public double GetDistance(int docid, double centerLat, double centerLng, double lat, double lng)
{
// check to see if we have distances
// if not calculate the distance
if (_distances == null)
{
return(DistanceUtils.GetInstance().GetDistanceMi(centerLat, centerLng, lat, lng));
}
// check to see if the doc id has a cached distance
double docd;
_distances.TryGetValue(docid, out docd);
if (docd > 0)
{
return(docd);
}
//check to see if we have a precision code
// and if another lat/long has been calculated at
// that rounded location
if (_precision.HasValue)
{
double xLat = GetPrecision(lat, _precision);
double xLng = GetPrecision(lng, _precision);
String k = xLat + "," + xLng;
Double d;
_distanceLookupCache.TryGetValue(k, out d);
if (d > 0)
{
return(d);
}
}
//all else fails calculate the distances
return(DistanceUtils.GetInstance().GetDistanceMi(centerLat, centerLng, lat, lng));
}