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f7aed02405
New feature: preload indexes into key cache. mi_preload.c: new file Many files: Added preload statement. sql/ha_myisam.h: Added preload statement. sql/handler.cc: Added preload statement. sql/lex.h: Added preload statement. sql/mysql_priv.h: Added preload statement. sql/sql_lex.h: Added preload statement. sql/sql_base.cc: Added preload statement. sql/sql_table.cc: New feature: preload indexes into key cache. sql/sql_parse.cc: New feature: preload indexes into key cache. sql/mysqld.cc: New feature: preload indexes into key cache. sql/set_var.cc: New feature: preload indexes into key cache. sql/sql_yacc.yy: New feature: preload indexes into key cache. sql/ha_myisam.cc: New feature: preload indexes into key cache. sql/table.h: New feature: preload indexes into key cache. mysys/mf_keycache.c: New feature: preload indexes into key cache. myisam/myisamdef.h: New feature: preload indexes into key cache. myisam/mi_extra.c: New feature: preload indexes into key cache. myisam/Makefile.am: New feature: preload indexes into key cache. include/my_base.h: New feature: preload indexes into key cache. include/my_sys.h: New feature: preload indexes into key cache. include/myisam.h: New feature: preload indexes into key cache.
118 lines
3.1 KiB
C
118 lines
3.1 KiB
C
/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult 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; either version 2 of the License, or
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(at your option) any later version.
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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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/*
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Preload indexes into key cache
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*/
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#include "myisamdef.h"
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/*
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Preload pages of the index file for a table into the key cache
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SYNOPSIS
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mi_preload()
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info open table
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map map of indexes to preload into key cache
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ignore_leaves only non-leaves pages are to be preloaded
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RETURN VALUE
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0 if a success. error code - otherwise.
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NOTES.
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At present pages for all indexes are preloaded.
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In future only pages for indexes specified in the key_map parameter
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of the table will be preloaded.
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*/
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int mi_preload(MI_INFO *info, ulonglong key_map, my_bool ignore_leaves)
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{
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uint i;
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uint length;
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uint block_length= 0;
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uchar *buff= NULL;
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MYISAM_SHARE* share= info->s;
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uint keys= share->state.header.keys;
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MI_KEYDEF *keyinfo= share->keyinfo;
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my_off_t key_file_length= share->state.state.key_file_length;
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my_off_t pos= share->base.keystart;
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if (!keys || !key_map || key_file_length == pos)
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return 0;
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block_length= keyinfo[0].block_length;
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if (!key_map)
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return 0;
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/* Check whether all indexes use the same block size */
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for (i= 1 ; i < keys ; i++)
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{
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if (keyinfo[i].block_length != block_length)
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return (my_errno= HA_ERR_NON_UNIQUE_BLOCK_SIZE);
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}
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length= info->preload_buff_size/block_length * block_length;
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set_if_bigger(length, block_length);
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if (!(buff= (uchar *) my_malloc(length, MYF(MY_WME))))
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return (my_errno= HA_ERR_OUT_OF_MEM);
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if (flush_key_blocks(share->kfile, FLUSH_RELEASE))
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goto err;
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do
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{
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/* Read the next block of index file into the preload buffer */
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set_if_smaller(length, key_file_length-pos);
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if (my_pread(share->kfile, (byte*) buff, length, pos, MYF(MY_FAE)))
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goto err;
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if (ignore_leaves)
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{
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uchar *end= buff+length;
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do
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{
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if (mi_test_if_nod(buff))
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{
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if (key_cache_insert(share->kfile, pos, (byte*) buff, block_length))
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goto err;
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}
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pos+= block_length;
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}
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while ((buff+= block_length) != end);
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buff= end-length;
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}
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else
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{
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if (key_cache_insert(share->kfile, pos, (byte*) buff, length))
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goto err;
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pos+= length;
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}
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}
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while (pos != key_file_length);
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my_free(buff, MYF(0));
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return 0;
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err:
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my_free(buff, MYF(MY_ALLOW_ZERO_PTR));
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return (my_errno= errno);
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}
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