# HG changeset patch
# User Pierre-Yves David <pierre-yves.david@octobus.net>
# Date 1578717898 -3600
# Node ID 8e09551206f54bb102cdcbf4c57b0b10284735ce
# Parent  7f67f53492f71ee4322d1280c69f038302fc7a61
transaction: add a `hasfinalize` method

The method allow code to check if an existing callback exists. It allow them to
skip potentially expensive setup for a callback.

Differential Revision: https://phab.mercurial-scm.org/D7832

diff -r 7f67f53492f7 -r 8e09551206f5 mercurial/transaction.py
--- a/mercurial/transaction.py	Sat Jan 11 04:57:29 2020 +0100
+++ b/mercurial/transaction.py	Sat Jan 11 05:44:58 2020 +0100
@@ -456,6 +456,12 @@
         return self._anypending
 
     @active
+    def hasfinalize(self, category):
+        """check is a callback already exist for a category
+        """
+        return category in self._finalizecallback
+
+    @active
     def addfinalize(self, category, callback):
         """add a callback to be called when the transaction is closed