/*
- * Copyright (c) 2008, 2009 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2012 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <config.h>
#include "hash.h"
#include <string.h>
+#include "unaligned.h"
/* Returns the hash of the 'n' 32-bit words at 'p', starting from 'basis'.
* 'p' must be properly aligned. */
a += p[0];
b += p[1];
c += p[2];
- HASH_MIX(a, b, c);
+ hash_mix(&a, &b, &c);
n -= 3;
p += 3;
}
/* fall through */
case 1:
a += p[0];
- HASH_FINAL(a, b, c);
+ hash_final(&a, &b, &c);
/* fall through */
case 0:
break;
return c;
}
-/* Returns the hash of the pair of aligned 32-bit words at 'p', starting from
- * 'basis'. */
+/* Returns the hash of 'a', 'b', and 'c'. */
uint32_t
-hash_2words(const uint32_t *p, uint32_t basis)
+hash_3words(uint32_t a, uint32_t b, uint32_t c)
{
- uint32_t a, b, c;
-
- a = b = c = 0xdeadbeef + (2 << 2) + basis;
- b += p[1];
- a += p[0];
- HASH_FINAL(a, b, c);
-
+ a += 0xdeadbeef;
+ b += 0xdeadbeef;
+ c += 0xdeadbeef;
+ hash_final(&a, &b, &c);
return c;
}
+/* Returns the hash of 'a' and 'b'. */
+uint32_t
+hash_2words(uint32_t a, uint32_t b)
+{
+ return hash_3words(a, b, 0);
+}
+
/* Returns the hash of the 'n' bytes at 'p', starting from 'basis'. */
uint32_t
hash_bytes(const void *p_, size_t n, uint32_t basis)
{
const uint8_t *p = p_;
uint32_t a, b, c;
- uint32_t tmp[3];
a = b = c = 0xdeadbeef + n + basis;
- while (n >= sizeof tmp) {
- memcpy(tmp, p, sizeof tmp);
- a += tmp[0];
- b += tmp[1];
- c += tmp[2];
- HASH_MIX(a, b, c);
- n -= sizeof tmp;
- p += sizeof tmp;
+ while (n >= 12) {
+ a += get_unaligned_u32((uint32_t *) p);
+ b += get_unaligned_u32((uint32_t *) (p + 4));
+ c += get_unaligned_u32((uint32_t *) (p + 8));
+ hash_mix(&a, &b, &c);
+ n -= 12;
+ p += 12;
}
if (n) {
+ uint32_t tmp[3];
+
tmp[0] = tmp[1] = tmp[2] = 0;
memcpy(tmp, p, n);
a += tmp[0];
b += tmp[1];
c += tmp[2];
- HASH_FINAL(a, b, c);
+ hash_final(&a, &b, &c);
}
return c;
}
+
+/* Returns the hash of the 'n' 32-bit words at 'p', starting from 'basis'.
+ * 'p' must be properly aligned. */
+uint32_t
+mhash_words(const uint32_t p[], size_t n_words, uint32_t basis)
+{
+ uint32_t hash;
+ size_t i;
+
+ hash = basis;
+ for (i = 0; i < n_words; i++) {
+ hash = mhash_add(hash, p[i]);
+ }
+ return mhash_finish(hash, n_words);
+}