It's premature optimisation time!

* Use easyjson instead of std json, this reduces CPU/RAM usage
* Use prepared messages when broadcasting
* Enable compression on websockets
* Prevent unmarshalling data into maps and then into objects

go.mod

@@ -10,7 +10,12 @@ require (
 	github.com/go-chi/chi/v5 v5.0.10
 	github.com/gofrs/uuid v4.4.0+incompatible
 	github.com/gorilla/websocket v1.5.0
-	github.com/mitchellh/mapstructure v1.5.0
+	github.com/mailru/easyjson v0.7.7
 	github.com/subosito/gotenv v1.6.0
 	golang.org/x/text v0.12.0
 )
+
+require (
+	github.com/josharian/intern v1.0.0 // indirect
+	github.com/stretchr/testify v1.8.0 // indirect
+)

go.sum

@@ -6,7 +6,9 @@ github.com/arbovm/levenshtein v0.0.0-20160628152529-48b4e1c0c4d0 h1:jfIu9sQUG6Ig
 github.com/arbovm/levenshtein v0.0.0-20160628152529-48b4e1c0c4d0/go.mod h1:t2tdKJDJF9BV14lnkjHmOQgcvEKgtqs5a1N3LNdJhGE=
 github.com/caarlos0/env/v9 v9.0.0 h1:SI6JNsOA+y5gj9njpgybykATIylrRMklbs5ch6wO6pc=
 github.com/caarlos0/env/v9 v9.0.0/go.mod h1:ye5mlCVMYh6tZ+vCgrs/B95sj88cg5Tlnc0XIzgZ020=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dgryski/trifles v0.0.0-20200323201526-dd97f9abfb48 h1:fRzb/w+pyskVMQ+UbP35JkH8yB7MYb4q/qhBarqZE6g=
 github.com/dgryski/trifles v0.0.0-20200323201526-dd97f9abfb48/go.mod h1:if7Fbed8SFyPtHLHbg49SI7NAdJiC5WIA09pe59rfAA=
 github.com/dustinkirkland/golang-petname v0.0.0-20230626224747-e794b9370d49 h1:6SNWi8VxQeCSwmLuTbEvJd7xvPmdS//zvMBWweZLgck=
@@ -17,12 +19,22 @@ github.com/gofrs/uuid v4.4.0+incompatible h1:3qXRTX8/NbyulANqlc0lchS1gqAVxRgsuW1
 github.com/gofrs/uuid v4.4.0+incompatible/go.mod h1:b2aQJv3Z4Fp6yNu3cdSllBxTCLRxnplIgP/c0N/04lM=
 github.com/gorilla/websocket v1.5.0 h1:PPwGk2jz7EePpoHN/+ClbZu8SPxiqlu12wZP/3sWmnc=
 github.com/gorilla/websocket v1.5.0/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
-github.com/mitchellh/mapstructure v1.5.0 h1:jeMsZIYE/09sWLaz43PL7Gy6RuMjD2eJVyuac5Z2hdY=
-github.com/mitchellh/mapstructure v1.5.0/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RRV2QTWOzhPopBRo=
+github.com/josharian/intern v1.0.0 h1:vlS4z54oSdjm0bgjRigI+G1HpF+tI+9rE5LLzOg8HmY=
+github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
+github.com/mailru/easyjson v0.7.7 h1:UGYAvKxe3sBsEDzO8ZeWOSlIQfWFlxbzLZe7hwFURr0=
+github.com/mailru/easyjson v0.7.7/go.mod h1:xzfreul335JAWq5oZzymOObrkdz5UnU4kGfJJLY9Nlc=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
-github.com/stretchr/testify v1.7.5 h1:s5PTfem8p8EbKQOctVV53k6jCJt3UX4IEJzwh+C324Q=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.0 h1:pSgiaMZlXftHpm5L7V1+rVB+AZJydKsMxsQBIJw4PKk=
+github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
 github.com/subosito/gotenv v1.6.0 h1:9NlTDc1FTs4qu0DDq7AEtTPNw6SVm7uBMsUCUjABIf8=
 github.com/subosito/gotenv v1.6.0/go.mod h1:Dk4QP5c2W3ibzajGcXpNraDfq2IrhjMIvMSWPKKo0FU=
 golang.org/x/text v0.12.0 h1:k+n5B8goJNdU7hSvEtMUz3d1Q6D/XW4COJSJR6fN0mc=
 golang.org/x/text v0.12.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/api/v1.go

@@ -119,7 +119,8 @@ func postLobby(writer http.ResponseWriter, request *http.Request) {
 		return
 	}
 
-	lobby.WriteJSON = WriteJSON
+	lobby.WriteObject = WriteObject
+	lobby.WritePreparedMessage = WritePreparedMessage
 	player.SetLastKnownAddress(GetIPAddressFromRequest(request))
 
 	SetUsersessionCookie(writer, player)
@@ -180,9 +181,10 @@ func postPlayer(writer http.ResponseWriter, request *http.Request) {
 
 // SetUsersessionCookie takes the players usersession and sets it as a cookie.
 func SetUsersessionCookie(w http.ResponseWriter, player *game.Player) {
+	session := player.GetUserSession().String()
 	http.SetCookie(w, &http.Cookie{
 		Name:     "usersession",
-		Value:    player.GetUserSession().String(),
+		Value:    session,
 		Path:     "/",
 		SameSite: http.SameSiteStrictMode,
 	})

internal/api/ws.go

@@ -1,7 +1,6 @@
 package api
 
 import (
-	"encoding/json"
 	"errors"
 	"fmt"
 	"log"
@@ -12,6 +11,7 @@ import (
 	"github.com/go-chi/chi/v5"
 	"github.com/gofrs/uuid"
 	"github.com/gorilla/websocket"
+	"github.com/mailru/easyjson"
 
 	"github.com/scribble-rs/scribble.rs/internal/game"
 	"github.com/scribble-rs/scribble.rs/internal/state"
@@ -21,9 +21,10 @@ var (
 	ErrPlayerNotConnected = errors.New("player not connected")
 
 	upgrader = websocket.Upgrader{
-		ReadBufferSize:  1024,
-		WriteBufferSize: 1024,
-		CheckOrigin:     func(r *http.Request) bool { return true },
+		ReadBufferSize:    1024,
+		WriteBufferSize:   1024,
+		CheckOrigin:       func(_ *http.Request) bool { return true },
+		EnableCompression: true,
 	}
 )
 
@@ -86,6 +87,8 @@ func wsListen(lobby *game.Lobby, player *game.Player, socket *websocket.Conn) {
 		}
 	}()
 
+	var event game.EventTypeOnly
+
 	for {
 		messageType, data, err := socket.ReadMessage()
 		if err != nil {
@@ -109,11 +112,9 @@ func wsListen(lobby *game.Lobby, player *game.Player, socket *websocket.Conn) {
 		}
 
 		if messageType == websocket.TextMessage {
-			received := &game.Event{}
-
-			if err := json.Unmarshal(data, received); err != nil {
+			if err := easyjson.Unmarshal(data, &event); err != nil {
 				log.Printf("Error unmarshalling message: %s\n", err)
-				err := WriteJSON(player, game.Event{
+				err := WriteObject(player, game.Event{
 					Type: game.EventTypeSystemMessage,
 					Data: fmt.Sprintf("error parsing message, please report this issue via Github: %s!", err),
 				})
@@ -123,16 +124,31 @@ func wsListen(lobby *game.Lobby, player *game.Player, socket *websocket.Conn) {
 				continue
 			}
 
-			if err := lobby.HandleEvent(received, player); err != nil {
+			if err := lobby.HandleEvent(event.Type, data, player); err != nil {
 				log.Printf("Error handling event: %s\n", err)
 			}
 		}
 	}
 }
 
-// WriteJSON marshals the given input into a JSON string and sends it to the
-// player using the currently established websocket connection.
-func WriteJSON(player *game.Player, object any) error {
+func WriteObject(player *game.Player, object easyjson.Marshaler) error {
+	player.GetWebsocketMutex().Lock()
+	defer player.GetWebsocketMutex().Unlock()
+
+	socket := player.GetWebsocket()
+	if socket == nil || !player.Connected {
+		return ErrPlayerNotConnected
+	}
+
+	bytes, err := easyjson.Marshal(object)
+	if err != nil {
+		return fmt.Errorf("error marshalling payload: %w", err)
+	}
+
+	return socket.WriteMessage(websocket.TextMessage, bytes)
+}
+
+func WritePreparedMessage(player *game.Player, message *websocket.PreparedMessage) error {
 	player.GetWebsocketMutex().Lock()
 	defer player.GetWebsocketMutex().Unlock()
 
@@ -141,5 +157,5 @@ func WriteJSON(player *game.Player, object any) error {
 		return ErrPlayerNotConnected
 	}
 
-	return socket.WriteJSON(object)
+	return socket.WritePreparedMessage(message)
 }

internal/frontend/create.go

@@ -147,7 +147,8 @@ func ssrCreateLobby(writer http.ResponseWriter, request *http.Request) {
 		return
 	}
 
-	lobby.WriteJSON = api.WriteJSON
+	lobby.WriteObject = api.WriteObject
+	lobby.WritePreparedMessage = api.WritePreparedMessage
 	player.SetLastKnownAddress(api.GetIPAddressFromRequest(request))
 
 	api.SetUsersessionCookie(writer, player)

internal/game/data.go

@@ -8,6 +8,7 @@ import (
 	discordemojimap "github.com/Bios-Marcel/discordemojimap/v2"
 	"github.com/gofrs/uuid"
 	"github.com/gorilla/websocket"
+	easyjson "github.com/mailru/easyjson"
 	"golang.org/x/text/cases"
 )
 
@@ -61,9 +62,9 @@ type Lobby struct {
 	// wordChoice represents the current choice of words present to the drawer.
 	wordChoice []string
 	Wordpack   string
-	// RoundEndTime represents the time at which the current round will end.
+	// roundEndTime represents the time at which the current round will end.
 	// This is a UTC unix-timestamp in milliseconds.
-	RoundEndTime int64
+	roundEndTime int64
 
 	timeLeftTicker        *time.Ticker
 	scoreEarnedByGuessers int
@@ -91,117 +92,14 @@ type Lobby struct {
 
 	mutex *sync.Mutex
 
-	WriteJSON func(player *Player, object any) error
-}
-
-// EditableLobbySettings represents all lobby settings that are editable by
-// the lobby owner after the lobby has already been opened.
-type EditableLobbySettings struct {
-	// MaxPlayers defines the maximum amount of players in a single lobby.
-	MaxPlayers int `json:"maxPlayers"`
-	// CustomWords are additional words that will be used in addition to the
-	// predefined words.
-	// Public defines whether the lobby is being broadcast to clients asking
-	// for available lobbies.
-	Public bool `json:"public"`
-	// EnableVotekick decides whether players are allowed to kick eachother
-	// by casting majority votes.
-	EnableVotekick bool `json:"enableVotekick"`
-	// CustomWordsChance determines the chance of each word being a custom
-	// word on the next word prompt. This needs to be an integer between
-	// 0 and 100. The value represents a percentage.
-	CustomWordsChance int `json:"customWordsChance"`
-	// ClientsPerIPLimit helps preventing griefing by reducing each player
-	// to one tab per IP address.
-	ClientsPerIPLimit int `json:"clientsPerIpLimit"`
-	// DrawingTime is the amount of seconds that each player has available to
-	// finish their drawing.
-	DrawingTime int `json:"drawingTime"`
-	// Rounds defines how many iterations a lobby does before the game ends.
-	// One iteration means every participant does one drawing.
-	Rounds int `json:"rounds"`
-}
-
-type State string
-
-const (
-	// Unstarted means the lobby has been opened but never started.
-	Unstarted State = "unstarted"
-	// Ongoing means the lobby has already been started.
-	Ongoing State = "ongoing"
-	// GameOver means that the lobby had been start, but the max round limit
-	// has already been reached.
-	GameOver State = "gameOver"
-)
-
-// WordHint describes a character of the word that is to be guessed, whether
-// the character should be shown and whether it should be underlined on the
-// UI.
-type WordHint struct {
-	Character rune `json:"character"`
-	Underline bool `json:"underline"`
-}
-
-// RGBColor represents a 24-bit color consisting of red, green and blue.
-type RGBColor struct {
-	R uint8 `json:"r"`
-	G uint8 `json:"g"`
-	B uint8 `json:"b"`
-}
-
-// Line is the struct that a client sends when drawing.
-type Line struct {
-	FromX     float32  `json:"fromX"`
-	FromY     float32  `json:"fromY"`
-	ToX       float32  `json:"toX"`
-	ToY       float32  `json:"toY"`
-	Color     RGBColor `json:"color"`
-	LineWidth float32  `json:"lineWidth"`
-}
-
-// Fill represents the usage of the fill bucket.
-type Fill struct {
-	X     float32  `json:"x"`
-	Y     float32  `json:"y"`
-	Color RGBColor `json:"color"`
+	WriteObject          func(*Player, easyjson.Marshaler) error
+	WritePreparedMessage func(*Player, *websocket.PreparedMessage) error
 }
 
 // MaxPlayerNameLength defines how long a string can be at max when used
 // as the playername.
 const MaxPlayerNameLength int = 30
 
-// Player represents a participant in a Lobby.
-type Player struct {
-	// userSession uniquely identifies the player.
-	userSession      uuid.UUID
-	ws               *websocket.Conn
-	socketMutex      *sync.Mutex
-	lastKnownAddress string
-	// disconnectTime is used to kick a player in case the lobby doesn't have
-	// space for new players. The player with the oldest disconnect.Time will
-	// get kicked.
-	disconnectTime *time.Time
-
-	votedForKick map[uuid.UUID]bool
-
-	// ID uniquely identified the Player.
-	ID uuid.UUID `json:"id"`
-	// Name is the players displayed name
-	Name string `json:"name"`
-	// Score is the points that the player got in the current Lobby.
-	Score int `json:"score"`
-	// Connected defines whether the players websocket connection is currently
-	// established. This has previously been in state but has been moved out
-	// in order to avoid losing the state on refreshing the page.
-	// While checking the websocket against nil would be enough, we still need
-	// this field for sending it via the APIs.
-	Connected bool `json:"connected"`
-	// Rank is the current ranking of the player in his Lobby
-	LastScore int         `json:"lastScore"`
-	Rank      int         `json:"rank"`
-	State     PlayerState `json:"state"`
-}
-
 // GetLastKnownAddress returns the last known IP-Address used for an HTTP request.
 func (player *Player) GetLastKnownAddress() string {
 	return player.lastKnownAddress
@@ -307,12 +205,6 @@ func SanitizeName(name string) string {
 	return generatePlayerName()
 }
 
-// Event contains an eventtype and optionally any data.
-type Event struct {
-	Data any    `json:"data"`
-	Type string `json:"type"`
-}
-
 // GetConnectedPlayerCount returns the amount of player that have currently
 // established a socket connection.
 func (lobby *Lobby) GetConnectedPlayerCount() int {