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

   1 /*******************************************************************************\r
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
   3  * in Industry THTH ry.\r
   4  * All rights reserved. This program and the accompanying materials\r
   5  * are made available under the terms of the Eclipse Public License v1.0\r
   6  * which accompanies this distribution, and is available at\r
   7  * http://www.eclipse.org/legal/epl-v10.html\r
   8  *\r
   9  * Contributors:\r
  10  *     VTT Technical Research Centre of Finland - initial API and implementation\r
  11  *******************************************************************************/\r
  12 package org.simantics.db.layer0.util;\r
  13 \r
  14 import java.util.Collection;\r
  15 \r
  16 import org.simantics.databoard.Accessors;\r
  17 import org.simantics.databoard.accessor.Accessor;\r
  18 import org.simantics.databoard.accessor.error.AccessorConstructionException;\r
  19 import org.simantics.databoard.accessor.error.AccessorException;\r
  20 import org.simantics.databoard.accessor.event.Event;\r
  21 import org.simantics.databoard.accessor.interestset.InterestSet;\r
  22 import org.simantics.databoard.binding.Binding;\r
  23 import org.simantics.db.ReadGraph;\r
  24 import org.simantics.db.RequestProcessor;\r
  25 import org.simantics.db.Resource;\r
  26 import org.simantics.db.WriteGraph;\r
  27 import org.simantics.db.common.request.WriteRequest;\r
  28 import org.simantics.db.exception.DatabaseException;\r
  29 import org.simantics.db.procedure.Listener;\r
  30 import org.simantics.db.request.Read;\r
  31 \r
  32 public class GraphAccessorUtils {\r
  33 \r
  34         static private class ValueReadRequest implements Read<Object> {\r
  35                 Resource resource;\r
  36                 Binding binding;\r
  37                 \r
  38                 public ValueReadRequest(Resource resource, Binding binding) {\r
  39                         this.resource = resource;\r
  40                         this.binding = binding;\r
  41                 }\r
  42 \r
  43                 @Override\r
  44                 public Object perform(ReadGraph graph) throws DatabaseException {\r
  45                         return graph.getValue(resource, binding);\r
  46                 }\r
  47         }\r
  48         \r
  49 \r
  50         static private class ValueReadRequest2 implements Read<Object> {\r
  51                 Resource resource;\r
  52                 Resource relation;\r
  53                 Object defaultValue;\r
  54                 Binding binding;\r
  55                 \r
  56                 public ValueReadRequest2(Resource resource, Resource relation, Object defaultValue, Binding binding) {\r
  57                         this.resource = resource;\r
  58                         this.relation = relation;\r
  59                         this.defaultValue = defaultValue;\r
  60                         this.binding = binding;\r
  61                 }\r
  62 \r
  63                 @Override\r
  64                 public Object perform(ReadGraph graph) throws DatabaseException {\r
  65                         Object value = graph.getPossibleRelatedValue(resource, relation, binding);\r
  66                         if(value != null)\r
  67                                 return value;\r
  68                         else\r
  69                                 return defaultValue;\r
  70                 }\r
  71         }\r
  72                 \r
  73         static private class ValueReadListener implements Listener<Object> {\r
  74 \r
  75                 Binding binding;\r
  76                 Accessor accessor;              \r
  77                 \r
  78                 public ValueReadListener(Binding binding) {\r
  79                         this.binding = binding;\r
  80                 }\r
  81 \r
  82                 @Override\r
  83                 public void exception(Throwable t) {\r
  84                 }\r
  85 \r
  86                 @Override\r
  87                 public void execute(Object result) {\r
  88                         if(accessor == null)\r
  89                                 try {\r
  90                                         accessor = Accessors.getAccessor(binding, result);                                      \r
  91                                 } catch (AccessorConstructionException e) {\r
  92                                         e.printStackTrace();\r
  93                                 }\r
  94                         else\r
  95                                 try {\r
  96                                         if(!binding.equals(accessor.getValue(binding), result))\r
  97                                                 accessor.setValue(binding, result);\r
  98                                 } catch (AccessorException e) {\r
  99                                         e.printStackTrace();\r
 100                                 }                       \r
 101                 }\r
 102 \r
 103                 @Override\r
 104                 public boolean isDisposed() {\r
 105                         // TODO Auto-generated method stub\r
 106                         return false;\r
 107                 }\r
 108                 \r
 109         }\r
 110         \r
 111         static private class AccessorListener implements Accessor.Listener {\r
 112 \r
 113                 Accessor accessor;\r
 114                 RequestProcessor rp;\r
 115                 Resource resource;\r
 116                 Binding binding;\r
 117                 \r
 118                 public AccessorListener(Accessor accessor, RequestProcessor rp,\r
 119                                 Resource resource, Binding binding) {\r
 120                         this.accessor = accessor;\r
 121                         this.rp = rp;\r
 122                         this.resource = resource;\r
 123                         this.binding = binding;\r
 124                 }\r
 125 \r
 126                 @Override\r
 127                 public void onEvents(Collection<Event> event) {\r
 128                         rp.asyncRequest(new WriteRequest() {                            \r
 129                                 @Override\r
 130                                 public void perform(WriteGraph graph) throws DatabaseException {\r
 131                                         try {\r
 132                                                 Object a = accessor.getValue(binding);\r
 133                                                 Object b = graph.getValue(resource, binding);\r
 134                                                 if(!binding.equals(a, b))\r
 135                                                         graph.claimValue(resource, a, binding);\r
 136                                         } catch (AccessorException e) {\r
 137                                                 throw new DatabaseException(e);\r
 138                                         }\r
 139                                 }\r
 140                         });\r
 141                 }\r
 142                 \r
 143         }\r
 144         \r
 145         static private class AccessorListener2 implements Accessor.Listener {\r
 146 \r
 147                 Accessor accessor;\r
 148                 RequestProcessor rp;\r
 149                 Resource resource;\r
 150                 Resource relation;\r
 151                 Binding binding;\r
 152                 \r
 153                 public AccessorListener2(Accessor accessor, RequestProcessor rp,\r
 154                                 Resource resource, Resource relation, Binding binding) {\r
 155                         this.accessor = accessor;\r
 156                         this.rp = rp;\r
 157                         this.resource = resource;\r
 158                         this.relation = relation;\r
 159                         this.binding = binding;\r
 160                 }\r
 161 \r
 162                 @Override\r
 163                 public void onEvents(Collection<Event> event) {\r
 164                         rp.asyncRequest(new WriteRequest() {                            \r
 165                                 @Override\r
 166                                 public void perform(WriteGraph graph) throws DatabaseException {\r
 167                                         try {\r
 168                                                 Object a = accessor.getValue(binding);\r
 169                                                 \r
 170                                                 Resource valueResource = graph.getPossibleObject(resource, relation);\r
 171                                                 if(valueResource == null) {\r
 172                                                         valueResource = graph.newResource(); \r
 173                                                         graph.claim(resource, relation, valueResource);\r
 174                                                         graph.claimValue(valueResource, a, binding);\r
 175                                                 }\r
 176                                                 else {\r
 177                                                         Object b = graph.getValue(valueResource, binding);\r
 178                                                         if(!binding.equals(a, b))\r
 179                                                                 graph.claimLiteral(resource, relation, a, binding);\r
 180                                                 }\r
 181                                         } catch (AccessorException e) {\r
 182                                                 throw new DatabaseException(e);\r
 183                                         }\r
 184                                 }\r
 185                         });\r
 186                 }\r
 187                 \r
 188         }\r
 189         \r
 190         public static Accessor create(RequestProcessor rp, Resource resource, Binding binding) throws DatabaseException {\r
 191                 ValueReadRequest request = new ValueReadRequest(resource, binding);\r
 192                 ValueReadListener listener = new ValueReadListener(binding);\r
 193                 rp.syncRequest(request, listener);\r
 194                 try {\r
 195                         listener.accessor.addListener(\r
 196                                 new AccessorListener(listener.accessor, rp, resource, binding), \r
 197                                 InterestSet.newInterestSet(listener.accessor.type(), true, false, true),\r
 198                                 null, null);\r
 199                 } catch (AccessorException e) {\r
 200                         e.printStackTrace();\r
 201                 }\r
 202                 return listener.accessor;               \r
 203         }\r
 204         \r
 205         public static Accessor create(RequestProcessor rp, Resource resource, Resource relation, Object defaultValue, Binding binding) throws DatabaseException {\r
 206                 ValueReadRequest2 request = new ValueReadRequest2(resource, relation, defaultValue, binding);\r
 207                 ValueReadListener listener = new ValueReadListener(binding);\r
 208                 rp.syncRequest(request, listener);\r
 209                 try {\r
 210                         listener.accessor.addListener(\r
 211                                 new AccessorListener2(listener.accessor, rp, resource, relation, binding), \r
 212                                 InterestSet.newInterestSet(listener.accessor.type(), true, false, true),\r
 213                                 null, null);\r
 214                 } catch (AccessorException e) {\r
 215                         e.printStackTrace();\r
 216                 }\r
 217                 return listener.accessor;               \r
 218         }\r
 219         \r
 220 }\r