#!/usr/bin/env python # -*- coding: utf-8 -*- # # Copyright 2011 Yesudeep Mangalapilly # Copyright 2012 Google, Inc. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. """ :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 :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 with_statement import os import threading from .inotify_buffer import InotifyBuffer from ..observers.api import ( EventEmitter, BaseObserver, DEFAULT_EMITTER_TIMEOUT, DEFAULT_OBSERVER_TIMEOUT ) from ..events import ( DirDeletedEvent, DirModifiedEvent, DirMovedEvent, DirCreatedEvent, FileDeletedEvent, FileModifiedEvent, FileMovedEvent, FileCreatedEvent, generate_sub_moved_events, generate_sub_created_events, ) from ..utils import unicode_paths 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`` """ def __init__(self, event_queue, watch, timeout=DEFAULT_EMITTER_TIMEOUT): EventEmitter.__init__(self, event_queue, watch, timeout) self._lock = threading.Lock() self._inotify = None def on_thread_start(self): path = unicode_paths.encode(self.watch.path) self._inotify = InotifyBuffer(path, self.watch.is_recursive) def on_thread_stop(self): if self._inotify: self._inotify.close() def queue_events(self, timeout, full_events=False): #If "full_events" is true, then the method will report unmatched move events as seperate events #This behavior is by default only called by a InotifyFullEmitter with self._lock: event = self._inotify.read_event() if event is None: return 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_event in generate_sub_moved_events(src_path, dest_path): self.queue_event(sub_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(None, 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_event in generate_sub_created_events(src_path): self.queue_event(sub_event) elif event.is_attrib: cls = DirModifiedEvent if event.is_directory else FileModifiedEvent self.queue_event(cls(src_path)) elif 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 = DireMovedEvent if event.is_directory else FileMovedEvent self.queue_event(cls(src_path, None)) 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))) def _decode_path(self, path): """ Decode path only if unicode string was passed to this emitter. """ if isinstance(self.watch.path, bytes): return path return unicode_paths.decode(path) 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. :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`` """ def __init__(self, event_queue, watch, timeout=DEFAULT_EMITTER_TIMEOUT): InotifyEmitter.__init__(self, event_queue, watch, timeout) def queue_events(self, timeout, events=True): InotifyEmitter.queue_events(self, timeout, full_events=events) class InotifyObserver(BaseObserver): """ Observer thread that schedules watching directories and dispatches calls to event handlers. """ def __init__(self, timeout=DEFAULT_OBSERVER_TIMEOUT, generate_full_events=False): if (generate_full_events): BaseObserver.__init__(self, emitter_class=InotifyFullEmitter, timeout=timeout) else: BaseObserver.__init__(self, emitter_class=InotifyEmitter, timeout=timeout)