Clean-up: sharing duplicate code in Item_field::val_bool_result() and

Item_ref::val_bool_result().

Author: Alexander Barkov

sql/field.h

@@ -738,6 +738,7 @@ class Field: public Value_source
  { return store(ls->str, ls->length, cs); }
  virtual double val_real(void)=0;
  virtual longlong val_int(void)=0;
+ virtual bool val_bool(void)= 0;
  virtual my_decimal *val_decimal(my_decimal *);
  inline String *val_str(String *str) { return val_str(str, str); }
  /*
@@ -1491,6 +1492,7 @@ class Field_num :public Field {
  bool eq_def(Field *field);
  int store_decimal(const my_decimal *);
  my_decimal *val_decimal(my_decimal *);
+ bool val_bool() { return val_int() != 0; }
  uint is_equal(Create_field *new_field);
  uint row_pack_length() const { return pack_length(); }
  uint32 pack_length_from_metadata(uint field_metadata) {
@@ -1537,6 +1539,7 @@ class Field_str :public Field {
  uint32 max_display_length() { return field_length; }
  friend class Create_field;
  my_decimal *val_decimal(my_decimal *);
+ bool val_bool() { return val_real() != 0e0; }
  virtual bool str_needs_quotes() { return TRUE; }
  uint is_equal(Create_field *new_field);
  bool eq_cmp_as_binary() { return MY_TEST(flags & BINARY_FLAG); }
@@ -1609,6 +1612,7 @@ class Field_real :public Field_num {
  int store_time_dec(MYSQL_TIME *ltime, uint dec);
  bool get_date(MYSQL_TIME *ltime, ulonglong fuzzydate);
  my_decimal *val_decimal(my_decimal *);
+ bool val_bool() { return val_real() != 0e0; }
  uint32 max_display_length() { return field_length; }
  uint size_of() const { return sizeof(*this); }
  Item *get_equal_const_item(THD *thd, const Context &ctx, Item *const_item);
@@ -1684,6 +1688,12 @@ class Field_new_decimal :public Field_num {
  my_decimal *val_decimal(my_decimal *);
  String *val_str(String*, String *);
  bool get_date(MYSQL_TIME *ltime, ulonglong fuzzydate);
+ bool val_bool()
+ {
+ my_decimal decimal_value;
+ my_decimal *val= val_decimal(&decimal_value);
+ return val ? !my_decimal_is_zero(val) : 0;
+ }
  int cmp(const uchar *, const uchar *);
  void sort_string(uchar *buff, uint length);
  bool zero_pack() const { return 0; }
@@ -2009,6 +2019,7 @@ class Field_null :public Field_str {
  int reset(void) { return 0; }
  double val_real(void)	{ return 0.0;}
  longlong val_int(void)	{ return 0;}
+ bool val_bool(void) { return false; }
  my_decimal *val_decimal(my_decimal *) { return 0; }
  String *val_str(String *value,String *value2)
  { value2->length(0); return value2;}
@@ -2054,6 +2065,7 @@ class Field_temporal: public Field {
  CHARSET_INFO *sort_charset(void) const { return &my_charset_bin; }
  bool binary() const { return true; }
  enum Item_result cmp_type () const { return TIME_RESULT; }
+ bool val_bool() { return val_real() != 0e0; }
  uint is_equal(Create_field *new_field);
  bool eq_def(Field *field)
  {
@@ -3267,6 +3279,7 @@ class Field_bit :public Field {
  String *val_str(String*, String *);
  virtual bool str_needs_quotes() { return TRUE; }
  my_decimal *val_decimal(my_decimal *);
+ bool val_bool() { return val_int() != 0; }
  int cmp(const uchar *a, const uchar *b)
  {
  DBUG_ASSERT(ptr == a || ptr == b);

sql/item.cc

@@ -2560,27 +2560,8 @@ my_decimal *Item_field::val_decimal_result(my_decimal *decimal_value)
 bool Item_field::val_bool_result()
 {
  if ((null_value= result_field->is_null()))
- return FALSE;
- switch (result_field->result_type()) {
- case INT_RESULT:
- return result_field->val_int() != 0;
- case DECIMAL_RESULT:
- {
- my_decimal decimal_value;
- my_decimal *val= result_field->val_decimal(&decimal_value);
- if (val)
- return !my_decimal_is_zero(val);
- return 0;
- }
- case REAL_RESULT:
- case STRING_RESULT:
- return result_field->val_real() != 0.0;
- case ROW_RESULT:
- case TIME_RESULT:
- DBUG_ASSERT(0);
- return 0; // Shut up compiler
- }
- return 0;
+ return false;
+ return result_field->val_bool();
 }
 
 
@@ -7204,25 +7185,8 @@ bool Item_ref::val_bool_result()
  if (result_field)
  {
  if ((null_value= result_field->is_null()))
- return 0;
- switch (result_field->result_type()) {
- case INT_RESULT:
- return result_field->val_int() != 0;
- case DECIMAL_RESULT:
- {
- my_decimal decimal_value;
- my_decimal *val= result_field->val_decimal(&decimal_value);
- if (val)
- return !my_decimal_is_zero(val);
- return 0;
- }
- case REAL_RESULT:
- case STRING_RESULT:
- return result_field->val_real() != 0.0;
- case ROW_RESULT:
- case TIME_RESULT:
- DBUG_ASSERT(0);
- }
+ return false;
+ return result_field->val_bool();
  }
  return val_bool();
 }