Cache session replay on client

2026-06-12 17:28:15 +08:00
parent ddf06c727d
commit 00a83ba4c3
4 changed files with 286 additions and 56 deletions
@@ -0,0 +1,115 @@
+"use client";
+
+export type SessionReplaySnapshot<TSession = unknown, TRun = unknown> = {
+	sessionId: string;
+	session: TSession;
+	runStatus: TRun | null;
+	signature: string;
+	fetchedAt: number;
+};
+
+const MAX_REPLAY_CACHE_SIZE = 50;
+const replayCache = new Map<string, SessionReplaySnapshot>();
+
+export function readCachedSessionReplay<TSession = unknown, TRun = unknown>(
+	sessionId: string,
+): SessionReplaySnapshot<TSession, TRun> | null {
+	const cached = replayCache.get(sessionId);
+	if (!cached) return null;
+	// Refresh recency for LRU behavior.
+	replayCache.delete(sessionId);
+	replayCache.set(sessionId, cached);
+	return cached as SessionReplaySnapshot<TSession, TRun>;
+}
+
+export function invalidateCachedSessionReplay(sessionId: string) {
+	replayCache.delete(sessionId);
+}
+
+export async function fetchSessionReplaySnapshot<
+	TSession = unknown,
+	TRun = unknown,
+>(
+	sessionId: string,
+	options: { signal?: AbortSignal } = {},
+): Promise<SessionReplaySnapshot<TSession, TRun> | null> {
+	const [sessionResponse, runStatus] = await Promise.all([
+		fetch(`/api/claw/sessions/${encodeURIComponent(sessionId)}`, {
+			cache: "no-store",
+			signal: options.signal,
+		}),
+		fetchLatestRunStatusForCache<TRun>(sessionId, options.signal),
+	]);
+	if (!sessionResponse.ok) return null;
+	const session = (await sessionResponse.json()) as TSession;
+	return writeCachedSessionReplay(sessionId, session, runStatus);
+}
+
+function writeCachedSessionReplay<TSession, TRun>(
+	sessionId: string,
+	session: TSession,
+	runStatus: TRun | null,
+): SessionReplaySnapshot<TSession, TRun> {
+	const snapshot: SessionReplaySnapshot<TSession, TRun> = {
+		sessionId,
+		session,
+		runStatus,
+		signature: sessionReplaySignature(session, runStatus),
+		fetchedAt: Date.now(),
+	};
+	replayCache.set(sessionId, snapshot as SessionReplaySnapshot);
+	while (replayCache.size > MAX_REPLAY_CACHE_SIZE) {
+		const oldest = replayCache.keys().next().value;
+		if (!oldest) break;
+		replayCache.delete(oldest);
+	}
+	return snapshot;
+}
+
+async function fetchLatestRunStatusForCache<TRun>(
+	sessionId: string,
+	signal?: AbortSignal,
+): Promise<TRun | null> {
+	try {
+		const url = new URL("/api/claw/runs/latest", window.location.origin);
+		url.searchParams.set("session_id", sessionId);
+		const response = await fetch(url, { cache: "no-store", signal });
+		if (!response.ok) return null;
+		return (await response.json()) as TRun;
+	} catch (error) {
+		if (error instanceof DOMException && error.name === "AbortError") {
+			throw error;
+		}
+		return null;
+	}
+}
+
+function sessionReplaySignature(session: unknown, runStatus: unknown) {
+	const sessionObject = isObject(session) ? session : {};
+	const runObject = isObject(runStatus) ? runStatus : {};
+	const messages = Array.isArray(sessionObject.messages)
+		? sessionObject.messages
+		: [];
+	const lastMessage = messages.at(-1);
+	const lastObject = isObject(lastMessage) ? lastMessage : {};
+	const metadata = isObject(lastObject.metadata) ? lastObject.metadata : {};
+	return [
+		sessionObject.session_id,
+		sessionObject.turns,
+		sessionObject.tool_calls,
+		messages.length,
+		lastObject.role,
+		lastObject.message_id,
+		typeof lastObject.content === "string" ? lastObject.content.length : "",
+		metadata.elapsed_ms,
+		runObject.run_id,
+		runObject.status,
+		runObject.updated_at,
+		runObject.finished_at,
+		runObject.elapsed_ms,
+	].join("|");
+}
+
+function isObject(value: unknown): value is Record<string, unknown> {
+	return Boolean(value) && typeof value === "object" && !Array.isArray(value);
+}