Handle both of stat and timer watchers are enabled and steady growing file case

[cosmo0920]

Signed-off-by: Hiroshi Hatake [email protected]

Which issue(s) this PR fixes:
Follows up #3185

What this PR does / why we need it:
In this case, timer watcher tells file contents every 1 seconds and file
contents changes is also notified from stats watcher.

In such circumstances, if some tailing files are steadily growing,
previous implementation does not prevent log ingestion for written
contents which is notified by stat watcher.

This commit also prevents log ingestion in such cases.

Docs Changes:

No needed.

Release Note:

Same as title.

Additional context

I can implement this edge case patch, but how can we write down into test cases...?

[ashie]

but how can we write down into test cases...?

@cosmo0920

An idea is that adding a hook to touch the test log file to limit_bytes_per_second_reached? by
rr's Proxy.
By this, it will make sure to update the file and emit inotify event on appropriate timing.

Please see the following example:
1c1ef8e#diff-b8d2266d24d2fe9459a77854ada3159ca968433b87c23b5b716ba3c132b57714R1931
Probably other test code can be almost same with existing one in #3185.

[cosmo0920]

An idea is that adding a hook to touch the test log file to limit_bytes_per_second_reached? by
rr's Proxy.
By this, it will make sure to update the file and emit inotify event on appropriate timing.

Please see the following example:
1c1ef8e#diff-b8d2266d24d2fe9459a77854ada3159ca968433b87c23b5b716ba3c132b57714R1931
Probably other test code can be almost same with existing one in #3185.

I'd considered this and I decided to add two testing scenarios.
One is already throttled scenario:
bc11e6c
The other is glitched writing timing scenario:
bee9125

Both scenarios return same number of events per emits.

[ashie]

I'm checking the tests, I feel some curious points.
In addition, I found that the test in #3185 is still inappropriate.
I'm now trying to fix them.

[ashie]

I'm now trying to fix them.

I've added a commit but probably it will fail on mac & windows.
(because it checks inotify events are surely occurred)

[cosmo0920]

Thanks!