rice.pastry.leafset
Class SimilarSet

java.lang.Object
  java.util.Observable
      rice.pastry.leafset.SimilarSet

All Implemented Interfaces:

NodeHandleSet, NodeSetI, java.util.Observer, java.io.Serializable

public class SimilarSet

extends java.util.Observable

implements NodeSetI, java.io.Serializable, java.util.Observer

A set of nodes, ordered by numerical distance of their nodeId from the local nodeId

Version:

$Id: SimilarSet.java 2741 2005-08-17 19:11:58Z jstewart $

Author:

Andrew Ladd, Peter Druschel

See Also:

Serialized Form

Constructor Summary

SimilarSet(LeafSet leafSet, NodeHandle localNode, int size, boolean cw)
Constructor.

Method Summary

NodeHandle	get(int i) Gets the ith element in the set.
NodeHandle	get(NodeHandle nh) DESCRIBE THE METHOD
NodeHandle	get(NodeId nid) Finds the NodeHandle associated with the NodeId.
java.util.Collection	getCollection() This is thread safe, in that it won't throw an error if not properly synchronized.
NodeHandle	getHandle(Id id) Finds the NodeHandle associated with the NodeId.
NodeHandle	getHandle(int i) Gets the ith element in the set.
int	getIndex(NodeHandle nh) Gets the Index attribute of the SimilarSet object
int	getIndex(NodeId nid) Gets the index of the element with the given node id.
int	getIndexHandle(Id id) Gets the index of the element with the given node id.
boolean	member(NodeHandle nid) Verifies if the set contains this particular id.
boolean	member(NodeId nid)
boolean	memberHandle(Id id) Verifies if the set contains this particular id.
int	mostSimilar(Id nid) Numerically closest node to a given a node.
boolean	put(NodeHandle handle) Puts a NodeHandle into the set.
boolean	putHandle(NodeHandle handle) Puts a NodeHandle into the set.
protected NodeHandle	remove(int i) Removes a node id and its handle from the set.
NodeHandle	remove(NodeHandle nh) DESCRIBE THE METHOD
NodeHandle	remove(NodeId nid) Removes a node id and its handle from the set.
NodeHandle	removeHandle(Id id) Removes a node id and its handle from the set.
int	size() Gets the current size of this set.
protected void	swap(int i, int j) swap two elements
boolean	test(NodeHandle handle) Test if a NodeHandle belongs into the set.
void	update(java.util.Observable o, java.lang.Object arg) Is called by the Observer pattern whenever the liveness or proximity of a registered node handle is changed.

Methods inherited from class java.util.Observable

addObserver, clearChanged, countObservers, deleteObserver, deleteObservers, hasChanged, notifyObservers, notifyObservers, setChanged

Methods inherited from class java.lang.Object

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

Constructor Detail

SimilarSet

public SimilarSet(LeafSet leafSet,
                  NodeHandle localNode,
                  int size,
                  boolean cw)

Constructor.

Parameters:

localNode - the local node

size - the size of the similar set.

cw - true if this is the clockwise leafset half

leafSet - DESCRIBE THE PARAMETER

Method Detail

get

public NodeHandle get(NodeId nid)

Finds the NodeHandle associated with the NodeId.

Specified by:

get in interface NodeSetI

Parameters:

nid - a node id.

Returns:

the handle associated with that id or null if no such handle is found.

get

public NodeHandle get(NodeHandle nh)

DESCRIBE THE METHOD

Parameters:

nh - DESCRIBE THE PARAMETER

Returns:

DESCRIBE THE RETURN VALUE

get

public NodeHandle get(int i)

Gets the ith element in the set.

Specified by:

get in interface NodeSetI

Parameters:

i - an index. i == -1 refers to the local node

Returns:

the handle associated with that id or null if no such handle is found.

getIndex

public int getIndex(NodeId nid)

Gets the index of the element with the given node id.

Specified by:

getIndex in interface NodeSetI

Parameters:

nid - the node id.

Returns:

the index or -1 if the element does not exist.

getIndex

public int getIndex(NodeHandle nh)

Gets the Index attribute of the SimilarSet object

Specified by:

getIndex in interface NodeSetI

Parameters:

nh - DESCRIBE THE PARAMETER

Returns:

The Index value

getHandle

public NodeHandle getHandle(Id id)

Finds the NodeHandle associated with the NodeId.

Specified by:

getHandle in interface NodeHandleSet

Parameters:

id - a node id.

Returns:

the handle associated with that id or null if no such handle is found.

getHandle

public NodeHandle getHandle(int i)

Gets the ith element in the set.

Specified by:

getHandle in interface NodeHandleSet

Parameters:

i - an index.

Returns:

the handle associated with that id or null if no such handle is found.

getIndexHandle

public int getIndexHandle(Id id)
                   throws java.util.NoSuchElementException

Gets the index of the element with the given node id.

Specified by:

getIndexHandle in interface NodeHandleSet

Parameters:

id - the id.

Returns:

the index or throws a NoSuchElementException.

Throws:

java.util.NoSuchElementException - DESCRIBE THE EXCEPTION

getCollection

public java.util.Collection getCollection()

This is thread safe, in that it won't throw an error if not properly synchronized.

Returns:

swap

protected void swap(int i,
                    int j)

swap two elements

Parameters:

i - the index of the first element

j - the indes of the second element

test

public boolean test(NodeHandle handle)

Test if a NodeHandle belongs into the set. Predicts if a put would succeed.

Parameters:

handle - the handle to test.

Returns:

true if a put would succeed, false otherwise.

put

public boolean put(NodeHandle handle)

Puts a NodeHandle into the set.

Specified by:

put in interface NodeSetI

Parameters:

handle - the handle to put.

Returns:

true if the put succeeded, false otherwise.

update

public void update(java.util.Observable o,
                   java.lang.Object arg)

Is called by the Observer pattern whenever the liveness or proximity of a registered node handle is changed.

Specified by:

update in interface java.util.Observer

Parameters:

o - The node handle

arg - the event type (PROXIMITY_CHANGE, DECLARED_LIVE, DECLARED_DEAD)

member

public boolean member(NodeHandle nid)

Verifies if the set contains this particular id.

Specified by:

member in interface NodeSetI

Parameters:

nid - a node id.

Returns:

true if that node id is in the set, false otherwise.

member

public boolean member(NodeId nid)

Parameters:

nid - DESCRIBE THE PARAMETER

Returns:

DESCRIBE THE RETURN VALUE

remove

public NodeHandle remove(NodeId nid)

Removes a node id and its handle from the set.

Parameters:

nid - the node to remove.

Returns:

the node handle removed or null if nothing.

remove

public NodeHandle remove(NodeHandle nh)

DESCRIBE THE METHOD

Specified by:

remove in interface NodeSetI

Parameters:

nh - DESCRIBE THE PARAMETER

Returns:

DESCRIBE THE RETURN VALUE

remove

protected NodeHandle remove(int i)

Removes a node id and its handle from the set.

Parameters:

i - the index of the node to remove.

Returns:

the node handle removed or null if nothing.

size

public int size()

Gets the current size of this set.

Specified by:

size in interface NodeSetI

Returns:

the size.

mostSimilar

public int mostSimilar(Id nid)

Numerically closest node to a given a node. Returns -1 if the local nodeId is the most similar and returns an index otherwise.

Parameters:

nid - a node id.

Returns:

-1 if the local nodeId is most similar, else the index of the most similar node.

putHandle

public boolean putHandle(NodeHandle handle)

Puts a NodeHandle into the set.

Specified by:

putHandle in interface NodeHandleSet

Parameters:

handle - the handle to put.

Returns:

true if the put succeeded, false otherwise.

memberHandle

public boolean memberHandle(Id id)

Verifies if the set contains this particular id.

Specified by:

memberHandle in interface NodeHandleSet

Parameters:

id - a node id.

Returns:

true if that node id is in the set, false otherwise.

removeHandle

public NodeHandle removeHandle(Id id)

Removes a node id and its handle from the set.

Specified by:

removeHandle in interface NodeHandleSet

Parameters:

id - DESCRIBE THE PARAMETER

Returns:

the node handle removed or null if nothing.