Add function to parse 'extradata’ in rows event

[chungeun-choi]

Hello, I am a developer contributing to py-mysql-replication.

While checking the source code, we developed it because the parsing-related part of 'rows event' to 'extra data' was not developed in the go-mysql package
(This feature has been added since Mysql 8.0.16)

Please leave a comment if there are any modifications or additions to the code!

Developed

• Added function 'decodeExtraData' that in file 'replication.row_event.go’

• The function is executed when the DecodeHeader function is executed and the dataLen value is greater than 2

• The extra data to be parsed is as follows

  	  +----------+--------------------------------------+
          |type_code |        extra_row_ndb_info            |
          +--- ------+--------------------------------------+
          | NDB      |Len of ndb_info |Format |ndb_data     |
          | 1 byte   |1 byte          |1 byte |len - 2 byte |
          +----------+----------------+-------+-------------+
  
          In case of INSERT/DELETE
          +-----------+----------------+
          | type_code | partition_info |
          +-----------+----------------+
          |   PART    |  partition_id  |
          | (1 byte)  |     2 byte     |
          +-----------+----------------+
  
          In case of UPDATE
          +-----------+------------------------------------+
          | type_code |        partition_info              |
          +-----------+--------------+---------------------+
          |   PART    | partition_id | source_partition_id |
          | (1 byte)  |    2 byte    |       2 byte        |
          +-----------+--------------+---------------------+

[lance6716]

Hi, can you mimic

go-mysql/replication/row_event_test.go

Line 942 in cfe6012

func TestTableMapOptMetaVisibility(t *testing.T) {

to dump some binlog content and test the new fields work as expected?

[lance6716]

seems it's complaining that the type of variables are not vertically aligned.

[chungeun-choi]

Thank you for your review! @lance6716
And I'll add a test code

[chungeun-choi]

Hello , @lance6716

I've made some significant improvements to codebase to ensure the proper parsing of 'extradata' within the 'rows event' functionality. Here's what this PR includes:

• Fix Incorrect Byte Parsing in NDB Info from Extra Data
• Add Test Code to Validate 'extradata' Parsing in 'rows event'

Please review the changes, and your feedback is highly appreciated.

[lance6716]

rest lgtm

[chungeun-choi]

I appreciate your review. and I can fix the three parts you mentioned!
Please check it again after modifying it.

[chungeun-choi]

fixed the three parts you mentioned :)

[lance6716]

I'm still not sure about it. MySQL enables it for UPDATE_ROWS_EVENT, UPDATE_ROWS_EVENT_V1 and PARTIAL_UPDATE_ROWS_EVENT, and we do it for UPDATE_ROWS_EVENTv2 and PARTIAL_UPDATE_ROWS_EVENT. I remember UPDATE_ROWS_EVENT and UPDATE_ROWS_EVENT_V1 has been deprecated so we really don't need to care about them. I'll check it later.

And it's helpful that you can also help me check and provide some reference 😄

[lance6716]

As you says in PR description, this feature is added in v8.0.16, and log_bin_use_v1_row_events is deprecated in v8.0.18, so we should also consider UPDATE_ROWS_EVENT_V1.

And MySQL's UPDATE_ROWS_EVENT (31) is our UPDATE_ROWS_EVENTv2