From b826ab586c9e0a9c0d438a75c28cf3a8ab485929 Mon Sep 17 00:00:00 2001 From: Tom Gundersen Date: Sun, 4 Oct 2015 00:22:41 +0200 Subject: hashmap: refactor hash_func All our hash functions are based on siphash24(), factor out siphash_init() and siphash24_finalize() and pass the siphash state to the hash functions rather than the hash key. This simplifies the hash functions, and in particular makes composition simpler as calling siphash24_compress() repeatedly on separate chunks of input has the same effect as first concatenating the input and then calling siphash23_compress() on the result. --- src/basic/hashmap.c | 32 +++++++++++++++----------------- 1 file changed, 15 insertions(+), 17 deletions(-) (limited to 'src/basic/hashmap.c') diff --git a/src/basic/hashmap.c b/src/basic/hashmap.c index 7d2a4160c6..3c05bee56d 100644 --- a/src/basic/hashmap.c +++ b/src/basic/hashmap.c @@ -276,10 +276,8 @@ static const struct hashmap_type_info hashmap_type_info[_HASHMAP_TYPE_MAX] = { }, }; -unsigned long string_hash_func(const void *p, const uint8_t hash_key[HASH_KEY_SIZE]) { - uint64_t u; - siphash24((uint8_t*) &u, p, strlen(p), hash_key); - return (unsigned long) u; +void string_hash_func(const void *p, struct siphash *state) { + siphash24_compress(p, strlen(p), state); } int string_compare_func(const void *a, const void *b) { @@ -291,10 +289,8 @@ const struct hash_ops string_hash_ops = { .compare = string_compare_func }; -unsigned long trivial_hash_func(const void *p, const uint8_t hash_key[HASH_KEY_SIZE]) { - uint64_t u; - siphash24((uint8_t*) &u, &p, sizeof(p), hash_key); - return (unsigned long) u; +void trivial_hash_func(const void *p, struct siphash *state) { + siphash24_compress(&p, sizeof(p), state); } int trivial_compare_func(const void *a, const void *b) { @@ -306,10 +302,8 @@ const struct hash_ops trivial_hash_ops = { .compare = trivial_compare_func }; -unsigned long uint64_hash_func(const void *p, const uint8_t hash_key[HASH_KEY_SIZE]) { - uint64_t u; - siphash24((uint8_t*) &u, p, sizeof(uint64_t), hash_key); - return (unsigned long) u; +void uint64_hash_func(const void *p, struct siphash *state) { + siphash24_compress(p, sizeof(uint64_t), state); } int uint64_compare_func(const void *_a, const void *_b) { @@ -325,10 +319,8 @@ const struct hash_ops uint64_hash_ops = { }; #if SIZEOF_DEV_T != 8 -unsigned long devt_hash_func(const void *p, const uint8_t hash_key[HASH_KEY_SIZE]) { - uint64_t u; - siphash24((uint8_t*) &u, p, sizeof(dev_t), hash_key); - return (unsigned long) u; +void devt_hash_func(const void *p, struct siphash *state) { + siphash24_compress(p, sizeof(dev_t), state); } int devt_compare_func(const void *_a, const void *_b) { @@ -379,7 +371,13 @@ static uint8_t *hash_key(HashmapBase *h) { } static unsigned base_bucket_hash(HashmapBase *h, const void *p) { - return (unsigned) (h->hash_ops->hash(p, hash_key(h)) % n_buckets(h)); + struct siphash state; + + siphash_init(&state, hash_key(h)); + + h->hash_ops->hash(p, &state); + + return (unsigned) (siphash24_finalize(&state) % n_buckets(h)); } #define bucket_hash(h, p) base_bucket_hash(HASHMAP_BASE(h), p) -- cgit v1.2.3-54-g00ecf