SharedObjectInputStream.java

/****************************************************************************
 * Copyright (c) 2004 Composent, Inc. and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Composent, Inc. - initial API and implementation
 *****************************************************************************/

package org.eclipse.ecf.example.collab.share.io;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.GZIPInputStream;

import org.eclipse.ecf.core.sharedobject.util.SimpleFIFOQueue;
import org.eclipse.ecf.internal.example.collab.Messages;

public class SharedObjectInputStream extends InputStream {
	protected SimpleFIFOQueue queue = new SimpleFIFOQueue();

	int currentLength;
	int currentRead;
	boolean useCompression;
	ByteArrayInputStream inputStream;
	GZIPInputStream compressor;

	public SharedObjectInputStream(boolean compression) {
		useCompression = compression;
	}

	public SharedObjectInputStream() {
		this(SharedObjectOutputStream.DEFAULT_COMPRESSION);
	}

	protected final void resetStreams(Data d) throws IOException {
		currentRead = 0;
		inputStream = new ByteArrayInputStream(d.getData());
		currentLength = d.getLength();
		if (useCompression) {
			compressor = new GZIPInputStream(inputStream);
		}
	}

	public final int read() throws IOException {
		if (currentRead >= currentLength) {
			Data d = (Data) queue.dequeue();
			if (d == null)
				throw new IOException(Messages.SharedObjectInputStream_EXCEPTION_NO_DATA);
			resetStreams(d);
		}
		currentRead++;
		return streamRead();
	}

	protected final int streamRead() throws IOException {
		if (useCompression) {
			return compressor.read();
		} else
			return inputStream.read();
	}

	// Method for replicated object to add data to stream
	public void add(int length, byte[] d) {
		queue.enqueue(new Data(length, d));
	}

	protected static class Data {
		int myLength;
		byte[] myData;

		protected Data(int length, byte[] d) {
			myLength = length;
			myData = d;
		}

		protected int getLength() {
			return myLength;
		}

		protected byte[] getData() {
			return myData;
		}
	}
}