refactor(thumb): new thumb pipeline model to generate thumb on-demand

pkg/filesystem/driver/cos/handler.go

@@ -222,7 +222,7 @@ func (handler Driver) Delete(ctx context.Context, files []string) ([]string, err
 }
 
 // Thumb 获取文件缩略图
-func (handler Driver) Thumb(ctx context.Context, path string) (*response.ContentResponse, error) {
+func (handler Driver) Thumb(ctx context.Context, file *model.File) (*response.ContentResponse, error) {
 	var (
 		thumbSize = [2]uint{400, 300}
 		ok        = false
@@ -234,7 +234,7 @@ func (handler Driver) Thumb(ctx context.Context, path string) (*response.Content
 
 	source, err := handler.signSourceURL(
 		ctx,
-		path,
+		file.SourceName,
 		int64(model.GetIntSetting("preview_timeout", 60)),
 		&urlOption{},
 	)

pkg/filesystem/driver/handler.go

@@ -2,12 +2,18 @@ package driver
 
 import (
 	"context"
+	"fmt"
+	model "github.com/cloudreve/Cloudreve/v3/models"
 	"github.com/cloudreve/Cloudreve/v3/pkg/filesystem/fsctx"
 	"github.com/cloudreve/Cloudreve/v3/pkg/filesystem/response"
 	"github.com/cloudreve/Cloudreve/v3/pkg/serializer"
 	"net/url"
 )
 
+var (
+	ErrorThumbNotExist = fmt.Errorf("thumb not exist")
+)
+
 // Handler 存储策略适配器
 type Handler interface {
 	// 上传文件, dst为文件存储路径，size 为文件大小。上下文关闭
@@ -22,7 +28,7 @@ type Handler interface {
 
 	// 获取缩略图，可直接在ContentResponse中返回文件数据流，也可指
 	// 定为重定向
-	Thumb(ctx context.Context, path string) (*response.ContentResponse, error)
+	Thumb(ctx context.Context, file *model.File) (*response.ContentResponse, error)
 
 	// 获取外链/下载地址，
 	// url - 站点本身地址,

pkg/filesystem/driver/local/handler.go

@@ -12,6 +12,7 @@ import (
 	model "github.com/cloudreve/Cloudreve/v3/models"
 	"github.com/cloudreve/Cloudreve/v3/pkg/auth"
 	"github.com/cloudreve/Cloudreve/v3/pkg/cache"
+	"github.com/cloudreve/Cloudreve/v3/pkg/filesystem/driver"
 	"github.com/cloudreve/Cloudreve/v3/pkg/filesystem/fsctx"
 	"github.com/cloudreve/Cloudreve/v3/pkg/filesystem/response"
 	"github.com/cloudreve/Cloudreve/v3/pkg/serializer"
@@ -194,15 +195,20 @@ func (handler Driver) Delete(ctx context.Context, files []string) ([]string, err
 }
 
 // Thumb 获取文件缩略图
-func (handler Driver) Thumb(ctx context.Context, path string) (*response.ContentResponse, error) {
-	file, err := handler.Get(ctx, path+model.GetSettingByNameWithDefault("thumb_file_suffix", "._thumb"))
+func (handler Driver) Thumb(ctx context.Context, file *model.File) (*response.ContentResponse, error) {
+	if file.MetadataSerialized[model.ThumbStatusMetadataKey] == model.ThumbStatusNotExist {
+		// Tell invoker to generate a thumb
+		return nil, driver.ErrorThumbNotExist
+	}
+
+	thumbFile, err := handler.Get(ctx, file.SourceName+model.GetSettingByNameWithDefault("thumb_file_suffix", "._thumb"))
 	if err != nil {
 		return nil, err
 	}
 
 	return &response.ContentResponse{
 		Redirect: false,
-		Content:  file,
+		Content:  thumbFile,
 	}, nil
 }
 

pkg/filesystem/driver/onedrive/handler.go

@@ -136,7 +136,7 @@ func (handler Driver) Delete(ctx context.Context, files []string) ([]string, err
 }
 
 // Thumb 获取文件缩略图
-func (handler Driver) Thumb(ctx context.Context, path string) (*response.ContentResponse, error) {
+func (handler Driver) Thumb(ctx context.Context, file *model.File) (*response.ContentResponse, error) {
 	var (
 		thumbSize = [2]uint{400, 300}
 		ok        = false
@@ -145,7 +145,7 @@ func (handler Driver) Thumb(ctx context.Context, path string) (*response.Content
 		return nil, errors.New("failed to get thumbnail size")
 	}
 
-	res, err := handler.Client.GetThumbURL(ctx, path, thumbSize[0], thumbSize[1])
+	res, err := handler.Client.GetThumbURL(ctx, file.SourceName, thumbSize[0], thumbSize[1])
 	if err != nil {
 		// 如果出现异常，就清空文件的pic_info
 		if file, ok := ctx.Value(fsctx.FileModelCtx).(model.File); ok {

pkg/filesystem/driver/oss/handler.go

@@ -293,7 +293,7 @@ func (handler *Driver) Delete(ctx context.Context, files []string) ([]string, er
 }
 
 // Thumb 获取文件缩略图
-func (handler *Driver) Thumb(ctx context.Context, path string) (*response.ContentResponse, error) {
+func (handler *Driver) Thumb(ctx context.Context, file *model.File) (*response.ContentResponse, error) {
 	// 初始化客户端
 	if err := handler.InitOSSClient(true); err != nil {
 		return nil, err
@@ -312,7 +312,7 @@ func (handler *Driver) Thumb(ctx context.Context, path string) (*response.Conten
 	thumbOption := []oss.Option{oss.Process(thumbParam)}
 	thumbURL, err := handler.signSourceURL(
 		ctx,
-		path,
+		file.SourceName,
 		int64(model.GetIntSetting("preview_timeout", 60)),
 		thumbOption,
 	)

pkg/filesystem/driver/qiniu/handler.go

@@ -230,7 +230,7 @@ func (handler *Driver) Delete(ctx context.Context, files []string) ([]string, er
 }
 
 // Thumb 获取文件缩略图
-func (handler *Driver) Thumb(ctx context.Context, path string) (*response.ContentResponse, error) {
+func (handler *Driver) Thumb(ctx context.Context, file *model.File) (*response.ContentResponse, error) {
 	var (
 		thumbSize = [2]uint{400, 300}
 		ok        = false
@@ -239,12 +239,12 @@ func (handler *Driver) Thumb(ctx context.Context, path string) (*response.Conten
 		return nil, errors.New("无法获取缩略图尺寸设置")
 	}
 
-	path = fmt.Sprintf("%s?imageView2/1/w/%d/h/%d", path, thumbSize[0], thumbSize[1])
+	thumb := fmt.Sprintf("%s?imageView2/1/w/%d/h/%d", file.SourceName, thumbSize[0], thumbSize[1])
 	return &response.ContentResponse{
 		Redirect: true,
 		URL: handler.signSourceURL(
 			ctx,
-			path,
+			thumb,
 			int64(model.GetIntSetting("preview_timeout", 60)),
 		),
 	}, nil

pkg/filesystem/driver/remote/handler.go

@@ -204,8 +204,8 @@ func (handler *Driver) Delete(ctx context.Context, files []string) ([]string, er
 }
 
 // Thumb 获取文件缩略图
-func (handler *Driver) Thumb(ctx context.Context, path string) (*response.ContentResponse, error) {
-	sourcePath := base64.RawURLEncoding.EncodeToString([]byte(path))
+func (handler *Driver) Thumb(ctx context.Context, file *model.File) (*response.ContentResponse, error) {
+	sourcePath := base64.RawURLEncoding.EncodeToString([]byte(file.SourceName))
 	thumbURL := handler.getAPIUrl("thumb") + "/" + sourcePath
 	ttl := model.GetIntSetting("preview_timeout", 60)
 	signedThumbURL, err := auth.SignURI(handler.AuthInstance, thumbURL, int64(ttl))

pkg/filesystem/driver/s3/handler.go

@@ -264,7 +264,7 @@ func (handler *Driver) Delete(ctx context.Context, files []string) ([]string, er
 }
 
 // Thumb 获取文件缩略图
-func (handler *Driver) Thumb(ctx context.Context, path string) (*response.ContentResponse, error) {
+func (handler *Driver) Thumb(ctx context.Context, file *model.File) (*response.ContentResponse, error) {
 	return nil, errors.New("未实现")
 }
 

pkg/filesystem/driver/shadow/masterinslave/handler.go

@@ -39,7 +39,7 @@ func (d *Driver) Get(ctx context.Context, path string) (response.RSCloser, error
 	return nil, ErrNotImplemented
 }
 
-func (d *Driver) Thumb(ctx context.Context, path string) (*response.ContentResponse, error) {
+func (d *Driver) Thumb(ctx context.Context, file *model.File) (*response.ContentResponse, error) {
 	return nil, ErrNotImplemented
 }
 

pkg/filesystem/driver/shadow/slaveinmaster/handler.go

@@ -102,7 +102,7 @@ func (d *Driver) Get(ctx context.Context, path string) (response.RSCloser, error
 	return nil, ErrNotImplemented
 }
 
-func (d *Driver) Thumb(ctx context.Context, path string) (*response.ContentResponse, error) {
+func (d *Driver) Thumb(ctx context.Context, file *model.File) (*response.ContentResponse, error) {
 	return nil, ErrNotImplemented
 }
 

pkg/filesystem/driver/upyun/handler.go

@@ -220,7 +220,7 @@ func (handler Driver) Delete(ctx context.Context, files []string) ([]string, err
 }
 
 // Thumb 获取文件缩略图
-func (handler Driver) Thumb(ctx context.Context, path string) (*response.ContentResponse, error) {
+func (handler Driver) Thumb(ctx context.Context, file *model.File) (*response.ContentResponse, error) {
 	var (
 		thumbSize = [2]uint{400, 300}
 		ok        = false
@@ -232,7 +232,7 @@ func (handler Driver) Thumb(ctx context.Context, path string) (*response.Content
 	thumbParam := fmt.Sprintf("!/fwfh/%dx%d", thumbSize[0], thumbSize[1])
 	thumbURL, err := handler.Source(
 		ctx,
-		path+thumbParam,
+		file.SourceName+thumbParam,
 		url.URL{},
 		int64(model.GetIntSetting("preview_timeout", 60)),
 		false,

pkg/filesystem/hooks.go

@@ -184,7 +184,6 @@ func SlaveAfterUpload(session *serializer.UploadSession) Hook {
 			Name:       fileInfo.FileName,
 			SourceName: fileInfo.SavePath,
 		}
-		fs.GenerateThumbnail(ctx, &file)
 
 		if session.Callback == "" {
 			return nil
@@ -231,21 +230,6 @@ func GenericAfterUpload(ctx context.Context, fs *FileSystem, fileHeader fsctx.Fi
 	return nil
 }
 
-// HookGenerateThumb 生成缩略图
-func HookGenerateThumb(ctx context.Context, fs *FileSystem, fileHeader fsctx.FileHeader) error {
-	// 异步尝试生成缩略图
-	fileMode := fileHeader.Info().Model.(*model.File)
-	if fs.Policy.IsThumbGenerateNeeded() {
-		fs.recycleLock.Lock()
-		go func() {
-			defer fs.recycleLock.Unlock()
-			_, _ = fs.Handler.Delete(ctx, []string{fileMode.SourceName + model.GetSettingByNameWithDefault("thumb_file_suffix", "._thumb")})
-			fs.GenerateThumbnail(ctx, fileMode)
-		}()
-	}
-	return nil
-}
-
 // HookClearFileHeaderSize 将FileHeader大小设定为0
 func HookClearFileHeaderSize(ctx context.Context, fs *FileSystem, fileHeader fsctx.FileHeader) error {
 	fileHeader.SetSize(0)

pkg/filesystem/image.go

@@ -2,13 +2,15 @@ package filesystem
 
 import (
 	"context"
-	"fmt"
+	"errors"
+	"io"
 	"sync"
 
 	"runtime"
 
 	model "github.com/cloudreve/Cloudreve/v3/models"
 	"github.com/cloudreve/Cloudreve/v3/pkg/conf"
+	"github.com/cloudreve/Cloudreve/v3/pkg/filesystem/driver"
 	"github.com/cloudreve/Cloudreve/v3/pkg/filesystem/fsctx"
 	"github.com/cloudreve/Cloudreve/v3/pkg/filesystem/response"
 	"github.com/cloudreve/Cloudreve/v3/pkg/thumb"
@@ -20,14 +22,11 @@ import (
    ================
 */
 
-// HandledExtension 可以生成缩略图的文件扩展名
-var HandledExtension = []string{"jpg", "jpeg", "png", "gif"}
-
 // GetThumb 获取文件的缩略图
 func (fs *FileSystem) GetThumb(ctx context.Context, id uint) (*response.ContentResponse, error) {
 	// 根据 ID 查找文件
 	err := fs.resetFileIDIfNotExist(ctx, id)
-	if err != nil || fs.FileTarget[0].PicInfo == "" {
+	if err != nil {
 		return &response.ContentResponse{
 			Redirect: false,
 		}, ErrObjectNotExist
@@ -36,12 +35,11 @@ func (fs *FileSystem) GetThumb(ctx context.Context, id uint) (*response.ContentR
 	w, h := fs.GenerateThumbnailSize(0, 0)
 	ctx = context.WithValue(ctx, fsctx.ThumbSizeCtx, [2]uint{w, h})
 	ctx = context.WithValue(ctx, fsctx.FileModelCtx, fs.FileTarget[0])
-	res, err := fs.Handler.Thumb(ctx, fs.FileTarget[0].SourceName)
-
-	// 本地存储策略出错时重新生成缩略图
-	if err != nil && fs.Policy.Type == "local" {
+	res, err := fs.Handler.Thumb(ctx, &fs.FileTarget[0])
+	if errors.Is(err, driver.ErrorThumbNotExist) {
+		// Regenerate thumb if the thumb is not initialized yet
 		fs.GenerateThumbnail(ctx, &fs.FileTarget[0])
-		res, err = fs.Handler.Thumb(ctx, fs.FileTarget[0].SourceName)
+		res, err = fs.Handler.Thumb(ctx, &fs.FileTarget[0])
 	}
 
 	if err == nil && conf.SystemConfig.Mode == "master" {
@@ -84,14 +82,8 @@ func (pool *Pool) releaseWorker() {
 	<-pool.worker
 }
 
-// GenerateThumbnail 尝试为本地策略文件生成缩略图并获取图像原始大小
-// TODO 失败时，如果之前还有图像信息，则清除
+// GenerateThumbnail generates thumb for given file, upload the thumb file back with given suffix
 func (fs *FileSystem) GenerateThumbnail(ctx context.Context, file *model.File) {
-	// 判断是否可以生成缩略图
-	if !IsInExtensionList(HandledExtension, file.Name) {
-		return
-	}
-
 	// 新建上下文
 	newCtx, cancel := context.WithCancel(context.Background())
 	defer cancel()
@@ -105,36 +97,50 @@ func (fs *FileSystem) GenerateThumbnail(ctx context.Context, file *model.File) {
 	getThumbWorker().addWorker()
 	defer getThumbWorker().releaseWorker()
 
-	image, err := thumb.NewThumbFromFile(source, file.Name)
-	if err != nil {
-		util.Log().Warning("Cannot generate thumb because of failed to parse image %q: %s", file.SourceName, err)
+	r, w := io.Pipe()
+	defer w.Close()
+
+	errChan := make(chan error, 1)
+	go func() {
+		errChan <- fs.Handler.Put(newCtx, &fsctx.FileStream{
+			Mode:     fsctx.Overwrite,
+			File:     io.NopCloser(r),
+			Seeker:   nil,
+			SavePath: file.SourceName + model.GetSettingByNameWithDefault("thumb_file_suffix", "._thumb"),
+		})
+	}()
+
+	if err = thumb.Generators.Generate(source, w, file.Name, model.GetSettingByNames(
+		"thumb_width",
+		"thumb_height",
+		"thumb_builtin_enabled",
+		"thumb_vips_enabled",
+		"thumb_ffmpeg_enabled",
+		"thumb_vips_path",
+		"thumb_ffmpeg_path",
+	)); err != nil {
+		util.Log().Warning("Failed to generate thumb for %s: %s", file.Name, err)
+		if errors.Is(err, thumb.ErrNotAvailable) {
+			// Mark this file as no thumb available
+			_ = updateThumbStatus(file, model.ThumbStatusNotAvailable)
+		}
+
 		return
 	}
 
-	// 获取原始图像尺寸
-	w, h := image.GetSize()
+	w.Close()
+	if err = <-errChan; err != nil {
+		util.Log().Warning("Failed to save thumb for %s: %s", file.Name, err)
+		return
+	}
 
-	// 生成缩略图
-	image.GetThumb(fs.GenerateThumbnailSize(w, h))
-	// 保存到文件
-	err = image.Save(util.RelativePath(file.SourceName + model.GetSettingByNameWithDefault("thumb_file_suffix", "._thumb")))
-	image = nil
 	if model.IsTrueVal(model.GetSettingByName("thumb_gc_after_gen")) {
 		util.Log().Debug("GenerateThumbnail runtime.GC")
 		runtime.GC()
 	}
 
-	if err != nil {
-		util.Log().Warning("Failed to save thumb: %s", err)
-		return
-	}
-
-	// 更新文件的图像信息
-	if file.Model.ID > 0 {
-		err = file.UpdatePicInfo(fmt.Sprintf("%d,%d", w, h))
-	} else {
-		file.PicInfo = fmt.Sprintf("%d,%d", w, h)
-	}
+	// Mark this file as thumb available
+	err = updateThumbStatus(file, model.ThumbStatusExist)
 
 	// 失败时删除缩略图文件
 	if err != nil {
@@ -144,5 +150,17 @@ func (fs *FileSystem) GenerateThumbnail(ctx context.Context, file *model.File) {
 
 // GenerateThumbnailSize 获取要生成的缩略图的尺寸
 func (fs *FileSystem) GenerateThumbnailSize(w, h int) (uint, uint) {
-	return uint(model.GetIntSetting("thumb_width", 400)), uint(model.GetIntSetting("thumb_width", 300))
+	return uint(model.GetIntSetting("thumb_width", 400)), uint(model.GetIntSetting("thumb_height", 300))
+}
+
+func updateThumbStatus(file *model.File, status string) error {
+	if file.Model.ID > 0 {
+		return file.UpdateMetadata(map[string]string{
+			model.ThumbStatusMetadataKey: status,
+		})
+	} else {
+		file.MetadataSerialized[model.ThumbStatusMetadataKey] = status
+	}
+
+	return nil
 }

pkg/filesystem/manage.go

@@ -341,7 +341,6 @@ func (fs *FileSystem) listObjects(ctx context.Context, parent string, files []mo
 			ID:         hashid.HashID(subFolder.ID, hashid.FolderID),
 			Name:       subFolder.Name,
 			Path:       processedPath,
-			Pic:        "",
 			Size:       0,
 			Type:       "dir",
 			Date:       subFolder.UpdatedAt,
@@ -363,7 +362,7 @@ func (fs *FileSystem) listObjects(ctx context.Context, parent string, files []mo
 				ID:            hashid.HashID(file.ID, hashid.FileID),
 				Name:          file.Name,
 				Path:          processedPath,
-				Pic:           file.PicInfo,
+				Thumb:         file.ShouldLoadThumb(),
 				Size:          file.Size,
 				Type:          "file",
 				Date:          file.UpdatedAt,

pkg/filesystem/upload.go

@@ -210,7 +210,6 @@ func (fs *FileSystem) UploadFromStream(ctx context.Context, file *fsctx.FileStre
 		fs.Use("BeforeUpload", HookValidateCapacity)
 		fs.Use("AfterUploadCanceled", HookDeleteTempFile)
 		fs.Use("AfterUpload", GenericAfterUpload)
-		fs.Use("AfterUpload", HookGenerateThumb)
 		fs.Use("AfterValidateFailed", HookDeleteTempFile)
 	}
 	fs.Lock.Unlock()

pkg/serializer/explorer.go

@@ -36,7 +36,7 @@ type Object struct {
 	ID            string    `json:"id"`
 	Name          string    `json:"name"`
 	Path          string    `json:"path"`
-	Pic           string    `json:"pic"`
+	Thumb         bool      `json:"thumb"`
 	Size          uint64    `json:"size"`
 	Type          string    `json:"type"`
 	Date          time.Time `json:"date"`

pkg/thumb/builtin.go

@@ -1,7 +1,6 @@
 package thumb
 
 import (
-	"errors"
 	"fmt"
 	"image"
 	"image/gif"
@@ -18,6 +17,10 @@ import (
 	"golang.org/x/image/draw"
 )
 
+func init() {
+	RegisterGenerator(&Builtin{})
+}
+
 // Thumb 缩略图
 type Thumb struct {
 	src image.Image
@@ -30,7 +33,7 @@ func NewThumbFromFile(file io.Reader, name string) (*Thumb, error) {
 	ext := strings.ToLower(filepath.Ext(name))
 	// 无扩展名时
 	if len(ext) == 0 {
-		return nil, errors.New("未知的图像类型")
+		return nil, fmt.Errorf("unknown image format: %w", ErrPassThrough)
 	}
 
 	var err error
@@ -45,7 +48,7 @@ func NewThumbFromFile(file io.Reader, name string) (*Thumb, error) {
 	case "png":
 		img, err = png.Decode(file)
 	default:
-		return nil, errors.New("unknown image format")
+		return nil, fmt.Errorf("unknown image format: %w", ErrPassThrough)
 	}
 	if err != nil {
 		return nil, err
@@ -70,18 +73,12 @@ func (image *Thumb) GetSize() (int, int) {
 }
 
 // Save 保存图像到给定路径
-func (image *Thumb) Save(path string) (err error) {
-	out, err := util.CreatNestedFile(path)
-
-	if err != nil {
-		return err
-	}
-	defer out.Close()
+func (image *Thumb) Save(w io.Writer) (err error) {
 	switch model.GetSettingByNameWithDefault("thumb_encode_method", "jpg") {
 	case "png":
-		err = png.Encode(out, image.src)
+		err = png.Encode(w, image.src)
 	default:
-		err = jpeg.Encode(out, image.src, &jpeg.Options{Quality: model.GetIntSetting("thumb_encode_quality", 85)})
+		err = jpeg.Encode(w, image.src, &jpeg.Options{Quality: model.GetIntSetting("thumb_encode_quality", 85)})
 	}
 
 	return err
@@ -141,9 +138,15 @@ func (image *Thumb) CreateAvatar(uid uint) error {
 	// 生成头像缩略图
 	src := image.src
 	for k, size := range []int{s, m, l} {
-		//image.src = resize.Resize(uint(size), uint(size), src, resize.Lanczos3)
+		out, err := util.CreatNestedFile(filepath.Join(savePath, fmt.Sprintf("avatar_%d_%d.png", uid, k)))
+
+		if err != nil {
+			return err
+		}
+		defer out.Close()
+
 		image.src = Resize(uint(size), uint(size), src)
-		err := image.Save(filepath.Join(savePath, fmt.Sprintf("avatar_%d_%d.png", uid, k)))
+		err = image.Save(out)
 		if err != nil {
 			return err
 		}
@@ -152,3 +155,23 @@ func (image *Thumb) CreateAvatar(uid uint) error {
 	return nil
 
 }
+
+type Builtin struct{}
+
+func (b Builtin) Generate(file io.Reader, w io.Writer, name string, options map[string]string) error {
+	img, err := NewThumbFromFile(file, name)
+	if err != nil {
+		return err
+	}
+
+	img.GetThumb(thumbSize(options))
+	return img.Save(w)
+}
+
+func (b Builtin) Priority() int {
+	return 300
+}
+
+func (b Builtin) EnableFlag() string {
+	return "thumb_builtin_enabled"
+}

pkg/thumb/pipeline.go

@@ -0,0 +1,88 @@
+package thumb
+
+import (
+	"errors"
+	"fmt"
+	model "github.com/cloudreve/Cloudreve/v3/models"
+	"github.com/cloudreve/Cloudreve/v3/pkg/util"
+	"io"
+	"sort"
+	"strconv"
+)
+
+// Generator generates a thumbnail for a given reader.
+type Generator interface {
+	Generate(file io.Reader, w io.Writer, name string, options map[string]string) error
+
+	// Priority of execution order, smaller value means higher priority.
+	Priority() int
+
+	// EnableFlag returns the setting name to enable this generator.
+	EnableFlag() string
+}
+
+type (
+	GeneratorType string
+	GeneratorList []Generator
+)
+
+var (
+	Generators = GeneratorList{}
+
+	ErrPassThrough  = errors.New("pass through")
+	ErrNotAvailable = fmt.Errorf("thumbnail not available: %w", ErrPassThrough)
+)
+
+func (g GeneratorList) Len() int {
+	return len(g)
+}
+
+func (g GeneratorList) Less(i, j int) bool {
+	return g[i].Priority() < g[j].Priority()
+}
+
+func (g GeneratorList) Swap(i, j int) {
+	g[i], g[j] = g[j], g[i]
+}
+
+// RegisterGenerator registers a thumbnail generator.
+func RegisterGenerator(generator Generator) {
+	Generators = append(Generators, generator)
+	sort.Sort(Generators)
+}
+
+func (p GeneratorList) Generate(file io.Reader, w io.Writer, name string, options map[string]string) error {
+	for _, generator := range p {
+		if model.IsTrueVal(options[generator.EnableFlag()]) {
+			err := generator.Generate(file, w, name, options)
+			if errors.Is(err, ErrPassThrough) {
+				util.Log().Debug("Failed to generate thumbnail for %s: %s, passing through to next generator.", name, err)
+				continue
+			}
+
+			return err
+		}
+	}
+	return ErrNotAvailable
+}
+
+func (p GeneratorList) Priority() int {
+	return 0
+}
+
+func (p GeneratorList) EnableFlag() string {
+	return ""
+}
+
+func thumbSize(options map[string]string) (uint, uint) {
+	w, h := uint(400), uint(300)
+	if wParsed, err := strconv.Atoi(options["thumb_width"]); err == nil {
+		w = uint(wParsed)
+	}
+
+	if hParsed, err := strconv.Atoi(options["thumb_height"]); err == nil {
+		h = uint(hParsed)
+	}
+
+	return w, h
+}

pkg/webdav/webdav.go

@@ -386,7 +386,6 @@ func (h *Handler) handlePut(w http.ResponseWriter, r *http.Request, fs *filesyst
 		fs.Use("AfterUploadCanceled", filesystem.HookDeleteTempFile)
 		fs.Use("AfterUploadCanceled", filesystem.HookCancelContext)
 		fs.Use("AfterUpload", filesystem.GenericAfterUpload)
-		fs.Use("AfterUpload", filesystem.HookGenerateThumb)
 		fs.Use("AfterValidateFailed", filesystem.HookDeleteTempFile)
 	}