pkg/utils: drop fswatcher

Dead code.

pkg/utils/fswatcher.go

@@ -1,159 +0,0 @@
-/*
-Copyright 2021 The Kubernetes Authors.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-package utils
-
-import (
-	"fmt"
-	"path/filepath"
-	"time"
-
-	"github.com/fsnotify/fsnotify"
-	"k8s.io/klog/v2"
-)
-
-// FsWatcher is a wrapper helper for watching files
-type FsWatcher struct {
-	*fsnotify.Watcher
-
-	Events    chan struct{}
-	ratelimit time.Duration
-	names     []string
-	paths     map[string]struct{}
-}
-
-// CreateFsWatcher creates a new FsWatcher
-func CreateFsWatcher(ratelimit time.Duration, names ...string) (*FsWatcher, error) {
-	w := &FsWatcher{
-		Events:    make(chan struct{}),
-		names:     names,
-		ratelimit: ratelimit,
-	}
-
-	if err := w.reset(names...); err != nil {
-		return nil, err
-	}
-
-	go w.watch()
-
-	return w, nil
-}
-
-// reset resets the file watches
-func (w *FsWatcher) reset(names ...string) error {
-	if err := w.initWatcher(); err != nil {
-		return err
-	}
-	if err := w.add(names...); err != nil {
-		return err
-	}
-
-	return nil
-}
-
-func (w *FsWatcher) initWatcher() error {
-	if w.Watcher != nil {
-		if err := w.Watcher.Close(); err != nil {
-			return fmt.Errorf("failed to close fsnotify watcher: %w", err)
-		}
-	}
-	w.paths = make(map[string]struct{})
-
-	watcher, err := fsnotify.NewWatcher()
-	if err != nil {
-		w.Watcher = nil
-		return fmt.Errorf("failed to create fsnotify watcher: %w", err)
-	}
-	w.Watcher = watcher
-
-	return nil
-}
-
-func (w *FsWatcher) add(names ...string) error {
-	for _, name := range names {
-		if name == "" {
-			continue
-		}
-
-		added := false
-		// Add watches for all directory components so that we catch e.g. renames
-		// upper in the tree
-		for p := name; ; p = filepath.Dir(p) {
-			if _, ok := w.paths[p]; !ok {
-				if err := w.Add(p); err != nil {
-					klog.V(1).ErrorS(err, "failed to add fsnotify watch", "path", p)
-				} else {
-					klog.V(1).InfoS("added fsnotify watch", "path", p)
-					added = true
-				}
-
-				w.paths[p] = struct{}{}
-			} else {
-				added = true
-			}
-			if filepath.Dir(p) == p {
-				break
-			}
-		}
-		if !added {
-			// Want to be sure that we watch something
-			return fmt.Errorf("failed to add any watch")
-		}
-	}
-
-	return nil
-}
-
-func (w *FsWatcher) watch() {
-	var ratelimiter <-chan time.Time
-	for {
-		select {
-		case e, ok := <-w.Watcher.Events:
-			// Watcher has been closed
-			if !ok {
-				klog.InfoS("watcher closed")
-				return
-			}
-
-			// If any of our paths change
-			name := filepath.Clean(e.Name)
-			if _, ok := w.paths[filepath.Clean(name)]; ok {
-				klog.V(2).InfoS("fsnotify event detected", "path", name, "fsNotifyEvent", e)
-
-				// Rate limiter. In certain filesystem operations we get
-				// numerous events in quick succession
-				ratelimiter = time.After(w.ratelimit)
-			}
-
-		case e, ok := <-w.Watcher.Errors:
-			// Watcher has been closed
-			if !ok {
-				klog.InfoS("watcher closed")
-				return
-			}
-			klog.ErrorS(e, "fswatcher error event detected")
-
-		case <-ratelimiter:
-			// Blindly remove existing watch and add a new one
-			if err := w.reset(w.names...); err != nil {
-				klog.ErrorS(err, "re-trying in 60 seconds")
-				ratelimiter = time.After(60 * time.Second)
-			}
-
-			w.Events <- struct{}{}
-		}
-	}
-}