1 /* 2 * ==================================================================== 3 * Licensed to the Apache Software Foundation (ASF) under one 4 * or more contributor license agreements. See the NOTICE file 5 * distributed with this work for additional information 6 * regarding copyright ownership. The ASF licenses this file 7 * to you under the Apache License, Version 2.0 (the 8 * "License"); you may not use this file except in compliance 9 * with the License. You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, 14 * software distributed under the License is distributed on an 15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16 * KIND, either express or implied. See the License for the 17 * specific language governing permissions and limitations 18 * under the License. 19 * ==================================================================== 20 * 21 * This software consists of voluntary contributions made by many 22 * individuals on behalf of the Apache Software Foundation. For more 23 * information on the Apache Software Foundation, please see 24 * <http://www.apache.org/>. 25 * 26 */ 27 28 package org.apache.hc.core5.http.nio; 29 30 import java.io.IOException; 31 import java.nio.ByteBuffer; 32 import java.util.List; 33 34 import org.apache.hc.core5.annotation.Contract; 35 import org.apache.hc.core5.annotation.ThreadingBehavior; 36 import org.apache.hc.core5.http.Header; 37 38 /** 39 * Abstract byte stream channel 40 * <p> 41 * Implementations are expected to be thread-safe. 42 * </p> 43 * 44 * @since 5.0 45 */ 46 @Contract(threading = ThreadingBehavior.SAFE) 47 public interface DataStreamChannel extends StreamChannel<ByteBuffer> { 48 49 /** 50 * Signals intent by the data producer to produce more data. 51 * Once the channel is able to accept data its handler is expected 52 * to trigger an event to notify the data producer. 53 */ 54 void requestOutput(); 55 56 /** 57 * Writes data from the buffer through this channel into the underlying byte stream. 58 * If the underlying byte stream is temporarily unable to accept more data 59 * it can return zero to indicate that no data could be written to the data 60 * stream. The data producer can choose to call {@link #requestOutput()} 61 * to signal its intent to produce more data. 62 * 63 * @param src source of data 64 * 65 * @return The number of bytes written, possibly zero 66 */ 67 @Override 68 int write(ByteBuffer src) throws IOException; 69 70 /** 71 * Terminates the underlying data stream and optionally writes 72 * a closing sequence with the given trailers. 73 * <p> 74 * Please note that some data streams may not support trailers 75 * and may silently ignore the trailers parameter. 76 * </p> 77 */ 78 void endStream(List<? extends Header> trailers) throws IOException; 79 80 }