[cleanup][ml] ManagedCursor clean up.

[dao-jun]

Motivation

Code clean up.

Modifications

Verifying this change

• Make sure that the change passes the CI checks.

(Please pick either of the following options)

This change is a trivial rework / code cleanup without any test coverage.

(or)

This change is already covered by existing tests, such as (please describe tests).

(or)

This change added tests and can be verified as follows:

(example:)

• Added integration tests for end-to-end deployment with large payloads (10MB)
• Extended integration test for recovery after broker failure

Does this pull request potentially affect one of the following parts:

If the box was checked, please highlight the changes

• Dependencies (add or upgrade a dependency)
• The public API
• The schema
• The default values of configurations
• The threading model
• The binary protocol
• The REST endpoints
• The admin CLI options
• The metrics
• Anything that affects deployment

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete

Matching PR in forked repository

PR in forked repository:

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 73.60%. Comparing base (bbc6224) to head (27f0f78).
Report is 36 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #22246      +/-   ##
============================================
+ Coverage     73.57%   73.60%   +0.02%     
- Complexity    32624    32754     +130     
============================================
  Files          1877     1879       +2     
  Lines        139502   139791     +289     
  Branches      15299    15335      +36     
============================================
+ Hits         102638   102892     +254     
- Misses        28908    28914       +6     
- Partials       7956     7985      +29     

Flag	Coverage Δ
inttests	26.50% <71.42%> (+1.91%)	⬆️
systests	24.31% <85.71%> (-0.01%)	⬇️
unittests	72.88% <100.00%> (+0.04%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
.../org/apache/bookkeeper/mledger/impl/EntryImpl.java	79.26% <100.00%> (+0.78%)	⬆️
...che/bookkeeper/mledger/impl/ManagedCursorImpl.java	79.12% <100.00%> (-0.18%)	⬇️

... and 73 files with indirect coverage changes

[nodece]

LGTM

[Technoboy-]

Hi @dao-jun Could you merge the pr at least two reviews approval?

[codelipenghui]

@dao-jun The PR touched the critical path of Pulsar, we should wait for more reviewers to review the PR. If a PR get merged with one reviewer and merged in a few hours, the committers will lost the chance to review your PR and new potential risks might introduce to the Pulsar codebase. Now, so many companies are relaying on the stable release, even if this is a trivial changes to cleanup the managed cursor, give more time for other reviewer will still benefit Pulsar. WDYT?

[dao-jun]

@dao-jun The PR touched the critical path of Pulsar, we should wait for more reviewers to review the PR. If a PR get merged with one reviewer and merged in a few hours, the committers will lost the chance to review your PR and new potential risks might introduce to the Pulsar codebase. Now, so many companies are relaying on the stable release, even if this is a trivial changes to cleanup the managed cursor, give more time for other reviewer will still benefit Pulsar. WDYT?

got it

[lhotari]

@dao-jun The PR touched the critical path of Pulsar, we should wait for more reviewers to review the PR. If a PR get merged with one reviewer and merged in a few hours, the committers will lost the chance to review your PR and new potential risks might introduce to the Pulsar codebase. Now, so many companies are relaying on the stable release, even if this is a trivial changes to cleanup the managed cursor, give more time for other reviewer will still benefit Pulsar. WDYT?

got it

@dao-jun It seems that this was merged without more reviews. I added a comment to the commit:
532b0d9#r140287388

does this change have a side-effect where it creates PositionImpl objects? A lot of effort has been put into reducing object allocations so that's why this could be causing a regression in that area.

[dao-jun]

@lhotari

It seems that this was merged without more reviews

Yes, my bad

[lhotari]

It seems that this was merged without more reviews

Yes, my bad

@dao-jun I'd recommend reverting the change that I have pinpointed in the comment 532b0d9#r140287388 , assuming that it creates new PositionImpl instances which were avoided before this change was made. /cc @codelipenghui

[dao-jun]

@lhotari I've replied your comment, 532b0d9#r140303950