1 /*
2 Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License, version 2.0,
6 as published by the Free Software Foundation.
7
8 This program is also distributed with certain software (including
9 but not limited to OpenSSL) that is licensed under separate terms,
10 as designated in a particular file or component or in included license
11 documentation. The authors of MySQL hereby grant you an additional
12 permission to link the program and your derivative works with the
13 separately licensed software that they have included with MySQL.
14
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License, version 2.0, for more details.
19
20 You should have received a copy of the GNU General Public License
21 along with this program; if not, write to the Free Software
22 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
23 */
24
25 #include "show_variable_query_extractor.h"
26 #include "instance_callback.h"
27
28 using namespace Mysql::Tools::Base;
29 using std::string;
30 using std::vector;
31
Show_variable_query_extractor()32 Show_variable_query_extractor::Show_variable_query_extractor()
33 : m_exists(false)
34 {}
35
extract_variable(const Mysql_query_runner::Row & result_row)36 int64 Show_variable_query_extractor::extract_variable(
37 const Mysql_query_runner::Row& result_row)
38 {
39 this->m_extracted_variable= result_row[0];
40 this->m_exists= true;
41 Mysql_query_runner::cleanup_result(result_row);
42 return 0;
43 }
44
get_variable_value(Mysql_query_runner * query_runner_to_copy,string variable,string & value,bool & exists)45 int64 Show_variable_query_extractor::get_variable_value(
46 Mysql_query_runner* query_runner_to_copy,
47 string variable, string& value, bool& exists)
48 {
49 Show_variable_query_extractor extractor;
50 Mysql_query_runner query_runner_to_use(*query_runner_to_copy);
51
52 Instance_callback<int64, const Mysql_query_runner::Row&,
53 Show_variable_query_extractor>
54 result_cb(&extractor, &Show_variable_query_extractor::extract_variable);
55
56 query_runner_to_use.add_result_callback(&result_cb);
57
58 /*
59 Note: Because MySQL uses the C escape syntax in strings (for example, '\n'
60 to represent newline), you must double any '\' that you use in your LIKE
61 strings. For example, to search for '\n', specify it as '\\n'.To search for
62 '\', specify it as '\\\\' (the backslashes are stripped once by the parser
63 and another time when the pattern match is done, leaving a single backslash
64 to be matched).
65
66 Example: "t\1" = > "t\\\\1"
67 */
68 string quoted_variable;
69 for (size_t i= 0; i < variable.size(); i++)
70 {
71 if (variable[i] == '\\')
72 {
73 quoted_variable.append(3, '\\');
74 }
75 else if (variable[i] == '\'' || variable[i] == '_' || variable[i] == '%')
76 {
77 quoted_variable+= '\\';
78 }
79 quoted_variable+= variable[i];
80 }
81
82 query_runner_to_use.run_query("SELECT @@global." + quoted_variable);
83
84 value= extractor.m_extracted_variable;
85 exists= extractor.m_exists;
86 return 0;
87 }
88