address review notes

filebeat/input/filestream/fswatch.go

@@ -131,13 +131,10 @@ func (w *fileWatcher) watch(ctx unison.Canceler) {
 	w.log.Info("Start next scan")
 
 	paths := w.scanner.GetFiles()
-	files := getKeys(paths)
 
 	newFiles := make(map[string]os.FileInfo)
 
-	for i := 0; i < len(paths); i++ {
-		path := files[i]
-		info := paths[path]
+	for path, info := range paths {
 
 		prevInfo, ok := w.prev[path]
 		if !ok {
@@ -149,7 +146,7 @@ func (w *fileWatcher) watch(ctx unison.Canceler) {
 			select {
 			case <-ctx.Done():
 				return
-			case w.events <- w.writeEvent(path, info):
+			case w.events <- writeEvent(path, info):
 			}
 		}
 
@@ -159,33 +156,33 @@ func (w *fileWatcher) watch(ctx unison.Canceler) {
 
 	// remaining files are in the prev map are the ones that are missing
 	// either because they have been deleted or renamed
-	for deletedPath, deletedInfo := range w.prev {
+	for removedPath, removedInfo := range w.prev {
 		for newPath, newInfo := range newFiles {
-			if os.SameFile(deletedInfo, newInfo) {
+			if os.SameFile(removedInfo, newInfo) {
 				select {
 				case <-ctx.Done():
 					return
-				case w.events <- w.renamedEvent(deletedPath, newPath, newInfo):
+				case w.events <- renamedEvent(removedPath, newPath, newInfo):
 					delete(newFiles, newPath)
-					goto CHECK_NEXT_DELETED
+					goto CHECK_NEXT_REMOVED
 				}
 			}
 		}
 
 		select {
 		case <-ctx.Done():
 			return
-		case w.events <- w.deleteEvent(deletedPath, deletedInfo):
+		case w.events <- deleteEvent(removedPath, removedInfo):
 		}
-	CHECK_NEXT_DELETED:
+	CHECK_NEXT_REMOVED:
 	}
 
 	// remaining files in newFiles are new
 	for path, info := range newFiles {
 		select {
 		case <-ctx.Done():
 			return
-		case w.events <- w.createEvent(path, info):
+		case w.events <- createEvent(path, info):
 		}
 
 	}
@@ -194,27 +191,19 @@ func (w *fileWatcher) watch(ctx unison.Canceler) {
 	w.prev = paths
 }
 
-func getKeys(paths map[string]os.FileInfo) []string {
-	files := make([]string, 0)
-	for file := range paths {
-		files = append(files, file)
-	}
-	return files
-}
-
-func (w *fileWatcher) createEvent(path string, fi os.FileInfo) loginp.FSEvent {
+func createEvent(path string, fi os.FileInfo) loginp.FSEvent {
 	return loginp.FSEvent{Op: loginp.OpCreate, OldPath: "", NewPath: path, Info: fi}
 }
 
-func (w *fileWatcher) writeEvent(path string, fi os.FileInfo) loginp.FSEvent {
+func writeEvent(path string, fi os.FileInfo) loginp.FSEvent {
 	return loginp.FSEvent{Op: loginp.OpWrite, OldPath: path, NewPath: path, Info: fi}
 }
 
-func (w *fileWatcher) renamedEvent(oldPath, path string, fi os.FileInfo) loginp.FSEvent {
+func renamedEvent(oldPath, path string, fi os.FileInfo) loginp.FSEvent {
 	return loginp.FSEvent{Op: loginp.OpRename, OldPath: oldPath, NewPath: path, Info: fi}
 }
 
-func (w *fileWatcher) deleteEvent(path string, fi os.FileInfo) loginp.FSEvent {
+func deleteEvent(path string, fi os.FileInfo) loginp.FSEvent {
 	return loginp.FSEvent{Op: loginp.OpDelete, OldPath: path, NewPath: "", Info: fi}
 }
 
@@ -295,7 +284,7 @@ func (s *fileScanner) normalizeGlobPatterns() error {
 // GetFiles returns a map of files and fileinfos which
 // match the configured paths.
 func (s *fileScanner) GetFiles() map[string]os.FileInfo {
-	paths := map[string]os.FileInfo{}
+	pathInfo := map[string]os.FileInfo{}
 
 	for _, path := range s.paths {
 		matches, err := filepath.Glob(path)
@@ -304,31 +293,30 @@ func (s *fileScanner) GetFiles() map[string]os.FileInfo {
 			continue
 		}
 
-	OUTER:
 		for _, file := range matches {
-			if s.skippedFile(file) {
+			if s.shouldSkipFile(file) {
 				continue
 			}
 
 			// If symlink is enabled, it is checked that original is not part of same input
 			// If original is harvested by other input, states will potentially overwrite each other
-			if s.isOriginalAndSymlinkConfigured(file, paths) {
-				continue OUTER
+			if s.isOriginalAndSymlinkConfigured(file, pathInfo) {
+				continue
 			}
 
 			fileInfo, err := os.Stat(file)
 			if err != nil {
 				s.log.Debug("stat(%s) failed: %s", file, err)
 				continue
 			}
-			paths[file] = fileInfo
+			pathInfo[file] = fileInfo
 		}
 	}
 
-	return paths
+	return pathInfo
 }
 
-func (s *fileScanner) skippedFile(file string) bool {
+func (s *fileScanner) shouldSkipFile(file string) bool {
 	if s.isFileExcluded(file) {
 		s.log.Debugf("Exclude file: %s", file)
 		return true
@@ -359,7 +347,7 @@ func (s *fileScanner) isOriginalAndSymlinkConfigured(file string, paths map[stri
 		fileInfo, err := os.Stat(file)
 		if err != nil {
 			s.log.Debugf("stat(%s) failed: %s", file, err)
-			return true
+			return false
 		}
 
 		for _, finfo := range paths {