From c3867b34737dc433a72814e543dcf1027150269b Mon Sep 17 00:00:00 2001
From: Charles Haley <cbhaley@i.wont.say.com>
Date: Wed, 23 Sep 2020 11:43:50 +0100
Subject: [PATCH] Use the template cache to speed up evaluation when searching
 using templates.

---
 src/calibre/db/search.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/calibre/db/search.py b/src/calibre/db/search.py
index c4610bc126..88ca72ee45 100644
--- a/src/calibre/db/search.py
+++ b/src/calibre/db/search.py
@@ -643,9 +643,12 @@ class Parser(SearchQueryParser):  # {{{
             matchkind, query = _matchkind(query, case_sensitive=case_sensitive)
             matches = set()
             error_string = '*@*TEMPLATE_ERROR*@*'
+            template_cache = {}
             for book_id in candidates:
                 mi = self.dbcache.get_proxy_metadata(book_id)
-                val = mi.formatter.safe_format(template, {}, error_string, mi)
+                val = mi.formatter.safe_format(template, {}, error_string, mi,
+                                            column_name='search template',
+                                            template_cache=template_cache)
                 if val.startswith(error_string):
                     raise ParseException(val[len(error_string):])
                 if sep == 't':