Use packet queue for bot framework.

Providing concurrently-safing for sending packets.

bot/client.go

@@ -1,15 +1,19 @@
 package bot
 
 import (
+	"errors"
+
 	"github.com/google/uuid"
 
 	"github.com/Tnze/go-mc/data/packetid"
 	"github.com/Tnze/go-mc/net"
+	pk "github.com/Tnze/go-mc/net/packet"
+	"github.com/Tnze/go-mc/net/queue"
 )
 
 // Client is used to access Minecraft server
 type Client struct {
-	Conn *net.Conn
+	Conn *Conn
 	Auth Auth
 
 	Name string
@@ -37,6 +41,71 @@ func NewClient() *Client {
 	}
 }
 
+// Conn is a concurrently-safe warpper of net.Conn with packet queue.
+// Note that not all methods are concurrently-safe.
+type Conn struct {
+	conn       *net.Conn
+	send, recv queue.Queue[pk.Packet]
+	rerr       error
+}
+
+func warpConn(c *net.Conn) *Conn {
+	wc := Conn{
+		conn: c,
+		send: make(queue.ChannelQueue[pk.Packet], 256),
+		recv: make(queue.ChannelQueue[pk.Packet], 256),
+		rerr: nil,
+	}
+	go func() {
+		for {
+			var p pk.Packet
+			if err := c.ReadPacket(&p); err != nil {
+				wc.rerr = err
+				break
+			}
+			if ok := wc.recv.Push(p); !ok {
+				break
+			}
+		}
+		wc.recv.Close()
+	}()
+	go func() {
+		for {
+			p, ok := wc.send.Pull()
+			if !ok {
+				break
+			}
+			if err := c.WritePacket(p); err != nil {
+				break
+			}
+		}
+	}()
+
+	return &wc
+}
+
+func (c *Conn) ReadPacket(p *pk.Packet) error {
+	packet, ok := c.recv.Pull()
+	if !ok {
+		return c.rerr
+	}
+	*p = packet
+	return nil
+}
+
+func (c *Conn) WritePacket(p pk.Packet) error {
+	ok := c.send.Push(p)
+	if !ok {
+		return errors.New("queue is full")
+	}
+	return nil
+}
+
+func (c *Conn) Close() error {
+	c.send.Close()
+	return c.conn.Close()
+}
+
 // Position is a 3D vector.
 type Position struct {
 	X, Y, Z int