hgext/largefiles/remotestore.py

largefiles: stat all largefiles in one batch before downloading

This avoids a lot of expensive roundtrips to remote repositories ... but might
be slightly slower for local operations.

This will also change some aborts on missing files to warnings. That will in
some situations make it possible to continue working on a repository with
missing largefiles.

# 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.

'''remote largefile store; the base class for wirestore'''

import urllib2

from mercurial import util
from mercurial.i18n import _
from mercurial.wireproto import remotebatch

import lfutil
import basestore

class remotestore(basestore.basestore):
    '''a largefile store accessed over a network'''
    def __init__(self, ui, repo, url):
        super(remotestore, self).__init__(ui, repo, url)

    def put(self, source, hash):
        if self.sendfile(source, hash):
            raise util.Abort(
                _('remotestore: could not put %s to remote store %s')
                % (source, self.url))
        self.ui.debug(
            _('remotestore: put %s to remote store %s') % (source, self.url))

    def exists(self, hashes):
        return dict((h, s == 0) for (h, s) in self._stat(hashes).iteritems())

    def sendfile(self, filename, hash):
        self.ui.debug('remotestore: sendfile(%s, %s)\n' % (filename, hash))
        fd = None
        try:
            try:
                fd = lfutil.httpsendfile(self.ui, filename)
            except IOError, e:
                raise util.Abort(
                    _('remotestore: could not open file %s: %s')
                    % (filename, str(e)))
            return self._put(hash, fd)
        finally:
            if fd:
                fd.close()

    def _getfile(self, tmpfile, filename, hash):
        try:
            chunks = self._get(hash)
        except urllib2.HTTPError, e:
            # 401s get converted to util.Aborts; everything else is fine being
            # turned into a StoreError
            raise basestore.StoreError(filename, hash, self.url, str(e))
        except urllib2.URLError, e:
            # This usually indicates a connection problem, so don't
            # keep trying with the other files... they will probably
            # all fail too.
            raise util.Abort('%s: %s' % (self.url, e.reason))
        except IOError, e:
            raise basestore.StoreError(filename, hash, self.url, str(e))

        return lfutil.copyandhash(chunks, tmpfile)

    def _verifyfile(self, cctx, cset, contents, standin, verified):
        filename = lfutil.splitstandin(standin)
        if not filename:
            return False
        fctx = cctx[standin]
        key = (filename, fctx.filenode())
        if key in verified:
            return False

        verified.add(key)

        expecthash = fctx.data()[0:40]
        stat = self._stat([expecthash])[expecthash]
        if not stat:
            return False
        elif stat == 1:
            self.ui.warn(
                _('changeset %s: %s: contents differ\n')
                % (cset, filename))
            return True # failed
        elif stat == 2:
            self.ui.warn(
                _('changeset %s: %s missing\n')
                % (cset, filename))
            return True # failed
        else:
            raise RuntimeError('verify failed: unexpected response from '
                               'statlfile (%r)' % stat)

    def batch(self):
        '''Support for remote batching.'''
        return remotebatch(self)