/*
 * Copyright (c) 2000, 2022, 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.
 */

#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/types.h>
#include <unistd.h>

#include <string.h>
#include <sys/socket.h>

#include "jni.h"
#include "jni_util.h"
#include "jlong.h"
#include "nio.h"
#include "nio_util.h"
#include "java_lang_Integer.h"
#include <assert.h>

static jlong
handle(JNIEnv *env, jlong rv, char *msg)
{
    if (rv >= 0)
        return rv;
    if (errno == EINTR)
        return IOS_INTERRUPTED;
    JNU_ThrowIOExceptionWithLastError(env, msg);
    return IOS_THROWN;
}

// AIX
JNIEXPORT jint JNICALL
Java_sun_nio_ch_FileDispatcherImpl_force0(JNIEnv *env, jobject this,
                                          jobject fdo, jboolean md)
{
    jint fd = fdval(env, fdo);
    int result = 0;

    if (md == JNI_FALSE) {
        result = fdatasync(fd);
    } else {
        /* Calling fsync on a file descriptor that is opened only for
         * reading results in an error ("EBADF: The FileDescriptor parameter is
         * not a valid file descriptor open for writing.").
         * However, at this point it is not possibly anymore to read the
         * 'writable' attribute of the corresponding file channel so we have to
         * use 'fcntl'.
         */
        int getfl = fcntl(fd, F_GETFL);
        if (getfl >= 0 && (getfl & O_ACCMODE) == O_RDONLY) {
            return 0;
        }
        result = fsync(fd);
    }

    return handle(env, result, "Force failed");
}

JNIEXPORT jlong JNICALL
Java_sun_nio_ch_FileDispatcherImpl_transferTo0(JNIEnv *env, jobject this,
                                                    jobject srcFDO,
                                                    jlong position, jlong count,
                                                    jobject dstFDO, jboolean append)
{
    jint srcFD = fdval(env, srcFDO);
    jint dstFD = fdval(env, dstFDO);

    jlong max = (jlong)java_lang_Integer_MAX_VALUE;
    struct sf_parms sf_iobuf;
    jlong result;

    if (position > max)
        return IOS_UNSUPPORTED_CASE;

    if (count > max)
        count = max;

    memset(&sf_iobuf, 0, sizeof(sf_iobuf));
    sf_iobuf.file_descriptor = srcFD;
    sf_iobuf.file_offset = (off_t)position;
    sf_iobuf.file_bytes = count;

    result = send_file(&dstFD, &sf_iobuf, SF_SYNC_CACHE);

    /* AIX send_file() will return 0 when this operation complete successfully,
     * return 1 when partial bytes transferred and return -1 when an error has
     * occurred.
     */
    if (result == -1) {
        if (errno == EWOULDBLOCK)
            return IOS_UNAVAILABLE;
        if ((errno == EINVAL) && ((ssize_t)count >= 0))
            return IOS_UNSUPPORTED_CASE;
        if (errno == EINTR)
            return IOS_INTERRUPTED;
        if (errno == ENOTSOCK)
            return IOS_UNSUPPORTED;
        JNU_ThrowIOExceptionWithLastError(env, "Transfer failed");
        return IOS_THROWN;
    }

    if (sf_iobuf.bytes_sent > 0)
        return (jlong)sf_iobuf.bytes_sent;

    return IOS_UNSUPPORTED_CASE;
}