/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program 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 program 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 program; If not, see
 * http://www.gnu.org/licenses/gpl-2.0.html
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 */

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <errno.h>
#include <time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/sendfile.h>
#include <sys/stat.h>
#include <sys/socket.h>

#include <lustre/lustreapi.h>

#define syserr(str) { perror(str); exit(-1); }

int main(int argc, char *argv[])
{
        char *sfile, *tfile;
        struct stat stbuf;
        int size;
        unsigned long bufsize = 1024 * 1024;
        int infd, outfd;
        int sd[2];
        int rc;
        char *buf;
        char cmd[1024];
        loff_t pos;

        if (argc < 3) {
                fprintf(stderr, "%s <source file> <dest file>\n", argv[0]);
                exit(-1);
        }

        sfile = argv[1];
        tfile = argv[2];

        if (stat(sfile, &stbuf) < 0) {
                if (errno == ENOENT) {
                        /* assume doing non-object file testing */
                        infd = open(sfile, O_LOV_DELAY_CREATE|O_CREAT|O_RDWR,
                                    0644);
                        if (infd < 0)
                                syserr("open source file:");

                        size = random() % (1 * 1024 * 1024) + 1024;
                        if (ftruncate(infd, (off_t)size) < 0)
                                syserr("truncate file error:");
                } else {
                        syserr("stat file: ");
                }
        } else if (S_ISREG(stbuf.st_mode)) {
                size = (int)stbuf.st_size;
                infd = open(sfile, O_RDONLY, 0644);
                if (infd < 0)
                        syserr("Open an existing file error:");
        } else {
                fprintf(stderr, "%s is not a regular file\n", sfile);
                exit(-1);
        }

        outfd = open(tfile, O_WRONLY|O_TRUNC|O_CREAT, 0666);
        if (outfd < 0)
                syserr("open dest file:");

        rc = socketpair(AF_LOCAL, SOCK_STREAM, 0, sd);
        if (rc < 0)
                syserr("socketpair");

        rc = fcntl(sd[0], F_SETFL, O_NONBLOCK);
        if (rc < 0)
                syserr("fcntl");

        rc = setsockopt(sd[0], SOL_SOCKET, SO_SNDBUF,
                        &bufsize, sizeof(bufsize));
        if (rc)
                syserr("setsockopt");

        srandom(time(NULL));

        pos = 0;
        while (size > 0) {
                int rc2;
                size_t seg_size;

                seg_size = random() % bufsize + 1;
                if (seg_size > size)
                        seg_size = size;

                while (seg_size) {
                        rc = sendfile(sd[0], infd, &pos, seg_size);
                        if (rc < 0)
                                syserr("sendfile:");

                        seg_size -= rc;
                        size -= rc;
                        if (size == 0)
                                close(sd[0]);

                        buf = malloc(rc);
                        if (read(sd[1], buf, rc) < 0)
                                syserr("read from socket:");

                        rc2 = write(outfd, buf, rc);
                        if (rc2 != rc)
                                syserr("write dest file error:");
                        free(buf);
                }
        }
        close(sd[1]), close(infd), close(outfd);

	snprintf(cmd, sizeof(cmd), "cmp %s %s\n", sfile, tfile);
        return system(cmd);
}