edu.berkeley.cs.db.yfilter.operators
Class NFAExecution

java.lang.Object
  |
  +--edu.berkeley.cs.db.yfilter.operators.NFAExecution

public class NFAExecution

extends java.lang.Object

Field Summary

protected static int	EMPTY_HENTRY
protected int[]	m_tmpStack

Constructor Summary

NFAExecution()

Method Summary

void	endDocument(QueryIndexBasic queryIndex, BottomStreams bottomStreams) in the current implementation, when this function is called, no post processing has been actually done yet.
protected java.util.ArrayList	getQueryPathContext(int last_htId, java.util.Stack runStack, java.util.Stack contextPath)
RunStackElementBasic	startDocument(QueryIndexBasic queryIndex) this function returns the start state of the NFA
void	startElement(QueryIndexBasic queryIndex, java.util.Stack runStack, java.util.Stack contextPath, java.lang.String attrname, BottomStreams bottomStreams) this function returns the next set of states given the current set of states.

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY_HENTRY

protected static int EMPTY_HENTRY

m_tmpStack

protected int[] m_tmpStack

Constructor Detail

NFAExecution

public NFAExecution()

Method Detail

startDocument

public RunStackElementBasic startDocument(QueryIndexBasic queryIndex)

this function returns the start state of the NFA

startElement

public void startElement(QueryIndexBasic queryIndex,
                         java.util.Stack runStack,
                         java.util.Stack contextPath,
                         java.lang.String attrname,
                         BottomStreams bottomStreams)

this function returns the next set of states given the current set of states. it handles the state transition lookup by hashing attrname into each of the hashtables corresponding to the current state set and returning the resulting pointed at results.

getQueryPathContext

protected java.util.ArrayList getQueryPathContext(int last_htId,
                                                  java.util.Stack runStack,
                                                  java.util.Stack contextPath)

endDocument

public void endDocument(QueryIndexBasic queryIndex,
                        BottomStreams bottomStreams)

in the current implementation, when this function is called, no post processing has been actually done yet. it doesnot work for mixed workload (single path, one predicate, or nested path) very well. for now, this function is called if there is at least one nested path per query.