Merge branch 'nxl/improve-compaction-strategy' into dev

packages/opencode/src/session/message-v2.ts

@@ -208,6 +208,7 @@ export const CompactionPart = PartBase.extend({
   type: z.literal("compaction"),
   auto: z.boolean(),
   overflow: z.boolean().optional(),
+  tail_start_id: MessageID.zod.optional(),
 }).meta({
   ref: "CompactionPart",
 })
@@ -923,8 +924,21 @@ export function get(input: { sessionID: SessionID; messageID: MessageID }): With
 export function filterCompacted(msgs: Iterable<WithParts>) {
   const result = [] as WithParts[]
   const completed = new Set<string>()
+  let retain: MessageID | undefined
   for (const msg of msgs) {
     result.push(msg)
+    if (retain) {
+      if (msg.info.id === retain) break
+      continue
+    }
+    if (msg.info.role === "user" && completed.has(msg.info.id)) {
+      const part = msg.parts.find((item): item is CompactionPart => item.type === "compaction")
+      if (!part) continue
+      if (!part.tail_start_id) break
+      retain = part.tail_start_id
+      if (msg.info.id === retain) break
+      continue
+    }
     if (msg.info.role === "user" && completed.has(msg.info.id) && msg.parts.some((part) => part.type === "compaction"))
       break
     if (msg.info.role === "assistant" && msg.info.summary && msg.info.finish && !msg.info.error)