protected override async Task ProtectedWriteAsync(
byte[] buffer,
int offset,
int count,
CancellationToken cancellationToken)
{
VerifyConnectionNotClosedAlready();
try
{
TraceSources.Compute.TraceVerbose($"WebSocketStream: begin WriteAsync({count} bytes)... [socket: {this.socket.State}]");
await this.socket.SendAsync(
new ArraySegment <byte>(buffer, offset, count),
WebSocketMessageType.Binary,
true,
cancellationToken).ConfigureAwait(false);
TraceSources.Compute.TraceVerbose($"WebSocketStream: end WriteAsync()... [socket: {this.socket.State}]");
}
catch (Exception e) when(IsSocketError(e, SocketError.ConnectionAborted))
{
TraceSources.Compute.TraceVerbose($"WebSocketStream.Send: connection aborted - {e}");
this.closeByServerReceived = new WebSocketStreamClosedByServerException(
WebSocketCloseStatus.NormalClosure,
e.Message);
throw this.closeByServerReceived;
}
}
protected override async Task <int> ProtectedReadAsync(
byte[] buffer,
int offset,
int count,
CancellationToken cancellationToken)
{
VerifyConnectionNotClosedAlready();
// Check buffer size. Zero-sized buffers are allowed for
// connection probing.
if (count > 0 && count < this.MinReadSize)
{
throw new IndexOutOfRangeException($"Read buffer too small, must be at least {this.MinReadSize}");
}
try
{
int bytesReceived = 0;
WebSocketReceiveResult result;
do
{
if (bytesReceived > 0 && bytesReceived == count)
{
throw new OverflowException("Buffer too small to receive an entire message");
}
TraceSources.Compute.TraceVerbose($"WebSocketStream: begin ReadAsync()... [socket: {this.socket.State}]");
result = await this.socket.ReceiveAsync(
new ArraySegment <byte>(
buffer,
offset + bytesReceived,
count - bytesReceived),
cancellationToken).ConfigureAwait(false);
bytesReceived += result.Count;
TraceSources.Compute.TraceVerbose($"WebSocketStream: end ReadAsync() - {result.Count} bytes read [socket: {this.socket.State}]");
}while (count > 0 && !result.EndOfMessage);
if (result.CloseStatus != null)
{
Debug.Assert(bytesReceived == 0);
TraceSources.Compute.TraceVerbose($"Connection closed by server: {result.CloseStatus}");
this.closeByServerReceived = new WebSocketStreamClosedByServerException(
result.CloseStatus.Value,
result.CloseStatusDescription);
// In case of a normal close, it is preferable to simply return 0. But
// if the connection was closed abnormally, the client needs to know
// the details.
if (result.CloseStatus.Value != WebSocketCloseStatus.NormalClosure)
{
throw this.closeByServerReceived;
}
else
{
Debug.Assert(bytesReceived == 0);
}
}
return(bytesReceived);
}
catch (Exception e) when(IsSocketError(e, SocketError.ConnectionAborted))
{
TraceSources.Compute.TraceVerbose($"WebSocketStream.Receive: connection aborted - {e}");
// ClientWebSocket/WinHttp can also throw an exception if
// the connection has been closed.
this.closeByServerReceived = new WebSocketStreamClosedByServerException(
WebSocketCloseStatus.NormalClosure,
e.Message);
throw this.closeByServerReceived;
}
}
