diff options
Diffstat (limited to 'src/encoding/binary/varint_test.go')
-rw-r--r-- | src/encoding/binary/varint_test.go | 247 |
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)) + } + } +} |