public int dist(UniverseGraph.SystemId sid1, UniverseGraph.SystemId sid2)
{
SystemPair pair = new SystemPair(sid1, sid2);
if (!distance.ContainsKey(pair))
return UNREACHABLE;
else
return distance[pair];
}
public void relax(UniverseGraph.SystemId sid1, UniverseGraph.SystemId sid2)
{
int distUpperBound = dist(sid1, sid2);
SystemPair pair = new SystemPair(sid1, sid2);
foreach (UniverseGraph.SystemId sid in graph.idToInfo.Keys)
{
int distCandidate = dist(sid1, sid) + dist(sid, sid2);
if (distCandidate < distUpperBound)
{
distance[pair] = distCandidate;
distUpperBound = distCandidate;
}
}
}
//todo : add some kind of control to keep cache size in check
public int getDistance(UniverseGraph.SystemId source, UniverseGraph.SystemId dest)
{
SystemPair key = new SystemPair(source.id, dest.id);
if (distanceCache.ContainsKey(key))
{
++cacheHits;
return distanceCache[key];
}
else
{
++cacheMisses;
int computedDist = findDist(source, dest);
distanceCache[key] = computedDist;
return computedDist;
}
}
public void importDistanceCache(string path)
{
StreamReader reader = new StreamReader(File.Open(path, FileMode.OpenOrCreate, FileAccess.ReadWrite));
String line = reader.ReadLine();
while((line!=null) & (line!=""))
{
char[] commas = {','};
String[] toks = line.Split(commas);
if (toks.Length == 3)
{
ushort id1 = UInt16.Parse(toks[0]);
ushort id2 = UInt16.Parse(toks[1]);
int dist = Int32.Parse(toks[2]);
SystemPair pair = new SystemPair(id1, id2);
distanceCache[pair] = dist;
}
line = reader.ReadLine();
if (line == null)
break;
}
reader.Close();
}
