memory: Use a string pool for Commands

socketserver/server/backend.go

@@ -62,7 +62,7 @@ func getCacheKey(remoteCommand, data string) string {
 	return fmt.Sprintf("%s/%s", remoteCommand, data)
 }
 
-// HBackendPublishRequest handles the /uncached_pub route.
+// HTTPBackendUncachedPublish handles the /uncached_pub route.
 // The backend can POST here to publish a message to clients with no caching.
 // The POST arguments are `cmd`, `args`, `channel`, and `scope`.
 // The `scope` argument is required because no attempt is made to infer the scope from the command, unlike /cached_pub.
@@ -93,7 +93,7 @@ func HTTPBackendUncachedPublish(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	cm := ClientMessage{MessageID: -1, Command: Command(cmd), origArguments: json}
+	cm := ClientMessage{MessageID: -1, Command: CommandPool.Intern(cmd), origArguments: json}
 	cm.parseOrigArguments()
 	var count int
 
@@ -219,7 +219,7 @@ type ErrBackendNotOK struct {
 	Code     int
 }
 
-// Implements the error interface.
+// Error Implements the error interface.
 func (noe ErrBackendNotOK) Error() string {
 	return fmt.Sprintf("backend returned %d: %s", noe.Code, noe.Response)
 }

socketserver/server/commands.go

@@ -41,6 +41,25 @@ var commandHandlers = map[Command]CommandHandler{
 	"user_history":          C2SHandleRemoteCommand,
 }
 
+func internCommands() {
+	CommandPool = NewStringPool()
+	CommandPool._Intern_Setup(HelloCommand)
+	CommandPool._Intern_Setup("ping")
+	CommandPool._Intern_Setup(SetUserCommand)
+	CommandPool._Intern_Setup(ReadyCommand)
+	CommandPool._Intern_Setup("sub")
+	CommandPool._Intern_Setup("unsub")
+	CommandPool._Intern_Setup("track_follow")
+	CommandPool._Intern_Setup("emoticon_uses")
+	CommandPool._Intern_Setup("twitch_emote")
+	CommandPool._Intern_Setup("get_link")
+	CommandPool._Intern_Setup("get_display_name")
+	CommandPool._Intern_Setup("update_follow_buttons")
+	CommandPool._Intern_Setup("chat_history")
+	CommandPool._Intern_Setup("user_history")
+	CommandPool._Intern_Setup("adjacent_history")
+}
+
 // DispatchC2SCommand handles a C2S Command in the provided ClientMessage.
 // It calls the correct CommandHandler function, catching panics.
 // It sends either the returned Reply ClientMessage, setting the correct messageID, or sends an ErrorCommand

socketserver/server/handlecore.go

@@ -60,6 +60,8 @@ var Configuration *ConfigFile
 
 var janitorsOnce sync.Once
 
+var CommandPool StringPool
+
 // SetupServerAndHandle starts all background goroutines and registers HTTP listeners on the given ServeMux.
 // Essentially, this function completely preps the server for a http.ListenAndServe call.
 // (Uses http.DefaultServeMux if `serveMux` is nil.)
@@ -115,6 +117,7 @@ func SetupServerAndHandle(config *ConfigFile, serveMux *http.ServeMux) {
 // startJanitors starts the 'is_init_func' goroutines
 func startJanitors() {
 	loadUniqueUsers()
+	internCommands()
 
 	go authorizationJanitor()
 	go bunchCacheJanitor()
@@ -508,11 +511,11 @@ func UnmarshalClientMessage(data []byte, payloadType int, v interface{}) (err er
 
 	spaceIdx = strings.IndexRune(dataStr, ' ')
 	if spaceIdx == -1 {
-		out.Command = Command(dataStr)
+		out.Command = CommandPool.Intern(dataStr)
 		out.Arguments = nil
 		return nil
 	} else {
-		out.Command = Command(dataStr[:spaceIdx])
+		out.Command = CommandPool.Intern(dataStr[:spaceIdx])
 	}
 	dataStr = dataStr[spaceIdx+1:]
 	argumentsJSON := dataStr

socketserver/server/intern.go

@@ -0,0 +1,37 @@
+package server
+
+import (
+	"sync"
+)
+
+type StringPool struct {
+	sync.RWMutex
+	lookup map[string]Command
+}
+
+func NewStringPool() *StringPool {
+	return &StringPool{lookup: make(map[string]Command)}
+}
+
+// doesn't lock, doesn't check for dupes.
+func (p *StringPool) _Intern_Setup(s string) {
+	p.lookup[s] = Command(s)
+}
+
+func (p *StringPool) Intern(s string) Command {
+	p.RLock()
+	ss, exists := p.lookup[s]
+	p.RUnlock()
+	if exists {
+		return ss
+	}
+
+	p.Lock()
+	defer p.Unlock()
+	ss, exists = p.lookup[s]
+	if exists {
+		return ss
+	}
+	p.lookup[s] = Command(string([]byte(s)))
+	return s
+}

socketserver/server/publisher.go

@@ -236,7 +236,7 @@ func HTTPBackendCachedPublish(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	cmd := Command(formData.Get("cmd"))
+	cmd := CommandPool.Intern(formData.Get("cmd"))
 	json := formData.Get("args")
 	channel := formData.Get("channel")
 	deleteMode := formData.Get("delete") != ""