~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

 *

 *  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 <drizzled/server_includes.h>

#include CSTDINT_H

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

#include <drizzled/error.h>

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

#include <drizzled/session.h>

void Item_func_repeat::fix_length_and_dec()

{

  collation.set(args[0]->collation);

  if (args[1]->const_item())

  {

    /* must be int64_t to avoid truncation */

    int64_t count= args[1]->val_int();

    /* Assumes that the maximum length of a String is < INT32_MAX. */

    /* Set here so that rest of code sees out-of-bound value as such. */

    if (count > INT32_MAX)

      count= INT32_MAX;

    uint64_t max_result_length= (uint64_t) args[0]->max_length * count;

    if (max_result_length >= MAX_BLOB_WIDTH)

    {

      max_result_length= MAX_BLOB_WIDTH;

      maybe_null= 1;

    }

    max_length= (ulong) max_result_length;

  }

  else

  {

    max_length= MAX_BLOB_WIDTH;

    maybe_null= 1;

  }

}

/**

  Item_func_repeat::str is carefully written to avoid reallocs

  as much as possible at the cost of a local buffer

*/

String *Item_func_repeat::val_str(String *str)

{

  assert(fixed == 1);

  uint32_t length,tot_length;

  char *to;

  /* must be int64_t to avoid truncation */

  int64_t count= args[1]->val_int();

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

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

    goto err;                           // string and/or delim are null

  null_value= 0;

  if (count <= 0 && (count == 0 || !args[1]->unsigned_flag))

    return &my_empty_string;

  /* Assumes that the maximum length of a String is < INT32_MAX. */

  /* Bounds check on count:  If this is triggered, we will error. */

  if ((uint64_t) count > INT32_MAX)

    count= INT32_MAX;

  if (count == 1)                       // To avoid reallocs

    return res;

  length=res->length();

  // Safe length check

  if (length > current_session->variables.max_allowed_packet / (uint) count)

  {

    push_warning_printf(current_session, DRIZZLE_ERROR::WARN_LEVEL_WARN,

                        ER_WARN_ALLOWED_PACKET_OVERFLOWED,

                        ER(ER_WARN_ALLOWED_PACKET_OVERFLOWED),

                        func_name(), current_session->variables.max_allowed_packet);

    goto err;

  }

  tot_length= length*(uint) count;

  if (!(res= alloc_buffer(res,str,&tmp_value,tot_length)))

    goto err;

  to=(char*) res->ptr()+length;

  while (--count)

  {

    memcpy(to,res->ptr(),length);

    to+=length;

  }

  return (res);

err:

  null_value=1;

  return 0;

}