func (s *BlockDevicesSuite) TestSetMachineBlockDevicesUnchanged(c *gc.C) {
sda := state.BlockDeviceInfo{DeviceName: "sda"}
err := s.machine.SetMachineBlockDevices(sda)
c.Assert(err, jc.ErrorIsNil)
s.assertBlockDevices(c, s.machine.MachineTag(), []state.BlockDeviceInfo{sda})
// Setting the same should not change txn-revno.
docID := state.DocID(s.State, s.machine.Id())
before, err := state.TxnRevno(s.State, state.BlockDevicesC, docID)
c.Assert(err, jc.ErrorIsNil)
err = s.machine.SetMachineBlockDevices(sda)
c.Assert(err, jc.ErrorIsNil)
after, err := state.TxnRevno(s.State, state.BlockDevicesC, docID)
c.Assert(err, jc.ErrorIsNil)
c.Assert(after, gc.Equals, before)
}
func (s *StorageStateSuite) storageInstanceExists(c *gc.C, tag names.StorageTag) bool {
_, err := state.TxnRevno(
s.State,
state.StorageInstancesC,
state.DocID(s.State, tag.Id()),
)
if err != nil {
c.Assert(err, gc.Equals, mgo.ErrNotFound)
return false
}
return true
}