/*
* 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.
* <p/>
*
* @author <a href="mailto:harald.kuhr@gmail.com">Harald Kuhr</a>
* @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.
* <p/>
* 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.
* <p/>
* 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);
}
}