src/hash/crc32/crc32_test.go - go - Git at Google

 // 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"
 	"math/rand"
 	"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"},
 }

 // testGoldenIEEE verifies that the given function returns
 // correct IEEE checksums.
 func testGoldenIEEE(t *testing.T, crcFunc func(b []byte) uint32) {
 	for _, g := range golden {
 		if crc := crcFunc([]byte(g.in)); crc != g.ieee {
 			t.Errorf("IEEE(%s) = 0x%x want 0x%x", g.in, crc, g.ieee)
 		}
 	}
 }

 // testGoldenCastagnoli verifies that the given function returns
 // correct IEEE checksums.
 func testGoldenCastagnoli(t *testing.T, crcFunc func(b []byte) uint32) {
 	for _, g := range golden {
 		if crc := crcFunc([]byte(g.in)); crc != g.castagnoli {
 			t.Errorf("Castagnoli(%s) = 0x%x want 0x%x", g.in, crc, g.castagnoli)
 		}
 	}
 }

 // testCrossCheck generates random buffers of various lengths and verifies that
 // the two "update" functions return the same result.
 func testCrossCheck(t *testing.T, crcFunc1, crcFunc2 func(crc uint32, b []byte) uint32) {
 	// The AMD64 implementation has some cutoffs at lengths 168*3=504 and
 	// 1344*3=4032. We should make sure lengths around these values are in the
 	// list.
 	lengths := []int{0, 1, 2, 3, 4, 5, 10, 16, 50, 100, 128,
 		500, 501, 502, 503, 504, 505, 512, 1000, 1024, 2000,
 		4030, 4031, 4032, 4033, 4036, 4040, 4048, 4096, 5000, 10000}
 	for _, length := range lengths {
 		p := make([]byte, length)
 		_, _ = rand.Read(p)
 		crcInit := uint32(rand.Int63())
 		crc1 := crcFunc1(crcInit, p)
 		crc2 := crcFunc2(crcInit, p)
 		if crc1 != crc2 {
 			t.Errorf("mismatch: 0x%x vs 0x%x (buffer length %d)", crc1, crc2, length)
 		}
 	}
 }

 // TestSimple tests the simple generic algorithm.
 func TestSimple(t *testing.T) {
 	tab := simpleMakeTable(IEEE)
 	testGoldenIEEE(t, func(b []byte) uint32 {
 		return simpleUpdate(0, tab, b)
 	})

 	tab = simpleMakeTable(Castagnoli)
 	testGoldenCastagnoli(t, func(b []byte) uint32 {
 		return simpleUpdate(0, tab, b)
 	})
 }

 // TestSimple tests the slicing-by-8 algorithm.
 func TestSlicing(t *testing.T) {
 	tab := slicingMakeTable(IEEE)
 	testGoldenIEEE(t, func(b []byte) uint32 {
 		return slicingUpdate(0, tab, b)
 	})

 	tab = slicingMakeTable(Castagnoli)
 	testGoldenCastagnoli(t, func(b []byte) uint32 {
 		return slicingUpdate(0, tab, b)
 	})

 	// Cross-check various polys against the simple algorithm.
 	for _, poly := range []uint32{IEEE, Castagnoli, Koopman, 0xD5828281} {
 		t1 := simpleMakeTable(poly)
 		f1 := func(crc uint32, b []byte) uint32 {
 			return simpleUpdate(crc, t1, b)
 		}
 		t2 := slicingMakeTable(poly)
 		f2 := func(crc uint32, b []byte) uint32 {
 			return slicingUpdate(crc, t2, b)
 		}
 		testCrossCheck(t, f1, f2)
 	}
 }

 func TestArchIEEE(t *testing.T) {
 	if !archAvailableIEEE() {
 		t.Skip("Arch-specific IEEE not available.")
 	}
 	archInitIEEE()
 	slicingTable := slicingMakeTable(IEEE)
 	testCrossCheck(t, archUpdateIEEE, func(crc uint32, b []byte) uint32 {
 		return slicingUpdate(crc, slicingTable, b)
 	})
 }

 func TestArchCastagnoli(t *testing.T) {
 	if !archAvailableCastagnoli() {
 		t.Skip("Arch-specific Castagnoli not available.")
 	}
 	archInitCastagnoli()
 	slicingTable := slicingMakeTable(Castagnoli)
 	testCrossCheck(t, archUpdateCastagnoli, func(crc uint32, b []byte) uint32 {
 		return slicingUpdate(crc, slicingTable, b)
 	})
 }

 func TestGolden(t *testing.T) {
 	testGoldenIEEE(t, ChecksumIEEE)

 	// Some implementations have special code to deal with misaligned
 	// data; test that as well.
 	for delta := 1; delta <= 7; delta++ {
 		testGoldenIEEE(t, func(b []byte) uint32 {
 			ieee := NewIEEE()
 			d := delta
 			if d >= len(b) {
 				d = len(b)
 			}
 			ieee.Write(b[:d])
 			ieee.Write(b[d:])
 			return ieee.Sum32()
 		})
 	}

 	castagnoliTab := MakeTable(Castagnoli)
 	if castagnoliTab == nil {
 		t.Errorf("nil Castagnoli Table")
 	}

 	testGoldenCastagnoli(t, func(b []byte) uint32 {
 		castagnoli := New(castagnoliTab)
 		castagnoli.Write(b)
 		return castagnoli.Sum32()
 	})

 	// Some implementations have special code to deal with misaligned
 	// data; test that as well.
 	for delta := 1; delta <= 7; delta++ {
 		testGoldenCastagnoli(t, func(b []byte) uint32 {
 			castagnoli := New(castagnoliTab)
 			d := delta
 			if d >= len(b) {
 				d = len(b)
 			}
 			castagnoli.Write(b[:d])
 			castagnoli.Write(b[d:])
 			return castagnoli.Sum32()
 		})
 	}
 }

 func BenchmarkIEEECrc40B(b *testing.B) {
 	benchmark(b, NewIEEE(), 40, 0)
 }

 func BenchmarkIEEECrc1KB(b *testing.B) {
 	benchmark(b, NewIEEE(), 1<<10, 0)
 }

 func BenchmarkIEEECrc4KB(b *testing.B) {
 	benchmark(b, NewIEEE(), 4<<10, 0)
 }

 func BenchmarkIEEECrc32KB(b *testing.B) {
 	benchmark(b, NewIEEE(), 32<<10, 0)
 }

 func BenchmarkCastagnoliCrc15B(b *testing.B) {
 	benchmark(b, New(MakeTable(Castagnoli)), 15, 0)
 }

 func BenchmarkCastagnoliCrc15BMisaligned(b *testing.B) {
 	benchmark(b, New(MakeTable(Castagnoli)), 15, 1)
 }

 func BenchmarkCastagnoliCrc40B(b *testing.B) {
 	benchmark(b, New(MakeTable(Castagnoli)), 40, 0)
 }

 func BenchmarkCastagnoliCrc40BMisaligned(b *testing.B) {
 	benchmark(b, New(MakeTable(Castagnoli)), 40, 1)
 }

 func BenchmarkCastagnoliCrc512(b *testing.B) {
 	benchmark(b, New(MakeTable(Castagnoli)), 512, 0)
 }

 func BenchmarkCastagnoliCrc512Misaligned(b *testing.B) {
 	benchmark(b, New(MakeTable(Castagnoli)), 512, 1)
 }

 func BenchmarkCastagnoliCrc1KB(b *testing.B) {
 	benchmark(b, New(MakeTable(Castagnoli)), 1<<10, 0)
 }

 func BenchmarkCastagnoliCrc1KBMisaligned(b *testing.B) {
 	benchmark(b, New(MakeTable(Castagnoli)), 1<<10, 1)
 }

 func BenchmarkCastagnoliCrc4KB(b *testing.B) {
 	benchmark(b, New(MakeTable(Castagnoli)), 4<<10, 0)
 }

 func BenchmarkCastagnoliCrc4KBMisaligned(b *testing.B) {
 	benchmark(b, New(MakeTable(Castagnoli)), 4<<10, 1)
 }

 func BenchmarkCastagnoliCrc32KB(b *testing.B) {
 	benchmark(b, New(MakeTable(Castagnoli)), 32<<10, 0)
 }

 func BenchmarkCastagnoliCrc32KBMisaligned(b *testing.B) {
 	benchmark(b, New(MakeTable(Castagnoli)), 32<<10, 1)
 }

 func benchmark(b *testing.B, h hash.Hash32, n, alignment int64) {
 	b.SetBytes(n)
 	data := make([]byte, n+alignment)
 	data = data[alignment:]
 	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)
 	}
 }
	// 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"
	"math/rand"
	"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"},
	}

	// testGoldenIEEE verifies that the given function returns
	// correct IEEE checksums.
	func testGoldenIEEE(t *testing.T, crcFunc func(b []byte) uint32) {
	for _, g := range golden {
	if crc := crcFunc([]byte(g.in)); crc != g.ieee {
	t.Errorf("IEEE(%s) = 0x%x want 0x%x", g.in, crc, g.ieee)
	}
	}
	}

	// testGoldenCastagnoli verifies that the given function returns
	// correct IEEE checksums.
	func testGoldenCastagnoli(t *testing.T, crcFunc func(b []byte) uint32) {
	for _, g := range golden {
	if crc := crcFunc([]byte(g.in)); crc != g.castagnoli {
	t.Errorf("Castagnoli(%s) = 0x%x want 0x%x", g.in, crc, g.castagnoli)
	}
	}
	}

	// testCrossCheck generates random buffers of various lengths and verifies that
	// the two "update" functions return the same result.
	func testCrossCheck(t *testing.T, crcFunc1, crcFunc2 func(crc uint32, b []byte) uint32) {
	// The AMD64 implementation has some cutoffs at lengths 168*3=504 and
	// 1344*3=4032. We should make sure lengths around these values are in the
	// list.
	lengths := []int{0, 1, 2, 3, 4, 5, 10, 16, 50, 100, 128,
	500, 501, 502, 503, 504, 505, 512, 1000, 1024, 2000,
	4030, 4031, 4032, 4033, 4036, 4040, 4048, 4096, 5000, 10000}
	for _, length := range lengths {
	p := make([]byte, length)
	_, _ = rand.Read(p)
	crcInit := uint32(rand.Int63())
	crc1 := crcFunc1(crcInit, p)
	crc2 := crcFunc2(crcInit, p)
	if crc1 != crc2 {
	t.Errorf("mismatch: 0x%x vs 0x%x (buffer length %d)", crc1, crc2, length)
	}
	}
	}

	// TestSimple tests the simple generic algorithm.
	func TestSimple(t *testing.T) {
	tab := simpleMakeTable(IEEE)
	testGoldenIEEE(t, func(b []byte) uint32 {
	return simpleUpdate(0, tab, b)
	})

	tab = simpleMakeTable(Castagnoli)
	testGoldenCastagnoli(t, func(b []byte) uint32 {
	return simpleUpdate(0, tab, b)
	})
	}

	// TestSimple tests the slicing-by-8 algorithm.
	func TestSlicing(t *testing.T) {
	tab := slicingMakeTable(IEEE)
	testGoldenIEEE(t, func(b []byte) uint32 {
	return slicingUpdate(0, tab, b)
	})

	tab = slicingMakeTable(Castagnoli)
	testGoldenCastagnoli(t, func(b []byte) uint32 {
	return slicingUpdate(0, tab, b)
	})

	// Cross-check various polys against the simple algorithm.
	for _, poly := range []uint32{IEEE, Castagnoli, Koopman, 0xD5828281} {
	t1 := simpleMakeTable(poly)
	f1 := func(crc uint32, b []byte) uint32 {
	return simpleUpdate(crc, t1, b)
	}
	t2 := slicingMakeTable(poly)
	f2 := func(crc uint32, b []byte) uint32 {
	return slicingUpdate(crc, t2, b)
	}
	testCrossCheck(t, f1, f2)
	}
	}

	func TestArchIEEE(t *testing.T) {
	if !archAvailableIEEE() {
	t.Skip("Arch-specific IEEE not available.")
	}
	archInitIEEE()
	slicingTable := slicingMakeTable(IEEE)
	testCrossCheck(t, archUpdateIEEE, func(crc uint32, b []byte) uint32 {
	return slicingUpdate(crc, slicingTable, b)
	})
	}

	func TestArchCastagnoli(t *testing.T) {
	if !archAvailableCastagnoli() {
	t.Skip("Arch-specific Castagnoli not available.")
	}
	archInitCastagnoli()
	slicingTable := slicingMakeTable(Castagnoli)
	testCrossCheck(t, archUpdateCastagnoli, func(crc uint32, b []byte) uint32 {
	return slicingUpdate(crc, slicingTable, b)
	})
	}

	func TestGolden(t *testing.T) {
	testGoldenIEEE(t, ChecksumIEEE)

	// Some implementations have special code to deal with misaligned
	// data; test that as well.
	for delta := 1; delta <= 7; delta++ {
	testGoldenIEEE(t, func(b []byte) uint32 {
	ieee := NewIEEE()
	d := delta
	if d >= len(b) {
	d = len(b)
	}
	ieee.Write(b[:d])
	ieee.Write(b[d:])
	return ieee.Sum32()
	})
	}

	castagnoliTab := MakeTable(Castagnoli)
	if castagnoliTab == nil {
	t.Errorf("nil Castagnoli Table")
	}

	testGoldenCastagnoli(t, func(b []byte) uint32 {
	castagnoli := New(castagnoliTab)
	castagnoli.Write(b)
	return castagnoli.Sum32()
	})

	// Some implementations have special code to deal with misaligned
	// data; test that as well.
	for delta := 1; delta <= 7; delta++ {
	testGoldenCastagnoli(t, func(b []byte) uint32 {
	castagnoli := New(castagnoliTab)
	d := delta
	if d >= len(b) {
	d = len(b)
	}
	castagnoli.Write(b[:d])
	castagnoli.Write(b[d:])
	return castagnoli.Sum32()
	})
	}
	}

	func BenchmarkIEEECrc40B(b *testing.B) {
	benchmark(b, NewIEEE(), 40, 0)
	}

	func BenchmarkIEEECrc1KB(b *testing.B) {
	benchmark(b, NewIEEE(), 1<<10, 0)
	}

	func BenchmarkIEEECrc4KB(b *testing.B) {
	benchmark(b, NewIEEE(), 4<<10, 0)
	}

	func BenchmarkIEEECrc32KB(b *testing.B) {
	benchmark(b, NewIEEE(), 32<<10, 0)
	}

	func BenchmarkCastagnoliCrc15B(b *testing.B) {
	benchmark(b, New(MakeTable(Castagnoli)), 15, 0)
	}

	func BenchmarkCastagnoliCrc15BMisaligned(b *testing.B) {
	benchmark(b, New(MakeTable(Castagnoli)), 15, 1)
	}

	func BenchmarkCastagnoliCrc40B(b *testing.B) {
	benchmark(b, New(MakeTable(Castagnoli)), 40, 0)
	}

	func BenchmarkCastagnoliCrc40BMisaligned(b *testing.B) {
	benchmark(b, New(MakeTable(Castagnoli)), 40, 1)
	}

	func BenchmarkCastagnoliCrc512(b *testing.B) {
	benchmark(b, New(MakeTable(Castagnoli)), 512, 0)
	}

	func BenchmarkCastagnoliCrc512Misaligned(b *testing.B) {
	benchmark(b, New(MakeTable(Castagnoli)), 512, 1)
	}

	func BenchmarkCastagnoliCrc1KB(b *testing.B) {
	benchmark(b, New(MakeTable(Castagnoli)), 1<<10, 0)
	}

	func BenchmarkCastagnoliCrc1KBMisaligned(b *testing.B) {
	benchmark(b, New(MakeTable(Castagnoli)), 1<<10, 1)
	}

	func BenchmarkCastagnoliCrc4KB(b *testing.B) {
	benchmark(b, New(MakeTable(Castagnoli)), 4<<10, 0)
	}

	func BenchmarkCastagnoliCrc4KBMisaligned(b *testing.B) {
	benchmark(b, New(MakeTable(Castagnoli)), 4<<10, 1)
	}

	func BenchmarkCastagnoliCrc32KB(b *testing.B) {
	benchmark(b, New(MakeTable(Castagnoli)), 32<<10, 0)
	}

	func BenchmarkCastagnoliCrc32KBMisaligned(b *testing.B) {
	benchmark(b, New(MakeTable(Castagnoli)), 32<<10, 1)
	}

	func benchmark(b *testing.B, h hash.Hash32, n, alignment int64) {
	b.SetBytes(n)
	data := make([]byte, n+alignment)
	data = data[alignment:]
	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)
	}
	}