cyclegraph.cc

   1 #include "cyclegraph.h"
   2 #include "action.h"
   3
   4 /** Initializes a CycleGraph object. */
   5 CycleGraph::CycleGraph() {
   6         hasCycles=false;
   7 }
   8
   9 /** Returns the CycleNode for a given ModelAction. */
  10 CycleNode * CycleGraph::getNode(ModelAction * action) {
  11         CycleNode *node=actionToNode.get(action);
  12         if (node==NULL) {
  13                 node=new CycleNode(action);
  14                 actionToNode.put(action, node);
  15         }
  16         return node;
  17 }
  18
  19 /** Adds an edge between two ModelActions. */
  20 void CycleGraph::addEdge(ModelAction *from, ModelAction *to) {
  21         CycleNode *fromnode=getNode(from);
  22         CycleNode *tonode=getNode(to);
  23         if (!hasCycles) {
  24                 // Check for Cycles
  25                 hasCycles=checkReachable(fromnode, tonode);
  26         }
  27         fromnode->addEdge(tonode);
  28 }
  29
  30 /** Checks whether the first CycleNode can reach the second one. */
  31 bool CycleGraph::checkReachable(CycleNode *from, CycleNode *to) {
  32         std::vector<CycleNode *> queue;
  33         HashTable<CycleNode *, CycleNode *, uintptr_t, 4> discovered;
  34
  35         queue.push_back(from);
  36         discovered.put(from, from);
  37         while(!queue.empty()) {
  38                 CycleNode * node=queue.back();
  39                 queue.pop_back();
  40                 if (node==to)
  41                         return true;
  42
  43                 for(unsigned int i=0;i<node->getEdges()->size();i++) {
  44                         CycleNode *next=(*node->getEdges())[i];
  45                         if (!discovered.contains(next)) {
  46                                 discovered.put(next,next);
  47                                 queue.push_back(next);
  48                         }
  49                 }
  50         }
  51         return false;
  52 }
  53
  54 /** Returns whether a CycleGraph contains cycles. */
  55 bool CycleGraph::checkForCycles() {
  56         return hasCycles;
  57 }
  58
  59 /** Constructor for a CycleNode. */
  60 CycleNode::CycleNode(ModelAction *modelaction) {
  61         action=modelaction;
  62 }
  63
  64 /** Returns a vector of the edges from a CycleNode. */
  65 std::vector<CycleNode *> * CycleNode::getEdges() {
  66         return &edges;
  67 }
  68
  69 /** Adds an edge to a CycleNode. */
  70 void CycleNode::addEdge(CycleNode * node) {
  71         edges.push_back(node);
  72 }