From d006c992ec0a5a3cce3bcaf109b7735c5e8fc3a2 Mon Sep 17 00:00:00 2001
From: vilmibm <vilmibm@github.com>
Date: Fri, 23 Dec 2022 21:31:08 -0800
Subject: [PATCH] refactor Gateway out

---
 server/cmd/main.go    | 46 +++++++++++++++++++++++++++++---------
 server/witch/witch.go | 51 +++++--------------------------------------
 2 files changed, 41 insertions(+), 56 deletions(-)

diff --git a/server/cmd/main.go b/server/cmd/main.go
index e428740..05e3c57 100644
--- a/server/cmd/main.go
+++ b/server/cmd/main.go
@@ -71,10 +71,12 @@ func _main() (err error) {
 type gameWorldServer struct {
 	proto.UnimplementedGameWorldServer
 
-	db        db.DB
-	mu        sync.Mutex // for msgRouter
-	msgRouter map[string]func(*proto.ClientMessage) error
-	Gateway   *witch.Gateway
+	db             db.DB
+	msgRouterMutex sync.Mutex
+	msgRouter      map[string]func(*proto.ClientMessage) error
+	Gateway        *witch.Gateway
+	scripts        map[int]*witch.ScriptContext
+	scriptsMutex   sync.RWMutex
 }
 
 func newServer() (*gameWorldServer, error) {
@@ -93,15 +95,39 @@ func newServer() (*gameWorldServer, error) {
 	}
 
 	s := &gameWorldServer{
-		msgRouter: make(map[string]func(*proto.ClientMessage) error),
-		db:        db,
+		msgRouter:    make(map[string]func(*proto.ClientMessage) error),
+		db:           db,
+		scripts:      make(map[int]*witch.ScriptContext),
+		scriptsMutex: sync.RWMutex{},
 	}
-	gw := witch.NewGateway(s.HandleCmd)
-	s.Gateway = gw
 
 	return s, nil
 }
 
+func (s *gameWorldServer) verbHandler(verb, rest string, sender, target db.Object) error {
+	/*
+		So right here is a problem: we are definitely making >1 LuaState per
+		goroutine. Top priority before anything else is getting a goroutine made
+		for the script contexts
+	*/
+	s.scriptsMutex.RLock()
+	sc, ok := s.scripts[target.ID]
+	s.scriptsMutex.RUnlock()
+
+	if !ok || sc.NeedsRefresh(target) {
+		sc, err := witch.NewScriptContext(target)
+		if err != nil {
+			return err
+		}
+
+		s.scriptsMutex.Lock()
+		s.scripts[target.ID] = sc
+		s.scriptsMutex.Unlock()
+	}
+
+	return sc.Handle(verb, rest, sender, target)
+}
+
 func (s *gameWorldServer) HandleCmd(verb, rest string, sender *db.Object) {
 	// TODO
 }
@@ -213,9 +239,9 @@ func (s *gameWorldServer) Ping(ctx context.Context, _ *proto.SessionInfo) (*prot
 }
 
 func (s *gameWorldServer) Messages(si *proto.SessionInfo, stream proto.GameWorld_MessagesServer) error {
-	s.mu.Lock()
+	s.msgRouterMutex.Lock()
 	s.msgRouter[si.SessionID] = stream.Send
-	s.mu.Unlock()
+	s.msgRouterMutex.Unlock()
 
 	// TODO this is clearly bad but it works. I should refactor this so that messages are received on a channel.
 	for {
diff --git a/server/witch/witch.go b/server/witch/witch.go
index ea5e722..bd9c84a 100644
--- a/server/witch/witch.go
+++ b/server/witch/witch.go
@@ -1,8 +1,6 @@
 package witch
 
 import (
-	"sync"
-
 	"github.com/vilmibm/hermeticum/server/db"
 	lua "github.com/yuin/gopher-lua"
 )
@@ -15,14 +13,14 @@ import (
 
 */
 
-type scriptContext struct {
+type ScriptContext struct {
 	script   string
 	l        *lua.LState
 	incoming chan string
 	// TODO whatever is needed to support calling a Go API
 }
 
-func (sc *scriptContext) NeedsRefresh(obj db.Object) bool {
+func (sc *ScriptContext) NeedsRefresh(obj db.Object) bool {
 	return sc.script != obj.Script
 }
 
@@ -62,7 +60,7 @@ end)
 // 	 - do i inject from Go or prepend some Lua code?
 // TODO figure out how the Lua code can affect Go and thus the database
 
-func newScriptContext(obj db.Object) (*scriptContext, error) {
+func NewScriptContext(obj db.Object) (*ScriptContext, error) {
 	l := lua.NewState()
 
 	l.SetGlobal("has", l.NewFunction(hasWrapper(obj)))
@@ -73,49 +71,10 @@ func newScriptContext(obj db.Object) (*scriptContext, error) {
 		return nil, err
 	}
 
-	return &scriptContext{}, nil
+	return &ScriptContext{}, nil
 }
 
-func (sc *scriptContext) Handle(verb, rest string, sender, target *db.Object) error {
-
+func (sc *ScriptContext) Handle(verb, rest string, sender, target db.Object) error {
 	// TODO call _handle function from the Lstate
 	return nil
 }
-
-type Gateway struct {
-	// maps game object IDs to script contexts
-	m  map[int]*scriptContext
-	mu sync.RWMutex
-	cb func(string, string, *db.Object)
-}
-
-func NewGateway(cb func(string, string, *db.Object)) *Gateway {
-	return &Gateway{
-		m:  map[int]*scriptContext{},
-		mu: sync.RWMutex{},
-		// TODO use cb from scriptContext
-		cb: cb,
-	}
-}
-
-func (g *Gateway) VerbHandler(verb, rest string, sender, target db.Object) error {
-	var sc *scriptContext
-	g.mu.RLock()
-	sc, ok := g.m[target.ID]
-	g.mu.RUnlock()
-
-	if !ok || sc.NeedsRefresh(target) {
-		sc, err := newScriptContext(target)
-		if err != nil {
-			return err
-		}
-
-		g.mu.Lock()
-		g.m[target.ID] = sc
-		g.mu.Unlock()
-	}
-
-	sc.Handle(verb, rest, &sender, &target)
-
-	return nil
-}