From cedb039693d41f31766d5944796677ad9ac373e1 Mon Sep 17 00:00:00 2001
From: nikpivkin <nikita.pivkin@smartforce.io>
Date: Tue, 7 May 2024 11:45:53 +0600
Subject: [PATCH] refactor: lazy writing symlinks

---
 pkg/iac/scanners/helm/parser/parser_tar.go | 28 ++++++++++++----------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/pkg/iac/scanners/helm/parser/parser_tar.go b/pkg/iac/scanners/helm/parser/parser_tar.go
index 4c859e092174..f8d692eaa977 100644
--- a/pkg/iac/scanners/helm/parser/parser_tar.go
+++ b/pkg/iac/scanners/helm/parser/parser_tar.go
@@ -116,13 +116,7 @@ func copySymlink(fsys *memoryfs.FS, src, dst string) error {
 		return nil
 	}
 
-	f, err := fsys.Open(src)
-	if err != nil {
-		return fmt.Errorf("open symlink error: %w", err)
-	}
-	defer f.Close()
-
-	if err := copyFile(fsys, f, dst); err != nil {
+	if err := copyFileLazy(fsys, src, dst); err != nil {
 		return fmt.Errorf("copy file error: %w", err)
 	}
 
@@ -158,12 +152,7 @@ func copyDir(fsys *memoryfs.FS, src, dst string) error {
 
 		dst := path.Join(dst, filePath[len(src):])
 
-		f, err := fsys.Open(filePath)
-		if err != nil {
-			return err
-		}
-
-		if err := copyFile(fsys, f, dst); err != nil {
+		if err := copyFileLazy(fsys, filePath, dst); err != nil {
 			return fmt.Errorf("copy file error: %w", err)
 		}
 		return nil
@@ -171,3 +160,16 @@ func copyDir(fsys *memoryfs.FS, src, dst string) error {
 
 	return fs.WalkDir(fsys, src, walkFn)
 }
+
+func copyFileLazy(fsys *memoryfs.FS, src, dst string) error {
+	if err := fsys.MkdirAll(path.Dir(dst), fs.ModePerm); err != nil && !errors.Is(err, fs.ErrExist) {
+		return fmt.Errorf("mkdir error: %w", err)
+	}
+	return fsys.WriteLazyFile(dst, func() (io.Reader, error) {
+		f, err := fsys.Open(src)
+		if err != nil {
+			return nil, err
+		}
+		return f, nil
+	}, fs.ModePerm)
+}