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Source file src/github.com/pierrec/lz4/v4/reader_test.go

Documentation: github.com/pierrec/lz4/v4

     1  package lz4_test
     2  
     3  import (
     4  	"bytes"
     5  	"errors"
     6  	"fmt"
     7  	"io"
     8  	"io/ioutil"
     9  	"os"
    10  	"reflect"
    11  	"runtime"
    12  	"strings"
    13  	"testing"
    14  
    15  	"github.com/pierrec/lz4/v4"
    16  )
    17  
    18  func _o(s ...lz4.Option) []lz4.Option {
    19  	return s
    20  }
    21  
    22  func TestReader(t *testing.T) {
    23  	goldenFiles := []struct {
    24  		name   string
    25  		isText bool
    26  	}{
    27  		{
    28  			name:   "testdata/e.txt.lz4",
    29  			isText: true,
    30  		},
    31  		{
    32  			name:   "testdata/gettysburg.txt.lz4",
    33  			isText: true,
    34  		},
    35  		{
    36  			name:   "testdata/Mark.Twain-Tom.Sawyer.txt.lz4",
    37  			isText: true,
    38  		},
    39  		{
    40  			name:   "testdata/Mark.Twain-Tom.Sawyer_long.txt.lz4",
    41  			isText: true,
    42  		},
    43  		{
    44  			name:   "testdata/Mark.Twain-Tom.Sawyer_linked.txt.lz4",
    45  			isText: true,
    46  		},
    47  		{
    48  			name:   "testdata/pg1661.txt.lz4",
    49  			isText: false,
    50  		},
    51  		{
    52  			name:   "testdata/pi.txt.lz4",
    53  			isText: true,
    54  		},
    55  		{
    56  			name:   "testdata/random.data.lz4",
    57  			isText: false,
    58  		},
    59  		{
    60  			name:   "testdata/repeat.txt.lz4",
    61  			isText: true,
    62  		},
    63  		{
    64  			name:   "testdata/pg_control.tar.lz4",
    65  			isText: false,
    66  		},
    67  	}
    68  
    69  	for _, golden := range goldenFiles {
    70  		for _, opts := range [][]lz4.Option{
    71  			nil,
    72  			_o(lz4.ConcurrencyOption(-1)),
    73  		} {
    74  			fname := golden.name
    75  			isText := golden.isText
    76  			label := fmt.Sprintf("%s %v", fname, opts)
    77  			t.Run(label, func(t *testing.T) {
    78  				t.Parallel()
    79  
    80  				f, err := os.Open(fname)
    81  				if err != nil {
    82  					t.Fatal(err)
    83  				}
    84  				defer f.Close()
    85  
    86  				rawfile := strings.TrimSuffix(fname, ".lz4")
    87  				_raw, err := ioutil.ReadFile(rawfile)
    88  				if err != nil {
    89  					t.Fatal(err)
    90  				}
    91  				var raw []byte
    92  				if isText && runtime.GOOS == "windows" {
    93  					raw = []byte(strings.ReplaceAll(string(_raw), "\r\n", "\n"))
    94  				} else {
    95  					raw = _raw
    96  				}
    97  
    98  				out := new(bytes.Buffer)
    99  				zr := lz4.NewReader(f)
   100  				if err := zr.Apply(opts...); err != nil {
   101  					t.Fatal(err)
   102  				}
   103  				n, err := io.Copy(out, zr)
   104  				if err != nil {
   105  					t.Error(err)
   106  				}
   107  
   108  				if got, want := int(n), len(raw); got != want {
   109  					t.Errorf("invalid size: got %d; want %d", got, want)
   110  				}
   111  
   112  				if got, want := out.Bytes(), raw; !reflect.DeepEqual(got, want) {
   113  					t.Fatal("uncompressed data does not match original")
   114  				}
   115  
   116  				if len(raw) < 20 {
   117  					return
   118  				}
   119  
   120  				f2, err := os.Open(fname)
   121  				if err != nil {
   122  					t.Fatal(err)
   123  				}
   124  				defer f2.Close()
   125  
   126  				out.Reset()
   127  				zr = lz4.NewReader(f2)
   128  				_, err = io.CopyN(out, zr, 10)
   129  				if err != nil {
   130  					t.Fatal(err)
   131  				}
   132  				if !reflect.DeepEqual(out.Bytes(), raw[:10]) {
   133  					t.Fatal("partial read does not match original")
   134  				}
   135  			})
   136  		}
   137  	}
   138  }
   139  
   140  func TestReader_Reset(t *testing.T) {
   141  	data := pg1661LZ4
   142  	buf := new(bytes.Buffer)
   143  	src := bytes.NewReader(data)
   144  	zr := lz4.NewReader(src)
   145  
   146  	// Partial read.
   147  	_, _ = io.CopyN(buf, zr, int64(len(data))/2)
   148  
   149  	buf.Reset()
   150  	src.Reset(data)
   151  	// Another time to maybe trigger some edge case.
   152  	src.Reset(data)
   153  	zr.Reset(src)
   154  	if _, err := io.Copy(buf, zr); err != nil {
   155  		t.Fatal(err)
   156  	}
   157  	if !reflect.DeepEqual(buf.Bytes(), pg1661) {
   158  		t.Fatal("result does not match original")
   159  	}
   160  }
   161  
   162  type brokenWriter int
   163  
   164  func (w *brokenWriter) Write(p []byte) (n int, err error) {
   165  	n = len(p)
   166  	if n > int(*w) {
   167  		n = int(*w)
   168  		err = errors.New("broken")
   169  	}
   170  	*w -= brokenWriter(n)
   171  	return
   172  }
   173  
   174  // WriteTo should report the number of bytes successfully written,
   175  // not the number successfully decompressed.
   176  func TestWriteToBrokenWriter(t *testing.T) {
   177  	const capacity = 10
   178  	w := brokenWriter(capacity)
   179  	r := lz4.NewReader(bytes.NewReader(pg1661LZ4))
   180  
   181  	n, err := r.WriteTo(&w)
   182  	switch {
   183  	case n > capacity:
   184  		t.Errorf("reported number of bytes written %d too big", n)
   185  	case err == nil:
   186  		t.Error("no error from broken Writer")
   187  	case err.Error() != "broken":
   188  		t.Errorf("unexpected error %q", err.Error())
   189  	}
   190  }
   191  
   192  func TestReaderLegacy(t *testing.T) {
   193  	goldenFiles := []string{
   194  		"testdata/vmlinux_LZ4_19377.lz4",
   195  		"testdata/bzImage_lz4_isolated.lz4",
   196  	}
   197  
   198  	for _, fname := range goldenFiles {
   199  		for _, opts := range [][]lz4.Option{
   200  			nil,
   201  			_o(lz4.ConcurrencyOption(-1)),
   202  		} {
   203  			label := fmt.Sprintf("%s %v", fname, opts)
   204  			t.Run(label, func(t *testing.T) {
   205  				fname := fname
   206  				t.Parallel()
   207  
   208  				var out bytes.Buffer
   209  				rawfile := strings.TrimSuffix(fname, ".lz4")
   210  				raw, err := ioutil.ReadFile(rawfile)
   211  				if err != nil {
   212  					t.Fatal(err)
   213  				}
   214  
   215  				f, err := os.Open(fname)
   216  				if err != nil {
   217  					t.Fatal(err)
   218  				}
   219  				defer f.Close()
   220  
   221  				zr := lz4.NewReader(f)
   222  				if err := zr.Apply(opts...); err != nil {
   223  					t.Fatal(err)
   224  				}
   225  				n, err := io.Copy(&out, zr)
   226  				if err != nil {
   227  					t.Fatal(err, n)
   228  				}
   229  
   230  				if got, want := int(n), len(raw); got != want {
   231  					t.Errorf("invalid sizes: got %d; want %d", got, want)
   232  				}
   233  
   234  				if got, want := out.Bytes(), raw; !bytes.Equal(got, want) {
   235  					t.Fatal("uncompressed data does not match original")
   236  				}
   237  
   238  				if len(raw) < 20 {
   239  					return
   240  				}
   241  
   242  				f2, err := os.Open(fname)
   243  				if err != nil {
   244  					t.Fatal(err)
   245  				}
   246  				defer f2.Close()
   247  
   248  				out.Reset()
   249  				zr = lz4.NewReader(f2)
   250  				_, err = io.CopyN(&out, zr, 10)
   251  				if err != nil {
   252  					t.Fatal(err)
   253  				}
   254  
   255  				if !bytes.Equal(out.Bytes(), raw[:10]) {
   256  					t.Fatal("partial read does not match original")
   257  				}
   258  
   259  				out.Reset()
   260  				_, err = io.CopyN(&out, zr, 10)
   261  				if err != nil {
   262  					t.Fatal(err)
   263  				}
   264  
   265  				if !bytes.Equal(out.Bytes(), raw[10:20]) {
   266  					t.Fatal("after seek, partial read does not match original")
   267  				}
   268  			})
   269  		}
   270  	}
   271  }
   272  
   273  func TestUncompressBadBlock(t *testing.T) {
   274  	f, err := os.Open("testdata/malformed.block.lz4")
   275  	if err != nil {
   276  		t.Fatal(err)
   277  	}
   278  	defer f.Close()
   279  	zr := lz4.NewReader(f)
   280  	if err := zr.Apply(lz4.ConcurrencyOption(4)); err != nil {
   281  		t.Fatal(err)
   282  	}
   283  	_, err = ioutil.ReadAll(zr)
   284  	if err == nil || !strings.Contains(err.Error(), "invalid block checksum") {
   285  		t.Error("bad block is not detected")
   286  	}
   287  }
   288  
   289  func TestValidFrameHeader(t *testing.T) {
   290  	for _, tt := range []struct {
   291  		name    string
   292  		inBytes []byte
   293  		want    bool
   294  		errNil  bool
   295  	}{
   296  		{
   297  			name:    "It is a LZ4",
   298  			inBytes: []byte{4, 34, 77, 24, 96, 112, 115, 113, 199, 14, 0, 194, 48, 55, 48, 55, 48, 49, 48, 48, 48, 48, 48, 48, 8, 0, 67, 52, 49, 101, 100, 16, 0, 12, 2, 0, 139, 49, 51, 53, 102, 48, 51, 56, 98, 23, 0, 15, 2, 0, 14, 20, 50, 33, 0, 41, 46, 0, 112, 0, 31, 50, 112, 0},
   299  			want:    true,
   300  			errNil:  true,
   301  		},
   302  		{
   303  			name:    "Not a LZ4",
   304  			inBytes: []byte("I am not a lz4 header"),
   305  			want:    false,
   306  			errNil:  true,
   307  		},
   308  		{
   309  			name:    "It is a legacy lz4",
   310  			inBytes: []byte{2, 33, 76, 24, 191, 4, 0, 0, 240, 18, 32, 32, 70, 111, 117, 114, 32, 115, 99, 111, 114, 101, 32, 97, 110, 100, 32, 115, 101, 118, 101, 110, 32, 121, 101, 97, 114, 115, 32, 97, 103, 111, 32, 30, 0, 240, 39, 102, 97, 116, 104, 101, 114, 115, 32, 98, 114, 111, 117, 103, 104, 116, 32, 102},
   311  			want:    true,
   312  			errNil:  true,
   313  		},
   314  	} {
   315  		t.Run(tt.name, func(t *testing.T) {
   316  			got, err := lz4.ValidFrameHeader(tt.inBytes)
   317  			if err != nil {
   318  				if tt.errNil {
   319  					t.Errorf("ValidFrameHeader(bytes.NewReader(%v)) returned error %v, want nil", tt.inBytes, err)
   320  				}
   321  				return
   322  			}
   323  			if got != tt.want {
   324  				t.Errorf("ValidFrameHeader(bytes.NewReader(%v)) returned %t, want %t", tt.inBytes, got, tt.want)
   325  			}
   326  		})
   327  	}
   328  }
   329  

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