From e30a8516d14c07e1a491ad5b417d3a1b235fcd03 Mon Sep 17 00:00:00 2001
From: AkmalFairuz <akmalf475@gmail.com>
Date: Thu, 20 Mar 2025 21:39:20 +0700
Subject: [PATCH 1/2] refactor: optimize client packet handling by using a map
 for ClientDecode

---
 session/handler.go | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/session/handler.go b/session/handler.go
index f9bf27f..b8efb9f 100644
--- a/session/handler.go
+++ b/session/handler.go
@@ -5,7 +5,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"slices"
 	"time"
 
 	packet2 "github.com/cooldogedev/spectrum/server/packet"
@@ -90,6 +89,11 @@ func handleClient(s *Session) {
 		}
 	}
 
+	clientDecode := make(map[uint32]struct{}, len(s.opts.ClientDecode))
+	for _, id := range s.opts.ClientDecode {
+		clientDecode[id] = struct{}{}
+	}
+
 loop:
 	for {
 		select {
@@ -105,7 +109,7 @@ loop:
 			break loop
 		}
 
-		if err := handleClientPacket(s, header, pool, shieldID, payload); err != nil {
+		if err := handleClientPacket(s, header, pool, shieldID, payload, clientDecode); err != nil {
 			s.Server().CloseWithError(fmt.Errorf("failed to write packet to server: %w", err))
 		}
 	}
@@ -131,14 +135,14 @@ loop:
 }
 
 // handleClientPacket processes and forwards the provided packet from the client to the server.
-func handleClientPacket(s *Session, header *packet.Header, pool packet.Pool, shieldID int32, payload []byte) (err error) {
+func handleClientPacket(s *Session, header *packet.Header, pool packet.Pool, shieldID int32, payload []byte, clientDecode map[uint32]struct{}) (err error) {
 	ctx := NewContext()
 	buf := bytes.NewBuffer(payload)
 	if err := header.Read(buf); err != nil {
 		return errors.New("failed to decode header")
 	}
 
-	if !slices.Contains(s.opts.ClientDecode, header.PacketID) {
+	if _, ok := clientDecode[header.PacketID]; !ok {
 		s.processor.ProcessClientEncoded(ctx, &payload)
 		if !ctx.Cancelled() {
 			return s.Server().Write(payload)

From e98f0eb396697af99167c95b9ca9b0bedab0354b Mon Sep 17 00:00:00 2001
From: AkmalFairuz <akmalf475@gmail.com>
Date: Thu, 20 Mar 2025 23:34:17 +0700
Subject: [PATCH 2/2] compatibility with session.SetOpts

---
 session/handler.go | 11 +++--------
 session/session.go |  5 +++++
 util/opts.go       |  9 +++++++++
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/session/handler.go b/session/handler.go
index 49543d5..4bea5b5 100644
--- a/session/handler.go
+++ b/session/handler.go
@@ -93,11 +93,6 @@ func handleClient(s *Session) {
 		}
 	}
 
-	clientDecode := make(map[uint32]struct{}, len(s.opts.ClientDecode))
-	for _, id := range s.opts.ClientDecode {
-		clientDecode[id] = struct{}{}
-	}
-
 loop:
 	for {
 		select {
@@ -113,7 +108,7 @@ loop:
 			break loop
 		}
 
-		if err := handleClientPacket(s, header, pool, shieldID, payload, clientDecode); err != nil {
+		if err := handleClientPacket(s, header, pool, shieldID, payload); err != nil {
 			s.Server().CloseWithError(fmt.Errorf("failed to write packet to server: %w", err))
 		}
 	}
@@ -139,14 +134,14 @@ loop:
 }
 
 // handleClientPacket processes and forwards the provided packet from the client to the server.
-func handleClientPacket(s *Session, header *packet.Header, pool packet.Pool, shieldID int32, payload []byte, clientDecode map[uint32]struct{}) (err error) {
+func handleClientPacket(s *Session, header *packet.Header, pool packet.Pool, shieldID int32, payload []byte) (err error) {
 	ctx := NewContext()
 	buf := bytes.NewBuffer(payload)
 	if err := header.Read(buf); err != nil {
 		return errors.New("failed to decode header")
 	}
 
-	if _, ok := clientDecode[header.PacketID]; !ok {
+	if _, ok := s.clientDecode[header.PacketID]; !ok {
 		s.processor.ProcessClientEncoded(ctx, &payload)
 		if !ctx.Cancelled() {
 			return s.Server().Write(payload)
diff --git a/session/session.go b/session/session.go
index 1777817..70675a6 100644
--- a/session/session.go
+++ b/session/session.go
@@ -44,6 +44,8 @@ type Session struct {
 	latency      atomic.Int64
 	transferring atomic.Bool
 	once         sync.Once
+
+	clientDecode map[uint32]struct{}
 }
 
 // NewSession creates a new Session instance using the provided minecraft.Conn.
@@ -61,6 +63,8 @@ func NewSession(client *minecraft.Conn, logger *slog.Logger, registry *Registry,
 		animation: &animation.Dimension{},
 		processor: NopProcessor{},
 		tracker:   newTracker(),
+
+		clientDecode: opts.ClientDecodeAsMap(),
 	}
 	s.ctx, s.cancelFunc = context.WithCancelCause(client.Context())
 	return s
@@ -234,6 +238,7 @@ func (s *Session) Opts() util.Opts {
 // SetOpts updates the session options.
 func (s *Session) SetOpts(opts util.Opts) {
 	s.opts = opts
+	s.clientDecode = opts.ClientDecodeAsMap()
 }
 
 // Processor returns the current processor.
diff --git a/util/opts.go b/util/opts.go
index 641fc34..fc88702 100644
--- a/util/opts.go
+++ b/util/opts.go
@@ -21,6 +21,15 @@ type Opts struct {
 	Token string `yaml:"token"`
 }
 
+// ClientDecodeAsMap converts the ClientDecode slice to a map for faster lookups.
+func (opts *Opts) ClientDecodeAsMap() map[uint32]struct{} {
+	m := make(map[uint32]struct{}, len(opts.ClientDecode))
+	for _, id := range opts.ClientDecode {
+		m[id] = struct{}{}
+	}
+	return m
+}
+
 // DefaultOpts returns the default configuration options for Spectrum.
 func DefaultOpts() *Opts {
 	return &Opts{