RandomAccessByteArrayOutputStream.java

/**
 * File Created at 2011-12-22
 * $Id$
 *
 * Copyright 2008 Alibaba.com Croporation Limited.
 * All rights reserved.
 *
 * This software is the confidential and proprietary information of
 * Alibaba Company. ("Confidential Information").  You shall not
 * disclose such Confidential Information and shall use it only in
 * accordance with the terms of the license agreement you entered into
 * with Alibaba.com.
 */
package com.alibaba.dubbo.rpc.protocol.thrift.io;

import com.alibaba.dubbo.common.io.Bytes;

import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;

/**
 * @author <a href="mailto:gang.lvg@alibaba-inc.com">kimi</a>
 */
public class RandomAccessByteArrayOutputStream extends OutputStream {

    protected byte buffer[];

    protected int count;

    public RandomAccessByteArrayOutputStream() {

        this( 32 );
    }

    public RandomAccessByteArrayOutputStream( int size ) {

        if ( size < 0 )
            throw new IllegalArgumentException( "Negative initial size: " + size );
        buffer = new byte[size];
    }

    public void write( int b ) {

        int newcount = count + 1;
        if ( newcount > buffer.length )
            buffer = Bytes.copyOf( buffer, Math.max( buffer.length << 1, newcount ) );
        buffer[count] = ( byte ) b;
        count = newcount;
    }

    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();
        if ( len == 0 )
            return;
        int newcount = count + len;
        if ( newcount > buffer.length )
            buffer = Bytes.copyOf( buffer, Math.max( buffer.length << 1, newcount ) );
        System.arraycopy( b, off, buffer, count, len );
        count = newcount;
    }

    public int size() {

        return count;
    }

    public void setWriteIndex( int index ) {
        count = index;
    }

    public void reset() {

        count = 0;
    }

    public byte[] toByteArray() {

        return Bytes.copyOf( buffer, count );
    }

    public ByteBuffer toByteBuffer() {

        return ByteBuffer.wrap( buffer, 0, count );
    }

    public void writeTo( OutputStream out ) throws IOException {

        out.write( buffer, 0, count );
    }

    public String toString() {

        return new String( buffer, 0, count );
    }

    public String toString( String charset ) throws UnsupportedEncodingException {

        return new String( buffer, 0, count, charset );
    }

    public void close() throws IOException {}

}