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      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 	"io/ioutil"
     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(ioutil.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 	// Twain is Mark Twain's classic English novel.
     31 	{"Twain", "../testdata/Mark.Twain-Tom.Sawyer.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(ioutil.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 := ioutil.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