core: more types

src/watchdog/events.py

@@ -451,7 +451,7 @@ def dispatch(self, event: FileSystemEvent) -> None:
 class LoggingEventHandler(FileSystemEventHandler):
     """Logs all the events captured."""
 
-    def __init__(self, logger: logging.Logger | None = None) -> None:
+    def __init__(self, *, logger: logging.Logger | None = None) -> None:
         super().__init__()
         self.logger = logger or logging.root
 

src/watchdog/observers/__init__.py

@@ -47,7 +47,7 @@
 
 
 class ObserverType(Protocol):
-    def __call__(self, *, timeout: int = ...) -> BaseObserver: ...
+    def __call__(self, *, timeout: float = ...) -> BaseObserver: ...
 
 
 def _get_observer_cls() -> ObserverType:

src/watchdog/observers/api.py

@@ -3,6 +3,7 @@
 import contextlib
 import queue
 import threading
+from collections import defaultdict
 from pathlib import Path
 from typing import TYPE_CHECKING
 
@@ -12,8 +13,8 @@
 if TYPE_CHECKING:
     from watchdog.events import FileSystemEvent, FileSystemEventHandler
 
-DEFAULT_EMITTER_TIMEOUT = 1  # in seconds.
-DEFAULT_OBSERVER_TIMEOUT = 1  # in seconds.
+DEFAULT_EMITTER_TIMEOUT = 1.0  # in seconds
+DEFAULT_OBSERVER_TIMEOUT = 1.0  # in seconds
 
 
 class EventQueue(SkipRepeatsQueue):
@@ -110,7 +111,7 @@ def __init__(
         event_queue: EventQueue,
         watch: ObservedWatch,
         *,
-        timeout: int = DEFAULT_EMITTER_TIMEOUT,
+        timeout: float = DEFAULT_EMITTER_TIMEOUT,
         event_filter: list[type[FileSystemEvent]] | None = None,
     ) -> None:
         super().__init__()
@@ -120,7 +121,7 @@ def __init__(
         self._event_filter = frozenset(event_filter) if event_filter is not None else None
 
     @property
-    def timeout(self) -> int:
+    def timeout(self) -> float:
         """Blocking timeout for reading events."""
         return self._timeout
 
@@ -141,7 +142,7 @@ def queue_event(self, event: FileSystemEvent) -> None:
         if self._event_filter is None or any(isinstance(event, cls) for cls in self._event_filter):
             self._event_queue.put((event, self.watch))
 
-    def queue_events(self, timeout: int) -> None:
+    def queue_events(self, timeout: float) -> None:
         """Override this method to populate the event queue with events
         per interval period.
 
@@ -171,13 +172,13 @@ class EventDispatcher(BaseThread):
     stop_event = object()
     """Event inserted into the queue to signal a requested stop."""
 
-    def __init__(self, *, timeout: int = DEFAULT_OBSERVER_TIMEOUT) -> None:
+    def __init__(self, *, timeout: float = DEFAULT_OBSERVER_TIMEOUT) -> None:
         super().__init__()
         self._event_queue = EventQueue()
         self._timeout = timeout
 
     @property
-    def timeout(self) -> int:
+    def timeout(self) -> float:
         """Timeout value to construct emitters with."""
         return self._timeout
 
@@ -217,12 +218,12 @@ def run(self) -> None:
 class BaseObserver(EventDispatcher):
     """Base observer."""
 
-    def __init__(self, emitter_class: type[EventEmitter], *, timeout: int = DEFAULT_OBSERVER_TIMEOUT) -> None:
+    def __init__(self, emitter_class: type[EventEmitter], *, timeout: float = DEFAULT_OBSERVER_TIMEOUT) -> None:
         super().__init__(timeout=timeout)
         self._emitter_class = emitter_class
         self._lock = threading.RLock()
         self._watches: set[ObservedWatch] = set()
-        self._handlers: dict[ObservedWatch, set[FileSystemEventHandler]] = {}
+        self._handlers: defaultdict[ObservedWatch, set[FileSystemEventHandler]] = defaultdict(set)
         self._emitters: set[EventEmitter] = set()
         self._emitter_for_watch: dict[ObservedWatch, EventEmitter] = {}
 
@@ -247,8 +248,6 @@ def _clear_emitters(self) -> None:
         self._emitter_for_watch.clear()
 
     def _add_handler_for_watch(self, event_handler: FileSystemEventHandler, watch: ObservedWatch) -> None:
-        if watch not in self._handlers:
-            self._handlers[watch] = set()
         self._handlers[watch].add(event_handler)
 
     def _remove_handlers_for_watch(self, watch: ObservedWatch) -> None:
@@ -307,7 +306,7 @@ def schedule(
             self._add_handler_for_watch(event_handler, watch)
 
             # If we don't have an emitter for this watch already, create it.
-            if self._emitter_for_watch.get(watch) is None:
+            if watch not in self._emitter_for_watch:
                 emitter = self._emitter_class(self.event_queue, watch, timeout=self.timeout, event_filter=event_filter)
                 if self.is_alive():
                     emitter.start()
@@ -367,9 +366,7 @@ def unschedule(self, watch: ObservedWatch) -> None:
             self._watches.remove(watch)
 
     def unschedule_all(self) -> None:
-        """Unschedules all watches and detaches all associated event
-        handlers.
-        """
+        """Unschedules all watches and detaches all associated event handlers."""
         with self._lock:
             self._handlers.clear()
             self._clear_emitters()
@@ -382,13 +379,14 @@ def dispatch_events(self, event_queue: EventQueue) -> None:
         entry = event_queue.get(block=True)
         if entry is EventDispatcher.stop_event:
             return
+
         event, watch = entry
 
         with self._lock:
             # To allow unschedule/stop and safe removal of event handlers
             # within event handlers itself, check if the handler is still
             # registered after every dispatch.
-            for handler in list(self._handlers.get(watch, [])):
-                if handler in self._handlers.get(watch, []):
+            for handler in self._handlers[watch].copy():
+                if handler in self._handlers[watch]:
                     handler.dispatch(event)
         event_queue.task_done()

src/watchdog/observers/fsevents.py

@@ -67,7 +67,7 @@ def __init__(
         event_queue: EventQueue,
         watch: ObservedWatch,
         *,
-        timeout: int = DEFAULT_EMITTER_TIMEOUT,
+        timeout: float = DEFAULT_EMITTER_TIMEOUT,
         event_filter: list[type[FileSystemEvent]] | None = None,
         suppress_history: bool = False,
     ) -> None:
@@ -156,7 +156,7 @@ def _is_meta_mod(event: _fsevents.NativeEvent) -> bool:
         """Returns True if the event indicates a change in metadata."""
         return event.is_inode_meta_mod or event.is_xattr_mod or event.is_owner_change
 
-    def queue_events(self, timeout: int, events: list[_fsevents.NativeEvent]) -> None:  # type: ignore[override]
+    def queue_events(self, timeout: float, events: list[_fsevents.NativeEvent]) -> None:  # type: ignore[override]
         if logger.getEffectiveLevel() <= logging.DEBUG:
             for event in events:
                 flags = ", ".join(attr for attr in dir(event) if getattr(event, attr) is True)
@@ -320,7 +320,7 @@ def _encode_path(self, path: bytes | str) -> bytes | str:
 
 
 class FSEventsObserver(BaseObserver):
-    def __init__(self, *, timeout: int = DEFAULT_OBSERVER_TIMEOUT) -> None:
+    def __init__(self, *, timeout: float = DEFAULT_OBSERVER_TIMEOUT) -> None:
         super().__init__(FSEventsEmitter, timeout=timeout)
 
     def schedule(

src/watchdog/observers/fsevents2.py

@@ -187,7 +187,7 @@ def __init__(
         event_queue: EventQueue,
         watch: ObservedWatch,
         *,
-        timeout: int = DEFAULT_EMITTER_TIMEOUT,
+        timeout: float = DEFAULT_EMITTER_TIMEOUT,
         event_filter: list[type[FileSystemEvent]] | None = None,
     ):
         super().__init__(event_queue, watch, timeout=timeout, event_filter=event_filter)
@@ -197,7 +197,7 @@ def __init__(
     def on_thread_stop(self) -> None:
         self._fsevents.stop()
 
-    def queue_events(self, timeout: int) -> None:
+    def queue_events(self, timeout: float) -> None:
         events = self._fsevents.read_events()
         if events is None:
             return
@@ -249,5 +249,5 @@ def queue_events(self, timeout: int) -> None:
 
 
 class FSEventsObserver2(BaseObserver):
-    def __init__(self, *, timeout: int = DEFAULT_OBSERVER_TIMEOUT) -> None:
+    def __init__(self, *, timeout: float = DEFAULT_OBSERVER_TIMEOUT) -> None:
         super().__init__(FSEventsEmitter, timeout=timeout)

src/watchdog/observers/inotify.py

@@ -106,7 +106,7 @@ def __init__(
         event_queue: EventQueue,
         watch: ObservedWatch,
         *,
-        timeout: int = DEFAULT_EMITTER_TIMEOUT,
+        timeout: float = DEFAULT_EMITTER_TIMEOUT,
         event_filter: list[type[FileSystemEvent]] | None = None,
     ) -> None:
         super().__init__(event_queue, watch, timeout=timeout, event_filter=event_filter)
@@ -123,7 +123,7 @@ def on_thread_stop(self) -> None:
             self._inotify.close()
             self._inotify = None
 
-    def queue_events(self, timeout: int, *, full_events: bool = False) -> None:
+    def queue_events(self, timeout: float, *, full_events: bool = False) -> None:
         # If "full_events" is true, then the method will report unmatched move events as separate events
         # This behavior is by default only called by a InotifyFullEmitter
         if self._inotify is None:
@@ -238,7 +238,7 @@ class InotifyFullEmitter(InotifyEmitter):
     Such move events will have a ``None`` value for the unmatched part.
     """
 
-    def queue_events(self, timeout: int, *, events: bool = True) -> None:  # type: ignore[override]
+    def queue_events(self, timeout: float, *, events: bool = True) -> None:  # type: ignore[override]
         super().queue_events(timeout, full_events=events)
 
 
@@ -247,6 +247,6 @@ class InotifyObserver(BaseObserver):
     calls to event handlers.
     """
 
-    def __init__(self, *, timeout: int = DEFAULT_OBSERVER_TIMEOUT, generate_full_events: bool = False) -> None:
+    def __init__(self, *, timeout: float = DEFAULT_OBSERVER_TIMEOUT, generate_full_events: bool = False) -> None:
         cls = InotifyFullEmitter if generate_full_events else InotifyEmitter
         super().__init__(cls, timeout=timeout)

src/watchdog/observers/kqueue.py

@@ -402,9 +402,9 @@ def __init__(
         event_queue: EventQueue,
         watch: ObservedWatch,
         *,
-        timeout: int = DEFAULT_EMITTER_TIMEOUT,
+        timeout: float = DEFAULT_EMITTER_TIMEOUT,
         event_filter: list[type[FileSystemEvent]] | None = None,
-        stat: Callable = os.stat,
+        stat: Callable[[str], os.stat_result] = os.stat,
     ) -> None:
         super().__init__(event_queue, watch, timeout=timeout, event_filter=event_filter)
 
@@ -590,7 +590,7 @@ def _gen_renamed_events(
                 yield FileDeletedEvent(src_path)
             yield self._parent_dir_modified(src_path)
 
-    def _read_events(self, timeout: float | None = None) -> list[select.kevent]:
+    def _read_events(self, timeout: float) -> list[select.kevent]:
         """Reads events from a call to the blocking
         :meth:`select.kqueue.control()` method.
 
@@ -601,7 +601,7 @@ def _read_events(self, timeout: float | None = None) -> list[select.kevent]:
         """
         return self._kq.control(self._descriptors.kevents, MAX_EVENTS, timeout=timeout)
 
-    def queue_events(self, timeout: int) -> None:
+    def queue_events(self, timeout: float) -> None:
         """Queues events by reading them from a call to the blocking
         :meth:`select.kqueue.control()` method.
 
@@ -651,5 +651,5 @@ class KqueueObserver(BaseObserver):
     calls to event handlers.
     """
 
-    def __init__(self, *, timeout: int = DEFAULT_OBSERVER_TIMEOUT) -> None:
+    def __init__(self, *, timeout: float = DEFAULT_OBSERVER_TIMEOUT) -> None:
         super().__init__(KqueueEmitter, timeout=timeout)

src/watchdog/observers/polling.py

@@ -36,6 +36,7 @@
 from watchdog.utils.dirsnapshot import DirectorySnapshot, DirectorySnapshotDiff, EmptyDirectorySnapshot
 
 if TYPE_CHECKING:
+    from collections.abc import Iterator
     from typing import Callable
 
     from watchdog.events import FileSystemEvent
@@ -52,10 +53,10 @@ def __init__(
         event_queue: EventQueue,
         watch: ObservedWatch,
         *,
-        timeout: int = DEFAULT_EMITTER_TIMEOUT,
+        timeout: float = DEFAULT_EMITTER_TIMEOUT,
         event_filter: list[type[FileSystemEvent]] | None = None,
-        stat: Callable = os.stat,
-        listdir: Callable = os.scandir,
+        stat: Callable[[str], os.stat_result] = os.stat,
+        listdir: Callable[[str | None], Iterator[os.DirEntry]] = os.scandir,
     ) -> None:
         super().__init__(event_queue, watch, timeout=timeout, event_filter=event_filter)
         self._snapshot: DirectorySnapshot = EmptyDirectorySnapshot()
@@ -70,7 +71,7 @@ def __init__(
     def on_thread_start(self) -> None:
         self._snapshot = self._take_snapshot()
 
-    def queue_events(self, timeout: int) -> None:
+    def queue_events(self, timeout: float) -> None:
         # We don't want to hit the disk continuously.
         # timeout behaves like an interval for polling emitters.
         if self.stopped_event.wait(timeout):
@@ -118,17 +119,23 @@ class PollingObserver(BaseObserver):
     system changes.
     """
 
-    def __init__(self, *, timeout: int = DEFAULT_OBSERVER_TIMEOUT) -> None:
+    def __init__(self, *, timeout: float = DEFAULT_OBSERVER_TIMEOUT) -> None:
         super().__init__(PollingEmitter, timeout=timeout)
 
 
 class PollingObserverVFS(BaseObserver):
     """File system independent observer that polls a directory to detect changes."""
 
-    def __init__(self, stat: Callable, listdir: Callable, *, polling_interval: int = 1) -> None:
+    def __init__(
+        self,
+        stat: Callable[[str], os.stat_result],
+        listdir: Callable[[str | None], Iterator[os.DirEntry]],
+        *,
+        polling_interval: int = 1,
+    ) -> None:
         """:param stat: stat function. See ``os.stat`` for details.
         :param listdir: listdir function. See ``os.scandir`` for details.
-        :type polling_interval: float
+        :type polling_interval: int
         :param polling_interval: interval in seconds between polling the file system.
         """
         emitter_cls = partial(PollingEmitter, stat=stat, listdir=listdir)

src/watchdog/observers/read_directory_changes.py

@@ -38,7 +38,7 @@ def __init__(
         event_queue: EventQueue,
         watch: ObservedWatch,
         *,
-        timeout: int = DEFAULT_EMITTER_TIMEOUT,
+        timeout: float = DEFAULT_EMITTER_TIMEOUT,
         event_filter: list[type[FileSystemEvent]] | None = None,
     ) -> None:
         super().__init__(event_queue, watch, timeout=timeout, event_filter=event_filter)
@@ -66,7 +66,7 @@ def _read_events(self) -> list[WinAPINativeEvent]:
             return []
         return read_events(self._whandle, self.watch.path, recursive=self.watch.is_recursive)
 
-    def queue_events(self, timeout: int) -> None:
+    def queue_events(self, timeout: float) -> None:
         winapi_events = self._read_events()
         with self._lock:
             last_renamed_src_path = ""
@@ -107,5 +107,5 @@ class WindowsApiObserver(BaseObserver):
     calls to event handlers.
     """
 
-    def __init__(self, *, timeout: int = DEFAULT_OBSERVER_TIMEOUT) -> None:
+    def __init__(self, *, timeout: float = DEFAULT_OBSERVER_TIMEOUT) -> None:
         super().__init__(WindowsApiEmitter, timeout=timeout)