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// Copyright (c) 2016-present Mattermost, Inc. All Rights Reserved.
// See License.txt for license information.
package model
import (
"encoding/json"
"net/http"
"time"
"github.com/gorilla/websocket"
)
const (
SOCKET_MAX_MESSAGE_SIZE_KB = 8 * 1024 // 8KB
PING_TIMEOUT_BUFFER_SECONDS = 5
)
type WebSocketClient struct {
Url string // The location of the server like "ws://localhost:8065"
ApiUrl string // The api location of the server like "ws://localhost:8065/api/v3"
ConnectUrl string // The websocket URL to connect to like "ws://localhost:8065/api/v3/path/to/websocket"
Conn *websocket.Conn // The WebSocket connection
AuthToken string // The token used to open the WebSocket
Sequence int64 // The ever-incrementing sequence attached to each WebSocket action
PingTimeoutChannel chan bool // The channel used to signal ping timeouts
EventChannel chan *WebSocketEvent
ResponseChannel chan *WebSocketResponse
ListenError *AppError
pingTimeoutTimer *time.Timer
}
// NewWebSocketClient constructs a new WebSocket client with convenience
// methods for talking to the server.
func NewWebSocketClient(url, authToken string) (*WebSocketClient, *AppError) {
return NewWebSocketClientWithDialer(websocket.DefaultDialer, url, authToken)
}
// NewWebSocketClientWithDialer constructs a new WebSocket client with convenience
// methods for talking to the server using a custom dialer.
func NewWebSocketClientWithDialer(dialer *websocket.Dialer, url, authToken string) (*WebSocketClient, *AppError) {
conn, _, err := dialer.Dial(url+API_URL_SUFFIX+"/websocket", nil)
if err != nil {
return nil, NewAppError("NewWebSocketClient", "model.websocket_client.connect_fail.app_error", nil, err.Error(), http.StatusInternalServerError)
}
client := &WebSocketClient{
url,
url + API_URL_SUFFIX,
url + API_URL_SUFFIX + "/websocket",
conn,
authToken,
1,
make(chan bool, 1),
make(chan *WebSocketEvent, 100),
make(chan *WebSocketResponse, 100),
nil,
nil,
}
client.configurePingHandling()
client.SendMessage(WEBSOCKET_AUTHENTICATION_CHALLENGE, map[string]interface{}{"token": authToken})
return client, nil
}
// NewWebSocketClient4 constructs a new WebSocket client with convenience
// methods for talking to the server. Uses the v4 endpoint.
func NewWebSocketClient4(url, authToken string) (*WebSocketClient, *AppError) {
return NewWebSocketClient4WithDialer(websocket.DefaultDialer, url, authToken)
}
// NewWebSocketClient4WithDialer constructs a new WebSocket client with convenience
// methods for talking to the server using a custom dialer. Uses the v4 endpoint.
func NewWebSocketClient4WithDialer(dialer *websocket.Dialer, url, authToken string) (*WebSocketClient, *AppError) {
return NewWebSocketClientWithDialer(dialer, url, authToken)
}
func (wsc *WebSocketClient) Connect() *AppError {
return wsc.ConnectWithDialer(websocket.DefaultDialer)
}
func (wsc *WebSocketClient) ConnectWithDialer(dialer *websocket.Dialer) *AppError {
var err error
wsc.Conn, _, err = dialer.Dial(wsc.ConnectUrl, nil)
if err != nil {
return NewAppError("Connect", "model.websocket_client.connect_fail.app_error", nil, err.Error(), http.StatusInternalServerError)
}
wsc.configurePingHandling()
wsc.EventChannel = make(chan *WebSocketEvent, 100)
wsc.ResponseChannel = make(chan *WebSocketResponse, 100)
wsc.SendMessage(WEBSOCKET_AUTHENTICATION_CHALLENGE, map[string]interface{}{"token": wsc.AuthToken})
return nil
}
func (wsc *WebSocketClient) Close() {
wsc.Conn.Close()
}
func (wsc *WebSocketClient) Listen() {
go func() {
defer func() {
wsc.Conn.Close()
close(wsc.EventChannel)
close(wsc.ResponseChannel)
}()
for {
var rawMsg json.RawMessage
var err error
if _, rawMsg, err = wsc.Conn.ReadMessage(); err != nil {
if !websocket.IsCloseError(err, websocket.CloseNormalClosure, websocket.CloseNoStatusReceived) {
wsc.ListenError = NewAppError("NewWebSocketClient", "model.websocket_client.connect_fail.app_error", nil, err.Error(), http.StatusInternalServerError)
}
return
}
var event WebSocketEvent
if err := json.Unmarshal(rawMsg, &event); err == nil && event.IsValid() {
wsc.EventChannel <- &event
continue
}
var response WebSocketResponse
if err := json.Unmarshal(rawMsg, &response); err == nil && response.IsValid() {
wsc.ResponseChannel <- &response
continue
}
}
}()
}
func (wsc *WebSocketClient) SendMessage(action string, data map[string]interface{}) {
req := &WebSocketRequest{}
req.Seq = wsc.Sequence
req.Action = action
req.Data = data
wsc.Sequence++
wsc.Conn.WriteJSON(req)
}
// UserTyping will push a user_typing event out to all connected users
// who are in the specified channel
func (wsc *WebSocketClient) UserTyping(channelId, parentId string) {
data := map[string]interface{}{
"channel_id": channelId,
"parent_id": parentId,
}
wsc.SendMessage("user_typing", data)
}
// GetStatuses will return a map of string statuses using user id as the key
func (wsc *WebSocketClient) GetStatuses() {
wsc.SendMessage("get_statuses", nil)
}
// GetStatusesByIds will fetch certain user statuses based on ids and return
// a map of string statuses using user id as the key
func (wsc *WebSocketClient) GetStatusesByIds(userIds []string) {
data := map[string]interface{}{
"user_ids": userIds,
}
wsc.SendMessage("get_statuses_by_ids", data)
}
func (wsc *WebSocketClient) configurePingHandling() {
wsc.Conn.SetPingHandler(wsc.pingHandler)
wsc.pingTimeoutTimer = time.NewTimer(time.Second * (60 + PING_TIMEOUT_BUFFER_SECONDS))
go wsc.pingWatchdog()
}
func (wsc *WebSocketClient) pingHandler(appData string) error {
if !wsc.pingTimeoutTimer.Stop() {
<-wsc.pingTimeoutTimer.C
}
wsc.pingTimeoutTimer.Reset(time.Second * (60 + PING_TIMEOUT_BUFFER_SECONDS))
wsc.Conn.WriteMessage(websocket.PongMessage, []byte{})
return nil
}
func (wsc *WebSocketClient) pingWatchdog() {
<-wsc.pingTimeoutTimer.C
wsc.PingTimeoutChannel <- true
}
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