~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 <m_string.h>

#include "my_static.h"

#include "mysys_err.h"

#include <errno.h>

#ifdef HAVE_PATHS_H

#include <paths.h>

#endif

/*

  @brief

  Create a temporary file with unique name in a given directory

  @details

  create_temp_file

    to             pointer to buffer where temporary filename will be stored

    dir            directory where to create the file

    prefix         prefix the filename with this

    mode           Flags to use for my_create/my_open

    MyFlags        Magic flags

  @return

    File descriptor of opened file if success

    -1 and sets errno if fails.

  @note

    The behaviour of this function differs a lot between

    implementation, it's main use is to generate a file with

    a name that does not already exist.

    When passing O_TEMPORARY flag in "mode" the file should

    be automatically deleted

    The implementation using mkstemp should be considered the

    reference implementation when adding a new or modifying an

    existing one

*/

File create_temp_file(char *to, const char *dir, const char *prefix,

		      int mode __attribute__((unused)),

		      myf MyFlags __attribute__((unused)))

{

  File file= -1;

  DBUG_ENTER("create_temp_file");

  DBUG_PRINT("enter", ("dir: %s, prefix: %s", dir, prefix));

#if defined(_ZTC__)

  if (!dir)

    dir=getenv("TMPDIR");

  if ((res=tempnam((char*) dir,(char *) prefix)))

  {

    strmake(to,res,FN_REFLEN-1);

    (*free)(res);

    file=my_create(to, 0, mode | O_EXCL | O_NOFOLLOW, MyFlags);

  }

#elif defined(HAVE_MKSTEMP)

  {

    char prefix_buff[30];

    uint pfx_len;

    File org_file;

    pfx_len= (uint) (strmov(strnmov(prefix_buff,

				    prefix ? prefix : "tmp.",

				    sizeof(prefix_buff)-7),"XXXXXX") -

		     prefix_buff);

    if (!dir && ! (dir =getenv("TMPDIR")))

      dir=P_tmpdir;

    if (strlen(dir)+ pfx_len > FN_REFLEN-2)

    {

      errno=my_errno= ENAMETOOLONG;

      DBUG_RETURN(file);

    }

    strmov(convert_dirname(to,dir,NullS),prefix_buff);

    org_file=mkstemp(to);

    if (mode & O_TEMPORARY)

      (void) my_delete(to, MYF(MY_WME | ME_NOINPUT));

    file=my_register_filename(org_file, to, FILE_BY_MKSTEMP,

			      EE_CANTCREATEFILE, MyFlags);

    /* If we didn't manage to register the name, remove the temp file */

    if (org_file >= 0 && file < 0)

    {

      int tmp=my_errno;

      close(org_file);

      (void) my_delete(to, MYF(MY_WME | ME_NOINPUT));

      my_errno=tmp;

    }

  }

#elif defined(HAVE_TEMPNAM)

  {

    char *res,**old_env,*temp_env[1];

    if (dir && !dir[0])

    {				/* Change empty string to current dir */

      to[0]= FN_CURLIB;

      to[1]= 0;

      dir=to;

    }

    old_env= (char**) environ;

    if (dir)

    {				/* Don't use TMPDIR if dir is given */

      environ=(const char**) temp_env;

      temp_env[0]=0;

    }

    if ((res=tempnam((char*) dir, (char*) prefix)))

    {

      strmake(to,res,FN_REFLEN-1);

      (*free)(res);

      file=my_create(to,0,

		     (int) (O_RDWR | O_BINARY | O_TRUNC | O_EXCL | O_NOFOLLOW |

			    O_TEMPORARY | O_SHORT_LIVED),

		     MYF(MY_WME));

    }

    else

    {

      DBUG_PRINT("error",("Got error: %d from tempnam",errno));

    }

    environ=(const char**) old_env;

  }

#else

#error No implementation found for create_temp_file

#endif

  if (file >= 0)

    thread_safe_increment(my_tmp_file_created,&THR_LOCK_open);

  DBUG_RETURN(file);

}