ClickHouse/dbms/include/DB/Common/HashTable/ClearableHashMap.h
2015-07-23 12:39:21 +03:00

44 lines
953 B
C++

#pragma once
#include <DB/Common/HashTable/HashMap.h>
#include <DB/Common/HashTable/ClearableHashSet.h>
template <typename Key, typename Mapped, typename Hash>
using ClearableHashMapCell = ClearableHashTableCell<Key, HashMapCell<Key, Mapped, Hash, ClearableHashSetState>>;
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:
typedef Key key_type;
typedef Mapped mapped_type;
typedef typename ClearableHashMap::cell_type::value_type value_type;
mapped_type & operator[](Key x)
{
typename ClearableHashMap::iterator it;
bool inserted;
this->emplace(x, it, inserted);
if (inserted)
new(&it->second) mapped_type();
return it->second;
}
void clear()
{
++this->version;
this->m_size = 0;
}
};