size += len(block)
	}
	return size
}

// Writes all the data blocks from encoded blocks until requested
// outSize length. Provides a way to skip bytes until the offset.
func writeDataBlocks(ctx context.Context, dst io.Writer, enBlocks [][]byte, dataBlocks int, offset int64, length int64) (int64, error) {
	// Offset and out size cannot be negative.
	if offset < 0 || length < 0 {
		return 0, errUnexpected
	}

			// For all errors that cannot be reconstructed fail the read operation.
			return -1, err
		}

		if err = e.DecodeDataBlocks(bufs); err != nil {
			return -1, err
		}

		n, err := writeDataBlocks(ctx, writer, bufs, e.dataBlocks, blockOffset, blockLength)
		if err != nil {
			return -1, err
		}

		bytesWritten += n
	}

	if bytesWritten != length {
		return bytesWritten, errLessData
	}