# HG changeset patch
# User Pierre-Yves David <pierre-yves.david@octobus.net>
# Date 1697246653 -7200
# Node ID 09d60aed5f5db6f3c028f789f5f4d439c524dded
# Parent  15a50bfaeb794a34b02ad11b1c9a30dfb808b9f5
revlog: avoid opening and closing the file for each cloned revision

The previous code was flushing files after each new revision, slowing things
down.

For exemple, with this change, the evolve repository can run
`hg debugupgraderepo --run --optimize re-delta-parent` in about 3.4s instead of
4.5 seconds.

diff -r 15a50bfaeb79 -r 09d60aed5f5d mercurial/revlog.py
--- a/mercurial/revlog.py	Fri Oct 13 23:21:46 2023 +0200
+++ b/mercurial/revlog.py	Sat Oct 14 03:24:13 2023 +0200
@@ -3461,7 +3461,7 @@
             )
             destrevlog.delta_config.delta_both_parents = delta_both_parents
 
-            with self.reading():
+            with self.reading(), destrevlog._writing(tr):
                 self._clone(
                     tr,
                     destrevlog,
@@ -3552,19 +3552,18 @@
                     )
                     flags = flags | new_flags[0] & ~new_flags[1]
 
-                with destrevlog._writing(tr):
-                    destrevlog._addrevision(
-                        node,
-                        rawtext,
-                        tr,
-                        linkrev,
-                        p1,
-                        p2,
-                        flags,
-                        cachedelta,
-                        deltacomputer=deltacomputer,
-                        sidedata=sidedata,
-                    )
+                destrevlog._addrevision(
+                    node,
+                    rawtext,
+                    tr,
+                    linkrev,
+                    p1,
+                    p2,
+                    flags,
+                    cachedelta,
+                    deltacomputer=deltacomputer,
+                    sidedata=sidedata,
+                )
 
             if addrevisioncb:
                 addrevisioncb(self, rev, node)