infoschema: introduce MetaOnlyInfoSchema to provide meta only information schema

[lcwangchao]

What problem does this PR solve?

Issue Number: close #52072

Problem Summary:

The API of infoschema.InfoSchema introduces too many dependencies. The main reason is that it not only provides "meta" of tables but also returns table.Table for table mutations. It brings two problems.

The first problem is the dependency cycle. infoschema.InfoSchema is a basic lib and is required by many other packages. This may cause a dependency cycle easily.

Another problem is that, if we want to break the dependency cycle. We have to use some "magic ways". For example, return infoschema.InfoSchemaVersion instead of infoschema.InfoSchema in function signature but cast it to infoschema.InfoSchema when using it. However, the casting is.(infoschema.InfoSchema) is ugly and may lost the benefit of static checks in compile phase.

What changed and how does it work?

In this PR, we extended infoschema.InfoschemaVersion to infoschema.MetaOnlyInfoSchema to provide more common use methods in API and avoid importing the table package there. In most scenes, we only need the table meta and do not want to modify it, so infoschema.MetaOnlyInfoSchema is enough.

We also added some methods to provide table meta only:

type MetaOnlyInfoSchema interface {
	// ...
	TableInfoByName(schema, table model.CIStr) (*model.TableInfo, error)
	TableInfoByID(id int64) (*model.TableInfo, bool)
	FindTableInfoByPartitionID(partitionID int64) (*model.TableInfo, *model.DBInfo, *model.PartitionDefinition)
	SchemaTableInfos(schema model.CIStr) []*model.TableInfo
	// ...
}

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No need to test

  • I checked and no code files have been changed.

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

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[codecov]

Codecov Report

Merging #52070 (3c23a06) into master (639fa00) will decrease coverage by 17.6641%.
Report is 11 commits behind head on master.
The diff coverage is 69.2307%.

Additional details and impacted files

@@                Coverage Diff                @@
##             master     #52070         +/-   ##
=================================================
- Coverage   72.3876%   54.7236%   -17.6641%     
=================================================
  Files          1485       1599        +114     
  Lines        365503     613536     +248033     
=================================================
+ Hits         264579     335749      +71170     
- Misses        81362     254456     +173094     
- Partials      19562      23331       +3769     

Flag	Coverage Δ
integration	36.7199% <7.6923%> (?)
unit	70.4637% <67.6923%> (-1.8062%)	⬇️

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

Components	Coverage Δ
dumpling	53.9957% <ø> (-2.3014%)	⬇️
parser	∅ <ø> (∅)
br	50.8033% <100.0000%> (+4.4794%)	⬆️

[lance6716]

public function will not trigger "unused" linter?

[lcwangchao]

I'm not sure, just copied from exists method like TableByName ...

[tangenta]

How about trying to remove it?

[lcwangchao]

ok, I'll try to remove it

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-03-25 11:55:49.790059055 +0000 UTC m=+1896176.812305442: ☑️ agreed by tiancaiamao.
• 2024-03-26 02:37:42.732553158 +0000 UTC m=+1949089.754799546: ☑️ agreed by lance6716.

[windtalker]

LGTM

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: lance6716, tangenta, tiancaiamao, windtalker

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• OWNERS [lance6716,tangenta,tiancaiamao,windtalker]
• br/pkg/lightning/OWNERS [lance6716]
• pkg/ddl/OWNERS [tangenta]
• pkg/expression/OWNERS [windtalker]
• pkg/infoschema/OWNERS [tangenta]
• pkg/table/OWNERS [tangenta]

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