fseventw.c

   1 // Copyright 2015 Google Inc. All rights reserved.
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 // You may obtain a copy of the License at
   6 //
   7 //     http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 // See the License for the specific language governing permissions and
  13 // limitations under the License.
  14
  15 #include <CoreServices/CoreServices.h>
  16 #include <dispatch/dispatch.h>
  17 #include <stdio.h>
  18
  19 void EventStreamCallback(ConstFSEventStreamRef event_stream,
  20                          void* callback_info,
  21                          size_t num_events,
  22                          void* event_paths_void,
  23                          const FSEventStreamEventFlags event_flags[],
  24                          const FSEventStreamEventId event_ids[]) {
  25   dispatch_queue_t log_queue = callback_info;
  26   const char** event_paths = event_paths_void;
  27
  28   for (size_t i = 0; i < num_events; ++i) {
  29     const FSEventStreamEventFlags flags = event_flags[i];
  30     const FSEventStreamEventId ids = event_ids[i];
  31
  32     char* path = strdup(event_paths[i]);
  33
  34     dispatch_async(log_queue, ^{
  35         printf("event %llx %x at %s\n", ids, flags, path);
  36         free(path);
  37     });
  38   }
  39 }
  40
  41 int main() {
  42   dispatch_queue_t log_queue = dispatch_queue_create("com.google.fseventw.logq", DISPATCH_QUEUE_SERIAL);
  43   dispatch_queue_t event_queue = dispatch_queue_create("com.google.fseventw.eventq", DISPATCH_QUEUE_CONCURRENT);
  44
  45   const CFStringRef kPath = CFSTR("/");
  46   const void* paths_to_watch_c[] = { kPath };
  47   CFArrayRef paths_to_watch = CFArrayCreate(NULL, paths_to_watch_c, 1, &kCFTypeArrayCallBacks);
  48
  49   FSEventStreamContext context = {
  50     .version = 0,
  51     .info = log_queue,
  52     .retain = (const void* (*)(const void*))&dispatch_retain,
  53     .release = (void (*)(const void*))&dispatch_release,
  54     .copyDescription = NULL
  55   };
  56   FSEventStreamRef event_stream =
  57       FSEventStreamCreate(NULL,
  58                           &EventStreamCallback,
  59                           &context,
  60                           paths_to_watch,
  61                           kFSEventStreamEventIdSinceNow,
  62                           1,
  63                           kFSEventStreamCreateFlagFileEvents);
  64
  65   CFRelease(paths_to_watch);
  66
  67   FSEventStreamSetDispatchQueue(event_stream, event_queue);
  68
  69   if (!FSEventStreamStart(event_stream)) {
  70     fprintf(stderr, "Failed to start FSEventStream\n");
  71     return EXIT_FAILURE;
  72   }
  73
  74   dispatch_main();
  75
  76   FSEventStreamStop(event_stream);
  77   FSEventStreamSetDispatchQueue(event_stream, NULL);
  78   FSEventStreamRelease(event_stream);
  79
  80   dispatch_release(event_queue);
  81   dispatch_barrier_sync(log_queue, ^{
  82       dispatch_release(log_queue);
  83   });
  84 }