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// Copyright 2009 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 flate
import (
"bytes"
"fmt"
"io"
"io/ioutil"
"sync"
"testing"
)
type deflateTest struct {
in []byte
level int
out []byte
}
type deflateInflateTest struct {
in []byte
}
type reverseBitsTest struct {
in uint16
bitCount uint8
out uint16
}
var deflateTests = []*deflateTest{
{[]byte{}, 0, []byte{1, 0, 0, 255, 255}},
{[]byte{0x11}, -1, []byte{18, 4, 4, 0, 0, 255, 255}},
{[]byte{0x11}, DefaultCompression, []byte{18, 4, 4, 0, 0, 255, 255}},
{[]byte{0x11}, 4, []byte{18, 4, 4, 0, 0, 255, 255}},
{[]byte{0x11}, 0, []byte{0, 1, 0, 254, 255, 17, 1, 0, 0, 255, 255}},
{[]byte{0x11, 0x12}, 0, []byte{0, 2, 0, 253, 255, 17, 18, 1, 0, 0, 255, 255}},
{[]byte{0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11}, 0,
[]byte{0, 8, 0, 247, 255, 17, 17, 17, 17, 17, 17, 17, 17, 1, 0, 0, 255, 255},
},
{[]byte{}, 1, []byte{1, 0, 0, 255, 255}},
{[]byte{0x11}, 1, []byte{18, 4, 4, 0, 0, 255, 255}},
{[]byte{0x11, 0x12}, 1, []byte{18, 20, 2, 4, 0, 0, 255, 255}},
{[]byte{0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11}, 1, []byte{18, 132, 2, 64, 0, 0, 0, 255, 255}},
{[]byte{}, 9, []byte{1, 0, 0, 255, 255}},
{[]byte{0x11}, 9, []byte{18, 4, 4, 0, 0, 255, 255}},
{[]byte{0x11, 0x12}, 9, []byte{18, 20, 2, 4, 0, 0, 255, 255}},
{[]byte{0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11}, 9, []byte{18, 132, 2, 64, 0, 0, 0, 255, 255}},
}
var deflateInflateTests = []*deflateInflateTest{
{[]byte{}},
{[]byte{0x11}},
{[]byte{0x11, 0x12}},
{[]byte{0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11}},
{[]byte{0x11, 0x10, 0x13, 0x41, 0x21, 0x21, 0x41, 0x13, 0x87, 0x78, 0x13}},
{largeDataChunk()},
}
var reverseBitsTests = []*reverseBitsTest{
{1, 1, 1},
{1, 2, 2},
{1, 3, 4},
{1, 4, 8},
{1, 5, 16},
{17, 5, 17},
{257, 9, 257},
{29, 5, 23},
}
func largeDataChunk() []byte {
result := make([]byte, 100000)
for i := range result {
result[i] = byte(i * i & 0xFF)
}
return result
}
func TestDeflate(t *testing.T) {
for _, h := range deflateTests {
var buf bytes.Buffer
w, err := NewWriter(&buf, h.level)
if err != nil {
t.Errorf("NewWriter: %v", err)
continue
}
w.Write(h.in)
w.Close()
if !bytes.Equal(buf.Bytes(), h.out) {
t.Errorf("Deflate(%d, %x) = %x, want %x", h.level, h.in, buf.Bytes(), h.out)
}
}
}
type syncBuffer struct {
buf bytes.Buffer
mu sync.RWMutex
closed bool
ready chan bool
}
func newSyncBuffer() *syncBuffer {
return &syncBuffer{ready: make(chan bool, 1)}
}
func (b *syncBuffer) Read(p []byte) (n int, err error) {
for {
b.mu.RLock()
n, err = b.buf.Read(p)
b.mu.RUnlock()
if n > 0 || b.closed {
return
}
<-b.ready
}
panic("unreachable")
}
func (b *syncBuffer) signal() {
select {
case b.ready <- true:
default:
}
}
func (b *syncBuffer) Write(p []byte) (n int, err error) {
n, err = b.buf.Write(p)
b.signal()
return
}
func (b *syncBuffer) WriteMode() {
b.mu.Lock()
}
func (b *syncBuffer) ReadMode() {
b.mu.Unlock()
b.signal()
}
func (b *syncBuffer) Close() error {
b.closed = true
b.signal()
return nil
}
func testSync(t *testing.T, level int, input []byte, name string) {
if len(input) == 0 {
return
}
t.Logf("--testSync %d, %d, %s", level, len(input), name)
buf := newSyncBuffer()
buf1 := new(bytes.Buffer)
buf.WriteMode()
w, err := NewWriter(io.MultiWriter(buf, buf1), level)
if err != nil {
t.Errorf("NewWriter: %v", err)
return
}
r := NewReader(buf)
// Write half the input and read back.
for i := 0; i < 2; i++ {
var lo, hi int
if i == 0 {
lo, hi = 0, (len(input)+1)/2
} else {
lo, hi = (len(input)+1)/2, len(input)
}
t.Logf("#%d: write %d-%d", i, lo, hi)
if _, err := w.Write(input[lo:hi]); err != nil {
t.Errorf("testSync: write: %v", err)
return
}
if i == 0 {
if err := w.Flush(); err != nil {
t.Errorf("testSync: flush: %v", err)
return
}
} else {
if err := w.Close(); err != nil {
t.Errorf("testSync: close: %v", err)
}
}
buf.ReadMode()
out := make([]byte, hi-lo+1)
m, err := io.ReadAtLeast(r, out, hi-lo)
t.Logf("#%d: read %d", i, m)
if m != hi-lo || err != nil {
t.Errorf("testSync/%d (%d, %d, %s): read %d: %d, %v (%d left)", i, level, len(input), name, hi-lo, m, err, buf.buf.Len())
return
}
if !bytes.Equal(input[lo:hi], out[:hi-lo]) {
t.Errorf("testSync/%d: read wrong bytes: %x vs %x", i, input[lo:hi], out[:hi-lo])
return
}
// This test originally checked that after reading
// the first half of the input, there was nothing left
// in the read buffer (buf.buf.Len() != 0) but that is
// not necessarily the case: the write Flush may emit
// some extra framing bits that are not necessary
// to process to obtain the first half of the uncompressed
// data. The test ran correctly most of the time, because
// the background goroutine had usually read even
// those extra bits by now, but it's not a useful thing to
// check.
buf.WriteMode()
}
buf.ReadMode()
out := make([]byte, 10)
if n, err := r.Read(out); n > 0 || err != io.EOF {
t.Errorf("testSync (%d, %d, %s): final Read: %d, %v (hex: %x)", level, len(input), name, n, err, out[0:n])
}
if buf.buf.Len() != 0 {
t.Errorf("testSync (%d, %d, %s): extra data at end", level, len(input), name)
}
r.Close()
// stream should work for ordinary reader too
r = NewReader(buf1)
out, err = ioutil.ReadAll(r)
if err != nil {
t.Errorf("testSync: read: %s", err)
return
}
r.Close()
if !bytes.Equal(input, out) {
t.Errorf("testSync: decompress(compress(data)) != data: level=%d input=%s", level, name)
}
}
func testToFromWithLevelAndLimit(t *testing.T, level int, input []byte, name string, limit int) {
var buffer bytes.Buffer
w, err := NewWriter(&buffer, level)
if err != nil {
t.Errorf("NewWriter: %v", err)
return
}
w.Write(input)
w.Close()
if limit > 0 && buffer.Len() > limit {
t.Errorf("level: %d, len(compress(data)) = %d > limit = %d", level, buffer.Len(), limit)
return
}
r := NewReader(&buffer)
out, err := ioutil.ReadAll(r)
if err != nil {
t.Errorf("read: %s", err)
return
}
r.Close()
if !bytes.Equal(input, out) {
t.Errorf("decompress(compress(data)) != data: level=%d input=%s", level, name)
return
}
testSync(t, level, input, name)
}
func testToFromWithLimit(t *testing.T, input []byte, name string, limit [10]int) {
for i := 0; i < 10; i++ {
testToFromWithLevelAndLimit(t, i, input, name, limit[i])
}
}
func TestDeflateInflate(t *testing.T) {
for i, h := range deflateInflateTests {
testToFromWithLimit(t, h.in, fmt.Sprintf("#%d", i), [10]int{})
}
}
func TestReverseBits(t *testing.T) {
for _, h := range reverseBitsTests {
if v := reverseBits(h.in, h.bitCount); v != h.out {
t.Errorf("reverseBits(%v,%v) = %v, want %v",
h.in, h.bitCount, v, h.out)
}
}
}
type deflateInflateStringTest struct {
filename string
label string
limit [10]int
}
var deflateInflateStringTests = []deflateInflateStringTest{
{
"../testdata/e.txt",
"2.718281828...",
[...]int{10013, 5065, 5096, 5115, 5093, 5079, 5079, 5079, 5079, 5079},
},
{
"../testdata/Mark.Twain-Tom.Sawyer.txt",
"Mark.Twain-Tom.Sawyer",
[...]int{407330, 187598, 180361, 172974, 169160, 163476, 160936, 160506, 160295, 160295},
},
}
func TestDeflateInflateString(t *testing.T) {
for _, test := range deflateInflateStringTests {
gold, err := ioutil.ReadFile(test.filename)
if err != nil {
t.Error(err)
}
testToFromWithLimit(t, gold, test.label, test.limit)
}
}
func TestReaderDict(t *testing.T) {
const (
dict = "hello world"
text = "hello again world"
)
var b bytes.Buffer
w, err := NewWriter(&b, 5)
if err != nil {
t.Fatalf("NewWriter: %v", err)
}
w.Write([]byte(dict))
w.Flush()
b.Reset()
w.Write([]byte(text))
w.Close()
r := NewReaderDict(&b, []byte(dict))
data, err := ioutil.ReadAll(r)
if err != nil {
t.Fatal(err)
}
if string(data) != "hello again world" {
t.Fatalf("read returned %q want %q", string(data), text)
}
}
func TestWriterDict(t *testing.T) {
const (
dict = "hello world"
text = "hello again world"
)
var b bytes.Buffer
w, err := NewWriter(&b, 5)
if err != nil {
t.Fatalf("NewWriter: %v", err)
}
w.Write([]byte(dict))
w.Flush()
b.Reset()
w.Write([]byte(text))
w.Close()
var b1 bytes.Buffer
w, _ = NewWriterDict(&b1, 5, []byte(dict))
w.Write([]byte(text))
w.Close()
if !bytes.Equal(b1.Bytes(), b.Bytes()) {
t.Fatalf("writer wrote %q want %q", b1.Bytes(), b.Bytes())
}
}
// See http://code.google.com/p/go/issues/detail?id=2508
func TestRegression2508(t *testing.T) {
w, err := NewWriter(ioutil.Discard, 1)
if err != nil {
t.Fatalf("NewWriter: %v", err)
}
buf := make([]byte, 1024)
for i := 0; i < 131072; i++ {
if _, err := w.Write(buf); err != nil {
t.Fatalf("writer failed: %v", err)
}
}
w.Close()
}