bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/elaboration/query/compilation/RelationConstraint.java

   1 package org.simantics.scl.compiler.elaboration.query.compilation;
   2
   3 import org.simantics.scl.compiler.elaboration.expressions.EVariable;
   4 import org.simantics.scl.compiler.elaboration.expressions.Variable;
   5 import org.simantics.scl.compiler.elaboration.query.QAtom;
   6
   7 public class RelationConstraint extends QueryConstraint {
   8
   9     // static
  10     QAtom atom;
  11
  12     int[] optionalVariableByParameter;
  13     Variable[] parameters;
  14
  15     long requiredVariablesMask;
  16
  17     public RelationConstraint(int[] variables, Variable[] parameters, QAtom atom, int[] optionalVariableByParameter,
  18             long requiredVariablesMask) {
  19         super(variables);
  20         this.atom = atom;
  21         this.parameters = parameters;
  22         this.optionalVariableByParameter = optionalVariableByParameter;
  23         this.requiredVariablesMask = requiredVariablesMask;
  24     }
  25
  26     @Override
  27     public boolean canBeSolvedFrom(long boundVariables) {
  28         return getSolutionBranching(boundVariables) != Double.POSITIVE_INFINITY;
  29     }
  30
  31     @Override
  32     public double getSolutionBranching(long boundVariables) {
  33         if( (boundVariables&requiredVariablesMask) != requiredVariablesMask )
  34             return Double.POSITIVE_INFINITY;
  35         return atom.relation.getSelectivity(getLocalBoundVariables(boundVariables));
  36     }
  37
  38     @Override
  39     public double getSolutionCost(long boundVariables) {
  40         return 1.0;
  41     }
  42
  43     @Override
  44     public void generate(QueryCompilationContext context) {
  45         atom.relation.generate(atom.location,
  46                 context, atom.typeParameters,
  47                 parameters, getLocalBoundVariables(finalBoundVariables));
  48         for(int i=atom.parameters.length-1;i>=0;--i)
  49             if(optionalVariableByParameter[i] < 0 && !(atom.parameters[i] instanceof EVariable))
  50                 context.let(parameters[i], atom.parameters[i]);
  51     }
  52
  53     private int getLocalBoundVariables(long boundVariables) {
  54         int localBoundVariables = 0;
  55         for(int i=0;i<optionalVariableByParameter.length;++i) {
  56             int v = optionalVariableByParameter[i];
  57             if(v < 0 || ((boundVariables >> v)&1) != 0)
  58                 localBoundVariables |= 1 << i;
  59         }
  60         return localBoundVariables;
  61     }
  62
  63     @Override
  64     public String toString() {
  65         return atom.toString();
  66     }
  67 }