QString getAssignmentChain(NetPath path, NetworkOverseer const& network)
{
if ( path.size() == 0 )
return QString("none");
QStringList result;
for ( NetPath::iterator i = path.begin(); i != path.end(); i++)
{
NetworkingElement * ne = *i;
if ( ne->isSwitch() )
{
uint uid = network.getIdByElement(ne);
result << QString().setNum(uid);
}
}
NetPath::iterator first = path.begin(), last = path.end();
if ( (*first)->isLink() && (*(--last))->isLink() )
{
Link * begin = static_cast<Link *>(*first);
Link * end = static_cast<Link *>(*last);
uint firstComp = network.getIdByElement(begin->getLinkedComputationalElement());
uint lastComp = network.getIdByElement(end->getLinkedComputationalElement());
result.prepend(QString().setNum(firstComp));
result.append(QString().setNum(lastComp));
}
return result.join(";");
}
long VirtualLinkRouter::calculateKShortestPathWeight(NetPath& path)
{
long result = 0l;
NetPath::iterator it = path.begin();
NetPath::iterator itEnd = path.end();
for ( ; it != itEnd; ++it )
{
result += (*it)->getCapacity();
}
return result;
}
void DijkstraRouter::printPath(const NetPath & path) const
{
if ( path.empty() )
return;
for ( NetPath::const_iterator i = path.begin(); i != path.end(); i++)
{
Element * element = *i;
printf("%s:%lu", element->getName().c_str(), element->getID());
if ( i + 1 != path.end() )
printf(" -> ");
}
printf("\n");
}
NetPath VirtualLinkRouter::searchPathDejkstra(VirtualLink * virtualLink, Network * network, SearchPathAlgorithm algorithm)
{
if ( virtualLink->getFirst() == virtualLink->getSecond() )
return NetPath();
// local variables
std::set<ElementWeight, WeightCompare> elementsToParse;
std::map<Element * , Link*> incomingEdge;
std::map<Element * , std::vector<Link *> > elementLinks;
// initializing parameters
Links::iterator it = network->getLinks().begin();
Links::iterator itEnd = network->getLinks().end();
std::vector<Link *> * vecLinks = NULL;
for ( ; it != itEnd; ++it )
{
if ((*it)->getFirst() != virtualLink->getFirst()) elementsToParse.insert(ElementWeight((*it)->getFirst(), LONG_MAX)); // LONG_MAX equals to inf
if ((*it)->getSecond() != virtualLink->getFirst()) elementsToParse.insert(ElementWeight((*it)->getSecond(), LONG_MAX));
vecLinks = &elementLinks[(*it)->getFirst()];
if (vecLinks->capacity() < NLinks) vecLinks->reserve(NLinks);
vecLinks->push_back(*it);
vecLinks = &elementLinks[(*it)->getSecond()];
if (vecLinks->capacity() < NLinks) vecLinks->reserve(NLinks);
vecLinks->push_back(*it);
}
elementsToParse.insert(ElementWeight(virtualLink->getFirst(), 0));
elementsToParse.insert(ElementWeight(virtualLink->getSecond(), LONG_MAX));
Element * currentElement = virtualLink->getFirst();
Link edge("dijkstra edge", 0);
ElementWeight temp(NULL, -LONG_MAX);
std::set<ElementWeight, WeightCompare>::iterator tempIter;
long curWeight = 0;
// algorithm itself
while ( currentElement != NULL && currentElement != virtualLink->getSecond() )
{
temp.element = currentElement;
tempIter = elementsToParse.find(temp);
assert(tempIter != elementsToParse.end());
curWeight = tempIter->weight;
// std::cerr << "currentElement = " << currentElement << ", tempIter->element = " << tempIter->element << ", weight = " << tempIter->weight << '\n';
elementsToParse.erase(tempIter);
// going through all neighbors of current element,
// parsing their weight and choosing the element with the
// lowest weight
if ( elementLinks.find(currentElement) == elementLinks.end() )
{
return NetPath(); // No links assosiated with element
}
std::vector<Link *>& curLinks = elementLinks[currentElement];
unsigned int sz = curLinks.size();
for(unsigned int index = 0; index < sz; ++ index)
{
Link * cur = curLinks[index];
Element * other = cur->getFirst() == currentElement ?
cur->getSecond() : cur->getFirst();
temp.element = other;
temp.weight = LONG_MAX;
tempIter = elementsToParse.find(temp);
if ( tempIter != elementsToParse.end() )
{
edge.setCapacity(cur->getCapacity());
edge.bindElements(currentElement, other);
// weight of reaching the next element from current element
long weight = getEdgeWeigth(edge, network, algorithm) + curWeight;
if ( weight < tempIter->weight )
{
// have to erase and reinsert because weight is a part of the key
temp.element = other;
temp.weight = weight;
elementsToParse.erase(tempIter);
elementsToParse.insert(temp);
incomingEdge[other] = cur;
}
}
temp.weight = -LONG_MAX;
}
if (elementsToParse.begin()->weight != LONG_MAX) currentElement = elementsToParse.begin()->element;
else return NetPath(); // if an infinite weight is the minimum, it is a fail
}
if ( currentElement != virtualLink->getSecond() )
return NetPath(); // no way from one element to another
// retrieving the way
NetPath answer;
Element * other = currentElement; // for parsing results with just one edge
while ( incomingEdge[currentElement]->getFirst() != virtualLink->getFirst()
&& incomingEdge[currentElement]->getSecond() != virtualLink->getFirst() )
{
answer.push_back(incomingEdge[currentElement]);
other = incomingEdge[currentElement]->getFirst() == currentElement ?
incomingEdge[currentElement]->getSecond() : incomingEdge[currentElement]->getFirst();
answer.push_back(static_cast<NetworkingElement *>(other));
currentElement = other;
}
answer.push_back(incomingEdge[other]);
// this step may be skiped, but doing for sure
std::reverse(answer.begin(), answer.end());
return answer;
}
NetPath VirtualLinkRouter::routeKShortestPathsALL(VirtualLink * virtualLink, Network * network, std::vector<NetPath> * pathStorage)
{
// links and switches that would be removed from the network,
// they should be restored after algorithm's finish
Links removedLinks;
Switches removedSwitches;
// first, create the graph with decreased capacities
decreaseCapacities(virtualLink, network, &removedLinks, &removedSwitches);
// Yen's algorithm
NetPath shortest = searchPathDejkstra(virtualLink, network, K_SHORTEST_PATHS);
if ( shortest.size() == 0 )
{
restoreCapacities(virtualLink, network, &removedLinks, &removedSwitches);
return NetPath(); // no path found!
}
pathStorage->push_back(shortest);
Links& links = network->getLinks();
unsigned pathsFound = 1;
long pathWeight = calculateKShortestPathWeight(shortest);
bool isNewPathFound = true;
while ( isNewPathFound && pathsFound < Criteria::kShortestPathDepth() )
{
NetPath candidate = shortest;
NetPath::iterator it = shortest.begin();
NetPath::iterator itEnd = shortest.end();
isNewPathFound = false;
bool isNewCandidateFound = false;
Link * linkToRemove = NULL;
for ( ; it != itEnd; ++it )
{
if ( (*it)->isLink() && links.find(static_cast<Link*>(*it)) != links.end() )
{
// removing link and trying dejkstra
links.erase(links.find(static_cast<Link*>(*it)));
NetPath newPath = searchPathDejkstra(virtualLink, network, K_SHORTEST_PATHS);
if ( newPath.size() == shortest.size() )
{
isNewPathFound = true;
pathStorage->push_back(newPath);
++pathsFound;
long weight = calculateKShortestPathWeight(newPath);
if ( weight > pathWeight )
{
isNewCandidateFound = true;
linkToRemove = static_cast<Link*>(*it);
pathWeight = weight;
candidate = newPath;
if ( pathsFound == Criteria::kShortestPathDepth() )
break;
}
if ( linkToRemove == NULL )
linkToRemove = static_cast<Link*>(*it); // to avoid the situation with removing NULL-link
}
links.insert(static_cast<Link*>(*it)); // inserting link again
}
}
if ( isNewCandidateFound )
shortest = candidate;
if ( isNewPathFound && pathsFound != Criteria::kShortestPathDepth() )
{
// restoring the capacity of link being removed
linkToRemove->RemoveAssignment(virtualLink);
links.erase(links.find(linkToRemove));
removedLinks.insert(linkToRemove);
}
}
// restoring removed capacities
restoreCapacities(virtualLink, network, &removedLinks, &removedSwitches);
return shortest;
}
NetPath DijkstraRouter::search()
{
if ( !validateInput() )
{
printf("[RD]Wrong input\n");
return NetPath();
}
if ( link->getFirst() == link->getSecond() )
return NetPath();
std::set<ElementWeight, WeightCompare> elementsToParse;
std::map<Element * , Link *> incomingEdge;
std::map<Element * , std::vector<Link *> > elementLinks;
Links & links = network->getLinks();
for ( Links::iterator i = links.begin(); i != links.end(); i++ )
{
Link * l = *i;
if ( l->getFirst() != link->getFirst() )
elementsToParse.insert(ElementWeight(l->getFirst(), LONG_MAX));
if ( l->getSecond() != link->getFirst() )
elementsToParse.insert(ElementWeight(l->getSecond(), LONG_MAX));
elementLinks[l->getFirst()].push_back(l);
elementLinks[l->getSecond()].push_back(l);
}
elementsToParse.insert(ElementWeight(link->getFirst(), 0));
elementsToParse.insert(ElementWeight(link->getSecond(), LONG_MAX));
Element * currentElement = link->getFirst();
Link edge("dijkstraedge", 0);
ElementWeight temp(0, -LONG_MAX);
std::set<ElementWeight, WeightCompare>::iterator tempIter;
long curWeight = 0;
while ( currentElement != 0 && currentElement != link->getSecond() )
{
temp.element = currentElement;
tempIter = elementsToParse.find(temp);
assert(tempIter != elementsToParse.end());
curWeight = tempIter->weight;
elementsToParse.erase(tempIter);
if ( elementLinks.find(currentElement) == elementLinks.end() )
return NetPath();
std::vector<Link *>& curLinks = elementLinks[currentElement];
unsigned int size = curLinks.size();
for(unsigned int index = 0; index < size; index++)
{
Link * cur = curLinks[index];
Element * other = cur->getFirst() == currentElement ?
cur->getSecond() : cur->getFirst();
temp.element = other;
temp.weight = LONG_MAX;
tempIter = elementsToParse.find(temp);
if ( tempIter != elementsToParse.end() )
{
edge.setCapacity(cur->getCapacity());
edge.bindElements(currentElement, other);
long weight = getEdgeWeight(&edge) + curWeight;
if ( weight < tempIter->weight )
{
temp.element = other;
temp.weight = weight;
elementsToParse.erase(tempIter);
elementsToParse.insert(temp);
incomingEdge[other] = cur;
}
}
temp.weight = -LONG_MAX;
}
if (elementsToParse.begin()->weight != LONG_MAX)
currentElement = elementsToParse.begin()->element;
else
return NetPath();
}
if ( currentElement != link->getSecond() )
return NetPath();
Element * other = currentElement;
NetPath result;
while ( incomingEdge[currentElement]->getFirst() != link->getFirst()
&& incomingEdge[currentElement]->getSecond() != link->getFirst() )
{
result.push_back(incomingEdge[currentElement]);
other = incomingEdge[currentElement]->getFirst() == currentElement ?
incomingEdge[currentElement]->getSecond() : incomingEdge[currentElement]->getFirst();
result.push_back((NetworkingElement *)other);
currentElement = other;
}
result.push_back(incomingEdge[other]);
std::reverse(result.begin(), result.end());
return result;
}
void NetworkManager::addAssignment(Link * vlink, NetPath & netPath)
{
for ( NetPath::iterator i = netPath.begin(); i != netPath.end(); i++ )
(*i)->assign(*vlink);
}
Algorithm::Result FirstFitAlgorithm::schedule()
{
for (Requests::iterator i = requests.begin(); i != requests.end(); i++)
{
Request * request = *i;
Assignment * assignment = new Assignment(request);
Algorithm::Result result = SUCCESS;
Nodes & vms = request->getVirtualMachines();
for (Nodes::iterator vmi = vms.begin(); vmi != vms.end(); vmi++)
{
Node * vm = *vmi;
Nodes & nodes = network->getNodes();
Nodes::iterator n;
for (n = nodes.begin(); n != nodes.end(); n++)
{
Node * node = *n;
if ( node->isAssignmentPossible(*vm) )
{
node->assign(*vm);
assignment->AddAssignment(vm, node);
break;
}
}
if ( n == nodes.end() )
{
result = FAILURE;
break;
}
}
Stores & storages = request->getStorages();
for (Stores::iterator s = storages.begin(); s != storages.end(); s++)
{
Store * storage = *s;
Stores & stores = network->getStores();
Stores::iterator si;
for ( si = stores.begin(); si != stores.end(); si++)
{
Store * store = *si;
if ( store->isAssignmentPossible(*storage) )
{
store->assign(*storage);
assignment->AddAssignment(storage, store);
break;
}
}
if ( si == storages.end() )
{
result = FAILURE;
break;
}
}
Links & vlinks = request->getVirtualLinks();
for (Links::iterator l = vlinks.begin(); l != vlinks.end(); l++)
{
Link * dummy = createDummyLink(*l, assignment);
if ( dummy == 0 )
{
result = FAILURE;
break;
}
NetPath netPath = VirtualLinkRouter::routeDejkstra(dummy, network);
delete dummy;
if ( netPath.size() == 0 )
{
result = FAILURE;
break;
}
for ( NetPath::iterator i = netPath.begin(); i != netPath.end(); i++)
{
(*i)->assign(**l);
}
assignment->AddAssignment(*l, netPath);
}
if ( result == FAILURE )
delete assignment;
else
assignments.insert(assignment);
}
printf("Assigned total of %d from %d requests", assignments.size(), requests.size());
if ( assignments.size() == requests.size() )
return SUCCESS;
else if ( assignments.size() != 0 )
return PARTIAL;
else
return FAILURE;
}