release/src/router/mysql/storage/heap/hp_rrnd.c

   1 /* Copyright (c) 2000-2002, 2004-2007 MySQL AB
   2
   3    This program is free software; you can redistribute it and/or modify
   4    it under the terms of the GNU General Public License as published by
   5    the Free Software Foundation; version 2 of the License.
   6
   7    This program is distributed in the hope that it will be useful,
   8    but WITHOUT ANY WARRANTY; without even the implied warranty of
   9    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10    GNU General Public License for more details.
  11
  12    You should have received a copy of the GNU General Public License
  13    along with this program; if not, write to the Free Software
  14    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA */
  15
  16 /* Read a record from a random position */
  17
  18 #include "heapdef.h"
  19
  20 /*
  21            Returns one of following values:
  22            0 = Ok.
  23            HA_ERR_RECORD_DELETED = Record is deleted.
  24            HA_ERR_END_OF_FILE = EOF.
  25 */
  26
  27 int heap_rrnd(register HP_INFO *info, uchar *record, uchar *pos)
  28 {
  29   HP_SHARE *share=info->s;
  30   DBUG_ENTER("heap_rrnd");
  31   DBUG_PRINT("enter",("info: 0x%lx  pos: %lx",(long) info, (long) pos));
  32
  33   info->lastinx= -1;
  34   if (!(info->current_ptr= pos))
  35   {
  36     info->update= 0;
  37     DBUG_RETURN(my_errno= HA_ERR_END_OF_FILE);
  38   }
  39   if (!info->current_ptr[share->reclength])
  40   {
  41     info->update= HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND;
  42     DBUG_RETURN(my_errno=HA_ERR_RECORD_DELETED);
  43   }
  44   info->update=HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND | HA_STATE_AKTIV;
  45   memcpy(record,info->current_ptr,(size_t) share->reclength);
  46   DBUG_PRINT("exit", ("found record at 0x%lx", (long) info->current_ptr));
  47   info->current_hash_ptr=0;                     /* Can't use rnext */
  48   DBUG_RETURN(0);
  49 } /* heap_rrnd */
  50
  51
  52 #ifdef WANT_OLD_HEAP_VERSION
  53
  54 /*
  55            If pos == -1 then read next record
  56            Returns one of following values:
  57            0 = Ok.
  58            HA_ERR_RECORD_DELETED = Record is deleted.
  59            HA_ERR_END_OF_FILE = EOF.
  60 */
  61
  62 int heap_rrnd_old(register HP_INFO *info, uchar *record, ulong pos)
  63 {
  64   HP_SHARE *share=info->s;
  65   DBUG_ENTER("heap_rrnd");
  66   DBUG_PRINT("enter",("info: 0x%lx  pos: %ld",info,pos));
  67
  68   info->lastinx= -1;
  69   if (pos == (ulong) -1)
  70   {
  71     pos= ++info->current_record;
  72     if (pos % share->block.records_in_block &&  /* Quick next record */
  73         pos < share->records+share->deleted &&
  74         (info->update & HA_STATE_PREV_FOUND))
  75     {
  76       info->current_ptr+=share->block.recbuffer;
  77       goto end;
  78     }
  79   }
  80   else
  81     info->current_record=pos;
  82
  83   if (pos >= share->records+share->deleted)
  84   {
  85     info->update= 0;
  86     DBUG_RETURN(my_errno= HA_ERR_END_OF_FILE);
  87   }
  88
  89         /* Find record number pos */
  90   hp_find_record(info, pos);
  91
  92 end:
  93   if (!info->current_ptr[share->reclength])
  94   {
  95     info->update= HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND;
  96     DBUG_RETURN(my_errno=HA_ERR_RECORD_DELETED);
  97   }
  98   info->update=HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND | HA_STATE_AKTIV;
  99   memcpy(record,info->current_ptr,(size_t) share->reclength);
 100   DBUG_PRINT("exit",("found record at 0x%lx",info->current_ptr));
 101   info->current_hash_ptr=0;                     /* Can't use rnext */
 102   DBUG_RETURN(0);
 103 } /* heap_rrnd */
 104
 105 #endif /* WANT_OLD_HEAP_VERSION */