Files
opencloud/thumbnails/pkg/thumbnail/storage/filesystem.go
2021-04-27 22:09:45 +02:00

81 lines
2.2 KiB
Go

package storage
import (
"github.com/owncloud/ocis/ocis-pkg/log"
"github.com/owncloud/ocis/thumbnails/pkg/config"
"github.com/pkg/errors"
"os"
"path/filepath"
"strconv"
)
const (
filesDir = "files"
)
// NewFileSystemStorage creates a new instance of FileSystem
func NewFileSystemStorage(cfg config.FileSystemStorage, logger log.Logger) *FileSystem {
return &FileSystem{
root: cfg.RootDirectory,
logger: logger,
}
}
// FileSystem represents a storage for the thumbnails using the local file system.
type FileSystem struct {
root string
logger log.Logger
}
// Get loads the image from the file system.
func (s *FileSystem) Get(key string) ([]byte, bool) {
img := filepath.Join(s.root, filesDir, key)
content, err := os.ReadFile(img)
if err != nil {
if !os.IsNotExist(err) {
s.logger.Debug().Str("err", err.Error()).Str("key", key).Msg("could not load thumbnail from store")
}
return nil, false
}
return content, true
}
// Set writes the image to the file system.
func (s *FileSystem) Put(key string, img []byte) error {
imgPath := filepath.Join(s.root, filesDir, key)
dir := filepath.Dir(imgPath)
if err := os.MkdirAll(dir, 0700); err != nil {
return errors.Wrapf(err, "error while creating directory %s", dir)
}
if _, err := os.Stat(imgPath); os.IsNotExist(err) {
f, err := os.Create(imgPath)
if err != nil {
return errors.Wrapf(err, "could not create file \"%s\"", key)
}
defer f.Close()
if _, err = f.Write(img); err != nil {
return errors.Wrapf(err, "could not write to file \"%s\"", key)
}
}
return nil
}
// BuildKey generate the unique key for a thumbnail.
// The key is structure as follows:
//
// <first two letters of checksum>/<next two letters of checksum>/<rest of checksum>/<width>x<height>.<filetype>
//
// e.g. 97/9f/4c8db98f7b82e768ef478d3c8612/500x300.png
//
// The key also represents the path to the thumbnail in the filesystem under the configured root directory.
func (s *FileSystem) BuildKey(r Request) string {
checksum := r.Checksum
filetype := r.Types[0]
filename := strconv.Itoa(r.Resolution.Dx()) + "x" + strconv.Itoa(r.Resolution.Dy()) + "." + filetype
return filepath.Join(checksum[:2], checksum[2:4], checksum[4:], filename)
}