annotate hgext/largefiles/localstore.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

# Copyright 2009-2010 Gregory P. Ward
# Copyright 2009-2010 Intelerad Medical Systems Incorporated
# Copyright 2010-2011 Fog Creek Software
# Copyright 2010-2011 Unity Technologies
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

'''store class for local filesystem'''
from __future__ import absolute_import

from mercurial.i18n import _
from mercurial import util

from . import (
    basestore,
    lfutil,
)

class localstore(basestore.basestore):
    '''localstore first attempts to grab files out of the store in the remote
    Mercurial repository.  Failing that, it attempts to grab the files from
    the user cache.'''

    def __init__(self, ui, repo, remote):
        self.remote = remote.local()
        super(localstore, self).__init__(ui, repo, self.remote.url())

    def put(self, source, hash):
        if lfutil.instore(self.remote, hash):
            return
        lfutil.link(source, lfutil.storepath(self.remote, hash))

    def exists(self, hashes):
        retval = {}
        for hash in hashes:
            retval[hash] = lfutil.instore(self.remote, hash)
        return retval

    def _getfile(self, tmpfile, filename, hash):
        path = lfutil.findfile(self.remote, hash)
        if not path:
            raise basestore.StoreError(filename, hash, self.url,
                _("can't get file locally"))
        with open(path, 'rb') as fd:
            return lfutil.copyandhash(
                util.filechunkiter(fd), tmpfile)

    def _verifyfiles(self, contents, filestocheck):
        failed = False
        for cset, filename, expectedhash in filestocheck:
            storepath, exists = lfutil.findstorepath(self.repo, expectedhash)
            if not exists:
                storepath, exists = lfutil.findstorepath(
                    self.remote, expectedhash)
            if not exists:
                self.ui.warn(
                    _('changeset %s: %s references missing %s\n')
                    % (cset, filename, storepath))
                failed = True
            elif contents:
                actualhash = lfutil.hashfile(storepath)
                if actualhash != expectedhash:
                    self.ui.warn(
                        _('changeset %s: %s references corrupted %s\n')
                        % (cset, filename, storepath))
                    failed = True
        return failed