/*
* 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.WritableComparator;
import org.apache.hadoop.mapred.JobConf;
import org.apache.pig.data.BinInterSedes;
import org.apache.pig.data.DataType;
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 WritableComparator mWrappedComp;
public PigBytesRawComparator() {
super(NullableBytesWritable.class);
mWrappedComp = new BinInterSedes.BinInterSedesTupleRawComparator();
}
public void setConf(Configuration conf) {
try {
mAsc = (boolean[])ObjectSerializer.deserialize(conf.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;
}
((BinInterSedes.BinInterSedesTupleRawComparator)mWrappedComp).setConf(conf);
}
public Configuration getConf() {
return null;
}
/**
* Compare two NullableBytesWritables as raw bytes.
* If both are null, then the indices are compared.
* If neither are null
* and both are bytearrays, then direct Writable.compareBytes is used.
* For non-bytearrays, we use BinInterSedesTupleRawComparator.
* If either is null, 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) {
// Checking if both of them are ByteArrays.
// b1[s1+1] is always TUPLE_1 so skipping.
// b1[s1+2] contains the datatype followed by a datasize.
// No need to read the actual size since it is given from l1&l2.
// We just need to skip those bytes here.
// This shortcut is placed here for performances purposes.(PIG-2975)
boolean dataByteArraysCompare=true;
int offset1,offset2,length1,length2;
switch(b1[s1 + 2]) {
case BinInterSedes.TINYBYTEARRAY:
// skipping mNull, TUPLE_1, TINYBYTEARRAY(1byte), size(1byte)
offset1 = s1 + 4;
length1 = l1 - 4;
break;
case BinInterSedes.SMALLBYTEARRAY:
// skipping mNull, TUPLE_1, SMALLBYTEARRAY(1byte), size(2byte)
offset1 = s1 + 5;
length1 = l1 - 5;
break;
case BinInterSedes.BYTEARRAY:
// skipping mNull, TUPLE_1, BYTEARRAY(1byte), size(4byte)
offset1 = s1 + 7;
length1 = l1 - 7;
break;
default:
offset1 = length1 = 0;
dataByteArraysCompare = false;
}
switch(b2[s2 + 2]) {
case BinInterSedes.TINYBYTEARRAY:
offset2 = s2 + 4;
length2 = l2 - 4;
break;
case BinInterSedes.SMALLBYTEARRAY:
offset2 = s2 + 5;
length2 = l2 - 5;
break;
case BinInterSedes.BYTEARRAY:
offset2 = s2 + 7;
length2 = l2 - 7;
break;
default:
offset2 = length2 = 0;
dataByteArraysCompare=false;
}
if( dataByteArraysCompare ) {
rc = WritableComparator.compareBytes(b1, offset1, length1, b2, offset2, length2);
} else {
// Subtract 2, one for null byte and one for index byte. Also, do not reverse the sign
// of rc when mAsc[0] is false because BinInterSedesTupleRawComparator.compare() already
// takes that into account.
return 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 = DataType.compare(nbw1.getValueAsPigType(), 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;
}
}