NNabla C Runtime uses platform independent and portable binary file
format that has name NNB.
In the NNB format, the following structure is adopted in order to
eliminate model dependency and realize a portable format.
@dotfile nnb.dot
- All members of the structure shall adopt something with a clear size. Since size often changes depending on system, enum specifies the size in the bit field.
- All actual data is managed by ID. When accessing data, refer to the relative position from the buffer area corresponding to the ID, as shown in the figure below, so that the pointer of the actual data can be acquired.
- In order to maintain downward compatibility, IDs determined at the
time of implementation such as
nn_function_t::typeandnn_variable_t::typeare kept unchanged, when new functions are added, when dealing with a new format We do not use the existing ID.
@dotfile nnb_memory.dot
@startuml skinparam monochrome true
hide methods
class nn_list_t { nn_size_t size pointer_index_t list }
class nn_data_type_t { NN_DATA_TYPE_FLOAT NN_DATA_TYPE_INT16 NN_DATA_TYPE_INT8 NN_DATA_TYPE_SIGN END_OF_NN_DATA_TYPE }
class nn_variable_t { uint32_t id nn_list_t shape nn_data_type_t type unsigned int fp_pos int32_t data_index }
class nn_function_type_t { NN_FUNCTION_XXXXX ... NN_END_OF_FUNCTION }
class nn_function_implement_t { NN_FUNCTION_IMPLEMENT_FLOAT NN_FUNCTION_IMPLEMENT_FIXED16 NN_FUNCTION_IMPLEMENT_FIXED8 NN_END_OF_SYSTEM_DEFINED_FUNCTION_IMPLEMENT NN_END_OF_IMPLEMENT }
class nn_function_t{ nn_function_type_t type nn_function_implement_t impl nn_list_t inputs nn_list_t outputs }
class nn_function_xxxxx_t { nn_function_type_t type nn_function_implement_t impl nn_list_t inputs nn_list_t outputs int32_t arg_for_xxxxx }
class nn_memory_t { nn_size_t num_of_data nn_size_t data_size }
class nn_network_t { uint32_t version nn_list_t buffers nn_list_t variables nn_list_t functions nn_list_t inputs nn_list_t outputs nn_memory_t memory }
nn_network_t *--- nn_list_t nn_function_t *--- nn_list_t nn_variable_t *--- nn_list_t
nn_variable_t *- nn_data_type_t
nn_network_t *-- nn_variable_t nn_network_t *-- nn_variable_t nn_network_t *-- nn_variable_t nn_network_t *-- nn_memory_t nn_network_t *- nn_function_t
nn_function_t <|-- nn_function_xxxxx_t nn_function_t *---- nn_function_type_t nn_function_t *---- nn_function_implement_t
@enduml