Detect file external modification and ask the user whether to reload or not

* Buffer now store a m_fs_timestamp field.
* Client in Normal mode checks current buffer file every 500 ms, or
  each time it goes back to Normal mode.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/buffer.hh b/src/buffer.hh
index fcc18a12..d1bad814 100644
--- a/src/buffer.hh
+++ b/src/buffer.hh
@@ -104,6 +104,8 @@ public:
     BufferIterator erase(BufferIterator begin, BufferIterator end);
 
     size_t         timestamp() const { return m_timestamp; }
+    time_t         fs_timestamp() const;
+    void           set_fs_timestamp(time_t ts);
 
     void           commit_undo_group();
     bool           undo();
@@ -197,6 +199,8 @@ private:
     size_t m_last_save_undo_index;
     size_t m_timestamp;
 
+    time_t m_fs_timestamp;
+
     // this is mutable as adding or removing listeners is not muting the
     // buffer observable state.
     mutable std::unordered_set<BufferChangeListener*> m_change_listeners;