Installation

The API is available via PyPI: pip install metaffi-api

MetaFFIRuntime Class

MetaFFIRuntime provides a simple FFI framework to connect Python with other languages. Pass the runtime plugin name to the constructor (e.g. "go", "openjdk"), and call load_runtime_plugin to load the runtime.

Once the runtime is loaded, use load_module to load a module and receive an instance of MetaFFIModule.

Methods

__init__(runtime_plugin: str)

Constructor specifying the requested runtime plugin to use.

Parameters:

  • runtime_plugin — The name of the runtime plugin (e.g. "go", "openjdk")

load_runtime_plugin()

Loads the runtime of the plugin.

release_runtime_plugin()

Releases the loaded runtime. After calling this function, any loaded entity must not be used.

load_module(module_path: str) -> MetaFFIModule

Loads a foreign module from the given module_path. Returns a MetaFFIModule object representing the foreign module.

The module_path may contain multiple modules separated by semicolons (for cases like dependencies). Each runtime plugin specifies in its documentation what it expects.

Parameters:

  • module_path — Path to the module(s) to load

Returns: Instance of MetaFFIModule

MetaFFIModule Class

Provides the load_entity method, which loads a foreign entity and returns it as a Callable.

The class should not be created directly — use MetaFFIRuntime.load_module instead.

Methods

load_entity(entity_path: str, params_metaffi_types: List[metaffi_type_info], retval_metaffi_types: List[metaffi_type_info]) -> Callable

Loads a foreign entity from the module and returns a Callable that invokes it.

If the entity is an instance method or field, the first parameter is the object instance (see Entity Path for the instance_required tag).

Parameters:

  • entity_path — Entity path string locating the entity within the module
  • params_metaffi_types — List of metaffi_type_info objects specifying parameter types, or None
  • retval_metaffi_types — List of metaffi_type_info objects specifying return types, or None

Returns: A Callable that accepts the parameters defined in params_metaffi_types and returns corresponding values. Raises an exception on error.

Callback

make_metaffi_callable(f: Callable) -> Callable

Wraps the given callable f and returns a cross-language callable. The returned callable can be passed to other languages.

Parameters:

  • f — A Python callable

Returns: MetaFFI-enabled Callable

MetaFFI Types in Python3

MetaFFI Type Python3 Type
metaffi_float64_type float
metaffi_float32_type float
metaffi_int8_type int
metaffi_int16_type int
metaffi_int32_type int
metaffi_int64_type int
metaffi_uint8_type int
metaffi_uint16_type int
metaffi_uint32_type int
metaffi_uint64_type int
metaffi_bool_type bool
metaffi_char8_type bytes
metaffi_char16_type bytes
metaffi_char32_type bytes
metaffi_string8_type str
metaffi_string16_type str
metaffi_string32_type str
metaffi_handle_type metaffi_handle
metaffi_any_type Any
metaffi_null_type None
metaffi_callable_type Callable (via make_metaffi_callable)
metaffi_float64_array_type list
metaffi_float32_array_type list
metaffi_int8_array_type list
metaffi_int16_array_type list
metaffi_int32_array_type list
metaffi_int64_array_type list
metaffi_uint8_array_type list
metaffi_uint16_array_type list
metaffi_uint32_array_type list
metaffi_uint64_array_type list
metaffi_bool_array_type list
metaffi_char8_array_type list
metaffi_string8_array_type list
metaffi_string16_array_type list
metaffi_string32_array_type list
metaffi_any_array_type list
metaffi_handle_array_type list
metaffi_size_array_type list