VReplication: Move ENUM and SET mappings from vplayer to vstreamer

[mattlord]

Description

This addresses the issues noted https://github.com/vitessio/vitess/issues/15750. You can see how to perform a manual test there as well.

It does this by removing the existing ENUM and SET field integer to string value mapping from the vplayer (consumer — where it was relying on OnlineDDL specific code that I think can be at least partially removed after this) and moving this work to the vstreamer (producer) so that Vitess provides uniform and intuitive vstream vevent behavior for ENUM and SET fields regardless of what phase the stream or workflow may be in.

In discussing this issue with the Debezium Vitess connector community they had asked if we could add something to the stream which would indicate that they do NOT need to do the string mappings in order to make it easier for them to transition from <= v19 to v20+ of Vitess. To support this I added a new flag to the FieldEvent type which will indicate when the ENUM and SET values are already strings. We always set that in FieldEvents during the copy phase as 1) we've always provided those values as strings in the copy phase and 2) we have one field event per row event batch (vstream_packet) so that extra byte is negligible and is cheaper than always searching the columns to see if there are any SET or ENUM columns. During the running phase, however, we know when we're managing the string mappings for a table and we only set this field when the table we're streaming events for contains a SET or ENUM column.

This PR also fixes https://github.com/vitessio/vitess/issues/15598 after the evalengine portion of it was fixed in https://github.com/vitessio/vitess/pull/15783.

Related Issue(s)

• Fixes: https://github.com/vitessio/vitess/issues/15750
• Fixes: https://github.com/vitessio/vitess/issues/15598

Checklist

• [x] "Backport to:" labels have been added if this change should be back-ported to release branches
• [x] If this change is to be back-ported to previous releases, a justification is included in the PR description
• [x] Tests were added or are not required
• [x] Did the new or modified tests pass consistently locally and on CI?
• [x] Documentation was added or is not required

[vitess-bot[bot]]

Review Checklist

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[shlomi-noach]

Cross reference for convenience: Online DDL/VReplication test suite: support ENUM as part of PRIMARY KEY

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 75.64103% with 19 lines in your changes are missing coverage. Please review.

Project coverage is 68.42%. Comparing base (4c2df48) to head (1584903). Report is 52 commits behind head on main.

Files	Patch %	Lines
go/vt/vttablet/tabletserver/vstreamer/vstreamer.go	73.23%	19 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #15723      +/-   ##
==========================================
- Coverage   68.44%   68.42%   -0.02%     
==========================================
  Files        1558     1559       +1     
  Lines      195822   196825    +1003     
==========================================
+ Hits       134025   134685     +660     
- Misses      61797    62140     +343     

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[rohit-nayak-ps]

@mattlord: TestSchemaChange/revertible/expanded:_enum is failing

[shlomi-noach]

@mattlord: TestSchemaChange/revertible/expanded:_enum is failing

consistent on my dev env. Let me quickly see if that's due to my own commit (unlikely because my commit removes unused code).

[mattlord]

@mattlord: TestSchemaChange/revertible/expanded:_enum is failing

It was never failing before others pushed commits 🙂

[shlomi-noach]

Yes, it does look to have been https://github.com/vitessio/vitess/pull/15723/commits/d2bfdaed62c264cd49a6629aa564e73181b781f1 ! I reverted and pushed.

[mattlord]

Thank you for the reviews, @shlomi-noach and @rohit-nayak-ps ! I believe that I have addressed all of your comments now.