jgit/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/InMemoryOutputStream.java

/*
 * Copyright (C) 2013, Google Inc.
 * and other copyright owners as documented in the project's IP log.
 *
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Distribution License v1.0 which
 * accompanies this distribution, is reproduced below, and is
 * available at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * 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 Eclipse Foundation, Inc. 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 OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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package org.eclipse.jgit.internal.storage.dfs;

import java.io.ByteArrayOutputStream;
import java.nio.ByteBuffer;

class InMemoryOutputStream extends DfsOutputStream {
	private final ByteArrayOutputStream dst = new ByteArrayOutputStream();

	private byte[] data;

	@Override
	public void write(byte[] buf, int off, int len) {
		data = null;
		dst.write(buf, off, len);
	}

	@Override
	public int read(long position, ByteBuffer buf) {
		byte[] d = getData();
		int n = Math.min(buf.remaining(), d.length - (int) position);
		if (n <= 0)
			return -1;
		buf.put(d, (int) position, n);
		return n;
	}

	byte[] getData() {
		if (data == null)
			data = dst.toByteArray();
		return data;
	}

	@Override
	public void flush() {
		// Default implementation does nothing;
	}

	@Override
	public void close() {
		flush();
	}
}