1// Copyright 2011 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package binary
6
7import (
8	"bytes"
9	"io"
10	"math"
11	"testing"
12)
13
14func testConstant(t *testing.T, w uint, max int) {
15	buf := make([]byte, MaxVarintLen64)
16	n := PutUvarint(buf, 1<<w-1)
17	if n != max {
18		t.Errorf("MaxVarintLen%d = %d; want %d", w, max, n)
19	}
20}
21
22func TestConstants(t *testing.T) {
23	testConstant(t, 16, MaxVarintLen16)
24	testConstant(t, 32, MaxVarintLen32)
25	testConstant(t, 64, MaxVarintLen64)
26}
27
28func testVarint(t *testing.T, x int64) {
29	buf := make([]byte, MaxVarintLen64)
30	n := PutVarint(buf, x)
31	y, m := Varint(buf[0:n])
32	if x != y {
33		t.Errorf("Varint(%d): got %d", x, y)
34	}
35	if n != m {
36		t.Errorf("Varint(%d): got n = %d; want %d", x, m, n)
37	}
38
39	buf2 := []byte("prefix")
40	buf2 = AppendVarint(buf2, x)
41	if string(buf2) != "prefix"+string(buf[:n]) {
42		t.Errorf("AppendVarint(%d): got %q, want %q", x, buf2, "prefix"+string(buf[:n]))
43	}
44
45	y, err := ReadVarint(bytes.NewReader(buf))
46	if err != nil {
47		t.Errorf("ReadVarint(%d): %s", x, err)
48	}
49	if x != y {
50		t.Errorf("ReadVarint(%d): got %d", x, y)
51	}
52}
53
54func testUvarint(t *testing.T, x uint64) {
55	buf := make([]byte, MaxVarintLen64)
56	n := PutUvarint(buf, x)
57	y, m := Uvarint(buf[0:n])
58	if x != y {
59		t.Errorf("Uvarint(%d): got %d", x, y)
60	}
61	if n != m {
62		t.Errorf("Uvarint(%d): got n = %d; want %d", x, m, n)
63	}
64
65	buf2 := []byte("prefix")
66	buf2 = AppendUvarint(buf2, x)
67	if string(buf2) != "prefix"+string(buf[:n]) {
68		t.Errorf("AppendUvarint(%d): got %q, want %q", x, buf2, "prefix"+string(buf[:n]))
69	}
70
71	y, err := ReadUvarint(bytes.NewReader(buf))
72	if err != nil {
73		t.Errorf("ReadUvarint(%d): %s", x, err)
74	}
75	if x != y {
76		t.Errorf("ReadUvarint(%d): got %d", x, y)
77	}
78}
79
80var tests = []int64{
81	-1 << 63,
82	-1<<63 + 1,
83	-1,
84	0,
85	1,
86	2,
87	10,
88	20,
89	63,
90	64,
91	65,
92	127,
93	128,
94	129,
95	255,
96	256,
97	257,
98	1<<63 - 1,
99}
100
101func TestVarint(t *testing.T) {
102	for _, x := range tests {
103		testVarint(t, x)
104		testVarint(t, -x)
105	}
106	for x := int64(0x7); x != 0; x <<= 1 {
107		testVarint(t, x)
108		testVarint(t, -x)
109	}
110}
111
112func TestUvarint(t *testing.T) {
113	for _, x := range tests {
114		testUvarint(t, uint64(x))
115	}
116	for x := uint64(0x7); x != 0; x <<= 1 {
117		testUvarint(t, x)
118	}
119}
120
121func TestBufferTooSmall(t *testing.T) {
122	buf := []byte{0x80, 0x80, 0x80, 0x80}
123	for i := 0; i <= len(buf); i++ {
124		buf := buf[0:i]
125		x, n := Uvarint(buf)
126		if x != 0 || n != 0 {
127			t.Errorf("Uvarint(%v): got x = %d, n = %d", buf, x, n)
128		}
129
130		x, err := ReadUvarint(bytes.NewReader(buf))
131		wantErr := io.EOF
132		if i > 0 {
133			wantErr = io.ErrUnexpectedEOF
134		}
135		if x != 0 || err != wantErr {
136			t.Errorf("ReadUvarint(%v): got x = %d, err = %s", buf, x, err)
137		}
138	}
139}
140
141// Ensure that we catch overflows of bytes going past MaxVarintLen64.
142// See issue https://golang.org/issues/41185
143func TestBufferTooBigWithOverflow(t *testing.T) {
144	tests := []struct {
145		in        []byte
146		name      string
147		wantN     int
148		wantValue uint64
149	}{
150		{
151			name: "invalid: 1000 bytes",
152			in: func() []byte {
153				b := make([]byte, 1000)
154				for i := range b {
155					b[i] = 0xff
156				}
157				b[999] = 0
158				return b
159			}(),
160			wantN:     -11,
161			wantValue: 0,
162		},
163		{
164			name:      "valid: math.MaxUint64-40",
165			in:        []byte{0xd7, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x01},
166			wantValue: math.MaxUint64 - 40,
167			wantN:     10,
168		},
169		{
170			name:      "invalid: with more than MaxVarintLen64 bytes",
171			in:        []byte{0xd7, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x01},
172			wantN:     -11,
173			wantValue: 0,
174		},
175		{
176			name:      "invalid: 10th byte",
177			in:        []byte{0xd7, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f},
178			wantN:     -10,
179			wantValue: 0,
180		},
181	}
182
183	for _, tt := range tests {
184		tt := tt
185		t.Run(tt.name, func(t *testing.T) {
186			value, n := Uvarint(tt.in)
187			if g, w := n, tt.wantN; g != w {
188				t.Errorf("bytes returned=%d, want=%d", g, w)
189			}
190			if g, w := value, tt.wantValue; g != w {
191				t.Errorf("value=%d, want=%d", g, w)
192			}
193		})
194	}
195}
196
197func testOverflow(t *testing.T, buf []byte, x0 uint64, n0 int, err0 error) {
198	x, n := Uvarint(buf)
199	if x != 0 || n != n0 {
200		t.Errorf("Uvarint(% X): got x = %d, n = %d; want 0, %d", buf, x, n, n0)
201	}
202
203	r := bytes.NewReader(buf)
204	len := r.Len()
205	x, err := ReadUvarint(r)
206	if x != x0 || err != err0 {
207		t.Errorf("ReadUvarint(%v): got x = %d, err = %s; want %d, %s", buf, x, err, x0, err0)
208	}
209	if read := len - r.Len(); read > MaxVarintLen64 {
210		t.Errorf("ReadUvarint(%v): read more than MaxVarintLen64 bytes, got %d", buf, read)
211	}
212}
213
214func TestOverflow(t *testing.T) {
215	testOverflow(t, []byte{0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x2}, 0, -10, errOverflow)
216	testOverflow(t, []byte{0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x1, 0, 0}, 0, -11, errOverflow)
217	testOverflow(t, []byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}, 1<<64-1, -11, errOverflow) // 11 bytes, should overflow
218}
219
220func TestNonCanonicalZero(t *testing.T) {
221	buf := []byte{0x80, 0x80, 0x80, 0}
222	x, n := Uvarint(buf)
223	if x != 0 || n != 4 {
224		t.Errorf("Uvarint(%v): got x = %d, n = %d; want 0, 4", buf, x, n)
225
226	}
227}
228
229func BenchmarkPutUvarint32(b *testing.B) {
230	buf := make([]byte, MaxVarintLen32)
231	b.SetBytes(4)
232	for i := 0; i < b.N; i++ {
233		for j := uint(0); j < MaxVarintLen32; j++ {
234			PutUvarint(buf, 1<<(j*7))
235		}
236	}
237}
238
239func BenchmarkPutUvarint64(b *testing.B) {
240	buf := make([]byte, MaxVarintLen64)
241	b.SetBytes(8)
242	for i := 0; i < b.N; i++ {
243		for j := uint(0); j < MaxVarintLen64; j++ {
244			PutUvarint(buf, 1<<(j*7))
245		}
246	}
247}
248