com.persistit

Interface Exchange.TraverseVisitor

Enclosing class:

Exchange

public static interface Exchange.TraverseVisitor

A visitor used with the Exchange.traverse(Key.Direction, boolean, int, TraverseVisitor) The visit(ReadOnlyExchange) method is called once for each Key traversed by the traverse method.

Method Summary

Modifier and Type	Method and Description
boolean	visit(ReadOnlyExchange ex) Receive an Exchange having Key and Value values set by Exchange.traverse(Key.Direction, boolean, int, TraverseVisitor) .

Method Detail

visit

boolean visit(ReadOnlyExchange ex)
       throws PersistitException

Receive an Exchange having Key and Value values set by Exchange.traverse(Key.Direction, boolean, int, TraverseVisitor) . This method will be called once for each key encountered in the traversal. This method may return false to stop traversing additional keys.

The implementation of this method:

• Must return quickly, especially in a multi-threaded environment, to avoid blocking other threads that may attempt to update records in the same Buffer,
• Must not perform update operations on any , especially in a multi-threaded environment, to prevent deadlocks,
• May read and modify the Key and Value fields of the supplied ReadOnlyExchange. Note, however, that modifying the Key affects the results of subsequent traversal operations.

Parameters:

ex - a ReadOnlyExchange from which the current Key and Value may be read

Returns:

true to continue traversing keys, or false to stop

Throws:

PersistitException