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go/src/encoding/binary/binary_test.go
Marcel van Lohuizen 6e2deaa1e1 encoding/binary: don't assume b.N > 0
Change-Id: I9e887a0b32baf0adc85fa9e4b85b319e8ef333e9
Reviewed-on: https://go-review.googlesource.com/20853
Reviewed-by: Russ Cox <rsc@golang.org>
2016-03-18 15:54:51 +00:00

447 lines
9.9 KiB
Go

// 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 binary
import (
"bytes"
"io"
"math"
"reflect"
"strings"
"testing"
)
type Struct struct {
Int8 int8
Int16 int16
Int32 int32
Int64 int64
Uint8 uint8
Uint16 uint16
Uint32 uint32
Uint64 uint64
Float32 float32
Float64 float64
Complex64 complex64
Complex128 complex128
Array [4]uint8
}
type T struct {
Int int
Uint uint
Uintptr uintptr
Array [4]int
}
var s = Struct{
0x01,
0x0203,
0x04050607,
0x08090a0b0c0d0e0f,
0x10,
0x1112,
0x13141516,
0x1718191a1b1c1d1e,
math.Float32frombits(0x1f202122),
math.Float64frombits(0x232425262728292a),
complex(
math.Float32frombits(0x2b2c2d2e),
math.Float32frombits(0x2f303132),
),
complex(
math.Float64frombits(0x333435363738393a),
math.Float64frombits(0x3b3c3d3e3f404142),
),
[4]uint8{0x43, 0x44, 0x45, 0x46},
}
var big = []byte{
1,
2, 3,
4, 5, 6, 7,
8, 9, 10, 11, 12, 13, 14, 15,
16,
17, 18,
19, 20, 21, 22,
23, 24, 25, 26, 27, 28, 29, 30,
31, 32, 33, 34,
35, 36, 37, 38, 39, 40, 41, 42,
43, 44, 45, 46, 47, 48, 49, 50,
51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66,
67, 68, 69, 70,
}
var little = []byte{
1,
3, 2,
7, 6, 5, 4,
15, 14, 13, 12, 11, 10, 9, 8,
16,
18, 17,
22, 21, 20, 19,
30, 29, 28, 27, 26, 25, 24, 23,
34, 33, 32, 31,
42, 41, 40, 39, 38, 37, 36, 35,
46, 45, 44, 43, 50, 49, 48, 47,
58, 57, 56, 55, 54, 53, 52, 51, 66, 65, 64, 63, 62, 61, 60, 59,
67, 68, 69, 70,
}
var src = []byte{1, 2, 3, 4, 5, 6, 7, 8}
var res = []int32{0x01020304, 0x05060708}
func checkResult(t *testing.T, dir string, order ByteOrder, err error, have, want interface{}) {
if err != nil {
t.Errorf("%v %v: %v", dir, order, err)
return
}
if !reflect.DeepEqual(have, want) {
t.Errorf("%v %v:\n\thave %+v\n\twant %+v", dir, order, have, want)
}
}
func testRead(t *testing.T, order ByteOrder, b []byte, s1 interface{}) {
var s2 Struct
err := Read(bytes.NewReader(b), order, &s2)
checkResult(t, "Read", order, err, s2, s1)
}
func testWrite(t *testing.T, order ByteOrder, b []byte, s1 interface{}) {
buf := new(bytes.Buffer)
err := Write(buf, order, s1)
checkResult(t, "Write", order, err, buf.Bytes(), b)
}
func TestLittleEndianRead(t *testing.T) { testRead(t, LittleEndian, little, s) }
func TestLittleEndianWrite(t *testing.T) { testWrite(t, LittleEndian, little, s) }
func TestLittleEndianPtrWrite(t *testing.T) { testWrite(t, LittleEndian, little, &s) }
func TestBigEndianRead(t *testing.T) { testRead(t, BigEndian, big, s) }
func TestBigEndianWrite(t *testing.T) { testWrite(t, BigEndian, big, s) }
func TestBigEndianPtrWrite(t *testing.T) { testWrite(t, BigEndian, big, &s) }
func TestReadSlice(t *testing.T) {
slice := make([]int32, 2)
err := Read(bytes.NewReader(src), BigEndian, slice)
checkResult(t, "ReadSlice", BigEndian, err, slice, res)
}
func TestWriteSlice(t *testing.T) {
buf := new(bytes.Buffer)
err := Write(buf, BigEndian, res)
checkResult(t, "WriteSlice", BigEndian, err, buf.Bytes(), src)
}
// Addresses of arrays are easier to manipulate with reflection than are slices.
var intArrays = []interface{}{
&[100]int8{},
&[100]int16{},
&[100]int32{},
&[100]int64{},
&[100]uint8{},
&[100]uint16{},
&[100]uint32{},
&[100]uint64{},
}
func TestSliceRoundTrip(t *testing.T) {
buf := new(bytes.Buffer)
for _, array := range intArrays {
src := reflect.ValueOf(array).Elem()
unsigned := false
switch src.Index(0).Kind() {
case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
unsigned = true
}
for i := 0; i < src.Len(); i++ {
if unsigned {
src.Index(i).SetUint(uint64(i * 0x07654321))
} else {
src.Index(i).SetInt(int64(i * 0x07654321))
}
}
buf.Reset()
srcSlice := src.Slice(0, src.Len())
err := Write(buf, BigEndian, srcSlice.Interface())
if err != nil {
t.Fatal(err)
}
dst := reflect.New(src.Type()).Elem()
dstSlice := dst.Slice(0, dst.Len())
err = Read(buf, BigEndian, dstSlice.Interface())
if err != nil {
t.Fatal(err)
}
if !reflect.DeepEqual(src.Interface(), dst.Interface()) {
t.Fatal(src)
}
}
}
func TestWriteT(t *testing.T) {
buf := new(bytes.Buffer)
ts := T{}
if err := Write(buf, BigEndian, ts); err == nil {
t.Errorf("WriteT: have err == nil, want non-nil")
}
tv := reflect.Indirect(reflect.ValueOf(ts))
for i, n := 0, tv.NumField(); i < n; i++ {
typ := tv.Field(i).Type().String()
if typ == "[4]int" {
typ = "int" // the problem is int, not the [4]
}
if err := Write(buf, BigEndian, tv.Field(i).Interface()); err == nil {
t.Errorf("WriteT.%v: have err == nil, want non-nil", tv.Field(i).Type())
} else if !strings.Contains(err.Error(), typ) {
t.Errorf("WriteT: have err == %q, want it to mention %s", err, typ)
}
}
}
type BlankFields struct {
A uint32
_ int32
B float64
_ [4]int16
C byte
_ [7]byte
_ struct {
f [8]float32
}
}
type BlankFieldsProbe struct {
A uint32
P0 int32
B float64
P1 [4]int16
C byte
P2 [7]byte
P3 struct {
F [8]float32
}
}
func TestBlankFields(t *testing.T) {
buf := new(bytes.Buffer)
b1 := BlankFields{A: 1234567890, B: 2.718281828, C: 42}
if err := Write(buf, LittleEndian, &b1); err != nil {
t.Error(err)
}
// zero values must have been written for blank fields
var p BlankFieldsProbe
if err := Read(buf, LittleEndian, &p); err != nil {
t.Error(err)
}
// quick test: only check first value of slices
if p.P0 != 0 || p.P1[0] != 0 || p.P2[0] != 0 || p.P3.F[0] != 0 {
t.Errorf("non-zero values for originally blank fields: %#v", p)
}
// write p and see if we can probe only some fields
if err := Write(buf, LittleEndian, &p); err != nil {
t.Error(err)
}
// read should ignore blank fields in b2
var b2 BlankFields
if err := Read(buf, LittleEndian, &b2); err != nil {
t.Error(err)
}
if b1.A != b2.A || b1.B != b2.B || b1.C != b2.C {
t.Errorf("%#v != %#v", b1, b2)
}
}
// An attempt to read into a struct with an unexported field will
// panic. This is probably not the best choice, but at this point
// anything else would be an API change.
type Unexported struct {
a int32
}
func TestUnexportedRead(t *testing.T) {
var buf bytes.Buffer
u1 := Unexported{a: 1}
if err := Write(&buf, LittleEndian, &u1); err != nil {
t.Fatal(err)
}
defer func() {
if recover() == nil {
t.Fatal("did not panic")
}
}()
var u2 Unexported
Read(&buf, LittleEndian, &u2)
}
func TestReadErrorMsg(t *testing.T) {
var buf bytes.Buffer
read := func(data interface{}) {
err := Read(&buf, LittleEndian, data)
want := "binary.Read: invalid type " + reflect.TypeOf(data).String()
if err == nil {
t.Errorf("%T: got no error; want %q", data, want)
return
}
if got := err.Error(); got != want {
t.Errorf("%T: got %q; want %q", data, got, want)
}
}
read(0)
s := new(struct{})
read(&s)
p := &s
read(&p)
}
func TestReadTruncated(t *testing.T) {
const data = "0123456789abcdef"
var b1 = make([]int32, 4)
var b2 struct {
A, B, C, D byte
E int32
F float64
}
for i := 0; i <= len(data); i++ {
var errWant error
switch i {
case 0:
errWant = io.EOF
case len(data):
errWant = nil
default:
errWant = io.ErrUnexpectedEOF
}
if err := Read(strings.NewReader(data[:i]), LittleEndian, &b1); err != errWant {
t.Errorf("Read(%d) with slice: got %v, want %v", i, err, errWant)
}
if err := Read(strings.NewReader(data[:i]), LittleEndian, &b2); err != errWant {
t.Errorf("Read(%d) with struct: got %v, want %v", i, err, errWant)
}
}
}
type byteSliceReader struct {
remain []byte
}
func (br *byteSliceReader) Read(p []byte) (int, error) {
n := copy(p, br.remain)
br.remain = br.remain[n:]
return n, nil
}
func BenchmarkReadSlice1000Int32s(b *testing.B) {
bsr := &byteSliceReader{}
slice := make([]int32, 1000)
buf := make([]byte, len(slice)*4)
b.SetBytes(int64(len(buf)))
b.ResetTimer()
for i := 0; i < b.N; i++ {
bsr.remain = buf
Read(bsr, BigEndian, slice)
}
}
func BenchmarkReadStruct(b *testing.B) {
bsr := &byteSliceReader{}
var buf bytes.Buffer
Write(&buf, BigEndian, &s)
b.SetBytes(int64(dataSize(reflect.ValueOf(s))))
t := s
b.ResetTimer()
for i := 0; i < b.N; i++ {
bsr.remain = buf.Bytes()
Read(bsr, BigEndian, &t)
}
b.StopTimer()
if b.N > 0 && !reflect.DeepEqual(s, t) {
b.Fatalf("struct doesn't match:\ngot %v;\nwant %v", t, s)
}
}
func BenchmarkReadInts(b *testing.B) {
var ls Struct
bsr := &byteSliceReader{}
var r io.Reader = bsr
b.SetBytes(2 * (1 + 2 + 4 + 8))
b.ResetTimer()
for i := 0; i < b.N; i++ {
bsr.remain = big
Read(r, BigEndian, &ls.Int8)
Read(r, BigEndian, &ls.Int16)
Read(r, BigEndian, &ls.Int32)
Read(r, BigEndian, &ls.Int64)
Read(r, BigEndian, &ls.Uint8)
Read(r, BigEndian, &ls.Uint16)
Read(r, BigEndian, &ls.Uint32)
Read(r, BigEndian, &ls.Uint64)
}
want := s
want.Float32 = 0
want.Float64 = 0
want.Complex64 = 0
want.Complex128 = 0
for i := range want.Array {
want.Array[i] = 0
}
b.StopTimer()
if b.N > 0 && !reflect.DeepEqual(ls, want) {
b.Fatalf("struct doesn't match:\ngot %v;\nwant %v", ls, want)
}
}
func BenchmarkWriteInts(b *testing.B) {
buf := new(bytes.Buffer)
var w io.Writer = buf
b.SetBytes(2 * (1 + 2 + 4 + 8))
b.ResetTimer()
for i := 0; i < b.N; i++ {
buf.Reset()
Write(w, BigEndian, s.Int8)
Write(w, BigEndian, s.Int16)
Write(w, BigEndian, s.Int32)
Write(w, BigEndian, s.Int64)
Write(w, BigEndian, s.Uint8)
Write(w, BigEndian, s.Uint16)
Write(w, BigEndian, s.Uint32)
Write(w, BigEndian, s.Uint64)
}
b.StopTimer()
if b.N > 0 && !bytes.Equal(buf.Bytes(), big[:30]) {
b.Fatalf("first half doesn't match: %x %x", buf.Bytes(), big[:30])
}
}
func BenchmarkWriteSlice1000Int32s(b *testing.B) {
slice := make([]int32, 1000)
buf := new(bytes.Buffer)
var w io.Writer = buf
b.SetBytes(4 * 1000)
b.ResetTimer()
for i := 0; i < b.N; i++ {
buf.Reset()
Write(w, BigEndian, slice)
}
b.StopTimer()
}