31 lines
656 B
Go
31 lines
656 B
Go
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package farm
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// Some primes between 2^63 and 2^64 for various uses.
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const k0 uint64 = 0xc3a5c85c97cb3127
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const k1 uint64 = 0xb492b66fbe98f273
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const k2 uint64 = 0x9ae16a3b2f90404f
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// Magic numbers for 32-bit hashing. Copied from Murmur3.
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const c1 uint32 = 0xcc9e2d51
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const c2 uint32 = 0x1b873593
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// A 32-bit to 32-bit integer hash copied from Murmur3.
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func fmix(h uint32) uint32 {
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h ^= h >> 16
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h *= 0x85ebca6b
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h ^= h >> 13
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h *= 0xc2b2ae35
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h ^= h >> 16
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return h
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}
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func mur(a, h uint32) uint32 {
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// Helper from Murmur3 for combining two 32-bit values.
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a *= c1
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a = rotate32(a, 17)
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a *= c2
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h ^= a
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h = rotate32(h, 19)
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return h*5 + 0xe6546b64
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}
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