[ColinLeeo]

Problem

The C++ implementation already has global switches for the parallel read/write paths and the worker-pool size, but they were not reachable from the C API or the Python binding, so users could not measure or tune them.

Change

• C API: tsfile_set_parallel_read_enabled, tsfile_set_parallel_write_enabled, tsfile_set_thread_count.
• Python: set_parallel_read_enabled, set_parallel_write_enabled, set_thread_count.

No behavior change for existing callers; the defaults are unchanged.

Why it matters

For single-table reads the worker pool is mostly idle: with the parallel read path disabled, a 3.2M-row full scan measured ~20% faster than the default (0.25 s vs 0.21 s). Exposing the switch lets users and benchmarks make that choice, and lets the default be revisited with data.

Testing

• Full C++ suite: 1454 tests passed.
• Python suite: 607 passed, 16 skipped; the three new functions verified importable and callable.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 91.66667% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 66.56%. Comparing base (90c7862) to head (eb8d1bf).
⚠️ Report is 2 commits behind head on develop.

Files with missing lines	Patch %	Lines
cpp/src/common/global.cc	80.00%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #1092      +/-   ##
===========================================
+ Coverage    66.51%   66.56%   +0.05%     
===========================================
  Files          778      782       +4     
  Lines        56577    56733     +156     
  Branches      9105     9135      +30     
===========================================
+ Hits         37633    37767     +134     
- Misses       17291    17305      +14     
- Partials      1653     1661       +8     

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[Copilot]

Warning

Copilot couldn't run its full agentic review because it didn't start before the timeout. Make sure your repository has a runner available, or add a copilot-code-review.yml file specifying one with the runs-on attribute. See the docs for more details.

Copilot review overview

2 open issues

• The comment notes exceptions must not cross the C API boundary, but this only catches… · New
• _check_int() currently only accepts built-in int, which will reject valid integer-like types… · New

What changed in this PR

Expose existing C++ global toggles for parallel read/write and worker thread-pool sizing through the C API and Python bindings so users can benchmark/tune these behaviors without changing defaults.

Changes:

• Add C API getters/setters for parallel read/write toggles and thread count; wire them into the C wrapper implementation.
• Expose the same controls in the Cython/Python layer (including config dict round-tripping).
• Add C++ and Python tests covering validation, round-trip behavior, and “set-before-first-use” lazy-init ordering.

File	Description
python/​tsfile/​tsfile_py_cpp.pyx	Adds Python-exposed getters/setters and config dict integration for the new switches.
python/​tsfile/​tsfile_py_cpp.pxd	Exports the new Python API functions.
python/​tsfile/​tsfile_cpp.pxd	Declares new C wrapper externs and config fields for Cython access.
python/​tsfile/​__init__.py	Re-exports new APIs at package top-level.
python/​tests/​test_write_and_read.py	Adds coverage for validation, config dict integration, and lazy-init ordering via subprocess.
python/​README.md	Documents the new Python controls and concurrency constraints.
cpp/​test/​cwrapper/​cwrapper_test.cc	Adds C wrapper tests for validation, lazy-init ordering, and read-result equivalence.
cpp/​src/​cwrapper/​tsfile_cwrapper.h	Adds C API declarations + documentation for toggles and thread count.
cpp/​src/​cwrapper/​tsfile_cwrapper.cc	Implements new C API functions by delegating to common.
cpp/​src/​common/​global.cc	Improves set_thread_count to avoid exception propagation and preserve old pool on failure.
cpp/​src/​common/​config/​config.h	Moves parallel toggle defaults to in-class initialization to survive lazy init.
cpp/​README.md	Updates documentation for runtime toggles and the global worker pool API.

_{Review effort: Lite}

[Copilot]

Warning

Copilot couldn't run its full agentic review because it didn't start before the timeout. Make sure your repository has a runner available, or add a copilot-code-review.yml file specifying one with the runs-on attribute. See the docs for more details.

Copilot review overview

6 open issues

• ConfigValue in cpp/src/common/config/config.h declares parallel_read_enabled_ /… · New
• The comment immediately above says to 'never propagate an exception across the C API boundary', but… · New
• Using int32_t as the Python-visible parameter type can raise OverflowError during… · New
• Using int32_t as the Python-visible parameter type can raise OverflowError during… · New
• _check_int() currently only accepts built-in int, which will reject valid integer-like types…
• The comment notes exceptions must not cross the C API boundary, but this only catches…

_{Review effort: Lite}