MySQL 9.0.0
Source Code Documentation
table_trigger_dispatcher.h
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23 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
24
25#ifndef TABLE_TRIGGER_DISPATCHER_H_INCLUDED
26#define TABLE_TRIGGER_DISPATCHER_H_INCLUDED
27
28///////////////////////////////////////////////////////////////////////////
29
30#include <assert.h>
31#include <string.h>
32
33#include "lex_string.h"
34#include "my_inttypes.h"
35#include "my_sys.h"
36#include "mysql_com.h" // MYSQL_ERRMSG_SIZE
37#include "mysqld_error.h" // ER_PARSE_ERROR
38#include "sql/table_trigger_field_support.h" // Table_trigger_field_support
39#include "sql/trigger_def.h" // enum_trigger_action_time_type
40
41class Field;
43class String;
44class THD;
45class Trigger;
46class Trigger_chain;
47struct MEM_ROOT;
48
49namespace dd {
50class Table;
51} // namespace dd
52struct TABLE;
53class Table_ref;
54template <class T>
55class List;
56
57///////////////////////////////////////////////////////////////////////////
58
59/**
60 This class holds all information about triggers of a table.
61*/
62
64 public:
65 static Table_trigger_dispatcher *create(TABLE *subject_table);
66
67 bool check_n_load(THD *thd, const dd::Table &table);
68
69 private:
70 Table_trigger_dispatcher(TABLE *subject_table);
71
72 public:
74
75 /**
76 Checks if there is a broken trigger for this table.
77
78 @retval false if all triggers are Ok.
79 @retval true in case there is at least one broken trigger (a trigger which
80 SQL-definition can not be parsed) for this table.
81 */
84 my_message(ER_PARSE_ERROR, m_parse_error_message, MYF(0));
85 return true;
86 }
87 return false;
88 }
89
90 /**
91 Create trigger for table.
92
93 @param thd Thread context
94 @param[out] binlog_create_trigger_stmt
95 Well-formed CREATE TRIGGER statement for putting into
96 binlog (after successful execution)
97 @param if_not_exists
98 True if 'IF NOT EXISTS' clause was specified
99 @param[out] already_exists
100 Set to true if trigger already exists on the same table
101
102 @note
103 - Assumes that trigger name is fully qualified.
104 - NULL-string means the following LEX_STRING instance:
105 { str = 0; length = 0 }.
106 - In other words, definer_user and definer_host should contain
107 simultaneously NULL-strings (non-SUID/old trigger) or valid strings
108 (SUID/new trigger).
109
110 @return Operation status.
111 @retval false Success
112 @retval true Failure
113 */
114 bool create_trigger(THD *thd, String *binlog_create_trigger_stmt,
115 bool if_not_exists, bool &already_exists);
116
119 bool old_row_is_record1);
120
121 Trigger_chain *get_triggers(int event, int action_time) {
122 assert(0 <= event && event < TRG_EVENT_MAX);
123 assert(0 <= action_time && action_time < TRG_ACTION_MAX);
124 return m_trigger_map[event][action_time];
125 }
126
127 const Trigger_chain *get_triggers(int event, int action_time) const {
128 assert(0 <= event && event < TRG_EVENT_MAX);
129 assert(0 <= action_time && action_time < TRG_ACTION_MAX);
130 return m_trigger_map[event][action_time];
131 }
132
133 Trigger *find_trigger(const LEX_STRING &trigger_name);
134
136 enum_trigger_action_time_type action_time) const {
137 return get_triggers(event, action_time) != nullptr;
138 }
139
140 bool has_update_triggers() const {
143 }
144
145 bool has_delete_triggers() const {
148 }
149
151
153 Query_tables_list *prelocking_ctx,
154 Table_ref *table_list);
155
158
159 void print_upgrade_warnings(THD *thd);
160
161 void parse_triggers(THD *thd, List<Trigger> *triggers, bool is_upgrade);
162
163 private:
167
169
170 /**
171 Remember a parse error that occurred while parsing trigger definitions
172 loaded from the Data Dictionary. This makes the Table_trigger_dispatcher
173 enter the error state flagged by m_has_unparseable_trigger == true. The
174 error message will be used whenever a statement invoking or manipulating
175 triggers is issued against the Table_trigger_dispatcher's table.
176
177 @param error_message The error message thrown by the parser.
178 */
179 void set_parse_error_message(const char *error_message) {
182 snprintf(m_parse_error_message, sizeof(m_parse_error_message), "%s",
183 error_message);
184 }
185 }
186
187 private:
188 /************************************************************************
189 * Table_trigger_field_support interface implementation.
190 ***********************************************************************/
191
193
195 int field_index) override {
196 return (v == TRG_OLD_ROW) ? m_old_field[field_index]
197 : m_new_field[field_index];
198 }
199
200 private:
201 /**
202 TABLE instance for which this triggers list object was created.
203 */
205
206 /// Triggers grouped by event, action_time.
208
209 /**
210 Copy of TABLE::Field array with field pointers set to TABLE::record[1]
211 buffer instead of TABLE::record[0] (used for OLD values in on UPDATE
212 trigger and DELETE trigger when it is called for REPLACE).
213 */
215
216 /**
217 During execution of trigger m_new_field and m_old_field should point to the
218 array of fields representing new or old version of row correspondingly
219 (so it can point to TABLE::field or to
220 Table_trigger_dispatcher::m_record1_field).
221 */
224
225 /**
226 This flag indicates that one of the triggers was not parsed successfully,
227 and as a precaution the object has entered the state where all trigger
228 operations result in errors until all the table triggers are dropped. It is
229 not safe to add triggers since it is unknown if the broken trigger has the
230 same name or event type. Nor is it safe to invoke any trigger. The only
231 safe operations are drop_trigger() and drop_all_triggers().
232
233 We can't use the value of m_parse_error_message as a flag to inform that
234 a trigger has a parse error since for multi-byte locale the first byte of
235 message can be 0 but the message still be meaningful. It means that just a
236 comparison against m_parse_error_message[0] can not be done safely.
237
238 @see Table_trigger_dispatcher::set_parse_error()
239 */
241
242 /**
243 This error will be displayed when the user tries to manipulate or invoke
244 triggers on a table that has broken triggers. It is set once per statement
245 and thus will contain the first parse error encountered in the trigger file.
246 */
248};
249
250///////////////////////////////////////////////////////////////////////////
251
252#endif // TABLE_TRIGGER_DISPATCHER_H_INCLUDED
Definition: field.h:577
Definition: sql_list.h:467
Definition: sql_lex.h:2613
Using this class is fraught with peril, and you need to be very careful when doing so.
Definition: sql_string.h:167
For each client connection we create a separate thread with THD serving as a thread/connection descri...
Definition: sql_lexer_thd.h:36
Definition: table.h:2871
This class holds all information about triggers of a table.
Definition: table_trigger_dispatcher.h:63
Table_trigger_dispatcher(TABLE *subject_table)
Private form of Table_trigger_dispatcher constructor.
Definition: table_trigger_dispatcher.cc:89
Trigger_chain * create_trigger_chain(MEM_ROOT *mem_root, enum_trigger_event_type event, enum_trigger_action_time_type action_time)
Make sure there is a chain for the specified event and action time.
Definition: table_trigger_dispatcher.cc:372
bool has_update_triggers() const
Definition: table_trigger_dispatcher.h:140
void disable_fields_temporary_nullability()
Reset "temporary nullable" flag from trigger fields.
Definition: table_trigger_dispatcher.cc:616
bool m_has_unparseable_trigger
This flag indicates that one of the triggers was not parsed successfully, and as a precaution the obj...
Definition: table_trigger_dispatcher.h:240
bool has_triggers(enum_trigger_event_type event, enum_trigger_action_time_type action_time) const
Definition: table_trigger_dispatcher.h:135
bool process_triggers(THD *thd, enum_trigger_event_type event, enum_trigger_action_time_type action_time, bool old_row_is_record1)
Execute trigger for given (event, time) pair.
Definition: table_trigger_dispatcher.cc:517
void print_upgrade_warnings(THD *thd)
Iterate along triggers and print necessary upgrade warnings.
Definition: table_trigger_dispatcher.cc:631
const Trigger_chain * get_triggers(int event, int action_time) const
Definition: table_trigger_dispatcher.h:127
Field ** m_new_field
During execution of trigger m_new_field and m_old_field should point to the array of fields represent...
Definition: table_trigger_dispatcher.h:222
void set_parse_error_message(const char *error_message)
Remember a parse error that occurred while parsing trigger definitions loaded from the Data Dictionar...
Definition: table_trigger_dispatcher.h:179
Field ** m_record1_field
Copy of TABLE::Field array with field pointers set to TABLE::record[1] buffer instead of TABLE::recor...
Definition: table_trigger_dispatcher.h:214
Trigger * find_trigger(const LEX_STRING &trigger_name)
Get trigger object by trigger name.
Definition: table_trigger_dispatcher.cc:397
bool check_for_broken_triggers()
Checks if there is a broken trigger for this table.
Definition: table_trigger_dispatcher.h:82
Field ** m_old_field
Definition: table_trigger_dispatcher.h:223
bool mark_fields(enum_trigger_event_type event)
Mark fields of subject table which we read/set in its triggers as such.
Definition: table_trigger_dispatcher.cc:662
void enable_fields_temporary_nullability(THD *thd)
Mark all trigger fields as "temporary nullable" and remember the current THD::check_for_truncated_fie...
Definition: table_trigger_dispatcher.cc:588
bool has_delete_triggers() const
Definition: table_trigger_dispatcher.h:145
bool create_trigger(THD *thd, String *binlog_create_trigger_stmt, bool if_not_exists, bool &already_exists)
Create trigger for table.
Definition: table_trigger_dispatcher.cc:115
Field * get_trigger_variable_field(enum_trigger_variable_type v, int field_index) override
Definition: table_trigger_dispatcher.h:194
Trigger_chain * get_triggers(int event, int action_time)
Definition: table_trigger_dispatcher.h:121
static Table_trigger_dispatcher * create(TABLE *subject_table)
Create an instance of Table_trigger_dispatcher for the given subject table.
Definition: table_trigger_dispatcher.cc:79
bool add_tables_and_routines_for_triggers(THD *thd, Query_tables_list *prelocking_ctx, Table_ref *table_list)
Add triggers for table to the set of routines used by statement.
Definition: table_trigger_dispatcher.cc:564
TABLE * get_subject_table() override
Definition: table_trigger_dispatcher.h:192
TABLE * m_subject_table
TABLE instance for which this triggers list object was created.
Definition: table_trigger_dispatcher.h:204
bool prepare_record1_accessors()
Prepare array of Field objects referencing to TABLE::record[1] instead of record<a href="they will re...
Definition: table_trigger_dispatcher.cc:275
char m_parse_error_message[MYSQL_ERRMSG_SIZE]
This error will be displayed when the user tries to manipulate or invoke triggers on a table that has...
Definition: table_trigger_dispatcher.h:247
~Table_trigger_dispatcher() override
Definition: table_trigger_dispatcher.cc:99
Trigger_chain * m_trigger_map[TRG_EVENT_MAX][TRG_ACTION_MAX]
Triggers grouped by event, action_time.
Definition: table_trigger_dispatcher.h:207
bool check_n_load(THD *thd, const dd::Table &table)
Load triggers for the table.
Definition: table_trigger_dispatcher.cc:311
void parse_triggers(THD *thd, List< Trigger > *triggers, bool is_upgrade)
Parse trigger definition statements (CREATE TRIGGER).
Definition: table_trigger_dispatcher.cc:432
This is an interface to be used from Item_trigger_field to access information about table trigger fie...
Definition: table_trigger_field_support.h:44
Definition: trigger_chain.h:41
This class represents a trigger object.
Definition: trigger.h:75
Definition: table.h:47
static MEM_ROOT mem_root
Definition: client_plugin.cc:114
void my_message(uint my_err, const char *str, myf MyFlags)
Print an error message.
Definition: my_error.cc:311
Some integer typedefs for easier portability.
#define MYF(v)
Definition: my_inttypes.h:97
Common header for many mysys elements.
Common definition between mysql server & client.
#define MYSQL_ERRMSG_SIZE
Max length of a error message.
Definition: mysql_com.h:881
static PFS_engine_table_share_proxy table
Definition: pfs.cc:61
The version of the current data dictionary table definitions.
Definition: dictionary_client.h:43
required string event
Definition: replication_group_member_actions.proto:32
The MEM_ROOT is a simple arena, where allocations are carved out of larger blocks.
Definition: my_alloc.h:83
Definition: mysql_lex_string.h:35
Definition: table.h:1407
This file defines all base public constants related to triggers in MySQL.
enum_trigger_variable_type
Enum constants to designate NEW and OLD trigger pseudo-variables.
Definition: trigger_def.h:73
@ TRG_OLD_ROW
Definition: trigger_def.h:73
enum_trigger_event_type
Constants to enumerate possible event types on which triggers can be fired.
Definition: trigger_def.h:42
@ TRG_EVENT_UPDATE
Definition: trigger_def.h:44
@ TRG_EVENT_MAX
Definition: trigger_def.h:46
@ TRG_EVENT_DELETE
Definition: trigger_def.h:45
enum_trigger_action_time_type
Constants to enumerate possible timings when triggers can be fired.
Definition: trigger_def.h:52
@ TRG_ACTION_BEFORE
Definition: trigger_def.h:53
@ TRG_ACTION_MAX
Definition: trigger_def.h:55
@ TRG_ACTION_AFTER
Definition: trigger_def.h:54