/*
* 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.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Iterator;
import java.util.Set;
import org.apache.pig.FuncSpec;
import org.apache.pig.PigException;
import org.apache.pig.impl.logicalLayer.schema.Schema;
import org.apache.pig.impl.plan.OperatorKey;
import org.apache.pig.impl.plan.ProjectionMap;
import org.apache.pig.impl.plan.RequiredFields;
import org.apache.pig.impl.plan.VisitorException;
import org.apache.pig.impl.plan.PlanVisitor;
import org.apache.pig.impl.util.Pair;
import org.apache.pig.data.DataType;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
public class LOSort extends LogicalOperator {
private static final long serialVersionUID = 2L;
private List<Boolean> mAscCols;
private FuncSpec mSortFunc;
private boolean mIsStar = false;
private long limit;
private List<LogicalPlan> mSortColPlans;
private static Log log = LogFactory.getLog(LOSort.class);
/**
* @param plan
* LogicalPlan this operator is a part of.
* @param key
* OperatorKey for this operator
* @param sortColPlans
* Array of column numbers that will be used for sorting data.
* @param ascCols
* Array of booleans. Should be same size as sortCols. True
* indicates sort ascending (default), false sort descending. If
* this array is null, then all columns will be sorted ascending.
* @param sortFunc
* the user defined sorting function
*/
public LOSort(
LogicalPlan plan,
OperatorKey key,
List<LogicalPlan> sortColPlans,
List<Boolean> ascCols,
FuncSpec sortFunc) {
super(plan, key);
mSortColPlans = sortColPlans;
mAscCols = ascCols;
mSortFunc = sortFunc;
limit = -1;
}
public LogicalOperator getInput() {
return mPlan.getPredecessors(this).get(0);
}
public List<LogicalPlan> getSortColPlans() {
return mSortColPlans;
}
public void setSortColPlans(List<LogicalPlan> sortPlans) {
mSortColPlans = sortPlans;
}
public List<Boolean> getAscendingCols() {
return mAscCols;
}
public void setAscendingCols(List<Boolean> ascCols) {
mAscCols = ascCols;
}
public FuncSpec getUserFunc() {
return mSortFunc;
}
public void setUserFunc(FuncSpec func) {
mSortFunc = func;
}
public boolean isStar() {
return mIsStar;
}
public void setStar(boolean b) {
mIsStar = b;
}
public void setLimit(long l)
{
limit = l;
}
public long getLimit()
{
return limit;
}
public boolean isLimited()
{
return (limit!=-1);
}
@Override
public String name() {
return "SORT " + mKey.scope + "-" + mKey.id;
}
@Override
public Schema getSchema() throws FrontendException {
if (!mIsSchemaComputed) {
// get our parent's schema
Collection<LogicalOperator> s = mPlan.getPredecessors(this);
ArrayList<Schema.FieldSchema> fss = new ArrayList<Schema.FieldSchema>();
try {
LogicalOperator op = s.iterator().next();
if (null == op) {
int errCode = 1006;
String msg = "Could not find operator in plan";
throw new FrontendException(msg, errCode, PigException.INPUT, false, null);
}
if(op instanceof ExpressionOperator) {
Schema.FieldSchema fs = new Schema.FieldSchema(((ExpressionOperator)op).getFieldSchema());
if(DataType.isSchemaType(fs.type)) {
mSchema = fs.schema;
} else {
fss.add(fs);
mSchema = new Schema(fss);
}
} else {
mSchema = op.getSchema();
}
mIsSchemaComputed = true;
} catch (FrontendException ioe) {
mSchema = null;
mIsSchemaComputed = false;
throw ioe;
}
}
return mSchema;
}
@Override
public boolean supportsMultipleInputs() {
return false;
}
public void visit(LOVisitor v) throws VisitorException {
v.visit(this);
}
public byte getType() {
return DataType.BAG ;
}
/**
* @see org.apache.pig.impl.logicalLayer.LogicalOperator#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 {
LOSort clone = (LOSort) super.clone();
// deep copy sort related attributes
if(mAscCols != null) {
clone.mAscCols = new ArrayList<Boolean>();
for (Iterator<Boolean> it = mAscCols.iterator(); it.hasNext();) {
clone.mAscCols.add(new Boolean(it.next()));
}
}
if(mSortFunc != null)
clone.mSortFunc = mSortFunc.clone();
if(mSortColPlans != null) {
clone.mSortColPlans = new ArrayList<LogicalPlan>();
for (Iterator<LogicalPlan> it = mSortColPlans.iterator(); it.hasNext();) {
LogicalPlanCloneHelper lpCloneHelper = new LogicalPlanCloneHelper(it.next());
clone.mSortColPlans.add(lpCloneHelper.getClonedPlan());
}
}
return clone;
}
@Override
public ProjectionMap getProjectionMap() {
Schema outputSchema;
try {
outputSchema = getSchema();
} catch (FrontendException fee) {
return null;
}
if(outputSchema == null) {
return null;
}
Schema inputSchema = null;
List<LogicalOperator> predecessors = (ArrayList<LogicalOperator>)mPlan.getPredecessors(this);
if(predecessors != null) {
try {
inputSchema = predecessors.get(0).getSchema();
} catch (FrontendException fee) {
return null;
}
} else {
return null;
}
if(inputSchema == null) {
return null;
}
if(Schema.equals(inputSchema, outputSchema, false, true)) {
//there is a one is to one mapping between input and output schemas
return new ProjectionMap(false);
} else {
//problem - input and output schemas for a sort have to match!
return null;
}
}
@Override
public List<RequiredFields> getRequiredFields() {
List<RequiredFields> requiredFields = new ArrayList<RequiredFields>();
Set<Pair<Integer, Integer>> fields = new HashSet<Pair<Integer, Integer>>();
Set<LOProject> projectSet = new HashSet<LOProject>();
boolean orderByStar = false;
for (LogicalPlan plan : getSortColPlans()) {
TopLevelProjectFinder projectFinder = new TopLevelProjectFinder(
plan);
try {
projectFinder.visit();
} catch (VisitorException ve) {
requiredFields.clear();
requiredFields.add(null);
return requiredFields;
}
projectSet.addAll(projectFinder.getProjectSet());
if(projectFinder.getProjectStarSet() != null) {
orderByStar = true;
}
}
if(orderByStar) {
requiredFields.add(new RequiredFields(true));
return requiredFields;
} else {
for (LOProject project : projectSet) {
for (int inputColumn : project.getProjection()) {
fields.add(new Pair<Integer, Integer>(0, inputColumn));
}
}
if(fields.size() == 0) {
requiredFields.add(new RequiredFields(false, true));
} else {
requiredFields.add(new RequiredFields(new ArrayList<Pair<Integer, Integer>>(fields)));
}
return (requiredFields.size() == 0? null: requiredFields);
}
}
}