~drizzle-trunk/drizzle/development

/* 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 */

#ifndef DRIZZLED_MEMORY_ROOT_H

#define DRIZZLED_MEMORY_ROOT_H

#include <cstddef>

#include <drizzled/definitions.h>

#if defined(__cplusplus)

extern "C" {

#endif

namespace drizzled

{

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:

  /* 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);

};

inline static bool alloc_root_inited(Root *root)

{

  return root->min_malloc != 0;

}

void init_alloc_root(Root *mem_root,

                     size_t block_size= ROOT_MIN_BLOCK_SIZE);

void *alloc_root(Root *mem_root, size_t Size);

void *multi_alloc_root(Root *mem_root, ...);

void free_root(Root *root, myf MyFLAGS);

void set_prealloc_root(Root *root, char *ptr);

void reset_root_defaults(Root *mem_root, size_t block_size,

                         size_t prealloc_size);

char *strdup_root(Root *root,const char *str);

char *strmake_root(Root *root,const char *str,size_t len);

void *memdup_root(Root *root,const void *str, size_t len);

}

}

#if defined(__cplusplus)

}

#endif

#endif /* DRIZZLED_MEMORY_ROOT_H */