chore: move LMDB imports into methods for performance

[njzjz]

Summary by CodeRabbit

• Improvements
  • Enhanced LMDB data format initialization to ensure proper library dependency handling during object construction.

[codspeed-hq]

Merging this PR will not alter performance

⚠️ Unknown Walltime execution environment detected

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✅ 2 untouched benchmarks
⏩ 2 skipped benchmarks¹

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_{Comparing njzjz:move-lmdb-imports (dc22e44) with devel (ae134fe)}

Footnotes

1. 2 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between ae134fe and dc22e44.

📒 Files selected for processing (1)

• dpdata/lmdb/format.py

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📝 Walkthrough

Walkthrough

The LMDBFormat class now includes an __init__ constructor that applies msgpack_numpy patching during instantiation. Module-level imports of lmdb and msgpack are deferred to individual methods, ensuring patching occurs at the appropriate initialization time.

Changes

Cohort / File(s)	Summary
LMDBFormat Initialization & Import Deferral dpdata/lmdb/format.py	Added __init__ constructor to trigger msgpack_numpy patching during object construction. Moved lmdb and msgpack imports from module-level to method-level in to_multi_systems, _dump_to_txn, and from_multi_systems to control patch timing.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~12 minutes

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 50.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: moving LMDB imports (lmdb, msgpack) from module-level to inside methods for performance optimization.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.37%. Comparing base (ae134fe) to head (dc22e44).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #945   +/-   ##
=======================================
  Coverage   86.37%   86.37%           
=======================================
  Files          86       86           
  Lines        8086     8090    +4     
=======================================
+ Hits         6984     6988    +4     
  Misses       1102     1102           

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