//
// evtch:
// 1. 来自Zookeeper驱动通知
// 2. 该通知最终需要通过 evtbus 传递给其他人
//
func (top *Topology) doWatch(evtch <-chan topo.Event, evtbus chan interface{}) {
e := <-evtch
// http://wiki.apache.org/hadoop/ZooKeeper/FAQ
// 如何处理? 照理说不会发生的
if e.State == topo.StateExpired || e.Type == topo.EventNotWatching {
log.Warnf("session expired: %+v", e)
evtbus <- e
return
}
log.Warnf("topo event %+v", e)
switch e.Type {
//case topo.EventNodeCreated:
//case topo.EventNodeDataChanged:
case topo.EventNodeChildrenChanged: //only care children changed
//todo:get changed node and decode event
default:
// log.Warnf("%+v", e)
}
evtbus <- e
}
// 读取Frame的完整的数据，包含
func (p *TBufferedFramedTransport) ReadFrame() (frame []byte, err error) {
if p.FrameSize != 0 {
err = thrift.NewTTransportExceptionFromError(
fmt.Errorf("Unexpected frame size: %d", p.FrameSize))
return nil, err
}
var frameSize int
// Reader来自transport, 中间被封装了多长
frameSize, err = p.readFrameHeader()
if err != nil {
err1, ok := err.(thrift.TTransportException)
if ok {
err = thrift.NewTTransportException(err1.TypeId(),
fmt.Sprintf("Frame Header Read Error: %s", err1.Error()))
} else {
err = thrift.NewTTransportExceptionFromError(
fmt.Errorf("Frame Header Read Error: %s", err.Error()))
}
return
}
bytes := getSlice(frameSize, frameSize)
// 什么时候会出现?
// 1. 如果tcp package比较大，则容易出现package的一部分先到，另一部分随后再到
// 2. 在同一个机器上的两个进程之间出现的概率低(Time Delay小); 跨机器访问，出现概率高
var l int
l, err = io.ReadFull(p.Reader, bytes)
// l, err = p.Reader.Read(bytes)
if l != frameSize {
log.Warnf(Red("<==== ReadFrame frame size: %d, Got: %d"), frameSize, l)
}
if err != nil {
err1, ok := err.(thrift.TTransportException)
if ok {
err = thrift.NewTTransportException(err1.TypeId(),
fmt.Sprintf("Frame Data Read Error: %s", err1.Error()))
} else {
err = thrift.NewTTransportExceptionFromError(
fmt.Errorf("Frame Data Read Error: %s", err.Error()))
}
return nil, err
}
return bytes, nil
}
//
// evtch:
// 1. 来自Zookeeper驱动通知
// 2. 该通知最终需要通过 evtbus 传递给其他人
//
func (top *Topology) doWatch(evtch <-chan topo.Event, evtbus chan interface{}) {
e := <-evtch
if e.State == topo.StateExpired || e.Type == topo.EventNotWatching {
log.Panicf("session expired: %+v", e)
}
log.Warnf("topo event %+v", e)
switch e.Type {
//case topo.EventNodeCreated:
//case topo.EventNodeDataChanged:
case topo.EventNodeChildrenChanged: //only care children changed
//todo:get changed node and decode event
default:
// log.Warnf("%+v", e)
}
evtbus <- e
}
func (s *Session) Serve(d Dispatcher, maxPipeline int) {
var errlist errors.ErrorList
defer func() {
log.Infof(Red("==> Session Over: %s, Print Error List: %d Errors"),
s.RemoteAddress, errlist.Len())
// 只打印第一个Error
if err := errlist.First(); err != nil {
log.Infof("==> Session [%p] closed, Error = %v", s, err)
} else {
log.Infof("==> Session [%p] closed, Quit", s)
}
}()
// 来自connection的各种请求
tasks := make(chan *Request, maxPipeline)
go func() {
defer func() {
// 出现错误了，直接关闭Session
s.Close()
// 扔掉所有的Tasks
log.Warnf(Red("Session Closed, Abandon %d Tasks"), len(tasks))
for task := range tasks {
task.Recycle()
}
}()
if err := s.loopWriter(tasks); err != nil {
errlist.PushBack(err)
}
}()
defer close(tasks)
// 从Client读取用户的请求，然后再交给Dispatcher来处理
if err := s.loopReader(tasks, d); err != nil {
errlist.PushBack(err)
}
log.Info(Cyan("LoopReader Over, Session#Serve Over"))
}