syncthing/vendor/github.com/golang/snappy/snappy_test.go

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// Copyright 2011 The Snappy-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 snappy
import (
"bytes"
"encoding/binary"
"flag"
"fmt"
"io"
"io/ioutil"
"math/rand"
"net/http"
"os"
"path/filepath"
"strings"
"testing"
)
var download = flag.Bool("download", false, "If true, download any missing files before running benchmarks")
func TestMaxEncodedLenOfMaxBlockSize(t *testing.T) {
got := maxEncodedLenOfMaxBlockSize
want := MaxEncodedLen(maxBlockSize)
if got != want {
t.Fatalf("got %d, want %d", got, want)
}
}
func cmp(a, b []byte) error {
if bytes.Equal(a, b) {
return nil
}
if len(a) != len(b) {
return fmt.Errorf("got %d bytes, want %d", len(a), len(b))
}
for i := range a {
if a[i] != b[i] {
return fmt.Errorf("byte #%d: got 0x%02x, want 0x%02x", i, a[i], b[i])
}
}
return nil
}
func roundtrip(b, ebuf, dbuf []byte) error {
d, err := Decode(dbuf, Encode(ebuf, b))
if err != nil {
return fmt.Errorf("decoding error: %v", err)
}
if err := cmp(d, b); err != nil {
return fmt.Errorf("roundtrip mismatch: %v", err)
}
return nil
}
func TestEmpty(t *testing.T) {
if err := roundtrip(nil, nil, nil); err != nil {
t.Fatal(err)
}
}
func TestSmallCopy(t *testing.T) {
for _, ebuf := range [][]byte{nil, make([]byte, 20), make([]byte, 64)} {
for _, dbuf := range [][]byte{nil, make([]byte, 20), make([]byte, 64)} {
for i := 0; i < 32; i++ {
s := "aaaa" + strings.Repeat("b", i) + "aaaabbbb"
if err := roundtrip([]byte(s), ebuf, dbuf); err != nil {
t.Errorf("len(ebuf)=%d, len(dbuf)=%d, i=%d: %v", len(ebuf), len(dbuf), i, err)
}
}
}
}
}
func TestSmallRand(t *testing.T) {
rng := rand.New(rand.NewSource(1))
for n := 1; n < 20000; n += 23 {
b := make([]byte, n)
for i := range b {
b[i] = uint8(rng.Intn(256))
}
if err := roundtrip(b, nil, nil); err != nil {
t.Fatal(err)
}
}
}
func TestSmallRegular(t *testing.T) {
for n := 1; n < 20000; n += 23 {
b := make([]byte, n)
for i := range b {
b[i] = uint8(i%10 + 'a')
}
if err := roundtrip(b, nil, nil); err != nil {
t.Fatal(err)
}
}
}
func TestInvalidVarint(t *testing.T) {
testCases := []struct {
desc string
input string
}{{
"invalid varint, final byte has continuation bit set",
"\xff",
}, {
"invalid varint, value overflows uint64",
"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\x00",
}, {
// https://github.com/google/snappy/blob/master/format_description.txt
// says that "the stream starts with the uncompressed length [as a
// varint] (up to a maximum of 2^32 - 1)".
"valid varint (as uint64), but value overflows uint32",
"\x80\x80\x80\x80\x10",
}}
for _, tc := range testCases {
input := []byte(tc.input)
if _, err := DecodedLen(input); err != ErrCorrupt {
t.Errorf("%s: DecodedLen: got %v, want ErrCorrupt", tc.desc, err)
}
if _, err := Decode(nil, input); err != ErrCorrupt {
t.Errorf("%s: Decode: got %v, want ErrCorrupt", tc.desc, err)
}
}
}
func TestDecode(t *testing.T) {
lit40Bytes := make([]byte, 40)
for i := range lit40Bytes {
lit40Bytes[i] = byte(i)
}
lit40 := string(lit40Bytes)
testCases := []struct {
desc string
input string
want string
wantErr error
}{{
`decodedLen=0; valid input`,
"\x00",
"",
nil,
}, {
`decodedLen=3; tagLiteral, 0-byte length; length=3; valid input`,
"\x03" + "\x08\xff\xff\xff",
"\xff\xff\xff",
nil,
}, {
`decodedLen=2; tagLiteral, 0-byte length; length=3; not enough dst bytes`,
"\x02" + "\x08\xff\xff\xff",
"",
ErrCorrupt,
}, {
`decodedLen=3; tagLiteral, 0-byte length; length=3; not enough src bytes`,
"\x03" + "\x08\xff\xff",
"",
ErrCorrupt,
}, {
`decodedLen=40; tagLiteral, 0-byte length; length=40; valid input`,
"\x28" + "\x9c" + lit40,
lit40,
nil,
}, {
`decodedLen=1; tagLiteral, 1-byte length; not enough length bytes`,
"\x01" + "\xf0",
"",
ErrCorrupt,
}, {
`decodedLen=3; tagLiteral, 1-byte length; length=3; valid input`,
"\x03" + "\xf0\x02\xff\xff\xff",
"\xff\xff\xff",
nil,
}, {
`decodedLen=1; tagLiteral, 2-byte length; not enough length bytes`,
"\x01" + "\xf4\x00",
"",
ErrCorrupt,
}, {
`decodedLen=3; tagLiteral, 2-byte length; length=3; valid input`,
"\x03" + "\xf4\x02\x00\xff\xff\xff",
"\xff\xff\xff",
nil,
}, {
`decodedLen=1; tagLiteral, 3-byte length; not enough length bytes`,
"\x01" + "\xf8\x00\x00",
"",
ErrCorrupt,
}, {
`decodedLen=3; tagLiteral, 3-byte length; length=3; valid input`,
"\x03" + "\xf8\x02\x00\x00\xff\xff\xff",
"\xff\xff\xff",
nil,
}, {
`decodedLen=1; tagLiteral, 4-byte length; not enough length bytes`,
"\x01" + "\xfc\x00\x00\x00",
"",
ErrCorrupt,
}, {
`decodedLen=1; tagLiteral, 4-byte length; length=3; not enough dst bytes`,
"\x01" + "\xfc\x02\x00\x00\x00\xff\xff\xff",
"",
ErrCorrupt,
}, {
`decodedLen=4; tagLiteral, 4-byte length; length=3; not enough src bytes`,
"\x04" + "\xfc\x02\x00\x00\x00\xff",
"",
ErrCorrupt,
}, {
`decodedLen=3; tagLiteral, 4-byte length; length=3; valid input`,
"\x03" + "\xfc\x02\x00\x00\x00\xff\xff\xff",
"\xff\xff\xff",
nil,
}, {
`decodedLen=4; tagCopy1, 1 extra length|offset byte; not enough extra bytes`,
"\x04" + "\x01",
"",
ErrCorrupt,
}, {
`decodedLen=4; tagCopy2, 2 extra length|offset bytes; not enough extra bytes`,
"\x04" + "\x02\x00",
"",
ErrCorrupt,
}, {
`decodedLen=4; tagCopy4; unsupported COPY_4 tag`,
"\x04" + "\x03\x00\x00\x00\x00",
"",
errUnsupportedCopy4Tag,
}, {
`decodedLen=4; tagLiteral (4 bytes "abcd"); valid input`,
"\x04" + "\x0cabcd",
"abcd",
nil,
}, {
`decodedLen=13; tagLiteral (4 bytes "abcd"); tagCopy1; length=9 offset=4; valid input`,
"\x0d" + "\x0cabcd" + "\x15\x04",
"abcdabcdabcda",
nil,
}, {
`decodedLen=8; tagLiteral (4 bytes "abcd"); tagCopy1; length=4 offset=4; valid input`,
"\x08" + "\x0cabcd" + "\x01\x04",
"abcdabcd",
nil,
}, {
`decodedLen=8; tagLiteral (4 bytes "abcd"); tagCopy1; length=4 offset=2; valid input`,
"\x08" + "\x0cabcd" + "\x01\x02",
"abcdcdcd",
nil,
}, {
`decodedLen=8; tagLiteral (4 bytes "abcd"); tagCopy1; length=4 offset=1; valid input`,
"\x08" + "\x0cabcd" + "\x01\x01",
"abcddddd",
nil,
}, {
`decodedLen=8; tagLiteral (4 bytes "abcd"); tagCopy1; length=4 offset=0; zero offset`,
"\x08" + "\x0cabcd" + "\x01\x00",
"",
ErrCorrupt,
}, {
`decodedLen=9; tagLiteral (4 bytes "abcd"); tagCopy1; length=4 offset=4; inconsistent dLen`,
"\x09" + "\x0cabcd" + "\x01\x04",
"",
ErrCorrupt,
}, {
`decodedLen=8; tagLiteral (4 bytes "abcd"); tagCopy1; length=4 offset=5; offset too large`,
"\x08" + "\x0cabcd" + "\x01\x05",
"",
ErrCorrupt,
}, {
`decodedLen=7; tagLiteral (4 bytes "abcd"); tagCopy1; length=4 offset=4; length too large`,
"\x07" + "\x0cabcd" + "\x01\x04",
"",
ErrCorrupt,
}, {
`decodedLen=6; tagLiteral (4 bytes "abcd"); tagCopy2; length=2 offset=3; valid input`,
"\x06" + "\x0cabcd" + "\x06\x03\x00",
"abcdbc",
nil,
}}
const (
// notPresentXxx defines a range of byte values [0xa0, 0xc5) that are
// not present in either the input or the output. It is written to dBuf
// to check that Decode does not write bytes past the end of
// dBuf[:dLen].
//
// The magic number 37 was chosen because it is prime. A more 'natural'
// number like 32 might lead to a false negative if, for example, a
// byte was incorrectly copied 4*8 bytes later.
notPresentBase = 0xa0
notPresentLen = 37
)
var dBuf [100]byte
loop:
for i, tc := range testCases {
input := []byte(tc.input)
for _, x := range input {
if notPresentBase <= x && x < notPresentBase+notPresentLen {
t.Errorf("#%d (%s): input shouldn't contain %#02x\ninput: % x", i, tc.desc, x, input)
continue loop
}
}
dLen, n := binary.Uvarint(input)
if n <= 0 {
t.Errorf("#%d (%s): invalid varint-encoded dLen", i, tc.desc)
continue
}
if dLen > uint64(len(dBuf)) {
t.Errorf("#%d (%s): dLen %d is too large", i, tc.desc, dLen)
continue
}
for j := range dBuf {
dBuf[j] = byte(notPresentBase + j%notPresentLen)
}
g, gotErr := Decode(dBuf[:], input)
if got := string(g); got != tc.want || gotErr != tc.wantErr {
t.Errorf("#%d (%s):\ngot %q, %v\nwant %q, %v",
i, tc.desc, got, gotErr, tc.want, tc.wantErr)
continue
}
for j, x := range dBuf {
if uint64(j) < dLen {
continue
}
if w := byte(notPresentBase + j%notPresentLen); x != w {
t.Errorf("#%d (%s): Decode overrun: dBuf[%d] was modified: got %#02x, want %#02x\ndBuf: % x",
i, tc.desc, j, x, w, dBuf)
continue loop
}
}
}
}
// TestDecodeLengthOffset tests decoding an encoding of the form literal +
// copy-length-offset + literal. For example: "abcdefghijkl" + "efghij" + "AB".
func TestDecodeLengthOffset(t *testing.T) {
const (
prefix = "abcdefghijklmnopqr"
suffix = "ABCDEFGHIJKLMNOPQR"
// notPresentXxx defines a range of byte values [0xa0, 0xc5) that are
// not present in either the input or the output. It is written to
// gotBuf to check that Decode does not write bytes past the end of
// gotBuf[:totalLen].
//
// The magic number 37 was chosen because it is prime. A more 'natural'
// number like 32 might lead to a false negative if, for example, a
// byte was incorrectly copied 4*8 bytes later.
notPresentBase = 0xa0
notPresentLen = 37
)
var gotBuf, wantBuf, inputBuf [128]byte
for length := 1; length <= 18; length++ {
for offset := 1; offset <= 18; offset++ {
loop:
for suffixLen := 0; suffixLen <= 18; suffixLen++ {
totalLen := len(prefix) + length + suffixLen
inputLen := binary.PutUvarint(inputBuf[:], uint64(totalLen))
inputBuf[inputLen] = tagLiteral + 4*byte(len(prefix)-1)
inputLen++
inputLen += copy(inputBuf[inputLen:], prefix)
inputBuf[inputLen+0] = tagCopy2 + 4*byte(length-1)
inputBuf[inputLen+1] = byte(offset)
inputBuf[inputLen+2] = 0x00
inputLen += 3
if suffixLen > 0 {
inputBuf[inputLen] = tagLiteral + 4*byte(suffixLen-1)
inputLen++
inputLen += copy(inputBuf[inputLen:], suffix[:suffixLen])
}
input := inputBuf[:inputLen]
for i := range gotBuf {
gotBuf[i] = byte(notPresentBase + i%notPresentLen)
}
got, err := Decode(gotBuf[:], input)
if err != nil {
t.Errorf("length=%d, offset=%d; suffixLen=%d: %v", length, offset, suffixLen, err)
continue
}
wantLen := 0
wantLen += copy(wantBuf[wantLen:], prefix)
for i := 0; i < length; i++ {
wantBuf[wantLen] = wantBuf[wantLen-offset]
wantLen++
}
wantLen += copy(wantBuf[wantLen:], suffix[:suffixLen])
want := wantBuf[:wantLen]
for _, x := range input {
if notPresentBase <= x && x < notPresentBase+notPresentLen {
t.Errorf("length=%d, offset=%d; suffixLen=%d: input shouldn't contain %#02x\ninput: % x",
length, offset, suffixLen, x, input)
continue loop
}
}
for i, x := range gotBuf {
if i < totalLen {
continue
}
if w := byte(notPresentBase + i%notPresentLen); x != w {
t.Errorf("length=%d, offset=%d; suffixLen=%d; totalLen=%d: "+
"Decode overrun: gotBuf[%d] was modified: got %#02x, want %#02x\ngotBuf: % x",
length, offset, suffixLen, totalLen, i, x, w, gotBuf)
continue loop
}
}
for _, x := range want {
if notPresentBase <= x && x < notPresentBase+notPresentLen {
t.Errorf("length=%d, offset=%d; suffixLen=%d: want shouldn't contain %#02x\nwant: % x",
length, offset, suffixLen, x, want)
continue loop
}
}
if !bytes.Equal(got, want) {
t.Errorf("length=%d, offset=%d; suffixLen=%d:\ninput % x\ngot % x\nwant % x",
length, offset, suffixLen, input, got, want)
continue
}
}
}
}
}
func TestDecodeGoldenInput(t *testing.T) {
src, err := ioutil.ReadFile("testdata/pi.txt.rawsnappy")
if err != nil {
t.Fatalf("ReadFile: %v", err)
}
got, err := Decode(nil, src)
if err != nil {
t.Fatalf("Decode: %v", err)
}
want, err := ioutil.ReadFile("testdata/pi.txt")
if err != nil {
t.Fatalf("ReadFile: %v", err)
}
if err := cmp(got, want); err != nil {
t.Fatal(err)
}
}
// TestSlowForwardCopyOverrun tests the "expand the pattern" algorithm
// described in decode_amd64.s and its claim of a 10 byte overrun worst case.
func TestSlowForwardCopyOverrun(t *testing.T) {
const base = 100
for length := 1; length < 18; length++ {
for offset := 1; offset < 18; offset++ {
highWaterMark := base
d := base
l := length
o := offset
// makeOffsetAtLeast8
for o < 8 {
if end := d + 8; highWaterMark < end {
highWaterMark = end
}
l -= o
d += o
o += o
}
// fixUpSlowForwardCopy
a := d
d += l
// finishSlowForwardCopy
for l > 0 {
if end := a + 8; highWaterMark < end {
highWaterMark = end
}
a += 8
l -= 8
}
dWant := base + length
overrun := highWaterMark - dWant
if d != dWant || overrun < 0 || 10 < overrun {
t.Errorf("length=%d, offset=%d: d and overrun: got (%d, %d), want (%d, something in [0, 10])",
length, offset, d, overrun, dWant)
}
}
}
}
// TestEncodeNoiseThenRepeats encodes input for which the first half is very
// incompressible and the second half is very compressible. The encoded form's
// length should be closer to 50% of the original length than 100%.
func TestEncodeNoiseThenRepeats(t *testing.T) {
for _, origLen := range []int{32 * 1024, 256 * 1024, 2048 * 1024} {
src := make([]byte, origLen)
rng := rand.New(rand.NewSource(1))
firstHalf, secondHalf := src[:origLen/2], src[origLen/2:]
for i := range firstHalf {
firstHalf[i] = uint8(rng.Intn(256))
}
for i := range secondHalf {
secondHalf[i] = uint8(i >> 8)
}
dst := Encode(nil, src)
if got, want := len(dst), origLen*3/4; got >= want {
t.Errorf("origLen=%d: got %d encoded bytes, want less than %d", origLen, got, want)
}
}
}
func TestFramingFormat(t *testing.T) {
// src is comprised of alternating 1e5-sized sequences of random
// (incompressible) bytes and repeated (compressible) bytes. 1e5 was chosen
// because it is larger than maxBlockSize (64k).
src := make([]byte, 1e6)
rng := rand.New(rand.NewSource(1))
for i := 0; i < 10; i++ {
if i%2 == 0 {
for j := 0; j < 1e5; j++ {
src[1e5*i+j] = uint8(rng.Intn(256))
}
} else {
for j := 0; j < 1e5; j++ {
src[1e5*i+j] = uint8(i)
}
}
}
buf := new(bytes.Buffer)
if _, err := NewWriter(buf).Write(src); err != nil {
t.Fatalf("Write: encoding: %v", err)
}
dst, err := ioutil.ReadAll(NewReader(buf))
if err != nil {
t.Fatalf("ReadAll: decoding: %v", err)
}
if err := cmp(dst, src); err != nil {
t.Fatal(err)
}
}
func TestWriterGoldenOutput(t *testing.T) {
buf := new(bytes.Buffer)
w := NewBufferedWriter(buf)
defer w.Close()
w.Write([]byte("abcd")) // Not compressible.
w.Flush()
w.Write(bytes.Repeat([]byte{'A'}, 100)) // Compressible.
w.Flush()
got := buf.String()
want := strings.Join([]string{
magicChunk,
"\x01\x08\x00\x00", // Uncompressed chunk, 8 bytes long (including 4 byte checksum).
"\x68\x10\xe6\xb6", // Checksum.
"\x61\x62\x63\x64", // Uncompressed payload: "abcd".
"\x00\x0d\x00\x00", // Compressed chunk, 13 bytes long (including 4 byte checksum).
"\x37\xcb\xbc\x9d", // Checksum.
"\x64", // Compressed payload: Uncompressed length (varint encoded): 100.
"\x00\x41", // Compressed payload: tagLiteral, length=1, "A".
"\xfe\x01\x00", // Compressed payload: tagCopy2, length=64, offset=1.
"\x8a\x01\x00", // Compressed payload: tagCopy2, length=35, offset=1.
}, "")
if got != want {
t.Fatalf("\ngot: % x\nwant: % x", got, want)
}
}
func TestNewBufferedWriter(t *testing.T) {
// Test all 32 possible sub-sequences of these 5 input slices.
//
// Their lengths sum to 400,000, which is over 6 times the Writer ibuf
// capacity: 6 * maxBlockSize is 393,216.
inputs := [][]byte{
bytes.Repeat([]byte{'a'}, 40000),
bytes.Repeat([]byte{'b'}, 150000),
bytes.Repeat([]byte{'c'}, 60000),
bytes.Repeat([]byte{'d'}, 120000),
bytes.Repeat([]byte{'e'}, 30000),
}
loop:
for i := 0; i < 1<<uint(len(inputs)); i++ {
var want []byte
buf := new(bytes.Buffer)
w := NewBufferedWriter(buf)
for j, input := range inputs {
if i&(1<<uint(j)) == 0 {
continue
}
if _, err := w.Write(input); err != nil {
t.Errorf("i=%#02x: j=%d: Write: %v", i, j, err)
continue loop
}
want = append(want, input...)
}
if err := w.Close(); err != nil {
t.Errorf("i=%#02x: Close: %v", i, err)
continue
}
got, err := ioutil.ReadAll(NewReader(buf))
if err != nil {
t.Errorf("i=%#02x: ReadAll: %v", i, err)
continue
}
if err := cmp(got, want); err != nil {
t.Errorf("i=%#02x: %v", i, err)
continue
}
}
}
func TestFlush(t *testing.T) {
buf := new(bytes.Buffer)
w := NewBufferedWriter(buf)
defer w.Close()
if _, err := w.Write(bytes.Repeat([]byte{'x'}, 20)); err != nil {
t.Fatalf("Write: %v", err)
}
if n := buf.Len(); n != 0 {
t.Fatalf("before Flush: %d bytes were written to the underlying io.Writer, want 0", n)
}
if err := w.Flush(); err != nil {
t.Fatalf("Flush: %v", err)
}
if n := buf.Len(); n == 0 {
t.Fatalf("after Flush: %d bytes were written to the underlying io.Writer, want non-0", n)
}
}
func TestReaderReset(t *testing.T) {
gold := bytes.Repeat([]byte("All that is gold does not glitter,\n"), 10000)
buf := new(bytes.Buffer)
if _, err := NewWriter(buf).Write(gold); err != nil {
t.Fatalf("Write: %v", err)
}
encoded, invalid, partial := buf.String(), "invalid", "partial"
r := NewReader(nil)
for i, s := range []string{encoded, invalid, partial, encoded, partial, invalid, encoded, encoded} {
if s == partial {
r.Reset(strings.NewReader(encoded))
if _, err := r.Read(make([]byte, 101)); err != nil {
t.Errorf("#%d: %v", i, err)
continue
}
continue
}
r.Reset(strings.NewReader(s))
got, err := ioutil.ReadAll(r)
switch s {
case encoded:
if err != nil {
t.Errorf("#%d: %v", i, err)
continue
}
if err := cmp(got, gold); err != nil {
t.Errorf("#%d: %v", i, err)
continue
}
case invalid:
if err == nil {
t.Errorf("#%d: got nil error, want non-nil", i)
continue
}
}
}
}
func TestWriterReset(t *testing.T) {
gold := bytes.Repeat([]byte("Not all those who wander are lost;\n"), 10000)
const n = 20
for _, buffered := range []bool{false, true} {
var w *Writer
if buffered {
w = NewBufferedWriter(nil)
defer w.Close()
} else {
w = NewWriter(nil)
}
var gots, wants [][]byte
failed := false
for i := 0; i <= n; i++ {
buf := new(bytes.Buffer)
w.Reset(buf)
want := gold[:len(gold)*i/n]
if _, err := w.Write(want); err != nil {
t.Errorf("#%d: Write: %v", i, err)
failed = true
continue
}
if buffered {
if err := w.Flush(); err != nil {
t.Errorf("#%d: Flush: %v", i, err)
failed = true
continue
}
}
got, err := ioutil.ReadAll(NewReader(buf))
if err != nil {
t.Errorf("#%d: ReadAll: %v", i, err)
failed = true
continue
}
gots = append(gots, got)
wants = append(wants, want)
}
if failed {
continue
}
for i := range gots {
if err := cmp(gots[i], wants[i]); err != nil {
t.Errorf("#%d: %v", i, err)
}
}
}
}
func TestWriterResetWithoutFlush(t *testing.T) {
buf0 := new(bytes.Buffer)
buf1 := new(bytes.Buffer)
w := NewBufferedWriter(buf0)
if _, err := w.Write([]byte("xxx")); err != nil {
t.Fatalf("Write #0: %v", err)
}
// Note that we don't Flush the Writer before calling Reset.
w.Reset(buf1)
if _, err := w.Write([]byte("yyy")); err != nil {
t.Fatalf("Write #1: %v", err)
}
if err := w.Flush(); err != nil {
t.Fatalf("Flush: %v", err)
}
got, err := ioutil.ReadAll(NewReader(buf1))
if err != nil {
t.Fatalf("ReadAll: %v", err)
}
if err := cmp(got, []byte("yyy")); err != nil {
t.Fatal(err)
}
}
type writeCounter int
func (c *writeCounter) Write(p []byte) (int, error) {
*c++
return len(p), nil
}
// TestNumUnderlyingWrites tests that each Writer flush only makes one or two
// Write calls on its underlying io.Writer, depending on whether or not the
// flushed buffer was compressible.
func TestNumUnderlyingWrites(t *testing.T) {
testCases := []struct {
input []byte
want int
}{
{bytes.Repeat([]byte{'x'}, 100), 1},
{bytes.Repeat([]byte{'y'}, 100), 1},
{[]byte("ABCDEFGHIJKLMNOPQRST"), 2},
}
var c writeCounter
w := NewBufferedWriter(&c)
defer w.Close()
for i, tc := range testCases {
c = 0
if _, err := w.Write(tc.input); err != nil {
t.Errorf("#%d: Write: %v", i, err)
continue
}
if err := w.Flush(); err != nil {
t.Errorf("#%d: Flush: %v", i, err)
continue
}
if int(c) != tc.want {
t.Errorf("#%d: got %d underlying writes, want %d", i, c, tc.want)
continue
}
}
}
func benchDecode(b *testing.B, src []byte) {
encoded := Encode(nil, src)
// Bandwidth is in amount of uncompressed data.
b.SetBytes(int64(len(src)))
b.ResetTimer()
for i := 0; i < b.N; i++ {
Decode(src, encoded)
}
}
func benchEncode(b *testing.B, src []byte) {
// Bandwidth is in amount of uncompressed data.
b.SetBytes(int64(len(src)))
dst := make([]byte, MaxEncodedLen(len(src)))
b.ResetTimer()
for i := 0; i < b.N; i++ {
Encode(dst, src)
}
}
func readFile(b testing.TB, filename string) []byte {
src, err := ioutil.ReadFile(filename)
if err != nil {
b.Skipf("skipping benchmark: %v", err)
}
if len(src) == 0 {
b.Fatalf("%s has zero length", filename)
}
return src
}
// expand returns a slice of length n containing repeated copies of src.
func expand(src []byte, n int) []byte {
dst := make([]byte, n)
for x := dst; len(x) > 0; {
i := copy(x, src)
x = x[i:]
}
return dst
}
func benchWords(b *testing.B, n int, decode bool) {
// Note: the file is OS-language dependent so the resulting values are not
// directly comparable for non-US-English OS installations.
data := expand(readFile(b, "/usr/share/dict/words"), n)
if decode {
benchDecode(b, data)
} else {
benchEncode(b, data)
}
}
func BenchmarkWordsDecode1e1(b *testing.B) { benchWords(b, 1e1, true) }
func BenchmarkWordsDecode1e2(b *testing.B) { benchWords(b, 1e2, true) }
func BenchmarkWordsDecode1e3(b *testing.B) { benchWords(b, 1e3, true) }
func BenchmarkWordsDecode1e4(b *testing.B) { benchWords(b, 1e4, true) }
func BenchmarkWordsDecode1e5(b *testing.B) { benchWords(b, 1e5, true) }
func BenchmarkWordsDecode1e6(b *testing.B) { benchWords(b, 1e6, true) }
func BenchmarkWordsEncode1e1(b *testing.B) { benchWords(b, 1e1, false) }
func BenchmarkWordsEncode1e2(b *testing.B) { benchWords(b, 1e2, false) }
func BenchmarkWordsEncode1e3(b *testing.B) { benchWords(b, 1e3, false) }
func BenchmarkWordsEncode1e4(b *testing.B) { benchWords(b, 1e4, false) }
func BenchmarkWordsEncode1e5(b *testing.B) { benchWords(b, 1e5, false) }
func BenchmarkWordsEncode1e6(b *testing.B) { benchWords(b, 1e6, false) }
func BenchmarkRandomEncode(b *testing.B) {
rng := rand.New(rand.NewSource(1))
data := make([]byte, 1<<20)
for i := range data {
data[i] = uint8(rng.Intn(256))
}
benchEncode(b, data)
}
// testFiles' values are copied directly from
// https://raw.githubusercontent.com/google/snappy/master/snappy_unittest.cc
// The label field is unused in snappy-go.
var testFiles = []struct {
label string
filename string
sizeLimit int
}{
{"html", "html", 0},
{"urls", "urls.10K", 0},
{"jpg", "fireworks.jpeg", 0},
{"jpg_200", "fireworks.jpeg", 200},
{"pdf", "paper-100k.pdf", 0},
{"html4", "html_x_4", 0},
{"txt1", "alice29.txt", 0},
{"txt2", "asyoulik.txt", 0},
{"txt3", "lcet10.txt", 0},
{"txt4", "plrabn12.txt", 0},
{"pb", "geo.protodata", 0},
{"gaviota", "kppkn.gtb", 0},
}
const (
// The benchmark data files are at this canonical URL.
benchURL = "https://raw.githubusercontent.com/google/snappy/master/testdata/"
// They are copied to this local directory.
benchDir = "testdata/bench"
)
func downloadBenchmarkFiles(b *testing.B, basename string) (errRet error) {
filename := filepath.Join(benchDir, basename)
if stat, err := os.Stat(filename); err == nil && stat.Size() != 0 {
return nil
}
if !*download {
b.Skipf("test data not found; skipping benchmark without the -download flag")
}
// Download the official snappy C++ implementation reference test data
// files for benchmarking.
if err := os.MkdirAll(benchDir, 0777); err != nil && !os.IsExist(err) {
return fmt.Errorf("failed to create %s: %s", benchDir, err)
}
f, err := os.Create(filename)
if err != nil {
return fmt.Errorf("failed to create %s: %s", filename, err)
}
defer f.Close()
defer func() {
if errRet != nil {
os.Remove(filename)
}
}()
url := benchURL + basename
resp, err := http.Get(url)
if err != nil {
return fmt.Errorf("failed to download %s: %s", url, err)
}
defer resp.Body.Close()
if s := resp.StatusCode; s != http.StatusOK {
return fmt.Errorf("downloading %s: HTTP status code %d (%s)", url, s, http.StatusText(s))
}
_, err = io.Copy(f, resp.Body)
if err != nil {
return fmt.Errorf("failed to download %s to %s: %s", url, filename, err)
}
return nil
}
func benchFile(b *testing.B, n int, decode bool) {
if err := downloadBenchmarkFiles(b, testFiles[n].filename); err != nil {
b.Fatalf("failed to download testdata: %s", err)
}
data := readFile(b, filepath.Join(benchDir, testFiles[n].filename))
if n := testFiles[n].sizeLimit; 0 < n && n < len(data) {
data = data[:n]
}
if decode {
benchDecode(b, data)
} else {
benchEncode(b, data)
}
}
// Naming convention is kept similar to what snappy's C++ implementation uses.
func Benchmark_UFlat0(b *testing.B) { benchFile(b, 0, true) }
func Benchmark_UFlat1(b *testing.B) { benchFile(b, 1, true) }
func Benchmark_UFlat2(b *testing.B) { benchFile(b, 2, true) }
func Benchmark_UFlat3(b *testing.B) { benchFile(b, 3, true) }
func Benchmark_UFlat4(b *testing.B) { benchFile(b, 4, true) }
func Benchmark_UFlat5(b *testing.B) { benchFile(b, 5, true) }
func Benchmark_UFlat6(b *testing.B) { benchFile(b, 6, true) }
func Benchmark_UFlat7(b *testing.B) { benchFile(b, 7, true) }
func Benchmark_UFlat8(b *testing.B) { benchFile(b, 8, true) }
func Benchmark_UFlat9(b *testing.B) { benchFile(b, 9, true) }
func Benchmark_UFlat10(b *testing.B) { benchFile(b, 10, true) }
func Benchmark_UFlat11(b *testing.B) { benchFile(b, 11, true) }
func Benchmark_ZFlat0(b *testing.B) { benchFile(b, 0, false) }
func Benchmark_ZFlat1(b *testing.B) { benchFile(b, 1, false) }
func Benchmark_ZFlat2(b *testing.B) { benchFile(b, 2, false) }
func Benchmark_ZFlat3(b *testing.B) { benchFile(b, 3, false) }
func Benchmark_ZFlat4(b *testing.B) { benchFile(b, 4, false) }
func Benchmark_ZFlat5(b *testing.B) { benchFile(b, 5, false) }
func Benchmark_ZFlat6(b *testing.B) { benchFile(b, 6, false) }
func Benchmark_ZFlat7(b *testing.B) { benchFile(b, 7, false) }
func Benchmark_ZFlat8(b *testing.B) { benchFile(b, 8, false) }
func Benchmark_ZFlat9(b *testing.B) { benchFile(b, 9, false) }
func Benchmark_ZFlat10(b *testing.B) { benchFile(b, 10, false) }
func Benchmark_ZFlat11(b *testing.B) { benchFile(b, 11, false) }