internal/pkg: return reader for files

This improves efficiency for cache hits.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/pkg/tar.go

@@ -2,7 +2,6 @@ package pkg
 
 import (
 	"archive/tar"
-	"bytes"
 	"compress/bzip2"
 	"compress/gzip"
 	"context"
@@ -78,12 +77,17 @@ func (a *tarArtifact) Cure(c *CureContext) (err error) {
 	var tr io.ReadCloser
 
 	{
-		var data []byte
-		data, err = c.LoadData(a.f)
-		if err != nil {
+
+		if tr, err = c.OpenFile(a.f); err != nil {
 			return
 		}
-		tr = io.NopCloser(bytes.NewReader(data))
+		defer func(f io.ReadCloser) {
+			closeErr := f.Close()
+			if err == nil {
+				err = closeErr
+			}
+		}(tr)
+		tr = io.NopCloser(tr)
 	}
 
 	defer func() {