gnulib/lib/file-set.c

/* Specialized functions to manipulate a set of files.
   Copyright (C) 2007, 2009-2020 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; either version 3 of the License, or
   (at your option) any later version.

   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, see <https://www.gnu.org/licenses/>.  */

/* written by Jim Meyering */

#include <config.h>
#include "file-set.h"

#include "hash-triple.h"
#include "xalloc.h"

/* Record file, FILE, and dev/ino from *STATS, in the hash table, HT.
   If HT is NULL, return immediately.
   If memory allocation fails, exit immediately.  */
void
record_file (Hash_table *ht, char const *file, struct stat const *stats)
{
  struct F_triple *ent;

  if (ht == NULL)
    return;

  ent = xmalloc (sizeof *ent);
  ent->name = xstrdup (file);
  ent->st_ino = stats->st_ino;
  ent->st_dev = stats->st_dev;

  {
    struct F_triple *ent_from_table = hash_insert (ht, ent);
    if (ent_from_table == NULL)
      {
        /* Insertion failed due to lack of memory.  */
        xalloc_die ();
      }

    if (ent_from_table != ent)
      {
        /* There was already a matching entry in the table, so ENT was
           not inserted.  Free it.  */
        triple_free (ent);
      }
  }
}

/* Return true if there is an entry in hash table, HT,
   for the file described by FILE and STATS.  */
bool
seen_file (Hash_table const *ht, char const *file,
           struct stat const *stats)
{
  struct F_triple new_ent;

  if (ht == NULL)
    return false;

  new_ent.name = (char *) file;
  new_ent.st_ino = stats->st_ino;
  new_ent.st_dev = stats->st_dev;

  return !!hash_lookup (ht, &new_ent);
}