view tests/test-revlog-mmapindex.t @ 48670:6d2ddea0721a stable

stream-clone: filter possible missing requirements using all supported one

The `supportedformat` requirements is missing some important requirements and it
seems better to filter out with all requirements we know, not just an
"arbitrary" subset.

The `supportedformat` set is lacking some important requirements (for example
`revlog-compression-zstd`). This is getting fixed on default (for Mercurial 6.1)

However, fixing that in 6.1 means the stream requirements sent over the wire
will contains more items. And if we don't apply this fix on older version, they
might end up complaining about lacking support for feature they actually support
for years.

This patch does not fix the deeper problem (advertised stream requirement
lacking some of them), but focus on the trivial part : Lets use the full set of
supported requirement for looking for unsupported ones.

This patch should be simple to backport to older version of Mercurial and
packager should be encouraged to do so.

This is a graft of d9017df70135 from default.

Differential Revision: https://phab.mercurial-scm.org/D12091

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 ..