Naanou.LookupService
Class Node

Node. The big mother of a class.

address

private Naanou.LookupService.NodeAddress address

backForwarder

private Naanou.LookupService.RequestForwarder backForwarder

backwardsFingerTable

private Naanou.LookupService.BackwardsFingerTable backwardsFingerTable

dispatch

private Naanou.LookupService.WorkDispatch.Dispatch dispatch

fingerTable

private Naanou.LookupService.FingerTable fingerTable

id

private Naanou.Common.Hash id

inNetwork

private bool inNetwork

Node is in a network

keyStorage

private Naanou.LookupService.KeyStorage keyStorage

logger

private Naanou.Common.ILogger logger

networkId

private Naanou.Common.Hash networkId

nodeCache

private Naanou.LookupService.Cache nodeCache

onCycle

private bool onCycle

partitionDetectionStart

private long partitionDetectionStart

partitionDetector

private Naanou.LookupService.PartitionDetect partitionDetector

performedNeighbourSync

private bool performedNeighbourSync

predecessorAddress

private Naanou.LookupService.NodeAddress predecessorAddress

random

private System.Random random

rnode

private Naanou.LookupService.RemoteNode rnode

seekingBetterPredecessor

private bool seekingBetterPredecessor

seekingBetterSuccessor

private bool seekingBetterSuccessor

shuttingDown

private bool shuttingDown

stabiliseCount

private int stabiliseCount

stabiliserThread

private System.Threading.Thread stabiliserThread

state

private Naanou.LookupService.NodeState state

successorList

private Naanou.LookupService.SuccessorList successorList

transport

private Naanou.LookupService.Network transport

Node

public Node(Naanou.Common.ILogger logger)

Constructor

Parameters:

name - Name for node

logger - Logger to use

Address

public Naanou.LookupService.NodeAddress Address

Gets an Address representation of this node

BackwardsFingers

public Naanou.LookupService.FingerTable BackwardsFingers

Gets backwards finger table

BackwardsForwarder

public Naanou.LookupService.RequestForwarder BackwardsForwarder

Gets the backwards method forwarder

Dispatch

public Naanou.LookupService.WorkDispatch.Dispatch Dispatch

Gets work dispatcer

FingersReady

public bool FingersReady

Returns true if both finger tables are ready, and dont need filling

ForwardFingers

public Naanou.LookupService.FingerTable ForwardFingers

Gets forward finger table

Id

public Naanou.Common.Hash Id

Gets the nodes id (derived from it's Name)

KeyCount

public int KeyCount

Gets the number of keys stored

Keys

public Naanou.LookupService.KeyStorage Keys

Gets key storage used by node

LocalAddress

public string LocalAddress

Logger

public Naanou.Common.ILogger Logger

Gets or sets the logging component

Network

public Naanou.LookupService.Network Network

Gets network

NetworkId

public Naanou.Common.Hash NetworkId

Gets the id of the network node is on

NodeCache

public Naanou.LookupService.Cache NodeCache

Gets a reference to the Node Cache

OnCycle

internal bool OnCycle

Is the node in a cycle?

PredecessorAddress

public Naanou.LookupService.NodeAddress PredecessorAddress

Gets the immediate predecessor's address

RemoteNode

internal Naanou.LookupService.RemoteNode RemoteNode

Gets the remote node for this node

ShuttingDown

public bool ShuttingDown

Gets whether node is in the process of shutting down

State

public Naanou.LookupService.NodeState State

Gets the node's current state

SuccessorAddress

public Naanou.LookupService.NodeAddress SuccessorAddress

Gets the immediate successor's address

SuccessorList

internal Naanou.LookupService.SuccessorList SuccessorList

Url

public string Url

Gets the remoting Url for this node

BackwardsProbe

public Naanou.LookupService.NodeAddress BackwardsProbe(Naanou.Common.BasicAddress address)

Used by RemoteNode.BackwardsProbe for fast strong stabilisation (pg 24, Chord paper)

Returns:

ClearKeys

public void ClearKeys()

Clears the keys the node stores

ClosestPreceedingAddress

private Naanou.Common.BasicAddress ClosestPreceedingAddress(Naanou.Common.Hash id,
                                                            bool quick)

Gets the closest preceeding addres of a key.

Parameters:

id - Key

quick - Quick search

Returns:

Closest address

ClosestPreceedingNode

internal Naanou.LookupService.NodeAddress ClosestPreceedingNode(Naanou.Common.Hash id,
                                                                bool quick)

Implementation of ClosestPreceedingNode. Attempts to find the closest node to id. Called by RemoteNode instance

Parameters:

id - Id to lookup

quick - Attempt to look up quickly, at the expense of accuracy

Returns:

DiscoveryCompleted

internal void DiscoveryCompleted()

Call back that discovery has been completed

DumpFingerTable

public string DumpFingerTable()

Dumps the finger tables

Returns:

String dump of forward and backward finger tables

DumpKeys

public string DumpKeys()

Dumps all keys and values node has stored to a string

Returns:

Keys and values node has stored

DumpNodeCache

public string DumpNodeCache()

Dumps the node cache into a string

Returns:

String dump of node cache

DumpSuccessorList

public string DumpSuccessorList()

Dumps the successor list into a string

Returns:

String dump of successor list

Finalize

protected void Finalize()

Deconstructor

FindSuccessorNode

internal void FindSuccessorNode(Naanou.Common.Hash id,
                                bool randomForward,
                                Naanou.Common.FindSuccessorDelegate callback)

Finds the successor node for a key

Parameters:

id - Big Integer serial for key

callback - Callback for result

FindSuccessorNode

internal void FindSuccessorNode(Naanou.Common.Hash id,
                                bool randomForward,
                                Naanou.Common.FindSuccessorResult result,
                                Naanou.Common.FindSuccessorDelegate callback,
                                bool closeOffState)

Finds the successor ndoe for a key

Parameters:

id - Key

result - Existing result chain

callback - Callback for result

FindSuccessorNodeAsync

public void FindSuccessorNodeAsync(Naanou.Common.Hash id,
                                   Naanou.Common.BasicAddress nodeToQuery,
                                   bool randomForward,
                                   Naanou.Common.FindSuccessorResult resultChain,
                                   Naanou.Common.FindSuccessorDelegate callback,
                                   string requestSerial)

Finds the successor for a key (Async)

Parameters:

id - Id

nodeToQuery - Node to query

resultChain - Result chain

callback - Callback for result

FindSuccessorNodeAsync

public void FindSuccessorNodeAsync(Naanou.Common.Hash id,
                                   Naanou.LookupService.NodeAddress nodeToQuery,
                                   bool randomForward,
                                   Naanou.Common.FindSuccessorResult resultChain,
                                   Naanou.Common.FindSuccessorDelegate callback,
                                   string requestSerial)

Finds the successor for a key (Async)

Parameters:

id - Id

nodeToQuery - Node to query

resultChain - Result chain

callback - Callback for result

FoundSuccessorNode

public void FoundSuccessorNode(Naanou.Common.FindSuccessorResult result,
                               Naanou.Common.BasicAddress nodeQueried)

Gets called remotely via Naanou.LookupService.Node.FindSuccessorNodeAsync(Naanou.Common.Hash,Naanou.Common.BasicAddress,System.Boolean,Naanou.Common.FindSuccessorResult,Naanou.Common.FindSuccessorDelegate,System.String)

Parameters:

result - Result

nodeQueried - Node queried for successor

GetJoinSuccessor

private Naanou.LookupService.NodeAddress GetJoinSuccessor(Naanou.LookupService.NodeAddress bootNode,
                                                          int hops)

Gets a node suitable for being our successor. Returns proxied address

Returns:

GetKeyAsync

public void GetKeyAsync(Naanou.Common.Hash id,
                        Naanou.Common.GotKeyDelegate callback,
                        string requestSerial)

Gets a item from a key

Parameters:

id - Key

callback - Callback when there is a result

Returns:

Item

Throws:

System.ArgumentException - Key cannot be retrieved

Naanou.LookupService.InvalidNodeState - Node is in an invalid state

GetKeyImpl

internal Naanou.Common.KeyContainer[] GetKeyImpl(Naanou.Common.Hash id)

Gets a data value. Does no range checking

Parameters:

id - Key

Returns:

Returns data value, or null if nothing is at that key

Throws:

Naanou.LookupService.InvalidNodeState - Node is in an invalid state

GetSuccessorList

internal Naanou.Common.BasicAddress[] GetSuccessorList()

GotKey

public void GotKey(Naanou.Common.GetKeyResult result)

Gets called from RemoteNode else via GetKey

Parameters:

result - Result

IdWithin

public bool IdWithin(Naanou.LookupService.NodeAddress context,
                     Naanou.LookupService.NodeAddress lower,
                     Naanou.LookupService.NodeAddress upper)

Checks whether id is above lower and under upper.

Parameters:

context - Context

lower - Lower bound

upper - Upper bound

Returns:

True if context is within bounds

IdWithin

public bool IdWithin(Naanou.Common.Hash id,
                     Naanou.Common.Hash lower,
                     Naanou.Common.Hash upper)

Checks whether id is above lower and under upper.

Parameters:

id - Id to check

lower - Lower bound

upper - Upper bound

Returns:

True if context is within bounds

Join

internal void Join(Naanou.LookupService.NodeAddress addressToJoin)

Join another node in a network

Parameters:

addressToJoin - Boot node

Throws:

Naanou.LookupService.NodeCommunicationException - Thrown when addressToJoin could not be contacted

JoinedNetwork

private void JoinedNetwork()

Does stuff that we need to do when we join a network, or when someone else joins us, forming a network

Log

public void Log(string message)

Logs a status message

Parameters:

message -

Log

public void Log(string message,
                Naanou.Common.LogLevel level)

Logs a message with a log level

Parameters:

message -

level -

MightHaveKey

internal bool MightHaveKey(Naanou.Common.Hash id)

NodeDied

internal void NodeDied(Naanou.LookupService.NodeAddress address)

General purpose notification point for when a node that we know about has died. Removes from cache, fingers and adjusts successor/predecessor if necessary

Parameters:

address -

OnBackFingerTableFillCompleted

private void OnBackFingerTableFillCompleted(object sender,
                                            System.EventArgs args)

OnBackFingerTableFillFailed

private void OnBackFingerTableFillFailed(object sender,
                                         System.EventArgs args)

OnFingerTableFillCompleted

private void OnFingerTableFillCompleted(object sender,
                                        System.EventArgs args)

OnFingerTableFillFailed

private void OnFingerTableFillFailed(object sender,
                                     System.EventArgs args)

OnKeyAdded

private void OnKeyAdded(object sender,
                        Naanou.LookupService.KeyAddedEventArgs args)

OnKeyRemoved

private void OnKeyRemoved(object sender,
                          Naanou.LookupService.KeyRemovedEventArgs args)

OnKeysCleared

private void OnKeysCleared(object sender)

OnNodeCacheAdded

private void OnNodeCacheAdded(object sender,
                              Naanou.LookupService.NodeEventArgs args)

Node has been added to cache. All extra node discoveries after initial discovery will flow through this event

Parameters:

sender -

args -

OnPartitionDetectionComplete

private void OnPartitionDetectionComplete(object sender,
                                          System.EventArgs args)

OnSuccessorChange

private void OnSuccessorChange(Naanou.LookupService.Node sender,
                               Naanou.LookupService.AddressChangeArgs args)

Triggered by the SuccessorList when the active successor has changed

Successor will changed when forced, or when our immediate successor dies

Parameters:

sender -

args -

PartedNetwork

private void PartedNetwork()

Called when we have left the network (forcibly or out of an error condition)

PartitionDetect

private void PartitionDetect()

Runs discovery again to detect partitions

PutKey

public void PutKey(Naanou.Common.KeyContainer key,
                   int hops)

Stores a key and associated data value in the distributed hashtable

Parameters:

key - Key to store

hops - Hop count

Throws:

System.ArgumentException - Key cannot be stored

Naanou.LookupService.InvalidNodeState - Node is in an invalid state

PutKey

public void PutKey(Naanou.Common.KeyContainer key,
                   int hops,
                   bool onlyLocalPut)

PutKeyImpl

internal void PutKeyImpl(Naanou.Common.KeyContainer key)

Stores a key and associated data value. Does no range checking

Parameters:

key - Key

Throws:

Naanou.LookupService.InvalidNodeState - Node is in an invalid state

PutKeyRemote

private int PutKeyRemote(Naanou.Common.KeyContainer key,
                         Naanou.Common.FindSuccessorResult location)

QueryAsync

public void QueryAsync(Naanou.Common.Search.SearchQuery query,
                       Naanou.Common.QueryProgressDelegate clientCallback,
                       Naanou.Common.BasicAddress client,
                       string requestSerial)

Async querying

Parameters:

query - Query to make

clientCallback - Callback to use for progress reportage

client - Client

QueryProgress

public void QueryProgress(Naanou.Common.Search.SearchResultSet result,
                          bool completed)

Gets called from RemoteNode via QueryProgress

Parameters:

result - Result

completed - Is this the last result from this source

QuerySync

internal void QuerySync(Naanou.Common.Search.SearchPart part,
                        Naanou.Common.QueryProgressDelegate callback,
                        string clientIdSerial,
                        string requestSerial)

Query

Parameters:

part - Query part

clientIdSerial - Client

callback - Callback for result reportage

RefreshAddress

public void RefreshAddress()

Refreshes the address's url and network settings to current instance variable values

SeekBetterPredecessor

private void SeekBetterPredecessor()

Attempts to seek a better predecessor than what we have now. Replaces current predecessor if it has died, or it is better

SeekBetterPredecessorImpl

private void SeekBetterPredecessorImpl()

SeekBetterSuccessor

private void SeekBetterSuccessor()

Attempts to seek a better successor than what we have now. Replaces current if it has died or we find a better one.

SeekBetterSuccessorImpl

private void SeekBetterSuccessorImpl()

SetError

public void SetError(string message)

Set error condition to be presented to user

Parameters:

message -

SetError

public void SetError(string message,
                     System.Exception exception)

Set node error condition, which is presented to user

Parameters:

message - Error

exception - Exception to wrap

SetOnCycle

private void SetOnCycle(bool cycle)

SetPredecessor

internal void SetPredecessor(Naanou.LookupService.NodeAddress address)

Sets the predecessor and fires Naanou.LookupService.Node.PredecessorChange event. Gets called from RemoteNode after a NotifyPredecessor call by a remote note too.

Parameters:

address - New predecessor

Throws:

System.ArgumentException - Thrown if predecessor is higher than node's id

SetState

internal void SetState(Naanou.LookupService.NodeState state)

Changes the node state and fires Naanou.LookupService.Node.StateChange event.

Parameters:

state -

SetSuccessor

internal void SetSuccessor(Naanou.LookupService.NodeAddress address)

Sets the successor, and fires the Naanou.LookupService.Node.SuccessorChange event Gets called from RemoteNode after a NotifySuccessor call by a remote node too.

Parameters:

address - New successor

Throws:

System.ArgumentException - Thrown if successor is not higher than node's id

SetSuccessor

internal void SetSuccessor(int rank,
                           Naanou.LookupService.NodeAddress address)

Sets the successor at a particular rank. Old element at its spot will be shuffled up

Parameters:

rank -

address -

StabiliseLoop

private void StabiliseLoop()

Runs in Stabilise thread. Runs Naanou.LookupService.Node.WeakStabilise according to Naanou.LookupService.Config.WeakStabiliseFrequency. Runs Naanou.LookupService.Node.StrongFastStabilise once for every Naanou.LookupService.Config.StrongStabiliseRatio weak stabilises. Also does a key storage GC for each strong stabilise

StabiliseLoopImpl

private void StabiliseLoopImpl()

Start

public void Start()

Starts communication services for node (transport, then discovery)

Returns:

Value indicating if start succeeded

StartStabiliser

private void StartStabiliser()

Starts stabilisationg

Stop

public void Stop()

Shuts down a node. Stops stabiliser thread, notifies current pred and succ, transfers keys and stops transport

StrongFastStabilise

private void StrongFastStabilise()

Strong stabilise (pg 24, Chord paper)

StrongSlowStabilise

private void StrongSlowStabilise()

Strong stabilise (Figure 9, pg 21 Chord paper)

UpdateBackwardFingers

private void UpdateBackwardFingers()

Updates backward fingers. CAlled from JoinedNetwork in a different thread

UpdateForwardFingers

private void UpdateForwardFingers()

Updates forward fingers. Called from JoinedNetwork in a different thread

UserWarningMessage

internal void UserWarningMessage(string message)

WeakStabilise

internal void WeakStabilise()

Weak stabilise. Verifies successor, and ensures they know about us

WeakStabiliseSuccessor

private void WeakStabiliseSuccessor()

ErrorState

public Naanou.LookupService.NodeErrorStateHandler ErrorState

Error state

PredecessorChange

public Naanou.LookupService.PredecessorChangeHandler PredecessorChange

Predecessor has changed

StateChange

public System.EventHandler StateChange

State has changed

SuccessorChange

public Naanou.LookupService.SuccessorChangeHandler SuccessorChange

Successor has changed

UserWarning

public Naanou.LookupService.UserWarningHandler UserWarning