/* | |
* Copyright 2009-2010 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.typing.NonPropagatingTypeEnvironment; | |
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() { | |
if (schema == null) { | |
schema = new ArrayList<LogicalVariable>(); | |
} | |
schema.clear(); | |
for (Mutable<ILogicalExpression> eRef : expressions) { | |
ILogicalExpression e = eRef.getValue(); | |
if (e.getExpressionTag() == LogicalExpressionTag.VARIABLE) { | |
VariableReferenceExpression v = (VariableReferenceExpression) e; | |
schema.add(v.getVariableReference()); | |
} | |
} | |
} | |
@Override | |
public VariablePropagationPolicy getVariablePropagationPolicy() { | |
return new VariablePropagationPolicy() { | |
@Override | |
public void propagateVariables(IOperatorSchema target, IOperatorSchema... sources) | |
throws AlgebricksException { | |
for (Mutable<ILogicalExpression> eRef : expressions) { | |
ILogicalExpression e = eRef.getValue(); | |
if (e.getExpressionTag() == LogicalExpressionTag.VARIABLE) { | |
VariableReferenceExpression v = (VariableReferenceExpression) e; | |
target.addVariable(v.getVariableReference()); | |
} | |
} | |
} | |
}; | |
} | |
@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 { | |
IVariableTypeEnvironment env = new NonPropagatingTypeEnvironment(ctx.getExpressionTypeComputer(), ctx.getMetadataProvider()); | |
IVariableTypeEnvironment childEnv = ctx.getOutputTypeEnvironment(inputs.get(0).getValue()); | |
for (Mutable<ILogicalExpression> exprRef : expressions) { | |
ILogicalExpression expr = exprRef.getValue(); | |
if (expr.getExpressionTag() == LogicalExpressionTag.VARIABLE) { | |
VariableReferenceExpression varRefExpr = (VariableReferenceExpression) expr; | |
env.setVarType(varRefExpr.getVariableReference(), childEnv.getType(expr)); | |
} | |
} | |
return env; | |
} | |
} |