|
Packit |
fd8b60 |
/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
|
|
Packit |
fd8b60 |
/* include/k5-hash.h - hash table interface definitions */
|
|
Packit |
fd8b60 |
/*
|
|
Packit |
fd8b60 |
* Copyright (C) 2018 by the Massachusetts Institute of Technology.
|
|
Packit |
fd8b60 |
* All rights reserved.
|
|
Packit |
fd8b60 |
*
|
|
Packit |
fd8b60 |
* Redistribution and use in source and binary forms, with or without
|
|
Packit |
fd8b60 |
* modification, are permitted provided that the following conditions
|
|
Packit |
fd8b60 |
* are met:
|
|
Packit |
fd8b60 |
*
|
|
Packit |
fd8b60 |
* * Redistributions of source code must retain the above copyright
|
|
Packit |
fd8b60 |
* notice, this list of conditions and the following disclaimer.
|
|
Packit |
fd8b60 |
*
|
|
Packit |
fd8b60 |
* * Redistributions in binary form must reproduce the above copyright
|
|
Packit |
fd8b60 |
* notice, this list of conditions and the following disclaimer in
|
|
Packit |
fd8b60 |
* the documentation and/or other materials provided with the
|
|
Packit |
fd8b60 |
* distribution.
|
|
Packit |
fd8b60 |
*
|
|
Packit |
fd8b60 |
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
Packit |
fd8b60 |
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
Packit |
fd8b60 |
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
Packit |
fd8b60 |
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
Packit |
fd8b60 |
* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
|
|
Packit |
fd8b60 |
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
|
Packit |
fd8b60 |
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
|
Packit |
fd8b60 |
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
Packit |
fd8b60 |
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
|
|
Packit |
fd8b60 |
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
Packit |
fd8b60 |
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
|
|
Packit |
fd8b60 |
* OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
Packit |
fd8b60 |
*/
|
|
Packit |
fd8b60 |
|
|
Packit |
fd8b60 |
/*
|
|
Packit |
fd8b60 |
* This file contains declarations for a simple hash table using siphash. Some
|
|
Packit |
fd8b60 |
* limitations which might need to be addressed in the future:
|
|
Packit |
fd8b60 |
*
|
|
Packit |
fd8b60 |
* - The table does not manage caller memory. This limitation could be
|
|
Packit |
fd8b60 |
* addressed by adding an optional free callback to k5_hashtab_create(), to
|
|
Packit |
fd8b60 |
* be called by k5_hashtab_free() and k5_hashtab_remove().
|
|
Packit |
fd8b60 |
*
|
|
Packit |
fd8b60 |
* - There is no way to iterate over a hash table.
|
|
Packit |
fd8b60 |
*
|
|
Packit |
fd8b60 |
* - k5_hashtab_add() does not check for duplicate entries.
|
|
Packit |
fd8b60 |
*/
|
|
Packit |
fd8b60 |
|
|
Packit |
fd8b60 |
#ifndef K5_HASH_H
|
|
Packit |
fd8b60 |
#define K5_HASH_H
|
|
Packit |
fd8b60 |
|
|
Packit |
fd8b60 |
#define K5_HASH_SEED_LEN 16
|
|
Packit |
fd8b60 |
|
|
Packit |
fd8b60 |
struct k5_hashtab;
|
|
Packit |
fd8b60 |
|
|
Packit |
fd8b60 |
/*
|
|
Packit |
fd8b60 |
* Create a new hash table in *ht_out. seed must point to random bytes if keys
|
|
Packit |
fd8b60 |
* might be under the control of an attacker; otherwise it may be NULL.
|
|
Packit |
fd8b60 |
* initial_buckets controls the initial allocation of hash buckets; pass zero
|
|
Packit |
fd8b60 |
* to use a default value. The number of hash buckets will be doubled as the
|
|
Packit |
fd8b60 |
* number of entries increases. Return 0 on success, ENOMEM on failure.
|
|
Packit |
fd8b60 |
*/
|
|
Packit |
fd8b60 |
int k5_hashtab_create(const uint8_t seed[K5_HASH_SEED_LEN],
|
|
Packit |
fd8b60 |
size_t initial_buckets, struct k5_hashtab **ht_out);
|
|
Packit |
fd8b60 |
|
|
Packit |
fd8b60 |
/* Release the memory used by a hash table. Keys and values are the caller's
|
|
Packit |
fd8b60 |
* responsibility. */
|
|
Packit |
fd8b60 |
void k5_hashtab_free(struct k5_hashtab *ht);
|
|
Packit |
fd8b60 |
|
|
Packit |
fd8b60 |
/* Add an entry to a hash table. key and val must remain valid until the entry
|
|
Packit |
fd8b60 |
* is removed or the hash table is freed. The caller must avoid duplicates. */
|
|
Packit |
fd8b60 |
int k5_hashtab_add(struct k5_hashtab *ht, const void *key, size_t klen,
|
|
Packit |
fd8b60 |
void *val);
|
|
Packit |
fd8b60 |
|
|
Packit |
fd8b60 |
/* Remove an entry from a hash table by key. Does not free key or the
|
|
Packit |
fd8b60 |
* associated value. Return 1 if the key was found and removed, 0 if not. */
|
|
Packit |
fd8b60 |
int k5_hashtab_remove(struct k5_hashtab *ht, const void *key, size_t klen);
|
|
Packit |
fd8b60 |
|
|
Packit |
fd8b60 |
/* Retrieve a value from a hash table by key. */
|
|
Packit |
fd8b60 |
void *k5_hashtab_get(struct k5_hashtab *ht, const void *key, size_t klen);
|
|
Packit |
fd8b60 |
|
|
Packit |
fd8b60 |
uint64_t k5_siphash24(const uint8_t *data, size_t len,
|
|
Packit |
fd8b60 |
const uint8_t seed[K5_HASH_SEED_LEN]);
|
|
Packit |
fd8b60 |
|
|
Packit |
fd8b60 |
#endif /* K5_HASH_H */
|