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| -rw-r--r-- | sql/sql_trigger.h | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/sql/sql_trigger.h b/sql/sql_trigger.h new file mode 100644 index 00000000..040d8eba --- /dev/null +++ b/sql/sql_trigger.h @@ -0,0 +1,331 @@ +#ifndef SQL_TRIGGER_INCLUDED +#define SQL_TRIGGER_INCLUDED + +/* + Copyright (c) 2004, 2011, Oracle and/or its affiliates. + Copyright (c) 2017, MariaDB Corporation. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */ + +#include <mysqld_error.h> + +/* Forward declarations */ + +class Item_trigger_field; +class sp_head; +class sp_name; +class Query_tables_list; +struct TABLE_LIST; +class Query_tables_list; + +/** Event on which trigger is invoked. */ +enum trg_event_type +{ + TRG_EVENT_INSERT= 0, + TRG_EVENT_UPDATE= 1, + TRG_EVENT_DELETE= 2, + TRG_EVENT_MAX +}; + +static inline uint8 trg2bit(enum trg_event_type trg) +{ return static_cast<uint8>(1 << static_cast<int>(trg)); } + +#include "table.h" /* GRANT_INFO */ + +/* + We need this two enums here instead of sql_lex.h because + at least one of them is used by Item_trigger_field interface. + + Time when trigger is invoked (i.e. before or after row actually + inserted/updated/deleted). +*/ +enum trg_action_time_type +{ + TRG_ACTION_BEFORE= 0, TRG_ACTION_AFTER= 1, TRG_ACTION_MAX +}; + +enum trigger_order_type +{ + TRG_ORDER_NONE= 0, + TRG_ORDER_FOLLOWS= 1, + TRG_ORDER_PRECEDES= 2 +}; + + +struct st_trg_execution_order +{ + /** + FOLLOWS or PRECEDES as specified in the CREATE TRIGGER statement. + */ + enum trigger_order_type ordering_clause; + + /** + Trigger name referenced in the FOLLOWS/PRECEDES clause of the + CREATE TRIGGER statement. + */ + LEX_CSTRING anchor_trigger_name; +}; + + +class Table_triggers_list; + +/** + The trigger object +*/ + +class Trigger :public Sql_alloc +{ +public: + Trigger(Table_triggers_list *base_arg, sp_head *code): + base(base_arg), body(code), next(0), trigger_fields(0), action_order(0) + { + bzero((char *)&subject_table_grants, sizeof(subject_table_grants)); + } + ~Trigger(); + Table_triggers_list *base; + sp_head *body; + Trigger *next; /* Next trigger of same type */ + + /** + Heads of the lists linking items for all fields used in triggers + grouped by event and action_time. + */ + Item_trigger_field *trigger_fields; + LEX_CSTRING name; + LEX_CSTRING on_table_name; /* Raw table name */ + LEX_CSTRING definition; + LEX_CSTRING definer; + + /* Character sets used */ + LEX_CSTRING client_cs_name; + LEX_CSTRING connection_cl_name; + LEX_CSTRING db_cl_name; + + GRANT_INFO subject_table_grants; + sql_mode_t sql_mode; + /* Store create time. Can't be mysql_time_t as this holds also sub seconds */ + ulonglong create_time; + trg_event_type event; + trg_action_time_type action_time; + uint action_order; + + bool is_fields_updated_in_trigger(MY_BITMAP *used_fields); + void get_trigger_info(LEX_CSTRING *stmt, LEX_CSTRING *body, + LEX_STRING *definer); + /* Functions executed over each active trigger */ + bool change_on_table_name(void* param_arg); + bool change_table_name(void* param_arg); + bool add_to_file_list(void* param_arg); +}; + +typedef bool (Trigger::*Triggers_processor)(void *arg); + +/** + This class holds all information about triggers of table. +*/ + +class Table_triggers_list: public Sql_alloc +{ + friend class Trigger; + + /* Points to first trigger for a certain type */ + Trigger *triggers[TRG_EVENT_MAX][TRG_ACTION_MAX]; + /** + Copy of TABLE::Field array which all fields made nullable + (using extra_null_bitmap, if needed). Used for NEW values in + BEFORE INSERT/UPDATE triggers. + */ + Field **record0_field; + uchar *extra_null_bitmap; + /** + Copy of TABLE::Field array with field pointers set to TABLE::record[1] + buffer instead of TABLE::record[0] (used for OLD values in on UPDATE + trigger and DELETE trigger when it is called for REPLACE). + */ + Field **record1_field; + /** + During execution of trigger new_field and old_field should point to the + array of fields representing new or old version of row correspondingly + (so it can point to TABLE::field or to Tale_triggers_list::record1_field) + */ + Field **new_field; + Field **old_field; + + /* TABLE instance for which this triggers list object was created */ + TABLE *trigger_table; + + /** + This flag indicates that one of the triggers was not parsed successfully, + and as a precaution the object has entered a state where all trigger + access results in errors until all such triggers are dropped. It is not + safe to add triggers since we don't know if the broken trigger has the + same name or event type. Nor is it safe to invoke any trigger for the + aforementioned reasons. The only safe operations are drop_trigger and + drop_all_triggers. + + @see Table_triggers_list::set_parse_error + */ + bool m_has_unparseable_trigger; + + /** + This error will be displayed when the user tries to manipulate or invoke + triggers on a table that has broken triggers. It will get set only once + per statement and thus will contain the first parse error encountered in + the trigger file. + */ + char m_parse_error_message[MYSQL_ERRMSG_SIZE]; + uint count; /* Number of triggers */ + +public: + /** + Field responsible for storing triggers definitions in file. + It have to be public because we are using it directly from parser. + */ + List<LEX_CSTRING> definitions_list; + /** + List of sql modes for triggers + */ + List<ulonglong> definition_modes_list; + /** Create times for triggers */ + List<ulonglong> create_times; + + List<LEX_CSTRING> definers_list; + + /* Character set context, used for parsing and executing triggers. */ + + List<LEX_CSTRING> client_cs_names; + List<LEX_CSTRING> connection_cl_names; + List<LEX_CSTRING> db_cl_names; + + /* End of character ser context. */ + + Table_triggers_list(TABLE *table_arg) + :record0_field(0), extra_null_bitmap(0), record1_field(0), + trigger_table(table_arg), + m_has_unparseable_trigger(false), count(0) + { + bzero((char *) triggers, sizeof(triggers)); + } + ~Table_triggers_list(); + + bool create_trigger(THD *thd, TABLE_LIST *table, String *stmt_query); + bool drop_trigger(THD *thd, TABLE_LIST *table, String *stmt_query); + bool process_triggers(THD *thd, trg_event_type event, + trg_action_time_type time_type, + bool old_row_is_record1); + void empty_lists(); + bool create_lists_needed_for_files(MEM_ROOT *root); + bool save_trigger_file(THD *thd, const LEX_CSTRING *db, const LEX_CSTRING *table_name); + + static bool check_n_load(THD *thd, const LEX_CSTRING *db, const LEX_CSTRING *table_name, + TABLE *table, bool names_only); + static bool drop_all_triggers(THD *thd, const LEX_CSTRING *db, + const LEX_CSTRING *table_name, myf MyFlags); + static bool change_table_name(THD *thd, const LEX_CSTRING *db, + const LEX_CSTRING *old_alias, + const LEX_CSTRING *old_table, + const LEX_CSTRING *new_db, + const LEX_CSTRING *new_table); + void add_trigger(trg_event_type event_type, + trg_action_time_type action_time, + trigger_order_type ordering_clause, + LEX_CSTRING *anchor_trigger_name, + Trigger *trigger); + Trigger *get_trigger(trg_event_type event_type, + trg_action_time_type action_time) + { + return triggers[event_type][action_time]; + } + /* Simpler version of the above, to avoid casts in the code */ + Trigger *get_trigger(uint event_type, uint action_time) + { + return get_trigger((trg_event_type) event_type, + (trg_action_time_type) action_time); + } + + bool has_triggers(trg_event_type event_type, + trg_action_time_type action_time) + { + return get_trigger(event_type,action_time) != 0; + } + bool has_delete_triggers() + { + return (has_triggers(TRG_EVENT_DELETE,TRG_ACTION_BEFORE) || + has_triggers(TRG_EVENT_DELETE,TRG_ACTION_AFTER)); + } + + void mark_fields_used(trg_event_type event); + + void set_parse_error_message(char *error_message); + + friend class Item_trigger_field; + + bool add_tables_and_routines_for_triggers(THD *thd, + Query_tables_list *prelocking_ctx, + TABLE_LIST *table_list); + + Field **nullable_fields() { return record0_field; } + void reset_extra_null_bitmap() + { + size_t null_bytes= (trigger_table->s->fields - + trigger_table->s->null_fields + 7)/8; + bzero(extra_null_bitmap, null_bytes); + } + + Trigger *find_trigger(const LEX_CSTRING *name, bool remove_from_list); + + Trigger* for_all_triggers(Triggers_processor func, void *arg); + +private: + bool prepare_record_accessors(TABLE *table); + Trigger *change_table_name_in_trignames(const LEX_CSTRING *old_db_name, + const LEX_CSTRING *new_db_name, + const LEX_CSTRING *new_table_name, + Trigger *trigger); + bool change_table_name_in_triggers(THD *thd, + const LEX_CSTRING *old_db_name, + const LEX_CSTRING *new_db_name, + const LEX_CSTRING *old_table_name, + const LEX_CSTRING *new_table_name); + + bool check_for_broken_triggers() + { + if (m_has_unparseable_trigger) + { + my_message(ER_PARSE_ERROR, m_parse_error_message, MYF(0)); + return true; + } + return false; + } +}; + +bool add_table_for_trigger(THD *thd, + const sp_name *trg_name, + bool continue_if_not_exist, + TABLE_LIST **table); + +void build_trn_path(THD *thd, const sp_name *trg_name, LEX_STRING *trn_path); + +bool check_trn_exists(const LEX_CSTRING *trn_path); + +bool load_table_name_for_trigger(THD *thd, + const sp_name *trg_name, + const LEX_CSTRING *trn_path, + LEX_CSTRING *tbl_name); +bool mysql_create_or_drop_trigger(THD *thd, TABLE_LIST *tables, bool create); + +extern const char * const TRG_EXT; +extern const char * const TRN_EXT; + +#endif /* SQL_TRIGGER_INCLUDED */ |