From 46d49198b2c3f4acc5b915544491505fe3f13c8e Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Mon, 12 Oct 2020 15:23:22 +0100
Subject: [PATCH] Scope transaction IDs to rooms

---
 synapse/handlers/message.py                           |  5 ++++-
 synapse/handlers/room_member.py                       |  2 +-
 synapse/storage/databases/main/events.py              |  1 +
 synapse/storage/databases/main/events_worker.py       | 11 ++++++++---
 .../databases/main/schema/delta/58/19txn_id.sql       |  3 ++-
 5 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 2ca65fc8d7..fc6a9c1ddf 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -711,7 +711,10 @@ class EventCreationHandler:
         with (await self.limiter.queue(event_dict["room_id"])):
             if txn_id and requester.access_token_id:
                 existing_event_id = await self.store.get_event_id_from_transaction_id(
-                    requester.user.to_string(), requester.access_token_id, txn_id,
+                    event_dict["room_id"],
+                    requester.user.to_string(),
+                    requester.access_token_id,
+                    txn_id,
                 )
                 if existing_event_id:
                     event = await self.store.get_event(existing_event_id)
diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py
index e196e95923..dfb86ba2b0 100644
--- a/synapse/handlers/room_member.py
+++ b/synapse/handlers/room_member.py
@@ -176,7 +176,7 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
         # do it up front for efficiency.)
         if txn_id and requester.access_token_id:
             existing_event_id = await self.store.get_event_id_from_transaction_id(
-                requester.user.to_string(), requester.access_token_id, txn_id,
+                room_id, requester.user.to_string(), requester.access_token_id, txn_id,
             )
             if existing_event_id:
                 event_pos = await self.store.get_position_for_event(existing_event_id)
diff --git a/synapse/storage/databases/main/events.py b/synapse/storage/databases/main/events.py
index ac565afbd9..1a9baa15f7 100644
--- a/synapse/storage/databases/main/events.py
+++ b/synapse/storage/databases/main/events.py
@@ -423,6 +423,7 @@ class PersistEventsStore:
                 to_insert.append(
                     {
                         "event_id": event.event_id,
+                        "room_id": event.room_id,
                         "user_id": event.sender,
                         "token_id": token_id,
                         "txn_id": txn_id,
diff --git a/synapse/storage/databases/main/events_worker.py b/synapse/storage/databases/main/events_worker.py
index 4e418c59fe..1e5d63c884 100644
--- a/synapse/storage/databases/main/events_worker.py
+++ b/synapse/storage/databases/main/events_worker.py
@@ -1314,14 +1314,19 @@ class EventsWorkerStore(SQLBaseStore):
         )
 
     async def get_event_id_from_transaction_id(
-        self, user_id: str, token_id: int, txn_id: str
+        self, room_id: str, user_id: str, token_id: int, txn_id: str
     ) -> Optional[str]:
         """Look up if we have already persisted an event for the transaction ID,
         returning the event ID if so.
         """
         return await self.db_pool.simple_select_one_onecol(
             table="event_txn_id",
-            keyvalues={"user_id": user_id, "token_id": token_id, "txn_id": txn_id},
+            keyvalues={
+                "room_id": room_id,
+                "user_id": user_id,
+                "token_id": token_id,
+                "txn_id": txn_id,
+            },
             retcol="event_id",
             allow_none=True,
             desc="get_event_id_from_transaction_id",
@@ -1342,7 +1347,7 @@ class EventsWorkerStore(SQLBaseStore):
             txn_id = getattr(event.internal_metadata, "txn_id", None)
             if token_id and txn_id:
                 existing = await self.get_event_id_from_transaction_id(
-                    event.sender, token_id, txn_id
+                    event.room_id, event.sender, token_id, txn_id
                 )
                 if existing:
                     mapping[event.event_id] = existing
diff --git a/synapse/storage/databases/main/schema/delta/58/19txn_id.sql b/synapse/storage/databases/main/schema/delta/58/19txn_id.sql
index 82c00dd908..b2454121a8 100644
--- a/synapse/storage/databases/main/schema/delta/58/19txn_id.sql
+++ b/synapse/storage/databases/main/schema/delta/58/19txn_id.sql
@@ -24,6 +24,7 @@
 -- events or access token we don't want to try and de-duplicate the event.
 CREATE TABLE IF NOT EXISTS event_txn_id (
     event_id TEXT NOT NULL,
+    room_id TEXT NOT NULL,
     user_id TEXT NOT NULL,
     token_id BIGINT NOT NULL,
     txn_id TEXT NOT NULL,
@@ -35,5 +36,5 @@ CREATE TABLE IF NOT EXISTS event_txn_id (
 );
 
 CREATE UNIQUE INDEX IF NOT EXISTS event_txn_id_event_id ON event_txn_id(event_id);
-CREATE UNIQUE INDEX IF NOT EXISTS event_txn_id_txn_id ON event_txn_id(user_id, token_id, txn_id);
+CREATE UNIQUE INDEX IF NOT EXISTS event_txn_id_txn_id ON event_txn_id(room_id, user_id, token_id, txn_id);
 CREATE INDEX IF NOT EXISTS event_txn_id_ts ON event_txn_id(inserted_ts);