1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8
9. 9
10. 10
11. 11
12. 12
13. 13
14. 14
15. 15
16. 16
17. 17
18. 18
19. 19
20. 20
21. 21
22. 22
23. 23
24. 24
25. 25
26. 26
27. 27
28. 28
29. 29
30. 30
31. 31
32. 32
33. 33
34. 34
35. 35
36. 36
37. 37
38. 38
39. 39
40. 40
41. 41
42. 42
43. 43
44. 44
45. 45
46. 46
47. 47
48. 48
49. 49
50. 50
51. 51
52. 52
53. 53
54. 54
55. 55
56. 56
57. 57
58. 58
59. 59
60. 60
61. 61
62. 62
63. 63
64. 64
65. 65
66. 66
67. 67
68. 68
69. 69
70. 70
71. 71
72. 72
73. 73
74. 74
75. 75
76. 76
77. 77
78. 78
79. 79
80. 80
81. 81
82. 82
83. 83
84. 84
85. 85
86. 86
87. 87
88. 88
89. 89
90. 90
91. 91
92. 92
93. 93
94. 94
95. 95
96. 96
97. 97
98. 98
99. 99
100. 100
101. 101
102. 102
103. 103
104. 104
105. 105
106. 106
107. 107
108. 108
109. 109
110. 110
111. 111
112. 112
113. 113
114. 114
115. 115
116. 116
117. 117
118. 118
119. 119
120. 120
121. 121
122. 122
123. 123
124. 124
125. 125
126. 126
127. 127
128. 128
129. 129
130. 130
131. 131
132. 132
133. 133
134. 134
135. 135
136. 136
137. 137
138. 138
139. 139
140. 140
141. 141
142. 142
143. 143
144. 144
145. 145
146. 146
147. 147
148. 148
149. 149
150. 150
151. 151
152. 152
153. 153
154. 154
155. 155
156. 156
157. 157
158. 158
159. 159
160. 160
161. 161
162. 162
163. 163
164. 164
165. 165
166. 166
167. 167
168. 168
169. 169
170. 170
171. 171
172. 172
173. 173
174. 174
175. 175
176. 176
177. 177
178. 178
179. 179
180. 180
181. 181
182. 182
183. 183
184. 184
185. 185
186. 186
187. 187
188. 188

//+build !noasm,!appengine,gc

// Copyright (c) 2020 MinIO Inc. All rights reserved.
// Use of this source code is governed by a license that can be
// found in the LICENSE file.

package md5simd

import (
	"encoding/binary"
	"errors"
	"fmt"
	"sync"
	"sync/atomic"
)

// md5Digest - Type for computing MD5 using either AVX2 or AVX512
type md5Digest struct {
	uid         uint64
	blocksCh    chan blockInput
	cycleServer chan uint64
	x           [BlockSize]byte
	nx          int
	len         uint64
	buffers     <-chan []byte
}

// NewHash - initialize instance for Md5 implementation.
func (s *md5Server) NewHash() Hasher {
	uid := atomic.AddUint64(&s.uidCounter, 1)
	blockCh := make(chan blockInput, buffersPerLane)
	s.newInput <- newClient{
		uid:   uid,
		input: blockCh,
	}
	return &md5Digest{
		uid:         uid,
		buffers:     s.buffers,
		blocksCh:    blockCh,
		cycleServer: s.cycle,
	}
}

// Size - Return size of checksum
func (d *md5Digest) Size() int { return Size }

// BlockSize - Return blocksize of checksum
func (d md5Digest) BlockSize() int { return BlockSize }

func (d *md5Digest) Reset() {
	if d.blocksCh == nil {
		panic("reset after close")
	}
	d.nx = 0
	d.len = 0
	d.sendBlock(blockInput{uid: d.uid, reset: true}, false)
}

// write to digest
func (d *md5Digest) Write(p []byte) (nn int, err error) {
	if d.blocksCh == nil {
		return 0, errors.New("md5Digest closed")
	}

	// break input into chunks of maximum internalBlockSize size
	for {
		l := len(p)
		if l > internalBlockSize {
			l = internalBlockSize
		}
		nnn, err := d.write(p[:l])
		if err != nil {
			return nn, err
		}
		nn += nnn
		p = p[l:]

		if len(p) == 0 {
			break
		}

	}
	return
}

func (d *md5Digest) write(p []byte) (nn int, err error) {

	nn = len(p)
	d.len += uint64(nn)
	if d.nx > 0 {
		n := copy(d.x[d.nx:], p)
		d.nx += n
		if d.nx == BlockSize {
			// Create a copy of the overflow buffer in order to send it async over the channel
			// (since we will modify the overflow buffer down below with any access beyond multiples of 64)
			tmp := <-d.buffers
			tmp = tmp[:BlockSize]
			copy(tmp, d.x[:])
			d.sendBlock(blockInput{uid: d.uid, msg: tmp}, len(p)-n < BlockSize)
			d.nx = 0
		}
		p = p[n:]
	}
	if len(p) >= BlockSize {
		n := len(p) &^ (BlockSize - 1)
		buf := <-d.buffers
		buf = buf[:n]
		copy(buf, p)
		d.sendBlock(blockInput{uid: d.uid, msg: buf}, len(p)-n < BlockSize)
		p = p[n:]
	}
	if len(p) > 0 {
		d.nx = copy(d.x[:], p)
	}
	return
}

func (d *md5Digest) Close() {
	if d.blocksCh != nil {
		close(d.blocksCh)
		d.blocksCh = nil
	}
}

var sumChPool sync.Pool

func init() {
	sumChPool.New = func() interface{} {
		return make(chan sumResult, 1)
	}
}

// Sum - Return MD5 sum in bytes
func (d *md5Digest) Sum(in []byte) (result []byte) {
	if d.blocksCh == nil {
		panic("sum after close")
	}

	trail := <-d.buffers
	trail = append(trail[:0], d.x[:d.nx]...)

	length := d.len
	// Padding.  Add a 1 bit and 0 bits until 56 bytes mod 64.
	var tmp [64]byte
	tmp[0] = 0x80
	if length%64 < 56 {
		trail = append(trail, tmp[0:56-length%64]...)
	} else {
		trail = append(trail, tmp[0:64+56-length%64]...)
	}

	// Length in bits.
	length <<= 3
	binary.LittleEndian.PutUint64(tmp[:], length) // append length in bits

	trail = append(trail, tmp[0:8]...)
	if len(trail)%BlockSize != 0 {
		panic(fmt.Errorf("internal error: sum block was not aligned. len=%d, nx=%d", len(trail), d.nx))
	}
	sumCh := sumChPool.Get().(chan sumResult)
	d.sendBlock(blockInput{uid: d.uid, msg: trail, sumCh: sumCh}, true)

	sum := <-sumCh
	sumChPool.Put(sumCh)

	return append(in, sum.digest[:]...)
}

// sendBlock will send a block for processing.
// If cycle is true we will block on cycle, otherwise we will only block
// if the block channel is full.
func (d *md5Digest) sendBlock(bi blockInput, cycle bool) {
	if cycle {
		select {
		case d.blocksCh <- bi:
			d.cycleServer <- d.uid
		}
		return
	}
	// Only block on cycle if we filled the buffer
	select {
	case d.blocksCh <- bi:
		return
	default:
		d.cycleServer <- d.uid
		d.blocksCh <- bi
	}
}