package storage import ( "fmt" "io" "time" "github.com/docker/docker-registry/digest" ) // Layer provides a readable and seekable layer object. Typically, // implementations are *not* goroutine safe. type Layer interface { // http.ServeContent requires an efficient implementation of // ReadSeeker.Seek(0, os.SEEK_END). io.ReadSeeker io.Closer // Name returns the repository under which this layer is linked. Name() string // TODO(stevvooe): struggling with nomenclature: should this be "repo" or "name"? // Digest returns the unique digest of the blob, which is the tarsum for // layers. Digest() digest.Digest // CreatedAt returns the time this layer was created. Until we implement // Stat call on storagedriver, this just returns the zero time. CreatedAt() time.Time } // LayerUpload provides a handle for working with in-progress uploads. // Instances can be obtained from the LayerService.Upload and // LayerService.Resume. type LayerUpload interface { io.WriteCloser // UUID returns the identifier for this upload. UUID() string // Name of the repository under which the layer will be linked. Name() string // Offset returns the position of the last byte written to this layer. Offset() int64 // Finish marks the upload as completed, returning a valid handle to the // uploaded layer. The final size and digest are validated against the // contents of the uploaded layer. Finish(size int64, digest digest.Digest) (Layer, error) // Cancel the layer upload process. Cancel() error } var ( // ErrLayerUnknown returned when layer cannot be found. ErrLayerUnknown = fmt.Errorf("unknown layer") // ErrLayerExists returned when layer already exists ErrLayerExists = fmt.Errorf("layer exists") // ErrLayerTarSumVersionUnsupported when tarsum is unsupported version. ErrLayerTarSumVersionUnsupported = fmt.Errorf("unsupported tarsum version") // ErrLayerUploadUnknown returned when upload is not found. ErrLayerUploadUnknown = fmt.Errorf("layer upload unknown") // ErrLayerInvalidDigest returned when tarsum check fails. ErrLayerInvalidDigest = fmt.Errorf("invalid layer digest") // ErrLayerInvalidLength returned when length check fails. ErrLayerInvalidLength = fmt.Errorf("invalid layer length") // ErrLayerClosed returned when an operation is attempted on a closed // Layer or LayerUpload. ErrLayerClosed = fmt.Errorf("layer closed") )