26 строки
683 Б
Go
26 строки
683 Б
Go
package main
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// This file contains functions that are also used by the runtime. These must be
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// kept in sync.
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// Get FNV-1a hash of this string.
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//
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// https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function#FNV-1a_hash
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func hashmapHash(data []byte) uint32 {
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var result uint32 = 2166136261 // FNV offset basis
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for _, c := range data {
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result ^= uint32(c)
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result *= 16777619 // FNV prime
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}
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return result
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}
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// Get the topmost 8 bits of the hash, without using a special value (like 0).
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func hashmapTopHash(hash uint32) uint8 {
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tophash := uint8(hash >> 24)
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if tophash < 1 {
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// 0 means empty slot, so make it bigger.
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tophash += 1
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}
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return tophash
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}
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