org.apache.calcite.rex.RexVisitor Java Examples

private static RexInputRef findRexInputRef(final RexNode node) {
  try {
    RexVisitor<Void> visitor =
        new RexVisitorImpl<Void>(true) {
          public Void visitCall(RexCall call) {
            for (RexNode child : call.getOperands()) {
              child.accept(this);
            }
            return super.visitCall(call);
          }

          public Void visitInputRef(RexInputRef inputRef) {
            throw new Util.FoundOne(inputRef);
          }
        };
    node.accept(visitor);
    return null;
  } catch (Util.FoundOne e) {
    Util.swallow(e, null);
    return (RexInputRef) e.getNode();
  }
}
 

/** Check if join condition only references RexInputRef. */
private static boolean referenceByMapping(
    RexNode joinCondition, List<RexNode>... projectsOfInputs) {
  List<RexNode> projects = new ArrayList<>();
  for (List<RexNode> projectsOfInput: projectsOfInputs) {
    projects.addAll(projectsOfInput);
  }

  try {
    RexVisitor rexVisitor = new RexVisitorImpl<Void>(true) {
      @Override public Void visitInputRef(RexInputRef inputRef) {
        if (!(projects.get(inputRef.getIndex()) instanceof RexInputRef)) {
          throw Util.FoundOne.NULL;
        }
        return super.visitInputRef(inputRef);
      }
    };
    joinCondition.accept(rexVisitor);
  } catch (Util.FoundOne e) {
    return false;
  }
  return true;
}
 

private Set<RelColumnOrigin> getMultipleColumns(RexNode rexNode, RelNode input,
    final RelMetadataQuery mq) {
  final Set<RelColumnOrigin> set = new HashSet<>();
  final RexVisitor<Void> visitor =
      new RexVisitorImpl<Void>(true) {
        public Void visitInputRef(RexInputRef inputRef) {
          Set<RelColumnOrigin> inputSet =
              mq.getColumnOrigins(input, inputRef.getIndex());
          if (inputSet != null) {
            set.addAll(inputSet);
          }
          return null;
        }
      };
  rexNode.accept(visitor);
  return set;
}
 

/**
 * Find whether the given project rel has unknown output schema. This would happen if the
 * project has CONVERT_FROMJSON which can only derive the schema after evaluation is performed
 * @param project : The project rel
 * @return : Return true if the project output schema is unknown. Otherwise, false.
 */
public static boolean isProjectOutputSchemaUnknown(Project project) {
    try {
        RexVisitor<Void> visitor = new RexVisitorImpl<Void>(true) {
            @Override
            public Void visitCall(RexCall call) {
                if ("convert_fromjson".equals(call.getOperator().getName().toLowerCase())) {
                    throw new Util.FoundOne(call); /* throw exception to interrupt tree walk (this is similar to
                                                   other utility methods in RexUtil.java */
                }
                return super.visitCall(call);
            }
        };
        for (RexNode rex : project.getProjects()) {
            rex.accept(visitor);
        }
    } catch (Util.FoundOne e) {
        Util.swallow(e, null);
        return true;
    }
    return false;
}
 

/**
 * check whether a node has some input which have correlation condition.
 * e.g. SELECT * FROM l WHERE EXISTS (SELECT * FROM r LEFT JOIN (SELECT * FROM t WHERE t.j=l.b) t1 ON r.f=t1.k)
 * the above sql can not be converted to semi-join plan,
 * because the right input of Left-Join has the correlation condition(t.j=l.b).
 */
private void checkCorConditionOfInput(final RelNode input) {
	final RelShuttleImpl shuttle = new RelShuttleImpl() {
		final RexVisitor<Void> visitor = new RexVisitorImpl<Void>(true) {
			@Override
			public Void visitCorrelVariable(RexCorrelVariable correlVariable) {
				hasUnsupportedCorCondition = true;
				return super.visitCorrelVariable(correlVariable);
			}
		};

		@Override
		public RelNode visit(LogicalFilter filter) {
			filter.getCondition().accept(visitor);
			return super.visit(filter);
		}

		@Override
		public RelNode visit(LogicalProject project) {
			for (RexNode rex : project.getProjects()) {
				rex.accept(visitor);
			}
			return super.visit(project);
		}

		@Override
		public RelNode visit(LogicalJoin join) {
			join.getCondition().accept(visitor);
			return super.visit(join);
		}
	};
	input.accept(shuttle);
}
 

public FunctionRenderer(
    boolean supportsV5Features,
    boolean scriptsEnabled,
    RenderMode mode,
    RexVisitor<FunctionRender> visitor) {
  super();
  this.supportsV5Features = supportsV5Features;
  this.scriptsEnabled = scriptsEnabled;
  this.mode = mode;
  this.visitor = visitor;
}
 

/**
 * Variant of {@link #trimFields(RelNode, ImmutableBitSet, Set)} for
 * {@link org.apache.calcite.rel.logical.LogicalFilter}.
 */
public TrimResult trimFields(Filter filter, ImmutableBitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
    final RelDataType rowType = filter.getRowType();
    final int fieldCount = rowType.getFieldCount();
    final RexNode conditionExpr = filter.getCondition();
    final RelNode input = filter.getInput();

    // We use the fields used by the consumer, plus any fields used in the
    // filter.
    final Set<RelDataTypeField> inputExtraFields = new LinkedHashSet<>(extraFields);
    RelOptUtil.InputFinder inputFinder = new RelOptUtil.InputFinder(inputExtraFields);
    inputFinder.inputBitSet.addAll(fieldsUsed);
    conditionExpr.accept(inputFinder);
    final ImmutableBitSet inputFieldsUsed = inputFinder.inputBitSet.build();

    // Create input with trimmed columns.
    TrimResult trimResult = trimChild(filter, input, inputFieldsUsed, inputExtraFields);
    RelNode newInput = trimResult.left;
    final Mapping inputMapping = trimResult.right;

    // If the input is unchanged, and we need to project all columns,
    // there's nothing we can do.
    if (newInput == input && fieldsUsed.cardinality() == fieldCount) {
        return result(filter, Mappings.createIdentity(fieldCount));
    }

    // Build new project expressions, and populate the mapping.
    final RexVisitor<RexNode> shuttle = new RexPermuteInputsShuttle(inputMapping, newInput);
    RexNode newConditionExpr = conditionExpr.accept(shuttle);

    // Use copy rather than relBuilder so that correlating variables get set.
    relBuilder.push(filter.copy(filter.getTraitSet(), newInput, newConditionExpr));

    // The result has the same mapping as the input gave us. Sometimes we
    // return fields that the consumer didn't ask for, because the filter
    // needs them for its condition.
    return result(relBuilder.build(), inputMapping);
}
 

private static List<RexInputRef> findAllRexInputRefs(final RexNode node) {
    List<RexInputRef> rexRefs = new ArrayList<>();
    RexVisitor<Void> visitor =
        new RexVisitorImpl<Void>(true) {
          public Void visitInputRef(RexInputRef inputRef) {
            rexRefs.add(inputRef);
            return super.visitInputRef(inputRef);
          }
        };
    node.accept(visitor);
    return rexRefs;
}
 

/**
 * Travesal RexNode to find at least one operator in the given collection. Continue search if RexNode has a
 * RexInputRef which refers to a RexNode in project expressions.
 *
 * @param node : RexNode to search
 * @param projExprs : the list of project expressions. Empty list means there is No project operator underneath.
 * @param operators collection of operators to find
 * @return : Return null if there is NONE; return the first appearance of item/flatten RexCall.
 */
public static RexCall findOperators(final RexNode node, final List<RexNode> projExprs,
        final Collection<String> operators) {
    try {
        RexVisitor<Void> visitor = new RexVisitorImpl<Void>(true) {
            @Override
            public Void visitCall(RexCall call) {
                if (operators.contains(call.getOperator().getName().toLowerCase())) {
                    throw new Util.FoundOne(call); /* throw exception to interrupt tree walk (this is similar to
                                                   other utility methods in RexUtil.java */
                }
                return super.visitCall(call);
            }

            @Override
            public Void visitInputRef(RexInputRef inputRef) {
                if (projExprs.size() == 0) {
                    return super.visitInputRef(inputRef);
                } else {
                    final int index = inputRef.getIndex();
                    RexNode n = projExprs.get(index);
                    if (n instanceof RexCall) {
                        RexCall r = (RexCall) n;
                        if (operators.contains(r.getOperator().getName().toLowerCase())) {
                            throw new Util.FoundOne(r);
                        }
                    }

                    return super.visitInputRef(inputRef);
                }
            }
        };
        node.accept(visitor);
        return null;
    } catch (Util.FoundOne e) {
        Util.swallow(e, null);
        return (RexCall) e.getNode();
    }
}
 

/**
 * check whether a node has some input which have correlation condition.
 * e.g. SELECT * FROM l WHERE EXISTS (SELECT * FROM r LEFT JOIN (SELECT * FROM t WHERE t.j=l.b) t1 ON r.f=t1.k)
 * the above sql can not be converted to semi-join plan,
 * because the right input of Left-Join has the correlation condition(t.j=l.b).
 */
private void checkCorConditionOfInput(final RelNode input) {
	final RelShuttleImpl shuttle = new RelShuttleImpl() {
		final RexVisitor<Void> visitor = new RexVisitorImpl<Void>(true) {
			@Override
			public Void visitCorrelVariable(RexCorrelVariable correlVariable) {
				hasUnsupportedCorCondition = true;
				return super.visitCorrelVariable(correlVariable);
			}
		};

		@Override
		public RelNode visit(LogicalFilter filter) {
			filter.getCondition().accept(visitor);
			return super.visit(filter);
		}

		@Override
		public RelNode visit(LogicalProject project) {
			for (RexNode rex : project.getProjects()) {
				rex.accept(visitor);
			}
			return super.visit(project);
		}

		@Override
		public RelNode visit(LogicalJoin join) {
			join.getCondition().accept(visitor);
			return super.visit(join);
		}
	};
	input.accept(shuttle);
}
 

@Override
public <R> R accept(RexVisitor<R> visitor) {
    return visitor.visitDynamicParam(this);
}
 

@Override
public <R> R accept(RexVisitor<R> visitor) {
    return visitor.visitCorrelVariable(this);
}
 

/**
 * Variant of {@link #trimFields(RelNode, ImmutableBitSet, Set)} for
 * {@link org.apache.calcite.rel.logical.LogicalFilter}.
 */
public TrimResult trimFields(
    Filter filter,
    ImmutableBitSet fieldsUsed,
    Set<RelDataTypeField> extraFields) {
  final RelDataType rowType = filter.getRowType();
  final int fieldCount = rowType.getFieldCount();
  final RexNode conditionExpr = filter.getCondition();
  final RelNode input = filter.getInput();

  // We use the fields used by the consumer, plus any fields used in the
  // filter.
  final Set<RelDataTypeField> inputExtraFields =
      new LinkedHashSet<>(extraFields);
  RelOptUtil.InputFinder inputFinder =
      new RelOptUtil.InputFinder(inputExtraFields, fieldsUsed);
  conditionExpr.accept(inputFinder);
  final ImmutableBitSet inputFieldsUsed = inputFinder.build();

  // Create input with trimmed columns.
  TrimResult trimResult =
      trimChild(filter, input, inputFieldsUsed, inputExtraFields);
  RelNode newInput = trimResult.left;
  final Mapping inputMapping = trimResult.right;

  // If the input is unchanged, and we need to project all columns,
  // there's nothing we can do.
  if (newInput == input
      && fieldsUsed.cardinality() == fieldCount) {
    return result(filter, Mappings.createIdentity(fieldCount));
  }

  // Build new project expressions, and populate the mapping.
  final RexVisitor<RexNode> shuttle =
      new RexPermuteInputsShuttle(inputMapping, newInput);
  RexNode newConditionExpr =
      conditionExpr.accept(shuttle);

  // Build new filter with trimmed input and condition.
  relBuilder.push(newInput)
      .filter(filter.getVariablesSet(), newConditionExpr);

  // The result has the same mapping as the input gave us. Sometimes we
  // return fields that the consumer didn't ask for, because the filter
  // needs them for its condition.
  return result(relBuilder.build(), inputMapping);
}
 

@Override
public <R> R accept(RexVisitor<R> visitor) {
    return visitor.visitInputRef(this);
}
 

public RexVisitor<FunctionRender> getVisitor() {
  return visitor;
}
 

@Override
public <R> R accept(RexVisitor<R> visitor) {
    return visitor.visitCall(this);
}
 

@Override
public <R> R accept(RexVisitor<R> visitor) {
    return visitor.visitOver(this);
}
 

@Override
public <R> R accept(RexVisitor<R> visitor) {
    return visitor.visitLiteral(this);
}
 

@Override
public <R> R accept(RexVisitor<R> visitor) {
    return visitor.visitLocalRef(this);
}
 

@Override
public <R> R accept(RexVisitor<R> visitor) {
    return visitor.visitSubQuery(this);
}
 

@Override
public <R> R accept(RexVisitor<R> visitor) {
    return visitor.visitFieldAccess(this);
}
 

@Override
public <R> R accept(RexVisitor<R> visitor) {
    return visitor.visitRangeRef(this);
}