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authorJan Moskyto Matejka <mq@ucw.cz>2016-05-12 16:16:25 +0200
committerJan Moskyto Matejka <mq@ucw.cz>2016-05-12 16:16:25 +0200
commit54ac0beceedb9b36eb58dd8599ba903c668382f6 (patch)
tree5e163d4c82e265b3c254301857afac5ed87dd092 /lib
parent286e2011d22ea6914d5f2db5de3f11911a1fb663 (diff)
Hash: fixed rta hashing wrt. structure padding
Diffstat (limited to 'lib')
-rw-r--r--lib/hash.h34
1 files changed, 27 insertions, 7 deletions
diff --git a/lib/hash.h b/lib/hash.h
index b0641466..b86a2eb1 100644
--- a/lib/hash.h
+++ b/lib/hash.h
@@ -178,16 +178,36 @@
#define HASH_WALK_FILTER_END } while (0)
-static inline uint
-mem_hash(void *p, int s)
+typedef mem_hash_t u64;
+
+static inline void
+mem_hash_init(mem_hash_t *h)
+{
+ *h = 0x001047d54778bcafULL;
+}
+
+static inline void
+mem_hash_mix(mem_hash_t *h, void *p, int s)
{
- const char *pp = p;
const u64 multiplier = 0xb38bc09a61202731ULL;
- u64 value = 0x001047d54778bcafULL;
- int i;
- for (i=0;i<s;i++)
- value = value*multiplier + pp[i];
+ const char *pp = p;
+ uint i;
+ for (i=0; i<s; i++)
+ *h = *h * multiplier + pp[i];
+}
+static inline uint
+mem_hash_value(mem_hash_t *h)
+{
return ((value >> 32) ^ (value & 0xffffffff));
}
+static inline uint
+mem_hash(void *p, int s)
+{
+ static mem_hash_t h;
+ mem_hash_init(&h);
+ mem_hash_mix(&h, p, s);
+ return mem_hash_value(&h);
+}
+