Commit ffe807f3 authored by Paul Sokolovsky's avatar Paul Sokolovsky
Browse files

extmod/moduheapq: Revert change for adhoc relative-time queue support.

Now that specialized utimeq module has been implenented, revert previous
adhoc changes to uheapq.

This reverts commit 0cbc0722.
parent efa206d9
......@@ -28,12 +28,9 @@
#include "py/objlist.h"
#include "py/runtime0.h"
#include "py/runtime.h"
#include "py/smallint.h"
#if MICROPY_PY_UHEAPQ
#define MODULO MICROPY_PY_UTIME_TICKS_PERIOD
// the algorithm here is modelled on CPython's heapq.py
STATIC mp_obj_list_t *get_heap(mp_obj_t heap_in) {
......@@ -43,33 +40,12 @@ STATIC mp_obj_list_t *get_heap(mp_obj_t heap_in) {
return MP_OBJ_TO_PTR(heap_in);
}
STATIC bool time_less_than(mp_obj_t item, mp_obj_t parent) {
if (!MP_OBJ_IS_TYPE(item, &mp_type_tuple) || !MP_OBJ_IS_TYPE(parent, &mp_type_tuple)) {
mp_raise_TypeError("");
}
mp_obj_tuple_t *item_p = MP_OBJ_TO_PTR(item);
mp_obj_tuple_t *parent_p = MP_OBJ_TO_PTR(parent);
mp_uint_t item_tm = MP_OBJ_SMALL_INT_VALUE(item_p->items[0]);
mp_uint_t parent_tm = MP_OBJ_SMALL_INT_VALUE(parent_p->items[0]);
mp_uint_t res = parent_tm - item_tm;
if ((mp_int_t)res < 0) {
res += MODULO;
}
return res < (MODULO / 2);
}
STATIC void heap_siftdown(mp_obj_list_t *heap, mp_uint_t start_pos, mp_uint_t pos, bool timecmp) {
STATIC void heap_siftdown(mp_obj_list_t *heap, mp_uint_t start_pos, mp_uint_t pos) {
mp_obj_t item = heap->items[pos];
while (pos > start_pos) {
mp_uint_t parent_pos = (pos - 1) >> 1;
mp_obj_t parent = heap->items[parent_pos];
bool lessthan;
if (MP_UNLIKELY(timecmp)) {
lessthan = time_less_than(item, parent);
} else {
lessthan = (mp_binary_op(MP_BINARY_OP_LESS, item, parent) == mp_const_true);
}
if (lessthan) {
if (mp_binary_op(MP_BINARY_OP_LESS, item, parent) == mp_const_true) {
heap->items[pos] = parent;
pos = parent_pos;
} else {
......@@ -79,43 +55,32 @@ STATIC void heap_siftdown(mp_obj_list_t *heap, mp_uint_t start_pos, mp_uint_t po
heap->items[pos] = item;
}
STATIC void heap_siftup(mp_obj_list_t *heap, mp_uint_t pos, bool timecmp) {
STATIC void heap_siftup(mp_obj_list_t *heap, mp_uint_t pos) {
mp_uint_t start_pos = pos;
mp_uint_t end_pos = heap->len;
mp_obj_t 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;
if (MP_UNLIKELY(timecmp)) {
lessthan = time_less_than(heap->items[child_pos], heap->items[child_pos + 1]);
} else {
lessthan = (mp_binary_op(MP_BINARY_OP_LESS, heap->items[child_pos], heap->items[child_pos + 1]) == mp_const_true);
}
if (!lessthan) {
child_pos += 1;
}
if (child_pos + 1 < end_pos && mp_binary_op(MP_BINARY_OP_LESS, heap->items[child_pos], heap->items[child_pos + 1]) == mp_const_false) {
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, timecmp);
heap_siftdown(heap, start_pos, pos);
}
STATIC mp_obj_t mod_uheapq_heappush(size_t n_args, const mp_obj_t *args) {
mp_obj_t heap_in = args[0];
STATIC mp_obj_t mod_uheapq_heappush(mp_obj_t heap_in, mp_obj_t item) {
mp_obj_list_t *heap = get_heap(heap_in);
mp_obj_list_append(heap_in, args[1]);
bool is_timeq = (n_args > 2 && args[2] == mp_const_true);
heap_siftdown(heap, 0, heap->len - 1, is_timeq);
mp_obj_list_append(heap_in, item);
heap_siftdown(heap, 0, heap->len - 1);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_uheapq_heappush_obj, 2, 3, mod_uheapq_heappush);
STATIC MP_DEFINE_CONST_FUN_OBJ_2(mod_uheapq_heappush_obj, mod_uheapq_heappush);
STATIC mp_obj_t mod_uheapq_heappop(size_t n_args, const mp_obj_t *args) {
mp_obj_t heap_in = args[0];
STATIC mp_obj_t mod_uheapq_heappop(mp_obj_t heap_in) {
mp_obj_list_t *heap = get_heap(heap_in);
if (heap->len == 0) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_IndexError, "empty heap"));
......@@ -125,17 +90,16 @@ STATIC mp_obj_t mod_uheapq_heappop(size_t n_args, const mp_obj_t *args) {
heap->items[0] = heap->items[heap->len];
heap->items[heap->len] = MP_OBJ_NULL; // so we don't retain a pointer
if (heap->len) {
bool is_timeq = (n_args > 1 && args[1] == mp_const_true);
heap_siftup(heap, 0, is_timeq);
heap_siftup(heap, 0);
}
return item;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_uheapq_heappop_obj, 1, 2, mod_uheapq_heappop);
STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_uheapq_heappop_obj, mod_uheapq_heappop);
STATIC mp_obj_t mod_uheapq_heapify(mp_obj_t heap_in) {
mp_obj_list_t *heap = get_heap(heap_in);
for (mp_uint_t i = heap->len / 2; i > 0;) {
heap_siftup(heap, --i, false);
heap_siftup(heap, --i);
}
return mp_const_none;
}
......
# Test adhoc extension to uheapq to support wraparound
# time (utime.ticks_ms() style) task queue.
from utime import ticks_add, ticks_diff
import uheapq as heapq
DEBUG = 0
MAX = ticks_add(0, -1)
MODULO_HALF = MAX // 2 + 1
if DEBUG:
def dprint(*v):
print(*v)
else:
def dprint(*v):
pass
# Try not to crash on invalid data
h = []
heapq.heappush(h, 1)
try:
heapq.heappush(h, 2, True)
assert False
except TypeError:
pass
heapq.heappush(h, 2)
try:
heapq.heappop(h, True)
assert False
except TypeError:
pass
def pop_all(h):
l = []
while h:
l.append(heapq.heappop(h, True))
dprint(l)
return l
def add(h, v):
heapq.heappush(h, (v, None), True)
h = []
add(h, 0)
add(h, MAX)
add(h, MAX - 1)
add(h, 101)
add(h, 100)
add(h, MAX - 2)
dprint(h)
l = pop_all(h)
for i in range(len(l) - 1):
diff = ticks_diff(l[i + 1][0], l[i][0])
assert diff > 0
def edge_case(edge, offset):
h = []
add(h, ticks_add(0, offset))
add(h, ticks_add(edge, offset))
dprint(h)
l = pop_all(h)
diff = ticks_diff(l[1][0], l[0][0])
dprint(diff, diff > 0)
return diff
dprint("===")
diff = edge_case(MODULO_HALF - 1, 0)
assert diff == MODULO_HALF - 1
assert edge_case(MODULO_HALF - 1, 100) == diff
assert edge_case(MODULO_HALF - 1, -100) == diff
# We expect diff to be always positive, per the definition of heappop() which should return
# the smallest value.
# This is the edge case where this invariant breaks, due to assymetry of two's-complement
# range - there's one more negative integer than positive, so heappushing values like below
# will then make ticks_diff() return the minimum negative value. We could make heappop
# return them in a different order, but ticks_diff() result would be the same. Conclusion:
# never add to a heap values where (a - b) == MODULO_HALF (and which are >= MODULO_HALF
# ticks apart in real time of course).
dprint("===")
diff = edge_case(MODULO_HALF, 0)
assert diff == -MODULO_HALF
assert edge_case(MODULO_HALF, 100) == diff
assert edge_case(MODULO_HALF, -100) == diff
dprint("===")
diff = edge_case(MODULO_HALF + 1, 0)
assert diff == MODULO_HALF - 1
assert edge_case(MODULO_HALF + 1, 100) == diff
assert edge_case(MODULO_HALF + 1, -100) == diff
print("OK")
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment