1 /* 2 * 3 * Copyright 2015 gRPC authors. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 19 #import <Foundation/Foundation.h> 20 21 #import "GRXWriteable.h" 22 #import "GRXWriter.h" 23 24 /** 25 * A buffered pipe is a Writer that also acts as a Writeable. 26 * Once it is started, whatever values are written into it (via -writeValue:) will be propagated 27 * immediately, unless flow control prevents it. 28 * If it is throttled and keeps receiving values, as well as if it receives values before being 29 * started, it will buffer them and propagate them in order as soon as its state becomes Started. 30 * If it receives an end of stream (via -writesFinishedWithError:), it will buffer the EOS after the 31 * last buffered value and issue it to the writeable after all buffered values are issued. 32 * 33 * Beware that a pipe of this type can't prevent receiving more values when it is paused (for 34 * example if used to write data to a congested network connection). Because in such situations the 35 * pipe will keep buffering all data written to it, your application could run out of memory and 36 * crash. If you want to react to flow control signals to prevent that, instead of using this class 37 * you can implement an object that conforms to GRXWriter. 38 * 39 * Thread-safety: 40 * The methods of an object of this class should not be called concurrently from different threads. 41 */ 42 @interface GRXBufferedPipe : GRXWriter<GRXWriteable> 43 44 /** Convenience constructor. */ 45 + (instancetype)pipe; 46 47 @end 48