Begin implementing all the PDU storage stuff in Events land

synapse/storage/event_federation.py

@@ -0,0 +1,143 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014 OpenMarket Ltd
+#
+# 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 ._base import SQLBaseStore
+from twisted.internet import defer
+
+import logging
+
+
+logger = logging.getLogger(__name__)
+
+
+class EventFederationStore(SQLBaseStore):
+
+    def _get_latest_events_in_room(self, txn, room_id):
+        self._simple_select_onecol_txn(
+            txn,
+            table="event_forward_extremities",
+            keyvalues={
+                "room_id": room_id,
+            },
+            retcol="event_id",
+        )
+
+        results = []
+        for pdu_id, origin, depth in txn.fetchall():
+            hashes = self._get_pdu_reference_hashes_txn(txn, pdu_id, origin)
+            sha256_bytes = hashes["sha256"]
+            prev_hashes = {"sha256": encode_base64(sha256_bytes)}
+            results.append((pdu_id, origin, prev_hashes, depth))
+
+    def _get_min_depth_interaction(self, txn, room_id):
+        min_depth = self._simple_select_one_onecol_txn(
+            txn,
+            table="room_depth",
+            keyvalues={"room_id": room_id,},
+            retcol="min_depth",
+            allow_none=True,
+        )
+
+        return int(min_depth) if min_depth is not None else None
+
+    def _update_min_depth_for_room_txn(self, txn, room_id, depth):
+        min_depth = self._get_min_depth_interaction(txn, room_id)
+
+        do_insert = depth < min_depth if min_depth else True
+
+        if do_insert:
+            self._simple_insert_txn(
+                txn,
+                table="room_depth",
+                values={
+                    "room_id": room_id,
+                    "min_depth": depth,
+                },
+                or_replace=True,
+            )
+
+    def _handle_prev_events(self, txn, outlier, event_id, prev_events,
+                            room_id):
+        for e_id in prev_events:
+            # TODO (erikj): This could be done as a bulk insert
+            self._simple_insert_txn(
+                txn,
+                table="event_edges",
+                values={
+                    "event_id": event_id,
+                    "prev_event": e_id,
+                    "room_id": room_id,
+                }
+            )
+
+        # Update the extremities table if this is not an outlier.
+        if not outlier:
+            for e_id in prev_events:
+                # TODO (erikj): This could be done as a bulk insert
+                self._simple_delete_txn(
+                    txn,
+                    table="event_forward_extremities",
+                    keyvalues={
+                        "event_id": e_id,
+                        "room_id": room_id,
+                    }
+                )
+
+
+
+            # We only insert as a forward extremity the new pdu if there are no
+            # other pdus that reference it as a prev pdu
+            query = (
+                "INSERT INTO %(table)s (event_id, room_id) "
+                "SELECT ?, ? WHERE NOT EXISTS ("
+                "SELECT 1 FROM %(event_edges)s WHERE "
+                "prev_event_id = ? "
+                ")"
+            ) % {
+                "table": "event_forward_extremities",
+                "event_edges": "event_edges",
+            }
+
+            logger.debug("query: %s", query)
+
+            txn.execute(query, (event_id, room_id, event_id))
+
+            # Insert all the prev_pdus as a backwards thing, they'll get
+            # deleted in a second if they're incorrect anyway.
+            for e_id in prev_events:
+                # TODO (erikj): This could be done as a bulk insert
+                self._simple_insert_txn(
+                    txn,
+                    table="event_backward_extremities",
+                    values={
+                        "event_id": e_id,
+                        "room_id": room_id,
+                    }
+                )
+
+            # Also delete from the backwards extremities table all ones that
+            # reference pdus that we have already seen
+            query = (
+                "DELETE FROM %(event_back)s as b WHERE EXISTS ("
+                "SELECT 1 FROM %(events)s AS events "
+                "WHERE "
+                "b.event_id = events.event_id "
+                "AND not events.outlier "
+                ")"
+            ) % {
+                "event_back": "event_backward_extremities",
+                "events": "events",
+            }
+            txn.execute(query)