int duk_bi_array_prototype_sort(duk_context *ctx) {
unsigned int len;
len = duk__push_this_obj_len_u32(ctx);
/* stack[0] = compareFn
* stack[1] = ToObject(this)
* stack[2] = ToUint32(length)
*/
duk__array_qsort(ctx, 0, len - 1);
DUK_ASSERT_TOP(ctx, 3);
duk_pop(ctx);
return 1; /* return ToObject(this) */
}
DUK_INTERNAL duk_ret_t duk_bi_array_prototype_sort(duk_context *ctx) {
duk_uint32_t len;
/* XXX: len >= 0x80000000 won't work below because a signed type
* is needed by qsort.
*/
len = duk__push_this_obj_len_u32_limited(ctx);
/* stack[0] = compareFn
* stack[1] = ToObject(this)
* stack[2] = ToUint32(length)
*/
if (len > 0) {
/* avoid degenerate cases, so that (len - 1) won't underflow */
duk__array_qsort(ctx, (duk_int_t) 0, (duk_int_t) (len - 1));
}
DUK_ASSERT_TOP(ctx, 3);
duk_pop(ctx);
return 1; /* return ToObject(this) */
}
DUK_LOCAL void duk__array_qsort(duk_context *ctx, duk_int_t lo, duk_int_t hi) {
duk_hthread *thr = (duk_hthread *) ctx;
duk_int_t p, l, r;
/* The lo/hi indices may be crossed and hi < 0 is possible at entry. */
DUK_DDD(DUK_DDDPRINT("duk__array_qsort: lo=%ld, hi=%ld, obj=%!T",
(long) lo, (long) hi, (duk_tval *) duk_get_tval(ctx, 1)));
DUK_ASSERT_TOP(ctx, 3);
/* In some cases it may be that lo > hi, or hi < 0; these
* degenerate cases happen e.g. for empty arrays, and in
* recursion leaves.
*/
/* trivial cases */
if (hi - lo < 1) {
DUK_DDD(DUK_DDDPRINT("degenerate case, return immediately"));
return;
}
DUK_ASSERT(hi > lo);
DUK_ASSERT(hi - lo + 1 >= 2);
/* randomized pivot selection */
p = lo + (duk_util_tinyrandom_get_bits(thr, 30) % (hi - lo + 1)); /* rnd in [lo,hi] */
DUK_ASSERT(p >= lo && p <= hi);
DUK_DDD(DUK_DDDPRINT("lo=%ld, hi=%ld, chose pivot p=%ld",
(long) lo, (long) hi, (long) p));
/* move pivot out of the way */
duk__array_sort_swap(ctx, p, lo);
p = lo;
DUK_DDD(DUK_DDDPRINT("pivot moved out of the way: %!T", (duk_tval *) duk_get_tval(ctx, 1)));
l = lo + 1;
r = hi;
for (;;) {
/* find elements to swap */
for (;;) {
DUK_DDD(DUK_DDDPRINT("left scan: l=%ld, r=%ld, p=%ld",
(long) l, (long) r, (long) p));
if (l >= hi) {
break;
}
if (duk__array_sort_compare(ctx, l, p) >= 0) { /* !(l < p) */
break;
}
l++;
}
for (;;) {
DUK_DDD(DUK_DDDPRINT("right scan: l=%ld, r=%ld, p=%ld",
(long) l, (long) r, (long) p));
if (r <= lo) {
break;
}
if (duk__array_sort_compare(ctx, p, r) >= 0) { /* !(p < r) */
break;
}
r--;
}
if (l >= r) {
goto done;
}
DUK_ASSERT(l < r);
DUK_DDD(DUK_DDDPRINT("swap %ld and %ld", (long) l, (long) r));
duk__array_sort_swap(ctx, l, r);
DUK_DDD(DUK_DDDPRINT("after swap: %!T", (duk_tval *) duk_get_tval(ctx, 1)));
l++;
r--;
}
done:
/* Note that 'l' and 'r' may cross, i.e. r < l */
DUK_ASSERT(l >= lo && l <= hi);
DUK_ASSERT(r >= lo && r <= hi);
/* XXX: there's no explicit recursion bound here now. For the average
* qsort recursion depth O(log n) that's not really necessary: e.g. for
* 2**32 recursion depth would be about 32 which is OK. However, qsort
* worst case recursion depth is O(n) which may be a problem.
*/
/* move pivot to its final place */
DUK_DDD(DUK_DDDPRINT("before final pivot swap: %!T", (duk_tval *) duk_get_tval(ctx, 1)));
duk__array_sort_swap(ctx, lo, r);
#if defined(DUK_USE_DDDPRINT)
duk__debuglog_qsort_state(ctx, lo, hi, r);
#endif
DUK_DDD(DUK_DDDPRINT("recurse: pivot=%ld, obj=%!T", (long) r, (duk_tval *) duk_get_tval(ctx, 1)));
duk__array_qsort(ctx, lo, r - 1);
duk__array_qsort(ctx, r + 1, hi);
}
