termux-packages/root-packages/mtr/hsearch/hcreate_r.c

64 lines
2.3 KiB
C

/*-
* Copyright (c) 2015 Nuxi, https://nuxi.nl/
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
//__FBSDID("$FreeBSD$");
#include "search.h"
#include <stdlib.h>
#include "hsearch.h"
int
hcreate_r(size_t nel, struct hsearch_data *htab)
{
struct __hsearch *hsearch;
/*
* Allocate a hash table object. Ignore the provided hint and start
* off with a table of sixteen entries. In most cases this hint is
* just a wild guess. Resizing the table dynamically if the use
* increases a threshold does not affect the worst-case running time.
*/
hsearch = malloc(sizeof(*hsearch));
if (hsearch == NULL)
return 0;
hsearch->entries = calloc(16, sizeof(ENTRY));
if (hsearch->entries == NULL) {
free(hsearch);
return 0;
}
/*
* Pick a random initialization for the FNV-1a hashing. This makes it
* hard to come up with a fixed set of keys to force hash collisions.
*/
arc4random_buf(&hsearch->offset_basis, sizeof(hsearch->offset_basis));
hsearch->index_mask = 0xf;
hsearch->entries_used = 0;
htab->__hsearch = hsearch;
return 1;
}