# HG changeset patch
# User Gregory Szorc <gregory.szorc@gmail.com>
# Date 1540943405 25200
# Node ID 39369475445cd11b7e0e4c2b2081560b29478d18
# Parent  66adfd58cb770a7fd54645d82fbec6cf1be80447
revlog: use single file handle when de-inlining revlog

_getsegmentforrevs() will eventually call into _datareadfp() to
resolve a file handle to read revision data. If no file handle
is passed into _getsegmentforrevs(), it opens a new one.

Explicit is better than implicit.

This commit changes _enforceinlinesize() to open a file handle
explicitly when converting inline revlogs to split revlogs and
to pass this file handle into _getsegmentforrevs().

I haven't measured, but this change should improve performance,
as we no longer reopen the revlog for reading for every revision
in the revlog when it is converted from inline to split. Instead,
we open it at most once and use it for the duration of the
operation. That being said, I /think/ the chunk cache may mitigate
the number of file opens required.

Differential Revision: https://phab.mercurial-scm.org/D5265

diff -r 66adfd58cb77 -r 39369475445c mercurial/revlog.py
--- a/mercurial/revlog.py	Tue Nov 13 18:44:09 2018 +0300
+++ b/mercurial/revlog.py	Tue Oct 30 16:50:05 2018 -0700
@@ -1732,9 +1732,9 @@
             fp.flush()
             fp.close()
 
-        with self._datafp('w') as df:
+        with self._indexfp('r') as ifh, self._datafp('w') as dfh:
             for r in self:
-                df.write(self._getsegmentforrevs(r, r)[1])
+                dfh.write(self._getsegmentforrevs(r, r, df=ifh)[1])
 
         with self._indexfp('w') as fp:
             self.version &= ~FLAG_INLINE_DATA