From 0d25823e5ec93ab441b0a3bf2db98261ce84612c Mon Sep 17 00:00:00 2001
From: Thibault Duplessis <t@lichess.org>
Date: Sun, 29 Aug 2021 10:26:36 +0200
Subject: [PATCH] dedup all timeline notifications - closes #9686

---
 modules/timeline/src/main/Env.scala                        | 2 +-
 .../timeline/src/main/{Push.scala => TimelinePush.scala}   | 7 +++++--
 2 files changed, 6 insertions(+), 3 deletions(-)
 rename modules/timeline/src/main/{Push.scala => TimelinePush.scala} (89%)

diff --git a/modules/timeline/src/main/Env.scala b/modules/timeline/src/main/Env.scala
index cf6f897c68..71fdee8b75 100644
--- a/modules/timeline/src/main/Env.scala
+++ b/modules/timeline/src/main/Env.scala
@@ -50,7 +50,7 @@ final class Env(
         }
     }
 
-  system.actorOf(Props(wire[Push]), name = config.userActorName)
+  system.actorOf(Props(wire[TimelinePush]), name = config.userActorName)
 
   lila.common.Bus.subscribeFun("shadowban") { case lila.hub.actorApi.mod.Shadowban(userId, true) =>
     entryApi.removeRecentFollowsBy(userId).unit
diff --git a/modules/timeline/src/main/Push.scala b/modules/timeline/src/main/TimelinePush.scala
similarity index 89%
rename from modules/timeline/src/main/Push.scala
rename to modules/timeline/src/main/TimelinePush.scala
index ab3d4144fb..ec93eb2ccd 100644
--- a/modules/timeline/src/main/Push.scala
+++ b/modules/timeline/src/main/TimelinePush.scala
@@ -2,6 +2,7 @@ package lila.timeline
 
 import akka.actor._
 import org.joda.time.DateTime
+import scala.concurrent.duration._
 
 import lila.common.config.Max
 import lila.hub.actorApi.timeline.propagation._
@@ -9,7 +10,7 @@ import lila.hub.actorApi.timeline.{ Atom, Propagate, ReloadTimelines }
 import lila.security.Permission
 import lila.user.{ User, UserRepo }
 
-final private[timeline] class Push(
+final private[timeline] class TimelinePush(
     relationApi: lila.relation.RelationApi,
     userRepo: UserRepo,
     entryApi: EntryApi,
@@ -18,8 +19,10 @@ final private[timeline] class Push(
 
   implicit def ec = context.dispatcher
 
+  private val dedup = lila.memo.OnceEvery.hashCode[Atom](10 minutes)
+
   def receive = { case Propagate(data, propagations) =>
-    propagate(propagations) flatMap { users =>
+    if (dedup(data)) propagate(propagations) flatMap { users =>
       unsubApi.filterUnsub(data.channel, users)
     } foreach { users =>
       if (users.nonEmpty)