| /* |
| * Copyright 2009-2013 by The Regents of the University of California |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * you may obtain a copy of the License from |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical;
|
|
|
| import java.util.ArrayList;
|
| import java.util.List;
|
|
|
| import org.apache.commons.lang3.mutable.Mutable;
|
|
|
| import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
|
| import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression;
|
| import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalExpressionTag;
|
| import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalOperatorTag;
|
| import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable;
|
| import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.IVariableTypeEnvironment;
|
| import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.VariableReferenceExpression;
|
| import edu.uci.ics.hyracks.algebricks.core.algebra.properties.VariablePropagationPolicy;
|
| import edu.uci.ics.hyracks.algebricks.core.algebra.typing.ITypingContext;
|
| import edu.uci.ics.hyracks.algebricks.core.algebra.visitors.ILogicalExpressionReferenceTransform;
|
| import edu.uci.ics.hyracks.algebricks.core.algebra.visitors.ILogicalOperatorVisitor;
|
|
|
| public class DistinctOperator extends AbstractLogicalOperator {
|
| private final List<Mutable<ILogicalExpression>> expressions;
|
|
|
| public DistinctOperator(List<Mutable<ILogicalExpression>> expressions) {
|
| this.expressions = expressions;
|
| }
|
|
|
| @Override
|
| public LogicalOperatorTag getOperatorTag() {
|
| return LogicalOperatorTag.DISTINCT;
|
| }
|
|
|
| public List<Mutable<ILogicalExpression>> getExpressions() {
|
| return expressions;
|
| }
|
|
|
| @Override
|
| public void recomputeSchema() {
|
| schema = new ArrayList<LogicalVariable>();
|
| schema.addAll(this.getDistinctByVarList());
|
| List<LogicalVariable> inputSchema = inputs.get(0).getValue().getSchema();
|
| for (LogicalVariable var : inputSchema) {
|
| if (!schema.contains(var)) {
|
| schema.add(var);
|
| }
|
| }
|
| }
|
|
|
| @Override
|
| public VariablePropagationPolicy getVariablePropagationPolicy() {
|
| return new VariablePropagationPolicy() {
|
| @Override
|
| public void propagateVariables(IOperatorSchema target, IOperatorSchema... sources)
|
| throws AlgebricksException {
|
| /** make sure distinct key vars laid-out first */
|
| for (LogicalVariable keyVar : getDistinctByVarList()) {
|
| target.addVariable(keyVar);
|
| }
|
| /** add other source vars */
|
| for (IOperatorSchema srcSchema : sources) {
|
| for (LogicalVariable srcVar : srcSchema)
|
| if (target.findVariable(srcVar) < 0) {
|
| target.addVariable(srcVar);
|
| }
|
| }
|
| }
|
| };
|
| }
|
|
|
| @Override
|
| public boolean acceptExpressionTransform(ILogicalExpressionReferenceTransform visitor) throws AlgebricksException {
|
| boolean changed = false;
|
| for (Mutable<ILogicalExpression> e : expressions) {
|
| if (visitor.transform(e)) {
|
| changed = true;
|
| }
|
| }
|
| return changed;
|
| }
|
|
|
| @Override
|
| public <R, T> R accept(ILogicalOperatorVisitor<R, T> visitor, T arg) throws AlgebricksException {
|
| return visitor.visitDistinctOperator(this, arg);
|
| }
|
|
|
| @Override
|
| public boolean isMap() {
|
| return false;
|
| }
|
|
|
| public List<LogicalVariable> getDistinctByVarList() {
|
| List<LogicalVariable> varList = new ArrayList<LogicalVariable>(expressions.size());
|
| for (Mutable<ILogicalExpression> eRef : expressions) {
|
| ILogicalExpression e = eRef.getValue();
|
| if (e.getExpressionTag() == LogicalExpressionTag.VARIABLE) {
|
| VariableReferenceExpression v = (VariableReferenceExpression) e;
|
| varList.add(v.getVariableReference());
|
| }
|
| }
|
| return varList;
|
| }
|
|
|
| public boolean isDistinctByVar(LogicalVariable var) {
|
| for (Mutable<ILogicalExpression> eRef : expressions) {
|
| ILogicalExpression e = eRef.getValue();
|
| if (e.getExpressionTag() == LogicalExpressionTag.VARIABLE) {
|
| VariableReferenceExpression v = (VariableReferenceExpression) e;
|
| if (v.getVariableReference() == var) {
|
| return true;
|
| }
|
| }
|
| }
|
| return false;
|
| }
|
|
|
| @Override
|
| public IVariableTypeEnvironment computeOutputTypeEnvironment(ITypingContext ctx) throws AlgebricksException {
|
| return createPropagatingAllInputsTypeEnvironment(ctx);
|
| }
|
|
|
| }
|