MySQL 8.2.0
Source Code Documentation
mysql_thd_attributes.h
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22
23#ifndef MYSQL_THD_ATTRIBUTES_H
24#define MYSQL_THD_ATTRIBUTES_H
25
28
29/**
30 @ingroup group_components_services_inventory
31
32 THD Attributes service allows to obtain data associated with the THD
33 object, which keeps various attributes of the user session.
34
35 Currently, following attributes are supported:
36
37 - Query Digest Text
38 - Query Text
39 - Host or IP
40 - Schema
41 - Command String ("command" of the return mysql_cstring_with_length type)
42 - SQL Command String ("sql_command" of the return mysql_cstring_with_length
43 type)
44 - Query Character Set ("query_charset" of the return mysql_cstring_with_length
45 type)
46
47 @section thd_attributes_init Initialization
48
49 The service can be instantiated using the registry service with the
50 "mysql_thd_attributes" name.
51
52 @code
53 SERVICE_TYPE(registry) *registry = mysql_plugin_registry_acquire();
54 my_service<SERVICE_TYPE(mysql_thd_attributes)>
55 svc("mysql_thd_attributes", registry);
56 if (svc.is_valid()) {
57 // The service is ready to be used
58 }
59 @endcode
60
61 @section thd_attributes_query_digest_text Query Digest Text
62
63 Query Digest represents converted SQL statement to normalized form. The code
64 below demonstrates how query digest can be obtained from the service.
65
66 @code
67 my_h_string str;
68
69 mysql_thd_attributes->get(m_thd, "query_digest",
70 reinterpret_cast<void *>(&str));
71 @endcode
72
73 The buffer can be fetched using the code below:
74
75 @code
76 char buf[1024]; // buffer must be big enough to store the digest
77
78 mysql_string_converter->convert_to_buffer(str, buf, sizeof(buf), "utf8mb3");
79 @endcode
80
81 After the string content has been copied into another buffer, it must be
82 destroyed:
83
84 @code
85 mysql_string_factory->destroy(str);
86 @endcode
87
88 @section thd_attributes_query_text Query Text
89
90 Query text represents complete SQL text currently being executed within a
91 given session. The example code is identical to the one for Query Digest, the
92 only difference is that attribute name "sql_text" should be used in this
93 case.
94
95 @section thd_attributes_host_or_ip Host or IP
96
97 Host or IP text contains host or IP (if host unavailable) belonging to a
98 client associated with a given session. The example code is identical to the
99 one for Query Digest, the only difference is that attribute name "host_or_ip"
100 should be used in this case.
101
102 @section thd_attributes_schema Schema
103
104 Schema text contains a name of database currently in use by a
105 client associated with a given session. The example code is identical to the
106 one for Query Digest, the only difference is that attribute name "schema"
107 should be used in this case.
108*/
109
111
112/**
113 Get THD attribute.
114
115 Currently, following attributes are supported:
116
117 - Query Digest Text ("query_digest" of the returned my_h_string type)
118 - Query Text ("sql_text" of the returned my_h_string type)
119 - Host or IP ("host_or_ip" of the returned my_h_string type)
120 - Schema ("schema" of the returned my_h_string type)
121 - Is Upgrade Thread ("is_upgrade_thread" of the returned bool type)
122 - Is Init File System Thread ("is_init_file_thread" of the returned bool type)
123 - Command String ("command" of the return mysql_cstring_with_length type)
124 - SQL Command String ("sql_command" of the return mysql_cstring_with_length
125 type)
126 - Query Character Set ("query_charset" of the return mysql_cstring_with_length
127 type)
128 - status variable ("thd_status" of the returned uint16 type). if session is
129 OK, session is killed, query is killed or timeout
130 - time-zone name variable ("time_zone_name" of the returned
131 mysql_cstring_with_length type)
132
133 @param thd Session THD object.
134 @param name Name of the attribute to be set.
135 @param[out] inout_pvalue Iterator pointer.
136
137 @return
138 @retval FALSE Succeeded.
139 @retval TRUE Failed.
140*/
141DECLARE_BOOL_METHOD(get, (MYSQL_THD thd, const char *name, void *inout_pvalue));
142
143/**
144 Set THD attribute.
145
146 Currently the implementation does not support setting of any attribute.
147
148 @param thd Session THD object.
149 @param name Name of the attribute to be set.
150 @param[out] inout_pvalue Iterator pointer.
151
152 @return The function always fail and return TRUE value.
153*/
154DECLARE_BOOL_METHOD(set, (MYSQL_THD thd, const char *name, void *inout_pvalue));
155
157
158#endif /* MYSQL_THD_ATTRIBUTES_H */
#define MYSQL_THD
Definition: backup_page_tracker.h:37
void get(PSI_field *, PSI_longlong *) noexcept
Definition: pfs_plugin_column_bigint_v1_all_empty.cc:31
std::set< Key, Compare, ut::allocator< Key > > set
Specialization of set which uses ut_allocator.
Definition: ut0new.h:2881
const mysql_service_mysql_thd_attributes_t * mysql_thd_attributes
Definition: rewriter_plugin.cc:58
#define END_SERVICE_DEFINITION(name)
A macro to end the last Service definition started with the BEGIN_SERVICE_DEFINITION macro.
Definition: service.h:90
#define BEGIN_SERVICE_DEFINITION(name)
Declares a new Service.
Definition: service.h:85
#define DECLARE_BOOL_METHOD(name, args)
Declares a method that returns bool as a part of the Service definition.
Definition: service.h:111
case opt name
Definition: sslopt-case.h:32