github.com/slayercat/go@v0.0.0-20170428012452-c51559813f61/src/hash/adler32/adler32_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 adler32
     6  
     7  import (
     8  	"strings"
     9  	"testing"
    10  )
    11  
    12  var golden = []struct {
    13  	out uint32
    14  	in  string
    15  }{
    16  	{0x00000001, ""},
    17  	{0x00620062, "a"},
    18  	{0x012600c4, "ab"},
    19  	{0x024d0127, "abc"},
    20  	{0x03d8018b, "abcd"},
    21  	{0x05c801f0, "abcde"},
    22  	{0x081e0256, "abcdef"},
    23  	{0x0adb02bd, "abcdefg"},
    24  	{0x0e000325, "abcdefgh"},
    25  	{0x118e038e, "abcdefghi"},
    26  	{0x158603f8, "abcdefghij"},
    27  	{0x3f090f02, "Discard medicine more than two years old."},
    28  	{0x46d81477, "He who has a shady past knows that nice guys finish last."},
    29  	{0x40ee0ee1, "I wouldn't marry him with a ten foot pole."},
    30  	{0x16661315, "Free! Free!/A trip/to Mars/for 900/empty jars/Burma Shave"},
    31  	{0x5b2e1480, "The days of the digital watch are numbered.  -Tom Stoppard"},
    32  	{0x8c3c09ea, "Nepal premier won't resign."},
    33  	{0x45ac18fd, "For every action there is an equal and opposite government program."},
    34  	{0x53c61462, "His money is twice tainted: 'taint yours and 'taint mine."},
    35  	{0x7e511e63, "There is no reason for any individual to have a computer in their home. -Ken Olsen, 1977"},
    36  	{0xe4801a6a, "It's a tiny change to the code and not completely disgusting. - Bob Manchek"},
    37  	{0x61b507df, "size:  a.out:  bad magic"},
    38  	{0xb8631171, "The major problem is with sendmail.  -Mark Horton"},
    39  	{0x8b5e1904, "Give me a rock, paper and scissors and I will move the world.  CCFestoon"},
    40  	{0x7cc6102b, "If the enemy is within range, then so are you."},
    41  	{0x700318e7, "It's well we cannot hear the screams/That we create in others' dreams."},
    42  	{0x1e601747, "You remind me of a TV show, but that's all right: I watch it anyway."},
    43  	{0xb55b0b09, "C is as portable as Stonehedge!!"},
    44  	{0x39111dd0, "Even if I could be Shakespeare, I think I should still choose to be Faraday. - A. Huxley"},
    45  	{0x91dd304f, "The fugacity of a constituent in a mixture of gases at a given temperature is proportional to its mole fraction.  Lewis-Randall Rule"},
    46  	{0x2e5d1316, "How can you write a big system without C++?  -Paul Glick"},
    47  	{0xd0201df6, "'Invariant assertions' is the most elegant programming technique!  -Tom Szymanski"},
    48  	{0x211297c8, strings.Repeat("\xff", 5548) + "8"},
    49  	{0xbaa198c8, strings.Repeat("\xff", 5549) + "9"},
    50  	{0x553499be, strings.Repeat("\xff", 5550) + "0"},
    51  	{0xf0c19abe, strings.Repeat("\xff", 5551) + "1"},
    52  	{0x8d5c9bbe, strings.Repeat("\xff", 5552) + "2"},
    53  	{0x2af69cbe, strings.Repeat("\xff", 5553) + "3"},
    54  	{0xc9809dbe, strings.Repeat("\xff", 5554) + "4"},
    55  	{0x69189ebe, strings.Repeat("\xff", 5555) + "5"},
    56  	{0x86af0001, strings.Repeat("\x00", 1e5)},
    57  	{0x79660b4d, strings.Repeat("a", 1e5)},
    58  	{0x110588ee, strings.Repeat("ABCDEFGHIJKLMNOPQRSTUVWXYZ", 1e4)},
    59  }
    60  
    61  // checksum is a slow but simple implementation of the Adler-32 checksum.
    62  // It is a straight port of the sample code in RFC 1950 section 9.
    63  func checksum(p []byte) uint32 {
    64  	s1, s2 := uint32(1), uint32(0)
    65  	for _, x := range p {
    66  		s1 = (s1 + uint32(x)) % mod
    67  		s2 = (s2 + s1) % mod
    68  	}
    69  	return s2<<16 | s1
    70  }
    71  
    72  func TestGolden(t *testing.T) {
    73  	for _, g := range golden {
    74  		in := g.in
    75  		if len(in) > 220 {
    76  			in = in[:100] + "..." + in[len(in)-100:]
    77  		}
    78  		p := []byte(g.in)
    79  		if got := checksum(p); got != g.out {
    80  			t.Errorf("simple implementation: checksum(%q) = 0x%x want 0x%x", in, got, g.out)
    81  			continue
    82  		}
    83  		if got := Checksum(p); got != g.out {
    84  			t.Errorf("optimized implementation: Checksum(%q) = 0x%x want 0x%x", in, got, g.out)
    85  			continue
    86  		}
    87  	}
    88  }
    89  
    90  func BenchmarkAdler32KB(b *testing.B) {
    91  	b.SetBytes(1024)
    92  	data := make([]byte, 1024)
    93  	for i := range data {
    94  		data[i] = byte(i)
    95  	}
    96  	h := New()
    97  	in := make([]byte, 0, h.Size())
    98  
    99  	b.ResetTimer()
   100  	for i := 0; i < b.N; i++ {
   101  		h.Reset()
   102  		h.Write(data)
   103  		h.Sum(in)
   104  	}
   105  }