Re-added NewReaderAtOffset

internal/toreader/offsetreader.go

@@ -0,0 +1,19 @@
+package toreader
+
+import "io"
+
+type OffsetReader struct {
+	r   io.ReaderAt
+	off int64
+}
+
+func NewOffsetReader(r io.ReaderAt, off int64) *OffsetReader {
+	return &OffsetReader{
+		r:   r,
+		off: off,
+	}
+}
+
+func (r OffsetReader) ReadAt(p []byte, off int64) (n int, e error) {
+	return r.r.ReadAt(p, off+r.off)
+}

reader.go

@@ -4,6 +4,7 @@ import (
 	"io"
 	"time"
 
+	"github.com/CalebQ42/squashfs/internal/toreader"
 	squashfslow "github.com/CalebQ42/squashfs/low"
 )
 
@@ -27,6 +28,10 @@ func NewReader(r io.ReaderAt) (*Reader, error) {
 	return out, nil
 }
 
+func NewReaderAtOffset(r io.ReaderAt, offset int64) (*Reader, error) {
+	return NewReader(toreader.NewOffsetReader(r, offset))
+}
+
 func (r *Reader) ModTime() time.Time {
 	return time.Unix(int64(r.Low.Superblock.ModTime), 0)
 }