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// Copyright 2011 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"
"testing"
)
func testConstant(t *testing.T, w uint, max int) {
buf := make([]byte, MaxVarintLen64)
n := PutUvarint(buf, 1<<w-1)
if n != max {
t.Errorf("MaxVarintLen%d = %d; want %d", w, max, n)
}
}
func TestConstants(t *testing.T) {
testConstant(t, 16, MaxVarintLen16)
testConstant(t, 32, MaxVarintLen32)
testConstant(t, 64, MaxVarintLen64)
}
func testVarint(t *testing.T, x int64) {
buf := make([]byte, MaxVarintLen64)
n := PutVarint(buf, x)
y, m := Varint(buf[0:n])
if x != y {
t.Errorf("Varint(%d): got %d", x, y)
}
if n != m {
t.Errorf("Varint(%d): got n = %d; want %d", x, m, n)
}
buf2 := []byte("prefix")
buf2 = AppendVarint(buf2, x)
if string(buf2) != "prefix"+string(buf[:n]) {
t.Errorf("AppendVarint(%d): got %q, want %q", x, buf2, "prefix"+string(buf[:n]))
}
y, err := ReadVarint(bytes.NewReader(buf))
if err != nil {
t.Errorf("ReadVarint(%d): %s", x, err)
}
if x != y {
t.Errorf("ReadVarint(%d): got %d", x, y)
}
}
func testUvarint(t *testing.T, x uint64) {
buf := make([]byte, MaxVarintLen64)
n := PutUvarint(buf, x)
y, m := Uvarint(buf[0:n])
if x != y {
t.Errorf("Uvarint(%d): got %d", x, y)
}
if n != m {
t.Errorf("Uvarint(%d): got n = %d; want %d", x, m, n)
}
buf2 := []byte("prefix")
buf2 = AppendUvarint(buf2, x)
if string(buf2) != "prefix"+string(buf[:n]) {
t.Errorf("AppendUvarint(%d): got %q, want %q", x, buf2, "prefix"+string(buf[:n]))
}
y, err := ReadUvarint(bytes.NewReader(buf))
if err != nil {
t.Errorf("ReadUvarint(%d): %s", x, err)
}
if x != y {
t.Errorf("ReadUvarint(%d): got %d", x, y)
}
}
var tests = []int64{
-1 << 63,
-1<<63 + 1,
-1,
0,
1,
2,
10,
20,
63,
64,
65,
127,
128,
129,
255,
256,
257,
1<<63 - 1,
}
func TestVarint(t *testing.T) {
for _, x := range tests {
testVarint(t, x)
testVarint(t, -x)
}
for x := int64(0x7); x != 0; x <<= 1 {
testVarint(t, x)
testVarint(t, -x)
}
}
func TestUvarint(t *testing.T) {
for _, x := range tests {
testUvarint(t, uint64(x))
}
for x := uint64(0x7); x != 0; x <<= 1 {
testUvarint(t, x)
}
}
func TestBufferTooSmall(t *testing.T) {
buf := []byte{0x80, 0x80, 0x80, 0x80}
for i := 0; i <= len(buf); i++ {
buf := buf[0:i]
x, n := Uvarint(buf)
if x != 0 || n != 0 {
t.Errorf("Uvarint(%v): got x = %d, n = %d", buf, x, n)
}
x, err := ReadUvarint(bytes.NewReader(buf))
wantErr := io.EOF
if i > 0 {
wantErr = io.ErrUnexpectedEOF
}
if x != 0 || err != wantErr {
t.Errorf("ReadUvarint(%v): got x = %d, err = %s", buf, x, err)
}
}
}
// Ensure that we catch overflows of bytes going past MaxVarintLen64.
// See issue https://golang.org/issues/41185
func TestBufferTooBigWithOverflow(t *testing.T) {
tests := []struct {
in []byte
name string
wantN int
wantValue uint64
}{
{
name: "invalid: 1000 bytes",
in: func() []byte {
b := make([]byte, 1000)
for i := range b {
b[i] = 0xff
}
b[999] = 0
return b
}(),
wantN: -11,
wantValue: 0,
},
{
name: "valid: math.MaxUint64-40",
in: []byte{0xd7, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x01},
wantValue: math.MaxUint64 - 40,
wantN: 10,
},
{
name: "invalid: with more than MaxVarintLen64 bytes",
in: []byte{0xd7, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x01},
wantN: -11,
wantValue: 0,
},
{
name: "invalid: 10th byte",
in: []byte{0xd7, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f},
wantN: -10,
wantValue: 0,
},
}
for _, tt := range tests {
tt := tt
t.Run(tt.name, func(t *testing.T) {
value, n := Uvarint(tt.in)
if g, w := n, tt.wantN; g != w {
t.Errorf("bytes returned=%d, want=%d", g, w)
}
if g, w := value, tt.wantValue; g != w {
t.Errorf("value=%d, want=%d", g, w)
}
})
}
}
func testOverflow(t *testing.T, buf []byte, x0 uint64, n0 int, err0 error) {
x, n := Uvarint(buf)
if x != 0 || n != n0 {
t.Errorf("Uvarint(% X): got x = %d, n = %d; want 0, %d", buf, x, n, n0)
}
r := bytes.NewReader(buf)
len := r.Len()
x, err := ReadUvarint(r)
if x != x0 || err != err0 {
t.Errorf("ReadUvarint(%v): got x = %d, err = %s; want %d, %s", buf, x, err, x0, err0)
}
if read := len - r.Len(); read > MaxVarintLen64 {
t.Errorf("ReadUvarint(%v): read more than MaxVarintLen64 bytes, got %d", buf, read)
}
}
func TestOverflow(t *testing.T) {
testOverflow(t, []byte{0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x2}, 0, -10, overflow)
testOverflow(t, []byte{0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x1, 0, 0}, 0, -11, overflow)
testOverflow(t, []byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}, 1<<64-1, -11, overflow) // 11 bytes, should overflow
}
func TestNonCanonicalZero(t *testing.T) {
buf := []byte{0x80, 0x80, 0x80, 0}
x, n := Uvarint(buf)
if x != 0 || n != 4 {
t.Errorf("Uvarint(%v): got x = %d, n = %d; want 0, 4", buf, x, n)
}
}
func BenchmarkPutUvarint32(b *testing.B) {
buf := make([]byte, MaxVarintLen32)
b.SetBytes(4)
for i := 0; i < b.N; i++ {
for j := uint(0); j < MaxVarintLen32; j++ {
PutUvarint(buf, 1<<(j*7))
}
}
}
func BenchmarkPutUvarint64(b *testing.B) {
buf := make([]byte, MaxVarintLen64)
b.SetBytes(8)
for i := 0; i < b.N; i++ {
for j := uint(0); j < MaxVarintLen64; j++ {
PutUvarint(buf, 1<<(j*7))
}
}
}