/** * Copyright (C) 2011-2015 The XDocReport Team <xdocreport@googlegroups.com> * * All rights reserved. * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ package fr.opensagres.odfdom.converter.core.utils; /* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.UnsupportedEncodingException; import java.util.ArrayList; import java.util.List; /** * This class implements an output stream in which the data is written into a byte array. The buffer automatically grows * as data is written to it. * <p> * The data can be retrieved using <code>toByteArray()</code> and <code>toString()</code>. * <p> * Closing a <tt>ByteArrayOutputStream</tt> has no effect. The methods in this class can be called after the stream has * been closed without generating an <tt>IOException</tt>. * <p> * This is an alternative implementation of the java.io.ByteArrayOutputStream class. The original implementation only * allocates 32 bytes at the beginning. As this class is designed for heavy duty it starts at 1024 bytes. In contrast to * the original it doesn't reallocate the whole memory block but allocates additional buffers. This way no buffers need * to be garbage collected and the contents don't have to be copied to the new buffer. This class is designed to behave * exactly like the original. The only exception is the deprecated toString(int) method that has been ignored. * * @author <a href="mailto:jeremias@apache.org">Jeremias Maerki</a> * @author Holger Hoffstatte * @version $Id: ByteArrayOutputStream.java 610010 2008-01-08 14:50:59Z niallp $ */ public class ByteArrayOutputStream extends OutputStream { /** A singleton empty byte array. */ private static final byte[] EMPTY_BYTE_ARRAY = new byte[0]; /** The list of buffers, which grows and never reduces. */ private List<byte[]> buffers = new ArrayList<byte[]>(); /** The index of the current buffer. */ private int currentBufferIndex; /** The total count of bytes in all the filled buffers. */ private int filledBufferSum; /** The current buffer. */ private byte[] currentBuffer; /** The total count of bytes written. */ private int count; /** * Creates a new byte array output stream. The buffer capacity is initially 1024 bytes, though its size increases if * necessary. */ public ByteArrayOutputStream() { this( 1024 ); } /** * Creates a new byte array output stream, with a buffer capacity of the specified size, in bytes. * * @param size the initial size * @throws IllegalArgumentException if size is negative */ public ByteArrayOutputStream( int size ) { if ( size < 0 ) { throw new IllegalArgumentException( "Negative initial size: " + size ); } needNewBuffer( size ); } /** * Return the appropriate <code>byte[]</code> buffer specified by index. * * @param index the index of the buffer required * @return the buffer */ private byte[] getBuffer( int index ) { return (byte[]) buffers.get( index ); } /** * Makes a new buffer available either by allocating a new one or re-cycling an existing one. * * @param newcount the size of the buffer if one is created */ private void needNewBuffer( int newcount ) { if ( currentBufferIndex < buffers.size() - 1 ) { // Recycling old buffer filledBufferSum += currentBuffer.length; currentBufferIndex++; currentBuffer = getBuffer( currentBufferIndex ); } else { // Creating new buffer int newBufferSize; if ( currentBuffer == null ) { newBufferSize = newcount; filledBufferSum = 0; } else { newBufferSize = Math.max( currentBuffer.length << 1, newcount - filledBufferSum ); filledBufferSum += currentBuffer.length; } currentBufferIndex++; currentBuffer = new byte[newBufferSize]; buffers.add( currentBuffer ); } } /** * Write the bytes to byte array. * * @param b the bytes to write * @param off The start offset * @param len The number of bytes to write */ public void write( byte[] b, int off, int len ) { if ( ( off < 0 ) || ( off > b.length ) || ( len < 0 ) || ( ( off + len ) > b.length ) || ( ( off + len ) < 0 ) ) { throw new IndexOutOfBoundsException(); } else if ( len == 0 ) { return; } synchronized ( this ) { int newcount = count + len; int remaining = len; int inBufferPos = count - filledBufferSum; while ( remaining > 0 ) { int part = Math.min( remaining, currentBuffer.length - inBufferPos ); System.arraycopy( b, off + len - remaining, currentBuffer, inBufferPos, part ); remaining -= part; if ( remaining > 0 ) { needNewBuffer( newcount ); inBufferPos = 0; } } count = newcount; } } /** * Write a byte to byte array. * * @param b the byte to write */ public synchronized void write( int b ) { int inBufferPos = count - filledBufferSum; if ( inBufferPos == currentBuffer.length ) { needNewBuffer( count + 1 ); inBufferPos = 0; } currentBuffer[inBufferPos] = (byte) b; count++; } /** * Writes the entire contents of the specified input stream to this byte stream. Bytes from the input stream are * read directly into the internal buffers of this streams. * * @param in the input stream to read from * @return total number of bytes read from the input stream (and written to this stream) * @throws IOException if an I/O error occurs while reading the input stream * @since Commons IO 1.4 */ public synchronized int write( InputStream in ) throws IOException { int readCount = 0; int inBufferPos = count - filledBufferSum; int n = in.read( currentBuffer, inBufferPos, currentBuffer.length - inBufferPos ); while ( n != -1 ) { readCount += n; inBufferPos += n; count += n; if ( inBufferPos == currentBuffer.length ) { needNewBuffer( currentBuffer.length ); inBufferPos = 0; } n = in.read( currentBuffer, inBufferPos, currentBuffer.length - inBufferPos ); } return readCount; } /** * Return the current size of the byte array. * * @return the current size of the byte array */ public synchronized int size() { return count; } /** * Closing a <tt>ByteArrayOutputStream</tt> has no effect. The methods in this class can be called after the stream * has been closed without generating an <tt>IOException</tt>. * * @throws IOException never (this method should not declare this exception but it has to now due to backwards * compatability) */ public void close() throws IOException { // nop } /** * @see java.io.ByteArrayOutputStream#reset() */ public synchronized void reset() { count = 0; filledBufferSum = 0; currentBufferIndex = 0; currentBuffer = getBuffer( currentBufferIndex ); } /** * Writes the entire contents of this byte stream to the specified output stream. * * @param out the output stream to write to * @throws IOException if an I/O error occurs, such as if the stream is closed * @see java.io.ByteArrayOutputStream#writeTo(OutputStream) */ public synchronized void writeTo( OutputStream out ) throws IOException { int remaining = count; for ( int i = 0; i < buffers.size(); i++ ) { byte[] buf = getBuffer( i ); int c = Math.min( buf.length, remaining ); out.write( buf, 0, c ); remaining -= c; if ( remaining == 0 ) { break; } } } /** * Gets the curent contents of this byte stream as a byte array. The result is independent of this stream. * * @return the current contents of this output stream, as a byte array * @see java.io.ByteArrayOutputStream#toByteArray() */ public synchronized byte[] toByteArray() { int remaining = count; if ( remaining == 0 ) { return EMPTY_BYTE_ARRAY; } byte newbuf[] = new byte[remaining]; int pos = 0; for ( int i = 0; i < buffers.size(); i++ ) { byte[] buf = getBuffer( i ); int c = Math.min( buf.length, remaining ); System.arraycopy( buf, 0, newbuf, pos, c ); pos += c; remaining -= c; if ( remaining == 0 ) { break; } } return newbuf; } /** * Gets the curent contents of this byte stream as a string. * * @return the contents of the byte array as a String * @see java.io.ByteArrayOutputStream#toString() */ public String toString() { return new String( toByteArray() ); } /** * Gets the curent contents of this byte stream as a string using the specified encoding. * * @param enc the name of the character encoding * @return the string converted from the byte array * @throws UnsupportedEncodingException if the encoding is not supported * @see java.io.ByteArrayOutputStream#toString(String) */ public String toString( String enc ) throws UnsupportedEncodingException { return new String( toByteArray(), enc ); } }