/// <summary>
/// Asynchronously get the stream backing this message.
/// </summary>
/// <param name="streamFuncAsync">A function that returns a task for the stream backing the message.</param>
/// <param name="isRequest">true if the message is a request message; false for a response message.</param>
/// <returns>A task that when completed returns the stream backing the message.</returns>
protected internal Task <Stream> GetStreamAsync(Func <Task <Stream> > streamFuncAsync, bool isRequest)
{
// Check whether we have an existing buffering read stream when reading
if (!this.writing)
{
Stream existingBufferingReadStream = this.TryGetBufferingReadStream();
Debug.Assert(!this.writing || existingBufferingReadStream == null, "The buffering read stream should only be used when reading.");
if (existingBufferingReadStream != null)
{
Debug.Assert(this.useBufferingReadStream.HasValue, "UseBufferingReadStream must have been set.");
return(TaskUtils.GetCompletedTask(existingBufferingReadStream));
}
}
Task <Stream> task = streamFuncAsync();
ValidateMessageStreamTask(task, isRequest);
// Wrap it in a non-disposing stream if requested
task = task.FollowOnSuccessWith(
streamTask =>
{
Stream messageStream = streamTask.Result;
ValidateMessageStream(messageStream, isRequest);
// When reading, wrap the stream in a byte counting stream if a max message size was specified.
// When requested, wrap the stream in a non-disposing stream.
bool needByteCountingStream = !this.writing && this.maxMessageSize > 0;
if (!this.enableMessageStreamDisposal && needByteCountingStream)
{
messageStream = MessageStreamWrapper.CreateNonDisposingStreamWithMaxSize(messageStream, this.maxMessageSize);
}
else if (!this.enableMessageStreamDisposal)
{
messageStream = MessageStreamWrapper.CreateNonDisposingStream(messageStream);
}
else if (needByteCountingStream)
{
messageStream = MessageStreamWrapper.CreateStreamWithMaxSize(messageStream, this.maxMessageSize);
}
return(messageStream);
});
// When we are reading, also buffer the input stream
if (!this.writing)
{
task = task
.FollowOnSuccessWithTask(
streamTask =>
{
return(BufferedReadStream.BufferStreamAsync(streamTask.Result));
})
.FollowOnSuccessWith(
streamTask =>
{
BufferedReadStream bufferedReadStream = streamTask.Result;
return((Stream)bufferedReadStream);
});
// If requested also create a buffering stream for payload kind detection
if (this.useBufferingReadStream == true)
{
task = task.FollowOnSuccessWith(
streamTask =>
{
Stream messageStream = streamTask.Result;
this.bufferingReadStream = new BufferingReadStream(messageStream);
messageStream = this.bufferingReadStream;
return(messageStream);
});
}
}
return(task);
}
