/*
* 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.backend.hadoop.executionengine.physicalLayer.relationalOperators;
import java.util.List;
import org.apache.pig.backend.executionengine.ExecException;
import org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMapReduceCounter;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.POStatus;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.Result;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.plans.PhyPlanVisitor;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.plans.PhysicalPlan;
import org.apache.pig.data.DataType;
import org.apache.pig.data.Tuple;
import org.apache.pig.data.TupleFactory;
import org.apache.pig.impl.plan.OperatorKey;
import org.apache.pig.impl.plan.VisitorException;
import org.apache.pig.pen.util.ExampleTuple;
import org.apache.pig.pen.util.LineageTracer;
/**
* This operator is part of the RANK operator implementation.
* It adds a local counter and a unique task id to each tuple.
* There are 2 modes of operations: regular and dense.
* The local counter is depends on the mode of operation.
* With regular rank is considered duplicate rows while assigning
* numbers to distinct values groups.
* With dense rank counts the number of distinct values, without
* considering duplicate rows. Depending on if it is considered.
* the entire tuple (row number) or a by a set of columns (rank by).
*
* This Physical Operator relies on some specific MR class,
* available at PigMapReduceCounter.
**/
public class POCounter extends PhysicalOperator {
private static final long serialVersionUID = 1L;
private static final Long ONE = 1L;
private List<PhysicalPlan> counterPlans;
private List<Boolean> mAscCols;
/**
* In case of RANK BY, it could by dense or not.
* Being a dense rank means to assign consecutive ranks
* to different values.
**/
private boolean isDenseRank = false;
/**
* In case of simple RANK, namely row number mode
* which is a consecutive number assigned to each tuple.
**/
private boolean isRowNumber = false;
protected static final TupleFactory mTupleFactory = TupleFactory.getInstance();
/**
* Local counter for tuples on the same task.
**/
private Long localCount = 1L;
/**
* Task ID to label each tuple analyzed by the corresponding task
**/
private String taskID = "-1";
/**
* Unique identifier that links POCounter and PORank,
* through the global counter labeled with it.
**/
private String operationID;
public POCounter(OperatorKey k) {
this(k, -1, null);
}
public POCounter(OperatorKey k, int rp) {
this(k, rp, null);
}
public POCounter(OperatorKey k, List<PhysicalOperator> inputs) {
this(k, -1, inputs);
}
public POCounter(OperatorKey k, int rp, List<PhysicalOperator> inputs) {
super(k, rp, inputs);
}
@SuppressWarnings({ "rawtypes", "unchecked" })
public POCounter(OperatorKey operatorKey, int requestedParallelism,
List inp, List<PhysicalPlan> counterPlans,
List<Boolean> ascendingCol) {
super(operatorKey, requestedParallelism, inp);
this.setCounterPlans(counterPlans);
this.setAscendingColumns(ascendingCol);
}
@Override
public Tuple illustratorMarkup(Object in, Object out, int eqClassIndex) {
if(illustrator != null){
return new ExampleTuple((Tuple)out);
}
return (Tuple) out;
}
@Override
public void visit(PhyPlanVisitor v) throws VisitorException {
v.visitCounter(this);
}
@Override
public Result getNextTuple() throws ExecException {
Result inp = null;
while (true) {
inp = processInput();
if (inp.returnStatus == POStatus.STATUS_EOP
|| inp.returnStatus == POStatus.STATUS_ERR)
break;
if (inp.returnStatus == POStatus.STATUS_NULL) {
continue;
}
return addCounterValue(inp);
}
return inp;
}
/**
* Add current task id and local counter value.
* @param input from the previous output
* @return a tuple within two values prepended to the tuple
* the task identifier and the local counter value.
* Local counter value could be incremented by one (is a row number or dense rank)
* or, could be incremented by the size of the bag on the previous tuple processed
**/
protected Result addCounterValue(Result input) throws ExecException {
Tuple in = (Tuple) input.result;
Tuple out = mTupleFactory.newTuple(in.getAll().size() + 2);
Long sizeBag = 0L;
int positionBag, i = 2;
// Tuples are added by two stamps before the tuple content:
// 1.- At position 0: Current taskId
out.set(0, getTaskId());
// 2.- At position 1: counter value
//On this case, each tuple is analyzed independently of the tuples grouped
if(isRowNumber() || isDenseRank()) {
//Only when is Dense Rank (attached to a reduce phase) it is incremented on this way
//Otherwise, the increment is done at mapper automatically
if(isDenseRank())
PigMapReduceCounter.PigReduceCounter.incrementCounter(POCounter.ONE);
out.set(1, getLocalCounter());
//and the local incrementer is sequentially increased.
incrementLocalCounter();
} else if(!isDenseRank()) {
//Standard rank: On this case is important the
//number of tuples on the same group.
positionBag = in.getAll().size()-1;
if (in.getType(positionBag) == DataType.BAG) {
sizeBag = ((org.apache.pig.data.DefaultAbstractBag)in.get(positionBag)).size();
}
//This value (the size of the tuples on the bag) is used to increment
//the current global counter and
PigMapReduceCounter.PigReduceCounter.incrementCounter(sizeBag);
out.set(1, getLocalCounter());
//the value for the next tuple on the current task
addToLocalCounter(sizeBag);
}
for (Object o : in) {
out.set(i++, o);
}
input.result = illustratorMarkup(in, out, 0);
return input;
}
@Override
public boolean supportsMultipleInputs() {
return false;
}
@Override
public boolean supportsMultipleOutputs() {
return false;
}
@Override
public String name() {
return getAliasString() + "POCounter" + "["
+ DataType.findTypeName(resultType) + "]" + " - "
+ mKey.toString();
}
public void setCounterPlans(List<PhysicalPlan> counterPlans) {
this.counterPlans = counterPlans;
}
public List<PhysicalPlan> getCounterPlans() {
return counterPlans;
}
public void setAscendingColumns(List<Boolean> mAscCols) {
this.mAscCols = mAscCols;
}
public List<Boolean> getAscendingColumns() {
return mAscCols;
}
/**
* Initialization step into the POCounter is to set
* up local counter to 1.
**/
public void resetLocalCounter() {
this.localCount = 1L;
}
/**
* Sequential counter used at ROW NUMBER and RANK BY DENSE mode
**/
public Long incrementLocalCounter() {
return localCount++;
}
public void setLocalCounter(Long localCount) {
this.localCount = localCount;
}
public Long getLocalCounter() {
return this.localCount;
}
public void addToLocalCounter(Long sizeBag) {
this.localCount += sizeBag;
}
/**
* Task ID: identifier of the task (map or reducer)
**/
public void setTaskId(String taskID) {
this.taskID = taskID;
}
public String getTaskId() {
return this.taskID;
}
/**
* Dense Rank flag
**/
public void setIsDenseRank(boolean isDenseRank) {
this.isDenseRank = isDenseRank;
}
public boolean isDenseRank() {
return isDenseRank;
}
/**
* Row number flag
**/
public void setIsRowNumber(boolean isRowNumber) {
this.isRowNumber = isRowNumber;
}
public boolean isRowNumber() {
return isRowNumber;
}
/**
* Operation ID: identifier shared within the corresponding PORank
**/
public void setOperationID(String operationID) {
this.operationID = operationID;
}
public String getOperationID() {
return operationID;
}
}