How to filter duplicate system messages from fsnotify-Golang-php.cn

How to filter duplicate system messages from fsnotify

王林

Release： 2024-02-11 10:03:08

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如何从 fsnotify 过滤重复的系统消息

php小编百草在这里与大家分享一种有效的方法，即如何从fsnotify过滤重复的系统消息。在日常的开发工作中，我们经常会遇到需要实时监控文件系统变化的场景，而fsnotify正是一个强大的工具。然而，当系统频繁变动时，可能会导致大量的重复消息出现，给我们的工作带来困扰。因此，本文将教您一种简单而实用的过滤重复系统消息的方法，帮助您提高工作效率。

问题内容

我使用“github.com/fsnotify/fsnotify”来监听文件更改，但是我应该如何多次过滤某些消息？

func listener() {
    watcher, err := fsnotify.newwatcher()
    if err != nil {
        log.fatal(err)
    }
    defer watcher.close()
    done := make(chan bool)
    go func() {
        for {
            select {
            case event, ok := <-watcher.events:
                if !ok {
                    return
                }
                log.println("event:", event.name, event.op)

                // writing in this way reduces some messages:
                if event.op&fsnotify.rename == fsnotify.rename {
                    // do ...
                } else if event.op&fsnotify.create == fsnotify.create {
                    // do ...
                } else if event.op&fsnotify.write == fsnotify.write {
                    // do ...
                } else if event.op&fsnotify.remove == fsnotify.remove {
                    // do ...
                }
            case _, ok := <-watcher.errors:
                if !ok {
                    return
                }
            }
        }
    }()
    
    err = watcher.add("e:/.../demo")
    if err != nil {
        log.fatal(err)
    }
    <-done
}

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比如write、create事件发生了好几次，我发现官方已经修复了bug，但是好像没有完全解决

2022/12/12 21:00:55 event: e:\...\demo\a.bbb create
2022/12/12 21:00:55 event: e:\...\demo\a.bbb create
2022/12/12 21:00:55 event: e:\...\demo\a.bbb create


2022/12/12 21:01:57 event: e:\...\demo\2.md write
2022/12/12 21:01:57 event: e:\...\demo\2.md write
2022/12/12 21:01:57 event: e:\...\demo\2.md write
2022/12/12 21:01:57 event: e:\...\demo\2.md write
2022/12/12 21:01:57 event: e:\...\demo\2.md write
2022/12/12 21:01:57 event: e:\...\demo\2.md write
2022/12/12 21:01:57 event: e:\...\demo\2.md write

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我应该如何过滤消息？

##############################

var syncMap sync.Map
go func() {
    for {
        select {
        case event, ok := <-watcher.Events:
            if !ok {
                return
            }
            fPath := strings.ReplaceAll(event.Name, "\\", "/")
            pathKey, _ := syncMap.Load(fPath)
            if pathKey != 1 {
                // ...
                syncMap.Store(fPath, 1)

                go func() {
                    time.Sleep(time.Second * 2)
                    syncMap.Delete(fPath)
                }()
            }
        case _, ok := <-watcher.Errors:
            if !ok {
                return
            }
        }
    }
}()

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解决方法

如果发出事件的库不在您的控制之下，您只能更改处理重复项的方式。您可以使用 map[string]bool 来跟踪您已经看到/处理的事件，因此修改您的代码可以执行以下操作：

seenMap := make(map[string]bool)
go func() {
    for {
        select {
        case event, ok := <-watcher.Events:
            if !ok {
                return
            }
            log.Println("event:", event.Name, event.Op)
            _, seen := seenMap[event.Name]
            if !seen {
                // Writing in this way reduces some messages:
                if event.Op&fsnotify.Rename == fsnotify.Rename {
                    // do ...
                } else if event.Op&fsnotify.Create == fsnotify.Create {
                    // do ...
                } else if event.Op&fsnotify.Write == fsnotify.Write {
                    // do ...
                } else if event.Op&fsnotify.Remove == fsnotify.Remove {
                    // do ...
                }
                seenMap[event.Name] = true
            }
        case _, ok := <-watcher.Errors:
            if !ok {
                return
            }
        }
    }
}()

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