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* Licensed to the Apache Software Foundation (ASF) under one
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* 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.logical.expression;
import java.util.List;
import org.apache.pig.FuncSpec;
import org.apache.pig.data.DataType;
import org.apache.pig.impl.builtin.ReadScalars;
import org.apache.pig.impl.logicalLayer.FrontendException;
import org.apache.pig.newplan.Operator;
import org.apache.pig.newplan.OperatorPlan;
import org.apache.pig.newplan.PlanVisitor;
import org.apache.pig.newplan.logical.relational.LogicalRelationalOperator;
import org.apache.pig.newplan.logical.relational.LogicalSchema;
import org.apache.pig.newplan.logical.relational.LogicalSchema.LogicalFieldSchema;
import org.apache.pig.parser.SourceLocation;
public class ScalarExpression extends UserFuncExpression {
private Operator implicitReferencedOperator = null;
private Operator attachedLogicalOperator = null; // The logical Operator where this udf is used.
private static FuncSpec funcSpec = new FuncSpec( ReadScalars.class.getName() );
public ScalarExpression(OperatorPlan plan) {
super( plan, funcSpec );
}
public ScalarExpression(OperatorPlan plan, Operator implicitReferencedOperator,
Operator attachedLogicalOperator) {
this( plan );
this.implicitReferencedOperator = implicitReferencedOperator;
this.attachedLogicalOperator = attachedLogicalOperator;
}
@Override
public LogicalSchema.LogicalFieldSchema getFieldSchema() throws FrontendException {
if (fieldSchema!=null)
return fieldSchema;
// TODO: apparently there is a problem with some test cases where implicitReferencedOperator can be null,
// even for a scalar UDF. Need more investigation. For now, simulate the old code to make these
// test case pass.
if( implicitReferencedOperator != null ) {
List<Operator> args = plan.getSuccessors(this);
if(args != null && args.size() > 0 ){
int pos = (Integer)((ConstantExpression)args.get(0)).getValue();
LogicalRelationalOperator inp = (LogicalRelationalOperator)implicitReferencedOperator;
if( inp.getSchema() != null){
LogicalFieldSchema inpFs = inp.getSchema().getField(pos);
fieldSchema = new LogicalFieldSchema(inpFs);
// fieldSchema.alias = "ReadScalars_" + fieldSchema.alias;
}else{
fieldSchema = new LogicalFieldSchema(null, null, DataType.BYTEARRAY);
}
return fieldSchema;
}else{
//predecessors haven't been setup, return null
return null;
}
} else {
return super.getFieldSchema();
}
}
@Override
public LogicalExpression deepCopy(LogicalExpressionPlan lgExpPlan) throws FrontendException {
ScalarExpression copy = null;
copy = new ScalarExpression( lgExpPlan, implicitReferencedOperator,
attachedLogicalOperator );
// Deep copy the input expressions.
List<Operator> inputs = plan.getSuccessors( this );
if( inputs != null ) {
for( Operator op : inputs ) {
LogicalExpression input = (LogicalExpression)op;
LogicalExpression inputCopy = input.deepCopy( lgExpPlan );
lgExpPlan.add( inputCopy );
lgExpPlan.connect( copy, inputCopy );
}
}
copy.setLocation( new SourceLocation( location ) );
return copy;
}
@Override
public void accept(PlanVisitor v) throws FrontendException {
if( !( v instanceof LogicalExpressionVisitor ) ) {
throw new FrontendException( "Expected LogicalExpressionVisitor", 2222 );
}
((LogicalExpressionVisitor)v).visit( this );
}
public Operator getImplicitReferencedOperator() {
return implicitReferencedOperator;
}
public void setImplicitReferencedOperator(Operator implicitReferencedOperator) {
this.implicitReferencedOperator = implicitReferencedOperator;
}
public void setAttachedLogicalOperator(Operator attachedLogicalOperator) {
this.attachedLogicalOperator = attachedLogicalOperator;
}
public Operator getAttachedLogicalOperator() {
return attachedLogicalOperator;
}
@Override
public String toString() {
StringBuilder msg = new StringBuilder();
msg.append( "(Name: ScalarExpression)" + " Type: ");
if (fieldSchema!=null)
msg.append(DataType.findTypeName(fieldSchema.type));
else
msg.append("null");
msg.append(" Uid: ");
if (fieldSchema!=null)
msg.append(fieldSchema.uid);
else
msg.append("null");
msg.append(")");
return msg.toString();
}
}