Drizzled Public API Documentation

random_string.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
9  * (at your option) any later version.
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
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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
17  * along with this program; if not, write to the Free Software
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 
32 #define LARGEST_RANDOM_STRING 512
33 
34 static const char ALPHANUMERICS[]=
35  "0123456789ABCDEFGHIJKLMNOPQRSTWXYZabcdefghijklmnopqrstuvwxyz";
36 
37 #define ALPHANUMERICS_SIZE (sizeof(ALPHANUMERICS)-1)
38 
39 static size_t get_alpha_num(void)
40 {
41  return (size_t)random() % ALPHANUMERICS_SIZE;
42 }
43 
44 utility_dictionary::RandomString::RandomString() :
45  plugin::TableFunction("DATA_DICTIONARY", "RANDOM_STRING")
46 {
47  add_field("VALUE", plugin::TableFunction::STRING, LARGEST_RANDOM_STRING, false);
48 }
49 
50 bool utility_dictionary::RandomString::Generator::populate()
51 {
52  if (lex().isSumExprUsed() && count > 0)
53  return false;
54 
55  if (lex().current_select->group_list.elements && count > 0)
56  return false;
57 
58  if (lex().current_select->explicit_limit or count == 0)
59  {
60  uint32_t random_char_number= random() % LARGEST_RANDOM_STRING;
61  char buffer[LARGEST_RANDOM_STRING];
62 
63  for (uint32_t x= 0; x < random_char_number; x++)
64  buffer[x]= ALPHANUMERICS[get_alpha_num()];
65  buffer[random_char_number]= 0;
66 
67  push(buffer, random_char_number);
68  }
69  else
70  {
71  return false;
72  }
73 
74  count++;
75 
76  return true;
77 }