90 lines
2.2 KiB
C++
90 lines
2.2 KiB
C++
//
|
|
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2018
|
|
//
|
|
// Distributed under the Boost Software License, Version 1.0. (See accompanying
|
|
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
|
|
//
|
|
#pragma once
|
|
|
|
#include "td/utils/common.h"
|
|
#include "td/utils/logging.h"
|
|
#include "td/utils/misc.h"
|
|
|
|
#include <set>
|
|
#include <utility>
|
|
|
|
namespace td {
|
|
|
|
template <class ValueT>
|
|
class Enumerator {
|
|
public:
|
|
using Key = int32;
|
|
template <class T>
|
|
Key add(T &&value) {
|
|
ValueT v = std::forward<T>(value);
|
|
container_->set_zero_value(&v);
|
|
auto it = set_.lower_bound(Key{0});
|
|
container_->set_zero_value(nullptr);
|
|
if (it != set_.end() && container_->get_value(*it) == v) {
|
|
return *it;
|
|
}
|
|
auto key = container_->add_value(std::move(v));
|
|
set_.insert(it, key);
|
|
return key;
|
|
}
|
|
ValueT &get(Key key) {
|
|
return container_->get_value(key);
|
|
}
|
|
const ValueT &get(Key key) const {
|
|
return container_->get_value(key);
|
|
}
|
|
|
|
private:
|
|
class Container {
|
|
public:
|
|
bool compare(Key a, Key b) const {
|
|
return get_value(a) < get_value(b);
|
|
}
|
|
const ValueT &get_value(Key key) const {
|
|
if (key == 0) {
|
|
CHECK(zero_value_);
|
|
return *zero_value_;
|
|
}
|
|
size_t pos = narrow_cast<size_t>(key - 1);
|
|
CHECK(pos < values_.size());
|
|
return values_[pos];
|
|
}
|
|
ValueT &get_value(Key key) {
|
|
return const_cast<ValueT &>(const_cast<const Container *>(this)->get_value(key));
|
|
}
|
|
void set_zero_value(ValueT *value) {
|
|
zero_value_ = value;
|
|
}
|
|
Key add_value(ValueT &&value) {
|
|
values_.push_back(std::move(value));
|
|
return narrow_cast<Key>(values_.size());
|
|
}
|
|
|
|
private:
|
|
std::vector<ValueT> values_;
|
|
ValueT *zero_value_ = nullptr;
|
|
};
|
|
|
|
class Comparator {
|
|
public:
|
|
explicit Comparator(Container *container) : container_(container) {
|
|
}
|
|
bool operator()(Key a, Key b) const {
|
|
return container_->compare(a, b);
|
|
}
|
|
|
|
private:
|
|
Container *container_;
|
|
};
|
|
|
|
std::unique_ptr<Container> container_{std::make_unique<Container>()};
|
|
std::set<Key, Comparator> set_{Comparator{container_.get()}};
|
|
};
|
|
|
|
} // namespace td
|