Mercurial > jhg
view src/org/tmatesoft/hg/util/CancelSupport.java @ 659:a5cf64f2e7e4 smartgit-4.6
Poor performance when reading/collecting branch information. Respect new cache location for recent mercurial revisions. Use different algorithm to build branch cache
author | Artem Tikhomirov <tikhomirov.artem@gmail.com> |
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date | Fri, 05 Jul 2013 20:42:45 +0200 (2013-07-05) |
parents | 9c9c442b5f2e |
children |
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/* * Copyright (c) 2011-2012 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.util; /** * Mix-in for objects that support cancellation. * * @author Artem Tikhomirov * @author TMate Software Ltd. */ public interface CancelSupport { /** * This method is invoked to check if target had been brought to canceled state. Shall silently return if target is * in regular state. * @throws CancelledException when target internal state has been changed to canceled. */ void checkCancelled() throws CancelledException; // Yeah, this factory class looks silly now, but perhaps in the future I'll need wrappers for other cancellation sources? // just don't want to have general Utils class with methods like get() below static class Factory { /** * Obtain non-null cancel support object. * * @param target any object (or <code>null</code>) that might have cancel support. For <code>null</code>, returns an instance than never cancels. * @return target if it's capable checking cancellation status or no-op implementation that never cancels. */ public static CancelSupport get(Object target) { CancelSupport cs = get(target, null); if (cs != null) { return cs; } class NoCancel implements CancelSupport { public void checkCancelled() { } }; return new NoCancel(); } public static CancelSupport get(Object target, CancelSupport defaultValue) { return Adaptable.Factory.getAdapter(target, CancelSupport.class, defaultValue); } } interface Target<T> { T set(CancelSupport cs); } }