ostore.dispatch
Class TrieNode

java.lang.Object
  |
  +--ostore.dispatch.TrieNode

Direct Known Subclasses:

TrieRoot

public class TrieNode

extends Object

A node of a trie for use with a Classifier object.

A TrieNode stores the SinkIFs associated with the Filter defined by the path from the root of the trie. It also stores enough information about its children to recursively classify QueueElementIFs. Information about the requirement represented by this TrieNode is stored on the edge to this node from its parent, not internally to this data structure.

Version:

$Id: TrieNode.java,v 1.16 2002/07/22 20:54:53 srhea Exp $

Author:

Dennis Geels

Field Summary

protected Vector	fields Contains the set of Fields checked by this node's children.
protected Vector	priorities Contains the priorities for the SinkIFs.
protected Vector	rates Contains the pass rates for the SinkIFs.
protected Vector	sinks Contains all of the SinkIFs to receive events which satisfy this node's requirement.
protected Vector	value_maps Contains the set of value->child mappings for each Field.

Constructor Summary

protected

TrieNode() Creates a new TrieNode with no sinks or children.

Method Summary

void	addChild(TrieNode child, Field field, Object value) Add a child node with a specified field-value restriction.
void	addSink(SinkIF sink, Integer priority, double acceptance_rate) Add a new SinkIF to receive for all QueueElementIF satisfying this node in the trie.
Object	clone() Performs a deeper copy than Object.clone would.
void	collectSinks(QueueElementIF event, HashMap found) Recursively find all TrieNodes which pass the specified event, collecting all the SinkIFs subscribed at each node.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

sinks

protected Vector sinks

Contains all of the SinkIFs to receive events which satisfy this node's requirement.

priorities

protected Vector priorities

Contains the priorities for the SinkIFs. This Vector is parallel to sinks.

rates

protected Vector rates

Contains the pass rates for the SinkIFs. This Vector is parallel to sinks.

fields

protected Vector fields

Contains the set of Fields checked by this node's children.

value_maps

protected Vector value_maps

Contains the set of value->child mappings for each Field. This Vector is parallel to fields.

Constructor Detail

TrieNode

protected TrieNode()

Creates a new TrieNode with no sinks or children.

Method Detail

collectSinks

public void collectSinks(QueueElementIF event,
                         HashMap found)

Recursively find all TrieNodes which pass the specified event, collecting all the SinkIFs subscribed at each node.

Parameters:

event - The QueueElementIF to evaluate.

found - The set of SinkIFs collected. Each SinkIF maps to its priority.

addChild

public void addChild(TrieNode child,
                     Field field,
                     Object value)

Add a child node with a specified field-value restriction. Any QueueElementIF which satisfies this node's restriction should test the new child's as well.

Parameters:

child - The node to add.

field - The Field restricted by the child.

value - The value that Field should have.

addSink

public void addSink(SinkIF sink,
                    Integer priority,
                    double acceptance_rate)

Add a new SinkIF to receive for all QueueElementIF satisfying this node in the trie.

Parameters:

sink - the SinkIF.

priority - a number between 0 (lowest priority) and 10 (highest).

acceptance_rate - the fraction of qualifying events to pass on to the sink. Useful for sampling the input stream.

clone

public Object clone()

Performs a deeper copy than Object.clone would. The entire trie is cloned, and may be modified independently of the original. The Fields and SinkIFs referenced by the TrieNodes are not cloned.

Overrides:

clone in class Object

Returns:

A new TrieNode with cloned internal data structures.

toString

public String toString()

Overrides:

toString in class Object