.

go/zodb/db.go

@@ -43,6 +43,7 @@ type DB struct {
 	connv	[]*Connection // order by ↑= .at
 
 	// information about invalidations
+	// XXX -> Storage. XXX or -> Cache? (so it is not duplicated many times for many DB case)
 	invTab	[]invEntry // order by ↑= .tid
 }
 
@@ -81,10 +82,13 @@ func (db *DB) Open(ctx context.Context) (*Connection, error) {
 	}
 
 	// wait till .invTab is up to date covering ≥ lastTid
+	// XXX reenable
+/*
 	err = db.invTab.Wait(ctx, at)
 	if err != nil {
 		return nil, err
 	}
+*/
 
 	// now we have both at and invalidation data covering it -> proceed to
 	// get connection from the pool.

go/zodb/zodb.go

@@ -328,6 +328,16 @@ type IStorageDriver interface {
 
 	Loader
 	Iterator
+
+	// Notifier returns storage driver notifier.
+	//
+	// The notifier represents invalidation channel (notify about changes
+	// made to DB not by us from outside).	XXX
+	//
+	// To simplify drivets, there must be only 1 logical user of
+	// storage-driver level notifier interface. Ccontrary IStorage allows
+	// for several users of notification channel.	XXX ok?
+	Notifier() Notifier
 }
 
 // Loader provides functionality to load objects.
@@ -391,9 +401,14 @@ type Committer interface {
 }
 
 
-// Notifier allows to be notified of database changes made by other clients.
+// Notifier allows to be notified of changes made to database by other clients.
 type Notifier interface {
-	// TODO: invalidation channel (notify about changes made to DB not by us from outside)
+
+	// Read returns next notification event.
+	//
+	// XXX ...
+	// XXX overflow -> special error
+	Read(ctx context.Context) (Tid, []Oid, error)
 }