Class EMFQueryRuntimeContext

    • Field Detail

      • indexedClasses

        protected final java.util.Map<org.eclipse.emf.ecore.EClass,​java.util.EnumSet<IndexingService>> indexedClasses
      • indexedDataTypes

        protected final java.util.Map<org.eclipse.emf.ecore.EDataType,​java.util.EnumSet<IndexingService>> indexedDataTypes
      • indexedFeatures

        protected final java.util.Map<org.eclipse.emf.ecore.EStructuralFeature,​java.util.EnumSet<IndexingService>> indexedFeatures
      • logger

        protected org.apache.log4j.Logger logger
    • Constructor Detail

      • EMFQueryRuntimeContext

        public EMFQueryRuntimeContext​(NavigationHelper baseIndex,
                                      org.apache.log4j.Logger logger,
                                      EMFScope emfScope)
    • Method Detail

      • getEmfScope

        public EMFScope getEmfScope()
      • dispose

        public void dispose()
      • coalesceTraversals

        public <V> V coalesceTraversals​(java.util.concurrent.Callable<V> callable)
                                 throws java.lang.reflect.InvocationTargetException
        Description copied from interface: IQueryRuntimeContext
        The given callable will be executed, and all model traversals will be delayed until the execution is done. If there are any outstanding information to be read from the model, a single coalesced model traversal will initialize the caches and deliver the notifications.

        Calls may be nested. A single coalesced traversal will happen at the end of the outermost call.

        Caution: results returned by the runtime context may be incomplete during the coalescing period, to be corrected by notifications sent during the final coalesced traversal. For example, if a certain input key is not cached yet, an empty relation may be reported during callable.call(); the cache will be constructed after the call terminates and notifications will deliver the entire content of the relation. Non-incremental query backends should therefore never enumerate input keys while coalesced (verify using IQueryRuntimeContext.isCoalescing()).

        Throws:
        java.lang.reflect.InvocationTargetException
      • getMetaContext

        public IQueryMetaContext getMetaContext()
        Description copied from interface: IQueryRuntimeContext
        Provides metamodel-specific info independent of the runtime instance model.
      • getCurrentIndexingServiceFor

        protected java.util.EnumSet<IndexingService> getCurrentIndexingServiceFor​(IInputKey key)
        Retrieve the current registered indexing services for the given key. May not return null, returns an empty set if no indexing is registered.
        Since:
        1.4
      • isIndexed

        public boolean isIndexed​(IInputKey key,
                                 IndexingService service)
        Description copied from interface: IQueryRuntimeContext
        Returns true if index is available for the given key providing the given service.
      • containsTuple

        public boolean containsTuple​(IInputKey key,
                                     ITuple seed)
        Description copied from interface: IQueryRuntimeContext
        Simpler form of #enumerateTuples(IInputKey, TupleMask, Tuple) in the case where all values of the tuples are bound by the seed.

        Returns whether the given tuple is in the extensional relation identified by the input key.

        Note: this call works for non-enumerable input keys as well.

        Parameters:
        key - an input key
        seed - the tuple of fixed values restricting the match set to be considered, in the same order as given in parameterSeedMask, so that for each considered match tuple, projectedParameterSeed.equals(parameterSeedMask.transform(match)) should hold. Must not be null.
        Returns:
        true iff there is at least a single tuple contained in the relation that corresponds to the seed tuple
      • enumerateTuples

        public java.lang.Iterable<Tuple> enumerateTuples​(IInputKey key,
                                                         TupleMask seedMask,
                                                         ITuple seed)
        Description copied from interface: IQueryRuntimeContext
        Returns the tuples in the extensional relation identified by the input key, optionally seeded with the given tuple.
        Parameters:
        key - an input key
        seedMask - a mask that extracts those parameters of the input key (from the entire parameter list) that should be bound to a fixed value; must not be null. Note: any given index must occur at most once in seedMask.
        seed - the tuple of fixed values restricting the match set to be considered, in the same order as given in parameterSeedMask, so that for each considered match tuple, projectedParameterSeed.equals(parameterSeedMask.transform(match)) should hold. Must not be null.
        Returns:
        the tuples in the model for the given key and seed

        Precondition: the given key is enumerable, see IQueryMetaContext.isEnumerable(IInputKey).

      • enumerateValues

        public java.lang.Iterable<? extends java.lang.Object> enumerateValues​(IInputKey key,
                                                                              TupleMask seedMask,
                                                                              ITuple seed)
        Description copied from interface: IQueryRuntimeContext
        Simpler form of #enumerateTuples(IInputKey, TupleMask, Tuple) in the case where all values of the tuples are bound by the seed except for one.

        Selects the tuples in the extensional relation identified by the input key, optionally seeded with the given tuple, and then returns the single value from each tuple which is not bound by the ssed mask.

        Parameters:
        key - an input key
        seedMask - a mask that extracts those parameters of the input key (from the entire parameter list) that should be bound to a fixed value; must not be null. Note: any given index must occur at most once in seedMask, and seedMask must include all parameters in any arbitrary order except one.
        seed - the tuple of fixed values restricting the match set to be considered, in the same order as given in parameterSeedMask, so that for each considered match tuple, projectedParameterSeed.equals(parameterSeedMask.transform(match)) should hold. Must not be null.
        Returns:
        the objects in the model for the given key and seed

        Precondition: the given key is enumerable, see IQueryMetaContext.isEnumerable(IInputKey).

      • countTuples

        public int countTuples​(IInputKey key,
                               TupleMask seedMask,
                               ITuple seed)
        Description copied from interface: IQueryRuntimeContext
        Returns the number of tuples in the extensional relation identified by the input key seeded with the given mask and tuple.
        Parameters:
        key - an input key
        seedMask - a mask that extracts those parameters of the input key (from the entire parameter list) that should be bound to a fixed value; must not be null. Note: any given index must occur at most once in seedMask.
        seed - the tuple of fixed values restricting the match set to be considered, in the same order as given in parameterSeedMask, so that for each considered match tuple, projectedParameterSeed.equals(parameterSeedMask.transform(match)) should hold. Must not be null.
        Returns:
        the number of tuples in the model for the given key and seed

        Precondition: the given key is enumerable, see IQueryMetaContext.isEnumerable(IInputKey).

      • estimateCardinality

        public java.util.Optional<java.lang.Long> estimateCardinality​(IInputKey key,
                                                                      TupleMask groupMask,
                                                                      Accuracy requiredAccuracy)
        Description copied from interface: IQueryRuntimeContext
        Gives an estimate of the number of different groups the tuples of the given relation are projected into by the given mask (e.g. for an identity mask, this means the full relation size). The estimate must meet the required accuracy.

        Must accept any input key, even non-enumerables or those not recognized by this runtime context. If there is insufficient information to provide an answer up to the required precision, Optional.empty() is returned.

        PRE: TupleMask.isNonrepeating() must hold for the group mask.

        Returns:
        if available, an estimate of the cardinality of the projection of the given extensional relation, with the desired accuracy.
        Since:
        2.1
      • estimateAverageBucketSize

        public java.util.Optional<java.lang.Double> estimateAverageBucketSize​(IInputKey key,
                                                                              TupleMask groupMask,
                                                                              Accuracy requiredAccuracy)
        Description copied from interface: IQueryRuntimeContext
        Gives an estimate of the average size of different groups the tuples of the given relation are projected into by the given mask (e.g. for an identity mask, this means 1, while for an empty mask, the result is the full relation size). The estimate must meet the required accuracy.

        Must accept any input key, even non-enumerables or those not recognized by this runtime context. If there is insufficient information to provide an answer up to the required precision, Optional.empty() may be returned.

        For an empty relation, zero is acceptable as an exact answer.

        PRE: TupleMask.isNonrepeating() must hold for the group mask.

        Returns:
        if available, an estimate of the average size of each projection group of the given extensional relation, with the desired accuracy.
        Since:
        2.1
      • ensureEnumerableKey

        public void ensureEnumerableKey​(IInputKey key)
      • ensureValidKey

        public void ensureValidKey​(IInputKey key)
      • illegalInputKey

        public void illegalInputKey​(IInputKey key)
      • illegalEnumerateValues

        public void illegalEnumerateValues​(Tuple seed)
      • ensureIndexed

        public void ensureIndexed​(org.eclipse.emf.ecore.EClass eClass,
                                  IndexingService service)
        Since:
        1.4
      • ensureIndexed

        public void ensureIndexed​(org.eclipse.emf.ecore.EDataType eDataType,
                                  IndexingService service)
        Since:
        1.4
      • ensureIndexed

        public void ensureIndexed​(org.eclipse.emf.ecore.EStructuralFeature feature,
                                  IndexingService service)
        Since:
        1.4
      • addUpdateListener

        public void addUpdateListener​(IInputKey key,
                                      Tuple seed,
                                      IQueryRuntimeContextListener listener)
        Description copied from interface: IQueryRuntimeContext
        Subscribes for updates in the extensional relation identified by the input key, optionally seeded with the given tuple.

        This should be called after invoking

        Parameters:
        key - an input key
        seed - can be null or a tuple with matching arity; if non-null, only those updates in the model are notified about that match the seed at positions where the seed is non-null.
        listener - will be notified of future changes

        Precondition: the given key is enumerable, see IQueryMetaContext.isEnumerable(IInputKey).

      • removeUpdateListener

        public void removeUpdateListener​(IInputKey key,
                                         Tuple seed,
                                         IQueryRuntimeContextListener listener)
        Description copied from interface: IQueryRuntimeContext
        Unsubscribes from updates in the extensional relation identified by the input key, optionally seeded with the given tuple.
        Parameters:
        key - an input key
        seed - can be null or a tuple with matching arity; if non-null, only those updates in the model are notified about that match the seed at positions where the seed is non-null.
        listener - will no longer be notified of future changes

        Precondition: the given key is enumerable, see IQueryMetaContext.isEnumerable(IInputKey).

      • unwrapElement

        public java.lang.Object unwrapElement​(java.lang.Object internalElement)
        Description copied from interface: IQueryRuntimeContext
        Unwraps the internal representation of the element into its original form

        internal object -> model element

        null must be mapped to null.

      • unwrapTuple

        public Tuple unwrapTuple​(Tuple internalElements)
        Description copied from interface: IQueryRuntimeContext
        Unwraps the tuple of internal representations of elements into their original forms

        internal objects -> model elements

        null must be mapped to null.

      • wrapElement

        public java.lang.Object wrapElement​(java.lang.Object externalElement)
        Description copied from interface: IQueryRuntimeContext
        Wraps the external element into the internal representation that is to be used by the query backend

        model element -> internal object.

        null must be mapped to null.

      • wrapTuple

        public Tuple wrapTuple​(Tuple externalElements)
        Description copied from interface: IQueryRuntimeContext
        Unwraps the tuple of elements into the internal representation that is to be used by the query backend

        model elements -> internal objects

        null must be mapped to null.

      • ensureWildcardIndexing

        public void ensureWildcardIndexing​(IndexingService service)
        Description copied from interface: IQueryRuntimeContext
        Starts wildcard indexing for the given service. After this call, no registration is required for this IndexingService. a previously set wildcard level cannot be lowered, only extended.
        Since:
        1.4
      • executeAfterTraversal

        public void executeAfterTraversal​(java.lang.Runnable runnable)
                                   throws java.lang.reflect.InvocationTargetException
        Description copied from interface: IQueryRuntimeContext
        Execute the given runnable after traversal. It is guaranteed that the runnable is executed as soon as the indexing is finished. The callback is executed only once, then is removed from the callback queue.
        Throws:
        java.lang.reflect.InvocationTargetException
        Since:
        1.4