kithara apple

kithara-apple

Documentation reviewed from source revision 19ca073f2. This records the documented contract at that revision; it is not a new runtime validation. API and usage · All crates.

kithara-apple is the canonical owner of the Apple framework ABI shared by Kithara crates.

Ownership

• Raw AudioToolbox structs, type aliases, constants, and extern declarations live in audio_toolbox::sys (the only publicly re-exported raw surface). Accelerate's raw externs stay private in accelerate::ffi.
• Safe RAII wrappers for AudioConverter, AudioFile, AudioBufferList, and POD byte copies (ApplePod, pod_from_prefix, pod_to_vec, pod_write_to_slice) live under audio_toolbox.
• Foundation and Objective-C binding crates are re-exported through foundation (ns, objc, block, urlsession). Consumers enable kithara-apple features instead of declaring block2, objc2, or objc2-foundation themselves.
• Codec decisions, gapless policy, HTTP semantics, stream read semantics, and resampler algorithms must not move into this crate.

Feature Surfaces

Each module needs both its feature and an Apple target (target_os = "macos" or "ios"); on any other target the crate compiles to nothing, so downstream crates need no cfg of their own beyond the feature.

• audio-toolbox exposes audio_toolbox.
• accelerate exposes accelerate.
• foundation exposes the Objective-C/Foundation binding surface needed by Apple platform adapters such as the NSURLSession HTTP backend; it is the only feature that pulls optional dependencies.

Unsafe Boundary

This crate is the canonical unsafe owner for shared Apple framework ABI. Unsafe is confined to the modules that directly bridge Apple C APIs and is justified at the call site. Callers should not need local Apple FFI declarations for shared AudioToolbox, Accelerate, or Foundation dependencies, and downstream crates keep their own unsafe policy strict except for leaf adapter glue that must implement Apple callback protocols.

Accelerate

Accelerate is an implementation support layer, not a resampler backend. The public helpers expose bounded vector operations — copy_f32, clear_f32, ramp_f32, linear_interpolate_f32, quadratic_interpolate_f32, and BiquadFilter; higher-level crates (currently kithara-resampler's glide engine) decide when those operations are useful.