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(";");
}
bool isReplica(Assignment * a, Element * element, NetPath& path)
{
if ( path.size() == 0 || !element->isStore() )
return false;
Element* first = static_cast<Link*>(path[0])->getLinkedComputationalElement();
Element* last = static_cast<Link*>(path[path.size()-1])->getLinkedComputationalElement();
if ( first->isStore() && a->isReplicaOnStore(static_cast<Storage*>(element),
static_cast<Store*>(first)) )
return true;
if ( last->isStore() && a->isReplicaOnStore(static_cast<Storage*>(element),
static_cast<Store*>(last)) )
return true;
return false;
}
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;
}
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;
}
