Clear cache (fanal#8)

cache/cache.go

@@ -5,20 +5,13 @@ import (
 	"os"
 	"path/filepath"
 
+	"github.com/knqyf263/fanal/utils"
+
 	"golang.org/x/xerrors"
 )
 
-func init() {
-	d, err := os.UserCacheDir()
-	if err != nil {
-		d = os.TempDir()
-	}
-	cacheDir = filepath.Join(d, "fanal")
-	os.MkdirAll(cacheDir, os.ModePerm)
-}
-
 var (
-	cacheDir string
+	cacheDir = utils.CacheDir()
 )
 
 func Get(key string) io.Reader {
@@ -32,6 +25,9 @@ func Get(key string) io.Reader {
 
 func Set(key string, file io.Reader) (io.Reader, error) {
 	filePath := filepath.Join(cacheDir, key)
+	if err := os.MkdirAll(cacheDir, os.ModePerm); err != nil {
+		return nil, xerrors.Errorf("failed to mkdir all: %w", err)
+	}
 	cacheFile, err := os.Create(filePath)
 	if err != nil {
 		return file, xerrors.Errorf("failed to create cache file: %w", err)
@@ -40,3 +36,10 @@ func Set(key string, file io.Reader) (io.Reader, error) {
 	tee := io.TeeReader(file, cacheFile)
 	return tee, nil
 }
+
+func Clear() error {
+	if err := os.RemoveAll(utils.CacheDir()); err != nil {
+		return xerrors.New("failed to remove cache")
+	}
+	return nil
+}

cmd/fanal/main.go

@@ -7,6 +7,10 @@ import (
 	"log"
 	"os"
 
+	"golang.org/x/xerrors"
+
+	"github.com/knqyf263/fanal/cache"
+
 	"github.com/knqyf263/fanal/analyzer"
 	_ "github.com/knqyf263/fanal/analyzer/library/bundler"
 	_ "github.com/knqyf263/fanal/analyzer/library/composer"
@@ -33,8 +37,15 @@ func main() {
 func run() (err error) {
 	ctx := context.Background()
 	tarPath := flag.String("f", "-", "layer.tar path")
+	clearCache := flag.Bool("clear", false, "clear cache")
 	flag.Parse()
 
+	if *clearCache {
+		if err = cache.Clear(); err != nil {
+			return xerrors.Errorf("error in cache clear: %w", err)
+		}
+	}
+
 	args := flag.Args()
 
 	var files extractor.FileMap

utils/utils.go

@@ -1,5 +1,19 @@
 package utils
 
+import (
+	"os"
+	"path/filepath"
+)
+
+func CacheDir() string {
+	cacheDir, err := os.UserCacheDir()
+	if err != nil {
+		cacheDir = os.TempDir()
+	}
+	dir := filepath.Join(cacheDir, "fanal")
+	return dir
+}
+
 func StringInSlice(a string, list []string) bool {
 	for _, b := range list {
 		if b == a {