64 lines
2.3 KiB
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;
|
||
|
|
}
|