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.http.io; 29 30 import java.io.IOException; 31 32 import org.apache.http.util.CharArrayBuffer; 33 34 /** 35 * Session input buffer for blocking connections. This interface is similar to 36 * InputStream class, but it also provides methods for reading lines of text. 37 * <p> 38 * Implementing classes are also expected to manage intermediate data buffering 39 * for optimal input performance. 40 * 41 * @since 4.0 42 */ 43 public interface SessionInputBuffer { 44 45 /** 46 * Reads up to {@code len} bytes of data from the session buffer into 47 * an array of bytes. An attempt is made to read as many as 48 * {@code len} bytes, but a smaller number may be read, possibly 49 * zero. The number of bytes actually read is returned as an integer. 50 * 51 * <p> This method blocks until input data is available, end of file is 52 * detected, or an exception is thrown. 53 * 54 * <p> If {@code off} is negative, or {@code len} is negative, or 55 * {@code off+len} is greater than the length of the array 56 * {@code b}, then an {@code IndexOutOfBoundsException} is 57 * thrown. 58 * 59 * @param b the buffer into which the data is read. 60 * @param off the start offset in array {@code b} 61 * at which the data is written. 62 * @param len the maximum number of bytes to read. 63 * @return the total number of bytes read into the buffer, or 64 * {@code -1} if there is no more data because the end of 65 * the stream has been reached. 66 * @throws IOException if an I/O error occurs. 67 */ 68 int read(byte[] b, int off, int len) throws IOException; 69 70 /** 71 * Reads some number of bytes from the session buffer and stores them into 72 * the buffer array {@code b}. The number of bytes actually read is 73 * returned as an integer. This method blocks until input data is 74 * available, end of file is detected, or an exception is thrown. 75 * 76 * @param b the buffer into which the data is read. 77 * @return the total number of bytes read into the buffer, or 78 * {@code -1} is there is no more data because the end of 79 * the stream has been reached. 80 * @throws IOException if an I/O error occurs. 81 */ 82 int read(byte[] b) throws IOException; 83 84 /** 85 * Reads the next byte of data from this session buffer. The value byte is 86 * returned as an {@code int} in the range {@code 0} to 87 * {@code 255}. If no byte is available because the end of the stream 88 * has been reached, the value {@code -1} is returned. This method 89 * blocks until input data is available, the end of the stream is detected, 90 * or an exception is thrown. 91 * 92 * @return the next byte of data, or {@code -1} if the end of the 93 * stream is reached. 94 * @throws IOException if an I/O error occurs. 95 */ 96 int read() throws IOException; 97 98 /** 99 * Reads a complete line of characters up to a line delimiter from this 100 * session buffer into the given line buffer. The number of chars actually 101 * read is returned as an integer. The line delimiter itself is discarded. 102 * If no char is available because the end of the stream has been reached, 103 * the value {@code -1} is returned. This method blocks until input 104 * data is available, end of file is detected, or an exception is thrown. 105 * <p> 106 * The choice of a char encoding and line delimiter sequence is up to the 107 * specific implementations of this interface. 108 * 109 * @param buffer the line buffer. 110 * @return one line of characters 111 * @throws IOException if an I/O error occurs. 112 */ 113 int readLine(CharArrayBuffer buffer) throws IOException; 114 115 /** 116 * Reads a complete line of characters up to a line delimiter from this 117 * session buffer. The line delimiter itself is discarded. If no char is 118 * available because the end of the stream has been reached, 119 * {@code null} is returned. This method blocks until input data is 120 * available, end of file is detected, or an exception is thrown. 121 * <p> 122 * The choice of a char encoding and line delimiter sequence is up to the 123 * specific implementations of this interface. 124 * 125 * @return HTTP line as a string 126 * @throws IOException if an I/O error occurs. 127 */ 128 String readLine() throws IOException; 129 130 /** Blocks until some data becomes available in the session buffer or the 131 * given timeout period in milliseconds elapses. If the timeout value is 132 * {@code 0} this method blocks indefinitely. 133 * 134 * @param timeout in milliseconds. 135 * @return {@code true} if some data is available in the session 136 * buffer or {@code false} otherwise. 137 * @throws IOException if an I/O error occurs. 138 * 139 * @deprecated (4.3) do not use. This function should be provided at the 140 * connection level 141 */ 142 @Deprecated 143 boolean isDataAvailable(int timeout) throws IOException; 144 145 /** 146 * Returns {@link HttpTransportMetrics} for this session buffer. 147 * 148 * @return transport metrics. 149 */ 150 HttpTransportMetrics getMetrics(); 151 152 }