1 /* Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.
2 
3    This program is free software; you can redistribute it and/or modify
4    it under the terms of the GNU General Public License, version 2.0,
5    as published by the Free Software Foundation.
6 
7    This program is also distributed with certain software (including
8    but not limited to OpenSSL) that is licensed under separate terms,
9    as designated in a particular file or component or in included license
10    documentation.  The authors of MySQL hereby grant you an additional
11    permission to link the program and your derivative works with the
12    separately licensed software that they have included with MySQL.
13 
14    This program is distributed in the hope that it will be useful,
15    but WITHOUT ANY WARRANTY; without even the implied warranty of
16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17    GNU General Public License, version 2.0, for more details.
18 
19    You should have received a copy of the GNU General Public License
20    along with this program; if not, write to the Free Software
21    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
22 
23 #include "sql/system_variables.h"
24 
25 #include <string.h>
26 
27 /*
28   Add all status variables to another status variable array
29 
30   SYNOPSIS
31    add_to_status()
32    to_var       add to this array
33    from_var     from this array
34 
35   NOTES
36     This function assumes that all variables are longlong/ulonglong.
37     If this assumption will change, then we have to explictely add
38     the other variables after the while loop
39 */
40 
add_to_status(System_status_var * to_var,System_status_var * from_var)41 void add_to_status(System_status_var *to_var, System_status_var *from_var) {
42   int c;
43   ulonglong *end = (ulonglong *)((uchar *)to_var +
44                                  offsetof(System_status_var, LAST_STATUS_VAR) +
45                                  sizeof(ulonglong));
46   ulonglong *to = (ulonglong *)to_var, *from = (ulonglong *)from_var;
47 
48   while (to != end) *(to++) += *(from++);
49 
50   to_var->com_other += from_var->com_other;
51 
52   for (c = 0; c < SQLCOM_END; c++)
53     to_var->com_stat[(uint)c] += from_var->com_stat[(uint)c];
54 }
55 
56 /*
57   Add the difference between two status variable arrays to another one.
58 
59   SYNOPSIS
60     add_diff_to_status
61     to_var       add to this array
62     from_var     from this array
63     dec_var      minus this array
64 
65   NOTE
66     This function assumes that all variables are longlong/ulonglong.
67 */
68 
add_diff_to_status(System_status_var * to_var,System_status_var * from_var,System_status_var * dec_var)69 void add_diff_to_status(System_status_var *to_var, System_status_var *from_var,
70                         System_status_var *dec_var) {
71   int c;
72   ulonglong *end = (ulonglong *)((uchar *)to_var +
73                                  offsetof(System_status_var, LAST_STATUS_VAR) +
74                                  sizeof(ulonglong));
75   ulonglong *to = (ulonglong *)to_var, *from = (ulonglong *)from_var,
76             *dec = (ulonglong *)dec_var;
77 
78   while (to != end) *(to++) += *(from++) - *(dec++);
79 
80   to_var->com_other += from_var->com_other - dec_var->com_other;
81 
82   for (c = 0; c < SQLCOM_END; c++)
83     to_var->com_stat[(uint)c] +=
84         from_var->com_stat[(uint)c] - dec_var->com_stat[(uint)c];
85 }
86 
87 /*
88   Reset a block of status variables.
89 
90   SYNOPSIS
91     reset_system_status_vars
92     status_vars    Struct of status variables to reset
93 */
reset_system_status_vars(System_status_var * status_vars)94 void reset_system_status_vars(System_status_var *status_vars) {
95   memset(status_vars, 0, sizeof(*status_vars));
96 }
97