1 files changed, 148 insertions, 0 deletions
diff --git a/synapse/federation/handler.py b/synapse/federation/handler.py
new file mode 100644
index 0000000000..31e8470b33
--- /dev/null
+++ b/synapse/federation/handler.py
@@ -0,0 +1,148 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014 matrix.org
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from twisted.internet import defer
+
+from .pdu_codec import PduCodec
+
+from synapse.api.errors import AuthError
+from synapse.util.logutils import log_function
+
+import logging
+
+
+logger = logging.getLogger(__name__)
+
+
+class FederationEventHandler(object):
+    """ Responsible for:
+        a) handling received Pdus before handing them on as Events to the rest
+        of the home server (including auth and state conflict resoultion)
+        b) converting events that were produced by local clients that may need
+        to be sent to remote home servers.
+    """
+
+    def __init__(self, hs):
+        self.store = hs.get_datastore()
+        self.replication_layer = hs.get_replication_layer()
+        self.state_handler = hs.get_state_handler()
+        # self.auth_handler = gs.get_auth_handler()
+        self.event_handler = hs.get_handlers().federation_handler
+        self.server_name = hs.hostname
+
+        self.lock_manager = hs.get_room_lock_manager()
+
+        self.replication_layer.set_handler(self)
+
+        self.pdu_codec = PduCodec(hs)
+
+    @log_function
+    @defer.inlineCallbacks
+    def handle_new_event(self, event):
+        """ Takes in an event from the client to server side, that has already
+        been authed and handled by the state module, and sends it to any
+        remote home servers that may be interested.
+
+        Args:
+            event
+
+        Returns:
+            Deferred: Resolved when it has successfully been queued for
+            processing.
+        """
+        yield self._fill_out_prev_events(event)
+
+        pdu = self.pdu_codec.pdu_from_event(event)
+
+        if not hasattr(pdu, "destinations") or not pdu.destinations:
+            pdu.destinations = []
+
+        yield self.replication_layer.send_pdu(pdu)
+
+    @log_function
+    @defer.inlineCallbacks
+    def backfill(self, room_id, limit):
+        # TODO: Work out which destinations to ask for pagination
+        # self.replication_layer.paginate(dest, room_id, limit)
+        pass
+
+    @log_function
+    def get_state_for_room(self, destination, room_id):
+        return self.replication_layer.get_state_for_context(
+            destination, room_id
+        )
+
+    @log_function
+    @defer.inlineCallbacks
+    def on_receive_pdu(self, pdu):
+        """ Called by the ReplicationLayer when we have a new pdu. We need to
+        do auth checks and put it throught the StateHandler.
+        """
+        event = self.pdu_codec.event_from_pdu(pdu)
+
+        try:
+            with (yield self.lock_manager.lock(pdu.context)):
+                if event.is_state:
+                    is_new_state = yield self.state_handler.handle_new_state(
+                        pdu
+                    )
+                    if not is_new_state:
+                        return
+                else:
+                    is_new_state = False
+
+            yield self.event_handler.on_receive(event, is_new_state)
+
+        except AuthError:
+            # TODO: Implement something in federation that allows us to
+            # respond to PDU.
+            raise
+
+        return
+
+    @defer.inlineCallbacks
+    def _on_new_state(self, pdu, new_state_event):
+        # TODO: Do any store stuff here. Notifiy C2S about this new
+        # state.
+
+        yield self.store.update_current_state(
+            pdu_id=pdu.pdu_id,
+            origin=pdu.origin,
+            context=pdu.context,
+            pdu_type=pdu.pdu_type,
+            state_key=pdu.state_key
+        )
+
+        yield self.event_handler.on_receive(new_state_event)
+
+    @defer.inlineCallbacks
+    def _fill_out_prev_events(self, event):
+        if hasattr(event, "prev_events"):
+            return
+
+        results = yield self.store.get_latest_pdus_in_context(
+            event.room_id
+        )
+
+        es = [
+            "%s@%s" % (p_id, origin) for p_id, origin, _ in results
+        ]
+
+        event.prev_events = [e for e in es if e != event.event_id]
+
+        if results:
+            event.depth = max([int(v) for _, _, v in results]) + 1
+        else:
+            event.depth = 0