Add backlog message class.

matrix/api.py

@@ -431,6 +431,25 @@ class MatrixRedactMessage(MatrixGenericMessage):
         )
 
 
+class MatrixBacklogMessage(MatrixGenericMessage):
+    def __init__(self, client, room_id, token, limit):
+        self.room_id = room_id
+
+        data = {
+            "room_id": self.room_id,
+            "start_token": token,
+            "direction": "b",
+            "limit": limit
+        }
+
+        MatrixGenericMessage.__init__(
+            self,
+            MessageType.ROOM_MSG,
+            client.room_get_messages,
+            data
+        )
+
+
 class MatrixUser:
     def __init__(self, name, display_name):
         self.name = name                  # type: str

matrix/commands.py

@@ -28,7 +28,8 @@ from matrix.api import (
     MatrixMessage,
     MessageType,
     MatrixTopicMessage,
-    MatrixRedactMessage
+    MatrixRedactMessage,
+    MatrixBacklogMessage
 )
 from matrix.utils import key_from_value, tags_from_line_data
 from matrix.plugin_options import DebugType
@@ -110,8 +111,12 @@ def matrix_fetch_old_messages(server, room_id):
     if not prev_batch:
         return
 
-    message = MatrixMessage(server, OPTIONS, MessageType.ROOM_MSG,
+    message = MatrixBacklogMessage(
-                            room_id=room_id, token=prev_batch)
+        server.client,
+        room_id=room_id,
+        token=prev_batch,
+        limit=OPTIONS.backlog_limit
+    )
 
     server.send_or_queue(message)