small enhancement of the create table options feature:

no unnecessary casting from void*, more type safety.
typos fixed.

sql/create_options.cc

@@ -258,7 +258,7 @@ static const size_t ha_option_type_sizeof[]=
   @retval FALSE OK
 */
 
-my_bool parse_option_list(THD* thd, void **option_struct,
+my_bool parse_option_list(THD* thd, void *option_struct_arg,
                           engine_option_value *option_list,
                           ha_create_table_option *rules,
                           my_bool suppress_warning,
@@ -267,6 +267,7 @@ my_bool parse_option_list(THD* thd, void **option_struct,
   ha_create_table_option *opt;
   size_t option_struct_size= 0;
   engine_option_value *val= option_list;
+  void **option_struct= (void**)option_struct_arg;
   DBUG_ENTER("parse_option_list");
   DBUG_PRINT("enter",
              ("struct: 0x%lx list: 0x%lx rules: 0x%lx suppres %u root 0x%lx",

sql/create_options.h

@@ -70,7 +70,7 @@ class Create_field;
 
 my_bool parse_engine_table_options(THD *thd, handlerton *ht,
                                    TABLE_SHARE *share);
-my_bool parse_option_list(THD* thd, void **option_struct,
+my_bool parse_option_list(THD* thd, void *option_struct,
                           engine_option_value *option_list,
                           ha_create_table_option *rules,
                           my_bool suppress_warning,

sql/field.h

@@ -32,6 +32,7 @@ class Send_field;
 class Protocol;
 class Create_field;
 class Relay_log_info;
+struct ha_field_option_struct;
 
 struct st_cache_field;
 int field_conv(Field *to,Field *from);
@@ -137,7 +138,7 @@ public:
   const char *field_name;
   /** reference to the list of options or NULL */
   engine_option_value *option_list;
-  void *option_struct;                  /* structure with parsed options */
+  ha_field_option_struct *option_struct;   /* structure with parsed options */
   LEX_STRING	comment;
   /* Field is part of the following keys */
   key_map	key_start, part_of_key, part_of_key_not_clustered;
@@ -2155,7 +2156,7 @@ public:
   Field *field;				// For alter table
   engine_option_value *option_list;
   /** structure with parsed options (for comparing fields in ALTER TABLE) */
-  void *option_struct;
+  ha_field_option_struct *option_struct;
 
   uint8 row,col,sc_length,interval_id;	// For rea_create_table
   uint	offset,pack_flag;

sql/handler.h

@@ -593,6 +593,11 @@ struct handler_log_file_data {
 
   See ha_example.cc for an example.
 */
+
+struct ha_table_option_struct;
+struct ha_field_option_struct;
+struct ha_index_option_struct;
+
 enum ha_option_type { HA_OPTION_TYPE_ULL,    /* unsigned long long */
                       HA_OPTION_TYPE_STRING, /* char * */
                       HA_OPTION_TYPE_ENUM,   /* uint */
@@ -1060,9 +1065,9 @@ typedef struct st_ha_create_information
   enum ha_choice page_checksum;         ///< If we have page_checksums
   engine_option_value *option_list;     ///< list of table create options
   /* the following three are only for ALTER TABLE, check_if_incompatible_data() */
-  void *option_struct;           ///< structure with parsed table options
-  void **fileds_option_struct;   ///< array of field option structures
-  void **indexes_option_struct;  ///< array of index option structures
+  ha_table_option_struct *option_struct;           ///< structure with parsed table options
+  ha_field_option_struct **fields_option_struct;   ///< array of field option structures
+  ha_index_option_struct **indexes_option_struct;  ///< array of index option structures
 } HA_CREATE_INFO;
 
 

sql/sql_table.cc

@@ -5855,10 +5855,10 @@ compare_tables(TABLE *table,
     DBUG_RETURN(0);
   }
 
-  if ((create_info->fileds_option_struct=
-       (void**)thd->calloc(sizeof(void*) * table->s->fields)) == NULL ||
-      (create_info->indexes_option_struct=
-       (void**)thd->calloc(sizeof(void*) * table->s->keys)) == NULL)
+  if ((create_info->fields_option_struct= (ha_field_option_struct**)
+         thd->calloc(sizeof(void*) * table->s->fields)) == NULL ||
+      (create_info->indexes_option_struct= (ha_index_option_struct**)
+         thd->calloc(sizeof(void*) * table->s->keys)) == NULL)
     DBUG_RETURN(1);
 
   /*
@@ -5879,7 +5879,7 @@ compare_tables(TABLE *table,
        tmp_new_field= tmp_new_field_it++)
   {
     DBUG_ASSERT(i < table->s->fields);
-    create_info->fileds_option_struct[i]= tmp_new_field->option_struct;
+    create_info->fields_option_struct[i]= tmp_new_field->option_struct;
 
     /* Make sure we have at least the default charset in use. */
     if (!new_field->charset)

sql/structs.h

@@ -69,6 +69,7 @@ typedef struct st_key_part_info {	/* Info about a key part */
 } KEY_PART_INFO ;
 
 class engine_option_value;
+struct ha_index_option_struct;
 
 typedef struct st_key {
   uint	key_length;			/* Tot length of key */
@@ -104,7 +105,7 @@ typedef struct st_key {
   struct st_table *table;
   /** reference to the list of options or NULL */
   engine_option_value *option_list;
-  void *option_struct;                  /* structure with parsed options */
+  ha_index_option_struct *option_struct;                  /* structure with parsed options */
 } KEY;
 
 

sql/table.h

@@ -343,7 +343,7 @@ typedef struct st_table_share
   struct st_table *open_tables;		/* link to open tables */
 #endif
   engine_option_value *option_list;     /* text options for table */
-  void *option_struct;                  /* structure with parsed options */
+  ha_table_option_struct *option_struct; /* structure with parsed options */
 
   /* The following is copied to each TABLE on OPEN */
   Field **field;

storage/example/ha_example.cc

@@ -115,13 +115,14 @@ pthread_mutex_t example_mutex;
 
 
 /**
-  structure for CREATE TABLE options (table options)
+  Structure for CREATE TABLE options (table options).
+  It needs to be called ha_table_option_struct.
 
-  These can be specified in the CREATE TABLE:
-  CREATE TABLE ( ... ) {...here...}
+  The option values can be specified in the CREATE TABLE at the end:
+  CREATE TABLE ( ... ) *here*
 */
 
-struct example_table_options_struct
+struct ha_table_option_struct
 {
   const char *strparam;
   ulonglong ullparam;
@@ -131,19 +132,26 @@ struct example_table_options_struct
 
 
 /**
-  structure for CREATE TABLE options (field options)
+  Structure for CREATE TABLE options (field options).
+  It needs to be called ha_field_option_struct.
 
-  These can be specified in the CREATE TABLE per field:
-  CREATE TABLE ( field ... {...here...}, ... )
+  The option values can be specified in the CREATE TABLE per field:
+  CREATE TABLE ( field ... *here*, ... )
 */
 
-struct example_field_options_struct
+struct ha_field_option_struct
 {
-  const char *compex_param_to_parse_it_in_engine;
+  const char *complex_param_to_parse_it_in_engine;
 };
 
-/* HA_TOPTION_* macros expect the structure called ha_table_option_struct */
-#define ha_table_option_struct example_table_options_struct
+/*
+  no example here, but index options can be declared similarly
+  using the ha_index_option_struct structure.
+
+  Their values can be specified in the CREATE TABLE per index:
+  CREATE TABLE ( field ..., .., INDEX .... *here*, ... )
+*/
+
 ha_create_table_option example_table_option_list[]=
 {
   /*
@@ -169,8 +177,6 @@ ha_create_table_option example_table_option_list[]=
   HA_TOPTION_END
 };
 
-/* HA_FOPTION_* macros expect the structure called ha_field_option_struct */
-#define ha_field_option_struct example_field_options_struct
 ha_create_table_option example_field_option_list[]=
 {
   /*
@@ -178,7 +184,7 @@ ha_create_table_option example_field_option_list[]=
     or boolean - for example a list - it needs to specify the option
     as a string and parse it internally.
   */
-  HA_FOPTION_STRING("COMPLEX", compex_param_to_parse_it_in_engine),
+  HA_FOPTION_STRING("COMPLEX", complex_param_to_parse_it_in_engine),
   HA_FOPTION_END
 };
 
@@ -368,8 +374,7 @@ int ha_example::open(const char *name, int mode, uint test_if_locked)
   thr_lock_data_init(&share->lock,&lock,NULL);
 
 #ifndef DBUG_OFF
-  example_table_options_struct *options=
-    (example_table_options_struct *)table->s->option_struct;
+  ha_table_option_struct *options= table->s->option_struct;
 
   DBUG_ASSERT(options);
   DBUG_PRINT("info", ("strparam: '%-.64s'  ullparam: %llu  enumparam: %u  "\
@@ -899,8 +904,7 @@ int ha_example::create(const char *name, TABLE *table_arg,
                        HA_CREATE_INFO *create_info)
 {
 #ifndef DBUG_OFF
-  example_table_options_struct *options=
-    (example_table_options_struct *)table_arg->s->option_struct;
+  ha_table_option_struct *options= table_arg->s->option_struct;
   DBUG_ENTER("ha_example::create");
   /*
     This example shows how to support custom engine specific table and field
@@ -913,13 +917,12 @@ int ha_example::create(const char *name, TABLE *table_arg,
                       options->ullparam, options->enumparam, options->boolparam));
   for (Field **field= table_arg->s->field; *field; field++)
   {
-    example_field_options_struct *field_options=
-      (example_field_options_struct *)(*field)->option_struct;
+    ha_field_option_struct *field_options= (*field)->option_struct;
     DBUG_ASSERT(field_options);
     DBUG_PRINT("info", ("field: %s  complex: '%-.64s'",
                          (*field)->field_name,
-                         (field_options->compex_param_to_parse_it_in_engine ?
-                          field_options->compex_param_to_parse_it_in_engine :
+                         (field_options->complex_param_to_parse_it_in_engine ?
+                          field_options->complex_param_to_parse_it_in_engine :
                           "<NULL>")));
   }
 #endif
@@ -941,21 +944,21 @@ int ha_example::create(const char *name, TABLE *table_arg,
 bool ha_example::check_if_incompatible_data(HA_CREATE_INFO *info,
                                             uint table_changes)
 {
-  example_table_options_struct *param_old, *param_new;
+  ha_table_option_struct *param_old, *param_new;
   uint i;
   DBUG_ENTER("ha_example::check_if_incompatible_data");
   /*
     This example shows how custom engine specific table and field
     options can be accessed from this function to be compared.
   */
-  param_new= (example_table_options_struct *)info->option_struct;
+  param_new= info->option_struct;
   DBUG_PRINT("info", ("new strparam: '%-.64s'  ullparam: %llu  enumparam: %u  "
                       "boolparam: %u",
                       (param_new->strparam ? param_new->strparam : "<NULL>"),
                       param_new->ullparam, param_new->enumparam,
                       param_new->boolparam));
 
-  param_old= (example_table_options_struct *)table->s->option_struct;
+  param_old= table->s->option_struct;
   DBUG_PRINT("info", ("old strparam: '%-.64s'  ullparam: %llu  enumparam: %u  "
                       "boolparam: %u",
                       (param_old->strparam ? param_old->strparam : "<NULL>"),
@@ -974,19 +977,19 @@ bool ha_example::check_if_incompatible_data(HA_CREATE_INFO *info,
 
   for (i= 0; i < table->s->fields; i++)
   {
-    example_field_options_struct *f_old, *f_new;
-    f_old= (example_field_options_struct *)table->s->field[i]->option_struct;
+    ha_field_option_struct *f_old, *f_new;
+    f_old= table->s->field[i]->option_struct;
     DBUG_ASSERT(f_old);
     DBUG_PRINT("info", ("old field: %u old complex: '%-.64s'", i,
-                         (f_old->compex_param_to_parse_it_in_engine ?
-                          f_old->compex_param_to_parse_it_in_engine :
+                         (f_old->complex_param_to_parse_it_in_engine ?
+                          f_old->complex_param_to_parse_it_in_engine :
                           "<NULL>")));
-    if (info->fileds_option_struct[i])
+    if (info->fields_option_struct[i])
     {
-      f_new= (example_field_options_struct *)info->fileds_option_struct[i];
+      f_new= info->fields_option_struct[i];
       DBUG_PRINT("info", ("old field: %u  new complex: '%-.64s'", i,
-                          (f_new->compex_param_to_parse_it_in_engine ?
-                           f_new->compex_param_to_parse_it_in_engine :
+                          (f_new->complex_param_to_parse_it_in_engine ?
+                           f_new->complex_param_to_parse_it_in_engine :
                            "<NULL>")));
     }
     else