Naanou.LookupService
Class FingerTable

Finger table

d

protected double d

Finger distance. As per pg42 of Chord docs

entries

protected Naanou.Common.Hash[] entries

Entries on finger table - i.e. finger locations. These remain static throughout entire instance of application

entriesSize

protected int entriesSize

How many entries (fingers)

FINGER_FILL_TIMEOUT

private int FINGER_FILL_TIMEOUT

Number of seconds to wait for a finger filler before giving up

fingerPowers

protected double fingerPowers

Computed finger distance. As per pg42 of Chord docs.

fingerRequestStart

protected long fingerRequestStart

Time (ticks) finger update was requested, or less than or equal to 0 if there are no outstanding requests

forward

protected bool forward

Is the finger table forward looking?

logName

protected string logName

Name to use for class in logging

node

protected Naanou.LookupService.Node node

Local node

nodeId

protected Naanou.Common.Hash nodeId

Local node id

nodes

protected System.Collections.Hashtable nodes

Nodes. Nodes are stored in hashtable by ids that match ones found in Naanou.LookupService.FingerTable.entries.

requestedFingersFrom

protected Naanou.Common.BasicAddress requestedFingersFrom

Where fingers were requested from

TABLE_SIZE

public int TABLE_SIZE

FingerTable

internal FingerTable(Naanou.LookupService.Node node)

Constructor

Parameters:

node - Node

Addresses

public Naanou.LookupService.NodeAddress[] Addresses

Gets all addresses contained by table

Count

public int Count

Gets the number of nodes fingered

FingerRequestExpired

private bool FingerRequestExpired

IsForward

public bool IsForward

Is the table forward looking?

Node

public Naanou.LookupService.Node Node

Gets the node associated with this table

Stats

public string Stats

Gets short stats about table (util, count, entries size)

Util

public double Util

Gets utilisation of finger table

AddressNotify

public void AddressNotify(Naanou.LookupService.NodeAddress address)

Called when Node knows about a new address. Try to put it into finger table somewhere

Parameters:

address - New node

BuildTable

protected void BuildTable()

Builds the finger table

ChangeKey

protected void ChangeKey(Naanou.Common.Hash fingerLocation,
                         Naanou.LookupService.NodeAddress newAddress,
                         Naanou.LookupService.NodeAddress oldAddress)

Changes a hash key

Parameters:

fingerLocation - Key

newAddress - New address

oldAddress - Old address (optional)

Clear

public void Clear()

Clear finger entries, but maintains finger locations

Dump

public string Dump()

Dumps out the fingers and their values

Returns:

String dump of finger

FindClosest

public Naanou.LookupService.NodeAddress FindClosest(Naanou.Common.Hash id)

Finds the closest node to id (Above internal node's id and below id). Only returns alive addresses.

Parameters:

id - Id

Returns:

Closest node or null if there is none

GetClosestEntriesIndex

protected int GetClosestEntriesIndex(Naanou.Common.Hash id)

Gets the closest index on the entries array to id=. Will fuzzy match the closest LOWER index if no exact can be found

Parameters:

id - Id

Returns:

Closest index or -1

GetKey

private Naanou.LookupService.NodeAddress GetKey(Naanou.Common.Hash key)

Gets a node at a particular key

Parameters:

key - Key

Returns:

Node at that key

GetReplacement

public Naanou.LookupService.NodeAddress GetReplacement(Naanou.Common.Hash id)

Gets the node nearest to id, but not the node with that id

Parameters:

id - Id

Returns:

Closest node, or null

NeedsFilling

internal bool NeedsFilling()

Gets whether table needs filling

Returns:

NotifyFingers

public void NotifyFingers(Naanou.Common.BasicAddress[] addresses,
                          Naanou.Common.BasicAddress source)

Notification passed in via Naanou.LookupService.FingerTable.Node from a remote object setting finger values

Parameters:

addresses - Values

source - Source of request

OnNodeAddedToCache

private void OnNodeAddedToCache(object sender,
                                Naanou.LookupService.NodeEventArgs e)

Triggered when the cache knows about a new node

Parameters:

sender -

e -

OnNodeRemovedFromCache

private void OnNodeRemovedFromCache(object sender,
                                    Naanou.LookupService.NodeEventArgs e)

Called when a node has been forcibly removed from cache - ie: died/shutdown. Need to update fingers

Parameters:

sender -

e -

RemoveNode

protected void RemoveNode(Naanou.LookupService.NodeAddress address)

Remove an address from finger table, and rearrange existing

Parameters:

address - Remotes a node

Reset

public void Reset(Naanou.LookupService.Node node)

Resets finger table, triggering a rebuild of fingers

Parameters:

node - Node

ToString

public string ToString()

Returns a string representation of the object

Returns:

UpdateFingers

internal void UpdateFingers(Naanou.LookupService.NodeAddress existingNode)

Updates fingers by interrogating an existing node

Parameters:

existingNode -

FingerFillFailed

public System.EventHandler FingerFillFailed

Finger fill has failed

FingerKeyChange

public Naanou.LookupService.FingerKeyChangeHandler FingerKeyChange

Triggered when a finger has changed