Release Multi-Hoster Uploader 3.3.108

lib/throttled-cache.js

@@ -0,0 +1,51 @@
+// Time-windowed memoization. Reuses a previously-computed value if the
+// signature + input identity match AND the cached entry is younger than
+// `refreshMs`. Used by the renderer's dynamic-key sort throttle (every
+// progress tick re-sorts a 5000-row queue → reuse for 200 ms, the user
+// can't perceive sub-200 ms reorder lag).
+//
+// Loaded both as a CommonJS module (Node tests) and as a browser global
+// (renderer/app.js via index.html script tag) — same single implementation
+// across runtime and tests.
+
+(function (root) {
+  'use strict';
+
+  /**
+   * Build a throttled cache. The clock is injected so tests don't have to
+   * sleep — pass `() => fakeClock.value` from tests.
+   *
+   * @param {number} refreshMs cache TTL in milliseconds
+   * @param {() => number} [now] clock source, defaults to Date.now
+   */
+  function makeThrottledCache(refreshMs, now) {
+    if (!Number.isFinite(refreshMs) || refreshMs < 0) {
+      throw new TypeError('refreshMs must be a non-negative finite number');
+    }
+    const clock = typeof now === 'function' ? now : () => Date.now();
+    let entry = null;
+    return {
+      get(sig, input) {
+        if (!entry) return undefined;
+        if (entry.sig !== sig) return undefined;
+        if (entry.input !== input) return undefined;
+        if (clock() - entry.ts >= refreshMs) return undefined;
+        return entry.value;
+      },
+      set(sig, input, value) {
+        entry = { sig, input, value, ts: clock() };
+        return value;
+      },
+      clear() { entry = null; },
+      // Introspection (mainly for tests/debug). Returns null when empty.
+      peek() {
+        if (!entry) return null;
+        return { sig: entry.sig, ts: entry.ts, age: clock() - entry.ts };
+      }
+    };
+  }
+
+  const api = { makeThrottledCache };
+  if (typeof module !== 'undefined' && module.exports) module.exports = api;
+  else if (root) root.ThrottledCache = api;
+})(typeof window !== 'undefined' ? window : this);