lib.rs

  1#![cfg(target_os = "macos")]
  2
  3use bitflags::bitflags;
  4use fsevent_sys::{self as fs, core_foundation as cf};
  5use parking_lot::Mutex;
  6use std::{
  7    convert::AsRef,
  8    ffi::{c_void, CStr, OsStr},
  9    os::unix::ffi::OsStrExt,
 10    path::{Path, PathBuf},
 11    slice,
 12    sync::Arc,
 13    time::Duration,
 14};
 15
 16#[derive(Clone, Debug)]
 17pub struct Event {
 18    pub event_id: u64,
 19    pub flags: StreamFlags,
 20    pub path: PathBuf,
 21}
 22
 23pub struct EventStream {
 24    stream: fs::FSEventStreamRef,
 25    state: Arc<Mutex<Lifecycle>>,
 26    callback: Box<Option<RunCallback>>,
 27}
 28
 29type RunCallback = Box<dyn FnMut(Vec<Event>) -> bool>;
 30
 31enum Lifecycle {
 32    New,
 33    Running(cf::CFRunLoopRef),
 34    Stopped,
 35}
 36
 37pub struct Handle(Arc<Mutex<Lifecycle>>);
 38
 39unsafe impl Send for EventStream {}
 40unsafe impl Send for Lifecycle {}
 41
 42impl EventStream {
 43    pub fn new(paths: &[&Path], latency: Duration) -> (Self, Handle) {
 44        unsafe {
 45            let callback = Box::new(None);
 46            let stream_context = fs::FSEventStreamContext {
 47                version: 0,
 48                info: callback.as_ref() as *const _ as *mut c_void,
 49                retain: None,
 50                release: None,
 51                copy_description: None,
 52            };
 53
 54            let cf_paths =
 55                cf::CFArrayCreateMutable(cf::kCFAllocatorDefault, 0, &cf::kCFTypeArrayCallBacks);
 56            assert!(!cf_paths.is_null());
 57
 58            for path in paths {
 59                let path_bytes = path.as_os_str().as_bytes();
 60                let cf_url = cf::CFURLCreateFromFileSystemRepresentation(
 61                    cf::kCFAllocatorDefault,
 62                    path_bytes.as_ptr() as *const i8,
 63                    path_bytes.len() as cf::CFIndex,
 64                    false,
 65                );
 66                let cf_path = cf::CFURLCopyFileSystemPath(cf_url, cf::kCFURLPOSIXPathStyle);
 67                cf::CFArrayAppendValue(cf_paths, cf_path);
 68                cf::CFRelease(cf_path);
 69                cf::CFRelease(cf_url);
 70            }
 71
 72            let stream = fs::FSEventStreamCreate(
 73                cf::kCFAllocatorDefault,
 74                Self::trampoline,
 75                &stream_context,
 76                cf_paths,
 77                fs::kFSEventStreamEventIdSinceNow,
 78                latency.as_secs_f64(),
 79                fs::kFSEventStreamCreateFlagFileEvents
 80                    | fs::kFSEventStreamCreateFlagNoDefer
 81                    | fs::kFSEventStreamCreateFlagWatchRoot,
 82            );
 83            cf::CFRelease(cf_paths);
 84
 85            let state = Arc::new(Mutex::new(Lifecycle::New));
 86
 87            (
 88                EventStream {
 89                    stream,
 90                    state: state.clone(),
 91                    callback,
 92                },
 93                Handle(state),
 94            )
 95        }
 96    }
 97
 98    pub fn run<F>(mut self, f: F)
 99    where
100        F: FnMut(Vec<Event>) -> bool + 'static,
101    {
102        *self.callback = Some(Box::new(f));
103        unsafe {
104            let run_loop = cf::CFRunLoopGetCurrent();
105            {
106                let mut state = self.state.lock();
107                match *state {
108                    Lifecycle::New => *state = Lifecycle::Running(run_loop),
109                    Lifecycle::Running(_) => unreachable!(),
110                    Lifecycle::Stopped => return,
111                }
112            }
113            fs::FSEventStreamScheduleWithRunLoop(self.stream, run_loop, cf::kCFRunLoopDefaultMode);
114
115            fs::FSEventStreamStart(self.stream);
116            cf::CFRunLoopRun();
117
118            fs::FSEventStreamFlushSync(self.stream);
119            fs::FSEventStreamStop(self.stream);
120            fs::FSEventStreamRelease(self.stream);
121        }
122    }
123
124    extern "C" fn trampoline(
125        stream_ref: fs::FSEventStreamRef,
126        info: *mut ::std::os::raw::c_void,
127        num: usize,                                 // size_t numEvents
128        event_paths: *mut ::std::os::raw::c_void,   // void *eventPaths
129        event_flags: *const ::std::os::raw::c_void, // const FSEventStreamEventFlags eventFlags[]
130        event_ids: *const ::std::os::raw::c_void,   // const FSEventStreamEventId eventIds[]
131    ) {
132        unsafe {
133            let event_paths = event_paths as *const *const ::std::os::raw::c_char;
134            let e_ptr = event_flags as *mut u32;
135            let i_ptr = event_ids as *mut u64;
136            let callback = (info as *mut Option<RunCallback>)
137                .as_mut()
138                .unwrap()
139                .as_mut()
140                .unwrap();
141
142            let paths = slice::from_raw_parts(event_paths, num);
143            let flags = slice::from_raw_parts_mut(e_ptr, num);
144            let ids = slice::from_raw_parts_mut(i_ptr, num);
145
146            let mut events = Vec::with_capacity(num);
147            for p in 0..num {
148                let path_c_str = CStr::from_ptr(paths[p]);
149                let path = PathBuf::from(OsStr::from_bytes(path_c_str.to_bytes()));
150                if let Some(flag) = StreamFlags::from_bits(flags[p]) {
151                    events.push(Event {
152                        event_id: ids[p],
153                        flags: flag,
154                        path,
155                    });
156                } else {
157                    debug_assert!(false, "unknown flag set for fs event: {}", flags[p]);
158                }
159            }
160
161            if !callback(events) {
162                fs::FSEventStreamStop(stream_ref);
163                cf::CFRunLoopStop(cf::CFRunLoopGetCurrent());
164            }
165        }
166    }
167}
168
169impl Drop for Handle {
170    fn drop(&mut self) {
171        let mut state = self.0.lock();
172        if let Lifecycle::Running(run_loop) = *state {
173            unsafe {
174                cf::CFRunLoopStop(run_loop);
175            }
176        }
177        *state = Lifecycle::Stopped;
178    }
179}
180
181// Synchronize with
182// /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/FSEvents.framework/Versions/A/Headers/FSEvents.h
183bitflags! {
184  #[repr(C)]
185  pub struct StreamFlags: u32 {
186    const NONE = 0x00000000;
187    const MUST_SCAN_SUBDIRS = 0x00000001;
188    const USER_DROPPED = 0x00000002;
189    const KERNEL_DROPPED = 0x00000004;
190    const IDS_WRAPPED = 0x00000008;
191    const HISTORY_DONE = 0x00000010;
192    const ROOT_CHANGED = 0x00000020;
193    const MOUNT = 0x00000040;
194    const UNMOUNT = 0x00000080;
195    const ITEM_CREATED = 0x00000100;
196    const ITEM_REMOVED = 0x00000200;
197    const INODE_META_MOD = 0x00000400;
198    const ITEM_RENAMED = 0x00000800;
199    const ITEM_MODIFIED = 0x00001000;
200    const FINDER_INFO_MOD = 0x00002000;
201    const ITEM_CHANGE_OWNER = 0x00004000;
202    const ITEM_XATTR_MOD = 0x00008000;
203    const IS_FILE = 0x00010000;
204    const IS_DIR = 0x00020000;
205    const IS_SYMLINK = 0x00040000;
206    const OWN_EVENT = 0x00080000;
207    const IS_HARDLINK = 0x00100000;
208    const IS_LAST_HARDLINK = 0x00200000;
209    const ITEM_CLONED = 0x400000;
210  }
211}
212
213impl std::fmt::Display for StreamFlags {
214    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
215        if self.contains(StreamFlags::MUST_SCAN_SUBDIRS) {
216            let _d = write!(f, "MUST_SCAN_SUBDIRS ");
217        }
218        if self.contains(StreamFlags::USER_DROPPED) {
219            let _d = write!(f, "USER_DROPPED ");
220        }
221        if self.contains(StreamFlags::KERNEL_DROPPED) {
222            let _d = write!(f, "KERNEL_DROPPED ");
223        }
224        if self.contains(StreamFlags::IDS_WRAPPED) {
225            let _d = write!(f, "IDS_WRAPPED ");
226        }
227        if self.contains(StreamFlags::HISTORY_DONE) {
228            let _d = write!(f, "HISTORY_DONE ");
229        }
230        if self.contains(StreamFlags::ROOT_CHANGED) {
231            let _d = write!(f, "ROOT_CHANGED ");
232        }
233        if self.contains(StreamFlags::MOUNT) {
234            let _d = write!(f, "MOUNT ");
235        }
236        if self.contains(StreamFlags::UNMOUNT) {
237            let _d = write!(f, "UNMOUNT ");
238        }
239        if self.contains(StreamFlags::ITEM_CREATED) {
240            let _d = write!(f, "ITEM_CREATED ");
241        }
242        if self.contains(StreamFlags::ITEM_REMOVED) {
243            let _d = write!(f, "ITEM_REMOVED ");
244        }
245        if self.contains(StreamFlags::INODE_META_MOD) {
246            let _d = write!(f, "INODE_META_MOD ");
247        }
248        if self.contains(StreamFlags::ITEM_RENAMED) {
249            let _d = write!(f, "ITEM_RENAMED ");
250        }
251        if self.contains(StreamFlags::ITEM_MODIFIED) {
252            let _d = write!(f, "ITEM_MODIFIED ");
253        }
254        if self.contains(StreamFlags::FINDER_INFO_MOD) {
255            let _d = write!(f, "FINDER_INFO_MOD ");
256        }
257        if self.contains(StreamFlags::ITEM_CHANGE_OWNER) {
258            let _d = write!(f, "ITEM_CHANGE_OWNER ");
259        }
260        if self.contains(StreamFlags::ITEM_XATTR_MOD) {
261            let _d = write!(f, "ITEM_XATTR_MOD ");
262        }
263        if self.contains(StreamFlags::IS_FILE) {
264            let _d = write!(f, "IS_FILE ");
265        }
266        if self.contains(StreamFlags::IS_DIR) {
267            let _d = write!(f, "IS_DIR ");
268        }
269        if self.contains(StreamFlags::IS_SYMLINK) {
270            let _d = write!(f, "IS_SYMLINK ");
271        }
272        if self.contains(StreamFlags::OWN_EVENT) {
273            let _d = write!(f, "OWN_EVENT ");
274        }
275        if self.contains(StreamFlags::IS_LAST_HARDLINK) {
276            let _d = write!(f, "IS_LAST_HARDLINK ");
277        }
278        if self.contains(StreamFlags::IS_HARDLINK) {
279            let _d = write!(f, "IS_HARDLINK ");
280        }
281        if self.contains(StreamFlags::ITEM_CLONED) {
282            let _d = write!(f, "ITEM_CLONED ");
283        }
284        write!(f, "")
285    }
286}
287
288#[test]
289fn test_event_stream() {
290    use std::{fs, sync::mpsc, time::Duration};
291    use tempdir::TempDir;
292
293    let dir = TempDir::new("test_observe").unwrap();
294    let path = dir.path().canonicalize().unwrap();
295    fs::write(path.join("a"), "a contents").unwrap();
296
297    let (tx, rx) = mpsc::channel();
298    let (stream, handle) = EventStream::new(&[&path], Duration::from_millis(50));
299    std::thread::spawn(move || stream.run(move |events| tx.send(events.to_vec()).is_ok()));
300
301    fs::write(path.join("b"), "b contents").unwrap();
302    let events = rx.recv_timeout(Duration::from_millis(500)).unwrap();
303    let event = events.last().unwrap();
304    assert_eq!(event.path, path.join("b"));
305    assert!(event.flags.contains(StreamFlags::ITEM_CREATED));
306
307    fs::remove_file(path.join("a")).unwrap();
308    let events = rx.recv_timeout(Duration::from_millis(500)).unwrap();
309    let event = events.last().unwrap();
310    assert_eq!(event.path, path.join("a"));
311    assert!(event.flags.contains(StreamFlags::ITEM_REMOVED));
312    drop(handle);
313}
314
315#[test]
316fn test_event_stream_shutdown() {
317    use std::{fs, sync::mpsc, time::Duration};
318    use tempdir::TempDir;
319
320    let dir = TempDir::new("test_observe").unwrap();
321    let path = dir.path().canonicalize().unwrap();
322
323    let (tx, rx) = mpsc::channel();
324    let (stream, handle) = EventStream::new(&[&path], Duration::from_millis(50));
325    std::thread::spawn(move || {
326        stream.run({
327            let tx = tx.clone();
328            move |_| {
329                tx.send(()).unwrap();
330                true
331            }
332        });
333        tx.send(()).unwrap();
334    });
335
336    fs::write(path.join("b"), "b contents").unwrap();
337    rx.recv_timeout(Duration::from_millis(500)).unwrap();
338
339    drop(handle);
340    rx.recv_timeout(Duration::from_millis(500)).unwrap();
341}
342
343#[test]
344fn test_event_stream_shutdown_before_run() {
345    use std::time::Duration;
346    use tempdir::TempDir;
347
348    let dir = TempDir::new("test_observe").unwrap();
349    let path = dir.path().canonicalize().unwrap();
350
351    let (stream, handle) = EventStream::new(&[&path], Duration::from_millis(50));
352    drop(handle);
353    stream.run(|_| true);
354}