+#ifndef TINC_HASH_H
+#define TINC_HASH_H
+
/*
hash.h -- header file for hash.c
- Copyright (C) 2012 Guus Sliepen <guus@tinc-vpn.org>
+ Copyright (C) 2012-2022 Guus Sliepen <guus@tinc-vpn.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-#ifndef __TINC_HASH_H__
-#define __TINC_HASH_H__
-typedef struct hash_t {
- size_t n;
- size_t size;
- char *keys;
- const void **values;
-} hash_t;
+/* Map 32 bits int onto 0..n-1, without throwing away too many bits if n is 2^8 or 2^16 */
+
+uint32_t modulo(uint32_t hash, size_t n);
+
+#define HASH_SEARCH_ITERATIONS 4
-extern hash_t *hash_alloc(size_t n, size_t size) __attribute__ ((__malloc__));
-extern void hash_free(hash_t *);
+#define hash_insert(t, ...) hash_insert_ ## t (__VA_ARGS__)
+#define hash_delete(t, ...) hash_delete_ ## t (__VA_ARGS__)
+#define hash_search(t, ...) hash_search_ ## t (__VA_ARGS__)
+#define hash_clear(t, n) hash_clear_ ## t ((n))
-extern void hash_insert(hash_t *, const void *key, const void *value);
+#define hash_define(t, n) \
+ typedef struct hash_ ## t { \
+ t keys[n]; \
+ const void *values[n]; \
+ } hash_ ## t; \
+ static inline uint32_t hash_modulo_ ## t(uint32_t hash) { \
+ return hash & (n - 1); \
+ } \
+ static inline void hash_insert_ ## t (hash_ ##t *hash, const t *key, const void *value) { \
+ uint32_t i = hash_modulo_ ## t(hash_function_ ## t(key)); \
+ for(uint8_t f=0; f< (HASH_SEARCH_ITERATIONS - 1); f++){ \
+ if(hash->values[i] == NULL || !memcmp(key, &hash->keys[i], sizeof(t))) { \
+ memcpy(&hash->keys[i], key, sizeof(t)); \
+ hash->values[i] = value; \
+ return; \
+ } \
+ if(++i == n) i = 0; \
+ } \
+ /* We always pick the last slot. It's unfair. But thats life */ \
+ memcpy(&hash->keys[i], key, sizeof(t)); \
+ hash->values[i] = value; \
+ } \
+ static inline void *hash_search_ ## t (const hash_ ##t *hash, const t *key) { \
+ uint32_t i = hash_modulo_ ## t(hash_function_ ## t(key)); \
+ for(uint8_t f=0; f<HASH_SEARCH_ITERATIONS; f++){ \
+ if(!memcmp(key, &hash->keys[i], sizeof(t))) { \
+ return (void *)hash->values[i]; \
+ } \
+ if(++i == n) i = 0; \
+ } \
+ return NULL; \
+ } \
+ static inline void hash_delete_ ## t (hash_ ##t *hash, const t *key) { \
+ uint32_t i = hash_modulo_ ## t(hash_function_ ## t(key)); \
+ for(uint8_t f=0; f<HASH_SEARCH_ITERATIONS; f++){ \
+ if(!memcmp(key, &hash->keys[i], sizeof(t))) { \
+ hash->values[i] = NULL; \
+ return; \
+ } \
+ if(++i == n) i = 0; \
+ } \
+ } \
+ static inline void hash_clear_ ## t(hash_ ##t *hash) { \
+ memset(hash->values, 0, n * sizeof(*hash->values)); \
+ memset(hash->keys, 0, n * sizeof(*hash->keys)); \
+ }
-extern void *hash_search(const hash_t *, const void *key);
-extern void *hash_search_or_insert(hash_t *, const void *key, const void *value);
-extern void hash_clear(hash_t *);
-extern void hash_resize(hash_t *, size_t n);
+#define hash_new(t, name) static hash_ ## t name
-#endif /* __TINC_HASH_H__ */
+#endif