From 5bd5b41c70791e9664d55425066cfe0be8282e35 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timo=20K=C3=B6sters?= <timo@koesters.xyz>
Date: Sat, 14 Aug 2021 23:29:25 +0200
Subject: [PATCH] fix: fetch event multiple times

---
 src/database/rooms.rs |  8 ++------
 src/server_server.rs  | 15 ++++++++++++---
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/src/database/rooms.rs b/src/database/rooms.rs
index 4a3ab71..2832cc2 100644
--- a/src/database/rooms.rs
+++ b/src/database/rooms.rs
@@ -845,10 +845,7 @@ impl Rooms {
     }
 
     /// Returns the json of a pdu.
-    pub fn get_outlier_pdu_json(
-        &self,
-        event_id: &EventId,
-    ) -> Result<Option<CanonicalJsonObject>> {
+    pub fn get_outlier_pdu_json(&self, event_id: &EventId) -> Result<Option<CanonicalJsonObject>> {
         self.eventid_outlierpdu
             .get(event_id.as_bytes())?
             .map(|pdu| {
@@ -1134,10 +1131,9 @@ impl Rooms {
             &serde_json::to_vec(&pdu_json).expect("CanonicalJsonObject is always a valid"),
         )?;
 
-        // This also replaces the eventid of any outliers with the correct
-        // pduid, removing the place holder.
         self.eventid_pduid
             .insert(pdu.event_id.as_bytes(), &pdu_id)?;
+        self.eventid_outlierpdu.remove(pdu.event_id.as_bytes())?;
 
         drop(insert_lock);
 
diff --git a/src/server_server.rs b/src/server_server.rs
index a293d1b..a4bfda5 100644
--- a/src/server_server.rs
+++ b/src/server_server.rs
@@ -884,9 +884,15 @@ pub async fn handle_incoming_pdu<'a>(
     }
 
     // 9. Fetch any missing prev events doing all checks listed here starting at 1. These are timeline events
+    let mut visited = HashSet::new();
     let mut todo_outlier_stack = incoming_pdu.prev_events.clone();
     let mut todo_timeline_stack = Vec::new();
     while let Some(prev_event_id) = todo_outlier_stack.pop() {
+        if visited.contains(&prev_event_id) {
+            continue;
+        }
+        visited.insert(prev_event_id.clone());
+
         if let Some((pdu, json_opt)) = fetch_and_handle_outliers(
             db,
             origin,
@@ -898,7 +904,9 @@ pub async fn handle_incoming_pdu<'a>(
         .await
         .pop()
         {
-            if let Some(json) = json_opt.or_else(|| db.rooms.get_outlier_pdu_json(&prev_event_id).ok().flatten()) {
+            if let Some(json) =
+                json_opt.or_else(|| db.rooms.get_outlier_pdu_json(&prev_event_id).ok().flatten())
+            {
                 if incoming_pdu.origin_server_ts
                     > db.rooms
                         .first_pdu_in_room(&room_id)
@@ -949,8 +957,6 @@ fn handle_outlier_pdu<'a>(
 ) -> AsyncRecursiveType<'a, StdResult<(Arc<PduEvent>, BTreeMap<String, CanonicalJsonValue>), String>>
 {
     Box::pin(async move {
-        let start_time = Instant::now();
-
         // TODO: For RoomVersion6 we must check that Raw<..> is canonical do we anywhere?: https://matrix.org/docs/spec/rooms/v6#canonical-json
 
         // We go through all the signatures we see on the value and fetch the corresponding signing
@@ -1109,6 +1115,9 @@ async fn upgrade_outlier_to_timeline_pdu(
     room_id: &RoomId,
     pub_key_map: &RwLock<BTreeMap<String, BTreeMap<String, String>>>,
 ) -> StdResult<Option<Vec<u8>>, String> {
+    if let Ok(Some(pduid)) = db.rooms.get_pdu_id(&incoming_pdu.event_id) {
+        return Ok(Some(pduid));
+    }
     // 10. Fetch missing state and auth chain events by calling /state_ids at backwards extremities
     //     doing all the checks in this list starting at 1. These are not timeline events.