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 stateAppend, err := h.(encoding.BinaryAppender).AppendBinary(make([]byte, 4, 32))
137 if err != nil {
138 t.Errorf("could not marshal: %v", err)
139 continue
140 }
141 stateAppend = stateAppend[4:]
142
143 if string(state) != g.halfStateIEEE {
144 t.Errorf("IEEE(%q) state = %q, want %q", g.in, state, g.halfStateIEEE)
145 continue
146 }
147
148 if string(stateAppend) != g.halfStateIEEE {
149 t.Errorf("IEEE(%q) state = %q, want %q", g.in, stateAppend, g.halfStateIEEE)
150 continue
151 }
152
153 if err := h2.(encoding.BinaryUnmarshaler).UnmarshalBinary(state); err != nil {
154 t.Errorf("could not unmarshal: %v", err)
155 continue
156 }
157
158 io.WriteString(h, g.in[len(g.in)/2:])
159 io.WriteString(h2, g.in[len(g.in)/2:])
160
161 if h.Sum32() != h2.Sum32() {
162 t.Errorf("IEEE(%s) = 0x%x != marshaled 0x%x", g.in, h.Sum32(), h2.Sum32())
163 }
164 }
165 })
166 t.Run("Castagnoli", func(t *testing.T) {
167 table := MakeTable(Castagnoli)
168 for _, g := range golden {
169 h := New(table)
170 h2 := New(table)
171
172 io.WriteString(h, g.in[:len(g.in)/2])
173
174 state, err := h.(encoding.BinaryMarshaler).MarshalBinary()
175 if err != nil {
176 t.Errorf("could not marshal: %v", err)
177 continue
178 }
179
180 stateAppend, err := h.(encoding.BinaryAppender).AppendBinary(make([]byte, 4, 32))
181 if err != nil {
182 t.Errorf("could not marshal: %v", err)
183 continue
184 }
185 stateAppend = stateAppend[4:]
186
187 if string(state) != g.halfStateCastagnoli {
188 t.Errorf("Castagnoli(%q) state = %q, want %q", g.in, state, g.halfStateCastagnoli)
189 continue
190 }
191
192 if string(stateAppend) != g.halfStateCastagnoli {
193 t.Errorf("Castagnoli(%q) state = %q, want %q", g.in, stateAppend, g.halfStateCastagnoli)
194 continue
195 }
196
197 if err := h2.(encoding.BinaryUnmarshaler).UnmarshalBinary(state); err != nil {
198 t.Errorf("could not unmarshal: %v", err)
199 continue
200 }
201
202 io.WriteString(h, g.in[len(g.in)/2:])
203 io.WriteString(h2, g.in[len(g.in)/2:])
204
205 if h.Sum32() != h2.Sum32() {
206 t.Errorf("Castagnoli(%s) = 0x%x != marshaled 0x%x", g.in, h.Sum32(), h2.Sum32())
207 }
208 }
209 })
210 }
211
212 func TestMarshalTableMismatch(t *testing.T) {
213 h1 := New(IEEETable)
214 h2 := New(MakeTable(Castagnoli))
215
216 state1, err := h1.(encoding.BinaryMarshaler).MarshalBinary()
217 if err != nil {
218 t.Errorf("could not marshal: %v", err)
219 }
220
221 if err := h2.(encoding.BinaryUnmarshaler).UnmarshalBinary(state1); err == nil {
222 t.Errorf("no error when one was expected")
223 }
224 }
225
226
227 func TestSlicing(t *testing.T) {
228 tab := slicingMakeTable(IEEE)
229 testGoldenIEEE(t, func(b []byte) uint32 {
230 return slicingUpdate(0, tab, b)
231 })
232
233 tab = slicingMakeTable(Castagnoli)
234 testGoldenCastagnoli(t, func(b []byte) uint32 {
235 return slicingUpdate(0, tab, b)
236 })
237
238
239 for _, poly := range []uint32{IEEE, Castagnoli, Koopman, 0xD5828281} {
240 t1 := simpleMakeTable(poly)
241 f1 := func(crc uint32, b []byte) uint32 {
242 return simpleUpdate(crc, t1, b)
243 }
244 t2 := slicingMakeTable(poly)
245 f2 := func(crc uint32, b []byte) uint32 {
246 return slicingUpdate(crc, t2, b)
247 }
248 testCrossCheck(t, f1, f2)
249 }
250 }
251
252 func TestArchIEEE(t *testing.T) {
253 if !archAvailableIEEE() {
254 t.Skip("Arch-specific IEEE not available.")
255 }
256 archInitIEEE()
257 slicingTable := slicingMakeTable(IEEE)
258 testCrossCheck(t, archUpdateIEEE, func(crc uint32, b []byte) uint32 {
259 return slicingUpdate(crc, slicingTable, b)
260 })
261 }
262
263 func TestArchCastagnoli(t *testing.T) {
264 if !archAvailableCastagnoli() {
265 t.Skip("Arch-specific Castagnoli not available.")
266 }
267 archInitCastagnoli()
268 slicingTable := slicingMakeTable(Castagnoli)
269 testCrossCheck(t, archUpdateCastagnoli, func(crc uint32, b []byte) uint32 {
270 return slicingUpdate(crc, slicingTable, b)
271 })
272 }
273
274 func TestGolden(t *testing.T) {
275 testGoldenIEEE(t, ChecksumIEEE)
276
277
278
279 for delta := 1; delta <= 7; delta++ {
280 testGoldenIEEE(t, func(b []byte) uint32 {
281 ieee := NewIEEE()
282 d := delta
283 if d >= len(b) {
284 d = len(b)
285 }
286 ieee.Write(b[:d])
287 ieee.Write(b[d:])
288 return ieee.Sum32()
289 })
290 }
291
292 castagnoliTab := MakeTable(Castagnoli)
293 if castagnoliTab == nil {
294 t.Errorf("nil Castagnoli Table")
295 }
296
297 testGoldenCastagnoli(t, func(b []byte) uint32 {
298 castagnoli := New(castagnoliTab)
299 castagnoli.Write(b)
300 return castagnoli.Sum32()
301 })
302
303
304
305 for delta := 1; delta <= 7; delta++ {
306 testGoldenCastagnoli(t, func(b []byte) uint32 {
307 castagnoli := New(castagnoliTab)
308 d := delta
309 if d >= len(b) {
310 d = len(b)
311 }
312 castagnoli.Write(b[:d])
313 castagnoli.Write(b[d:])
314 return castagnoli.Sum32()
315 })
316 }
317 }
318
319 func BenchmarkCRC32(b *testing.B) {
320 b.Run("poly=IEEE", benchmarkAll(NewIEEE()))
321 b.Run("poly=Castagnoli", benchmarkAll(New(MakeTable(Castagnoli))))
322 b.Run("poly=Koopman", benchmarkAll(New(MakeTable(Koopman))))
323 }
324
325 func benchmarkAll(h hash.Hash32) func(b *testing.B) {
326 return func(b *testing.B) {
327 for _, size := range []int{15, 40, 512, 1 << 10, 4 << 10, 32 << 10} {
328 name := fmt.Sprint(size)
329 if size >= 1024 {
330 name = fmt.Sprintf("%dkB", size/1024)
331 }
332 b.Run("size="+name, func(b *testing.B) {
333 for align := 0; align <= 1; align++ {
334 b.Run(fmt.Sprintf("align=%d", align), func(b *testing.B) {
335 benchmark(b, h, int64(size), int64(align))
336 })
337 }
338 })
339 }
340 }
341 }
342
343 func benchmark(b *testing.B, h hash.Hash32, n, alignment int64) {
344 b.SetBytes(n)
345 data := make([]byte, n+alignment)
346 data = data[alignment:]
347 for i := range data {
348 data[i] = byte(i)
349 }
350 in := make([]byte, 0, h.Size())
351
352
353 h.Reset()
354 h.Write(data)
355 h.Sum(in)
356
357 in = in[:0]
358
359 b.ResetTimer()
360 for i := 0; i < b.N; i++ {
361 h.Reset()
362 h.Write(data)
363 h.Sum(in)
364 in = in[:0]
365 }
366 }
367
View as plain text