| /Repository/Mirrors.cs |
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| @@ -0,0 +1,143 @@ |
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| /////////////////////////////////////////////////////////////////////////// |
| // Copyright (C) Wizardry and Steamworks 2017 - License: GNU GPLv3 // |
| // Please see: http://www.gnu.org/licenses/gpl.html for legal details, // |
| // rights of fair usage, the disclaimer and warranty conditions. // |
| /////////////////////////////////////////////////////////////////////////// |
| |
| using System; |
| using System.Collections.Generic; |
| using System.IO; |
| using System.Linq; |
| using System.Net; |
| using MaxMind.GeoIP2.Responses; |
| using wasDAVClient; |
| using wasSharp.Geo; |
| using wasStitchNET.GeoIP; |
| using wasStitchNET.Structures; |
| |
| namespace wasStitchNET.Repository |
| { |
| public static class Mirrors |
| { |
| /// <summary> |
| /// Returns a list of valid Stitch mirrors. |
| /// </summary> |
| /// <param name="localCity">the local city from where the method is invoked</param> |
| /// <param name="mirror">the mirror to get the distance to</param> |
| /// <param name="client">the was DAV client to use</param> |
| /// <param name="server">the Stitch server to query</param> |
| /// <returns>a list of discovered Stitch mirrors</returns> |
| public static IEnumerable<StitchMirror> InitializeMirrors(CityResponse localCity, Client client, string server) |
| { |
| Func<string, StitchMirror> computeMirrorDistance = o => |
| { |
| var mirrorDistance = GetMirrorDistance(localCity, o); |
| if (mirrorDistance.Equals(default(KeyValuePair<string, Distance>))) |
| return default(StitchMirror); |
| return new StitchMirror(mirrorDistance.Key, mirrorDistance.Value); |
| }; |
| |
| var mirrors = new List<string> {server}; |
| yield return computeMirrorDistance(server); |
| |
| foreach (var stitchMirror in mirrors.AsParallel().SelectMany( |
| mirror => FetchStitchMirrors(client, mirror) |
| .AsParallel() |
| .Where(o => !string.IsNullOrEmpty(o) && !mirrors.Contains(o)) |
| .Select(computeMirrorDistance))) |
| { |
| if (stitchMirror.Equals(default(StitchMirror))) |
| continue; |
| mirrors.Add(stitchMirror.Address); |
| yield return stitchMirror; |
| } |
| } |
| |
| /// <summary> |
| /// Retrieves a list of mirrors from a Stitch repository. |
| /// </summary> |
| /// <param name="client">the was DAV client to use</param> |
| /// <param name="server">the Stitch server to retrieve the mirrors from</param> |
| /// <returns>a list of mirrors</returns> |
| public static IEnumerable<string> FetchStitchMirrors(Client client, string server) |
| { |
| // Set the server. |
| client.Server = server; |
| |
| // Set the mirror path |
| var mirrorsPath = @"/" + |
| string.Join(@"/", STITCH_CONSTANTS.UPDATE_PATH, STITCH_CONSTANTS.PROGRESSIVE_PATH, |
| STITCH_CONSTANTS.UPDATE_MIRRORS_FILE); |
| |
| using (var stream = client.Download(mirrorsPath).Result) |
| { |
| if (stream == null) |
| yield break; |
| |
| using (var streamReader = new StreamReader(stream)) |
| { |
| string mirror; |
| do |
| { |
| mirror = streamReader.ReadLine(); |
| |
| if (string.IsNullOrEmpty(mirror)) |
| continue; |
| |
| yield return mirror; |
| } while (!string.IsNullOrEmpty(mirror)); |
| } |
| } |
| } |
| |
| /// <summary> |
| /// Gets the distance to a mirror. |
| /// </summary> |
| /// <param name="localCity">the local city from where the method is invoked</param> |
| /// <param name="mirror">the mirror to get the distance to</param> |
| /// <returns>a key-value pair of mirror by distance</returns> |
| public static KeyValuePair<string, Distance> GetMirrorDistance(CityResponse localCity, string mirror) |
| { |
| // Check that the mirror has a proper URI. |
| Uri mirrorUri; |
| if (!Uri.TryCreate(mirror, UriKind.Absolute, out mirrorUri)) |
| return default(KeyValuePair<string, Distance>); |
| |
| // If we do not know the local city, then just return the mirror. |
| if (localCity == null) |
| return new KeyValuePair<string, Distance>(mirror, null); |
| |
| // Resolve the mirror hostname to an IP address. |
| IPAddress address; |
| try |
| { |
| address = Dns.GetHostAddresses(mirrorUri.Host).FirstOrDefault(); |
| } |
| catch (Exception) |
| { |
| return |
| new KeyValuePair<string, Distance>(mirror, null); |
| } |
| |
| // Resolve the IP address to a city response. |
| var remoteCity = address.GeoIPGetCity(); |
| if (remoteCity == null) |
| return new KeyValuePair<string, Distance>(mirror, null); |
| |
| // Compute the distance to the mirror. |
| switch (remoteCity.Location.HasCoordinates) |
| { |
| case true: |
| var local = new GeographicCoordinate(localCity.Location.Latitude.Value, |
| localCity.Location.Longitude.Value); |
| var remote = new GeographicCoordinate(remoteCity.Location.Latitude.Value, |
| remoteCity.Location.Longitude.Value); |
| return |
| new KeyValuePair<string, Distance>(mirror, local.HaversineDistanceTo(remote)); |
| default: |
| return |
| new KeyValuePair<string, Distance>(mirror, null); |
| } |
| } |
| } |
| } |
