diff mercurial/changelog.py @ 35308:137a08d82232

transaction: build changes['revs'] as range instead of a set

Revisions are added consecutively, so a range can easily represent them
in the changes list. This saves around 45 Bytes / revision on 64bit
platforms and reduces the memory footprint of issue5691 by 15MB.

Don't copy changes['revs'] in getobsoleted. Ranges have a very efficient
contains implementation already.

Differential Revision: https://phab.mercurial-scm.org/D1615

--- a/mercurial/changelog.py	Wed Dec 06 16:43:07 2017 -0500
+++ b/mercurial/changelog.py	Fri Dec 08 01:23:34 2017 +0100
@@ -541,5 +541,10 @@
                                                    *args, **kwargs)
         revs = transaction.changes.get('revs')
         if revs is not None:
-            revs.add(rev)
+            if revs:
+                assert revs[-1] + 1 == rev
+                revs = xrange(revs[0], rev + 1)
+            else:
+                revs = xrange(rev, rev + 1)
+            transaction.changes['revs'] = revs
         return node