From 71eeedd1a05d5dd200c77527ea15086bf43e1a26 Mon Sep 17 00:00:00 2001 From: Dimitri Staessens Date: Wed, 12 Feb 2020 22:31:17 +0100 Subject: lib: Move hashtable from lib to unicast The hashtable is only used for forwarding tables in the unicast IPCP. This moves the generic hashtable out of the library into the unicast IPCP to prepare a more tailored implementation specific to routing tables containing address lists. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders --- src/ipcpd/unicast/pol/hashtable.c | 222 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 222 insertions(+) create mode 100644 src/ipcpd/unicast/pol/hashtable.c (limited to 'src/ipcpd/unicast/pol/hashtable.c') diff --git a/src/ipcpd/unicast/pol/hashtable.c b/src/ipcpd/unicast/pol/hashtable.c new file mode 100644 index 00000000..596219f3 --- /dev/null +++ b/src/ipcpd/unicast/pol/hashtable.c @@ -0,0 +1,222 @@ +/* + * Ouroboros - Copyright (C) 2016 - 2020 + * + * Hash table with integer keys with separate chaining on collisions + * + * Dimitri Staessens + * Sander Vrijders + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * 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, write to the Free Software + * Foundation, Inc., http://www.fsf.org/about/contact/. + */ + +#if defined(__linux__) || defined(__CYGWIN__) +#define _DEFAULT_SOURCE +#endif + +#include +#include +#include + +#include "hashtable.h" + +#include +#include + +struct htable_entry { + struct list_head next; + uint64_t key; + void * val; + size_t len; +}; + +struct htable { + struct list_head * buckets; + bool hash_key; + uint64_t buckets_size; +}; + +struct htable * htable_create(uint64_t buckets, + bool hash_key) +{ + struct htable * tmp; + unsigned int i; + + if (buckets == 0) + return NULL; + + buckets--; + buckets |= buckets >> 1; + buckets |= buckets >> 2; + buckets |= buckets >> 4; + buckets |= buckets >> 8; + buckets |= buckets >> 16; + buckets |= buckets >> 32; + buckets++; + + tmp = malloc(sizeof(*tmp)); + if (tmp == NULL) + return NULL; + + tmp->hash_key = hash_key; + tmp->buckets_size = buckets; + + tmp->buckets = malloc(buckets * sizeof(*tmp->buckets)); + if (tmp->buckets == NULL) { + free(tmp); + return NULL; + } + + for (i = 0; i < buckets; i++) + list_head_init(&(tmp->buckets[i])); + + return tmp; +} + +void htable_destroy(struct htable * table) +{ + assert(table); + assert(table->buckets); + + htable_flush(table); + free(table->buckets); + free(table); +} + +void htable_flush(struct htable * table) +{ + unsigned int i; + struct list_head * pos = NULL; + struct list_head * n = NULL; + struct htable_entry * entry; + + assert(table); + + for (i = 0; i < table->buckets_size; i++) { + list_for_each_safe(pos, n, &(table->buckets[i])) { + entry = list_entry(pos, struct htable_entry, next); + list_del(&entry->next); + free(entry->val); + free(entry); + } + } +} + +static uint64_t hash(uint64_t key) +{ + void * res; + uint64_t ret; + uint8_t keys[4]; + + memcpy(keys, &key, 4); + + mem_hash(HASH_MD5, &res, keys, 4); + + ret = (* (uint64_t *) res); + + free(res); + + return ret; +} + +static uint64_t calc_key(struct htable * table, + uint64_t key) +{ + if (table->hash_key) + key = hash(key); + + return (key & (table->buckets_size - 1)); +} + +int htable_insert(struct htable * table, + uint64_t key, + void * val, + size_t len) +{ + struct htable_entry * entry; + uint64_t lookup_key; + struct list_head * pos = NULL; + + assert(table); + + lookup_key = calc_key(table, key); + + list_for_each(pos, &(table->buckets[lookup_key])) { + entry = list_entry(pos, struct htable_entry, next); + if (entry->key == key) + return -1; + } + + entry = malloc(sizeof(*entry)); + if (entry == NULL) + return -ENOMEM; + + entry->key = key; + entry->val = val; + entry->len = len; + list_head_init(&entry->next); + + list_add(&entry->next, &(table->buckets[lookup_key])); + + return 0; +} + +int htable_lookup(struct htable * table, + uint64_t key, + void ** val, + size_t * len) +{ + struct htable_entry * entry; + struct list_head * pos = NULL; + uint64_t lookup_key; + + assert(table); + + lookup_key = calc_key(table, key); + + list_for_each(pos, &(table->buckets[lookup_key])) { + entry = list_entry(pos, struct htable_entry, next); + if (entry->key == key) { + *val = entry->val; + *len = entry->len; + return 0; + } + } + + return -1; +} + +int htable_delete(struct htable * table, + uint64_t key) +{ + struct htable_entry * entry; + uint64_t lookup_key; + struct list_head * pos = NULL; + struct list_head * n = NULL; + + assert(table); + + lookup_key = calc_key(table, key); + + list_for_each_safe(pos, n, &(table->buckets[lookup_key])) { + entry = list_entry(pos, struct htable_entry, next); + if (entry->key == key) { + list_del(&entry->next); + free(entry->val); + free(entry); + return 0; + } + } + + return -1; +} -- cgit v1.2.3