| /* |
| * 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 org.apache.hyracks.algebricks.core.algebra.operators.logical; |
| |
| import org.apache.commons.lang3.mutable.Mutable; |
| import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException; |
| import org.apache.hyracks.algebricks.core.algebra.base.ILogicalExpression; |
| import org.apache.hyracks.algebricks.core.algebra.base.LogicalOperatorTag; |
| import org.apache.hyracks.algebricks.core.algebra.visitors.ILogicalExpressionReferenceTransform; |
| import org.apache.hyracks.algebricks.core.algebra.visitors.ILogicalOperatorVisitor; |
| |
| /** |
| * Split Operator receives an expression. This expression will be evaluated to an integer value during the runtime. |
| * Based on its value, it propagates each tuple to the corresponding output frame. (e.g., first output = 0, ...) |
| * Thus, unlike Replicate operator that does unconditional propagation to all outputs, |
| * this does a conditional propagate operation. |
| */ |
| public class SplitOperator extends AbstractReplicateOperator { |
| |
| // Expression that keeps the output branch information for each tuple |
| private final Mutable<ILogicalExpression> branchingExpression; |
| // Default branch when there is no value from the given branching expression. The default is 0. |
| private final int defaultBranch; |
| // When the following is set to true, defaultBranch will be ignored and incoming tuples will be |
| // propagated to all output branches. The default is false. |
| private final boolean propageToAllBranchAsDefault; |
| |
| public SplitOperator(int outputArity, Mutable<ILogicalExpression> branchingExpression) { |
| this(outputArity, branchingExpression, 0, false); |
| } |
| |
| public SplitOperator(int outputArity, Mutable<ILogicalExpression> branchingExpression, int defaultBranch, |
| boolean propageToAllBranchForMissingExprValue) { |
| super(outputArity); |
| this.branchingExpression = branchingExpression; |
| this.defaultBranch = defaultBranch; |
| this.propageToAllBranchAsDefault = propageToAllBranchForMissingExprValue; |
| } |
| |
| @Override |
| public LogicalOperatorTag getOperatorTag() { |
| return LogicalOperatorTag.SPLIT; |
| } |
| |
| @Override |
| public <R, T> R accept(ILogicalOperatorVisitor<R, T> visitor, T arg) throws AlgebricksException { |
| return visitor.visitSplitOperator(this, arg); |
| } |
| |
| public Mutable<ILogicalExpression> getBranchingExpression() { |
| return branchingExpression; |
| } |
| |
| public int getDefaultBranch() { |
| return defaultBranch; |
| } |
| |
| public boolean getPropageToAllBranchAsDefault() { |
| return propageToAllBranchAsDefault; |
| } |
| |
| @Override |
| public boolean acceptExpressionTransform(ILogicalExpressionReferenceTransform visitor) throws AlgebricksException { |
| return visitor.transform(branchingExpression); |
| } |
| } |