solidity/libdevcore/InvertibleMap.h
2019-06-20 18:43:37 +02:00

94 lines
2.0 KiB
C++

/*
This file is part of solidity.
solidity 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.
solidity 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.
You should have received a copy of the GNU General Public License
along with solidity. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <map>
#include <set>
/**
* Data structure that keeps track of values and keys of a mapping.
*/
template <class K, class V>
struct InvertibleMap
{
std::map<K, V> values;
// references[x] == {y | values[y] == x}
std::map<V, std::set<K>> references;
void set(K _key, V _value)
{
if (values.count(_key))
references[values[_key]].erase(_key);
values[_key] = _value;
references[_value].insert(_key);
}
void eraseKey(K _key)
{
if (values.count(_key))
references[values[_key]].erase(_key);
values.erase(_key);
}
void eraseValue(V _value)
{
if (references.count(_value))
{
for (V v: references[_value])
values.erase(v);
references.erase(_value);
}
}
void clear()
{
values.clear();
references.clear();
}
};
template <class T>
struct InvertibleRelation
{
/// forward[x] contains y <=> backward[y] contains x
std::map<T, std::set<T>> forward;
std::map<T, std::set<T>> backward;
void insert(T _key, T _value)
{
forward[_key].insert(_value);
backward[_value].insert(_key);
}
void set(T _key, std::set<T> _values)
{
for (T v: forward[_key])
backward[v].erase(_key);
for (T v: _values)
backward[v].insert(_key);
forward[_key] = std::move(_values);
}
void eraseKey(T _key)
{
for (auto const& v: forward[_key])
backward[v].erase(_key);
forward.erase(_key);
}
};