tdesktop/Telegram/SourceFiles/base/flat_map.h

685 lines
18 KiB
C++

/*
This file is part of Telegram Desktop,
the official desktop version of Telegram messaging app, see https://telegram.org
Telegram Desktop is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
It is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
In addition, as a special exception, the copyright holders give permission
to link the code of portions of this program with the OpenSSL library.
Full license: https://github.com/telegramdesktop/tdesktop/blob/master/LICENSE
Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
*/
#pragma once
#include <deque>
#include "base/optional.h"
#include "base/algorithm.h"
namespace base {
template <
typename Key,
typename Type,
typename Compare = std::less<>>
class flat_map;
template <
typename Key,
typename Type,
typename Compare = std::less<>>
class flat_multi_map;
template <
typename Key,
typename Type,
typename Compare,
typename iterator_impl,
typename pointer_impl,
typename reference_impl>
class flat_multi_map_iterator_base_impl;
template <
typename Key,
typename Type,
typename Compare,
typename iterator_impl,
typename pointer_impl,
typename reference_impl>
class flat_multi_map_iterator_base_impl {
public:
using iterator_category = typename iterator_impl::iterator_category;
using value_type = typename flat_multi_map<Key, Type, Compare>::value_type;
using difference_type = typename iterator_impl::difference_type;
using pointer = pointer_impl;
using const_pointer = typename flat_multi_map<Key, Type, Compare>::const_pointer;
using reference = reference_impl;
using const_reference = typename flat_multi_map<Key, Type, Compare>::const_reference;
flat_multi_map_iterator_base_impl(iterator_impl impl = iterator_impl())
: _impl(impl) {
}
reference operator*() {
return *_impl;
}
const_reference operator*() const {
return *_impl;
}
pointer operator->() {
return std::addressof(**this);
}
const_pointer operator->() const {
return std::addressof(**this);
}
flat_multi_map_iterator_base_impl &operator++() {
++_impl;
return *this;
}
flat_multi_map_iterator_base_impl operator++(int) {
return _impl++;
}
flat_multi_map_iterator_base_impl &operator--() {
--_impl;
return *this;
}
flat_multi_map_iterator_base_impl operator--(int) {
return _impl--;
}
flat_multi_map_iterator_base_impl &operator+=(difference_type offset) {
_impl += offset;
return *this;
}
flat_multi_map_iterator_base_impl operator+(difference_type offset) const {
return _impl + offset;
}
flat_multi_map_iterator_base_impl &operator-=(difference_type offset) {
_impl -= offset;
return *this;
}
flat_multi_map_iterator_base_impl operator-(difference_type offset) const {
return _impl - offset;
}
template <
typename other_iterator_impl,
typename other_pointer_impl,
typename other_reference_impl>
difference_type operator-(
const flat_multi_map_iterator_base_impl<
Key,
Type,
Compare,
other_iterator_impl,
other_pointer_impl,
other_reference_impl> &right) const {
return _impl - right._impl;
}
reference operator[](difference_type offset) {
return _impl[offset];
}
const_reference operator[](difference_type offset) const {
return _impl[offset];
}
template <
typename other_iterator_impl,
typename other_pointer_impl,
typename other_reference_impl>
bool operator==(
const flat_multi_map_iterator_base_impl<
Key,
Type,
Compare,
other_iterator_impl,
other_pointer_impl,
other_reference_impl> &right) const {
return _impl == right._impl;
}
template <
typename other_iterator_impl,
typename other_pointer_impl,
typename other_reference_impl>
bool operator!=(
const flat_multi_map_iterator_base_impl<
Key,
Type,
Compare,
other_iterator_impl,
other_pointer_impl,
other_reference_impl> &right) const {
return _impl != right._impl;
}
template <
typename other_iterator_impl,
typename other_pointer_impl,
typename other_reference_impl>
bool operator<(
const flat_multi_map_iterator_base_impl<
Key,
Type,
Compare,
other_iterator_impl,
other_pointer_impl,
other_reference_impl> &right) const {
return _impl < right._impl;
}
private:
iterator_impl _impl;
friend class flat_multi_map<Key, Type, Compare>;
template <
typename OtherKey,
typename OtherType,
typename OtherCompare,
typename other_iterator_impl,
typename other_pointer_impl,
typename other_reference_impl>
friend class flat_multi_map_iterator_base_impl;
};
template <typename Key, typename Type, typename Compare>
class flat_multi_map {
class key_const_wrap {
public:
constexpr key_const_wrap(const Key &value) : _value(value) {
}
constexpr key_const_wrap(Key &&value) : _value(std::move(value)) {
}
inline constexpr operator const Key&() const {
return _value;
}
private:
Key _value;
};
using pair_type = std::pair<key_const_wrap, Type>;
class compare {
public:
template <
typename OtherType1,
typename OtherType2,
typename = std::enable_if_t<
!std::is_same_v<std::decay_t<OtherType1>, key_const_wrap> &&
!std::is_same_v<std::decay_t<OtherType1>, pair_type> &&
!std::is_same_v<std::decay_t<OtherType2>, key_const_wrap> &&
!std::is_same_v<std::decay_t<OtherType2>, pair_type>>>
inline constexpr auto operator()(
OtherType1 &&a,
OtherType2 &b) const {
return Compare()(
std::forward<OtherType1>(a),
std::forward<OtherType2>(b));
}
inline constexpr auto operator()(
const key_const_wrap &a,
const key_const_wrap &b) const {
return operator()(
static_cast<const Key&>(a),
static_cast<const Key&>(b));
}
template <
typename OtherType,
typename = std::enable_if_t<
!std::is_same_v<std::decay_t<OtherType>, key_const_wrap> &&
!std::is_same_v<std::decay_t<OtherType>, pair_type>>>
inline constexpr auto operator()(
const key_const_wrap &a,
OtherType &&b) const {
return operator()(
static_cast<const Key&>(a),
std::forward<OtherType>(b));
}
template <
typename OtherType,
typename = std::enable_if_t<
!std::is_same_v<std::decay_t<OtherType>, key_const_wrap> &&
!std::is_same_v<std::decay_t<OtherType>, pair_type>>>
inline constexpr auto operator()(
OtherType &&a,
const key_const_wrap &b) const {
return operator()(
std::forward<OtherType>(a),
static_cast<const Key&>(b));
}
inline constexpr auto operator()(
const pair_type &a,
const pair_type &b) const {
return operator()(a.first, b.first);
}
template <
typename OtherType,
typename = std::enable_if_t<
!std::is_same_v<std::decay_t<OtherType>, pair_type>>>
inline constexpr auto operator()(
const pair_type &a,
OtherType &&b) const {
return operator()(a.first, std::forward<OtherType>(b));
}
template <
typename OtherType,
typename = std::enable_if_t<
!std::is_same_v<std::decay_t<OtherType>, pair_type>>>
inline constexpr auto operator()(
OtherType &&a,
const pair_type &b) const {
return operator()(std::forward<OtherType>(a), b.first);
}
};
using impl = std::deque<pair_type>;
using iterator_base = flat_multi_map_iterator_base_impl<
Key,
Type,
Compare,
typename impl::iterator,
pair_type*,
pair_type&>;
using const_iterator_base = flat_multi_map_iterator_base_impl<
Key,
Type,
Compare,
typename impl::const_iterator,
const pair_type*,
const pair_type&>;
using reverse_iterator_base = flat_multi_map_iterator_base_impl<
Key,
Type,
Compare,
typename impl::reverse_iterator,
pair_type*,
pair_type&>;
using const_reverse_iterator_base = flat_multi_map_iterator_base_impl<
Key,
Type,
Compare,
typename impl::const_reverse_iterator,
const pair_type*,
const pair_type&>;
public:
using value_type = pair_type;
using size_type = typename impl::size_type;
using difference_type = typename impl::difference_type;
using pointer = pair_type*;
using const_pointer = const pair_type*;
using reference = pair_type&;
using const_reference = const pair_type&;
class const_iterator;
class iterator : public iterator_base {
public:
using iterator_base::iterator_base;
iterator(const iterator_base &other) : iterator_base(other) {
}
friend class const_iterator;
};
class const_iterator : public const_iterator_base {
public:
using const_iterator_base::const_iterator_base;
const_iterator(const_iterator_base other) : const_iterator_base(other) {
}
const_iterator(const iterator &other) : const_iterator_base(other._impl) {
}
};
class const_reverse_iterator;
class reverse_iterator : public reverse_iterator_base {
public:
using reverse_iterator_base::reverse_iterator_base;
reverse_iterator(reverse_iterator_base other) : reverse_iterator_base(other) {
}
friend class const_reverse_iterator;
};
class const_reverse_iterator : public const_reverse_iterator_base {
public:
using const_reverse_iterator_base::const_reverse_iterator_base;
const_reverse_iterator(const_reverse_iterator_base other) : const_reverse_iterator_base(other) {
}
const_reverse_iterator(const reverse_iterator &other) : const_reverse_iterator_base(other._impl) {
}
};
size_type size() const {
return _impl.size();
}
bool empty() const {
return _impl.empty();
}
void clear() {
_impl.clear();
}
iterator begin() {
return _impl.begin();
}
iterator end() {
return _impl.end();
}
const_iterator begin() const {
return _impl.begin();
}
const_iterator end() const {
return _impl.end();
}
const_iterator cbegin() const {
return _impl.cbegin();
}
const_iterator cend() const {
return _impl.cend();
}
reverse_iterator rbegin() {
return _impl.rbegin();
}
reverse_iterator rend() {
return _impl.rend();
}
const_reverse_iterator rbegin() const {
return _impl.rbegin();
}
const_reverse_iterator rend() const {
return _impl.rend();
}
const_reverse_iterator crbegin() const {
return _impl.crbegin();
}
const_reverse_iterator crend() const {
return _impl.crend();
}
reference front() {
return *begin();
}
const_reference front() const {
return *begin();
}
reference back() {
return *(end() - 1);
}
const_reference back() const {
return *(end() - 1);
}
iterator insert(const value_type &value) {
if (empty() || compare()(value.first, front().first)) {
_impl.push_front(value);
return begin();
} else if (!compare()(value.first, back().first)) {
_impl.push_back(value);
return (end() - 1);
}
auto where = getUpperBound(value.first);
return _impl.insert(where, value);
}
iterator insert(value_type &&value) {
if (empty() || compare()(value.first, front().first)) {
_impl.push_front(std::move(value));
return begin();
} else if (!compare()(value.first, back().first)) {
_impl.push_back(std::move(value));
return (end() - 1);
}
auto where = getUpperBound(value.first);
return _impl.insert(where, std::move(value));
}
template <typename... Args>
iterator emplace(Args&&... args) {
return insert(value_type(std::forward<Args>(args)...));
}
bool removeOne(const Key &key) {
if (empty()
|| compare()(key, front().first)
|| compare()(back().first, key)) {
return false;
}
auto where = getLowerBound(key);
if (compare()(key, where->first)) {
return false;
}
_impl.erase(where);
return true;
}
int removeAll(const Key &key) {
if (empty()
|| compare()(key, front().first)
|| compare()(back().first, key)) {
return 0;
}
auto range = getEqualRange(key);
if (range.first == range.second) {
return 0;
}
_impl.erase(range.first, range.second);
return (range.second - range.first);
}
iterator erase(const_iterator where) {
return _impl.erase(where._impl);
}
iterator erase(const_iterator from, const_iterator till) {
return _impl.erase(from._impl, till._impl);
}
iterator findFirst(const Key &key) {
if (empty()
|| compare()(key, front().first)
|| compare()(back().first, key)) {
return end();
}
auto where = getLowerBound(key);
return compare()(key, where->first) ? _impl.end() : where;
}
const_iterator findFirst(const Key &key) const {
if (empty()
|| compare()(key, front().first)
|| compare()(back().first, key)) {
return end();
}
auto where = getLowerBound(key);
return compare()(key, where->first) ? _impl.end() : where;
}
bool contains(const Key &key) const {
return findFirst(key) != end();
}
int count(const Key &key) const {
if (empty()
|| compare()(key, front().first)
|| compare()(back().first, key)) {
return 0;
}
auto range = getEqualRange(key);
return (range.second - range.first);
}
private:
impl _impl;
friend class flat_map<Key, Type, Compare>;
typename impl::iterator getLowerBound(const Key &key) {
return base::lower_bound(_impl, key, compare());
}
typename impl::const_iterator getLowerBound(const Key &key) const {
return base::lower_bound(_impl, key, compare());
}
typename impl::iterator getUpperBound(const Key &key) {
return base::upper_bound(_impl, key, compare());
}
typename impl::const_iterator getUpperBound(const Key &key) const {
return base::upper_bound(_impl, key, compare());
}
std::pair<
typename impl::iterator,
typename impl::iterator
> getEqualRange(const Key &key) {
return base::equal_range(_impl, key, compare());
}
std::pair<
typename impl::const_iterator,
typename impl::const_iterator
> getEqualRange(const Key &key) const {
return base::equal_range(_impl, key, compare());
}
};
template <typename Key, typename Type, typename Compare>
class flat_map : private flat_multi_map<Key, Type, Compare> {
using parent = flat_multi_map<Key, Type, Compare>;
using compare = typename parent::compare;
using pair_type = typename parent::pair_type;
public:
using value_type = typename parent::value_type;
using size_type = typename parent::size_type;
using difference_type = typename parent::difference_type;
using pointer = typename parent::pointer;
using const_pointer = typename parent::const_pointer;
using reference = typename parent::reference;
using const_reference = typename parent::const_reference;
using iterator = typename parent::iterator;
using const_iterator = typename parent::const_iterator;
using reverse_iterator = typename parent::reverse_iterator;
using const_reverse_iterator = typename parent::const_reverse_iterator;
using parent::parent;
using parent::size;
using parent::empty;
using parent::clear;
using parent::begin;
using parent::end;
using parent::cbegin;
using parent::cend;
using parent::rbegin;
using parent::rend;
using parent::crbegin;
using parent::crend;
using parent::front;
using parent::back;
using parent::erase;
using parent::contains;
std::pair<iterator, bool> insert(const value_type &value) {
if (this->empty() || compare()(value.first, this->front().first)) {
this->_impl.push_front(value);
return { this->begin(), true };
} else if (compare()(this->back().first, value.first)) {
this->_impl.push_back(value);
return { this->end() - 1, true };
}
auto where = this->getLowerBound(value.first);
if (compare()(value.first, where->first)) {
return { this->_impl.insert(where, value), true };
}
return { where, false };
}
std::pair<iterator, bool> insert(value_type &&value) {
if (this->empty() || compare()(value.first, this->front().first)) {
this->_impl.push_front(std::move(value));
return { this->begin(), true };
} else if (compare()(this->back().first, value.first)) {
this->_impl.push_back(std::move(value));
return { this->end() - 1, true };
}
auto where = this->getLowerBound(value.first);
if (compare()(value.first, where->first)) {
return { this->_impl.insert(where, std::move(value)), true };
}
return { where, false };
}
template <typename... Args>
std::pair<iterator, bool> emplace(
const Key &key,
Args&&... args) {
return this->insert(value_type(
key,
Type(std::forward<Args>(args)...)));
}
template <typename... Args>
std::pair<iterator, bool> try_emplace(
const Key &key,
Args&&... args) {
if (this->empty() || compare()(key, this->front().first)) {
this->_impl.push_front(value_type(
key,
Type(std::forward<Args>(args)...)));
return { this->begin(), true };
} else if (compare()(this->back().first, key)) {
this->_impl.push_back(value_type(
key,
Type(std::forward<Args>(args)...)));
return { this->end() - 1, true };
}
auto where = this->getLowerBound(key);
if (compare()(key, where->first)) {
return {
this->_impl.insert(
where,
value_type(
key,
Type(std::forward<Args>(args)...))),
true
};
}
return { where, false };
}
bool remove(const Key &key) {
return this->removeOne(key);
}
iterator find(const Key &key) {
return this->findFirst(key);
}
const_iterator find(const Key &key) const {
return this->findFirst(key);
}
Type &operator[](const Key &key) {
if (this->empty() || compare()(key, this->front().first)) {
this->_impl.push_front({ key, Type() });
return this->front().second;
} else if (compare()(this->back().first, key)) {
this->_impl.push_back({ key, Type() });
return this->back().second;
}
auto where = this->getLowerBound(key);
if (compare()(key, where->first)) {
return this->_impl.insert(where, { key, Type() })->second;
}
return where->second;
}
optional<Type> take(const Key &key) {
auto it = find(key);
if (it == this->end()) {
return base::none;
}
auto result = std::move(it->second);
this->erase(it);
return std::move(result);
}
};
} // namespace base