diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 7b2c33a922..792edc7579 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -22,7 +22,7 @@ from canonicaljson import encode_canonical_json, json
from twisted.internet import defer
from twisted.internet.defer import succeed
-from synapse.api.constants import EventTypes, Membership
+from synapse.api.constants import EventTypes, Membership, RelationTypes
from synapse.api.errors import (
AuthError,
Codes,
@@ -601,6 +601,20 @@ class EventCreationHandler(object):
self.validator.validate_new(event)
+ # If this event is an annotation then we check that that the sender
+ # can't annotate the same way twice (e.g. stops users from liking an
+ # event multiple times).
+ relation = event.content.get("m.relates_to", {})
+ if relation.get("rel_type") == RelationTypes.ANNOTATION:
+ relates_to = relation["event_id"]
+ aggregation_key = relation["key"]
+
+ already_exists = yield self.store.has_user_annotated_event(
+ relates_to, event.type, aggregation_key, event.sender,
+ )
+ if already_exists:
+ raise SynapseError(400, "Can't send same reaction twice")
+
logger.debug(
"Created event %s",
event.event_id,
diff --git a/synapse/storage/relations.py b/synapse/storage/relations.py
index 493abe405e..7d51b38d77 100644
--- a/synapse/storage/relations.py
+++ b/synapse/storage/relations.py
@@ -350,9 +350,7 @@ class RelationsWorkerStore(SQLBaseStore):
"""
def _get_applicable_edit_txn(txn):
- txn.execute(
- sql, (event_id, RelationTypes.REPLACE,)
- )
+ txn.execute(sql, (event_id, RelationTypes.REPLACE))
row = txn.fetchone()
if row:
return row[0]
@@ -367,6 +365,50 @@ class RelationsWorkerStore(SQLBaseStore):
edit_event = yield self.get_event(edit_id, allow_none=True)
defer.returnValue(edit_event)
+ def has_user_annotated_event(self, parent_id, event_type, aggregation_key, sender):
+ """Check if a user has already annotated an event with the same key
+ (e.g. already liked an event).
+
+ Args:
+ parent_id (str): The event being annotated
+ event_type (str): The event type of the annotation
+ aggregation_key (str): The aggregation key of the annotation
+ sender (str): The sender of the annotation
+
+ Returns:
+ Deferred[bool]
+ """
+
+ sql = """
+ SELECT 1 FROM event_relations
+ INNER JOIN events USING (event_id)
+ WHERE
+ relates_to_id = ?
+ AND relation_type = ?
+ AND type = ?
+ AND sender = ?
+ AND aggregation_key = ?
+ LIMIT 1;
+ """
+
+ def _get_if_user_has_annotated_event(txn):
+ txn.execute(
+ sql,
+ (
+ parent_id,
+ RelationTypes.ANNOTATION,
+ event_type,
+ sender,
+ aggregation_key,
+ ),
+ )
+
+ return bool(txn.fetchone())
+
+ return self.runInteraction(
+ "get_if_user_has_annotated_event", _get_if_user_has_annotated_event
+ )
+
class RelationsStore(RelationsWorkerStore):
def _handle_event_relations(self, txn, event):
|
