hgext/largefiles/storefactory.py

censor: extract the part about recomputing delta in a function

The v2_censor function is huge, now that its content has settled a bit it is a
good time to split individual part inside dedicated function.

It is now the turn of the logic that recompute new delta to replace the one
based on the revision that are going away.

Differential Revision: https://phab.mercurial-scm.org/D10900

# 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

import re

from mercurial.i18n import _
from mercurial.pycompat import getattr
from mercurial import (
    error,
    hg,
    util,
)
from mercurial.utils import (
    urlutil,
)

from . import (
    lfutil,
    localstore,
    wirestore,
)


# During clone this function is passed the src's ui object
# but it needs the dest's ui object so it can read out of
# the config file. Use repo.ui instead.
def openstore(repo=None, remote=None, put=False, ui=None):
    if ui is None:
        ui = repo.ui

    if not remote:
        lfpullsource = getattr(repo, 'lfpullsource', None)
        if put:
            path = urlutil.get_unique_push_path(
                b'lfpullsource', repo, ui, lfpullsource
            )
        else:
            path, _branches = urlutil.get_unique_pull_path(
                b'lfpullsource', repo, ui, lfpullsource
            )

        # XXX we should not explicitly pass b'default', as this will result in
        # b'default' being returned if no `paths.default` was defined. We
        # should explicitely handle the lack of value instead.
        if repo is None:
            path, _branches = urlutil.get_unique_pull_path(
                b'lfs', repo, ui, b'default'
            )
            remote = hg.peer(repo or ui, {}, path)
        elif path == b'default-push' or path == b'default':
            remote = repo
        else:
            path, _branches = urlutil.parseurl(path)
            remote = hg.peer(repo or ui, {}, path)

    # The path could be a scheme so use Mercurial's normal functionality
    # to resolve the scheme to a repository and use its path
    path = util.safehasattr(remote, b'url') and remote.url() or remote.path

    match = _scheme_re.match(path)
    if not match:  # regular filesystem path
        scheme = b'file'
    else:
        scheme = match.group(1)

    try:
        storeproviders = _storeprovider[scheme]
    except KeyError:
        raise error.Abort(_(b'unsupported URL scheme %r') % scheme)

    for classobj in storeproviders:
        try:
            return classobj(ui, repo, remote)
        except lfutil.storeprotonotcapable:
            pass

    raise error.Abort(
        _(b'%s does not appear to be a largefile store')
        % urlutil.hidepassword(path)
    )


_storeprovider = {
    b'file': [localstore.localstore],
    b'http': [wirestore.wirestore],
    b'https': [wirestore.wirestore],
    b'ssh': [wirestore.wirestore],
}

_scheme_re = re.compile(br'^([a-zA-Z0-9+-.]+)://')


def getlfile(ui, hash):
    return util.chunkbuffer(openstore(ui=ui)._get(hash))