private static void UploadTrackingDataAndFlushBuffer()
{
if (bufferedTrackedPositions == null)
return;
if (bufferedTrackedPositions.Count == 0)
return;
//copy tracking data and clear buffer
TrackedPosition[] tmp;
lock (bufferedTrackedPositionsLock)
{
int numPositions = bufferedTrackedPositions.Count;
tmp = new TrackedPosition[numPositions];
bufferedTrackedPositions.CopyTo(tmp);
bufferedTrackedPositions.Clear();
}
radiomapEntities context = new radiomapEntities(radiomapUri);
foreach (TrackedPosition pos in tmp)
{
context.AddToTrackedPositions(pos);
}
context.BeginSaveChanges(SaveChangesOptions.Batch, OnPositionEstimatesSaved, context);
}
/// <summary>
/// Both the sniffer backend and radiomap backend define a PositionEstimate entity.
/// Therefore, we convert WifiSniffer position estimates to radiomap position-estimates when
/// we save tracking data to the radio map backend (which houses the tracking data as well)
/// </summary>
/// <param name="?"></param>
/// <returns></returns>
private static TrackedPosition CreateTrackedPosition(WifiSnifferPositioningService.PositionEstimate org)
{
TrackedPosition res = new TrackedPosition();
res.Accuracy = org.Accuracy;
res.Altitude = org.Altitude;
res.Bearing = org.Bearing;
res.Building_ID = org.Building_ID;
res.HasAccuracy = org.HasAccuracy;
res.HasBearing = org.HasBearing;
res.HasSpeed = org.HasSpeed;
res.Latitude = org.Latitude;
res.Longitude = org.Longitude;
res.Provider = org.Provider;
res.Speed = org.Speed;
res.Time = DateTime.Now; //org.Time;
res.VertexID = org.VertexID;
res.ClientID = ClientId; //A guid
return res;
}
private static TrackedPosition CreateTrackedPosition(System.Device.Location.GeoCoordinate org)
{
TrackedPosition res = new TrackedPosition();
//NaN numbers cause an exception on MSSQL Server so they must be avoided.
bool hasAccuracy = false;
bool hasBearing = false;
bool hasSpeed = false;
if (!double.IsNaN(org.HorizontalAccuracy))
{
res.Accuracy = org.HorizontalAccuracy;
hasAccuracy = true;
}
if (!double.IsNaN(org.Course))
{
res.Bearing = org.Course;
hasBearing = true;
}
if (!double.IsNaN(org.Speed))
{
res.Speed = org.Speed;
hasSpeed = true;
}
//res.Building_ID = -1;
//Latitude, longitude, altitude are non-nullable (but should also never be NaN's)
const double errorVal = -999;
res.Latitude = !double.IsNaN(org.Latitude) ? org.Latitude : errorVal;
res.Longitude = !double.IsNaN(org.Longitude) ? org.Longitude : errorVal;
res.Altitude = !double.IsNaN(org.Altitude) ? org.Altitude : errorVal;
res.Provider = "MS Location API (GPS)";
res.Time = DateTime.Now;
//res.VertexID = -1;
res.HasAccuracy = hasAccuracy;
res.HasBearing = hasBearing;
res.HasSpeed = hasSpeed;
res.ClientID = ClientId; //A guid
return res;
}
/// <summary>
/// Add a position estimate to the buffer of tracked positions.
/// When the buffer is full, the data are flushed to the backend
/// </summary>
/// <param name="pos"></param>
private static void AddToTrackedPositions(TrackedPosition pos)
{
// Wi-Fi and GPS can potentially be adding at the same time so we lock the buffer.
lock (bufferedTrackedPositionsLock)
{
bufferedTrackedPositions.Add(pos);
}
if (IsTimeToSendTrackingData())
{
UploadTrackingDataAndFlushBuffer();
}
}
