[Bug] StreamSink lose infomation sometimes

[guchengxi1994]

Describe the bug

I am using StreamSink to send information to flutter, but sometimes information would lose, only the last one will be accepted by flutter.
Here are codes.

• flutter

import 'package:flutter/material.dart';

import 'bridge/native.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  bool started = false;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            TextButton(
                onPressed: () {
                  setState(() {
                    started = true;
                  });
                  api.startScan();
                },
                child: const Text("Start scan")),
            if (started)
              StreamBuilder(
                  stream: api.fileScanStream(),
                  builder: (c, d) {
                    print(d.data);
                    return Text(d.data.toString());
                  })
          ],
        ),
      ),
    );
  }
}

• rust

use anyhow::Result;
use core::time;
use flutter_rust_bridge::StreamSink;
use std::{sync::RwLock, thread};

pub static SEND_TO_DART_FILE_STREAM_SINK: RwLock<Option<StreamSink<String>>> = RwLock::new(None);

pub fn file_scan_stream(s: StreamSink<String>) -> Result<()> {
    let mut stream = SEND_TO_DART_FILE_STREAM_SINK.write().unwrap();
    *stream = Some(s);
    Ok(())
}

pub fn start_scan() {
    thread::sleep(time::Duration::from_millis(10));

    let mut i = 0;

    loop {
        i += 1;
        if i >= 20 {
            break;
        } else {
            match SEND_TO_DART_FILE_STREAM_SINK.try_read() {
                Ok(s) => {
                    match s.as_ref() {
                        Some(s0) => {
                            let _f = String::from(format!("Test name {:?}",i) );
                            s0.add(_f);
                            // println!("got types: {:?}", l);
                        }
                        None => {
                            println!("Stream is None");
                        }
                    }
                }
                Err(_) => {
                    println!("Stream read error");
                }
            }
        }
    }
}

but if i add a sleep function to rust side, the stream works well

I dont know why this happened, and also, if i use tokio multi thread, to send infomation, even with a sleep function, some infomation still will lose.

Codegen logs with RUST_LOG=debug environment variable

PS D:\secret_data\filescan_client\small_demo> flutter_rust_bridge_codegen --rust-input native/src/api.rs --dart-output ./lib/bridge/bridge_generated.dart         2023/02/08 09:48:56 [WARN] Skipping unresolvable module web (tried \\?\D:\secret_data\filescan_client\small_demo\native\src\web.rs, \\?\D:\secret_data\filescan_client\small_demo\native\src\web\mod.rs, \\?\D:\secret_data\filescan_client\small_demo\native\src\bridge_generated\web.rs, \\?\D:\secret_data\filescan_client\small_demo\native\src\bridge_generated\web\mod.rs, )
2023/02/08 09:48:56 [WARN] Skipping unresolvable module io (tried \\?\D:\secret_data\filescan_client\small_demo\native\src\io.rs, \\?\D:\secret_data\filescan_client\small_demo\native\src\io\mod.rs, \\?\D:\secret_data\filescan_client\small_demo\native\src\bridge_generated\io.rs, \\?\D:\secret_data\filescan_client\small_demo\native\src\bridge_generated\io\mod.rs, )
Flutter 3.7.1 • channel stable • https://github.com/flutter/flutter.git
Framework • revision 7048ed95a5 (6 days ago) • 2023-02-01 09:07:31 -0800
Engine • revision 800594f1f4
Tools • Dart 2.19.1 • DevTools 2.20.1
2023/02/08 09:48:57 [INFO] Picked config: Opts { rust_input_path: "D:\\secret_data\\filescan_client\\small_demo\\native/src/api.rs", dart_output_path: "D:\\secret_data\\filescan_client\\small_demo\\./lib/bridge/bridge_generated.dart", dart_decl_output_path: None, c_output_path: ["C:\\Users\\XIAOSH~1\\AppData\\Local\\Temp\\.tmpeqIQL6.h"], rust_crate_dir: "D:\\secret_data\\filescan_client\\small_demo\\native", rust_output_path: "D:\\secret_data\\filescan_client\\small_demo\\native/src\\bridge_generated.rs", class_name: "Native", dart_format_line_length: 80, skip_add_mod_to_lib: false, llvm_path: ["/opt/homebrew/opt/llvm", "/usr/local/opt/llvm", "/usr/lib/llvm-9", "/usr/lib/llvm-10", "/usr/lib/llvm-11", "/usr/lib/llvm-12", "/usr/lib/llvm-13", "/usr/lib/llvm-14", "/usr/lib/", "/usr/lib64/", "C:/Program Files/llvm", "C:/msys64/mingw64"], llvm_compiler_opts: "", manifest_path: "D:\\secret_data\\filescan_client\\small_demo\\native\\Cargo.toml", dart_root: Some("D:\\secret_data\\filescan_client\\small_demo"), build_runner: true, block_index: BlockIndex(0), skip_deps_check: false, wasm_enabled: false, inline_rust: false }    
2023/02/08 09:48:57 [INFO] Phase: Parse source code to AST, then to IR
Running in Directory: 'D:\secret_data\filescan_client\small_demo'Input Headers: [C:\Users\XIAOSH~1\AppData\Local\Temp\.tmp7BpVx8.h][WARNING]: Generated declaration '_Dart_Handle' start's with '_' and therefore will be private.
Finished, Bindings generated in C:\Users\XIAOSH~1\AppData\Local\Temp\.tmp5sK7zlthe path is "C:\\Users\\XIAOSH~1\\AppData\\Local\\Temp\\.tmpeqIQL6.h"2023/02/08 09:49:00 [INFO] Phase: Running build_runner
2023/02/08 09:49:00 [INFO] Phase: Formatting Dart code
Formatted D:\\secret_data\\filescan_client\\small_demo\\./lib/bridge/bridge_generated.dart
Formatted 1 file (1 changed) in 0.20 seconds.
2023/02/08 09:49:01 [INFO] Success!
2023/02/08 09:49:01 [INFO] Now go and use it :)

To Reproduce

No response

Expected behavior

No response

Generated binding code

No response

OS

windows 11

Version of flutter_rust_bridge_codegen

1.62.1

Flutter info

[✓] Flutter (Channel stable, 3.7.1, on Microsoft Windows [版本 10.0.22621.1105], locale zh-CN)
    • Flutter version 3.7.1 on channel stable at D:\flutter\flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 7048ed95a5 (6 days ago), 2023-02-01 09:07:31 -0800
    • Engine revision 800594f1f4
    • Dart version 2.19.1
    • DevTools version 2.20.1
    • Pub download mirror https://pub.flutter-io.cn
    • Flutter download mirror https://storage.flutter-io.cn

[✗] Windows Version (Unable to confirm if installed Windows version is 10 or greater)

[!] Android toolchain - develop for Android devices (Android SDK version 30.0.3)
    • Android SDK at D:\androidSDK
    ✗ cmdline-tools component is missing
      Run `path/to/sdkmanager --install "cmdline-tools;latest"`
      See https://developer.android.com/studio/command-line for more details.
    ✗ Android license status unknown.
      Run `flutter doctor --android-licenses` to accept the SDK licenses.
      See https://flutter.dev/docs/get-started/install/windows#android-setup for more details.

[✓] Chrome - develop for the web
    • Chrome at C:\Program Files\Google\Chrome\Application\chrome.exe

[✓] Visual Studio - develop for Windows (Visual Studio Community 2022 17.3.1)
    • Visual Studio at C:\Program Files\Microsoft Visual Studio\2022\Community
    • Visual Studio Community 2022 version 17.3.32811.315
    • Windows 10 SDK version 10.0.19041.0

[✓] Android Studio (version 4.1)
    • Android Studio at D:\AndroidStudio
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b01)

[✓] IntelliJ IDEA Ultimate Edition (version 2020.2)
    • IntelliJ at D:\IntelliJ IDEA 2020.2.3
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[✓] Connected device (3 available)
    • Windows (desktop) • windows • windows-x64    • Microsoft Windows [版本 10.0.22621.1105]
    • Chrome (web)      • chrome  • web-javascript • Google Chrome 109.0.5414.120
    • Edge (web)        • edge    • web-javascript • Microsoft Edge 109.0.1518.78

[✓] HTTP Host Availability
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Version of clang++

No response

Version of ffigen

6.1.2

Additional context

No response

[welcome]

Hi! Thanks for opening your first issue here! 😄

[fzyzcjy]

Hmm looks like the stream has not been there, i.e. StreamSink is None?

[guchengxi1994]

StreamSink is None at the first time, but when I clicked more times, it is not None. You can see the former gif, after I clicked the button several times, the stream returns Test name 19, but Test name 0 to Test name 18 are missing.

[fzyzcjy]

Without detailed examination, I guess then you are just sending data to the old stream while you indeed want to see data in the new stream.

[guchengxi1994]

Is this problem related to #517? I found that issue the stream is None too.

[rogurotus]

looks familiar, but I'm not sure.
You can try stream.listen(_).onData(function)

[guchengxi1994]

@fzyzcjy @rogurotus using a stream.listen(e){ setState() }, not using stream in StreamBuilder solves the problem, thanks!

[github-actions]

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