github.com/tcnksm/go@v0.0.0-20141208075154-439b32936367/src/hash/crc32/crc32_test.go (about)

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package crc32
     6  
     7  import (
     8  	"io"
     9  	"testing"
    10  )
    11  
    12  type test struct {
    13  	ieee, castagnoli uint32
    14  	in               string
    15  }
    16  
    17  var golden = []test{
    18  	{0x0, 0x0, ""},
    19  	{0xe8b7be43, 0xc1d04330, "a"},
    20  	{0x9e83486d, 0xe2a22936, "ab"},
    21  	{0x352441c2, 0x364b3fb7, "abc"},
    22  	{0xed82cd11, 0x92c80a31, "abcd"},
    23  	{0x8587d865, 0xc450d697, "abcde"},
    24  	{0x4b8e39ef, 0x53bceff1, "abcdef"},
    25  	{0x312a6aa6, 0xe627f441, "abcdefg"},
    26  	{0xaeef2a50, 0xa9421b7, "abcdefgh"},
    27  	{0x8da988af, 0x2ddc99fc, "abcdefghi"},
    28  	{0x3981703a, 0xe6599437, "abcdefghij"},
    29  	{0x6b9cdfe7, 0xb2cc01fe, "Discard medicine more than two years old."},
    30  	{0xc90ef73f, 0xe28207f, "He who has a shady past knows that nice guys finish last."},
    31  	{0xb902341f, 0xbe93f964, "I wouldn't marry him with a ten foot pole."},
    32  	{0x42080e8, 0x9e3be0c3, "Free! Free!/A trip/to Mars/for 900/empty jars/Burma Shave"},
    33  	{0x154c6d11, 0xf505ef04, "The days of the digital watch are numbered.  -Tom Stoppard"},
    34  	{0x4c418325, 0x85d3dc82, "Nepal premier won't resign."},
    35  	{0x33955150, 0xc5142380, "For every action there is an equal and opposite government program."},
    36  	{0x26216a4b, 0x75eb77dd, "His money is twice tainted: 'taint yours and 'taint mine."},
    37  	{0x1abbe45e, 0x91ebe9f7, "There is no reason for any individual to have a computer in their home. -Ken Olsen, 1977"},
    38  	{0xc89a94f7, 0xf0b1168e, "It's a tiny change to the code and not completely disgusting. - Bob Manchek"},
    39  	{0xab3abe14, 0x572b74e2, "size:  a.out:  bad magic"},
    40  	{0xbab102b6, 0x8a58a6d5, "The major problem is with sendmail.  -Mark Horton"},
    41  	{0x999149d7, 0x9c426c50, "Give me a rock, paper and scissors and I will move the world.  CCFestoon"},
    42  	{0x6d52a33c, 0x735400a4, "If the enemy is within range, then so are you."},
    43  	{0x90631e8d, 0xbec49c95, "It's well we cannot hear the screams/That we create in others' dreams."},
    44  	{0x78309130, 0xa95a2079, "You remind me of a TV show, but that's all right: I watch it anyway."},
    45  	{0x7d0a377f, 0xde2e65c5, "C is as portable as Stonehedge!!"},
    46  	{0x8c79fd79, 0x297a88ed, "Even if I could be Shakespeare, I think I should still choose to be Faraday. - A. Huxley"},
    47  	{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"},
    48  	{0x8e0bb443, 0xdcded527, "How can you write a big system without C++?  -Paul Glick"},
    49  }
    50  
    51  func TestGolden(t *testing.T) {
    52  	castagnoliTab := MakeTable(Castagnoli)
    53  
    54  	for _, g := range golden {
    55  		ieee := NewIEEE()
    56  		io.WriteString(ieee, g.in)
    57  		s := ieee.Sum32()
    58  		if s != g.ieee {
    59  			t.Errorf("IEEE(%s) = 0x%x want 0x%x", g.in, s, g.ieee)
    60  		}
    61  
    62  		castagnoli := New(castagnoliTab)
    63  		io.WriteString(castagnoli, g.in)
    64  		s = castagnoli.Sum32()
    65  		if s != g.castagnoli {
    66  			t.Errorf("Castagnoli(%s) = 0x%x want 0x%x", g.in, s, g.castagnoli)
    67  		}
    68  
    69  		if len(g.in) > 0 {
    70  			// The SSE4.2 implementation of this has code to deal
    71  			// with misaligned data so we ensure that we test that
    72  			// too.
    73  			castagnoli = New(castagnoliTab)
    74  			io.WriteString(castagnoli, g.in[:1])
    75  			io.WriteString(castagnoli, g.in[1:])
    76  			s = castagnoli.Sum32()
    77  			if s != g.castagnoli {
    78  				t.Errorf("Castagnoli[misaligned](%s) = 0x%x want 0x%x", g.in, s, g.castagnoli)
    79  			}
    80  		}
    81  	}
    82  }
    83  
    84  func BenchmarkCrc32KB(b *testing.B) {
    85  	b.SetBytes(1024)
    86  	data := make([]byte, 1024)
    87  	for i := range data {
    88  		data[i] = byte(i)
    89  	}
    90  	h := NewIEEE()
    91  	in := make([]byte, 0, h.Size())
    92  
    93  	b.ResetTimer()
    94  	for i := 0; i < b.N; i++ {
    95  		h.Reset()
    96  		h.Write(data)
    97  		h.Sum(in)
    98  	}
    99  }