MDEV-6112 multiple triggers per table

This is similar to MysQL Worklog 3253, but with
a different implementation. The disk format and
SQL syntax is identical with MySQL 5.7.

Fetures supported:
- "Any" ammount of any trigger
- Supports FOLLOWS and PRECEDES to be
  able to put triggers in a certain execution order.

Implementation details:
- Class Trigger added to hold information about a trigger.
  Before this trigger information was stored in a set of lists in
  Table_triggers_list and in Table_triggers_list::bodies
- Each Trigger has a next field that poinst to the next Trigger with the
  same action and time.
- When accessing a trigger, we now always access all linked triggers
- The list are now only used to load and save trigger files.
- MySQL trigger test case (trigger_wl3253) added and we execute these
  identically.
- Even more gracefully handling of wrong trigger files than before. This
  is useful if a trigger file uses functions or syntax not provided by
  the server.
- Each trigger now has a "Created" field that shows when the trigger was
  created, with 2 decimals.

Other comments:
- Many of the changes in test files was done because of the new "Created"
  field in the trigger file. This shows up in SHOW ... TRIGGER and when
  using information_schema.trigger.
- Don't check if all memory is released if on uses --gdb;  This is needed
  to be able to get a list from safemalloc of not freed memory while
  debugging.
- Added option to trim_whitespace() to know how many prefix characters
  was skipped.
- Changed a few ulonglong sql_mode to sql_mode_t, to find some wrong usage
  of sql_mode.

1 files changed, 113 insertions, 61 deletions

diff --git a/sql/sql_trigger.h b/sql/sql_trigger.h
index fa858a0582b..f1161cdd967 100644
--- a/sql/sql_trigger.h
+++ b/sql/sql_trigger.h
@@ -51,22 +51,92 @@ 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_STRING anchor_trigger_name;
+};
 
-/**
-  This class holds all information about triggers of table.
 
-  TODO: Will it be merged into TABLE in the future ?
+class Table_triggers_list;
+
+/**
+   The trigger object
 */
 
-class Table_triggers_list: public Sql_alloc
+class Trigger :public Sql_alloc
 {
-  /** Triggers as SPs grouped by event, action_time */
-  sp_head *bodies[TRG_EVENT_MAX][TRG_ACTION_MAX];
+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[TRG_EVENT_MAX][TRG_ACTION_MAX];
+  Item_trigger_field *trigger_fields;
+  LEX_STRING name;
+  LEX_STRING on_table_name;                     /* Raw table name */
+  LEX_STRING definition;
+  LEX_STRING definer;
+
+  /* Character sets used */
+  LEX_STRING client_cs_name;
+  LEX_STRING connection_cl_name;
+  LEX_STRING db_cl_name;
+
+  GRANT_INFO subject_table_grants;
+  ulonglong 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_STRING *stmt, LEX_STRING *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
@@ -90,22 +160,6 @@ class Table_triggers_list: public Sql_alloc
 
   /* TABLE instance for which this triggers list object was created */
   TABLE *trigger_table;
-  /**
-    Names of triggers.
-    Should correspond to order of triggers on definitions_list,
-    used in CREATE/DROP TRIGGER for looking up trigger by name.
-  */
-  List<LEX_STRING>  names_list;
-  /**
-    List of "ON table_name" parts in trigger definitions, used for
-    updating trigger definitions during RENAME TABLE.
-  */
-  List<LEX_STRING>  on_table_names_list;
-
-  /**
-    Grant information for each trigger (pair: subject table, trigger definer).
-  */
-  GRANT_INFO        subject_table_grants[TRG_EVENT_MAX][TRG_ACTION_MAX];
 
   /**
      This flag indicates that one of the triggers was not parsed successfully,
@@ -127,6 +181,7 @@ class Table_triggers_list: public Sql_alloc
     the trigger file.
    */
   char m_parse_error_message[MYSQL_ERRMSG_SIZE];
+  uint count;                                   /* Number of triggers */
 
 public:
   /**
@@ -138,6 +193,8 @@ public:
     List of sql modes for triggers
   */
   List<ulonglong> definition_modes_list;
+  /** Create times for triggers */
+  List<ulonglong> create_times;
 
   List<LEX_STRING>  definers_list;
 
@@ -152,11 +209,9 @@ public:
   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)
+    m_has_unparseable_trigger(false), count(0)
   {
-    bzero((char *)bodies, sizeof(bodies));
-    bzero((char *)trigger_fields, sizeof(trigger_fields));
-    bzero((char *)&subject_table_grants, sizeof(subject_table_grants));
+    bzero((char *) triggers, sizeof(triggers));
   }
   ~Table_triggers_list();
 
@@ -165,26 +220,9 @@ public:
   bool process_triggers(THD *thd, trg_event_type event,
                         trg_action_time_type time_type,
                         bool old_row_is_record1);
-
-  bool get_trigger_info(THD *thd, trg_event_type event,
-                        trg_action_time_type time_type,
-                        LEX_STRING *trigger_name, LEX_STRING *trigger_stmt,
-                        ulong *sql_mode,
-                        LEX_STRING *definer,
-                        LEX_STRING *client_cs_name,
-                        LEX_STRING *connection_cl_name,
-                        LEX_STRING *db_cl_name);
-
-  void get_trigger_info(THD *thd,
-                        int trigger_idx,
-                        LEX_STRING *trigger_name,
-                        ulonglong *sql_mode,
-                        LEX_STRING *sql_original_stmt,
-                        LEX_STRING *client_cs_name,
-                        LEX_STRING *connection_cl_name,
-                        LEX_STRING *db_cl_name);
-
-  int find_trigger_by_name(const LEX_STRING *trigger_name);
+  void empty_lists();
+  bool create_lists_needed_for_files(MEM_ROOT *root);
+  bool save_trigger_file(THD *thd, const char *db, const char *table_name);
 
   static bool check_n_load(THD *thd, const char *db, const char *table_name,
                            TABLE *table, bool names_only);
@@ -194,15 +232,32 @@ public:
                                 const char *old_table,
                                 const char *new_db,
                                 const char *new_table);
+  void add_trigger(trg_event_type event_type, 
+                   trg_action_time_type action_time,
+                   trigger_order_type ordering_clause,
+                   LEX_STRING *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 (bodies[event_type][action_time] != NULL);
+    return get_trigger(event_type,action_time) != 0;
   }
   bool has_delete_triggers()
   {
-    return (bodies[TRG_EVENT_DELETE][TRG_ACTION_BEFORE] ||
-            bodies[TRG_EVENT_DELETE][TRG_ACTION_AFTER]);
+    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);
@@ -215,10 +270,6 @@ public:
                                             Query_tables_list *prelocking_ctx,
                                             TABLE_LIST *table_list);
 
-  bool is_fields_updated_in_trigger(MY_BITMAP *used_fields,
-                                    trg_event_type event_type,
-                                    trg_action_time_type action_time);
-
   Field **nullable_fields() { return record0_field; }
   void reset_extra_null_bitmap()
   {
@@ -227,12 +278,16 @@ public:
     bzero(extra_null_bitmap, null_bytes);
   }
 
+  Trigger *find_trigger(const LEX_STRING *name, bool remove_from_list);
+
+  Trigger* for_all_triggers(Triggers_processor func, void *arg);
+
 private:
   bool prepare_record_accessors(TABLE *table);
-  LEX_STRING* change_table_name_in_trignames(const char *old_db_name,
-                                             const char *new_db_name,
-                                             LEX_STRING *new_table_name,
-                                             LEX_STRING *stopper);
+  Trigger *change_table_name_in_trignames(const char *old_db_name,
+                                          const char *new_db_name,
+                                          LEX_STRING *new_table_name,
+                                          Trigger *trigger);
   bool change_table_name_in_triggers(THD *thd,
                                      const char *old_db_name,
                                      const char *new_db_name,
@@ -257,9 +312,6 @@ inline Field **TABLE::field_to_fill()
 }
 
 
-extern const LEX_STRING trg_action_time_type_names[];
-extern const LEX_STRING trg_event_type_names[];
-
 bool add_table_for_trigger(THD *thd,
                            const sp_name *trg_name,
                            bool continue_if_not_exist,