package basic.nio;

import java.io.BufferedOutputStream;

import java.io.DataOutputStream;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.RandomAccessFile;

import java.nio.IntBuffer;

import java.nio.channels.FileChannel;

public class MappedIO {

private static int numOfInts = 4000000;

private static int numOfUbuffInts = 200000;

private abstract static class Testter {

private String name;

public Testter(String name) {

this.name = name;

}

public void runTest() {

try {

long start = System.nanoTime();

test();

double duration = System.nanoTime() - start;

System.out.format("%.2f\n", duration / 1.0e9);

} catch (IOException e) {

throw new RuntimeException(e);

}

}

public abstract void test() throws IOException;

}

private static Testter[] tests = {

new Testter("Stream Write") {

@Override

public void test() throws IOException {

DataOutputStream dos = new DataOutputStream(

new BufferedOutputStream(new FileOutputStream(new File("temp.tmp"))));

for (int i = 0; i < numOfInts; i++) {

dos.writeInt(1);

}

dos.close();

}

},

new Testter("Mapped Writer") {

@Override

public void test() throws IOException {

FileChannel fc = new RandomAccessFile("temp.tmp", "rw").getChannel();

IntBuffer ib = fc.map(FileChannel.MapMode.READ_WRITE, 0, fc.size()).asIntBuffer();

for (int i = 0; i < numOfInts; i++) {

ib.put(i);

}

fc.close();

}

}

};

}