Package org.terracotta.context

Class ContextManager

java.lang.Object

org.terracotta.context.ContextManager

Direct Known Subclasses:

StatisticsManager

public class ContextManager
extends Object

A ContextManager instances allows for rooting, querying and access to select portions of the global context graph.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	ContextManager.Association	Creates parent and child associations to the target context node.
static interface	ContextManager.Dissociation	Removes existing parent and child associations from the target context node.

Field Summary

Fields

Modifier and Type	Field	Description
private static final WeakIdentityHashMap<Object,MutableTreeNode>	CONTEXT_OBJECTS
private static final Collection<ContextCreationListener>	contextCreationListeners
private static final org.slf4j.Logger	LOGGER
private final RootNode	root

Constructor Summary

Constructors

Constructor	Description
ContextManager()

Method Summary

Modifier and Type	Method	Description
static ContextManager.Association	associate(Object object)	Create an Association instance for the supplied object.
private static void	associate(Object child, Object parent)
private static void	contextCreated(Object object)
static void	deregisterContextCreationListener(ContextCreationListener listener)
void	deregisterContextListener(ContextListener listener)	Removes a previously registered listener from the listener set.
private static void	discoverAssociations(Object origin)
static ContextManager.Dissociation	dissociate(Object object)	Create a Dissociation instance for the supplied object.
private static void	dissociate(Object child, Object parent)
private static MutableTreeNode	getOrCreateTreeNode(Object object)
private static MutableTreeNode	getTreeNode(Object object)
static TreeNode	nodeFor(Object object)	Return the TreeNode associated with this object.
Set<TreeNode>	query(Query query)	Run the supplied Query against this ContextManager's root context.
TreeNode	queryForSingleton(Query query)	Return the unique node selected by running this query against this ContextManager's root context.
static void	registerContextCreationListener(ContextCreationListener listener)
void	registerContextListener(ContextListener listener)	Registers a listener for additions and removals to this ContextManager's context graph.
void	root(Object object)	Root the given object's context node in this ContextManager instance.
void	uproot(Object object)	Remove the given object's context node from this ContextManager root set.

Methods inherited from class java.lang.Object

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

Field Details

LOGGER

private static final org.slf4j.Logger LOGGER

CONTEXT_OBJECTS

private static final WeakIdentityHashMap<Object,MutableTreeNode> CONTEXT_OBJECTS

contextCreationListeners

private static final Collection<ContextCreationListener> contextCreationListeners

root

private final RootNode root

Constructor Details

ContextManager

public ContextManager()

Method Details

associate

public static ContextManager.Association associate(Object object)

Create an Association instance for the supplied object.

Parameters:

object - the object to be associated

Returns:

an association instance

dissociate

public static ContextManager.Dissociation dissociate(Object object)

Create a Dissociation instance for the supplied object.

Parameters:

object - the object to be dissociated

Returns:

a dissociation instance

nodeFor

public static TreeNode nodeFor(Object object)

Return the TreeNode associated with this object.

Returns null if the supplied object has no associated context node.

Parameters:

object - object to lookup node for

Returns:

TreeNode associated with this object

registerContextCreationListener

public static void registerContextCreationListener(ContextCreationListener listener)

deregisterContextCreationListener

public static void deregisterContextCreationListener(ContextCreationListener listener)

associate

private static void associate(Object child,
 Object parent)

dissociate

private static void dissociate(Object child,
 Object parent)

getTreeNode

private static MutableTreeNode getTreeNode(Object object)

getOrCreateTreeNode

private static MutableTreeNode getOrCreateTreeNode(Object object)

discoverAssociations

private static void discoverAssociations(Object origin)

contextCreated

private static void contextCreated(Object object)

root

public void root(Object object)

Root the given object's context node in this ContextManager instance.

Parameters:

object - object whose context will be rooted

uproot

public void uproot(Object object)

Remove the given object's context node from this ContextManager root set.

Parameters:

object - object whose context will be uprooted

query

public Set<TreeNode> query(Query query)

Run the supplied Query against this ContextManager's root context.

The initial node in the queries traversal will be the node whose children form the root set of this ContextManager. That is, the following code will select the root set of this instance.

 public static Set<TreeNode> roots(ContextManager manager) {
   return manager.query(QueryBuilder.queryBuilder().children().build());
 }
 

Parameters:

query - the query to execute

Returns:

the set of nodes selected by the query

queryForSingleton

public TreeNode queryForSingleton(Query query)
                           throws IllegalStateException

Return the unique node selected by running this query against this ContextManager's root context.

If this query does not return a single unique result then an IllegalStateException will be thrown. More details on the query execution context can be found in query(Query).

Parameters:

query - the query to execute

Returns:

the node selected by the query

Throws:

IllegalStateException - if the query does not select a unique node

See Also:

• query(Query)
• QueryBuilder.ensureUnique()

registerContextListener

public void registerContextListener(ContextListener listener)

Registers a listener for additions and removals to this ContextManager's context graph.

Parameters:

listener - listener to be registered

deregisterContextListener

public void deregisterContextListener(ContextListener listener)

Removes a previously registered listener from the listener set.

Parameters:

listener - listener to be deregistered