org.apache.jackrabbit.oak.spi.state

Interface NodeStateDiff

All Known Implementing Classes:

AbstractRebaseDiff, ApplyDiff, CancelableDiff, ConflictAnnotatingRebaseDiff, CountingDiff, DefaultNodeStateDiff, EditorDiff, EqualsDiff, JsopDiff, LoggingEqualsDiff, LoggingHook, MergingNodeStateDiff, ModifiedPathDiff, PersistingDiff

public interface NodeStateDiff

Handler of node state differences. The NodeState.compareAgainstBaseState(NodeState, NodeStateDiff) method reports detected node state differences by calling methods of a handler instance that implements this interface.

The compare method goes through all properties and child nodes of the two states, calling the relevant added, changed or deleted methods where appropriate. Differences in the ordering of properties or child nodes do not affect the comparison, and the order in which such differences are reported is unspecified.

The methods in this interface all return a boolean value to signify whether the comparison should continue or abort. If a method returns false, then the comparison is immediately stopped, that means sibling nodes and sibling nodes of all parents are not further processed. Otherwise it continues until all changes have been reported.

Note that the NodeState.compareAgainstBaseState(NodeState, NodeStateDiff) method only compares the given states without recursing to the subtrees below. An implementation of this interface should recursively call that method for the relevant child node entries to find out all the changes across the entire subtree below the given node.

Method Summary

Modifier and Type	Method and Description
boolean	childNodeAdded(String name, NodeState after) Called for all added child nodes.
boolean	childNodeChanged(String name, NodeState before, NodeState after) Called for all child nodes that may contain changes between the before and after states.
boolean	childNodeDeleted(String name, NodeState before) Called for all deleted child nodes.
boolean	propertyAdded(PropertyState after) Called for all added properties.
boolean	propertyChanged(PropertyState before, PropertyState after) Called for all changed properties.
boolean	propertyDeleted(PropertyState before) Called for all deleted properties.

Method Detail

propertyAdded

boolean propertyAdded(PropertyState after)

Called for all added properties.

Parameters:

after - property state after the change

Returns:

true to continue the comparison, false to abort. Abort will stop comparing completely, that means sibling nodes and sibling nodes of all parents are not further compared.

propertyChanged

boolean propertyChanged(PropertyState before,
                        PropertyState after)

Called for all changed properties. The names of the given two property states are guaranteed to be the same.

Parameters:

before - property state before the change

after - property state after the change

Returns:

true to continue the comparison, false to abort. Abort will stop comparing completely, that means sibling nodes and sibling nodes of all parents are not further compared.

propertyDeleted

boolean propertyDeleted(PropertyState before)

Called for all deleted properties.

Parameters:

before - property state before the change

Returns:

true to continue the comparison, false to abort. Abort will stop comparing completely, that means sibling nodes and sibling nodes of all parents are not further compared.

childNodeAdded

boolean childNodeAdded(String name,
                       NodeState after)

Called for all added child nodes.

Parameters:

name - name of the added child node

after - child node state after the change

Returns:

true to continue the comparison, false to abort. Abort will stop comparing completely, that means sibling nodes and sibling nodes of all parents are not further compared.

childNodeChanged

boolean childNodeChanged(String name,
                         NodeState before,
                         NodeState after)

Called for all child nodes that may contain changes between the before and after states. The comparison implementation is expected to make an effort to avoid calling this method on child nodes under which nothing has changed.

Parameters:

name - name of the changed child node

before - child node state before the change

after - child node state after the change

Returns:

true to continue the comparison, false to abort. Abort will stop comparing completely, that means sibling nodes and sibling nodes of all parents are not further compared.

childNodeDeleted

boolean childNodeDeleted(String name,
                         NodeState before)

Called for all deleted child nodes.

Parameters:

name - name of the deleted child node

before - child node state before the change

Returns:

true to continue the comparison, false to abort. Abort will stop comparing completely, that means sibling nodes and sibling nodes of all parents are not further compared.