~drizzle-trunk/drizzle/development

/* Copyright (C) 2000 MySQL AB

   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

#include "mysys_priv.h"

#include "my_static.h"

#include <mystrings/m_string.h>

/*

  set how many open files we want to be able to handle

  SYNOPSIS

    set_maximum_open_files()

    max_file_limit		Files to open

  NOTES

    The request may not fulfilled becasue of system limitations

  RETURN

    Files available to open.

    May be more or less than max_file_limit!

*/

#if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)

#ifndef RLIM_INFINITY

#define RLIM_INFINITY ((uint) 0xffffffff)

#endif

static uint set_max_open_files(uint max_file_limit)

{

  struct rlimit rlimit;

  uint old_cur;

  if (!getrlimit(RLIMIT_NOFILE,&rlimit))

  {

    old_cur= (uint) rlimit.rlim_cur;

    if (rlimit.rlim_cur == RLIM_INFINITY)

      rlimit.rlim_cur = max_file_limit;

    if (rlimit.rlim_cur >= max_file_limit)

      return(rlimit.rlim_cur);		/* purecov: inspected */

    rlimit.rlim_cur= rlimit.rlim_max= max_file_limit;

    if (setrlimit(RLIMIT_NOFILE, &rlimit))

      max_file_limit= old_cur;			/* Use original value */

    else

    {

      rlimit.rlim_cur= 0;			/* Safety if next call fails */

      (void) getrlimit(RLIMIT_NOFILE,&rlimit);

      if (rlimit.rlim_cur)			/* If call didn't fail */

	max_file_limit= (uint) rlimit.rlim_cur;

    }

  }

  return(max_file_limit);

}

#else

static int set_max_open_files(uint max_file_limit)

{

  /* We don't know the limit. Return best guess */

  return cmin(max_file_limit, OS_FILE_LIMIT);

}

#endif

/*

  Change number of open files

  SYNOPSIS:

    my_set_max_open_files()

    files		Number of requested files

  RETURN

    number of files available for open

*/

uint my_set_max_open_files(uint files)

{

  struct st_my_file_info *tmp;

  files= set_max_open_files(cmin(files, OS_FILE_LIMIT));

  if (files <= MY_NFILE)

    return(files);

  if (!(tmp= (struct st_my_file_info*) my_malloc(sizeof(*tmp) * files,

						 MYF(MY_WME))))

    return(MY_NFILE);

  /* Copy any initialized files */

  memcpy(tmp, my_file_info, sizeof(*tmp) * cmin(my_file_limit, files));

  /*

    The int cast is necessary since 'my_file_limits' might be greater

    than 'files'.

  */

  memset(tmp + my_file_limit, 0,

         cmax((int) (files - my_file_limit), 0)*sizeof(*tmp));

  my_free_open_file_info();			/* Free if already allocated */

  my_file_info= tmp;

  my_file_limit= files;

  return(files);

}

void my_free_open_file_info()

{

  if (my_file_info != my_file_info_default)

  {

    /* Copy data back for my_print_open_files */

    memcpy(my_file_info_default, my_file_info,

           sizeof(*my_file_info_default)* MY_NFILE);

    my_free((char*) my_file_info, MYF(0));

    my_file_info= my_file_info_default;

    my_file_limit= MY_NFILE;

  }

  return;

}