| Current File : //usr/include/mysql/server/private/sql_array.h |
#ifndef SQL_ARRAY_INCLUDED
#define SQL_ARRAY_INCLUDED
/* Copyright (c) 2003, 2005-2007 MySQL AB, 2009 Sun Microsystems, Inc.
Use is subject to license terms.
Copyright (c) 2020, MariaDB Corporation.
This program 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; version 2 of the License.
This program 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 this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
#include <my_sys.h>
/**
A wrapper class which provides array bounds checking.
We do *not* own the array, we simply have a pointer to the first element,
and a length.
@remark
We want the compiler-generated versions of:
- the copy CTOR (memberwise initialization)
- the assignment operator (memberwise assignment)
@param Element_type The type of the elements of the container.
*/
template <typename Element_type> class Bounds_checked_array
{
public:
Bounds_checked_array()= default;
Bounds_checked_array(Element_type *el, size_t size_arg)
: m_array(el), m_size(size_arg)
{}
void reset() { m_array= NULL; m_size= 0; }
void reset(Element_type *array_arg, size_t size_arg)
{
m_array= array_arg;
m_size= size_arg;
}
/**
Set a new bound on the array. Does not resize the underlying
array, so the new size must be smaller than or equal to the
current size.
*/
void resize(size_t new_size)
{
DBUG_ASSERT(new_size <= m_size);
m_size= new_size;
}
Element_type &operator[](size_t n)
{
DBUG_ASSERT(n < m_size);
return m_array[n];
}
const Element_type &operator[](size_t n) const
{
DBUG_ASSERT(n < m_size);
return m_array[n];
}
size_t element_size() const { return sizeof(Element_type); }
size_t size() const { return m_size; }
bool is_null() const { return m_array == NULL; }
void pop_front()
{
DBUG_ASSERT(m_size > 0);
m_array+= 1;
m_size-= 1;
}
Element_type *array() const { return m_array; }
Element_type *begin() const { return array(); }
Element_type *end() const { return array() + m_size; }
bool operator==(const Bounds_checked_array<Element_type>&rhs) const
{
return m_array == rhs.m_array && m_size == rhs.m_size;
}
bool operator!=(const Bounds_checked_array<Element_type>&rhs) const
{
return m_array != rhs.m_array || m_size != rhs.m_size;
}
private:
Element_type *m_array= nullptr;
size_t m_size= 0;
};
/*
A typesafe wrapper around DYNAMIC_ARRAY
TODO: Change creator to take a THREAD_SPECIFIC option.
*/
template <class Elem> class Dynamic_array
{
DYNAMIC_ARRAY array;
public:
Dynamic_array(PSI_memory_key psi_key, uint prealloc=16, uint increment=16)
{
init(psi_key, prealloc, increment);
}
Dynamic_array(MEM_ROOT *root, uint prealloc=16, uint increment=16)
{
void *init_buffer= alloc_root(root, sizeof(Elem) * prealloc);
init_dynamic_array2(root->m_psi_key, &array, sizeof(Elem), init_buffer,
prealloc, increment, MYF(0));
}
void init(PSI_memory_key psi_key, uint prealloc=16, uint increment=16)
{
init_dynamic_array2(psi_key, &array, sizeof(Elem), 0, prealloc, increment, MYF(0));
}
/**
@note Though formally this could be declared "const" it would be
misleading at it returns a non-const pointer to array's data.
*/
Elem& at(size_t idx)
{
DBUG_ASSERT(idx < array.elements);
return *(((Elem*)array.buffer) + idx);
}
/// Const variant of at(), which cannot change data
const Elem& at(size_t idx) const
{
return *(((Elem*)array.buffer) + idx);
}
Elem& operator[](size_t idx)
{
return at(idx);
}
/// Const variant of operator[]
const Elem& operator[](size_t idx) const
{
return at(idx);
}
/// @returns pointer to first element
Elem *front()
{
return (Elem*)array.buffer;
}
/// @returns pointer to first element
const Elem *front() const
{
return (const Elem*)array.buffer;
}
/// @returns pointer to last element
Elem *back()
{
return ((Elem*)array.buffer) + array.elements - 1;
}
/// @returns pointer to last element
const Elem *back() const
{
return ((const Elem*)array.buffer) + array.elements - 1;
}
size_t size() const { return array.elements; }
const Elem *end() const
{
return back() + 1;
}
/// @returns pointer to n-th element
Elem *get_pos(size_t idx)
{
return ((Elem*)array.buffer) + idx;
}
/// @returns pointer to n-th element
const Elem *get_pos(size_t idx) const
{
return ((const Elem*)array.buffer) + idx;
}
/**
@retval false ok
@retval true OOM, @c my_error() has been called.
*/
bool append(const Elem &el)
{
return insert_dynamic(&array, &el);
}
bool append_val(Elem el)
{
return (insert_dynamic(&array, (uchar*)&el));
}
bool push(Elem &el)
{
return append(el);
}
/// Pops the last element. Does nothing if array is empty.
Elem& pop()
{
return *((Elem*)pop_dynamic(&array));
}
void del(size_t idx)
{
DBUG_ASSERT(idx <= array.max_element);
delete_dynamic_element(&array, (uint)idx);
}
size_t elements() const
{
return array.elements;
}
void elements(size_t num_elements)
{
DBUG_ASSERT(num_elements <= array.max_element);
array.elements= (uint)num_elements;
}
void clear()
{
elements(0);
}
void set(uint idx, const Elem &el)
{
set_dynamic(&array, &el, idx);
}
void freeze()
{
freeze_size(&array);
}
bool reserve(size_t new_size)
{
return allocate_dynamic(&array, (uint)new_size);
}
bool resize(size_t new_size, Elem default_val)
{
size_t old_size= elements();
if (reserve(new_size))
return true;
if (new_size > old_size)
{
set_dynamic(&array, (uchar*)&default_val, (uint)(new_size - 1));
/*for (size_t i= old_size; i != new_size; i++)
{
at(i)= default_val;
}*/
}
return false;
}
~Dynamic_array()
{
delete_dynamic(&array);
}
void free_memory()
{
delete_dynamic(&array);
}
typedef int (*CMP_FUNC)(const Elem *el1, const Elem *el2);
void sort(CMP_FUNC cmp_func)
{
my_qsort(array.buffer, array.elements, sizeof(Elem), (qsort_cmp)cmp_func);
}
typedef int (*CMP_FUNC2)(void *, const Elem *el1, const Elem *el2);
void sort(CMP_FUNC2 cmp_func, void *data)
{
my_qsort2(array.buffer, array.elements, sizeof(Elem), (qsort2_cmp)cmp_func, data);
}
};
typedef Bounds_checked_array<Item*> Ref_ptr_array;
#endif /* SQL_ARRAY_INCLUDED */