feat: generate thumbnail while get and improve thumbnail quality (#1680)

* Use disintegration/imaging to optimize thumbnail quality

* Generate thumbnail if not exists while GET it

* Changes for `go mod tidy`

* Changes for golang comments lint

---------
Co-authored-by: Athurg Feng <athurg@gooth.org>

common/image.go

@@ -4,18 +4,49 @@ import (
 	"bytes"
 	"fmt"
 	"image"
-
 	"image/jpeg"
 	"image/png"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/disintegration/imaging"
+)
+
+const (
+	ThumbnailDir  = ".thumbnail_cache"
+	ThumbnailSize = 302 // Thumbnail size should be defined by frontend
 )
 
-const ThumbnailPath = ".thumbnail_cache"
+func ResizeImageFile(dst, src string, mime string) error {
+	srcBytes, err := os.ReadFile(src)
+	if err != nil {
+		return fmt.Errorf("Failed to open %s: %s", src, err)
+	}
+
+	dstBytes, err := ResizeImageBlob(srcBytes, ThumbnailSize, mime)
+	if err != nil {
+		return fmt.Errorf("Failed to resise %s: %s", src, err)
+	}
+
+	err = os.MkdirAll(filepath.Dir(dst), os.ModePerm)
+	if err != nil {
+		return fmt.Errorf("Failed to mkdir for %s: %s", dst, err)
+	}
+
+	err = os.WriteFile(dst, dstBytes, 0666)
+	if err != nil {
+		return fmt.Errorf("Failed to write %s: %s", dst, err)
+	}
+
+	return nil
+}
 
 func ResizeImageBlob(data []byte, maxSize int, mime string) ([]byte, error) {
 	var err error
 	var oldImage image.Image
 
-	switch mime {
+	switch strings.ToLower(mime) {
 	case "image/jpeg":
 		oldImage, err = jpeg.Decode(bytes.NewReader(data))
 	case "image/png":
@@ -28,29 +59,7 @@ func ResizeImageBlob(data []byte, maxSize int, mime string) ([]byte, error) {
 		return nil, err
 	}
 
-	bounds := oldImage.Bounds()
-	if bounds.Dx() <= maxSize && bounds.Dy() <= maxSize {
-		return data, nil
-	}
-
-	oldBounds := oldImage.Bounds()
-
-	dy := maxSize
-	r := float32(oldBounds.Dy()) / float32(maxSize)
-	dx := int(float32(oldBounds.Dx()) / r)
-	if oldBounds.Dx() > oldBounds.Dy() {
-		dx = maxSize
-		r = float32(oldBounds.Dx()) / float32(maxSize)
-		dy = int(float32(oldBounds.Dy()) / r)
-	}
-
-	newBounds := image.Rect(0, 0, dx, dy)
-	newImage := image.NewRGBA(newBounds)
-	for x := 0; x < newBounds.Dx(); x++ {
-		for y := 0; y < newBounds.Dy(); y++ {
-			newImage.Set(x, y, oldImage.At(int(float32(x)*r), int(float32(y)*r)))
-		}
-	}
+	newImage := imaging.Resize(oldImage, maxSize, 0, imaging.NearestNeighbor)
 
 	var newBuffer bytes.Buffer
 	switch mime {

go.mod

@@ -8,6 +8,7 @@ require (
 	github.com/aws/aws-sdk-go-v2/credentials v1.13.12
 	github.com/aws/aws-sdk-go-v2/feature/s3/manager v1.11.51
 	github.com/aws/aws-sdk-go-v2/service/s3 v1.30.3
+	github.com/disintegration/imaging v1.6.2
 	github.com/google/uuid v1.3.0
 	github.com/gorilla/feeds v1.1.1
 	github.com/labstack/echo/v4 v4.9.0
@@ -24,6 +25,8 @@ require (
 	golang.org/x/oauth2 v0.5.0
 )
 
+require golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8 // indirect
+
 require (
 	github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.4.10 // indirect
 	github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.12.22 // indirect

go.sum

@@ -92,6 +92,8 @@ github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ3
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/disintegration/imaging v1.6.2 h1:w1LecBlG2Lnp8B3jk5zSuNqd7b4DXhcjwek1ei82L+c=
+github.com/disintegration/imaging v1.6.2/go.mod h1:44/5580QXChDfwIclfc/PCwrr44amcmDAg8hxG0Ewe4=
 github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1mIlRU8Am5FuJP05cCM98=
@@ -296,6 +298,8 @@ golang.org/x/exp v0.0.0-20230111222715-75897c7a292a h1:/YWeLOBWYV5WAQORVPkZF3Pq9
 golang.org/x/exp v0.0.0-20230111222715-75897c7a292a/go.mod h1:CxIveKay+FTh1D0yPZemJVgC/95VzuuOLq5Qi4xnoYc=
 golang.org/x/image v0.0.0-20190227222117-0694c2d4d067/go.mod h1:kZ7UVZpmo3dzQBMxlp+ypCbDeSB+sBbTgSJuh5dn5js=
 golang.org/x/image v0.0.0-20190802002840-cff245a6509b/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
+golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8 h1:hVwzHzIUGRjiF7EcUjqNxk3NCfkPxbDKRdnNE1Rpg0U=
+golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
 golang.org/x/lint v0.0.0-20190227174305-5b3e6a55c961/go.mod h1:wehouNa3lNwaWXcvxsM5YxQ5yQlVC4a0KAMCusXpPoU=
 golang.org/x/lint v0.0.0-20190301231843-5614ed5bae6f/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=

server/resource.go

@@ -164,29 +164,11 @@ func (s *Server) registerResourceRoutes(g *echo.Group) {
 			}
 
 			if filetype == "image/jpeg" || filetype == "image/png" {
-				_, err := sourceFile.Seek(0, io.SeekStart)
-				if err != nil {
-					return echo.NewHTTPError(http.StatusInternalServerError, "Failed to seek file").SetInternal(err)
-				}
-
-				fileBytes, err := io.ReadAll(sourceFile)
-				if err != nil {
-					return echo.NewHTTPError(http.StatusInternalServerError, "Failed to load file").SetInternal(err)
-				}
-
-				thumbnailBytes, err := common.ResizeImageBlob(fileBytes, 302, filetype)
+				thumbnailPath := path.Join(s.Profile.Data, common.ThumbnailDir, publicID)
+				err := common.ResizeImageFile(thumbnailPath, filePath, filetype)
 				if err != nil {
 					return echo.NewHTTPError(http.StatusInternalServerError, "Failed to generate thumbnail").SetInternal(err)
 				}
-
-				dir := filepath.Join(s.Profile.Data, common.ThumbnailPath)
-				if err = os.MkdirAll(dir, os.ModePerm); err != nil {
-					return echo.NewHTTPError(http.StatusInternalServerError, "Failed to create directory").SetInternal(err)
-				}
-				err = os.WriteFile(filepath.Join(dir, publicID), thumbnailBytes, 0666)
-				if err != nil {
-					return echo.NewHTTPError(http.StatusInternalServerError, "Failed to create thumbnail").SetInternal(err)
-				}
 			}
 
 			resourceCreate = &api.ResourceCreate{
@@ -346,7 +328,7 @@ func (s *Server) registerResourceRoutes(g *echo.Group) {
 				log.Warn(fmt.Sprintf("failed to delete local file with path %s", resource.InternalPath), zap.Error(err))
 			}
 
-			thumbnailPath := filepath.Join(s.Profile.Data, common.ThumbnailPath, resource.PublicID)
+			thumbnailPath := path.Join(s.Profile.Data, common.ThumbnailDir, resource.PublicID)
 			err = os.Remove(thumbnailPath)
 			if err != nil {
 				log.Warn(fmt.Sprintf("failed to delete local thumbnail with path %s", thumbnailPath), zap.Error(err))
@@ -442,9 +424,18 @@ func (s *Server) registerResourcePublicRoutes(g *echo.Group) {
 		if resource.InternalPath != "" {
 			resourcePath := resource.InternalPath
 			if c.QueryParam("thumbnail") == "1" && (resource.Type == "image/jpeg" || resource.Type == "image/png") {
-				thumbnailPath := filepath.Join(s.Profile.Data, common.ThumbnailPath, resource.PublicID)
+				thumbnailPath := path.Join(s.Profile.Data, common.ThumbnailDir, resource.PublicID)
 				if _, err := os.Stat(thumbnailPath); err == nil {
 					resourcePath = thumbnailPath
+				} else if os.IsNotExist(err) {
+					err := common.ResizeImageFile(thumbnailPath, resourcePath, resource.Type)
+					if err != nil {
+						return echo.NewHTTPError(http.StatusInternalServerError, fmt.Sprintf("Failed to resize resource: %s", resourcePath)).SetInternal(err)
+					}
+
+					resourcePath = thumbnailPath
+				} else {
+					return echo.NewHTTPError(http.StatusInternalServerError, fmt.Sprintf("Failed to check resource thumbnail stat: %s", thumbnailPath)).SetInternal(err)
 				}
 			}