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linedance-app/venv/lib/python3.12/site-packages/watchdog/observers/polling.py

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+""":module: watchdog.observers.polling
+:synopsis: Polling emitter implementation.
+:author: yesudeep@google.com (Yesudeep Mangalapilly)
+:author: contact@tiger-222.fr (Mickaël Schoentgen)
+
+Classes
+-------
+.. autoclass:: PollingObserver
+   :members:
+   :show-inheritance:
+
+.. autoclass:: PollingObserverVFS
+   :members:
+   :show-inheritance:
+   :special-members:
+"""
+
+from __future__ import annotations
+
+import os
+import threading
+from functools import partial
+from typing import TYPE_CHECKING
+
+from watchdog.events import (
+    DirCreatedEvent,
+    DirDeletedEvent,
+    DirModifiedEvent,
+    DirMovedEvent,
+    FileCreatedEvent,
+    FileDeletedEvent,
+    FileModifiedEvent,
+    FileMovedEvent,
+)
+from watchdog.observers.api import DEFAULT_EMITTER_TIMEOUT, DEFAULT_OBSERVER_TIMEOUT, BaseObserver, EventEmitter
+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
+    from watchdog.observers.api import EventQueue, ObservedWatch
+
+
+class PollingEmitter(EventEmitter):
+    """Platform-independent emitter that polls a directory to detect file
+    system changes.
+    """
+
+    def __init__(
+        self,
+        event_queue: EventQueue,
+        watch: ObservedWatch,
+        *,
+        timeout: float = DEFAULT_EMITTER_TIMEOUT,
+        event_filter: list[type[FileSystemEvent]] | None = None,
+        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()
+        self._lock = threading.Lock()
+        self._take_snapshot: Callable[[], DirectorySnapshot] = lambda: DirectorySnapshot(
+            self.watch.path,
+            recursive=self.watch.is_recursive,
+            stat=stat,
+            listdir=listdir,
+        )
+
+    def on_thread_start(self) -> None:
+        self._snapshot = self._take_snapshot()
+
+    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):
+            return
+
+        with self._lock:
+            if not self.should_keep_running():
+                return
+
+            # Get event diff between fresh snapshot and previous snapshot.
+            # Update snapshot.
+            try:
+                new_snapshot = self._take_snapshot()
+            except OSError:
+                self.queue_event(DirDeletedEvent(self.watch.path))
+                self.stop()
+                return
+
+            events = DirectorySnapshotDiff(self._snapshot, new_snapshot)
+            self._snapshot = new_snapshot
+
+            # Files.
+            for src_path in events.files_deleted:
+                self.queue_event(FileDeletedEvent(src_path))
+            for src_path in events.files_modified:
+                self.queue_event(FileModifiedEvent(src_path))
+            for src_path in events.files_created:
+                self.queue_event(FileCreatedEvent(src_path))
+            for src_path, dest_path in events.files_moved:
+                self.queue_event(FileMovedEvent(src_path, dest_path))
+
+            # Directories.
+            for src_path in events.dirs_deleted:
+                self.queue_event(DirDeletedEvent(src_path))
+            for src_path in events.dirs_modified:
+                self.queue_event(DirModifiedEvent(src_path))
+            for src_path in events.dirs_created:
+                self.queue_event(DirCreatedEvent(src_path))
+            for src_path, dest_path in events.dirs_moved:
+                self.queue_event(DirMovedEvent(src_path, dest_path))
+
+
+class PollingObserver(BaseObserver):
+    """Platform-independent observer that polls a directory to detect file
+    system changes.
+    """
+
+    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[[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: int
+        :param polling_interval: interval in seconds between polling the file system.
+        """
+        emitter_cls = partial(PollingEmitter, stat=stat, listdir=listdir)
+        super().__init__(emitter_cls, timeout=polling_interval)  # type: ignore[arg-type]