From d9bffef1b21426af3c5c93ef5f891d84e52806b7 Mon Sep 17 00:00:00 2001
From: Erik Olsson <valross2@gmail.com>
Date: Fri, 18 Oct 2024 09:55:53 +0200
Subject: [PATCH 1/2] avoid cached scrollbacks if stream contains a renderable
 event

---
 packages/sdk/src/syncedStream.ts | 43 +++++++++++++++++++++++++++-----
 1 file changed, 37 insertions(+), 6 deletions(-)

diff --git a/packages/sdk/src/syncedStream.ts b/packages/sdk/src/syncedStream.ts
index 53eeb305a..1f5ccfddb 100644
--- a/packages/sdk/src/syncedStream.ts
+++ b/packages/sdk/src/syncedStream.ts
@@ -9,7 +9,7 @@ import { StreamEvents } from './streamEvents'
 import { isChannelStreamId, isDMChannelStreamId, isGDMChannelStreamId } from './id'
 import { ISyncedStream } from './syncedStreamsLoop'
 
-const CACHED_SCROLLBACK_COUNT = 3
+const MAX_CACHED_SCROLLBACK_COUNT = 3
 export class SyncedStream extends Stream implements ISyncedStream {
     log: DLogger
     isUpToDate = false
@@ -46,10 +46,12 @@ export class SyncedStream extends Stream implements ISyncedStream {
             return false
         }
 
-        const prependedMiniblocks = await this.cachedScrollback(
-            miniblocks[0].header.prevSnapshotMiniblockNum,
-            miniblocks[0].header.miniblockNum,
-        )
+        const prependedMiniblocks = hasTopLevelRenderableEvent(miniblocks)
+            ? []
+            : await this.cachedScrollback(
+                  miniblocks[0].header.prevSnapshotMiniblockNum,
+                  miniblocks[0].header.miniblockNum,
+              )
 
         const snapshotEventIds = eventIdsFromSnapshot(snapshot)
         const eventIds = miniblocks.flatMap((mb) => mb.events.map((e) => e.hashStr))
@@ -210,7 +212,7 @@ export class SyncedStream extends Stream implements ISyncedStream {
             return []
         }
         let miniblocks: ParsedMiniblock[] = []
-        for (let i = 0; i < CACHED_SCROLLBACK_COUNT; i++) {
+        for (let i = 0; i < MAX_CACHED_SCROLLBACK_COUNT; i++) {
             if (toExclusive <= 0n) {
                 break
             }
@@ -223,6 +225,9 @@ export class SyncedStream extends Stream implements ISyncedStream {
                 miniblocks = [...result, ...miniblocks]
                 fromInclusive = result[0].header.prevSnapshotMiniblockNum
                 toExclusive = result[0].header.miniblockNum
+                if (hasTopLevelRenderableEvent(miniblocks)) {
+                    break
+                }
             } else {
                 break
             }
@@ -261,3 +266,29 @@ function eventIdsFromSnapshot(snapshot: Snapshot): string[] {
             return [...usernameEventIds, ...displayNameEventIds]
     }
 }
+
+function hasTopLevelRenderableEvent(miniblocks: ParsedMiniblock[]): boolean {
+    for (const mb of miniblocks) {
+        if (topLevelRenderableEventInMiniblock(mb)) {
+            return true
+        }
+    }
+    return false
+}
+
+function topLevelRenderableEventInMiniblock(miniblock: ParsedMiniblock): boolean {
+    for (const e of miniblock.events) {
+        switch (e.event.payload.case) {
+            case 'channelPayload':
+            case 'gdmChannelPayload':
+            case 'dmChannelPayload':
+                switch (e.event.payload.value.content.case) {
+                    case 'message':
+                        if (!e.event.payload.value.content.value.refEventId) {
+                            return true
+                        }
+                }
+        }
+    }
+    return false
+}

From a1ddc74ef875d6f15a0ca3b3b10f3d3ca1a261c8 Mon Sep 17 00:00:00 2001
From: Erik Olsson <valross2@gmail.com>
Date: Fri, 18 Oct 2024 10:27:39 +0200
Subject: [PATCH 2/2] only check channel streams

---
 packages/sdk/src/syncedStream.ts | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/packages/sdk/src/syncedStream.ts b/packages/sdk/src/syncedStream.ts
index 1f5ccfddb..d3aae0c92 100644
--- a/packages/sdk/src/syncedStream.ts
+++ b/packages/sdk/src/syncedStream.ts
@@ -46,12 +46,18 @@ export class SyncedStream extends Stream implements ISyncedStream {
             return false
         }
 
-        const prependedMiniblocks = hasTopLevelRenderableEvent(miniblocks)
-            ? []
-            : await this.cachedScrollback(
-                  miniblocks[0].header.prevSnapshotMiniblockNum,
-                  miniblocks[0].header.miniblockNum,
-              )
+        const isChannelStream =
+            isChannelStreamId(this.streamId) ||
+            isDMChannelStreamId(this.streamId) ||
+            isGDMChannelStreamId(this.streamId)
+        const prependedMiniblocks = isChannelStream
+            ? hasTopLevelRenderableEvent(miniblocks)
+                ? []
+                : await this.cachedScrollback(
+                      miniblocks[0].header.prevSnapshotMiniblockNum,
+                      miniblocks[0].header.miniblockNum,
+                  )
+            : []
 
         const snapshotEventIds = eventIdsFromSnapshot(snapshot)
         const eventIds = miniblocks.flatMap((mb) => mb.events.map((e) => e.hashStr))