From aa78bcd4398b3e9775a67a542d11c0acaa82035e Mon Sep 17 00:00:00 2001
From: Adam Brown <adampsbrown@gmail.com>
Date: Wed, 13 Apr 2022 21:52:37 +0100
Subject: [PATCH] extracting the room members caching to its own class - need
 an upper limit to be set

---
 .../app/dapk/st/matrix/room/RoomService.kt    |  3 ++-
 .../st/matrix/room/internal/RoomMembers.kt    | 22 +++++++++++--------
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/matrix/services/room/src/main/kotlin/app/dapk/st/matrix/room/RoomService.kt b/matrix/services/room/src/main/kotlin/app/dapk/st/matrix/room/RoomService.kt
index b5eb838..03a7dd9 100644
--- a/matrix/services/room/src/main/kotlin/app/dapk/st/matrix/room/RoomService.kt
+++ b/matrix/services/room/src/main/kotlin/app/dapk/st/matrix/room/RoomService.kt
@@ -10,6 +10,7 @@ import app.dapk.st.matrix.common.RoomMember
 import app.dapk.st.matrix.common.UserId
 import app.dapk.st.matrix.room.internal.DefaultRoomService
 import app.dapk.st.matrix.room.internal.RoomMembers
+import app.dapk.st.matrix.room.internal.RoomMembersCache
 
 private val SERVICE_KEY = RoomService::class
 
@@ -40,7 +41,7 @@ fun MatrixServiceInstaller.installRoomService(
     roomMessenger: ServiceDepFactory<RoomMessenger>,
 ) {
     this.install { (httpClient, _, services, logger) ->
-        SERVICE_KEY to DefaultRoomService(httpClient, logger, RoomMembers(memberStore), roomMessenger.create(services))
+        SERVICE_KEY to DefaultRoomService(httpClient, logger, RoomMembers(memberStore, RoomMembersCache()), roomMessenger.create(services))
     }
 }
 
diff --git a/matrix/services/room/src/main/kotlin/app/dapk/st/matrix/room/internal/RoomMembers.kt b/matrix/services/room/src/main/kotlin/app/dapk/st/matrix/room/internal/RoomMembers.kt
index ae156d2..3ee369d 100644
--- a/matrix/services/room/src/main/kotlin/app/dapk/st/matrix/room/internal/RoomMembers.kt
+++ b/matrix/services/room/src/main/kotlin/app/dapk/st/matrix/room/internal/RoomMembers.kt
@@ -5,19 +5,17 @@ import app.dapk.st.matrix.common.RoomMember
 import app.dapk.st.matrix.common.UserId
 import app.dapk.st.matrix.room.MemberStore
 
-class RoomMembers(private val memberStore: MemberStore) {
-
-    private val cache = mutableMapOf<RoomId, MutableMap<UserId, RoomMember>>()
+class RoomMembers(private val memberStore: MemberStore, private val membersCache: RoomMembersCache) {
 
     suspend fun findMember(roomId: RoomId, userId: UserId): RoomMember? {
         return findMembers(roomId, listOf(userId)).firstOrNull()
     }
 
     suspend fun findMembers(roomId: RoomId, userIds: List<UserId>): List<RoomMember> {
-        val roomCache = cache[roomId]
+        val roomCache = membersCache.room(roomId)
 
         return if (roomCache.isNullOrEmpty()) {
-            memberStore.query(roomId, userIds).also { cache(roomId, it) }
+            memberStore.query(roomId, userIds).also { membersCache.insert(roomId, it) }
         } else {
             val (cachedMembers, missingIds) = userIds.fold(mutableListOf<RoomMember>() to mutableListOf<UserId>()) { acc, current ->
                 when (val member = roomCache[current]) {
@@ -29,7 +27,7 @@ class RoomMembers(private val memberStore: MemberStore) {
 
             when {
                 missingIds.isNotEmpty() -> {
-                    (memberStore.query(roomId, missingIds).also { cache(roomId, it) } + cachedMembers)
+                    (memberStore.query(roomId, missingIds).also { membersCache.insert(roomId, it) } + cachedMembers)
                 }
                 else -> cachedMembers
             }
@@ -37,13 +35,19 @@ class RoomMembers(private val memberStore: MemberStore) {
     }
 
     suspend fun insert(roomId: RoomId, members: List<RoomMember>) {
-        cache(roomId, members)
+        membersCache.insert(roomId, members)
         memberStore.insert(roomId, members)
     }
+}
 
-    private fun cache(roomId: RoomId, members: List<RoomMember>) {
+class RoomMembersCache {
+
+    private val cache = mutableMapOf<RoomId, MutableMap<UserId, RoomMember>>()
+
+    fun room(roomId: RoomId) = cache[roomId]
+
+    fun insert(roomId: RoomId, members: List<RoomMember>) {
         val map = cache.getOrPut(roomId) { mutableMapOf() }
         members.forEach { map[it.id] = it }
     }
-
 }
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