Watchdog detects changes half a second later than dsoprea/PyInotify under Linux

[Larivact]

I am working on a project where the file changes should be detected as soon as possible.
I started out using watchdog since it's crossplatform and conveniently abstracts the filesystem events,
but I noticed that watchdog takes 0.5s longer than dsoprea/PyInotify to detect file changes. Is this just the price you have to pay for the abstraction? Or could watchdog be more optimized?

Code I used for benchmarking:

import time
import watchdog.events
import watchdog.observers

class EventHandler(watchdog.events.FileSystemEventHandler):
	def on_any_event(self, event):
		print(time.time())

observer = watchdog.observers.Observer()
observer.schedule(EventHandler(), '.', recursive=True)
observer.start()
input()

import time
import inotify.adapters

i = inotify.adapters.InotifyTree(b'.')

for event in i.event_gen():
	if event and 'IN_CLOSE_WRITE' in event[1]:
		print(time.time())

[DonyorM]

This has to do with how watchdog creates move events. In order to match inotify's move_from and move_to events to become a single move event as offered by watchdog, there needs to be a buffer time to find the matching event. This is set to 0.5 seconds I believe.

[Larivact]

Buffering all events when only moved_from needs to be matched with moved_to seems to be inefficient. Wouldn't it be better to only wait 0.5s when moved_from occurs?

I don't get why my testing resulted in a 0.5s delay the timeouts all seem to be set to 1s.
Anyway is there a way to disable the buffering if you don't need the move events to be merged?

[DonyorM]

The delay is found in the inotify_buffer module with the delay variable being set to 0.5 on line 30. Right now there doesn't seem to be a way to disable it. However, you could just edit the code and set the delay variable to 0.

[Larivact]

@DonyorM thanks. I monkey patched it using

watchdog.observers.inotify_buffer.InotifyBuffer.delay = 0

While this got rid of the delay the move events interestingly still seem to get merged.

[BoboTiG]

Closed with 2b2091a.