cwhisper: bug fixes and refactoring

[bom-d-van]

• refactor cmd/compare.go
• refactor cmd/dump.go
• refactor tests
• fix ooo write for single retention cwhisper files Points with repeated timestamps overwrites database cyclicaly #20
• return data in previous/lower archive buffers

Some of the changes were ported from a pr 18, which I decide to give up due to the challenges/problems of supporting both out of order writes and aggregation.

As always, all changes shouldn't affect standard whisper file reads/writes.

[bom-d-van]

Hi @deniszh @Civil , I have tried to fix some of the deepsource failures, but the rest of them are kinda hard/sad to correct, if you disagree and find any of the existing ones should definitely be fixed, please let me know.

[Civil]

It all looks good to me, and yeah, I agree that overall codebase of go-whisper is sometimes rather hard to correct, I guess that's why it's like that.

[bom-d-van]

@Civil haha, it's mostly complaining compress.go. It's mostly the style ones are left unhandled, some of them were not really introduced in this PR so I'm not very enthusiastic to have them corrected.

[deniszh]

I like static code analysers, but they are not replacement for human eyes ofc. I would treat them only as recommendation.

[dgryski]

I'm fine leaving these analysis issues unfixed.

[bom-d-van]

Got it, thanks for all your comments!

@dgryski haha, I have to say I'm a bit surprised that you also have an open attitude toward analysis issues, given that you have shown a strong favor of linter and things in your tweets and works. :D

[dgryski]

Yeah, but some fixes are just code churn and don't provide value. I think the remaining issues fall into that category. (Although I did notice err = fmt.Errorf("Unable to read header: %s", err.Error()) and just having err instead of err.Error() is sufficient, since %s will call Error() for you).

[deniszh]

Should I merge it, @bom-d-van ?
Or you want to add something?

[bom-d-van]

@deniszh oh, thanks for reminding me. Yep, just pushed error message fix suggested by Damian. Should be ready to merge now.