text: /* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to
   * deal in the Software without restriction, including without limitation the
   * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
   * sell copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
   * IN THE SOFTWARE.
   */
  
  #include "uv.h"
  #include "internal.h"
  
  #include <assert.h>
  #include <stdlib.h>
  #include <string.h>
  #include <errno.h>
  
  #include <sys/sysctl.h>
  #include <sys/types.h>
  #include <sys/event.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <time.h>
  
  static void uv__fs_event(EV_P_ ev_io* w, int revents);
  
  
  static void uv__fs_event_start(uv_fs_event_t* handle) {
    ev_io_init(&handle->event_watcher,
               uv__fs_event,
               handle->fd,
               EV_LIBUV_KQUEUE_HACK);
    ev_io_start(handle->loop->ev, &handle->event_watcher);
  }
  
  
  static void uv__fs_event_stop(uv_fs_event_t* handle) {
    ev_io_stop(handle->loop->ev, &handle->event_watcher);
  }
  
  
  static void uv__fs_event(EV_P_ ev_io* w, int revents) {
    uv_fs_event_t* handle;
    int events;
  
    assert(revents == EV_LIBUV_KQUEUE_HACK);
  
    handle = container_of(w, uv_fs_event_t, event_watcher);
  
    if (handle->fflags & (NOTE_ATTRIB | NOTE_EXTEND))
      events = UV_CHANGE;
    else
      events = UV_RENAME;
  
    handle->cb(handle, NULL, events, 0);
  
    if (handle->fd == -1)
      return;
  
    /* File watcher operates in one-shot mode, re-arm it. */
    uv__fs_event_stop(handle);
    uv__fs_event_start(handle);
  }
  
  
  /* Called by libev, don't touch. */
  void uv__kqueue_hack(EV_P_ int fflags, ev_io *w) {
    uv_fs_event_t* handle;
  
    handle = container_of(w, uv_fs_event_t, event_watcher);
    handle->fflags = fflags;
  }
  
  
  int uv_fs_event_init(uv_loop_t* loop,
                       uv_fs_event_t* handle,
                       const char* filename,
                       uv_fs_event_cb cb,
                       int flags) {
    int fd;
  #if defined(__APPLE__)
    struct stat statbuf;
  #endif /* defined(__APPLE__) */
  
    /* We don't support any flags yet. */
    assert(!flags);
  
    /* TODO open asynchronously - but how do we report back errors? */
    if ((fd = open(filename, O_RDONLY)) == -1) {
      uv__set_sys_error(loop, errno);
      return -1;
    }
  
    uv__handle_init(loop, (uv_handle_t*)handle, UV_FS_EVENT);
    uv__handle_start(handle); /* FIXME shouldn't start automatically */
    handle->filename = strdup(filename);
    handle->fflags = 0;
    handle->cb = cb;
    handle->fd = fd;
  
  #if defined(__APPLE__)
    /* Nullify field to perform checks later */
    handle->cf_eventstream = NULL;
  
    if (fstat(fd, &statbuf))
      goto fallback;
    /* FSEvents works only with directories */
    if (!(statbuf.st_mode & S_IFDIR))
      goto fallback;
  
    return uv__fsevents_init(handle);
  
  fallback:
  #endif /* defined(__APPLE__) */
  
    uv__fs_event_start(handle);
  
    return 0;
  }
  
  
  void uv__fs_event_close(uv_fs_event_t* handle) {
  #if defined(__APPLE__)
    if (uv__fsevents_close(handle))
      uv__fs_event_stop(handle);
  #else
    uv__fs_event_stop(handle);
  #endif /* defined(__APPLE__) */
  
    uv__handle_stop(handle);
    free(handle->filename);
    close(handle->fd);
    handle->fd = -1;
  }
  