Refactor hpc_load and entangled logics in CheckpointConnector

[tarepan]

What does this PR do?

Refactor CheckpointConnector by reducing duplicated parts and separating different functionality.
Fixes #5370
All changes are highlighted in the issue.

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[pep8speaks]

Hello @tarepan! Thanks for updating this PR.

There are currently no PEP 8 issues detected in this Pull Request. Cheers! 🍻

Comment last updated at 2021-02-04 23:55:02 UTC

[codecov]

Codecov Report

Merging #5371 (73a1e19) into release/1.2-dev (d2c2e50) will decrease coverage by 5%.
The diff coverage is 97%.

@@               Coverage Diff                @@
##           release/1.2-dev   #5371    +/-   ##
================================================
- Coverage               88%     83%    -5%     
================================================
  Files                  181     181            
  Lines                12912   12911     -1     
================================================
- Hits                 11397   10727   -670     
- Misses                1515    2184   +669     

[archsyscall]

Great Work
I have a minor question

[awaelchli]

@tarepan could you rebase onto 1.2?

[tarepan]

@awaelchli
In my understanding, refactoring PR should be merged toward master.
It is because refactoring PR is a brother of BugFix PR (not minor change, but patch change) and BugFix goes to master.
This PR is refactoring PR, so should this PR be merged toward master?
I understand about rebase in #5379, I will rebase onto 1.2.

[carmocca]

@tarepan Can you resolve conflicts and fix the tests?

Removing the ready-to-go label until then :)

[tarepan]

@carmocca thanks for ping!
Conflict resolved, and CI failures are fixed (remainings are from upstream and random error).
Ready to merge :)

[Borda]

@tarepan mind resolve conflicts related to. changed destination branch... 🐰

[edenlightning]

@tarepan mind taking a look? We would love to get this PR merged!

[Borda]

@tarepan seems just in front of the finish line, mind resolve conflicts so we can let it land?