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- // Copyright 2013 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 bytes_test
- import (
- . "bytes"
- "internal/testenv"
- "testing"
- )
- var compareTests = []struct {
- a, b []byte
- i int
- }{
- {[]byte(""), []byte(""), 0},
- {[]byte("a"), []byte(""), 1},
- {[]byte(""), []byte("a"), -1},
- {[]byte("abc"), []byte("abc"), 0},
- {[]byte("abd"), []byte("abc"), 1},
- {[]byte("abc"), []byte("abd"), -1},
- {[]byte("ab"), []byte("abc"), -1},
- {[]byte("abc"), []byte("ab"), 1},
- {[]byte("x"), []byte("ab"), 1},
- {[]byte("ab"), []byte("x"), -1},
- {[]byte("x"), []byte("a"), 1},
- {[]byte("b"), []byte("x"), -1},
- // test runtime·memeq's chunked implementation
- {[]byte("abcdefgh"), []byte("abcdefgh"), 0},
- {[]byte("abcdefghi"), []byte("abcdefghi"), 0},
- {[]byte("abcdefghi"), []byte("abcdefghj"), -1},
- {[]byte("abcdefghj"), []byte("abcdefghi"), 1},
- // nil tests
- {nil, nil, 0},
- {[]byte(""), nil, 0},
- {nil, []byte(""), 0},
- {[]byte("a"), nil, 1},
- {nil, []byte("a"), -1},
- }
- func TestCompare(t *testing.T) {
- for _, tt := range compareTests {
- numShifts := 16
- buffer := make([]byte, len(tt.b)+numShifts)
- // vary the input alignment of tt.b
- for offset := 0; offset <= numShifts; offset++ {
- shiftedB := buffer[offset : len(tt.b)+offset]
- copy(shiftedB, tt.b)
- cmp := Compare(tt.a, shiftedB)
- if cmp != tt.i {
- t.Errorf(`Compare(%q, %q), offset %d = %v; want %v`, tt.a, tt.b, offset, cmp, tt.i)
- }
- }
- }
- }
- func TestCompareIdenticalSlice(t *testing.T) {
- var b = []byte("Hello Gophers!")
- if Compare(b, b) != 0 {
- t.Error("b != b")
- }
- if Compare(b, b[:1]) != 1 {
- t.Error("b > b[:1] failed")
- }
- }
- func TestCompareBytes(t *testing.T) {
- lengths := make([]int, 0) // lengths to test in ascending order
- for i := 0; i <= 128; i++ {
- lengths = append(lengths, i)
- }
- lengths = append(lengths, 256, 512, 1024, 1333, 4095, 4096, 4097)
- if !testing.Short() || testenv.Builder() != "" {
- lengths = append(lengths, 65535, 65536, 65537, 99999)
- }
- n := lengths[len(lengths)-1]
- a := make([]byte, n+1)
- b := make([]byte, n+1)
- for _, len := range lengths {
- // randomish but deterministic data. No 0 or 255.
- for i := 0; i < len; i++ {
- a[i] = byte(1 + 31*i%254)
- b[i] = byte(1 + 31*i%254)
- }
- // data past the end is different
- for i := len; i <= n; i++ {
- a[i] = 8
- b[i] = 9
- }
- cmp := Compare(a[:len], b[:len])
- if cmp != 0 {
- t.Errorf(`CompareIdentical(%d) = %d`, len, cmp)
- }
- if len > 0 {
- cmp = Compare(a[:len-1], b[:len])
- if cmp != -1 {
- t.Errorf(`CompareAshorter(%d) = %d`, len, cmp)
- }
- cmp = Compare(a[:len], b[:len-1])
- if cmp != 1 {
- t.Errorf(`CompareBshorter(%d) = %d`, len, cmp)
- }
- }
- for k := 0; k < len; k++ {
- b[k] = a[k] - 1
- cmp = Compare(a[:len], b[:len])
- if cmp != 1 {
- t.Errorf(`CompareAbigger(%d,%d) = %d`, len, k, cmp)
- }
- b[k] = a[k] + 1
- cmp = Compare(a[:len], b[:len])
- if cmp != -1 {
- t.Errorf(`CompareBbigger(%d,%d) = %d`, len, k, cmp)
- }
- b[k] = a[k]
- }
- }
- }
- func TestEndianBaseCompare(t *testing.T) {
- // This test compares byte slices that are almost identical, except one
- // difference that for some j, a[j]>b[j] and a[j+1]<b[j+1]. If the implementation
- // compares large chunks with wrong endianness, it gets wrong result.
- // no vector register is larger than 512 bytes for now
- const maxLength = 512
- a := make([]byte, maxLength)
- b := make([]byte, maxLength)
- // randomish but deterministic data. No 0 or 255.
- for i := 0; i < maxLength; i++ {
- a[i] = byte(1 + 31*i%254)
- b[i] = byte(1 + 31*i%254)
- }
- for i := 2; i <= maxLength; i <<= 1 {
- for j := 0; j < i-1; j++ {
- a[j] = b[j] - 1
- a[j+1] = b[j+1] + 1
- cmp := Compare(a[:i], b[:i])
- if cmp != -1 {
- t.Errorf(`CompareBbigger(%d,%d) = %d`, i, j, cmp)
- }
- a[j] = b[j] + 1
- a[j+1] = b[j+1] - 1
- cmp = Compare(a[:i], b[:i])
- if cmp != 1 {
- t.Errorf(`CompareAbigger(%d,%d) = %d`, i, j, cmp)
- }
- a[j] = b[j]
- a[j+1] = b[j+1]
- }
- }
- }
- func BenchmarkCompareBytesEqual(b *testing.B) {
- b1 := []byte("Hello Gophers!")
- b2 := []byte("Hello Gophers!")
- for i := 0; i < b.N; i++ {
- if Compare(b1, b2) != 0 {
- b.Fatal("b1 != b2")
- }
- }
- }
- func BenchmarkCompareBytesToNil(b *testing.B) {
- b1 := []byte("Hello Gophers!")
- var b2 []byte
- for i := 0; i < b.N; i++ {
- if Compare(b1, b2) != 1 {
- b.Fatal("b1 > b2 failed")
- }
- }
- }
- func BenchmarkCompareBytesEmpty(b *testing.B) {
- b1 := []byte("")
- b2 := b1
- for i := 0; i < b.N; i++ {
- if Compare(b1, b2) != 0 {
- b.Fatal("b1 != b2")
- }
- }
- }
- func BenchmarkCompareBytesIdentical(b *testing.B) {
- b1 := []byte("Hello Gophers!")
- b2 := b1
- for i := 0; i < b.N; i++ {
- if Compare(b1, b2) != 0 {
- b.Fatal("b1 != b2")
- }
- }
- }
- func BenchmarkCompareBytesSameLength(b *testing.B) {
- b1 := []byte("Hello Gophers!")
- b2 := []byte("Hello, Gophers")
- for i := 0; i < b.N; i++ {
- if Compare(b1, b2) != -1 {
- b.Fatal("b1 < b2 failed")
- }
- }
- }
- func BenchmarkCompareBytesDifferentLength(b *testing.B) {
- b1 := []byte("Hello Gophers!")
- b2 := []byte("Hello, Gophers!")
- for i := 0; i < b.N; i++ {
- if Compare(b1, b2) != -1 {
- b.Fatal("b1 < b2 failed")
- }
- }
- }
- func BenchmarkCompareBytesBigUnaligned(b *testing.B) {
- b.StopTimer()
- b1 := make([]byte, 0, 1<<20)
- for len(b1) < 1<<20 {
- b1 = append(b1, "Hello Gophers!"...)
- }
- b2 := append([]byte("hello"), b1...)
- b.StartTimer()
- for i := 0; i < b.N; i++ {
- if Compare(b1, b2[len("hello"):]) != 0 {
- b.Fatal("b1 != b2")
- }
- }
- b.SetBytes(int64(len(b1)))
- }
- func BenchmarkCompareBytesBig(b *testing.B) {
- b.StopTimer()
- b1 := make([]byte, 0, 1<<20)
- for len(b1) < 1<<20 {
- b1 = append(b1, "Hello Gophers!"...)
- }
- b2 := append([]byte{}, b1...)
- b.StartTimer()
- for i := 0; i < b.N; i++ {
- if Compare(b1, b2) != 0 {
- b.Fatal("b1 != b2")
- }
- }
- b.SetBytes(int64(len(b1)))
- }
- func BenchmarkCompareBytesBigIdentical(b *testing.B) {
- b.StopTimer()
- b1 := make([]byte, 0, 1<<20)
- for len(b1) < 1<<20 {
- b1 = append(b1, "Hello Gophers!"...)
- }
- b2 := b1
- b.StartTimer()
- for i := 0; i < b.N; i++ {
- if Compare(b1, b2) != 0 {
- b.Fatal("b1 != b2")
- }
- }
- b.SetBytes(int64(len(b1)))
- }
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