[bitborne]

Description

Structure the local hot cache environment settings by grouping their definitions in mooncake-common and moving their parsing and fallback behavior into LocalHotCacheConfig::FromEnvironment(). Client::InitLocalHotCache() now consumes the parsed configuration while retaining ownership of cache allocation, Transfer Engine registration, and handler initialization.

This preserves the existing defaults, environment precedence, permissive numeric-prefix parsing, warning messages, checksum short-circuit, and exact "1" behavior for shared memory. Direct configuration tests cover unset, valid, empty, zero, negative, malformed, overflow, legacy numeric-prefix, admission-threshold, and shared-memory values.

Module

• Transfer Engine (mooncake-transfer-engine)
• Mooncake Store (mooncake-store)
• Reshard (mooncake-reshard)
• Mooncake EP (mooncake-ep)
• Mooncake PG (mooncake-pg)
• Integration (mooncake-integration)
• P2P Store (mooncake-p2p-store)
• Python Wheel (mooncake-wheel)
• Common (mooncake-common)
• Mooncake RL (mooncake-rl)
• CI/CD
• Docs
• Other

Type of Change

• Bug fix
• New feature
• Refactor
• Breaking change
• Documentation update
• Performance improvement
• Other

How Has This Been Tested?

Test commands:

cmake --build build --target local_hot_cache_config_test client_local_hot_cache_test dummy_client_get_buffer_test -j32
ctest --test-dir build -R '^(local_hot_cache_config_test|client_local_hot_cache_test|dummy_client_get_buffer_test)$' --output-on-failure
pre-commit run --files mooncake-common/include/environment_variables.h mooncake-store/include/client_service.h mooncake-store/include/local_hot_cache.h mooncake-store/src/CMakeLists.txt mooncake-store/src/client_service.cpp mooncake-store/src/config/local_hot_cache_config.cpp mooncake-store/tests/CMakeLists.txt mooncake-store/tests/local_hot_cache_config_test.cpp

Test results:

• Unit tests pass
• Integration tests pass (if applicable)
• Manual testing done (describe below)

Checklist

• I have performed a self-review of my own code
• I have formatted my code using ./scripts/code_format.sh
• I have run pre-commit on the files changed in this PR and all hooks pass
• I have updated the documentation (if applicable)
• I have added tests to prove my changes are effective
• For changes >500 LOC: I have filed an RFC issue

AI Assistance Disclosure

• No AI tools were used
• AI tools were used (specify below)

Codex was used to inspect the existing environment behavior, implement the refactor and tests, run focused validation, and review the diff. I reviewed the changes and remain responsible for the contribution.

[Aionw]

LGTM