Drizzled Public API Documentation

counter.cc
1 /* - mode: c; c-basic-offset: 2; indent-tabs-mode: nil; -*-
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3  *
4  * Copyright (C) 2010 Brian Aker
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
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10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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14  * GNU General Public License for more details.
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16  * You should have received a copy of the GNU General Public License
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18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include <config.h>
22 
23 #include <plugin/utility_dictionary/dictionary.h>
24 
25 #include <drizzled/atomics.h>
26 #include <drizzled/session.h>
27 #include <drizzled/sql_lex.h>
28 
29 using namespace drizzled;
30 using namespace std;
31 
33 
34 utility_dictionary::Counter::Counter() :
35  plugin::TableFunction("DATA_DICTIONARY", "COUNTER")
36 {
37  add_field("VALUE", plugin::TableFunction::NUMBER, 0, false);
38 }
39 
40 bool utility_dictionary::Counter::Generator::populate()
41 {
42  if (lex().isSumExprUsed() && count > 0)
43  return false;
44 
45  if (lex().current_select->group_list.elements && count > 0)
46  return false;
47 
48  if (lex().current_select->explicit_limit or count == 0)
49  {
50  push(counter.increment());
51  }
52  else
53  {
54  return false;
55  }
56 
57  count++;
58 
59  return true;
60 }