bundles/org.simantics.db.impl/src/org/simantics/db/impl/graph/PossibleObjectProcedure.java

   1 package org.simantics.db.impl.graph;
   2
   3 import org.simantics.db.Resource;
   4 import org.simantics.db.exception.DatabaseException;
   5 import org.simantics.db.impl.query.IntProcedure;
   6 import org.simantics.db.impl.query.QueryProcessor;
   7
   8 public class PossibleObjectProcedure implements IntProcedure {
   9
  10         private static DatabaseException DUMMY = new DatabaseException();
  11
  12         final private QueryProcessor processor;
  13         private DatabaseException exception;
  14         private Resource result;
  15
  16         public PossibleObjectProcedure(QueryProcessor processor) {
  17                 this.processor = processor;
  18         }
  19
  20         @Override
  21         public void execute(ReadGraphImpl graph, int i) {
  22                 Resource resource = processor.querySupport.getResource(i);
  23                 if(result != null) {
  24                         exception = DUMMY;
  25                 } else {
  26                         result = resource;
  27                 }
  28         }
  29
  30         @Override
  31         public void finished(ReadGraphImpl graph) {
  32         }
  33
  34         @Override
  35         public void exception(ReadGraphImpl graph, Throwable throwable) {
  36                 if(throwable instanceof DatabaseException) exception = (DatabaseException)throwable;
  37                 else throwable = new DatabaseException(throwable);
  38         }
  39
  40         public Resource get() throws DatabaseException {
  41                 if(exception == DUMMY) return null;
  42                 else if(exception != null) throw exception;
  43                 else return result;
  44         }
  45
  46 }