Avoid unneeded update of selections when we are going to overwrite them

6 files changed, 27 insertions, 18 deletions

diff --git a/src/client.cc b/src/client.cc
index 27a56c80..0d729bc3 100644
--- a/src/client.cc
+++ b/src/client.cc
@@ -138,7 +138,7 @@ void Client::change_buffer(Buffer& buffer)
     m_window->options().register_watcher(*this);
     m_ui->set_ui_options(m_window->options()["ui_options"].get<UserInterface::Options>());
 
-    context().m_selections = std::move(ws.selections);
+    context().selections_write_only() = std::move(ws.selections);
     context().set_window(*m_window);
     m_window->set_dimensions(ui().dimensions());
 
@@ -177,7 +177,7 @@ void Client::reload_buffer()
     ByteCoord cursor_pos = context().selections().main().cursor();
     Buffer* buf = create_buffer_from_file(buffer.name());
     kak_assert(buf == &buffer);
-    context().selections() = SelectionList{buffer, buffer.clamp(cursor_pos)};
+    context().selections_write_only() = SelectionList{buffer, buffer.clamp(cursor_pos)};
     context().window().set_position(view_pos);
     context().print_status({ "'" + buffer.display_name() + "' reloaded",
                              get_face("Information") });
diff --git a/src/commands.cc b/src/commands.cc
index 964ae0e1..66ba66d9 100644
--- a/src/commands.cc
+++ b/src/commands.cc
@@ -175,7 +175,7 @@ void edit(const ParametersParser& parser, Context& context)
                      std::max(0, str_to_int(parser[2]) - 1) : 0;
 
         auto& buffer = context.buffer();
-        context.selections() = { buffer, buffer.clamp({ line,  column }) };
+        context.selections_write_only() = { buffer, buffer.clamp({ line,  column }) };
         if (context.has_window())
             context.window().center_line(context.selections().main().cursor().line);
     }
@@ -1180,7 +1180,7 @@ void context_wrap(const ParametersParser& parser, Context& context, Func func)
             ScopedEdition edition{c};
             for (auto& sel : sels)
             {
-                c.selections() = SelectionList{ sels.buffer(), sel, sels.timestamp() };
+                c.selections_write_only() = SelectionList{ sels.buffer(), sel, sels.timestamp() };
                 c.selections().update();
 
                 func(parser, c);
@@ -1489,7 +1489,7 @@ const CommandDesc select_cmd = {
     CommandCompleter{},
     [](const ParametersParser& parser, Context& context)
     {
-        context.selections() = selection_list_from_string(context.buffer(), parser[0]);
+        context.selections_write_only() = selection_list_from_string(context.buffer(), parser[0]);
     }
 };
 
diff --git a/src/context.cc b/src/context.cc
index ca186cb1..bd67a6b3 100644
--- a/src/context.cc
+++ b/src/context.cc
@@ -197,6 +197,13 @@ SelectionList& Context::selections()
     return *m_selections;
 }
 
+SelectionList& Context::selections_write_only()
+{
+    if (not m_selections)
+        throw runtime_error("no selections in context");
+    return *m_selections;
+}
+
 const SelectionList& Context::selections() const
 {
     return const_cast<Context&>(*this).selections();
diff --git a/src/context.hh b/src/context.hh
index 4ff765de..48b01a87 100644
--- a/src/context.hh
+++ b/src/context.hh
@@ -90,6 +90,9 @@ public:
     const SelectionList& selections() const;
     Vector<String>  selections_content() const;
 
+    // Return potentially out of date selections
+    SelectionList& selections_write_only();
+
     void change_buffer(Buffer& buffer);
 
     void set_client(Client& client);
@@ -141,7 +144,6 @@ private:
     SafePtr<Window>       m_window;
     SafePtr<Client>       m_client;
 
-    friend class Client;
     Optional<SelectionList> m_selections;
 
     String m_name;
diff --git a/src/input_handler.cc b/src/input_handler.cc
index 8b672288..98f2436a 100644
--- a/src/input_handler.cc
+++ b/src/input_handler.cc
@@ -60,7 +60,7 @@ struct MouseHandler
         {
             m_dragging = true;
             m_anchor = context.window().buffer_coord(key.mouse_coord());
-            context.selections() = SelectionList{ context.buffer(), m_anchor };
+            context.selections_write_only() = SelectionList{ context.buffer(), m_anchor };
             return true;
         }
         if (key.modifiers == Key::Modifiers::MouseRelease)
@@ -69,7 +69,7 @@ struct MouseHandler
                 return true;
             m_dragging = false;
             auto cursor = context.window().buffer_coord(key.mouse_coord());
-            context.selections() = SelectionList{ context.buffer(), Selection{m_anchor, cursor} };
+            context.selections_write_only() = SelectionList{ context.buffer(), Selection{m_anchor, cursor} };
             return true;
         }
         if (key.modifiers == Key::Modifiers::MousePos)
@@ -77,7 +77,7 @@ struct MouseHandler
             if (not m_dragging)
                 return true;
             auto cursor = context.window().buffer_coord(key.mouse_coord());
-            context.selections() = SelectionList{ context.buffer(), Selection{m_anchor, cursor} };
+            context.selections_write_only() = SelectionList{ context.buffer(), Selection{m_anchor, cursor} };
             return true;
         }
         if (key.modifiers == Key::Modifiers::MouseWheelDown)
diff --git a/src/normal.cc b/src/normal.cc
index 7f737032..8bd8691e 100644
--- a/src/normal.cc
+++ b/src/normal.cc
@@ -563,7 +563,7 @@ void regex_prompt(Context& context, const String prompt, T func)
                 if (event != PromptEvent::Change and context.has_ui())
                     context.ui().info_hide();
                 selections.update();
-                context.selections() = selections;
+                context.selections_write_only() = selections;
                 context.input_handler().set_prompt_face(get_face("Prompt"));
                 if (event == PromptEvent::Abort)
                     return;
@@ -600,7 +600,7 @@ void regex_prompt(Context& context, const String prompt, T func)
             }
             catch (runtime_error&)
             {
-                context.selections() = selections;
+                context.selections_write_only() = selections;
                 // only validation should propagate errors,
                 // incremental search should not.
                 if (event == PromptEvent::Validate)
@@ -733,7 +733,7 @@ void join_lines_select_spaces(Context& context, NormalParams)
     }
     if (selections.empty())
         return;
-    context.selections() = selections;
+    context.selections_write_only() = std::move(selections);
     ScopedEdition edition(context);
     context.selections().insert(" "_str, InsertMode::Replace);
 }
@@ -743,7 +743,7 @@ void join_lines(Context& context, NormalParams params)
     SelectionList sels{context.selections()};
     auto restore_sels = on_scope_end([&]{
         sels.update();
-        context.selections() = std::move(sels);
+        context.selections_write_only() = std::move(sels);
     });
 
     join_lines_select_spaces(context, params);
@@ -766,7 +766,7 @@ void keep(Context& context, NormalParams)
         }
         if (keep.empty())
             throw runtime_error("no selections remaining");
-        context.selections() = std::move(keep);
+        context.selections_write_only() = std::move(keep);
     });
 }
 
@@ -788,7 +788,7 @@ void keep_pipe(Context& context, NormalParams)
             }
             if (keep.empty())
                 throw runtime_error("no selections remaining");
-            context.selections() = std::move(keep);
+            context.selections_write_only() = std::move(keep);
     });
 }
 template<bool indent_empty = false>
@@ -1100,7 +1100,7 @@ void jump(Context& context, NormalParams)
     BufferManager::instance().set_last_used_buffer(buffer);
     if (&buffer != &context.buffer())
         context.change_buffer(buffer);
-    context.selections() = jump;
+    context.selections_write_only() = jump;
 }
 
 void save_selections(Context& context, NormalParams)
@@ -1267,7 +1267,7 @@ void undo(Context& context, NormalParams)
     {
         auto ranges = compute_modified_ranges(buffer, timestamp);
         if (not ranges.empty())
-            context.selections() = std::move(ranges);
+            context.selections_write_only() = std::move(ranges);
         context.selections().avoid_eol();
     }
     else if (not res)
@@ -1284,7 +1284,7 @@ void redo(Context& context, NormalParams)
     {
         auto ranges = compute_modified_ranges(buffer, timestamp);
         if (not ranges.empty())
-            context.selections() = std::move(ranges);
+            context.selections_write_only() = std::move(ranges);
         context.selections().avoid_eol();
     }