bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/MultiReadEntry.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.impl.query;
  13
  14 import java.util.ArrayList;
  15
  16 import org.simantics.db.AsyncReadGraph;
  17 import org.simantics.db.common.exception.DebugException;
  18 import org.simantics.db.exception.DatabaseException;
  19 import org.simantics.db.impl.graph.ReadGraphImpl;
  20 import org.simantics.db.impl.query.QueryProcessor.AsyncBarrier;
  21 import org.simantics.db.procedure.AsyncMultiProcedure;
  22 import org.simantics.db.request.MultiRead;
  23 import org.simantics.db.request.RequestFlags;
  24 import org.simantics.utils.datastructures.Pair;
  25
  26 final public class MultiReadEntry<T> extends CacheEntryBase<AsyncMultiProcedure<T>> {
  27
  28     protected MultiRead<T> request;
  29
  30     MultiReadEntry(MultiRead<T> request) {
  31         this.request = request;
  32     }
  33
  34     @Override
  35     int makeHash() {
  36         return request.hashCode();
  37     }
  38
  39     @Override
  40     public Object getOriginalRequest() {
  41         return request;
  42     }
  43
  44     @Override
  45     public void discard() {
  46         super.discard();
  47         request = null;
  48         setResult(null);
  49     }
  50
  51     synchronized public void finish(AsyncReadGraph graph) {
  52
  53         assert(isPending());
  54
  55         ArrayList<Pair<AsyncMultiProcedure<T>, AsyncBarrier>> p = null;
  56
  57         synchronized(this) {
  58                 setReady();
  59         }
  60
  61     }
  62
  63     @Override
  64     final public void clearResult(QuerySupport support) {
  65         setResult(new ArrayList<T>());
  66     }
  67
  68     final synchronized public void addOrSet(Object item) {
  69
  70         assert(isPending());
  71
  72         ArrayList<T> value = (ArrayList<T>)getResult();
  73         value.add((T)item);
  74
  75     }
  76
  77     @Override
  78     final public Query getQuery() {
  79
  80         return new Query() {
  81
  82                         @Override
  83                         public void recompute(ReadGraphImpl graph) {
  84
  85                                 try {
  86
  87                                     request.perform(graph , new AsyncMultiProcedure<T>() {
  88
  89                         @Override
  90                         public void execute(AsyncReadGraph graph, T result) {
  91                             addOrSet(result);
  92                         }
  93
  94                         public void finished(AsyncReadGraph graph) {
  95                                 finish(graph);
  96                         };
  97
  98                                         @Override
  99                                         public void exception(AsyncReadGraph graph, Throwable t) {
 100                             except(t);
 101                             }
 102
 103                     });
 104
 105                                 } catch (Throwable t) {
 106                     except(t);
 107                     if(DebugException.DEBUG) new DebugException(t).printStackTrace();
 108                 }
 109
 110                         }
 111
 112                         @Override
 113                         public void removeEntry(QueryProcessor processor) {
 114                         processor.cache.remove(MultiReadEntry.this);
 115                         }
 116
 117                         @Override
 118                         public int type() {
 119                                 return RequestFlags.INVALIDATE;
 120                         }
 121
 122                         @Override
 123                         public String toString() {
 124                                 if(request == null) return "DISCARDED";
 125                                 else return request.toString() + statusOrException;
 126                         }
 127
 128         };
 129
 130     }
 131
 132     public void performFromCache(AsyncReadGraph graph, Object provider, Object procedure) {
 133
 134         AsyncMultiProcedure<T> proc = (AsyncMultiProcedure<T>)procedure;
 135
 136         if(isExcepted()) {
 137
 138             try {
 139                 proc.exception(graph, (Throwable)getResult());
 140             } catch (Throwable t) {
 141                 t.printStackTrace();
 142             }
 143 //            parentBarrier.dec();
 144
 145         } else {
 146
 147             final ArrayList<T> values = (ArrayList<T>)getResult();
 148             for(T value : values) {
 149                 try {
 150                     proc.execute(graph, value);
 151                 } catch (Throwable t) {
 152                     t.printStackTrace();
 153                 }
 154             }
 155
 156             try {
 157                 proc.finished(graph);
 158             } catch (Throwable t) {
 159                 t.printStackTrace();
 160             }
 161 //            parentBarrier.dec();
 162
 163         }
 164
 165     }
 166
 167         @Override
 168         public Object performFromCache(ReadGraphImpl graph, AsyncMultiProcedure<T> proc) {
 169
 170         if(isExcepted()) {
 171
 172             try {
 173                 proc.exception(graph, (Throwable)getResult());
 174             } catch (Throwable t) {
 175                 t.printStackTrace();
 176             }
 177
 178         } else {
 179
 180             final ArrayList<T> values = (ArrayList<T>)getResult();
 181             for(T value : values) {
 182                 try {
 183                     proc.execute(graph, value);
 184                 } catch (Throwable t) {
 185                     t.printStackTrace();
 186                 }
 187             }
 188
 189             try {
 190                 proc.finished(graph);
 191             } catch (Throwable t) {
 192                 t.printStackTrace();
 193             }
 194
 195         }
 196
 197                 return null;
 198
 199         }
 200
 201         @Override
 202         public String toString() {
 203                 if(request == null) return "DISCARDED";
 204                 else return request.toString() + statusOrException;
 205         }
 206
 207         @Override
 208         public Object compute(ReadGraphImpl graph, AsyncMultiProcedure<T> procedure) throws DatabaseException {
 209         return graph.processor.cache.performQuery(graph, request, this, procedure);
 210         }
 211
 212 }