Mercurial > hg4j
view src/org/tmatesoft/hg/internal/FilterByteChannel.java @ 705:b4242b7e7dfe
Merge command: implement conflict resolution alternatives
author | Artem Tikhomirov <tikhomirov.artem@gmail.com> |
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date | Thu, 15 Aug 2013 18:43:50 +0200 |
parents | 91d75e1bac9f |
children |
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/* * 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@hg4j.com */ package org.tmatesoft.hg.internal; import java.io.IOException; import java.nio.ByteBuffer; import java.util.ArrayList; import java.util.Collection; import java.util.List; import org.tmatesoft.hg.util.Adaptable; import org.tmatesoft.hg.util.ByteChannel; import org.tmatesoft.hg.util.CancelledException; /** * * @author Artem Tikhomirov * @author TMate Software Ltd. */ public class FilterByteChannel implements ByteChannel, Adaptable { 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 IOException, CancelledException { 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 } // adapters or implemented interfaces of the original class shall not be obfuscated by filter public <T> T getAdapter(Class<T> adapterClass) { if (adapterClass == Preview.class) { ArrayList<Preview> previewers = new ArrayList<Preview>(filters.length); Adaptable.Factory<Preview> factory = new Adaptable.Factory<Preview>(Preview.class); for (Filter f : filters) { Preview p = factory.get(f); if (p != null) { previewers.add(p); } } if (!previewers.isEmpty()) { @SuppressWarnings("unchecked") T rv = (T) new PreviewSupport(previewers); return rv; } // fall through to let delegate answer } return Adaptable.Factory.getAdapter(delegate, adapterClass, null); } private static class PreviewSupport implements Preview { private final Preview[] participants; public PreviewSupport(List<Preview> previewers) { participants = new Preview[previewers.size()]; previewers.toArray(participants); } public void preview(ByteBuffer src) { final int originalPos = src.position(); for (Preview p : participants) { p.preview(src); // reset to initial state src.position(originalPos); } } } }