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/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult 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; either version 2 of the License, or
(at your option) any later version.
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 */
#ifdef __GNUC__
#pragma implementation /* gcc: Class implementation */
#endif
#include <my_global.h>
#include <my_sys.h>
#include "cache_manager.h"
/*
cache_manager.cc
-----------------------------------------------------------------------
The cache_manager class manages a number of blocks (which are allocatable
units of memory).
-----------------------------------------------------------------------
*/
#define HEADER_LENGTH ALIGN_SIZE(8)
#define SUFFIX_LENGTH 4
#define ALLOC_MASK 0x3FFFFFFFL
#define FREE_BIT (1L << 31)
#define LOCK_BIT (1L << 30)
#define SMALLEST_BLOCK 32
/*
** Internal Methods
** --------------------
*/
/* list manipulation methods */
void *cache_manager::init_list(void)
{
return;
}
void *cache_manager::link_into_abs(void *ptr)
{
for (int i(0); (*abs_list)[i] != NULL; i++);
(*abs_list)[i] = ptr;
return (abs_list)[i]; // ???
}
bool *cache_manager::unlink_from_abs(void *ptr)
{
(*ptr) = NULL;
return;
}
/* memory allocation methods */
void *cache_manager::find_in_llist(uint)
{
return;
}
void cache_manager::defrag(void)
{
printf("Defragging: ..........");
return;
}
/*
** Public Methods
** ------------------
*/
cache_manager::cache_manager(uint size)
{
base_ptr = my_malloc(size, MY_WME); /* MY_WME = write mesg on err */
return;
}
cache_manager::~cache_manager(void)
{
free(base_ptr);
delete base_ptr;
return;
}
void *cache_manager::alloc(uint size)
{
void *llist;
void *abs_ptr;
size=ALIGN_SIZE(size+HEADER_LENGTH+SUFFIX_LENGTH);
if (!(llist = find_in_llist(size)))
{
//defrag();
if (!(llist = find_in_llist(size)))
return 0; /* return null pointer, buffer exhausted! */
}
size_of_found_block=int4korr((char*) llist) & ALLOC_MASK;
// if (size_of_found_block < SMALLEST_BLOCK)
abs_ptr = link_into_abs(llist);
return abs_ptr;
}
void cache_manager::dealloc(void)
{
printf("Deallocating: ..........\n");
return;
}
void cache_manager::clear(void)
{
// reset the internal linked list, forgetting all pointers to mem blks
return;
}
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