Feat: Reworked ENTIRE Project for Readability

src/core/cache/imageCache.ts

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+import { fetch as tauriFetch } from "@tauri-apps/plugin-http";
+import { store } from "@store/state.svelte";
+
+const cache    = new Map<string, string>();
+const inflight = new Map<string, Promise<string>>();
+const MAX_CONCURRENT = 6;
+let   active = 0;
+let   drainScheduled = false;
+
+interface QueueEntry {
+  url:      string;
+  priority: number;
+  resolve:  (v: string) => void;
+  reject:   (e: unknown) => void;
+}
+
+const queue: QueueEntry[] = [];
+
+function getAuthHeaders(): Record<string, string> {
+  const user = store.settings.serverAuthUser?.trim() ?? "";
+  const pass = store.settings.serverAuthPass?.trim() ?? "";
+  return user && pass ? { Authorization: `Basic ${btoa(`${user}:${pass}`)}` } : {};
+}
+
+async function doFetch(url: string): Promise<string> {
+  const res = await tauriFetch(url, { method: "GET", headers: getAuthHeaders() });
+  if (!res.ok) throw new Error(`${res.status}`);
+  const blobUrl = URL.createObjectURL(await res.blob());
+  cache.set(url, blobUrl);
+  return blobUrl;
+}
+
+function insertSorted(entry: QueueEntry) {
+  let lo = 0, hi = queue.length;
+  while (lo < hi) {
+    const mid = (lo + hi) >>> 1;
+    if (queue[mid].priority > entry.priority) lo = mid + 1;
+    else hi = mid;
+  }
+  queue.splice(lo, 0, entry);
+}
+
+function drain() {
+  drainScheduled = false;
+  while (active < MAX_CONCURRENT && queue.length > 0) {
+    const entry = queue.shift()!;
+    active++;
+    doFetch(entry.url)
+      .then(entry.resolve, entry.reject)
+      .finally(() => { inflight.delete(entry.url); active--; drain(); });
+  }
+}
+
+function scheduleDrain() {
+  if (drainScheduled) return;
+  drainScheduled = true;
+  requestAnimationFrame(drain);
+}
+
+function enqueue(url: string, priority: number): Promise<string> {
+  const promise = new Promise<string>((resolve, reject) => { insertSorted({ url, priority, resolve, reject }); });
+  inflight.set(url, promise);
+  scheduleDrain();
+  return promise;
+}
+
+export function getBlobUrl(url: string, priority = 0): Promise<string> {
+  if (!url) return Promise.resolve("");
+  const cached = cache.get(url);
+  if (cached) return Promise.resolve(cached);
+  const existing = inflight.get(url);
+  if (existing) {
+    const idx = queue.findIndex(e => e.url === url);
+    if (idx !== -1 && priority > queue[idx].priority) {
+      const [entry] = queue.splice(idx, 1);
+      entry.priority = priority;
+      insertSorted(entry);
+    }
+    return existing;
+  }
+  return enqueue(url, priority);
+}
+
+export function preloadBlobUrls(urls: string[], basePriority = 0): void {
+  urls.forEach((url, i) => {
+    if (!url || cache.has(url) || inflight.has(url)) return;
+    enqueue(url, basePriority - i);
+  });
+}
+
+export function revokeBlobUrl(url: string): void {
+  const blob = cache.get(url);
+  if (blob) { URL.revokeObjectURL(blob); cache.delete(url); }
+}
+
+export function deprioritizeQueue(): void {
+  for (const entry of queue) entry.priority = 0;
+  queue.sort((a, b) => b.priority - a.priority);
+}
+
+export function clearBlobCache(): void {
+  cache.forEach(blob => URL.revokeObjectURL(blob));
+  cache.clear();
+}