rom/filesys/fat/cache.h

   1 /*
   2     Copyright © 2010-2015, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Disk cache.
   6 */
   7
   8 #ifndef CACHE_H
   9 #define CACHE_H
  10
  11 #include <exec/types.h>
  12 #include <exec/lists.h>
  13
  14 struct BlockRange
  15 {
  16     struct MinNode node1;    /* links into hash table */
  17     struct MinNode node2;    /* links into free and dirty lists */
  18     ULONG use_count;    /* number of users of this block */
  19     UWORD state;
  20     ULONG num;    /* start block number */
  21     UBYTE *data;    /* actual block data */
  22 };
  23
  24 struct Cache
  25 {
  26     struct ExecBase *sys_base;
  27     struct DosLibrary *dos_base;
  28     APTR  priv;         /* private data sent to AccessDisk() */
  29     ULONG block_count;  /* number of blocks allocated */
  30     ULONG block_size;   /* size of a disk block */
  31     ULONG hash_size;    /* size of hash table */
  32     struct BlockRange **blocks;    /* array of pointers to all blocks */
  33     struct MinList *hash_table;    /* hash table of all valid cache blocks */
  34     struct MinList dirty_list;    /* the dirty list */
  35     struct MinList free_list;    /* the free list */
  36 };
  37
  38 /* Block states */
  39
  40 #define BS_EMPTY 0
  41 #define BS_VALID 1
  42 #define BS_DIRTY 2
  43
  44 /* Prototypes */
  45
  46 APTR Cache_CreateCache(APTR priv, ULONG hash_size, ULONG block_count,
  47     ULONG block_size, struct ExecBase *sys_base, struct DosLibrary *dos_base);
  48 VOID Cache_DestroyCache(APTR cache);
  49 APTR Cache_GetBlock(APTR cache, ULONG blockNum, UBYTE **data);
  50 VOID Cache_FreeBlock(APTR cache, APTR block);
  51 VOID Cache_MarkBlockDirty(APTR cache, APTR block);
  52 BOOL Cache_Flush(APTR cache);
  53
  54 LONG AccessDisk(BOOL do_write, ULONG num, ULONG nblocks, ULONG block_size,
  55     UBYTE *data, APTR priv);
  56
  57 #endif