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connection.go
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connection.go
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package websocket
import (
"bytes"
"errors"
"io"
"net"
"net/http"
"strconv"
"sync"
"time"
"github.com/gorilla/websocket"
)
type (
connectionValue struct {
key []byte
value interface{}
}
// ConnectionValues is the temporary connection's memory store
ConnectionValues []connectionValue
)
// Set sets a value based on the key
func (r *ConnectionValues) Set(key string, value interface{}) {
args := *r
n := len(args)
for i := 0; i < n; i++ {
kv := &args[i]
if string(kv.key) == key {
kv.value = value
return
}
}
c := cap(args)
if c > n {
args = args[:n+1]
kv := &args[n]
kv.key = append(kv.key[:0], key...)
kv.value = value
*r = args
return
}
kv := connectionValue{}
kv.key = append(kv.key[:0], key...)
kv.value = value
*r = append(args, kv)
}
// Get returns a value based on its key
func (r *ConnectionValues) Get(key string) interface{} {
args := *r
n := len(args)
for i := 0; i < n; i++ {
kv := &args[i]
if string(kv.key) == key {
return kv.value
}
}
return nil
}
// Reset clears the values
func (r *ConnectionValues) Reset() {
*r = (*r)[:0]
}
// UnderlineConnection is the underline connection, nothing to think about,
// it's used internally mostly but can be used for extreme cases with other libraries.
type UnderlineConnection interface {
// SetWriteDeadline sets the write deadline on the underlying network
// connection. After a write has timed out, the websocket state is corrupt and
// all future writes will return an error. A zero value for t means writes will
// not time out.
SetWriteDeadline(t time.Time) error
// SetReadDeadline sets the read deadline on the underlying network connection.
// After a read has timed out, the websocket connection state is corrupt and
// all future reads will return an error. A zero value for t means reads will
// not time out.
SetReadDeadline(t time.Time) error
// SetReadLimit sets the maximum size for a message read from the peer. If a
// message exceeds the limit, the connection sends a close frame to the peer
// and returns ErrReadLimit to the application.
SetReadLimit(limit int64)
// SetPongHandler sets the handler for pong messages received from the peer.
// The appData argument to h is the PONG frame application data. The default
// pong handler does nothing.
SetPongHandler(h func(appData string) error)
// SetPingHandler sets the handler for ping messages received from the peer.
// The appData argument to h is the PING frame application data. The default
// ping handler sends a pong to the peer.
SetPingHandler(h func(appData string) error)
// WriteControl writes a control message with the given deadline. The allowed
// message types are CloseMessage, PingMessage and PongMessage.
WriteControl(messageType int, data []byte, deadline time.Time) error
// WriteMessage is a helper method for getting a writer using NextWriter,
// writing the message and closing the writer.
WriteMessage(messageType int, data []byte) error
// ReadMessage is a helper method for getting a reader using NextReader and
// reading from that reader to a buffer.
ReadMessage() (messageType int, p []byte, err error)
// NextWriter returns a writer for the next message to send. The writer's Close
// method flushes the complete message to the network.
//
// There can be at most one open writer on a connection. NextWriter closes the
// previous writer if the application has not already done so.
NextWriter(messageType int) (io.WriteCloser, error)
// Close closes the underlying network connection without sending or waiting for a close frame.
Close() error
}
// -------------------------------------------------------------------------------------
// -------------------------------------------------------------------------------------
// -------------------------------Connection implementation-----------------------------
// -------------------------------------------------------------------------------------
// -------------------------------------------------------------------------------------
type (
// DisconnectFunc is the callback which is fired when a client/connection closed
DisconnectFunc func()
// LeaveRoomFunc is the callback which is fired when a client/connection leaves from any room.
// This is called automatically when client/connection disconnected
// (because websocket server automatically leaves from all joined rooms)
LeaveRoomFunc func(roomName string)
// ErrorFunc is the callback which fires whenever an error occurs
ErrorFunc (func(error))
// NativeMessageFunc is the callback for native websocket messages, receives one []byte parameter which is the raw client's message
NativeMessageFunc func([]byte)
// MessageFunc is the second argument to the Emitter's Emit functions.
// A callback which should receives one parameter of type string, int, bool or any valid JSON/Go struct
MessageFunc interface{}
// PingFunc is the callback which fires each ping
PingFunc func()
// PongFunc is the callback which fires on pong message received
PongFunc func()
// Connection is the front-end API that you will use to communicate with the client side
Connection interface {
// Emitter implements EmitMessage & Emit
Emitter
// Err is not nil if the upgrader failed to upgrade http to websocket connection.
Err() error
// ID returns the connection's identifier
ID() string
// Request returns the http.Request ptr of the original http
// request.
Request() *http.Request
// Server returns the websocket server instance
// which this connection is listening to.
//
// Its connection-relative operations are safe for use.
Server() *Server
// Write writes a raw websocket message with a specific type to the client
// used by ping messages and any CloseMessage types.
Write(websocketMessageType int, data []byte) error
// OnDisconnect registers a callback which is fired when this connection is closed by an error or manual
OnDisconnect(DisconnectFunc)
// OnError registers a callback which fires when this connection occurs an error
OnError(ErrorFunc)
// OnPing registers a callback which fires on each ping
OnPing(PingFunc)
// OnPong registers a callback which fires on pong message received
OnPong(PongFunc)
// FireOnError can be used to send a custom error message to the connection
//
// It does nothing more than firing the OnError listeners. It doesn't send anything to the client.
FireOnError(err error)
// To defines on what "room" (see Join) the server should send a message
// returns an Emmiter(`EmitMessage` & `Emit`) to send messages.
To(string) Emitter
// OnMessage registers a callback which fires when native websocket message received
OnMessage(NativeMessageFunc)
// On registers a callback to a particular event which is fired when a message to this event is received
On(string, MessageFunc)
// Join registers this connection to a room, if it doesn't exist then it creates a new. One room can have one or more connections. One connection can be joined to many rooms. All connections are joined to a room specified by their `ID` automatically.
Join(string)
// IsJoined returns true when this connection is joined to the room, otherwise false.
// It Takes the room name as its input parameter.
IsJoined(roomName string) bool
// Leave removes this connection entry from a room
// Returns true if the connection has actually left from the particular room.
Leave(string) bool
// OnLeave registers a callback which fires when this connection left from any joined room.
// This callback is called automatically on Disconnected client, because websocket server automatically
// deletes the disconnected connection from any joined rooms.
//
// Note: the callback(s) called right before the server deletes the connection from the room
// so the connection theoretical can still send messages to its room right before it is being disconnected.
OnLeave(roomLeaveCb LeaveRoomFunc)
// Wait starts the pinger and the messages reader,
// it's named as "Wait" because it should be called LAST,
// after the "On" events IF server's `Upgrade` is used,
// otherise you don't have to call it because the `Handler()` does it automatically.
Wait()
// Disconnect disconnects the client, close the underline websocket conn and removes it from the conn list
// returns the error, if any, from the underline connection
Disconnect() error
// SetValue sets a key-value pair on the connection's mem store.
SetValue(key string, value interface{})
// GetValue gets a value by its key from the connection's mem store.
GetValue(key string) interface{}
// GetValueArrString gets a value as []string by its key from the connection's mem store.
GetValueArrString(key string) []string
// GetValueString gets a value as string by its key from the connection's mem store.
GetValueString(key string) string
// GetValueInt gets a value as integer by its key from the connection's mem store.
GetValueInt(key string) int
}
connection struct {
err error
underline UnderlineConnection
id string
messageType int
disconnected bool
onDisconnectListeners []DisconnectFunc
onRoomLeaveListeners []LeaveRoomFunc
onErrorListeners []ErrorFunc
onPingListeners []PingFunc
onPongListeners []PongFunc
onNativeMessageListeners []NativeMessageFunc
onEventListeners map[string][]MessageFunc
started bool
// these were maden for performance only
self Emitter // pre-defined emitter than sends message to its self client
broadcast Emitter // pre-defined emitter that sends message to all except this
all Emitter // pre-defined emitter which sends message to all clients
values ConnectionValues
request *http.Request
server *Server
// #119 , websocket writers are not protected by locks inside the gorilla's websocket code
// so we must protect them otherwise we're getting concurrent connection error on multi writers in the same time.
writerMu sync.Mutex
// same exists for reader look here: https://godoc.org/github.com/gorilla/websocket#hdr-Control_Messages
// but we only use one reader in one goroutine, so we are safe.
// readerMu sync.Mutex
}
)
var _ Connection = &connection{}
// CloseMessage denotes a close control message. The optional message
// payload contains a numeric code and text. Use the FormatCloseMessage
// function to format a close message payload.
//
// Use the `Connection#Disconnect` instead.
const CloseMessage = websocket.CloseMessage
func newConnection(r *http.Request, s *Server, underlineConn UnderlineConnection, id string) *connection {
c := &connection{
underline: underlineConn,
id: id,
messageType: websocket.TextMessage,
onDisconnectListeners: make([]DisconnectFunc, 0),
onRoomLeaveListeners: make([]LeaveRoomFunc, 0),
onErrorListeners: make([]ErrorFunc, 0),
onNativeMessageListeners: make([]NativeMessageFunc, 0),
onEventListeners: make(map[string][]MessageFunc, 0),
onPongListeners: make([]PongFunc, 0),
started: false,
request: r,
server: s,
}
if s.config.BinaryMessages {
c.messageType = websocket.BinaryMessage
}
c.self = newEmitter(c, c.id)
c.broadcast = newEmitter(c, Broadcast)
c.all = newEmitter(c, All)
return c
}
// Err is not nil if the upgrader failed to upgrade http to websocket connection.
func (c *connection) Err() error {
return c.err
}
// Write writes a raw websocket message with a specific type to the client
// used by ping messages and any CloseMessage types.
func (c *connection) Write(websocketMessageType int, data []byte) error {
// for any-case the app tries to write from different goroutines,
// we must protect them because they're reporting that as bug...
c.writerMu.Lock()
if writeTimeout := c.server.config.WriteTimeout; writeTimeout > 0 {
// set the write deadline based on the configuration
c.underline.SetWriteDeadline(time.Now().Add(writeTimeout))
}
// .WriteMessage same as NextWriter and close (flush)
err := c.underline.WriteMessage(websocketMessageType, data)
c.writerMu.Unlock()
if err != nil {
// if failed then the connection is off, fire the disconnect
c.Disconnect()
}
return err
}
// writeDefault is the same as write but the message type is the configured by c.messageType
// if BinaryMessages is enabled then it's raw []byte as you expected to work with protobufs
func (c *connection) writeDefault(data []byte) {
c.Write(c.messageType, data)
}
const (
// WriteWait is 1 second at the internal implementation,
// same as here but this can be changed at the future*
WriteWait = 1 * time.Second
)
func (c *connection) startPinger() {
// this is the default internal handler, we just change the writeWait because of the actions we must do before
// the server sends the ping-pong.
pingHandler := func(message string) error {
err := c.underline.WriteControl(websocket.PongMessage, []byte(message), time.Now().Add(WriteWait))
if err == websocket.ErrCloseSent {
return nil
} else if e, ok := err.(net.Error); ok && e.Temporary() {
return nil
}
return err
}
c.underline.SetPingHandler(pingHandler)
go func() {
for {
// using sleep avoids the ticker error that causes a memory leak
time.Sleep(c.server.config.PingPeriod)
if c.disconnected {
// verifies if already disconected
break
}
//fire all OnPing methods
c.fireOnPing()
// try to ping the client, if failed then it disconnects
err := c.Write(websocket.PingMessage, []byte{})
if err != nil {
// must stop to exit the loop and finish the go routine
break
}
}
}()
}
func (c *connection) fireOnPing() {
// fire the onPingListeners
for i := range c.onPingListeners {
c.onPingListeners[i]()
}
}
func (c *connection) fireOnPong() {
// fire the onPongListeners
for i := range c.onPongListeners {
c.onPongListeners[i]()
}
}
func (c *connection) startReader() {
conn := c.underline
hasReadTimeout := c.server.config.ReadTimeout > 0
conn.SetReadLimit(c.server.config.MaxMessageSize)
conn.SetPongHandler(func(s string) error {
if hasReadTimeout {
conn.SetReadDeadline(time.Now().Add(c.server.config.ReadTimeout))
}
//fire all OnPong methods
go c.fireOnPong()
return nil
})
defer func() {
c.Disconnect()
}()
for {
if hasReadTimeout {
// set the read deadline based on the configuration
conn.SetReadDeadline(time.Now().Add(c.server.config.ReadTimeout))
}
_, data, err := conn.ReadMessage()
if err != nil {
if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway) {
c.FireOnError(err)
}
break
} else {
c.messageReceived(data)
}
}
}
// messageReceived checks the incoming message and fire the nativeMessage listeners or the event listeners (ws custom message)
func (c *connection) messageReceived(data []byte) {
if bytes.HasPrefix(data, c.server.config.EvtMessagePrefix) {
//it's a custom ws message
receivedEvt := c.server.messageSerializer.getWebsocketCustomEvent(data)
listeners, ok := c.onEventListeners[string(receivedEvt)]
if !ok || len(listeners) == 0 {
return // if not listeners for this event exit from here
}
customMessage, err := c.server.messageSerializer.deserialize(receivedEvt, data)
if customMessage == nil || err != nil {
return
}
for i := range listeners {
if fn, ok := listeners[i].(func()); ok { // its a simple func(){} callback
fn()
} else if fnString, ok := listeners[i].(func(string)); ok {
if msgString, is := customMessage.(string); is {
fnString(msgString)
} else if msgInt, is := customMessage.(int); is {
// here if server side waiting for string but client side sent an int, just convert this int to a string
fnString(strconv.Itoa(msgInt))
}
} else if fnInt, ok := listeners[i].(func(int)); ok {
fnInt(customMessage.(int))
} else if fnBool, ok := listeners[i].(func(bool)); ok {
fnBool(customMessage.(bool))
} else if fnBytes, ok := listeners[i].(func([]byte)); ok {
fnBytes(customMessage.([]byte))
} else {
listeners[i].(func(interface{}))(customMessage)
}
}
} else {
// it's native websocket message
for i := range c.onNativeMessageListeners {
c.onNativeMessageListeners[i](data)
}
}
}
func (c *connection) ID() string {
return c.id
}
func (c *connection) Request() *http.Request {
return c.request
}
func (c *connection) Server() *Server {
return c.server
}
func (c *connection) Values() ConnectionValues {
return c.values
}
func (c *connection) fireDisconnect() {
for i := range c.onDisconnectListeners {
c.onDisconnectListeners[i]()
}
}
func (c *connection) OnDisconnect(cb DisconnectFunc) {
c.onDisconnectListeners = append(c.onDisconnectListeners, cb)
}
func (c *connection) OnError(cb ErrorFunc) {
c.onErrorListeners = append(c.onErrorListeners, cb)
}
func (c *connection) OnPing(cb PingFunc) {
c.onPingListeners = append(c.onPingListeners, cb)
}
func (c *connection) OnPong(cb PongFunc) {
c.onPongListeners = append(c.onPongListeners, cb)
}
func (c *connection) FireOnError(err error) {
for _, cb := range c.onErrorListeners {
cb(err)
}
}
func (c *connection) To(to string) Emitter {
if to == Broadcast { // if send to all except me, then return the pre-defined emitter, and so on
return c.broadcast
} else if to == All {
return c.all
} else if to == c.id {
return c.self
}
// is an emitter to another client/connection
return newEmitter(c, to)
}
func (c *connection) EmitMessage(nativeMessage []byte) error {
return c.self.EmitMessage(nativeMessage)
}
func (c *connection) Emit(event string, message interface{}) error {
return c.self.Emit(event, message)
}
func (c *connection) OnMessage(cb NativeMessageFunc) {
c.onNativeMessageListeners = append(c.onNativeMessageListeners, cb)
}
func (c *connection) On(event string, cb MessageFunc) {
if c.onEventListeners[event] == nil {
c.onEventListeners[event] = make([]MessageFunc, 0)
}
c.onEventListeners[event] = append(c.onEventListeners[event], cb)
}
func (c *connection) Join(roomName string) {
c.server.Join(roomName, c.id)
}
func (c *connection) IsJoined(roomName string) bool {
return c.server.IsJoined(roomName, c.id)
}
func (c *connection) Leave(roomName string) bool {
return c.server.Leave(roomName, c.id)
}
func (c *connection) OnLeave(roomLeaveCb LeaveRoomFunc) {
c.onRoomLeaveListeners = append(c.onRoomLeaveListeners, roomLeaveCb)
// note: the callbacks are called from the server on the '.leave' and '.LeaveAll' funcs.
}
func (c *connection) fireOnLeave(roomName string) {
// check if connection is already closed
if c == nil {
return
}
// fire the onRoomLeaveListeners
for i := range c.onRoomLeaveListeners {
c.onRoomLeaveListeners[i](roomName)
}
}
// Wait starts the pinger and the messages reader,
// it's named as "Wait" because it should be called LAST,
// after the "On" events IF server's `Upgrade` is used,
// otherise you don't have to call it because the `Handler()` does it automatically.
func (c *connection) Wait() {
if c.started {
return
}
c.started = true
// start the ping
c.startPinger()
// start the messages reader
c.startReader()
}
// ErrAlreadyDisconnected can be reported on the `Connection#Disconnect` function whenever the caller tries to close the
// connection when it is already closed by the client or the caller previously.
var ErrAlreadyDisconnected = errors.New("already disconnected")
func (c *connection) Disconnect() error {
if c == nil || c.disconnected {
return ErrAlreadyDisconnected
}
return c.server.Disconnect(c.ID())
}
// mem per-conn store
func (c *connection) SetValue(key string, value interface{}) {
c.values.Set(key, value)
}
func (c *connection) GetValue(key string) interface{} {
return c.values.Get(key)
}
func (c *connection) GetValueArrString(key string) []string {
if v := c.values.Get(key); v != nil {
if arrString, ok := v.([]string); ok {
return arrString
}
}
return nil
}
func (c *connection) GetValueString(key string) string {
if v := c.values.Get(key); v != nil {
if s, ok := v.(string); ok {
return s
}
}
return ""
}
func (c *connection) GetValueInt(key string) int {
if v := c.values.Get(key); v != nil {
if i, ok := v.(int); ok {
return i
} else if s, ok := v.(string); ok {
if iv, err := strconv.Atoi(s); err == nil {
return iv
}
}
}
return 0
}