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by brian
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/* Copyright (C) 2000-2002, 2004 MySQL AB
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
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/* Read a record with random-access. The position to the record must
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get by MI_INFO. The next record can be read with pos= MI_POS_ERROR */
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#include "myisamdef.h" |
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/*
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Read a row based on position.
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If filepos= HA_OFFSET_ERROR then read next row
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Return values
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Returns one of following values:
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0 = Ok.
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HA_ERR_RECORD_DELETED = Record is deleted.
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HA_ERR_END_OF_FILE = EOF.
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*/
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int mi_rrnd(MI_INFO *info, uchar *buf, register my_off_t filepos) |
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{
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my_bool skip_deleted_blocks; |
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DBUG_ENTER("mi_rrnd"); |
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skip_deleted_blocks=0; |
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if (filepos == HA_OFFSET_ERROR) |
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{
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skip_deleted_blocks=1; |
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if (info->lastpos == HA_OFFSET_ERROR) /* First read ? */ |
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filepos= info->s->pack.header_length; /* Read first record */ |
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else
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filepos= info->nextpos; |
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}
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if (info->once_flags & RRND_PRESERVE_LASTINX) |
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info->once_flags&= ~RRND_PRESERVE_LASTINX; |
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else
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info->lastinx= -1; /* Can't forward or backward */ |
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/* Init all but update-flag */
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info->update&= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED); |
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if (info->opt_flag & WRITE_CACHE_USED && flush_io_cache(&info->rec_cache)) |
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DBUG_RETURN(my_errno); |
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DBUG_RETURN ((*info->s->read_rnd)(info,buf,filepos,skip_deleted_blocks)); |
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}
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