feat: ensure proper closing of gzip and file writers/readers to preve…

…nt resource leaks (ethereum-optimism#11475)

* add gzipCloser struct

* add Close method

* fix OpenDecompressed func

* fix CompressByFileType func

* knit

* Apply suggestions from code review

close both even if one fails

Co-authored-by: Adrian Sutton <[email protected]>

* fix WriteCloser Close method

* fix name for more general

* fix writercloser name for more geneeral

* add construction function for WrappedCloser

* using construction func

* seperate wrapped closer struct to wrapped_closer.go

---------

Co-authored-by: Adrian Sutton <[email protected]>

op-service/ioutil/gzip.go

@@ -12,23 +12,23 @@ import (
 // OpenDecompressed opens a reader for the specified file and automatically gzip decompresses the content
 // if the filename ends with .gz
 func OpenDecompressed(path string) (io.ReadCloser, error) {
-	var r io.ReadCloser
 	r, err := os.Open(path)
 	if err != nil {
 		return nil, err
 	}
 	if IsGzip(path) {
-		r, err = gzip.NewReader(r)
+		gr, err := gzip.NewReader(r)
 		if err != nil {
+			r.Close()
 			return nil, fmt.Errorf("failed to create gzip reader: %w", err)
 		}
+		return NewWrappedReadCloser(gr, r), nil
 	}
 	return r, nil
 }
 
 // OpenCompressed opens a file for writing and automatically compresses the content if the filename ends with .gz
 func OpenCompressed(file string, flag int, perm os.FileMode) (io.WriteCloser, error) {
-	var out io.WriteCloser
 	out, err := os.OpenFile(file, flag, perm)
 	if err != nil {
 		return nil, err
@@ -70,7 +70,7 @@ func IsGzip(path string) bool {
 
 func CompressByFileType(file string, out io.WriteCloser) io.WriteCloser {
 	if IsGzip(file) {
-		return gzip.NewWriter(out)
+		return NewWrappedWriteCloser(gzip.NewWriter(out), out)
 	}
 	return out
 }

op-service/ioutil/wrapped_closer.go

@@ -0,0 +1,44 @@
+package ioutil
+
+import (
+	"errors"
+	"io"
+)
+
+// WrappedReadCloser is a struct that closes both the gzip.Reader and the underlying io.Closer.
+type WrappedReadCloser struct {
+	io.ReadCloser
+	closer io.Closer
+}
+
+// WrappedWriteCloser is a struct that closes both the gzip.Writer and the underlying io.Closer.
+type WrappedWriteCloser struct {
+	io.WriteCloser
+	closer io.Closer
+}
+
+// Close closes both the gzip.Reader and the underlying reader.
+func (g *WrappedReadCloser) Close() error {
+	return errors.Join(g.ReadCloser.Close(), g.closer.Close())
+}
+
+// Close closes both the gzip.Writer and the underlying writer.
+func (g *WrappedWriteCloser) Close() error {
+	return errors.Join(g.WriteCloser.Close(), g.closer.Close())
+}
+
+// NewWrappedReadCloser is a constructor function that initializes a WrappedReadCloser structure.
+func NewWrappedReadCloser(r io.ReadCloser, c io.Closer) *WrappedReadCloser {
+	return &WrappedReadCloser{
+		ReadCloser: r,
+		closer:     c,
+	}
+}
+
+// NewWrappedWriteCloser is a constructor function that initializes a WrappedWriteCloser structure.
+func NewWrappedWriteCloser(r io.WriteCloser, c io.Closer) *WrappedWriteCloser {
+	return &WrappedWriteCloser{
+		WriteCloser: r,
+		closer:      c,
+	}
+}