From 74470a788283f93bac5df3558545ed7a6235dcdd Mon Sep 17 00:00:00 2001
From: Vishnu Mohandas <vishnu@vishnu.tech>
Date: Mon, 10 May 2021 18:53:53 +0530
Subject: [PATCH] Smoothen the first load experience

---
 lib/services/sync_service.dart |  9 ++++++++-
 lib/utils/file_sync_util.dart  | 29 ++++++++++++++++++++++-------
 2 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/lib/services/sync_service.dart b/lib/services/sync_service.dart
index eb3d9e4ec..36633f5b4 100644
--- a/lib/services/sync_service.dart
+++ b/lib/services/sync_service.dart
@@ -1,5 +1,6 @@
 import 'dart:async';
 import 'dart:io';
+import 'package:computer/computer.dart';
 import 'package:connectivity/connectivity.dart';
 import 'package:flutter/foundation.dart';
 import 'package:logging/logging.dart';
@@ -33,6 +34,7 @@ class SyncService {
   final _uploader = FileUploader.instance;
   final _collectionsService = CollectionsService.instance;
   final _diffFetcher = DiffFetcher();
+  final Computer _computer = Computer();
   bool _syncStopRequested = false;
   bool _isBackground = false;
   Completer<bool> _existingSync;
@@ -78,6 +80,7 @@ class SyncService {
       await PhotoManager.clearFileCache();
       _logger.info("Cleared file cache");
     }
+    await _computer.turnOn(workersCount: 1);
   }
 
   Future<bool> existingSync() async {
@@ -211,6 +214,7 @@ class SyncService {
       }
     }
     final lastDBUpdationTime = _prefs.getInt(kDbUpdationTimeKey) ?? 0;
+    final startTime = DateTime.now().microsecondsSinceEpoch;
     if (lastDBUpdationTime != 0) {
       await _loadAndStorePhotos(
           lastDBUpdationTime, syncStartTime, existingLocalFileIDs);
@@ -232,6 +236,9 @@ class SyncService {
       Bus.instance
           .fire(SyncStatusUpdate(SyncStatus.completed_first_gallery_import));
     }
+    final endTime = DateTime.now().microsecondsSinceEpoch;
+    final duration = Duration(microseconds: endTime - startTime);
+    _logger.info("Load took " + duration.inMilliseconds.toString() + "ms");
   }
 
   Future<void> _loadAndStorePhotos(
@@ -240,7 +247,7 @@ class SyncService {
         DateTime.fromMicrosecondsSinceEpoch(fromTime).toString() +
         " to " +
         DateTime.fromMicrosecondsSinceEpoch(toTime).toString());
-    final files = await getDeviceFiles(fromTime, toTime);
+    final files = await getDeviceFiles(fromTime, toTime, _computer);
     if (files.isNotEmpty) {
       _logger.info("Fetched " + files.length.toString() + " files.");
       final updatedFiles =
diff --git a/lib/utils/file_sync_util.dart b/lib/utils/file_sync_util.dart
index 0c2820eb5..1371c2eb0 100644
--- a/lib/utils/file_sync_util.dart
+++ b/lib/utils/file_sync_util.dart
@@ -1,24 +1,26 @@
 import 'dart:math';
 
+import 'package:computer/computer.dart';
 import 'package:logging/logging.dart';
 import 'package:photo_manager/photo_manager.dart';
 import 'package:photos/models/file.dart';
 
 final _logger = Logger("FileSyncUtil");
 
-Future<List<File>> getDeviceFiles(int fromTime, int toTime) async {
+Future<List<File>> getDeviceFiles(
+    int fromTime, int toTime, Computer computer) async {
   final pathEntities = await _getGalleryList(fromTime, toTime);
-  final files = List<File>();
+  List<File> files = [];
   AssetPathEntity recents;
   for (AssetPathEntity pathEntity in pathEntities) {
     if (pathEntity.name == "Recent" || pathEntity.name == "Recents") {
       recents = pathEntity;
     } else {
-      await _addToPhotos(pathEntity, fromTime, files);
+      files = await _computeFiles(pathEntity, fromTime, files, computer);
     }
   }
   if (recents != null) {
-    await _addToPhotos(recents, fromTime, files);
+    files = await _computeFiles(recents, fromTime, files, computer);
   }
   files.sort(
       (first, second) => first.creationTime.compareTo(second.creationTime));
@@ -51,9 +53,21 @@ Future<List<AssetPathEntity>> _getGalleryList(
   return galleryList;
 }
 
-Future _addToPhotos(
-    AssetPathEntity pathEntity, int fromTime, List<File> files) async {
-  final assetList = await pathEntity.assetList;
+Future<List<File>> _computeFiles(AssetPathEntity pathEntity, int fromTime,
+    List<File> files, Computer computer) async {
+  final args = Map<String, dynamic>();
+  args["pathEntity"] = pathEntity;
+  args["assetList"] = await pathEntity.assetList;
+  args["fromTime"] = fromTime;
+  args["files"] = files;
+  return await computer.compute(_getFiles, param: args);
+}
+
+Future<List<File>> _getFiles(Map<String, dynamic> args) async {
+  final pathEntity = args["pathEntity"];
+  final assetList = args["assetList"];
+  final fromTime = args["fromTime"];
+  final files = args["files"];
   for (AssetEntity entity in assetList) {
     if (max(entity.createDateTime.microsecondsSinceEpoch,
             entity.modifiedDateTime.microsecondsSinceEpoch) >
@@ -68,4 +82,5 @@ Future _addToPhotos(
       }
     }
   }
+  return files;
 }