From ece947fd207cd66ef3cead0b328208d35d6f5513 Mon Sep 17 00:00:00 2001
From: Thibault Duplessis <t@lichess.org>
Date: Sun, 28 Nov 2021 18:30:37 +0100
Subject: [PATCH] only propagate cloud eval when depth increases

this should reduce the number of redis messages greatly.

Before that, you could get cevals for pvs greater than yours,
even if your depth is already higher.
---
 .../evalCache/src/main/EvalCacheUpgrade.scala | 26 ++++++++++++-------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/modules/evalCache/src/main/EvalCacheUpgrade.scala b/modules/evalCache/src/main/EvalCacheUpgrade.scala
index ce31bb558b..d0cd72800b 100644
--- a/modules/evalCache/src/main/EvalCacheUpgrade.scala
+++ b/modules/evalCache/src/main/EvalCacheUpgrade.scala
@@ -22,8 +22,8 @@ final private class EvalCacheUpgrade(setting: SettingStore[Boolean], scheduler:
   import EvalCacheUpgrade._
 
   private val members       = mutable.AnyRefMap.empty[SriString, WatchingMember]
-  private val evals         = mutable.AnyRefMap.empty[SetupId, Set[SriString]]
-  private val expirableSris = new ExpireCallbackMemo(20 minutes, sri => unregister(Socket.Sri(sri)))
+  private val evals         = mutable.AnyRefMap.empty[SetupId, EvalState]
+  private val expirableSris = new ExpireCallbackMemo(10 minutes, sri => unregister(Socket.Sri(sri)))
 
   private val upgradeMon = lila.mon.evalCache.upgrade
 
@@ -34,15 +34,19 @@ final private class EvalCacheUpgrade(setting: SettingStore[Boolean], scheduler:
       }
       val setupId = makeSetupId(variant, fen, multiPv)
       members += (sri.value -> WatchingMember(push, setupId, path))
-      evals += (setupId     -> (~evals.get(setupId) + sri.value))
+      evals += (setupId     -> evals.get(setupId).fold(EvalState(Set(sri.value), 0))(_ addSri sri))
       expirableSris put sri.value
     }
 
   def onEval(input: EvalCacheEntry.Input, sri: Socket.Sri): Unit = if (setting.get()) {
     (1 to input.eval.multiPv) flatMap { multiPv =>
-      evals get makeSetupId(input.id.variant, input.fen, multiPv)
-    } foreach { sris =>
-      val wms = sris.withFilter(sri.value !=) flatMap members.get
+      val setupId = makeSetupId(input.id.variant, input.fen, multiPv)
+      evals get setupId map (setupId -> _)
+    } filter {
+      _._2.depth < input.eval.depth
+    } foreach { case (setupId, eval) =>
+      evals += (setupId -> eval.copy(depth = input.eval.depth))
+      val wms = eval.sris.withFilter(sri.value !=) flatMap members.get
       if (wms.nonEmpty) {
         val json = JsonHandlers.writeEval(input.eval, input.fen)
         wms foreach { wm =>
@@ -61,10 +65,10 @@ final private class EvalCacheUpgrade(setting: SettingStore[Boolean], scheduler:
     }
 
   private def unregisterEval(setupId: SetupId, sri: Socket.Sri): Unit =
-    evals get setupId foreach { sris =>
-      val newSris = sris - sri.value
+    evals get setupId foreach { eval =>
+      val newSris = eval.sris - sri.value
       if (newSris.isEmpty) evals -= setupId
-      else evals += (setupId -> newSris)
+      else evals += (setupId -> eval.copy(sris = newSris))
     }
 
   scheduler.scheduleWithFixedDelay(1 minute, 1 minute) { () =>
@@ -80,6 +84,10 @@ private object EvalCacheUpgrade {
   private type SetupId   = String
   private type Push      = JsObject => Unit
 
+  private case class EvalState(sris: Set[SriString], depth: Int) {
+    def addSri(sri: Socket.Sri) = copy(sris = sris + sri.value)
+  }
+
   private def makeSetupId(variant: Variant, fen: FEN, multiPv: Int): SetupId =
     s"${variant.id}${EvalCacheEntry.SmallFen.make(variant, fen).value}^$multiPv"