Reduce usage of strlen()

Changes:
- To detect automatic strlen() I removed the methods in String that
  uses 'const char *' without a length:
  - String::append(const char*)
  - Binary_string(const char *str)
  - String(const char *str, CHARSET_INFO *cs)
  - append_for_single_quote(const char *)
  All usage of append(const char*) is changed to either use
  String::append(char), String::append(const char*, size_t length) or
  String::append(LEX_CSTRING)
- Added STRING_WITH_LEN() around constant string arguments to
  String::append()
- Added overflow argument to escape_string_for_mysql() and
  escape_quotes_for_mysql() instead of returning (size_t) -1 on overflow.
  This was needed as most usage of the above functions never tested the
  result for -1 and would have given wrong results or crashes in case
  of overflows.
- Added Item_func_or_sum::func_name_cstring(), which returns LEX_CSTRING.
  Changed all Item_func::func_name()'s to func_name_cstring()'s.
  The old Item_func_or_sum::func_name() is now an inline function that
  returns func_name_cstring().str.
- Changed Item::mode_name() and Item::func_name_ext() to return
  LEX_CSTRING.
- Changed for some functions the name argument from const char * to
  to const LEX_CSTRING &:
  - Item::Item_func_fix_attributes()
  - Item::check_type_...()
  - Type_std_attributes::agg_item_collations()
  - Type_std_attributes::agg_item_set_converter()
  - Type_std_attributes::agg_arg_charsets...()
  - Type_handler_hybrid_field_type::aggregate_for_result()
  - Type_handler_geometry::check_type_geom_or_binary()
  - Type_handler::Item_func_or_sum_illegal_param()
  - Predicant_to_list_comparator::add_value_skip_null()
  - Predicant_to_list_comparator::add_value()
  - cmp_item_row::prepare_comparators()
  - cmp_item_row::aggregate_row_elements_for_comparison()
  - Cursor_ref::print_func()
- Removes String_space() as it was only used in one cases and that
  could be simplified to not use String_space(), thanks to the fixed
  my_vsnprintf().
- Added some const LEX_CSTRING's for common strings:
  - NULL_clex_str, DATA_clex_str, INDEX_clex_str.
- Changed primary_key_name to a LEX_CSTRING
- Renamed String::set_quick() to String::set_buffer_if_not_allocated() to
  clarify what the function really does.
- Rename of protocol function:
  bool store(const char *from, CHARSET_INFO *cs) to
  bool store_string_or_null(const char *from, CHARSET_INFO *cs).
  This was done to both clarify the difference between this 'store' function
  and also to make it easier to find unoptimal usage of store() calls.
- Added Protocol::store(const LEX_CSTRING*, CHARSET_INFO*)
- Changed some 'const char*' arrays to instead be of type LEX_CSTRING.
- class Item_func_units now used LEX_CSTRING for name.

Other things:
- Fixed a bug in mysql.cc:construct_prompt() where a wrong escape character
  in the prompt would cause some part of the prompt to be duplicated.
- Fixed a lot of instances where the length of the argument to
  append is known or easily obtain but was not used.
- Removed some not needed 'virtual' definition for functions that was
  inherited from the parent. I added override to these.
- Fixed Ordered_key::print() to preallocate needed buffer. Old code could
  case memory overruns.
- Simplified some loops when adding char * to a String with delimiters.

1 files changed, 12 insertions, 9 deletions

diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc
index 186693fb128..fc5b4deb9ac 100644
--- a/sql/item_strfunc.cc
+++ b/sql/item_strfunc.cc
@@ -554,7 +554,7 @@ String *Item_func_decode_histogram::val_str(String *str)
     size_t size= my_snprintf(numbuf, sizeof(numbuf),
                           representation_by_type[type], val - prev);
     str->append(numbuf, size);
-    str->append(",");
+    str->append(',');
     prev= val;
   }
   /* show delta with max */
@@ -2145,7 +2145,7 @@ void Item_func_trim::print(String *str, enum_query_type query_type)
     Item_func::print(str, query_type);
     return;
   }
-  str->append(Item_func_trim::func_name());
+  str->append(Item_func_trim::func_name_cstring());
   str->append(func_name_ext());
   str->append('(');
   str->append(mode_name());
@@ -2934,13 +2934,14 @@ String *Item_func_make_set::val_str(String *str)
 
 void Item_func_char::print(String *str, enum_query_type query_type)
 {
-  str->append(Item_func_char::func_name());
+  str->append(Item_func_char::func_name_cstring());
   str->append('(');
   print_args(str, 0, query_type);
   if (collation.collation != &my_charset_bin)
   {
     str->append(STRING_WITH_LEN(" using "));
-    str->append(collation.collation->csname);
+    str->append(collation.collation->csname,
+                strlen(collation.collation->csname));
   }
   str->append(')');
 }
@@ -3223,7 +3224,7 @@ bool Item_func_pad::fix_length_and_dec()
       return TRUE;
     pad_str.set_charset(collation.collation);
     pad_str.length(0);
-    pad_str.append(" ", 1);
+    pad_str.append(' ');
   }
 
   DBUG_ASSERT(collation.collation->mbmaxlen > 0);
@@ -3533,7 +3534,8 @@ void Item_func_conv_charset::print(String *str, enum_query_type query_type)
   str->append(STRING_WITH_LEN("convert("));
   args[0]->print(str, query_type);
   str->append(STRING_WITH_LEN(" using "));
-  str->append(collation.collation->csname);
+  str->append(collation.collation->csname,
+              strlen(collation.collation->csname));
   str->append(')');
 }
 
@@ -3573,7 +3575,7 @@ void Item_func_set_collation::print(String *str, enum_query_type query_type)
 {
   args[0]->print_parenthesised(str, query_type, precedence());
   str->append(STRING_WITH_LEN(" collate "));
-  str->append(m_set_collation->name);
+  str->append(m_set_collation->name, strlen(m_set_collation->name));
 }
 
 String *Item_func_charset::val_str(String *str)
@@ -3704,7 +3706,7 @@ nl:
 
 void Item_func_weight_string::print(String *str, enum_query_type query_type)
 {
-  str->append(func_name());
+  str->append(func_name_cstring());
   str->append('(');
   args[0]->print(str, query_type);
   str->append(',');
@@ -4631,7 +4633,8 @@ void Item_func_dyncol_create::print_arguments(String *str,
       if (defs[i].cs)
       {
         str->append(STRING_WITH_LEN(" charset "));
-        str->append(defs[i].cs->csname);
+        const char *cs= defs[i].cs->csname;
+        str->append(cs, strlen(cs));
         str->append(' ');
       }
       break;