snapshot of https://github.com/seaweedfs/seaweedfs.git (master, 2026-09-16; blobs > 131072B omitted)

weed/s3api/lance/markers.go

@@ -0,0 +1,93 @@
+package lance
+
+import (
+	"net/http"
+	"time"
+
+	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
+	"github.com/seaweedfs/seaweedfs/weed/s3api/s3tables"
+)
+
+// Marker files the Lance Directory Catalog reads. Writing them beside the
+// dataset keeps a client that bypasses this namespace, and lists the storage
+// prefix directly, seeing the same table states the catalog reports.
+const (
+	reservedMarker     = ".lance-reserved"
+	deregisteredMarker = ".lance-deregistered"
+	versionsDir        = "_versions"
+)
+
+// datasetDir maps a table location onto the filer directory holding it.
+func datasetDir(location string) string {
+	return s3tables.TableDataDirFromMetadataLocation(location)
+}
+
+func (s *Server) entryExists(r *http.Request, dir, name string) (bool, error) {
+	found := false
+	err := s.filerClient.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
+		_, lookupErr := filer_pb.LookupEntry(r.Context(), client, &filer_pb.LookupDirectoryEntryRequest{
+			Directory: dir,
+			Name:      name,
+		})
+		if lookupErr == filer_pb.ErrNotFound {
+			return nil
+		}
+		if lookupErr != nil {
+			return lookupErr
+		}
+		found = true
+		return nil
+	})
+	return found, err
+}
+
+// writeMarker drops a zero-length marker into the dataset directory. The
+// directory has to exist already: a table declared through this namespace has
+// one, and a table registered at a location that does not yet exist has no
+// storage to mark.
+func (s *Server) writeMarker(r *http.Request, location, name string) error {
+	dir := datasetDir(location)
+	if dir == "" {
+		return nil
+	}
+	now := time.Now().Unix()
+	return s.filerClient.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
+		return filer_pb.CreateEntry(r.Context(), client, &filer_pb.CreateEntryRequest{
+			Directory: dir,
+			Entry: &filer_pb.Entry{
+				Name: name,
+				Attributes: &filer_pb.FuseAttributes{
+					Mtime:    now,
+					Crtime:   now,
+					FileMode: uint32(0644),
+				},
+			},
+		})
+	})
+}
+
+func (s *Server) removeMarker(r *http.Request, location, name string) error {
+	dir := datasetDir(location)
+	if dir == "" {
+		return nil
+	}
+	return s.filerClient.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
+		return filer_pb.DoRemove(r.Context(), client, dir, name, true, false, true, false, nil)
+	})
+}
+
+// datasetState reports the two things the spec asks about a table's storage:
+// whether it has been deregistered, and whether it holds data yet. A dataset
+// holds data once it has a version manifest, which is how a directory catalog
+// decides the same question.
+func (s *Server) datasetState(r *http.Request, location string) (deregistered, hasData bool, err error) {
+	dir := datasetDir(location)
+	if dir == "" {
+		return false, false, nil
+	}
+	if deregistered, err = s.entryExists(r, dir, deregisteredMarker); err != nil {
+		return false, false, err
+	}
+	hasData, err = s.entryExists(r, dir, versionsDir)
+	return deregistered, hasData, err
+}