Fix crash when prehandle snapshot

[lidezhu]

What problem does this PR solve?

Issue Number: close #4072

Problem Summary: When apply snapshot, it will first get a schema snapshot for decoding. And in the schema snapshot we store a pointer to the column infos. So if the schema of the column infos changed, the pointer may be invalid and it will cause crash.

What is changed and how it works?

Copy the value of the column infos instead of storing a pointer when creating schema snapshot.

Check List

Tests

• Unit test
• Integration test (3 tiflash nodes with two tiflash replica, under heavy dml + ddl workload and with region-shuffle-scheduler, the cluster works normally)
• Manual test (add detailed scripts or steps below)
• No code

Release note

Avoid the potential of crash when apply snapshot under heavy ddl scenario

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• JaySon-Huang

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[lidezhu]

/run-all-tests

[sre-bot]

Coverage for changed files

Filename                            Regions    Missed Regions     Cover   Functions  Missed Functions  Executed       Lines      Missed Lines     Cover    Branches   Missed Branches     Cover
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
DecodingStorageSchemaSnapshot.h          35                 1    97.14%           1                 0   100.00%          61                 1    98.36%          26                 2    92.31%
PartitionStreams.cpp                    238               189    20.59%          21                13    38.10%         571               391    31.52%         130               109    16.15%
RegionBlockReader.cpp                    82                26    68.29%           3                 0   100.00%         163                25    84.66%          60                24    60.00%
RowCodec.cpp                            243                33    86.42%          19                 0   100.00%         389                58    85.09%         204                45    77.94%
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
TOTAL                                   598               249    58.36%          44                13    70.45%        1184               475    59.88%         420               180    57.14%

Coverage summary

Functions  MissedFunctions  Executed  Lines   MissedLines  Cover
16676      9482             43.14%    184701  95690        48.19%

full coverage report (for internal network access only)

[lidezhu]

/merge

[ti-chi-bot]

@lidezhu: It seems you want to merge this PR, I will help you trigger all the tests:

/run-all-tests

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[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 73178f3

[sre-bot]

Coverage for changed files

Filename                            Regions    Missed Regions     Cover   Functions  Missed Functions  Executed       Lines      Missed Lines     Cover    Branches   Missed Branches     Cover
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
DecodingStorageSchemaSnapshot.h          35                 1    97.14%           1                 0   100.00%          61                 1    98.36%          26                 2    92.31%
PartitionStreams.cpp                    238               189    20.59%          21                13    38.10%         571               391    31.52%         130               109    16.15%
RegionBlockReader.cpp                    82                26    68.29%           3                 0   100.00%         163                25    84.66%          60                24    60.00%
RowCodec.cpp                            243                33    86.42%          19                 0   100.00%         389                58    85.09%         204                45    77.94%
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
TOTAL                                   598               249    58.36%          44                13    70.45%        1184               475    59.88%         420               180    57.14%

Coverage summary

Functions  MissedFunctions  Executed  Lines   MissedLines  Cover
16691      9483             43.18%    184951  95719        48.25%

full coverage report (for internal network access only)

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #4143.

[sre-bot]

Coverage for changed files

Filename                            Regions    Missed Regions     Cover   Functions  Missed Functions  Executed       Lines      Missed Lines     Cover    Branches   Missed Branches     Cover
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
DecodingStorageSchemaSnapshot.h          35                 1    97.14%           1                 0   100.00%          61                 1    98.36%          26                 2    92.31%
PartitionStreams.cpp                    238               189    20.59%          21                13    38.10%         571               391    31.52%         130               109    16.15%
RegionBlockReader.cpp                    82                26    68.29%           3                 0   100.00%         163                25    84.66%          60                24    60.00%
RowCodec.cpp                            243                33    86.42%          19                 0   100.00%         389                58    85.09%         204                45    77.94%
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
TOTAL                                   598               249    58.36%          44                13    70.45%        1184               475    59.88%         420               180    57.14%

Coverage summary

Functions  MissedFunctions  Executed  Lines   MissedLines  Cover
16691      9483             43.18%    184951  95707        48.25%

full coverage report (for internal network access only)