bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/util/RemoverUtil.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management
   3  * in Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.db.layer0.util;
  13
  14 import java.util.ArrayList;
  15 import java.util.Collection;
  16 import java.util.HashMap;
  17 import java.util.List;
  18 import java.util.Map;
  19
  20 import org.simantics.db.ReadGraph;
  21 import org.simantics.db.Resource;
  22 import org.simantics.db.WriteGraph;
  23 import org.simantics.db.common.CommentMetadata;
  24 import org.simantics.db.common.request.UniqueRead;
  25 import org.simantics.db.common.request.WriteRequest;
  26 import org.simantics.db.common.request.WriteResultRequest;
  27 import org.simantics.db.common.utils.NameUtils;
  28 import org.simantics.db.exception.DatabaseException;
  29 import org.simantics.db.layer0.adapter.Remover;
  30 import org.simantics.db.layer0.adapter.impl.AbstractRemover;
  31 import org.simantics.db.layer0.adapter.impl.EntityRemover;
  32 import org.simantics.db.layer0.exception.CannotRemoveException;
  33 import org.simantics.db.layer0.internal.SimanticsInternal;
  34 import org.simantics.utils.strings.EString;
  35
  36 /**
  37  * Utility for working with {@link Remover}s.
  38  *
  39  * @author Tuukka Lehtonen
  40  *
  41  * @see Remover
  42  * @see AbstractRemover
  43  */
  44 public final class RemoverUtil {
  45
  46         public static boolean canRemove(ReadGraph graph, Resource resource) throws DatabaseException {
  47         Remover remover = RemoverUtil.getPossibleRemover(graph, resource);
  48         if (remover != null) {
  49             String problem = remover.canRemove(graph, new HashMap<>(4));
  50             if (problem != null) return false;
  51         }
  52         return true;
  53         }
  54
  55     public static void remove(WriteGraph graph, Resource resource) throws DatabaseException {
  56         if (!tryRemover(graph, resource))
  57             EntityRemover.remove(graph, resource, true);
  58     }
  59
  60     public static boolean tryRemover(WriteGraph graph, Resource resource) throws DatabaseException {
  61         Remover remover = getPossibleRemover(graph, resource);
  62         if (remover != null) {
  63             remover.remove(graph);
  64             return true;
  65         }
  66         return false;
  67     }
  68
  69     /**
  70      * @param graph
  71      * @param resource
  72      * @return
  73      * @throws DatabaseException
  74      * @since 1.6
  75      */
  76     public static Remover getPossibleRemover(ReadGraph graph, Resource resource) throws DatabaseException {
  77         return graph.getPossibleAdapter(resource, Remover.class);
  78     }
  79
  80     public static String testRemoval(final Collection<Resource> rs) throws DatabaseException {
  81         return SimanticsInternal.getSession().syncRequest(new UniqueRead<String>() {
  82             @Override
  83             public String perform(ReadGraph graph) throws DatabaseException {
  84                 return testRemoval(graph, rs, null);
  85             }
  86         });
  87     }
  88
  89     public static String testRemoval(ReadGraph graph, final Collection<Resource> rs, List<Remover> removers) throws DatabaseException {
  90         if (removers == null)
  91             removers = new ArrayList<>(rs.size());
  92
  93         for (Resource r : rs) {
  94             Remover remover = graph.getPossibleAdapter(r, Remover.class);
  95             if (remover != null)
  96                 removers.add(remover);
  97         }
  98
  99         Map<Object, Object> aux = new HashMap<>();
 100         List<String> errors = new ArrayList<>(2);
 101         for (Remover remover : removers) {
 102             String error = remover.canRemove(graph, aux);
 103             if (error != null)
 104                 errors.add(error);
 105         }
 106         if (!errors.isEmpty()) {
 107             return EString.implode(errors);
 108         }
 109
 110         return null;
 111     }
 112
 113     public static String testRemoval(ReadGraph graph, final Collection<Resource> rs) throws DatabaseException {
 114         return testRemoval(graph, rs, null);
 115     }
 116
 117     public static String checkedRemoval(final Collection<Resource> rs) throws DatabaseException {
 118         String problems = testRemoval(rs);
 119         if (problems != null) return problems;
 120
 121         SimanticsInternal.getSession().syncRequest(new WriteRequest() {
 122
 123             @Override
 124             public void perform(WriteGraph graph) throws DatabaseException {
 125                 CommentMetadata cm = graph.getMetadata(CommentMetadata.class);
 126                 for (Resource r : rs) {
 127                     // Add comment to change set.
 128                     graph.addMetadata(cm.add("Removing " + r + "."));
 129                 }
 130
 131                 List<Remover> removers = new ArrayList<>(rs.size());
 132                 String error = testRemoval(graph, rs, removers);
 133                 if (error != null)
 134                     throw new CannotRemoveException(error);
 135
 136                 for (Remover remover : removers)
 137                     remover.remove(graph);
 138             }
 139
 140         });
 141
 142         return null;
 143     }
 144
 145     /**
 146      * Try to remove the provided collection of resources. Removal will commence
 147      * only if all resources in the provided collection have the exact same
 148      * principal types.
 149      *
 150      * @param rs
 151      *            collection of resources to remove in one go
 152      * @return <code>true</code> if removal was successful or <code>false</code>
 153      *         if the principal types of all resources in the provided
 154      *         collection did not match
 155      * @throws CannotRemoveException
 156      *             if removal cannot commence because at least one of the
 157      *             {@link Remover} instances adapted from the provided resource
 158      *             set succeeds.
 159      * @throws DatabaseException
 160      */
 161     public static boolean tryCollectionRemover(final Collection<Resource> rs) throws DatabaseException {
 162         return SimanticsInternal.getSession().syncRequest(new WriteResultRequest<Boolean>() {
 163             @Override
 164             public Boolean perform(WriteGraph graph) throws DatabaseException {
 165                 graph.markUndoPoint();
 166
 167                 List<Remover> removers = new ArrayList<>();
 168                 Map<Remover, String> removedResources = new HashMap<>();
 169                 for (Resource r : rs) {
 170                     Remover remover = graph.getPossibleAdapter(r, Remover.class);
 171                     if (remover != null) {
 172                         removers.add(remover);
 173                         removedResources.put(remover, NameUtils.getSafeName(graph, r, true));
 174                     }
 175                 }
 176
 177                 Map<Object, Object> aux = new HashMap<>();
 178                 List<String> errors = new ArrayList<>(removers.size());
 179                 for (Remover remover : removers) {
 180                     String error = remover.canRemove(graph, aux);
 181                     if (error != null)
 182                         errors.add(error);
 183                 }
 184                 if (!errors.isEmpty()) {
 185                     throw new CannotRemoveException(EString.implode(errors));
 186                 }
 187
 188                 CommentMetadata cm = graph.getMetadata(CommentMetadata.class);
 189                 for (Remover remover : removers) {
 190                     remover.remove(graph);
 191                     graph.addMetadata(cm.add("Removed " + removedResources.get(remover) + "."));
 192                 }
 193
 194                 return true;
 195             }
 196         });
 197     }
 198
 199 }