SQL: start_end_t members as LEX_CSTRING

8 files changed, 176 insertions, 168 deletions

diff --git a/sql/handler.cc b/sql/handler.cc
index 8ec9feab7c5..32d5c5fd2db 100644
--- a/sql/handler.cc
+++ b/sql/handler.cc
@@ -6584,13 +6584,12 @@ int del_global_index_stat(THD *thd, TABLE* table, KEY* key_info)
 bool Vers_parse_info::is_trx_start(const char *name) const
 {
   DBUG_ASSERT(name);
-  return generated_as_row.start &&
-         !strcmp(generated_as_row.start->c_ptr(), name);
+  return generated_as_row.start && generated_as_row.start == LString_i(name);
 }
 bool Vers_parse_info::is_trx_end(const char *name) const
 {
   DBUG_ASSERT(name);
-  return generated_as_row.end && !strcmp(generated_as_row.end->c_ptr(), name);
+  return generated_as_row.end && generated_as_row.end == LString_i(name);
 }
 bool Vers_parse_info::is_trx_start(const Create_field &f) const
 {
@@ -6601,14 +6600,9 @@ bool Vers_parse_info::is_trx_end(const Create_field &f) const
   return f.flags & VERS_SYS_END_FLAG;
 }
 
-static bool create_string(MEM_ROOT *mem_root, String **s, const char *value)
-{
-  *s= new (mem_root) String(value, system_charset_info);
-  return *s == NULL;
-}
 
 static bool vers_create_sys_field(THD *thd, const char *field_name,
-                                 Alter_info *alter_info, String **s,
+                                 Alter_info *alter_info,
                                  int flags,
                                  bool integer_fields)
 {
@@ -6635,9 +6629,6 @@ static bool vers_create_sys_field(THD *thd, const char *field_name,
   if (f->check(thd))
     return true;
 
-  if (create_string(thd->mem_root, s, field_name))
-    return true;
-
   alter_info->create_list.push_back(f);
   return false;
 }
@@ -6652,19 +6643,18 @@ bool Vers_parse_info::fix_implicit(THD *thd, Alter_info *alter_info,
 
   alter_info->flags|= Alter_info::ALTER_ADD_COLUMN;
 
-  static const char * sys_trx_start= "sys_trx_start";
-  static const char * sys_trx_end= "sys_trx_end";
+  static const LString sys_trx_start= "sys_trx_start";
+  static const LString sys_trx_end= "sys_trx_end";
+
+  period_for_system_time= start_end_t(sys_trx_start, sys_trx_end);
+  generated_as_row= period_for_system_time;
 
   return vers_create_sys_field(thd, sys_trx_start, alter_info,
-                              &generated_as_row.start, VERS_SYS_START_FLAG,
+                              VERS_SYS_START_FLAG,
                               integer_fields) ||
          vers_create_sys_field(thd, sys_trx_end, alter_info,
-                              &generated_as_row.end, VERS_SYS_END_FLAG,
-                              integer_fields) ||
-         create_string(thd->mem_root, &period_for_system_time.start,
-                       sys_trx_start) ||
-         create_string(thd->mem_root, &period_for_system_time.end,
-                       sys_trx_end);
+                              VERS_SYS_END_FLAG,
+                              integer_fields);
 }
 
 bool Vers_parse_info::check_and_fix_implicit(
@@ -6731,7 +6721,7 @@ bool Vers_parse_info::check_and_fix_implicit(
           return true;
         }
         orig_table= f->field->orig_table;
-        generated_as_row.start= new (thd->mem_root) String(f->field_name, system_charset_info);
+        generated_as_row.start= f->field_name;
         period_for_system_time.start= generated_as_row.start;
       }
       continue;
@@ -6746,7 +6736,7 @@ bool Vers_parse_info::check_and_fix_implicit(
           goto err_different_tables;
         }
         orig_table= f->field->orig_table;
-        generated_as_row.end= new (thd->mem_root) String(f->field_name, system_charset_info);
+        generated_as_row.end= f->field_name;
         period_for_system_time.end= generated_as_row.end;
       }
       continue;
@@ -6866,11 +6856,8 @@ bool Vers_parse_info::check_and_fix_alter(THD *thd, Alter_info *alter_info,
     const char *end= share->vers_end_field()->field_name;
     DBUG_ASSERT(start && end);
 
-    if (create_string(thd->mem_root, &generated_as_row.start, start) ||
-        create_string(thd->mem_root, &generated_as_row.end, end) ||
-        create_string(thd->mem_root, &period_for_system_time.start, start) ||
-        create_string(thd->mem_root, &period_for_system_time.end, end))
-      return true;
+    generated_as_row= start_end_t(start, end);
+    period_for_system_time= generated_as_row;
 
     if (alter_info->create_list.elements)
     {
@@ -6935,14 +6922,8 @@ bool Vers_parse_info::fix_create_like(THD *thd, Alter_info *alter_info,
     return true;
   }
 
-  if (create_string(thd->mem_root, &generated_as_row.start, f_start->field_name) ||
-      create_string(thd->mem_root, &period_for_system_time.start, f_start->field_name) ||
-      create_string(thd->mem_root, &generated_as_row.end, f_end->field_name) ||
-      create_string(thd->mem_root, &period_for_system_time.end, f_end->field_name))
-  {
-    sql_print_error("Failed to allocate memory for Vers_parse_info::fix_create_like()");
-    return true;
-  }
+  generated_as_row= start_end_t(f_start->field_name, f_end->field_name);
+  period_for_system_time= generated_as_row;
 
   create_info->options|= HA_VERSIONED_TABLE;
   return false;
@@ -6972,16 +6953,14 @@ bool Vers_parse_info::check_with_conditions(const char *table_name) const
     return true;
   }
 
-  if (my_strcasecmp(system_charset_info, generated_as_row.start->c_ptr(),
-                    period_for_system_time.start->c_ptr()))
+  if (generated_as_row.start != period_for_system_time.start)
   {
     my_error(ER_VERS_WRONG_PARAMS, MYF(0), table_name,
              "'PERIOD FOR SYSTEM_TIME' and 'GENERATED AS ROW START' mismatch");
     return true;
   }
 
-  if (my_strcasecmp(system_charset_info, generated_as_row.end->c_ptr(),
-                    period_for_system_time.end->c_ptr()))
+  if (generated_as_row.end != period_for_system_time.end)
   {
     my_error(ER_VERS_WRONG_PARAMS, MYF(0), table_name,
              "'PERIOD FOR SYSTEM_TIME' and 'GENERATED AS ROW END' mismatch");
diff --git a/sql/handler.h b/sql/handler.h
index 6f65853256c..9c2b1bcf209 100644
--- a/sql/handler.h
+++ b/sql/handler.h
@@ -36,6 +36,7 @@
 #include "sql_array.h"          /* Dynamic_array<> */
 #include "mdl.h"
 #include "vtq.h"
+#include "vers_string.h"
 
 #include "sql_analyze_stmt.h" // for Exec_time_tracker 
 
@@ -1684,17 +1685,19 @@ struct Vers_parse_info
 
   struct start_end_t
   {
-    start_end_t() :
-      start(NULL),
-      end(NULL) {}
-    String *start;
-    String *end;
+    start_end_t()
+    {}
+    start_end_t(const char* _start, const char* _end) :
+      start(_start),
+      end(_end) {}
+    LString_i start;
+    LString_i end;
   };
 
   start_end_t period_for_system_time;
   start_end_t generated_as_row;
 
-  void set_period_for_system_time(String *start, String *end)
+  void set_period_for_system_time(LString start, LString end)
   {
     period_for_system_time.start = start;
     period_for_system_time.end = end;
@@ -1713,10 +1716,10 @@ private:
       has_unversioned_fields ||
       declared_with_system_versioning ||
       declared_without_system_versioning ||
-      period_for_system_time.start ||
-      period_for_system_time.end ||
-      generated_as_row.start ||
-      generated_as_row.end;
+      period_for_system_time.start.str ||
+      period_for_system_time.end.str ||
+      generated_as_row.start.str ||
+      generated_as_row.end.str;
   }
   bool check_with_conditions(const char *table_name) const;
   bool check_generated_type(const char *table_name, Alter_info *alter_info,
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 7aeb1854e24..4c1ab495651 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -4326,9 +4326,9 @@ vers_prepare_keys(THD *thd,
 {
   DBUG_ASSERT(create_info->versioned());
 
-  const char *row_start_field= create_info->vers_info.generated_as_row.start->c_ptr();
+  const char *row_start_field= create_info->vers_info.generated_as_row.start;
   DBUG_ASSERT(row_start_field);
-  const char *row_end_field= create_info->vers_info.generated_as_row.end->c_ptr();
+  const char *row_end_field= create_info->vers_info.generated_as_row.end;
   DBUG_ASSERT(row_end_field);
 
   List_iterator<Key> key_it(alter_info->key_list);
@@ -4354,10 +4354,8 @@ vers_prepare_keys(THD *thd,
     if (key_part)
       continue; // Key already contains Sys_start or Sys_end
 
-    const LEX_STRING &lex_sys_end=
-      create_info->vers_info.generated_as_row.end->lex_string();
     Key_part_spec *key_part_sys_end_col=
-      new(thd->mem_root) Key_part_spec(lex_sys_end, 0);
+      new(thd->mem_root) Key_part_spec(create_info->vers_info.generated_as_row.end, 0);
     key->columns.push_back(key_part_sys_end_col);
   }
 
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index ec09803a46e..73860aadca5 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -1622,6 +1622,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
         opt_constraint constraint opt_ident
         sp_decl_ident
         sp_block_label
+        period_for_system_time_column_id
 
 %type <lex_string_with_metadata>
         TEXT_STRING
@@ -1651,7 +1652,6 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 
 %type <string>
         text_string hex_or_bin_String opt_gconcat_separator
-        period_for_system_time_column_id
 
 %type <field_type> int_type real_type
 
@@ -6167,7 +6167,7 @@ period_for_system_time:
           PERIOD_SYM FOR_SYSTEM_TIME_SYM '(' period_for_system_time_column_id ',' period_for_system_time_column_id ')'
           {
             Vers_parse_info &info= Lex->vers_get_info();
-            if (!my_strcasecmp(system_charset_info, $4->c_ptr(), $6->c_ptr()))
+            if (!my_strcasecmp(system_charset_info, $4.str, $6.str))
             {
               my_yyabort_error((ER_VERS_WRONG_PARAMS, MYF(0),
                 Lex->create_last_non_select_table->table_name,
@@ -6284,14 +6284,10 @@ field_def:
           {
             LEX *lex= Lex;
             Vers_parse_info &info= lex->vers_get_info();
-            String *field_name= new (thd->mem_root)
-              String((const char*)lex->last_field->field_name, system_charset_info);
-            if (!field_name)
-              MYSQL_YYABORT;
-
+            const char *field_name= lex->last_field->field_name;
             const char *table_name= lex->create_last_non_select_table->table_name;
 
-            String **p= NULL;
+            LString_i *p;
             const char* err;
             switch ($4)
             {
@@ -6310,6 +6306,7 @@ field_def:
               MYSQL_YYABORT;
               break;
             }
+            DBUG_ASSERT(p);
             if (*p)
             {
               my_yyabort_error((ER_VERS_WRONG_PARAMS, MYF(0), table_name, err));
@@ -16237,10 +16234,7 @@ column_list:
 period_for_system_time_column_id:
           ident
           {
-            String *new_str= new (thd->mem_root) String((const char*) $1.str,$1.length,system_charset_info);
-            if (new_str == NULL)
-              MYSQL_YYABORT;
-            $$= new_str;
+            $$= $1;
           }
         ;
 
diff --git a/sql/unireg.cc b/sql/unireg.cc
index cffc98d2e35..7a5aadb1c22 100644
--- a/sql/unireg.cc
+++ b/sql/unireg.cc
@@ -101,8 +101,8 @@ vers_get_field(HA_CREATE_INFO *create_info, List<Create_field> &create_fields, b
 
   const char *row_field =
     row_start ?
-      create_info->vers_info.generated_as_row.start->c_ptr() :
-      create_info->vers_info.generated_as_row.end->c_ptr();
+      create_info->vers_info.generated_as_row.start :
+      create_info->vers_info.generated_as_row.end;
   DBUG_ASSERT(row_field);
 
   for (unsigned field_no = 0; (sql_field = it++); ++field_no)
diff --git a/sql/vers_string.h b/sql/vers_string.h
new file mode 100644
index 00000000000..ddd691276db
--- /dev/null
+++ b/sql/vers_string.h
@@ -0,0 +1,131 @@
+#ifndef VERS_STRING_INCLUDED
+#define VERS_STRING_INCLUDED
+
+struct Compare_strncmp
+{
+  int operator()(const LEX_CSTRING& a, const LEX_CSTRING& b) const
+  {
+    return strncmp(a.str, b.str, a.length);
+  }
+  static CHARSET_INFO* charset()
+  {
+    return system_charset_info;
+  }
+};
+
+template <CHARSET_INFO* &CS= system_charset_info>
+struct Compare_my_strcasecmp
+{
+  int operator()(const LEX_CSTRING& a, const LEX_CSTRING& b) const
+  {
+    DBUG_ASSERT(a.str[a.length] == 0 && b.str[b.length] == 0);
+    return my_strcasecmp(CS, a.str, b.str);
+  }
+  static CHARSET_INFO* charset()
+  {
+    return CS;
+  }
+};
+
+typedef Compare_my_strcasecmp<files_charset_info> Compare_fs;
+typedef Compare_my_strcasecmp<table_alias_charset> Compare_t;
+
+template <class Storage= LEX_CSTRING>
+struct LEX_STRING_u : public Storage
+{
+  LEX_STRING_u()
+  {
+    Storage::str= NULL;
+    Storage::length= 0;
+  }
+  LEX_STRING_u(const char *_str, uint32 _len, CHARSET_INFO *)
+  {
+    Storage::str= _str;
+    Storage::length= _len;
+  }
+  uint32 length() const
+  {
+    return Storage::length;
+  }
+  const char *ptr() const
+  {
+    return Storage::str;
+  }
+  void set(const char *_str, uint32 _len, CHARSET_INFO *)
+  {
+    Storage::str= _str;
+    Storage::length= _len;
+  }
+  const LEX_CSTRING& lex_cstring() const
+  {
+    return *this;
+  }
+};
+
+template <class Compare= Compare_strncmp, class Storage= LEX_STRING_u<> >
+struct XString : public Storage
+{
+public:
+  XString() {}
+  XString(const char *_str, size_t _len) :
+    Storage(_str, _len, Compare::charset())
+  {
+  }
+  XString(LEX_STRING& src) :
+    Storage(src.str, src.length, Compare::charset())
+  {
+  }
+  XString(const char *_str) :
+    Storage(_str, strlen(_str), Compare::charset())
+  {
+  }
+  XString& operator= (const char *_str)
+  {
+    DBUG_ASSERT(_str);
+    Storage::set(_str, strlen(_str), Compare::charset());
+    return *this;
+  }
+  bool operator== (const XString& b) const
+  {
+    return Storage::length() == b.length() && 0 == Compare()(this->lex_cstring(), b.lex_cstring());
+  }
+  bool operator!= (const XString& b) const
+  {
+    return !(*this == b);
+  }
+  operator const char* () const
+  {
+    return Storage::ptr();
+  }
+  operator LEX_CSTRING& () const
+  {
+    return this->lex_cstring();
+  }
+  operator LEX_STRING () const
+  {
+    LEX_STRING res;
+    res.str= const_cast<char *>(this->ptr());
+    res.length= this->length();
+    return res;
+  }
+  operator bool () const
+  {
+    return Storage::ptr() != NULL;
+  }
+};
+
+typedef XString<> LString;
+typedef XString<Compare_fs> LString_fs;
+typedef XString<Compare_my_strcasecmp<> > LString_i;
+
+typedef XString<Compare_strncmp, String> SString;
+typedef XString<Compare_fs, String> SString_fs;
+typedef XString<Compare_t, String> SString_t;
+
+
+#define XSTRING_WITH_LEN(X) (X).ptr(), (X).length()
+#define DB_WITH_LEN(X) (X).db, (X).db_length
+#define TABLE_NAME_WITH_LEN(X) (X).table_name, (X).table_name_length
+
+
+#endif // VERS_STRING_INCLUDED
diff --git a/sql/vers_utils.h b/sql/vers_utils.h
index ee08fcbb2bc..948139bfa9b 100644
--- a/sql/vers_utils.h
+++ b/sql/vers_utils.h
@@ -3,6 +3,7 @@
 
 #include "table.h"
 #include "sql_class.h"
+#include "vers_string.h"
 
 class MDL_auto_lock
 {
@@ -30,104 +31,6 @@ public:
   bool acquire_error() const { return error; }
 };
 
-struct Compare_strncmp
-{
-  int operator()(const LEX_STRING& a, const LEX_STRING& b) const
-  {
-    return strncmp(a.str, b.str, a.length);
-  }
-  static CHARSET_INFO* charset()
-  {
-    return system_charset_info;
-  }
-};
-
-template <CHARSET_INFO* &CS= system_charset_info>
-struct Compare_my_strcasecmp
-{
-  int operator()(const LEX_STRING& a, const LEX_STRING& b) const
-  {
-    DBUG_ASSERT(a.str[a.length] == 0 && b.str[b.length] == 0);
-    return my_strcasecmp(CS, a.str, b.str);
-  }
-  static CHARSET_INFO* charset()
-  {
-    return CS;
-  }
-};
-
-typedef Compare_my_strcasecmp<files_charset_info> Compare_fs;
-typedef Compare_my_strcasecmp<table_alias_charset> Compare_t;
-
-struct LEX_STRING_u : public LEX_STRING
-{
-  LEX_STRING_u()
-  {
-    str= NULL;
-    LEX_STRING::length= 0;
-  }
-  LEX_STRING_u(const char *_str, uint32 _len, CHARSET_INFO *)
-  {
-    str= const_cast<char *>(_str);
-    LEX_STRING::length= _len;
-  }
-  uint32 length() const
-  {
-    return LEX_STRING::length;
-  }
-  const char *ptr() const
-  {
-    return LEX_STRING::str;
-  }
-  const LEX_STRING& lex_string() const
-  {
-    return *this;
-  }
-};
-
-template <class Compare= Compare_strncmp, class Storage= LEX_STRING_u>
-struct XString : public Storage
-{
-public:
-  XString() {}
-  XString(char *_str, size_t _len) :
-    Storage(_str, _len, Compare::charset())
-  {
-  }
-  XString(LEX_STRING& src) :
-    Storage(src.str, src.length, Compare::charset())
-  {
-  }
-  XString(char *_str) :
-    Storage(_str, strlen(_str), Compare::charset())
-  {
-  }
-  bool operator== (const XString& b) const
-  {
-    return Storage::length() == b.length() && 0 == Compare()(this->lex_string(), b.lex_string());
-  }
-  bool operator!= (const XString& b) const
-  {
-    return !(*this == b);
-  }
-  operator const char* () const
-  {
-    return Storage::ptr();
-  }
-};
-
-typedef XString<> LString;
-typedef XString<Compare_fs> LString_fs;
-
-typedef XString<Compare_strncmp, String> SString;
-typedef XString<Compare_fs, String> SString_fs;
-typedef XString<Compare_t, String> SString_t;
-
-
-#define XSTRING_WITH_LEN(X) (X).ptr(), (X).length()
-#define DB_WITH_LEN(X) (X).db, (X).db_length
-#define TABLE_NAME_WITH_LEN(X) (X).table_name, (X).table_name_length
-
 
 class Local_da : public Diagnostics_area
 {
diff --git a/sql/vtmd.cc b/sql/vtmd.cc
index 65620bd2cb0..83a6fb512ef 100644
--- a/sql/vtmd.cc
+++ b/sql/vtmd.cc
@@ -416,7 +416,7 @@ VTMD_rename::try_rename(THD *thd, LString new_db, LString new_alias, const char
     return false;
 
   bool same_db= true;
-  if (LString_fs(DB_WITH_LEN(about)) != new_db)
+  if (LString_fs(DB_WITH_LEN(about)) != LString_fs(new_db))
   {
     // Move archives before VTMD so if the operation is interrupted, it could be continued.
     if (move_archives(thd, new_db))