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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package crc32
import (
"hash"
"io"
"testing"
)
type test struct {
ieee, castagnoli uint32
in string
}
var golden = []test{
{0x0, 0x0, ""},
{0xe8b7be43, 0xc1d04330, "a"},
{0x9e83486d, 0xe2a22936, "ab"},
{0x352441c2, 0x364b3fb7, "abc"},
{0xed82cd11, 0x92c80a31, "abcd"},
{0x8587d865, 0xc450d697, "abcde"},
{0x4b8e39ef, 0x53bceff1, "abcdef"},
{0x312a6aa6, 0xe627f441, "abcdefg"},
{0xaeef2a50, 0xa9421b7, "abcdefgh"},
{0x8da988af, 0x2ddc99fc, "abcdefghi"},
{0x3981703a, 0xe6599437, "abcdefghij"},
{0x6b9cdfe7, 0xb2cc01fe, "Discard medicine more than two years old."},
{0xc90ef73f, 0xe28207f, "He who has a shady past knows that nice guys finish last."},
{0xb902341f, 0xbe93f964, "I wouldn't marry him with a ten foot pole."},
{0x42080e8, 0x9e3be0c3, "Free! Free!/A trip/to Mars/for 900/empty jars/Burma Shave"},
{0x154c6d11, 0xf505ef04, "The days of the digital watch are numbered. -Tom Stoppard"},
{0x4c418325, 0x85d3dc82, "Nepal premier won't resign."},
{0x33955150, 0xc5142380, "For every action there is an equal and opposite government program."},
{0x26216a4b, 0x75eb77dd, "His money is twice tainted: 'taint yours and 'taint mine."},
{0x1abbe45e, 0x91ebe9f7, "There is no reason for any individual to have a computer in their home. -Ken Olsen, 1977"},
{0xc89a94f7, 0xf0b1168e, "It's a tiny change to the code and not completely disgusting. - Bob Manchek"},
{0xab3abe14, 0x572b74e2, "size: a.out: bad magic"},
{0xbab102b6, 0x8a58a6d5, "The major problem is with sendmail. -Mark Horton"},
{0x999149d7, 0x9c426c50, "Give me a rock, paper and scissors and I will move the world. CCFestoon"},
{0x6d52a33c, 0x735400a4, "If the enemy is within range, then so are you."},
{0x90631e8d, 0xbec49c95, "It's well we cannot hear the screams/That we create in others' dreams."},
{0x78309130, 0xa95a2079, "You remind me of a TV show, but that's all right: I watch it anyway."},
{0x7d0a377f, 0xde2e65c5, "C is as portable as Stonehedge!!"},
{0x8c79fd79, 0x297a88ed, "Even if I could be Shakespeare, I think I should still choose to be Faraday. - A. Huxley"},
{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"},
{0x8e0bb443, 0xdcded527, "How can you write a big system without C++? -Paul Glick"},
}
func TestGolden(t *testing.T) {
castagnoliTab := MakeTable(Castagnoli)
for _, g := range golden {
ieee := NewIEEE()
io.WriteString(ieee, g.in)
s := ieee.Sum32()
if s != g.ieee {
t.Errorf("IEEE(%s) = 0x%x want 0x%x", g.in, s, g.ieee)
}
castagnoli := New(castagnoliTab)
io.WriteString(castagnoli, g.in)
s = castagnoli.Sum32()
if s != g.castagnoli {
t.Errorf("Castagnoli(%s) = 0x%x want 0x%x", g.in, s, g.castagnoli)
}
if len(g.in) > 0 {
// The SSE4.2 implementation of this has code to deal
// with misaligned data so we ensure that we test that
// too.
castagnoli = New(castagnoliTab)
io.WriteString(castagnoli, g.in[:1])
io.WriteString(castagnoli, g.in[1:])
s = castagnoli.Sum32()
if s != g.castagnoli {
t.Errorf("Castagnoli[misaligned](%s) = 0x%x want 0x%x", g.in, s, g.castagnoli)
}
}
}
}
func BenchmarkIEEECrc40B(b *testing.B) {
benchmark(b, NewIEEE(), 40)
}
func BenchmarkIEEECrc1KB(b *testing.B) {
benchmark(b, NewIEEE(), 1<<10)
}
func BenchmarkIEEECrc4KB(b *testing.B) {
benchmark(b, NewIEEE(), 4<<10)
}
func BenchmarkIEEECrc32KB(b *testing.B) {
benchmark(b, NewIEEE(), 32<<10)
}
func BenchmarkCastagnoliCrc40B(b *testing.B) {
benchmark(b, New(MakeTable(Castagnoli)), 40)
}
func BenchmarkCastagnoliCrc1KB(b *testing.B) {
benchmark(b, New(MakeTable(Castagnoli)), 1<<10)
}
func BenchmarkCastagnoliCrc4KB(b *testing.B) {
benchmark(b, New(MakeTable(Castagnoli)), 4<<10)
}
func BenchmarkCastagnoliCrc32KB(b *testing.B) {
benchmark(b, New(MakeTable(Castagnoli)), 32<<10)
}
func benchmark(b *testing.B, h hash.Hash32, n int64) {
b.SetBytes(n)
data := make([]byte, n)
for i := range data {
data[i] = byte(i)
}
in := make([]byte, 0, h.Size())
// Warm up
h.Reset()
h.Write(data)
h.Sum(in)
b.ResetTimer()
for i := 0; i < b.N; i++ {
h.Reset()
h.Write(data)
h.Sum(in)
}
}
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