ann_router.registry module

Backend registry — the single lookup table from name to adapter class.

Every backend adapter is a subclass of ann_router.base.ANNIndex; this module is the one place that maps the seven backend names to those classes and answers the two questions the router asks about each: what can it do (capabilities, readable without the dependency) and can it run here (is the optional dependency importable). Importing this module — and therefore ann_router — must stay dependency-free, so the adapter modules it imports all defer their heavy imports.

Consumes: the seven ann_router.backends.* adapter modules. Produces: BACKENDS, get_backend(), available_backends(), all_capabilities().

Author: Warith Harchaoui <warith.harchaoui@deraison.ai>

ann_router.registry.all_capabilities()

Return the capability descriptor of every registered backend.

Returns:

{name: Capabilities} — readable even for uninstalled backends.

Return type:

dict

Examples

>>> all_capabilities()["annoy"].supports_remove
False

ann_router.registry.available_backends()

Return the names of backends whose dependency is importable here.

Returns:

Sorted-by-preference subset of BACKENDS that can actually run.

Return type:

list of str

Examples

>>> "exact" in available_backends()   # numpy is always present
True

ann_router.registry.get_backend(name)

Return the adapter class registered under name.

Parameters:

name (str) – A backend identifier (see ann_router.spec.BackendName).

Returns:

The adapter class (not an instance).

Return type:

type[ANNIndex]

Raises:

KeyError – If name is not a known backend.

Examples

>>> get_backend("exact").__name__
'ExactIndex'