com.datasalt.pangool.tuplemr.mapred.BaseComparator.java Source code

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Here is the source code for com.datasalt.pangool.tuplemr.mapred.BaseComparator.java

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/**
 * 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.io.Serializable;

import org.apache.hadoop.conf.Configurable;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.RawComparator;

import com.datasalt.pangool.io.Schema.Field.Type;
import com.datasalt.pangool.tuplemr.TupleMRConfig;
import com.datasalt.pangool.tuplemr.TupleMRException;
import com.datasalt.pangool.tuplemr.serialization.SingleFieldDeserializer;

@SuppressWarnings("serial")
public abstract class BaseComparator<T> implements RawComparator<T>, Serializable, Configurable {

    private Configuration conf;
    private SingleFieldDeserializer fieldDeser1;
    private SingleFieldDeserializer fieldDeser2;
    private final Type type;
    private final Class<?> objectClazz;
    private T object1 = null;
    private T object2 = null;

    public BaseComparator(Type type) {
        this.type = type;
        this.objectClazz = null;
    }

    public BaseComparator(Type type, Class<?> clazz) {
        this.type = type;
        this.objectClazz = clazz;
    }

    @Override
    public void setConf(Configuration conf) {
        try {
            TupleMRConfig mrConfig = TupleMRConfig.get(conf);
            fieldDeser1 = new SingleFieldDeserializer(conf, mrConfig, type, objectClazz);
            fieldDeser2 = new SingleFieldDeserializer(conf, mrConfig, type, objectClazz);

        } catch (IOException e) {
            throw new RuntimeException(e);
        } catch (TupleMRException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public Configuration getConf() {
        return conf;
    }

    /**
     * Objects can be null. 
     */
    @Override
    public abstract int compare(T object1, T object2);

    @SuppressWarnings("unchecked")
    @Override
    public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) {
        try {
            object1 = (T) fieldDeser1.deserialize(b1, s1);
            object2 = (T) fieldDeser2.deserialize(b2, s2);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }

        return compare(object1, object2);
    }
}