tinymq/line.go

package tinymq

import (
	"log"
	"net"
	"runtime/debug"
	"strings"
	"sync"
	"time"

	"git.me9.top/git/tinymq/config"
	"git.me9.top/git/tinymq/conn"
)

// 建立一个虚拟连接，包括生成命令，发送命令和响应命令

type Line struct {
	cf             *config.Config
	hub            *Hub
	conn           conn.Connect
	channel        string       // 连接对端的频道
	state          ConnectState // 连接状态
	host           *HostInfo    // 如果有值说明是客户端，就是主动连接端
	autoReconnect  bool         // 指示是否自动重连
	pingID         uint16       // 只有客户端使用
	pingWrongCount uint8        // 记录 ping id 反馈错误次数，超过3次则重新连接

	Extra sync.Map // 附加临时信息，由应用端决定具体内容，断线会自动清理
	Keep  sync.Map // 附加固定信息，由应用端决定具体内容，断线不会自动清理，不过也不能保证一直保持有值，断线后可能会被系统清理

	// 当前连接的管道
	sendRequest  chan *RequestData  // 发送请求数据
	sendResponse chan *ResponseData // 发送回应包
	pingRequest  chan *PingData     // Ping请求
	closeConnect chan bool          // 关闭连接信号，true表示外部进行关闭，false表示连接已经出问题或超时关闭

	lastRead time.Time // 记录最后一次读到数据的时间，在客户端如果超时则重连

	started time.Time // 开始时间
	updated time.Time // 更新时间
}

// 获取当前连接信息
func (c *Line) Host() *HostInfo {
	return c.host
}

// 获取开始时间
func (c *Line) Started() time.Time {
	return c.started
}

// 获取更新时间
func (c *Line) Updated() time.Time {
	return c.updated
}

// 获取当前连接状态
func (c *Line) State() ConnectState {
	return c.state
}

// 获取频道名
func (c *Line) Channel() string {
	return c.channel
}

// 设置频道名
// 检查是否包含@，只替换@前面部分
func (c *Line) SetChannelName(name string) {
	if strings.Contains(name, "@") {
		c.channel = name
	} else {
		if inx := strings.Index(c.channel, "@"); inx >= 0 {
			c.channel = name + c.channel[inx:]
		} else {
			c.channel = name + "@" + c.channel
		}
	}
}

// 删除频道名，用于退出登录等操作
func (c *Line) RemoveChannelName() {
	if inx := strings.Index(c.channel, "@"); inx >= 0 {
		c.channel = c.channel[inx+1:]
	}
}

// 频道是否相等，不包括@前面部分和参数部分
func (c *Line) IsChannelEqual(channel string) bool {
	if inx := strings.Index(channel, "@"); inx >= 0 {
		channel = channel[inx+1:]
	}
	if inx := strings.Index(channel, "?"); inx > 0 {
		channel = channel[0:inx]
	}
	origin := c.channel
	if inx := strings.Index(origin, "@"); inx >= 0 {
		origin = origin[inx+1:]
	}
	if inx := strings.Index(origin, "?"); inx > 0 {
		origin = origin[0:inx]
	}
	return channel == origin
}

// 获取远程的地址
func (c *Line) RemoteIP() net.IP {
	if c.state == Connected {
		return c.conn.RemoteIP()
	} else {
		return nil
	}
}

// 获取本地的地址
func (c *Line) LocalIP() net.IP {
	if c.state == Connected {
		return c.conn.LocalIP()
	} else {
		return nil
	}
}

// 获取通讯消息ID号
func (c *Line) getPingID() uint16 {
	c.pingID++
	if c.pingID <= 0 || c.pingID >= config.ID_MAX {
		c.pingID = 1
	}
	return c.pingID
}

// 读信息循环通道，采用新线程
func (c *Line) readPump() {
	for {
		msgType, id, cmd, state, data, err := c.conn.ReadMessage(c.cf.LongReadWait)
		if err != nil {
			if !strings.Contains(err.Error(), "EOF") {
				log.Println("[readPump]", err)
			}
			c.Close(false)
			return
		}
		// 记录最后读到数据的时间
		c.lastRead = time.Now()
		switch msgType {
		case conn.PingMsg:
			// ping或pong包
			c.pingRequest <- &PingData{
				Id: id,
			}
		case conn.RequestMsg:
			// 请求数据包
			go c.hub.requestFromNet(&RequestData{
				Id:   id,
				Cmd:  cmd,
				Data: data,
				conn: c,
			})
		case conn.ResponseMsg:
			// 网络回应数据包
			go c.hub.outResponse(&ResponseData{
				Id:    id,
				State: state & 0x7F,
				Data:  data,
				conn:  c,
			})
		}
	}
}

// 检查管道并处理不同的消息，新go程调用
// 为了防止多线程的冲突，主要的处理都在这里进行
func (c *Line) writePump() {
	pingTicker := time.NewTicker(time.Duration(c.cf.PingInterval * int(time.Millisecond)))
	// 定义恢复函数
	defer func() {
		pingTicker.Stop()
		c.conn.Close()
		// 检查是否需要重新连接
		if c.autoReconnect && c.host != nil && c.state != Closed && c.state != Connected {
			go func() {
				defer func() {
					if err := recover(); err != nil {
						c.state = Disconnected
						log.Println(err)
						debug.PrintStack()
					}
				}()
				c.host.Errors++
				c.host.Updated = time.Now()

				delay := 5 * time.Second * time.Duration(c.host.Errors)
				log.Println("[Line] will reconnect with delay:", delay)
				time.Sleep(delay)
				if c.host.Errors < 2 {
					c.hub.ConnectToServerX(c.channel, false, c.host)
				} else {
					c.hub.ConnectToServerX(c.channel, false, nil)
				}
			}()
		}
	}()
	// 清空closeConnect
	c.cleanClose()
	// 开始处理信息循环
	for {
		select {
		case request := <-c.sendRequest: // 发送请求包
			err := c.conn.WriteRequest(request.Id, request.Cmd, request.Data)
			if err != nil {
				log.Println("[writePump WriteRequest]", err)
				return
			}
		case response := <-c.sendResponse: // 接收到的响应包
			// 发送响应数据
			err := c.conn.WriteResponse(response.Id, response.State, response.Data)
			if err != nil {
				log.Println("[writePump WriteResponse]", err)
				return
			}
		case ping := <-c.pingRequest: // 发送ping包到网络
			if c.cf.PrintPing {
				log.Println("[PING]<-", c.channel, ping.Id)
			}
			// 只有服务器端需要回应ping包
			if c.host == nil {
				if c.cf.PrintPing {
					log.Println("[RESP PING]->", c.channel, ping.Id)
				}
				err := c.conn.WritePing(ping.Id)
				if err != nil {
					log.Println("[ping] failed", err)
					return
				}
			} else {
				// 检查 ping id 是否正确
				if c.pingID == ping.Id {
					c.pingWrongCount = 0
				} else {
					c.pingWrongCount++
					if c.pingWrongCount > 3 {
						log.Println("[wrong ping id]", ping.Id)
						c.Close(false)
						return
					}
				}
			}
		case <-pingTicker.C:
			// 检查是否已经很久时间没有使用连接了
			dr := time.Since(c.lastRead)
			if dr > time.Duration(c.cf.PingInterval*3*int(time.Millisecond)) {
				// 超时关闭当前的连接
				log.Println("[Connect timeout]", c.channel)
				// 有可能连接出现问题，断开并重新连接
				// 检测到浏览器会出现休眠的状态，服务端就不主动关闭，只有客户端关闭
				if c.host != nil {
					c.Close(false)
					return
				}
			}
			// 只需要客户端发送
			if c.host != nil {
				// 发送ping包
				if dr >= time.Duration(c.cf.PingInterval*int(time.Millisecond)) {
					id := c.getPingID()
					// 发送ping数据包
					if c.cf.PrintPing {
						log.Println("[SEND PING]->", c.channel, id)
					}
					err := c.conn.WritePing(id)
					if err != nil {
						log.Println("[writePump WritePing]", err)
						return
					}
				}
			}
		case <-c.closeConnect:
			c.cleanClose()
			// 退出循环
			return
		}
	}
}

// 关闭连接
func (c *Line) Close(quick bool) {
	defer recover() //避免管道已经关闭而引起panic
	c.conn.Close()
	c.closeConnect <- quick
	if quick {
		if c.state != Closed {
			c.state = Closed
			c.hub.connectStatusFunc(c)
		}
		c.hub.removeLine(c)
	} else {
		if c.state != Disconnected {
			c.state = Disconnected
			c.hub.connectStatusFunc(c)
			go c.hub.cleanDeadConnect()
		}
	}
	c.Extra.Clear()
	c.updated = time.Now()
}

// 清空余留下来的管道消息
func (c *Line) cleanClose() {
	for {
		select {
		case <-c.closeConnect:
		default:
			return
		}
	}
}

// 连接开始运行
func (c *Line) Start(channel string, conn conn.Connect, host *HostInfo) {
	now := time.Now()
	c.updated = now
	c.lastRead = now // 避免默认为0时被清理
	c.channel = channel
	c.conn = conn
	c.host = host
	c.state = Connected
	go c.readPump()
	go c.writePump()
	c.hub.connectStatusFunc(c)
}

// 请求入口函数
func NewConnect(
	cf *config.Config,
	hub *Hub,
	channel string,
	conn conn.Connect,
	host *HostInfo,
	autoReconnect bool,
) *Line {
	now := time.Now()
	cc := &Line{
		cf:            cf,
		channel:       channel,
		hub:           hub,
		pingID:        uint16(now.UnixNano()) % config.ID_MAX,
		autoReconnect: autoReconnect,

		sendRequest:  make(chan *RequestData, 32),
		sendResponse: make(chan *ResponseData, 32),
		pingRequest:  make(chan *PingData, 5),
		closeConnect: make(chan bool, 5),

		lastRead: now, // 避免默认为0时被清理
		started:  now,
		updated:  now,
	}
	cc.Start(channel, conn, host)
	return cc
}