diff options
| -rw-r--r-- | immutables/map.py | 28 |
1 files changed, 17 insertions, 11 deletions
diff --git a/immutables/map.py b/immutables/map.py index 83c02bc..9f9554c 100644 --- a/immutables/map.py +++ b/immutables/map.py @@ -1,5 +1,6 @@ import collections.abc import reprlib +import sys def map_hash(o): @@ -28,11 +29,6 @@ def map_bitindex(bitmap, bit): return map_bitcount(bitmap & (bit - 1)) -def shuffle_bits(h): - # used in Map.__hash__ - return ((h ^ 89869747) ^ (h << 16)) * 3644798167 - - W_EMPTY, W_NEWNODE, W_NOT_FOUND = range(3) @@ -430,18 +426,28 @@ class Map: if self.__hash != -1: return self.__hash - h = 0 + MAX = sys.maxsize + MASK = 2 * MAX + 1 + + h = 1927868237 * (self.__count * 2 + 1) + h &= MASK + for key, value in self.__root.items(): - h ^= shuffle_bits(hash(key)) - h ^= shuffle_bits(hash(value)) + hx = hash(key) + h ^= (hx ^ (hx << 16) ^ 89869747) * 3644798167 + h &= MASK - h ^= (self.__count * 2 + 1) * 1927868237 + hx = hash(value) + h ^= (hx ^ (hx << 16) ^ 89869747) * 3644798167 + h &= MASK - h ^= (h >> 11) ^ (h >> 25) h = h * 69069 + 907133923 + h &= MASK + if h > MAX: + h -= MASK + 1 if h == -1: - h = -2 + h = 590923713 self.__hash = h return h |