Initial QSfera import

Server/services/thumbnails/pkg/thumbnail/storage/filesystem.go

@@ -0,0 +1,118 @@
+package storage
+
+import (
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	"github.com/pkg/errors"
+
+	"github.com/qsfera/server/pkg/log"
+	"github.com/qsfera/server/services/thumbnails/pkg/config"
+)
+
+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
+}
+
+// Stat returns if a file for the given key exists on the filesystem
+func (s FileSystem) Stat(key string) bool {
+	img := filepath.Join(s.root, filesDir, key)
+	if _, err := os.Stat(img); err != nil {
+		return false
+	}
+	return true
+}
+
+// Get returns the file content for the given key
+func (s FileSystem) Get(key string) ([]byte, error) {
+	img := filepath.Join(s.root, filesDir, key)
+	content, err := os.ReadFile(img)
+	if err != nil {
+		if !errors.Is(err, fs.ErrNotExist) {
+			s.logger.Debug().Str("err", err.Error()).Str("key", key).Msg("could not load thumbnail from store")
+		}
+		return nil, err
+	}
+	return content, nil
+}
+
+// Put stores image data in the file system for the given key
+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.CreateTemp(dir, "tmpthumb")
+		if err != nil {
+			return errors.Wrapf(err, "could not create temporary file for \"%s\"", key)
+		}
+		defer f.Close()
+
+		// if there was a problem writing, remove the temporary file
+		if _, writeErr := f.Write(img); writeErr != nil {
+			if remErr := os.Remove(f.Name()); remErr != nil {
+				return errors.Wrapf(remErr, "could not cleanup temporary file for \"%s\"", key)
+			}
+			return errors.Wrapf(writeErr, "could not write to temporary file for \"%s\"", key)
+		}
+
+		// if there wasn't a problem, ensure the data is written into disk
+		if synErr := f.Sync(); synErr != nil {
+			return errors.Wrapf(synErr, "could not sync temporary file data into the disk for \"%s\"", key)
+		}
+
+		// rename the temporary file to the final file
+		if renErr := os.Rename(f.Name(), imgPath); renErr != nil {
+			// if we couldn't rename, remove the temporary file
+			if remErr := os.Remove(f.Name()); remErr != nil {
+				return errors.Wrapf(remErr, "rename failed and could not cleanup temporary file for \"%s\"", key)
+			}
+			return errors.Wrapf(renErr, "could not rename temporary file to \"%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]
+
+	parts := []string{strconv.Itoa(r.Resolution.Dx()), "x", strconv.Itoa(r.Resolution.Dy())}
+
+	if r.Characteristic != "" {
+		parts = append(parts, "-", r.Characteristic)
+	}
+
+	parts = append(parts, ".", filetype)
+
+	return filepath.Join(checksum[:2], checksum[2:4], checksum[4:], strings.Join(parts, ""))
+}