mirror of
https://github.com/ClusterCockpit/cc-backend
synced 2025-06-08 00:23:48 +02:00
74 lines
1.4 KiB
Go
74 lines
1.4 KiB
Go
// Copyright (C) 2023 NHR@FAU, University Erlangen-Nuremberg.
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// All rights reserved.
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// Use of this source code is governed by a MIT-style
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// license that can be found in the LICENSE file.
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package util
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import (
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"sync"
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"github.com/ClusterCockpit/cc-backend/pkg/log"
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"github.com/fsnotify/fsnotify"
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)
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type Listener interface {
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EventCallback()
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EventMatch(event string) bool
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}
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var (
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initOnce sync.Once
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w *fsnotify.Watcher
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listeners []Listener
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)
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func AddListener(path string, l Listener) {
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var err error
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initOnce.Do(func() {
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var err error
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w, err = fsnotify.NewWatcher()
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if err != nil {
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log.Error("creating a new watcher: %w", err)
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}
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listeners = make([]Listener, 0)
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go watchLoop(w)
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})
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listeners = append(listeners, l)
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err = w.Add(path)
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if err != nil {
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log.Warnf("%q: %s", path, err)
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}
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}
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func FsWatcherShutdown() {
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w.Close()
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}
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func watchLoop(w *fsnotify.Watcher) {
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for {
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select {
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// Read from Errors.
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case err, ok := <-w.Errors:
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if !ok { // Channel was closed (i.e. Watcher.Close() was called).
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return
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}
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log.Errorf("watch event loop: %s", err)
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// Read from Events.
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case e, ok := <-w.Events:
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if !ok { // Channel was closed (i.e. Watcher.Close() was called).
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return
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}
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log.Infof("Event %s", e)
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for _, l := range listeners {
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if l.EventMatch(e.String()) {
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l.EventCallback()
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}
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}
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}
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}
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}
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