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-rw-r--r--src/ipcpd/unicast/pol/hashtable.c222
1 files changed, 222 insertions, 0 deletions
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 <dimitri.staessens@ugent.be>
+ * Sander Vrijders <sander.vrijders@ugent.be>
+ *
+ * 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 <ouroboros/list.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/hash.h>
+
+#include "hashtable.h"
+
+#include <assert.h>
+#include <string.h>
+
+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;
+}