fr.tse.fi2.hpp.labs.queries.impl.lab5.BloomFilterQuery.java Source code

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Here is the source code for fr.tse.fi2.hpp.labs.queries.impl.lab5.BloomFilterQuery.java

Source

package fr.tse.fi2.hpp.labs.queries.impl.lab5;

import java.io.UnsupportedEncodingException;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.BitSet;

import org.apache.commons.lang.RandomStringUtils;

import fr.tse.fi2.hpp.labs.beans.DebsRecord;
import fr.tse.fi2.hpp.labs.beans.measure.QueryProcessorMeasure;
import fr.tse.fi2.hpp.labs.queries.AbstractQueryProcessor;

public class BloomFilterQuery extends AbstractQueryProcessor {

    private final int k;
    private String[] salt;
    private BitSet bloomFilter;

    public BloomFilterQuery(QueryProcessorMeasure measure) {
        super(measure);

        k = 10;
        bloomFilter = new BitSet(14378);
        salt = new String[k];
        for (int i = 0; i < k; i++) {
            salt[i] = RandomStringUtils.random(10);
        }

    }

    @Override
    protected void process(DebsRecord record) {
        // TODO Auto-generated method stub
        String str = record.getHack_license() + record.getDropoff_latitude() + record.getDropoff_longitude()
                + record.getPickup_latitude() + record.getPickup_longitude();

        MessageDigest md = null;
        try {
            md = MessageDigest.getInstance("SHA-256");
        } catch (NoSuchAlgorithmException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }

        String[] str2hash = new String[k];
        for (int i = 0; i < 10; i++) {
            str2hash[i] = salt[i] + str;
            try {
                md.update(str2hash[i].toString().getBytes("UTF-8"));
            } catch (UnsupportedEncodingException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            byte[] res = md.digest();
            BigInteger indiceB = new BigInteger(res);
            int indice = indiceB.intValue();
            if (indice < 0)
                indice = -indice;
            indice = indice % 14378;
            if (!bloomFilter.get(indice))
                bloomFilter.set(indice);
        }

    }

    public boolean contain(String plaque, float loD, float laD, float loA, float laA) {
        String str = plaque + laA + loA + laD + loD;
        String[] str2hash = new String[k];

        MessageDigest md = null;
        try {
            md = MessageDigest.getInstance("SHA-256");
        } catch (NoSuchAlgorithmException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }

        for (int i = 0; i < 10; i++) {
            str2hash[i] = salt[i] + str;
            try {
                md.update(str2hash.toString().getBytes("UTF-16"));
            } catch (UnsupportedEncodingException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            byte[] res = md.digest();
            BigInteger indiceB = new BigInteger(res);
            int indice = indiceB.intValue();

            if (indice < 0)
                indice = -indice;
            indice = indice % 14378;
            if (!bloomFilter.get(indice))
                return false;
        }
        return true;
    }

}