Dont read the full notes table every time book details is rendered

Instead check if our particular items have notes only. This is a bit
more work when no notes are present but is much less work when a
significant number of notes are present.

src/calibre/ebooks/metadata/book/render.py

@@ -109,7 +109,7 @@ def mi_to_html(
         mi,
         field_list=None, default_author_link=None, use_roman_numbers=True,
         rating_font='Liberation Serif', rtl=False, comments_heading_pos='hide',
-        for_qt=False, vertical_fields=(), show_links=True, all_notes=None
+        for_qt=False, vertical_fields=(), show_links=True, item_id_if_has_note=None
     ):
 
     link_markup =  '↗️'
@@ -130,13 +130,11 @@ def mi_to_html(
                 link = ' <a title="{0}: {1}" href="{1}">{2}</a>'.format(_('Click to open'), link, link_markup)
             else:
                 link = ''
-            if field_value in all_notes.get(field, set()):
-                note = ' <a title="{0}" href="{1}">{2}</a>'.format(_('Click to open note'),
-                                            notes_action(field=field, value=field_value,
-                                                         item_id=all_notes.get(field).get(field_value)),
-                                                         note_markup)
-            else:
             note = ''
+            item_id = None if item_id_if_has_note is None else item_id_if_has_note(field, field_value)
+            if item_id is not None:
+                note = ' <a title="{0}" href="{1}">{2}</a>'.format(
+                    _('Click to open note'), notes_action(field=field, value=field_value, item_id=item_id), note_markup)
             return link + note
         return ''
 

src/calibre/gui2/book_details.py

@@ -322,13 +322,19 @@ def render_data(mi, use_roman_numbers=True, all_fields=False, pref_name='book_di
     field_list = [(x, all_fields or display) for x, display in field_list]
     db, _ = db_for_mi(mi)
     db = db.new_api
-    an = db.get_all_items_that_have_notes()
+
-    all_notes = {fld: {db.get_item_name(fld, id_):id_ for id_ in an[fld]} for fld in an.keys()}
+    def item_id_if_has_note(field, item_val):
+        if db.field_supports_notes(field):
+            item_id = db.get_item_id(field, item_val)
+            if item_id is not None:
+                if db.notes_for(field, item_id):
+                    return item_id
+
     return mi_to_html(
         mi, field_list=field_list, use_roman_numbers=use_roman_numbers, rtl=is_rtl(),
         rating_font=rating_font(), default_author_link=default_author_link(),
         comments_heading_pos=gprefs['book_details_comments_heading_pos'], for_qt=True,
-        vertical_fields=vertical_fields, show_links=show_links, all_notes=all_notes
+        vertical_fields=vertical_fields, show_links=show_links, item_id_if_has_note=item_id_if_has_note
     )
 
 # }}}

src/calibre/gui2/tag_browser/ui.py

@@ -450,11 +450,6 @@ class TagBrowserMixin:  # {{{
         d = EnumValuesEdit(parent, db, key)
         d.exec()
 
-    def do_tag_item_renamed(self):
-        # The method name was changed. Keep the old one here for compatibility,
-        # in case some plugin uses it.
-        self.do_field_item_value_changed()
-
     def do_field_item_value_changed(self):
         # Clean up library view and search, which also cleans up book details
 
@@ -468,6 +463,7 @@ class TagBrowserMixin:  # {{{
         m.research()
         self.library_view.select_rows(ids)
         # refreshing the tags view happens at the emit()/call() site
+    do_tag_item_renamed = do_field_item_value_changed  # alias for backcompat
 
     def do_author_sort_edit(self, parent, id_, select_sort=True,
                             select_link=False, is_first_letter=False,