MDEV-17905 Add class Charset

2 files changed, 81 insertions, 53 deletions

diff --git a/sql/sql_string.cc b/sql/sql_string.cc
index 39d9438d5bf..78255f7c775 100644
--- a/sql/sql_string.cc
+++ b/sql/sql_string.cc
@@ -126,7 +126,7 @@ bool String::set_int(longlong num, bool unsigned_flag, CHARSET_INFO *cs)
   if (alloc(l))
     return TRUE;
   str_length=(uint32) (cs->cset->longlong10_to_str)(cs,Ptr,l,base,num);
-  str_charset=cs;
+  set_charset(cs);
   return FALSE;
 }
 
@@ -191,7 +191,7 @@ bool String::set_real(double num,uint decimals, CHARSET_INFO *cs)
   uint dummy_errors;
   size_t len;
 
-  str_charset=cs;
+  set_charset(cs);
   if (decimals >= FLOATING_POINT_DECIMALS)
   {
     len= my_gcvt(num, MY_GCVT_ARG_DOUBLE, sizeof(buff) - 1, buff, NULL);
@@ -231,7 +231,7 @@ bool String::copy(const String &str)
   str_length=str.str_length;
   bmove(Ptr,str.Ptr,str_length);		// May be overlapping
   Ptr[str_length]=0;
-  str_charset=str.str_charset;
+  set_charset(str);
   return FALSE;
 }
 
@@ -252,7 +252,7 @@ bool String::copy(const char *str,size_t arg_length, CHARSET_INFO *cs)
   else if ((str_length=uint32(arg_length)))
     memcpy(Ptr,str,arg_length);
   Ptr[arg_length]=0;
-  str_charset=cs;
+  set_charset(cs);
   return FALSE;
 }
 
@@ -270,7 +270,7 @@ bool String::copy_or_move(const char *str,size_t arg_length, CHARSET_INFO *cs)
   if ((str_length=uint32(arg_length)))
     memmove(Ptr,str,arg_length);
   Ptr[arg_length]=0;
-  str_charset=cs;
+  set_charset(cs);
   return FALSE;
 }
 
@@ -396,7 +396,7 @@ bool String::copy_aligned(const char *str, size_t arg_length, size_t offset,
   Ptr[aligned_length]=0;
   /* str_length is always >= 0 as arg_length is != 0 */
   str_length= (uint32)aligned_length;
-  str_charset= cs;
+  set_charset(cs);
   return FALSE;
 }
 
@@ -449,7 +449,7 @@ bool String::copy(const char *str, size_t arg_length,
     return TRUE;
   str_length=copy_and_convert((char*) Ptr, new_length, to_cs,
                               str, arg_length, from_cs, errors);
-  str_charset=to_cs;
+  set_charset(to_cs);
   return FALSE;
 }
 
@@ -475,13 +475,14 @@ bool String::copy(const char *str, size_t arg_length,
 
 bool String::set_ascii(const char *str, size_t arg_length)
 {
-  if (str_charset->mbminlen == 1)
+  if (mbminlen() == 1)
   {
-    set(str, arg_length, str_charset);
+    set(str, arg_length, charset());
     return 0;
   }
   uint dummy_errors;
-  return copy(str, (uint32)arg_length, &my_charset_latin1, str_charset, &dummy_errors);
+  return copy(str, (uint32) arg_length, &my_charset_latin1,
+              charset(), &dummy_errors);
 }
 
 
@@ -503,7 +504,7 @@ bool String::fill(uint32 max_length,char fill_char)
 
 void String::strip_sp()
 {
-   while (str_length && my_isspace(str_charset,Ptr[str_length-1]))
+   while (str_length && my_isspace(charset(), Ptr[str_length-1]))
     str_length--;
 }
 
@@ -534,13 +535,13 @@ bool String::append(const char *s,size_t size)
   /*
     For an ASCII incompatible string, e.g. UCS-2, we need to convert
   */
-  if (str_charset->mbminlen > 1)
+  if (mbminlen() > 1)
   {
-    uint32 add_length=arg_length * str_charset->mbmaxlen;
+    uint32 add_length= arg_length * mbmaxlen();
     uint dummy_errors;
     if (realloc_with_extra_if_needed(str_length+ add_length))
       return TRUE;
-    str_length+= copy_and_convert(Ptr+str_length, add_length, str_charset,
+    str_length+= copy_and_convert(Ptr + str_length, add_length, charset(),
 				  s, arg_length, &my_charset_latin1,
                                   &dummy_errors);
     return FALSE;
@@ -594,13 +595,13 @@ bool String::append(const char *s, size_t arg_length, CHARSET_INFO *cs)
 {
   uint32 offset;
   
-  if (needs_conversion((uint32)arg_length, cs, str_charset, &offset))
+  if (needs_conversion((uint32)arg_length, cs, charset(), &offset))
   {
     size_t add_length;
     if ((cs == &my_charset_bin) && offset)
     {
-      DBUG_ASSERT(str_charset->mbminlen > offset);
-      offset= str_charset->mbminlen - offset; // How many characters to pad
+      DBUG_ASSERT(mbminlen() > offset);
+      offset= mbminlen() - offset; // How many characters to pad
       add_length= arg_length + offset;
       if (realloc(str_length + add_length))
         return TRUE;
@@ -610,12 +611,12 @@ bool String::append(const char *s, size_t arg_length, CHARSET_INFO *cs)
       return FALSE;
     }
 
-    add_length= arg_length / cs->mbminlen * str_charset->mbmaxlen;
+    add_length= arg_length / cs->mbminlen * mbmaxlen();
     uint dummy_errors;
     if (realloc_with_extra_if_needed(str_length + add_length)) 
       return TRUE;
-    str_length+= copy_and_convert(Ptr+str_length, (uint32)add_length, str_charset,
-				  s, (uint32)arg_length, cs, &dummy_errors);
+    str_length+= copy_and_convert(Ptr + str_length, (uint32)add_length, charset(),
+                                  s, (uint32)arg_length, cs, &dummy_errors);
   }
   else
   {
@@ -675,17 +676,6 @@ bool String::append_with_prefill(const char *s,uint32 arg_length,
   return FALSE;
 }
 
-uint32 String::numchars() const
-{
-  return (uint32) str_charset->cset->numchars(str_charset, Ptr, Ptr+str_length);
-}
-
-int String::charpos(longlong i,uint32 offset)
-{
-  if (i <= 0)
-    return (int)i;
-  return (int)str_charset->cset->charpos(str_charset,Ptr+offset,Ptr+str_length,(size_t)i);
-}
 
 int String::strstr(const String &s,uint32 offset)
 {
@@ -999,7 +989,7 @@ String *copy_if_not_alloced(String *to,String *from,uint32 from_length)
     return from;				// Actually an error
   if ((to->str_length=MY_MIN(from->str_length,from_length)))
     memcpy(to->Ptr,from->Ptr,to->str_length);
-  to->str_charset=from->str_charset;
+  to->set_charset(*from);
   return to; // "from" was of types #a, #b, #e, or small #c.
 }
 
@@ -1175,7 +1165,7 @@ void String::swap(String &s)
   swap_variables(uint32, str_length, s.str_length);
   swap_variables(uint32, Alloced_length, s.Alloced_length);
   swap_variables(bool, alloced, s.alloced);
-  swap_variables(CHARSET_INFO*, str_charset, s.str_charset);
+  Charset::swap(s);
 }
 
 
diff --git a/sql/sql_string.h b/sql/sql_string.h
index 0ae68cb3796..cb45876c277 100644
--- a/sql/sql_string.h
+++ b/sql/sql_string.h
@@ -126,31 +126,64 @@ uint convert_to_printable(char *to, size_t to_len,
                           const char *from, size_t from_len,
                           CHARSET_INFO *from_cs, size_t nbytes= 0);
 
-class String
+
+class Charset
+{
+  CHARSET_INFO *m_charset;
+public:
+  Charset() :m_charset(&my_charset_bin) { }
+  Charset(CHARSET_INFO *cs) :m_charset(cs) { }
+
+  CHARSET_INFO *charset() const { return m_charset; }
+  uint mbminlen() const { return m_charset->mbminlen; }
+  uint mbmaxlen() const { return m_charset->mbmaxlen; }
+
+  size_t numchars(const char *str, const char *end) const
+  {
+    return m_charset->cset->numchars(m_charset, str, end);
+  }
+  size_t charpos(const char *str, const char *end, size_t pos) const
+  {
+    return m_charset->cset->charpos(m_charset, str, end, pos);
+  }
+  void set_charset(CHARSET_INFO *charset_arg)
+  {
+    m_charset= charset_arg;
+  }
+  void set_charset(const Charset &other)
+  {
+    m_charset= other.m_charset;
+  }
+  void swap(Charset &other)
+  {
+    swap_variables(CHARSET_INFO*, m_charset, other.m_charset);
+  }
+};
+
+
+
+class String: public Charset
 {
   char *Ptr;
   uint32 str_length,Alloced_length, extra_alloc;
   bool alloced,thread_specific;
-  CHARSET_INFO *str_charset;
 public:
   String()
   { 
     Ptr=0; str_length=Alloced_length=extra_alloc=0;
     alloced= thread_specific= 0; 
-    str_charset= &my_charset_bin; 
   }
   String(size_t length_arg)
   { 
     alloced= thread_specific= 0;
     Alloced_length= extra_alloc= 0; (void) real_alloc(length_arg); 
-    str_charset= &my_charset_bin;
   }
   String(const char *str, CHARSET_INFO *cs)
+   :Charset(cs)
   { 
     Ptr=(char*) str; str_length= (uint32) strlen(str);
     Alloced_length= extra_alloc= 0;
     alloced= thread_specific= 0;
-    str_charset=cs;
   }
   /*
     NOTE: If one intend to use the c_ptr() method, the following two
@@ -158,23 +191,23 @@ public:
     room for zero termination).
   */
   String(const char *str,size_t len, CHARSET_INFO *cs)
+   :Charset(cs)
   { 
     Ptr=(char*) str; str_length=(uint32)len; Alloced_length= extra_alloc=0;
     alloced= thread_specific= 0;
-    str_charset=cs;
   }
   String(char *str,size_t len, CHARSET_INFO *cs)
+   :Charset(cs)
   { 
     Ptr=(char*) str; Alloced_length=str_length=(uint32)len; extra_alloc= 0;
     alloced= thread_specific= 0;
-    str_charset=cs;
   }
   String(const String &str)
+   :Charset(str)
   { 
     Ptr=str.Ptr ; str_length=str.str_length ;
     Alloced_length=str.Alloced_length; extra_alloc= 0;
     alloced= thread_specific= 0;
-    str_charset=str.str_charset;
   }
   static void *operator new(size_t size, MEM_ROOT *mem_root) throw ()
   { return (void*) alloc_root(mem_root, size); }
@@ -201,9 +234,6 @@ public:
     if (!alloced)
       thread_specific= 1;
   }
-  inline void set_charset(CHARSET_INFO *charset_arg)
-  { str_charset= charset_arg; }
-  inline CHARSET_INFO *charset() const { return str_charset; }
   inline uint32 length() const { return str_length;}
   inline uint32 alloced_length() const { return Alloced_length;}
   inline uint32 extra_allocation() const { return extra_alloc;}
@@ -255,7 +285,7 @@ public:
     Ptr=(char*) str.ptr()+offset; str_length=(uint32)arg_length;
     if (str.Alloced_length)
       Alloced_length=(uint32)(str.Alloced_length-offset);
-    str_charset=str.str_charset;
+    set_charset(str);
   }
 
 
@@ -271,13 +301,13 @@ public:
   {
     free();
     Ptr=(char*) str; str_length=Alloced_length=(uint32)arg_length;
-    str_charset=cs;
+    set_charset(cs);
   }
   inline void set(const char *str,size_t arg_length, CHARSET_INFO *cs)
   {
     free();
     Ptr=(char*) str; str_length=(uint32)arg_length;
-    str_charset=cs;
+    set_charset(cs);
   }
   bool set_ascii(const char *str, size_t arg_length);
   inline void set_quick(char *str,size_t arg_length, CHARSET_INFO *cs)
@@ -286,7 +316,7 @@ public:
     {
       Ptr=(char*) str; str_length=Alloced_length=(uint32)arg_length;
     }
-    str_charset=cs;
+    set_charset(cs);
   }
   bool set_int(longlong num, bool unsigned_flag, CHARSET_INFO *cs);
   bool set(int num, CHARSET_INFO *cs) { return set_int(num, false, cs); }
@@ -308,7 +338,7 @@ public:
     Ptr= ptr_arg;
     str_length= (uint32)length_arg;
     Alloced_length= (uint32)alloced_length_arg;
-    str_charset= cs;
+    set_charset(cs);
     alloced= ptr_arg != 0;
   }
 
@@ -429,7 +459,7 @@ public:
       DBUG_ASSERT(!s.uses_buffer_owned_by(this));
       free();
       Ptr=s.Ptr ; str_length=s.str_length ; Alloced_length=s.Alloced_length;
-      str_charset=s.str_charset;
+      set_charset(s);
     }
     return *this;
   }
@@ -461,7 +491,7 @@ public:
       return true;
     str_length= copier->well_formed_copy(tocs, Ptr, Alloced_length,
                                          fromcs, src, (uint)src_length, (uint)nchars);
-    str_charset= tocs;
+    set_charset(tocs);
     return false;
   }
   void move(String &s)
@@ -539,8 +569,16 @@ public:
   friend int stringcmp(const String *a,const String *b);
   friend String *copy_if_not_alloced(String *a,String *b,uint32 arg_length);
   friend class Field;
-  uint32 numchars() const;
-  int charpos(longlong i,uint32 offset=0);
+  uint32 numchars() const
+  {
+    return (uint32) Charset::numchars(ptr(), end());
+  }
+  int charpos(longlong i, uint32 offset=0)
+  {
+    if (i <= 0)
+      return (int) i;
+    return (int) Charset::charpos(ptr() + offset, end(), (size_t) i);
+  }
 
   int reserve(size_t space_needed)
   {