/*

 * Copyright (c) 2019, 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.

 */

/**

 * @test

 * @bug 8231358

 * @run main/othervm Basic 32000 32000 nagle-off

 * @run main/othervm Basic default default nagle-off

 * @summary Basic test for Unix Domain and Inet socket and server socket channels

 */

import java.io.IOException;

import java.net.*;

import java.nio.ByteBuffer;

import java.nio.channels.*;

import java.nio.file.Files;

import java.nio.file.Path;

import java.util.LinkedList;

import java.util.List;

public class Basic {

    static int sockRxBufsize, sockTxBufsize;

    static boolean nagle;

    public static void main(String args[]) throws Exception {

        if (args.length != 3)

            usage();

        sockRxBufsize = getInt(args[0]);

        sockTxBufsize = getInt(args[1]);

        if (args[2].equals("nagle-on"))

            nagle = true;

        else if (args[2].equals("nagle-off"))

            nagle = false;

        warmup();

        test(128, 1000);

        test(8 * 1024, 10000);

        test(16 * 1024, 10000);

        test(32 * 1024, 10000);

    }

    static int getInt(String s) {

        if (s.equalsIgnoreCase("default"))

            return -1;

        else

            return Integer.parseInt(s);

    }

    static void usage() {

        System.out.println("usage: java Basic " +

            "<kernel sock read buf size> <kernel sock send buf size> {nagle-on|nagle-off}");

        System.out.println("nagle setting only affects TCP sockets");

        System.exit(-1);

    }

    static void warmup() throws Exception {

        Server server = new Server(StandardProtocolFamily.UNIX, 1024);

        Client client = new Client(server, 128, 100);

        server.start();

        client.run();

        server = new Server(StandardProtocolFamily.INET, 1024);

        client = new Client(server, 128, 100);

        server.start();

        client.run();

    }

    static void test(int bufsize, int nbufs) throws Exception {

        long unix = testUnix(bufsize, nbufs);

        long inet = testInet(bufsize, nbufs);

        // expect unix to be faster (express as percentage of inet)

        long percent = (unix * 100) / inet;

        System.out.printf ("Unix elapsed time is %d%% of the INET time\n\n", percent);

    }

    static long testUnix(int bufsize, int nbufs) throws Exception {

        Server server = new Server(StandardProtocolFamily.UNIX, bufsize);

        Client client = new Client(server, bufsize, nbufs);

        System.out.printf("Test (family=unix bufsize=%d, nbufs=%d) ", bufsize, nbufs);

        server.start();

        client.run();

        long unix = client.elapsed();

        int sbuf = client.sendSocketBufsize();

        int rbuf = client.receiveSocketBufsize();

        System.out.printf("completed in %d ns (sbuf=%d, rbuf=%d)\n", unix, sbuf, rbuf);

        System.gc();

        return unix;

    }

    static long testInet(int bufsize, int nbufs) throws Exception {

        Server server = new Server(StandardProtocolFamily.INET, bufsize);

        Client client = new Client(server, bufsize, nbufs);

        System.out.printf("Test (family=inet bufsize=%d, nbufs=%d) ", bufsize, nbufs);

        server.start();

        client.run();

        long inet = client.elapsed();

        System.gc();

        int sbuf = client.sendSocketBufsize();

        int rbuf = client.receiveSocketBufsize();

        System.out.printf("completed in %d ns (sbuf=%d, rbuf=%d)\n", inet, sbuf, rbuf);

        return inet;

    }

    static void setNagle(SocketChannel chan, boolean value) throws IOException {

        if (chan.getRemoteAddress() instanceof InetSocketAddress) {

            chan.setOption(StandardSocketOptions.TCP_NODELAY, value);

        }

    }

    static void setSendBufferSize(SocketChannel chan, int bufsize) throws IOException {

        if (bufsize < 0)

            return;

        chan.setOption(StandardSocketOptions.SO_SNDBUF, bufsize);

    }

    static void setRecvBufferSize(SocketChannel chan, int bufsize) throws IOException {

        if (bufsize < 0)

            return;

        chan.setOption(StandardSocketOptions.SO_RCVBUF, bufsize);

    }

    static class Server extends Thread {

        ServerSocketChannel server;

        SocketAddress address;

        SocketChannel connection;

        SelectionKey ckey;

        List<ByteBuffer> toSend = new LinkedList<>();

        final int bufsize;

        Server(ProtocolFamily family, int bufsize) throws IOException {

            setDaemon(true);

            SocketAddress addr;

            this.bufsize = bufsize;

            if (family == StandardProtocolFamily.UNIX) {

                server = ServerSocketChannel.open(family);

                Path sockfile = Path.of("server.sock");

                Files.deleteIfExists(sockfile);

                addr = new UnixDomainSocketAddress(sockfile);

            } else {

                server = ServerSocketChannel.open();

                addr = new InetSocketAddress(InetAddress.getLoopbackAddress(), 0);

            }

            server.bind(addr);

            address = server.getLocalAddress();

        }

        SocketAddress getAddress() {

            return address;

        }

        public void  run() {

            try {

                server.configureBlocking(false);

                Selector sel = Selector.open();

                server.register(sel, SelectionKey.OP_ACCEPT, server);

                while (true) {

                    int n = sel.select();

                    var keys = sel.selectedKeys();

                    for (SelectionKey key : keys) {

                        if (key.isAcceptable()) {

                            if (connection != null)

                                throw new RuntimeException("One connection per server");

                            ServerSocketChannel server = (ServerSocketChannel)key.attachment();

                            connection = server.accept();

                            connection.configureBlocking(false);

                            setNagle(connection, nagle);

                            setSendBufferSize(connection, sockTxBufsize);

                            setRecvBufferSize(connection, sockRxBufsize);

                            ckey = connection.register(sel, SelectionKey.OP_READ, connection);

                        }

                        if (key.isReadable()) {

                            ByteBuffer buf = ByteBuffer.allocate(bufsize);

                            SocketChannel channel = (SocketChannel)key.attachment();

                            int m = channel.read(buf);

                            if (m == -1) {

                                channel.close();

                                server.close();

                                return;

                            } else {

                                buf.flip();

                                // ECHO

                                toSend.add(buf);

                                ckey.interestOpsOr(SelectionKey.OP_WRITE);

                            }

                        }

                        if (key.isWritable()) {

                            if (toSend.isEmpty()) {

                                ckey.interestOpsAnd(~SelectionKey.OP_WRITE);

                            } else {

                                ByteBuffer b = toSend.get(0);

                                connection.write(b);

                                if (b.remaining() == 0)

                                    toSend.remove(0);

                            }

                        }

                    }

                    keys.clear();

                }

            } catch (IOException e) {

                throw new RuntimeException(e);

            }

        }

    }

    static void fill(ByteBuffer buf) {

        int n = buf.remaining();

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

            buf.put((byte)(i % 127));

        }

    }

    static void check(ByteBuffer buf, int expected, int iteration) throws Exception {

        if (buf.remaining() != expected)

            throw new RuntimeException();

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

            int b = buf.get();

            if (b != (i % 127)) {

                System.out.printf("b = %d , i = %d\n", b, i);

                throw new RuntimeException("Iteration " + Integer.toString(iteration));

            }

        }

    }

// read until buf is full

    static void readFully(SocketChannel chan, ByteBuffer buf) throws Exception {

        int n = buf.remaining();

        while (n > 0) {

            int c = chan.read(buf);

            if (c == -1)

                throw new RuntimeException("EOF");

            n -= c;

        }

    }

    static class Client {

        Server server;

        int bufsize, nbufs, sbuf, rbuf;

        long elapsed;

        Client(Server server, int bufsize, int nbufs) {

            this.server = server;

            this.bufsize = bufsize;

            this.nbufs = nbufs;

        }

        public void run() throws Exception {

            SocketAddress remote = server.getAddress();

            long start = System.nanoTime();

            SocketChannel c = null;

            String fam;

            if (remote instanceof UnixDomainSocketAddress) {

                c = SocketChannel.open(StandardProtocolFamily.UNIX);

                fam = "unix";

            } else {

                c = SocketChannel.open();

                fam = "inet";

            }

            setNagle(c, nagle);

            c.connect(remote);

            setSendBufferSize(c, sockTxBufsize);

            setRecvBufferSize(c, sockRxBufsize);

            ByteBuffer tx = ByteBuffer.allocate(bufsize);

            ByteBuffer rx = ByteBuffer.allocate(bufsize);

            fill(tx);

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

                tx.rewind();

                c.write(tx);

                rx.clear();

                readFully(c, rx);

                rx.flip();

                check(rx, bufsize, i);

            }

            long end = System.nanoTime();

            elapsed = end - start;

            sbuf = c.getOption(StandardSocketOptions.SO_SNDBUF);

            rbuf = c.getOption(StandardSocketOptions.SO_SNDBUF);

            c.close();

        }

        long elapsed() {

            return elapsed;

        }

        int receiveSocketBufsize() {return rbuf;}

        int sendSocketBufsize() {return sbuf;}

    }

}