org.eclipse.viatra.query.runtime.api

Interface IRunOnceQueryEngine

All Known Implementing Classes:

RunOnceQueryEngine

public interface IRunOnceQueryEngine

A run-once query engine is used to get matches for queries without incremental support. Users can create a query engine with a given Notifier as scope and use a query specification to retrieve the current match set with this scope (see getAllMatches(org.eclipse.viatra.query.runtime.api.IQuerySpecification<? extends org.eclipse.viatra.query.runtime.api.ViatraQueryMatcher<Match>>)).

Method Summary

Modifier and Type	Method and Description
<Match extends IPatternMatch> java.util.Collection<Match>	getAllMatches(IQuerySpecification<? extends ViatraQueryMatcher<Match>> querySpecification) Returns the set of all matches for the given query in the scope of the engine.
BaseIndexOptions	getBaseIndexOptions() The base index options specifies how the base index is built, including wildcard mode (defaults to false) and dynamic EMF mode (defaults to false).
org.eclipse.emf.common.notify.Notifier	getScope()
void	resampleOnNextCall() If automatic resampling is enabled and the value of derived features may change without model modifications, calling this method will make sure that re-sampling will occur before returning match results.
void	setAutomaticResampling(boolean automaticResampling) When set to true, the run-once query engine will not dispose it's engine and will resample the values of derived features before returning matches if the model changed since the last call.

Method Detail

getAllMatches

<Match extends IPatternMatch> java.util.Collection<Match> getAllMatches(IQuerySpecification<? extends ViatraQueryMatcher<Match>> querySpecification)
                                                                 throws ViatraQueryException

Returns the set of all matches for the given query in the scope of the engine.

Parameters:

querySpecification - the query that is evaluated

Returns:

matches represented as a Match object.

Throws:

ViatraQueryException

getScope

org.eclipse.emf.common.notify.Notifier getScope()

Returns:

the scope of pattern matching, i.e. the root of the EMF model tree that this engine is attached to.

getBaseIndexOptions

BaseIndexOptions getBaseIndexOptions()

The base index options specifies how the base index is built, including wildcard mode (defaults to false) and dynamic EMF mode (defaults to false). See NavigationHelper for the explanation of wildcard mode and dynamic EMF mode.

The returned options can be modified in order to affect subsequent calls of getAllMatches(org.eclipse.viatra.query.runtime.api.IQuerySpecification<? extends org.eclipse.viatra.query.runtime.api.ViatraQueryMatcher<Match>>).

Returns:

the base index options used by the engine.

setAutomaticResampling

void setAutomaticResampling(boolean automaticResampling)

When set to true, the run-once query engine will not dispose it's engine and will resample the values of derived features before returning matches if the model changed since the last call. If the values of derived features may change without any model modification, call resampleOnNextCall() before subsequent calls of getAllMatches(org.eclipse.viatra.query.runtime.api.IQuerySpecification<? extends org.eclipse.viatra.query.runtime.api.ViatraQueryMatcher<Match>>).

Parameters:

automaticResampling -

resampleOnNextCall

void resampleOnNextCall()

If automatic resampling is enabled and the value of derived features may change without model modifications, calling this method will make sure that re-sampling will occur before returning match results.