bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/AsyncReadEntry.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 org.simantics.db.AsyncReadGraph;
  15 import org.simantics.db.exception.DatabaseException;
  16 import org.simantics.db.impl.DebugPolicy;
  17 import org.simantics.db.impl.graph.ReadGraphImpl;
  18 import org.simantics.db.procedure.AsyncProcedure;
  19 import org.simantics.db.request.AsyncRead;
  20
  21 final public class AsyncReadEntry<T> extends CacheEntryBase<AsyncProcedure<T>> {
  22
  23     protected AsyncRead<T> request;
  24
  25     AsyncReadEntry(AsyncRead<T> request) {
  26         this.request = request;
  27         if(DebugPolicy.QUERY_STATE) System.out.println("[QUERY STATE]: created " + this);
  28     }
  29
  30     @Override
  31     int makeHash() {
  32         return request.hashCode();
  33     }
  34
  35     @Override
  36     public Object getOriginalRequest() {
  37         return request;
  38     }
  39
  40     @Override
  41     public void discard() {
  42         super.discard();
  43         setResult(null);
  44     }
  45
  46     final public void addOrSet(AsyncReadGraph graph, Object item) {
  47
  48 //      System.err.println("addOrSet " + request + " " + Thread.currentThread() + " " + item);
  49
  50         assert(isPending());
  51
  52         synchronized(this) {
  53             setResult(item);
  54                 setReady();
  55         }
  56
  57     }
  58
  59
  60     public void except(AsyncReadGraph graph, Throwable t) {
  61
  62         assert(isPending());
  63
  64         synchronized(this) {
  65             except(t);
  66         }
  67
  68     }
  69
  70
  71     @Override
  72     final public Query getQuery() {
  73
  74         return new Query() {
  75
  76                         @Override
  77                         public void recompute(ReadGraphImpl graph) {
  78
  79                                 try {
  80
  81                                     request.perform(graph , new AsyncProcedure<T>() {
  82
  83                         @Override
  84                         public void execute(AsyncReadGraph graph, T result) {
  85                             addOrSet(graph, result);
  86                         }
  87
  88                                 @Override
  89                                 public void exception(AsyncReadGraph graph, Throwable t) {
  90                                     except(t);
  91                         }
  92
  93                     });
  94
  95                                 } catch (Throwable t) {
  96                                     except(t);
  97                 }
  98
  99                         }
 100
 101                         @Override
 102                         public void removeEntry(QueryProcessor qp) {
 103                         qp.cache.remove(AsyncReadEntry.this);
 104                         }
 105
 106                         @Override
 107                         public int type() {
 108                                 return request.getFlags();
 109                         }
 110
 111                         @Override
 112                         public String toString() {
 113                                 if(request == null) return "DISCARDED";
 114                                 else if(isExcepted()) return request.toString() + " " + getResult();
 115                                 else return request.toString() + " " + statusOrException;
 116                         }
 117
 118         };
 119
 120     }
 121
 122     @Override
 123         public Object performFromCache(ReadGraphImpl graph, AsyncProcedure<T> proc) {
 124
 125             if(isExcepted()) {
 126
 127             try {
 128                 proc.exception(graph, (Throwable)getResult());
 129             } catch (Throwable t) {
 130                 t.printStackTrace();
 131             }
 132
 133         } else {
 134
 135             try {
 136                 proc.execute(graph, (T)getResult());
 137             } catch (Throwable t) {
 138                 t.printStackTrace();
 139             }
 140
 141         }
 142
 143             return getResult();
 144
 145         }
 146
 147     //@Override
 148     public Object compute(ReadGraphImpl graph, AsyncProcedure<T> procedure) throws DatabaseException {
 149
 150         ReadGraphImpl queryGraph = graph.withParent(this);
 151
 152         request.perform(queryGraph, new AsyncProcedure<T>() {
 153
 154                 @Override
 155                 public void execute(AsyncReadGraph returnGraph, T result) {
 156                         ReadGraphImpl impl = (ReadGraphImpl)returnGraph;
 157                         AsyncReadEntry.this.addOrSet(graph, result);
 158                         try {
 159                                 procedure.execute(graph, result);
 160                         } catch (Throwable t) {
 161                                 t.printStackTrace();
 162                         }
 163                         //                                      parentBarrier.dec(query);
 164                 }
 165
 166                 @Override
 167                 public void exception(AsyncReadGraph returnGraph, Throwable t) {
 168                         ReadGraphImpl impl = (ReadGraphImpl)returnGraph;
 169                         //                                      AsyncReadGraph resumeGraph = finalParentGraph.newAsync();
 170                         AsyncReadEntry.this.except(graph, t);
 171                         try {
 172                                 procedure.exception(graph, t);
 173                         } catch (Throwable t2) {
 174                                 t2.printStackTrace();
 175                         }
 176                         //                                      parentBarrier.dec(query);
 177                 }
 178
 179                 @Override
 180                 public String toString() {
 181                         return procedure.toString();
 182                 }
 183
 184         });
 185
 186                 return getResult();
 187
 188     }
 189
 190     public static <T> void computeForEach(ReadGraphImpl parentGraph, AsyncRead<T> request, AsyncReadEntry<T> entry, AsyncProcedure<T> procedure) throws DatabaseException {
 191
 192                 ReadGraphImpl queryGraph = parentGraph.withParent(entry);
 193
 194                 request.perform(queryGraph, new AsyncProcedure<T>() {
 195
 196                         @Override
 197                         public void execute(AsyncReadGraph returnGraph, T result) {
 198                                 ReadGraphImpl impl = (ReadGraphImpl)returnGraph;
 199                                 if(entry != null) entry.addOrSet(parentGraph, result);
 200                                 try {
 201                                         procedure.execute(parentGraph, result);
 202                                 } catch (Throwable t) {
 203                                         t.printStackTrace();
 204                                 }
 205                         }
 206
 207                         @Override
 208                         public void exception(AsyncReadGraph returnGraph, Throwable t) {
 209                                 ReadGraphImpl impl = (ReadGraphImpl)returnGraph;
 210                                 if(entry != null) entry.except(parentGraph, t);
 211                                 try {
 212                                         procedure.exception(parentGraph, t);
 213                                 } catch (Throwable t2) {
 214                                         t2.printStackTrace();
 215                                 }
 216                         }
 217
 218                         @Override
 219                         public String toString() {
 220                                 return procedure.toString();
 221                         }
 222
 223                 });
 224
 225     }
 226
 227
 228         @Override
 229         public String toString() {
 230                 if(isDiscarded()) return "DISCARDED " + request.toString();
 231                 else if(isExcepted()) return request.toString() + " " + getResult();
 232                 else return request.toString() + " " + statusOrException;
 233         }
 234
 235 }