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EngineServiceLoader

What it is​

  • A small loader that builds an IEngine.Services container based on which services are required by loaded modules.
  • It consults an EngineConfiguration to instantiate services and wires them via services.wire_services().

Public API​

  • class EngineServiceLoader
    • __init__(configuration: EngineConfiguration)
      • Stores the engine configuration used to load service instances.
    • load_services(module_dependencies: Dict[str, ModuleDependencies]) -> IEngine.Services
      • Collects requested service types from each module’s ModuleDependencies.services.
      • Loads only the required services from EngineConfiguration.services.*.load().
      • Calls wire_services() on the resulting IEngine.Services container.
    • _should_load_service(service_type: type, services_to_load: List[type]) -> bool
      • Helper to decide whether a given service should be loaded.
      • Also loads implicit dependencies defined in SERVICES_DEPENDENCIES.

Configuration/Dependencies​

  • Requires an EngineConfiguration instance that exposes loaders under:
    • configuration.services.object_storage.load()
    • configuration.services.triple_store.load()
    • configuration.services.vector_store.load()
    • configuration.services.secret.load()
    • configuration.services.bus.load()
    • configuration.services.kv.load()
  • Uses module requirements from ModuleDependencies.services (a list of service types).
  • Implicit service dependency map:
    • TripleStoreService depends on BusService
      • If TripleStoreService is requested, BusService will also be loaded (even if not explicitly requested).
  • Logs the resolved unique service types list via naas_abi_core.logger.debug.

Usage​

from naas_abi_core.engine.engine_loaders.EngineServiceLoader import EngineServiceLoader
from naas_abi_core.engine.engine_configuration.EngineConfiguration import EngineConfiguration

# module_dependencies must map module names to ModuleDependencies instances,
# each containing a `.services` list of service types to request.
module_dependencies = {
    # "my_module": ModuleDependencies(services=[...], ...)
}

configuration = EngineConfiguration(...)  # must be properly constructed for your environment
loader = EngineServiceLoader(configuration)

services = loader.load_services(module_dependencies)
# services is an IEngine.Services container with requested services loaded (others are None).

Caveats​

  • Any service not requested (directly or via SERVICES_DEPENDENCIES) is set to None in IEngine.Services.
  • Only the dependency TripleStoreService -> BusService is handled; no other dependency relationships are defined in this file.