org.jboss.cache
Interface DataContainer

All Known Implementing Classes:

DataContainerImpl

public interface DataContainer

This class defines the functionality needed for node manipulation.

Since:

2.2

Author:

Mircea.Markus@jboss.com

See Also:

DataContainerImpl

Method Summary

List<NodeData>	buildNodeData(List<NodeData> list, NodeSPI node, boolean mapSafe) Prepares a list of NodeData objects for a specified node and all its children.
Object[]	createNodes(Fqn fqn) Traverses the tree to the given Fqn, creating nodes if needed.
boolean	evict(Fqn fqn) Following scenarios define how eviction works.
void	evict(Fqn fqn, boolean recursive) Evicts the given node.
boolean	exists(Fqn fqn) Tests if an Fqn exists and is valid and not deleted.
Set<Fqn>	getInternalFqns() Returns a Set of Fqns of the topmost node of internal regions that should not included in standard state transfers.
List<Fqn>	getNodesForEviction(Fqn fqn, boolean recursive) Generates a list of nodes for eviction.
int	getNumberOfAttributes() Returns an approximation of the total number of attributes in the cache.
int	getNumberOfAttributes(Fqn fqn) Returns an approximation of the total number of attributes in this sub cache.
int	getNumberOfLocksHeld() Returns the number of read or write locks held across the entire cache.
int	getNumberOfNodes() Returns an approximation of the total number of nodes in the cache.
NodeSPI	getRoot() Deprecated. use Cache.getRoot();
boolean	hasChildren(Fqn fqn) Returns true if the Fqn exists, is valid and is not deleted, and the node has children.
boolean	isResident(Fqn fqn)
NodeSPI	peek(Fqn fqn) Deprecated. Note that this only supports legacy locking schemes (OL and PL) and will be removed when those schemes are removed.
NodeSPI	peek(Fqn fqn, boolean includeDeletedNodes) Deprecated. Note that this only supports legacy locking schemes (OL and PL) and will be removed when those schemes are removed.
NodeSPI	peek(Fqn fqn, boolean includeDeletedNodes, boolean includeInvalidNodes) Deprecated. Note that this only supports legacy locking schemes (OL and PL) and will be removed when those schemes are removed.
InternalNode	peekInternalNode(Fqn f, boolean includeInvalidNodes) Similar to peek(Fqn) except that the underlying node is NOT wrapped as a NodeSPI.
InternalNode[]	peekInternalNodeAndDirectParent(Fqn fqn, boolean includeInvalidNodes) Similar to peekInternalNode(Fqn, boolean) except that the node AND its *direct* parent are retrieved.
String	printDetails()
void	registerInternalFqn(Fqn fqn) Adds the specified Fqn to the list of Fqns to be considered "internal".
boolean	removeFromDataStructure(Fqn f, boolean skipMarkerCheck) Removes the actual node from the tree data structure.
void	setRoot(Object nodeInvocationDelegate) Sets a new root node

Method Detail

getRoot

@Deprecated
NodeSPI getRoot()

Deprecated. use Cache.getRoot();

Retrieves the root node.

Returns:

the root node

registerInternalFqn

void registerInternalFqn(Fqn fqn)

Adds the specified Fqn to the list of Fqns to be considered "internal".

Parameters:

fqn - fqn to add to list

peek

@Deprecated
NodeSPI peek(Fqn fqn)

Deprecated. Note that this only supports legacy locking schemes (OL and PL) and will be removed when those schemes are removed.

Finds a node given a fully qualified name, directly off the interceptor chain. In the event of an exception, returns null. Does not include invalid or deleted nodes.

Parameters:

fqn - Fully qualified name for the corresponding node.

Returns:

Node referenced by the given Fqn, or null if the node cannot be found or if there is an exception.

peek

@Deprecated
NodeSPI peek(Fqn fqn,
                        boolean includeDeletedNodes)

Deprecated. Note that this only supports legacy locking schemes (OL and PL) and will be removed when those schemes are removed.

Same as calling peek(fqn, includeDeletedNodes, false).

Parameters:

fqn - Fqn to find

includeDeletedNodes - if true, deleted nodes are considered

Returns:

the node, if found, or null otherwise.

peek

@Deprecated
NodeSPI peek(Fqn fqn,
                        boolean includeDeletedNodes,
                        boolean includeInvalidNodes)

Deprecated. Note that this only supports legacy locking schemes (OL and PL) and will be removed when those schemes are removed.

Peeks for a specified node. This involves a direct walk of the tree, starting at the root, until the required node is found. If the node is not found, a null is returned.

Parameters:

fqn - Fqn of the node to find

includeDeletedNodes - if true, deleted nodes are also considered

includeInvalidNodes - if true, invalid nodes are also considered

Returns:

the node, if found, or null otherwise.

exists

boolean exists(Fqn fqn)

Tests if an Fqn exists and is valid and not deleted.

Parameters:

fqn - the fqn representing the node to test

Returns:

true if the node exists, false otherwise.

hasChildren

boolean hasChildren(Fqn fqn)

Returns true if the Fqn exists, is valid and is not deleted, and the node has children.

Parameters:

fqn - the fqn to test

Returns:

true if the Fqn exists, is valid and is not deleted, and the node has children.

buildNodeData

List<NodeData> buildNodeData(List<NodeData> list,
                             NodeSPI node,
                             boolean mapSafe)

Prepares a list of NodeData objects for a specified node and all its children.

Parameters:

list - List of NodeData objects, which will be added to.

node - node to recursively add to the list

mapSafe - if true, the node's data map reference is passed to the NodeData instance created. Otherwise, the map is copied.

Returns:

the same list passed in

getNodesForEviction

List<Fqn> getNodesForEviction(Fqn fqn,
                              boolean recursive)

Generates a list of nodes for eviction. This filters out nodes that cannot be evicted, such as those which are marked as resident. See Node.setResident(boolean).

Parameters:

fqn - the node to consider for eviction

recursive - if recursive, child nodes are also considered

Returns:

a list of Fqns that can be considered for eviction

getInternalFqns

Set<Fqn> getInternalFqns()

Returns a Set of Fqns of the topmost node of internal regions that should not included in standard state transfers. Will include BuddyManager.BUDDY_BACKUP_SUBTREE if buddy replication is enabled.

Returns:

an unmodifiable Set. Will not return null.

getNumberOfLocksHeld

int getNumberOfLocksHeld()

Returns the number of read or write locks held across the entire cache.

getNumberOfNodes

int getNumberOfNodes()

Returns an approximation of the total number of nodes in the cache. Since this method doesn't acquire any locks, the number might be incorrect, or the method might even throw a ConcurrentModificationException

getNumberOfAttributes

int getNumberOfAttributes(Fqn fqn)

Returns an approximation of the total number of attributes in this sub cache.

getNumberOfAttributes

int getNumberOfAttributes()

Returns an approximation of the total number of attributes in the cache. Since this method doesn't acquire any locks, the number might be incorrect, or the method might even throw a ConcurrentModificationException

Returns:

number of attribs

removeFromDataStructure

boolean removeFromDataStructure(Fqn f,
                                boolean skipMarkerCheck)

Removes the actual node from the tree data structure.

Parameters:

f - the Fqn of the node to remove

skipMarkerCheck - if true, skips checking the boolean NodeSPI.isDeleted() flag and deletes the node anyway.

Returns:

Returns true if the node was found and removed, false if not.

evict

void evict(Fqn fqn,
           boolean recursive)

Evicts the given node. If recursive is set to true then all child nodes are recusively evicted.

evict

boolean evict(Fqn fqn)

 Following scenarios define how eviction works.
 1. If the given node is a leaf then it is entirely removed from the data structure. The node is marked as invalid.
 2. If the given node is a leaf then only the data map is cleared.
 3. If the given node is the root node then the cildren nodes are evicted. For each child node 1. or 2. applies
 

Returns:

true if the FQN is leaf and was removed; false if is an intermediate FQN and only contained data is droped.

createNodes

Object[] createNodes(Fqn fqn)

Traverses the tree to the given Fqn, creating nodes if needed. Returns a list of nodes created, as well as a reference to the last node.

E.g., Object[] results = createNode(myFqn); results[0] // this is a List<NodeSPI> of nodes created in getting to the target node. results[1] // is a NodeSPI reference to the target node, regardless of whether it was created or just found.

Parameters:

fqn - fqn to find

Returns:

see above.

peekInternalNode

InternalNode peekInternalNode(Fqn f,
                              boolean includeInvalidNodes)

Similar to peek(Fqn) except that the underlying node is NOT wrapped as a NodeSPI.

Parameters:

f - fqn to peek

includeInvalidNodes - if true, invalid nodes will be considered as well.

Returns:

internal node

peekInternalNodeAndDirectParent

InternalNode[] peekInternalNodeAndDirectParent(Fqn fqn,
                                               boolean includeInvalidNodes)

Similar to peekInternalNode(Fqn, boolean) except that the node AND its *direct* parent are retrieved.

Parameters:

fqn - fqn to find

includeInvalidNodes - if true, invalid nodes are considered.

Returns:

an array of InternalNodes, containing 2 elements. Element [0] is the node being peeked, and element [1] is its direct parent.

setRoot

void setRoot(Object nodeInvocationDelegate)

Sets a new root node

Parameters:

nodeInvocationDelegate -

isResident

boolean isResident(Fqn fqn)

Parameters:

fqn - fqn to check

Returns:

true if the node exists and is marked as resident, false otherwise.

printDetails

String printDetails()

Returns:

a string representation of the contents of the data container