利用缓冲信道来实现网游帐号验证消息的分发和等待

type Msg struct {
    data []byte
    ch chan []byte
}

type Connection interface {
    Write([]byte)
    Read() []byte
}

type AccountServer struct {
    conn Connection // 与帐号数据库服务器的网络链接
    tokens chan chan []byte
    msg chan Msg
}

func NewAccountServer(conn Connection, maxclientcount int) *AccountServer {
    p := &AccountServer{}
    p.conn = conn 
    p.tokens = make(chan chan []byte, maxclientcount)
    p.msg = make(chan Msg, maxclientcount)
    for i := 0; i < maxclientcount; i++ {
        p.tokens <- make(chan []byte)
    }
    go p.run()
    return p
}

func (p *AccountServer) run() {
    rch := make(chan []byte)
    sch := make(chan []byte)
    go func() {
        for {p.conn.Write(<-sch)}
    }()
    go func() {
        for {rch <- p.conn.Read()}
    }()
    p.manage(sch, rch)
}

func (p *AccountServer) manage(sch chan<- []byte, rch <-chan []byte) {
    var id uint32
    players := make(map[uint32]chan []byte)
    for {
        select {
        case msg := <-p.msg:
            id++
            // 在数据包前面附上一个uint32，用于标识发送数据的玩家
            buff := make([]byte, 4+len(msg.data))
            buff[0] = byte(id & 0xff)
            buff[1] = byte((id >> 8) & 0xff)
            buff[2] = byte((id >> 16) & 0xff)
            buff[3] = byte((id >> 24) & 0xff)
            copy(buff[4:], msg.data)
            sch <- buff
            players[id] = msg.ch
        case data := <-rch:
            if len(data) <= 4 {
                break
            }
            // 从帐号数据库服务器返回的数据前四个字节会附带同样的uint32，，用于标识玩家
            var key uint32
            key = uint32(data[0])
            key |= uint32(data[1]) << 8
            key |= uint32(data[2]) << 16
            key |= uint32(data[3]) << 24
            ch, ok := players[key]
            if ok {
                ch <- data[4:]
            }
        }
    }
}
// 玩家对应的goroutine调用此函数向帐号服务器发送数据并等待返回
func (p *AccountServer) SendAndReceive(data []byte) []byte {
// 获取一个用于获取返回数据的信道
ch := <-p.tokens
// 回收信道
defer func() { p.tokens <- ch }()
p.msg <- Msg{data, ch}
return <-ch
}