improved performance and battery usage on older devices

lib/view/pages/files/search/local_cache_search.dart

@@ -1,49 +1,29 @@
 import 'dart:convert';
 
-import 'package:localstore/localstore.dart';
+import 'package:flutter/foundation.dart';
 
+import '../../../../api/cache_store.dart';
 import '../../../../api/marianumcloud/webdav/queries/list_files/cacheable_file.dart';
 import '../../../../api/marianumcloud/webdav/queries/list_files/list_files_response.dart';
-import '../../../../api/request_cache.dart';
 
 /// Document key prefix used by `ListFilesCache._documentId`.
 const String _folderCachePrefix = 'wd-folder-';
 
-/// Scans every cached folder listing in Localstore and returns files/folders
-/// whose name contains [query] (case-insensitive).
-///
-/// [pathScope] restricts results to entries whose WebDAV path starts with
-/// the given folder. Pass an empty list (or null) to search globally.
-///
-/// [docs] is an injection seam for tests — production callers leave it null
-/// so the helper reads from the real Localstore.
-Future<List<CacheableFile>> searchLocalCaches(
-  String query, {
-  List<String>? pathScope,
-  Map<String, dynamic>? docs,
-}) async {
-  final trimmed = query.trim();
-  if (trimmed.isEmpty) return const [];
-  final needle = trimmed.toLowerCase();
-  final scopePrefix = pathScope == null || pathScope.isEmpty
-      ? ''
-      : '${pathScope.join('/')}/';
-
-  final raw =
-      docs ??
-      await Localstore.instance.collection(RequestCache.collection).get();
-  if (raw == null || raw.isEmpty) return const [];
-
-  final results = <String, CacheableFile>{};
-  for (final entry in raw.entries) {
-    final docKey = entry.key.split('/').last;
-    if (!docKey.startsWith(_folderCachePrefix)) continue;
-
-    final value = entry.value;
-    if (value is! Map) continue;
-    final json = value['json'];
-    if (json is! String) continue;
+/// Every file and folder from the cached folder listings, deduplicated by
+/// path. Built once per search session: reading and parsing all listings on
+/// each keystroke used to stall typing.
+Future<List<CacheableFile>> loadLocalCacheIndex() async {
+  final entries = await CacheStore.instance.readAll(prefix: _folderCachePrefix);
+  if (entries.isEmpty) return const [];
+  final payloads = [for (final entry in entries.values) entry.json];
+  return compute(buildLocalCacheIndex, payloads);
+}
 
+/// Parses cached `ListFilesResponse` payloads into a deduplicated file list.
+/// Unparsable payloads are skipped.
+List<CacheableFile> buildLocalCacheIndex(List<String> payloads) {
+  final byPath = <String, CacheableFile>{};
+  for (final json in payloads) {
     final ListFilesResponse listing;
     try {
       listing = ListFilesResponse.fromJson(
@@ -52,14 +32,32 @@ Future<List<CacheableFile>> searchLocalCaches(
     } on Object {
       continue;
     }
-
     for (final file in listing.files) {
-      if (!file.name.toLowerCase().contains(needle)) continue;
-      if (scopePrefix.isNotEmpty && !file.path.startsWith(scopePrefix)) {
-        continue;
-      }
-      results[file.path] ??= file;
+      byPath[file.path] ??= file;
     }
   }
-  return results.values.toList();
+  return byPath.values.toList();
+}
+
+/// Files in [index] whose name contains [query] (case-insensitive).
+///
+/// [pathScope] restricts results to entries whose WebDAV path starts with
+/// the given folder. Pass an empty list (or null) to search globally.
+List<CacheableFile> searchLocalCacheIndex(
+  List<CacheableFile> index,
+  String query, {
+  List<String>? pathScope,
+}) {
+  final trimmed = query.trim();
+  if (trimmed.isEmpty) return const [];
+  final needle = trimmed.toLowerCase();
+  final scopePrefix = pathScope == null || pathScope.isEmpty
+      ? ''
+      : '${pathScope.join('/')}/';
+  return [
+    for (final file in index)
+      if (file.lowerName.contains(needle) &&
+          (scopePrefix.isEmpty || file.path.startsWith(scopePrefix)))
+        file,
+  ];
 }