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[ox/std] Add support for integral types as keys in HashMap

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This commit is contained in:
Gary Talent 2022-08-07 10:23:09 -05:00
parent 28960dd680
commit 714d9fe433
2 changed files with 31 additions and 14 deletions
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30
deps/ox/src/ox/std/hashmap.hpp vendored
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@ -76,7 +76,7 @@ class HashMap {
/**
* K is assumed to be a null terminated string.
*/
constexpr static uint64_t hash(K, int len = 0xFFFF) noexcept;
constexpr static uint64_t hash(auto) noexcept;
/**
* K is assumed to be a null terminated string.
@ -182,16 +182,13 @@ constexpr void HashMap<K, T>::erase(const K &k) {
return;
}
auto h = hash(k) % m_pairs.size();
char hashStr[sizeof(h) + 1];
ox_memcpy(hashStr, &h, sizeof(h));
hashStr[sizeof(h)] = 0;
while (true) {
const auto &p = m_pairs[h];
if (p == nullptr || ox_strcmp(p->key, k) == 0) {
oxIgnoreError(m_pairs.erase(h));
break;
} else {
h = hash(hashStr, 8) % m_pairs.size();
h = hash(h) % m_pairs.size();
}
}
oxIgnoreError(m_keys.erase(ox::find(m_keys.begin(), m_keys.end(), k)));
@ -232,10 +229,18 @@ constexpr void HashMap<K, T>::expand() {
}
template<typename K, typename T>
constexpr uint64_t HashMap<K, T>::hash(K k, int len) noexcept {
constexpr uint64_t HashMap<K, T>::hash(auto k) noexcept {
uint64_t sum = 1;
for (auto i = 0u; i < static_cast<uint64_t>(len) && k[i]; ++i) {
sum += ((sum + static_cast<uint64_t>(k[i])) * 7) * sum;
if constexpr(is_integral_v<decltype(k)>) {
for (auto i = 0u; i < sizeof(K); ++i) {
const auto shift = i * 8;
const auto v = static_cast<uint64_t>(k >> shift & 0xff);
sum += (sum + v) * 7 * sum;
}
} else {
for (auto i = 0u; k[i]; ++i) {
sum += ((sum + static_cast<uint64_t>(k[i])) * 7) * sum;
}
}
return sum;
}
@ -258,7 +263,14 @@ constexpr typename HashMap<K, T>::Pair *&HashMap<K, T>::access(Vector<Pair*> &pa
auto h = hash(k) % pairs.size();
while (true) {
auto &p = pairs[h];
if (p == nullptr || ox_strcmp(p->key, k) == 0) {
bool matches = [&] {
if constexpr (is_integral_v<K>) {
return p == nullptr || k == p->key;
} else {
return p == nullptr || ox_strcmp(p->key, k) == 0;
}
}();
if (matches) {
return p;
} else {
h = (h + 1) % pairs.size();

15
deps/ox/src/ox/std/test/tests.cpp vendored
View File

@ -109,11 +109,16 @@ std::map<ox::String, ox::Error(*)()> tests = {
{
"HashMap",
[] {
ox::HashMap<const char*, int> v;
v["asdf"] = 42;
v["aoeu"] = 100;
oxAssert(v["asdf"] == 42, "asdf != 42");
oxAssert(v["aoeu"] == 100, "aoeu != 100");
ox::HashMap<const char*, int> si;
si["asdf"] = 42;
si["aoeu"] = 100;
oxAssert(si["asdf"] == 42, "asdf != 42");
oxAssert(si["aoeu"] == 100, "aoeu != 100");
ox::HashMap<int, int> ii;
ii[4] = 42;
ii[5] = 100;
oxAssert(ii[4] == 42, "4 != 42");
oxAssert(ii[5] == 100, "5 != 100");
return OxError(0);
}
},