cyclegraph.cc

   1 #include "cyclegraph.h"
   2 #include "action.h"
   3
   4 /** Initializes a CycleGraph object. */
   5
   6 CycleGraph::CycleGraph() {
   7         hasCycles=false;
   8 }
   9
  10 /** Returns the CycleNode for a given ModelAction. */
  11
  12 CycleNode * CycleGraph::getNode(ModelAction * action) {
  13         CycleNode *node=actionToNode.get(action);
  14         if (node==NULL) {
  15                 node=new CycleNode(action);
  16                 actionToNode.put(action, node);
  17         }
  18         return node;
  19 }
  20
  21 /** Adds an edge between two ModelActions. */
  22
  23 void CycleGraph::addEdge(ModelAction *from, ModelAction *to) {
  24         CycleNode *fromnode=getNode(from);
  25         CycleNode *tonode=getNode(to);
  26         if (!hasCycles) {
  27                 // Check for Cycles
  28                 hasCycles=checkReachable(fromnode, tonode);
  29         }
  30         fromnode->addEdge(tonode);
  31 }
  32
  33 /** Checks whether the first CycleNode can reach the second one. */
  34
  35 bool CycleGraph::checkReachable(CycleNode *from, CycleNode *to) {
  36         std::vector<CycleNode *> queue;
  37         HashTable<CycleNode *, CycleNode *, uintptr_t, 4> discovered;
  38
  39         queue.push_back(from);
  40         discovered.put(from, from);
  41         while(!queue.empty()) {
  42                 CycleNode * node=queue.back();
  43                 queue.pop_back();
  44                 if (node==to)
  45                         return true;
  46
  47                 for(unsigned int i=0;i<node->getEdges()->size();i++) {
  48                         CycleNode *next=(*node->getEdges())[i];
  49                         if (!discovered.contains(next)) {
  50                                 discovered.put(next,next);
  51                                 queue.push_back(next);
  52                         }
  53                 }
  54         }
  55         return false;
  56 }
  57
  58 /** Returns whether a CycleGraph contains cycles. */
  59 bool checkForCycles() {
  60         return hasCycles;
  61 }
  62
  63 /** Constructor for a CycleNode. */
  64
  65 CycleNode::CycleNode(ModelAction *modelaction) {
  66         action=modelaction;
  67 }
  68
  69 /** Returns a vector of the edges from a CycleNode. */
  70
  71 std::vector<CycleNode *> * CycleNode::getEdges() {
  72         return &edges;
  73 }
  74
  75 /** Adds an edge to a CycleNode. */
  76
  77 void CycleNode::addEdge(CycleNode * node) {
  78         edges.push_back(node);
  79 }