hgext/largefiles/remotestore.py

branchmap: store branchcache in a dedicated object

Value and key of branchcache would benefit from being hold by the same object.
Moreover some logic (update, write, validation) could be move on such object.

The creation of this object is the first step toward this move. The result will
clarify branchcache related code and hide most of the detail in the class
itself. This encapsulation will greatly helps implementation of branchcache for
filtered view of the repo.

# 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 self._verify(hashes)

    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):
        # quit if the largefile isn't there
        stat = self._stat(hash)
        if stat == 1:
            raise util.Abort(_('remotestore: largefile %s is invalid') % hash)
        elif stat == 2:
            raise util.Abort(_('remotestore: largefile %s is missing') % hash)

        try:
            length, infile = 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))

        # Mercurial does not close its SSH connections after writing a stream
        if length is not None:
            infile = lfutil.limitreader(infile, length)
        return lfutil.copyandhash(lfutil.blockstream(infile), tmpfile)

    def _verify(self, hashes):
        return self._stat(hashes)

    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)

        stat = self._stat(hash)
        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)