gistfile1.java

/*
 OSSCUBE 2014
 */
package com.onepointltd.file.operations;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;
import java.util.logging.Level;
import java.util.logging.Logger;
import net.openhft.collections.HugeConfig;
import net.openhft.collections.HugeHashMap;
import org.junit.Test;

/**
 * Tests the behaviour of huge hash map compared.
 * 
 * 
 *
 * @author onepoint
 */
public class HugeMapTest {

    /**
     * The dictionary file.
     */
    public static final String DICT = "src/test/resources/dict.out";

    /**
     * Writes the content of a dictionary into HugeMap.
     */
    @Test
    public void testHugeMap() {

        System.out.println("Started hugemap ...");
        HugeConfig config = HugeConfig.DEFAULT.clone();

        final Map<CharSequence, CharSequence> map
                = new HugeHashMap<>(
                        config, CharSequence.class, CharSequence.class);
        try {
            putAndDump(map, new File("hugeMap.txt"));
        } catch (IOException ex) {
            Logger.getLogger(HugeMapTest.class.getName()).log(Level.SEVERE, null, ex);
        }

    }

    /**
     * Writes the content of a dictionary into a normal hash map.
     */
    @Test
    public void testNormalMap() {

        System.out.println("Started normal map ...");

        final Map<CharSequence, CharSequence> map = new HashMap<>();
        try {
            putAndDump(map, new File("normalMap.txt"));
        } catch (IOException ex) {
            Logger.getLogger(HugeMapTest.class.getName()).log(Level.SEVERE, null, ex);
        }

    }

    /**
     * Puts a dictionary into a map and dumps it to a file.
     *
     * @param map The map to test.
     * @param dumpFile The dictionary file.
     * @throws IOException
     */
    public void putAndDump(final Map<CharSequence, CharSequence> map, File dumpFile) throws IOException {
        if (!Files.exists(Paths.get(DICT))) {
            downloadDict();
        }
        try (PrintWriter writer = new PrintWriter(dumpFile)) {
            try (Scanner scanner = new Scanner(Paths.get(DICT))) {
                while (scanner.hasNext()) {
                    String term = scanner.next();
                    map.put(term, term);
                }
            } catch (IOException ex) {
                Logger.getLogger(HugeMapTest.class.getName()).log(Level.SEVERE, null, ex);
            }

            System.out.printf("#### %s%n", map.size());
            for (Map.Entry<CharSequence, CharSequence> entry : map.entrySet()) {
                writer.println(":: " + entry);
            }
        }
    }

    /**
     * Downloads the dictionary.
     */
    private void downloadDict() {
        try (BufferedReader reader = new BufferedReader(new InputStreamReader(
                new URL("https://raw.githubusercontent.com/eneko/data-repository/master/data/words.txt").openStream()));
                PrintWriter writer = new PrintWriter("dict.out")) {
            String line;
            while ((line = reader.readLine()) != null) {
                writer.println(line);
            }

        } catch (IOException ex) {
            Logger.getLogger(HugeMapTest.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
}