~drizzle-trunk/drizzle/development

/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-

 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:

 *

 *  Copyright (C) 2008 Sun Microsystems

 *  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/session.h>

using namespace std;

using namespace drizzled;

#include <drizzled/function/str/strfunc.h>

class UserFunction :public Item_str_func

{

protected:

  bool init (const char *user, const char *host);

public:

  UserFunction()

  {

    str_value.set("", 0, system_charset_info);

  }

  String *val_str(String *)

  {

    assert(fixed == 1);

    return (null_value ? 0 : &str_value);

  }

  bool fix_fields(Session *session, Item **ref);

  void fix_length_and_dec()

  {

    max_length= (USERNAME_CHAR_LENGTH + HOSTNAME_LENGTH + 1) *

                system_charset_info->mbmaxlen;

  }

  const char *func_name() const { return "user"; }

  const char *fully_qualified_func_name() const { return "user()"; }

  int save_in_field(Field *field,

                    bool )

  {

    return save_str_value_in_field(field, &str_value);

  }

};

/**

  @todo

  make USER() replicate properly (currently it is replicated to "")

*/

bool UserFunction::init(const char *user, const char *host)

{

  assert(fixed == 1);

  // For system threads (e.g. replication SQL thread) user may be empty

  if (user)

  {

    const CHARSET_INFO * const cs= str_value.charset();

    uint32_t res_length= (strlen(user)+strlen(host)+2) * cs->mbmaxlen;

    if (str_value.alloc(res_length))

    {

      null_value=1;

      return true;

    }

    res_length=cs->cset->snprintf(cs, (char*)str_value.ptr(), res_length,

                                  "%s@%s", user, host);

    str_value.length(res_length);

    str_value.mark_as_const();

  }

  return false;

}

bool UserFunction::fix_fields(Session *session, Item **ref)

{

  return (Item_str_func::fix_fields(session, ref) ||

          init(session->getSecurityContext().getUser().c_str(),

               session->getSecurityContext().getIp().c_str()));

}

plugin::Create_function<UserFunction> *user_function= NULL;

static int initialize(drizzled::module::Context &context)

{

  user_function= new plugin::Create_function<UserFunction>("user");

  context.add(user_function);

  return 0;

}

DRIZZLE_DECLARE_PLUGIN

{

  DRIZZLE_VERSION_ID,

  "user_function",

  "1.0",

  "Stewart Smith",

  "USER() and CURRENT_USER()",

  PLUGIN_LICENSE_GPL,

  initialize, /* Plugin Init */

  NULL,   /* system variables */

  NULL    /* config options */

}

DRIZZLE_DECLARE_PLUGIN_END;