66 lines
2.4 KiB
C++
66 lines
2.4 KiB
C++
/* Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
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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, version 2.0,
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as published by the Free Software Foundation.
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This program is also distributed with certain software (including
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but not limited to OpenSSL) that is licensed under separate terms,
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as designated in a particular file or component or in included license
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documentation. The authors of MySQL hereby grant you an additional
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permission to link the program and your derivative works with the
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separately licensed software that they have included with MySQL.
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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, version 2.0, 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 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 "my_dbug.h"
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#include "my_inttypes.h"
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#include "storage/myisam/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, my_off_t filepos) {
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bool skip_deleted_blocks;
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DBUG_TRACE;
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skip_deleted_blocks = 0;
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if (filepos == HA_OFFSET_ERROR) {
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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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return my_errno();
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return (*info->s->read_rnd)(info, buf, filepos, skip_deleted_blocks);
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}
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