libgo/go/hash/adler32/adler32_test.go

   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 }