Initial commit

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

middleware/requestid/requestid.go

@@ -0,0 +1,39 @@
+package requestid
+
+import (
+	"strings"
+
+	"github.com/gin-gonic/gin"
+)
+
+func New(opts ...Option) gin.HandlerFunc {
+	var cfg config = config{
+		generator: DefaultFenerator,
+	}
+	for _, opt := range opts {
+		opt(&cfg)
+	}
+	return func(c *gin.Context) {
+		rid := strings.TrimSpace(c.GetHeader(HeaderKey))
+		clientProvided := rid != "" && len(rid) <= 128
+		if !clientProvided {
+			rid = cfg.generator()
+		}
+		c.Request.Header.Set(HeaderKey, rid)
+		c.Header(HeaderKey, rid)
+		c.Set(ContextKey, rid)
+		c.Set(ClientProvidedContextKey, clientProvided)
+	}
+}
+
+// FromClient 仅返回客户端显式提供且长度合规的请求ID。
+func FromClient(c *gin.Context) (string, bool) {
+	if c == nil {
+		return "", false
+	}
+	provided, ok := c.Get(ClientProvidedContextKey)
+	if !ok || provided != true {
+		return "", false
+	}
+	return c.GetHeader(HeaderKey), true
+}