package queue

import(

"errors"

"container/list"

"sync"

)

var(

_lock=new (sync.Mutex) //互斥锁

Error_QueueIsEmpty=errors.New("queue is already empty") //队列为空

)

type QueueMemory struct{

queue *list.List

//类型 0:先入先出

queueType int

}

//入队

func(this *QueueMemory) Enqueue(msg *Message) error{

if this.queue==nil{

this.queue=list.New()

}

this.queue.PushBack(msg)

return nil

}

//出队

func(this *QueueMemory) Dequeue() (*Message,error){

if this.queue==nil || this.queue.Len()==0{

return nil,Error_QueueIsEmpty

}

var msg *Message

//判断队列类型

switch(this.queueType){

case 0: //先入先出

ele:=this.queue.Front()

_lock.Lock() //修改时使用 互斥锁

msg= this.queue.Remove(ele).(*Message)

_lock.Unlock()

break

}

return msg,nil

}

func(this *QueueMemory) Count() int{

if this.queue==nil{

return 0

}

return this.queue.Len()

}