reader_test.go

Documentation: compress/zlib

		 1  // Copyright 2009 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 zlib
		 6  
		 7  import (
		 8  	"bytes"
		 9  	"io"
		10  	"testing"
		11  )
		12  
		13  type zlibTest struct {
		14  	desc			 string
		15  	raw				string
		16  	compressed []byte
		17  	dict			 []byte
		18  	err				error
		19  }
		20  
		21  // Compare-to-golden test data was generated by the ZLIB example program at
		22  // https://www.zlib.net/zpipe.c
		23  
		24  var zlibTests = []zlibTest{
		25  	{
		26  		"truncated empty",
		27  		"",
		28  		[]byte{},
		29  		nil,
		30  		io.ErrUnexpectedEOF,
		31  	},
		32  	{
		33  		"truncated dict",
		34  		"",
		35  		[]byte{0x78, 0xbb},
		36  		[]byte{0x00},
		37  		io.ErrUnexpectedEOF,
		38  	},
		39  	{
		40  		"truncated checksum",
		41  		"",
		42  		[]byte{0x78, 0xbb, 0x00, 0x01, 0x00, 0x01, 0xca, 0x48,
		43  			0xcd, 0xc9, 0xc9, 0xd7, 0x51, 0x28, 0xcf, 0x2f,
		44  			0xca, 0x49, 0x01, 0x04, 0x00, 0x00, 0xff, 0xff,
		45  		},
		46  		[]byte{0x00},
		47  		io.ErrUnexpectedEOF,
		48  	},
		49  	{
		50  		"empty",
		51  		"",
		52  		[]byte{0x78, 0x9c, 0x03, 0x00, 0x00, 0x00, 0x00, 0x01},
		53  		nil,
		54  		nil,
		55  	},
		56  	{
		57  		"goodbye",
		58  		"goodbye, world",
		59  		[]byte{
		60  			0x78, 0x9c, 0x4b, 0xcf, 0xcf, 0x4f, 0x49, 0xaa,
		61  			0x4c, 0xd5, 0x51, 0x28, 0xcf, 0x2f, 0xca, 0x49,
		62  			0x01, 0x00, 0x28, 0xa5, 0x05, 0x5e,
		63  		},
		64  		nil,
		65  		nil,
		66  	},
		67  	{
		68  		"bad header",
		69  		"",
		70  		[]byte{0x78, 0x9f, 0x03, 0x00, 0x00, 0x00, 0x00, 0x01},
		71  		nil,
		72  		ErrHeader,
		73  	},
		74  	{
		75  		"bad checksum",
		76  		"",
		77  		[]byte{0x78, 0x9c, 0x03, 0x00, 0x00, 0x00, 0x00, 0xff},
		78  		nil,
		79  		ErrChecksum,
		80  	},
		81  	{
		82  		"not enough data",
		83  		"",
		84  		[]byte{0x78, 0x9c, 0x03, 0x00, 0x00, 0x00},
		85  		nil,
		86  		io.ErrUnexpectedEOF,
		87  	},
		88  	{
		89  		"excess data is silently ignored",
		90  		"",
		91  		[]byte{
		92  			0x78, 0x9c, 0x03, 0x00, 0x00, 0x00, 0x00, 0x01,
		93  			0x78, 0x9c, 0xff,
		94  		},
		95  		nil,
		96  		nil,
		97  	},
		98  	{
		99  		"dictionary",
	 100  		"Hello, World!\n",
	 101  		[]byte{
	 102  			0x78, 0xbb, 0x1c, 0x32, 0x04, 0x27, 0xf3, 0x00,
	 103  			0xb1, 0x75, 0x20, 0x1c, 0x45, 0x2e, 0x00, 0x24,
	 104  			0x12, 0x04, 0x74,
	 105  		},
	 106  		[]byte{
	 107  			0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x20, 0x57, 0x6f, 0x72, 0x6c, 0x64, 0x0a,
	 108  		},
	 109  		nil,
	 110  	},
	 111  	{
	 112  		"wrong dictionary",
	 113  		"",
	 114  		[]byte{
	 115  			0x78, 0xbb, 0x1c, 0x32, 0x04, 0x27, 0xf3, 0x00,
	 116  			0xb1, 0x75, 0x20, 0x1c, 0x45, 0x2e, 0x00, 0x24,
	 117  			0x12, 0x04, 0x74,
	 118  		},
	 119  		[]byte{
	 120  			0x48, 0x65, 0x6c, 0x6c,
	 121  		},
	 122  		ErrDictionary,
	 123  	},
	 124  	{
	 125  		"truncated zlib stream amid raw-block",
	 126  		"hello",
	 127  		[]byte{
	 128  			0x78, 0x9c, 0x00, 0x0c, 0x00, 0xf3, 0xff, 0x68, 0x65, 0x6c, 0x6c, 0x6f,
	 129  		},
	 130  		nil,
	 131  		io.ErrUnexpectedEOF,
	 132  	},
	 133  	{
	 134  		"truncated zlib stream amid fixed-block",
	 135  		"He",
	 136  		[]byte{
	 137  			0x78, 0x9c, 0xf2, 0x48, 0xcd,
	 138  		},
	 139  		nil,
	 140  		io.ErrUnexpectedEOF,
	 141  	},
	 142  }
	 143  
	 144  func TestDecompressor(t *testing.T) {
	 145  	b := new(bytes.Buffer)
	 146  	for _, tt := range zlibTests {
	 147  		in := bytes.NewReader(tt.compressed)
	 148  		zr, err := NewReaderDict(in, tt.dict)
	 149  		if err != nil {
	 150  			if err != tt.err {
	 151  				t.Errorf("%s: NewReader: %s", tt.desc, err)
	 152  			}
	 153  			continue
	 154  		}
	 155  		defer zr.Close()
	 156  
	 157  		// Read and verify correctness of data.
	 158  		b.Reset()
	 159  		n, err := io.Copy(b, zr)
	 160  		if err != nil {
	 161  			if err != tt.err {
	 162  				t.Errorf("%s: io.Copy: %v want %v", tt.desc, err, tt.err)
	 163  			}
	 164  			continue
	 165  		}
	 166  		s := b.String()
	 167  		if s != tt.raw {
	 168  			t.Errorf("%s: got %d-byte %q want %d-byte %q", tt.desc, n, s, len(tt.raw), tt.raw)
	 169  		}
	 170  
	 171  		// Check for sticky errors.
	 172  		if n, err := zr.Read([]byte{0}); n != 0 || err != io.EOF {
	 173  			t.Errorf("%s: Read() = (%d, %v), want (0, io.EOF)", tt.desc, n, err)
	 174  		}
	 175  		if err := zr.Close(); err != nil {
	 176  			t.Errorf("%s: Close() = %v, want nil", tt.desc, err)
	 177  		}
	 178  	}
	 179  }
	 180
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