state: add InstanceId type

state/machine.go

 package state
 
 import (
         "fmt"
         "labix.org/v2/mgo"
         "labix.org/v2/mgo/txn"
         "launchpad.net/juju-core/state/presence"
         "launchpad.net/juju-core/trivial"
         "time"
 )
 
-// InstanceId values hold provider-specific instance identifiers.

[niemeyer, 2012/11/28 18:17:17]

// An InstanceId is a provider-specific identifier associated with an
// instance (physical or virtual machine allocated in the provider).

[fwereade, 2012/11/28 18:41:00]

Done.

+// An InstanceId is a provider-specific identifier associated with an
+// instance (physical or virtual machine allocated in the provider).
 type InstanceId string
 
 // Machine represents the state of a machine.
 type Machine struct {
         st  *State
         doc machineDoc
 }
 
 // machineDoc represents the internal state of a machine in MongoDB.
 type machineDoc struct {
@@ skipping 196 matching lines @@
                 return fmt.Errorf("cannot set instance id of machine %v: %v", m, onAbort(err, errNotAlive))
         }
         m.doc.InstanceId = id
         return nil
 }
 
 // String returns a unique description of this machine.
 func (m *Machine) String() string {
         return m.doc.Id
 }