view hgext/largefiles/storefactory.py @ 31740:a40e979b9d97

largefiles: use readasstandin() to read hex hash directly from filectx

BTW, C implementation of hexdigest() for SHA-1/256/512 returns hex
hash in lower case, and doctest in Python standard hashlib assumes
that, too. But it isn't explicitly described in API document or so.

Therefore, we can't assume that hexdigest() always returns hex hash in
lower case, for any hash algorithms, on any Python runtimes and
versions.

From point of view of that, it is reasonable for portability that
40800668e019 applies lower() on hex hash in overridefilemerge().

But on the other hand, in largefiles extension, there are still many
code paths comparing between hex hashes or storing hex hash into
standin file, without lower().

Switching to hash algorithm other than SHA-1 may be good chance to
clarify our policy about hexdigest()-ed hash value string.

  - assume that hexdigest() always returns hex hash in lower case, or

  - apply lower() on hex hash in appropriate layers to ensure
    lower-case-ness of it for portability

# 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 import (
    error,
    hg,
    util,
)

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, remote=None, put=False):
    ui = repo.ui

    if not remote:
        lfpullsource = getattr(repo, 'lfpullsource', None)
        if lfpullsource:
            path = ui.expandpath(lfpullsource)
        elif put:
            path = ui.expandpath('default-push', 'default')
        else:
            path = ui.expandpath('default')

        # ui.expandpath() leaves 'default-push' and 'default' alone if
        # they cannot be expanded: fallback to the empty string,
        # meaning the current directory.
        if path == 'default-push' or path == 'default':
            path = ''
            remote = repo
        else:
            path, _branches = hg.parseurl(path)
            remote = hg.peer(repo, {}, 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, 'url') and remote.url() or remote.path

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

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

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

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

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

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