use PipedDecompressor for xz

Native xzcat is 4x as fast

backend/opendecompress.go

@@ -9,19 +9,18 @@ import (
 	"path/filepath"
 
 	gzip "github.com/klauspost/pgzip"
-	"github.com/ulikunitz/xz"
 )
 
-//PipedDecompressor not used right now, but may come in handy
+//PipedDecompressor is used to wrap higher performing native decompression tools
 type PipedDecompressor struct {
 	io.ReadCloser
 	wrapped io.ReadCloser
 	cmd     *exec.Cmd
 }
 
-func NewPipedDecompressor(f *os.File, prog string) (*PipedDecompressor, error) {
+func NewPipedDecompressor(r io.ReadCloser, prog string) (*PipedDecompressor, error) {
 	cmd := exec.Command(prog)
-	cmd.Stdin = f
+	cmd.Stdin = r
 	out, err := cmd.StdoutPipe()
 	if err != nil {
 		return nil, err
@@ -31,7 +30,7 @@ func NewPipedDecompressor(f *os.File, prog string) (*PipedDecompressor, error) {
 	}
 	pd := &PipedDecompressor{
 		ReadCloser: out,
-		wrapped:    f,
+		wrapped:    r,
 		cmd:        cmd,
 	}
 	return pd, err
@@ -78,14 +77,8 @@ func OpenDecompress(fn string) (r io.ReadCloser, err error) {
 			wrapped:    f,
 		}, nil
 	case ".xz":
-		xzr, err := xz.NewReader(f)
-		if err != nil {
-			return nil, err
-		}
-		return &WrappedDecompressor{
-			ReadCloser: ioutil.NopCloser(xzr),
-			wrapped:    f,
-		}, nil
+		xzr, err := NewPipedDecompressor(f, "xzcat")
+		return xzr, err
 	default:
 		return f, err
 	}

cmd/version.go

@@ -7,7 +7,7 @@ import (
 )
 
 const (
-	VERSION = "0.2.1"
+	VERSION = "0.2.2"
 )
 
 var cmdVersion = &cobra.Command{

go.mod

@@ -21,7 +21,6 @@ require (
 	github.com/spf13/pflag v1.0.3 // indirect
 	github.com/syndtr/goleveldb v0.0.0-20180128140416-211f78098806
 	github.com/tinylib/msgp v1.0.2
-	github.com/ulikunitz/xz v0.5.5
 	github.com/willf/bitset v1.1.9
 	golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4 // indirect
 	google.golang.org/appengine v1.0.0 // indirect

go.sum

@@ -48,8 +48,6 @@ github.com/syndtr/goleveldb v0.0.0-20180128140416-211f78098806 h1:lb1fuqOputZmuX
 github.com/syndtr/goleveldb v0.0.0-20180128140416-211f78098806/go.mod h1:Z4AUp2Km+PwemOoO/VB5AOx9XSsIItzFjoJlOSiYmn0=
 github.com/tinylib/msgp v1.0.2 h1:DfdQrzQa7Yh2es9SuLkixqxuXS2SxsdYn0KbdrOGWD8=
 github.com/tinylib/msgp v1.0.2/go.mod h1:+d+yLhGm8mzTaHzB+wgMYrodPfmZrzkirds8fDWklFE=
-github.com/ulikunitz/xz v0.5.5 h1:pFrO0lVpTBXLpYw+pnLj6TbvHuyjXMfjGeCwSqCVwok=
-github.com/ulikunitz/xz v0.5.5/go.mod h1:2bypXElzHzzJZwzH67Y6wb67pO62Rzfn7BSiF4ABRW8=
 github.com/willf/bitset v1.1.9 h1:GBtFynGY9ZWZmEC9sWuu41/7VBXPFCOAbCbqTflOg9c=
 github.com/willf/bitset v1.1.9/go.mod h1:RjeCKbqT1RxIR/KWY6phxZiaY1IyutSBfGjNPySAYV4=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd h1:nTDtHvHSdCn1m6ITfMRqtOd/9+7a3s8RBNOZ3eYZzJA=