84 lines
2.6 KiB
C++
84 lines
2.6 KiB
C++
/* Copyright (c) 2006, 2015, 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 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
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#ifndef FILESORT_INCLUDED
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#define FILESORT_INCLUDED
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#include "my_global.h" /* uint, uchar */
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#include "my_base.h" /* ha_rows */
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#include "sql_list.h" /* Sql_alloc */
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class THD;
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struct TABLE;
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struct st_sort_field;
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struct st_order;
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class Addon_fields;
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class Field;
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class QEP_TAB;
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/**
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Sorting related info.
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*/
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class Filesort: public Sql_alloc
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{
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public:
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/// The QEP entry for the table to be sorted
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QEP_TAB *const tab;
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/// List of expressions to order the table by
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st_order *order;
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/// Maximum number of rows to return
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ha_rows limit;
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/// ORDER BY list with some precalculated info for filesort
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st_sort_field *sortorder;
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/// true means we are using Priority Queue for order by with limit.
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bool using_pq;
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/// Addon fields descriptor
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Addon_fields *addon_fields;
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Filesort(QEP_TAB *tab_arg, st_order *order_arg, ha_rows limit_arg):
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tab(tab_arg),
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order(order_arg),
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limit(limit_arg),
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sortorder(NULL),
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using_pq(false),
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addon_fields(NULL)
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{
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DBUG_ASSERT(order);
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};
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/* Prepare ORDER BY list for sorting. */
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uint make_sortorder();
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Addon_fields *get_addon_fields(ulong max_length_for_sort_data,
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Field **ptabfield,
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uint sortlength, uint *plength,
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uint *ppackable_length);
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private:
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void cleanup();
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};
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bool filesort(THD *thd, Filesort *fsort, bool sort_positions,
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ha_rows *examined_rows, ha_rows *found_rows,
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ha_rows *returned_rows);
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void filesort_free_buffers(TABLE *table, bool full);
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void change_double_for_sort(double nr,uchar *to);
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/// Declared here so we can unit test it.
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uint sortlength(THD *thd, st_sort_field *sortorder, uint s_length,
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bool *multi_byte_charset, bool *use_hash);
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#endif /* FILESORT_INCLUDED */
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