-
Notifications
You must be signed in to change notification settings - Fork 14
/
Copy pathmurmur128_gen.go
236 lines (202 loc) · 4.86 KB
/
murmur128_gen.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
//go:build !go1.5 || !amd64 || gccgo
// +build !go1.5 !amd64 gccgo
package murmur3
import "math/bits"
// Sum128 returns the murmur3 sum of data. It is equivalent to the following
// sequence (without the extra burden and the extra allocation):
//
// hasher := New128()
// hasher.Write(data)
// return hasher.Sum128()
func Sum128(data []byte) (h1 uint64, h2 uint64) {
return SeedSum128(0, 0, data)
}
// SeedSum128 returns the murmur3 sum of data with digests initialized to seed1
// and seed2.
//
// The canonical implementation allows only one uint32 seed; to imitate that
// behavior, use the same, uint32-max seed for seed1 and seed2.
//
// This reads and processes the data in chunks of little endian uint64s;
// thus, the returned hashes are portable across architectures.
func SeedSum128(seed1, seed2 uint64, data []byte) (h1 uint64, h2 uint64) {
h1, h2 = seed1, seed2
clen := len(data)
for len(data) >= 16 {
// yes, this is faster than using binary.LittleEndian.Uint64
k1 := uint64(data[0]) | uint64(data[1])<<8 | uint64(data[2])<<16 | uint64(data[3])<<24 | uint64(data[4])<<32 | uint64(data[5])<<40 | uint64(data[6])<<48 | uint64(data[7])<<56
k2 := uint64(data[8]) | uint64(data[9])<<8 | uint64(data[10])<<16 | uint64(data[11])<<24 | uint64(data[12])<<32 | uint64(data[13])<<40 | uint64(data[14])<<48 | uint64(data[15])<<56
data = data[16:]
k1 *= c1_128
k1 = bits.RotateLeft64(k1, 31)
k1 *= c2_128
h1 ^= k1
h1 = bits.RotateLeft64(h1, 27)
h1 += h2
h1 = h1*5 + 0x52dce729
k2 *= c2_128
k2 = bits.RotateLeft64(k2, 33)
k2 *= c1_128
h2 ^= k2
h2 = bits.RotateLeft64(h2, 31)
h2 += h1
h2 = h2*5 + 0x38495ab5
}
var k1, k2 uint64
switch len(data) {
case 15:
k2 ^= uint64(data[14]) << 48
fallthrough
case 14:
k2 ^= uint64(data[13]) << 40
fallthrough
case 13:
k2 ^= uint64(data[12]) << 32
fallthrough
case 12:
k2 ^= uint64(data[11]) << 24
fallthrough
case 11:
k2 ^= uint64(data[10]) << 16
fallthrough
case 10:
k2 ^= uint64(data[9]) << 8
fallthrough
case 9:
k2 ^= uint64(data[8]) << 0
k2 *= c2_128
k2 = bits.RotateLeft64(k2, 33)
k2 *= c1_128
h2 ^= k2
fallthrough
case 8:
k1 ^= uint64(data[7]) << 56
fallthrough
case 7:
k1 ^= uint64(data[6]) << 48
fallthrough
case 6:
k1 ^= uint64(data[5]) << 40
fallthrough
case 5:
k1 ^= uint64(data[4]) << 32
fallthrough
case 4:
k1 ^= uint64(data[3]) << 24
fallthrough
case 3:
k1 ^= uint64(data[2]) << 16
fallthrough
case 2:
k1 ^= uint64(data[1]) << 8
fallthrough
case 1:
k1 ^= uint64(data[0]) << 0
k1 *= c1_128
k1 = bits.RotateLeft64(k1, 31)
k1 *= c2_128
h1 ^= k1
}
h1 ^= uint64(clen)
h2 ^= uint64(clen)
h1 += h2
h2 += h1
h1 = fmix64(h1)
h2 = fmix64(h2)
h1 += h2
h2 += h1
return h1, h2
}
// StringSum128 is the string version of Sum128.
func StringSum128(data string) (h1 uint64, h2 uint64) {
return SeedStringSum128(0, 0, data)
}
// SeedStringSum128 is the string version of SeedSum128.
func SeedStringSum128(seed1, seed2 uint64, data string) (h1 uint64, h2 uint64) {
h1, h2 = seed1, seed2
clen := len(data)
for len(data) >= 16 {
// yes, this is faster than using binary.LittleEndian.Uint64
k1 := uint64(data[0]) | uint64(data[1])<<8 | uint64(data[2])<<16 | uint64(data[3])<<24 | uint64(data[4])<<32 | uint64(data[5])<<40 | uint64(data[6])<<48 | uint64(data[7])<<56
k2 := uint64(data[8]) | uint64(data[9])<<8 | uint64(data[10])<<16 | uint64(data[11])<<24 | uint64(data[12])<<32 | uint64(data[13])<<40 | uint64(data[14])<<48 | uint64(data[15])<<56
data = data[16:]
k1 *= c1_128
k1 = bits.RotateLeft64(k1, 31)
k1 *= c2_128
h1 ^= k1
h1 = bits.RotateLeft64(h1, 27)
h1 += h2
h1 = h1*5 + 0x52dce729
k2 *= c2_128
k2 = bits.RotateLeft64(k2, 33)
k2 *= c1_128
h2 ^= k2
h2 = bits.RotateLeft64(h2, 31)
h2 += h1
h2 = h2*5 + 0x38495ab5
}
var k1, k2 uint64
switch len(data) {
case 15:
k2 ^= uint64(data[14]) << 48
fallthrough
case 14:
k2 ^= uint64(data[13]) << 40
fallthrough
case 13:
k2 ^= uint64(data[12]) << 32
fallthrough
case 12:
k2 ^= uint64(data[11]) << 24
fallthrough
case 11:
k2 ^= uint64(data[10]) << 16
fallthrough
case 10:
k2 ^= uint64(data[9]) << 8
fallthrough
case 9:
k2 ^= uint64(data[8]) << 0
k2 *= c2_128
k2 = bits.RotateLeft64(k2, 33)
k2 *= c1_128
h2 ^= k2
fallthrough
case 8:
k1 ^= uint64(data[7]) << 56
fallthrough
case 7:
k1 ^= uint64(data[6]) << 48
fallthrough
case 6:
k1 ^= uint64(data[5]) << 40
fallthrough
case 5:
k1 ^= uint64(data[4]) << 32
fallthrough
case 4:
k1 ^= uint64(data[3]) << 24
fallthrough
case 3:
k1 ^= uint64(data[2]) << 16
fallthrough
case 2:
k1 ^= uint64(data[1]) << 8
fallthrough
case 1:
k1 ^= uint64(data[0]) << 0
k1 *= c1_128
k1 = bits.RotateLeft64(k1, 31)
k1 *= c2_128
h1 ^= k1
}
h1 ^= uint64(clen)
h2 ^= uint64(clen)
h1 += h2
h2 += h1
h1 = fmix64(h1)
h2 = fmix64(h2)
h1 += h2
h2 += h1
return h1, h2
}