private City[] ConvertToCities(byte[] file, int offset, int count)
{
var cities = new City[count];
for (int i = 0; i < count; i++)
{
var city = converterService.ConvertToCity(file, offset);
cities[i] = city;
offset += 96;
}
return(cities);
}
public City[] BinarySearchByIpAddress(string ip)
{
var intAddress = IpAddressHelpers.IpToUint(ip);
if (_repository.Db == null)
{
throw new Exception("База данных не загружена");
}
var firstIndex = 0;
var lastIndex = _repository.Db.Header.Records;
while (firstIndex <= lastIndex)
{
int midIndex = firstIndex + (lastIndex - firstIndex) / 2;
var midRangeFrom = _repository.Db.IpRanges[midIndex, 0];
var midRangeTo = _repository.Db.IpRanges[midIndex, 1];
if (intAddress >= midRangeFrom && intAddress <= midRangeTo)
{
var index = _repository.Db.IpRanges[midIndex, 2];
return(new City[] { _converterService.ConvertToCity(_repository.Db.Cities, (int)index * Constants.CitySize) });
}
if (intAddress < midRangeFrom)
{
lastIndex = midIndex - 1;
}
else
{
firstIndex = midIndex + 1;
}
}
return(new City[] { });
}