1 files changed, 247 insertions, 0 deletions
diff --git a/src/encoding/binary/varint_test.go b/src/encoding/binary/varint_test.go
new file mode 100644
index 0000000..a3caea8
--- /dev/null
+++ b/src/encoding/binary/varint_test.go
@@ -0,0 +1,247 @@
+// 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))
+		}
+	}
+}