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package archiver
import (
"fmt"
"io"
"path/filepath"
"github.com/dsnet/compress/bzip2"
)
// Bz2 facilitates bzip2 compression.
type Bz2 struct {
CompressionLevel int
}
// Compress reads in, compresses it, and writes it to out.
func (bz *Bz2) Compress(in io.Reader, out io.Writer) error {
w, err := bzip2.NewWriter(out, &bzip2.WriterConfig{
Level: bz.CompressionLevel,
})
if err != nil {
return err
}
defer w.Close()
_, err = io.Copy(w, in)
return err
}
// Decompress reads in, decompresses it, and writes it to out.
func (bz *Bz2) Decompress(in io.Reader, out io.Writer) error {
r, err := bzip2.NewReader(in, nil)
if err != nil {
return err
}
defer r.Close()
_, err = io.Copy(out, r)
return err
}
// CheckExt ensures the file extension matches the format.
func (bz *Bz2) CheckExt(filename string) error {
if filepath.Ext(filename) != ".bz2" {
return fmt.Errorf("filename must have a .bz2 extension")
}
return nil
}
func (bz *Bz2) String() string { return "bz2" }
// NewBz2 returns a new, default instance ready to be customized and used.
func NewBz2() *Bz2 {
return &Bz2{
CompressionLevel: bzip2.DefaultCompression,
}
}
// Compile-time checks to ensure type implements desired interfaces.
var (
_ = Compressor(new(Bz2))
_ = Decompressor(new(Bz2))
)
// DefaultBz2 is a default instance that is conveniently ready to use.
var DefaultBz2 = NewBz2()
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