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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2008 Sun Microsystems, Inc.
* Copyright (C) 2010 Stewart Smith
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <config.h>
#include <drizzled/plugin/function.h>
#include <drizzled/function/str/strfunc.h>
#include <drizzled/charset.h>
using namespace drizzled;
class ReverseFunction :public Item_str_func
{
String tmp_value;
public:
ReverseFunction() :Item_str_func() {}
String *val_str(String *);
void fix_length_and_dec();
const char *func_name() const { return "reverse"; }
bool check_argument_count(int n)
{
return n == 1;
}
};
String *ReverseFunction::val_str(String *str)
{
assert(fixed == 1);
String *res = args[0]->val_str(str);
char *ptr, *end, *tmp;
if ((null_value=args[0]->null_value))
return 0;
/* An empty string is a special case as the string pointer may be null */
if (!res->length())
return &my_empty_string;
if (tmp_value.alloced_length() < res->length())
tmp_value.realloc(res->length());
tmp_value.length(res->length());
tmp_value.set_charset(res->charset());
ptr= (char *) res->ptr();
end= ptr + res->length();
tmp= (char *) tmp_value.ptr() + tmp_value.length();
if (use_mb(res->charset()))
{
register uint32_t l;
while (ptr < end)
{
if ((l= my_ismbchar(res->charset(),ptr,end)))
{
tmp-= l;
memcpy(tmp,ptr,l);
ptr+= l;
}
else
*--tmp= *ptr++;
}
}
else
{
while (ptr < end)
*--tmp= *ptr++;
}
return &tmp_value;
}
void ReverseFunction::fix_length_and_dec()
{
collation.set(args[0]->collation);
max_length = args[0]->max_length;
}
plugin::Create_function<ReverseFunction> *reverse_function= NULL;
static int initialize(drizzled::module::Context &context)
{
reverse_function= new plugin::Create_function<ReverseFunction>("reverse");
context.add(reverse_function);
return 0;
}
DRIZZLE_DECLARE_PLUGIN
{
DRIZZLE_VERSION_ID,
"reverse_function",
"1.0",
"Stewart Smith",
"reverses a string",
PLUGIN_LICENSE_GPL,
initialize, /* Plugin Init */
NULL, /* depends */
NULL /* config options */
}
DRIZZLE_DECLARE_PLUGIN_END;
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