hgext/infinitepush/common.py

infinitepush: move the extension to core from fb-hgext

This patch moves the infinitepush extension from fb-hgext to core. The
extension is used to store incoming bundles during a push in bundlestore rather
than applying them to the revlog.

The extension was copied from the repository revision at
f27f094e91553d3cae5167c0b1c42ae940f888d5 and following changes were made:

  * added `from __future__ import absolute_import` where missing
  * fixed module imports to follow the core style
  * minor fixes for test-check-code.t
  * registered the configs
  * adding the testedwith value to match core's convention
  * removed double newlines to make test-check-commit.t happy
  * added one line doc about extension and marked it as experimental

Only one test file test-infinitepush-bundlestore.t is moved to core and
following changes are made to file:

  * remove dependency of library.sh
  * split the tests into two tests i.e. test-infinitepush.t and
    test-infinitepush-bundlestore.t
  * removed testing related to other facebook's extensions pushrebase, inhibit,
    fbamend

library-infinitepush.sh is also copied from fb-hgext from the same revision and
following changes are made:

  * change the path to infinitepush extension as it's in core with this patch
  * removed sql handling from the file as we are not testing that initially

Currently at this revision, test-check-module-imports.t does not pass as there
is import of a module from fb/hgext in one the of the file which will be removed
in the next patch.

This extension right now has a lot of things which we don't require in core like
`--to`, `--create` flags to `hg bookmark`, logic related to remotenames
extension and another facebook's extensions, custom bundle2parts which can be
prevented by using bookmarks bundle part and also logic related to sql store
which is probably we don't want initially.

The next patches in this series will remove all the unwanted and unrequired
things from the extension and will make this a nice one.

The end goal is to have a very lighweight extension with no or very less
wrapping on the client side.

Differential Revision: https://phab.mercurial-scm.org/D2096

# Copyright 2017 Facebook, Inc.
#
# 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 json
import os
import struct
import tempfile

from mercurial.node import hex

from mercurial import (
    error,
    extensions,
)

def isremotebooksenabled(ui):
    return ('remotenames' in extensions._extensions and
            ui.configbool('remotenames', 'bookmarks'))

def encodebookmarks(bookmarks):
    encoded = {}
    for bookmark, node in bookmarks.iteritems():
        encoded[bookmark] = node
    dumped = json.dumps(encoded)
    result = struct.pack('>i', len(dumped)) + dumped
    return result

def downloadbundle(repo, unknownbinhead):
    index = repo.bundlestore.index
    store = repo.bundlestore.store
    bundleid = index.getbundle(hex(unknownbinhead))
    if bundleid is None:
        raise error.Abort('%s head is not known' % hex(unknownbinhead))
    bundleraw = store.read(bundleid)
    return _makebundlefromraw(bundleraw)

def _makebundlefromraw(data):
    fp = None
    fd, bundlefile = tempfile.mkstemp()
    try:  # guards bundlefile
        try:  # guards fp
            fp = os.fdopen(fd, 'wb')
            fp.write(data)
        finally:
            fp.close()
    except Exception:
        try:
            os.unlink(bundlefile)
        except Exception:
            # we would rather see the original exception
            pass
        raise

    return bundlefile