public class XmlDebugListener
extends java.lang.Object
XmlStackFrame
argument to the methods of this class gives access to the point in the query
plan corresponding to the current execution state, as well as the execution stack trace and
parts of the dynamic context for that stack frame.
During evaluation of a query, BDB XML will evaluate the sub-expressions of the query.
The start(com.sleepycat.dbxml.XmlStackFrame)
method is called when evaluation of a sub-expression starts and
the end(com.sleepycat.dbxml.XmlStackFrame)
method
is called when it ends. This can occur more than once for the same sub-expression
if the expression is in a loop or in a function that is called more than once.
When evaluating a sub-expression BDB XML calls into that sub-expression a number of times
to retrieve parts of its result. For eager evaluation, this will happen only once, but for
lazy evalution this will happen once per item in the result. The enter(com.sleepycat.dbxml.XmlStackFrame)
method is called when BDB XML requests results from a sub-expression and the
exit(com.sleepycat.dbxml.XmlStackFrame)
method is called when the results
requested have been calculated.Constructor and Description |
---|
XmlDebugListener() |
Modifier and Type | Method and Description |
---|---|
void |
delete()
Releases the native resources associated with this object
|
void |
end(XmlStackFrame stack)
This method is called when BDB XML ends evaluation of a sub-expression.
|
void |
enter(XmlStackFrame stack)
This method is called when BDB XML requests results from a sub-expression.
|
void |
error(XmlException error,
XmlStackFrame stack)
This method is called if an error occurs during query evaluation.
|
void |
exit(XmlStackFrame stack)
This method is called when a sub-expression has finished calculating the results
requested.
|
void |
start(XmlStackFrame stack)
This method is called when BDB XML starts evaluation of a sub-expression.
|
public void delete()
public void start(XmlStackFrame stack) throws XmlException
stack
- The XmlStackFrame
for the current execution context.XmlException
public void end(XmlStackFrame stack) throws XmlException
stack
- The XmlStackFrame
for the current execution context.XmlException
public void enter(XmlStackFrame stack) throws XmlException
stack
- The XmlStackFrame
for the current execution context.XmlException
public void exit(XmlStackFrame stack) throws XmlException
stack
- The XmlStackFrame
for the current execution context.XmlException
public void error(XmlException error, XmlStackFrame stack) throws XmlException
XmlException
argument at the end of an implementation of the method.error
- The XmlException
representing the error.stack
- The XmlStackFrame
for the current execution context.XmlException
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