Skip to content

rust_guidelines.md

Latest commit

 

History

History
11 lines (8 loc) · 1003 Bytes

rust_guidelines.md

File metadata and controls

11 lines (8 loc) · 1003 Bytes

Rust Implementation Guidelines

Unless Lance upstream conventions dictate otherwise, follow the defaults below. These are guidelines, not immutable constraints.

Unsafe & FFI Conventions

  • Every unsafe block must have a // SAFETY: comment. Minimize unsafe scope.
  • All public FFI functions follow a two-layer pattern: an outer #[no_mangle] pub unsafe extern "C" wrapper that converts between C types and error codes, and an inner function returning FfiResult<T>. See existing functions in rust/ffi/ for the canonical pattern.
  • Return 0 for success, -1 for error. On error, store details via set_last_error(code, message) into thread-local storage. C++ retrieves errors via lance_last_error_code() / lance_last_error_message().
  • Transfer ownership to C with Box::into_raw(); reclaim with Box::from_raw() in the corresponding lance_free_*() function.
  • When adding new error variants, append to the ErrorCode enum in rust/error.rs rather than reusing existing codes.