view src/org/tmatesoft/hg/internal/ByteArrayChannel.java @ 709:497e697636fc

Report merged lines as changed block if possible, not as a sequence of added/deleted blocks. To facilitate access to merge parent lines AddBlock got mergeLineAt() method that reports index of the line in the second parent (if any), while insertedAt() has been changed to report index in the first parent always
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Wed, 21 Aug 2013 16:23:27 +0200
parents e1b29756f901
children
line wrap: on
line source
/*
 * Copyright (c) 2011-2013 TMate Software Ltd
 *  
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * For information on how to redistribute this software under
 * the terms of a license other than GNU General Public License
 * contact TMate Software at support@hg4j.com
 */
package org.tmatesoft.hg.internal;

import java.nio.ByteBuffer;
import java.util.LinkedList;
import java.util.List;

import org.tmatesoft.hg.util.ByteChannel;

/**
 * {@link ByteChannel} implementation that serializes data into a byte array
 * 
 * @author Artem Tikhomirov
 * @author TMate Software Ltd.
 */
public class ByteArrayChannel implements ByteChannel {
	private final List<ByteBuffer> buffers;
	private ByteBuffer target;
	private byte[] result;
	
	public ByteArrayChannel() {
		this(-1);
	}
	
	public ByteArrayChannel(int size) {
		if (size == -1) {
			buffers = new LinkedList<ByteBuffer>();
		} else {
			if (size < 0) {
				throw new IllegalArgumentException(String.valueOf(size));
			}
			buffers = null;
			target = ByteBuffer.allocate(size);
		}
	}

	/*
	 * {@link #toArray()} calls do not clear data collected so far, subsequent {@link #write(ByteBuffer)}  
	 * augment collected content.
	 */
	public int write(ByteBuffer buffer) {
		int rv = buffer.remaining();
		if (buffers == null) {
			target.put(buffer);
		} else {
			ByteBuffer copy = ByteBuffer.allocate(rv);
			copy.put(buffer);
			buffers.add(copy);
		}
		result = null;
		return rv;
	}

	/**
	 * @return content accumulated so far
	 */
	public byte[] toArray() {
		if (result != null) {
			return result;
		}
		if (buffers == null) {
			assert target.hasArray();
			// int total = target.position();
			// System.arraycopy(target.array(), new byte[total]);
			// I don't want to duplicate byte[] for now
			// although correct way of doing things is to make a copy and discard target
			return target.array();
		} else {
			int total = 0;
			for (ByteBuffer bb : buffers) {
				bb.flip();
				total += bb.limit();
			}
			result = new byte[total];
			int off = 0;
			for (ByteBuffer bb : buffers) {
				bb.get(result, off, bb.limit());
				off += bb.limit();
			}
			return result;
		}
	}
}