Interface Fetcher

pkg/blob/fetcher.go:35–50

Fetcher is the minimal interface for retrieving a blob from storage. The full storage interface is blobserver.Storage.

// Fetcher is the minimal interface for retrieving a blob from storage.
// The full storage interface is blobserver.Storage.
type Fetcher interface {
	// Fetch returns a blob. If the blob is not found then
	// os.ErrNotExist should be returned for the error (not a wrapped
	// error with a ErrNotExist inside)
	//
	// The contents are not guaranteed to match the digest of the
	// provided Ref (e.g. when streamed over HTTP). Paranoid
	// callers should verify them.
	//
	// The caller must close blob.
	//
	// The provided context is used until blob is closed and its
	// cancellation should but may not necessarily cause reads from
	// blob to fail with an error.
	Fetch(context.Context, Ref) (blob io.ReadCloser, size uint32, err error)
}

// ErrUnimplemented is returned by optional interfaces when their
// wrapped values don't implemented the optional interface.