1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
|
#include "app.hpp"
#include "compat/hash.hpp"
#include "compat/array-size.hpp"
#include "src/global-coords.hpp"
#include "src/world.hpp"
#include <cr/StringView.h>
#include <bitset>
#include <memory>
#include <mg/Functions.h>
namespace floormat {
namespace {
void test_simple()
{
constexpr StringView list[] = {
"foo"_s, "bar"_s, "bar\0"_s, "bar2"_s, "baz"_s,
"The quick brown fox jumps over the lazy dog"_s,
"The quick brown fox jumps over the lazy cog"_s,
};
constexpr auto size = array_size(list);
size_t hashes[size] = {};
for (auto i = 0uz; i < size; i++)
hashes[i] = hash_buf(list[i].data(), list[i].size());
for (auto i = 0uz; i < size; i++)
for (auto j = i+1; j < size; j++)
{
if (hashes[i] == hashes[j])
fm_abort("hash collision between '%s' and '%s': 0x%p",
list[i].data(), list[j].data(), (void*)hashes[i]);
}
}
template<int16_t CoordMax, int8_t ZMax, uint32_t MaxCollisions>
[[nodiscard]] bool test_collisions(const char* name)
{
constexpr size_t Iters = (CoordMax*2 + 1)*(CoordMax*2 + 1)*(1+ZMax); // NOLINT(*-implicit-widening-of-multiplication-result)
constexpr size_t BucketCount = Math::max(world::initial_capacity, size_t(Math::ceil(Iters / world::max_load_factor)));
uint32_t num_collisions = 0, iters = 0;
auto bitset_ = std::make_unique<std::bitset<BucketCount>>(false);
auto& bitset = *bitset_;
for (int16_t j = -CoordMax; j <= CoordMax; j++)
for (int16_t i = -CoordMax; i <= CoordMax; i++)
for (int8_t k = 0; k <= ZMax; k++)
{
auto p = global_coords{i, j, k};
auto h = p.hash();
h %= BucketCount;
auto ref = bitset[h];
if (ref) [[unlikely]]
++num_collisions;
else
ref = true;
(void)ref;
iters++;
}
fm_assert_equal(Iters, iters);
//#define FM_TEST_DEBUG_PRINT
if (num_collisions > MaxCollisions)
{
DBG_nospace << Debug::color(Debug::Color::Magenta)
<< "fail" << Debug::resetColor << ": test/hash(\"" << name << "\")"
<< " collisions " << num_collisions << " > " << MaxCollisions
<< " (iters:" << iters << " buckets:" << BucketCount << ")";
#ifdef FM_TEST_DEBUG_PRINT
return false;
#else
fm_abort("test/hash: too many collisions");
#endif
}
else if (num_collisions != MaxCollisions)
{
#ifdef FM_TEST_DEBUG_PRINT
DBG_nospace << Debug::color(Debug::Color::Cyan) << "pass" << Debug::resetColor
<< ": test/hash(\"" << name << "\") collisions "
<< num_collisions << " <= " << MaxCollisions
<< " (iters:" << iters << " buckets:" << BucketCount << ")";
#endif
}
return true;
}
} // namespace
void Test::test_hash()
{
test_simple();
bool success = true;
#ifdef FM_TEST_DEBUG_PRINT
DBG_nospace << "";
#endif
#ifdef FM_TEST_DEBUG_PRINT
#define FM_MAYBE_FAIL void()
#else
#define FM_MAYBE_FAIL FM_MAYBE_FAIL_
#endif
#define FM_MAYBE_FAIL_ do { if (!success) { DBG_nospace << ""; fm_abort("test/hash: too many collisions"); } } while (false)
success &= test_collisions< 2, 1, 1 >("small1"); FM_MAYBE_FAIL;
success &= test_collisions< 3, 0, 1 >("small2"); FM_MAYBE_FAIL;
success &= test_collisions< 4, 0, 1 >("small3"); FM_MAYBE_FAIL;
success &= test_collisions< 5, 0, 1 >("small4"); FM_MAYBE_FAIL;
success &= test_collisions< 6, 0, 4 >("mid1"); FM_MAYBE_FAIL;
success &= test_collisions< 7, 0, 7 >("mid2"); FM_MAYBE_FAIL;
success &= test_collisions< 8, 0, 10 >("mid3"); FM_MAYBE_FAIL;
success &= test_collisions< 9, 0, 15 >("mid4"); FM_MAYBE_FAIL;
success &= test_collisions< 10, 0, 22 >("large1"); FM_MAYBE_FAIL;
success &= test_collisions< 12, 0, 51 >("large2"); FM_MAYBE_FAIL;
success &= test_collisions< 14, 0, 94 >("large3"); FM_MAYBE_FAIL;
success &= test_collisions< 15, 0, 118 >("large4"); FM_MAYBE_FAIL;
success &= test_collisions< 16, 0, 107 >("large5"); FM_MAYBE_FAIL;
success &= test_collisions< 3, 1, 2 >("zsmall1"); FM_MAYBE_FAIL;
success &= test_collisions< 4, 1, 3 >("zsmall2"); FM_MAYBE_FAIL;
success &= test_collisions< 2, 3, 1 >("zmid1"); FM_MAYBE_FAIL;
success &= test_collisions< 3, 3, 7 >("zmid1"); FM_MAYBE_FAIL;
success &= test_collisions< 2, 6, 4 >("zmid2"); FM_MAYBE_FAIL;
success &= test_collisions< 2, 10, 14 >("zmid3"); FM_MAYBE_FAIL;
success &= test_collisions< 6, 2, 35 >("zmid4"); FM_MAYBE_FAIL;
success &= test_collisions< 7, 1, 28 >("zmid5"); FM_MAYBE_FAIL;
success &= test_collisions< 10, 1, 89 >("zlarge1"); FM_MAYBE_FAIL;
success &= test_collisions< 10, 4, 274 >("zlarge2"); FM_MAYBE_FAIL;
success &= test_collisions< 16, 8, 1126 >("zlarge3"); FM_MAYBE_FAIL;
success &= test_collisions< 32, 8, 4397 >("zlarge4"); FM_MAYBE_FAIL;
(void)success;
//FM_MAYBE_FAIL_;
}
} // namespace floormat
|
