Struct LV2_URI_Map_Feature 

#[repr(C)]
pub struct LV2_URI_Map_Feature {
    pub callback_data: LV2_URI_Map_Callback_Data,
    pub uri_to_id: Option<unsafe extern "C" fn(callback_data: LV2_URI_Map_Callback_Data, map: *const c_char, uri: *const c_char) -> u32>,
}

URI Map Feature.

To support this feature the host must pass an LV2_Feature struct to the plugin’s instantiate method with URI “http://lv2plug.in/ns/ext/uri-map” and data pointed to an instance of this struct.

Fields

callback_data: LV2_URI_Map_Callback_Data

Opaque pointer to host data.

The plugin MUST pass this to any call to functions in this struct. Otherwise, it must not be interpreted in any way.

uri_to_id: Option<unsafe extern "C" fn(callback_data: LV2_URI_Map_Callback_Data, map: *const c_char, uri: *const c_char) -> u32>

Get the numeric ID of a URI from the host.

@param callback_data Must be the callback_data member of this struct. @param map The ‘context’ of this URI. Certain extensions may define a URI that must be passed here with certain restrictions on the return value (e.g. limited range). This value may be NULL if the plugin needs an ID for a URI in general. Extensions SHOULD NOT define a context unless there is a specific need to do so, e.g. to restrict the range of the returned value. @param uri The URI to be mapped to an integer ID.

This function is referentially transparent; any number of calls with the same arguments is guaranteed to return the same value over the life of a plugin instance (though the same URI may return different values with a different map parameter). However, this function is not necessarily very fast: plugins SHOULD cache any IDs they might need in performance critical situations.

The return value 0 is reserved and indicates that an ID for that URI could not be created for whatever reason. Extensions MAY define more precisely what this means in a certain context, but in general plugins SHOULD handle this situation as gracefully as possible. However, hosts SHOULD NOT return 0 from this function in non-exceptional circumstances (e.g. the URI map SHOULD be dynamic). Hosts that statically support only a fixed set of URIs should not expect plugins to function correctly.

Trait Implementations

impl Clone for LV2_URI_Map_Feature

fn clone(&self) -> LV2_URI_Map_Feature

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for LV2_URI_Map_Feature

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Copy for LV2_URI_Map_Feature