hgext/largefiles/wirestore.py

demandimport: support "absolute_import" for external libraries (issue4029)

Before this patch, demandimport of Mercurial may fail to load external
libraries using "from __future__ import absolute_import": for example,
importing "foo" in "bar.baz" module will load "bar.foo" if it exists,
even though "absolute_import" is enabled in "bar.baz" module.

So, extensions for Mercurial can't use such external libraries.

This patch saves "level" of import request for on-demand module
loading in the future: default value of level is -1, and level is 0
when "absolute_import" is enabled.

"level" value is passed to built-in import function in
"_demandmod._load()" and it should load target module correctly.

This patch changes only one "_demandmod" construction case other than
cases below:

    - construction in "_demandmod._load()"

      this code path should be used only in relative sub-module
      loading case

    - constructions other than patched one in"_demandimport()"

      these code paths shouldn't be used in "level != -1" case

# Copyright 2010-2011 Fog Creek Software
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

'''largefile store working over Mercurial's wire protocol'''

import lfutil
import remotestore

class wirestore(remotestore.remotestore):
    def __init__(self, ui, repo, remote):
        cap = remote.capable('largefiles')
        if not cap:
            raise lfutil.storeprotonotcapable([])
        storetypes = cap.split(',')
        if 'serve' not in storetypes:
            raise lfutil.storeprotonotcapable(storetypes)
        self.remote = remote
        super(wirestore, self).__init__(ui, repo, remote.url())

    def _put(self, hash, fd):
        return self.remote.putlfile(hash, fd)

    def _get(self, hash):
        return self.remote.getlfile(hash)

    def _stat(self, hashes):
        '''For each hash, return 0 if it is available, other values if not.
        It is usually 2 if the largefile is missing, but might be 1 the server
        has a corrupted copy.'''
        batch = self.remote.batch()
        futures = {}
        for hash in hashes:
            futures[hash] = batch.statlfile(hash)
        batch.submit()
        retval = {}
        for hash in hashes:
            retval[hash] = futures[hash].value
        return retval