From 7883e6df8a9f19f6ef89ab8cbce0910ecc074d35 Mon Sep 17 00:00:00 2001
From: dtonon <git@dtonon.com>
Date: Thu, 20 Aug 2026 11:20:04 +0100
Subject: [PATCH] Cache server snapshots for 5 minutes and profiles for an hour

---
 src/lib/ssr/relay.ts | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/src/lib/ssr/relay.ts b/src/lib/ssr/relay.ts
index 9f647b1..3cf95f9 100644
--- a/src/lib/ssr/relay.ts
+++ b/src/lib/ssr/relay.ts
@@ -8,12 +8,17 @@ import type { Query } from "$lib/forum/query";
 // Anonymous relay access for server rendering. The server has no signer, so
 // it only ever sees what the relay serves the public; members get their
 // private rooms once the client takes over. Every query is bounded so a slow
-// relay degrades to an empty page, never a hung request, and results are
-// cached briefly to absorb crawler bursts.
+// relay degrades to an empty page, never a hung request.
+//
+// Results are cached in memory. Freshness only matters to crawlers and cold
+// refreshes — the browser always refetches live data after hydration — so
+// forum data lives as long as the edge cache (CACHE_CONTROL's s-maxage) and
+// profiles, which rarely change, for an hour.
 const QUERY_TIMEOUT = 2500;
 const PROFILE_TIMEOUT = 1500;
 const CONNECT_TIMEOUT = 1500;
-const CACHE_TTL = 30_000;
+const FORUM_TTL = 5 * 60_000;
+const PROFILE_TTL = 60 * 60_000;
 const DEAD_RELAY_TTL = 5 * 60_000;
 const CACHE_MAX = 2000;
 
@@ -89,11 +94,12 @@ function cachedQuery(
   relays: string[],
   filter: Filter,
   maxWait: number,
+  ttl: number,
 ): Promise<Event[]> {
   const key = relays.join(",") + "|" + JSON.stringify(filter);
   const now = Date.now();
   const hit = cache.get(key);
-  if (hit && now - hit.at < CACHE_TTL) return hit.result;
+  if (hit && now - hit.at < ttl) return hit.result;
   if (cache.size >= CACHE_MAX) cache.clear();
   const result = boundedQuery(relays, filter, maxWait);
   cache.set(key, { at: now, result });
@@ -101,9 +107,14 @@ function cachedQuery(
 }
 
 export const forumQuery: Query = (filter) =>
-  cachedQuery([RELAY_URL], filter, QUERY_TIMEOUT);
+  cachedQuery([RELAY_URL], filter, QUERY_TIMEOUT, FORUM_TTL);
 
 // Profiles mostly live off the forum relay; ask it too for members who only
 // published there.
 export const profileQuery: Query = (filter) =>
-  cachedQuery([RELAY_URL, ...PROFILE_RELAYS], filter, PROFILE_TIMEOUT);
+  cachedQuery(
+    [RELAY_URL, ...PROFILE_RELAYS],
+    filter,
+    PROFILE_TIMEOUT,
+    PROFILE_TTL,
+  );