siphash

* random.c (rb_memhash): use siphash.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@37585 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 23 insertions, 0 deletions

diff --git a/random.c b/random.c
index a137551772..196fd14f1e 100644
--- a/random.c
+++ b/random.c
@@ -1326,7 +1326,15 @@ random_s_rand(int argc, VALUE *argv, VALUE obj)
     return rand_random(argc, argv, rand_start(&default_rand));
 }
 
+#define SIP_HASH_STREAMING 0
+#define sip_hash24 ruby_sip_hash24
+#include "siphash.c"
+
 static st_index_t hashseed;
+static union {
+    uint8_t key[16];
+    uint32_t u32[(16 * sizeof(uint8_t) - 1) / sizeof(uint32_t)];
+} sipseed;
 
 static VALUE
 init_randomseed(struct MT *mt, unsigned int initial[DEFAULT_SEED_CNT])
@@ -1346,6 +1354,7 @@ Init_RandomSeed(void)
     unsigned int initial[DEFAULT_SEED_CNT];
     struct MT *mt = &r->mt;
     VALUE seed = init_randomseed(mt, initial);
+    int i;
 
     hashseed = genrand_int32(mt);
 #if SIZEOF_ST_INDEX_T*CHAR_BIT > 4*8
@@ -1361,6 +1370,9 @@ Init_RandomSeed(void)
     hashseed |= genrand_int32(mt);
 #endif
 
+    for (i = 0; i < numberof(sipseed.u32); ++i)
+	sipseed.u32[i] = genrand_int32(mt);
+
     rb_global_variable(&r->seed);
     r->seed = seed;
 }
@@ -1371,6 +1383,17 @@ rb_hash_start(st_index_t h)
     return st_hash_start(hashseed + h);
 }
 
+st_index_t
+rb_memhash(const void *ptr, long len)
+{
+    sip_uint64_t h = sip_hash24(sipseed.key, ptr, len);
+#ifdef HAVE_UINT64_T
+    return (st_index_t)h;
+#else
+    return (st_index_t)(h.u32[0] ^ h.u32[1]);
+#endif
+}
+
 static void
 Init_RandomSeed2(void)
 {