LibUv Networking (#65)

Projects/Server/LibUv/LibuvOutputConsumer.cs

@@ -0,0 +1,111 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.IO.Pipelines;
+using System.Threading.Tasks;
+using Libuv.Internal;
+
+namespace Libuv
+{
+  public class LibuvOutputConsumer
+  {
+    private readonly LibuvThread _thread;
+    private readonly UvStreamHandle _socket;
+    private readonly string _connectionId;
+    private readonly ILibuvTrace _log;
+    private readonly PipeReader _pipe;
+
+    public LibuvOutputConsumer(
+      PipeReader pipe,
+      LibuvThread thread,
+      UvStreamHandle socket,
+      string connectionId,
+      ILibuvTrace log)
+    {
+      _pipe = pipe;
+      _thread = thread;
+      _socket = socket;
+      _connectionId = connectionId;
+      _log = log;
+    }
+
+    public async Task WriteOutputAsync()
+    {
+      var pool = _thread.WriteReqPool;
+
+      while (true)
+      {
+        var result = await _pipe.ReadAsync();
+
+        var buffer = result.Buffer;
+        var consumed = buffer.End;
+
+        try
+        {
+          if (result.IsCanceled) break;
+
+          if (!buffer.IsEmpty)
+          {
+            var writeReq = pool.Allocate();
+
+            try
+            {
+              if (_socket.IsClosed) break;
+
+              var writeResult = await writeReq.WriteAsync(_socket, buffer);
+
+              LogWriteInfo(writeResult.Status, writeResult.Error);
+
+              if (writeResult.Error != null)
+              {
+                consumed = buffer.Start;
+                throw writeResult.Error;
+              }
+            }
+            finally
+            {
+              // Make sure we return the writeReq to the pool
+              pool.Return(writeReq);
+
+              // Null out writeReq so it doesn't get caught by CheckUvReqLeaks.
+              // It is rooted by a TestSink scope through Pipe continuations in
+              // ResponseTests.HttpsConnectionClosedWhenResponseDoesNotSatisfyMinimumDataRate
+              writeReq = null;
+            }
+          }
+
+          if (result.IsCompleted) break;
+        }
+        finally
+        {
+          _pipe.AdvanceTo(consumed);
+        }
+      }
+    }
+
+    private void LogWriteInfo(int status, Exception error)
+    {
+      if (error == null)
+      {
+        _log.ConnectionWriteCallback(_connectionId, status);
+      }
+      else
+      {
+        // Log connection resets at a lower (Debug) level.
+        if (status == LibuvConstants.ECANCELED)
+        {
+          // Connection was aborted.
+        }
+        else if (LibuvConstants.IsConnectionReset(status))
+        {
+          _log.ConnectionReset(_connectionId);
+        }
+        else
+        {
+          _log.ConnectionError(_connectionId, error);
+        }
+      }
+    }
+  }
+}