circuitpython/examples/usercmodule/cexample/examplemodule.c
Laurens Valk a67989aa20 examples/usercmodule: Add example of a native C class.
This shows how ports can add their own custom types/classes.

It is part of the unix coverage build, so we can use it for tests too.

Signed-off-by: Laurens Valk <laurens@pybricks.com>
2022-11-23 11:46:17 +11:00

92 lines
3.7 KiB
C

// Include MicroPython API.
#include "py/runtime.h"
// Used to get the time in the Timer class example.
#include "py/mphal.h"
// This is the function which will be called from Python as cexample.add_ints(a, b).
STATIC mp_obj_t example_add_ints(mp_obj_t a_obj, mp_obj_t b_obj) {
// Extract the ints from the micropython input objects.
int a = mp_obj_get_int(a_obj);
int b = mp_obj_get_int(b_obj);
// Calculate the addition and convert to MicroPython object.
return mp_obj_new_int(a + b);
}
// Define a Python reference to the function above.
STATIC MP_DEFINE_CONST_FUN_OBJ_2(example_add_ints_obj, example_add_ints);
// This structure represents Timer instance objects.
typedef struct _example_Timer_obj_t {
// All objects start with the base.
mp_obj_base_t base;
// Everything below can be thought of as instance attributes, but they
// cannot be accessed by MicroPython code directly. In this example we
// store the time at which the object was created.
mp_uint_t start_time;
} example_Timer_obj_t;
// This is the Timer.time() method. After creating a Timer object, this
// can be called to get the time elapsed since creating the Timer.
STATIC mp_obj_t example_Timer_time(mp_obj_t self_in) {
// The first argument is self. It is cast to the *example_Timer_obj_t
// type so we can read its attributes.
example_Timer_obj_t *self = MP_OBJ_TO_PTR(self_in);
// Get the elapsed time and return it as a MicroPython integer.
mp_uint_t elapsed = mp_hal_ticks_ms() - self->start_time;
return mp_obj_new_int_from_uint(elapsed);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(example_Timer_time_obj, example_Timer_time);
// This represents Timer.__new__ and Timer.__init__, which is called when
// the user instantiates a Timer object.
STATIC mp_obj_t example_Timer_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
// Allocates the new object and sets the type.
example_Timer_obj_t *self = m_new_obj(example_Timer_obj_t);
self->base.type = (mp_obj_type_t *)type;
// Initializes the time for this Timer instance.
self->start_time = mp_hal_ticks_ms();
// The make_new function always returns self.
return MP_OBJ_FROM_PTR(self);
}
// This collects all methods and other static class attributes of the Timer.
// The table structure is similar to the module table, as detailed below.
STATIC const mp_rom_map_elem_t example_Timer_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR_time), MP_ROM_PTR(&example_Timer_time_obj) },
};
STATIC MP_DEFINE_CONST_DICT(example_Timer_locals_dict, example_Timer_locals_dict_table);
// This defines the type(Timer) object.
MP_DEFINE_CONST_OBJ_TYPE(
example_type_Timer,
MP_QSTR_Timer,
MP_TYPE_FLAG_NONE,
make_new, example_Timer_make_new,
locals_dict, &example_Timer_locals_dict
);
// Define all properties of the module.
// Table entries are key/value pairs of the attribute name (a string)
// and the MicroPython object reference.
// All identifiers and strings are written as MP_QSTR_xxx and will be
// optimized to word-sized integers by the build system (interned strings).
STATIC const mp_rom_map_elem_t example_module_globals_table[] = {
{ MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_cexample) },
{ MP_ROM_QSTR(MP_QSTR_add_ints), MP_ROM_PTR(&example_add_ints_obj) },
{ MP_ROM_QSTR(MP_QSTR_Timer), MP_ROM_PTR(&example_type_Timer) },
};
STATIC MP_DEFINE_CONST_DICT(example_module_globals, example_module_globals_table);
// Define module object.
const mp_obj_module_t example_user_cmodule = {
.base = { &mp_type_module },
.globals = (mp_obj_dict_t *)&example_module_globals,
};
// Register the module to make it available in Python.
MP_REGISTER_MODULE(MP_QSTR_cexample, example_user_cmodule);