/**
* Copyright [2012] [Datasalt Systems S.L.]
*
* 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 com.datasalt.pangool.tuplemr.mapred;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.hadoop.conf.Configuration;
import com.datasalt.pangool.io.ITuple;
import com.datasalt.pangool.io.Schema;
import com.datasalt.pangool.io.Schema.Field.FieldSerializer;
import com.datasalt.pangool.tuplemr.Criteria;
import com.datasalt.pangool.tuplemr.Criteria.SortElement;
import com.datasalt.pangool.tuplemr.TupleMRConfigBuilder;
/**
*
* Tuple-based MapRed jobs binary group comparator. Used to group tuples
* according to {@link TupleMRConfigBuilder#setGroupByFields(String...)}
*
*/
public class GroupComparator extends SortComparator {
private Criteria groupCriteria;
public GroupComparator(){}
@Override
public int compare(ITuple w1, ITuple w2) {
int schemaId1 = tupleMRConf.getSchemaIdByName(w1.getSchema().getName());
int schemaId2 = tupleMRConf.getSchemaIdByName(w2.getSchema().getName());
int[] indexes1 = serInfo.getGroupSchemaIndexTranslation(schemaId1);
int[] indexes2 = serInfo.getGroupSchemaIndexTranslation(schemaId2);
FieldSerializer[] serializers = serInfo.getGroupSchemaSerializers();
return compare(w1.getSchema(), groupCriteria, w1, indexes1, w2, indexes2,serializers);
}
@Override
public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) {
try{
Schema groupSchema = serInfo.getGroupSchema();
return compare(b1,s1,b2,s2,groupSchema,groupCriteria,offsets);
} catch(IOException e){
throw new RuntimeException(e);
}
}
@Override
public void setConf(Configuration conf) {
super.setConf(conf);
//THIS SHOULD BE IN SerInfo
List<SortElement> sortElements = tupleMRConf.getCommonCriteria().getElements();
int numGroupByFields = tupleMRConf.getGroupByFields().size();
List<SortElement> groupSortElements = new ArrayList<SortElement>();
groupSortElements.addAll(sortElements);
groupSortElements = groupSortElements.subList(0,numGroupByFields);
groupCriteria = new Criteria(groupSortElements);
TupleMRConfigBuilder.initializeComparators(conf, tupleMRConf);
}
}