blenc

type AuthInfo = []byte

type BE interface {

	// Open opens given blob data for reading.
	//
	// If returned error is not nil, the reader must be nil. Otherwise it is required to
	// close the reader once done working with it.
	Open(ctx context.Context, name common.BlobName, key EncryptionKey) (io.ReadCloser, error)

	// Create completely new blob with given dataset, as a result, the blob name and optional
	// AuthInfo that allows blob's update is returned
	Create(ctx context.Context, blobType common.BlobType, r io.Reader) (common.BlobName, EncryptionKey, AuthInfo, error)

	// Update updates given blob type with new data,
	// The update must happen within a single blob name (i.e. it can not end up with blob with different name)
	// and may not be available for certain blob types such as static blobs.
	// A valid writer info is necessary to ensure a correct new content can be created
	Update(ctx context.Context, name common.BlobName, ai AuthInfo, key EncryptionKey, r io.Reader) error

	// Exists does check whether blob of given name exists. It forwards the call
	// to underlying datastore.
	Exists(ctx context.Context, name common.BlobName) (bool, error)

	// Delete tries to remove blob with given name. It forwards the call to
	// underlying datastore.
	Delete(ctx context.Context, name common.BlobName) error
}

type EncryptionKey = cipherfactory.Key