~drizzle-trunk/drizzle/development : contents of plugin/reverse_function/reverse

~drizzle-trunk/drizzle/development : (revision 1994.4.18)

/* -*- 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>

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()))
  {
    null_value= 1;
    return 0;
  }
  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,   /* system variables */
  NULL    /* config options */
}
DRIZZLE_DECLARE_PLUGIN_END;

1300.4.2 by Stewart Smith make REVERSE() a plugin instead of built in function. Generalise the code for such keyword functions otu into reserved_keyword_function() in sql_yacc.	1	/* -- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; --
	2	* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
	3	*
1999.6.1 by kalebral at gmail update Copyright strings to a more common format to help with creating the master debian copyright file	4	* Copyright (C) 2008 Sun Microsystems, Inc.
1300.4.2 by Stewart Smith make REVERSE() a plugin instead of built in function. Generalise the code for such keyword functions otu into reserved_keyword_function() in sql_yacc.	5	* Copyright (C) 2010 Stewart Smith
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License as published by
	9	* the Free Software Foundation; version 2 of the License.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	19	*/
	20
	21	#include "config.h"
	22
	23	#include <drizzled/plugin/function.h>
	24	#include <drizzled/function/str/strfunc.h>
	25
	26	using namespace drizzled;
	27
	28	class ReverseFunction :public Item_str_func
	29	{
	30	String tmp_value;
	31	public:
	32	ReverseFunction() :Item_str_func() {}
	33	String val_str(String );
	34	void fix_length_and_dec();
	35	const char *func_name() const { return "reverse"; }
	36
	37	bool check_argument_count(int n)
	38	{
	39	return n == 1;
	40	}
	41	};
	42
	43	String ReverseFunction::val_str(String str)
	44	{
	45	assert(fixed == 1);
	46	String *res = args[0]->val_str(str);
	47	char ptr, end, *tmp;
	48
	49	if ((null_value=args[0]->null_value))
	50	return 0;
	51	/* An empty string is a special case as the string pointer may be null */
	52	if (!res->length())
	53	return &my_empty_string;
	54	if (tmp_value.alloced_length() < res->length() &&
	55	tmp_value.realloc(res->length()))
	56	{
	57	null_value= 1;
	58	return 0;
	59	}
	60	tmp_value.length(res->length());
	61	tmp_value.set_charset(res->charset());
	62	ptr= (char *) res->ptr();
	63	end= ptr + res->length();
	64	tmp= (char *) tmp_value.ptr() + tmp_value.length();
	65	if (use_mb(res->charset()))
	66	{
	67	register uint32_t l;
	68	while (ptr < end)
69	{
70	if ((l= my_ismbchar(res->charset(),ptr,end)))
71	{
72	tmp-= l;
73	memcpy(tmp,ptr,l);
74	ptr+= l;
75	}
76	else
77	--tmp= ptr++;
78	}
79	}
80	else
81	{
82	while (ptr < end)
83	--tmp= ptr++;
84	}
85	return &tmp_value;
86	}
87
88	void ReverseFunction::fix_length_and_dec()
89	{
90	collation.set(args[0]->collation);
91	max_length = args[0]->max_length;
92	}
93
94	plugin::Create_function<ReverseFunction> *reverse_function= NULL;
95
1530.2.6 by Monty Taylor Moved plugin::Context to module::Context.	96	static int initialize(drizzled::module::Context &context)
1300.4.2 by Stewart Smith make REVERSE() a plugin instead of built in function. Generalise the code for such keyword functions otu into reserved_keyword_function() in sql_yacc.	97	{
	98	reverse_function= new plugin::Create_function<ReverseFunction>("reverse");
1324.2.2 by Monty Taylor Use the plugin::Context everywhere.	99	context.add(reverse_function);
1300.4.2 by Stewart Smith make REVERSE() a plugin instead of built in function. Generalise the code for such keyword functions otu into reserved_keyword_function() in sql_yacc.	100	return 0;
	101	}
	102
	103	DRIZZLE_DECLARE_PLUGIN
	104	{
	105	DRIZZLE_VERSION_ID,
	106	"reverse_function",
	107	"1.0",
	108	"Stewart Smith",
	109	"reverses a string",
	110	PLUGIN_LICENSE_GPL,
	111	initialize, /* Plugin Init */
	112	NULL, /* system variables */
	113	NULL /* config options */
	114	}
	115	DRIZZLE_DECLARE_PLUGIN_END;