poll.go

   1 package main
   2
   3 import (
   4         "github.com/Shopify/go-lua"
   5         "github.com/anon55555/mt"
   6         "reflect"
   7         "time"
   8 )
   9
  10 func l_poll(l *lua.State) int {
  11         clients := make([]*Client, 0)
  12
  13         lua.CheckType(l, 1, lua.TypeTable)
  14         i := 1
  15         for {
  16                 l.RawGetInt(1, i)
  17                 if l.IsNil(-1) {
  18                         l.Pop(1)
  19                         break
  20                 }
  21
  22                 clients = append(clients, l.ToUserData(-1).(*Client))
  23                 i++
  24         }
  25
  26         var timeout time.Duration
  27         hasTimeout := false
  28         if l.IsNumber(3) {
  29                 timeout = time.Duration(lua.CheckNumber(l, 3) * float64(time.Second))
  30                 hasTimeout = true
  31         }
  32
  33         for {
  34                 cases := make([]reflect.SelectCase, 0, len(clients)+2)
  35
  36                 for _, client := range clients {
  37                         if client.state != csConnected {
  38                                 continue
  39                         }
  40
  41                         cases = append(cases, reflect.SelectCase{
  42                                 Dir:  reflect.SelectRecv,
  43                                 Chan: reflect.ValueOf(client.queue),
  44                         })
  45                 }
  46
  47                 offset := len(cases)
  48
  49                 if offset < 1 {
  50                         l.PushBoolean(false)
  51                         return 1
  52                 }
  53
  54                 cases = append(cases, reflect.SelectCase{
  55                         Dir:  reflect.SelectRecv,
  56                         Chan: reflect.ValueOf(signalChannel()),
  57                 })
  58
  59                 if hasTimeout {
  60                         cases = append(cases, reflect.SelectCase{
  61                                 Dir:  reflect.SelectRecv,
  62                                 Chan: reflect.ValueOf(time.After(timeout)),
  63                         })
  64                 }
  65
  66                 idx, value, ok := reflect.Select(cases)
  67
  68                 if idx >= offset {
  69                         l.PushBoolean(true)
  70                         return 1
  71                 }
  72
  73                 client := clients[idx]
  74
  75                 var pkt *mt.Pkt = nil
  76                 if ok {
  77                         pkt = value.Interface().(*mt.Pkt)
  78                 } else {
  79                         client.state = csDisconnected
  80                 }
  81
  82                 for _, handler := range client.handlers {
  83                         handler.handle(pkt, l, idx+1)
  84                 }
  85         }
  86
  87         panic("impossible")
  88         return 0
  89 }