mercurial/cacheutil.py

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

# scmutil.py - Mercurial core utility functions
#
#  Copyright Matt Mackall <[e-mail]> and other
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import

from . import repoview

def cachetocopy(srcrepo):
    """return the list of cache file valuable to copy during a clone"""
    # In local clones we're copying all nodes, not just served
    # ones. Therefore copy all branch caches over.
    cachefiles = ['branch2']
    cachefiles += ['branch2-%s' % f for f in repoview.filtertable]
    cachefiles += ['rbc-names-v1', 'rbc-revs-v1']
    cachefiles += ['tags2']
    cachefiles += ['tags2-%s' % f for f in repoview.filtertable]
    cachefiles += ['hgtagsfnodes1']
    return cachefiles