feat: use sse to fetch new messages (close #70)

middleware/sse.go

@@ -0,0 +1,13 @@
+package middleware
+
+import "github.com/gin-gonic/gin"
+
+func SetSSEHeaders() func(c *gin.Context) {
+	return func(c *gin.Context) {
+		c.Writer.Header().Set("Content-Type", "text/event-stream")
+		c.Writer.Header().Set("Cache-Control", "no-cache")
+		c.Writer.Header().Set("Connection", "keep-alive")
+		c.Writer.Header().Set("Transfer-Encoding", "chunked")
+		c.Next()
+	}
+}