micropython/extmod/modutimeq.c

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2014 Damien P. George
* Copyright (c) 2016-2017 Paul Sokolovsky
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <string.h>
#include "py/objlist.h"
#include "py/runtime.h"
#include "py/smallint.h"
#if MICROPY_PY_UTIMEQ
#define MODULO MICROPY_PY_UTIME_TICKS_PERIOD
#define DEBUG 0
// the algorithm here is modelled on CPython's heapq.py
struct qentry {
mp_uint_t time;
mp_uint_t id;
mp_obj_t callback;
mp_obj_t args;
};
typedef struct _mp_obj_utimeq_t {
mp_obj_base_t base;
mp_uint_t alloc;
mp_uint_t len;
struct qentry items[];
} mp_obj_utimeq_t;
STATIC mp_uint_t utimeq_id;
STATIC mp_obj_utimeq_t *get_heap(mp_obj_t heap_in) {
return MP_OBJ_TO_PTR(heap_in);
}
STATIC bool time_less_than(struct qentry *item, struct qentry *parent) {
mp_uint_t item_tm = item->time;
mp_uint_t parent_tm = parent->time;
mp_uint_t res = parent_tm - item_tm;
if (res == 0) {
// TODO: This actually should use the same "ring" logic
// as for time, to avoid artifacts when id's overflow.
return item->id < parent->id;
}
if ((mp_int_t)res < 0) {
res += MODULO;
}
return res && res < (MODULO / 2);
}
STATIC mp_obj_t utimeq_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
mp_arg_check_num(n_args, n_kw, 1, 1, false);
mp_uint_t alloc = mp_obj_get_int(args[0]);
mp_obj_utimeq_t *o = m_new_obj_var(mp_obj_utimeq_t, struct qentry, alloc);
o->base.type = type;
memset(o->items, 0, sizeof(*o->items) * alloc);
o->alloc = alloc;
o->len = 0;
return MP_OBJ_FROM_PTR(o);
}
STATIC void heap_siftdown(mp_obj_utimeq_t *heap, mp_uint_t start_pos, mp_uint_t pos) {
struct qentry item = heap->items[pos];
while (pos > start_pos) {
mp_uint_t parent_pos = (pos - 1) >> 1;
struct qentry *parent = &heap->items[parent_pos];
bool lessthan = time_less_than(&item, parent);
if (lessthan) {
heap->items[pos] = *parent;
pos = parent_pos;
} else {
break;
}
}
heap->items[pos] = item;
}
STATIC void heap_siftup(mp_obj_utimeq_t *heap, mp_uint_t pos) {
mp_uint_t start_pos = pos;
mp_uint_t end_pos = heap->len;
struct qentry item = heap->items[pos];
for (mp_uint_t child_pos = 2 * pos + 1; child_pos < end_pos; child_pos = 2 * pos + 1) {
// choose right child if it's <= left child
if (child_pos + 1 < end_pos) {
bool lessthan = time_less_than(&heap->items[child_pos], &heap->items[child_pos + 1]);
if (!lessthan) {
child_pos += 1;
}
}
// bubble up the smaller child
heap->items[pos] = heap->items[child_pos];
pos = child_pos;
}
heap->items[pos] = item;
heap_siftdown(heap, start_pos, pos);
}
STATIC mp_obj_t mod_utimeq_heappush(size_t n_args, const mp_obj_t *args) {
(void)n_args;
mp_obj_t heap_in = args[0];
mp_obj_utimeq_t *heap = get_heap(heap_in);
if (heap->len == heap->alloc) {
mp_raise_msg(&mp_type_IndexError, "queue overflow");
}
mp_uint_t l = heap->len;
heap->items[l].time = MP_OBJ_SMALL_INT_VALUE(args[1]);
heap->items[l].id = utimeq_id++;
heap->items[l].callback = args[2];
heap->items[l].args = args[3];
heap_siftdown(heap, 0, heap->len);
heap->len++;
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_utimeq_heappush_obj, 4, 4, mod_utimeq_heappush);
STATIC mp_obj_t mod_utimeq_heappop(mp_obj_t heap_in, mp_obj_t list_ref) {
mp_obj_utimeq_t *heap = get_heap(heap_in);
if (heap->len == 0) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_IndexError, "empty heap"));
}
mp_obj_list_t *ret = MP_OBJ_TO_PTR(list_ref);
if (!MP_OBJ_IS_TYPE(list_ref, &mp_type_list) || ret->len < 3) {
mp_raise_TypeError(NULL);
}
struct qentry *item = &heap->items[0];
ret->items[0] = MP_OBJ_NEW_SMALL_INT(item->time);
ret->items[1] = item->callback;
ret->items[2] = item->args;
heap->len -= 1;
heap->items[0] = heap->items[heap->len];
heap->items[heap->len].callback = MP_OBJ_NULL; // so we don't retain a pointer
heap->items[heap->len].args = MP_OBJ_NULL;
if (heap->len) {
heap_siftup(heap, 0);
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(mod_utimeq_heappop_obj, mod_utimeq_heappop);
STATIC mp_obj_t mod_utimeq_peektime(mp_obj_t heap_in) {
mp_obj_utimeq_t *heap = get_heap(heap_in);
if (heap->len == 0) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_IndexError, "empty heap"));
}
struct qentry *item = &heap->items[0];
return MP_OBJ_NEW_SMALL_INT(item->time);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_utimeq_peektime_obj, mod_utimeq_peektime);
#if DEBUG
STATIC mp_obj_t mod_utimeq_dump(mp_obj_t heap_in) {
mp_obj_utimeq_t *heap = get_heap(heap_in);
for (int i = 0; i < heap->len; i++) {
printf(UINT_FMT "\t%p\t%p\n", heap->items[i].time,
MP_OBJ_TO_PTR(heap->items[i].callback), MP_OBJ_TO_PTR(heap->items[i].args));
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_utimeq_dump_obj, mod_utimeq_dump);
#endif
STATIC mp_obj_t utimeq_unary_op(mp_unary_op_t op, mp_obj_t self_in) {
mp_obj_utimeq_t *self = MP_OBJ_TO_PTR(self_in);
switch (op) {
case MP_UNARY_OP_BOOL: return mp_obj_new_bool(self->len != 0);
case MP_UNARY_OP_LEN: return MP_OBJ_NEW_SMALL_INT(self->len);
default: return MP_OBJ_NULL; // op not supported
}
}
STATIC const mp_rom_map_elem_t utimeq_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR_push), MP_ROM_PTR(&mod_utimeq_heappush_obj) },
{ MP_ROM_QSTR(MP_QSTR_pop), MP_ROM_PTR(&mod_utimeq_heappop_obj) },
{ MP_ROM_QSTR(MP_QSTR_peektime), MP_ROM_PTR(&mod_utimeq_peektime_obj) },
#if DEBUG
{ MP_ROM_QSTR(MP_QSTR_dump), MP_ROM_PTR(&mod_utimeq_dump_obj) },
#endif
};
STATIC MP_DEFINE_CONST_DICT(utimeq_locals_dict, utimeq_locals_dict_table);
STATIC const mp_obj_type_t utimeq_type = {
{ &mp_type_type },
.name = MP_QSTR_utimeq,
.make_new = utimeq_make_new,
.unary_op = utimeq_unary_op,
.locals_dict = (void*)&utimeq_locals_dict,
};
STATIC const mp_rom_map_elem_t mp_module_utimeq_globals_table[] = {
{ MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_utimeq) },
{ MP_ROM_QSTR(MP_QSTR_utimeq), MP_ROM_PTR(&utimeq_type) },
};
STATIC MP_DEFINE_CONST_DICT(mp_module_utimeq_globals, mp_module_utimeq_globals_table);
const mp_obj_module_t mp_module_utimeq = {
.base = { &mp_type_module },
.globals = (mp_obj_dict_t*)&mp_module_utimeq_globals,
};
#endif //MICROPY_PY_UTIMEQ