bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/ValueQuery.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.exception.DatabaseException;
  15 import org.simantics.db.impl.graph.ReadGraphImpl;
  16 import org.simantics.db.impl.procedure.InternalProcedure;
  17
  18 final public class ValueQuery extends UnaryQuery<InternalProcedure<byte[]>> {
  19
  20     ValueQuery(final int resource) {
  21         super(resource);
  22     }
  23
  24         @Override
  25         final public void removeEntry(QueryProcessor provider) {
  26                 provider.cache.remove(this);
  27         }
  28
  29         public static byte[] computeForEach(ReadGraphImpl graph, final int r, final ValueQuery entry, final InternalProcedure<byte[]> procedure) throws DatabaseException {
  30
  31                 graph.ensureLoaded(r);
  32
  33                 byte[] value = graph.getValue(r);
  34                 if(entry != null) {
  35                         entry.setResult(value);
  36                         entry.setReady();
  37                 }
  38                 if(procedure != null) {
  39                         procedure.execute(graph, value);
  40                 }
  41
  42                 return value;
  43
  44         }
  45
  46     public static byte[] computeForEach(ReadGraphImpl graph, final int r) {
  47
  48         graph.ensureLoaded(r);
  49
  50         return graph.getValue(r);
  51
  52     }
  53
  54         @Override
  55         public Object compute(ReadGraphImpl graph, final InternalProcedure<byte[]> procedure) throws DatabaseException {
  56                 return computeForEach(graph, id, this, procedure);
  57     }
  58
  59     @Override
  60     public String toString() {
  61         return "Value[" + id + "]";
  62     }
  63
  64     @Override
  65     public Object performFromCache(ReadGraphImpl graph, InternalProcedure<byte[]> procedure) throws DatabaseException {
  66         return compute(graph, procedure);
  67     }
  68
  69     @Override
  70     public void recompute(ReadGraphImpl graph) throws DatabaseException {
  71
  72         compute(graph,  new InternalProcedure<byte[]>() {
  73
  74             @Override
  75             public void execute(ReadGraphImpl graph, byte[] result) {
  76             }
  77
  78                         @Override
  79                         public void exception(ReadGraphImpl graph, Throwable t) {
  80                                 throw new Error("Error in recompute.", t);
  81             }
  82
  83         });
  84
  85     }
  86
  87     @Override
  88     boolean isImmutable(ReadGraphImpl graph) {
  89         return graph.processor.isImmutable(id);
  90     }
  91
  92 }