WCF 服务未正确流式传输小块 (NetTcpBinding)

如何解决WCF 服务未正确流式传输小块 (NetTcpBinding)

我遇到了 WCF 服务的问题，其中较小的数据块无法立即流式传输。

[OperationContract]
Stream DoTask(int taskId);

实现如下：

public IO.Stream DoTask(int taskId) {
   var stream = new MessageStream();
   Task.Factory.StartNew(new Action(() => {
      RunTask(stream,taskId);
   }));
   return stream;
}

在 MessageStream 类中，我实现了几个函数来传输消息、状态值和文档。

读取函数总是被阻塞，直到通过底层 BlockingCollection 发生下一个事件，因此流保持打开状态，直到我完成我的任务。

如果任务正在运行，它会将各种信息流式传输到客户端。在这里，您可以看到 ChannelDispatcher 如何总是在新数据可用时立即根据需要读出我的流。

18:10:28 app>>stream: [message] Connecting to vault [progress] 5
18:10:28 wcf<<stream : 23 bytes
18:10:28 app>>stream: [message] Getting metadata [progress] 10
18:10:28 wcf<<stream : 20 bytes
18:10:28 app>>stream: [message] Downloading [progress] 15
18:10:28 wcf<<stream : 15 bytes
18:10:29 app>>stream: [message] Connecting to Inventor [progress] 20
18:10:29 wcf<<stream : 26 bytes
18:10:29 app>>stream: [message] Failed. Waiting until Inventor is started [progress] 30
18:10:29 wcf<<stream : 45 bytes
18:10:32 app>>stream: [message] Loading document [progress] 35
18:10:32 wcf<<stream : 20 bytes
18:10:32 app>>stream: [message] Unwrapping model [progress] 55
18:10:32 wcf<<stream : 20 bytes
18:10:32 app>>stream: [message] Exporting DXF to file [progress] 80
18:10:32 wcf<<stream : 25 bytes
18:10:33 app>>stream: [message] Streaming [progress] 90
18:10:33 wcf<<stream : 13 bytes
18:10:33 app>>stream: [file] 342938 [name] 00045135.dxf
18:10:33 wcf<<stream : 256 bytes
18:10:33 wcf<<stream : 4096 bytes
18:10:33 wcf<<stream : 65536 bytes
18:10:33 wcf<<stream : 65536 bytes
18:10:33 wcf<<stream : 65536 bytes
18:10:33 wcf<<stream : 65536 bytes
18:10:33 wcf<<stream : 65536 bytes
18:10:33 wcf<<stream : 10975 bytes
18:10:33 app>>stream: [message] Completed [progress] 100
18:10:33 wcf<<stream : 13 bytes

不幸的是，客户端看到了这一点：（从时间上可以看出第一条消息都被延迟了。）

18:10:33 [message] Connecting to vault [progress] (5%)
18:10:33 [message] Getting metadata [progress] (10%)
18:10:33 [message] Downloading [progress] (15%)
18:10:33 [message] Connecting to Inventor [progress] (20%)
18:10:33 [message] Failed. Waiting until Inventor is started [progress] (30%)
18:10:33 [message] Loading document [progress] (35%)
18:10:33 [message] Unwrapping model [progress] (55%)
18:10:33 [message] Exporting DXF to file [progress] (80%)
18:10:33 [message] Streaming [progress] (90%)
18:10:33 [file] 00045135.dxf [bytes] 342938
18:10:33 [message] Completed [progress] (100%)

所以调度器似乎只有在至少 256 字节可用或我的 MessageStream 完成时才传输数据。

绑定是并且 TransferMode=Streamed。

  <system.serviceModel>
    <bindings>
      <netTcpBinding>
        <binding name="Binding2" transferMode="Streamed"></binding>
      </netTcpBinding>
    </bindings>
    <services>
      <service name="...Service">
        <endpoint address=""
                 binding="netTcpBinding" bindingConfiguration="Binding2"
                 contract="...IService"></endpoint>
        <host>
          <baseAddresses>
            <add baseAddress="net.tcp://localhost:8241/service"/>
          </baseAddresses>
        </host>
      </service>
    </services>
  </system.serviceModel>

基本上，我缺少一种在服务端执行某种“刷新”的方法。 如果我将空数据附加到消息中超过 256 字节，则立即传输每条消息。

有谁知道如何正确地做到这一点？感谢您的每一个提示！