From cada21fc25669ee8a3c7c6cdb7d029b826a77872 Mon Sep 17 00:00:00 2001
From: franzap <_@franzap.com>
Date: Tue, 18 Jun 2024 12:43:47 -0300
Subject: [PATCH] Move streaming hash computation to isolate (both memory and
 CPU efficient)

Do not auto-dispose installationProgressProvider
---
 lib/models/app.dart                 | 48 +++++++++++++++++++++--------
 lib/models/settings.dart            |  1 -
 lib/navigation/mobile_scaffold.dart |  1 -
 pubspec.lock                        |  2 +-
 pubspec.yaml                        |  1 +
 5 files changed, 37 insertions(+), 16 deletions(-)

diff --git a/lib/models/app.dart b/lib/models/app.dart
index 351a893..6329b7d 100644
--- a/lib/models/app.dart
+++ b/lib/models/app.dart
@@ -1,8 +1,10 @@
 import 'dart:async';
 import 'dart:io';
+import 'dart:isolate';
 import 'dart:typed_data';
 
 import 'package:android_package_manager/android_package_manager.dart';
+import 'package:async/async.dart';
 import 'package:collection/collection.dart';
 import 'package:convert/convert.dart';
 import 'package:crypto/crypto.dart';
@@ -114,12 +116,10 @@ class App extends BaseApp with DataModelMixin<App> {
     final dir = await getApplicationSupportDirectory();
     final file = File(path.join(dir.path, hash));
 
-    installOnDevice({String? downloadedFileHash}) async {
+    installOnDevice() async {
       notifier.state = DeviceInstallProgress();
 
-      // Only check hash when passed to this function
-      // (when installing from local file, it has already been checked)
-      if (downloadedFileHash != null && downloadedFileHash != hash) {
+      if (await _isHashMismatch(file.path, hash)) {
         var e = 'Hash mismatch, ';
         if (size == await file.length()) {
           e += 'likely a malicious file.';
@@ -162,13 +162,9 @@ class App extends BaseApp with DataModelMixin<App> {
       }
       final totalBytes = response.contentLength ?? size;
 
-      final digestOutputSink = AccumulatorSink<Digest>();
-      final digestInputSink = sha256.startChunkedConversion(digestOutputSink);
-
       sub = response.stream.listen((chunk) {
         final data = Uint8List.fromList(chunk);
         sink.add(data);
-        digestInputSink.add(data);
         downloadedBytes += data.length;
         notifier.state =
             DownloadingInstallProgress(downloadedBytes / totalBytes);
@@ -177,10 +173,8 @@ class App extends BaseApp with DataModelMixin<App> {
       }, onDone: () async {
         await sub?.cancel();
         await sink.close();
-        digestInputSink.close();
         client.close();
-        final digest = digestOutputSink.events.single.toString();
-        await installOnDevice(downloadedFileHash: digest);
+        await installOnDevice();
       });
     }
   }
@@ -342,6 +336,33 @@ mixin AppAdapter on Adapter<App> {
   }
 }
 
+Future<bool> _isHashMismatch(String path, String hash) async {
+  return await Isolate.run(() async {
+    final file = File(path);
+    final fileStream = file.openRead();
+    final reader = ChunkedStreamReader(fileStream);
+    final digestOutputSink = AccumulatorSink<Digest>();
+    final digestInputSink = sha256.startChunkedConversion(digestOutputSink);
+    String? digest;
+
+    try {
+      while (true) {
+        final chunk = await reader.readChunk(1024 * 1024);
+        if (chunk.isEmpty) {
+          break; // EOF
+        }
+        digestInputSink.add(chunk);
+      }
+    } finally {
+      digestInputSink.close();
+      digest = digestOutputSink.events.single.toString();
+      digestOutputSink.close();
+      reader.cancel();
+    }
+    return digest != hash;
+  });
+}
+
 // install support
 
 enum AppInstallStatus {
@@ -376,5 +397,6 @@ class ErrorInstallProgress extends AppInstallProgress {
 final installedAppProvider =
     StateProvider<Map<String, (String, int)>>((_) => {});
 
-final installationProgressProvider = StateProvider.autoDispose
-    .family<AppInstallProgress, String>((_, arg) => IdleInstallProgress());
+final installationProgressProvider =
+    StateProvider.family<AppInstallProgress, String>(
+        (_, arg) => IdleInstallProgress());
diff --git a/lib/models/settings.dart b/lib/models/settings.dart
index 56da4ea..5511556 100644
--- a/lib/models/settings.dart
+++ b/lib/models/settings.dart
@@ -27,6 +27,5 @@ mixin SettingsAdapter on Adapter<Settings> {
     if (!existsId('_')) {
       Settings().saveLocal();
     }
-    print('initing and db version is ${findOneLocalById('_')!.dbVersion} ');
   }
 }
diff --git a/lib/navigation/mobile_scaffold.dart b/lib/navigation/mobile_scaffold.dart
index f809821..4343196 100644
--- a/lib/navigation/mobile_scaffold.dart
+++ b/lib/navigation/mobile_scaffold.dart
@@ -1,7 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:hooks_riverpod/hooks_riverpod.dart';
 import 'package:zapstore/main.data.dart';
-import 'package:zapstore/models/app.dart';
 import 'package:zapstore/utils/theme.dart';
 import 'package:zapstore/widgets/drawer_container.dart';
 
diff --git a/pubspec.lock b/pubspec.lock
index c678e71..cff378e 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -42,7 +42,7 @@ packages:
     source: hosted
     version: "2.5.0"
   async:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: async
       sha256: "947bfcf187f74dbc5e146c9eb9c0f10c9f8b30743e341481c1e2ed3ecc18c20c"
diff --git a/pubspec.yaml b/pubspec.yaml
index a35c7bf..1e376e1 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -44,6 +44,7 @@ dependencies:
   system_info2: ^4.0.0
   badges: ^3.1.2
   convert: ^3.1.1
+  async: ^2.11.0
 
 dependency_overrides:
   purplebase: