Replace gorilla with melody for websocket API (#1205)

bridge/api/api.go

@@ -6,9 +6,10 @@ import (
 	"sync"
 	"time"
 
+	"gopkg.in/olahol/melody.v1"
+
 	"github.com/42wim/matterbridge/bridge"
 	"github.com/42wim/matterbridge/bridge/config"
-	"github.com/gorilla/websocket"
 	"github.com/labstack/echo/v4"
 	"github.com/labstack/echo/v4/middleware"
 	ring "github.com/zfjagann/golang-ring"
@@ -18,6 +19,7 @@ type API struct {
 	Messages ring.Ring
 	sync.RWMutex
 	*bridge.Config
+	mrouter *melody.Melody
 }
 
 type Message struct {
@@ -33,6 +35,32 @@ func New(cfg *bridge.Config) bridge.Bridger {
 	e := echo.New()
 	e.HideBanner = true
 	e.HidePort = true
+
+	b.mrouter = melody.New()
+	b.mrouter.HandleMessage(func(s *melody.Session, msg []byte) {
+		message := config.Message{}
+		err := json.Unmarshal(msg, &message)
+		if err != nil {
+			b.Log.Errorf("failed to decode message from byte[] '%s'", string(msg))
+			return
+		}
+		b.handleWebsocketMessage(message)
+	})
+	b.mrouter.HandleConnect(func(session *melody.Session) {
+		greet := b.getGreeting()
+		data, err := json.Marshal(greet)
+		if err != nil {
+			b.Log.Errorf("failed to encode message '%v'", greet)
+			return
+		}
+		err = session.Write(data)
+		if err != nil {
+			b.Log.Errorf("failed to write message '%s'", string(data))
+			return
+		}
+		// TODO: send message history buffer from `b.Messages` here
+	})
+
 	b.Messages = ring.Ring{}
 	if b.GetInt("Buffer") != 0 {
 		b.Messages.SetCapacity(b.GetInt("Buffer"))
@@ -67,13 +95,13 @@ func New(cfg *bridge.Config) bridge.Bridger {
 func (b *API) Connect() error {
 	return nil
 }
+
 func (b *API) Disconnect() error {
 	return nil
-
 }
+
 func (b *API) JoinChannel(channel config.ChannelInfo) error {
 	return nil
-
 }
 
 func (b *API) Send(msg config.Message) (string, error) {
@@ -83,7 +111,14 @@ func (b *API) Send(msg config.Message) (string, error) {
 	if msg.Event == config.EventMsgDelete {
 		return "", nil
 	}
-	b.Messages.Enqueue(&msg)
+	b.Log.Debugf("enqueueing message from %s on ring buffer", msg.Username)
+	b.Messages.Enqueue(msg)
+
+	data, err := json.Marshal(msg)
+	if err != nil {
+		b.Log.Errorf("failed to encode message  '%s'", msg)
+	}
+	_ = b.mrouter.Broadcast(data)
 	return "", nil
 }
 
@@ -131,6 +166,7 @@ func (b *API) handleStream(c echo.Context) error {
 	}
 	c.Response().Flush()
 	for {
+		// TODO: this causes issues, messages should be broadcasted to all connected clients
 		msg := b.Messages.Dequeue()
 		if msg != nil {
 			if err := json.NewEncoder(c.Response()).Encode(msg); err != nil {
@@ -153,40 +189,12 @@ func (b *API) handleWebsocketMessage(message config.Message) {
 	b.Remote <- message
 }
 
-func (b *API) writePump(conn *websocket.Conn) {
-	for {
-		msg := b.Messages.Dequeue()
-		if msg != nil {
-			err := conn.WriteJSON(msg)
-			if err != nil {
-				break
-			}
-		}
-	}
-}
-
-func (b *API) readPump(conn *websocket.Conn) {
-	for {
-		message := config.Message{}
-		err := conn.ReadJSON(&message)
-		if err != nil {
-			break
-		}
-		b.handleWebsocketMessage(message)
-	}
-}
-
 func (b *API) handleWebsocket(c echo.Context) error {
-	conn, err := websocket.Upgrade(c.Response().Writer, c.Request(), nil, 1024, 1024)
+	err := b.mrouter.HandleRequest(c.Response(), c.Request())
 	if err != nil {
+		b.Log.Errorf("error in websocket handling  '%v'", err)
 		return err
 	}
 
-	greet := b.getGreeting()
-	_ = conn.WriteJSON(greet)
-
-	go b.writePump(conn)
-	go b.readPump(conn)
-
 	return nil
 }

go.mod

@@ -50,6 +50,7 @@ require (
 	golang.org/x/image v0.0.0-20200618115811-c13761719519
 	golang.org/x/oauth2 v0.0.0-20200107190931-bf48bf16ab8d
 	gomod.garykim.dev/nc-talk v0.0.2
+	gopkg.in/olahol/melody.v1 v1.0.0-20170518105555-d52139073376
 )
 
 go 1.13

go.sum

@@ -928,6 +928,8 @@ gopkg.in/ini.v1 v1.55.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
 gopkg.in/mail.v2 v2.3.1/go.mod h1:htwXN1Qh09vZJ1NVKxQqHPBaCBbzKhp5GzuJEA4VJWw=
 gopkg.in/natefinch/lumberjack.v2 v2.0.0 h1:1Lc07Kr7qY4U2YPouBjpCLxpiyxIVoxqXgkXLknAOE8=
 gopkg.in/natefinch/lumberjack.v2 v2.0.0/go.mod h1:l0ndWWf7gzL7RNwBG7wST/UCcT4T24xpD6X8LsfU/+k=
+gopkg.in/olahol/melody.v1 v1.0.0-20170518105555-d52139073376 h1:sY2a+y0j4iDrajJcorb+a0hJIQ6uakU5gybjfLWHlXo=
+gopkg.in/olahol/melody.v1 v1.0.0-20170518105555-d52139073376/go.mod h1:BHKOc1m5wm8WwQkMqYBoo4vNxhmF7xg8+xhG8L+Cy3M=
 gopkg.in/olivere/elastic.v6 v6.2.30/go.mod h1:2cTT8Z+/LcArSWpCgvZqBgt3VOqXiy7v00w12Lz8bd4=
 gopkg.in/resty.v1 v1.12.0/go.mod h1:mDo4pnntr5jdWRML875a/NmxYqAlA73dVijT2AXvQQo=
 gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 h1:uRGJdciOHaEIrze2W8Q3AKkepLTh2hOroT7a+7czfdQ=

matterbridge.toml.sample

@@ -1540,6 +1540,8 @@ Buffer=1000
 
 #Bearer token used for authentication
 #curl -H "Authorization: Bearer token" http://localhost:4242/api/messages
+# https://github.com/vi/websocat
+# websocat -H="Authorization: Bearer token" ws://127.0.0.1:4242/api/websocket
 #OPTIONAL (no authorization if token is empty)
 Token="mytoken"
 

vendor/gopkg.in/olahol/melody.v1/.gitignore

@@ -0,0 +1,5 @@
+.DS_Store
+benchmark
+*.swp
+coverage.out
+Makefile

vendor/gopkg.in/olahol/melody.v1/.travis.yml

@@ -0,0 +1,10 @@
+language: go
+sudo: required
+go:
+- 1.6
+- 1.7
+- 1.8
+install:
+  - go get github.com/gorilla/websocket
+script:
+  - go test

vendor/gopkg.in/olahol/melody.v1/CHANGELOG.md

@@ -0,0 +1,44 @@
+## 2017-05-18
+
+* Fix `HandleSentMessageBinary`.
+
+## 2017-04-11
+
+* Allow any origin by default.
+* Add `BroadcastMultiple`.
+
+## 2017-04-09
+
+* Add control message support.
+* Add `IsClosed` to Session.
+
+## 2017-02-10
+
+* Return errors for some exposed methods.
+* Add `HandleRequestWithKeys`.
+* Add `HandleSentMessage` and `HandleSentMessageBinary`.
+
+## 2017-01-20
+
+* Add `Len()` to fetch number of connected sessions.
+
+## 2016-12-09
+
+* Add metadata management for sessions.
+
+## 2016-05-09
+
+* Add method `HandlePong` to melody instance.
+
+## 2015-10-07
+
+* Add broadcast methods for binary messages.
+
+## 2015-09-03
+
+* Add `Close` method to melody instance.
+
+### 2015-06-10
+
+* Support for binary messages.
+* BroadcastOthers method.

vendor/gopkg.in/olahol/melody.v1/LICENSE

@@ -0,0 +1,22 @@
+Copyright (c) 2015 Ola Holmström. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+  Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+  Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/gopkg.in/olahol/melody.v1/README.md

@@ -0,0 +1,185 @@
+# melody
+
+[![Build Status](https://travis-ci.org/olahol/melody.svg)](https://travis-ci.org/olahol/melody)
+[![Coverage Status](https://img.shields.io/coveralls/olahol/melody.svg?style=flat)](https://coveralls.io/r/olahol/melody)
+[![GoDoc](https://godoc.org/github.com/olahol/melody?status.svg)](https://godoc.org/github.com/olahol/melody)
+
+> :notes: Minimalist websocket framework for Go.
+
+Melody is websocket framework based on [github.com/gorilla/websocket](https://github.com/gorilla/websocket)
+that abstracts away the tedious parts of handling websockets. It gets out of
+your way so you can write real-time apps. Features include:
+
+* [x] Clear and easy interface similar to `net/http` or Gin.
+* [x] A simple way to broadcast to all or selected connected sessions.
+* [x] Message buffers making concurrent writing safe.
+* [x] Automatic handling of ping/pong and session timeouts.
+* [x] Store data on sessions.
+
+## Install
+
+```bash
+go get gopkg.in/olahol/melody.v1
+```
+
+## [Example: chat](https://github.com/olahol/melody/tree/master/examples/chat)
+
+[![Chat](https://cdn.rawgit.com/olahol/melody/master/examples/chat/demo.gif "Demo")](https://github.com/olahol/melody/tree/master/examples/chat)
+
+Using [Gin](https://github.com/gin-gonic/gin):
+```go
+package main
+
+import (
+	"github.com/gin-gonic/gin"
+	"gopkg.in/olahol/melody.v1"
+	"net/http"
+)
+
+func main() {
+	r := gin.Default()
+	m := melody.New()
+
+	r.GET("/", func(c *gin.Context) {
+		http.ServeFile(c.Writer, c.Request, "index.html")
+	})
+
+	r.GET("/ws", func(c *gin.Context) {
+		m.HandleRequest(c.Writer, c.Request)
+	})
+
+	m.HandleMessage(func(s *melody.Session, msg []byte) {
+		m.Broadcast(msg)
+	})
+
+	r.Run(":5000")
+}
+```
+
+Using [Echo](https://github.com/labstack/echo):
+```go
+package main
+
+import (
+	"github.com/labstack/echo"
+	"github.com/labstack/echo/engine/standard"
+	"github.com/labstack/echo/middleware"
+	"gopkg.in/olahol/melody.v1"
+	"net/http"
+)
+
+func main() {
+	e := echo.New()
+	m := melody.New()
+
+	e.Use(middleware.Logger())
+	e.Use(middleware.Recover())
+
+	e.GET("/", func(c echo.Context) error {
+		http.ServeFile(c.Response().(*standard.Response).ResponseWriter, c.Request().(*standard.Request).Request, "index.html")
+		return nil
+	})
+
+	e.GET("/ws", func(c echo.Context) error {
+		m.HandleRequest(c.Response().(*standard.Response).ResponseWriter, c.Request().(*standard.Request).Request)
+		return nil
+	})
+
+	m.HandleMessage(func(s *melody.Session, msg []byte) {
+		m.Broadcast(msg)
+	})
+
+	e.Run(standard.New(":5000"))
+}
+```
+
+## [Example: gophers](https://github.com/olahol/melody/tree/master/examples/gophers)
+
+[![Gophers](https://cdn.rawgit.com/olahol/melody/master/examples/gophers/demo.gif "Demo")](https://github.com/olahol/melody/tree/master/examples/gophers)
+
+```go
+package main
+
+import (
+	"github.com/gin-gonic/gin"
+	"gopkg.in/olahol/melody.v1"
+	"net/http"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+type GopherInfo struct {
+	ID, X, Y string
+}
+
+func main() {
+	router := gin.Default()
+	mrouter := melody.New()
+	gophers := make(map[*melody.Session]*GopherInfo)
+	lock := new(sync.Mutex)
+	counter := 0
+
+	router.GET("/", func(c *gin.Context) {
+		http.ServeFile(c.Writer, c.Request, "index.html")
+	})
+
+	router.GET("/ws", func(c *gin.Context) {
+		mrouter.HandleRequest(c.Writer, c.Request)
+	})
+
+	mrouter.HandleConnect(func(s *melody.Session) {
+		lock.Lock()
+		for _, info := range gophers {
+			s.Write([]byte("set " + info.ID + " " + info.X + " " + info.Y))
+		}
+		gophers[s] = &GopherInfo{strconv.Itoa(counter), "0", "0"}
+		s.Write([]byte("iam " + gophers[s].ID))
+		counter += 1
+		lock.Unlock()
+	})
+
+	mrouter.HandleDisconnect(func(s *melody.Session) {
+		lock.Lock()
+		mrouter.BroadcastOthers([]byte("dis "+gophers[s].ID), s)
+		delete(gophers, s)
+		lock.Unlock()
+	})
+
+	mrouter.HandleMessage(func(s *melody.Session, msg []byte) {
+		p := strings.Split(string(msg), " ")
+		lock.Lock()
+		info := gophers[s]
+		if len(p) == 2 {
+			info.X = p[0]
+			info.Y = p[1]
+			mrouter.BroadcastOthers([]byte("set "+info.ID+" "+info.X+" "+info.Y), s)
+		}
+		lock.Unlock()
+	})
+
+	router.Run(":5000")
+}
+```
+
+### [More examples](https://github.com/olahol/melody/tree/master/examples)
+
+## [Documentation](https://godoc.org/github.com/olahol/melody)
+
+## Contributors
+
+* Ola Holmström (@olahol)
+* Shogo Iwano (@shiwano)
+* Matt Caldwell (@mattcaldwell)
+* Heikki Uljas (@huljas)
+* Robbie Trencheny (@robbiet480)
+* yangjinecho (@yangjinecho)
+
+## FAQ
+
+If you are getting a `403` when trying  to connect to your websocket you can [change allow all origin hosts](http://godoc.org/github.com/gorilla/websocket#hdr-Origin_Considerations):
+
+```go
+m := melody.New()
+m.Upgrader.CheckOrigin = func(r *http.Request) bool { return true }
+```

vendor/gopkg.in/olahol/melody.v1/config.go

@@ -0,0 +1,22 @@
+package melody
+
+import "time"
+
+// Config melody configuration struct.
+type Config struct {
+	WriteWait         time.Duration // Milliseconds until write times out.
+	PongWait          time.Duration // Timeout for waiting on pong.
+	PingPeriod        time.Duration // Milliseconds between pings.
+	MaxMessageSize    int64         // Maximum size in bytes of a message.
+	MessageBufferSize int           // The max amount of messages that can be in a sessions buffer before it starts dropping them.
+}
+
+func newConfig() *Config {
+	return &Config{
+		WriteWait:         10 * time.Second,
+		PongWait:          60 * time.Second,
+		PingPeriod:        (60 * time.Second * 9) / 10,
+		MaxMessageSize:    512,
+		MessageBufferSize: 256,
+	}
+}

vendor/gopkg.in/olahol/melody.v1/doc.go

@@ -0,0 +1,22 @@
+// Copyright 2015 Ola Holmström. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package melody implements a framework for dealing with WebSockets.
+//
+// Example
+//
+// A broadcasting echo server:
+//
+//  func main() {
+//  	r := gin.Default()
+//  	m := melody.New()
+//  	r.GET("/ws", func(c *gin.Context) {
+//  		m.HandleRequest(c.Writer, c.Request)
+//  	})
+//  	m.HandleMessage(func(s *melody.Session, msg []byte) {
+//  		m.Broadcast(msg)
+//  	})
+//  	r.Run(":5000")
+//  }
+package melody

vendor/gopkg.in/olahol/melody.v1/envelope.go

@@ -0,0 +1,7 @@
+package melody
+
+type envelope struct {
+	t      int
+	msg    []byte
+	filter filterFunc
+}

vendor/gopkg.in/olahol/melody.v1/hub.go

@@ -0,0 +1,80 @@
+package melody
+
+import (
+	"sync"
+)
+
+type hub struct {
+	sessions   map[*Session]bool
+	broadcast  chan *envelope
+	register   chan *Session
+	unregister chan *Session
+	exit       chan *envelope
+	open       bool
+	rwmutex    *sync.RWMutex
+}
+
+func newHub() *hub {
+	return &hub{
+		sessions:   make(map[*Session]bool),
+		broadcast:  make(chan *envelope),
+		register:   make(chan *Session),
+		unregister: make(chan *Session),
+		exit:       make(chan *envelope),
+		open:       true,
+		rwmutex:    &sync.RWMutex{},
+	}
+}
+
+func (h *hub) run() {
+loop:
+	for {
+		select {
+		case s := <-h.register:
+			h.rwmutex.Lock()
+			h.sessions[s] = true
+			h.rwmutex.Unlock()
+		case s := <-h.unregister:
+			if _, ok := h.sessions[s]; ok {
+				h.rwmutex.Lock()
+				delete(h.sessions, s)
+				h.rwmutex.Unlock()
+			}
+		case m := <-h.broadcast:
+			h.rwmutex.RLock()
+			for s := range h.sessions {
+				if m.filter != nil {
+					if m.filter(s) {
+						s.writeMessage(m)
+					}
+				} else {
+					s.writeMessage(m)
+				}
+			}
+			h.rwmutex.RUnlock()
+		case m := <-h.exit:
+			h.rwmutex.Lock()
+			for s := range h.sessions {
+				s.writeMessage(m)
+				delete(h.sessions, s)
+				s.Close()
+			}
+			h.open = false
+			h.rwmutex.Unlock()
+			break loop
+		}
+	}
+}
+
+func (h *hub) closed() bool {
+	h.rwmutex.RLock()
+	defer h.rwmutex.RUnlock()
+	return !h.open
+}
+
+func (h *hub) len() int {
+	h.rwmutex.RLock()
+	defer h.rwmutex.RUnlock()
+
+	return len(h.sessions)
+}

vendor/gopkg.in/olahol/melody.v1/melody.go

@@ -0,0 +1,313 @@
+package melody
+
+import (
+	"errors"
+	"net/http"
+	"sync"
+
+	"github.com/gorilla/websocket"
+)
+
+// Close codes defined in RFC 6455, section 11.7.
+// Duplicate of codes from gorilla/websocket for convenience.
+const (
+	CloseNormalClosure           = 1000
+	CloseGoingAway               = 1001
+	CloseProtocolError           = 1002
+	CloseUnsupportedData         = 1003
+	CloseNoStatusReceived        = 1005
+	CloseAbnormalClosure         = 1006
+	CloseInvalidFramePayloadData = 1007
+	ClosePolicyViolation         = 1008
+	CloseMessageTooBig           = 1009
+	CloseMandatoryExtension      = 1010
+	CloseInternalServerErr       = 1011
+	CloseServiceRestart          = 1012
+	CloseTryAgainLater           = 1013
+	CloseTLSHandshake            = 1015
+)
+
+// Duplicate of codes from gorilla/websocket for convenience.
+var validReceivedCloseCodes = map[int]bool{
+	// see http://www.iana.org/assignments/websocket/websocket.xhtml#close-code-number
+
+	CloseNormalClosure:           true,
+	CloseGoingAway:               true,
+	CloseProtocolError:           true,
+	CloseUnsupportedData:         true,
+	CloseNoStatusReceived:        false,
+	CloseAbnormalClosure:         false,
+	CloseInvalidFramePayloadData: true,
+	ClosePolicyViolation:         true,
+	CloseMessageTooBig:           true,
+	CloseMandatoryExtension:      true,
+	CloseInternalServerErr:       true,
+	CloseServiceRestart:          true,
+	CloseTryAgainLater:           true,
+	CloseTLSHandshake:            false,
+}
+
+type handleMessageFunc func(*Session, []byte)
+type handleErrorFunc func(*Session, error)
+type handleCloseFunc func(*Session, int, string) error
+type handleSessionFunc func(*Session)
+type filterFunc func(*Session) bool
+
+// Melody implements a websocket manager.
+type Melody struct {
+	Config                   *Config
+	Upgrader                 *websocket.Upgrader
+	messageHandler           handleMessageFunc
+	messageHandlerBinary     handleMessageFunc
+	messageSentHandler       handleMessageFunc
+	messageSentHandlerBinary handleMessageFunc
+	errorHandler             handleErrorFunc
+	closeHandler             handleCloseFunc
+	connectHandler           handleSessionFunc
+	disconnectHandler        handleSessionFunc
+	pongHandler              handleSessionFunc
+	hub                      *hub
+}
+
+// New creates a new melody instance with default Upgrader and Config.
+func New() *Melody {
+	upgrader := &websocket.Upgrader{
+		ReadBufferSize:  1024,
+		WriteBufferSize: 1024,
+		CheckOrigin:     func(r *http.Request) bool { return true },
+	}
+
+	hub := newHub()
+
+	go hub.run()
+
+	return &Melody{
+		Config:                   newConfig(),
+		Upgrader:                 upgrader,
+		messageHandler:           func(*Session, []byte) {},
+		messageHandlerBinary:     func(*Session, []byte) {},
+		messageSentHandler:       func(*Session, []byte) {},
+		messageSentHandlerBinary: func(*Session, []byte) {},
+		errorHandler:             func(*Session, error) {},
+		closeHandler:             nil,
+		connectHandler:           func(*Session) {},
+		disconnectHandler:        func(*Session) {},
+		pongHandler:              func(*Session) {},
+		hub:                      hub,
+	}
+}
+
+// HandleConnect fires fn when a session connects.
+func (m *Melody) HandleConnect(fn func(*Session)) {
+	m.connectHandler = fn
+}
+
+// HandleDisconnect fires fn when a session disconnects.
+func (m *Melody) HandleDisconnect(fn func(*Session)) {
+	m.disconnectHandler = fn
+}
+
+// HandlePong fires fn when a pong is received from a session.
+func (m *Melody) HandlePong(fn func(*Session)) {
+	m.pongHandler = fn
+}
+
+// HandleMessage fires fn when a text message comes in.
+func (m *Melody) HandleMessage(fn func(*Session, []byte)) {
+	m.messageHandler = fn
+}
+
+// HandleMessageBinary fires fn when a binary message comes in.
+func (m *Melody) HandleMessageBinary(fn func(*Session, []byte)) {
+	m.messageHandlerBinary = fn
+}
+
+// HandleSentMessage fires fn when a text message is successfully sent.
+func (m *Melody) HandleSentMessage(fn func(*Session, []byte)) {
+	m.messageSentHandler = fn
+}
+
+// HandleSentMessageBinary fires fn when a binary message is successfully sent.
+func (m *Melody) HandleSentMessageBinary(fn func(*Session, []byte)) {
+	m.messageSentHandlerBinary = fn
+}
+
+// HandleError fires fn when a session has an error.
+func (m *Melody) HandleError(fn func(*Session, error)) {
+	m.errorHandler = fn
+}
+
+// HandleClose sets the handler for close messages received from the session.
+// The code argument to h is the received close code or CloseNoStatusReceived
+// if the close message is empty. The default close handler sends a close frame
+// back to the session.
+//
+// The application must read the connection to process close messages as
+// described in the section on Control Frames above.
+//
+// The connection read methods return a CloseError when a close frame is
+// received. Most applications should handle close messages as part of their
+// normal error handling. Applications should only set a close handler when the
+// application must perform some action before sending a close frame back to
+// the session.
+func (m *Melody) HandleClose(fn func(*Session, int, string) error) {
+	if fn != nil {
+		m.closeHandler = fn
+	}
+}
+
+// HandleRequest upgrades http requests to websocket connections and dispatches them to be handled by the melody instance.
+func (m *Melody) HandleRequest(w http.ResponseWriter, r *http.Request) error {
+	return m.HandleRequestWithKeys(w, r, nil)
+}
+
+// HandleRequestWithKeys does the same as HandleRequest but populates session.Keys with keys.
+func (m *Melody) HandleRequestWithKeys(w http.ResponseWriter, r *http.Request, keys map[string]interface{}) error {
+	if m.hub.closed() {
+		return errors.New("melody instance is closed")
+	}
+
+	conn, err := m.Upgrader.Upgrade(w, r, nil)
+
+	if err != nil {
+		return err
+	}
+
+	session := &Session{
+		Request: r,
+		Keys:    keys,
+		conn:    conn,
+		output:  make(chan *envelope, m.Config.MessageBufferSize),
+		melody:  m,
+		open:    true,
+		rwmutex: &sync.RWMutex{},
+	}
+
+	m.hub.register <- session
+
+	m.connectHandler(session)
+
+	go session.writePump()
+
+	session.readPump()
+
+	if !m.hub.closed() {
+		m.hub.unregister <- session
+	}
+
+	session.close()
+
+	m.disconnectHandler(session)
+
+	return nil
+}
+
+// Broadcast broadcasts a text message to all sessions.
+func (m *Melody) Broadcast(msg []byte) error {
+	if m.hub.closed() {
+		return errors.New("melody instance is closed")
+	}
+
+	message := &envelope{t: websocket.TextMessage, msg: msg}
+	m.hub.broadcast <- message
+
+	return nil
+}
+
+// BroadcastFilter broadcasts a text message to all sessions that fn returns true for.
+func (m *Melody) BroadcastFilter(msg []byte, fn func(*Session) bool) error {
+	if m.hub.closed() {
+		return errors.New("melody instance is closed")
+	}
+
+	message := &envelope{t: websocket.TextMessage, msg: msg, filter: fn}
+	m.hub.broadcast <- message
+
+	return nil
+}
+
+// BroadcastOthers broadcasts a text message to all sessions except session s.
+func (m *Melody) BroadcastOthers(msg []byte, s *Session) error {
+	return m.BroadcastFilter(msg, func(q *Session) bool {
+		return s != q
+	})
+}
+
+// BroadcastMultiple broadcasts a text message to multiple sessions given in the sessions slice.
+func (m *Melody) BroadcastMultiple(msg []byte, sessions []*Session) error {
+	for _, sess := range sessions {
+		if writeErr := sess.Write(msg); writeErr != nil {
+			return writeErr
+		}
+	}
+	return nil
+}
+
+// BroadcastBinary broadcasts a binary message to all sessions.
+func (m *Melody) BroadcastBinary(msg []byte) error {
+	if m.hub.closed() {
+		return errors.New("melody instance is closed")
+	}
+
+	message := &envelope{t: websocket.BinaryMessage, msg: msg}
+	m.hub.broadcast <- message
+
+	return nil
+}
+
+// BroadcastBinaryFilter broadcasts a binary message to all sessions that fn returns true for.
+func (m *Melody) BroadcastBinaryFilter(msg []byte, fn func(*Session) bool) error {
+	if m.hub.closed() {
+		return errors.New("melody instance is closed")
+	}
+
+	message := &envelope{t: websocket.BinaryMessage, msg: msg, filter: fn}
+	m.hub.broadcast <- message
+
+	return nil
+}
+
+// BroadcastBinaryOthers broadcasts a binary message to all sessions except session s.
+func (m *Melody) BroadcastBinaryOthers(msg []byte, s *Session) error {
+	return m.BroadcastBinaryFilter(msg, func(q *Session) bool {
+		return s != q
+	})
+}
+
+// Close closes the melody instance and all connected sessions.
+func (m *Melody) Close() error {
+	if m.hub.closed() {
+		return errors.New("melody instance is already closed")
+	}
+
+	m.hub.exit <- &envelope{t: websocket.CloseMessage, msg: []byte{}}
+
+	return nil
+}
+
+// CloseWithMsg closes the melody instance with the given close payload and all connected sessions.
+// Use the FormatCloseMessage function to format a proper close message payload.
+func (m *Melody) CloseWithMsg(msg []byte) error {
+	if m.hub.closed() {
+		return errors.New("melody instance is already closed")
+	}
+
+	m.hub.exit <- &envelope{t: websocket.CloseMessage, msg: msg}
+
+	return nil
+}
+
+// Len return the number of connected sessions.
+func (m *Melody) Len() int {
+	return m.hub.len()
+}
+
+// IsClosed returns the status of the melody instance.
+func (m *Melody) IsClosed() bool {
+	return m.hub.closed()
+}
+
+// FormatCloseMessage formats closeCode and text as a WebSocket close message.
+func FormatCloseMessage(closeCode int, text string) []byte {
+	return websocket.FormatCloseMessage(closeCode, text)
+}

vendor/gopkg.in/olahol/melody.v1/session.go

@@ -0,0 +1,219 @@
+package melody
+
+import (
+	"errors"
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/gorilla/websocket"
+)
+
+// Session wrapper around websocket connections.
+type Session struct {
+	Request *http.Request
+	Keys    map[string]interface{}
+	conn    *websocket.Conn
+	output  chan *envelope
+	melody  *Melody
+	open    bool
+	rwmutex *sync.RWMutex
+}
+
+func (s *Session) writeMessage(message *envelope) {
+	if s.closed() {
+		s.melody.errorHandler(s, errors.New("tried to write to closed a session"))
+		return
+	}
+
+	select {
+	case s.output <- message:
+	default:
+		s.melody.errorHandler(s, errors.New("session message buffer is full"))
+	}
+}
+
+func (s *Session) writeRaw(message *envelope) error {
+	if s.closed() {
+		return errors.New("tried to write to a closed session")
+	}
+
+	s.conn.SetWriteDeadline(time.Now().Add(s.melody.Config.WriteWait))
+	err := s.conn.WriteMessage(message.t, message.msg)
+
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (s *Session) closed() bool {
+	s.rwmutex.RLock()
+	defer s.rwmutex.RUnlock()
+
+	return !s.open
+}
+
+func (s *Session) close() {
+	if !s.closed() {
+		s.rwmutex.Lock()
+		s.open = false
+		s.conn.Close()
+		close(s.output)
+		s.rwmutex.Unlock()
+	}
+}
+
+func (s *Session) ping() {
+	s.writeRaw(&envelope{t: websocket.PingMessage, msg: []byte{}})
+}
+
+func (s *Session) writePump() {
+	ticker := time.NewTicker(s.melody.Config.PingPeriod)
+	defer ticker.Stop()
+
+loop:
+	for {
+		select {
+		case msg, ok := <-s.output:
+			if !ok {
+				break loop
+			}
+
+			err := s.writeRaw(msg)
+
+			if err != nil {
+				s.melody.errorHandler(s, err)
+				break loop
+			}
+
+			if msg.t == websocket.CloseMessage {
+				break loop
+			}
+
+			if msg.t == websocket.TextMessage {
+				s.melody.messageSentHandler(s, msg.msg)
+			}
+
+			if msg.t == websocket.BinaryMessage {
+				s.melody.messageSentHandlerBinary(s, msg.msg)
+			}
+		case <-ticker.C:
+			s.ping()
+		}
+	}
+}
+
+func (s *Session) readPump() {
+	s.conn.SetReadLimit(s.melody.Config.MaxMessageSize)
+	s.conn.SetReadDeadline(time.Now().Add(s.melody.Config.PongWait))
+
+	s.conn.SetPongHandler(func(string) error {
+		s.conn.SetReadDeadline(time.Now().Add(s.melody.Config.PongWait))
+		s.melody.pongHandler(s)
+		return nil
+	})
+
+	if s.melody.closeHandler != nil {
+		s.conn.SetCloseHandler(func(code int, text string) error {
+			return s.melody.closeHandler(s, code, text)
+		})
+	}
+
+	for {
+		t, message, err := s.conn.ReadMessage()
+
+		if err != nil {
+			s.melody.errorHandler(s, err)
+			break
+		}
+
+		if t == websocket.TextMessage {
+			s.melody.messageHandler(s, message)
+		}
+
+		if t == websocket.BinaryMessage {
+			s.melody.messageHandlerBinary(s, message)
+		}
+	}
+}
+
+// Write writes message to session.
+func (s *Session) Write(msg []byte) error {
+	if s.closed() {
+		return errors.New("session is closed")
+	}
+
+	s.writeMessage(&envelope{t: websocket.TextMessage, msg: msg})
+
+	return nil
+}
+
+// WriteBinary writes a binary message to session.
+func (s *Session) WriteBinary(msg []byte) error {
+	if s.closed() {
+		return errors.New("session is closed")
+	}
+
+	s.writeMessage(&envelope{t: websocket.BinaryMessage, msg: msg})
+
+	return nil
+}
+
+// Close closes session.
+func (s *Session) Close() error {
+	if s.closed() {
+		return errors.New("session is already closed")
+	}
+
+	s.writeMessage(&envelope{t: websocket.CloseMessage, msg: []byte{}})
+
+	return nil
+}
+
+// CloseWithMsg closes the session with the provided payload.
+// Use the FormatCloseMessage function to format a proper close message payload.
+func (s *Session) CloseWithMsg(msg []byte) error {
+	if s.closed() {
+		return errors.New("session is already closed")
+	}
+
+	s.writeMessage(&envelope{t: websocket.CloseMessage, msg: msg})
+
+	return nil
+}
+
+// Set is used to store a new key/value pair exclusivelly for this session.
+// It also lazy initializes s.Keys if it was not used previously.
+func (s *Session) Set(key string, value interface{}) {
+	if s.Keys == nil {
+		s.Keys = make(map[string]interface{})
+	}
+
+	s.Keys[key] = value
+}
+
+// Get returns the value for the given key, ie: (value, true).
+// If the value does not exists it returns (nil, false)
+func (s *Session) Get(key string) (value interface{}, exists bool) {
+	if s.Keys != nil {
+		value, exists = s.Keys[key]
+	}
+
+	return
+}
+
+// MustGet returns the value for the given key if it exists, otherwise it panics.
+func (s *Session) MustGet(key string) interface{} {
+	if value, exists := s.Get(key); exists {
+		return value
+	}
+
+	panic("Key \"" + key + "\" does not exist")
+}
+
+// IsClosed returns the status of the connection.
+func (s *Session) IsClosed() bool {
+	return s.closed()
+}

vendor/modules.txt

@@ -338,5 +338,7 @@ google.golang.org/protobuf/types/descriptorpb
 gopkg.in/ini.v1
 # gopkg.in/natefinch/lumberjack.v2 v2.0.0
 gopkg.in/natefinch/lumberjack.v2
+# gopkg.in/olahol/melody.v1 v1.0.0-20170518105555-d52139073376
+gopkg.in/olahol/melody.v1
 # gopkg.in/yaml.v2 v2.2.8
 gopkg.in/yaml.v2