139 lines
2.6 KiB
Go
139 lines
2.6 KiB
Go
package filewatch
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import (
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"fmt"
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"os"
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"path/filepath"
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"strings"
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"sync"
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"time"
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"github.com/fsnotify/fsnotify"
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)
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type Watcher struct {
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watcher *fsnotify.Watcher
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emitEvent func(name string, data ...any)
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mu sync.Mutex
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watched string // 当前监听的文件绝对路径
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}
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func NewWatcher(emitEvent func(name string, data ...any)) *Watcher {
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return &Watcher{emitEvent: emitEvent}
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}
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// WatchFile 开始监听指定文件的变化。切换文件时自动取消旧监听。
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func (w *Watcher) WatchFile(path string) error {
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w.mu.Lock()
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defer w.mu.Unlock()
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absPath, err := filepath.Abs(path)
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if err != nil {
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return fmt.Errorf("解析路径失败: %w", err)
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}
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// 同一文件不重复监听
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if absPath == w.watched {
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return nil
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}
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// 停止旧监听
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w.stopLocked()
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// 检查文件是否存在
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if _, err := os.Stat(absPath); err != nil {
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return fmt.Errorf("文件不存在: %s", absPath)
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}
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// 创建 fsnotify watcher
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fw, err := fsnotify.NewWatcher()
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if err != nil {
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return fmt.Errorf("创建文件监听器失败: %w", err)
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}
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w.watcher = fw
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// fsnotify 在某些系统上不支持直接监听文件，监听其所在目录
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dir := filepath.Dir(absPath)
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if err := fw.Add(dir); err != nil {
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fw.Close()
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return fmt.Errorf("监听目录失败: %w", err)
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}
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w.watched = absPath
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// 后台消费事件
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go w.consumeEvents()
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return nil
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}
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// UnwatchFile 停止监听
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func (w *Watcher) UnwatchFile() {
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w.mu.Lock()
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defer w.mu.Unlock()
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w.stopLocked()
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}
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func (w *Watcher) stopLocked() {
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if w.watcher != nil {
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w.watcher.Close()
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w.watcher = nil
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}
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w.watched = ""
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}
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func (w *Watcher) consumeEvents() {
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debounceDelay := 300 * time.Millisecond
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var debounceTimer *time.Timer
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for {
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select {
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case event, ok := <-w.watcher.Events:
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if !ok {
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return
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}
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// 只处理目标文件的 Write/Create/Rename 事件
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if event.Op&(fsnotify.Write|fsnotify.Create|fsnotify.Rename) == 0 {
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continue
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}
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w.mu.Lock()
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target := w.watched
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w.mu.Unlock()
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if target == "" {
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return // 已停止监听
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}
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// 路径比较（忽略大小写，Windows）
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if !strings.EqualFold(event.Name, target) {
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continue
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}
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// 防抖
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if debounceTimer != nil {
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debounceTimer.Stop()
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}
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debounceTimer = time.AfterFunc(debounceDelay, func() {
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// 文件已不存在则跳过（如被删除）
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if _, err := os.Stat(target); err != nil {
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return
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}
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if w.emitEvent != nil {
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w.emitEvent("file-changed", target)
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}
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})
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case _, ok := <-w.watcher.Errors:
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if !ok {
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return
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}
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}
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}
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}
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// Close 释放资源
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func (w *Watcher) Close() {
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w.UnwatchFile()
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}
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