db2/btree/bt_conv.c

   1 /*-
   2  * See the file LICENSE for redistribution information.
   3  *
   4  * Copyright (c) 1996, 1997, 1998
   5  *      Sleepycat Software.  All rights reserved.
   6  */
   7
   8 #include "config.h"
   9
  10 #ifndef lint
  11 static const char sccsid[] = "@(#)bt_conv.c     10.6 (Sleepycat) 4/10/98";
  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 --
  25  *      Convert host-specific page layout from the host-independent format
  26  *      stored on disk.
  27  *
  28  * PUBLIC: int __bam_pgin __P((db_pgno_t, void *, DBT *));
  29  */
  30 int
  31 __bam_pgin(pg, pp, cookie)
  32         db_pgno_t pg;
  33         void *pp;
  34         DBT *cookie;
  35 {
  36         DB_PGINFO *pginfo;
  37
  38         pginfo = (DB_PGINFO *)cookie->data;
  39         if (!pginfo->needswap)
  40                 return (0);
  41         return (pg == PGNO_METADATA ?
  42             __bam_mswap(pp) : __db_pgin(pg, pginfo->db_pagesize, pp));
  43 }
  44
  45 /*
  46  * __bam_pgout --
  47  *      Convert host-specific page layout to the host-independent format
  48  *      stored on disk.
  49  *
  50  * PUBLIC: int __bam_pgout __P((db_pgno_t, void *, DBT *));
  51  */
  52 int
  53 __bam_pgout(pg, pp, cookie)
  54         db_pgno_t pg;
  55         void *pp;
  56         DBT *cookie;
  57 {
  58         DB_PGINFO *pginfo;
  59
  60         pginfo = (DB_PGINFO *)cookie->data;
  61         if (!pginfo->needswap)
  62                 return (0);
  63         return (pg == PGNO_METADATA ?
  64             __bam_mswap(pp) : __db_pgout(pg, pginfo->db_pagesize, pp));
  65 }
  66
  67 /*
  68  * __bam_mswap --
  69  *      Swap the bytes on the btree metadata page.
  70  *
  71  * PUBLIC: int __bam_mswap __P((PAGE *));
  72  */
  73 int
  74 __bam_mswap(pg)
  75         PAGE *pg;
  76 {
  77         u_int8_t *p;
  78
  79         p = (u_int8_t *)pg;
  80
  81         /* Swap the meta-data information. */
  82         SWAP32(p);              /* lsn.file */
  83         SWAP32(p);              /* lsn.offset */
  84         SWAP32(p);              /* pgno */
  85         SWAP32(p);              /* magic */
  86         SWAP32(p);              /* version */
  87         SWAP32(p);              /* pagesize */
  88         SWAP32(p);              /* maxkey */
  89         SWAP32(p);              /* minkey */
  90         SWAP32(p);              /* free */
  91         SWAP32(p);              /* flags */
  92
  93         /* Swap the statistics. */
  94         p = (u_int8_t *)&((BTMETA *)pg)->stat;
  95         SWAP32(p);              /* bt_freed */
  96         SWAP32(p);              /* bt_pfxsaved */
  97         SWAP32(p);              /* bt_split */
  98         SWAP32(p);              /* bt_rootsplit */
  99         SWAP32(p);              /* bt_fastsplit */
 100         SWAP32(p);              /* bt_added */
 101         SWAP32(p);              /* bt_deleted */
 102         SWAP32(p);              /* bt_get */
 103         SWAP32(p);              /* bt_cache_hit */
 104         SWAP32(p);              /* bt_cache_miss */
 105
 106         return (0);
 107 }