forgejo/vendor/github.com/mholt/archiver/v3/zstd.go

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package archiver
import (
"fmt"
"io"
"path/filepath"
"github.com/klauspost/compress/zstd"
)
// Zstd facilitates Zstandard compression.
type Zstd struct {
EncoderOptions []zstd.EOption
DecoderOptions []zstd.DOption
}
// Compress reads in, compresses it, and writes it to out.
func (zs *Zstd) Compress(in io.Reader, out io.Writer) error {
w, err := zstd.NewWriter(out, zs.EncoderOptions...)
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 (zs *Zstd) Decompress(in io.Reader, out io.Writer) error {
r, err := zstd.NewReader(in, zs.DecoderOptions...)
if err != nil {
return err
}
defer r.Close()
_, err = io.Copy(out, r)
return err
}
// CheckExt ensures the file extension matches the format.
func (zs *Zstd) CheckExt(filename string) error {
if filepath.Ext(filename) != ".zst" {
return fmt.Errorf("filename must have a .zst extension")
}
return nil
}
func (zs *Zstd) String() string { return "zstd" }
// NewZstd returns a new, default instance ready to be customized and used.
func NewZstd() *Zstd {
return new(Zstd)
}
// Compile-time checks to ensure type implements desired interfaces.
var (
_ = Compressor(new(Zstd))
_ = Decompressor(new(Zstd))
)
// DefaultZstd is a default instance that is conveniently ready to use.
var DefaultZstd = NewZstd()