/// <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.disableMessageStreamDisposal && needByteCountingStream) { messageStream = MessageStreamWrapper.CreateNonDisposingStreamWithMaxSize(messageStream, this.maxMessageSize); } else if (this.disableMessageStreamDisposal) { 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); }