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MySQL 5.1: Item_func_replace Class Reference

Item_func_replace Class Reference

#include <item_strfunc.h>

Inheritance diagram for Item_func_replace:

[legend]Collaboration diagram for Item_func_replace:

[legend]List of all members.


Public Member Functions
	Item_func_replace (Item org, Item find, Item *replace)
String *	val_str (String *)
void	fix_length_and_dec ()
const char *	func_name () const
Private Attributes
String	tmp_value
String	tmp_value2

Detailed Description

Definition at line 118 of file item_strfunc.h.

Constructor & Destructor Documentation

Item_func_replace::Item_func_replace	(	Item *	org,
		Item *	find,
		Item *	replace
	)			`[inline]`

Definition at line 122 of file item_strfunc.h.

00123     :Item_str_func(org,find,replace) {}

Member Function Documentation

void Item_func_replace::fix_length_and_dec ( ) [virtual]

Implements Item_result_field.

Definition at line 927 of file item_strfunc.cc.

References Item_func::agg_arg_charsets(), Item_func::args, Item::collation, int(), MAX_BLOB_WIDTH, Item::max_length, Item::maybe_null, and MY_COLL_CMP_CONV.

00928 {
00929   ulonglong max_result_length= args[0]->max_length;
00930   int diff=(int) (args[2]->max_length - args[1]->max_length);
00931   if (diff > 0 && args[1]->max_length)
00932   {                                             // Calculate of maxreplaces
00933     ulonglong max_substrs= max_result_length/args[1]->max_length;
00934     max_result_length+= max_substrs * (uint) diff;
00935   }
00936   if (max_result_length >= MAX_BLOB_WIDTH)
00937   {
00938     max_result_length= MAX_BLOB_WIDTH;
00939     maybe_null= 1;
00940   }
00941   max_length= (ulong) max_result_length;
00942   
00943   if (agg_arg_charsets(collation, args, 3, MY_COLL_CMP_CONV, 1))
00944     return;
00945 }

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const char* Item_func_replace::func_name ( ) const [inline, virtual]

Implements Item_func.

Definition at line 126 of file item_strfunc.h.

Referenced by val_str().

00126 { return "replace"; }

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String * Item_func_replace::val_str ( String * ) [virtual]

Implements Item.

Definition at line 812 of file item_strfunc.cc.

References Item_func::args, String::charset(), DTCollation::collation, Item::collation, copy_if_not_alloced(), current_thd, DBUG_ASSERT, ER, ER_WARN_ALLOWED_PACKET_OVERFLOWED, Item::fixed, func_name(), int(), String::length(), MY_CS_BINSORT, my_ismbchar, Item::null_value, offset, String::ptr(), push_warning_printf(), String::replace(), search_end(), String::set_charset(), skip(), charset_info_st::state, strend(), String::strstr(), tmp_value, tmp_value2, use_mb, Item::val_str(), and MYSQL_ERROR::WARN_LEVEL_WARN.

00813 {
00814   DBUG_ASSERT(fixed == 1);
00815   String *res,*res2,*res3;
00816   int offset;
00817   uint from_length,to_length;
00818   bool alloced=0;
00819 #ifdef USE_MB
00820   const char *ptr,*end,*strend,*search,*search_end;
00821   register uint32 l;
00822   bool binary_cmp;
00823 #endif
00824 
00825   null_value=0;
00826   res=args[0]->val_str(str);
00827   if (args[0]->null_value)
00828     goto null;
00829   res2=args[1]->val_str(&tmp_value);
00830   if (args[1]->null_value)
00831     goto null;
00832 
00833   res->set_charset(collation.collation);
00834 
00835 #ifdef USE_MB
00836   binary_cmp = ((res->charset()->state & MY_CS_BINSORT) || !use_mb(res->charset()));
00837 #endif
00838 
00839   if (res2->length() == 0)
00840     return res;
00841 #ifndef USE_MB
00842   if ((offset=res->strstr(*res2)) < 0)
00843     return res;
00844 #else
00845   offset=0;
00846   if (binary_cmp && (offset=res->strstr(*res2)) < 0)
00847     return res;
00848 #endif
00849   if (!(res3=args[2]->val_str(&tmp_value2)))
00850     goto null;
00851   from_length= res2->length();
00852   to_length=   res3->length();
00853 
00854 #ifdef USE_MB
00855   if (!binary_cmp)
00856   {
00857     search=res2->ptr();
00858     search_end=search+from_length;
00859 redo:
00860     ptr=res->ptr()+offset;
00861     strend=res->ptr()+res->length();
00862     end=strend-from_length+1;
00863     while (ptr < end)
00864     {
00865         if (*ptr == *search)
00866         {
00867           register char *i,*j;
00868           i=(char*) ptr+1; j=(char*) search+1;
00869           while (j != search_end)
00870             if (*i++ != *j++) goto skip;
00871           offset= (int) (ptr-res->ptr());
00872           if (res->length()-from_length + to_length >
00873               current_thd->variables.max_allowed_packet)
00874           {
00875             push_warning_printf(current_thd, MYSQL_ERROR::WARN_LEVEL_WARN,
00876                                 ER_WARN_ALLOWED_PACKET_OVERFLOWED,
00877                                 ER(ER_WARN_ALLOWED_PACKET_OVERFLOWED),
00878                                 func_name(),
00879                                 current_thd->variables.max_allowed_packet);
00880 
00881             goto null;
00882           }
00883           if (!alloced)
00884           {
00885             alloced=1;
00886             res=copy_if_not_alloced(str,res,res->length()+to_length);
00887           }
00888           res->replace((uint) offset,from_length,*res3);
00889           offset+=(int) to_length;
00890           goto redo;
00891         }
00892 skip:
00893         if ((l=my_ismbchar(res->charset(), ptr,strend))) ptr+=l;
00894         else ++ptr;
00895     }
00896   }
00897   else
00898 #endif /* USE_MB */
00899     do
00900     {
00901       if (res->length()-from_length + to_length >
00902           current_thd->variables.max_allowed_packet)
00903       {
00904         push_warning_printf(current_thd, MYSQL_ERROR::WARN_LEVEL_WARN,
00905                             ER_WARN_ALLOWED_PACKET_OVERFLOWED,
00906                             ER(ER_WARN_ALLOWED_PACKET_OVERFLOWED), func_name(),
00907                             current_thd->variables.max_allowed_packet);
00908         goto null;
00909       }
00910       if (!alloced)
00911       {
00912         alloced=1;
00913         res=copy_if_not_alloced(str,res,res->length()+to_length);
00914       }
00915       res->replace((uint) offset,from_length,*res3);
00916       offset+=(int) to_length;
00917     }
00918     while ((offset=res->strstr(*res2,(uint) offset)) >= 0);
00919   return res;
00920 
00921 null:
00922   null_value=1;
00923   return 0;
00924 }