/*
* 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.mapReduceLayer;
import java.io.IOException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configurable;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.BytesWritable;
import org.apache.hadoop.io.WritableComparator;
import org.apache.hadoop.mapred.JobConf;
import org.apache.pig.data.DataByteArray;
import org.apache.pig.impl.io.NullableBytesWritable;
import org.apache.pig.impl.util.ObjectSerializer;
public class PigBytesRawComparator extends WritableComparator implements Configurable {
private final Log mLog = LogFactory.getLog(getClass());
private boolean[] mAsc;
private BytesWritable.Comparator mWrappedComp;
public PigBytesRawComparator() {
super(NullableBytesWritable.class);
mWrappedComp = new BytesWritable.Comparator();
}
public void setConf(Configuration conf) {
if (!(conf instanceof JobConf)) {
mLog.warn("Expected jobconf in setConf, got " +
conf.getClass().getName());
return;
}
JobConf jconf = (JobConf)conf;
try {
mAsc = (boolean[])ObjectSerializer.deserialize(jconf.get(
"pig.sortOrder"));
} catch (IOException ioe) {
mLog.error("Unable to deserialize pig.sortOrder " +
ioe.getMessage());
throw new RuntimeException(ioe);
}
if (mAsc == null) {
mAsc = new boolean[1];
mAsc[0] = true;
}
}
public Configuration getConf() {
return null;
}
/**
* Compare two NullableBytesWritables as raw bytes. If neither are null,
* then IntWritable.compare() is used. If both are null then the indices
* are compared. Otherwise the null one is defined to be less.
*/
public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) {
int rc = 0;
// If either are null, handle differently.
if (b1[s1] == 0 && b2[s2] == 0) {
// Subtract 2, one for null byte and one for index byte
rc = mWrappedComp.compare(b1, s1 + 1, l1 - 2, b2, s2 + 1, l2 - 2);
} else {
// For sorting purposes two nulls are equal.
if (b1[s1] != 0 && b2[s2] != 0) rc = 0;
else if (b1[s1] != 0) rc = -1;
else rc = 1;
}
if (!mAsc[0]) rc *= -1;
return rc;
}
public int compare(Object o1, Object o2) {
NullableBytesWritable nbw1 = (NullableBytesWritable)o1;
NullableBytesWritable nbw2 = (NullableBytesWritable)o2;
int rc = 0;
// If either are null, handle differently.
if (!nbw1.isNull() && !nbw2.isNull()) {
rc = ((DataByteArray)nbw1.getValueAsPigType()).compareTo((DataByteArray)nbw2.getValueAsPigType());
} else {
// For sorting purposes two nulls are equal.
if (nbw1.isNull() && nbw2.isNull()) rc = 0;
else if (nbw1.isNull()) rc = -1;
else rc = 1;
}
if (!mAsc[0]) rc *= -1;
return rc;
}
}