ClickHouse/dbms/Common/HashTable/ClearableHashMap.h
Ivan 97f2a2213e
Move all folders inside /dbms one level up (#9974)
* Move some code outside dbms/src folder
* Fix paths
2020-04-02 02:51:21 +03:00

46 lines
1.2 KiB
C++

#pragma once
#include <Common/HashTable/HashMap.h>
#include <Common/HashTable/ClearableHashSet.h>
template <typename Key, typename Mapped, typename Hash>
struct ClearableHashMapCell : public ClearableHashTableCell<Key, HashMapCell<Key, Mapped, Hash, ClearableHashSetState>>
{
using Base = ClearableHashTableCell<Key, HashMapCell<Key, Mapped, Hash, ClearableHashSetState>>;
using Base::Base;
ClearableHashMapCell(const typename Base::value_type & value_, const typename Base::State & state)
: Base::BaseCell(value_, state), Base::version(state.version) {}
};
template
<
typename Key,
typename Mapped,
typename Hash = DefaultHash<Key>,
typename Grower = HashTableGrower<>,
typename Allocator = HashTableAllocator
>
class ClearableHashMap : public HashTable<Key, ClearableHashMapCell<Key, Mapped, Hash>, Hash, Grower, Allocator>
{
public:
Mapped & operator[](const Key & x)
{
typename ClearableHashMap::LookupResult it;
bool inserted;
this->emplace(x, it, inserted);
if (inserted)
new (&it->getMapped()) Mapped();
return it->getMapped();
}
void clear()
{
++this->version;
this->m_size = 0;
}
};