diff options
Diffstat (limited to 'lib/hash.h')
| -rw-r--r-- | lib/hash.h | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/lib/hash.h b/lib/hash.h index 5f6409cb1..109612fb7 100644 --- a/lib/hash.h +++ b/lib/hash.h @@ -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. @@ -49,7 +49,8 @@ } while (0) uint32_t hash_words(const uint32_t *, size_t n_word, uint32_t basis); -uint32_t hash_2words(const uint32_t *, uint32_t basis); +uint32_t hash_2words(uint32_t, uint32_t); +uint32_t hash_3words(uint32_t, uint32_t, uint32_t); uint32_t hash_bytes(const void *, size_t n_bytes, uint32_t basis); static inline uint32_t hash_string(const char *s, uint32_t basis) @@ -58,7 +59,11 @@ static inline uint32_t hash_string(const char *s, uint32_t basis) } /* This is Bob Jenkins' integer hash from - * http://burtleburtle.net/bob/hash/integer.html, modified for style. */ + * http://burtleburtle.net/bob/hash/integer.html, modified for style. + * + * This hash is faster than hash_2words(), but it isn't as good when 'basis' is + * important. So use this function for speed or hash_2words() for hash + * quality. */ static inline uint32_t hash_int(uint32_t x, uint32_t basis) { x -= x << 6; @@ -87,7 +92,7 @@ static inline uint32_t hash_double(double x, uint32_t basis) BUILD_ASSERT_DECL(sizeof x == sizeof value); memcpy(value, &x, sizeof value); - return hash_2words(value, basis); + return hash_3words(value[0], value[1], basis); } static inline uint32_t hash_pointer(const void *p, uint32_t basis) |