cache.h

Go to the documentation of this file.

/*
    libparted - a library for manipulating disk partitions
    Copyright (C) 2004-2005, 2007, 2009-2014, 2019-2023 Free Software
    Foundation, Inc.
 
    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 3 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, see <http://www.gnu.org/licenses/>.
*/
 
#ifndef _CACHE_H
#define _CACHE_H
 
#include <parted/parted.h>
#include <parted/endian.h>
#include <parted/debug.h>
 
#include "hfs.h"
 
/* CR => CACHE REF */
#define CR_NULL                  0 /* reserved */
#define CR_PRIM_CAT              1
#define CR_PRIM_EXT              2
#define CR_PRIM_ATTR             3
#define CR_PRIM_ALLOC            4
#define CR_PRIM_START            5
#define CR_BTREE_CAT             6
#define CR_BTREE_ATTR            7
#define CR_BTREE_EXT_0           8
#define CR_BTREE_EXT_CAT         9
#define CR_BTREE_EXT_EXT        10 /* should not happen ! */
#define CR_BTREE_EXT_ATTR       11
#define CR_BTREE_EXT_ALLOC      12
#define CR_BTREE_EXT_START      13 /* unneeded in current code */
#define CR_BTREE_CAT_JIB        14 /* journal info block */
#define CR_BTREE_CAT_JL         15 /* journal */
/* 16 -> 31 || high order bit */   /* reserved */
 
/* tuning */
#define CR_SHIFT                 8 /* number of bits to shift start_block by */
                                   /* to get the index of the linked list */
#define CR_OVER_DIV             16 /* alloc a table for (1+1/CR_OVER_DIV) *
                                      file_number + CR_ADD_CST */
#define CR_ADD_CST              16
#define CR_NEW_ALLOC_DIV         4 /* divide the size of the first alloc table
                                      by this value to allocate next tables */
 
/* See DOC for an explaination of this structure */
/* Access read only from outside cache.c */
struct _HfsCPrivateExtent {
        struct _HfsCPrivateExtent*      next;
        uint32_t                        ext_start;
        uint32_t                        ext_length;
        uint32_t                        ref_block;
        uint16_t                        ref_offset;
        uint8_t                         sect_by_block;
        unsigned                        where : 5;
        unsigned                        ref_index : 3; /* 0 -> 7 */
};
typedef struct _HfsCPrivateExtent HfsCPrivateExtent;
 
/* Internaly used by cache.c for custom memory managment only */
struct _HfsCPrivateCacheTable {
        struct _HfsCPrivateCacheTable*  next_cache;
        HfsCPrivateExtent*              table;
        unsigned int                    table_size;
        unsigned int                    table_first_free;
        /* first_elemt ? */
};
typedef struct _HfsCPrivateCacheTable HfsCPrivateCacheTable;
 
/* Internaly used by cache.c for custom memory managment
   and cache handling only */
struct _HfsCPrivateCache {
        HfsCPrivateCacheTable*          table_list;
        HfsCPrivateCacheTable*          last_table;
        HfsCPrivateExtent**             linked_ref;
        unsigned int                    linked_ref_size;
        unsigned int                    block_number;
        unsigned int                    first_cachetable_size;
        unsigned int                    needed_alloc_size;
};
typedef struct _HfsCPrivateCache HfsCPrivateCache;
 
HfsCPrivateCache*
hfsc_new_cache(unsigned int block_number, unsigned int file_number);
 
void
hfsc_delete_cache(HfsCPrivateCache* cache);
 
HfsCPrivateExtent*
hfsc_cache_add_extent(HfsCPrivateCache* cache, uint32_t start, uint32_t length,
                      uint32_t block, uint16_t offset, uint8_t sbb,
                      uint8_t where, uint8_t index);
 
HfsCPrivateExtent*
hfsc_cache_search_extent(HfsCPrivateCache* cache, uint32_t start);
 
HfsCPrivateExtent*
hfsc_cache_move_extent(HfsCPrivateCache* cache, uint32_t old_start,
                        uint32_t new_start);
 
static __inline__ unsigned int
hfsc_cache_needed_buffer(HfsCPrivateCache* cache)
{
        return cache->needed_alloc_size;
}
 
#endif /* _CACHE_H */