db2/btree/bt_conv.c

   1 /*-
   2  * See the file LICENSE for redistribution information.
   3  *
   4  * Copyright (c) 1996, 1997
   5  *      Sleepycat Software.  All rights reserved.
   6  */
   7
   8 #include "config.h"
   9
  10 #ifndef lint
  11 static const char sccsid[] = "@(#)bt_conv.c     10.4 (Sleepycat) 9/3/97";
  12 #endif /* not lint */
  13
  14 #ifndef NO_SYSTEM_INCLUDES
  15 #include <sys/types.h>
  16 #endif
  17
  18 #include "db_int.h"
  19 #include "db_page.h"
  20 #include "db_swap.h"
  21 #include "btree.h"
  22
  23 /*
  24  * __bam_pgin, __bam_pgout --
  25  *      Convert host-specific page layout to/from the host-independent
  26  *      format stored on disk.
  27  *
  28  * PUBLIC: int __bam_pgin __P((db_pgno_t, void *, DBT *));
  29  * PUBLIC: int __bam_pgout __P((db_pgno_t, void *, DBT *));
  30  */
  31 int
  32 __bam_pgin(pg, pp, cookie)
  33         db_pgno_t pg;
  34         void *pp;
  35         DBT *cookie;
  36 {
  37         DB_PGINFO *pginfo;
  38
  39         pginfo = (DB_PGINFO *)cookie->data;
  40         if (!pginfo->needswap)
  41                 return (0);
  42         return (pg == PGNO_METADATA ? __bam_mswap(pp) : __db_pgin(pg, pp));
  43 }
  44
  45 int
  46 __bam_pgout(pg, pp, cookie)
  47         db_pgno_t pg;
  48         void *pp;
  49         DBT *cookie;
  50 {
  51         DB_PGINFO *pginfo;
  52
  53         pginfo = (DB_PGINFO *)cookie->data;
  54         if (!pginfo->needswap)
  55                 return (0);
  56         return (pg == PGNO_METADATA ? __bam_mswap(pp) : __db_pgout(pg, pp));
  57 }
  58
  59 /*
  60  * __bam_mswap --
  61  *      Swap the bytes on the btree metadata page.
  62  *
  63  * PUBLIC: int __bam_mswap __P((PAGE *));
  64  */
  65 int
  66 __bam_mswap(pg)
  67         PAGE *pg;
  68 {
  69         u_int8_t *p;
  70
  71         p = (u_int8_t *)pg;
  72
  73         /* Swap the meta-data information. */
  74         SWAP32(p);              /* lsn.file */
  75         SWAP32(p);              /* lsn.offset */
  76         SWAP32(p);              /* pgno */
  77         SWAP32(p);              /* magic */
  78         SWAP32(p);              /* version */
  79         SWAP32(p);              /* pagesize */
  80         SWAP32(p);              /* maxkey */
  81         SWAP32(p);              /* minkey */
  82         SWAP32(p);              /* free */
  83         SWAP32(p);              /* flags */
  84
  85         /* Swap the statistics. */
  86         p = (u_int8_t *)&((BTMETA *)pg)->stat;
  87         SWAP32(p);              /* bt_freed */
  88         SWAP32(p);              /* bt_pfxsaved */
  89         SWAP32(p);              /* bt_split */
  90         SWAP32(p);              /* bt_rootsplit */
  91         SWAP32(p);              /* bt_fastsplit */
  92         SWAP32(p);              /* bt_added */
  93         SWAP32(p);              /* bt_deleted */
  94         SWAP32(p);              /* bt_get */
  95         SWAP32(p);              /* bt_cache_hit */
  96         SWAP32(p);              /* bt_cache_miss */
  97
  98         return (0);
  99 }