first commit

framing.go

@@ -0,0 +1,39 @@
+package gobridge
+
+import (
+	"encoding/binary"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net"
+)
+
+// writeMsg 将消息以 [4字节长度][JSON载荷] 格式写入连接
+func writeMsg(conn net.Conn, msg Message) error {
+	data, err := json.Marshal(msg)
+	if err != nil {
+		return fmt.Errorf("marshal message: %w", err)
+	}
+	header := make([]byte, 4)
+	binary.BigEndian.PutUint32(header, uint32(len(data)))
+	_, err = conn.Write(append(header, data...))
+	return err
+}
+
+// readMsg 从连接中读取一条消息
+func readMsg(conn net.Conn) (Message, error) {
+	header := make([]byte, 4)
+	if _, err := io.ReadFull(conn, header); err != nil {
+		return Message{}, fmt.Errorf("read header: %w", err)
+	}
+	length := binary.BigEndian.Uint32(header)
+	body := make([]byte, length)
+	if _, err := io.ReadFull(conn, body); err != nil {
+		return Message{}, fmt.Errorf("read body: %w", err)
+	}
+	var msg Message
+	if err := json.Unmarshal(body, &msg); err != nil {
+		return Message{}, fmt.Errorf("unmarshal message: %w", err)
+	}
+	return msg, nil
+}