mercurial-scm/hg: mercurial/bundlerepo.py comparison

comparison mercurial/bundlerepo.py @ 39604:335ae4d0a552

bundlerepo: dynamically create repository type from base repository Previously, bundlerepository inherited from localrepo.localrepository. You simply instantiated a bundlerepository and its __init__ called localrepo.localrepository.__init__. Things were simple. Unfortunately, this strategy is limiting because it assumes that the base repository is a localrepository instance. And it assumes various properties of localrepository, such as the arguments its __init__ takes. And it prevents us from changing behavior of localrepository.__init__ without also having to change derived classes. Previous and ongoing work to abstract storage revealed these limitations. This commit changes the initialization strategy of bundle repositories to dynamically create a type to represent the repository. Instead of a static type, we instantiate a new local repo instance via localrepo.instance(). We then combine its __class__ with bundlerepository to produce a new type. This ensures that no matter how localrepo.instance() decides to create a repository object, we can derive a bundle repo object from it. i.e. localrepo.instance() could return a type that isn't a localrepository and it would "just work." Well, it would "just work" if bundlerepository's custom implementations only accessed attributes in the documented repository interface. I'm pretty sure it violates the interface contract in a handful of places. But we can worry about that another day. This change gets us closer to doing more clever things around instantiating repository instances without having to worry about teaching bundlerepository about them. .. api:: ``bundlerepo.bundlerepository`` is no longer usable on its own. The class is combined with the class of the base repository it is associated with at run-time. New bundlerepository instances can be obtained by calling ``bundlerepo.instance()`` or ``bundlerepo.makebundlerepository()``. Differential Revision: https://phab.mercurial-scm.org/D4555

author	Gregory Szorc <gregory.szorc@gmail.com>
date	Tue, 11 Sep 2018 19:50:07 -0700
parents	a8d2faeca49e
children	5ccd791344f3

comparison

equal deleted inserted replaced

-:a8d2faeca49e
+:335ae4d0a552
 filespos[fname] = cgunpacker.tell()
 for chunk in iter(lambda: cgunpacker.deltachunk(None), {}):
 pass
 return filespos
-class bundlerepository(localrepo.localrepository):
+class bundlerepository(object):
 """A repository instance that is a union of a local repo and a bundle.
 Instances represent a read-only repository composed of a local repository
 with the contents of a bundle file applied. The repository instance is
 conceptually similar to the state of a repository after an
 ``hg unbundle`` operation. However, the contents of the bundle are never
 applied to the actual base repository.
+Instances constructed directly are not usable as repository objects.
+Use instance() or makebundlerepository() to create instances.
 """
-def __init__(self, ui, repopath, bundlepath):
+def __init__(self, bundlepath, url, tempparent):
-self._tempparent = None
+self._tempparent = tempparent
-try:
+self._url = url
-localrepo.localrepository.__init__(self, ui, repopath)
-except error.RepoError:
-self._tempparent = pycompat.mkdtemp()
-localrepo.instance(ui, self._tempparent, create=True)
-localrepo.localrepository.__init__(self, ui, self._tempparent)
 self.ui.setconfig('phases', 'publish', False, 'bundlerepo')
-if repopath:
-self._url = 'bundle:' + util.expandpath(repopath) + '+' + bundlepath
-else:
-self._url = 'bundle:' + bundlepath
 self.tempfile = None
 f = util.posixfile(bundlepath, "rb")
-bundle = exchange.readbundle(ui, f, bundlepath)
+bundle = exchange.readbundle(self.ui, f, bundlepath)
 if isinstance(bundle, bundle2.unbundle20):
 self._bundlefile = bundle
 self._cgunpacker = None
 elif isinstance(bundle, changegroup.cg1unpacker):
 if bundle.compressed():
 f = self._writetempbundle(bundle.read, '.hg10un',
 header='HG10UN')
-bundle = exchange.readbundle(ui, f, bundlepath, self.vfs)
+bundle = exchange.readbundle(self.ui, f, bundlepath, self.vfs)
 self._bundlefile = bundle
 self._cgunpacker = bundle
 else:
 raise error.Abort(_('bundle type %s cannot be read') %
 return makebundlerepository(ui, repopath, bundlename)
 def makebundlerepository(ui, repopath, bundlepath):
 """Make a bundle repository object based on repo and bundle paths."""
-return bundlerepository(ui, repopath, bundlepath)
+if repopath:
+url = 'bundle:%s+%s' % (util.expandpath(repopath), bundlepath)
+else:
+url = 'bundle:%s' % bundlepath
+# Because we can't make any guarantees about the type of the base
+# repository, we can't have a static class representing the bundle
+# repository. We also can't make any guarantees about how to even
+# call the base repository's constructor!
+#
+# So, our strategy is to go through ``localrepo.instance()`` to construct
+# a repo instance. Then, we dynamically create a new type derived from
+# both it and our ``bundlerepository`` class which overrides some
+# functionality. We then change the type of the constructed repository
+# to this new type and initialize the bundle-specific bits of it.
+try:
+parentrepo = localrepo.instance(ui, repopath, create=False)
+tempparent = None
+except error.RepoError:
+tempparent = pycompat.mkdtemp()
+try:
+parentrepo = localrepo.instance(ui, tempparent, create=True)
+except Exception:
+shutil.rmtree(tempparent)
+raise
+class derivedbundlerepository(bundlerepository, parentrepo.__class__):
+pass
+repo = parentrepo
+repo.__class__ = derivedbundlerepository
+bundlerepository.__init__(repo, bundlepath, url, tempparent)
+return repo
 class bundletransactionmanager(object):
 def transaction(self):
 return None

Mercurial > public > mercurial-scm > hg

comparison mercurial/bundlerepo.py @ 39604:335ae4d0a552