Chord's successor list module. More...

#include <ChordSuccessorList.h>

Public Member Functions
virtual int	numInitStages () const
virtual void	initialize (int stage)
virtual void	handleMessage (cMessage *msg)
virtual void	initializeList (uint32_t size, NodeHandle owner, Chord *overlay)
	Initializes the successor list.
virtual uint32_t	getSize ()
	Returns number of neighbors in the successor list.
virtual bool	isEmpty ()
	Checks if the successor list is empty.
virtual const NodeHandle &	getSuccessor (uint32_t pos=0)
	Returns a particular successor.
virtual void	addSuccessor (NodeHandle successor, bool resize=true)
	Adds new successor nodes to the successor list.
virtual void	updateList (NotifyResponse *notify)
bool	handleFailedNode (const TransportAddress &failed)
void	display ()

Protected Member Functions
void	removeOldSuccessors ()
void	updateDisplayString ()
	Displays the current number of successors in the list.
void	updateTooltip ()
	Displays the first 4 successor nodes as tooltip.

Protected Attributes
NodeHandle	thisNode
	own node handle
std::map< OverlayKey, SuccessorListEntry >	successorMap
	internal representation of the successor list
uint32_t	successorListSize
	maximum size of the successor list
Chord *	overlay
	pointer to the main chord module

Detailed Description

Chord's successor list module.

This modul contains the successor list of the Chord implementation.

Author: Markus Mauch, Ingmar Baumgart

See Also: Chord

Definition at line 58 of file ChordSuccessorList.h.

Member Function Documentation

void oversim::ChordSuccessorList::addSuccessor	(	NodeHandle	successor,
		bool	resize = `true`
	)

virtual

Adds new successor nodes to the successor list.

Adds new successor nodes to the successor list and sorts the list using the corresponding chord keys. If the list size exceeds the maximum size nodes at the end of the list will be removed.

Parameters

successor	the node handle of the successor to be added
resize	if true, shrink the list to successorListSize

Definition at line 122 of file ChordSuccessorList.cc.

{
    OverlayKey sum = successor.getKey() - (thisNode.getKey() + OverlayKey::ONE);
    std::map<OverlayKey, SuccessorListEntry>::iterator it =
        successorMap.find(sum);
    // Make a CommonAPI update() upcall to inform application
    // about our new neighbor in the successor list
    if (it == successorMap.end()) {
        // TODO: first add node and than call update()
        overlay->callUpdate(successor, true);
    } else {
        successorMap.erase(it);
    }
    SuccessorListEntry entry;
    entry.nodeHandle = successor;
    entry.newEntry = true;
    successorMap.insert(make_pair(sum, entry));
    if ((resize == true) && (successorMap.size() > (uint32_t)successorListSize)) {
        it = successorMap.end();
        it--;
        overlay->callUpdate(it->second.nodeHandle, false);
        successorMap.erase(it);
    }
}

void oversim::ChordSuccessorList::display ( )

Definition at line 233 of file ChordSuccessorList.cc.

{
    cout << "Content of ChordSuccessorList:" << endl;
    for (std::map<OverlayKey,SuccessorListEntry>::iterator it =
        successorMap.begin(); it != successorMap.end(); it++)
        cout << it->first << " with Node: " << it->second.nodeHandle << endl;
}

uint32_t oversim::ChordSuccessorList::getSize ( )

virtual

Returns number of neighbors in the successor list.

Returns: number of neighbors

Definition at line 67 of file ChordSuccessorList.cc.

{
    return successorMap.size();
}

const NodeHandle & oversim::ChordSuccessorList::getSuccessor ( uint32_t pos = 0 )

virtual

Returns a particular successor.

Parameters

pos	position in the successor list

Returns: successor at position pos

Definition at line 80 of file ChordSuccessorList.cc.

{
    // check boundaries
    if (pos == 0 && successorMap.size() == 0)
        return NodeHandle::UNSPECIFIED_NODE;
    if (pos >= successorMap.size()) {
        error("Index out of bound (ChordSuccessorList, getSuccessor())");
    }
    std::map<OverlayKey, SuccessorListEntry>::iterator it =
        successorMap.begin();
    for (uint32_t i= 0; i < pos; i++) {
        it++;
        if (i == (pos-1))
            return it->second.nodeHandle;
    }
    return it->second.nodeHandle;
}

bool oversim::ChordSuccessorList::handleFailedNode ( const TransportAddress & failed )

Definition at line 153 of file ChordSuccessorList.cc.

{
    assert(failed != thisNode);
    for (std::map<OverlayKey, SuccessorListEntry>::iterator iter =
         successorMap.begin(); iter != successorMap.end(); ++iter) {
        if (failed == iter->second.nodeHandle) {
            successorMap.erase(iter);
            overlay->callUpdate(failed, false);
            // ensure that thisNode is always in the successor list
            if (getSize() == 0)
                addSuccessor(thisNode);
            return true;
        }
    }
    return false;
}

void oversim::ChordSuccessorList::handleMessage ( cMessage * msg )

virtual

Definition at line 52 of file ChordSuccessorList.cc.

{
    error("this module doesn't handle messages, it runs only in initialize()");
}

void oversim::ChordSuccessorList::initialize ( int stage )

virtual

Definition at line 42 of file ChordSuccessorList.cc.

{
    // because of IPAddressResolver, we need to wait until interfaces
    // are registered, address auto-assignment takes place etc.
    if (stage != MIN_STAGE_OVERLAY)
        return;
    WATCH_MAP(successorMap);
}

void oversim::ChordSuccessorList::initializeList	(	uint32_t	size,
		NodeHandle	owner,
		Chord *	overlay
	)

virtual

Initializes the successor list.

This should be called on startup

Parameters

size	maximum number of neighbors in the successor list
owner	the node owner is added to the successor list
overlay	pointer to the main chord module

Definition at line 57 of file ChordSuccessorList.cc.

Referenced by oversim::Koorde::initializeFriendModules().

{
    successorMap.clear();
    successorListSize = size;
    thisNode = owner;
    this->overlay = overlay;
    addSuccessor(thisNode);
}

bool oversim::ChordSuccessorList::isEmpty ( )

virtual

Checks if the successor list is empty.

Returns: returns false if the successor list contains other nodes than this node, true otherwise.

Definition at line 72 of file ChordSuccessorList.cc.

{
    if (successorMap.size() == 1 && getSuccessor() == thisNode)
        return true;
    else
        return false;
}

virtual int oversim::ChordSuccessorList::numInitStages ( ) const

inlinevirtual

Definition at line 61 of file ChordSuccessorList.h.

    {
        return MAX_STAGE_OVERLAY + 1;
    }

void oversim::ChordSuccessorList::removeOldSuccessors ( )

protected

Definition at line 170 of file ChordSuccessorList.cc.

{
    std::map<OverlayKey,SuccessorListEntry>::iterator it;
    for (it = successorMap.begin(); it != successorMap.end();) {
        if (it->second.newEntry == false) {
            overlay->callUpdate(it->second.nodeHandle, false);
            successorMap.erase(it++);
        } else {
            it->second.newEntry = false;
            it++;
        }
    }
    it = successorMap.end();
    it--;
    while (successorMap.size() > successorListSize) {
        successorMap.erase(it--);
    }
    if (getSize() == 0)
        addSuccessor(thisNode);
}

void oversim::ChordSuccessorList::updateDisplayString ( )

protected

Displays the current number of successors in the list.

Definition at line 197 of file ChordSuccessorList.cc.

{
    // FIXME: doesn't work without tcl/tk
    //          if (ev.isGUI()) {
    if (1) {
        char buf[80];
        if (successorMap.size() == 1) {
            sprintf(buf, "1 successor");
        } else {
            sprintf(buf, "%zi successors", successorMap.size());
        }
        getDisplayString().setTagArg("t", 0, buf);
        getDisplayString().setTagArg("t", 2, "blue");
    }
}

void oversim::ChordSuccessorList::updateList ( NotifyResponse * notify )

virtual

Definition at line 101 of file ChordSuccessorList.cc.

{
    addSuccessor(notifyResponse->getSrcNode(), false);
    for (uint32_t k = 0; ((k < static_cast<uint32_t>(notifyResponse->getSucNum()))
                     && (k < (successorListSize - 1))); k++) {
        NodeHandle successor = notifyResponse->getSucNode(k);
        // don't add nodes, if this would change our successor
        if (successor.getKey().isBetweenLR(thisNode.getKey(),
                                      notifyResponse->getSrcNode().getKey()))
            continue;
        addSuccessor(successor, false);
    }
    removeOldSuccessors();
    assert(!isEmpty());
}

void oversim::ChordSuccessorList::updateTooltip ( )

protected

Displays the first 4 successor nodes as tooltip.

Definition at line 216 of file ChordSuccessorList.cc.

{
    if (ev.isGUI()) {
        std::stringstream str;
        for (uint32_t i = 0; i < successorMap.size(); i++)      {
            str << getSuccessor(i);
            if ( i != successorMap.size() - 1 )
                str << endl;
        }
        char buf[1024];
        sprintf(buf, "%s", str.str().c_str());
        getDisplayString().setTagArg("tt", 0, buf);
    }
}

Member Data Documentation

Chord* oversim::ChordSuccessorList::overlay

protected

pointer to the main chord module

Definition at line 126 of file ChordSuccessorList.h.

uint32_t oversim::ChordSuccessorList::successorListSize

protected

maximum size of the successor list

Definition at line 124 of file ChordSuccessorList.h.

std::map<OverlayKey, SuccessorListEntry> oversim::ChordSuccessorList::successorMap

protected

internal representation of the successor list

Definition at line 122 of file ChordSuccessorList.h.

NodeHandle oversim::ChordSuccessorList::thisNode

protected

own node handle

Definition at line 121 of file ChordSuccessorList.h.

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

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Function Documentation

Member Data Documentation