org.eclipse.viatra.query.runtime.matchers.backend

Interface IQueryBackendFactory

All Known Implementing Classes:

LocalSearchBackendFactory, ReteBackendFactory

public interface IQueryBackendFactory

A Query Backend Factory identifies a query evaluator implementation, and can create an evaluator instance (an IQueryBackend) tied to a specific VIATRA Query engine upon request.

The factory is used as a lookup key for the backend instance, therefore implementors should either be singletons, or implement equals() / hashCode() accordingly.

Method Summary

Modifier and Type	Method and Description
IMatcherCapability	calculateRequiredCapability(PQuery query, QueryEvaluationHint hint) Calculate the required capabilities, which are needed to execute the given pattern
IQueryBackend	create(IQueryBackendContext context) Creates a new IQueryBackend instance tied to the given context elements.
java.lang.Class<? extends IQueryBackend>	getBackendClass() The backend instances created by this factory are guaranteed to conform to the returned class.

Method Detail

create

IQueryBackend create(IQueryBackendContext context)

Creates a new IQueryBackend instance tied to the given context elements.

Returns:

an instance of the class returned by getBackendClass() that operates in the given context.

Since:

1.5

getBackendClass

java.lang.Class<? extends IQueryBackend> getBackendClass()

The backend instances created by this factory are guaranteed to conform to the returned class.

calculateRequiredCapability

IMatcherCapability calculateRequiredCapability(PQuery query,
                                               QueryEvaluationHint hint)

Calculate the required capabilities, which are needed to execute the given pattern

Since:

1.4