SemaphoreSlim 以某种方式破坏了 SendAsync？

Question

我有一个相当复杂的案例...我正在从其他 API 调用我自己的 API。我一次这样做 6 次。在第一次调用期间，我需要获取访问令牌并将其缓存，以便所有其他请求都可以使用它。如果我首先同步调用，然后立即异步休息 5 个 - 一切正常。但同时出现所有 6 个 - 我收到来自 SendAsync 的错误（访问令牌正确生成）：

The archive entry was compressed using an unsupported compression method.

如果我从代码中删除 SemaphoreSlim，并且所有 6 个调用都将自行生成令牌（因为所有调用都无法从缓存中获取它），那么它也可以工作...... 令牌的代码（此类是为每个请求单独创建的，这就是信号量是静态的原因）：

public class AzureCredentialCached : ChainedTokenCredential
{
    private static readonly SemaphoreSlim _semaphore = new SemaphoreSlim(1, 1);

    public override async ValueTask<AccessToken> GetTokenAsync(TokenRequestContext requestContext, CancellationToken cancellationToken = default)
    {
        AccessToken? cachedToken = _cacheService.TryGetToken(requestContext, _uri);
        if (cachedToken is null)
        {
            await _semaphore.WaitAsync(cancellationToken);
            try
            {
                cachedToken = _cacheService.TryGetToken(requestContext, _uri);
                if (cachedToken is null)
                {
                    cachedToken = await base.GetTokenAsync(requestContext, cancellationToken);
                    _cacheService.InsertNewToken((AccessToken)cachedToken, requestContext, _uri);
                }
            }
            finally
            {
                _semaphore.Release();
            }
        }

        return (AccessToken)cachedToken;
    }
}

委托处理者：

public class StorageApiAuthorizeRequestHandler : DelegatingHandler
{
    private readonly IAzureCredentialCacheService _credentialCacheService;
    private readonly GeneralSection _generalConfig;
    private readonly StorageApiSection _storageConfig;

    public StorageApiAuthorizeRequestHandler(IAzureCredentialCacheService credentialCacheService, IOptions<StorageApiSection> storageConfig, IOptions<GeneralSection> generalConfig)
    {
        _credentialCacheService = credentialCacheService;
        _generalConfig = generalConfig.Value;
        _storageConfig = storageConfig.Value;
    }

    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
    {
        var credential = new AzureCredentialCached(_credentialCacheService, new Uri(_storageConfig.Address, UriKind.Absolute), new Azure.Core.TokenCredential[]
        {
            new ManagedIdentityCredential(_generalConfig.ManagedIdentityClientId),
            new VisualStudioCredential()
        });

        var scopes = new[] { _storageConfig.Scope };
        var accessToken = (await credential.GetTokenAsync(new Azure.Core.TokenRequestContext(scopes))).Token;

        request.Headers.Add(HeaderNames.Authorization, $"Bearer {accessToken}");

        try
        {
            return await base.SendAsync(request, cancellationToken);
        }
        catch (Exception ex)
        {
            throw;
        }
    }
}

The archive entry was compressed using an unsupported compression method.
 at System.IO.Compression.Inflater.Inflate(FlushCode flushCode)
   at System.IO.Compression.Inflater.ReadInflateOutput(Byte* bufPtr, Int32 length, FlushCode flushCode, Int32& bytesRead)
   at System.IO.Compression.Inflater.ReadOutput(Byte* bufPtr, Int32 length, Int32& bytesRead)
   at System.IO.Compression.Inflater.InflateVerified(Byte* bufPtr, Int32 length)
   at System.IO.Compression.DeflateStream.CopyToStream.<WriteAsyncCore>d__10.MoveNext()
   at System.IO.Stream.<<CopyToAsync>g__Core|29_0>d.MoveNext()
   at System.IO.Compression.DeflateStream.CopyToStream.<CopyFromSourceToDestinationAsync>d__6.MoveNext()
   at System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable.ConfiguredValueTaskAwaiter.GetResult()
   at System.Net.Http.HttpContent.<<CopyToAsync>g__WaitAsync|56_0>d.MoveNext()
   at System.Net.Http.MultipartContent.<SerializeToStreamAsyncCore>d__23.MoveNext()
   at System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable.ConfiguredValueTaskAwaiter.GetResult()
   at System.Net.Http.HttpContent.<<CopyToAsync>g__WaitAsync|56_0>d.MoveNext()
   at System.Net.Http.HttpConnection.<SendRequestContentAsync>d__70.MoveNext()
   at System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable.ConfiguredValueTaskAwaiter.GetResult()
   at System.Net.Http.HttpConnection.<SendAsyncCore>d__64.MoveNext()
   at System.Net.Http.HttpConnection.<SendAsyncCore>d__64.MoveNext()
   at System.Net.Http.HttpConnectionPool.<SendWithVersionDetectionAndRetryAsync>d__84.MoveNext()
   at System.Net.Http.DiagnosticsHandler.<SendAsyncCore>d__8.MoveNext()
   at System.Threading.Tasks.ValueTask`1.get_Result()
   at System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable`1.ConfiguredValueTaskAwaiter.GetResult()
   at System.Net.Http.RedirectHandler.<SendAsync>d__4.MoveNext()
   at Microsoft.Extensions.Http.Logging.LoggingHttpMessageHandler.<SendAsync>d__5.MoveNext()
   at MyAPP.ApiAuthentication.StorageApiAuthorizeRequestHandler.<SendAsync>d__4.MoveNext() in C:\MyAPP\ApiAuthentication\StorageApiAuthorizeRequestHandler.cs:line 37

Answer 1

这个问题实际上与我发送的内容有关。我们使用 ZipArchive 类从 ZIP 存档中提取文件并将它们上传到我们的另一个 API。所以流程是这样的：

1. 我正在打开 ZIP 文件的流
2. 我正在请求中使用此流进行 SendAsync
3. 打开另一个全新的流到另一个文件
4. 我正在请求中使用此流执行 SendAsync ...
5. 与此同时，第二个 API 启动并加载配置。它收到多个请求，但由于信号量，每个请求都在等待第一个请求从 Azure 加载 APP 配置
6. 完成后，它会尝试同时从第一个 API 拉取流
7. 看起来甚至 ZipArchive 库中的不同流也不能同时使用。 SendAsync 抛出异常，因为我认为这些流是动态解压缩的并且以某种方式彼此相交。

解决方案是将所有这些流复制到单独的 MemoryStreams（并且由于它们首先被一个接一个解压缩）。现在所有 SendAsyncs 同时工作，没有任何问题......