From ede07cac66c9b145b7c178d59bac050488d8da34 Mon Sep 17 00:00:00 2001
From: Eric Eastwood <erice@element.io>
Date: Fri, 18 Nov 2022 19:44:45 -0600
Subject: [PATCH] Add more tracing to filter_events_for_client

---
 synapse/storage/databases/state/store.py |  8 ++++++++
 synapse/visibility.py                    | 21 +++++++++++++++++----
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/synapse/storage/databases/state/store.py b/synapse/storage/databases/state/store.py
index f8cfcaca83..0145fee496 100644
--- a/synapse/storage/databases/state/store.py
+++ b/synapse/storage/databases/state/store.py
@@ -18,6 +18,7 @@ from typing import TYPE_CHECKING, Collection, Dict, Iterable, List, Optional, Se
 import attr
 
 from synapse.api.constants import EventTypes
+from synapse.logging.tracing import SynapseTags, set_tag, tag_args, trace
 from synapse.storage._base import SQLBaseStore
 from synapse.storage.database import (
     DatabasePool,
@@ -158,6 +159,8 @@ class StateGroupDataStore(StateBackgroundUpdateStore, SQLBaseStore):
         )
 
     @cancellable
+    @trace
+    @tag_args
     async def _get_state_groups_from_groups(
         self, groups: List[int], state_filter: StateFilter
     ) -> Dict[int, StateMap[str]]:
@@ -171,6 +174,11 @@ class StateGroupDataStore(StateBackgroundUpdateStore, SQLBaseStore):
         Returns:
             Dict of state group to state map.
         """
+        set_tag(
+            SynapseTags.FUNC_ARG_PREFIX + "groups.length",
+            str(len(groups)),
+        )
+
         results: Dict[int, StateMap[str]] = {}
 
         chunks = [groups[i : i + 100] for i in range(0, len(groups), 100)]
diff --git a/synapse/visibility.py b/synapse/visibility.py
index 40a9c5b53f..c92eade62b 100644
--- a/synapse/visibility.py
+++ b/synapse/visibility.py
@@ -23,7 +23,13 @@ from synapse.api.constants import EventTypes, HistoryVisibility, Membership
 from synapse.events import EventBase
 from synapse.events.snapshot import EventContext
 from synapse.events.utils import prune_event
-from synapse.logging.opentracing import trace
+from synapse.logging.opentracing import (
+    start_active_span,
+    SynapseTags,
+    set_tag,
+    tag_args,
+    trace,
+)
 from synapse.storage.controllers import StorageControllers
 from synapse.storage.databases.main import DataStore
 from synapse.storage.state import StateFilter
@@ -53,6 +59,7 @@ _HISTORY_VIS_KEY: Final[Tuple[str, str]] = (EventTypes.RoomHistoryVisibility, ""
 
 
 @trace
+@tag_args
 async def filter_events_for_client(
     storage: StorageControllers,
     user_id: str,
@@ -82,6 +89,11 @@ async def filter_events_for_client(
     Returns:
         The filtered events.
     """
+    set_tag(
+        SynapseTags.FUNC_ARG_PREFIX + "events.length",
+        str(len(events)),
+    )
+
     # Filter out events that have been soft failed so that we don't relay them
     # to clients.
     events_before_filtering = events
@@ -130,9 +142,10 @@ async def filter_events_for_client(
             sender_erased=erased_senders.get(event.sender, False),
         )
 
-    # Check each event: gives an iterable of None or (a potentially modified)
-    # EventBase.
-    filtered_events = map(allowed, events)
+    with start_active_span("filtering events against allowed function"):
+        # Check each event: gives an iterable of None or (a potentially modified)
+        # EventBase.
+        filtered_events = map(allowed, events)
 
     # Turn it into a list and remove None entries before returning.
     return [ev for ev in filtered_events if ev]