Beispiel #1
0
 private void bindDeferred(JavaFrame frame, final RelNode rel) {
   final StatementList statementList = getStatementList();
   if (frame.bind == null) {
     // this relational expression has not bound itself, so we presume
     // that we can call its implementSelf() method
     if (!(rel instanceof JavaSelfRel)) {
       throw Util.newInternal(
           "In order to bind-deferred, a "
               + "relational expression must implement JavaSelfRel: "
               + rel);
     }
     final JavaSelfRel selfRel = (JavaSelfRel) rel;
     LazyBind lazyBind =
         new LazyBind(
             newVariable(),
             statementList,
             getTypeFactory(),
             rel.getRowType(),
             new VariableInitializerThunk() {
               public VariableInitializer getInitializer() {
                 return selfRel.implementSelf(JavaRelImplementor.this);
               }
             });
     bind(rel, lazyBind);
   } else if ((frame.bind instanceof LazyBind)
       && (((LazyBind) frame.bind).statementList != statementList)) {
     // Frame is already bound, but to a variable declared in a different
     // scope. Re-bind it.
     final LazyBind lazyBind = (LazyBind) frame.bind;
     lazyBind.statementList = statementList;
     lazyBind.bound = false;
   }
 }
Beispiel #2
0
 /**
  * Returns the index of the first field in <code>rel</code> which comes from its <code>ordinal
  * </code>th input.
  *
  * <p>For example, if rel joins T0(A,B,C) to T1(D,E), then countFields(0,rel) yields 0, and
  * countFields(1,rel) yields 3.
  */
 private int computeFieldOffset(RelNode rel, int ordinal) {
   if (ordinal == 0) {
     // short-circuit for the common case
     return 0;
   }
   int fieldOffset = 0;
   final List<RelNode> inputs = rel.getInputs();
   for (int i = 0; i < ordinal; i++) {
     RelNode input = inputs.get(i);
     fieldOffset += input.getRowType().getFieldList().size();
   }
   return fieldOffset;
 }
Beispiel #3
0
  /**
   * Declares a variable, and binds it lazily, so it only gets initialized if it is actually used.
   *
   * @return the Variable so declared
   */
  public Variable bind(
      RelNode rel, StatementList statementList, final VariableInitializer initializer) {
    VariableInitializerThunk thunk =
        new VariableInitializerThunk() {
          public VariableInitializer getInitializer() {
            return initializer;
          }
        };

    Variable variable = newVariable();
    LazyBind bind =
        new LazyBind(variable, statementList, getTypeFactory(), rel.getRowType(), thunk);
    bind(rel, bind);
    return bind.getVariable();
  }