001/* 002 * ==================================================================== 003 * Licensed to the Apache Software Foundation (ASF) under one 004 * or more contributor license agreements. See the NOTICE file 005 * distributed with this work for additional information 006 * regarding copyright ownership. The ASF licenses this file 007 * to you under the Apache License, Version 2.0 (the 008 * "License"); you may not use this file except in compliance 009 * with the License. You may obtain a copy of the License at 010 * 011 * http://www.apache.org/licenses/LICENSE-2.0 012 * 013 * Unless required by applicable law or agreed to in writing, 014 * software distributed under the License is distributed on an 015 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 016 * KIND, either express or implied. See the License for the 017 * specific language governing permissions and limitations 018 * under the License. 019 * ==================================================================== 020 * 021 * This software consists of voluntary contributions made by many 022 * individuals on behalf of the Apache Software Foundation. For more 023 * information on the Apache Software Foundation, please see 024 * <http://www.apache.org/>. 025 * 026 */ 027 028package org.apache.http.nio.reactor; 029 030import java.io.IOException; 031import java.nio.ByteBuffer; 032import java.nio.channels.ReadableByteChannel; 033import java.nio.channels.WritableByteChannel; 034import java.nio.charset.CharacterCodingException; 035 036import org.apache.http.util.CharArrayBuffer; 037 038/** 039 * Session output buffer for non-blocking connections. This interface 040 * facilitates intermediate buffering of output data streamed out to 041 * a destination channel and writing data to the buffer from a source, usually 042 * {@link ByteBuffer} or {@link ReadableByteChannel}. This interface also 043 * provides methods for writing lines of text. 044 * 045 * @since 4.0 046 */ 047public interface SessionOutputBuffer { 048 049 /** 050 * Determines if the buffer contains data. 051 * 052 * @return {@code true} if there is data in the buffer, 053 * {@code false} otherwise. 054 */ 055 boolean hasData(); 056 057 /** 058 * Returns the length of this buffer. 059 * 060 * @return buffer length. 061 */ 062 int length(); 063 064 /** 065 * Makes an attempt to flush the content of this buffer to the given 066 * destination {@link WritableByteChannel}. 067 * 068 * @param channel the destination channel. 069 * @return The number of bytes written, possibly zero. 070 * @throws IOException in case of an I/O error. 071 */ 072 int flush(WritableByteChannel channel) 073 throws IOException; 074 075 /** 076 * Copies content of the source buffer into this buffer. The capacity of 077 * the destination will be expanded in order to accommodate the entire 078 * content of the source buffer. 079 * 080 * @param src the source buffer. 081 */ 082 void write(ByteBuffer src); 083 084 /** 085 * Reads a sequence of bytes from the source channel into this buffer. 086 * 087 * @param src the source channel. 088 */ 089 void write(ReadableByteChannel src) 090 throws IOException; 091 092 /** 093 * Copies content of the source buffer into this buffer as one line of text 094 * including a line delimiter. The capacity of the destination will be 095 * expanded in order to accommodate the entire content of the source buffer. 096 * <p> 097 * The choice of a char encoding and line delimiter sequence is up to the 098 * specific implementations of this interface. 099 * 100 * @param src the source buffer. 101 */ 102 void writeLine(CharArrayBuffer src) 103 throws CharacterCodingException; 104 105 /** 106 * Copies content of the given string into this buffer as one line of text 107 * including a line delimiter. 108 * The capacity of the destination will be expanded in order to accommodate 109 * the entire string. 110 * <p> 111 * The choice of a char encoding and line delimiter sequence is up to the 112 * specific implementations of this interface. 113 * 114 * @param s the string. 115 */ 116 void writeLine(String s) 117 throws IOException; 118 119}