move shim to new package

packages/shim/src/fs/input-cache.js

@@ -0,0 +1,123 @@
+// Dedicated cache for files picked via browser file dialogs.
+// Avoids server round trips for input-only files (e.g., importer plugin).
+//
+// - 200MB size limit (higher than content cache; import batches can be large)
+// - 5-minute TTL per entry
+// - Entries kept until TTL expires (plugins may read the same file multiple times)
+
+const MAX_SIZE = 200 * 1024 * 1024;
+const TTL_MS = 5 * 60 * 1000;
+
+const cache = new Map(); // path -> { data, size, createdAt }
+let currentSize = 0;
+
+function normalize(p) {
+  return (p || "")
+    .replace(/\\/g, "/")
+    .replace(/^\/+/, "")
+    .replace(/\/+$/, "");
+}
+
+function evictExpired() {
+  const now = Date.now();
+
+  for (const [key, entry] of cache) {
+    if (now - entry.createdAt > TTL_MS) {
+      currentSize -= entry.size;
+      cache.delete(key);
+    }
+  }
+}
+
+function evictOldest() {
+  let oldest = null;
+  let oldestTime = Infinity;
+
+  for (const [key, entry] of cache) {
+    if (entry.createdAt < oldestTime) {
+      oldest = key;
+      oldestTime = entry.createdAt;
+    }
+  }
+
+  if (oldest) {
+    currentSize -= cache.get(oldest).size;
+    cache.delete(oldest);
+  }
+}
+
+export function inputCacheHas(path) {
+  const norm = normalize(path);
+  const entry = cache.get(norm);
+
+  if (!entry) {
+    return false;
+  }
+
+  if (Date.now() - entry.createdAt > TTL_MS) {
+    currentSize -= entry.size;
+    cache.delete(norm);
+    return false;
+  }
+
+  return true;
+}
+
+export function inputCacheGet(path) {
+  const norm = normalize(path);
+  const entry = cache.get(norm);
+
+  if (!entry) {
+    return null;
+  }
+
+  if (Date.now() - entry.createdAt > TTL_MS) {
+    currentSize -= entry.size;
+    cache.delete(norm);
+    return null;
+  }
+
+  return entry.data;
+}
+
+export function inputCacheSet(path, data) {
+  const norm = normalize(path);
+  const size = data ? data.length || data.byteLength || 0 : 0;
+
+  // Remove existing entry if replacing
+  if (cache.has(norm)) {
+    currentSize -= cache.get(norm).size;
+    cache.delete(norm);
+  }
+
+  // Evict expired entries first
+  evictExpired();
+
+  // Evict oldest entries if still over limit
+  while (currentSize + size > MAX_SIZE && cache.size > 0) {
+    evictOldest();
+  }
+
+  cache.set(norm, { data, size, createdAt: Date.now() });
+  currentSize += size;
+}
+
+export function inputCacheDelete(path) {
+  const norm = normalize(path);
+  const entry = cache.get(norm);
+
+  if (entry) {
+    currentSize -= entry.size;
+    cache.delete(norm);
+  }
+}
+
+export function inputCacheClear() {
+  cache.clear();
+  currentSize = 0;
+}
+
+export function isInputCachePath(path) {
+  const norm = normalize(path);
+  return norm.startsWith(".obsidian/imports/");
+}