直播：画质可选、只读 /live/info、弹幕 WS 透传；Nginx 弹幕路径

Made-with: Cursor

server/pkg/weblive/danmaku.go

@@ -0,0 +1,96 @@
+package weblive
+
+import (
+	"encoding/json"
+	"strings"
+	"sync"
+	"time"
+	"unicode/utf8"
+
+	"github.com/gin-gonic/gin"
+	"github.com/gorilla/websocket"
+)
+
+const maxDanmakuRunes = 120
+
+var (
+	danmakuClientsMu sync.Mutex
+	danmakuClients   = make(map[*websocket.Conn]struct{})
+)
+
+// handleDanmakuWS 弹幕：客户端发 JSON {"text":"..."}，服务端立刻向所有连接广播 {"type":"dm","text","ts"}，不落库
+func handleDanmakuWS(c *gin.Context) {
+	ws, err := upgrader.Upgrade(c.Writer, c.Request, nil)
+	if err != nil {
+		return
+	}
+	ws.SetReadLimit(4096)
+
+	danmakuClientsMu.Lock()
+	danmakuClients[ws] = struct{}{}
+	danmakuClientsMu.Unlock()
+
+	defer func() {
+		danmakuClientsMu.Lock()
+		delete(danmakuClients, ws)
+		danmakuClientsMu.Unlock()
+		_ = ws.Close()
+	}()
+
+	for {
+		mt, payload, err := ws.ReadMessage()
+		if err != nil {
+			return
+		}
+		if mt != websocket.TextMessage {
+			continue
+		}
+		text := extractDanmakuText(payload)
+		if text == "" {
+			continue
+		}
+		out, err := json.Marshal(map[string]interface{}{
+			"type": "dm",
+			"text": text,
+			"ts":   time.Now().UnixMilli(),
+		})
+		if err != nil {
+			continue
+		}
+		danmakuBroadcast(out)
+	}
+}
+
+func extractDanmakuText(payload []byte) string {
+	var v struct {
+		Text string `json:"text"`
+	}
+	if err := json.Unmarshal(payload, &v); err != nil {
+		return ""
+	}
+	t := strings.TrimSpace(v.Text)
+	if t == "" {
+		return ""
+	}
+	if utf8.RuneCountInString(t) <= maxDanmakuRunes {
+		return t
+	}
+	runes := []rune(t)
+	return string(runes[:maxDanmakuRunes])
+}
+
+func danmakuBroadcast(b []byte) {
+	danmakuClientsMu.Lock()
+	defer danmakuClientsMu.Unlock()
+	dead := make([]*websocket.Conn, 0)
+	for conn := range danmakuClients {
+		_ = conn.SetWriteDeadline(time.Now().Add(8 * time.Second))
+		if err := conn.WriteMessage(websocket.TextMessage, b); err != nil {
+			dead = append(dead, conn)
+		}
+	}
+	for _, conn := range dead {
+		delete(danmakuClients, conn)
+		_ = conn.Close()
+	}
+}