Struct PluginParamLoader 

pub struct PluginParamLoader { /* private fields */ }

Plugin loader that extracts parameter metadata and the dev audio processor vtable via FFI.

Safety

This struct manages the lifecycle of a dynamically loaded library. The library must remain loaded while any data from it is in use. The PluginParamLoader ensures proper cleanup via Drop.

Drop Ordering

Struct fields are dropped in declaration order (first declared = first dropped). _library is the last field so it is dropped last, ensuring the dynamic library remains loaded while parameters and dev_processor_vtable are cleaned up.

External invariant: any FfiProcessor created from the vtable must be dropped before this loader to keep vtable function pointers valid. The caller must ensure this via local variable declaration order (later declared = first dropped).

Implementations

impl PluginParamLoader

pub fn load_params_from_file<P: AsRef<Path>>( json_path: P, ) -> Result<Vec<ParameterInfo>, PluginLoaderError>

Load parameters from a sidecar JSON file (bypasses FFI/dlopen).

Used by wavecraft start to read cached parameter metadata without loading the plugin dylib (which triggers nih-plug static initializers).

pub fn load<P: AsRef<Path>>(dylib_path: P) -> Result<Self, PluginLoaderError>

Load a plugin from the given path and extract its parameter metadata.

pub fn load_params_only<P: AsRef<Path>>( dylib_path: P, ) -> Result<Vec<ParameterInfo>, PluginLoaderError>

Load parameters only (skip processor vtable loading).

Used by hot-reload where only parameter metadata is needed. Avoids potential side effects from vtable construction.

pub fn parameters(&self) -> &[ParameterInfo]

Get the loaded parameter information.

pub fn get_parameter(&self, id: &str) -> Option<&ParameterInfo>

Get a parameter by ID.

pub fn dev_processor_vtable(&self) -> &DevProcessorVTable

Returns the validated dev processor vtable.