/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 at
*
* 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.pig.newplan;
import java.util.List;
import org.apache.pig.Expression.OpType;
import org.apache.pig.impl.logicalLayer.FrontendException;
import org.apache.pig.newplan.logical.expression.AddExpression;
import org.apache.pig.newplan.logical.expression.AndExpression;
import org.apache.pig.newplan.logical.expression.BinaryExpression;
import org.apache.pig.newplan.logical.expression.CastExpression;
import org.apache.pig.newplan.logical.expression.DivideExpression;
import org.apache.pig.newplan.logical.expression.EqualExpression;
import org.apache.pig.newplan.logical.expression.GreaterThanEqualExpression;
import org.apache.pig.newplan.logical.expression.GreaterThanExpression;
import org.apache.pig.newplan.logical.expression.IsNullExpression;
import org.apache.pig.newplan.logical.expression.LessThanEqualExpression;
import org.apache.pig.newplan.logical.expression.LessThanExpression;
import org.apache.pig.newplan.logical.expression.LogicalExpressionPlan;
import org.apache.pig.newplan.logical.expression.ModExpression;
import org.apache.pig.newplan.logical.expression.MultiplyExpression;
import org.apache.pig.newplan.logical.expression.NotEqualExpression;
import org.apache.pig.newplan.logical.expression.NotExpression;
import org.apache.pig.newplan.logical.expression.OrExpression;
import org.apache.pig.newplan.logical.expression.ProjectExpression;
import org.apache.pig.newplan.logical.expression.RegexExpression;
import org.apache.pig.newplan.logical.expression.SubtractExpression;
import org.apache.pig.newplan.logical.expression.UnaryExpression;
/**
*
* We traverse the expression plan bottom up and separate it into two plans
* - pushdownExprPlan, plan that can be pushed down to the loader and
* - filterExprPlan, remaining plan that needs to be evaluated by pig
*
* If the predicate is not removable then filterExprPlan will not have
* the pushdownExprPlan removed.
*/
public class PredicatePushDownFilterExtractor extends FilterExtractor {
private List<String> predicateCols;
private List<OpType> supportedOpTypes;
public PredicatePushDownFilterExtractor(LogicalExpressionPlan plan, List<String> predicateCols,
List<OpType> supportedOpTypes) {
super(plan);
this.predicateCols = predicateCols;
this.supportedOpTypes = supportedOpTypes;
}
@Override
public void visit() throws FrontendException {
super.visit();
if (supportedOpTypes.contains(OpType.OP_BETWEEN)) {
// TODO: Collapse multiple ORs into BETWEEN
} else if (supportedOpTypes.contains(OpType.OP_IN)) {
// TODO: Collapse multiple ORs into IN
}
}
@Override
protected KeyState checkPushDown(ProjectExpression project) throws FrontendException {
String fieldName = project.getFieldSchema().alias;
KeyState state = new KeyState();
if(predicateCols.contains(fieldName)) {
state.filterExpr = null;
state.pushdownExpr = project;
} else {
state.filterExpr = addToFilterPlan(project);
state.pushdownExpr = null;
}
return state;
}
@Override
protected boolean isSupportedOpType(BinaryExpression binOp) {
if(binOp instanceof AddExpression) {
return supportedOpTypes.contains(OpType.OP_PLUS );
} else if(binOp instanceof SubtractExpression) {
return supportedOpTypes.contains(OpType.OP_MINUS);
} else if(binOp instanceof MultiplyExpression) {
return supportedOpTypes.contains(OpType.OP_TIMES);
} else if(binOp instanceof DivideExpression) {
return supportedOpTypes.contains(OpType.OP_DIV);
} else if(binOp instanceof ModExpression) {
return supportedOpTypes.contains(OpType.OP_MOD);
} else if(binOp instanceof AndExpression) {
return supportedOpTypes.contains(OpType.OP_AND);
} else if(binOp instanceof OrExpression) {
return supportedOpTypes.contains(OpType.OP_OR);
} else if(binOp instanceof EqualExpression) {
return supportedOpTypes.contains(OpType.OP_EQ);
} else if(binOp instanceof NotEqualExpression) {
return supportedOpTypes.contains(OpType.OP_NE);
} else if(binOp instanceof GreaterThanExpression) {
return supportedOpTypes.contains(OpType.OP_GT);
} else if(binOp instanceof GreaterThanEqualExpression) {
return supportedOpTypes.contains(OpType.OP_GE);
} else if(binOp instanceof LessThanExpression) {
return supportedOpTypes.contains(OpType.OP_LT);
} else if(binOp instanceof LessThanEqualExpression) {
return supportedOpTypes.contains(OpType.OP_LE);
} else if(binOp instanceof RegexExpression) {
return supportedOpTypes.contains(OpType.OP_MATCH);
} else {
return false;
}
}
@Override
protected boolean isSupportedOpType(UnaryExpression unaryOp) {
if (unaryOp instanceof CastExpression) {
return true;
} else if(unaryOp instanceof IsNullExpression) {
return supportedOpTypes.contains(OpType.OP_NULL);
} else if(unaryOp instanceof NotExpression) {
return supportedOpTypes.contains(OpType.OP_NOT);
} else {
return false;
}
}
}