = %d AND tid = %d'
+            % (self._getReadablePartition(oid), oid, tid))
+        if r:
+            r = r[0]
+            compression = r[1]
+            if compression and compression & 0x80:
+                return (r[0], compression & 0x7f, r[2],
+                    ''.join(self._bigData(data)), r[4])
+            return r
+
     def getReplicationObjectList(self, min_tid, max_tid, length, partition,
             min_oid):
         u64 = util.u64

neo/storage/database/sqlite.py

@@ -532,6 +532,17 @@ class SQLiteDatabaseManager(DatabaseManager):
              self._getPackTID(), offset, length))
             ] or None
 
+    def _fetchObject(self, oid, tid):
+        for serial, compression, checksum, data, value_serial in self.query(
+                'SELECT tid, compression, data.hash, value, value_tid'
+                ' FROM obj LEFT JOIN data ON obj.data_id = data.id'
+                ' WHERE partition=? AND oid=? AND tid=?',
+                (self._getReadablePartition(oid), oid, tid)):
+            if checksum:
+                checksum = str(checksum)
+                data = str(data)
+            return serial, compression, checksum, data, value_serial
+
     def getReplicationObjectList(self, min_tid, max_tid, length, partition,
             min_oid):
         u64 = util.u64

neo/storage/handlers/storage.py

@@ -255,15 +255,14 @@ class StorageOperationHandler(EventHandler):
                             if not oid_set:
                                 del object_dict[serial]
                             continue
-                    object = dm.getObject(oid, serial)
+                    object = dm.fetchObject(oid, serial)
                     if not object:
                         conn.send(Errors.ReplicationError(
                             "partition %u dropped or truncated"
                             % partition), msg_id)
                         return
                     # Same as in askFetchTransactions.
-                    conn.send(Packets.AddObject(oid, serial, *object[2:]),
-                              msg_id)
+                    conn.send(Packets.AddObject(oid, *object), msg_id)
                     yield conn.buffering
                 conn.send(Packets.AnswerFetchObjects(
                     pack_tid, next_tid, next_oid, object_dict), msg_id)