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Diffstat (limited to 'internal/compress/flate/writer_test.go')
-rw-r--r--internal/compress/flate/writer_test.go544
1 files changed, 544 insertions, 0 deletions
diff --git a/internal/compress/flate/writer_test.go b/internal/compress/flate/writer_test.go
new file mode 100644
index 00000000..ea448298
--- /dev/null
+++ b/internal/compress/flate/writer_test.go
@@ -0,0 +1,544 @@
+// Copyright 2012 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 (
+ "archive/zip"
+ "bytes"
+ "compress/flate"
+ "fmt"
+ "io"
+ "math"
+ "math/rand"
+ "os"
+ "runtime"
+ "strconv"
+ "strings"
+ "testing"
+)
+
+func TestWriterMemUsage(t *testing.T) {
+ testMem := func(t *testing.T, fn func()) {
+ var before, after runtime.MemStats
+ runtime.GC()
+ runtime.ReadMemStats(&before)
+ fn()
+ runtime.GC()
+ runtime.ReadMemStats(&after)
+ t.Logf("%s: Memory Used: %dKB, %d allocs", t.Name(), (after.HeapInuse-before.HeapInuse)/1024, after.HeapObjects-before.HeapObjects)
+ }
+ data := make([]byte, 100000)
+ t.Run("stateless", func(t *testing.T) {
+ testMem(t, func() {
+ StatelessDeflate(io.Discard, data, false, nil)
+ })
+ })
+ for level := HuffmanOnly; level <= BestCompression; level++ {
+ t.Run(fmt.Sprint("level-", level), func(t *testing.T) {
+ var zr *Writer
+ var err error
+ testMem(t, func() {
+ zr, err = NewWriter(io.Discard, level)
+ if err != nil {
+ t.Fatal(err)
+ }
+ zr.Write(data)
+ })
+ zr.Close()
+ })
+ }
+ for level := HuffmanOnly; level <= BestCompression; level++ {
+ t.Run(fmt.Sprint("stdlib-", level), func(t *testing.T) {
+ var zr *flate.Writer
+ var err error
+ testMem(t, func() {
+ zr, err = flate.NewWriter(io.Discard, level)
+ if err != nil {
+ t.Fatal(err)
+ }
+ zr.Write(data)
+ })
+ zr.Close()
+ })
+ }
+}
+
+func TestWriterRegression(t *testing.T) {
+ data, err := os.ReadFile("testdata/regression.zip")
+ if err != nil {
+ t.Fatal(err)
+ }
+ for level := HuffmanOnly; level <= BestCompression; level++ {
+ t.Run(fmt.Sprint("level_", level), func(t *testing.T) {
+ zr, err := zip.NewReader(bytes.NewReader(data), int64(len(data)))
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ for _, tt := range zr.File {
+ if !strings.HasSuffix(t.Name(), "") {
+ continue
+ }
+
+ t.Run(tt.Name, func(t *testing.T) {
+ if testing.Short() && tt.FileInfo().Size() > 10000 {
+ t.SkipNow()
+ }
+ r, err := tt.Open()
+ if err != nil {
+ t.Error(err)
+ return
+ }
+ in, err := io.ReadAll(r)
+ if err != nil {
+ t.Error(err)
+ }
+ msg := "level " + strconv.Itoa(level) + ":"
+ buf := new(bytes.Buffer)
+ fw, err := NewWriter(buf, level)
+ if err != nil {
+ t.Fatal(msg + err.Error())
+ }
+ n, err := fw.Write(in)
+ if n != len(in) {
+ t.Fatal(msg + "short write")
+ }
+ if err != nil {
+ t.Fatal(msg + err.Error())
+ }
+ err = fw.Close()
+ if err != nil {
+ t.Fatal(msg + err.Error())
+ }
+ fr1 := NewReader(buf)
+ data2, err := io.ReadAll(fr1)
+ if err != nil {
+ t.Fatal(msg + err.Error())
+ }
+ if !bytes.Equal(in, data2) {
+ t.Fatal(msg + "not equal")
+ }
+ // Do it again...
+ msg = "level " + strconv.Itoa(level) + " (reset):"
+ buf.Reset()
+ fw.Reset(buf)
+ n, err = fw.Write(in)
+ if n != len(in) {
+ t.Fatal(msg + "short write")
+ }
+ if err != nil {
+ t.Fatal(msg + err.Error())
+ }
+ err = fw.Close()
+ if err != nil {
+ t.Fatal(msg + err.Error())
+ }
+ fr1 = NewReader(buf)
+ data2, err = io.ReadAll(fr1)
+ if err != nil {
+ t.Fatal(msg + err.Error())
+ }
+ if !bytes.Equal(in, data2) {
+ t.Fatal(msg + "not equal")
+ }
+ })
+ }
+ })
+ }
+}
+
+func benchmarkEncoder(b *testing.B, testfile, level, n int) {
+ b.SetBytes(int64(n))
+ buf0, err := os.ReadFile(testfiles[testfile])
+ if err != nil {
+ b.Fatal(err)
+ }
+ if len(buf0) == 0 {
+ b.Fatalf("test file %q has no data", testfiles[testfile])
+ }
+ buf1 := make([]byte, n)
+ for i := 0; i < n; i += len(buf0) {
+ if len(buf0) > n-i {
+ buf0 = buf0[:n-i]
+ }
+ copy(buf1[i:], buf0)
+ }
+ buf0 = nil
+ runtime.GC()
+ w, err := NewWriter(io.Discard, level)
+ if err != nil {
+ b.Fatal(err)
+ }
+ b.ResetTimer()
+ b.ReportAllocs()
+ for i := 0; i < b.N; i++ {
+ w.Reset(io.Discard)
+ _, err = w.Write(buf1)
+ if err != nil {
+ b.Fatal(err)
+ }
+ err = w.Close()
+ if err != nil {
+ b.Fatal(err)
+ }
+ }
+}
+
+func BenchmarkEncodeDigitsConstant1e4(b *testing.B) { benchmarkEncoder(b, digits, constant, 1e4) }
+func BenchmarkEncodeDigitsConstant1e5(b *testing.B) { benchmarkEncoder(b, digits, constant, 1e5) }
+func BenchmarkEncodeDigitsConstant1e6(b *testing.B) { benchmarkEncoder(b, digits, constant, 1e6) }
+func BenchmarkEncodeDigitsSpeed1e4(b *testing.B) { benchmarkEncoder(b, digits, speed, 1e4) }
+func BenchmarkEncodeDigitsSpeed1e5(b *testing.B) { benchmarkEncoder(b, digits, speed, 1e5) }
+func BenchmarkEncodeDigitsSpeed1e6(b *testing.B) { benchmarkEncoder(b, digits, speed, 1e6) }
+func BenchmarkEncodeDigitsDefault1e4(b *testing.B) { benchmarkEncoder(b, digits, default_, 1e4) }
+func BenchmarkEncodeDigitsDefault1e5(b *testing.B) { benchmarkEncoder(b, digits, default_, 1e5) }
+func BenchmarkEncodeDigitsDefault1e6(b *testing.B) { benchmarkEncoder(b, digits, default_, 1e6) }
+func BenchmarkEncodeDigitsCompress1e4(b *testing.B) { benchmarkEncoder(b, digits, compress, 1e4) }
+func BenchmarkEncodeDigitsCompress1e5(b *testing.B) { benchmarkEncoder(b, digits, compress, 1e5) }
+func BenchmarkEncodeDigitsCompress1e6(b *testing.B) { benchmarkEncoder(b, digits, compress, 1e6) }
+func BenchmarkEncodeDigitsSL1e4(b *testing.B) { benchmarkStatelessEncoder(b, digits, 1e4) }
+func BenchmarkEncodeDigitsSL1e5(b *testing.B) { benchmarkStatelessEncoder(b, digits, 1e5) }
+func BenchmarkEncodeDigitsSL1e6(b *testing.B) { benchmarkStatelessEncoder(b, digits, 1e6) }
+func BenchmarkEncodeTwainConstant1e4(b *testing.B) { benchmarkEncoder(b, twain, constant, 1e4) }
+func BenchmarkEncodeTwainConstant1e5(b *testing.B) { benchmarkEncoder(b, twain, constant, 1e5) }
+func BenchmarkEncodeTwainConstant1e6(b *testing.B) { benchmarkEncoder(b, twain, constant, 1e6) }
+func BenchmarkEncodeTwainSpeed1e4(b *testing.B) { benchmarkEncoder(b, twain, speed, 1e4) }
+func BenchmarkEncodeTwainSpeed1e5(b *testing.B) { benchmarkEncoder(b, twain, speed, 1e5) }
+func BenchmarkEncodeTwainSpeed1e6(b *testing.B) { benchmarkEncoder(b, twain, speed, 1e6) }
+func BenchmarkEncodeTwainDefault1e4(b *testing.B) { benchmarkEncoder(b, twain, default_, 1e4) }
+func BenchmarkEncodeTwainDefault1e5(b *testing.B) { benchmarkEncoder(b, twain, default_, 1e5) }
+func BenchmarkEncodeTwainDefault1e6(b *testing.B) { benchmarkEncoder(b, twain, default_, 1e6) }
+func BenchmarkEncodeTwainCompress1e4(b *testing.B) { benchmarkEncoder(b, twain, compress, 1e4) }
+func BenchmarkEncodeTwainCompress1e5(b *testing.B) { benchmarkEncoder(b, twain, compress, 1e5) }
+func BenchmarkEncodeTwainCompress1e6(b *testing.B) { benchmarkEncoder(b, twain, compress, 1e6) }
+func BenchmarkEncodeTwainSL1e4(b *testing.B) { benchmarkStatelessEncoder(b, twain, 1e4) }
+func BenchmarkEncodeTwainSL1e5(b *testing.B) { benchmarkStatelessEncoder(b, twain, 1e5) }
+func BenchmarkEncodeTwainSL1e6(b *testing.B) { benchmarkStatelessEncoder(b, twain, 1e6) }
+
+func BenchmarkEncodeTwain1024Win1e4(b *testing.B) { benchmarkEncoder(b, twain, oneK, 1e4) }
+func BenchmarkEncodeTwain1024Win1e5(b *testing.B) { benchmarkEncoder(b, twain, oneK, 1e5) }
+func BenchmarkEncodeTwain1024Win1e6(b *testing.B) { benchmarkEncoder(b, twain, oneK, 1e6) }
+
+func benchmarkStatelessEncoder(b *testing.B, testfile, n int) {
+ b.SetBytes(int64(n))
+ buf0, err := os.ReadFile(testfiles[testfile])
+ if err != nil {
+ b.Fatal(err)
+ }
+ if len(buf0) == 0 {
+ b.Fatalf("test file %q has no data", testfiles[testfile])
+ }
+ buf1 := make([]byte, n)
+ for i := 0; i < n; i += len(buf0) {
+ if len(buf0) > n-i {
+ buf0 = buf0[:n-i]
+ }
+ copy(buf1[i:], buf0)
+ }
+ buf0 = nil
+ runtime.GC()
+ b.ResetTimer()
+ b.ReportAllocs()
+ for i := 0; i < b.N; i++ {
+ w := NewStatelessWriter(io.Discard)
+ _, err = w.Write(buf1)
+ if err != nil {
+ b.Fatal(err)
+ }
+ err = w.Close()
+ if err != nil {
+ b.Fatal(err)
+ }
+ }
+}
+
+// A writer that fails after N writes.
+type errorWriter struct {
+ N int
+}
+
+func (e *errorWriter) Write(b []byte) (int, error) {
+ if e.N <= 0 {
+ return 0, io.ErrClosedPipe
+ }
+ e.N--
+ return len(b), nil
+}
+
+// Test if errors from the underlying writer is passed upwards.
+func TestWriteError(t *testing.T) {
+ buf := new(bytes.Buffer)
+ n := 65536
+ if !testing.Short() {
+ n *= 4
+ }
+ for i := 0; i < n; i++ {
+ fmt.Fprintf(buf, "asdasfasf%d%dfghfgujyut%dyutyu\n", i, i, i)
+ }
+ in := buf.Bytes()
+ // We create our own buffer to control number of writes.
+ copyBuf := make([]byte, 128)
+ for l := range 10 {
+ for fail := 1; fail <= 256; fail *= 2 {
+ // Fail after 'fail' writes
+ ew := &errorWriter{N: fail}
+ w, err := NewWriter(ew, l)
+ if err != nil {
+ t.Fatalf("NewWriter: level %d: %v", l, err)
+ }
+ n, err := copyBuffer(w, bytes.NewBuffer(in), copyBuf)
+ if err == nil {
+ t.Fatalf("Level %d: Expected an error, writer was %#v", l, ew)
+ }
+ n2, err := w.Write([]byte{1, 2, 2, 3, 4, 5})
+ if n2 != 0 {
+ t.Fatal("Level", l, "Expected 0 length write, got", n)
+ }
+ if err == nil {
+ t.Fatal("Level", l, "Expected an error")
+ }
+ err = w.Flush()
+ if err == nil {
+ t.Fatal("Level", l, "Expected an error on flush")
+ }
+ err = w.Close()
+ if err == nil {
+ t.Fatal("Level", l, "Expected an error on close")
+ }
+
+ w.Reset(io.Discard)
+ n2, err = w.Write([]byte{1, 2, 3, 4, 5, 6})
+ if err != nil {
+ t.Fatal("Level", l, "Got unexpected error after reset:", err)
+ }
+ if n2 == 0 {
+ t.Fatal("Level", l, "Got 0 length write, expected > 0")
+ }
+ if testing.Short() {
+ return
+ }
+ }
+ }
+}
+
+// Test if errors from the underlying writer is passed upwards.
+func TestWriter_Reset(t *testing.T) {
+ buf := new(bytes.Buffer)
+ n := 65536
+ if !testing.Short() {
+ n *= 4
+ }
+ for i := 0; i < n; i++ {
+ fmt.Fprintf(buf, "asdasfasf%d%dfghfgujyut%dyutyu\n", i, i, i)
+ }
+ in := buf.Bytes()
+ for l := range 10 {
+ if testing.Short() && l > 1 {
+ continue
+ }
+ t.Run(fmt.Sprintf("level-%d", l), func(t *testing.T) {
+ t.Parallel()
+ offset := 1
+ if testing.Short() {
+ offset = 256
+ }
+ for ; offset <= 256; offset *= 2 {
+ // Fail after 'fail' writes
+ w, err := NewWriter(io.Discard, l)
+ if err != nil {
+ t.Fatalf("NewWriter: level %d: %v", l, err)
+ }
+ if w.d.fast == nil {
+ t.Skip("Not Fast...")
+ return
+ }
+ for i := 0; i < (bufferReset-len(in)-offset-maxMatchOffset)/maxMatchOffset; i++ {
+ // skip ahead to where we are close to wrap around...
+ w.d.fast.Reset()
+ }
+ w.d.fast.Reset()
+ _, err = w.Write(in)
+ if err != nil {
+ t.Fatal(err)
+ }
+ for range 50 {
+ // skip ahead again... This should wrap around...
+ w.d.fast.Reset()
+ }
+ w.d.fast.Reset()
+
+ _, err = w.Write(in)
+ if err != nil {
+ t.Fatal(err)
+ }
+ for range (math.MaxUint32 - bufferReset) / maxMatchOffset {
+ // skip ahead to where we are close to wrap around...
+ w.d.fast.Reset()
+ }
+
+ _, err = w.Write(in)
+ if err != nil {
+ t.Fatal(err)
+ }
+ err = w.Close()
+ if err != nil {
+ t.Fatal(err)
+ }
+ }
+ })
+ }
+}
+
+func TestDeterministicL1(t *testing.T) { testDeterministic(1, t) }
+func TestDeterministicL2(t *testing.T) { testDeterministic(2, t) }
+func TestDeterministicL3(t *testing.T) { testDeterministic(3, t) }
+func TestDeterministicL4(t *testing.T) { testDeterministic(4, t) }
+func TestDeterministicL5(t *testing.T) { testDeterministic(5, t) }
+func TestDeterministicL6(t *testing.T) { testDeterministic(6, t) }
+func TestDeterministicL7(t *testing.T) { testDeterministic(7, t) }
+func TestDeterministicL8(t *testing.T) { testDeterministic(8, t) }
+func TestDeterministicL9(t *testing.T) { testDeterministic(9, t) }
+func TestDeterministicL0(t *testing.T) { testDeterministic(0, t) }
+func TestDeterministicLM2(t *testing.T) { testDeterministic(-2, t) }
+
+func testDeterministic(i int, t *testing.T) {
+ // Test so much we cross a good number of block boundaries.
+ var length = maxStoreBlockSize*30 + 500
+ if testing.Short() {
+ length /= 10
+ }
+
+ // Create a random, but compressible stream.
+ rng := rand.New(rand.NewSource(1))
+ t1 := make([]byte, length)
+ for i := range t1 {
+ t1[i] = byte(rng.Int63() & 7)
+ }
+
+ // Do our first encode.
+ var b1 bytes.Buffer
+ br := bytes.NewBuffer(t1)
+ w, err := NewWriter(&b1, i)
+ if err != nil {
+ t.Fatal(err)
+ }
+ // Use a very small prime sized buffer.
+ cbuf := make([]byte, 787)
+ _, err = copyBuffer(w, br, cbuf)
+ if err != nil {
+ t.Fatal(err)
+ }
+ w.Close()
+
+ // We choose a different buffer size,
+ // bigger than a maximum block, and also a prime.
+ var b2 bytes.Buffer
+ cbuf = make([]byte, 81761)
+ br2 := bytes.NewBuffer(t1)
+ w2, err := NewWriter(&b2, i)
+ if err != nil {
+ t.Fatal(err)
+ }
+ _, err = copyBuffer(w2, br2, cbuf)
+ if err != nil {
+ t.Fatal(err)
+ }
+ w2.Close()
+
+ b1b := b1.Bytes()
+ b2b := b2.Bytes()
+
+ if !bytes.Equal(b1b, b2b) {
+ t.Errorf("level %d did not produce deterministic result, result mismatch, len(a) = %d, len(b) = %d", i, len(b1b), len(b2b))
+ }
+
+ // Test using io.WriterTo interface.
+ var b3 bytes.Buffer
+ br = bytes.NewBuffer(t1)
+ w, err = NewWriter(&b3, i)
+ if err != nil {
+ t.Fatal(err)
+ }
+ _, err = br.WriteTo(w)
+ if err != nil {
+ t.Fatal(err)
+ }
+ w.Close()
+
+ b3b := b3.Bytes()
+ if !bytes.Equal(b1b, b3b) {
+ t.Errorf("level %d (io.WriterTo) did not produce deterministic result, result mismatch, len(a) = %d, len(b) = %d", i, len(b1b), len(b3b))
+ }
+}
+
+// copyBuffer is a copy of io.CopyBuffer, since we want to support older go versions.
+// This is modified to never use io.WriterTo or io.ReaderFrom interfaces.
+func copyBuffer(dst io.Writer, src io.Reader, buf []byte) (written int64, err error) {
+ if buf == nil {
+ buf = make([]byte, 32*1024)
+ }
+ for {
+ nr, er := src.Read(buf)
+ if nr > 0 {
+ nw, ew := dst.Write(buf[0:nr])
+ if nw > 0 {
+ written += int64(nw)
+ }
+ if ew != nil {
+ err = ew
+ break
+ }
+ if nr != nw {
+ err = io.ErrShortWrite
+ break
+ }
+ }
+ if er == io.EOF {
+ break
+ }
+ if er != nil {
+ err = er
+ break
+ }
+ }
+ return written, err
+}
+
+func BenchmarkCompressAllocations(b *testing.B) {
+ payload := []byte(strings.Repeat("Tiny payload", 20))
+ for j := -2; j <= 9; j++ {
+ b.Run("level("+strconv.Itoa(j)+")", func(b *testing.B) {
+ b.Run("flate", func(b *testing.B) {
+ b.ReportAllocs()
+
+ for i := 0; i < b.N; i++ {
+ w, err := NewWriter(io.Discard, j)
+ if err != nil {
+ b.Fatal(err)
+ }
+ w.Write(payload)
+ w.Close()
+ }
+ })
+ })
+ }
+}
+
+func BenchmarkCompressAllocationsSingle(b *testing.B) {
+ payload := []byte(strings.Repeat("Tiny payload", 20))
+ const level = 2
+ b.Run("flate", func(b *testing.B) {
+ b.ReportAllocs()
+
+ for i := 0; i < b.N; i++ {
+ w, err := NewWriter(io.Discard, level)
+ if err != nil {
+ b.Fatal(err)
+ }
+ w.Write(payload)
+ w.Close()
+ }
+ })
+}
generated by cgit v1.3.1-10-gc9f91 (git 2.54.0) at 2026-05-25 14:46:59 +0000