BufferedInputStream.java revision 325ff8c68ed5e530e9e1d487b9e2e6d8f8e2bd37
1adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project/* 2adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Licensed to the Apache Software Foundation (ASF) under one or more 3adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * contributor license agreements. See the NOTICE file distributed with 4adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * this work for additional information regarding copyright ownership. 5adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * The ASF licenses this file to You under the Apache License, Version 2.0 6adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * (the "License"); you may not use this file except in compliance with 7adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * the License. You may obtain a copy of the License at 8adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * 9adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * http://www.apache.org/licenses/LICENSE-2.0 10adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * 11adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Unless required by applicable law or agreed to in writing, software 12adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * distributed under the License is distributed on an "AS IS" BASIS, 13adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * See the License for the specific language governing permissions and 15adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * limitations under the License. 16adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 17adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 18adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectpackage java.io; 19adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 20a1603838fe9e865575c87982e32c6343740e464cElliott Hughesimport java.util.Arrays; 21a1603838fe9e865575c87982e32c6343740e464cElliott Hughes 22adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project/** 23adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Wraps an existing {@link InputStream} and <em>buffers</em> the input. 24adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Expensive interaction with the underlying input stream is minimized, since 25adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * most (smaller) requests can be satisfied by accessing the buffer alone. The 26adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * drawback is that some extra space is required to hold the buffer and that 27adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * copying takes place when filling that buffer, but this is usually outweighed 28adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * by the performance benefits. 29f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 30adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * <p/>A typical application pattern for the class looks like this:<p/> 31f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 32adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * <pre> 33adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * BufferedInputStream buf = new BufferedInputStream(new FileInputStream("file.java")); 34adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * </pre> 35f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 36adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @see BufferedOutputStream 37adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 38adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectpublic class BufferedInputStream extends FilterInputStream { 39adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 40adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * The buffer containing the current bytes read from the target InputStream. 41adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 42adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project protected volatile byte[] buf; 43adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 44adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 45adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * The total number of bytes inside the byte array {@code buf}. 46adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 47adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project protected int count; 48adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 49adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 50adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * The current limit, which when passed, invalidates the current mark. 51adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 52adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project protected int marklimit; 53adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 54adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 55adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * The currently marked position. -1 indicates no mark has been set or the 56adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * mark has been invalidated. 57adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 58adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project protected int markpos = -1; 59adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 60adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 61adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * The current position within the byte array {@code buf}. 62adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 63adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project protected int pos; 64adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 65adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 66fb4616d0efbba1903b9237c0a428b59868365a69Elliott Hughes * Constructs a new {@code BufferedInputStream}, providing {@code in} with a buffer 67fb4616d0efbba1903b9237c0a428b59868365a69Elliott Hughes * of 8192 bytes. 68f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 69858dd42310622fd1b77bfa0fbd85ec851b3925c1Jesse Wilson * <p><strong>Warning:</strong> passing a null source creates a closed 70858dd42310622fd1b77bfa0fbd85ec851b3925c1Jesse Wilson * {@code BufferedInputStream}. All read operations on such a stream will 71858dd42310622fd1b77bfa0fbd85ec851b3925c1Jesse Wilson * fail with an IOException. 72858dd42310622fd1b77bfa0fbd85ec851b3925c1Jesse Wilson * 73fb4616d0efbba1903b9237c0a428b59868365a69Elliott Hughes * @param in the {@code InputStream} the buffer reads from. 74adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 75adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public BufferedInputStream(InputStream in) { 76fb4616d0efbba1903b9237c0a428b59868365a69Elliott Hughes this(in, 8192); 77adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 78adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 79adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 80fb4616d0efbba1903b9237c0a428b59868365a69Elliott Hughes * Constructs a new {@code BufferedInputStream}, providing {@code in} with {@code size} bytes 81fb4616d0efbba1903b9237c0a428b59868365a69Elliott Hughes * of buffer. 82f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 83858dd42310622fd1b77bfa0fbd85ec851b3925c1Jesse Wilson * <p><strong>Warning:</strong> passing a null source creates a closed 84858dd42310622fd1b77bfa0fbd85ec851b3925c1Jesse Wilson * {@code BufferedInputStream}. All read operations on such a stream will 85858dd42310622fd1b77bfa0fbd85ec851b3925c1Jesse Wilson * fail with an IOException. 86858dd42310622fd1b77bfa0fbd85ec851b3925c1Jesse Wilson * 87fb4616d0efbba1903b9237c0a428b59868365a69Elliott Hughes * @param in the {@code InputStream} the buffer reads from. 88fb4616d0efbba1903b9237c0a428b59868365a69Elliott Hughes * @param size the size of buffer in bytes. 89fb4616d0efbba1903b9237c0a428b59868365a69Elliott Hughes * @throws IllegalArgumentException if {@code size <= 0}. 90adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 91adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public BufferedInputStream(InputStream in, int size) { 92adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project super(in); 93adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (size <= 0) { 94b1396870f92135aa140bd2b86221768dea5bc11dElliott Hughes throw new IllegalArgumentException("size <= 0"); 95adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 96adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project buf = new byte[size]; 97adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 98adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 99adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 100582d926fbf5f5fd4800def67f86ecfedee44681eElliott Hughes * Returns an estimated number of bytes that can be read or skipped without blocking for more 101582d926fbf5f5fd4800def67f86ecfedee44681eElliott Hughes * input. This method returns the number of bytes available in the buffer 102582d926fbf5f5fd4800def67f86ecfedee44681eElliott Hughes * plus those available in the source stream, but see {@link InputStream#available} for 103582d926fbf5f5fd4800def67f86ecfedee44681eElliott Hughes * important caveats. 104f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 105582d926fbf5f5fd4800def67f86ecfedee44681eElliott Hughes * @return the estimated number of bytes available 106582d926fbf5f5fd4800def67f86ecfedee44681eElliott Hughes * @throws IOException if this stream is closed or an error occurs 107adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 108adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project @Override 109adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public synchronized int available() throws IOException { 110f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson InputStream localIn = in; // 'in' could be invalidated by close() 111f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson if (buf == null || localIn == null) { 112b1396870f92135aa140bd2b86221768dea5bc11dElliott Hughes throw streamClosed(); 113adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 114f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson return count - pos + localIn.available(); 115adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 116adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 117b1396870f92135aa140bd2b86221768dea5bc11dElliott Hughes private IOException streamClosed() throws IOException { 118b1396870f92135aa140bd2b86221768dea5bc11dElliott Hughes throw new IOException("BufferedInputStream is closed"); 119b1396870f92135aa140bd2b86221768dea5bc11dElliott Hughes } 120b1396870f92135aa140bd2b86221768dea5bc11dElliott Hughes 121adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 122adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Closes this stream. The source stream is closed and any resources 123adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * associated with it are released. 124f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 125adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @throws IOException 126adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * if an error occurs while closing this stream. 127adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 128adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project @Override 129f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson public void close() throws IOException { 130adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project buf = null; 131f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson InputStream localIn = in; 132f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson in = null; 133f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson if (localIn != null) { 134f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson localIn.close(); 135f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson } 136adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 137adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 138f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson private int fillbuf(InputStream localIn, byte[] localBuf) 139f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson throws IOException { 140adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (markpos == -1 || (pos - markpos >= marklimit)) { 141adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /* Mark position not set or exceeded readlimit */ 142f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson int result = localIn.read(localBuf); 143adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (result > 0) { 144adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project markpos = -1; 145adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project pos = 0; 146adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project count = result == -1 ? 0 : result; 147adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 148adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return result; 149adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 150f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson if (markpos == 0 && marklimit > localBuf.length) { 151f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson /* Increase buffer size to accommodate the readlimit */ 152f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson int newLength = localBuf.length * 2; 153adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (newLength > marklimit) { 154adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project newLength = marklimit; 155adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 156adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project byte[] newbuf = new byte[newLength]; 157f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson System.arraycopy(localBuf, 0, newbuf, 0, localBuf.length); 158f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson // Reassign buf, which will invalidate any local references 159f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson // FIXME: what if buf was null? 160f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson localBuf = buf = newbuf; 161adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } else if (markpos > 0) { 162f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson System.arraycopy(localBuf, markpos, localBuf, 0, localBuf.length 163f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson - markpos); 164adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 165adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /* Set the new position and mark position */ 166adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project pos -= markpos; 167adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project count = markpos = 0; 168f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson int bytesread = localIn.read(localBuf, pos, localBuf.length - pos); 169adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project count = bytesread <= 0 ? pos : pos + bytesread; 170adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return bytesread; 171adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 172adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 173adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 174adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Sets a mark position in this stream. The parameter {@code readlimit} 175adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * indicates how many bytes can be read before a mark is invalidated. 176adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Calling {@code reset()} will reposition the stream back to the marked 177adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * position if {@code readlimit} has not been surpassed. The underlying 178adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * buffer may be increased in size to allow {@code readlimit} number of 179adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * bytes to be supported. 180f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 181adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @param readlimit 182adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * the number of bytes that can be read before the mark is 183adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * invalidated. 184adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @see #reset() 185adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 186adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project @Override 187adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public synchronized void mark(int readlimit) { 188adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project marklimit = readlimit; 189adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project markpos = pos; 190adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 191adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 192adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 193adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Indicates whether {@code BufferedInputStream} supports the {@code mark()} 194adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * and {@code reset()} methods. 195f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 196adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @return {@code true} for BufferedInputStreams. 197adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @see #mark(int) 198adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @see #reset() 199adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 200adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project @Override 201adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public boolean markSupported() { 202adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return true; 203adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 204adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 205adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 206adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Reads a single byte from this stream and returns it as an integer in the 207adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * range from 0 to 255. Returns -1 if the end of the source string has been 208adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * reached. If the internal buffer does not contain any available bytes then 209adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * it is filled from the source stream and the first byte is returned. 210f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 211adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @return the byte read or -1 if the end of the source stream has been 212adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * reached. 213adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @throws IOException 214adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * if this stream is closed or another IOException occurs. 215adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 216adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project @Override 217adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public synchronized int read() throws IOException { 218f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson // Use local refs since buf and in may be invalidated by an 219f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson // unsynchronized close() 220f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson byte[] localBuf = buf; 221f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson InputStream localIn = in; 222f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson if (localBuf == null || localIn == null) { 223b1396870f92135aa140bd2b86221768dea5bc11dElliott Hughes throw streamClosed(); 224adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 225adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 226adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /* Are there buffered bytes available? */ 227f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson if (pos >= count && fillbuf(localIn, localBuf) == -1) { 228adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return -1; /* no, fill buffer */ 229adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 230f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson // localBuf may have been invalidated by fillbuf 231f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson if (localBuf != buf) { 232f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson localBuf = buf; 233f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson if (localBuf == null) { 234b1396870f92135aa140bd2b86221768dea5bc11dElliott Hughes throw streamClosed(); 235f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson } 236f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson } 237adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 238adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /* Did filling the buffer fail with -1 (EOF)? */ 239adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (count - pos > 0) { 240f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson return localBuf[pos++] & 0xFF; 241adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 242adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return -1; 243adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 244adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 245325ff8c68ed5e530e9e1d487b9e2e6d8f8e2bd37Elliott Hughes @Override public synchronized int read(byte[] buffer, int byteOffset, int byteCount) throws IOException { 246f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson // Use local ref since buf may be invalidated by an unsynchronized 247f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson // close() 248f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson byte[] localBuf = buf; 249f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson if (localBuf == null) { 250b1396870f92135aa140bd2b86221768dea5bc11dElliott Hughes throw streamClosed(); 251adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 252325ff8c68ed5e530e9e1d487b9e2e6d8f8e2bd37Elliott Hughes Arrays.checkOffsetAndCount(buffer.length, byteOffset, byteCount); 253a1603838fe9e865575c87982e32c6343740e464cElliott Hughes if (byteCount == 0) { 254adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return 0; 255adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 256f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson InputStream localIn = in; 257f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson if (localIn == null) { 258b1396870f92135aa140bd2b86221768dea5bc11dElliott Hughes throw streamClosed(); 259adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 260adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 261adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int required; 262adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (pos < count) { 263adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /* There are bytes available in the buffer. */ 264a1603838fe9e865575c87982e32c6343740e464cElliott Hughes int copylength = count - pos >= byteCount ? byteCount : count - pos; 265325ff8c68ed5e530e9e1d487b9e2e6d8f8e2bd37Elliott Hughes System.arraycopy(localBuf, pos, buffer, byteOffset, copylength); 266adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project pos += copylength; 267a1603838fe9e865575c87982e32c6343740e464cElliott Hughes if (copylength == byteCount || localIn.available() == 0) { 268adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return copylength; 269adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 270325ff8c68ed5e530e9e1d487b9e2e6d8f8e2bd37Elliott Hughes byteOffset += copylength; 271a1603838fe9e865575c87982e32c6343740e464cElliott Hughes required = byteCount - copylength; 272adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } else { 273a1603838fe9e865575c87982e32c6343740e464cElliott Hughes required = byteCount; 274adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 275adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 276adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project while (true) { 277adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project int read; 278adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /* 279adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * If we're not marked and the required size is greater than the 280adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * buffer, simply read the bytes directly bypassing the buffer. 281adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 282f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson if (markpos == -1 && required >= localBuf.length) { 283325ff8c68ed5e530e9e1d487b9e2e6d8f8e2bd37Elliott Hughes read = localIn.read(buffer, byteOffset, required); 284adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (read == -1) { 285a1603838fe9e865575c87982e32c6343740e464cElliott Hughes return required == byteCount ? -1 : byteCount - required; 286adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 287adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } else { 288f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson if (fillbuf(localIn, localBuf) == -1) { 289a1603838fe9e865575c87982e32c6343740e464cElliott Hughes return required == byteCount ? -1 : byteCount - required; 290adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 291f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson // localBuf may have been invalidated by fillbuf 292f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson if (localBuf != buf) { 293f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson localBuf = buf; 294f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson if (localBuf == null) { 295b1396870f92135aa140bd2b86221768dea5bc11dElliott Hughes throw streamClosed(); 296f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson } 297f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson } 298f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson 299adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project read = count - pos >= required ? required : count - pos; 300325ff8c68ed5e530e9e1d487b9e2e6d8f8e2bd37Elliott Hughes System.arraycopy(localBuf, pos, buffer, byteOffset, read); 301adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project pos += read; 302adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 303adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project required -= read; 304adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (required == 0) { 305a1603838fe9e865575c87982e32c6343740e464cElliott Hughes return byteCount; 306adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 307f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson if (localIn.available() == 0) { 308a1603838fe9e865575c87982e32c6343740e464cElliott Hughes return byteCount - required; 309adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 310325ff8c68ed5e530e9e1d487b9e2e6d8f8e2bd37Elliott Hughes byteOffset += read; 311adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 312adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 313adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 314adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 315adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Resets this stream to the last marked location. 316f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 317adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @throws IOException 318adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * if this stream is closed, no mark has been set or the mark is 319adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * no longer valid because more than {@code readlimit} bytes 320adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * have been read since setting the mark. 321adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @see #mark(int) 322adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 323adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project @Override 324adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public synchronized void reset() throws IOException { 325f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson if (buf == null) { 326adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project throw new IOException("Stream is closed"); 327adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 328adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (-1 == markpos) { 329adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project throw new IOException("Mark has been invalidated."); 330adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 331adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project pos = markpos; 332adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 333adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 334adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 335f9480f317cddcec859025833b748f096247a40aaElliott Hughes * Skips {@code byteCount} bytes in this stream. Subsequent calls to 336f9480f317cddcec859025833b748f096247a40aaElliott Hughes * {@code read} will not return these bytes unless {@code reset} is 337adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * used. 338f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson * 339f9480f317cddcec859025833b748f096247a40aaElliott Hughes * @param byteCount 340adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * the number of bytes to skip. {@code skip} does nothing and 341f9480f317cddcec859025833b748f096247a40aaElliott Hughes * returns 0 if {@code byteCount} is less than zero. 342adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @return the number of bytes actually skipped. 343adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @throws IOException 344adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * if this stream is closed or another IOException occurs. 345adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 346adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project @Override 347f9480f317cddcec859025833b748f096247a40aaElliott Hughes public synchronized long skip(long byteCount) throws IOException { 348f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson // Use local refs since buf and in may be invalidated by an 349f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson // unsynchronized close() 350f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson byte[] localBuf = buf; 351f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson InputStream localIn = in; 352f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson if (localBuf == null) { 353b1396870f92135aa140bd2b86221768dea5bc11dElliott Hughes throw streamClosed(); 354adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 355f9480f317cddcec859025833b748f096247a40aaElliott Hughes if (byteCount < 1) { 356adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return 0; 357adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 358f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson if (localIn == null) { 359b1396870f92135aa140bd2b86221768dea5bc11dElliott Hughes throw streamClosed(); 360f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson } 361adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 362f9480f317cddcec859025833b748f096247a40aaElliott Hughes if (count - pos >= byteCount) { 363f9480f317cddcec859025833b748f096247a40aaElliott Hughes pos += byteCount; 364f9480f317cddcec859025833b748f096247a40aaElliott Hughes return byteCount; 365adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 366adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project long read = count - pos; 367adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project pos = count; 368adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 369adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project if (markpos != -1) { 370f9480f317cddcec859025833b748f096247a40aaElliott Hughes if (byteCount <= marklimit) { 371f5597e626ecf7949d249dea08c1a2964d890ec11Jesse Wilson if (fillbuf(localIn, localBuf) == -1) { 372adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return read; 373adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 374f9480f317cddcec859025833b748f096247a40aaElliott Hughes if (count - pos >= byteCount - read) { 375f9480f317cddcec859025833b748f096247a40aaElliott Hughes pos += byteCount - read; 376f9480f317cddcec859025833b748f096247a40aaElliott Hughes return byteCount; 377adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 378adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project // Couldn't get all the bytes, skip what we read 379adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project read += (count - pos); 380adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project pos = count; 381adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return read; 382adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 383adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 384f9480f317cddcec859025833b748f096247a40aaElliott Hughes return read + localIn.skip(byteCount - read); 385adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 386adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project} 387