/***********************************************************************************************************************
* Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
*
* 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 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 eu.stratosphere.api.java.record.operators;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.commons.lang3.Validate;
import eu.stratosphere.api.common.operators.Operator;
import eu.stratosphere.api.common.operators.RecordOperator;
import eu.stratosphere.api.common.operators.base.CrossOperatorBase;
import eu.stratosphere.api.common.operators.util.UserCodeClassWrapper;
import eu.stratosphere.api.common.operators.util.UserCodeObjectWrapper;
import eu.stratosphere.api.common.operators.util.UserCodeWrapper;
import eu.stratosphere.api.java.record.functions.CrossFunction;
import eu.stratosphere.api.java.record.functions.FunctionAnnotation;
import eu.stratosphere.types.Key;
import eu.stratosphere.types.Record;
/**
* CrossOperator that applies a {@link CrossFunction} to each element of the Cartesian Product.
*
* @see CrossFunction
*/
public class CrossOperator extends CrossOperatorBase<Record, Record, Record, CrossFunction> implements RecordOperator {
/**
* Creates a Builder with the provided {@link CrossFunction} implementation.
*
* @param udf The {@link CrossFunction} implementation for this Cross operator.
*/
public static Builder builder(CrossFunction udf) {
return new Builder(new UserCodeObjectWrapper<CrossFunction>(udf));
}
/**
* Creates a Builder with the provided {@link CrossFunction} implementation.
*
* @param udf The {@link CrossFunction} implementation for this Cross operator.
*/
public static Builder builder(Class<? extends CrossFunction> udf) {
return new Builder(new UserCodeClassWrapper<CrossFunction>(udf));
}
/**
* The private constructor that only gets eIinvoked from the Builder.
* @param builder
*/
protected CrossOperator(Builder builder) {
super(builder.udf, OperatorInfoHelper.binary(), builder.name);
if (builder.inputs1 != null && !builder.inputs1.isEmpty()) {
setFirstInput(Operator.createUnionCascade(builder.inputs1));
}
if (builder.inputs2 != null && !builder.inputs2.isEmpty()) {
setSecondInput(Operator.createUnionCascade(builder.inputs2));
}
setBroadcastVariables(builder.broadcastInputs);
setSemanticProperties(FunctionAnnotation.readDualConstantAnnotations(builder.udf));
}
@Override
public Class<? extends Key<?>>[] getKeyClasses() {
return emptyClassArray();
}
// --------------------------------------------------------------------------------------------
/**
* Builder pattern, straight from Joshua Bloch's Effective Java (2nd Edition).
*/
public static class Builder {
/* The required parameters */
private final UserCodeWrapper<CrossFunction> udf;
/* The optional parameters */
private List<Operator<Record>> inputs1;
private List<Operator<Record>> inputs2;
private Map<String, Operator<Record>> broadcastInputs;
private String name;
/**
* Creates a Builder with the provided {@link CrossFunction} implementation.
*
* @param udf The {@link CrossFunction} implementation for this Cross operator.
*/
protected Builder(UserCodeWrapper<CrossFunction> udf) {
this.udf = udf;
this.inputs1 = new ArrayList<Operator<Record>>();
this.inputs2 = new ArrayList<Operator<Record>>();
this.broadcastInputs = new HashMap<String, Operator<Record>>();
}
/**
* Sets the first input.
*
* @param input The first input.
*/
public Builder input1(Operator<Record> input) {
Validate.notNull(input, "The input must not be null");
this.inputs1.clear();
this.inputs1.add(input);
return this;
}
/**
* Sets the second input.
*
* @param input The second input.
*/
public Builder input2(Operator<Record> input) {
Validate.notNull(input, "The input must not be null");
this.inputs2.clear();
this.inputs2.add(input);
return this;
}
/**
* Sets one or several inputs (union) for input 1.
*
* @param inputs
*/
public Builder input1(Operator<Record>...inputs) {
this.inputs1.clear();
for (Operator<Record> c : inputs) {
this.inputs1.add(c);
}
return this;
}
/**
* Sets one or several inputs (union) for input 2.
*
* @param inputs
*/
public Builder input2(Operator<Record>...inputs) {
this.inputs2.clear();
for (Operator<Record> c : inputs) {
this.inputs2.add(c);
}
return this;
}
/**
* Sets the first inputs.
*
* @param inputs
*/
public Builder inputs1(List<Operator<Record>> inputs) {
this.inputs1 = inputs;
return this;
}
/**
* Sets the second inputs.
*
* @param inputs
*/
public Builder inputs2(List<Operator<Record>> inputs) {
this.inputs2 = inputs;
return this;
}
/**
* Binds the result produced by a plan rooted at {@code root} to a
* variable used by the UDF wrapped in this operator.
*/
public Builder setBroadcastVariable(String name, Operator<Record> input) {
this.broadcastInputs.put(name, input);
return this;
}
/**
* Binds multiple broadcast variables.
*/
public Builder setBroadcastVariables(Map<String, Operator<Record>> inputs) {
this.broadcastInputs.clear();
this.broadcastInputs.putAll(inputs);
return this;
}
/**
* Sets the name of this operator.
*
* @param name
*/
public Builder name(String name) {
this.name = name;
return this;
}
/**
* Creates and returns a CrossOperator from using the values given
* to the builder.
*
* @return The created operator
*/
public CrossOperator build() {
setNameIfUnset();
return new CrossOperator(this);
}
protected void setNameIfUnset() {
if (name == null) {
name = udf.getUserCodeClass().getName();
}
}
}
}