/// <summary>
/// Fetch all data from db
/// </summary>
public void Fetch()
{
using (var fr = new CustomFileReader())
{
if (!fr.Open(FilePath))
{
Console.WriteLine("Не получилось открыть запрашиваемый файл");
return;
}
var headerBuffer = new byte[60];
fr.Read(headerBuffer, 0, 60);
var recordCount = BitConverter.ToInt32(headerBuffer, 44);
ThreadPool.SetMaxThreads(Environment.ProcessorCount, Environment.ProcessorCount);
// Async fetch for ip locations
var ipLocWaiter = new ManualResetEventSlim();
var ipLocations = new IpLocation[recordCount];
var offset = 20 * recordCount;
var buffer = new byte[offset];
fr.Read(buffer, 0, offset);
ThreadPool.QueueUserWorkItem(FetchIpLocations, new ThreadParams<IpLocation>
{
Buffer = buffer,
RecordCount = recordCount,
Waiter = ipLocWaiter,
Result = ipLocations
});
// Async multithreaded fetch for ip locations
int locWaiterThreadCount = Environment.ProcessorCount;
var locWaiter = new Dictionary<int, LocationArgs>();
for (int i = 0; i < locWaiterThreadCount; i++)
{
locWaiter[i] = new LocationArgs(recordCount / locWaiterThreadCount);
}
offset = 96 * recordCount;
for (int i = 0; i < locWaiterThreadCount; i++)
{
buffer = new byte[offset / locWaiterThreadCount];
fr.Read(buffer, 0, offset / locWaiterThreadCount);
ThreadPool.QueueUserWorkItem(FetchLocations, new ThreadParams<Location>
{
Buffer = buffer,
RecordCount = recordCount / locWaiterThreadCount,
Waiter = locWaiter[i].Waiter,
Result = locWaiter[i].Data
});
}
// Async fetch for indexes
offset = 4 * recordCount;
buffer = new byte[offset];
fr.Read(buffer, 0, offset);
var indexWaiter = new ManualResetEventSlim();
var indexes = new uint[recordCount];
ThreadPool.QueueUserWorkItem(FetchIndexes, new ThreadParams<uint>
{
Buffer = buffer,
RecordCount = recordCount,
Waiter = indexWaiter,
Result = indexes
});
// Fetch for header
FetchHeader(headerBuffer, recordCount);
ipLocWaiter.Wait();
indexWaiter.Wait();
var locations = new List<Location>(recordCount);
for (int i = 0; i < locWaiterThreadCount; i++)
{
var locationArgs = locWaiter[i];
locationArgs.Waiter.Wait();
locations.InsertRange(locWaiterThreadCount * i, locationArgs.Data);
}
IpLocations = ipLocations;
Locations = locations
.OrderBy(l => l.City);
Indexes = indexes;
}
}
/// <summary>
/// Fetch ip locations
/// </summary>
/// <param name="data">Parameters for async thread starting (ThreadParams<IpLocation/>)</param>
private static void FetchIpLocations(object data)
{
var pars = (ThreadParams<IpLocation>)data;
var position = 0;
var buffer = pars.Buffer;
var recordCount = pars.RecordCount;
var ipLocations = pars.Result;
for (int i = 0; i < recordCount; i++)
{
var fromIp = CustomBitConvert.ToUInt64(buffer, position);
position += 8;
var toIp = CustomBitConvert.ToUInt64(buffer, position);
position += 8;
var index = CustomBitConvert.ToUInt32(buffer, position);
position += 4;
ipLocations[i] = new IpLocation
{
FromIp = fromIp,
ToIp = toIp,
Index = index
};
}
pars.Waiter.Set();
}
