# HG changeset patch
# User Pierre-Yves David <pierre-yves.david@octobus.net>
# Date 1697246653 -7200
# Node ID 315c749119933e65b4c1013eabb7e6e83ff34ce2
# Parent  2dec23658969c6c194fa6de1437b76677d8f0a4b
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 2dec23658969 -r 315c74911993 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
@@ -3196,14 +3196,15 @@
 
             destrevlog._deltabothparents = forcedeltabothparents or oldamd
 
-            self._clone(
-                tr,
-                destrevlog,
-                addrevisioncb,
-                deltareuse,
-                forcedeltabothparents,
-                sidedata_helpers,
-            )
+            with self.reading(), destrevlog._writing(tr):
+                self._clone(
+                    tr,
+                    destrevlog,
+                    addrevisioncb,
+                    deltareuse,
+                    forcedeltabothparents,
+                    sidedata_helpers,
+                )
 
         finally:
             destrevlog._lazydelta = oldlazydelta
@@ -3288,19 +3289,18 @@
                     )
                     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)