view hgext/largefiles/storefactory.py @ 43033:21025a4107d4

sidedata: add a new module with basic documentation

For now the storage strategy is very simple. We can augment it in the future if
needed.

Code to actually support what is described will be introduced in later
changesets.

Differential Revision: https://phab.mercurial-scm.org/D6889

# 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=None, remote=None, put=False, ui=None):
    if ui is None:
        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 repo is None:
            path = ui.expandpath('default')
            path, _branches = hg.parseurl(path)
            remote = hg.peer(repo or ui, {}, path)
        elif path == 'default-push' or path == 'default':
            remote = repo
        else:
            path, _branches = hg.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, '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(br'^([a-zA-Z0-9+-.]+)://')

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