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Versions: 54
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Stored size: 1.09 KB
Contents
# frozen_string_literal: true
class Murmur3
## MurmurHash3 was written by Austin Appleby, and is placed in the public
## domain. The author hereby disclaims copyright to this source code.
MASK32 = 0xffffffff
def self.murmur3_32_rotl(x, r)
((x << r) | (x >> (32 - r))) & MASK32
end
def self.murmur3_32_fmix(h)
h &= MASK32
h ^= h >> 16
h = (h * 0x85ebca6b) & MASK32
h ^= h >> 13
h = (h * 0xc2b2ae35) & MASK32
h ^ (h >> 16)
end
def self.murmur3_32__mmix(k1)
k1 = (k1 * 0xcc9e2d51) & MASK32
k1 = murmur3_32_rotl(k1, 15)
(k1 * 0x1b873593) & MASK32
end
def self.murmur3_32(str, seed = 0)
h1 = seed
numbers = str.unpack('V*C*')
tailn = str.length % 4
tail = numbers.slice!(numbers.size - tailn, tailn)
for k1 in numbers
h1 ^= murmur3_32__mmix(k1)
h1 = murmur3_32_rotl(h1, 13)
h1 = (h1 * 5 + 0xe6546b64) & MASK32
end
unless tail.empty?
k1 = 0
tail.reverse_each do |c1|
k1 = (k1 << 8) | c1
end
h1 ^= murmur3_32__mmix(k1)
end
h1 ^= str.length
murmur3_32_fmix(h1)
end
end
Version data entries
54 entries across 54 versions & 1 rubygems