bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/ValueQuery.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 java.util.concurrent.Semaphore;\r
  15 \r
  16 import org.simantics.db.impl.graph.ReadGraphImpl;\r
  17 import org.simantics.db.impl.procedure.InternalProcedure;\r
  18 import org.simantics.db.procedure.ListenerBase;\r
  19 \r
  20 final public class ValueQuery extends UnaryQuery<InternalProcedure<byte[]>> {\r
  21     \r
  22     private ValueQuery(final int resource) {\r
  23         super(resource);\r
  24     }\r
  25     \r
  26     final static ValueQuery entry(final QueryProcessor provider, final int r) {\r
  27         return (ValueQuery)provider.valueMap.get(r);\r
  28     }\r
  29 \r
  30     final static byte[] runner(final ReadGraphImpl graph, final int r, CacheEntry parent, final ListenerBase listener, final InternalProcedure<byte[]> procedure) {\r
  31 \r
  32         QueryProcessor processor = graph.processor;\r
  33         \r
  34         ValueQuery entry = (ValueQuery)processor.valueMap.get(r); \r
  35         if(entry == null) {\r
  36                 \r
  37                 entry = new ValueQuery(r);\r
  38                 entry.setPending();\r
  39                 entry.clearResult(processor.querySupport);\r
  40                 entry.putEntry(processor);\r
  41                 \r
  42                 return (byte[])processor.performForEach(graph, entry, parent, listener, procedure);\r
  43             \r
  44         } else {\r
  45                 \r
  46                 return (byte[])processor.performForEach(graph, entry, parent, listener, procedure);\r
  47             \r
  48         }\r
  49 \r
  50     }\r
  51     \r
  52     final public static byte[] queryEach(ReadGraphImpl graph, final int r, final CacheEntry parent, final ListenerBase listener, final InternalProcedure<byte[]> procedure) {\r
  53         \r
  54         assert(r != 0);\r
  55         \r
  56         if(graph.parent == null && listener == null) {\r
  57                 return ValueQuery.computeForEach(graph, r, null, procedure);\r
  58         } else {\r
  59                 return runner(graph, r, parent, listener, procedure);\r
  60         }\r
  61          \r
  62     }\r
  63 \r
  64     final public static byte[] queryEach(ReadGraphImpl graph, final int r, final CacheEntry parent) {\r
  65         \r
  66         assert(r != 0);\r
  67         \r
  68         if(graph.parent == null) {\r
  69             return ValueQuery.computeForEach(graph, r);\r
  70         } else {\r
  71             return runner(graph, r, parent, null, null);\r
  72         }\r
  73          \r
  74     }\r
  75     \r
  76         @Override\r
  77         public UnaryQuery<InternalProcedure<byte[]>> getEntry(QueryProcessor provider) {\r
  78         return provider.valueMap.get(id);\r
  79         }\r
  80         \r
  81         @Override\r
  82         public void putEntry(QueryProcessor provider) {\r
  83         provider.valueMap.put(id, this);\r
  84         }\r
  85 \r
  86         @Override\r
  87         final public void removeEntry(QueryProcessor provider) {\r
  88                 provider.valueMap.remove(id);\r
  89         }\r
  90         \r
  91                 \r
  92         public static byte[] computeForEach(ReadGraphImpl graph, final int r, final ValueQuery entry, final InternalProcedure<byte[]> procedure) {\r
  93 \r
  94                 graph.ensureLoaded(r);\r
  95                 \r
  96                 byte[] value = graph.getValue(r);\r
  97                 if(entry != null) {\r
  98                         entry.setResult(value);\r
  99                         entry.setReady();\r
 100                 }\r
 101                 if(procedure != null) {\r
 102                         procedure.execute(graph, value);\r
 103                 }\r
 104                 \r
 105                 return value;\r
 106                 \r
 107         }\r
 108 \r
 109     public static byte[] computeForEach(ReadGraphImpl graph, final int r) {\r
 110 \r
 111         graph.ensureLoaded(r);\r
 112         \r
 113         return graph.getValue(r);\r
 114         \r
 115     }\r
 116         \r
 117         @Override\r
 118         public Object computeForEach(ReadGraphImpl graph, final QueryProcessor queryProvider, final InternalProcedure<byte[]> procedure, final boolean store) {\r
 119                 return computeForEach(graph, id, this, procedure);\r
 120     }\r
 121     \r
 122     @Override\r
 123     public String toString() {\r
 124         return "Value[" + id + "]";\r
 125     }\r
 126 \r
 127     @Override\r
 128     public Object performFromCache(ReadGraphImpl graph, QueryProcessor queryProvider, InternalProcedure<byte[]> procedure) {\r
 129         return computeForEach(graph, queryProvider, procedure, false);\r
 130     }\r
 131     \r
 132     @Override\r
 133     public void recompute(ReadGraphImpl graph, QueryProcessor provider) {\r
 134 \r
 135         final Semaphore s = new Semaphore(0);\r
 136         \r
 137         computeForEach(graph, provider, new InternalProcedure<byte[]>() {\r
 138 \r
 139             @Override\r
 140             public void execute(ReadGraphImpl graph, byte[] result) {\r
 141                 s.release();\r
 142             }\r
 143                         \r
 144                         @Override\r
 145                         public void exception(ReadGraphImpl graph, Throwable t) {\r
 146                                 throw new Error("Error in recompute.", t);\r
 147             }\r
 148 \r
 149         }, true);\r
 150         \r
 151         while(!s.tryAcquire()) {\r
 152                 provider.resume(graph);\r
 153         }\r
 154         \r
 155     }\r
 156     \r
 157     @Override\r
 158     boolean isImmutable(ReadGraphImpl graph) {\r
 159         return graph.processor.isImmutable(id);\r
 160     }    \r
 161     \r
 162 }\r