poll.go

   1 package main
   2
   3 import (
   4         "github.com/anon55555/mt"
   5         "github.com/yuin/gopher-lua"
   6         "reflect"
   7         "time"
   8 )
   9
  10 func doPoll(l *lua.LState, clients []*Client) (*Client, *mt.Pkt, bool) {
  11         var timeout time.Duration
  12         hasTimeout := false
  13         if l.GetTop() > 1 {
  14                 timeout = time.Duration(float64(l.ToNumber(2)) * float64(time.Second))
  15                 hasTimeout = true
  16         }
  17
  18         cases := make([]reflect.SelectCase, 0, len(clients)+2)
  19         for _, client := range clients {
  20                 if client.state != csConnected {
  21                         continue
  22                 }
  23
  24                 cases = append(cases, reflect.SelectCase{
  25                         Dir:  reflect.SelectRecv,
  26                         Chan: reflect.ValueOf(client.queue),
  27                 })
  28         }
  29
  30         offset := len(cases)
  31
  32         if offset < 1 {
  33                 return nil, nil, false
  34         }
  35
  36         cases = append(cases, reflect.SelectCase{
  37                 Dir:  reflect.SelectRecv,
  38                 Chan: reflect.ValueOf(signalChannel()),
  39         })
  40
  41         if hasTimeout {
  42                 cases = append(cases, reflect.SelectCase{
  43                         Dir:  reflect.SelectRecv,
  44                         Chan: reflect.ValueOf(time.After(timeout)),
  45                 })
  46         }
  47
  48         idx, value, ok := reflect.Select(cases)
  49
  50         if idx >= offset {
  51                 return nil, nil, true
  52         }
  53
  54         client := clients[idx]
  55
  56         var pkt *mt.Pkt = nil
  57         if ok {
  58                 pkt = value.Interface().(*mt.Pkt)
  59         } else {
  60                 client.state = csDisconnected
  61         }
  62
  63         return client, pkt, false
  64 }