tikhomirov@115: /*
tikhomirov@115:  * Copyright (c) 2011 TMate Software Ltd
tikhomirov@115:  *  
tikhomirov@115:  * This program is free software; you can redistribute it and/or modify
tikhomirov@115:  * it under the terms of the GNU General Public License as published by
tikhomirov@115:  * the Free Software Foundation; version 2 of the License.
tikhomirov@115:  *
tikhomirov@115:  * This program is distributed in the hope that it will be useful,
tikhomirov@115:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
tikhomirov@115:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
tikhomirov@115:  * GNU General Public License for more details.
tikhomirov@115:  *
tikhomirov@115:  * For information on how to redistribute this software under
tikhomirov@115:  * the terms of a license other than GNU General Public License
tikhomirov@130:  * contact TMate Software at support@hg4j.com
tikhomirov@115:  */
tikhomirov@115: package org.tmatesoft.hg.internal;
tikhomirov@115: 
tikhomirov@148: import java.io.IOException;
tikhomirov@115: import java.nio.ByteBuffer;
tikhomirov@115: import java.util.Collection;
tikhomirov@115: 
tikhomirov@115: import org.tmatesoft.hg.util.ByteChannel;
tikhomirov@148: import org.tmatesoft.hg.util.CancelledException;
tikhomirov@115: 
tikhomirov@115: /**
tikhomirov@115:  *
tikhomirov@115:  * @author Artem Tikhomirov
tikhomirov@115:  * @author TMate Software Ltd.
tikhomirov@115:  */
tikhomirov@115: public class FilterByteChannel implements ByteChannel {
tikhomirov@115: 	private final Filter[] filters;
tikhomirov@115: 	private final ByteChannel delegate;
tikhomirov@115: 	
tikhomirov@115: 	public FilterByteChannel(ByteChannel delegateChannel, Collection<Filter> filtersToApply) {
tikhomirov@115: 		if (delegateChannel == null || filtersToApply == null) {
tikhomirov@115: 			throw new IllegalArgumentException();
tikhomirov@115: 		}
tikhomirov@115: 		delegate = delegateChannel;
tikhomirov@115: 		filters = filtersToApply.toArray(new Filter[filtersToApply.size()]);
tikhomirov@115: 	}
tikhomirov@115: 
tikhomirov@148: 	public int write(ByteBuffer buffer) throws IOException, CancelledException {
tikhomirov@115: 		final int srcPos = buffer.position();
tikhomirov@115: 		ByteBuffer processed = buffer;
tikhomirov@115: 		for (Filter f : filters) {
tikhomirov@115: 			// each next filter consumes not more than previous
tikhomirov@115: 			// hence total consumed equals position shift in the original buffer
tikhomirov@115: 			processed = f.filter(processed);
tikhomirov@115: 		}
tikhomirov@115: 		delegate.write(processed);
tikhomirov@115: 		return buffer.position() - srcPos; // consumed as much from original buffer
tikhomirov@115: 	}
tikhomirov@115: 
tikhomirov@115: }