Features for mapping URIs to and from integers.
This extension defines a simple mechanism for plugins to map URIs to and from integers, usually for performance reasons (e.g. processing events typed by URIs in real time). Typically, plugins map URIs to integers for things they "understand" at instantiation time, and store those values for use in the audio thread without doing any string comparison. This allows for the extensibility of RDF but with the performance of integers. This extension is intended as an improved and simplified replacement for the uri-map extension, since the map context parameter has been found problematic. New implementations are strongly encouraged to use this extension for URI mapping.
A feature which is used to map URIs to integers. To support this feature, the host must pass an LV2_Feature to LV2_Descriptor::instantiate() with URI LV2_URID_MAP_URI and data pointed to an instance of LV2_URID_Map.
A feature which is used to unmap URIs previously mapped to integers by urid:map. To support this feature, the host must pass an LV2_Feature to LV2_Descriptor::instantiate() with URI LV2_URID_UNMAP_URI and data pointed to an instance of LV2_URID_Unmap.