1 files changed, 17 insertions, 3 deletions

diff --git a/echo/middleware/cache_headers_middleware.go b/echo/middleware/cache_headers_middleware.go
index f168dfd..73df9b2 100644
--- a/echo/middleware/cache_headers_middleware.go
+++ b/echo/middleware/cache_headers_middleware.go
@@ -10,19 +10,33 @@ import (
 )
 
 var (
+        CacheNeverMiddleware    = CacheHeadersMiddleware(0)
         CacheOneHourMiddleware  = CacheHeadersMiddleware(1 * time.Hour)
         CacheOneDayMiddleware   = CacheHeadersMiddleware(1 * gltime.Day)
         CacheOneMonthMiddleware = CacheHeadersMiddleware(30 * gltime.Day)
 )
 
+func setHeaderMissing(c echo.Context, name string, value string) {
+        h := c.Response().Header()
+        if v := h.Get(name); v == "" {
+                h.Set(name, value)
+        }
+}
+
 func CacheHeadersMiddleware(d time.Duration) echo.MiddlewareFunc {
         ds := int(d.Seconds())
 
         return func(next echo.HandlerFunc) echo.HandlerFunc {
                 return func(c echo.Context) error {
-                        c.Response().Header().Set("Vary", "Accept-Encoding")
-                        c.Response().Header().Set("Cache-Control", fmt.Sprintf("public, max-age=%d", ds))
-                        c.Response().Header().Set("Expires", time.Now().Add(d).Format(time.RFC1123))
+                        c.Response().Header().Add(echo.HeaderVary, "Accept-Encoding")
+
+                        if ds == 0 {
+                                setHeaderMissing(c, "Cache-Control", "private, max-age=0, no-cache, no-store")
+                                setHeaderMissing(c, "Expires", time.Now().Add(-time.Hour).Format(time.RFC1123))
+                        } else {
+                                setHeaderMissing(c, "Cache-Control", fmt.Sprintf("public, max-age=%d", ds))
+                                setHeaderMissing(c, "Expires", time.Now().Add(d).Format(time.RFC1123))
+                        }
                         return next(c)
                 }
         }