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/* Copyright (C) 2000 MySQL AB
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/**
* @file
* @brief Memory root declarations
*/
#ifndef DRIZZLED_MEMORY_ROOT_H
#define DRIZZLED_MEMORY_ROOT_H
#include <cstddef>
#include <drizzled/definitions.h>
namespace drizzled
{
/**
* @namespace drizzled::memory
* Memory allocation utils
*
* NB: This namespace documentation may not seem very useful, but without a
* comment on the namespace Doxygen won't extract any documentation for
* namespace members.
*/
namespace memory
{
static const int KEEP_PREALLOC= 1;
/* move used to free list and reuse them */
static const int MARK_BLOCKS_FREE= 2;
namespace internal
{
class UsedMemory
{ /* struct for once_alloc (block) */
public:
UsedMemory *next; /* Next block in use */
size_t left; /* memory left in block */
size_t size; /* size of block */
};
}
static const size_t ROOT_MIN_BLOCK_SIZE= (MALLOC_OVERHEAD + sizeof(internal::UsedMemory) + 8);
class Root
{
public:
Root() { }
Root(size_t block_size_arg)
{
free= used= pre_alloc= 0;
min_malloc= 32;
block_size= block_size_arg - memory::ROOT_MIN_BLOCK_SIZE;
error_handler= 0;
block_num= 4; /* We shift this with >>2 */
first_block_usage= 0;
}
/**
* blocks with free memory in it
*/
internal::UsedMemory *free;
/**
* blocks almost without free memory
*/
internal::UsedMemory *used;
/**
* preallocated block
*/
internal::UsedMemory *pre_alloc;
/**
* if block have less memory it will be put in 'used' list
*/
size_t min_malloc;
size_t block_size; ///< initial block size
unsigned int block_num; ///< allocated blocks counter
/**
* first free block in queue test counter (if it exceed
* MAX_BLOCK_USAGE_BEFORE_DROP block will be dropped in 'used' list)
*/
unsigned int first_block_usage;
void (*error_handler)(void);
void reset_root_defaults(size_t block_size, size_t prealloc_size);
void *alloc_root(size_t Size);
void mark_blocks_free();
void *memdup_root(const void *str, size_t len);
char *strdup_root(const char *str);
char *strmake_root(const char *str,size_t len);
void init_alloc_root(size_t block_size= ROOT_MIN_BLOCK_SIZE);
inline bool alloc_root_inited()
{
return min_malloc != 0;
}
void free_root(myf MyFLAGS);
};
void *multi_alloc_root(Root *mem_root, ...);
} /* namespace memory */
} /* namespace drizzled */
#endif /* DRIZZLED_MEMORY_ROOT_H */
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