Added thumbnail urls to book cover srcsets with cache busting ids

cps/helper.py

@@ -533,6 +533,21 @@ def delete_book(book, calibrepath, book_format):
         return delete_book_file(book, calibrepath, book_format)
 
 
+def get_thumbnails_for_books(books):
+    books_with_covers = list(filter(lambda b: b.has_cover, books))
+    book_ids = list(map(lambda b: b.id, books_with_covers))
+    return ub.session\
+        .query(ub.Thumbnail)\
+        .filter(ub.Thumbnail.book_id.in_(book_ids))\
+        .filter(ub.Thumbnail.expiration > datetime.utcnow())\
+        .all()
+
+
+def get_thumbnails_for_book_series(series):
+    books = list(map(lambda s: s[0], series))
+    return get_thumbnails_for_books(books)
+
+
 def get_cover_on_failure(use_generic_cover):
     if use_generic_cover:
         return send_from_directory(_STATIC_DIR, "generic_cover.jpg")
@@ -558,6 +573,29 @@ def get_cached_book_cover(cache_id):
     return get_book_cover_internal(book, use_generic_cover_on_failure=True, resolution=resolution)
 
 
+def get_cached_book_cover_thumbnail(cache_id):
+    parts = cache_id.split('_')
+    thumbnail_uuid = parts[0] if len(parts) else None
+    thumbnail = None
+    if thumbnail_uuid:
+        thumbnail = ub.session\
+            .query(ub.Thumbnail)\
+            .filter(ub.Thumbnail.uuid == thumbnail_uuid)\
+            .first()
+
+    if thumbnail and thumbnail.expiration > datetime.utcnow():
+        cache = fs.FileSystem()
+        if cache.get_cache_file_path(thumbnail.filename, fs.CACHE_TYPE_THUMBNAILS):
+            return send_from_directory(cache.get_cache_dir(fs.CACHE_TYPE_THUMBNAILS), thumbnail.filename)
+
+    elif thumbnail:
+        book = calibre_db.get_book(thumbnail.book_id)
+        return get_book_cover_internal(book, use_generic_cover_on_failure=True)
+
+    else:
+        return get_cover_on_failure(True)
+
+
 def get_book_cover_internal(book, use_generic_cover_on_failure, resolution=None):
     if book and book.has_cover: