/*
* 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.impl.logicalLayer;
import java.util.List;
import java.util.ArrayList;
import org.apache.pig.EvalFunc;
import org.apache.pig.FuncSpec;
import org.apache.pig.PigException;
import org.apache.pig.impl.PigContext;
import org.apache.pig.impl.plan.VisitorException;
import org.apache.pig.impl.logicalLayer.schema.Schema;
import org.apache.pig.impl.logicalLayer.schema.Schema.FieldSchema;
import org.apache.pig.data.DataType;
import org.apache.pig.impl.plan.OperatorKey;
public class LOUserFunc extends ExpressionOperator {
private static final long serialVersionUID = 2L;
private FuncSpec mFuncSpec;
private LogicalOperator implicitReferencedOperator = null;
/**
* @param plan
* LogicalPlan this operator is a part of.
* @param k
* OperatorKey for this operator.
* @param funcSpec
* name of the user defined function.
* @param returnType
* return type of this function.
*/
public LOUserFunc(LogicalPlan plan, OperatorKey k, FuncSpec funcSpec,
byte returnType) {
super(plan, k, -1);
mFuncSpec = funcSpec;
mType = returnType;
}
public FuncSpec getFuncSpec() {
return mFuncSpec;
}
/**
* Used for scalar alias. return the source logical operator
* this ReadScalars udf is associated with
* @return input logical operator
*/
public LogicalOperator getImplicitReferencedOperator() {
return implicitReferencedOperator;
}
/**
* Used for scalar alias. set the source logical operator
* this ReadScalars udf is associated with
* @param implicitReferencedOperator input logical operator
*/
public void setImplicitReferencedOperator(
LogicalOperator implicitReferencedOperator) {
this.implicitReferencedOperator = implicitReferencedOperator;
}
public List<ExpressionOperator> getArguments() {
List<LogicalOperator> preds = getPlan().getPredecessors(this);
List<ExpressionOperator> args = new ArrayList<ExpressionOperator>();
if(preds == null)
return args;
for(LogicalOperator lo : preds){
args.add((ExpressionOperator)lo);
}
return args;
}
@Override
public boolean supportsMultipleInputs() {
return true;
}
@Override
public String name() {
return "UserFunc " + mKey.scope + "-" + mKey.id + " function: " + mFuncSpec;
}
@Override
public Schema getSchema() {
return mSchema;
}
@Override
public Schema.FieldSchema getFieldSchema() throws FrontendException {
if(!mIsFieldSchemaComputed) {
if(implicitReferencedOperator != null ){
// if this is a ReadScalars udf for scalar operation, use the
// FieldSchema corresponding to this position in input
List<ExpressionOperator> args = getArguments();
if(args != null && args.size() > 0 ){
int pos = (Integer)((LOConst)getArguments().get(0)).getValue();
LogicalOperator inp = implicitReferencedOperator;
if(inp.getSchema() != null){
// input logical operator has schema, copy and link
//to corresponding FieldSchema
FieldSchema inpFs = inp.getSchema().getField(pos);
mFieldSchema = Schema.FieldSchema.copyAndLink(inpFs, inp);
}else{
// no schema for input logicaloperator, use bytearray
// and set it as parent
mFieldSchema = new FieldSchema(null, DataType.BYTEARRAY);
mFieldSchema.setParent(null, inp);
}
mIsFieldSchemaComputed = true;
return mFieldSchema;
}else{
//predecessors haven't been setup, return null
return null;
}
}
Schema inputSchema = new Schema();
List<ExpressionOperator> args = getArguments();
for(ExpressionOperator op: args) {
if (!DataType.isUsableType(op.getType())) {
mFieldSchema = null;
mIsFieldSchemaComputed = false;
int errCode = 1014;
String msg = "Problem with input: " + op + " of User-defined function: " + this ;
throw new FrontendException(msg, errCode, PigException.INPUT, false, null) ;
}
inputSchema.add(op.getFieldSchema());
}
EvalFunc<?> ef = (EvalFunc<?>) PigContext.instantiateFuncFromSpec(mFuncSpec);
Schema udfSchema = ef.outputSchema(inputSchema);
byte returnType = DataType.findType(ef.getReturnType());
if (null != udfSchema) {
Schema.FieldSchema fs;
// try {
if(udfSchema.size() == 0) {
fs = new Schema.FieldSchema(null, null, returnType);
} else if(udfSchema.size() == 1) {
fs = new Schema.FieldSchema(udfSchema.getField(0));
} else {
fs = new Schema.FieldSchema(null, udfSchema, DataType.TUPLE);
}
// } catch (ParseException pe) {
// throw new FrontendException(pe.getMessage());
// }
setType(fs.type);
mFieldSchema = fs;
mIsFieldSchemaComputed = true;
} else {
setType(returnType);
mFieldSchema = new Schema.FieldSchema(null, null, returnType);
mIsFieldSchemaComputed = true;
}
}
return mFieldSchema;
}
@Override
public void visit(LOVisitor v) throws VisitorException {
v.visit(this);
}
/**
* @param funcSpec the FuncSpec to set
*/
public void setFuncSpec(FuncSpec funcSpec) {
mFuncSpec = funcSpec;
}
/**
* @see org.apache.pig.impl.logicalLayer.ExpressionOperator#clone()
* Do not use the clone method directly. Operators are cloned when logical plans
* are cloned using {@link LogicalPlanCloner}
*/
@Override
protected Object clone() throws CloneNotSupportedException {
LOUserFunc clone = (LOUserFunc)super.clone();
//note that mFuncSpec cannot be null in LOUserFunc
clone.mFuncSpec = mFuncSpec.clone();
return clone;
}
}