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- using System;
- using System.Collections.Generic;
- using System.IO;
- using System.Linq;
- using System.Net;
- using System.Text;
- using Shadowsocks.Model;
- using System.IO;
- using System.Net.NetworkInformation;
- using System.Threading;
- using Shadowsocks.Model;
-
- namespace Shadowsocks.Controller.Strategy
- {
- class StatisticsStrategy : IStrategy
- {
- private readonly ShadowsocksController _controller;
- private Server _currentServer;
- private readonly Timer _timer;
- private Dictionary<string, StatisticsData> _statistics;
- private const int CachedInterval = 30*60*1000; //choose a new server every 30 minutes
- private const int RetryInterval = 2*60*1000; //choose a new server every 30 minutes
-
- public StatisticsStrategy(ShadowsocksController controller)
- {
- _controller = controller;
- var servers = controller.GetCurrentConfiguration().configs;
- var randomIndex = new Random().Next() % servers.Count();
- _currentServer = servers[randomIndex]; //choose a server randomly at first
- _timer = new Timer(ReloadStatisticsAndChooseAServer);
- }
-
- private void ReloadStatisticsAndChooseAServer(object obj)
- {
- Logging.Debug("Reloading statistics and choose a new server....");
- var servers = _controller.GetCurrentConfiguration().configs;
- LoadStatistics();
- ChooseNewServer(servers);
- }
-
- /*
- return a dict:
- {
- 'ServerFriendlyName1':StatisticsData,
- 'ServerFriendlyName2':...
- }
- */
- private void LoadStatistics()
- {
- try
- {
- var path = AvailabilityStatistics.AvailabilityStatisticsFile;
- Logging.Debug($"loading statistics from {path}");
- if (!File.Exists(path))
- {
- LogWhenEnabled($"statistics file does not exist, try to reload {RetryInterval} minutes later");
- _timer.Change(RetryInterval, CachedInterval);
- return;
- }
- _statistics = (from l in File.ReadAllLines(path)
- .Skip(1)
- let strings = l.Split(new[] { "," }, StringSplitOptions.RemoveEmptyEntries)
- let rawData = new
- {
- ServerName = strings[1],
- IPStatus = strings[2],
- RoundtripTime = int.Parse(strings[3])
- }
- group rawData by rawData.ServerName into server
- select new
- {
- ServerName = server.Key,
- data = new StatisticsData
- {
- SuccessTimes = server.Count(data => IPStatus.Success.ToString().Equals(data.IPStatus)),
- TimedOutTimes = server.Count(data => IPStatus.TimedOut.ToString().Equals(data.IPStatus)),
- AverageResponse = Convert.ToInt32(server.Average(data => data.RoundtripTime)),
- MinResponse = server.Min(data => data.RoundtripTime),
- MaxResponse = server.Max(data => data.RoundtripTime)
- }
- }).ToDictionary(server => server.ServerName, server => server.data);
- }
- catch (Exception e)
- {
- Logging.LogUsefulException(e);
- }
- }
-
- //return the score by data
- //server with highest score will be choosen
- private static double GetScore(StatisticsData data)
- {
- return (double)data.SuccessTimes / (data.SuccessTimes + data.TimedOutTimes); //simply choose min package loss
- }
-
- private class StatisticsData
- {
- public int SuccessTimes;
- public int TimedOutTimes;
- public int AverageResponse;
- public int MinResponse;
- public int MaxResponse;
- }
-
- private void ChooseNewServer(List<Server> servers)
- {
- if (_statistics == null || servers.Count == 0)
- {
- return;
- }
- try
- {
- var bestResult = (from server in servers
- let name = server.FriendlyName()
- where _statistics.ContainsKey(name)
- select new
- {
- server,
- score = GetScore(_statistics[name])
- }
- ).Aggregate((result1, result2) => result1.score > result2.score ? result1 : result2);
-
- if (!_currentServer.Equals(bestResult.server)) //output when enabled
- {
- LogWhenEnabled($"Switch to server: {bestResult.server.FriendlyName()} by package loss:{1 - bestResult.score}");
- }
- _currentServer = bestResult.server;
- }
- catch (Exception e)
- {
- Logging.LogUsefulException(e);
- }
- }
-
- private void LogWhenEnabled(string log)
- {
- if (_controller.GetCurrentStrategy()?.ID == ID) //output when enabled
- {
- Console.WriteLine(log);
- }
- }
-
- public string ID => "com.shadowsocks.strategy.scbs";
-
- public string Name => I18N.GetString("Choose By Total Package Loss");
-
- public Server GetAServer(IStrategyCallerType type, IPEndPoint localIPEndPoint)
- {
- var oldServer = _currentServer;
- if (oldServer == null)
- {
- ChooseNewServer(_controller.GetCurrentConfiguration().configs);
- }
- if (oldServer != _currentServer)
- {
- }
- return _currentServer; //current server cached for CachedInterval
- }
-
- public void ReloadServers()
- {
- ChooseNewServer(_controller.GetCurrentConfiguration().configs);
- _timer?.Change(0, CachedInterval);
- }
-
- public void SetFailure(Server server)
- {
- Logging.Debug($"failure: {server.FriendlyName()}");
- }
-
- public void UpdateLastRead(Server server)
- {
- //TODO: combine this part of data with ICMP statics
- }
-
- public void UpdateLastWrite(Server server)
- {
- //TODO: combine this part of data with ICMP statics
- }
-
- public void UpdateLatency(Server server, TimeSpan latency)
- {
- //TODO: combine this part of data with ICMP statics
- }
-
- }
- }
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