view tests/test-revlog-mmapindex.t @ 40501:30a7d3b6b281

narrow: rework logic to check whether we need to widen and narrow

This patch reworks logic which calculates whether we need to extend or narrow
our working copy or not.

We filter the addincludes, removeincludes, addexcludes and removeexcludes passed
from user to the actual added and removed includes and excludes. What that means
is a user can pass an already included path as addincludes, a path which is not
included as removeincludes etc. In such situations the old logic use to think we
need to do some work, whereas we don't need to do that work.

In old logic, even if we don't have anything new to include but it believes we
need to call widen, this adds some good amount of work on large repository. A
widen calls involves computing incomming csets, calling the narrow_widen() which
in non-ellipses cases goes through all the set of csets which are available
which can take ~2-3 mins on large repos. Those 2-3 minutes are spend on doing
nothing which a client can prevent by checking is there really anything which
needs to be included.

The tests changes shows that we don't go to the server anymore in such cases
which is nice.

Differential Revision: https://phab.mercurial-scm.org/D5183

create verbosemmap.py
  $ cat << EOF > verbosemmap.py
  > # extension to make util.mmapread verbose
  > 
  > from __future__ import absolute_import
  > 
  > from mercurial import (
  >     extensions,
  >     pycompat,
  >     util,
  > )
  > 
  > def extsetup(ui):
  >     def mmapread(orig, fp):
  >         ui.write(b"mmapping %s\n" % pycompat.bytestr(fp.name))
  >         ui.flush()
  >         return orig(fp)
  > 
  >     extensions.wrapfunction(util, 'mmapread', mmapread)
  > EOF

setting up base repo
  $ hg init a
  $ cd a
  $ touch a
  $ hg add a
  $ hg commit -qm base
  $ for i in `$TESTDIR/seq.py 1 100` ; do
  > echo $i > a
  > hg commit -qm $i
  > done

set up verbosemmap extension
  $ cat << EOF >> $HGRCPATH
  > [extensions]
  > verbosemmap=$TESTTMP/verbosemmap.py
  > EOF

mmap index which is now more than 4k long
  $ hg log -l 5 -T '{rev}\n' --config experimental.mmapindexthreshold=4k
  mmapping $TESTTMP/a/.hg/store/00changelog.i
  100
  99
  98
  97
  96

do not mmap index which is still less than 32k
  $ hg log -l 5 -T '{rev}\n' --config experimental.mmapindexthreshold=32k
  100
  99
  98
  97
  96

  $ cd ..