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, 77 insertions, 44 deletions

diff --git a/client/mysql.cc b/client/mysql.cc
index 494d4c2fbd1..131b3036df8 100644
--- a/client/mysql.cc
+++ b/client/mysql.cc
@@ -2062,13 +2062,14 @@ static int read_and_execute(bool interactive)
         {
           status.exit_status= 1;
           String msg;
-          msg.append("ASCII '\\0' appeared in the statement, but this is not "
-                     "allowed unless option --binary-mode is enabled and mysql is "
-                     "run in non-interactive mode. Set --binary-mode to 1 if ASCII "
-                     "'\\0' is expected. Query: '");
+          msg.append(STRING_WITH_LEN(
+          "ASCII '\\0' appeared in the statement, but this is not "
+          "allowed unless option --binary-mode is enabled and mysql is "
+          "run in non-interactive mode. Set --binary-mode to 1 if ASCII "
+          "'\\0' is expected. Query: '"));
           msg.append(glob_buffer);
-          msg.append(line);
-          msg.append("'.");
+          msg.append(line, strlen(line));
+          msg.append(STRING_WITH_LEN("'."));
           put_info(msg.c_ptr(), INFO_ERROR);
           break;
         }
@@ -2462,8 +2463,9 @@ static bool add_line(String &buffer, char *line, size_t line_length,
                                  my_isspace(charset_info, pos[2]))))
       {
         // Add trailing single line comments to this statement
-        buffer.append(pos);
-        pos+= strlen(pos);
+        size_t length= strlen(pos);
+        buffer.append(pos, length);
+        pos+= length;
       }
 
       pos--;
@@ -2509,7 +2511,7 @@ static bool add_line(String &buffer, char *line, size_t line_length,
       {
         bool started_with_nothing= !buffer.length();
 
-        buffer.append(pos);
+        buffer.append(pos, strlen(pos));
 
         /*
           A single-line comment by itself gets sent immediately so that
@@ -2667,7 +2669,7 @@ static void fix_history(String *final_command)
 	 not in string, change to space
 	 if in string, leave it alone 
       */
-      fixed_buffer.append(str_char == '\0' ? " " : "\n");
+      fixed_buffer.append(str_char == '\0' ? ' ' : '\n');
       total_lines++;
       break;
     case '\\':
@@ -3313,7 +3315,8 @@ com_go(String *buffer,char *line __attribute__((unused)))
 #ifdef HAVE_READLINE
   if (status.add_to_history) 
   {  
-    buffer->append(vertical ? "\\G" : delimiter);
+    const char *delim= vertical ? "\\G" : delimiter;
+    buffer->append(delim, strlen(delim));
     /* Append final command onto history */
     fix_history(buffer);
   }
@@ -5227,20 +5230,27 @@ static const char *construct_prompt()
 	add_int_to_prompt(++prompt_counter);
 	break;
       case 'v':
-	if (connected)
-	  processed_prompt.append(mysql_get_server_info(&mysql));
-	else
-	  processed_prompt.append("not_connected");
+      {
+        const char *info= (connected ?
+                           mysql_get_server_info(&mysql) :
+                           "not_connected");
+        processed_prompt.append(info, strlen(info));
 	break;
+      }
       case 'd':
-	processed_prompt.append(current_db ? current_db : "(none)");
-	break;
+      {
+        const char *db= current_db ? current_db : "(none)";
+        processed_prompt.append(db, strlen(db));
+        break;
+      }
       case 'N':
-        if (connected)
-          processed_prompt.append(mysql_get_server_name(&mysql));
-        else
-          processed_prompt.append("unknown");
+      {
+        const char *name= (connected ?
+                           mysql_get_server_name(&mysql) :
+                           "unknown");
+        processed_prompt.append(name, strlen(name));
         break;
+      }
       case 'h':
       case 'H':
       {
@@ -5249,16 +5259,20 @@ static const char *construct_prompt()
         if (strstr(prompt, "Localhost") || strstr(prompt, "localhost "))
         {
           if (*c == 'h')
-            processed_prompt.append("localhost");
+            processed_prompt.append(STRING_WITH_LEN("localhost"));
           else
           {
             static char hostname[FN_REFLEN];
-            if (hostname[0])
-              processed_prompt.append(hostname);
+            static size_t hostname_length;
+            if (hostname_length)
+              processed_prompt.append(hostname, hostname_length);
             else if (gethostname(hostname, sizeof(hostname)) == 0)
-              processed_prompt.append(hostname);
+            {
+              hostname_length= strlen(hostname);
+              processed_prompt.append(hostname, hostname_length);
+            }
             else
-              processed_prompt.append("gethostname(2) failed");
+              processed_prompt.append(STRING_WITH_LEN("gethostname(2) failed"));
           }
         }
         else
@@ -5273,38 +5287,47 @@ static const char *construct_prompt()
 #ifndef EMBEDDED_LIBRARY
 	if (!connected)
 	{
-	  processed_prompt.append("not_connected");
+	  processed_prompt.append(STRING_WITH_LEN("not_connected"));
 	  break;
 	}
 
 	const char *host_info = mysql_get_host_info(&mysql);
 	if (strstr(host_info, "memory")) 
 	{
-		processed_prompt.append( mysql.host );
+          processed_prompt.append( mysql.host, strlen(mysql.host));
 	}
 	else if (strstr(host_info,"TCP/IP") ||
 	    !mysql.unix_socket)
 	  add_int_to_prompt(mysql.port);
 	else
 	{
-	  char *pos=strrchr(mysql.unix_socket,'/');
- 	  processed_prompt.append(pos ? pos+1 : mysql.unix_socket);
+          char *pos= strrchr(mysql.unix_socket,'/');
+          const char *tmp= pos ? pos+1 : mysql.unix_socket;
+          processed_prompt.append(tmp, strlen(tmp));
 	}
 #endif
       }
 	break;
       case 'U':
+      {
+        const char *name;
 	if (!full_username)
 	  init_username();
-        processed_prompt.append(full_username ? full_username :
-                                (current_user ?  current_user : "(unknown)"));
+        name= (full_username ? full_username :
+               (current_user ?  current_user : "(unknown)"));
+        processed_prompt.append(name, strlen(name));
 	break;
+      }
       case 'u':
+      {
+        const char *name;
 	if (!full_username)
 	  init_username();
-        processed_prompt.append(part_username ? part_username :
-                                (current_user ?  current_user : "(unknown)"));
+        name= (part_username ? part_username :
+               (current_user ?  current_user : "(unknown)"));
+        processed_prompt.append(name, strlen(name));
 	break;
+      }
       case PROMPT_CHAR:
 	processed_prompt.append(PROMPT_CHAR);
 	break;
@@ -5345,29 +5368,39 @@ static const char *construct_prompt()
 	add_int_to_prompt(t->tm_year+1900);
 	break;
       case 'D':
+      {
 	char* dateTime;
+        const char *tmp;
 	dateTime = ctime(&lclock);
-	processed_prompt.append(strtok(dateTime,"\n"));
+        tmp= strtok(dateTime,"\n");
+	processed_prompt.append(tmp, strlen(tmp));
 	break;
+      }
       case 's':
 	if (t->tm_sec < 10)
 	  processed_prompt.append('0');
 	add_int_to_prompt(t->tm_sec);
 	break;
       case 'w':
-	processed_prompt.append(day_names[t->tm_wday]);
-	break;
+      {
+        const char *name= day_names[t->tm_wday];
+        processed_prompt.append(name, strlen(name));
+        break;
+      }
       case 'P':
-	processed_prompt.append(t->tm_hour < 12 ? "am" : "pm");
+	processed_prompt.append(t->tm_hour < 12 ? "am" : "pm", 2);
 	break;
       case 'o':
 	add_int_to_prompt(t->tm_mon+1);
 	break;
       case 'O':
-	processed_prompt.append(month_names[t->tm_mon]);
+      {
+        const char *name= month_names[t->tm_mon];
+        processed_prompt.append(name, strlen(name));
 	break;
+      }
       case '\'':
-	processed_prompt.append("'");
+	processed_prompt.append('\'');
 	break;
       case '"':
 	processed_prompt.append('"');
@@ -5379,10 +5412,10 @@ static const char *construct_prompt()
 	processed_prompt.append('\t');
 	break;
       case 'l':
-	processed_prompt.append(delimiter_str);
+	processed_prompt.append(delimiter_str, strlen(delimiter_str));
 	break;
       default:
-	processed_prompt.append(c);
+	processed_prompt.append(*c);
       }
     }
   }
@@ -5394,8 +5427,8 @@ static const char *construct_prompt()
 static void add_int_to_prompt(int toadd)
 {
   char buffer[16];
-  int10_to_str(toadd,buffer,10);
-  processed_prompt.append(buffer);
+  size_t length= (size_t) (int10_to_str(toadd,buffer,10) - buffer);
+  processed_prompt.append(buffer, length);
 }
 
 static void init_username()