From c63cc5a2d25909cc4e2f2e7235f276ec66c32bf2 Mon Sep 17 00:00:00 2001
From: Ramires Viana <59319979+ramiresviana@users.noreply.github.com>
Date: Fri, 6 Aug 2021 12:31:39 +0000
Subject: [PATCH] fix: file caching directive

---
 http/preview.go | 27 ++++++++++-----------------
 http/raw.go     |  6 +-----
 http/utils.go   |  9 ---------
 3 files changed, 11 insertions(+), 31 deletions(-)

diff --git a/http/preview.go b/http/preview.go
index 051498ba..2fd46e3a 100644
--- a/http/preview.go
+++ b/http/preview.go
@@ -80,33 +80,26 @@ func handleImagePreview(w http.ResponseWriter, r *http.Request, imgSvc ImgServic
 		return errToStatus(err), err
 	}
 
-	isFresh := checkEtag(w, r, file.ModTime.Unix(), file.Size)
-	if isFresh {
-		return http.StatusNotModified, nil
-	}
-
 	cacheKey := previewCacheKey(file.Path, file.ModTime.Unix(), previewSize)
-	cachedFile, ok, err := fileCache.Load(r.Context(), cacheKey)
+	resizedImage, ok, err := fileCache.Load(r.Context(), cacheKey)
 	if err != nil {
 		return errToStatus(err), err
 	}
-	if ok {
-		_, _ = w.Write(cachedFile)
-		return 0, nil
+	if !ok {
+		resizedImage, err = createPreview(imgSvc, fileCache, file, previewSize, enableThumbnails, resizePreview)
+		if err != nil {
+			return errToStatus(err), err
+		}
 	}
 
-	resizedImage, err := createPreview(imgSvc, fileCache, file, previewSize, enableThumbnails, resizePreview)
-	if err != nil {
-		return errToStatus(err), err
-	}
-
-	_, _ = w.Write(resizedImage.Bytes())
+	w.Header().Set("Cache-Control", "private")
+	http.ServeContent(w, r, file.Name, file.ModTime, bytes.NewReader(resizedImage))
 
 	return 0, nil
 }
 
 func createPreview(imgSvc ImgService, fileCache FileCache,
-	file *files.FileInfo, previewSize PreviewSize, enableThumbnails, resizePreview bool) (*bytes.Buffer, error) {
+	file *files.FileInfo, previewSize PreviewSize, enableThumbnails, resizePreview bool) ([]byte, error) {
 	fd, err := file.Fs.Open(file.Path)
 	if err != nil {
 		return nil, err
@@ -144,7 +137,7 @@ func createPreview(imgSvc ImgService, fileCache FileCache,
 		}
 	}()
 
-	return buf, nil
+	return buf.Bytes(), nil
 }
 
 func previewCacheKey(fPath string, fTime int64, previewSize PreviewSize) string {
diff --git a/http/raw.go b/http/raw.go
index a24d474a..5004365a 100644
--- a/http/raw.go
+++ b/http/raw.go
@@ -200,11 +200,6 @@ func rawDirHandler(w http.ResponseWriter, r *http.Request, d *data, file *files.
 }
 
 func rawFileHandler(w http.ResponseWriter, r *http.Request, file *files.FileInfo) (int, error) {
-	isFresh := checkEtag(w, r, file.ModTime.Unix(), file.Size)
-	if isFresh {
-		return http.StatusNotModified, nil
-	}
-
 	fd, err := file.Fs.Open(file.Path)
 	if err != nil {
 		return http.StatusInternalServerError, err
@@ -213,6 +208,7 @@ func rawFileHandler(w http.ResponseWriter, r *http.Request, file *files.FileInfo
 
 	setContentDisposition(w, r, file)
 
+	w.Header().Set("Cache-Control", "private")
 	http.ServeContent(w, r, file.Name, file.ModTime, fd)
 	return 0, nil
 }
diff --git a/http/utils.go b/http/utils.go
index 48ae2f40..c1c3fa65 100644
--- a/http/utils.go
+++ b/http/utils.go
@@ -3,7 +3,6 @@ package http
 import (
 	"encoding/json"
 	"errors"
-	"fmt"
 	"net/http"
 	"net/url"
 	"os"
@@ -67,11 +66,3 @@ func stripPrefix(prefix string, h http.Handler) http.Handler {
 		h.ServeHTTP(w, r2)
 	})
 }
-
-func checkEtag(w http.ResponseWriter, r *http.Request, fTime, fSize int64) bool {
-	etag := fmt.Sprintf("%x%x", fTime, fSize)
-	w.Header().Set("Cache-Control", "private")
-	w.Header().Set("Etag", etag)
-
-	return r.Header.Get("If-None-Match") == etag
-}