1 files changed, 76 insertions, 0 deletions
diff --git a/src/tools/rbd_mirror/image_map/StateTransition.h b/src/tools/rbd_mirror/image_map/StateTransition.h
new file mode 100644
index 000000000..02a5ce4e9
--- /dev/null
+++ b/src/tools/rbd_mirror/image_map/StateTransition.h
@@ -0,0 +1,76 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_RBD_MIRROR_IMAGE_MAP_STATE_TRANSITION_H
+#define CEPH_RBD_MIRROR_IMAGE_MAP_STATE_TRANSITION_H
+
+#include "tools/rbd_mirror/image_map/Types.h"
+#include <boost/optional.hpp>
+#include <map>
+
+namespace rbd {
+namespace mirror {
+namespace image_map {
+
+class StateTransition {
+public:
+  enum State {
+    STATE_UNASSOCIATED,
+    STATE_INITIALIZING,
+    STATE_ASSOCIATING,
+    STATE_ASSOCIATED,
+    STATE_SHUFFLING,
+    STATE_DISSOCIATING
+  };
+
+  enum PolicyAction {
+    POLICY_ACTION_MAP,
+    POLICY_ACTION_UNMAP,
+    POLICY_ACTION_REMOVE
+  };
+
+  struct Transition {
+    // image map action
+    ActionType action_type = ACTION_TYPE_NONE;
+
+    // policy internal action
+    boost::optional<PolicyAction> start_policy_action;
+    boost::optional<PolicyAction> finish_policy_action;
+
+    // state machine complete
+    boost::optional<State> finish_state;
+
+    Transition() {
+    }
+    Transition(ActionType action_type,
+               const boost::optional<PolicyAction>& start_policy_action,
+               const boost::optional<PolicyAction>& finish_policy_action,
+               const boost::optional<State>& finish_state)
+      : action_type(action_type), start_policy_action(start_policy_action),
+        finish_policy_action(finish_policy_action), finish_state(finish_state) {
+    }
+  };
+
+  static bool is_idle(State state) {
+    return (state == STATE_UNASSOCIATED || state == STATE_ASSOCIATED);
+  }
+
+  static void transit(State state, Transition* transition);
+
+private:
+  typedef std::pair<State, ActionType> TransitionKey;
+  typedef std::map<TransitionKey, Transition> TransitionTable;
+
+  // image transition table
+  static const TransitionTable s_transition_table;
+};
+
+std::ostream &operator<<(std::ostream &os, const StateTransition::State &state);
+std::ostream &operator<<(std::ostream &os,
+                         const StateTransition::PolicyAction &policy_action);
+
+} // namespace image_map
+} // namespace mirror
+} // namespace rbd
+
+#endif // CEPH_RBD_MIRROR_IMAGE_MAP_STATE_TRANSITION_H