From 1002a9bcddde3feb7afbd4bc866f22e0e8878eef Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 11 Jun 2020 09:03:35 +0530
Subject: [PATCH] Move code that deals with the dirtied table into backend

---
 src/calibre/db/backend.py | 10 ++++++++++
 src/calibre/db/cache.py   | 14 +++++---------
 2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/src/calibre/db/backend.py b/src/calibre/db/backend.py
index b326321e82..047bd393b9 100644
--- a/src/calibre/db/backend.py
+++ b/src/calibre/db/backend.py
@@ -1756,6 +1756,16 @@ class DB(object):
         else:
             self.execute('DELETE FROM books_plugin_data WHERE name=?', (name,))
 
+    def dirtied_books(self):
+        for (book_id,) in self.execute('SELECT book FROM metadata_dirtied'):
+            yield book_id
+
+    def dirty_books(self, book_ids):
+        self.executemany('INSERT OR IGNORE INTO metadata_dirtied (book) VALUES (?)', ((x,) for x in book_ids))
+
+    def mark_book_as_clean(self, book_id):
+        self.execute('DELETE FROM metadata_dirtied WHERE book=?', (book_id,))
+
     def get_ids_for_custom_book_data(self, name):
         return frozenset(r[0] for r in self.execute('SELECT book FROM books_plugin_data WHERE name=?', (name,)))
 
diff --git a/src/calibre/db/cache.py b/src/calibre/db/cache.py
index 55f8fb08e7..148d6dc2ed 100644
--- a/src/calibre/db/cache.py
+++ b/src/calibre/db/cache.py
@@ -212,8 +212,7 @@ class Cache(object):
 
     @write_api
     def initialize_dynamic(self):
-        self.dirtied_cache = {x:i for i, (x,) in enumerate(
-            self.backend.execute('SELECT book FROM metadata_dirtied'))}
+        self.dirtied_cache = {x:i for i, x in enumerate(self.backend.dirtied_books())}
         if self.dirtied_cache:
             self.dirtied_sequence = max(itervalues(self.dirtied_cache))+1
         self._initialize_dynamic_categories()
@@ -1086,17 +1085,15 @@ class Cache(object):
             self.dirtied_sequence = max(itervalues(already_dirtied)) + 1
         self.dirtied_cache.update(already_dirtied)
         if new_dirtied:
-            self.backend.executemany('INSERT OR IGNORE INTO metadata_dirtied (book) VALUES (?)',
-                                    ((x,) for x in new_dirtied))
+            self.backend.dirty_books(new_dirtied)
             new_dirtied = {book_id:self.dirtied_sequence+i for i, book_id in enumerate(new_dirtied)}
             self.dirtied_sequence = max(itervalues(new_dirtied)) + 1
             self.dirtied_cache.update(new_dirtied)
 
     @write_api
     def commit_dirty_cache(self):
-        book_ids = [(x,) for x in self.dirtied_cache]
-        if book_ids:
-            self.backend.executemany('INSERT OR IGNORE INTO metadata_dirtied (book) VALUES (?)', book_ids)
+        if self.dirtied_cache:
+            self.backend.dirty_books(self.dirtied_cache)
 
     @write_api
     def set_field(self, name, book_id_to_val_map, allow_case_change=True, do_path_update=True):
@@ -1195,8 +1192,7 @@ class Cache(object):
         # The last step is clearing the indicator
         dc_sequence = self.dirtied_cache.get(book_id, None)
         if dc_sequence is None or sequence is None or dc_sequence == sequence:
-            self.backend.execute('DELETE FROM metadata_dirtied WHERE book=?',
-                    (book_id,))
+            self.backend.mark_book_as_clean(book_id)
             self.dirtied_cache.pop(book_id, None)
 
     @write_api