/*

 * Copyright (c) 2014 Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package org.openjdk.bench.java.net;

import java.io.IOException;

import java.net.InetAddress;

import java.net.InetSocketAddress;

import java.net.StandardProtocolFamily;

import java.nio.channels.UnixDomainSocketAddress;

import java.nio.ByteBuffer;

import java.nio.channels.ClosedChannelException;

import java.nio.channels.ServerSocketChannel;

import java.nio.channels.SocketChannel;

import java.nio.file.*;

import java.util.concurrent.TimeUnit;

import java.util.concurrent.atomic.AtomicInteger;

import org.openjdk.jmh.annotations.*;

/**

 * Tests sending a 128 byte message on a second, to a thread which

 * echo's it back and received by the original thread.

 * Benchmark is performed for "inet" channels over TCP/IP

 * and "unix" domain channels.

 */

@BenchmarkMode(Mode.Throughput)

@OutputTimeUnit(TimeUnit.MILLISECONDS)

@State(Scope.Thread)

public class SocketChannelCompare {

    static final int BUFSIZE = 128; // message size sent and received

    private ServerSocketChannel ssc;

    private SocketChannel s1, s2;

    private EchoThread rt;

    private ByteBuffer bb = ByteBuffer.allocate(BUFSIZE);

    private static volatile String tempDir;

    private static final AtomicInteger count = new AtomicInteger(0);

    private volatile Path socket;

    @Param({"inet", "unix"})

    private volatile String family;

    static {

        try {

            Path p = Files.createTempDirectory("readWriteTest");

            tempDir = p.toString();

        } catch (IOException e) {

            tempDir = null;

        }

    }

    private ServerSocketChannel getServerSocketChannel() throws IOException {

        if (family.equals("inet"))

            return getInetServerSocketChannel();

        else if (family.equals("unix"))

            return getUnixServerSocketChannel();

        throw new InternalError();

    }

    private ServerSocketChannel getInetServerSocketChannel() throws IOException {

        InetAddress iaddr = InetAddress.getLoopbackAddress();

        return ServerSocketChannel.open().bind(null);

    }

    private ServerSocketChannel getUnixServerSocketChannel() throws IOException {

        int next = count.incrementAndGet();

        socket = Paths.get(tempDir, Integer.toString(next));

        UnixDomainSocketAddress addr = new UnixDomainSocketAddress(socket);

        return ServerSocketChannel.open(StandardProtocolFamily.UNIX).bind(addr);

    }

    @Setup(Level.Trial)

    public void beforeRun() throws IOException {

        ssc = getServerSocketChannel();

        s1 = SocketChannel.open(ssc.getLocalAddress());

        s2 = ssc.accept();

        rt = new EchoThread(s2);

        rt.start();

    }

    @TearDown(Level.Trial)

    public void afterRun() throws IOException, InterruptedException {

        s1.close();

        s2.close();

        ssc.close();

        if (family.equals("unix")) {

            Files.delete(socket);

            Files.delete(Path.of(tempDir));

        }

        rt.join();

    }

    @Benchmark

    public void test() throws IOException {

        bb.position(0).limit(BUFSIZE);

        s1.write(bb);

        bb.clear();

        readFully(s1, bb);

    }

    // read until buf is full, or EOF. Always returns number of bytes read

    static int readFully(SocketChannel chan, ByteBuffer buf) throws IOException {

        int n = buf.remaining();

        int count = 0;

        while (n > 0) {

            int c = chan.read(buf);

            if (c == -1)

                return count;

            n -= c;

            count += c;

        }

        return count;

    }

    static class EchoThread extends Thread {

        private SocketChannel sc;

        public EchoThread(SocketChannel s2) {

            this.sc = s2;

        }

        public void run() {

            try {

                ByteBuffer bb = ByteBuffer.allocate(BUFSIZE);

                while (true) {

                    bb.clear();

                    int c = readFully(sc, bb);

                    if (c == 0) {

                        sc.close();

                        return;

                    }

                    bb.flip();

                    sc.write(bb);

                }

            } catch (ClosedChannelException ex) {

                // shutdown time

            } catch (IOException ioex) {

            }

        }

    }

}