27010 : Add new files to parsing queue on every loop of dag processsing

[pavansharma36]

closes: #27010

Once file paths are refreshed on dag_dir_list interval. If there are any new files added, add them to parsing queue at start so those can be parsed immediately instead of waiting of existing parsing queue to finish

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[ephraimbuddy]

We need tests to prove that this works. Also, benchmarking may be required.

cc: @ashb

[potiuk]

I saw quite a few users complaining recently about similar behaviour, so it would be great to review and merge it before 2.4.3.

Deque should be fine when it comes to performance (at least all the comparision and micro-benchmarking I saw confirm that). But I think we should review this one carefully also taking into account the processing order the user can choose.

[potiuk]

conflicts need resolving and some benchmarks would be coo. Also cc: @ashb for comments.

[potiuk]

LGTM but it needs another committer as this is very core change.

[ashb]

I'll look at the code in a moment, but how is this different from setting the existing dag dir refresh interval config to 0?

[pavansharma36]

@ashb

Existing implementation adds new file to parsing queue only if parsing queue is empty.
Consider we set refresh interval to 5 seconds and have 10k existing dag files which takes around 5 minutes to parse, Even though file paths are refreshed every 5 seconds new files are not added to parsing queue until all 10k files are parsed and queue becomes empty

This change to make sure if file_path is refreshed on list_interval config, new files are added to parsing queue without waiting for existing file parsing.

[ashb]

Got it thanks! (I was on my phone and it was difficult to read the code fully there)

Feature LGTM!

[potiuk]

LGTM too. Nice and simple solution.