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matterbridge/vendor/github.com/bwmarrin/discordgo/wsapi.go
2018-11-13 00:02:07 +01:00

887 lines
23 KiB
Go

// Discordgo - Discord bindings for Go
// Available at https://github.com/bwmarrin/discordgo
// Copyright 2015-2016 Bruce Marriner <bruce@sqls.net>. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// This file contains low level functions for interacting with the Discord
// data websocket interface.
package discordgo
import (
"bytes"
"compress/zlib"
"encoding/json"
"errors"
"fmt"
"io"
"net/http"
"runtime"
"sync/atomic"
"time"
"github.com/gorilla/websocket"
)
// ErrWSAlreadyOpen is thrown when you attempt to open
// a websocket that already is open.
var ErrWSAlreadyOpen = errors.New("web socket already opened")
// ErrWSNotFound is thrown when you attempt to use a websocket
// that doesn't exist
var ErrWSNotFound = errors.New("no websocket connection exists")
// ErrWSShardBounds is thrown when you try to use a shard ID that is
// less than the total shard count
var ErrWSShardBounds = errors.New("ShardID must be less than ShardCount")
type resumePacket struct {
Op int `json:"op"`
Data struct {
Token string `json:"token"`
SessionID string `json:"session_id"`
Sequence int64 `json:"seq"`
} `json:"d"`
}
// Open creates a websocket connection to Discord.
// See: https://discordapp.com/developers/docs/topics/gateway#connecting
func (s *Session) Open() error {
s.log(LogInformational, "called")
var err error
// Prevent Open or other major Session functions from
// being called while Open is still running.
s.Lock()
defer s.Unlock()
// If the websock is already open, bail out here.
if s.wsConn != nil {
return ErrWSAlreadyOpen
}
// Get the gateway to use for the Websocket connection
if s.gateway == "" {
s.gateway, err = s.Gateway()
if err != nil {
return err
}
// Add the version and encoding to the URL
s.gateway = s.gateway + "?v=" + APIVersion + "&encoding=json"
}
// Connect to the Gateway
s.log(LogInformational, "connecting to gateway %s", s.gateway)
header := http.Header{}
header.Add("accept-encoding", "zlib")
s.wsConn, _, err = websocket.DefaultDialer.Dial(s.gateway, header)
if err != nil {
s.log(LogWarning, "error connecting to gateway %s, %s", s.gateway, err)
s.gateway = "" // clear cached gateway
s.wsConn = nil // Just to be safe.
return err
}
s.wsConn.SetCloseHandler(func(code int, text string) error {
return nil
})
defer func() {
// because of this, all code below must set err to the error
// when exiting with an error :) Maybe someone has a better
// way :)
if err != nil {
s.wsConn.Close()
s.wsConn = nil
}
}()
// The first response from Discord should be an Op 10 (Hello) Packet.
// When processed by onEvent the heartbeat goroutine will be started.
mt, m, err := s.wsConn.ReadMessage()
if err != nil {
return err
}
e, err := s.onEvent(mt, m)
if err != nil {
return err
}
if e.Operation != 10 {
err = fmt.Errorf("expecting Op 10, got Op %d instead", e.Operation)
return err
}
s.log(LogInformational, "Op 10 Hello Packet received from Discord")
s.LastHeartbeatAck = time.Now().UTC()
var h helloOp
if err = json.Unmarshal(e.RawData, &h); err != nil {
err = fmt.Errorf("error unmarshalling helloOp, %s", err)
return err
}
// Now we send either an Op 2 Identity if this is a brand new
// connection or Op 6 Resume if we are resuming an existing connection.
sequence := atomic.LoadInt64(s.sequence)
if s.sessionID == "" && sequence == 0 {
// Send Op 2 Identity Packet
err = s.identify()
if err != nil {
err = fmt.Errorf("error sending identify packet to gateway, %s, %s", s.gateway, err)
return err
}
} else {
// Send Op 6 Resume Packet
p := resumePacket{}
p.Op = 6
p.Data.Token = s.Token
p.Data.SessionID = s.sessionID
p.Data.Sequence = sequence
s.log(LogInformational, "sending resume packet to gateway")
s.wsMutex.Lock()
err = s.wsConn.WriteJSON(p)
s.wsMutex.Unlock()
if err != nil {
err = fmt.Errorf("error sending gateway resume packet, %s, %s", s.gateway, err)
return err
}
}
// A basic state is a hard requirement for Voice.
// We create it here so the below READY/RESUMED packet can populate
// the state :)
// XXX: Move to New() func?
if s.State == nil {
state := NewState()
state.TrackChannels = false
state.TrackEmojis = false
state.TrackMembers = false
state.TrackRoles = false
state.TrackVoice = false
s.State = state
}
// Now Discord should send us a READY or RESUMED packet.
mt, m, err = s.wsConn.ReadMessage()
if err != nil {
return err
}
e, err = s.onEvent(mt, m)
if err != nil {
return err
}
if e.Type != `READY` && e.Type != `RESUMED` {
// This is not fatal, but it does not follow their API documentation.
s.log(LogWarning, "Expected READY/RESUMED, instead got:\n%#v\n", e)
}
s.log(LogInformational, "First Packet:\n%#v\n", e)
s.log(LogInformational, "We are now connected to Discord, emitting connect event")
s.handleEvent(connectEventType, &Connect{})
// A VoiceConnections map is a hard requirement for Voice.
// XXX: can this be moved to when opening a voice connection?
if s.VoiceConnections == nil {
s.log(LogInformational, "creating new VoiceConnections map")
s.VoiceConnections = make(map[string]*VoiceConnection)
}
// Create listening chan outside of listen, as it needs to happen inside the
// mutex lock and needs to exist before calling heartbeat and listen
// go rountines.
s.listening = make(chan interface{})
// Start sending heartbeats and reading messages from Discord.
go s.heartbeat(s.wsConn, s.listening, h.HeartbeatInterval)
go s.listen(s.wsConn, s.listening)
s.log(LogInformational, "exiting")
return nil
}
// listen polls the websocket connection for events, it will stop when the
// listening channel is closed, or an error occurs.
func (s *Session) listen(wsConn *websocket.Conn, listening <-chan interface{}) {
s.log(LogInformational, "called")
for {
messageType, message, err := wsConn.ReadMessage()
if err != nil {
// Detect if we have been closed manually. If a Close() has already
// happened, the websocket we are listening on will be different to
// the current session.
s.RLock()
sameConnection := s.wsConn == wsConn
s.RUnlock()
if sameConnection {
s.log(LogWarning, "error reading from gateway %s websocket, %s", s.gateway, err)
// There has been an error reading, close the websocket so that
// OnDisconnect event is emitted.
err := s.Close()
if err != nil {
s.log(LogWarning, "error closing session connection, %s", err)
}
s.log(LogInformational, "calling reconnect() now")
s.reconnect()
}
return
}
select {
case <-listening:
return
default:
s.onEvent(messageType, message)
}
}
}
type heartbeatOp struct {
Op int `json:"op"`
Data int64 `json:"d"`
}
type helloOp struct {
HeartbeatInterval time.Duration `json:"heartbeat_interval"`
Trace []string `json:"_trace"`
}
// FailedHeartbeatAcks is the Number of heartbeat intervals to wait until forcing a connection restart.
const FailedHeartbeatAcks time.Duration = 5 * time.Millisecond
// HeartbeatLatency returns the latency between heartbeat acknowledgement and heartbeat send.
func (s *Session) HeartbeatLatency() time.Duration {
return s.LastHeartbeatAck.Sub(s.LastHeartbeatSent)
}
// heartbeat sends regular heartbeats to Discord so it knows the client
// is still connected. If you do not send these heartbeats Discord will
// disconnect the websocket connection after a few seconds.
func (s *Session) heartbeat(wsConn *websocket.Conn, listening <-chan interface{}, heartbeatIntervalMsec time.Duration) {
s.log(LogInformational, "called")
if listening == nil || wsConn == nil {
return
}
var err error
ticker := time.NewTicker(heartbeatIntervalMsec * time.Millisecond)
defer ticker.Stop()
for {
s.RLock()
last := s.LastHeartbeatAck
s.RUnlock()
sequence := atomic.LoadInt64(s.sequence)
s.log(LogDebug, "sending gateway websocket heartbeat seq %d", sequence)
s.wsMutex.Lock()
s.LastHeartbeatSent = time.Now().UTC()
err = wsConn.WriteJSON(heartbeatOp{1, sequence})
s.wsMutex.Unlock()
if err != nil || time.Now().UTC().Sub(last) > (heartbeatIntervalMsec*FailedHeartbeatAcks) {
if err != nil {
s.log(LogError, "error sending heartbeat to gateway %s, %s", s.gateway, err)
} else {
s.log(LogError, "haven't gotten a heartbeat ACK in %v, triggering a reconnection", time.Now().UTC().Sub(last))
}
s.Close()
s.reconnect()
return
}
s.Lock()
s.DataReady = true
s.Unlock()
select {
case <-ticker.C:
// continue loop and send heartbeat
case <-listening:
return
}
}
}
// UpdateStatusData ia provided to UpdateStatusComplex()
type UpdateStatusData struct {
IdleSince *int `json:"since"`
Game *Game `json:"game"`
AFK bool `json:"afk"`
Status string `json:"status"`
}
type updateStatusOp struct {
Op int `json:"op"`
Data UpdateStatusData `json:"d"`
}
func newUpdateStatusData(idle int, gameType GameType, game, url string) *UpdateStatusData {
usd := &UpdateStatusData{
Status: "online",
}
if idle > 0 {
usd.IdleSince = &idle
}
if game != "" {
usd.Game = &Game{
Name: game,
Type: gameType,
URL: url,
}
}
return usd
}
// UpdateStatus is used to update the user's status.
// If idle>0 then set status to idle.
// If game!="" then set game.
// if otherwise, set status to active, and no game.
func (s *Session) UpdateStatus(idle int, game string) (err error) {
return s.UpdateStatusComplex(*newUpdateStatusData(idle, GameTypeGame, game, ""))
}
// UpdateStreamingStatus is used to update the user's streaming status.
// If idle>0 then set status to idle.
// If game!="" then set game.
// If game!="" and url!="" then set the status type to streaming with the URL set.
// if otherwise, set status to active, and no game.
func (s *Session) UpdateStreamingStatus(idle int, game string, url string) (err error) {
gameType := GameTypeGame
if url != "" {
gameType = GameTypeStreaming
}
return s.UpdateStatusComplex(*newUpdateStatusData(idle, gameType, game, url))
}
// UpdateListeningStatus is used to set the user to "Listening to..."
// If game!="" then set to what user is listening to
// Else, set user to active and no game.
func (s *Session) UpdateListeningStatus(game string) (err error) {
return s.UpdateStatusComplex(*newUpdateStatusData(0, GameTypeListening, game, ""))
}
// UpdateStatusComplex allows for sending the raw status update data untouched by discordgo.
func (s *Session) UpdateStatusComplex(usd UpdateStatusData) (err error) {
s.RLock()
defer s.RUnlock()
if s.wsConn == nil {
return ErrWSNotFound
}
s.wsMutex.Lock()
err = s.wsConn.WriteJSON(updateStatusOp{3, usd})
s.wsMutex.Unlock()
return
}
type requestGuildMembersData struct {
GuildID string `json:"guild_id"`
Query string `json:"query"`
Limit int `json:"limit"`
}
type requestGuildMembersOp struct {
Op int `json:"op"`
Data requestGuildMembersData `json:"d"`
}
// RequestGuildMembers requests guild members from the gateway
// The gateway responds with GuildMembersChunk events
// guildID : The ID of the guild to request members of
// query : String that username starts with, leave empty to return all members
// limit : Max number of items to return, or 0 to request all members matched
func (s *Session) RequestGuildMembers(guildID, query string, limit int) (err error) {
s.log(LogInformational, "called")
s.RLock()
defer s.RUnlock()
if s.wsConn == nil {
return ErrWSNotFound
}
data := requestGuildMembersData{
GuildID: guildID,
Query: query,
Limit: limit,
}
s.wsMutex.Lock()
err = s.wsConn.WriteJSON(requestGuildMembersOp{8, data})
s.wsMutex.Unlock()
return
}
// onEvent is the "event handler" for all messages received on the
// Discord Gateway API websocket connection.
//
// If you use the AddHandler() function to register a handler for a
// specific event this function will pass the event along to that handler.
//
// If you use the AddHandler() function to register a handler for the
// "OnEvent" event then all events will be passed to that handler.
func (s *Session) onEvent(messageType int, message []byte) (*Event, error) {
var err error
var reader io.Reader
reader = bytes.NewBuffer(message)
// If this is a compressed message, uncompress it.
if messageType == websocket.BinaryMessage {
z, err2 := zlib.NewReader(reader)
if err2 != nil {
s.log(LogError, "error uncompressing websocket message, %s", err)
return nil, err2
}
defer func() {
err3 := z.Close()
if err3 != nil {
s.log(LogWarning, "error closing zlib, %s", err)
}
}()
reader = z
}
// Decode the event into an Event struct.
var e *Event
decoder := json.NewDecoder(reader)
if err = decoder.Decode(&e); err != nil {
s.log(LogError, "error decoding websocket message, %s", err)
return e, err
}
s.log(LogDebug, "Op: %d, Seq: %d, Type: %s, Data: %s\n\n", e.Operation, e.Sequence, e.Type, string(e.RawData))
// Ping request.
// Must respond with a heartbeat packet within 5 seconds
if e.Operation == 1 {
s.log(LogInformational, "sending heartbeat in response to Op1")
s.wsMutex.Lock()
err = s.wsConn.WriteJSON(heartbeatOp{1, atomic.LoadInt64(s.sequence)})
s.wsMutex.Unlock()
if err != nil {
s.log(LogError, "error sending heartbeat in response to Op1")
return e, err
}
return e, nil
}
// Reconnect
// Must immediately disconnect from gateway and reconnect to new gateway.
if e.Operation == 7 {
s.log(LogInformational, "Closing and reconnecting in response to Op7")
s.Close()
s.reconnect()
return e, nil
}
// Invalid Session
// Must respond with a Identify packet.
if e.Operation == 9 {
s.log(LogInformational, "sending identify packet to gateway in response to Op9")
err = s.identify()
if err != nil {
s.log(LogWarning, "error sending gateway identify packet, %s, %s", s.gateway, err)
return e, err
}
return e, nil
}
if e.Operation == 10 {
// Op10 is handled by Open()
return e, nil
}
if e.Operation == 11 {
s.Lock()
s.LastHeartbeatAck = time.Now().UTC()
s.Unlock()
s.log(LogDebug, "got heartbeat ACK")
return e, nil
}
// Do not try to Dispatch a non-Dispatch Message
if e.Operation != 0 {
// But we probably should be doing something with them.
// TEMP
s.log(LogWarning, "unknown Op: %d, Seq: %d, Type: %s, Data: %s, message: %s", e.Operation, e.Sequence, e.Type, string(e.RawData), string(message))
return e, nil
}
// Store the message sequence
atomic.StoreInt64(s.sequence, e.Sequence)
// Map event to registered event handlers and pass it along to any registered handlers.
if eh, ok := registeredInterfaceProviders[e.Type]; ok {
e.Struct = eh.New()
// Attempt to unmarshal our event.
if err = json.Unmarshal(e.RawData, e.Struct); err != nil {
s.log(LogError, "error unmarshalling %s event, %s", e.Type, err)
}
// Send event to any registered event handlers for it's type.
// Because the above doesn't cancel this, in case of an error
// the struct could be partially populated or at default values.
// However, most errors are due to a single field and I feel
// it's better to pass along what we received than nothing at all.
// TODO: Think about that decision :)
// Either way, READY events must fire, even with errors.
s.handleEvent(e.Type, e.Struct)
} else {
s.log(LogWarning, "unknown event: Op: %d, Seq: %d, Type: %s, Data: %s", e.Operation, e.Sequence, e.Type, string(e.RawData))
}
// For legacy reasons, we send the raw event also, this could be useful for handling unknown events.
s.handleEvent(eventEventType, e)
return e, nil
}
// ------------------------------------------------------------------------------------------------
// Code related to voice connections that initiate over the data websocket
// ------------------------------------------------------------------------------------------------
type voiceChannelJoinData struct {
GuildID *string `json:"guild_id"`
ChannelID *string `json:"channel_id"`
SelfMute bool `json:"self_mute"`
SelfDeaf bool `json:"self_deaf"`
}
type voiceChannelJoinOp struct {
Op int `json:"op"`
Data voiceChannelJoinData `json:"d"`
}
// ChannelVoiceJoin joins the session user to a voice channel.
//
// gID : Guild ID of the channel to join.
// cID : Channel ID of the channel to join.
// mute : If true, you will be set to muted upon joining.
// deaf : If true, you will be set to deafened upon joining.
func (s *Session) ChannelVoiceJoin(gID, cID string, mute, deaf bool) (voice *VoiceConnection, err error) {
s.log(LogInformational, "called")
s.RLock()
voice, _ = s.VoiceConnections[gID]
s.RUnlock()
if voice == nil {
voice = &VoiceConnection{}
s.Lock()
s.VoiceConnections[gID] = voice
s.Unlock()
}
voice.Lock()
voice.GuildID = gID
voice.ChannelID = cID
voice.deaf = deaf
voice.mute = mute
voice.session = s
voice.Unlock()
// Send the request to Discord that we want to join the voice channel
data := voiceChannelJoinOp{4, voiceChannelJoinData{&gID, &cID, mute, deaf}}
s.wsMutex.Lock()
err = s.wsConn.WriteJSON(data)
s.wsMutex.Unlock()
if err != nil {
return
}
// doesn't exactly work perfect yet.. TODO
err = voice.waitUntilConnected()
if err != nil {
s.log(LogWarning, "error waiting for voice to connect, %s", err)
voice.Close()
return
}
return
}
// ChannelVoiceJoinManual initiates a voice session to a voice channel, but does not complete it.
//
// This should only be used when the VoiceServerUpdate will be intercepted and used elsewhere.
//
// gID : Guild ID of the channel to join.
// cID : Channel ID of the channel to join.
// mute : If true, you will be set to muted upon joining.
// deaf : If true, you will be set to deafened upon joining.
func (s *Session) ChannelVoiceJoinManual(gID, cID string, mute, deaf bool) (err error) {
s.log(LogInformational, "called")
// Send the request to Discord that we want to join the voice channel
data := voiceChannelJoinOp{4, voiceChannelJoinData{&gID, &cID, mute, deaf}}
s.wsMutex.Lock()
err = s.wsConn.WriteJSON(data)
s.wsMutex.Unlock()
if err != nil {
return
}
return
}
// onVoiceStateUpdate handles Voice State Update events on the data websocket.
func (s *Session) onVoiceStateUpdate(st *VoiceStateUpdate) {
// If we don't have a connection for the channel, don't bother
if st.ChannelID == "" {
return
}
// Check if we have a voice connection to update
s.RLock()
voice, exists := s.VoiceConnections[st.GuildID]
s.RUnlock()
if !exists {
return
}
// We only care about events that are about us.
if s.State.User.ID != st.UserID {
return
}
// Store the SessionID for later use.
voice.Lock()
voice.UserID = st.UserID
voice.sessionID = st.SessionID
voice.ChannelID = st.ChannelID
voice.Unlock()
}
// onVoiceServerUpdate handles the Voice Server Update data websocket event.
//
// This is also fired if the Guild's voice region changes while connected
// to a voice channel. In that case, need to re-establish connection to
// the new region endpoint.
func (s *Session) onVoiceServerUpdate(st *VoiceServerUpdate) {
s.log(LogInformational, "called")
s.RLock()
voice, exists := s.VoiceConnections[st.GuildID]
s.RUnlock()
// If no VoiceConnection exists, just skip this
if !exists {
return
}
// If currently connected to voice ws/udp, then disconnect.
// Has no effect if not connected.
voice.Close()
// Store values for later use
voice.Lock()
voice.token = st.Token
voice.endpoint = st.Endpoint
voice.GuildID = st.GuildID
voice.Unlock()
// Open a connection to the voice server
err := voice.open()
if err != nil {
s.log(LogError, "onVoiceServerUpdate voice.open, %s", err)
}
}
type identifyProperties struct {
OS string `json:"$os"`
Browser string `json:"$browser"`
Device string `json:"$device"`
Referer string `json:"$referer"`
ReferringDomain string `json:"$referring_domain"`
}
type identifyData struct {
Token string `json:"token"`
Properties identifyProperties `json:"properties"`
LargeThreshold int `json:"large_threshold"`
Compress bool `json:"compress"`
Shard *[2]int `json:"shard,omitempty"`
}
type identifyOp struct {
Op int `json:"op"`
Data identifyData `json:"d"`
}
// identify sends the identify packet to the gateway
func (s *Session) identify() error {
properties := identifyProperties{runtime.GOOS,
"Discordgo v" + VERSION,
"",
"",
"",
}
data := identifyData{s.Token,
properties,
250,
s.Compress,
nil,
}
if s.ShardCount > 1 {
if s.ShardID >= s.ShardCount {
return ErrWSShardBounds
}
data.Shard = &[2]int{s.ShardID, s.ShardCount}
}
op := identifyOp{2, data}
s.wsMutex.Lock()
err := s.wsConn.WriteJSON(op)
s.wsMutex.Unlock()
return err
}
func (s *Session) reconnect() {
s.log(LogInformational, "called")
var err error
if s.ShouldReconnectOnError {
wait := time.Duration(1)
for {
s.log(LogInformational, "trying to reconnect to gateway")
err = s.Open()
if err == nil {
s.log(LogInformational, "successfully reconnected to gateway")
// I'm not sure if this is actually needed.
// if the gw reconnect works properly, voice should stay alive
// However, there seems to be cases where something "weird"
// happens. So we're doing this for now just to improve
// stability in those edge cases.
s.RLock()
defer s.RUnlock()
for _, v := range s.VoiceConnections {
s.log(LogInformational, "reconnecting voice connection to guild %s", v.GuildID)
go v.reconnect()
// This is here just to prevent violently spamming the
// voice reconnects
time.Sleep(1 * time.Second)
}
return
}
// Certain race conditions can call reconnect() twice. If this happens, we
// just break out of the reconnect loop
if err == ErrWSAlreadyOpen {
s.log(LogInformational, "Websocket already exists, no need to reconnect")
return
}
s.log(LogError, "error reconnecting to gateway, %s", err)
<-time.After(wait * time.Second)
wait *= 2
if wait > 600 {
wait = 600
}
}
}
}
// Close closes a websocket and stops all listening/heartbeat goroutines.
// TODO: Add support for Voice WS/UDP connections
func (s *Session) Close() (err error) {
s.log(LogInformational, "called")
s.Lock()
s.DataReady = false
if s.listening != nil {
s.log(LogInformational, "closing listening channel")
close(s.listening)
s.listening = nil
}
// TODO: Close all active Voice Connections too
// this should force stop any reconnecting voice channels too
if s.wsConn != nil {
s.log(LogInformational, "sending close frame")
// To cleanly close a connection, a client should send a close
// frame and wait for the server to close the connection.
s.wsMutex.Lock()
err := s.wsConn.WriteMessage(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseNormalClosure, ""))
s.wsMutex.Unlock()
if err != nil {
s.log(LogInformational, "error closing websocket, %s", err)
}
// TODO: Wait for Discord to actually close the connection.
time.Sleep(1 * time.Second)
s.log(LogInformational, "closing gateway websocket")
err = s.wsConn.Close()
if err != nil {
s.log(LogInformational, "error closing websocket, %s", err)
}
s.wsConn = nil
}
s.Unlock()
s.log(LogInformational, "emit disconnect event")
s.handleEvent(disconnectEventType, &Disconnect{})
return
}