1  using Logging;
  2  
  3  namespace AutoClient
  4  {
  5      public class LoadBalancer
  6      {
  7          private readonly List<Cdx> instances;
  8          private readonly object instanceLock = new object();
  9  
 10          private class Cdx
 11          {
 12              private readonly ILog log;
 13              private readonly CodexWrapper instance;
 14              private readonly List<Action<CodexWrapper>> queue = new List<Action<CodexWrapper>>();
 15              private readonly object queueLock = new object();
 16              private bool running = true;
 17              private Task worker = Task.CompletedTask;
 18  
 19              public Cdx(App app, CodexWrapper instance)
 20              {
 21                  Id = instance.Node.GetName();
 22                  log = new LogPrefixer(app.Log, $"[Queue-{Id}]");
 23                  this.instance = instance;
 24              }
 25  
 26              public string Id { get; }
 27  
 28              public void Start()
 29              {
 30                  worker = Task.Run(Worker);
 31              }
 32  
 33              public void Stop()
 34              {
 35                  running = false;
 36                  worker.Wait();
 37              }
 38  
 39              public void CheckErrors()
 40              {
 41                  if (worker.IsFaulted) throw worker.Exception;
 42              }
 43  
 44              public void Queue(Action<CodexWrapper> action)
 45              {
 46                  if (queue.Count > 2) log.Log("Queue full. Waiting...");
 47                  while (queue.Count > 2)
 48                  {
 49                      Thread.Sleep(TimeSpan.FromSeconds(5.0));
 50                  }
 51  
 52                  lock (queueLock)
 53                  {
 54                      queue.Add(action);
 55                  }
 56              }
 57  
 58              private void Worker()
 59              {
 60                  try
 61                  {
 62                      while (running)
 63                      {
 64                          while (queue.Count == 0) Thread.Sleep(TimeSpan.FromSeconds(5.0));
 65  
 66                          Action<CodexWrapper> action = w => { };
 67                          lock (queueLock)
 68                          {
 69                              action = queue[0];
 70                              queue.RemoveAt(0);
 71                          }
 72  
 73                          action(instance);
 74                      }
 75                  }
 76                  catch (Exception ex)
 77                  {
 78                      log.Error("Exception in worker: " + ex);
 79                      throw;
 80                  }
 81              }
 82          }
 83  
 84          public LoadBalancer(App app, CodexWrapper[] instances)
 85          {
 86              this.instances = instances.Select(i => new Cdx(app, i)).ToList();
 87          }
 88  
 89          public void Start()
 90          {
 91              foreach (var i in instances) i.Start();
 92          }
 93  
 94          public void Stop()
 95          {
 96              foreach (var i in instances) i.Stop();
 97          }
 98  
 99          public void DispatchOnCodex(Action<CodexWrapper> action)
100          {
101              lock (instanceLock)
102              {
103                  var i = instances.First();
104                  instances.RemoveAt(0);
105                  instances.Add(i);
106  
107                  i.Queue(action);
108              }
109          }
110  
111          public void DispatchOnSpecificCodex(Action<CodexWrapper> action, string id)
112          {
113              lock (instanceLock)
114              {
115                  var i = instances.Single(a => a.Id == id);
116                  instances.Remove(i);
117                  instances.Add(i);
118  
119                  i.Queue(action);
120              }
121          }
122  
123          public void CheckErrors()
124          {
125              lock (instanceLock)
126              {
127                  foreach (var i in instances) i.CheckErrors();
128              }
129          }
130      }
131  }