reader_test.go

Documentation: compress/flate

     1  // Copyright 2012 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package flate
     6  
     7  import (
     8  	"bytes"
     9  	"io"
    10  	"os"
    11  	"runtime"
    12  	"strings"
    13  	"testing"
    14  )
    15  
    16  func TestNlitOutOfRange(t *testing.T) {
    17  	// Trying to decode this bogus flate data, which has a Huffman table
    18  	// with nlit=288, should not panic.
    19  	io.Copy(io.Discard, NewReader(strings.NewReader(
    20  		"\xfc\xfe\x36\xe7\x5e\x1c\xef\xb3\x55\x58\x77\xb6\x56\xb5\x43\xf4"+
    21  			"\x6f\xf2\xd2\xe6\x3d\x99\xa0\x85\x8c\x48\xeb\xf8\xda\x83\x04\x2a"+
    22  			"\x75\xc4\xf8\x0f\x12\x11\xb9\xb4\x4b\x09\xa0\xbe\x8b\x91\x4c")))
    23  }
    24  
    25  var suites = []struct{ name, file string }{
    26  	// Digits is the digits of the irrational number e. Its decimal representation
    27  	// does not repeat, but there are only 10 possible digits, so it should be
    28  	// reasonably compressible.
    29  	{"Digits", "../testdata/e.txt"},
    30  	// Newton is Isaac Newtons's educational text on Opticks.
    31  	{"Newton", "../../testdata/Isaac.Newton-Opticks.txt"},
    32  }
    33  
    34  func BenchmarkDecode(b *testing.B) {
    35  	doBench(b, func(b *testing.B, buf0 []byte, level, n int) {
    36  		b.ReportAllocs()
    37  		b.StopTimer()
    38  		b.SetBytes(int64(n))
    39  
    40  		compressed := new(bytes.Buffer)
    41  		w, err := NewWriter(compressed, level)
    42  		if err != nil {
    43  			b.Fatal(err)
    44  		}
    45  		for i := 0; i < n; i += len(buf0) {
    46  			if len(buf0) > n-i {
    47  				buf0 = buf0[:n-i]
    48  			}
    49  			io.Copy(w, bytes.NewReader(buf0))
    50  		}
    51  		w.Close()
    52  		buf1 := compressed.Bytes()
    53  		buf0, compressed, w = nil, nil, nil
    54  		runtime.GC()
    55  		b.StartTimer()
    56  		for i := 0; i < b.N; i++ {
    57  			io.Copy(io.Discard, NewReader(bytes.NewReader(buf1)))
    58  		}
    59  	})
    60  }
    61  
    62  var levelTests = []struct {
    63  	name  string
    64  	level int
    65  }{
    66  	{"Huffman", HuffmanOnly},
    67  	{"Speed", BestSpeed},
    68  	{"Default", DefaultCompression},
    69  	{"Compression", BestCompression},
    70  }
    71  
    72  var sizes = []struct {
    73  	name string
    74  	n    int
    75  }{
    76  	{"1e4", 1e4},
    77  	{"1e5", 1e5},
    78  	{"1e6", 1e6},
    79  }
    80  
    81  func doBench(b *testing.B, f func(b *testing.B, buf []byte, level, n int)) {
    82  	for _, suite := range suites {
    83  		buf, err := os.ReadFile(suite.file)
    84  		if err != nil {
    85  			b.Fatal(err)
    86  		}
    87  		if len(buf) == 0 {
    88  			b.Fatalf("test file %q has no data", suite.file)
    89  		}
    90  		for _, l := range levelTests {
    91  			for _, s := range sizes {
    92  				b.Run(suite.name+"/"+l.name+"/"+s.name, func(b *testing.B) {
    93  					f(b, buf, l.level, s.n)
    94  				})
    95  			}
    96  		}
    97  	}
    98  }
    99
View as plain text