Feat: UDP 框架

cmd/internal/peer/udp_client.go

@@ -0,0 +1,202 @@
+package peer
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"path/filepath"
+	"sync/atomic"
+
+	"omnisocketgo/cmd/internal/latencylog"
+	"omnisocketgo/cmd/internal/protocol"
+	"omnisocketgo/cmd/internal/transport"
+)
+
+// UDPClient 表示一个通过 UDP 连接到 server 的 peer。
+type UDPClient struct {
+	id     string
+	conn   *transport.UDPConn
+	logger latencylog.Logger
+
+	nextID uint64
+}
+
+// DialUDP 通过 UDP 连接到 server，并发送 register 消息完成身份注册。
+func DialUDP(serverAddr, peerID string, opts ...Option) (*UDPClient, error) {
+	options := clientOptions{
+		logger: latencylog.NoopLogger{},
+	}
+	for _, opt := range opts {
+		opt(&options)
+	}
+	if options.logger == nil {
+		options.logger = latencylog.NoopLogger{}
+	}
+
+	udpServerAddr, err := net.ResolveUDPAddr("udp", serverAddr)
+	if err != nil {
+		return nil, fmt.Errorf("peer: resolve udp server addr %s: %w", serverAddr, err)
+	}
+
+	var localAddr *net.UDPAddr
+	if options.bindIP != "" {
+		ip := net.ParseIP(options.bindIP)
+		if ip == nil {
+			return nil, fmt.Errorf("peer: invalid bind ip %q", options.bindIP)
+		}
+		localAddr = &net.UDPAddr{IP: ip}
+	}
+
+	rawConn, err := net.DialUDP("udp", localAddr, udpServerAddr)
+	if err != nil {
+		return nil, fmt.Errorf("peer: dial udp server %s: %w", serverAddr, err)
+	}
+
+	conn, err := transport.NewUDPConn(
+		rawConn,
+		nil, // peer 侧已连接模式，不需要指定 peerAddr
+		transport.WithUDPLogger(options.logger, latencylog.NodeRolePeer, peerID),
+		transport.WithUDPTXTimestampDebugLogger(options.txTimestampDebugLogger),
+	)
+	if err != nil {
+		_ = rawConn.Close()
+		return nil, fmt.Errorf("peer: create udp transport conn: %w", err)
+	}
+
+	client := &UDPClient{
+		id:     peerID,
+		conn:   conn,
+		logger: options.logger,
+	}
+
+	// 发送 register 消息完成身份注册
+	if err := conn.Send(protocol.Message{
+		Type: protocol.MessageTypeRegister,
+		From: peerID,
+		To:   protocol.ServerPeerID,
+	}); err != nil {
+		_ = conn.Close()
+		return nil, fmt.Errorf("peer: udp register with server: %w", err)
+	}
+
+	return client, nil
+}
+
+// ID 返回当前 client 的 peer 标识。
+func (c *UDPClient) ID() string {
+	return c.id
+}
+
+// SendText 向目标 peer 发送一条文本消息。
+func (c *UDPClient) SendText(to, body string) error {
+	msg := protocol.Message{
+		Type: protocol.MessageTypeText,
+		ID:   c.nextMessageID(),
+		From: c.id,
+		To:   to,
+	}
+	latencylog.LogMessageEvent(c.logger, latencylog.NodeRolePeer, c.id, latencylog.EventAAppPrepBegin, msg)
+
+	msg.Body = []byte(body)
+
+	return c.conn.Send(msg)
+}
+
+// SendFile 向目标 peer 发送一条文件消息。
+func (c *UDPClient) SendFile(to, fileName string, body []byte) error {
+	msg := protocol.Message{
+		Type:     protocol.MessageTypeFile,
+		ID:       c.nextMessageID(),
+		From:     c.id,
+		To:       to,
+		FileName: fileName,
+	}
+	latencylog.LogMessageEvent(c.logger, latencylog.NodeRolePeer, c.id, latencylog.EventAAppPrepBegin, msg)
+
+	bodyCopy := make([]byte, len(body))
+	copy(bodyCopy, body)
+
+	msg.Body = bodyCopy
+
+	return c.conn.Send(msg)
+}
+
+// SendFilePath 从本地文件读取内容并发送给目标 peer。
+func (c *UDPClient) SendFilePath(to, path string) error {
+	msg := protocol.Message{
+		Type:     protocol.MessageTypeFile,
+		ID:       c.nextMessageID(),
+		From:     c.id,
+		To:       to,
+		FileName: filepath.Base(path),
+	}
+	latencylog.LogMessageEvent(c.logger, latencylog.NodeRolePeer, c.id, latencylog.EventAAppPrepBegin, msg)
+
+	body, err := os.ReadFile(path)
+	if err != nil {
+		return fmt.Errorf("peer: read file %s: %w", path, err)
+	}
+
+	msg.Body = body
+
+	return c.conn.Send(msg)
+}
+
+// Receive 读取一条来自 server 的消息。
+func (c *UDPClient) Receive() (protocol.Message, error) {
+	msg, _, err := c.conn.Receive()
+	if err != nil {
+		return protocol.Message{}, fmt.Errorf("peer: udp receive from server: %w", err)
+	}
+
+	latencylog.LogMessageEvent(c.logger, latencylog.NodeRolePeer, c.id, latencylog.EventBAppRecv, msg)
+
+	return msg, nil
+}
+
+// ReceiveLoop 持续接收 server 消息并交给 handler 处理。
+func (c *UDPClient) ReceiveLoop(handler func(protocol.Message) error) error {
+	return c.conn.ReceiveLoop(func(msg protocol.Message, _ *net.UDPAddr) error {
+		switch msg.Type {
+		case protocol.MessageTypeText, protocol.MessageTypeFile, protocol.MessageTypeError:
+			latencylog.LogMessageEvent(c.logger, latencylog.NodeRolePeer, c.id, latencylog.EventBAppRecv, msg)
+			return handler(msg)
+		default:
+			return fmt.Errorf("peer: unexpected message type from server: %s", msg.Type)
+		}
+	})
+}
+
+// PersistMessage 将收到的业务消息写入本地磁盘。
+func (c *UDPClient) PersistMessage(msg protocol.Message, inboxDir string) (string, error) {
+	if !latencylog.IsBusinessMessage(msg) {
+		return "", fmt.Errorf("peer: cannot persist message type %s", msg.Type)
+	}
+	if inboxDir == "" {
+		return "", fmt.Errorf("peer: inbox directory is required")
+	}
+
+	latencylog.LogMessageEvent(c.logger, latencylog.NodeRolePeer, c.id, latencylog.EventBPersistBegin, msg)
+
+	if err := os.MkdirAll(inboxDir, 0o755); err != nil {
+		return "", fmt.Errorf("peer: create inbox dir %s: %w", inboxDir, err)
+	}
+
+	path, err := persistMessageToDisk(msg, inboxDir)
+	if err != nil {
+		return "", err
+	}
+
+	latencylog.LogMessageEvent(c.logger, latencylog.NodeRolePeer, c.id, latencylog.EventBPersistEnd, msg)
+
+	return path, nil
+}
+
+// Close 关闭与 server 的 UDP 连接。
+func (c *UDPClient) Close() error {
+	return c.conn.Close()
+}
+
+func (c *UDPClient) nextMessageID() uint64 {
+	return atomic.AddUint64(&c.nextID, 1)
+}