nps/lib/mux/queue.go

96 lines
2.0 KiB
Go

package mux
import (
"container/list"
"github.com/cnlh/nps/lib/common"
"sync"
)
type Queue struct {
list *list.List
readOp chan struct{}
cleanOp chan struct{}
popWait bool
mutex sync.Mutex
}
func (Self *Queue) New() {
Self.list = list.New()
Self.readOp = make(chan struct{})
Self.cleanOp = make(chan struct{}, 2)
}
func (Self *Queue) Push(packager *common.MuxPackager) {
Self.mutex.Lock()
if Self.popWait {
defer Self.allowPop()
}
if packager.Flag == common.MUX_CONN_CLOSE {
Self.insert(packager) // the close package may need priority,
// prevent wait too long to close
} else {
Self.list.PushBack(packager)
}
Self.mutex.Unlock()
return
}
func (Self *Queue) allowPop() (closed bool) {
Self.mutex.Lock()
Self.popWait = false
Self.mutex.Unlock()
select {
case Self.readOp <- struct{}{}:
return false
case <-Self.cleanOp:
return true
}
}
func (Self *Queue) insert(packager *common.MuxPackager) {
element := Self.list.Back()
for {
if element == nil { // Queue dose not have any of msg package with this close package id
Self.list.PushFront(packager) // insert close package to first
break
}
if element.Value.(*common.MuxPackager).Flag == common.MUX_NEW_MSG &&
element.Value.(*common.MuxPackager).Id == packager.Id {
Self.list.InsertAfter(packager, element) // Queue has some msg package
// with this close package id, insert close package after last msg package
break
}
element = element.Prev()
}
}
func (Self *Queue) Pop() (packager *common.MuxPackager) {
Self.mutex.Lock()
element := Self.list.Front()
if element != nil {
packager = element.Value.(*common.MuxPackager)
Self.list.Remove(element)
Self.mutex.Unlock()
return
}
Self.popWait = true // Queue is empty, notice Push method
Self.mutex.Unlock()
select {
case <-Self.readOp:
return Self.Pop()
case <-Self.cleanOp:
return nil
}
}
func (Self *Queue) Len() (n int) {
n = Self.list.Len()
return
}
func (Self *Queue) Clean() {
Self.cleanOp <- struct{}{}
Self.cleanOp <- struct{}{}
close(Self.cleanOp)
}