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    Length: 3887 (0xf2f)
    Types: TextFile
    Names: »gdbmreorg.c«

└─⟦a05ed705a⟧ Bits:30007078 DKUUG GNU 2/12/89
    └─⟦0befd2614⟧ »./gdbm-0.8.tar.Z« 
        └─⟦b993d2893⟧ 
            └─⟦this⟧ »gdbm/gdbmreorg.c« 

TextFile

/* gdbmreorg.c - Reorganize the database file. */

/*  GNU DBM  - DataBase Manager (database subroutines) by Philip A. Nelson
    Copyright (C) 1989  Free Software Foundation, 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.

    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., 675 Mass Ave, Cambridge, MA 02139, USA.

    You may contact the author by:
       e-mail:  phil@wwu.edu
      us-mail:  Philip A. Nelson
                Computer Science Department
                Western Washington University
                Bellingham, WA 98226
        phone:  (206) 676-3035
       
************************************************************************/


#include <stdio.h>
#include <sys/file.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "gdbm.h"
#include "gdbmerrno.h"
extern gdbm_error gdbm_errno;
#include "extern.h"


/* Reorganize the database.  This requires creating a new file and inserting
   all the elements in the old file DBF into the new file.  The new file
   is then renamed to the same name as the old file and DBF is updated to
   contain all the correct information about the new file. */

gdbm_reorganize (dbf)
     dbm_file_info *dbf;

{
  dbm_file_info *new_dbf;
  char *new_name;
  int  len;
  datum key, nextkey, data;
  struct stat fileinfo;
  int fd;

  /* Readers can not reorganize! */
  if (dbf->read_write != DBM_WRITER)
    {
      gdbm_errno = READER_CANT_REORGANIZE;
      return -1;
    }

  /* Construct new name for temporary file. */
  len = strlen (dbf->name);
  new_name = (char *) malloc (len + 3);
  if (new_name == NULL)
    {
      gdbm_errno = MALLOC_ERROR;
      return -1;
    }
  strcpy (&new_name[1], dbf->name);
  new_name[0] = '#';
  new_name[len+1] = '#';
  new_name[len+2] = 0;

  /* Touch new file and open with gdbm. */
  fstat(dbf->desc,&fileinfo);
  close(fd = open(new_name,O_RDWR|O_CREAT,fileinfo.st_mode));


  new_dbf = gdbm_open (new_name, dbf->header.block_size, DBM_WRITER,
		       dbf->fatal_err);

  if (new_dbf == NULL)
    {
      gdbm_errno = REORGANIZE_FAILED;
      free(new_name);
      return -1;
    }

  if (dbf->header.update_state == -1)
    gdbm_recovery (new_dbf, FALSE);
  
  /* For each item in the old database, add an entry in the new. */
  key = gdbm_firstkey (dbf);

  while (key.dptr != NULL)
    {
      data = gdbm_fetch (dbf, key);
      if (data.dptr != NULL)
	{
	  /* Add the data to the new file. */
	  gdbm_store (new_dbf, key, data);
	}
      else
	{
	  /* ERROR! Abort and don't finish reorganize. */
	  gdbm_close (new_dbf);
	  gdbm_errno = REORGANIZE_FAILED;
	  unlink (new_name);
	  return -1;
	}
      nextkey = gdbm_nextkey (dbf, key);
      free(key.dptr);
      key = nextkey;
    }

 
  /* Move the new file to old name. */

  if (rename (new_name, dbf->name) != 0)
    {
      gdbm_errno = REORGANIZE_FAILED;
      gdbm_close (new_dbf);
      return -1;
    }

  /* Fix up DBF to have the correct information for the new file. */
  flock (dbf->desc, LOCK_UN);
  close (dbf->desc);
  free (dbf->dir);
  free (dbf->bucket);
  free (dbf->avail);
  dbf->desc       = new_dbf->desc;
  dbf->header     = new_dbf->header;
  dbf->dir        = new_dbf->dir;
  dbf->bucket     = new_dbf->bucket;
  dbf->bucket_adr = new_dbf->bucket_adr;
  dbf->bucket_dir = new_dbf->bucket_dir;
  dbf->avail      = new_dbf->avail;
  dbf->avail_adr  = new_dbf->avail_adr;
  free(new_dbf);

  return 0;
}