filebrowser/http/preview.go
2020-07-27 19:26:45 +02:00

128 lines
3.1 KiB
Go

package http
import (
"bytes"
"context"
"fmt"
"io"
"net/http"
"github.com/gorilla/mux"
"github.com/filebrowser/filebrowser/v2/files"
"github.com/filebrowser/filebrowser/v2/img"
)
const (
sizeThumb = "thumb"
sizeBig = "big"
)
type ImgService interface {
FormatFromExtension(ext string) (img.Format, error)
Resize(ctx context.Context, in io.Reader, width, height int, out io.Writer, options ...img.Option) error
}
type FileCache interface {
Store(ctx context.Context, key string, value []byte) error
Load(ctx context.Context, key string) ([]byte, bool, error)
}
func previewHandler(imgSvc ImgService, fileCache FileCache, enableThumbnails, resizePreview bool) handleFunc {
return withUser(func(w http.ResponseWriter, r *http.Request, d *data) (int, error) {
if !d.user.Perm.Download {
return http.StatusAccepted, nil
}
vars := mux.Vars(r)
size := vars["size"]
if size != sizeBig && size != sizeThumb {
return http.StatusNotImplemented, nil
}
file, err := files.NewFileInfo(files.FileOptions{
Fs: d.user.Fs,
Path: "/" + vars["path"],
Modify: d.user.Perm.Modify,
Expand: true,
Checker: d,
})
if err != nil {
return errToStatus(err), err
}
setContentDisposition(w, r, file)
switch file.Type {
case "image":
return handleImagePreview(w, r, imgSvc, fileCache, file, size, enableThumbnails, resizePreview)
default:
return http.StatusNotImplemented, fmt.Errorf("can't create preview for %s type", file.Type)
}
})
}
func handleImagePreview(w http.ResponseWriter, r *http.Request, imgSvc ImgService, fileCache FileCache,
file *files.FileInfo, size string, enableThumbnails, resizePreview bool) (int, error) {
format, err := imgSvc.FormatFromExtension(file.Extension)
if err != nil {
// Unsupported extensions directly return the raw data
if err == img.ErrUnsupportedFormat {
return rawFileHandler(w, r, file)
}
return errToStatus(err), err
}
cacheKey := file.Path + size
cachedFile, ok, err := fileCache.Load(r.Context(), cacheKey)
if err != nil {
return errToStatus(err), err
}
if ok {
_, _ = w.Write(cachedFile)
return 0, nil
}
fd, err := file.Fs.Open(file.Path)
if err != nil {
return errToStatus(err), err
}
defer fd.Close()
var (
width int
height int
options []img.Option
)
switch {
case size == sizeBig && resizePreview && format != img.FormatGif:
width = 1080
height = 1080
options = append(options, img.WithMode(img.ResizeModeFit), img.WithQuality(img.QualityMedium))
case size == sizeThumb && enableThumbnails:
width = 128
height = 128
options = append(options, img.WithMode(img.ResizeModeFill), img.WithQuality(img.QualityLow), img.WithFormat(img.FormatJpeg))
default:
if _, err := rawFileHandler(w, r, file); err != nil {
return errToStatus(err), err
}
return 0, nil
}
buf := &bytes.Buffer{}
if err := imgSvc.Resize(context.Background(), fd, width, height, buf, options...); err != nil {
return 0, err
}
go func() {
if err := fileCache.Store(context.Background(), cacheKey, buf.Bytes()); err != nil {
fmt.Printf("failed to cache resized image: %v", err)
}
}()
_, _ = w.Write(buf.Bytes())
return 0, nil
}