package pb import ( "context" "fmt" "github.com/seaweedfs/seaweedfs/weed/glog" "github.com/seaweedfs/seaweedfs/weed/pb/filer_pb" "github.com/seaweedfs/seaweedfs/weed/util" "google.golang.org/grpc" "io" "time" ) type EventErrorType int const ( TrivialOnError EventErrorType = iota FatalOnError RetryForeverOnError ) // MetadataFollowOption is used to control the behavior of the metadata following // process. Part of it is used as a cursor to resume the following process. type MetadataFollowOption struct { ClientName string ClientId int32 ClientEpoch int32 SelfSignature int32 PathPrefix string AdditionalPathPrefixes []string DirectoriesToWatch []string StartTsNs int64 StopTsNs int64 EventErrorType EventErrorType } type ProcessMetadataFunc func(resp *filer_pb.SubscribeMetadataResponse) error func FollowMetadata(filerAddress ServerAddress, grpcDialOption grpc.DialOption, option *MetadataFollowOption, processEventFn ProcessMetadataFunc) error { err := WithFilerClient(true, option.SelfSignature, filerAddress, grpcDialOption, makeSubscribeMetadataFunc(option, processEventFn)) if err != nil { return fmt.Errorf("subscribing filer meta change: %v", err) } return err } func WithFilerClientFollowMetadata(filerClient filer_pb.FilerClient, option *MetadataFollowOption, processEventFn ProcessMetadataFunc) error { err := filerClient.WithFilerClient(true, makeSubscribeMetadataFunc(option, processEventFn)) if err != nil { return fmt.Errorf("subscribing filer meta change: %v", err) } return nil } func makeSubscribeMetadataFunc(option *MetadataFollowOption, processEventFn ProcessMetadataFunc) func(client filer_pb.SeaweedFilerClient) error { return func(client filer_pb.SeaweedFilerClient) error { ctx, cancel := context.WithCancel(context.Background()) defer cancel() stream, err := client.SubscribeMetadata(ctx, &filer_pb.SubscribeMetadataRequest{ ClientName: option.ClientName, PathPrefix: option.PathPrefix, PathPrefixes: option.AdditionalPathPrefixes, Directories: option.DirectoriesToWatch, SinceNs: option.StartTsNs, Signature: option.SelfSignature, ClientId: option.ClientId, ClientEpoch: option.ClientEpoch, UntilNs: option.StopTsNs, }) if err != nil { return fmt.Errorf("subscribe: %v", err) } for { resp, listenErr := stream.Recv() if listenErr == io.EOF { return nil } if listenErr != nil { return listenErr } if err := processEventFn(resp); err != nil { switch option.EventErrorType { case TrivialOnError: glog.Errorf("process %v: %v", resp, err) case FatalOnError: glog.Fatalf("process %v: %v", resp, err) case RetryForeverOnError: util.RetryForever("followMetaUpdates", func() error { return processEventFn(resp) }, func(err error) bool { glog.Errorf("process %v: %v", resp, err) return true }) default: glog.Errorf("process %v: %v", resp, err) } } option.StartTsNs = resp.TsNs } } } func AddOffsetFunc(processEventFn ProcessMetadataFunc, offsetInterval time.Duration, offsetFunc func(counter int64, offset int64) error) ProcessMetadataFunc { var counter int64 var lastWriteTime time.Time return func(resp *filer_pb.SubscribeMetadataResponse) error { if err := processEventFn(resp); err != nil { return err } counter++ if lastWriteTime.Add(offsetInterval).Before(time.Now()) { lastWriteTime = time.Now() if err := offsetFunc(counter, resp.TsNs); err != nil { return err } counter = 0 } return nil } }