EMFQueryRuntimeContext

java.lang.Object
- org.eclipse.incquery.runtime.emf.EMFQueryRuntimeContext

All Implemented Interfaces:

IQueryRuntimeContext

Direct Known Subclasses:

DynamicEMFQueryRuntimeContext
```
public class EMFQueryRuntimeContext
extends java.lang.Object
implements IQueryRuntimeContext
```
The EMF-based runtime query context, backed by an IQBase NavigationHelper.

Author:

Bergmann Gabor
TODO: containsTuple(IInputKey, Tuple) and countTuples(IInputKey, Tuple) are inefficient as they first enumerate the collections.
TODO: ensureIndexed(EClass) may be inefficient if supertype already cached.

Constructor Summary

Constructors
Constructor and Description

EMFQueryRuntimeContext(NavigationHelper baseIndex, org.apache.log4j.Logger logger, EMFScope emfScope)

Constructors
Constructor and Description
`EMFQueryRuntimeContext(NavigationHelper baseIndex, org.apache.log4j.Logger logger, EMFScope emfScope)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addUpdateListener(IInputKey key, Tuple seed, IQueryRuntimeContextListener listener)` Subscribes for updates in the extensional relation identified by the input key, optionally seeded with the given tuple.
`<V> V`	`coalesceTraversals(java.util.concurrent.Callable<V> callable)` The given callable will be executed, and all model traversals will be delayed until the execution is done.
`boolean`	`containsTuple(IInputKey key, Tuple seed)` Simpler form of `IQueryRuntimeContext.enumerateTuples(IInputKey, Tuple)` in the case where all values of the tuples are bound by the seed.
`int`	`countTuples(IInputKey key, Tuple seed)` Returns the number of tuples in the extensional relation identified by the input key, optionally seeded with the given tuple.
`void`	`dispose()`
`void`	`ensureEnumerableKey(IInputKey key)`
`void`	`ensureIndexed(org.eclipse.emf.ecore.EClass eClass)`
`void`	`ensureIndexed(org.eclipse.emf.ecore.EDataType eDataType)`
`void`	`ensureIndexed(org.eclipse.emf.ecore.EStructuralFeature feature)`
`void`	`ensureIndexed(IInputKey key)` If the given (enumerable) input key is not yet indexed, the model will be traversed (after the end of the outermost coalescing block, see `IQueryRuntimeContext.coalesceTraversals(Callable)`) so that the index can be built.
`void`	`ensureValidKey(IInputKey key)`
`java.lang.Iterable<Tuple>`	`enumerateTuples(IInputKey key, Tuple seed)` Returns the tuples in the extensional relation identified by the input key, optionally seeded with the given tuple.
`java.lang.Iterable<? extends java.lang.Object>`	`enumerateValues(IInputKey key, Tuple seed)` Simpler form of `IQueryRuntimeContext.enumerateTuples(IInputKey, Tuple)` in the case where all values of the tuples are bound by the seed except for one.
`EMFScope`	`getEmfScope()`
`IQueryMetaContext`	`getMetaContext()` Provides metamodel-specific info independent of the runtime instance model.
`void`	`illegalEnumerateValues(Tuple seed)`
`void`	`illegalInputKey(IInputKey key)`
`boolean`	`isCoalescing()`
`boolean`	`isIndexed(IInputKey key)`
`void`	`removeUpdateListener(IInputKey key, Tuple seed, IQueryRuntimeContextListener listener)` Unsubscribes from updates in the extensional relation identified by the input key, optionally seeded with the given tuple.
`java.lang.Object`	`unwrapElement(java.lang.Object internalElement)` Unwraps the internal representation of the element into its original form
`Tuple`	`unwrapTuple(Tuple internalElements)` Unwraps the tuple of internal representations of elements into their original forms
`java.lang.Object`	`wrapElement(java.lang.Object externalElement)` Wraps the external element into the internal representation that is to be used by the query backend
`Tuple`	`wrapTuple(Tuple externalElements)` Unwraps the tuple of elements into the internal representation that is to be used by the query backend

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 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()).
    
    Specified by:
    
    coalesceTraversals in interface IQueryRuntimeContext
    
    Throws:
    
    java.lang.reflect.InvocationTargetException
  - isCoalescing
```
public boolean isCoalescing()
```
    Specified by:
    
    isCoalescing in interface IQueryRuntimeContext
    
    Returns:
    
    true iff currently within a coalescing section (i.e. within the callable of a call to IQueryRuntimeContext.coalesceTraversals(Callable)).
  - getMetaContext
```
public IQueryMetaContext getMetaContext()
```
    Description copied from interface: IQueryRuntimeContext
    
    Provides metamodel-specific info independent of the runtime instance model.
    
    Specified by:
    
    getMetaContext in interface IQueryRuntimeContext
  - ensureIndexed
```
public void ensureIndexed(IInputKey key)
```
    Description copied from interface: IQueryRuntimeContext
    
    If the given (enumerable) input key is not yet indexed, the model will be traversed (after the end of the outermost coalescing block, see IQueryRuntimeContext.coalesceTraversals(Callable)) so that the index can be built.
    Postcondition: After invoking this method, IQueryRuntimeContext.isIndexed(IInputKey) for the same key will be guaranteed to return true as soon as IQueryRuntimeContext.isCoalescing() first returns false.
    Precondition: the given key is enumerable, see IQueryMetaContext.isEnumerable(IInputKey).
    
    Specified by:
    
    ensureIndexed in interface IQueryRuntimeContext
  - isIndexed
```
public boolean isIndexed(IInputKey key)
```
    Specified by:
    
    isIndexed in interface IQueryRuntimeContext
    
    Returns:
    
    true iff the given input key is already indexed, and contents are available without costly model traversal.
  - containsTuple
```
public boolean containsTuple(IInputKey key,
                             Tuple seed)
```
    Description copied from interface: IQueryRuntimeContext
    
    Simpler form of IQueryRuntimeContext.enumerateTuples(IInputKey, 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.
    
    Specified by:
    
    containsTuple in interface IQueryRuntimeContext
    
    Parameters:
    
    key - an input key
    
    seed - a tuple with matching arity, consisting of non-null elements (null can be used in the 0-ary case).
    
    Returns:
    
    true iff the seed tuple is contained in the relation
  - enumerateTuples
```
public java.lang.Iterable<Tuple> enumerateTuples(IInputKey key,
                                                 Tuple seed)
```
    Description copied from interface: IQueryRuntimeContext
    
    Returns the tuples in the extensional relation identified by the input key, optionally seeded with the given tuple.
    
    Specified by:
    
    enumerateTuples in interface IQueryRuntimeContext
    
    Parameters:
    
    key - an input key
    
    seed - can be null or a tuple with matching arity; if non-null, only those tuples in the model are enumerated that match the seed at positions where the seed is non-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,
                                                                      Tuple seed)
```
    Description copied from interface: IQueryRuntimeContext
    
    Simpler form of IQueryRuntimeContext.enumerateTuples(IInputKey, 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 corresponds to the only null value in the seed.
    
    Specified by:
    
    enumerateValues in interface IQueryRuntimeContext
    
    Parameters:
    
    key - an input key
    
    seed - can be null (if key is unary) or a tuple with matching arity; if non-null, only those tuples in the model are enumerated that match the seed at positions where the seed is non-null; the seed is null at exactly one position.
    
    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,
                       Tuple seed)
```
    Description copied from interface: IQueryRuntimeContext
    
    Returns the number of tuples in the extensional relation identified by the input key, optionally seeded with the given tuple.
    
    Specified by:
    
    countTuples in interface IQueryRuntimeContext
    
    Parameters:
    
    key - an input key
    
    seed - can be null or a tuple with matching arity; if non-null, only those tuples in the model are counted that match the seed at positions where the seed is non-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).
  - 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)
```
  - ensureIndexed
```
public void ensureIndexed(org.eclipse.emf.ecore.EDataType eDataType)
```
  - ensureIndexed
```
public void ensureIndexed(org.eclipse.emf.ecore.EStructuralFeature feature)
```
  - 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
    
    Specified by:
    
    addUpdateListener in interface IQueryRuntimeContext
    
    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.
    
    Specified by:
    
    removeUpdateListener in interface IQueryRuntimeContext
    
    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.
    
    Specified by:
    
    unwrapElement in interface IQueryRuntimeContext
  - 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.
    
    Specified by:
    
    unwrapTuple in interface IQueryRuntimeContext
  - 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.
    
    Specified by:
    
    wrapElement in interface IQueryRuntimeContext
  - 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.
    
    Specified by:
    
    wrapTuple in interface IQueryRuntimeContext

Class EMFQueryRuntimeContext

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

EMFQueryRuntimeContext

Method Detail

getEmfScope

dispose

coalesceTraversals

isCoalescing

getMetaContext

ensureIndexed

isIndexed

containsTuple

enumerateTuples

enumerateValues

countTuples

ensureEnumerableKey

ensureValidKey

illegalInputKey

illegalEnumerateValues

ensureIndexed

ensureIndexed

ensureIndexed

addUpdateListener

removeUpdateListener

unwrapElement

unwrapTuple

wrapElement

wrapTuple