MySQL 8.0.31
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
39 @section Initialization
40
41 The service can be instantiated using the registry service with the
42 "mysql_thd_attributes" name.
43
44 @code
45 SERVICE_TYPE(registry) *registry = mysql_plugin_registry_acquire();
46 my_service<SERVICE_TYPE(mysql_thd_attributes)>
47 svc("mysql_thd_attributes", registry);
48 if (svc.is_valid()) {
49 // The service is ready to be used
50 }
51 @endcode
52
53 @section Query Digest Text
54
55 Query Digest represents converted SQL statement to normalized form. The code
56 below demonstrates how query digest can be obtained from the service.
57
58 @code
59 my_h_string str;
60
61 mysql_thd_attributes->get(m_thd, "query_digest",
62 reinterpret_cast<void *>(&str));
63 @endcode
64
65 The buffer can be fetched using the code below:
66
67 @code
68 char buf[1024]; // buffer must be big enough to store the digest
69
70 mysql_string_converter->convert_to_buffer(str, buf, sizeof(buf), "utf8mb3");
71 @endcode
72
73 After the string content has been copied into another buffer, it must be
74 destroyed:
75
76 @code
77 mysql_string_factory->destroy(str);
78 @endcode
79*/
81
82/**
83 Get THD attribute.
84
85 Currently, following attributes are supported:
86
87 - Query Digest Text ("query_digest" of the returned my_h_string type).
88
89 @param thd Session THD object.
90 @param name Name of the attribute to be set.
91 @param[out] inout_pvalue Iterator pointer.
92
93 @return
94 @retval FALSE Succeeded.
95 @retval TRUE Failed.
96*/
97DECLARE_BOOL_METHOD(get, (MYSQL_THD thd, const char *name, void *inout_pvalue));
98
99/**
100 Set THD attribute.
101
102 Currently the implementation does not support setting of any attribute.
103
104 @param thd Session THD object.
105 @param name Name of the attribute to be set.
106 @param[out] inout_pvalue Iterator pointer.
107
108 @return The function always fail and return TRUE value.
109*/
110DECLARE_BOOL_METHOD(set, (MYSQL_THD thd, const char *name, void *inout_pvalue));
111
113
114#endif /* MYSQL_THD_ATTRIBUTES_H */
#define MYSQL_THD
Definition: backup_page_tracker.h:37
static mysql_service_status_t get(reference_caching_cache cache, unsigned service_name_index, const my_h_service **refs) noexcept
Definition: component.cc:113
std::set< Key, Compare, ut::allocator< Key > > set
Specialization of set which uses ut_allocator.
Definition: ut0new.h:2863
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