/*      $NetBSD: vnode.c,v 1.5 2008/12/29 05:56:02 christos Exp $       */

/*-
 * Copyright (c) 2002 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Luke Mewburn.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/event.h>
#include <sys/time.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <inttypes.h>

int
main(int argc, char **argv)
{
        struct timespec timeout;
        struct timeval  then, now, diff;
        struct kevent   event[2];
        char            buffer[128], *pref;
        int             fd, kq, n, i;

        if (argc != 2)
                errx(1, "Usage: %s file", argv[0]);
        
        fd = open(argv[1], O_RDONLY|O_CREAT, 0644);
        if (fd == -1)
                err(1, "open: %s", argv[1]);

#if 0
        sprintf(buffer, "/mnt/fd/%d", fd);
        if ((fd = open(buffer, O_RDONLY)) < 0)
                err(1, "open fdesc: %s", buffer);
#endif

#ifdef READ_TEST
        lseek(fd, 0, SEEK_END);
#endif

        kq = kqueue();
        if (kq == -1)
                err(1, "kqueue");

        i=0;
        EV_SET(&event[i], fd, EVFILT_VNODE, EV_ADD | EV_ENABLE | EV_CLEAR,
                NOTE_DELETE | NOTE_WRITE | NOTE_EXTEND | NOTE_ATTRIB |
                NOTE_LINK | NOTE_RENAME | NOTE_REVOKE, 0, 0);
        i++;

#ifdef READ_TEST
        EV_SET(&event[i], fd, EVFILT_READ, EV_ADD | EV_ENABLE, 0, NULL, NULL);
        i++;
        printf("i is %d\n", i);
#endif

        n = kevent(kq, event, i, NULL, 0, NULL);
        if (n == -1)
                err(1, "kevent(1)");
        
        timeout.tv_sec = 60;
        timeout.tv_nsec = 0;

        for (;;) {
                pref="";
                if (gettimeofday(&then, NULL) == -1)
                        err(1, "gettimeofday then");
                n = kevent(kq, NULL, 0, event, 1, &timeout);
                if (gettimeofday(&now, NULL) == -1)
                        err(1, "gettimeofday now");
                timersub(&now, &then, &diff);
                printf("vnode '%s': kevent returned %d in %lld.%06ld\n",
                        argv[1],
                        n, (long long)diff.tv_sec, (long)diff.tv_usec);

                if (n == -1)
                        err(1, "kevent");
                else if (n == 0)
                        continue;

                printf("vnode '%s': kevent: filter %d flags: 0x%02x, fflags: 0x%02x [",
                    argv[1],
                    event[0].filter, event[0].flags, event[0].fflags);

#define DUMPFLAG(x) \
        do \
                if (event[0].fflags & x) { \
                        printf ("%s%s", pref, #x); \
                        pref=", "; \
                } \
        while (0)

                DUMPFLAG(NOTE_DELETE);
                DUMPFLAG(NOTE_WRITE);
                DUMPFLAG(NOTE_EXTEND);
                DUMPFLAG(NOTE_ATTRIB);
                DUMPFLAG(NOTE_LINK);
                DUMPFLAG(NOTE_RENAME);
                DUMPFLAG(NOTE_REVOKE);
                printf("], data %" PRId64 "\n", event[0].data);

                if (event[0].filter == EVFILT_READ) {
                        if (event[0].data < 0)
                                lseek(fd, 0, SEEK_END);
                        n = read(fd, buffer, 128);
                        if (n < 0)
                                err(1, "read");
                        buffer[n] = '\0';
                        printf("[%d] %s", n, buffer);
                }

                if (event[0].fflags & NOTE_REVOKE) {
                        printf("%s revoked\n", argv[1]);
                        break;
                }
        }
        return (0);
}