/* * Copyright (C) 2014 Shashank Tulsyan * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package neembuu.release1.app; import java.io.File; import java.io.FileNotFoundException; import java.io.IOException; import java.io.RandomAccessFile; import java.nio.MappedByteBuffer; import java.nio.channels.FileChannel; import static java.nio.file.StandardOpenOption.*; public class MemoryMapWriter { public static void main(String[] args) throws FileNotFoundException, IOException, InterruptedException { File f = new File("f:\\tempimages\\mapped.txt"); f.delete(); FileChannel fc = FileChannel.open(f.toPath(), READ, WRITE); //new RandomAccessFile(f, "rw").getChannel(); long bufferSize = 8 * 1000; MappedByteBuffer mem = fc.map(FileChannel.MapMode.READ_WRITE, 0, bufferSize); int start = 0; long counter = 1; long HUNDREDK = 100000; long startT = System.currentTimeMillis(); long noOfMessage = HUNDREDK * 10 * 10; for (;;) { if (!mem.hasRemaining()) { start += mem.position(); mem = fc.map(FileChannel.MapMode.READ_WRITE, start, bufferSize); } mem.putLong(counter); counter++; if (counter > noOfMessage) { break; } } long endT = System.currentTimeMillis(); long tot = endT - startT; System.out.println(String.format("No Of Message %s , Time(ms) %s ", noOfMessage, tot)); } }