mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-09-22 17:50:47 +00:00
348 lines
7.0 KiB
C++
348 lines
7.0 KiB
C++
#pragma once
|
||
|
||
#include <DB/Interpreters/HashMap.h>
|
||
|
||
|
||
namespace DB
|
||
{
|
||
|
||
|
||
/** См. HashMap.h
|
||
*/
|
||
|
||
template
|
||
<
|
||
typename Key,
|
||
typename Hash = default_hash<Key>,
|
||
typename ZeroTraits = default_zero_traits<Key>,
|
||
int INITIAL_SIZE_DEGREE = 16,
|
||
int GROWTH_DEGREE = 2
|
||
>
|
||
class HashSet : private boost::noncopyable
|
||
{
|
||
private:
|
||
friend class const_iterator;
|
||
friend class iterator;
|
||
|
||
typedef size_t HashValue;
|
||
typedef HashSet<Key, Hash, ZeroTraits, INITIAL_SIZE_DEGREE, GROWTH_DEGREE> Self;
|
||
|
||
size_t m_size; /// Количество элементов
|
||
UInt8 size_degree; /// Размер таблицы в виде степени двух
|
||
bool has_zero; /// Хэш-таблица содержит элемент со значением ключа = 0.
|
||
Key * buf; /// Кусок памяти для всех элементов кроме элемента с ключём 0.
|
||
|
||
Hash hash;
|
||
|
||
#ifdef DBMS_HASH_MAP_COUNT_COLLISIONS
|
||
mutable size_t collisions;
|
||
#endif
|
||
|
||
inline size_t buf_size() const { return 1 << size_degree; }
|
||
inline size_t max_fill() const { return 1 << (size_degree - 1); }
|
||
inline size_t mask() const { return buf_size() - 1; }
|
||
inline size_t place(HashValue x) const { return x & mask(); }
|
||
|
||
|
||
/// Увеличить размер буфера в 2 ^ GROWTH_DEGREE раз
|
||
void resize()
|
||
{
|
||
size_t old_size = buf_size();
|
||
|
||
size_degree += GROWTH_DEGREE;
|
||
Key * new_buf = reinterpret_cast<Key*>(calloc(buf_size(), sizeof(Key)));
|
||
Key * old_buf = buf;
|
||
buf = new_buf;
|
||
|
||
for (size_t i = 0; i < old_size; ++i)
|
||
if (!ZeroTraits::check(old_buf[i]))
|
||
reinsert(old_buf[i]);
|
||
|
||
free(reinterpret_cast<void*>(old_buf));
|
||
}
|
||
|
||
|
||
/** Вставить в новый буфер значение, которое было в старом буфере.
|
||
* Используется при увеличении размера буфера.
|
||
*/
|
||
void reinsert(const Key & x)
|
||
{
|
||
size_t place_value = place(hash(x));
|
||
while (!ZeroTraits::check(buf[place_value]))
|
||
{
|
||
++place_value;
|
||
place_value &= mask();
|
||
#ifdef DBMS_HASH_MAP_COUNT_COLLISIONS
|
||
++collisions;
|
||
#endif
|
||
}
|
||
memcpy(&buf[place_value], &x, sizeof(x));
|
||
}
|
||
|
||
|
||
public:
|
||
typedef Key key_type;
|
||
typedef Key value_type;
|
||
|
||
|
||
HashSet() :
|
||
m_size(0),
|
||
size_degree(INITIAL_SIZE_DEGREE),
|
||
has_zero(false)
|
||
{
|
||
buf = reinterpret_cast<Key*>(calloc(buf_size(), sizeof(Key)));
|
||
#ifdef DBMS_HASH_MAP_COUNT_COLLISIONS
|
||
collisions = 0;
|
||
#endif
|
||
}
|
||
|
||
~HashSet()
|
||
{
|
||
for (iterator it = begin(); it != end(); ++it)
|
||
it->~Key();
|
||
free(reinterpret_cast<void*>(buf));
|
||
}
|
||
|
||
|
||
class iterator
|
||
{
|
||
Self * container;
|
||
Key * ptr;
|
||
|
||
friend class HashSet;
|
||
|
||
iterator(Self * container_, Key * ptr_) : container(container_), ptr(ptr_) {}
|
||
|
||
public:
|
||
iterator() {}
|
||
|
||
bool operator== (const iterator & rhs) const { return ptr == rhs.ptr; }
|
||
bool operator!= (const iterator & rhs) const { return ptr != rhs.ptr; }
|
||
|
||
iterator & operator++()
|
||
{
|
||
if (unlikely(!ptr))
|
||
ptr = container->buf;
|
||
else
|
||
++ptr;
|
||
|
||
while (ptr < container->buf + container->buf_size() && ZeroTraits::check(*ptr))
|
||
++ptr;
|
||
|
||
return *this;
|
||
}
|
||
|
||
Key & operator* () const { return *ptr; }
|
||
Key * operator->() const { return ptr; }
|
||
};
|
||
|
||
|
||
class const_iterator
|
||
{
|
||
const Self * container;
|
||
const Key * ptr;
|
||
|
||
friend class HashSet;
|
||
|
||
const_iterator(const Self * container_, const Key * ptr_) : container(container_), ptr(ptr_) {}
|
||
|
||
public:
|
||
const_iterator() {}
|
||
const_iterator(const iterator & rhs) : container(rhs.container), ptr(rhs.ptr) {}
|
||
|
||
bool operator== (const const_iterator & rhs) const { return ptr == rhs.ptr; }
|
||
bool operator!= (const const_iterator & rhs) const { return ptr != rhs.ptr; }
|
||
|
||
const_iterator & operator++()
|
||
{
|
||
if (unlikely(!ptr))
|
||
ptr = container->buf;
|
||
else
|
||
++ptr;
|
||
|
||
while (ptr < container->buf + container->buf_size() && ZeroTraits::check(*ptr))
|
||
++ptr;
|
||
|
||
return *this;
|
||
}
|
||
|
||
const Key & operator* () const { return *ptr; }
|
||
const Key * operator->() const { return ptr; }
|
||
};
|
||
|
||
|
||
const_iterator begin() const
|
||
{
|
||
if (has_zero)
|
||
return const_iterator(this, NULL);
|
||
|
||
const Key * ptr = buf;
|
||
while (ptr < buf + buf_size() && ZeroTraits::check(*ptr))
|
||
++ptr;
|
||
|
||
return const_iterator(this, ptr);
|
||
}
|
||
|
||
iterator begin()
|
||
{
|
||
if (has_zero)
|
||
return iterator(this, NULL);
|
||
|
||
Key * ptr = buf;
|
||
while (ptr < buf + buf_size() && ZeroTraits::check(*ptr))
|
||
++ptr;
|
||
|
||
return iterator(this, ptr);
|
||
}
|
||
|
||
const_iterator end() const { return const_iterator(this, buf + buf_size()); }
|
||
iterator end() { return iterator(this, buf + buf_size()); }
|
||
|
||
|
||
/// Вставить ключ.
|
||
std::pair<iterator, bool> insert(const Key & x)
|
||
{
|
||
if (ZeroTraits::check(x))
|
||
{
|
||
if (!has_zero)
|
||
{
|
||
++m_size;
|
||
has_zero = true;
|
||
return std::make_pair(begin(), true);
|
||
}
|
||
return std::make_pair(begin(), false);
|
||
}
|
||
|
||
size_t place_value = place(hash(x));
|
||
while (!ZeroTraits::check(buf[place_value]) && buf[place_value] != x)
|
||
{
|
||
++place_value;
|
||
place_value &= mask();
|
||
#ifdef DBMS_HASH_MAP_COUNT_COLLISIONS
|
||
++collisions;
|
||
#endif
|
||
}
|
||
|
||
iterator res(this, &buf[place_value]);
|
||
|
||
if (!ZeroTraits::check(buf[place_value]) && buf[place_value] == x)
|
||
return std::make_pair(res, false);
|
||
|
||
buf[place_value] = x;
|
||
++m_size;
|
||
|
||
if (unlikely(m_size > max_fill()))
|
||
{
|
||
resize();
|
||
return std::make_pair(find(x), true);
|
||
}
|
||
|
||
return std::make_pair(res, true);
|
||
}
|
||
|
||
|
||
void emplace(Key x, iterator & it, bool & inserted)
|
||
{
|
||
if (ZeroTraits::check(x))
|
||
{
|
||
if (!has_zero)
|
||
{
|
||
++m_size;
|
||
has_zero = true;
|
||
inserted = true;
|
||
}
|
||
else
|
||
inserted = false;
|
||
|
||
it = begin();
|
||
return;
|
||
}
|
||
|
||
size_t place_value = place(hash(x));
|
||
while (!ZeroTraits::check(buf[place_value]) && buf[place_value] != x)
|
||
{
|
||
++place_value;
|
||
place_value &= mask();
|
||
#ifdef DBMS_HASH_MAP_COUNT_COLLISIONS
|
||
++collisions;
|
||
#endif
|
||
}
|
||
|
||
it = iterator(this, &buf[place_value]);
|
||
|
||
if (!ZeroTraits::check(buf[place_value]) && buf[place_value] == x)
|
||
{
|
||
inserted = false;
|
||
return;
|
||
}
|
||
|
||
new(&buf[place_value]) Key(x);
|
||
inserted = true;
|
||
++m_size;
|
||
|
||
if (unlikely(m_size > max_fill()))
|
||
{
|
||
resize();
|
||
it = find(x);
|
||
}
|
||
}
|
||
|
||
|
||
iterator find(Key x)
|
||
{
|
||
if (ZeroTraits::check(x))
|
||
return has_zero ? begin() : end();
|
||
|
||
size_t place_value = place(hash(x));
|
||
while (!ZeroTraits::check(buf[place_value]) && buf[place_value] != x)
|
||
{
|
||
++place_value;
|
||
place_value &= mask();
|
||
#ifdef DBMS_HASH_MAP_COUNT_COLLISIONS
|
||
++collisions;
|
||
#endif
|
||
}
|
||
|
||
return !ZeroTraits::check(buf[place_value]) ? iterator(this, &buf[place_value]) : end();
|
||
}
|
||
|
||
|
||
const_iterator find(Key x) const
|
||
{
|
||
if (ZeroTraits::check(x))
|
||
return has_zero ? begin() : end();
|
||
|
||
size_t place_value = place(hash(x));
|
||
while (!ZeroTraits::check(buf[place_value]) && buf[place_value] != x)
|
||
{
|
||
++place_value;
|
||
place_value &= mask();
|
||
#ifdef DBMS_HASH_MAP_COUNT_COLLISIONS
|
||
++collisions;
|
||
#endif
|
||
}
|
||
|
||
return !ZeroTraits::check(buf[place_value]) ? const_iterator(this, &buf[place_value]) : end();
|
||
}
|
||
|
||
|
||
size_t size() const
|
||
{
|
||
return m_size;
|
||
}
|
||
|
||
bool empty() const
|
||
{
|
||
return 0 == m_size;
|
||
}
|
||
|
||
#ifdef DBMS_HASH_MAP_COUNT_COLLISIONS
|
||
size_t getCollisions() const
|
||
{
|
||
return collisions;
|
||
}
|
||
#endif
|
||
};
|
||
|
||
}
|