hash: Make functions for hashing a few words easier to use.

It's easier for the client to pass in data directly than it is for the
client to stuff it into an array.

These functions will have new users in upcoming commits.

1 files changed, 13 insertions, 10 deletions

diff --git a/lib/hash.c b/lib/hash.c
index 63b4784fc..61e17b278 100644
--- a/lib/hash.c
+++ b/lib/hash.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -52,21 +52,24 @@ hash_words(const uint32_t *p, size_t n, uint32_t basis)
     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];
+    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)