/*
* 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.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.WritableComparator;
import org.apache.hadoop.mapred.JobConf;
import org.apache.pig.backend.executionengine.ExecException;
import org.apache.pig.data.BinInterSedes;
import org.apache.pig.data.DataType;
import org.apache.pig.data.Tuple;
import org.apache.pig.data.TupleFactory;
import org.apache.pig.data.TupleRawComparator;
import org.apache.pig.impl.io.NullableTuple;
import org.apache.pig.impl.util.ObjectSerializer;
public class PigTupleDefaultRawComparator extends WritableComparator implements TupleRawComparator {
private final Log mLog = LogFactory.getLog(getClass());
private boolean[] mAsc;
private boolean mWholeTuple;
private boolean mHasNullField;
public PigTupleDefaultRawComparator() {
super(TupleFactory.getInstance().tupleClass());
}
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;
}
// If there's only one entry in mAsc, it means it's for the whole
// tuple. So we can't be looking for each column.
mWholeTuple = (mAsc.length == 1);
}
public Configuration getConf() {
return null;
}
@Override
public boolean hasComparedTupleNull() {
return mHasNullField;
}
private static final BinInterSedes bis = new BinInterSedes();
/**
* Compare two NullableTuples 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;
mHasNullField = false;
Tuple t1;
Tuple t2;
// This can't be done on the raw data. Users are allowed to
// implement their own versions of tuples, which means we have no
// idea what the underlying representation is. So step one is to
// instantiate each object as a tuple.
try {
t1 = bis.readTuple(new DataInputStream(new ByteArrayInputStream(b1, s1, l1)));
t2 = bis.readTuple(new DataInputStream(new ByteArrayInputStream(b2, s2, l2)));
} catch (IOException ioe) {
mLog.error("Unable to instantiate tuples for comparison: " + ioe.getMessage());
throw new RuntimeException(ioe.getMessage(), ioe);
}
rc = compareTuple(t1, t2); //TODO think about how SchemaTuple could speed this up
return rc;
}
public int compare(Object o1, Object o2) {
NullableTuple nt1 = (NullableTuple) o1;
NullableTuple nt2 = (NullableTuple) o2;
int rc = 0;
// If either are null, handle differently.
if (!nt1.isNull() && !nt2.isNull()) {
rc = compareTuple((Tuple) nt1.getValueAsPigType(), (Tuple) nt2.getValueAsPigType());
} else {
// For sorting purposes two nulls are equal.
if (nt1.isNull() && nt2.isNull())
rc = 0;
else if (nt1.isNull())
rc = -1;
else
rc = 1;
if (mWholeTuple && !mAsc[0])
rc *= -1;
}
return rc;
}
private int compareTuple(Tuple t1, Tuple t2) {
int sz1 = t1.size();
int sz2 = t2.size();
if (sz2 < sz1) {
return 1;
} else if (sz2 > sz1) {
return -1;
} else {
for (int i = 0; i < sz1; i++) {
try {
Object o1 = t1.get(i);
Object o2 = t2.get(i);
if (o1==null || o2==null)
mHasNullField = true;
int c = DataType.compare(o1, o2);
if (c != 0) {
if (!mWholeTuple && !mAsc[i])
c *= -1;
else if (mWholeTuple && !mAsc[0])
c *= -1;
return c;
}
} catch (ExecException e) {
throw new RuntimeException("Unable to compare tuples", e);
}
}
return 0;
}
}
}