/// <summary>
/// Read Through Cache
/// </summary>
/// <param name="getParams"></param>
/// <returns></returns>
private ClusterMarkersResponse GetMarkersHelper(GetMarkersParams getParams)
{
try
{
var neLat = getParams.NorthEastLatitude;
var neLong = getParams.NorthEastLongitude;
var swLat = getParams.SouthWestLatitude;
var swLong = getParams.SouthWestLongitude;
var zoomLevel = getParams.ZoomLevel;
var filter = getParams.Filter ?? "";
// values are validated there
var markersInput = new MarkersInput(neLat, neLong, swLat, swLong, zoomLevel, filter);
var grid = GridCluster.GetBoundaryExtended(markersInput);
var cacheKeyHelper = string.Format("{0}_{1}_{2}", markersInput.Zoomlevel, markersInput.FilterHashCode(), grid.GetHashCode());
var cacheKey = CacheKeys.GetMarkers(cacheKeyHelper.GetHashCode());
var response = new ClusterMarkersResponse();
markersInput.Viewport.ValidateLatLon(); // Validate google map viewport input (should be always valid)
markersInput.Viewport.Normalize();
// Get all points from memory
IList <MapPoint> points = _pointCollection.Get(getParams.PointType); // _pointsDatabase.GetPoints();
// Filter points
points = FilterUtil.FilterByType(
points,
new FilterData {
TypeFilterExclude = markersInput.TypeFilterExclude
}
);
// Create new instance for every ajax request with input all points and json data
var clusterAlgo = new GridCluster(points, markersInput);
var clusteringEnabled = markersInput.IsClusteringEnabled ||
GmcConfiguration.Get.AlwaysClusteringEnabledWhenZoomLevelLess > markersInput.Zoomlevel;
// Clustering
if (clusteringEnabled && markersInput.Zoomlevel < GmcConfiguration.Get.ZoomlevelClusterStop)
{
IList <MapPoint> markers = clusterAlgo.RunCluster();
response = new ClusterMarkersResponse
{
Markers = markers,
Polylines = clusterAlgo.GetPolyLines()
};
}
else
{
// If we are here then there are no clustering
// The number of items returned is restricted to avoid json data overflow
IList <MapPoint> filteredDataset = FilterUtil.FilterDataByViewport(points, markersInput.Viewport);
IList <MapPoint> filteredDatasetMaxPoints = filteredDataset.Take(GmcConfiguration.Get.MaxMarkersReturned).ToList();
response = new ClusterMarkersResponse
{
Markers = filteredDatasetMaxPoints,
Polylines = clusterAlgo.GetPolyLines(),
Mia = filteredDataset.Count - filteredDatasetMaxPoints.Count,
};
}
// if client ne and sw is inside a specific grid box then cache the grid box and the result
// next time test if ne and sw is inside the grid box and return the cached result
if (GmcConfiguration.Get.CacheServices)
{
_memCache.Set(cacheKey, response, TimeSpan.FromMinutes(10)); // cache data
}
return(response);
}
catch (Exception ex)
{
return(new ClusterMarkersResponse
{
OperationResult = "0",
ErrorMessage = string.Format("MapService says: exception {0}", ex.Message)
});
}
}