1 files changed, 145 insertions, 0 deletions
diff --git a/src/librbd/ImageState.h b/src/librbd/ImageState.h
new file mode 100644
index 00000000..7f28d1ee
--- /dev/null
+++ b/src/librbd/ImageState.h
@@ -0,0 +1,145 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_LIBRBD_IMAGE_STATE_H
+#define CEPH_LIBRBD_IMAGE_STATE_H
+
+#include "include/int_types.h"
+#include "common/Mutex.h"
+#include <list>
+#include <string>
+#include <utility>
+#include "cls/rbd/cls_rbd_types.h"
+
+class Context;
+class RWLock;
+
+namespace librbd {
+
+class ImageCtx;
+class ImageUpdateWatchers;
+class UpdateWatchCtx;
+
+template <typename ImageCtxT = ImageCtx>
+class ImageState {
+public:
+  ImageState(ImageCtxT *image_ctx);
+  ~ImageState();
+
+  int open(uint64_t flags);
+  void open(uint64_t flags, Context *on_finish);
+
+  int close();
+  void close(Context *on_finish);
+
+  void handle_update_notification();
+
+  bool is_refresh_required() const;
+
+  int refresh();
+  int refresh_if_required();
+  void refresh(Context *on_finish);
+
+  void snap_set(uint64_t snap_id, Context *on_finish);
+
+  void prepare_lock(Context *on_ready);
+  void handle_prepare_lock_complete();
+
+  int register_update_watcher(UpdateWatchCtx *watcher, uint64_t *handle);
+  int unregister_update_watcher(uint64_t handle);
+  void flush_update_watchers(Context *on_finish);
+  void shut_down_update_watchers(Context *on_finish);
+
+private:
+  enum State {
+    STATE_UNINITIALIZED,
+    STATE_OPEN,
+    STATE_CLOSED,
+    STATE_OPENING,
+    STATE_CLOSING,
+    STATE_REFRESHING,
+    STATE_SETTING_SNAP,
+    STATE_PREPARING_LOCK
+  };
+
+  enum ActionType {
+    ACTION_TYPE_OPEN,
+    ACTION_TYPE_CLOSE,
+    ACTION_TYPE_REFRESH,
+    ACTION_TYPE_SET_SNAP,
+    ACTION_TYPE_LOCK
+  };
+
+  struct Action {
+    ActionType action_type;
+    uint64_t refresh_seq = 0;
+    uint64_t snap_id = CEPH_NOSNAP;
+    Context *on_ready = nullptr;
+
+    Action(ActionType action_type) : action_type(action_type) {
+    }
+    inline bool operator==(const Action &action) const {
+      if (action_type != action.action_type) {
+        return false;
+      }
+      switch (action_type) {
+      case ACTION_TYPE_REFRESH:
+        return (refresh_seq == action.refresh_seq);
+      case ACTION_TYPE_SET_SNAP:
+        return (snap_id == action.snap_id);
+      case ACTION_TYPE_LOCK:
+        return false;
+      default:
+        return true;
+      }
+    }
+  };
+
+  typedef std::list<Context *> Contexts;
+  typedef std::pair<Action, Contexts> ActionContexts;
+  typedef std::list<ActionContexts> ActionsContexts;
+
+  ImageCtxT *m_image_ctx;
+  State m_state;
+
+  mutable Mutex m_lock;
+  ActionsContexts m_actions_contexts;
+
+  uint64_t m_last_refresh;
+  uint64_t m_refresh_seq;
+
+  ImageUpdateWatchers *m_update_watchers;
+
+  uint64_t m_open_flags;
+
+  bool is_transition_state() const;
+  bool is_closed() const;
+
+  const Action *find_pending_refresh() const;
+
+  void append_context(const Action &action, Context *context);
+  void execute_next_action_unlock();
+  void execute_action_unlock(const Action &action, Context *context);
+  void complete_action_unlock(State next_state, int r);
+
+  void send_open_unlock();
+  void handle_open(int r);
+
+  void send_close_unlock();
+  void handle_close(int r);
+
+  void send_refresh_unlock();
+  void handle_refresh(int r);
+
+  void send_set_snap_unlock();
+  void handle_set_snap(int r);
+
+  void send_prepare_lock_unlock();
+
+};
+
+} // namespace librbd
+
+extern template class librbd::ImageState<librbd::ImageCtx>;
+
+#endif // CEPH_LIBRBD_IMAGE_STATE_H