Commit 12e62a8e authored by unknown's avatar unknown
Browse files

Optimize stack usage of ha_federated::update_row(). 


sql/ha_federated.cc:
  We only need one string buffer for fields in ::update_row()
parent f3c3c9c3

sql/ha_federated.cc

+13 −20
Original line number Diff line number Diff line
@@ -1817,18 +1817,12 @@ int ha_federated::update_row(const byte *old_data, byte *new_data) 
  /* 

    buffers for following strings

  */

  char old_field_value_buffer[STRING_BUFFER_USUAL_SIZE];

  char new_field_value_buffer[STRING_BUFFER_USUAL_SIZE];

  char field_value_buffer[STRING_BUFFER_USUAL_SIZE];

  char update_buffer[FEDERATED_QUERY_BUFFER_SIZE];

  char where_buffer[FEDERATED_QUERY_BUFFER_SIZE];



  /* stores the value to be replaced of the field were are updating */

  String old_field_value(old_field_value_buffer,

                         sizeof(old_field_value_buffer),

                         &my_charset_bin);

  /* stores the new value of the field */

  String new_field_value(new_field_value_buffer,

                         sizeof(new_field_value_buffer),

  /* Work area for field values */

  String field_value(field_value_buffer, sizeof(field_value_buffer),

                     &my_charset_bin);

  /* stores the update query */

  String update_string(update_buffer,
@@ -1842,8 +1836,7 @@ int ha_federated::update_row(const byte *old_data, byte *new_data) 
  /* 

    set string lengths to 0 to avoid misc chars in string

  */

  old_field_value.length(0);

  new_field_value.length(0);

  field_value.length(0);

  update_string.length(0);

  where_string.length(0);
@@ -1874,10 +1867,10 @@ int ha_federated::update_row(const byte *old_data, byte *new_data) 
    else

    {

      /* otherwise = */

      (*field)->val_str(&new_field_value);

      (*field)->quote_data(&new_field_value);

      update_string.append(new_field_value);

      new_field_value.length(0);

      (*field)->val_str(&field_value);

      (*field)->quote_data(&field_value);

      update_string.append(field_value);

      field_value.length(0);

    }



    if (field_in_record_is_null(table, *field, (char*) old_data))
@@ -1885,11 +1878,11 @@ int ha_federated::update_row(const byte *old_data, byte *new_data) 
    else

    {

      where_string.append(FEDERATED_EQ);

      (*field)->val_str(&old_field_value,

      (*field)->val_str(&field_value,

                        (char*) (old_data + (*field)->offset()));

      (*field)->quote_data(&old_field_value);

      where_string.append(old_field_value);

      old_field_value.length(0);

      (*field)->quote_data(&field_value);

      where_string.append(field_value);

      field_value.length(0);

    }



    /*