view tests/test-custom-filters.t @ 40390:7e3b6c4f01a2

localrepo: support marking repos as having shallow file storage

Various operations against repositories need to know if repository
storage is full or partial. For example, a checkout (including possibly
a widening of a sparse checkout), needs to know if it can assume all file
revisions are available or whether to look for missing revisions first.

This commit lays the plumbing for doing that.

We define a repo creation option that indicates that shallow file storage
is desired.

The SQLite store uses this creation option to add an extra repo requirement
indicating file storage is shallow.

A new repository feature has been added to indicate that file storage is
shallow. The SQLite store adds this feature when the shallow file store
requirement is present.

Code can now look at repo.features to determine if repo file storage may
be shallow and take additional actions if so.

While we're here, we also teach the SQLite store to handle the narrow repo
requirement, which gets added when making narrow clones.

Differential Revision: https://phab.mercurial-scm.org/D5166

  $ hg init

  $ cat > .hg/hgrc <<EOF
  > [extensions]
  > prefixfilter = prefix.py
  > [encode]
  > *.txt = stripprefix: Copyright 2046, The Masters
  > [decode]
  > *.txt = insertprefix: Copyright 2046, The Masters
  > EOF

  $ cat > prefix.py <<EOF
  > from mercurial import error
  > def stripprefix(s, cmd, filename, **kwargs):
  >     header = b'%s\n' % cmd
  >     if s[:len(header)] != header:
  >         raise error.Abort(b'missing header "%s" in %s' % (cmd, filename))
  >     return s[len(header):]
  > def insertprefix(s, cmd):
  >     return b'%s\n%s' % (cmd, s)
  > def reposetup(ui, repo):
  >     repo.adddatafilter(b'stripprefix:', stripprefix)
  >     repo.adddatafilter(b'insertprefix:', insertprefix)
  > EOF

  $ cat > .hgignore <<EOF
  > .hgignore
  > prefix.py
  > prefix.pyc
  > EOF

  $ cat > stuff.txt <<EOF
  > Copyright 2046, The Masters
  > Some stuff to ponder very carefully.
  > EOF
  $ hg add stuff.txt
  $ hg ci -m stuff

Repository data:

  $ hg cat stuff.txt
  Some stuff to ponder very carefully.

Fresh checkout:

  $ rm stuff.txt
  $ hg up -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat stuff.txt
  Copyright 2046, The Masters
  Some stuff to ponder very carefully.
  $ echo "Very very carefully." >> stuff.txt
  $ hg stat
  M stuff.txt

  $ echo "Unauthorized material subject to destruction." > morestuff.txt

Problem encoding:

  $ hg add morestuff.txt
  $ hg ci -m morestuff
  abort: missing header "Copyright 2046, The Masters" in morestuff.txt
  [255]
  $ hg stat
  M stuff.txt
  A morestuff.txt