77 lines
1.6 KiB
Go
77 lines
1.6 KiB
Go
package archiver
|
|
|
|
import (
|
|
"compress/gzip"
|
|
"fmt"
|
|
"io"
|
|
"path/filepath"
|
|
|
|
pgzip "github.com/klauspost/pgzip"
|
|
)
|
|
|
|
// Gz facilitates gzip compression.
|
|
type Gz struct {
|
|
CompressionLevel int
|
|
SingleThreaded bool
|
|
}
|
|
|
|
// Compress reads in, compresses it, and writes it to out.
|
|
func (gz *Gz) Compress(in io.Reader, out io.Writer) error {
|
|
var w io.WriteCloser
|
|
var err error
|
|
if gz.SingleThreaded {
|
|
w, err = gzip.NewWriterLevel(out, gz.CompressionLevel)
|
|
} else {
|
|
w, err = pgzip.NewWriterLevel(out, gz.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 (gz *Gz) Decompress(in io.Reader, out io.Writer) error {
|
|
var r io.ReadCloser
|
|
var err error
|
|
if gz.SingleThreaded {
|
|
r, err = gzip.NewReader(in)
|
|
} else {
|
|
r, err = pgzip.NewReader(in)
|
|
}
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer r.Close()
|
|
_, err = io.Copy(out, r)
|
|
return err
|
|
}
|
|
|
|
// CheckExt ensures the file extension matches the format.
|
|
func (gz *Gz) CheckExt(filename string) error {
|
|
if filepath.Ext(filename) != ".gz" {
|
|
return fmt.Errorf("filename must have a .gz extension")
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (gz *Gz) String() string { return "gz" }
|
|
|
|
// NewGz returns a new, default instance ready to be customized and used.
|
|
func NewGz() *Gz {
|
|
return &Gz{
|
|
CompressionLevel: gzip.DefaultCompression,
|
|
}
|
|
}
|
|
|
|
// Compile-time checks to ensure type implements desired interfaces.
|
|
var (
|
|
_ = Compressor(new(Gz))
|
|
_ = Decompressor(new(Gz))
|
|
)
|
|
|
|
// DefaultGz is a default instance that is conveniently ready to use.
|
|
var DefaultGz = NewGz()
|