org.elasticsearch.common.io.stream.BytesStreamOutput Maven / Gradle / Ivy
/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.
*/
package org.elasticsearch.common.io.stream;
import org.apache.lucene.util.ArrayUtil;
import org.elasticsearch.common.bytes.BytesArray;
import org.elasticsearch.common.bytes.BytesReference;
import org.elasticsearch.common.io.BytesStream;
import java.io.IOException;
/**
*
*/
public class BytesStreamOutput extends StreamOutput implements BytesStream {
public static final int DEFAULT_SIZE = 2 * 1024;
public static final int OVERSIZE_LIMIT = 256 * 1024;
/**
* The buffer where data is stored.
*/
protected byte buf[];
/**
* The number of valid bytes in the buffer.
*/
protected int count;
public BytesStreamOutput() {
this(DEFAULT_SIZE);
}
public BytesStreamOutput(int size) {
this.buf = new byte[size];
}
@Override
public boolean seekPositionSupported() {
return true;
}
@Override
public long position() throws IOException {
return count;
}
@Override
public void seek(long position) throws IOException {
if (position > Integer.MAX_VALUE) {
throw new UnsupportedOperationException();
}
count = (int) position;
}
@Override
public void writeByte(byte b) throws IOException {
int newcount = count + 1;
if (newcount > buf.length) {
buf = grow(newcount);
}
buf[count] = b;
count = newcount;
}
public void skip(int length) {
int newcount = count + length;
if (newcount > buf.length) {
buf = grow(newcount);
}
count = newcount;
}
@Override
public void writeBytes(byte[] b, int offset, int length) throws IOException {
if (length == 0) {
return;
}
int newcount = count + length;
if (newcount > buf.length) {
buf = grow(newcount);
}
System.arraycopy(b, offset, buf, count, length);
count = newcount;
}
private byte[] grow(int newCount) {
// try and grow faster while we are small...
if (newCount < OVERSIZE_LIMIT) {
newCount = Math.max(buf.length << 1, newCount);
}
return ArrayUtil.grow(buf, newCount);
}
public void seek(int seekTo) {
count = seekTo;
}
public void reset() {
count = 0;
}
public int bufferSize() {
return buf.length;
}
@Override
public void flush() throws IOException {
// nothing to do there
}
@Override
public void close() throws IOException {
// nothing to do here
}
@Override
public BytesReference bytes() {
return new BytesArray(buf, 0, count);
}
/**
* Returns the current size of the buffer.
*
* @return the value of the count
field, which is the number
* of valid bytes in this output stream.
* @see java.io.ByteArrayOutputStream#count
*/
public int size() {
return count;
}
}