NodeModel Class Reference

This is node-specific part of the datamodel. More...

#include <nodemodel.h>

Inheritance diagram for NodeModel:

Collaboration diagram for NodeModel:

Signals
void	error (MController::CAErrorSituation aError, const QString &aExplanation)
Signals inherited from ModelBase
void	error (MController::CAErrorSituation aError, const QString &aExplanation)

Public Member Functions
	NodeModel (MController *aController, const Model &aModel)
	~NodeModel ()
virtual Hash &	nodeFingerPrint ()
virtual int	listenPortOfThisNode ()
virtual void	setListenPortOfThisNode (int port)
virtual const QSslCertificate &	nodeCert () const
virtual const QSslKey &	nodeKey () const
virtual QByteArray *	getNextItemToSend (Connection &aConnection)
virtual Node *	nodeByHash (const Hash &aHash)
virtual QList< HostConnectQueueItem >	getHotAddresses ()
QList< Node * > *	getHotNodes (int aMaxNodes)
virtual bool	nodeGreetingReceived (Node &aNode, bool aWasInitialGreeting=false)
virtual QList< Node * > *	getNodesAfterHash (const Hash &aHash, unsigned aMaxNodes, int aMaxInactivityMinutes=-1)
bool	updateNodeLastConnectTimeInDb (Node &aNode)
virtual bool	updateNodeLastMutualConnectTimeInDb (const Hash &aNodeFp, quint32 aTime)
virtual QList< Node * > *	getNodesBeforeHash (const Hash &aHash, unsigned aMaxNodes)
virtual void	closeOldestInactiveConnection ()
QString	dataDir ()
virtual void	addNodeFromBroadcast (const Hash &aNodeFingerPrint, const QHostAddress &aAddr, int aPort)
virtual bool	addNodeToConnectionWishList (Node *aNode)
virtual bool	addNodeToConnectionWishList (const Hash &aNode)
virtual Node *	nextConnectionWishListItem ()
virtual bool	isNodeAlreadyConnected (const Node &aNode) const
virtual bool	isNodeAlreadyConnected (const Hash &aHash) const
virtual Hash	bucketEndHash (const Hash &aFingerPrintOfNodeAsking)
virtual void	setDnsName (QString aName)
virtual QString	getDnsName ()
virtual void	offerNodeToRecentlyFailedList (const Hash &aFailedNodeHash)
Public Member Functions inherited from ModelBase
	ModelBase (QString aDataTableName, unsigned aMaxRowsToKeep)
	~ModelBase ()
bool	setTimeLastReference (const Hash &aObjectFingerPrint, quint32 aTimeWhenLastReferenced)
unsigned	getMaxRowsToKeep ()
void	setMaxRowsToKeep (unsigned aRows)
void	truncateDataTableToMaxRows (void)
void	updateDbTableRowCount ()

Protected Member Functions
bool	insertNodeToDb (Node &aNode)
bool	updateNodeInDb (Node &aNode)
void	retrieveListOfHotConnections ()
void	timerEvent (QTimerEvent *event)

Private Member Functions
bool	openOrCreateSSLCertificate ()
bool	saveSslCertToDb (const QByteArray &aCert)
bool	saveSslKeyToDb (const QByteArray &aKey)
bool	loadSslCertFromDb ()
bool	loadSslKeyFromDb ()
void	deleteOldestConnectedNode ()
void	countNodes ()
Q_IPV6ADDR	ipv6AddrFromUints (quint32 aLeastSignificant, quint32 aLessSignificant, quint32 aMoreSignificant, quint32 aMostSignificant) const
void	removeNodeFromRecentlyFailedList (const Hash &aConnectedHostFingerPrint)

Private Attributes
MController *	iController
Hash *	iFingerPrintOfThisNode
QSslCertificate *	iThisNodeCert
QSslKey *	iThisNodeKey
QList< HostConnectQueueItem >	iHotAddresses
const Model &	iModel
QString	iDataDir
QList< Node * >	iConnectionWishList
QList< QPair< Hash, unsigned > >	iRecentlyFailedNodes
int	iTimerId

Additional Inherited Members
Public Types inherited from MNodeModelProtocolInterface
typedef struct MNodeModelProtocolInterface::HostConnectQueueItemStructure	HostConnectQueueItem
Protected Attributes inherited from ModelBase
QString	iDataTableName
unsigned	iMaxRowsToKeep
unsigned	iCurrentDbTableRowCount

Detailed Description

This is node-specific part of the datamodel.

This is node-specific part of the datamodel ; this handled storage and handling of data that is directly related to nodes themselves. Node is a peer in network.

Constructor & Destructor Documentation

NodeModel::NodeModel	(	MController *	aController,
		const Model &	aModel
	)

NodeModel::~NodeModel

(

)

Member Function Documentation

virtual void NodeModel::addNodeFromBroadcast ( const Hash &  aNodeFingerPrint, const QHostAddress &  aAddr, int  aPort  )

virtual

method for adding node reference from broadcast. this needs difference in handling because in IPv4 network this typically contains private addr space addresses that we don't want to permanently store nor give to others as node-references.

For making connections inside LANs of organisations having NATs and firewalls and whatnot this might still be a handy feature.

Implements MNodeModelProtocolInterface.

virtual bool NodeModel::addNodeToConnectionWishList ( Node *  aNode )

virtual

method for adding a node to connection-wishlist. network connector engine will then later pick them up. nodemodel will take ownership of the node and delete the object later.

Returns

true if connection was queued

Implements MNodeModelProtocolInterface.

virtual bool NodeModel::addNodeToConnectionWishList ( const Hash &  aNode )

virtual

method for adding a node to connection-wishlist. network connector engine will then later pick them up.

Returns

true if connection was queued

Implements MNodeModelProtocolInterface.

virtual Hash NodeModel::bucketEndHash ( const Hash &  aFingerPrintOfNodeAsking )

virtual

Important method regarding churn here. This is called from Connection class and this method is used to determine what content belongs to same bucket with the node that is being served by that Connection. Content in the same bucket with the node is then sent over to node ; to keep the content alive in the network.

Intent here is find bucket size where we have approximately 20 live nodes in a bucket. If size of nodes alive in network is less than 20, returned hash is same as the one given in argument, methods using the value must then implement something like "send all data".

This is done so that we order the recently-seen nodes by hash value of the node, then start from the fingerprint of the node that is asking, and from that point we count to 20. The fingerprint of the node at position 20 is the end of the bucket. The fingerprint of the node that asks is the start.

Parameters

aFingerPrintOfNodeAsking

fingerprint of node that wants to have its bucket filled

Returns

Ending-address of the nodes bucket.

Implements MNodeModelProtocolInterface.

virtual void NodeModel::closeOldestInactiveConnection ( )

virtual

method that picks up a connection that may be closed with smallest amount of hassle..

method also works a bit conditionally, it may be that if there is for instance a lot of connections from same subnet with us, it will not close any connection..

Implements MNodeModelProtocolInterface.

void NodeModel::countNodes ( )

private

internal book-keeping

QString NodeModel::dataDir

(

)

Method that returns path of directory where datafiles are kept

void NodeModel::deleteOldestConnectedNode ( )

private

prevent db table from overflowing

void NodeModel::error ( MController::CAErrorSituation  aError, const QString &  aExplanation  )

signal

virtual QString NodeModel::getDnsName ( )

virtual

called from settings dialog and own node construction

Implements MNodeModelProtocolInterface.

virtual QList<HostConnectQueueItem> NodeModel::getHotAddresses ( )

virtual

method for getting node-connection prospects. lock() must be called by caller. This does not return addresses of nodes that are already connected-to. And this does not return address of this same node. Idea is to use this method internally to fish out some addresses that might be worth connecting.

Implements MNodeModelProtocolInterface.

QList<Node *>* NodeModel::getHotNodes ( int  aMaxNodes )

virtual

method for getting node-connection prospects with idea that we make node-greetings out of those and send to neighboring node. This may and will also return address of this node and this may and will also return addresses of nodes currently connected ; it makes sense to give others list of addresses that are known to be online.

Parameters

aMaxNodes

max number of nodes to return

Returns

a qlist that the caller must delete after it is used.

Implements MNodeModelProtocolInterface.

virtual QByteArray* NodeModel::getNextItemToSend ( Connection &  aConnection )

virtual

Method that network connections use to request for more stuff to send to peers

Parameters

aConnection

is the connection in question

Returns

octets in QByteArray. Ownership of bytes is transferred, datamodel does not keep a copy and caller is responsible for deleting the returned bytes after they've been sent.

Implements MNodeModelProtocolInterface.

virtual QList<Node *>* NodeModel::getNodesAfterHash ( const Hash &  aHash, unsigned  aMaxNodes, int  aMaxInactivityMinutes = -1  )

virtual

Method for getting node-connection prospects around a given hash. This is used to obtain nodes that might contain content with hash-value near hash-values of nodes.

Parameters

aHash	is hash where to start returning
aMaxNodes	max number of nodes to return
aMaxInactivityMinutes	leave out nodes that have last activity time older than this many minutes, if negative value specified, just include all.

Returns

a qlist that the caller must delete after it is used.

Implements MNodeModelProtocolInterface.

virtual QList<Node *>* NodeModel::getNodesBeforeHash ( const Hash &  aHash, unsigned  aMaxNodes  )

virtual

We'll try to maintain the connections in hash-space in ring-like structure where each node is connected to the adjacent node, "adjacency" means that nodes whose hash-values are closest to ours, are our adjacent nodes. For this purpose have methods for retrieving list of nodes just before us in the ring and later list of nodes just after us in the ring.

Implements MNodeModelProtocolInterface.

bool NodeModel::insertNodeToDb ( Node &  aNode )

protected

Q_IPV6ADDR NodeModel::ipv6AddrFromUints ( quint32  aLeastSignificant, quint32  aLessSignificant, quint32  aMoreSignificant, quint32  aMostSignificant  ) const

private

virtual bool NodeModel::isNodeAlreadyConnected ( const Node &  aNode ) const

virtual

method for checking if a node is already connected. This will try matching against hash and network addresses.

Implements MNodeModelProtocolInterface.

virtual bool NodeModel::isNodeAlreadyConnected ( const Hash &  aHash ) const

virtual

Method for checking if a node is already connected. This version checks only hash, not addresses.

Implements MNodeModelProtocolInterface.

virtual int NodeModel::listenPortOfThisNode ( )

virtual

TCP listen port number method

Implements MNodeModelProtocolInterface.

bool NodeModel::loadSslCertFromDb ( )

private

bool NodeModel::loadSslKeyFromDb ( )

private

virtual Node* NodeModel::nextConnectionWishListItem ( )

virtual

method for getting one node from wishlist. caller is obliged to delete the node returned.

Returns

node or null if there is nothing in wishlist

Implements MNodeModelProtocolInterface.

virtual Node* NodeModel::nodeByHash ( const Hash &  aHash )

virtual

Method for getting node details by hash

Parameters

aHash

tells which node to retrieve

Returns

node or NULL if not known

Implements MNodeModelProtocolInterface.

virtual const QSslCertificate& NodeModel::nodeCert ( ) const

virtual

getter for ssl certificate of SSL sock

Implements MNodeModelProtocolInterface.

virtual Hash& NodeModel::nodeFingerPrint ( )

virtual

returns fingerprint of this node

Implements MNodeModelProtocolInterface.

virtual bool NodeModel::nodeGreetingReceived ( Node &  aNode, bool  aWasInitialGreeting = false  )

virtual

From MModelProtocolInterface.

Method related to node database handling ; generic node reference update method, that is used also to update reference of this node (self). NodeModel must be locked before this is used.

Practically this is called on 2 occasions: one is a new connection to peer, there peer sends node greeing as the first thing. This may trigger other things inside datamodel.

Second possibility is that we've asked for node references (around some hash) and then we'll receive.

Parameters

aNode	is the node that had its ref sent
aWasInitialGreeting	is true if this call was due to initial node greeting sent just as first time after connect

Returns

true if data update was successful

Implements MNodeModelProtocolInterface.

virtual const QSslKey& NodeModel::nodeKey ( ) const

virtual

getter for ssl certificate of SSL sock

Implements MNodeModelProtocolInterface.

virtual void NodeModel::offerNodeToRecentlyFailedList ( const Hash &  aFailedNodeHash )

virtual

used to offer node to list of recently failed connections. this model maintains a list of such nodes and tries to not immediately re-connect a recently failed node

Implements MNodeModelProtocolInterface.

bool NodeModel::openOrCreateSSLCertificate ( )

private

opens the node cert that is for network traffic

void NodeModel::removeNodeFromRecentlyFailedList ( const Hash &  aConnectedHostFingerPrint )

private

void NodeModel::retrieveListOfHotConnections ( )

protected

bool NodeModel::saveSslCertToDb ( const QByteArray &  aCert )

private

bool NodeModel::saveSslKeyToDb ( const QByteArray &  aKey )

private

virtual void NodeModel::setDnsName ( QString  aName )

virtual

called from settings dialog

Implements MNodeModelProtocolInterface.

virtual void NodeModel::setListenPortOfThisNode ( int  port )

virtual

Setting of TCP listen port number method

Implements MNodeModelProtocolInterface.

void NodeModel::timerEvent ( QTimerEvent *  event )

protected

for periodical stuff inside datamodel

bool NodeModel::updateNodeInDb ( Node &  aNode )

protected

method for updating existing node in db table

Parameters

aNode

is the node to update

Returns

true if success

bool NodeModel::updateNodeLastConnectTimeInDb ( Node &  aNode )

virtual

this is like updateNodeInDb but updates only the time of last connect

Implements MNodeModelProtocolInterface.

virtual bool NodeModel::updateNodeLastMutualConnectTimeInDb ( const Hash &  aNodeFp, quint32  aTime  )

virtual

method for updating last mutual connect time of a node

Implements MNodeModelProtocolInterface.

Member Data Documentation

QList<Node *> NodeModel::iConnectionWishList

private

MController* NodeModel::iController

private

QString NodeModel::iDataDir

private

Hash* NodeModel::iFingerPrintOfThisNode

private

set by method openOrCreateSSLCertificate

QList<HostConnectQueueItem> NodeModel::iHotAddresses

private

const Model& NodeModel::iModel

private

QList<QPair<Hash,unsigned> > NodeModel::iRecentlyFailedNodes

private

this variable holds list of nodes that we've tried to connect and failed. purpose of this is that we don't immediately try again

QSslCertificate* NodeModel::iThisNodeCert

private

set by method openOrCreateSSLCertificate

QSslKey* NodeModel::iThisNodeKey

private

set by method openOrCreateSSLCertificate

int NodeModel::iTimerId

private

periodical timer

---

The documentation for this class was generated from the following file:

• /tmp/classified-ads/classified_ads/datamodel/nodemodel.h