public double distance(Location loc)
{
double delta_lat, delta_lon;
double temp;
double lat1 = latitude;
double lon1 = longitude;
double lat2 = loc.latitude;
double lon2 = loc.longitude;
// convert degrees to radians
lat1 *= RAD_CONVERT;
lat2 *= RAD_CONVERT;
// find the deltas
delta_lat = lat2 - lat1;
delta_lon = (lon2 - lon1) * RAD_CONVERT;
// Find the great circle distance
temp = Math.Pow(Math.Sin(delta_lat/2),2) + Math.Cos(lat1) * Math.Cos(lat2) * Math.Pow(Math.Sin(delta_lon/2),2);
return EARTH_DIAMETER * Math.Atan2(Math.Sqrt(temp),Math.Sqrt(1-temp));
}
public Location getLocation(long ipnum)
{
int record_pointer;
byte[] record_buf = new byte[FULL_RECORD_LENGTH];
char[] record_buf2 = new char[FULL_RECORD_LENGTH];
int record_buf_offset = 0;
Location record = new Location();
int str_length = 0;
int j, Seek_country;
double latitude = 0, longitude = 0;
try {
Seek_country = SeekCountry(ipnum);
if (Seek_country == databaseSegments[0]) {
return null;
}
record_pointer = Seek_country + ((2 * recordLength - 1) * databaseSegments[0]);
if ((dboptions & GEOIP_MEMORY_CACHE) == 1){
Array.Copy(dbbuffer, record_pointer, record_buf, 0, Math.Min(dbbuffer.Length - record_pointer, FULL_RECORD_LENGTH));
} else {
file.Seek(record_pointer,SeekOrigin.Begin);
file.Read(record_buf,0,FULL_RECORD_LENGTH);
}
for (int a0 = 0;a0 < FULL_RECORD_LENGTH;a0++){
record_buf2[a0] = Convert.ToChar(record_buf[a0]);
}
// get country
record.countryCode = countryCode[unsignedByteToInt(record_buf[0])];
record.countryName = countryName[unsignedByteToInt(record_buf[0])];
record_buf_offset++;
// get region
while (record_buf[record_buf_offset + str_length] != '\0')
str_length++;
if (str_length > 0) {
record.region = new String(record_buf2, record_buf_offset, str_length);
}
record_buf_offset += str_length + 1;
str_length = 0;
// get region_name
record.regionName = RegionName.getRegionName( record.countryCode, record.region );
// get city
while (record_buf[record_buf_offset + str_length] != '\0')
str_length++;
if (str_length > 0) {
record.city = new String(record_buf2, record_buf_offset, str_length);
}
record_buf_offset += (str_length + 1);
str_length = 0;
// get postal code
while (record_buf[record_buf_offset + str_length] != '\0')
str_length++;
if (str_length > 0) {
record.postalCode = new String(record_buf2, record_buf_offset, str_length);
}
record_buf_offset += (str_length + 1);
// get latitude
for (j = 0; j < 3; j++)
latitude += (unsignedByteToInt(record_buf[record_buf_offset + j]) << (j * 8));
record.latitude = (float) latitude/10000 - 180;
record_buf_offset += 3;
// get longitude
for (j = 0; j < 3; j++)
longitude += (unsignedByteToInt(record_buf[record_buf_offset + j]) << (j * 8));
record.longitude = (float) longitude/10000 - 180;
record.metro_code = record.dma_code = 0;
record.area_code = 0;
if (databaseType == DatabaseInfo.CITY_EDITION_REV1) {
// get metro_code
int metroarea_combo = 0;
if (record.countryCode == "US"){
record_buf_offset += 3;
for (j = 0; j < 3; j++)
metroarea_combo += (unsignedByteToInt(record_buf[record_buf_offset + j]) << (j * 8));
record.metro_code = record.dma_code = metroarea_combo/1000;
record.area_code = metroarea_combo % 1000;
}
}
}
catch (IOException) {
Console.Write("IO Exception while seting up segments");
}
return record;
}