/*

 * Copyright (c) 2000, 2017, 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 sun.nio.ch;

import java.io.FileDescriptor;

import java.io.IOException;

import jdk.internal.misc.SharedSecrets;

import jdk.internal.misc.JavaIOFileDescriptorAccess;

import sun.security.action.GetPropertyAction;

import java.io.File;

import java.nio.CharBuffer;

class FileDispatcherImpl extends FileDispatcher {

    private static final JavaIOFileDescriptorAccess fdAccess =

        SharedSecrets.getJavaIOFileDescriptorAccess();

    // set to true if fast file transmission (TransmitFile) is enabled

    private static final boolean fastFileTransfer;

    FileDispatcherImpl() { }

    @Override

    boolean needsPositionLock() {

        return true;

    }

    int read(FileDescriptor fd, long address, int len)

        throws IOException

    {

        return read0(fd, address, len);

    }

    int pread(FileDescriptor fd, long address, int len, long position)

        throws IOException

    {

        return pread0(fd, address, len, position);

    }

    long readv(FileDescriptor fd, long address, int len) throws IOException {

        return readv0(fd, address, len);

    }

    int write(FileDescriptor fd, long address, int len) throws IOException {

        return write0(fd, address, len, fdAccess.getAppend(fd));

    }

    int pwrite(FileDescriptor fd, long address, int len, long position)

        throws IOException

    {

        return pwrite0(fd, address, len, position);

    }

    long writev(FileDescriptor fd, long address, int len) throws IOException {

        return writev0(fd, address, len, fdAccess.getAppend(fd));

    }

    int force(FileDescriptor fd, boolean metaData) throws IOException {

        return force0(fd, metaData);

    }

    int truncate(FileDescriptor fd, long size) throws IOException {

        return truncate0(fd, size);

    }

    int allocate(FileDescriptor fd, long size) throws IOException {

        // truncate0() works for extending and truncating file size

        return truncate0(fd, size);

    }

    long size(FileDescriptor fd) throws IOException {

        return size0(fd);

    }

    int lock(FileDescriptor fd, boolean blocking, long pos, long size,

             boolean shared) throws IOException

    {

        return lock0(fd, blocking, pos, size, shared);

    }

    void release(FileDescriptor fd, long pos, long size) throws IOException {

        release0(fd, pos, size);

    }

    void close(FileDescriptor fd) throws IOException {

        fdAccess.close(fd);

    }

    FileDescriptor duplicateForMapping(FileDescriptor fd) throws IOException {

        // on Windows we need to keep a handle to the file

        FileDescriptor result = new FileDescriptor();

        long handle = duplicateHandle(fdAccess.getHandle(fd));

        fdAccess.setHandle(result, handle);

        return result;

    }

    boolean canTransferToDirectly(java.nio.channels.SelectableChannel sc) {

        return fastFileTransfer && sc.isBlocking();

    }

    boolean transferToDirectlyNeedsPositionLock() {

        return true;

    }

    int setDirectIO(FileDescriptor fd, String path)

    {

        int result = -1;

        String filePath = path.substring(0, path.lastIndexOf(File.separator));

        CharBuffer buffer = CharBuffer.allocate(filePath.length());

        buffer.put(filePath);

        try {

            result = setDirect0(fd, buffer);

        } catch (IOException e) {

            throw new UnsupportedOperationException

                ("Error setting up DirectIO", e);

        }

        return result;

    }

    static boolean isFastFileTransferRequested() {

        String fileTransferProp = GetPropertyAction

                .privilegedGetProperty("jdk.nio.enableFastFileTransfer");

        boolean enable;

        if ("".equals(fileTransferProp)) {

            enable = true;

        } else {

            enable = Boolean.parseBoolean(fileTransferProp);

        }

        return enable;

    }

    static {

        IOUtil.load();

        fastFileTransfer = isFastFileTransferRequested();

    }

    //-- Native methods

    static native int read0(FileDescriptor fd, long address, int len)

        throws IOException;

    static native int pread0(FileDescriptor fd, long address, int len,

                             long position) throws IOException;

    static native long readv0(FileDescriptor fd, long address, int len)

        throws IOException;

    static native int write0(FileDescriptor fd, long address, int len, boolean append)

        throws IOException;

    static native int pwrite0(FileDescriptor fd, long address, int len,

                             long position) throws IOException;

    static native long writev0(FileDescriptor fd, long address, int len, boolean append)

        throws IOException;

    static native int force0(FileDescriptor fd, boolean metaData)

        throws IOException;

    static native int truncate0(FileDescriptor fd, long size)

        throws IOException;

    static native long size0(FileDescriptor fd) throws IOException;

    static native int lock0(FileDescriptor fd, boolean blocking, long pos,

                            long size, boolean shared) throws IOException;

    static native void release0(FileDescriptor fd, long pos, long size)

        throws IOException;

    static native void close0(FileDescriptor fd) throws IOException;

    static native long duplicateHandle(long fd) throws IOException;

    static native int setDirect0(FileDescriptor fd, CharBuffer buffer) throws IOException;

}