| #region Copyright notice and license |
| |
| // Copyright 2015 gRPC authors. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #endregion |
| |
| using System.Threading; |
| using System.Threading.Tasks; |
| |
| namespace Grpc.Core |
| { |
| /// <summary> |
| /// A stream of messages to be read. |
| /// Messages can be awaited <c>await reader.MoveNext()</c>, that returns <c>true</c> |
| /// if there is a message available and <c>false</c> if there are no more messages |
| /// (i.e. the stream has been closed). |
| /// <para> |
| /// On the client side, the last invocation of <c>MoveNext()</c> either returns <c>false</c> |
| /// if the call has finished successfully or throws <c>RpcException</c> if call finished |
| /// with an error. Once the call finishes, subsequent invocations of <c>MoveNext()</c> will |
| /// continue yielding the same result (returning <c>false</c> or throwing an exception). |
| /// </para> |
| /// <para> |
| /// On the server side, <c>MoveNext()</c> does not throw exceptions. |
| /// In case of a failure, the request stream will appear to be finished |
| /// (<c>MoveNext</c> will return <c>false</c>) and the <c>CancellationToken</c> |
| /// associated with the call will be cancelled to signal the failure. |
| /// </para> |
| /// <para> |
| /// <c>MoveNext()</c> operations can be cancelled via a cancellation token. Cancelling |
| /// an individual read operation has the same effect as cancelling the entire call |
| /// (which will also result in the read operation returning prematurely), but the per-read cancellation |
| /// tokens passed to MoveNext() only result in cancelling the call if the read operation haven't finished |
| /// yet. |
| /// </para> |
| /// </summary> |
| /// <typeparam name="T">The message type.</typeparam> |
| public interface IAsyncStreamReader<out T> |
| { |
| /// <summary> |
| /// Gets the current element in the iteration. |
| /// </summary> |
| T Current { get; } |
| |
| /// <summary> |
| /// Advances the reader to the next element in the sequence, returning the result asynchronously. |
| /// </summary> |
| /// <param name="cancellationToken">Cancellation token that can be used to cancel the operation.</param> |
| /// <returns> |
| /// Task containing the result of the operation: true if the reader was successfully advanced |
| /// to the next element; false if the reader has passed the end of the sequence.</returns> |
| Task<bool> MoveNext(CancellationToken cancellationToken); |
| } |
| } |