PlexKodiConnect/resources/lib/watchdog/observers/inotify_buffer.py

98 lines
3.7 KiB
Python

# coding: utf-8
#
# Copyright 2014 Thomas Amland <thomas.amland@gmail.com>
#
# 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.
import logging
from ..utils import BaseThread
from ..utils.delayed_queue import DelayedQueue
from .inotify_c import Inotify
logger = logging.getLogger(__name__)
class InotifyBuffer(BaseThread):
"""A wrapper for `Inotify` that holds events for `delay` seconds. During
this time, IN_MOVED_FROM and IN_MOVED_TO events are paired.
"""
delay = 0.5
def __init__(self, path, recursive=False):
BaseThread.__init__(self)
self._queue = DelayedQueue(self.delay)
self._inotify = Inotify(path, recursive)
self.start()
def read_event(self):
"""Returns a single event or a tuple of from/to events in case of a
paired move event. If this buffer has been closed, immediately return
None.
"""
return self._queue.get()
def on_thread_stop(self):
self._inotify.close()
self._queue.close()
def close(self):
self.stop()
self.join()
def _group_events(self, event_list):
"""Group any matching move events"""
grouped = []
for inotify_event in event_list:
logger.debug("in-event %s", inotify_event)
def matching_from_event(event):
return (not isinstance(event, tuple) and event.is_moved_from
and event.cookie == inotify_event.cookie)
if inotify_event.is_moved_to:
# Check if move_from is already in the buffer
for index, event in enumerate(grouped):
if matching_from_event(event):
grouped[index] = (event, inotify_event)
break
else:
# Check if move_from is in delayqueue already
from_event = self._queue.remove(matching_from_event)
if from_event is not None:
grouped.append((from_event, inotify_event))
else:
logger.debug("could not find matching move_from event")
grouped.append(inotify_event)
else:
grouped.append(inotify_event)
return grouped
def run(self):
"""Read event from `inotify` and add them to `queue`. When reading a
IN_MOVE_TO event, remove the previous added matching IN_MOVE_FROM event
and add them back to the queue as a tuple.
"""
deleted_self = False
while self.should_keep_running() and not deleted_self:
inotify_events = self._inotify.read_events()
grouped_events = self._group_events(inotify_events)
for inotify_event in grouped_events:
# Only add delay for unmatched move_from events
delay = not isinstance(inotify_event, tuple) and inotify_event.is_moved_from
self._queue.put(inotify_event, delay)
if not isinstance(inotify_event, tuple) and inotify_event.is_delete_self and \
inotify_event.src_path == self._inotify.path:
# Deleted the watched directory, stop watching for events
deleted_self = True