rm_/lib/hash-triple.c

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2020-09-02 16:47:03 +08:00
/* Hash functions for file-related triples: name, device, inode.
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 "hash-triple.h"
#include <stdlib.h>
#include <string.h>
#include "hash-pjw.h"
#include "same.h"
#include "same-inode.h"
#define STREQ(a, b) (strcmp (a, b) == 0)
/* Hash an F_triple, and *do* consider the file name. */
size_t
triple_hash (void const *x, size_t table_size)
{
struct F_triple const *p = x;
size_t tmp = hash_pjw (p->name, table_size);
/* Ignoring the device number here should be fine. */
return (tmp ^ p->st_ino) % table_size;
}
/* Hash an F_triple, without considering the file name. */
size_t
triple_hash_no_name (void const *x, size_t table_size)
{
struct F_triple const *p = x;
/* Ignoring the device number here should be fine. */
return p->st_ino % table_size;
}
/* Compare two F_triple structs. */
bool
triple_compare (void const *x, void const *y)
{
struct F_triple const *a = x;
struct F_triple const *b = y;
return (SAME_INODE (*a, *b) && same_name (a->name, b->name)) ? true : false;
}
bool
triple_compare_ino_str (void const *x, void const *y)
{
struct F_triple const *a = x;
struct F_triple const *b = y;
return (SAME_INODE (*a, *b) && STREQ (a->name, b->name)) ? true : false;
}
/* Free an F_triple. */
void
triple_free (void *x)
{
struct F_triple *a = x;
free (a->name);
free (a);
}