Graceful disconnect

Reviewed-on: #1

README.md

@@ -0,0 +1,75 @@
+# GoonServer
+
+The server component for GoonScape, handling multiplayer synchronization and chat.
+
+## Features
+
+- Tick-based game state synchronization
+- Player movement validation
+- Global chat system
+- Client connection management
+- Protobuf-based network protocol
+
+## Prerequisites
+
+- Go 1.23 or higher
+- Protocol Buffers compiler (protoc)
+
+## Installation
+
+1. Clone the repository:
+```bash
+git clone https://gitea.boner.be/bdnugget/goonserver.git
+cd goonserver
+```
+
+2. Install dependencies:
+```bash
+go mod tidy
+```
+
+3. Build and run:
+```bash
+go run main.go
+```
+
+## Configuration
+
+Server settings can be modified in `main.go`:
+```go
+const (
+    port     = ":6969"               // Port to listen on
+    tickRate = 600 * time.Millisecond // Server tick rate
+)
+```
+
+## Protocol
+
+The server uses Protocol Buffers for client-server communication. The protocol is defined in `actions/actions.proto`:
+
+- `Action`: Player actions (movement, chat)
+- `ActionBatch`: Grouped actions from a player
+- `ServerMessage`: Game state updates to clients
+- `PlayerState`: Individual player state
+- `ChatMessage`: Player chat messages
+
+## Development
+
+After modifying the protocol (`actions.proto`), regenerate the Go code:
+```bash
+protoc --go_out=. actions/actions.proto
+```
+
+## Deployment
+
+The server is designed to run on a single instance. For production deployment:
+
+1. Build the binary:
+```bash
+go build -o goonserver
+```
+
+2. Run with logging:
+```bash
+./goonserver > server.log 2>&1 &
+```

actions/actions.pb.go

@@ -1,6 +1,6 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
-// 	protoc-gen-go v1.36.2
+// 	protoc-gen-go v1.36.3
 // 	protoc        v5.29.2
 // source: actions.proto
 
@@ -25,6 +25,7 @@ type Action_ActionType int32
 const (
 	Action_MOVE       Action_ActionType = 0
 	Action_CHAT       Action_ActionType = 1
+	Action_DISCONNECT Action_ActionType = 2
 )
 
 // Enum value maps for Action_ActionType.
@@ -32,10 +33,12 @@ var (
 	Action_ActionType_name = map[int32]string{
 		0: "MOVE",
 		1: "CHAT",
+		2: "DISCONNECT",
 	}
 	Action_ActionType_value = map[string]int32{
 		"MOVE":       0,
 		"CHAT":       1,
+		"DISCONNECT": 2,
 	}
 )
 
@@ -394,7 +397,7 @@ var File_actions_proto protoreflect.FileDescriptor
 
 var file_actions_proto_rawDesc = []byte{
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@@ -404,9 +407,10 @@ var file_actions_proto_rawDesc = []byte{
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actions/actions.proto

@@ -8,6 +8,7 @@ message Action {
     enum ActionType {
         MOVE = 0;
         CHAT = 1;
+        DISCONNECT = 2;
     }
 
     ActionType type = 1;

main.go

@@ -1,7 +1,10 @@
 package main
 
 import (
+	"bufio"
+	"encoding/binary"
 	"fmt"
+	"io"
 	"log"
 	"net"
 	"sync"
@@ -40,6 +43,11 @@ func main() {
 	defer ln.Close()
 	fmt.Printf("Server is listening on port %s\n", port)
 
+	// Create ticker for fixed game state updates
+	ticker := time.NewTicker(tickRate)
+	defer ticker.Stop()
+
+	// Handle incoming connections in a separate goroutine
 	go func() {
 		for {
 			conn, err := ln.Accept()
@@ -51,13 +59,10 @@ func main() {
 		}
 	}()
 
-	lastTick := time.Now()
-	for {
-		if time.Since(lastTick) >= tickRate {
-			lastTick = time.Now()
+	// Main game loop
+	for range ticker.C {
 		processActions()
 	}
-	}
 }
 
 func handleConnection(conn net.Conn) {
@@ -76,22 +81,29 @@ func handleConnection(conn net.Conn) {
 		PlayerId:    int32(playerID),
 		CurrentTick: 0,
 	}
-	data, err := proto.Marshal(serverMsg)
-	if err != nil {
-		log.Printf("Failed to marshal ServerMessage for player %d: %v", playerID, err)
-		return
-	}
-	if _, err := conn.Write(data); err != nil {
+	if err := writeMessage(conn, serverMsg); err != nil {
 		log.Printf("Failed to send player ID to player %d: %v", playerID, err)
 		return
 	}
 
 	// Listen for incoming actions from this player
-	buf := make([]byte, 4096)
+	reader := bufio.NewReader(conn)
 	for {
-		n, err := conn.Read(buf)
-		if err != nil {
-			log.Printf("Error reading from player %d: %v", playerID, err)
+		// Read message length
+		lengthBuf := make([]byte, 4)
+		if _, err := io.ReadFull(reader, lengthBuf); err != nil {
+			log.Printf("Error reading message length from player %d: %v", playerID, err)
+			delete(players, playerID)
+			delete(playerConns, playerID)
+			delete(actionQueue, playerID)
+			return
+		}
+		messageLength := binary.BigEndian.Uint32(lengthBuf)
+
+		// Read message body
+		messageBuf := make([]byte, messageLength)
+		if _, err := io.ReadFull(reader, messageBuf); err != nil {
+			log.Printf("Error reading message from player %d: %v", playerID, err)
 			delete(players, playerID)
 			delete(playerConns, playerID)
 			delete(actionQueue, playerID)
@@ -99,13 +111,22 @@ func handleConnection(conn net.Conn) {
 		}
 
 		batch := &pb.ActionBatch{}
-		if err := proto.Unmarshal(buf[:n], batch); err != nil {
+		if err := proto.Unmarshal(messageBuf, batch); err != nil {
 			log.Printf("Failed to unmarshal action batch for player %d: %v", playerID, err)
 			continue
 		}
 
 		// Queue the actions for processing
 		if batch.PlayerId == int32(playerID) {
+			for _, action := range batch.Actions {
+				if action.Type == pb.Action_DISCONNECT {
+					log.Printf("Player %d disconnected gracefully", playerID)
+					delete(players, playerID)
+					delete(playerConns, playerID)
+					delete(actionQueue, playerID)
+					return
+				}
+			}
 			actionQueue[playerID] = append(actionQueue[playerID], batch.Actions...)
 		}
 	}
@@ -154,8 +175,10 @@ func processActions() {
 	currentTick := time.Now().UnixNano() / int64(tickRate)
 	state := &pb.ServerMessage{
 		CurrentTick: currentTick,
+		Players:     make([]*pb.PlayerState, 0, len(players)),
 	}
 
+	// Convert players to PlayerState
 	for id, p := range players {
 		p.Lock()
 		state.Players = append(state.Players, &pb.PlayerState{
@@ -166,21 +189,34 @@ func processActions() {
 		p.Unlock()
 	}
 
-	// Add chat messages to the server message
+	// Add chat messages to the state
 	chatMutex.RLock()
-	state.ChatMessages = chatHistory
+	state.ChatMessages = chatHistory[max(0, len(chatHistory)-5):] // Only send last 5 messages
 	chatMutex.RUnlock()
 
-	data, err := proto.Marshal(state)
-	if err != nil {
-		log.Printf("Failed to marshal game state: %v", err)
-		return
-	}
-
 	// Send to each connected player
 	for _, conn := range playerConns {
-		if _, err := conn.Write(data); err != nil {
+		if err := writeMessage(conn, state); err != nil {
 			log.Printf("Failed to send update: %v", err)
 		}
 	}
 }
+
+// Helper function to write length-prefixed messages
+func writeMessage(conn net.Conn, msg proto.Message) error {
+	data, err := proto.Marshal(msg)
+	if err != nil {
+		return err
+	}
+
+	// Write length prefix
+	lengthBuf := make([]byte, 4)
+	binary.BigEndian.PutUint32(lengthBuf, uint32(len(data)))
+	if _, err := conn.Write(lengthBuf); err != nil {
+		return err
+	}
+
+	// Write message body
+	_, err = conn.Write(data)
+	return err
+}