Source file
src/hash/crc32/crc32_test.go
1
2
3
4
5 package crc32
6
7 import (
8 "encoding"
9 "fmt"
10 "hash"
11 "io"
12 "math/rand"
13 "testing"
14 )
15
16
17 func TestCastagnoliRace(t *testing.T) {
18
19
20
21 ieee := NewIEEE()
22 go MakeTable(Castagnoli)
23 ieee.Write([]byte("hello"))
24 }
25
26 type test struct {
27 ieee, castagnoli uint32
28 in string
29 halfStateIEEE string
30 halfStateCastagnoli string
31 }
32
33 var golden = []test{
34 {0x0, 0x0, "", "crc\x01ʇ\x91M\x00\x00\x00\x00", "crc\x01wB\x84\x81\x00\x00\x00\x00"},
35 {0xe8b7be43, 0xc1d04330, "a", "crc\x01ʇ\x91M\x00\x00\x00\x00", "crc\x01wB\x84\x81\x00\x00\x00\x00"},
36 {0x9e83486d, 0xe2a22936, "ab", "crc\x01ʇ\x91M跾C", "crc\x01wB\x84\x81\xc1\xd0C0"},
37 {0x352441c2, 0x364b3fb7, "abc", "crc\x01ʇ\x91M跾C", "crc\x01wB\x84\x81\xc1\xd0C0"},
38 {0xed82cd11, 0x92c80a31, "abcd", "crc\x01ʇ\x91M\x9e\x83Hm", "crc\x01wB\x84\x81\xe2\xa2)6"},
39 {0x8587d865, 0xc450d697, "abcde", "crc\x01ʇ\x91M\x9e\x83Hm", "crc\x01wB\x84\x81\xe2\xa2)6"},
40 {0x4b8e39ef, 0x53bceff1, "abcdef", "crc\x01ʇ\x91M5$A\xc2", "crc\x01wB\x84\x816K?\xb7"},
41 {0x312a6aa6, 0xe627f441, "abcdefg", "crc\x01ʇ\x91M5$A\xc2", "crc\x01wB\x84\x816K?\xb7"},
42 {0xaeef2a50, 0xa9421b7, "abcdefgh", "crc\x01ʇ\x91M\xed\x82\xcd\x11", "crc\x01wB\x84\x81\x92\xc8\n1"},
43 {0x8da988af, 0x2ddc99fc, "abcdefghi", "crc\x01ʇ\x91M\xed\x82\xcd\x11", "crc\x01wB\x84\x81\x92\xc8\n1"},
44 {0x3981703a, 0xe6599437, "abcdefghij", "crc\x01ʇ\x91M\x85\x87\xd8e", "crc\x01wB\x84\x81\xc4P֗"},
45 {0x6b9cdfe7, 0xb2cc01fe, "Discard medicine more than two years old.", "crc\x01ʇ\x91M\xfd\xe5\xc2J", "crc\x01wB\x84\x81S\"(\xe0"},
46 {0xc90ef73f, 0xe28207f, "He who has a shady past knows that nice guys finish last.", "crc\x01ʇ\x91M\x01Nj+", "crc\x01wB\x84\x81'\xdaR\x15"},
47 {0xb902341f, 0xbe93f964, "I wouldn't marry him with a ten foot pole.", "crc\x01ʇ\x91M\x9d\x13\xce\x10", "crc\x01wB\x84\x81\xc3\xed\xabG"},
48 {0x42080e8, 0x9e3be0c3, "Free! Free!/A trip/to Mars/for 900/empty jars/Burma Shave", "crc\x01ʇ\x91M-\xed\xf7\x94", "crc\x01wB\x84\x81\xce\xceb\x81"},
49 {0x154c6d11, 0xf505ef04, "The days of the digital watch are numbered. -Tom Stoppard", "crc\x01ʇ\x91MOa\xa5\r", "crc\x01wB\x84\x81\xd3s\x9dP"},
50 {0x4c418325, 0x85d3dc82, "Nepal premier won't resign.", "crc\x01ʇ\x91M\xa8S9\x85", "crc\x01wB\x84\x81{\x90\x8a\x14"},
51 {0x33955150, 0xc5142380, "For every action there is an equal and opposite government program.", "crc\x01ʇ\x91Ma\xe9>\x86", "crc\x01wB\x84\x81\xaa@\xc4\x1c"},
52 {0x26216a4b, 0x75eb77dd, "His money is twice tainted: 'taint yours and 'taint mine.", "crc\x01ʇ\x91M\\\x1an\x88", "crc\x01wB\x84\x81W\a8Z"},
53 {0x1abbe45e, 0x91ebe9f7, "There is no reason for any individual to have a computer in their home. -Ken Olsen, 1977", "crc\x01ʇ\x91M\xb7\xf5\xf2\xca", "crc\x01wB\x84\x81\xc4o\x9d\x85"},
54 {0xc89a94f7, 0xf0b1168e, "It's a tiny change to the code and not completely disgusting. - Bob Manchek", "crc\x01ʇ\x91M\x84g1\xe8", "crc\x01wB\x84\x81#\x98\f\xab"},
55 {0xab3abe14, 0x572b74e2, "size: a.out: bad magic", "crc\x01ʇ\x91M\x8a\x0f\xad\b", "crc\x01wB\x84\x81\x80\xc9n\xd8"},
56 {0xbab102b6, 0x8a58a6d5, "The major problem is with sendmail. -Mark Horton", "crc\x01ʇ\x91M\a\xf0\xb3\x15", "crc\x01wB\x84\x81liS\xcc"},
57 {0x999149d7, 0x9c426c50, "Give me a rock, paper and scissors and I will move the world. CCFestoon", "crc\x01ʇ\x91M\x0fa\xbc.", "crc\x01wB\x84\x81\xdb͏C"},
58 {0x6d52a33c, 0x735400a4, "If the enemy is within range, then so are you.", "crc\x01ʇ\x91My\x1b\x99\xf8", "crc\x01wB\x84\x81\xaaB\x037"},
59 {0x90631e8d, 0xbec49c95, "It's well we cannot hear the screams/That we create in others' dreams.", "crc\x01ʇ\x91M\bqfY", "crc\x01wB\x84\x81\x16y\xa1\xd2"},
60 {0x78309130, 0xa95a2079, "You remind me of a TV show, but that's all right: I watch it anyway.", "crc\x01ʇ\x91M\xbdO,\xc2", "crc\x01wB\x84\x81f&\xc5\xe4"},
61 {0x7d0a377f, 0xde2e65c5, "C is as portable as Stonehedge!!", "crc\x01ʇ\x91M\xf7\xd6\x00\xd5", "crc\x01wB\x84\x81de\\\xf8"},
62 {0x8c79fd79, 0x297a88ed, "Even if I could be Shakespeare, I think I should still choose to be Faraday. - A. Huxley", "crc\x01ʇ\x91Ml+\xb8\xa7", "crc\x01wB\x84\x81\xbf\xd6S\xdd"},
63 {0xa20b7167, 0x66ed1d8b, "The fugacity of a constituent in a mixture of gases at a given temperature is proportional to its mole fraction. Lewis-Randall Rule", "crc\x01ʇ\x91M<lR[", "crc\x01wB\x84\x81{\xaco\xb1"},
64 {0x8e0bb443, 0xdcded527, "How can you write a big system without C++? -Paul Glick", "crc\x01ʇ\x91M\x0e\x88\x89\xed", "crc\x01wB\x84\x813\xd7C\u007f"},
65 }
66
67
68
69 func testGoldenIEEE(t *testing.T, crcFunc func(b []byte) uint32) {
70 for _, g := range golden {
71 if crc := crcFunc([]byte(g.in)); crc != g.ieee {
72 t.Errorf("IEEE(%s) = 0x%x want 0x%x", g.in, crc, g.ieee)
73 }
74 }
75 }
76
77
78
79 func testGoldenCastagnoli(t *testing.T, crcFunc func(b []byte) uint32) {
80 for _, g := range golden {
81 if crc := crcFunc([]byte(g.in)); crc != g.castagnoli {
82 t.Errorf("Castagnoli(%s) = 0x%x want 0x%x", g.in, crc, g.castagnoli)
83 }
84 }
85 }
86
87
88
89 func testCrossCheck(t *testing.T, crcFunc1, crcFunc2 func(crc uint32, b []byte) uint32) {
90
91
92
93 lengths := []int{0, 1, 2, 3, 4, 5, 10, 16, 50, 63, 64, 65, 100,
94 127, 128, 129, 255, 256, 257, 300, 312, 384, 416, 448, 480,
95 500, 501, 502, 503, 504, 505, 512, 513, 1000, 1024, 2000,
96 4030, 4031, 4032, 4033, 4036, 4040, 4048, 4096, 5000, 10000}
97 for _, length := range lengths {
98 p := make([]byte, length)
99 _, _ = rand.Read(p)
100 crcInit := uint32(rand.Int63())
101 crc1 := crcFunc1(crcInit, p)
102 crc2 := crcFunc2(crcInit, p)
103 if crc1 != crc2 {
104 t.Errorf("mismatch: 0x%x vs 0x%x (buffer length %d)", crc1, crc2, length)
105 }
106 }
107 }
108
109
110 func TestSimple(t *testing.T) {
111 tab := simpleMakeTable(IEEE)
112 testGoldenIEEE(t, func(b []byte) uint32 {
113 return simpleUpdate(0, tab, b)
114 })
115
116 tab = simpleMakeTable(Castagnoli)
117 testGoldenCastagnoli(t, func(b []byte) uint32 {
118 return simpleUpdate(0, tab, b)
119 })
120 }
121
122 func TestGoldenMarshal(t *testing.T) {
123 t.Run("IEEE", func(t *testing.T) {
124 for _, g := range golden {
125 h := New(IEEETable)
126 h2 := New(IEEETable)
127
128 io.WriteString(h, g.in[:len(g.in)/2])
129
130 state, err := h.(encoding.BinaryMarshaler).MarshalBinary()
131 if err != nil {
132 t.Errorf("could not marshal: %v", err)
133 continue
134 }
135
136 if string(state) != g.halfStateIEEE {
137 t.Errorf("IEEE(%q) state = %q, want %q", g.in, state, g.halfStateIEEE)
138 continue
139 }
140
141 if err := h2.(encoding.BinaryUnmarshaler).UnmarshalBinary(state); err != nil {
142 t.Errorf("could not unmarshal: %v", err)
143 continue
144 }
145
146 io.WriteString(h, g.in[len(g.in)/2:])
147 io.WriteString(h2, g.in[len(g.in)/2:])
148
149 if h.Sum32() != h2.Sum32() {
150 t.Errorf("IEEE(%s) = 0x%x != marshaled 0x%x", g.in, h.Sum32(), h2.Sum32())
151 }
152 }
153 })
154 t.Run("Castagnoli", func(t *testing.T) {
155 table := MakeTable(Castagnoli)
156 for _, g := range golden {
157 h := New(table)
158 h2 := New(table)
159
160 io.WriteString(h, g.in[:len(g.in)/2])
161
162 state, err := h.(encoding.BinaryMarshaler).MarshalBinary()
163 if err != nil {
164 t.Errorf("could not marshal: %v", err)
165 continue
166 }
167
168 if string(state) != g.halfStateCastagnoli {
169 t.Errorf("Castagnoli(%q) state = %q, want %q", g.in, state, g.halfStateCastagnoli)
170 continue
171 }
172
173 if err := h2.(encoding.BinaryUnmarshaler).UnmarshalBinary(state); err != nil {
174 t.Errorf("could not unmarshal: %v", err)
175 continue
176 }
177
178 io.WriteString(h, g.in[len(g.in)/2:])
179 io.WriteString(h2, g.in[len(g.in)/2:])
180
181 if h.Sum32() != h2.Sum32() {
182 t.Errorf("Castagnoli(%s) = 0x%x != marshaled 0x%x", g.in, h.Sum32(), h2.Sum32())
183 }
184 }
185 })
186 }
187
188 func TestMarshalTableMismatch(t *testing.T) {
189 h1 := New(IEEETable)
190 h2 := New(MakeTable(Castagnoli))
191
192 state1, err := h1.(encoding.BinaryMarshaler).MarshalBinary()
193 if err != nil {
194 t.Errorf("could not marshal: %v", err)
195 }
196
197 if err := h2.(encoding.BinaryUnmarshaler).UnmarshalBinary(state1); err == nil {
198 t.Errorf("no error when one was expected")
199 }
200 }
201
202
203 func TestSlicing(t *testing.T) {
204 tab := slicingMakeTable(IEEE)
205 testGoldenIEEE(t, func(b []byte) uint32 {
206 return slicingUpdate(0, tab, b)
207 })
208
209 tab = slicingMakeTable(Castagnoli)
210 testGoldenCastagnoli(t, func(b []byte) uint32 {
211 return slicingUpdate(0, tab, b)
212 })
213
214
215 for _, poly := range []uint32{IEEE, Castagnoli, Koopman, 0xD5828281} {
216 t1 := simpleMakeTable(poly)
217 f1 := func(crc uint32, b []byte) uint32 {
218 return simpleUpdate(crc, t1, b)
219 }
220 t2 := slicingMakeTable(poly)
221 f2 := func(crc uint32, b []byte) uint32 {
222 return slicingUpdate(crc, t2, b)
223 }
224 testCrossCheck(t, f1, f2)
225 }
226 }
227
228 func TestArchIEEE(t *testing.T) {
229 if !archAvailableIEEE() {
230 t.Skip("Arch-specific IEEE not available.")
231 }
232 archInitIEEE()
233 slicingTable := slicingMakeTable(IEEE)
234 testCrossCheck(t, archUpdateIEEE, func(crc uint32, b []byte) uint32 {
235 return slicingUpdate(crc, slicingTable, b)
236 })
237 }
238
239 func TestArchCastagnoli(t *testing.T) {
240 if !archAvailableCastagnoli() {
241 t.Skip("Arch-specific Castagnoli not available.")
242 }
243 archInitCastagnoli()
244 slicingTable := slicingMakeTable(Castagnoli)
245 testCrossCheck(t, archUpdateCastagnoli, func(crc uint32, b []byte) uint32 {
246 return slicingUpdate(crc, slicingTable, b)
247 })
248 }
249
250 func TestGolden(t *testing.T) {
251 testGoldenIEEE(t, ChecksumIEEE)
252
253
254
255 for delta := 1; delta <= 7; delta++ {
256 testGoldenIEEE(t, func(b []byte) uint32 {
257 ieee := NewIEEE()
258 d := delta
259 if d >= len(b) {
260 d = len(b)
261 }
262 ieee.Write(b[:d])
263 ieee.Write(b[d:])
264 return ieee.Sum32()
265 })
266 }
267
268 castagnoliTab := MakeTable(Castagnoli)
269 if castagnoliTab == nil {
270 t.Errorf("nil Castagnoli Table")
271 }
272
273 testGoldenCastagnoli(t, func(b []byte) uint32 {
274 castagnoli := New(castagnoliTab)
275 castagnoli.Write(b)
276 return castagnoli.Sum32()
277 })
278
279
280
281 for delta := 1; delta <= 7; delta++ {
282 testGoldenCastagnoli(t, func(b []byte) uint32 {
283 castagnoli := New(castagnoliTab)
284 d := delta
285 if d >= len(b) {
286 d = len(b)
287 }
288 castagnoli.Write(b[:d])
289 castagnoli.Write(b[d:])
290 return castagnoli.Sum32()
291 })
292 }
293 }
294
295 func BenchmarkCRC32(b *testing.B) {
296 b.Run("poly=IEEE", benchmarkAll(NewIEEE()))
297 b.Run("poly=Castagnoli", benchmarkAll(New(MakeTable(Castagnoli))))
298 b.Run("poly=Koopman", benchmarkAll(New(MakeTable(Koopman))))
299 }
300
301 func benchmarkAll(h hash.Hash32) func(b *testing.B) {
302 return func(b *testing.B) {
303 for _, size := range []int{15, 40, 512, 1 << 10, 4 << 10, 32 << 10} {
304 name := fmt.Sprint(size)
305 if size >= 1024 {
306 name = fmt.Sprintf("%dkB", size/1024)
307 }
308 b.Run("size="+name, func(b *testing.B) {
309 for align := 0; align <= 1; align++ {
310 b.Run(fmt.Sprintf("align=%d", align), func(b *testing.B) {
311 benchmark(b, h, int64(size), int64(align))
312 })
313 }
314 })
315 }
316 }
317 }
318
319 func benchmark(b *testing.B, h hash.Hash32, n, alignment int64) {
320 b.SetBytes(n)
321 data := make([]byte, n+alignment)
322 data = data[alignment:]
323 for i := range data {
324 data[i] = byte(i)
325 }
326 in := make([]byte, 0, h.Size())
327
328
329 h.Reset()
330 h.Write(data)
331 h.Sum(in)
332
333 b.ResetTimer()
334 for i := 0; i < b.N; i++ {
335 h.Reset()
336 h.Write(data)
337 h.Sum(in)
338 }
339 }
340
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