cleanup: remove special case from store_key::store_key(), add Field_blob::new_key_field

(prep for MDEV-6065)

sql/field.cc

@@ -1965,8 +1965,8 @@ Field *Field::new_field(MEM_ROOT *root, TABLE *new_table,
 
 
 Field *Field::new_key_field(MEM_ROOT *root, TABLE *new_table,
-                            uchar *new_ptr, uchar *new_null_ptr,
-                            uint new_null_bit)
+                            uchar *new_ptr, uint32 length,
+                            uchar *new_null_ptr, uint new_null_bit)
 {
   Field *tmp;
   if ((tmp= new_field(root, new_table, table == new_table)))
@@ -7204,17 +7204,14 @@ Field *Field_varstring::new_field(MEM_ROOT *root, TABLE *new_table,
 }
 
 
-Field *Field_varstring::new_key_field(MEM_ROOT *root,
-                                      TABLE *new_table,
-                                      uchar *new_ptr, uchar *new_null_ptr,
-                                      uint new_null_bit)
+Field *Field_varstring::new_key_field(MEM_ROOT *root, TABLE *new_table,
+                                      uchar *new_ptr, uint32 length,
+                                      uchar *new_null_ptr, uint new_null_bit)
 {
   Field_varstring *res;
-  if ((res= (Field_varstring*) Field::new_key_field(root,
-                                                    new_table,
-                                                    new_ptr,
-                                                    new_null_ptr,
-                                                    new_null_bit)))
+  if ((res= (Field_varstring*) Field::new_key_field(root, new_table,
+                                                    new_ptr, length,
+                                                    new_null_ptr, new_null_bit)))
   {
     /* Keys length prefixes are always packed with 2 bytes */
     res->length_bytes= 2;
@@ -7222,7 +7219,6 @@ Field *Field_varstring::new_key_field(MEM_ROOT *root,
   return res;
 }
 
-
 uint Field_varstring::is_equal(Create_field *new_field)
 {
   if (new_field->sql_type == real_type() &&
@@ -7579,6 +7575,18 @@ int Field_blob::key_cmp(const uchar *a,const uchar *b)
 }
 
 
+Field *Field_blob::new_key_field(MEM_ROOT *root, TABLE *new_table,
+                                 uchar *new_ptr, uint32 length,
+                                 uchar *new_null_ptr, uint new_null_bit)
+{
+  Field_varstring *res= new (root) Field_varstring(new_ptr, length, 2,
+                                      new_null_ptr, new_null_bit, Field::NONE,
+                                      field_name, table->s, charset());
+  res->init(new_table);
+  return res;
+}
+
+
 /**
    Save the field metadata for blob fields.
 
@@ -8426,15 +8434,13 @@ Field_bit::do_last_null_byte() const
 }
 
 
-Field *Field_bit::new_key_field(MEM_ROOT *root,
-                                TABLE *new_table,
-                                uchar *new_ptr, uchar *new_null_ptr,
-                                uint new_null_bit)
+Field *Field_bit::new_key_field(MEM_ROOT *root, TABLE *new_table,
+                                uchar *new_ptr, uint32 length, 
+                                uchar *new_null_ptr, uint new_null_bit)
 {
   Field_bit *res;
-  if ((res= (Field_bit*) Field::new_key_field(root, new_table,
-                                              new_ptr, new_null_ptr,
-                                              new_null_bit)))
+  if ((res= (Field_bit*) Field::new_key_field(root, new_table, new_ptr, length,
+                                              new_null_ptr, new_null_bit)))
   {
     /* Move bits normally stored in null_pointer to new_ptr */
     res->bit_ptr= new_ptr;

sql/field.h

@@ -253,9 +253,13 @@ class Field
   Field(const Item &);				/* Prevent use of these */
   void operator=(Field &);
 public:
+  static void *operator new(size_t size, MEM_ROOT *mem_root) throw ()
+  { return alloc_root(mem_root, size); }
   static void *operator new(size_t size) throw ()
   { return sql_alloc(size); }
   static void operator delete(void *ptr_arg, size_t size) { TRASH(ptr_arg, size); }
+  static void operator delete(void *ptr, MEM_ROOT *mem_root)
+  { DBUG_ASSERT(0); }
 
   uchar		*ptr;			// Position to field in record
   /**
@@ -709,8 +713,8 @@ public:
   virtual Field *new_field(MEM_ROOT *root, TABLE *new_table,
                            bool keep_type);
   virtual Field *new_key_field(MEM_ROOT *root, TABLE *new_table,
-                               uchar *new_ptr, uchar *new_null_ptr,
-                               uint new_null_bit);
+                               uchar *new_ptr, uint32 length,
+                               uchar *new_null_ptr, uint new_null_bit);
   Field *clone(MEM_ROOT *mem_root, TABLE *new_table);
   Field *clone(MEM_ROOT *mem_root, TABLE *new_table, my_ptrdiff_t diff,
                bool stat_flag= FALSE);
@@ -2323,8 +2327,8 @@ public:
   { return charset() == &my_charset_bin ? FALSE : TRUE; }
   Field *new_field(MEM_ROOT *root, TABLE *new_table, bool keep_type);
   Field *new_key_field(MEM_ROOT *root, TABLE *new_table,
-                       uchar *new_ptr, uchar *new_null_ptr,
-                       uint new_null_bit);
+                       uchar *new_ptr, uint32 length,
+                       uchar *new_null_ptr, uint new_null_bit);
   uint is_equal(Create_field *new_field);
   void hash(ulong *nr, ulong *nr2);
   uint length_size() { return length_bytes; }
@@ -2457,6 +2461,9 @@ public:
   }
   uint get_key_image(uchar *buff,uint length, imagetype type);
   void set_key_image(const uchar *buff,uint length);
+  Field *new_key_field(MEM_ROOT *root, TABLE *new_table,
+                       uchar *new_ptr, uint32 length,
+                       uchar *new_null_ptr, uint new_null_bit);
   void sql_type(String &str) const;
   inline bool copy()
   {
@@ -2727,8 +2734,8 @@ public:
   virtual void set_default();
 
   Field *new_key_field(MEM_ROOT *root, TABLE *new_table,
-                       uchar *new_ptr, uchar *new_null_ptr,
-                       uint new_null_bit);
+                       uchar *new_ptr, uint32 length,
+                       uchar *new_null_ptr, uint new_null_bit);
   void set_bit_ptr(uchar *bit_ptr_arg, uchar bit_ofs_arg)
   {
     bit_ptr= bit_ptr_arg;

sql/opt_subselect.cc

@@ -4120,6 +4120,7 @@ SJ_TMP_TABLE::create_sj_weedout_tmp_table(THD *thd)
       {
 	if (!(key_field= field->new_key_field(thd->mem_root, table,
                                               group_buff,
+                                              key_part_info->length,
                                               field->null_ptr,
                                               field->null_bit)))
 	  goto err;

sql/sql_select.cc

@@ -16204,6 +16204,7 @@ create_tmp_table(THD *thd, TMP_TABLE_PARAM *param, List<Item> &fields,
 	if (!(cur_group->field= field->new_key_field(thd->mem_root,table,
                                                      group_buff +
                                                      MY_TEST(maybe_null),
+                                                     key_part_info->length,
                                                      field->null_ptr,
                                                      field->null_bit)))
 	  goto err; /* purecov: inspected */

sql/sql_select.h

@@ -1548,21 +1548,8 @@ public:
   store_key(THD *thd, Field *field_arg, uchar *ptr, uchar *null, uint length)
     :null_key(0), null_ptr(null), err(0)
   {
-    if (field_arg->type() == MYSQL_TYPE_BLOB
-        || field_arg->type() == MYSQL_TYPE_GEOMETRY)
-    {
-      /* 
-        Key segments are always packed with a 2 byte length prefix.
-        See mi_rkey for details.
-      */
-      to_field= new Field_varstring(ptr, length, 2, null, 1, 
-                                    Field::NONE, field_arg->field_name,
-                                    field_arg->table->s, field_arg->charset());
-      to_field->init(field_arg->table);
-    }
-    else
-      to_field=field_arg->new_key_field(thd->mem_root, field_arg->table,
-                                        ptr, null, 1);
+    to_field=field_arg->new_key_field(thd->mem_root, field_arg->table,
+                                      ptr, length, null, 1);
   }
   store_key(store_key &arg)
     :Sql_alloc(), null_key(arg.null_key), to_field(arg.to_field),