| /* |
| * Copyright (c) 2004-2014 Eike Stepper (Berlin, Germany) 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: |
| * Eike Stepper - initial API and implementation |
| */ |
| package org.eclipse.emf.internal.cdo.transaction; |
| |
| import org.eclipse.emf.cdo.transaction.CDOConflictResolver3; |
| import org.eclipse.emf.cdo.transaction.CDOMerger; |
| import org.eclipse.emf.cdo.transaction.CDOTransaction; |
| |
| import org.eclipse.emf.internal.cdo.bundle.OM; |
| |
| import org.eclipse.net4j.util.container.IManagedContainer; |
| import org.eclipse.net4j.util.container.IPluginContainer; |
| import org.eclipse.net4j.util.factory.ProductCreationException; |
| |
| import org.eclipse.emf.spi.cdo.CDOMergingConflictResolver; |
| import org.eclipse.emf.spi.cdo.DefaultCDOMerger.ResolutionPreference; |
| |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.Comparator; |
| import java.util.List; |
| |
| /** |
| * If the meaning of this type isn't clear, there really should be more of a description here... |
| * |
| * @author Eike Stepper |
| * @since 4.4 |
| */ |
| public class CDOHandlingConflictResolver extends CDOMergingConflictResolver implements CDOConflictResolver3 |
| { |
| private ConflictHandlerSelector conflictHandlerSelector; |
| |
| public CDOHandlingConflictResolver() |
| { |
| } |
| |
| public CDOHandlingConflictResolver(boolean ensureRemoteNotifications) |
| { |
| super(ensureRemoteNotifications); |
| } |
| |
| public CDOHandlingConflictResolver(CDOMerger merger, boolean ensureRemoteNotifications) |
| { |
| super(merger, ensureRemoteNotifications); |
| } |
| |
| public CDOHandlingConflictResolver(CDOMerger merger) |
| { |
| super(merger); |
| } |
| |
| public CDOHandlingConflictResolver(ResolutionPreference resolutionPreference, boolean ensureRemoteNotifications, |
| ConflictHandler conflictHandler) |
| { |
| super(resolutionPreference, ensureRemoteNotifications); |
| } |
| |
| public CDOHandlingConflictResolver(ResolutionPreference resolutionPreference) |
| { |
| super(resolutionPreference); |
| } |
| |
| public final ConflictHandlerSelector getConflictHandlerSelector() |
| { |
| return conflictHandlerSelector; |
| } |
| |
| public final void setConflictHandlerSelector(ConflictHandlerSelector conflictHandlerSelector) |
| { |
| this.conflictHandlerSelector = conflictHandlerSelector; |
| } |
| |
| public boolean preCommit() |
| { |
| if (isConflict()) |
| { |
| CDOTransaction transaction = getTransaction(); |
| ConflictHandler conflictHandler; |
| |
| try |
| { |
| conflictHandler = getConflictHandler(transaction); |
| } |
| catch (CancelException ex) |
| { |
| return false; |
| } |
| |
| if (conflictHandler != null) |
| { |
| long lastNonConflictTimeStamp = getLastNonConflictTimeStamp(); |
| return handleConflict(conflictHandler, lastNonConflictTimeStamp); |
| } |
| } |
| |
| return true; |
| } |
| |
| protected boolean handleConflict(ConflictHandler conflictHandler, long lastNonConflictTimeStamp) |
| { |
| return conflictHandler.handleConflict(this, lastNonConflictTimeStamp); |
| } |
| |
| protected IManagedContainer getContainer() |
| { |
| return IPluginContainer.INSTANCE; |
| } |
| |
| protected ConflictHandler getConflictHandler(CDOTransaction transaction) throws CancelException |
| { |
| if (conflictHandlerSelector == null) |
| { |
| return null; |
| } |
| |
| List<ConflictHandler> conflictHandlers = getConflictHandlers(transaction); |
| if (conflictHandlers.isEmpty()) |
| { |
| return null; |
| } |
| |
| ConflictHandler conflictHandler = conflictHandlerSelector.selectConflictHandler(transaction, conflictHandlers); |
| if (conflictHandler == null) |
| { |
| throw new CancelException(); |
| } |
| |
| return conflictHandler; |
| } |
| |
| protected List<ConflictHandler> getConflictHandlers(CDOTransaction transaction) |
| { |
| List<ConflictHandler> result = new ArrayList<ConflictHandler>(); |
| |
| IManagedContainer container = getContainer(); |
| String productGroup = ConflictHandler.Factory.PRODUCT_GROUP; |
| |
| for (String factoryType : container.getFactoryTypes(productGroup)) |
| { |
| try |
| { |
| ConflictHandler conflictHandler = (ConflictHandler)container.getElement(productGroup, factoryType, null); |
| result.add(conflictHandler); |
| } |
| catch (Exception ex) |
| { |
| OM.LOG.error(ex); |
| } |
| } |
| |
| Collections.sort(result, new Comparator<ConflictHandler>() |
| { |
| public int compare(ConflictHandler h1, ConflictHandler h2) |
| { |
| return h1.getPriority() - h2.getPriority(); |
| } |
| }); |
| |
| return result; |
| } |
| |
| /** |
| * @author Eike Stepper |
| */ |
| protected static final class CancelException extends Exception |
| { |
| private static final long serialVersionUID = 1L; |
| |
| public CancelException() |
| { |
| } |
| } |
| |
| /** |
| * @author Eike Stepper |
| */ |
| public interface ConflictHandler |
| { |
| public static final int DEFAULT_PRIORITY = 500; |
| |
| public String getLabel(); |
| |
| public int getPriority(); |
| |
| public boolean canHandleConflict(CDOMergingConflictResolver conflictResolver, long lastNonConflictTimeStamp); |
| |
| /** |
| * @return <code>false</code> to abort the commit operation, <code>true</code> otherwise. |
| */ |
| public boolean handleConflict(CDOMergingConflictResolver conflictResolver, long lastNonConflictTimeStamp); |
| |
| /** |
| * @author Eike Stepper |
| */ |
| public static abstract class Factory extends org.eclipse.net4j.util.factory.Factory |
| { |
| public static final String PRODUCT_GROUP = "org.eclipse.emf.cdo.conflictHandlers"; |
| |
| public Factory(String type) |
| { |
| super(PRODUCT_GROUP, type); |
| } |
| |
| public abstract ConflictHandler create(String description) throws ProductCreationException; |
| } |
| } |
| |
| /** |
| * @author Eike Stepper |
| */ |
| public interface ConflictHandlerSelector |
| { |
| public ConflictHandler selectConflictHandler(CDOTransaction transaction, List<ConflictHandler> choices); |
| } |
| } |