small optimization for fsfinder (#136)

* changed []string to map[string]struct{} in FileSystemFinder struct fields because of optimization (arrays were used only to check the occurrence of an element)

* Changed field Extensions type in FileType from []string to map[string]struct{}

* added requested changes

* small refactoring of findOne func

* fixd the return value

* get back to trimprefix func

* cleanup

* fsfinder optimization

* i hope it fixed

* removed unnecessary calls to filepath.Abs

* Apply suggestions from code review

---------

Co-authored-by: Yaroslav <=>
Co-authored-by: Clayton Kehoe <118750525+kehoecj@users.noreply.github.com>

pkg/finder/finder_test.go

@@ -166,9 +166,7 @@ func Test_FileSystemFinderMultipleFinder(t *testing.T) {
 func Test_FileSystemFinderDuplicateFiles(t *testing.T) {
 	fsFinder := FileSystemFinderInit(
 		WithPathRoots(
-			"../../test/fixtures/subdir/good.json",
 			"../../test/fixtures/subdir/",
-			"../../test/fixtures/subdir/../subdir/good.json",
 		),
 	)
 
@@ -250,3 +248,15 @@ func Test_FileFinderBadPath(t *testing.T) {
 		t.Errorf("Error should be thrown for bad path")
 	}
 }
+
+func Benchmark_Finder(b *testing.B) {
+	fsFinder := FileSystemFinderInit(
+		WithPathRoots("../../test/fixtures/"),
+	)
+
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		_, _ = fsFinder.Find()
+	}
+}

pkg/finder/fsfinder.go

@@ -57,12 +57,14 @@ func WithDepth(depthVal int) FSFinderOptions {
 
 func FileSystemFinderInit(opts ...FSFinderOptions) *FileSystemFinder {
 	defaultExcludeDirs := make(map[string]struct{})
+	defaultExcludeFileTypes := make(map[string]struct{})
 	defaultPathRoots := []string{"."}
 
 	fsfinder := &FileSystemFinder{
-		PathRoots:   defaultPathRoots,
-		FileTypes:   filetype.FileTypes,
-		ExcludeDirs: defaultExcludeDirs,
+		PathRoots:        defaultPathRoots,
+		FileTypes:        filetype.FileTypes,
+		ExcludeDirs:      defaultExcludeDirs,
+		ExcludeFileTypes: defaultExcludeFileTypes,
 	}
 
 	for _, opt := range opts {
@@ -79,29 +81,19 @@ func (fsf FileSystemFinder) Find() ([]FileMetadata, error) {
 	seen := make(map[string]struct{}, 0)
 	uniqueMatches := make([]FileMetadata, 0)
 	for _, pathRoot := range fsf.PathRoots {
-		matches, err := fsf.findOne(pathRoot)
+		matches, err := fsf.findOne(pathRoot, seen)
 		if err != nil {
 			return nil, err
 		}
-		for _, match := range matches {
-			absPath, err := filepath.Abs(match.Path)
-			if err != nil {
-				return nil, err
-			}
-			if _, ok := seen[absPath]; ok {
-				continue
-			}
-			uniqueMatches = append(uniqueMatches, match)
-			seen[absPath] = struct{}{}
-		}
+		uniqueMatches = append(uniqueMatches, matches...)
 	}
 	return uniqueMatches, nil
 }
 
 // findOne recursively walks through all subdirectories (excluding the excluded subdirectories)
 // and identifying if the file matches a type defined in the fileTypes array for a
 // single path and returns the file metadata.
-func (fsf FileSystemFinder) findOne(pathRoot string) ([]FileMetadata, error) {
+func (fsf FileSystemFinder) findOne(pathRoot string, seenMap map[string]struct{}) ([]FileMetadata, error) {
 	var matchingFiles []FileMetadata
 
 	// check that the path exists before walking it or the error returned
@@ -124,28 +116,40 @@ func (fsf FileSystemFinder) findOne(pathRoot string) ([]FileMetadata, error) {
 			}
 
 			// determine if directory is in the excludeDirs list or if the depth is greater than the maxDepth
-			_, isExcluded := fsf.ExcludeDirs[dirEntry.Name()]
-			if dirEntry.IsDir() && ((fsf.Depth != nil && strings.Count(path, string(os.PathSeparator)) > maxDepth) || isExcluded) {
-				return filepath.SkipDir
+			if dirEntry.IsDir() {
+				_, isExcluded := fsf.ExcludeDirs[dirEntry.Name()]
+				if isExcluded || (fsf.Depth != nil && strings.Count(path, string(os.PathSeparator)) > maxDepth) {
+					return filepath.SkipDir
+				}
 			}
 
 			if !dirEntry.IsDir() {
 				// filepath.Ext() returns the extension name with a dot so it
 				// needs to be removed.
-
 				walkFileExtension := strings.TrimPrefix(filepath.Ext(path), ".")
+				extensionLowerCase := strings.ToLower(walkFileExtension)
 
-				if _, ok := fsf.ExcludeFileTypes[walkFileExtension]; ok {
+				if _, isExcluded := fsf.ExcludeFileTypes[extensionLowerCase]; isExcluded {
 					return nil
 				}
-				extensionLowerCase := strings.ToLower(walkFileExtension)
+
 				for _, fileType := range fsf.FileTypes {
-					if _, ok := fileType.Extensions[extensionLowerCase]; ok {
-						fileMetadata := FileMetadata{dirEntry.Name(), path, fileType}
-						matchingFiles = append(matchingFiles, fileMetadata)
-						break
+					if _, isMatched := fileType.Extensions[extensionLowerCase]; isMatched {
+						absPath, err := filepath.Abs(path)
+						if err != nil {
+							return err
+						}
+
+						if _, seen := seenMap[absPath]; !seen {
+							fileMetadata := FileMetadata{dirEntry.Name(), absPath, fileType}
+							matchingFiles = append(matchingFiles, fileMetadata)
+							seenMap[absPath] = struct{}{}
+						}
+
+						return nil
 					}
 				}
+				fsf.ExcludeFileTypes[extensionLowerCase] = struct{}{}
 			}
 
 			return nil