tdutils: FlatHashMap
This commit is contained in:
Arseny Smirnov
parent
822257b90a
commit
088ce02832
|
|
@ -298,6 +298,7 @@ set(TDUTILS_TEST_SOURCE
|
|||
${CMAKE_CURRENT_SOURCE_DIR}/test/filesystem.cpp
|
||||
${CMAKE_CURRENT_SOURCE_DIR}/test/gzip.cpp
|
||||
${CMAKE_CURRENT_SOURCE_DIR}/test/HazardPointers.cpp
|
||||
${CMAKE_CURRENT_SOURCE_DIR}/test/HashSet.cpp
|
||||
${CMAKE_CURRENT_SOURCE_DIR}/test/heap.cpp
|
||||
${CMAKE_CURRENT_SOURCE_DIR}/test/HttpUrl.cpp
|
||||
${CMAKE_CURRENT_SOURCE_DIR}/test/json.cpp
|
||||
|
|
|
|||
376
tdutils/td/utils/FlatHashMap.h
Normal file
376
tdutils/td/utils/FlatHashMap.h
Normal file
|
|
@ -0,0 +1,376 @@
|
|||
#pragma once
|
||||
|
||||
#include <unordered_map>
|
||||
#include <utility>
|
||||
#include <vector>
|
||||
|
||||
namespace td {
|
||||
|
||||
template <class KeyT, class ValueT, class HashT = std::hash<KeyT>, class EqualT = std::equal_to<KeyT>>
|
||||
class FlatHashMapImpl {
|
||||
struct Node {
|
||||
KeyT first{};
|
||||
union {
|
||||
ValueT second;
|
||||
};
|
||||
const auto &key() const {
|
||||
return first;
|
||||
}
|
||||
auto &value() {
|
||||
return second;
|
||||
}
|
||||
|
||||
Node() {
|
||||
}
|
||||
~Node() {
|
||||
if (!empty()) {
|
||||
second.~ValueT();
|
||||
}
|
||||
}
|
||||
Node(Node &&other) {
|
||||
*this = std::move(other);
|
||||
}
|
||||
Node &operator=(Node &&other) {
|
||||
DCHECK(empty());
|
||||
DCHECK(!other.empty());
|
||||
first = std::move(other.first);
|
||||
other.first = KeyT{};
|
||||
new (&second) ValueT(std::move(other.second));
|
||||
other.second.~ValueT();
|
||||
return *this;
|
||||
}
|
||||
bool empty() const {
|
||||
return is_key_empty(key());
|
||||
}
|
||||
void clear() {
|
||||
DCHECK(!empty());
|
||||
first = KeyT();
|
||||
second.~ValueT();
|
||||
DCHECK(empty());
|
||||
}
|
||||
template <class... ArgsT>
|
||||
void emplace(KeyT key, ArgsT &&...args) {
|
||||
DCHECK(empty());
|
||||
first = std::move(key);
|
||||
new (&second) ValueT(std::forward<ArgsT>(args)...);
|
||||
CHECK(!empty());
|
||||
}
|
||||
};
|
||||
using Self = FlatHashMapImpl<KeyT, ValueT, HashT, EqualT>;
|
||||
using NodeIterator = typename std::vector<Node>::iterator;
|
||||
using ConstNodeIterator = typename std::vector<Node>::const_iterator;
|
||||
|
||||
public:
|
||||
struct Iterator {
|
||||
public:
|
||||
using iterator_category = std::bidirectional_iterator_tag;
|
||||
using difference_type = std::ptrdiff_t;
|
||||
using value_type = Node;
|
||||
using pointer = Node *;
|
||||
using reference = Node &;
|
||||
|
||||
friend class FlatHashMapImpl;
|
||||
Iterator &operator++() {
|
||||
do {
|
||||
++it_;
|
||||
} while (it_ != map_->nodes_.end() && it_->empty());
|
||||
return *this;
|
||||
}
|
||||
Iterator &operator--() {
|
||||
do {
|
||||
--it_;
|
||||
} while (it_->empty());
|
||||
return *this;
|
||||
}
|
||||
Node &operator*() {
|
||||
return *it_;
|
||||
}
|
||||
Node *operator->() {
|
||||
return &*it_;
|
||||
}
|
||||
bool operator==(const Iterator &other) const {
|
||||
DCHECK(map_ == other.map_);
|
||||
return it_ == other.it_;
|
||||
}
|
||||
bool operator!=(const Iterator &other) const {
|
||||
DCHECK(map_ == other.map_);
|
||||
return it_ != other.it_;
|
||||
}
|
||||
|
||||
Iterator() = default;
|
||||
Iterator(const Iterator &other) = default;
|
||||
Iterator &operator=(const Iterator &other) = default;
|
||||
Iterator(Iterator &&other) = default;
|
||||
Iterator &operator=(Iterator &&other) = default;
|
||||
Iterator(NodeIterator it, Self *map) : it_(std::move(it)), map_(map) {
|
||||
}
|
||||
|
||||
private:
|
||||
NodeIterator it_;
|
||||
Self *map_;
|
||||
};
|
||||
struct ConstIterator {
|
||||
public:
|
||||
using iterator_category = std::bidirectional_iterator_tag;
|
||||
using difference_type = std::ptrdiff_t;
|
||||
using value_type = Node;
|
||||
using pointer = const Node *;
|
||||
using reference = const Node &;
|
||||
|
||||
friend class FlatHashMapImpl;
|
||||
ConstIterator &operator++() {
|
||||
do {
|
||||
++it_;
|
||||
} while (it_ != map_->nodes_.end() && it_->empty());
|
||||
return *this;
|
||||
}
|
||||
ConstIterator &operator--() {
|
||||
do {
|
||||
--it_;
|
||||
} while (it_->empty());
|
||||
return *this;
|
||||
}
|
||||
const Node &operator*() {
|
||||
return *it_;
|
||||
}
|
||||
const Node *operator->() {
|
||||
return &*it_;
|
||||
}
|
||||
bool operator==(const ConstIterator &other) const {
|
||||
DCHECK(map_ == other.map_);
|
||||
return it_ == other.it_;
|
||||
}
|
||||
bool operator!=(const ConstIterator &other) const {
|
||||
DCHECK(map_ == other.map_);
|
||||
return it_ != other.it_;
|
||||
}
|
||||
|
||||
ConstIterator() = default;
|
||||
ConstIterator(const ConstIterator &other) = default;
|
||||
ConstIterator &operator=(const ConstIterator &other) = default;
|
||||
ConstIterator(ConstIterator &&other) = default;
|
||||
ConstIterator &operator=(ConstIterator &&other) = default;
|
||||
ConstIterator(ConstNodeIterator it, const Self *map) : it_(std::move(it)), map_(map) {
|
||||
}
|
||||
ConstIterator(Iterator iterator) : it_(std::move(iterator.it_)), map_(iterator.map_) {
|
||||
}
|
||||
|
||||
private:
|
||||
ConstNodeIterator it_;
|
||||
const Self *map_;
|
||||
};
|
||||
|
||||
using iterator = Iterator;
|
||||
using key_type = KeyT;
|
||||
using value_type = std::pair<const KeyT, ValueT>;
|
||||
|
||||
FlatHashMapImpl() = default;
|
||||
FlatHashMapImpl(FlatHashMapImpl &&other) : nodes_(std::move(other.nodes_)), used_nodes_(other.used_nodes_) {
|
||||
other.used_nodes_ = 0;
|
||||
}
|
||||
FlatHashMapImpl &operator=(FlatHashMapImpl &&other) {
|
||||
nodes_ = std::move(other.nodes_);
|
||||
used_nodes_ = other.used_nodes_;
|
||||
other.used_nodes_ = 0;
|
||||
return *this;
|
||||
}
|
||||
template <class ItT>
|
||||
FlatHashMapImpl(ItT begin, ItT end) {
|
||||
assign(begin, end);
|
||||
}
|
||||
FlatHashMapImpl(const FlatHashMapImpl &other) : FlatHashMapImpl(other.begin(), other.end()) {
|
||||
}
|
||||
FlatHashMapImpl &operator=(const FlatHashMapImpl &other) {
|
||||
assign(other.begin(), other.end());
|
||||
return *this;
|
||||
}
|
||||
|
||||
template <class ItT>
|
||||
void assign(ItT begin, ItT end) {
|
||||
resize(std::distance(begin, end)); // TODO: should be conditional
|
||||
for (; begin != end; ++begin) {
|
||||
emplace(begin->first, begin->second);
|
||||
}
|
||||
}
|
||||
|
||||
Iterator find(const KeyT &key) {
|
||||
if (empty()) {
|
||||
return end();
|
||||
}
|
||||
auto it = find_bucket_for_insert(key);
|
||||
if (it->empty()) {
|
||||
return end();
|
||||
}
|
||||
return Iterator(it, this);
|
||||
}
|
||||
ConstIterator find(const KeyT &key) const {
|
||||
if (empty()) {
|
||||
return end();
|
||||
}
|
||||
auto it = find_bucket_for_insert(key);
|
||||
if (it->empty()) {
|
||||
return end();
|
||||
}
|
||||
return ConstIterator(it, this);
|
||||
}
|
||||
size_t size() const {
|
||||
return used_nodes_;
|
||||
}
|
||||
bool empty() const {
|
||||
return size() == 0;
|
||||
}
|
||||
auto begin() {
|
||||
if (empty()) {
|
||||
return end();
|
||||
}
|
||||
auto it = nodes_.begin();
|
||||
while (it->empty()) {
|
||||
it++;
|
||||
}
|
||||
return Iterator(it, this);
|
||||
}
|
||||
auto end() {
|
||||
return Iterator(nodes_.end(), this);
|
||||
}
|
||||
auto begin() const {
|
||||
if (empty()) {
|
||||
return end();
|
||||
}
|
||||
auto it = nodes_.begin();
|
||||
while (it->empty()) {
|
||||
it++;
|
||||
}
|
||||
return ConstIterator(it, this);
|
||||
}
|
||||
auto end() const {
|
||||
return ConstIterator(nodes_.end(), this);
|
||||
}
|
||||
|
||||
template <class... ArgsT>
|
||||
std::pair<Iterator, bool> emplace(KeyT key, ArgsT &&...args) {
|
||||
if (should_resize()) {
|
||||
resize(used_nodes_ + 1);
|
||||
}
|
||||
auto it = find_bucket_for_insert(key);
|
||||
if (it->empty()) {
|
||||
it->emplace(std::move(key), std::forward<ArgsT>(args)...);
|
||||
used_nodes_++;
|
||||
return std::make_pair(Iterator(it, this), true);
|
||||
}
|
||||
return std::make_pair(Iterator(it, this), false);
|
||||
}
|
||||
|
||||
ValueT &operator[](const KeyT &key) {
|
||||
DCHECK(!is_key_empty(key));
|
||||
|
||||
if (should_resize()) {
|
||||
resize(used_nodes_ + 1);
|
||||
}
|
||||
|
||||
auto it = find_bucket_for_insert(key);
|
||||
if (it->empty()) {
|
||||
it->emplace(key);
|
||||
used_nodes_++;
|
||||
}
|
||||
return it->second;
|
||||
}
|
||||
|
||||
size_t erase(const KeyT &key) {
|
||||
auto it = find(key);
|
||||
if (it == end()) {
|
||||
return 0;
|
||||
}
|
||||
erase(it);
|
||||
return 1;
|
||||
}
|
||||
size_t count(const KeyT &key) const {
|
||||
return find(key) != end();
|
||||
}
|
||||
|
||||
void clear() {
|
||||
used_nodes_ = 0;
|
||||
nodes_.clear();
|
||||
}
|
||||
|
||||
void erase(Iterator it) {
|
||||
DCHECK(it != end());
|
||||
DCHECK(!is_key_empty(it->key()));
|
||||
size_t empty_i = it.it_ - nodes_.begin();
|
||||
auto empty_bucket = empty_i;
|
||||
DCHECK(0 <= empty_i < nodes_.size());
|
||||
nodes_[empty_bucket].clear();
|
||||
used_nodes_--;
|
||||
|
||||
for (size_t test_i = empty_i + 1;; test_i++) {
|
||||
auto test_bucket = test_i;
|
||||
if (test_bucket >= nodes_.size()) {
|
||||
test_bucket -= nodes_.size();
|
||||
}
|
||||
|
||||
if (is_key_empty(nodes_[test_bucket].key())) {
|
||||
break;
|
||||
}
|
||||
|
||||
auto want_i = HashT()(nodes_[test_bucket].key()) % nodes_.size();
|
||||
if (want_i < empty_i) {
|
||||
want_i += nodes_.size();
|
||||
}
|
||||
|
||||
if (want_i <= empty_i || want_i > test_i) {
|
||||
nodes_[empty_bucket] = std::move(nodes_[test_bucket]);
|
||||
empty_i = test_i;
|
||||
empty_bucket = test_bucket;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
private:
|
||||
static bool is_key_empty(const KeyT &key) {
|
||||
return key == KeyT();
|
||||
}
|
||||
std::vector<Node> nodes_;
|
||||
size_t used_nodes_{};
|
||||
|
||||
bool should_resize() const {
|
||||
return (used_nodes_ + 1) * 10 > nodes_.size() * 6;
|
||||
}
|
||||
size_t calc_bucket(const KeyT &key) const {
|
||||
return HashT()(key) % nodes_.size();
|
||||
}
|
||||
auto find_bucket_for_insert(const KeyT &key) {
|
||||
size_t bucket = calc_bucket(key);
|
||||
while (!(nodes_[bucket].key() == key) && !is_key_empty(nodes_[bucket].key())) {
|
||||
bucket++;
|
||||
if (bucket == nodes_.size()) {
|
||||
bucket = 0;
|
||||
}
|
||||
}
|
||||
return nodes_.begin() + bucket;
|
||||
}
|
||||
auto find_bucket_for_insert(const KeyT &key) const {
|
||||
size_t bucket = calc_bucket(key);
|
||||
while (!EqualT()(nodes_[bucket].key(), key) && !is_key_empty(nodes_[bucket].key())) {
|
||||
bucket++;
|
||||
if (bucket == nodes_.size()) {
|
||||
bucket = 0;
|
||||
}
|
||||
}
|
||||
return nodes_.begin() + bucket;
|
||||
}
|
||||
void resize(size_t size) {
|
||||
auto old_nodes = std::move(nodes_);
|
||||
nodes_.resize(td::max(old_nodes.size(), size) * 2 + 1); // TODO: some other logic
|
||||
for (auto &node : old_nodes) {
|
||||
if (is_key_empty(node.key())) {
|
||||
continue;
|
||||
}
|
||||
*find_bucket_for_insert(node.key()) = std::move(node);
|
||||
}
|
||||
}
|
||||
};
|
||||
//template <class KeyT, class ValueT, class HashT = std::hash<KeyT>, class EqualT = std::equal_to<KeyT>>
|
||||
//using FlatHashMap = FlatHashMapImpl<KeyT, ValueT, HashT, EqualT>;
|
||||
template <class KeyT, class ValueT, class HashT = std::hash<KeyT>, class EqualT = std::equal_to<KeyT>>
|
||||
using FlatHashMap = std::unordered_map<KeyT, ValueT, HashT, EqualT>;
|
||||
|
||||
} // namespace td
|
||||
25
tdutils/test/HashSet.cpp
Normal file
25
tdutils/test/HashSet.cpp
Normal file
|
|
@ -0,0 +1,25 @@
|
|||
#include "td/utils/tests.h"
|
||||
#include "td/utils/FlatHashMap.h"
|
||||
#include <array>
|
||||
#include <string>
|
||||
|
||||
TEST(FlatHashMap, basic) {
|
||||
td::FlatHashMap<int, int> map;
|
||||
map[1] = 2;
|
||||
ASSERT_EQ(2, map[1]);
|
||||
ASSERT_EQ(1, map.find(1)->first);
|
||||
ASSERT_EQ(2, map.find(1)->second);
|
||||
// ASSERT_EQ(1, map.find(1)->key());
|
||||
// ASSERT_EQ(2, map.find(1)->value());
|
||||
for (auto &kv : map) {
|
||||
ASSERT_EQ(1, kv.first);
|
||||
ASSERT_EQ(2, kv.second);
|
||||
}
|
||||
map.erase(map.find(1));
|
||||
auto map_copy = map;
|
||||
|
||||
td::FlatHashMap<int, std::array<std::unique_ptr<std::string>, 20>> x;
|
||||
auto y = std::move(x);
|
||||
x[12];
|
||||
x.erase(x.find(12));
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user