package lfs import ( "code.gitea.io/gitea/models" "crypto/sha256" "encoding/hex" "errors" "io" "os" "path/filepath" ) var ( errHashMismatch = errors.New("Content hash does not match OID") errSizeMismatch = errors.New("Content size does not match") ) // ContentStore provides a simple file system based storage. type ContentStore struct { BasePath string } // Get takes a Meta object and retrieves the content from the store, returning // it as an io.Reader. If fromByte > 0, the reader starts from that byte func (s *ContentStore) Get(meta *models.LFSMetaObject, fromByte int64) (io.ReadCloser, error) { path := filepath.Join(s.BasePath, transformKey(meta.Oid)) f, err := os.Open(path) if err != nil { return nil, err } if fromByte > 0 { _, err = f.Seek(fromByte, os.SEEK_CUR) } return f, err } // Put takes a Meta object and an io.Reader and writes the content to the store. func (s *ContentStore) Put(meta *models.LFSMetaObject, r io.Reader) error { path := filepath.Join(s.BasePath, transformKey(meta.Oid)) tmpPath := path + ".tmp" dir := filepath.Dir(path) if err := os.MkdirAll(dir, 0750); err != nil { return err } file, err := os.OpenFile(tmpPath, os.O_CREATE|os.O_WRONLY|os.O_EXCL, 0640) if err != nil { return err } defer os.Remove(tmpPath) hash := sha256.New() hw := io.MultiWriter(hash, file) written, err := io.Copy(hw, r) if err != nil { file.Close() return err } file.Close() if written != meta.Size { return errSizeMismatch } shaStr := hex.EncodeToString(hash.Sum(nil)) if shaStr != meta.Oid { return errHashMismatch } return os.Rename(tmpPath, path) } // Exists returns true if the object exists in the content store. func (s *ContentStore) Exists(meta *models.LFSMetaObject) bool { path := filepath.Join(s.BasePath, transformKey(meta.Oid)) if _, err := os.Stat(path); os.IsNotExist(err) { return false } return true } func transformKey(key string) string { if len(key) < 5 { return key } return filepath.Join(key[0:2], key[2:4], key[4:]) }