org.eclipse.emf.ecp.common.spi.cachetree

Class AbstractCachedTree<T>

java.lang.Object

org.eclipse.emf.ecp.common.spi.cachetree.AbstractCachedTree<T>

Type Parameters:

T - the actual value type that is stored by the tree

Direct Known Subclasses:

DiagnosticCache, EMFStoreDirtyDecoratorCachedTree, ValidationService

public abstract class AbstractCachedTree<T>
extends Object

A cached tree resembles a tree structure where each node is associated with a specific value. The value stored by parent nodes within the tree hereby are influenced by the values stored within their children. Thus, if the value of a child changes, it needs to be propagated upwards. Analogously, if the child is deleted the value associated with the deleted child must not influence the value of the parent anymore. This class is responsible for adding and removing nodes and for correctly maintaining such parent/child relationships.

Since:

1.5

Author:

emueller, Tobias Verhoeven

Constructor Summary

Constructors

Constructor and Description
AbstractCachedTree(IExcludedObjectsCallback callback) Private constructor.

Method Summary

Modifier and Type	Method and Description
void	clear() Clears the cache.
protected abstract CachedTreeNode<T>	createdCachedTreeNode(T value) Creates a cached tree node.
T	getCachedValue(Object eObject) Returns the cached value stored for the given EObject.
abstract T	getDefaultValue() Returns the default value for a cached node. The root value will be initialized with this value, too
protected Map<Object,CachedTreeNode<T>>	getNodes() Gets the Nodes of the cached tree containing necessary information.
T	getRootValue() Returns the root value of this tree. Note that the root is purely notional.
void	remove(org.eclipse.emf.ecore.EObject eObject) Removes the cache entry that contains the given EObject.
Set<org.eclipse.emf.ecore.EObject>	update(org.eclipse.emf.ecore.EObject eObject, T value) Updates the cached entry for the given EObject with the given value. If the cached entry does not yet exist, it will be created.
protected void	updateNodeObject(Object object) Helper method which gets called when an update on the specified object is performed.
protected void	updateParentNode(Object parent, Object object, T value) Updates the passed parent nodes cached value.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractCachedTree

public AbstractCachedTree(IExcludedObjectsCallback callback)

Private constructor.

Parameters:

callback - the IExcludedObjectsCallback to use when checking when to stop

Method Detail

getNodes

protected Map<Object,CachedTreeNode<T>> getNodes()

Gets the Nodes of the cached tree containing necessary information.

Returns:

the nodes

getDefaultValue

public abstract T getDefaultValue()

Returns the default value for a cached node.
The root value will be initialized with this value, too

Returns:

the default value for a cached tree node

createdCachedTreeNode

protected abstract CachedTreeNode<T> createdCachedTreeNode(T value)

Creates a cached tree node.

Parameters:

value - the value stored by the cached tree node

Returns:

the created node

update

public Set<org.eclipse.emf.ecore.EObject> update(org.eclipse.emf.ecore.EObject eObject,
                                                 T value)

Updates the cached entry for the given EObject with the given value.
If the cached entry does not yet exist, it will be created.

Parameters:

eObject - the EObject

value - the value associated with the EObject

Returns:

set of affected eobjects

updateNodeObject

protected void updateNodeObject(Object object)

Helper method which gets called when an update on the specified object is performed. Implementors can use this method when they need to perform special behaviour one a node changes.

Parameters:

object - The upject for which an update on the tree is performed

getRootValue

public T getRootValue()

Returns the root value of this tree.
Note that the root is purely notional.

Returns:

the node

getCachedValue

public T getCachedValue(Object eObject)

Returns the cached value stored for the given EObject.

Parameters:

eObject - the EObject whose cached value should be found

Returns:

the cached value associated with the given EObject, if found, otherwise the default value which is returned via getDefaultValue()

remove

public void remove(org.eclipse.emf.ecore.EObject eObject)

Removes the cache entry that contains the given EObject.

Parameters:

eObject - the EObject that needs to be removed from the cached tree

updateParentNode

protected void updateParentNode(Object parent,
                                Object object,
                                T value)

Updates the passed parent nodes cached value.

Parameters:

parent - the parent object to be updated

object - the object for which the cached value should be changed.

value - the the cached value for the object

clear

public void clear()

Clears the cache.