gf/encoding/ghash/ghash.go

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// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
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//
// This Source Code Form is subject to the terms of the MIT License.
// If a copy of the MIT was not distributed with this file,
// You can obtain one at https://github.com/gogf/gf.
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// Package ghash provides some classic hash functions(uint32/uint64) in go.
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package ghash
// BKDR Hash Function
func BKDRHash(str []byte) uint32 {
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var seed uint32 = 131 // 31 131 1313 13131 131313 etc..
var hash uint32 = 0
for i := 0; i < len(str); i++ {
hash = hash*seed + uint32(str[i])
}
return hash
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}
// BKDR Hash Function 64
func BKDRHash64(str []byte) uint64 {
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var seed uint64 = 131 // 31 131 1313 13131 131313 etc..
var hash uint64 = 0
for i := 0; i < len(str); i++ {
hash = hash*seed + uint64(str[i])
}
return hash
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}
// SDBM Hash
func SDBMHash(str []byte) uint32 {
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var hash uint32 = 0
for i := 0; i < len(str); i++ {
// equivalent to: hash = 65599*hash + uint32(str[i]);
hash = uint32(str[i]) + (hash << 6) + (hash << 16) - hash
}
return hash
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}
// SDBM Hash 64
func SDBMHash64(str []byte) uint64 {
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var hash uint64 = 0
for i := 0; i < len(str); i++ {
// equivalent to: hash = 65599*hash + uint32(str[i])
hash = uint64(str[i]) + (hash << 6) + (hash << 16) - hash
}
return hash
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}
// RS Hash Function
func RSHash(str []byte) uint32 {
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var b uint32 = 378551
var a uint32 = 63689
var hash uint32 = 0
for i := 0; i < len(str); i++ {
hash = hash*a + uint32(str[i])
a *= b
}
return hash
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}
// RS Hash Function 64
func RSHash64(str []byte) uint64 {
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var b uint64 = 378551
var a uint64 = 63689
var hash uint64 = 0
for i := 0; i < len(str); i++ {
hash = hash*a + uint64(str[i])
a *= b
}
return hash
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}
// JS Hash Function
func JSHash(str []byte) uint32 {
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var hash uint32 = 1315423911
for i := 0; i < len(str); i++ {
hash ^= (hash << 5) + uint32(str[i]) + (hash >> 2)
}
return hash
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}
// JS Hash Function 64
func JSHash64(str []byte) uint64 {
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var hash uint64 = 1315423911
for i := 0; i < len(str); i++ {
hash ^= (hash << 5) + uint64(str[i]) + (hash >> 2)
}
return hash
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}
// P. J. Weinberger Hash Function
func PJWHash(str []byte) uint32 {
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var BitsInUnignedInt uint32 = 4 * 8
var ThreeQuarters uint32 = (BitsInUnignedInt * 3) / 4
var OneEighth uint32 = BitsInUnignedInt / 8
var HighBits uint32 = (0xFFFFFFFF) << (BitsInUnignedInt - OneEighth)
var hash uint32 = 0
var test uint32 = 0
for i := 0; i < len(str); i++ {
hash = (hash << OneEighth) + uint32(str[i])
if test = hash & HighBits; test != 0 {
hash = (hash ^ (test >> ThreeQuarters)) & (^HighBits + 1)
}
}
return hash
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}
// P. J. Weinberger Hash Function 64
func PJWHash64(str []byte) uint64 {
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var BitsInUnignedInt uint64 = 4 * 8
var ThreeQuarters uint64 = (BitsInUnignedInt * 3) / 4
var OneEighth uint64 = BitsInUnignedInt / 8
var HighBits uint64 = (0xFFFFFFFFFFFFFFFF) << (BitsInUnignedInt - OneEighth)
var hash uint64 = 0
var test uint64 = 0
for i := 0; i < len(str); i++ {
hash = (hash << OneEighth) + uint64(str[i])
if test = hash & HighBits; test != 0 {
hash = (hash ^ (test >> ThreeQuarters)) & (^HighBits + 1)
}
}
return hash
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}
// ELF Hash Function
func ELFHash(str []byte) uint32 {
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var hash uint32 = 0
var x uint32 = 0
for i := 0; i < len(str); i++ {
hash = (hash << 4) + uint32(str[i])
if x = hash & 0xF0000000; x != 0 {
hash ^= x >> 24
hash &= ^x + 1
}
}
return hash
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}
// ELF Hash Function 64
func ELFHash64(str []byte) uint64 {
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var hash uint64 = 0
var x uint64 = 0
for i := 0; i < len(str); i++ {
hash = (hash << 4) + uint64(str[i])
if x = hash & 0xF000000000000000; x != 0 {
hash ^= x >> 24
hash &= ^x + 1
}
}
return hash
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}
// DJB Hash Function
func DJBHash(str []byte) uint32 {
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var hash uint32 = 5381
for i := 0; i < len(str); i++ {
hash += (hash << 5) + uint32(str[i])
}
return hash
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}
// DJB Hash Function 64.
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func DJBHash64(str []byte) uint64 {
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var hash uint64 = 5381
for i := 0; i < len(str); i++ {
hash += (hash << 5) + uint64(str[i])
}
return hash
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}
// AP Hash Function
func APHash(str []byte) uint32 {
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var hash uint32 = 0
for i := 0; i < len(str); i++ {
if (i & 1) == 0 {
hash ^= (hash << 7) ^ uint32(str[i]) ^ (hash >> 3)
} else {
hash ^= ^((hash << 11) ^ uint32(str[i]) ^ (hash >> 5)) + 1
}
}
return hash
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}
// AP Hash Function 64
func APHash64(str []byte) uint64 {
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var hash uint64 = 0
for i := 0; i < len(str); i++ {
if (i & 1) == 0 {
hash ^= (hash << 7) ^ uint64(str[i]) ^ (hash >> 3)
} else {
hash ^= ^((hash << 11) ^ uint64(str[i]) ^ (hash >> 5)) + 1
}
}
return hash
}