com.twelvemonkeys.io.FastByteArrayOutputStream Maven / Gradle / Ivy
/*
* Copyright (c) 2008, Harald Kuhr
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* * Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.twelvemonkeys.io;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
/**
* An unsynchronized {@code ByteArrayOutputStream} implementation. This version
* also has a constructor that lets you create a stream with initial content.
*
* @author Harald Kuhr
* @version $Id: FastByteArrayOutputStream.java#2 $
*/
// TODO: Performance test of a stream impl that uses list of fixed size blocks, rather than contiguous block
public final class FastByteArrayOutputStream extends ByteArrayOutputStream {
/** Max grow size (unless if writing more than this amount of bytes) */
protected int maxGrowSize = 1024 * 1024; // 1 MB
/**
* Creates a {@code ByteArrayOutputStream} with the given initial buffer
* size.
*
* @param pSize initial buffer size
*/
public FastByteArrayOutputStream(int pSize) {
super(pSize);
}
/**
* Creates a {@code ByteArrayOutputStream} with the given initial content.
*
* Note that the buffer is not cloned, for maximum performance.
*
*
* @param pBuffer initial buffer
*/
public FastByteArrayOutputStream(byte[] pBuffer) {
super(0); // Don't allocate array
buf = pBuffer;
count = pBuffer.length;
}
@Override
public void write(byte pBytes[], int pOffset, int pLength) {
if ((pOffset < 0) || (pOffset > pBytes.length) || (pLength < 0) ||
((pOffset + pLength) > pBytes.length) || ((pOffset + pLength) < 0)) {
throw new IndexOutOfBoundsException();
}
else if (pLength == 0) {
return;
}
int newCount = count + pLength;
growIfNeeded(newCount);
System.arraycopy(pBytes, pOffset, buf, count, pLength);
count = newCount;
}
@Override
public void write(int pByte) {
int newCount = count + 1;
growIfNeeded(newCount);
buf[count] = (byte) pByte;
count = newCount;
}
private void growIfNeeded(int pNewCount) {
if (pNewCount > buf.length) {
int newSize = Math.max(Math.min(buf.length << 1, buf.length + maxGrowSize), pNewCount);
byte newBuf[] = new byte[newSize];
System.arraycopy(buf, 0, newBuf, 0, count);
buf = newBuf;
}
}
// Non-synchronized version of writeTo
@Override
public void writeTo(OutputStream pOut) throws IOException {
pOut.write(buf, 0, count);
}
// Non-synchronized version of toByteArray
@Override
public byte[] toByteArray() {
byte newBuf[] = new byte[count];
System.arraycopy(buf, 0, newBuf, 0, count);
return newBuf;
}
/**
* Creates a {@code ByteArrayInputStream} that reads directly from this
* {@code FastByteArrayOutputStream}'s byte buffer.
* The buffer is not cloned, for maximum performance.
*
* Note that care needs to be taken to avoid writes to
* this output stream after the input stream is created.
* Failing to do so, may result in unpredictable behaviour.
*
*
* @return a new {@code ByteArrayInputStream}, reading from this stream's buffer.
*/
public ByteArrayInputStream createInputStream() {
return new ByteArrayInputStream(buf, 0, count);
}
}