~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, Inc.

 *

 *  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/function/str/insert.h>

#include <drizzled/error.h>

#include <drizzled/session.h>

namespace drizzled

{

String *Item_func_insert::val_str(String *str)

{

  assert(fixed == 1);

  String *res,*res2;

  int64_t start, length;  /* must be int64_t to avoid truncation */

  null_value=0;

  res=args[0]->val_str(str);

  res2=args[3]->val_str(&tmp_value);

  start= args[1]->val_int() - 1;

  length= args[2]->val_int();

  if (args[0]->null_value || args[1]->null_value || args[2]->null_value ||

      args[3]->null_value)

    goto null;

  if ((start < 0) || (start > static_cast<int64_t>(res->length())))

    return res;                                 // Wrong param; skip insert

  if ((length < 0) || (length > static_cast<int64_t>(res->length())))

    length= res->length();

  /* start and length are now sufficiently valid to pass to charpos function */

   start= res->charpos((int) start);

   length= res->charpos((int) length, (uint32_t) start);

  /* Re-testing with corrected params */

  if (start > static_cast<int64_t>(res->length()))

    return res;

  if (length > static_cast<int64_t>(res->length()) - start)

    length= res->length() - start;

  if ((uint64_t) (res->length() - length + res2->length()) >

      (uint64_t) session.variables.max_allowed_packet)

  {

    push_warning_printf(&session, DRIZZLE_ERROR::WARN_LEVEL_WARN,

			ER_WARN_ALLOWED_PACKET_OVERFLOWED,

			ER(ER_WARN_ALLOWED_PACKET_OVERFLOWED),

			func_name(), session.variables.max_allowed_packet);

    goto null;

  }

  res=copy_if_not_alloced(str,res,res->length());

  res->replace((uint32_t) start,(uint32_t) length,*res2);

  return res;

null:

  null_value=1;

  return 0;

}

void Item_func_insert::fix_length_and_dec()

{

  uint64_t max_result_length;

  // Handle character set for args[0] and args[3].

  if (agg_arg_charsets(collation, &args[0], 2, MY_COLL_ALLOW_CONV, 3))

    return;

  max_result_length= ((uint64_t) args[0]->max_length+

                      (uint64_t) args[3]->max_length);

  if (max_result_length >= MAX_BLOB_WIDTH)

  {

    max_result_length= MAX_BLOB_WIDTH;

    maybe_null= 1;

  }

  max_length= (ulong) max_result_length;

}

} /* namespace drizzled */