bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/ReadEntry.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.impl.query;\r
  13 \r
  14 import org.simantics.db.AsyncReadGraph;\r
  15 import org.simantics.db.exception.DatabaseException;\r
  16 import org.simantics.db.impl.graph.ReadGraphImpl;\r
  17 import org.simantics.db.impl.graph.WriteGraphImpl;\r
  18 import org.simantics.db.procedure.AsyncProcedure;\r
  19 import org.simantics.db.request.Read;\r
  20 import org.simantics.db.request.ReadExt;\r
  21 import org.simantics.db.request.RequestFlags;\r
  22 \r
  23 final public class ReadEntry<T> extends CacheEntryBase {\r
  24 \r
  25         protected Read<T> request;\r
  26 \r
  27         public ReadEntry(Read<T> request) {\r
  28         this.request = request;\r
  29     }\r
  30     \r
  31     @Override\r
  32     int makeHash() {\r
  33         return request.hashCode();\r
  34     }\r
  35         \r
  36     @Override\r
  37     public Object getOriginalRequest() {\r
  38         return request;\r
  39     }\r
  40     \r
  41     @Override\r
  42     public void discard() {\r
  43         super.discard();\r
  44         setResult(null);\r
  45     }\r
  46         \r
  47     final public void addOrSet(AsyncReadGraph graph, Object item) {\r
  48 \r
  49         assert(assertPending());\r
  50         \r
  51 //        ArrayList<Pair<AsyncProcedure<T>, AsyncBarrier>> p = null;\r
  52 \r
  53         synchronized(this) {\r
  54             \r
  55             setResult(item);\r
  56                 setReady();\r
  57 //              p = procs;\r
  58 //              procs = null;\r
  59                 \r
  60         }\r
  61 \r
  62 //        if(p != null)\r
  63 //              for(Pair<AsyncProcedure<T>, AsyncBarrier> proc : p) {\r
  64 //                      proc.first.execute(graph, (T)item);\r
  65 //                      proc.second.dec();\r
  66 //              }\r
  67         \r
  68     }\r
  69 \r
  70     @Override\r
  71     final public Query getQuery() {\r
  72         \r
  73         return new Query() {\r
  74 \r
  75                         @Override\r
  76                         public void recompute(ReadGraphImpl graph_, Object provider, CacheEntry entry) {\r
  77                                 \r
  78                                 QueryProcessor qp = (QueryProcessor)provider;\r
  79                                 \r
  80                         WriteGraphImpl write = qp.getCore().getSession().getService(WriteGraphImpl.class);\r
  81                                 \r
  82                         ReadGraphImpl graph = write.newSync(entry);\r
  83 \r
  84                                 try {\r
  85 \r
  86                                         entry.setPending();\r
  87                                     T result = request.perform(graph);\r
  88                                     addOrSet(graph, result);\r
  89 \r
  90                                 } catch (Throwable t) {\r
  91 \r
  92                                         except(t);\r
  93                     \r
  94                 }\r
  95                                 \r
  96                         }\r
  97 \r
  98                         @Override\r
  99                         public void removeEntry(QueryProcessor processor) {\r
 100                                 processor.readMap.remove(request);\r
 101                         }\r
 102 \r
 103                         @Override\r
 104                         public int type() {\r
 105                                 if(request instanceof ReadExt) {\r
 106                                         return ((ReadExt)request).getType();\r
 107                                 } else {\r
 108                                         return RequestFlags.INVALIDATE;\r
 109                                 }\r
 110                         }\r
 111                         \r
 112                         @Override\r
 113                         public String toString() {\r
 114                                 if(request == null) return "DISCARDED";\r
 115                                 else return request.toString() + statusOrException;\r
 116                         }\r
 117                 \r
 118         };\r
 119         \r
 120     }\r
 121     \r
 122         public void performFromCache(ReadGraphImpl graph, Object provider,      Object procedure) {\r
 123             \r
 124         AsyncProcedure<T> proc = (AsyncProcedure<T>)procedure;\r
 125 \r
 126             if(isExcepted()) {\r
 127 \r
 128             try {\r
 129                 proc.exception(graph, (Throwable)getResult());\r
 130             } catch (Throwable t) {\r
 131                 t.printStackTrace();\r
 132             }\r
 133                 \r
 134             } else {\r
 135                 \r
 136             try {\r
 137                 proc.execute(graph, (T)getResult());\r
 138             } catch (Throwable t) {\r
 139                 t.printStackTrace();\r
 140             }\r
 141 \r
 142             }\r
 143                 \r
 144         }\r
 145         \r
 146         @Override\r
 147         public String toString() {\r
 148                 if(request == null) return "DISCARDED";\r
 149                 else return request.toString() + " - " + statusOrException;\r
 150         }\r
 151         \r
 152         public Object get(ReadGraphImpl graph, QueryProcessor processor, Object procedure) throws DatabaseException {\r
 153                 if(procedure != null) performFromCache(graph, processor, procedure);\r
 154                 checkAndThrow();\r
 155                 return getResult();\r
 156         }\r
 157         \r
 158         @Override\r
 159         boolean isImmutable(ReadGraphImpl graph) throws DatabaseException {\r
 160                 if(request instanceof ReadExt) {\r
 161                         return ((ReadExt)request).isImmutable(graph);\r
 162                 }\r
 163                 return false;\r
 164         }\r
 165 \r
 166 }\r