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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2008 Sun Microsystems
*
* 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 02110-1301 USA
*/
#ifndef DRIZZLED_SQL_ARRAY_H
#define DRIZZLED_SQL_ARRAY_H
#include <mysys/my_sys.h>
/*
Array of pointers to Elem that uses memory from MEM_ROOT
MEM_ROOT has no realloc() so this is supposed to be used for cases when
reallocations are rare.
*/
template <class Elem> class Array
{
enum {alloc_increment = 16};
Elem **buffer;
uint32_t n_elements, max_element;
public:
Array(MEM_ROOT *mem_root, uint32_t prealloc=16)
{
buffer= (Elem**)alloc_root(mem_root, prealloc * sizeof(Elem**));
max_element = buffer? prealloc : 0;
n_elements= 0;
}
Elem& at(int idx)
{
return *(((Elem*)buffer) + idx);
}
Elem **front()
{
return buffer;
}
Elem **back()
{
return buffer + n_elements;
}
bool append(MEM_ROOT *mem_root, Elem *el)
{
if (n_elements == max_element)
{
Elem **newbuf;
if (!(newbuf= (Elem**)alloc_root(mem_root, (n_elements + alloc_increment)*
sizeof(Elem**))))
{
return false;
}
memcpy(newbuf, buffer, n_elements*sizeof(Elem*));
buffer= newbuf;
}
buffer[n_elements++]= el;
return false;
}
int elements()
{
return n_elements;
}
void clear()
{
n_elements= 0;
}
typedef int (*CMP_FUNC)(Elem * const *el1, Elem *const *el2);
void sort(CMP_FUNC cmp_func)
{
my_qsort(buffer, n_elements, sizeof(Elem*), (qsort_cmp)cmp_func);
}
};
#endif /* DRIZZLED_SQL_ARRAY_H */
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