Mercurial > hg4j
diff src/org/tmatesoft/hg/internal/FilterByteChannel.java @ 115:c0cc2535462c
Introduced channels to pipeline (and easily filter) data streams
author | Artem Tikhomirov <tikhomirov.artem@gmail.com> |
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date | Thu, 03 Feb 2011 23:32:08 +0100 |
parents | |
children | 7567f4a42fe5 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/org/tmatesoft/hg/internal/FilterByteChannel.java Thu Feb 03 23:32:08 2011 +0100 @@ -0,0 +1,53 @@ +/* + * Copyright (c) 2011 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@svnkit.com + */ +package org.tmatesoft.hg.internal; + +import java.nio.ByteBuffer; +import java.util.Collection; + +import org.tmatesoft.hg.util.ByteChannel; + +/** + * + * @author Artem Tikhomirov + * @author TMate Software Ltd. + */ +public class FilterByteChannel implements ByteChannel { + private final Filter[] filters; + private final ByteChannel delegate; + + public FilterByteChannel(ByteChannel delegateChannel, Collection<Filter> filtersToApply) { + if (delegateChannel == null || filtersToApply == null) { + throw new IllegalArgumentException(); + } + delegate = delegateChannel; + filters = filtersToApply.toArray(new Filter[filtersToApply.size()]); + } + + public int write(ByteBuffer buffer) throws Exception { + final int srcPos = buffer.position(); + ByteBuffer processed = buffer; + for (Filter f : filters) { + // each next filter consumes not more than previous + // hence total consumed equals position shift in the original buffer + processed = f.filter(processed); + } + delegate.write(processed); + return buffer.position() - srcPos; // consumed as much from original buffer + } + +}