org.eclipse.viatra.query.runtime.matchers.psystem.analysis

Class QueryAnalyzer

java.lang.Object

org.eclipse.viatra.query.runtime.matchers.psystem.analysis.QueryAnalyzer

public final class QueryAnalyzer
extends java.lang.Object

Object responsible for computing and caching static query analysis results.

Any client can instantiate this to statically analyze queries. Query backends should share an instance obtained via IQueryBackendContext to save resources.

Precondition: all involved queries must be initialized.

Since:

1.5

No Instantiate:

Considered unstable API; subject to change in future versions. Either use the analyzer provided by IQueryBackendContext, or anticipate potential future breakage when instantiating your own analyzer.

Constructor Summary

Constructors

Constructor and Description
QueryAnalyzer(IQueryMetaContext metaContext)

Method Summary

Modifier and Type	Method and Description
java.util.Map<java.util.Set<PVariable>,java.util.Set<PVariable>>	getFunctionalDependencies(java.util.Set<PConstraint> constraints, boolean strict) Functional dependency information, expressed on PVariables within a body, that the selected constraints imply.
java.util.Map<java.util.Set<java.lang.Integer>,java.util.Set<java.lang.Integer>>	getProjectedFunctionalDependencies(PQuery query, boolean strict) Functional dependency information, expressed on query parameters, that the match set of the query is guaranteed to respect.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

QueryAnalyzer

public QueryAnalyzer(IQueryMetaContext metaContext)

Method Detail

getProjectedFunctionalDependencies

public java.util.Map<java.util.Set<java.lang.Integer>,java.util.Set<java.lang.Integer>> getProjectedFunctionalDependencies(PQuery query,
                                                                                                                           boolean strict)

Functional dependency information, expressed on query parameters, that the match set of the query is guaranteed to respect.

The type dependencies shall be expressed on the parameter index integers, NOT the PParameter object.

Parameters:

strict - if true, only "hard" dependencies are taken into account that are strictly enforced by the model representation; if false, user-provided soft dependencies (@FunctionalDependency) are included as well, that are anticipated but not guaranteed by the storage mechanism; use true if superfluous dependencies may taint the correctness of a computation, false if they would merely impact performance

Returns:

a non-null map of functional dependencies on parameters that can be processed by FunctionalDependencyHelper

Since:

1.5

getFunctionalDependencies

public java.util.Map<java.util.Set<PVariable>,java.util.Set<PVariable>> getFunctionalDependencies(java.util.Set<PConstraint> constraints,
                                                                                                  boolean strict)

Functional dependency information, expressed on PVariables within a body, that the selected constraints imply.

Parameters:

constraints - the set of constraints whose consequences will be analyzed

strict - if true, only "hard" dependencies are taken into account that are strictly enforced by the model representation; if false, user-provided soft dependencies (@FunctionalDependency) are included as well, that are anticipated but not guaranteed by the storage mechanism; use true if superfluous dependencies may taint the correctness of a computation, false if they would merely impact performance

Returns:

a non-null map of functional dependencies on PVariables that can be processed by FunctionalDependencyHelper

Since:

1.5