Add config option to disable following symbolic links.

notify/src/config.rs

@@ -37,11 +37,13 @@ impl RecursiveMode {
 /// Some options can be changed during runtime, others have to be set when creating the watcher backend.
 #[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
 pub struct Config {
-    /// See [BackendConfig::with_poll_interval]
+    /// See [Config::with_poll_interval]
     poll_interval: Option<Duration>,
 
-    /// See [BackendConfig::with_compare_contents]
+    /// See [Config::with_compare_contents]
     compare_contents: bool,
+
+    follow_symlinks: bool,
 }
 
 impl Config {
@@ -94,13 +96,30 @@ impl Config {
     pub fn compare_contents(&self) -> bool {
         self.compare_contents
     }
+
+    /// For the [INotifyWatcher](crate::INotifyWatcher), [KqueueWatcher](crate::KqueueWatcher),
+    /// and [PollWatcher](crate::PollWatcher).
+    ///
+    /// Determine if sybolic links should be followed when recursively watching a directory.
+    ///
+    /// This can't be changed during runtime. On by default.
+    pub fn with_follow_symlinks(mut self, follow_symlinks: bool) -> Self {
+        self.follow_symlinks = follow_symlinks;
+        self
+    }
+
+    /// Returns current setting
+    pub fn follow_symlinks(&self) -> bool {
+        self.follow_symlinks
+    }
 }
 
 impl Default for Config {
     fn default() -> Self {
         Self {
             poll_interval: Some(Duration::from_secs(30)),
             compare_contents: false,
+            follow_symlinks: true,
         }
     }
 }

notify/src/inotify.rs

@@ -40,6 +40,7 @@ struct EventLoop {
     watches: HashMap<PathBuf, (WatchDescriptor, WatchMask, bool, bool)>,
     paths: HashMap<WatchDescriptor, PathBuf>,
     rename_event: Option<Event>,
+    follow_links: bool,
 }
 
 /// Watcher implementation based on inotify
@@ -90,7 +91,11 @@ fn remove_watch_by_event(
 }
 
 impl EventLoop {
-    pub fn new(inotify: Inotify, event_handler: Box<dyn EventHandler>) -> Result<Self> {
+    pub fn new(
+        inotify: Inotify,
+        event_handler: Box<dyn EventHandler>,
+        follow_links: bool,
+    ) -> Result<Self> {
         let (event_loop_tx, event_loop_rx) = unbounded::<EventLoopMsg>();
         let poll = mio::Poll::new()?;
 
@@ -112,6 +117,7 @@ impl EventLoop {
             watches: HashMap::new(),
             paths: HashMap::new(),
             rename_event: None,
+            follow_links,
         };
         Ok(event_loop)
     }
@@ -398,7 +404,7 @@ impl EventLoop {
         }
 
         for entry in WalkDir::new(path)
-            .follow_links(true)
+            .follow_links(self.follow_links)
             .into_iter()
             .filter_map(filter_dir)
         {
@@ -522,9 +528,12 @@ fn filter_dir(e: walkdir::Result<walkdir::DirEntry>) -> Option<walkdir::DirEntry
 }
 
 impl INotifyWatcher {
-    fn from_event_handler(event_handler: Box<dyn EventHandler>) -> Result<Self> {
+    fn from_event_handler(
+        event_handler: Box<dyn EventHandler>,
+        follow_links: bool,
+    ) -> Result<Self> {
         let inotify = Inotify::init()?;
-        let event_loop = EventLoop::new(inotify, event_handler)?;
+        let event_loop = EventLoop::new(inotify, event_handler, follow_links)?;
         let channel = event_loop.event_loop_tx.clone();
         let waker = event_loop.event_loop_waker.clone();
         event_loop.run();
@@ -566,8 +575,8 @@ impl INotifyWatcher {
 
 impl Watcher for INotifyWatcher {
     /// Create a new watcher.
-    fn new<F: EventHandler>(event_handler: F, _config: Config) -> Result<Self> {
-        Self::from_event_handler(Box::new(event_handler))
+    fn new<F: EventHandler>(event_handler: F, config: Config) -> Result<Self> {
+        Self::from_event_handler(Box::new(event_handler), config.follow_symlinks())
     }
 
     fn watch(&mut self, path: &Path, recursive_mode: RecursiveMode) -> Result<()> {

notify/src/kqueue.rs

@@ -34,6 +34,7 @@ struct EventLoop {
     kqueue: kqueue::Watcher,
     event_handler: Box<dyn EventHandler>,
     watches: HashMap<PathBuf, bool>,
+    follow_symlinks: bool,
 }
 
 /// Watcher implementation based on inotify
@@ -50,7 +51,11 @@ enum EventLoopMsg {
 }
 
 impl EventLoop {
-    pub fn new(kqueue: kqueue::Watcher, event_handler: Box<dyn EventHandler>) -> Result<Self> {
+    pub fn new(
+        kqueue: kqueue::Watcher,
+        event_handler: Box<dyn EventHandler>,
+        follow_symlinks: bool,
+    ) -> Result<Self> {
         let (event_loop_tx, event_loop_rx) = unbounded::<EventLoopMsg>();
         let poll = mio::Poll::new()?;
 
@@ -70,6 +75,7 @@ impl EventLoop {
             kqueue,
             event_handler,
             watches: HashMap::new(),
+            follow_symlinks,
         };
         Ok(event_loop)
     }
@@ -292,7 +298,10 @@ impl EventLoop {
         if !is_recursive || !metadata(&path).map_err(Error::io)?.is_dir() {
             self.add_single_watch(path, false)?;
         } else {
-            for entry in WalkDir::new(path).follow_links(true).into_iter() {
+            for entry in WalkDir::new(path)
+                .follow_links(self.follow_symlinks)
+                .into_iter()
+            {
                 let entry = entry.map_err(map_walkdir_error)?;
                 self.add_single_watch(entry.path().to_path_buf(), is_recursive)?;
             }
@@ -338,7 +347,10 @@ impl EventLoop {
                     .map_err(|e| Error::io(e).add_path(path.clone()))?;
 
                 if is_recursive || remove_recursive {
-                    for entry in WalkDir::new(path).follow_links(true).into_iter() {
+                    for entry in WalkDir::new(path)
+                        .follow_links(self.follow_symlinks)
+                        .into_iter()
+                    {
                         let p = entry.map_err(map_walkdir_error)?.path().to_path_buf();
                         self.kqueue
                             .remove_filename(&p, EventFilter::EVFILT_VNODE)
@@ -362,9 +374,12 @@ fn map_walkdir_error(e: walkdir::Error) -> Error {
 }
 
 impl KqueueWatcher {
-    fn from_event_handler(event_handler: Box<dyn EventHandler>) -> Result<Self> {
+    fn from_event_handler(
+        event_handler: Box<dyn EventHandler>,
+        follow_symlinks: bool,
+    ) -> Result<Self> {
         let kqueue = kqueue::Watcher::new()?;
-        let event_loop = EventLoop::new(kqueue, event_handler)?;
+        let event_loop = EventLoop::new(kqueue, event_handler, follow_symlinks)?;
         let channel = event_loop.event_loop_tx.clone();
         let waker = event_loop.event_loop_waker.clone();
         event_loop.run();
@@ -416,8 +431,8 @@ impl KqueueWatcher {
 
 impl Watcher for KqueueWatcher {
     /// Create a new watcher.
-    fn new<F: EventHandler>(event_handler: F, _config: Config) -> Result<Self> {
-        Self::from_event_handler(Box::new(event_handler))
+    fn new<F: EventHandler>(event_handler: F, config: Config) -> Result<Self> {
+        Self::from_event_handler(Box::new(event_handler), config.follow_symlinks())
     }
 
     fn watch(&mut self, path: &Path, recursive_mode: RecursiveMode) -> Result<()> {

notify/src/poll.rs

@@ -127,8 +127,9 @@ mod data {
             &self,
             root: PathBuf,
             is_recursive: bool,
+            follow_symlinks: bool,
         ) -> Option<WatchData> {
-            WatchData::new(self, root, is_recursive)
+            WatchData::new(self, root, is_recursive, follow_symlinks)
         }
 
         /// Create [`PathData`].
@@ -151,6 +152,7 @@ mod data {
         // config part, won't change.
         root: PathBuf,
         is_recursive: bool,
+        follow_symlinks: bool,
 
         // current status part.
         all_path_data: HashMap<PathBuf, PathData>,
@@ -162,7 +164,12 @@ mod data {
         /// # Side effect
         ///
         /// This function may send event by `data_builder.emitter`.
-        fn new(data_builder: &DataBuilder, root: PathBuf, is_recursive: bool) -> Option<Self> {
+        fn new(
+            data_builder: &DataBuilder,
+            root: PathBuf,
+            is_recursive: bool,
+            follow_symlinks: bool,
+        ) -> Option<Self> {
             // If metadata read error at `root` path, it will emit
             // a error event and stop to create the whole `WatchData`.
             //
@@ -186,12 +193,19 @@ mod data {
                 return None;
             }
 
-            let all_path_data =
-                Self::scan_all_path_data(data_builder, root.clone(), is_recursive, true).collect();
+            let all_path_data = Self::scan_all_path_data(
+                data_builder,
+                root.clone(),
+                is_recursive,
+                follow_symlinks,
+                true,
+            )
+            .collect();
 
             Some(Self {
                 root,
                 is_recursive,
+                follow_symlinks,
                 all_path_data,
             })
         }
@@ -203,9 +217,13 @@ mod data {
         /// This function may emit event by `data_builder.emitter`.
         pub(super) fn rescan(&mut self, data_builder: &mut DataBuilder) {
             // scan current filesystem.
-            for (path, new_path_data) in
-                Self::scan_all_path_data(data_builder, self.root.clone(), self.is_recursive, false)
-            {
+            for (path, new_path_data) in Self::scan_all_path_data(
+                data_builder,
+                self.root.clone(),
+                self.is_recursive,
+                self.follow_symlinks,
+                false,
+            ) {
                 let old_path_data = self
                     .all_path_data
                     .insert(path.clone(), new_path_data.clone());
@@ -247,6 +265,7 @@ mod data {
             data_builder: &'_ DataBuilder,
             root: PathBuf,
             is_recursive: bool,
+            follow_symlinks: bool,
             // whether this is an initial scan, used only for events
             is_initial: bool,
         ) -> impl Iterator<Item = (PathBuf, PathData)> + '_ {
@@ -256,7 +275,7 @@ mod data {
             //
             // See: https://docs.rs/walkdir/2.0.1/walkdir/struct.WalkDir.html#method.new
             WalkDir::new(root)
-                .follow_links(true)
+                .follow_links(follow_symlinks)
                 .max_depth(Self::dir_scan_depth(is_recursive))
                 .into_iter()
                 //
@@ -480,6 +499,7 @@ pub struct PollWatcher {
     /// currently used only for manual polling
     message_channel: Sender<()>,
     delay: Option<Duration>,
+    follow_sylinks: bool,
 }
 
 impl PollWatcher {
@@ -523,6 +543,7 @@ impl PollWatcher {
             data_builder: Arc::new(Mutex::new(data_builder)),
             want_to_stop: Arc::new(AtomicBool::new(false)),
             delay: config.poll_interval(),
+            follow_sylinks: config.follow_symlinks(),
             message_channel: tx,
         };
 
@@ -582,8 +603,11 @@ impl PollWatcher {
         {
             data_builder.update_timestamp();
 
-            let watch_data =
-                data_builder.build_watch_data(path.to_path_buf(), recursive_mode.is_recursive());
+            let watch_data = data_builder.build_watch_data(
+                path.to_path_buf(),
+                recursive_mode.is_recursive(),
+                self.follow_sylinks,
+            );
 
             // if create watch_data successful, add it to watching list.
             if let Some(watch_data) = watch_data {