package provider import ( "bytes" "crypto/md5" "io/ioutil" "os" "time" "github.com/Dreamacro/clash/log" ) var ( fileMode os.FileMode = 0666 ) type parser = func([]byte) (interface{}, error) type fetcher struct { name string vehicle Vehicle updatedAt *time.Time ticker *time.Ticker hash [16]byte parser parser onUpdate func(interface{}) } func (f *fetcher) Name() string { return f.name } func (f *fetcher) VehicleType() VehicleType { return f.vehicle.Type() } func (f *fetcher) Initial() (interface{}, error) { var buf []byte var err error var isLocal bool if stat, err := os.Stat(f.vehicle.Path()); err == nil { buf, err = ioutil.ReadFile(f.vehicle.Path()) modTime := stat.ModTime() f.updatedAt = &modTime isLocal = true } else { buf, err = f.vehicle.Read() } if err != nil { return nil, err } proxies, err := f.parser(buf) if err != nil { if !isLocal { return nil, err } // parse local file error, fallback to remote buf, err = f.vehicle.Read() if err != nil { return nil, err } proxies, err = f.parser(buf) if err != nil { return nil, err } } if err := ioutil.WriteFile(f.vehicle.Path(), buf, fileMode); err != nil { return nil, err } f.hash = md5.Sum(buf) // pull proxies automatically if f.ticker != nil { go f.pullLoop() } return proxies, nil } func (f *fetcher) Update() (interface{}, bool, error) { buf, err := f.vehicle.Read() if err != nil { return nil, false, err } now := time.Now() hash := md5.Sum(buf) if bytes.Equal(f.hash[:], hash[:]) { f.updatedAt = &now return nil, true, nil } proxies, err := f.parser(buf) if err != nil { return nil, false, err } if err := ioutil.WriteFile(f.vehicle.Path(), buf, fileMode); err != nil { return nil, false, err } f.updatedAt = &now f.hash = hash return proxies, false, nil } func (f *fetcher) Destroy() error { if f.ticker != nil { f.ticker.Stop() } return nil } func (f *fetcher) pullLoop() { for range f.ticker.C { elm, same, err := f.Update() if err != nil { log.Warnln("[Provider] %s pull error: %s", f.Name(), err.Error()) continue } if same { log.Debugln("[Provider] %s's proxies doesn't change", f.Name()) continue } log.Infoln("[Provider] %s's proxies update", f.Name()) if f.onUpdate != nil { f.onUpdate(elm) } } } func newFetcher(name string, interval time.Duration, vehicle Vehicle, parser parser, onUpdate func(interface{})) *fetcher { var ticker *time.Ticker if interval != 0 { ticker = time.NewTicker(interval) } return &fetcher{ name: name, ticker: ticker, vehicle: vehicle, parser: parser, onUpdate: onUpdate, } }