Ready for a crowd: idle rooms sleep, share cards render once

Memory now carries only live tables — a sweep puts finished rooms to
bed after 30 minutes and anything untouched after a day, and getRoom
wakes a sleeping room from its ledger the moment anyone asks (the
seed plus the log IS the game). The room cap counts ledgers on disk,
not just rooms awake. Share-card PNGs render once per share id and
cache immutable. Rate-limit kicks use terminate() so an abuser cannot
hold the socket open by ignoring the closing handshake.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015RCWSTnb1KYTPyL4GmhGnF

packages/server/src/rooms.ts

@@ -22,7 +22,7 @@ import {
   type PlayerId,
   CURRENT_RULES_REV,
 } from "@wizwar/engine";
-import { appendLine, archiveRoomFile, ensureDataDir, readAllRooms, roomFileExists, type RoomLine } from "./store";
+import { appendLine, archiveRoomFile, countRoomFiles, ensureDataDir, readAllRooms, readRoom, roomFileExists, type RoomLine } from "./store";
 import { recordRoom } from "./stats";
 
 export interface LoggedCommand {
@@ -50,6 +50,8 @@ export interface Room {
   chat: { player: PlayerId; text: string; at: string }[];
   /** Seats the server itself plays: temperament, tier, and secrecy. */
   bots: Map<PlayerId, { style: AutomatonStyle; secret: boolean; tier: AutomatonTier }>;
+  /** Last time anything looked at this room (memory eviction clock). */
+  touchedAt?: number;
 }
 
 const rooms = new Map<string, Room>();
@@ -86,7 +88,7 @@ function makeRoomCode(): string {
 }
 
 export function roomCount(): number {
-  return rooms.size;
+  return countRoomFiles();
 }
 
 /** Every restored, still-running room — so boot can wake their bot pumps. */
@@ -110,6 +112,7 @@ export function createRoom(hostId: PlayerId): { room: Room; token: string } {
     events: [],
     chat: [],
     bots: new Map(),
+    touchedAt: Date.now(),
   };
   rooms.set(room.id, room);
   recordRoom(room);
@@ -125,7 +128,45 @@ export function createRoom(hostId: PlayerId): { room: Room; token: string } {
 }
 
 export function getRoom(id: string): Room | undefined {
-  return rooms.get(id.toUpperCase());
+  const code = id.toUpperCase();
+  const live = rooms.get(code);
+  if (live) {
+    live.touchedAt = Date.now();
+    return live;
+  }
+  // A room out of memory sleeps in its ledger; wake it on demand.
+  const lines = readRoom(code);
+  if (!lines) return undefined;
+  try {
+    const room = rebuildRoom(code, lines);
+    if (!room) return undefined;
+    room.touchedAt = Date.now();
+    rooms.set(code, room);
+    return room;
+  } catch (e) {
+    console.error(`could not wake room ${code}:`, e);
+    return undefined;
+  }
+}
+
+/** Put idle rooms back to sleep: their ledger holds everything, so memory
+ * only carries rooms someone is actually at. A room leaves when no socket
+ * is attached and it has sat untouched past its allowance — a finished
+ * game soon, anything else after a day. */
+export function evictIdleRooms(hasSockets: (roomId: string) => boolean): number {
+  const now = Date.now();
+  const FINISHED_MS = Number(process.env.WIZWAR_EVICT_FINISHED_MS ?? 30 * 60_000);
+  const IDLE_MS = Number(process.env.WIZWAR_EVICT_IDLE_MS ?? 24 * 60 * 60_000);
+  let evicted = 0;
+  for (const [id, room] of rooms) {
+    if (hasSockets(id)) continue;
+    const idle = now - (room.touchedAt ?? now);
+    const allowance = room.state?.phase === "finished" ? FINISHED_MS : IDLE_MS;
+    if (idle < allowance) continue;
+    rooms.delete(id);
+    evicted++;
+  }
+  return evicted;
 }
 
 export function joinRoom(
@@ -611,31 +652,30 @@ export function claimTransferCode(code: string): { roomId: string; name: PlayerI
 }
 
 /** Rebuild every persisted room by replaying its file. */
-export function loadPersistedRooms(): void {
-  ensureDataDir();
-  let restored = 0;
-  for (const [id, lines] of readAllRooms()) {
-    try {
-      const meta = lines[0] as Extract<RoomLine, { kind: "meta" }>;
-      const hostHash = meta.hostTokenHash ?? (meta.hostToken ? hashToken(meta.hostToken) : null);
-      if (!hostHash) throw new Error("meta line has no host token");
-      const room: Room = {
-        id,
-        hostId: meta.hostId,
-        players: [meta.hostId],
-        tokens: new Map([[meta.hostId, hostHash]]),
-        seed: meta.seed,
-        expansion: false,
-        colorChoices: new Map(),
-        createdAt: meta.createdAt,
-        state: null,
-        log: [],
-        events: [],
-        chat: [],
-        bots: new Map(),
-      };
-      if (lines.some((l) => l.kind === "abandon")) continue;
-      for (const line of lines.slice(1)) {
+/** Rebuild one room from its ledger lines — the seed plus the log IS the
+ * game. Returns null for an abandoned room; throws on a corrupt ledger. */
+function rebuildRoom(id: string, lines: RoomLine[]): Room | null {
+  const meta = lines[0] as Extract<RoomLine, { kind: "meta" }>;
+  const hostHash = meta.hostTokenHash ?? (meta.hostToken ? hashToken(meta.hostToken) : null);
+  if (!hostHash) throw new Error("meta line has no host token");
+  const room: Room = {
+    id,
+    hostId: meta.hostId,
+    players: [meta.hostId],
+    tokens: new Map([[meta.hostId, hostHash]]),
+    seed: meta.seed,
+    expansion: false,
+    colorChoices: new Map(),
+    createdAt: meta.createdAt,
+    state: null,
+    log: [],
+    events: [],
+    chat: [],
+    bots: new Map(),
+    touchedAt: Date.now(),
+  };
+  if (lines.some((l) => l.kind === "abandon")) return null;
+  for (const line of lines.slice(1)) {
         if (line.kind === "kick") {
           room.players = room.players.filter((p) => p !== line.name);
           room.tokens.delete(line.name);
@@ -672,7 +712,17 @@ export function loadPersistedRooms(): void {
           room.log.push({ seq: line.seq, playerId: line.playerId, command: line.command as Command, at: line.at });
           room.events.push(...result.events);
         }
-      }
+  }
+  return room;
+}
+
+export function loadPersistedRooms(): void {
+  ensureDataDir();
+  let restored = 0;
+  for (const [id, lines] of readAllRooms()) {
+    try {
+      const room = rebuildRoom(id, lines);
+      if (!room) continue;
       rooms.set(id, room);
       recordRoom(room);
       restored++;