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MySQL 5.1: Item_func_reverse Class Reference

Item_func_reverse Class Reference

#include <item_strfunc.h>

Inheritance diagram for Item_func_reverse:

[legend]Collaboration diagram for Item_func_reverse:

[legend]List of all members.


Public Member Functions
	Item_func_reverse (Item *a)
String *	val_str (String *)
void	fix_length_and_dec ()
const char *	func_name () const
bool	check_partition_func_processor (byte *bool_arg)
Private Attributes
String	tmp_value

Detailed Description

Definition at line 106 of file item_strfunc.h.

Constructor & Destructor Documentation

Item_func_reverse::Item_func_reverse ( Item * a ) [inline]

Definition at line 110 of file item_strfunc.h.

00110 :Item_str_func(a) {}

Member Function Documentation

bool Item_func_reverse::check_partition_func_processor ( byte * bool_arg ) [inline, virtual]

Reimplemented from Item.

Definition at line 114 of file item_strfunc.h.

00114 { return 0;}

void Item_func_reverse::fix_length_and_dec ( ) [virtual]

Implements Item_result_field.

Definition at line 799 of file item_strfunc.cc.

References Item_func::args, Item::collation, Item::max_length, and DTCollation::set().

00800 {
00801   collation.set(args[0]->collation);
00802   max_length = args[0]->max_length;
00803 }

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

Implements Item_func.

Definition at line 113 of file item_strfunc.h.

00113 { return "reverse"; }

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

Implements Item.

Definition at line 751 of file item_strfunc.cc.

References String::alloced_length(), Item_func::args, String::charset(), DBUG_ASSERT, Item::fixed, String::length(), memcpy, my_empty_string(), my_ismbchar, Item::null_value, String::ptr(), String::realloc(), String::set_charset(), tmp_value, use_mb, and Item::val_str().

00752 {
00753   DBUG_ASSERT(fixed == 1);
00754   String *res = args[0]->val_str(str);
00755   char *ptr, *end, *tmp;
00756 
00757   if ((null_value=args[0]->null_value))
00758     return 0;
00759   /* An empty string is a special case as the string pointer may be null */
00760   if (!res->length())
00761     return &my_empty_string;
00762   if (tmp_value.alloced_length() < res->length() &&
00763       tmp_value.realloc(res->length()))
00764   {
00765     null_value= 1;
00766     return 0;
00767   }
00768   tmp_value.length(res->length());
00769   tmp_value.set_charset(res->charset());
00770   ptr= (char *) res->ptr();
00771   end= ptr + res->length();
00772   tmp= (char *) tmp_value.ptr() + tmp_value.length();
00773 #ifdef USE_MB
00774   if (use_mb(res->charset()))
00775   {
00776     register uint32 l;
00777     while (ptr < end)
00778     {
00779       if ((l= my_ismbchar(res->charset(),ptr,end)))
00780       {
00781         tmp-= l;
00782         memcpy(tmp,ptr,l);
00783         ptr+= l;
00784       }
00785       else
00786         *--tmp= *ptr++;
00787     }
00788   }
00789   else
00790 #endif /* USE_MB */
00791   {
00792     while (ptr < end)
00793       *--tmp= *ptr++;
00794   }
00795   return &tmp_value;
00796 }

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Member Data Documentation

String Item_func_reverse::tmp_value [private]

Definition at line 108 of file item_strfunc.h.

Referenced by val_str().

The documentation for this class was generated from the following files:

mysql/src/5.1-dbg/sql/item_strfunc.h
mysql/src/5.1-dbg/sql/item_strfunc.cc

Generated on Sat Sep 9 21:41:26 2006 for MySQL 5.1 by

1.4.7