/*
 * Copyright (c) 2018, 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * 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 jdk.internal.net.rdma;

import java.io.FileDescriptor;
import java.io.IOException;
import java.security.AccessController;
import java.security.PrivilegedAction;
import sun.nio.ch.SocketDispatcher;

/**
 * Allows different platforms to call different native methods
 * for read and write operations.
 */

public class RdmaSocketDispatcher extends SocketDispatcher
{
    private static PlatformRdmaSocketDispatcher platformRdmaSocketDispatcher =
            PlatformRdmaSocketDispatcher.get();

    protected int read(FileDescriptor fd, long address, int len)
            throws IOException {
        return platformRdmaSocketDispatcher.read(fd, address, len);
    }

    protected long readv(FileDescriptor fd, long address, int len)
            throws IOException {
        return platformRdmaSocketDispatcher.readv(fd, address, len);
    }

    protected int write(FileDescriptor fd, long address, int len)
            throws IOException {
        return platformRdmaSocketDispatcher.write(fd, address, len);
    }

    protected long writev(FileDescriptor fd, long address, int len)
            throws IOException {
        return platformRdmaSocketDispatcher.writev(fd, address, len);
    }

    protected void close(FileDescriptor fd) throws IOException {
        platformRdmaSocketDispatcher.close(fd);
    }

    public void preClose(FileDescriptor fd) throws IOException {
        platformRdmaSocketDispatcher.preClose(fd);
    }

    static class PlatformRdmaSocketDispatcher {
        @SuppressWarnings("unchecked")
        private static PlatformRdmaSocketDispatcher newInstance(String cn) {
            Class<PlatformRdmaSocketDispatcher> c;
            try {
                c = (Class<PlatformRdmaSocketDispatcher>)Class.forName(cn);
                return c.getConstructor(new Class<?>[] {}).newInstance();
            } catch (ReflectiveOperationException x) {
                throw new AssertionError(x);
            }
        }

        private static PlatformRdmaSocketDispatcher create() {
            String osname = AccessController.doPrivileged(
                    new PrivilegedAction<String>() {
                        public String run() {
                            return System.getProperty("os.name");
                        }
                    });
            if ("Linux".equals(osname))
                return newInstance(
                        "jdk.internal.net.rdma.LinuxRdmaSocketDispatcher");
            return new PlatformRdmaSocketDispatcher();
        }

        private static final PlatformRdmaSocketDispatcher instance = create();

        static PlatformRdmaSocketDispatcher get() {
            return instance;
        }

        protected int read(FileDescriptor fd, long address, int len)
                throws IOException {
            throw new UnsupportedOperationException(
                    "unsupported socket operation");
        }

        protected long readv(FileDescriptor fd, long address, int len)
                throws IOException {
            throw new UnsupportedOperationException(
                    "unsupported socket operation");
        }

        protected int write(FileDescriptor fd, long address, int len)
                throws IOException {
            throw new UnsupportedOperationException(
                    "unsupported socket operation");
        }

        protected long writev(FileDescriptor fd, long address, int len)
                throws IOException {
            throw new UnsupportedOperationException(
                    "unsupported socket operation");
        }

        protected void close(FileDescriptor fd) throws IOException {
            throw new UnsupportedOperationException(
                    "unsupported socket operation");
        }

        public void preClose(FileDescriptor fd) throws IOException {
            throw new UnsupportedOperationException(
                    "unsupported socket operation");
        }
    }
}