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, 43 insertions, 33 deletions

diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 794b46217c5..9b9a6653793 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -61,7 +61,11 @@
 #include <io.h>
 #endif
 
-const char *primary_key_name="PRIMARY";
+const LEX_CSTRING primary_key_name= { STRING_WITH_LEN("PRIMARY") };
+static const LEX_CSTRING generated_by_server=
+{ STRING_WITH_LEN(" /* generated by server */") };
+static const LEX_CSTRING SEQUENCE_clex_str= { STRING_WITH_LEN("SEQUENCE") };
+static const LEX_CSTRING TABLE_clex_str= { STRING_WITH_LEN("TABLE") };
 
 static int check_if_keyname_exists(const char *name,KEY *start, KEY *end);
 static char *make_unique_key_name(THD *, const char *, KEY *, KEY *);
@@ -2241,7 +2245,9 @@ int mysql_rm_table_no_locks(THD *thd, TABLE_LIST *tables, bool if_exists,
   bool non_tmp_table_deleted= 0;
   bool is_drop_tmp_if_exists_added= 0;
   bool was_view= 0, was_table= 0, log_if_exists= if_exists;
-  const char *object_to_drop= (drop_sequence) ? "SEQUENCE" : "TABLE";
+  const LEX_CSTRING *object_to_drop= ((drop_sequence) ?
+                                      &SEQUENCE_clex_str :
+                                      &TABLE_clex_str);
   String normal_tables;
   String built_trans_tmp_query, built_non_trans_tmp_query;
   DBUG_ENTER("mysql_rm_table_no_locks");
@@ -2286,13 +2292,13 @@ int mysql_rm_table_no_locks(THD *thd, TABLE_LIST *tables, bool if_exists,
   if (!dont_log_query)
   {
     built_trans_tmp_query.set_charset(system_charset_info);
-    built_trans_tmp_query.append("DROP TEMPORARY ");
+    built_trans_tmp_query.append(STRING_WITH_LEN("DROP TEMPORARY "));
     built_trans_tmp_query.append(object_to_drop);
     built_trans_tmp_query.append(' ');
     if (thd->is_current_stmt_binlog_format_row() || if_exists)
     {
       is_drop_tmp_if_exists_added= true;
-      built_trans_tmp_query.append("IF EXISTS ");
+      built_trans_tmp_query.append(STRING_WITH_LEN("IF EXISTS "));
     }
     built_non_trans_tmp_query.set_charset(system_charset_info);
     built_non_trans_tmp_query.copy(built_trans_tmp_query);
@@ -2400,10 +2406,10 @@ int mysql_rm_table_no_locks(THD *thd, TABLE_LIST *tables, bool if_exists,
             is_drop_tmp_if_exists_added )
         {
           append_identifier(thd, built_ptr_query, &db);
-          built_ptr_query->append(".");
+          built_ptr_query->append('.');
         }
         append_identifier(thd, built_ptr_query, &table_name);
-        built_ptr_query->append(",");
+        built_ptr_query->append(',');
       }
       /*
         This means that a temporary table was droped and as such there
@@ -2670,11 +2676,11 @@ int mysql_rm_table_no_locks(THD *thd, TABLE_LIST *tables, bool if_exists,
       if (thd->db.str == NULL || cmp(&db, &thd->db) != 0)
       {
         append_identifier(thd, &normal_tables, &db);
-        normal_tables.append(".");
+        normal_tables.append('.');
       }
 
       append_identifier(thd, &normal_tables, &table_name);
-      normal_tables.append(",");
+      normal_tables.append(',');
     }
     DBUG_PRINT("table", ("table: %p  s: %p", table->table,
                          table->table ?  table->table->s :  NULL));
@@ -2718,7 +2724,7 @@ err:
       {
           /* Chop of the last comma */
           built_non_trans_tmp_query.chop();
-          built_non_trans_tmp_query.append(" /* generated by server */");
+          built_non_trans_tmp_query.append(generated_by_server);
           error |= (thd->binlog_query(THD::STMT_QUERY_TYPE,
                                       built_non_trans_tmp_query.ptr(),
                                       built_non_trans_tmp_query.length(),
@@ -2730,7 +2736,7 @@ err:
       {
           /* Chop of the last comma */
           built_trans_tmp_query.chop();
-          built_trans_tmp_query.append(" /* generated by server */");
+          built_trans_tmp_query.append(generated_by_server);
           error |= (thd->binlog_query(THD::STMT_QUERY_TYPE,
                                       built_trans_tmp_query.ptr(),
                                       built_trans_tmp_query.length(),
@@ -2745,24 +2751,24 @@ err:
         uint32 comment_len;
 
         built_query.set_charset(thd->charset());
-        built_query.append("DROP ");
+        built_query.append(STRING_WITH_LEN("DROP "));
         built_query.append(object_to_drop);
         built_query.append(' ');
         if (log_if_exists)
-          built_query.append("IF EXISTS ");
+          built_query.append(STRING_WITH_LEN("IF EXISTS "));
 
         /* Preserve comment in original query */
         if ((comment_len= comment_length(thd, if_exists ? 17:9,
                                          &comment_start)))
         {
           built_query.append(comment_start, comment_len);
-          built_query.append(" ");
+          built_query.append(' ');
         }
 
         /* Chop of the last comma */
         normal_tables.chop();
         built_query.append(normal_tables.ptr(), normal_tables.length());
-        built_query.append(" /* generated by server */");
+        built_query.append(generated_by_server);
         error |= (thd->binlog_query(THD::STMT_QUERY_TYPE,
                                     built_query.ptr(),
                                     built_query.length(),
@@ -2845,7 +2851,7 @@ bool log_drop_table(THD *thd, const LEX_CSTRING *db_name,
     query.append(STRING_WITH_LEN("TEMPORARY "));
   query.append(STRING_WITH_LEN("TABLE IF EXISTS "));
   append_identifier(thd, &query, db_name);
-  query.append(".");
+  query.append('.');
   append_identifier(thd, &query, table_name);
   query.append(STRING_WITH_LEN("/* Generated to handle "
                                "failed CREATE OR REPLACE */"));
@@ -2956,9 +2962,9 @@ static int sort_keys(KEY *a, KEY *b)
       /* Sort NOT NULL keys before other keys */
       return (a_flags & HA_NULL_PART_KEY) ? 1 : -1;
     }
-    if (a->name.str == primary_key_name)
+    if (a->name.str == primary_key_name.str)
       return -1;
-    if (b->name.str == primary_key_name)
+    if (b->name.str == primary_key_name.str)
       return 1;
     /* Sort keys don't containing partial segments before others */
     if ((a_flags ^ b_flags) & HA_KEY_HAS_PART_KEY_SEG)
@@ -3616,7 +3622,7 @@ mysql_prepare_create_table(THD *thd, HA_CREATE_INFO *create_info,
     if (!(file->ha_table_flags() & HA_CAN_TABLES_WITHOUT_ROLLBACK))
     {
       my_error(ER_ILLEGAL_HA_CREATE_OPTION, MYF(0), file->table_type(),
-               "SEQUENCE");
+               SEQUENCE_clex_str.str);
       DBUG_RETURN(TRUE);
     }
 
@@ -3864,13 +3870,14 @@ mysql_prepare_create_table(THD *thd, HA_CREATE_INFO *create_info,
     else
       (*key_count)--;
     if (key->name.str && !tmp_table && (key->type != Key::PRIMARY) &&
-	!my_strcasecmp(system_charset_info, key->name.str, primary_key_name))
+	!my_strcasecmp(system_charset_info, key->name.str,
+                       primary_key_name.str))
     {
       my_error(ER_WRONG_NAME_FOR_INDEX, MYF(0), key->name.str);
       DBUG_RETURN(TRUE);
     }
     if (key->type == Key::PRIMARY && key->name.str &&
-        my_strcasecmp(system_charset_info, key->name.str, primary_key_name) != 0)
+        my_strcasecmp(system_charset_info, key->name.str, primary_key_name.str) != 0)
     {
       bool sav_abort_on_warning= thd->abort_on_warning;
       thd->abort_on_warning= FALSE; /* Don't make an error out of this. */
@@ -3891,7 +3898,7 @@ mysql_prepare_create_table(THD *thd, HA_CREATE_INFO *create_info,
   {
     if (key->name.str == ignore_key || key->type == Key::FOREIGN_KEY)
       continue;
-    /* Create the key->ame based on the first column (if not given) */
+    /* Create the key name based on the first column (if not given) */
     if (key->type == Key::PRIMARY)
     {
       if (primary_key)
@@ -3900,7 +3907,7 @@ mysql_prepare_create_table(THD *thd, HA_CREATE_INFO *create_info,
                    MYF(0));
         DBUG_RETURN(true);
       }
-      key_name=primary_key_name;
+      key_name= primary_key_name.str;
       primary_key=1;
     }
     else if (!(key_name= key->name.str))
@@ -5696,7 +5703,7 @@ make_unique_key_name(THD *thd, const char *field_name,KEY *start,KEY *end)
   char buff[MAX_FIELD_NAME],*buff_end;
 
   if (!check_if_keyname_exists(field_name,start,end) &&
-      my_strcasecmp(system_charset_info,field_name,primary_key_name))
+      my_strcasecmp(system_charset_info,field_name,primary_key_name.str))
     return (char*) field_name;			// Use fieldname
   buff_end=strmake(buff,field_name, sizeof(buff)-4);
 
@@ -6713,7 +6720,7 @@ drop_create_field:
             key->type == Key::PRIMARY &&
             table->s->primary_key != MAX_KEY &&
             (keyname= table->s->key_info[table->s->primary_key].name.str) &&
-            my_strcasecmp(system_charset_info, keyname, primary_key_name) == 0;
+            my_strcasecmp(system_charset_info, keyname, primary_key_name.str) == 0;
       if (dup_primary_key)
         goto remove_key;
 
@@ -6722,7 +6729,7 @@ drop_create_field:
       if ((keyname= key->name.str) == NULL)
       {
         if (key->type == Key::PRIMARY)
-          keyname= primary_key_name;
+          keyname= primary_key_name.str;
         else
         {
           List_iterator<Key_part_spec> part_it(key->columns);
@@ -7437,7 +7444,7 @@ static bool fill_alter_inplace_info(THD *thd, TABLE *table, bool varchar,
   const KEY* const new_pk= (ha_alter_info->key_count > 0 &&
                             (!my_strcasecmp(system_charset_info,
                                 ha_alter_info->key_info_buffer->name.str,
-                                primary_key_name) ||
+                                primary_key_name.str) ||
                             is_candidate_key(ha_alter_info->key_info_buffer))) ?
                            ha_alter_info->key_info_buffer : NULL;
   const KEY *const old_pk= table->s->primary_key == MAX_KEY ? NULL :
@@ -8918,13 +8925,13 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
     {
       if (!my_strcasecmp(system_charset_info, key_name, rename_key->old_name.str))
       {
-        if (!my_strcasecmp(system_charset_info, key_name, primary_key_name))
+        if (!my_strcasecmp(system_charset_info, key_name, primary_key_name.str))
         {
           my_error(ER_WRONG_NAME_FOR_INDEX, MYF(0), rename_key->old_name.str);
           goto err;
         }
         else if (!my_strcasecmp(system_charset_info, rename_key->new_name.str,
-                                primary_key_name))
+                                primary_key_name.str))
         {
           my_error(ER_WRONG_NAME_FOR_INDEX, MYF(0), rename_key->new_name.str);
           goto err;
@@ -9081,7 +9088,7 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
         key_type= Key::SPATIAL;
       else if (key_info->flags & HA_NOSAME)
       {
-        if (! my_strcasecmp(system_charset_info, key_name, primary_key_name))
+        if (! my_strcasecmp(system_charset_info, key_name, primary_key_name.str))
           key_type= Key::PRIMARY;
         else
           key_type= Key::UNIQUE;
@@ -9144,7 +9151,8 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
         goto err;
       new_key_list.push_back(key, thd->mem_root);
       if (key->name.str &&
-	  !my_strcasecmp(system_charset_info, key->name.str, primary_key_name))
+	  !my_strcasecmp(system_charset_info, key->name.str,
+                         primary_key_name.str))
       {
 	my_error(ER_WRONG_NAME_FOR_INDEX, MYF(0), key->name.str);
         goto err;
@@ -11837,11 +11845,13 @@ bool mysql_checksum_table(THD *thd, TABLE_LIST *tables,
   /* Open one table after the other to keep lock time as short as possible. */
   for (table= tables; table; table= table->next_local)
   {
-    char table_name[SAFE_NAME_LEN*2+2];
+    char table_name_buff[SAFE_NAME_LEN*2+2];
+    LEX_CSTRING table_name= { table_name_buff, 0};
     TABLE *t;
     TABLE_LIST *save_next_global;
 
-    strxmov(table_name, table->db.str ,".", table->table_name.str, NullS);
+    table_name.length= strxmov(table_name_buff, table->db.str ,".",
+                               table->table_name.str, NullS) - table_name_buff;
 
     /* Remember old 'next' pointer and break the list.  */
     save_next_global= table->next_global;
@@ -11861,7 +11871,7 @@ bool mysql_checksum_table(THD *thd, TABLE_LIST *tables,
     table->next_global= save_next_global;
 
     protocol->prepare_for_resend();
-    protocol->store(table_name, system_charset_info);
+    protocol->store(&table_name, system_charset_info);
 
     if (!t)
     {