继承自 Stephen Cleary 的 Nito.Disposables NuGet 包

Question

我看到了 Stephen Cleary 的 Disposables NuGet 包的实现，它在我的情况下似乎是完美的，即使如此，我也找不到关于如何继承它的例子。

我的想法是让UnsubscribeAsync().GetAwaiter().GetResult();变成await UnsubscribeAsync();，这意味着它应该被包装成一个IAsyncDisposable。我怎样才能用密封的 class 实现它？

public sealed class LiveTradeManager : ITradeManager, IDisposable
{
    private bool _disposed;
    private readonly ILogger<LiveTradeManager> _logger;
    private readonly TradeOptions _tradeOptions;
    private readonly IBotClient _client;
    
    private string _listenKey;
    private UpdateSubscription _candleSubscription, _accountUpdateSubscription;
    private IDictionary<string, Channel<IBinanceStreamKlineData>> _channels;
    
    public LiveTradeManager(ILogger<LiveTradeManager> logger, IOptions<TradeOptions> tradeOptions, IOptions<ExchangeOptions> exchangeOptions, IBotClientFactory clientFactory)
    {
        _logger = logger;
        _tradeOptions = tradeOptions.Value;
        _client = clientFactory.GetBotClient(exchangeOptions.Value.BotClientType);
    }
    
    public bool IsPaused { get; set; }

    public async Task RunAsync(CancellationToken cancellationToken)
    {
        try
        {
            await SubscribeAsync(cancellationToken).ConfigureAwait(false);
        }
        catch (TaskCanceledException)
        {
        }
        catch (Exception ex) when (Handle(() => _logger.LogError(ex, "Unexpected error.")))
        {
        }
    }
    
    private async Task SubscribeAsync(CancellationToken cancellationToken)
    {
        // Subscribe to account updates
        _listenKey = await _client.GetListenKeyAsync(cancellationToken).ConfigureAwait(false);

        void OnOrderUpdate(BinanceStreamOrderUpdate order)
        {
            // order update logic
        }

        _accountUpdateSubscription = await _client.SubscribeToUserDataUpdatesAsync(_listenKey, OnOrderUpdate).ConfigureAwait(false);

        _ = Task.Run(async () =>
        {
            while (!cancellationToken.IsCancellationRequested)
            {
                await _client.KeepAliveListenKeyAsync(_listenKey, cancellationToken).ConfigureAwait(false);
                await Task.Delay(TimeSpan.FromMinutes(30), cancellationToken).ConfigureAwait(false);
            }
        }, cancellationToken);

        // Subscribe to candle updates
        var symbols = _tradeOptions.Symbols.Select(x => x.ToString()).ToList();

        _channels = symbols.ToDictionary(x => x, _ =>
            Channel.CreateBounded<IBinanceStreamKlineData>(new BoundedChannelOptions(1)
                {FullMode = BoundedChannelFullMode.DropOldest}));

        async void OnCandleReceived(IBinanceStreamKlineData data)
        {
            if (IsPaused) return;

            try
            {
                var ohlcv = data.Data.ToCandle();

                if (data.Data.Final)
                {
                    _logger.LogInformation(
                        $"[{data.Symbol}] Finalized candle | Open time: {ohlcv.Timestamp.ToDateTimeFormat()} | Price: {ohlcv.Close}");

                    _ = Task.Run(async () =>
                    {
                        await Task.Delay(10000, cancellationToken).ConfigureAwait(false);
                    }, cancellationToken);
                }
                else
                {
                    _logger.LogInformation(
                        $"[{data.Symbol}] Candle update | Open time: {ohlcv.Timestamp.ToDateTimeFormat()} | Price: {ohlcv.Close}");
                    
                    await _channels[data.Symbol].Writer.WriteAsync(data, cancellationToken).ConfigureAwait(false);
                }
            }
            catch (TaskCanceledException)
            {
            }
        }

        _candleSubscription = await _client
            .SubscribeToCandleUpdatesAsync(symbols, KlineInterval.OneMinute, OnCandleReceived)
            .ConfigureAwait(false);

        var tasks = _channels.Values.Select(async channel =>
        {
            await foreach (var data in channel.Reader.ReadAllAsync(cancellationToken))
            {
                // long-running logic...

                await Task.Delay(10000, cancellationToken).ConfigureAwait(false);
            }
        });

        // NOTE: this would block further logic
        await Task.WhenAll(tasks).ConfigureAwait(false);
    }

    private async Task UnsubscribeAsync()
    {
        // Unsubscribe account updates
        if (!string.IsNullOrEmpty(_listenKey))
        {
            await _client.StopListenKeyAsync(_listenKey).ConfigureAwait(false);
        }

        if (_accountUpdateSubscription != null)
        {
            await _client.UnsubscribeAsync(_accountUpdateSubscription).ConfigureAwait(false);
        }

        // Unsubscribe candle updates
        if (_candleSubscription != null)
        {
            await _client.UnsubscribeAsync(_candleSubscription).ConfigureAwait(false);
        }

        // Channels
        if (_channels != null)
        {
            foreach (var channel in _channels.Values)
            {
                channel.Writer.Complete();
            }

            _channels.Clear();
        }
    }
    
    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    private void Dispose(bool disposing)
    {
        if (_disposed) return;

        if (disposing)
        {
            UnsubscribeAsync().GetAwaiter().GetResult();
        }

        _disposed = true;
    }
}

public class BotManagerService : BackgroundService
{
    private readonly IHostApplicationLifetime _hostApplicationLifetime;
    private readonly IDiscordClient _discordClient;
    private readonly ITradeManager _tradeManager;
    
    public BotManagerService(
        IHostApplicationLifetime hostApplicationLifetime,
        IOptions<ExchangeOptions> options,
        IDiscordClient discordClient,
        ITradeManagerFactory tradeManagerFactory)
    {
        _hostApplicationLifetime = hostApplicationLifetime;
        _discordClient = discordClient;
        _tradeManager = tradeManagerFactory.GetTradeManager(options.Value.TradeManagerType);
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        try
        {
            var task1 = _tradeManager.RunAsync(stoppingToken);
            var task2 = _discordClient.StartAsync();

            await Task.WhenAll(task1, task2).ConfigureAwait(false);
        }
        finally
        {
            _hostApplicationLifetime.StopApplication();
        }
    }
}

Answer 1

I couldn't find examples on how to inherit from it.

Nito.Disposables，和我写的绝大多数代码一样，都是为composition rather than inheritance.

写的

因此，如果您有一个需要实现 IAsyncDisposable 的类型，它应该包含一个 IAsyncDisposable 实现并将其接口方法转发给包含的那个对象：

public sealed class LiveTradeManager : ITradeManager, IAsyncDisposable
{
  private readonly AsyncDisposable _disposable;
  ...
    
  public LiveTradeManager(...)
  {
    ...
    _disposable = new(async () => await UnsubscribeAsync());
  }

  public ValueTask DisposeAsync() => _disposable.DisposeAsync();    
}

继承自 Stephen Cleary 的 Nito.Disposables NuGet 包

Inheriting from Stephen Cleary's Nito.Disposables NuGet package

c#

idisposable

disposable

iasyncdisposable