zip_test.go

Documentation: github.com/klauspost/compress/zstd

     1  package zstd_test
     2  
     3  import (
     4  	"archive/zip"
     5  	"bytes"
     6  	"fmt"
     7  	"io"
     8  
     9  	"github.com/klauspost/compress/zstd"
    10  )
    11  
    12  func ExampleZipCompressor() {
    13  	// Get zstandard de/compressors for zip.
    14  	// These can be used by multiple readers and writers.
    15  	compr := zstd.ZipCompressor(zstd.WithWindowSize(1<<20), zstd.WithEncoderCRC(false))
    16  	decomp := zstd.ZipDecompressor()
    17  
    18  	// Try it out...
    19  	var buf bytes.Buffer
    20  	zw := zip.NewWriter(&buf)
    21  	zw.RegisterCompressor(zstd.ZipMethodWinZip, compr)
    22  	zw.RegisterCompressor(zstd.ZipMethodPKWare, compr)
    23  
    24  	// Create 1MB data
    25  	tmp := make([]byte, 1<<20)
    26  	for i := range tmp {
    27  		tmp[i] = byte(i)
    28  	}
    29  	w, err := zw.CreateHeader(&zip.FileHeader{
    30  		Name:   "file1.txt",
    31  		Method: zstd.ZipMethodWinZip,
    32  	})
    33  	if err != nil {
    34  		panic(err)
    35  	}
    36  	w.Write(tmp)
    37  
    38  	// Another...
    39  	w, err = zw.CreateHeader(&zip.FileHeader{
    40  		Name:   "file2.txt",
    41  		Method: zstd.ZipMethodPKWare,
    42  	})
    43  	w.Write(tmp)
    44  	zw.Close()
    45  
    46  	zr, err := zip.NewReader(bytes.NewReader(buf.Bytes()), int64(buf.Len()))
    47  	if err != nil {
    48  		panic(err)
    49  	}
    50  	zr.RegisterDecompressor(zstd.ZipMethodWinZip, decomp)
    51  	zr.RegisterDecompressor(zstd.ZipMethodPKWare, decomp)
    52  	for _, file := range zr.File {
    53  		rc, err := file.Open()
    54  		if err != nil {
    55  			panic(err)
    56  		}
    57  		b, err := io.ReadAll(rc)
    58  		rc.Close()
    59  		if bytes.Equal(b, tmp) {
    60  			fmt.Println(file.Name, "ok")
    61  		} else {
    62  			fmt.Println(file.Name, "mismatch")
    63  		}
    64  	}
    65  	// Output:
    66  	// file1.txt ok
    67  	// file2.txt ok
    68  }
    69
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