view tests/test-revlog-mmapindex.t @ 39232:0a5b20c107a6

repository: remove storedeltachains from ifilestorage

The ifilestorage interface was bootstrapped from requirements of
callers outside the storage implementation (revlogs). I believe we
even made some members public so they could be part of the interface!

Historically, the changegroup code was a gross offender when it
came to accessing low-level storage primitives. There are a handful
of members on the ifilestorage interface that are/were used only
for changegroup code.

With the recent refactor of changegroup code and the establishment
of a formal API on the storage interface for producing revision
deltas, the changegroup code is no longer accessing these low-level
primitives related to delta generation directly. Instead, things
are abstracted away in the storage implementation.

This means we can remove elements from the storage interface that
are no longer needed.

We start with "storedeltachains."

We remove it from the interface. Then we make it a private
attribute and update all references.

.. api:: storedeltachains has been dropped from ifilestorage interface

.. api:: storedeltachains on revlog classes is now _storedeltachains

Differential Revision: https://phab.mercurial-scm.org/D4227

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 ..