implement DiskUsage for the rest of the datastores

autobatch/autobatch.go

@@ -92,3 +92,8 @@ func (d *Datastore) Query(q dsq.Query) (dsq.Results, error) {
 
 	return d.child.Query(q)
 }
+
+// DiskUsage implements the PersistentDatastore interface.
+func (d *Datastore) DiskUsage() (uint64, error) {
+	return ds.DiskUsage(d.child)
+}

failstore/failstore.go

@@ -76,6 +76,14 @@ func (d *Failstore) Query(q dsq.Query) (dsq.Results, error) {
 	return d.child.Query(q)
 }
 
+// DiskUsage implements the PersistentDatastore interface.
+func (d *Failstore) DiskUsage() (uint64, error) {
+	if err := d.errfunc("disk-usage"); err != nil {
+		return 0, err
+	}
+	return ds.DiskUsage(d.child)
+}
+
 // FailBatch implements batching operations on the Failstore.
 type FailBatch struct {
 	cb     ds.Batch

namespace/namespace.go

@@ -85,6 +85,11 @@ func (d *datastore) Query(q dsq.Query) (dsq.Results, error) {
 	}), nil
 }
 
+// DiskUsage implements the PersistentDatastore interface.
+func (d *datastore) DiskUsage() (uint64, error) {
+	return ds.DiskUsage(d.raw)
+}
+
 func (d *datastore) Batch() (ds.Batch, error) {
 	if bds, ok := d.Datastore.(ds.Batching); ok {
 		return bds.Batch()

retrystore/retrystore.go

@@ -43,6 +43,17 @@ func (d *Datastore) runOp(op func() error) error {
 	return fmt.Errorf(errFmtString, err)
 }
 
+// DiskUsage implements the PersistentDatastore interface.
+func (d *Datastore) DiskUsage() (uint64, error) {
+	var size uint64
+	err := d.runOp(func() error {
+		var err error
+		size, err = ds.DiskUsage(d.Batching)
+		return err
+	})
+	return size, err
+}
+
 // Get retrieves a value given a key.
 func (d *Datastore) Get(k ds.Key) (interface{}, error) {
 	var val interface{}