""":module: watchdog.observers.inotify :synopsis: ``inotify(7)`` based emitter implementation. :author: Sebastien Martini :author: Luke McCarthy :author: yesudeep@google.com (Yesudeep Mangalapilly) :author: Tim Cuthbertson :author: contact@tiger-222.fr (Mickaël Schoentgen) :platforms: Linux 2.6.13+. .. ADMONITION:: About system requirements Recommended minimum kernel version: 2.6.25. Quote from the inotify(7) man page: "Inotify was merged into the 2.6.13 Linux kernel. The required library interfaces were added to glibc in version 2.4. (IN_DONT_FOLLOW, IN_MASK_ADD, and IN_ONLYDIR were only added in version 2.5.)" Therefore, you must ensure the system is running at least these versions appropriate libraries and the kernel. .. ADMONITION:: About recursiveness, event order, and event coalescing Quote from the inotify(7) man page: If successive output inotify events produced on the inotify file descriptor are identical (same wd, mask, cookie, and name) then they are coalesced into a single event if the older event has not yet been read (but see BUGS). The events returned by reading from an inotify file descriptor form an ordered queue. Thus, for example, it is guaranteed that when renaming from one directory to another, events will be produced in the correct order on the inotify file descriptor. ... Inotify monitoring of directories is not recursive: to monitor subdirectories under a directory, additional watches must be created. This emitter implementation therefore automatically adds watches for sub-directories if running in recursive mode. Some extremely useful articles and documentation: .. _inotify FAQ: http://inotify.aiken.cz/?section=inotify&page=faq&lang=en .. _intro to inotify: http://www.linuxjournal.com/article/8478 """ from __future__ import annotations import logging import os import threading from typing import TYPE_CHECKING from watchdog.events import ( DirCreatedEvent, DirDeletedEvent, DirModifiedEvent, DirMovedEvent, FileClosedEvent, FileClosedNoWriteEvent, FileCreatedEvent, FileDeletedEvent, FileModifiedEvent, FileMovedEvent, FileOpenedEvent, FileSystemEvent, generate_sub_created_events, generate_sub_moved_events, ) from watchdog.observers.api import DEFAULT_EMITTER_TIMEOUT, DEFAULT_OBSERVER_TIMEOUT, BaseObserver, EventEmitter from watchdog.observers.inotify_buffer import InotifyBuffer from watchdog.observers.inotify_c import InotifyConstants if TYPE_CHECKING: from watchdog.observers.api import EventQueue, ObservedWatch logger = logging.getLogger(__name__) class InotifyEmitter(EventEmitter): """inotify(7)-based event emitter. :param event_queue: The event queue to fill with events. :param watch: A watch object representing the directory to monitor. :type watch: :class:`watchdog.observers.api.ObservedWatch` :param timeout: Read events blocking timeout (in seconds). :type timeout: ``float`` :param event_filter: Collection of event types to emit, or None for no filtering (default). :type event_filter: Iterable[:class:`watchdog.events.FileSystemEvent`] | None """ def __init__( self, event_queue: EventQueue, watch: ObservedWatch, *, timeout: float = DEFAULT_EMITTER_TIMEOUT, event_filter: list[type[FileSystemEvent]] | None = None, ) -> None: super().__init__(event_queue, watch, timeout=timeout, event_filter=event_filter) self._lock = threading.Lock() self._inotify: InotifyBuffer | None = None def on_thread_start(self) -> None: path = os.fsencode(self.watch.path) event_mask = self.get_event_mask_from_filter() self._inotify = InotifyBuffer(path, recursive=self.watch.is_recursive, event_mask=event_mask) def on_thread_stop(self) -> None: if self._inotify: self._inotify.close() self._inotify = 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: logger.error("InotifyEmitter.queue_events() called when the thread is inactive") return with self._lock: if self._inotify is None: logger.error("InotifyEmitter.queue_events() called when the thread is inactive") return event = self._inotify.read_event() if event is None: return cls: type[FileSystemEvent] if isinstance(event, tuple): move_from, move_to = event src_path = self._decode_path(move_from.src_path) dest_path = self._decode_path(move_to.src_path) cls = DirMovedEvent if move_from.is_directory else FileMovedEvent self.queue_event(cls(src_path, dest_path)) self.queue_event(DirModifiedEvent(os.path.dirname(src_path))) self.queue_event(DirModifiedEvent(os.path.dirname(dest_path))) if move_from.is_directory and self.watch.is_recursive: for sub_moved_event in generate_sub_moved_events(src_path, dest_path): self.queue_event(sub_moved_event) return src_path = self._decode_path(event.src_path) if event.is_moved_to: if full_events: cls = DirMovedEvent if event.is_directory else FileMovedEvent self.queue_event(cls("", src_path)) else: cls = DirCreatedEvent if event.is_directory else FileCreatedEvent self.queue_event(cls(src_path)) self.queue_event(DirModifiedEvent(os.path.dirname(src_path))) if event.is_directory and self.watch.is_recursive: for sub_created_event in generate_sub_created_events(src_path): self.queue_event(sub_created_event) elif event.is_attrib or event.is_modify: cls = DirModifiedEvent if event.is_directory else FileModifiedEvent self.queue_event(cls(src_path)) elif event.is_delete or (event.is_moved_from and not full_events): cls = DirDeletedEvent if event.is_directory else FileDeletedEvent self.queue_event(cls(src_path)) self.queue_event(DirModifiedEvent(os.path.dirname(src_path))) elif event.is_moved_from and full_events: cls = DirMovedEvent if event.is_directory else FileMovedEvent self.queue_event(cls(src_path, "")) self.queue_event(DirModifiedEvent(os.path.dirname(src_path))) elif event.is_create: cls = DirCreatedEvent if event.is_directory else FileCreatedEvent self.queue_event(cls(src_path)) self.queue_event(DirModifiedEvent(os.path.dirname(src_path))) elif event.is_delete_self and src_path == self.watch.path: cls = DirDeletedEvent if event.is_directory else FileDeletedEvent self.queue_event(cls(src_path)) self.stop() elif not event.is_directory: if event.is_open: cls = FileOpenedEvent self.queue_event(cls(src_path)) elif event.is_close_write: cls = FileClosedEvent self.queue_event(cls(src_path)) self.queue_event(DirModifiedEvent(os.path.dirname(src_path))) elif event.is_close_nowrite: cls = FileClosedNoWriteEvent self.queue_event(cls(src_path)) def _decode_path(self, path: bytes | str) -> bytes | str: """Decode path only if unicode string was passed to this emitter.""" return path if isinstance(self.watch.path, bytes) else os.fsdecode(path) def get_event_mask_from_filter(self) -> int | None: """Optimization: Only include events we are filtering in inotify call.""" if self._event_filter is None: return None # Always listen to delete self event_mask = InotifyConstants.IN_DELETE_SELF for cls in self._event_filter: if cls in {DirMovedEvent, FileMovedEvent}: event_mask |= InotifyConstants.IN_MOVE elif cls in {DirCreatedEvent, FileCreatedEvent}: event_mask |= InotifyConstants.IN_MOVE | InotifyConstants.IN_CREATE elif cls is DirModifiedEvent: event_mask |= ( InotifyConstants.IN_MOVE | InotifyConstants.IN_ATTRIB | InotifyConstants.IN_MODIFY | InotifyConstants.IN_CREATE | InotifyConstants.IN_CLOSE_WRITE ) elif cls is FileModifiedEvent: event_mask |= InotifyConstants.IN_ATTRIB | InotifyConstants.IN_MODIFY elif cls in {DirDeletedEvent, FileDeletedEvent}: event_mask |= InotifyConstants.IN_DELETE elif cls is FileClosedEvent: event_mask |= InotifyConstants.IN_CLOSE_WRITE elif cls is FileClosedNoWriteEvent: event_mask |= InotifyConstants.IN_CLOSE_NOWRITE elif cls is FileOpenedEvent: event_mask |= InotifyConstants.IN_OPEN return event_mask class InotifyFullEmitter(InotifyEmitter): """inotify(7)-based event emitter. By default this class produces move events even if they are not matched Such move events will have a ``None`` value for the unmatched part. """ def queue_events(self, timeout: float, *, events: bool = True) -> None: # type: ignore[override] super().queue_events(timeout, full_events=events) class InotifyObserver(BaseObserver): """Observer thread that schedules watching directories and dispatches calls to event handlers. """ 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)