lib.rs

  1#![cfg(target_os = "macos")]
  2
  3use bitflags::bitflags;
  4use fsevent_sys::{self as fs, core_foundation as cf};
  5use std::{
  6    convert::AsRef,
  7    ffi::{c_void, CStr, OsStr},
  8    os::unix::ffi::OsStrExt,
  9    path::{Path, PathBuf},
 10    slice,
 11    sync::mpsc::Sender,
 12    time::Duration,
 13};
 14
 15#[derive(Debug)]
 16pub struct Event {
 17    pub event_id: u64,
 18    pub flags: StreamFlags,
 19    pub path: PathBuf,
 20}
 21
 22pub struct EventStream {
 23    stream: fs::FSEventStreamRef,
 24    _sender: Box<Sender<Vec<Event>>>,
 25}
 26
 27unsafe impl Send for EventStream {}
 28
 29impl EventStream {
 30    pub fn new(paths: &[&Path], latency: Duration, event_sender: Sender<Vec<Event>>) -> Self {
 31        unsafe {
 32            let sender = Box::new(event_sender);
 33            let stream_context = fs::FSEventStreamContext {
 34                version: 0,
 35                info: sender.as_ref() as *const _ as *mut c_void,
 36                retain: None,
 37                release: None,
 38                copy_description: None,
 39            };
 40
 41            let cf_paths =
 42                cf::CFArrayCreateMutable(cf::kCFAllocatorDefault, 0, &cf::kCFTypeArrayCallBacks);
 43            assert!(!cf_paths.is_null());
 44
 45            for path in paths {
 46                let path_bytes = path.as_os_str().as_bytes();
 47                let cf_url = cf::CFURLCreateFromFileSystemRepresentation(
 48                    cf::kCFAllocatorDefault,
 49                    path_bytes.as_ptr() as *const i8,
 50                    path_bytes.len() as cf::CFIndex,
 51                    false,
 52                );
 53                let cf_path = cf::CFURLCopyFileSystemPath(cf_url, cf::kCFURLPOSIXPathStyle);
 54                cf::CFArrayAppendValue(cf_paths, cf_path);
 55                cf::CFRelease(cf_path);
 56                cf::CFRelease(cf_url);
 57            }
 58
 59            let stream = fs::FSEventStreamCreate(
 60                cf::kCFAllocatorDefault,
 61                callback,
 62                &stream_context,
 63                cf_paths,
 64                fs::kFSEventStreamEventIdSinceNow,
 65                latency.as_secs_f64(),
 66                fs::kFSEventStreamCreateFlagFileEvents | fs::kFSEventStreamCreateFlagNoDefer,
 67            );
 68            cf::CFRelease(cf_paths);
 69
 70            EventStream {
 71                stream,
 72                _sender: sender,
 73            }
 74        }
 75    }
 76
 77    pub fn run(self) {
 78        unsafe {
 79            fs::FSEventStreamScheduleWithRunLoop(
 80                self.stream,
 81                cf::CFRunLoopGetCurrent(),
 82                cf::kCFRunLoopDefaultMode,
 83            );
 84
 85            fs::FSEventStreamStart(self.stream);
 86            cf::CFRunLoopRun();
 87
 88            fs::FSEventStreamFlushSync(self.stream);
 89            fs::FSEventStreamStop(self.stream);
 90            fs::FSEventStreamRelease(self.stream);
 91        }
 92    }
 93}
 94
 95extern "C" fn callback(
 96    stream_ref: fs::FSEventStreamRef,
 97    info: *mut ::std::os::raw::c_void,
 98    num: usize,                                 // size_t numEvents
 99    event_paths: *mut ::std::os::raw::c_void,   // void *eventPaths
100    event_flags: *const ::std::os::raw::c_void, // const FSEventStreamEventFlags eventFlags[]
101    event_ids: *const ::std::os::raw::c_void,   // const FSEventStreamEventId eventIds[]
102) {
103    unsafe {
104        let event_paths = event_paths as *const *const ::std::os::raw::c_char;
105        let e_ptr = event_flags as *mut u32;
106        let i_ptr = event_ids as *mut u64;
107        let sender = (info as *mut Sender<Vec<Event>>).as_mut().unwrap();
108
109        let paths = slice::from_raw_parts(event_paths, num);
110        let flags = slice::from_raw_parts_mut(e_ptr, num);
111        let ids = slice::from_raw_parts_mut(i_ptr, num);
112
113        let mut events = Vec::with_capacity(num);
114        for p in 0..num {
115            let path_c_str = CStr::from_ptr(paths[p]);
116            let path = PathBuf::from(OsStr::from_bytes(path_c_str.to_bytes()));
117            if let Some(flag) = StreamFlags::from_bits(flags[p]) {
118                events.push(Event {
119                    event_id: ids[p],
120                    flags: flag,
121                    path,
122                });
123            } else {
124                debug_assert!(false, "unknown flag set for fs event: {}", flags[p]);
125            }
126        }
127
128        if sender.send(events).is_err() {
129            fs::FSEventStreamStop(stream_ref);
130            cf::CFRunLoopStop(cf::CFRunLoopGetCurrent());
131        }
132    }
133}
134
135// Synchronize with
136// /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/FSEvents.framework/Versions/A/Headers/FSEvents.h
137bitflags! {
138  #[repr(C)]
139  pub struct StreamFlags: u32 {
140    const NONE = 0x00000000;
141    const MUST_SCAN_SUBDIRS = 0x00000001;
142    const USER_DROPPED = 0x00000002;
143    const KERNEL_DROPPED = 0x00000004;
144    const IDS_WRAPPED = 0x00000008;
145    const HISTORY_DONE = 0x00000010;
146    const ROOT_CHANGED = 0x00000020;
147    const MOUNT = 0x00000040;
148    const UNMOUNT = 0x00000080;
149    const ITEM_CREATED = 0x00000100;
150    const ITEM_REMOVED = 0x00000200;
151    const INODE_META_MOD = 0x00000400;
152    const ITEM_RENAMED = 0x00000800;
153    const ITEM_MODIFIED = 0x00001000;
154    const FINDER_INFO_MOD = 0x00002000;
155    const ITEM_CHANGE_OWNER = 0x00004000;
156    const ITEM_XATTR_MOD = 0x00008000;
157    const IS_FILE = 0x00010000;
158    const IS_DIR = 0x00020000;
159    const IS_SYMLINK = 0x00040000;
160    const OWN_EVENT = 0x00080000;
161    const IS_HARDLINK = 0x00100000;
162    const IS_LAST_HARDLINK = 0x00200000;
163    const ITEM_CLONED = 0x400000;
164  }
165}
166
167impl std::fmt::Display for StreamFlags {
168    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
169        if self.contains(StreamFlags::MUST_SCAN_SUBDIRS) {
170            let _d = write!(f, "MUST_SCAN_SUBDIRS ");
171        }
172        if self.contains(StreamFlags::USER_DROPPED) {
173            let _d = write!(f, "USER_DROPPED ");
174        }
175        if self.contains(StreamFlags::KERNEL_DROPPED) {
176            let _d = write!(f, "KERNEL_DROPPED ");
177        }
178        if self.contains(StreamFlags::IDS_WRAPPED) {
179            let _d = write!(f, "IDS_WRAPPED ");
180        }
181        if self.contains(StreamFlags::HISTORY_DONE) {
182            let _d = write!(f, "HISTORY_DONE ");
183        }
184        if self.contains(StreamFlags::ROOT_CHANGED) {
185            let _d = write!(f, "ROOT_CHANGED ");
186        }
187        if self.contains(StreamFlags::MOUNT) {
188            let _d = write!(f, "MOUNT ");
189        }
190        if self.contains(StreamFlags::UNMOUNT) {
191            let _d = write!(f, "UNMOUNT ");
192        }
193        if self.contains(StreamFlags::ITEM_CREATED) {
194            let _d = write!(f, "ITEM_CREATED ");
195        }
196        if self.contains(StreamFlags::ITEM_REMOVED) {
197            let _d = write!(f, "ITEM_REMOVED ");
198        }
199        if self.contains(StreamFlags::INODE_META_MOD) {
200            let _d = write!(f, "INODE_META_MOD ");
201        }
202        if self.contains(StreamFlags::ITEM_RENAMED) {
203            let _d = write!(f, "ITEM_RENAMED ");
204        }
205        if self.contains(StreamFlags::ITEM_MODIFIED) {
206            let _d = write!(f, "ITEM_MODIFIED ");
207        }
208        if self.contains(StreamFlags::FINDER_INFO_MOD) {
209            let _d = write!(f, "FINDER_INFO_MOD ");
210        }
211        if self.contains(StreamFlags::ITEM_CHANGE_OWNER) {
212            let _d = write!(f, "ITEM_CHANGE_OWNER ");
213        }
214        if self.contains(StreamFlags::ITEM_XATTR_MOD) {
215            let _d = write!(f, "ITEM_XATTR_MOD ");
216        }
217        if self.contains(StreamFlags::IS_FILE) {
218            let _d = write!(f, "IS_FILE ");
219        }
220        if self.contains(StreamFlags::IS_DIR) {
221            let _d = write!(f, "IS_DIR ");
222        }
223        if self.contains(StreamFlags::IS_SYMLINK) {
224            let _d = write!(f, "IS_SYMLINK ");
225        }
226        if self.contains(StreamFlags::OWN_EVENT) {
227            let _d = write!(f, "OWN_EVENT ");
228        }
229        if self.contains(StreamFlags::IS_LAST_HARDLINK) {
230            let _d = write!(f, "IS_LAST_HARDLINK ");
231        }
232        if self.contains(StreamFlags::IS_HARDLINK) {
233            let _d = write!(f, "IS_HARDLINK ");
234        }
235        if self.contains(StreamFlags::ITEM_CLONED) {
236            let _d = write!(f, "ITEM_CLONED ");
237        }
238        write!(f, "")
239    }
240}
241
242#[test]
243fn test_observe() {
244    use std::{fs, sync::mpsc, time::Duration};
245    use tempdir::TempDir;
246
247    let dir = TempDir::new("test_observe").unwrap();
248    let path = dir.path().canonicalize().unwrap();
249    fs::write(path.join("a"), "a contents").unwrap();
250
251    let (tx, rx) = mpsc::channel();
252    let stream = EventStream::new(&[&path], Duration::from_millis(50), tx);
253    std::thread::spawn(move || stream.run());
254
255    fs::write(path.join("b"), "b contents").unwrap();
256    let events = rx.recv_timeout(Duration::from_millis(500)).unwrap();
257    let event = events.last().unwrap();
258    assert_eq!(event.path, path.join("b"));
259    assert!(event.flags.contains(StreamFlags::ITEM_CREATED));
260
261    fs::remove_file(path.join("a")).unwrap();
262    let events = rx.recv_timeout(Duration::from_millis(500)).unwrap();
263    let event = events.last().unwrap();
264    assert_eq!(event.path, path.join("a"));
265    assert!(event.flags.contains(StreamFlags::ITEM_REMOVED));
266}