/// <summary>
/// create a <seealso cref="GeoHashCircleQuery"/> with the given center point and a
/// radius in meters.
/// </summary>
public GeoHashCircleQuery(WGS84Point center, double radius)
{
m_radius = radius;
m_center = center;
WGS84Point northEast = VincentyGeodesy.MoveInDirection(VincentyGeodesy.MoveInDirection(center, 0, radius), 90, radius);
WGS84Point southWest = VincentyGeodesy.MoveInDirection(VincentyGeodesy.MoveInDirection(center, 180, radius), 270, radius);
BoundingBox bbox = new BoundingBox(northEast, southWest);
m_query = new GeoHashBoundingBoxQuery(bbox);
}
/// <summary>
/// create a <seealso cref="GeoHashCircleQuery"/> with the given center point and a
/// radius in meters.
/// </summary>
public GeoHashCircleQuery(WGS84Point center, double radius)
{
m_radius = radius;
m_center = center;
WGS84Point northEast = VincentyGeodesy.MoveInDirection(VincentyGeodesy.MoveInDirection(center, 0, radius), 90, radius);
WGS84Point southWest = VincentyGeodesy.MoveInDirection(VincentyGeodesy.MoveInDirection(center, 180, radius), 270, radius);
BoundingBox bbox = new BoundingBox(northEast, southWest);
m_query = new GeoHashBoundingBoxQuery(bbox);
}
public static HashSet<GeoObj> SearchGeoHashIndex(SessionBase session, double minLat, double minLon, double maxLat, double maxLon)
{
HashSet<GeoObj> resultSet = new HashSet<GeoObj>();
if (minLat > maxLat)
{
double t = minLat;
minLat = maxLat;
maxLat = t;
}
if (minLon > maxLon)
{
double t = minLon;
minLon = maxLon;
maxLon = t;
}
WGS84Point min = new WGS84Point(minLat, minLon);
WGS84Point max = new WGS84Point(maxLat, maxLon);
BoundingBox bbox = new BoundingBox(min, max);
GeoHashBoundingBoxQuery query = new GeoHashBoundingBoxQuery(bbox);
var btreeSet = session.AllObjects<BTreeSet<GeoObj>>().FirstOrDefault();
foreach (GeoHash hash in query.SearchHashes)
{
var itr = btreeSet.Iterator();
itr.GoTo(new GeoObj(hash.LongValue));
var current = itr.Current();
while (current != null)
{
GeoHash geoHash = GeoHash.FromLongValue(current.GeoHash);
if ((geoHash.SignificantBits >= hash.SignificantBits && geoHash.Within(hash)) || (geoHash.SignificantBits < hash.SignificantBits && hash.Within(geoHash)))
{
if (!(current.Latitude < bbox.MinLat || current.Latitude > bbox.MaxLat || current.Longitude < bbox.MinLon || current.Longitude > bbox.MaxLon))
resultSet.Add(current);
current = itr.Next();
}
else
break;
}
}
return resultSet;
}
public static HashSet<Person> SearchGeoHashIndex(string bootDirectory, double minLat, double minLon, double maxLat, double maxLon)
{
HashSet<Person> resultSet = new HashSet<Person>();
if (minLat > maxLat)
{
double t = minLat;
minLat = maxLat;
maxLat = t;
}
if (minLon > maxLon)
{
double t = minLon;
minLon = maxLon;
maxLon = t;
}
WGS84Point min = new WGS84Point(minLat, minLon);
WGS84Point max = new WGS84Point(maxLat, maxLon);
BoundingBox bbox = new BoundingBox(min, max);
GeoHashBoundingBoxQuery query = new GeoHashBoundingBoxQuery(bbox);
using (SessionNoServer session = new SessionNoServer(bootDirectory))
{
session.BeginRead();
BTreeMap<Int64, VelocityDbList<Person>> btreeMap = session.AllObjects<BTreeMap<Int64, VelocityDbList<Person>>>().FirstOrDefault();
foreach (GeoHash hash in query.SearchHashes)
{
BTreeMapIterator<Int64, VelocityDbList<Person>> itr = btreeMap.Iterator();
itr.GoTo(hash.LongValue);
var current = itr.Current();
while (current.Value != null)
{
GeoHash geoHash = GeoHash.FromLongValue(current.Key);
if (geoHash.Within(hash) || (geoHash.SignificantBits > hash.SignificantBits && hash.Within(geoHash)))
{
foreach (Person person in current.Value)
{
resultSet.Add(person);
}
current = itr.Next();
}
else
break;
}
}
// actual geohash bounding box may be including some that are not within requested bounding box so remove such items if any
HashSet<Person> notWithin = new HashSet<Person>();
foreach (Person person in resultSet)
{
if (person.Lattitude < min.Latitude || person.Lattitude > max.Latitude || person.Longitude < min.Longitude || person.Lattitude > max.Latitude)
notWithin.Add(person);
}
foreach (Person person in notWithin)
resultSet.Remove(person);
foreach (Person person in resultSet)
{
Console.WriteLine(person.ToString() + " Lattitude: " + person.Lattitude + " Longitude: " + person.Longitude);
}
session.Commit();
}
return resultSet;
}
