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path: root/src/compress/flate/deflate_test.go
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-rw-r--r--src/compress/flate/deflate_test.go490
1 files changed, 490 insertions, 0 deletions
diff --git a/src/compress/flate/deflate_test.go b/src/compress/flate/deflate_test.go
new file mode 100644
index 000000000..730234c38
--- /dev/null
+++ b/src/compress/flate/deflate_test.go
@@ -0,0 +1,490 @@
+// 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"
+ "reflect"
+ "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)
+ }
+ }
+}
+
+// A sparseReader returns a stream consisting of 0s followed by 1<<16 1s.
+// This tests missing hash references in a very large input.
+type sparseReader struct {
+ l int64
+ cur int64
+}
+
+func (r *sparseReader) Read(b []byte) (n int, err error) {
+ if r.cur >= r.l {
+ return 0, io.EOF
+ }
+ n = len(b)
+ cur := r.cur + int64(n)
+ if cur > r.l {
+ n -= int(cur - r.l)
+ cur = r.l
+ }
+ for i := range b[0:n] {
+ if r.cur+int64(i) >= r.l-1<<16 {
+ b[i] = 1
+ } else {
+ b[i] = 0
+ }
+ }
+ r.cur = cur
+ return
+}
+
+func TestVeryLongSparseChunk(t *testing.T) {
+ if testing.Short() {
+ t.Skip("skipping sparse chunk during short test")
+ }
+ w, err := NewWriter(ioutil.Discard, 1)
+ if err != nil {
+ t.Errorf("NewWriter: %v", err)
+ return
+ }
+ if _, err = io.Copy(w, &sparseReader{l: 23E8}); err != nil {
+ t.Errorf("Compress failed: %v", err)
+ return
+ }
+}
+
+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
+ }
+}
+
+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{100018, 50650, 50960, 51150, 50930, 50790, 50790, 50790, 50790, 50790},
+ },
+ {
+ "../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)
+ if testing.Short() {
+ break
+ }
+ }
+}
+
+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) {
+ if testing.Short() {
+ t.Logf("test disabled with -short")
+ return
+ }
+ 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()
+}
+
+func TestWriterReset(t *testing.T) {
+ for level := 0; level <= 9; level++ {
+ if testing.Short() && level > 1 {
+ break
+ }
+ w, err := NewWriter(ioutil.Discard, level)
+ if err != nil {
+ t.Fatalf("NewWriter: %v", err)
+ }
+ buf := []byte("hello world")
+ for i := 0; i < 1024; i++ {
+ w.Write(buf)
+ }
+ w.Reset(ioutil.Discard)
+
+ wref, err := NewWriter(ioutil.Discard, level)
+ if err != nil {
+ t.Fatalf("NewWriter: %v", err)
+ }
+
+ // DeepEqual doesn't compare functions.
+ w.d.fill, wref.d.fill = nil, nil
+ w.d.step, wref.d.step = nil, nil
+ if !reflect.DeepEqual(w, wref) {
+ t.Errorf("level %d Writer not reset after Reset", level)
+ }
+ }
+ testResetOutput(t, func(w io.Writer) (*Writer, error) { return NewWriter(w, NoCompression) })
+ testResetOutput(t, func(w io.Writer) (*Writer, error) { return NewWriter(w, DefaultCompression) })
+ testResetOutput(t, func(w io.Writer) (*Writer, error) { return NewWriter(w, BestCompression) })
+ dict := []byte("we are the world")
+ testResetOutput(t, func(w io.Writer) (*Writer, error) { return NewWriterDict(w, NoCompression, dict) })
+ testResetOutput(t, func(w io.Writer) (*Writer, error) { return NewWriterDict(w, DefaultCompression, dict) })
+ testResetOutput(t, func(w io.Writer) (*Writer, error) { return NewWriterDict(w, BestCompression, dict) })
+}
+
+func testResetOutput(t *testing.T, newWriter func(w io.Writer) (*Writer, error)) {
+ buf := new(bytes.Buffer)
+ w, err := newWriter(buf)
+ if err != nil {
+ t.Fatalf("NewWriter: %v", err)
+ }
+ b := []byte("hello world")
+ for i := 0; i < 1024; i++ {
+ w.Write(b)
+ }
+ w.Close()
+ out1 := buf.String()
+
+ buf2 := new(bytes.Buffer)
+ w.Reset(buf2)
+ for i := 0; i < 1024; i++ {
+ w.Write(b)
+ }
+ w.Close()
+ out2 := buf2.String()
+
+ if out1 != out2 {
+ t.Errorf("got %q, expected %q", out2, out1)
+ }
+ t.Logf("got %d bytes", len(out1))
+}
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