MySQL  8.0.23
Source Code Documentation
table_trigger_dispatcher.h
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23 
24 #ifndef TABLE_TRIGGER_DISPATCHER_H_INCLUDED
25 #define TABLE_TRIGGER_DISPATCHER_H_INCLUDED
26 
27 ///////////////////////////////////////////////////////////////////////////
28 
29 #include <string.h>
30 
31 #include "lex_string.h"
32 #include "my_dbug.h"
33 #include "my_inttypes.h"
34 #include "my_sys.h"
35 #include "mysql_com.h" // MYSQL_ERRMSG_SIZE
36 #include "mysqld_error.h" // ER_PARSE_ERROR
37 #include "sql/table_trigger_field_support.h" // Table_trigger_field_support
38 #include "sql/trigger_def.h" // enum_trigger_action_time_type
39 
40 class Field;
41 class Query_tables_list;
42 class String;
43 class THD;
44 class Trigger;
45 class Trigger_chain;
46 struct MEM_ROOT;
47 
48 namespace dd {
49 class Table;
50 } // namespace dd
51 struct TABLE;
52 struct TABLE_LIST;
53 template <class T>
54 class List;
55 
56 ///////////////////////////////////////////////////////////////////////////
57 
58 /**
59  This class holds all information about triggers of a table.
60 */
61 
63  public:
64  static Table_trigger_dispatcher *create(TABLE *subject_table);
65 
66  bool check_n_load(THD *thd, const dd::Table &table);
67 
68  /*
69  During upgrade from 5.7, we need to use the trigger chains to fix
70  the trigger order.
71  */
73 
74  private:
75  Table_trigger_dispatcher(TABLE *subject_table);
76 
77  public:
78  ~Table_trigger_dispatcher() override;
79 
80  /**
81  Checks if there is a broken trigger for this table.
82 
83  @retval false if all triggers are Ok.
84  @retval true in case there is at least one broken trigger (a trigger which
85  SQL-definition can not be parsed) for this table.
86  */
89  my_message(ER_PARSE_ERROR, m_parse_error_message, MYF(0));
90  return true;
91  }
92  return false;
93  }
94 
95  bool create_trigger(THD *thd, String *binlog_create_trigger_stmt);
96 
99  bool old_row_is_record1);
100 
101  Trigger_chain *get_triggers(int event, int action_time) {
102  DBUG_ASSERT(0 <= event && event < TRG_EVENT_MAX);
103  DBUG_ASSERT(0 <= action_time && action_time < TRG_ACTION_MAX);
104  return m_trigger_map[event][action_time];
105  }
106 
107  const Trigger_chain *get_triggers(int event, int action_time) const {
108  DBUG_ASSERT(0 <= event && event < TRG_EVENT_MAX);
109  DBUG_ASSERT(0 <= action_time && action_time < TRG_ACTION_MAX);
110  return m_trigger_map[event][action_time];
111  }
112 
113  Trigger *find_trigger(const LEX_STRING &trigger_name);
114 
116  enum_trigger_action_time_type action_time) const {
117  return get_triggers(event, action_time) != nullptr;
118  }
119 
120  bool has_update_triggers() const {
123  }
124 
125  bool has_delete_triggers() const {
128  }
129 
131 
133  Query_tables_list *prelocking_ctx,
134  TABLE_LIST *table_list);
135 
138 
139  void print_upgrade_warnings(THD *thd);
140 
141  void parse_triggers(THD *thd, List<Trigger> *triggers, bool is_upgrade);
142 
143  private:
146  enum_trigger_action_time_type action_time);
147 
149 
150  /**
151  Remember a parse error that occurred while parsing trigger definitions
152  loaded from the Data Dictionary. This makes the Table_trigger_dispatcher
153  enter the error state flagged by m_has_unparseable_trigger == true. The
154  error message will be used whenever a statement invoking or manipulating
155  triggers is issued against the Table_trigger_dispatcher's table.
156 
157  @param error_message The error message thrown by the parser.
158  */
159  void set_parse_error_message(const char *error_message) {
162  strncpy(m_parse_error_message, error_message,
163  sizeof(m_parse_error_message));
164  }
165  }
166 
167  private:
168  /************************************************************************
169  * Table_trigger_field_support interface implementation.
170  ***********************************************************************/
171 
172  TABLE *get_subject_table() override { return m_subject_table; }
173 
175  int field_index) override {
176  return (v == TRG_OLD_ROW) ? m_old_field[field_index]
177  : m_new_field[field_index];
178  }
179 
180  private:
181  /**
182  TABLE instance for which this triggers list object was created.
183  */
185 
186  /// Triggers grouped by event, action_time.
188 
189  /**
190  Copy of TABLE::Field array with field pointers set to TABLE::record[1]
191  buffer instead of TABLE::record[0] (used for OLD values in on UPDATE
192  trigger and DELETE trigger when it is called for REPLACE).
193  */
195 
196  /**
197  During execution of trigger m_new_field and m_old_field should point to the
198  array of fields representing new or old version of row correspondingly
199  (so it can point to TABLE::field or to
200  Table_trigger_dispatcher::m_record1_field).
201  */
204 
205  /**
206  This flag indicates that one of the triggers was not parsed successfully,
207  and as a precaution the object has entered the state where all trigger
208  operations result in errors until all the table triggers are dropped. It is
209  not safe to add triggers since it is unknown if the broken trigger has the
210  same name or event type. Nor is it safe to invoke any trigger. The only
211  safe operations are drop_trigger() and drop_all_triggers().
212 
213  We can't use the value of m_parse_error_message as a flag to inform that
214  a trigger has a parse error since for multi-byte locale the first byte of
215  message can be 0 but the message still be meaningful. It means that just a
216  comparison against m_parse_error_message[0] can not be done safely.
217 
218  @see Table_trigger_dispatcher::set_parse_error()
219  */
221 
222  /**
223  This error will be displayed when the user tries to manipulate or invoke
224  triggers on a table that has broken triggers. It is set once per statement
225  and thus will contain the first parse error encountered in the trigger file.
226  */
228 };
229 
230 ///////////////////////////////////////////////////////////////////////////
231 
232 #endif // TABLE_TRIGGER_DISPATCHER_H_INCLUDED
THD
Definition: sql_class.h:807
trigger_def.h
This file defines all base public constants related to triggers in MySQL.
TRG_EVENT_DELETE
@ TRG_EVENT_DELETE
Definition: trigger_def.h:44
Table_trigger_dispatcher::m_new_field
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:202
Table_trigger_dispatcher::m_trigger_map
Trigger_chain * m_trigger_map[TRG_EVENT_MAX][TRG_ACTION_MAX]
Triggers grouped by event, action_time.
Definition: table_trigger_dispatcher.h:187
Table_trigger_dispatcher::find_trigger
Trigger * find_trigger(const LEX_STRING &trigger_name)
Get trigger object by trigger name.
Definition: table_trigger_dispatcher.cc:409
Table_trigger_dispatcher::get_trigger_variable_field
Field * get_trigger_variable_field(enum_trigger_variable_type v, int field_index) override
Definition: table_trigger_dispatcher.h:174
Table_trigger_dispatcher::m_parse_error_message
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:227
string.h
Table_trigger_dispatcher::get_triggers
Trigger_chain * get_triggers(int event, int action_time)
Definition: table_trigger_dispatcher.h:101
Table_trigger_dispatcher::reorder_57_list
bool reorder_57_list(MEM_ROOT *mem_root, List< Trigger > *triggers)
Definition: table.cc:106
my_dbug.h
String
Using this class is fraught with peril, and you need to be very careful when doing so.
Definition: sql_string.h:164
Table_trigger_dispatcher::check_for_broken_triggers
bool check_for_broken_triggers()
Checks if there is a broken trigger for this table.
Definition: table_trigger_dispatcher.h:87
TABLE
Definition: table.h:1364
Table_trigger_dispatcher::Table_trigger_dispatcher
Table_trigger_dispatcher(TABLE *subject_table)
Private form of Table_trigger_dispatcher constructor.
Definition: table_trigger_dispatcher.cc:85
Table_trigger_dispatcher::disable_fields_temporary_nullability
void disable_fields_temporary_nullability()
Reset "temporary nullable" flag from trigger fields.
Definition: table_trigger_dispatcher.cc:628
mem_root
static MEM_ROOT mem_root
Definition: client_plugin.cc:109
Table_trigger_dispatcher::prepare_record1_accessors
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:287
dd
The version of the current data dictionary table definitions.
Definition: dictionary_client.h:40
MYSQL_ERRMSG_SIZE
#define MYSQL_ERRMSG_SIZE
Max length of a error message.
Definition: mysql_com.h:852
Table_trigger_dispatcher::print_upgrade_warnings
void print_upgrade_warnings(THD *thd)
Iterate along triggers and print necessary upgrade warnings.
Definition: table_trigger_dispatcher.cc:643
Table_trigger_dispatcher::m_subject_table
TABLE * m_subject_table
TABLE instance for which this triggers list object was created.
Definition: table_trigger_dispatcher.h:184
Table_trigger_dispatcher::has_triggers
bool has_triggers(enum_trigger_event_type event, enum_trigger_action_time_type action_time) const
Definition: table_trigger_dispatcher.h:115
Table_trigger_dispatcher::add_tables_and_routines_for_triggers
bool add_tables_and_routines_for_triggers(THD *thd, Query_tables_list *prelocking_ctx, TABLE_LIST *table_list)
Add triggers for table to the set of routines used by statement.
Definition: table_trigger_dispatcher.cc:576
Table_trigger_dispatcher::enable_fields_temporary_nullability
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:600
Table_trigger_dispatcher::mark_fields
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:674
Table_trigger_dispatcher::m_record1_field
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:194
my_inttypes.h
Table_trigger_dispatcher::has_delete_triggers
bool has_delete_triggers() const
Definition: table_trigger_dispatcher.h:125
Query_tables_list
Definition: sql_lex.h:2422
MEM_ROOT
The MEM_ROOT is a simple arena, where allocations are carved out of larger blocks.
Definition: my_alloc.h:77
lex_string.h
TRG_EVENT_MAX
@ TRG_EVENT_MAX
Definition: trigger_def.h:45
mysql_com.h
enum_trigger_action_time_type
enum_trigger_action_time_type
Constants to enumerate possible timings when triggers can be fired.
Definition: trigger_def.h:51
TABLE_LIST
Definition: table.h:2541
Table_trigger_dispatcher::parse_triggers
void parse_triggers(THD *thd, List< Trigger > *triggers, bool is_upgrade)
Parse trigger definition statements (CREATE TRIGGER).
Definition: table_trigger_dispatcher.cc:444
Table_trigger_dispatcher::create
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:75
Trigger
This class represents a trigger object.
Definition: trigger.h:73
my_message
void my_message(uint my_err, const char *str, myf MyFlags)
Print an error message.
Definition: my_error.cc:310
Trigger_chain
Definition: trigger_chain.h:40
dd::Table
Definition: table.h:46
Table_trigger_dispatcher::check_n_load
bool check_n_load(THD *thd, const dd::Table &table)
Load triggers for the table.
Definition: table_trigger_dispatcher.cc:323
Table_trigger_dispatcher
This class holds all information about triggers of a table.
Definition: table_trigger_dispatcher.h:62
Table_trigger_dispatcher::m_old_field
Field ** m_old_field
Definition: table_trigger_dispatcher.h:203
TRG_ACTION_AFTER
@ TRG_ACTION_AFTER
Definition: trigger_def.h:53
Table_trigger_dispatcher::set_parse_error_message
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:159
TRG_ACTION_MAX
@ TRG_ACTION_MAX
Definition: trigger_def.h:54
MYSQL_LEX_STRING
Definition: mysql_lex_string.h:34
Table_trigger_dispatcher::get_subject_table
TABLE * get_subject_table() override
Definition: table_trigger_dispatcher.h:172
DBUG_ASSERT
#define DBUG_ASSERT(A)
Definition: my_dbug.h:199
table_trigger_field_support.h
Table_trigger_dispatcher::has_update_triggers
bool has_update_triggers() const
Definition: table_trigger_dispatcher.h:120
TRG_OLD_ROW
@ TRG_OLD_ROW
Definition: trigger_def.h:72
Table_trigger_field_support
This is an interface to be used from Item_trigger_field to access information about table trigger fie...
Definition: table_trigger_field_support.h:43
enum_trigger_variable_type
enum_trigger_variable_type
Enum constants to designate NEW and OLD trigger pseudo-variables.
Definition: trigger_def.h:72
enum_trigger_event_type
enum_trigger_event_type
Constants to enumerate possible event types on which triggers can be fired.
Definition: trigger_def.h:41
Table_trigger_dispatcher::~Table_trigger_dispatcher
~Table_trigger_dispatcher() override
Definition: table_trigger_dispatcher.cc:95
TRG_ACTION_BEFORE
@ TRG_ACTION_BEFORE
Definition: trigger_def.h:52
Table_trigger_dispatcher::m_has_unparseable_trigger
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:220
MYF
#define MYF(v)
Definition: my_inttypes.h:96
List
Definition: auth_common.h:57
Field
Definition: field.h:568
Table_trigger_dispatcher::process_triggers
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:529
Table_trigger_dispatcher::get_triggers
const Trigger_chain * get_triggers(int event, int action_time) const
Definition: table_trigger_dispatcher.h:107
Table_trigger_dispatcher::create_trigger_chain
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:384
my_sys.h
TRG_EVENT_UPDATE
@ TRG_EVENT_UPDATE
Definition: trigger_def.h:43
Table_trigger_dispatcher::create_trigger
bool create_trigger(THD *thd, String *binlog_create_trigger_stmt)
Create trigger for table.
Definition: table_trigger_dispatcher.cc:130