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[ox/std] Fix HashMap collision handling
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This commit is contained in:
Gary Talent 2025-01-25 22:16:42 -06:00
parent 6898f8eda1
commit 449022f9ae
2 changed files with 80 additions and 62 deletions
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132
deps/ox/src/ox/std/hashmap.hpp vendored
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@ -11,6 +11,7 @@
#include "algorithm.hpp"
#include "hash.hpp"
#include "ignore.hpp"
#include "optional.hpp"
#include "stringview.hpp"
#include "strops.hpp"
#include "vector.hpp"
@ -26,11 +27,12 @@ class HashMap {
private:
struct Pair {
UPtr<Pair> next;
K key = {};
T value{};
};
Vector<K> m_keys;
Vector<Pair*> m_pairs;
Vector<UPtr<Pair>> m_pairs;
public:
explicit constexpr HashMap(std::size_t size = 127);
@ -73,10 +75,10 @@ class HashMap {
constexpr void expand();
template<typename KK>
constexpr Pair *const&access(Vector<Pair*> const&pairs, KK const&key) const;
constexpr UPtr<Pair> const &access(Vector<UPtr<Pair>> const &pairs, KK const &key) const;
template<typename KK>
constexpr Pair *&access(Vector<Pair*> &pairs, KK const&key);
constexpr UPtr<Pair> &access(Vector<UPtr<Pair>> &pairs, KK const &key);
};
@ -85,14 +87,13 @@ constexpr HashMap<K, T>::HashMap(std::size_t size): m_pairs(size) {
}
template<typename K, typename T>
constexpr HashMap<K, T>::HashMap(HashMap<K, T> const&other) {
m_pairs = other.m_pairs;
constexpr HashMap<K, T>::HashMap(HashMap const &other) {
operator=(other);
}
template<typename K, typename T>
constexpr HashMap<K, T>::HashMap(HashMap<K, T> &&other) noexcept {
m_keys = std::move(other.m_keys);
m_pairs = std::move(other.m_pairs);
constexpr HashMap<K, T>::HashMap(HashMap &&other) noexcept {
operator=(std::move(other));
}
template<typename K, typename T>
@ -101,7 +102,7 @@ constexpr HashMap<K, T>::~HashMap() {
}
template<typename K, typename T>
constexpr bool HashMap<K, T>::operator==(HashMap const&other) const {
constexpr bool HashMap<K, T>::operator==(HashMap const &other) const {
if (m_keys != other.m_keys) {
return false;
}
@ -115,19 +116,25 @@ constexpr bool HashMap<K, T>::operator==(HashMap const&other) const {
}
template<typename K, typename T>
constexpr HashMap<K, T> &HashMap<K, T>::operator=(HashMap<K, T> const&other) {
constexpr HashMap<K, T> &HashMap<K, T>::operator=(HashMap const &other) {
if (this != &other) {
clear();
m_keys = other.m_keys;
m_pairs = other.m_pairs;
m_pairs.resize(other.m_pairs.size());
for (auto const&k : m_keys) {
auto const &src = access(other.m_pairs, k);
auto &dst = access(m_pairs, k);
dst = ox::make_unique<Pair>();
dst->key = src->key;
dst->value = src->value;
}
}
return *this;
}
template<typename K, typename T>
constexpr HashMap<K, T> &HashMap<K, T>::operator=(HashMap<K, T> &&other) noexcept {
constexpr HashMap<K, T> &HashMap<K, T>::operator=(HashMap &&other) noexcept {
if (this != &other) {
clear();
m_keys = std::move(other.m_keys);
m_pairs = std::move(other.m_pairs);
}
@ -135,60 +142,52 @@ constexpr HashMap<K, T> &HashMap<K, T>::operator=(HashMap<K, T> &&other) noexcep
}
template<typename K, typename T>
constexpr T &HashMap<K, T>::operator[](MaybeView_t<K> const&k) {
auto p = &access(m_pairs, k);
constexpr T &HashMap<K, T>::operator[](MaybeView_t<K> const &key) {
auto p = &access(m_pairs, key);
if (*p == nullptr) {
if (static_cast<double>(m_pairs.size()) * 0.7 <
static_cast<double>(m_keys.size())) {
expand();
p = &access(m_pairs, k);
p = &access(m_pairs, key);
}
*p = new Pair;
(*p)->key = k;
m_keys.emplace_back(k);
*p = ox::make_unique<Pair>();
(*p)->key = key;
m_keys.emplace_back(key);
}
return (*p)->value;
}
template<typename K, typename T>
constexpr Result<T*> HashMap<K, T>::at(MaybeView_t<K> const&k) noexcept {
auto p = access(m_pairs, k);
constexpr Result<T*> HashMap<K, T>::at(MaybeView_t<K> const &key) noexcept {
auto &p = access(m_pairs, key);
if (!p) {
return {nullptr, ox::Error(1, "value not found for given key")};
return ox::Error{1, "value not found for given key"};
}
return &p->value;
}
template<typename K, typename T>
constexpr Result<const T*> HashMap<K, T>::at(MaybeView_t<K> const&k) const noexcept {
auto p = access(m_pairs, k);
constexpr Result<const T*> HashMap<K, T>::at(MaybeView_t<K> const &key) const noexcept {
auto &p = access(m_pairs, key);
if (!p) {
return {nullptr, ox::Error(1, "value not found for given key")};
return ox::Error{1, "value not found for given key"};
}
return &p->value;
}
template<typename K, typename T>
constexpr void HashMap<K, T>::erase(MaybeView_t<K> const&k) {
if (!contains(k)) {
constexpr void HashMap<K, T>::erase(MaybeView_t<K> const &key) {
if (!contains(key)) {
return;
}
auto h = ox::hash<MaybeView_t<K>>{}(k) % m_pairs.size();
while (true) {
const auto &p = m_pairs[h];
if (p == nullptr || p->key == k) {
std::ignore = m_pairs.erase(h);
break;
} else {
h = ox::hash<MaybeView_t<K>>{}(k) % m_pairs.size();
}
}
std::ignore = m_keys.erase(ox::find(m_keys.begin(), m_keys.end(), k));
auto &c = access(m_pairs, key);
c = std::move(c->next);
std::ignore = m_keys.erase(ox::find(m_keys.begin(), m_keys.end(), key));
}
template<typename K, typename T>
constexpr bool HashMap<K, T>::contains(MaybeView_t<K> const&k) const noexcept {
return access(m_pairs, k) != nullptr;
constexpr bool HashMap<K, T>::contains(MaybeView_t<K> const &key) const noexcept {
return access(m_pairs, key).get() != nullptr;
}
template<typename K, typename T>
@ -204,27 +203,26 @@ constexpr Vector<K> const&HashMap<K, T>::keys() const noexcept {
template<typename K, typename T>
constexpr Vector<T> HashMap<K, T>::values() const noexcept {
Vector<T> out;
out.reserve(m_pairs.size());
for (auto const&p : m_pairs) {
out.emplace_back(p->value);
out.reserve(m_keys.size());
for (auto const &p : m_pairs) {
if (out) {
out.emplace_back(p->value);
}
}
return out;
}
template<typename K, typename T>
constexpr void HashMap<K, T>::clear() {
for (std::size_t i = 0; i < m_pairs.size(); i++) {
delete m_pairs[i];
}
m_pairs.clear();
m_pairs.resize(127);
}
template<typename K, typename T>
constexpr void HashMap<K, T>::expand() {
Vector<Pair*> r(m_pairs.size() * 2);
Vector<UPtr<Pair>> r{m_pairs.size() * 2};
for (std::size_t i = 0; i < m_keys.size(); ++i) {
auto const&k = m_keys[i];
auto const &k = m_keys[i];
access(r, k) = std::move(access(m_pairs, k));
}
m_pairs = std::move(r);
@ -232,29 +230,39 @@ constexpr void HashMap<K, T>::expand() {
template<typename K, typename T>
template<typename KK>
constexpr typename HashMap<K, T>::Pair *const&HashMap<K, T>::access(Vector<Pair*> const&pairs, KK const&k) const {
auto h = static_cast<std::size_t>(ox::hash<KK>{}(k) % pairs.size());
constexpr UPtr<typename HashMap<K, T>::Pair> const &HashMap<K, T>::access(
Vector<UPtr<Pair>> const& pairs,
KK const &key) const {
auto const h = static_cast<std::size_t>(ox::hash<KK>{}(key) % pairs.size());
auto const &p = *pairs.at(h).unwrap();
if (p == nullptr || p->key == key) {
return p;
}
auto c = &p->next;
while (true) {
auto const&p = *pairs.at(h).unwrap();
if (p == nullptr || p->key == k) {
return p;
} else {
h = (h + 1) % pairs.size();
if (*c == nullptr || (*c)->key == key) {
return *c;
}
c = &(*c)->next;
}
}
template<typename K, typename T>
template<typename KK>
constexpr typename HashMap<K, T>::Pair *&HashMap<K, T>::access(Vector<Pair*> &pairs, KK const&k) {
auto h = static_cast<std::size_t>(ox::hash<KK>{}(k) % pairs.size());
constexpr UPtr<typename HashMap<K, T>::Pair> &HashMap<K, T>::access(
Vector<UPtr<Pair>> &pairs,
KK const &key) {
auto const h = static_cast<std::size_t>(ox::hash<KK>{}(key) % pairs.size());
auto &p = *pairs.at(h).unwrap();
if (p == nullptr || p->key == key) {
return p;
}
auto c = &p->next;
while (true) {
auto &p = *pairs.at(h).unwrap();
if (p == nullptr || p->key == k) {
return p;
} else {
h = (h + 1) % pairs.size();
if (*c == nullptr || (*c)->key == key) {
return *c;
}
c = &(*c)->next;
}
}

10
deps/ox/src/ox/std/test/tests.cpp vendored
View File

@ -273,6 +273,16 @@ OX_CLANG_NOWARN_END
si["aoeu"] = 100;
oxAssert(si["asdf"] == 42, "asdf != 42");
oxAssert(si["aoeu"] == 100, "aoeu != 100");
si.erase("asdf");
oxAssert(!si.contains("asdf"), "wrongly contains asdf");
oxAssert(si.contains("aoeu"), "does not contains aoeu");
oxAssert(!si.at("asdf").ok(), "asdf != 0");
oxExpect(si["asdf"], 0);
oxAssert(si["aoeu"] == 100, "aoeu != 100");
auto si2 = si;
oxDebugf("{}", si2["asdf"]);
oxExpect(si2["asdf"], 0);
oxAssert(si2["aoeu"] == 100, "aoeu != 100");
ox::HashMap<int, int> ii;
ii[4] = 42;
ii[5] = 100;