Fix blobstore truncate unexpected normal files

[jiaqizho]

What problem does this PR solve?

Issue Number: close #xxx

Problem Summary:

• If LRUCache has already removed a BlobFile instance, the next time we open the file for reading, we will get a truncated file with valid data thrown away.

What is changed and how it works?

Check List

Tests

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

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

None

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• JaySon-Huang

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[JaySon-Huang]

/merge

[ti-chi-bot]

@JaySon-Huang: 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: 6a9fa32

[ti-chi-bot]

@jiaqizho: Your PR was out of date, I have automatically updated it for you.

At the same time I will also trigger all tests for you:

/run-all-tests

If the CI test fails, you just re-trigger the test that failed and the bot will merge the PR for you after the CI passes.

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[sre-bot]

Coverage for changed files

Filename                      Regions    Missed Regions     Cover   Functions  Missed Functions  Executed       Lines      Missed Lines     Cover    Branches   Missed Branches     Cover
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
BlobFile.cpp                       23                 9    60.87%           6                 1    83.33%          46                18    60.87%          10                 7    30.00%
BlobFile.h                          2                 0   100.00%           2                 0   100.00%           6                 0   100.00%           0                 0         -
BlobStore.cpp                     344               118    65.70%          39                 6    84.62%         726               212    70.80%         210                84    60.00%
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
TOTAL                             369               127    65.58%          47                 7    85.11%         778               230    70.44%         220                91    58.64%

Coverage summary

Functions  MissedFunctions  Executed  Lines   MissedLines  Cover
16367      9721             40.61%    179510  98571        45.09%

full coverage report (for internal network access only)