Added page cache middleware.

middleware/cache.go

@@ -4,9 +4,48 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/eko/gocache/v2/cache"
+	"github.com/eko/gocache/v2/marshaler"
+	"github.com/go-redis/redis/v8"
 	"github.com/labstack/echo/v4"
 )
 
+type CachedPage struct {
+	URL        string
+	HTML       []byte
+	StatusCode int
+	Headers    map[string]string
+}
+
+func PageCache(ch *cache.Cache) echo.MiddlewareFunc {
+	return func(next echo.HandlerFunc) echo.HandlerFunc {
+		return func(c echo.Context) error {
+			key := c.Request().URL.String()
+			res, err := marshaler.New(ch).Get(c.Request().Context(), key, new(CachedPage))
+			if err != nil {
+				if err == redis.Nil {
+					c.Logger().Infof("no cached page for: %s", key)
+				} else {
+					c.Logger().Errorf("failed getting cached page: %s", key)
+					c.Logger().Error(err)
+				}
+				return next(c)
+			}
+
+			page := res.(*CachedPage)
+
+			if page.Headers != nil {
+				for k, v := range page.Headers {
+					c.Response().Header().Set(k, v)
+				}
+			}
+			c.Logger().Infof("serving cached page for: %s", key)
+
+			return c.HTMLBlob(page.StatusCode, page.HTML)
+		}
+	}
+}
+
 func CacheControl(maxAge time.Duration) echo.MiddlewareFunc {
 	return func(next echo.HandlerFunc) echo.HandlerFunc {
 		return func(c echo.Context) error {