typing: make `bundlerepository` subclass `localrepository` while type checking

Currently, `mercurial/bundlerepo.py` is excluded from pytype, mostly because it
complains that various `ui` and `vfs` fields in `localrepository` are missing.
(`bundlerepository` dynamically subclasses `localrepository` when it is
instantiated, so it works at runtime.)  This makes that class hierarchy known to
pytype.

Having a protocol for `Repository` is probably the right thing to do, but that
will be a lot of work and this still reflects the class at runtime.  Subclassing
also has the benefit of making sure any method overrides have a matching
signature, so maybe this is a situation where we do both of these things.  (I'm
not sure how clear the diagnostics are if a class *almost* implements a
protocol, but is missing a method argument or similar.)  The subclassing is not
done outside of type checking runs to avoid any side effects on already complex
code.

mercurial/bundlerepo.py

@@ -1,759 +1,766
 # bundlerepo.py - repository class for viewing uncompressed bundles
 #
 # Copyright 2006, 2007 Benoit Boissinot <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 """Repository class for viewing uncompressed bundles.
 
 This provides a read-only repository interface to bundles as if they
 were part of the actual repository.
 """
 
 from __future__ import annotations
 
 import contextlib
 import os
 import shutil
+import typing
 
 from .i18n import _
 from .node import (
     hex,
     nullrev,
 )
 
 from . import (
     bundle2,
     changegroup,
     changelog,
     cmdutil,
     discovery,
     encoding,
     error,
     exchange,
     filelog,
     localrepo,
     manifest,
     mdiff,
     pathutil,
     phases,
     pycompat,
     revlog,
     revlogutils,
     util,
     vfs as vfsmod,
 )
 from .utils import (
     urlutil,
 )
 
 from .revlogutils import (
     constants as revlog_constants,
 )
 
 
 class bundlerevlog(revlog.revlog):
     def __init__(self, opener, target, radix, cgunpacker, linkmapper):
         # How it works:
         # To retrieve a revision, we need to know the offset of the revision in
         # the bundle (an unbundle object). We store this offset in the index
         # (start). The base of the delta is stored in the base field.
         #
         # To differentiate a rev in the bundle from a rev in the revlog, we
         # check revision against repotiprev.
         opener = vfsmod.readonlyvfs(opener)
         revlog.revlog.__init__(self, opener, target=target, radix=radix)
         self.bundle = cgunpacker
         n = len(self)
         self.repotiprev = n - 1
         self.bundlerevs = set()  # used by 'bundle()' revset expression
         for deltadata in cgunpacker.deltaiter():
             node, p1, p2, cs, deltabase, delta, flags, sidedata = deltadata
 
             size = len(delta)
             start = cgunpacker.tell() - size
 
             if self.index.has_node(node):
                 # this can happen if two branches make the same change
                 self.bundlerevs.add(self.index.rev(node))
                 continue
             if cs == node:
                 linkrev = nullrev
             else:
                 linkrev = linkmapper(cs)
 
             for p in (p1, p2):
                 if not self.index.has_node(p):
                     raise error.LookupError(
                         p, self.display_id, _(b"unknown parent")
                     )
 
             if not self.index.has_node(deltabase):
                 raise error.LookupError(
                     deltabase, self.display_id, _(b'unknown delta base')
                 )
 
             baserev = self.rev(deltabase)
             # start, size, full unc. size, base (unused), link, p1, p2, node, sidedata_offset (unused), sidedata_size (unused)
             e = revlogutils.entry(
                 flags=flags,
                 data_offset=start,
                 data_compressed_length=size,
                 data_delta_base=baserev,
                 link_rev=linkrev,
                 parent_rev_1=self.rev(p1),
                 parent_rev_2=self.rev(p2),
                 node_id=node,
             )
             self.index.append(e)
             self.bundlerevs.add(n)
             n += 1
 
     @contextlib.contextmanager
     def reading(self):
         if self.repotiprev < 0:
             yield
         else:
             with super().reading() as x:
                 yield x
 
     def _chunk(self, rev):
         # Warning: in case of bundle, the diff is against what we stored as
         # delta base, not against rev - 1
         # XXX: could use some caching
         if rev <= self.repotiprev:
             return revlog.revlog._chunk(self, rev)
         self.bundle.seek(self.start(rev))
         return self.bundle.read(self.length(rev))
 
     def revdiff(self, rev1, rev2):
         """return or calculate a delta between two revisions"""
         if rev1 > self.repotiprev and rev2 > self.repotiprev:
             # hot path for bundle
             revb = self.index[rev2][3]
             if revb == rev1:
                 return self._chunk(rev2)
         elif rev1 <= self.repotiprev and rev2 <= self.repotiprev:
             return revlog.revlog.revdiff(self, rev1, rev2)
 
         return mdiff.textdiff(self.rawdata(rev1), self.rawdata(rev2))
 
     def _rawtext(self, node, rev):
         if rev is None:
             rev = self.rev(node)
         validated = False
         rawtext = None
         chain = []
         iterrev = rev
         # reconstruct the revision if it is from a changegroup
         while iterrev > self.repotiprev:
             if (
                 self._inner._revisioncache
                 and self._inner._revisioncache[1] == iterrev
             ):
                 rawtext = self._inner._revisioncache[2]
                 break
             chain.append(iterrev)
             iterrev = self.index[iterrev][3]
         if iterrev == nullrev:
             rawtext = b''
         elif rawtext is None:
             r = super(bundlerevlog, self)._rawtext(
                 self.node(iterrev),
                 iterrev,
             )
             __, rawtext, validated = r
         if chain:
             validated = False
         while chain:
             delta = self._chunk(chain.pop())
             rawtext = mdiff.patches(rawtext, [delta])
         return rev, rawtext, validated
 
     def addrevision(self, *args, **kwargs):
         raise NotImplementedError
 
     def addgroup(self, *args, **kwargs):
         raise NotImplementedError
 
     def strip(self, *args, **kwargs):
         raise NotImplementedError
 
     def checksize(self):
         raise NotImplementedError
 
 
 class bundlechangelog(bundlerevlog, changelog.changelog):
     def __init__(self, opener, cgunpacker):
         changelog.changelog.__init__(self, opener)
         linkmapper = lambda x: x
         bundlerevlog.__init__(
             self,
             opener,
             (revlog_constants.KIND_CHANGELOG, None),
             self.radix,
             cgunpacker,
             linkmapper,
         )
 
 
 class bundlemanifest(bundlerevlog, manifest.manifestrevlog):
     def __init__(
         self,
         nodeconstants,
         opener,
         cgunpacker,
         linkmapper,
         dirlogstarts=None,
         dir=b'',
     ):
         # XXX manifestrevlog is not actually a revlog , so mixing it with
         # bundlerevlog is not a good idea.
         manifest.manifestrevlog.__init__(self, nodeconstants, opener, tree=dir)
         bundlerevlog.__init__(
             self,
             opener,
             (revlog_constants.KIND_MANIFESTLOG, dir),
             self._revlog.radix,
             cgunpacker,
             linkmapper,
         )
         if dirlogstarts is None:
             dirlogstarts = {}
             if self.bundle.version == b"03":
                 dirlogstarts = _getfilestarts(self.bundle)
         self._dirlogstarts = dirlogstarts
         self._linkmapper = linkmapper
 
     def dirlog(self, d):
         if d in self._dirlogstarts:
             self.bundle.seek(self._dirlogstarts[d])
             return bundlemanifest(
                 self.nodeconstants,
                 self.opener,
                 self.bundle,
                 self._linkmapper,
                 self._dirlogstarts,
                 dir=d,
             )
         return super(bundlemanifest, self).dirlog(d)
 
 
 class bundlefilelog(filelog.filelog):
     def __init__(self, opener, path, cgunpacker, linkmapper):
         filelog.filelog.__init__(self, opener, path)
         self._revlog = bundlerevlog(
             opener,
             # XXX should use the unencoded path
             target=(revlog_constants.KIND_FILELOG, path),
             radix=self._revlog.radix,
             cgunpacker=cgunpacker,
             linkmapper=linkmapper,
         )
 
 
 class bundlepeer(localrepo.localpeer):
     def canpush(self):
         return False
 
 
 class bundlephasecache(phases.phasecache):
     def __init__(self, *args, **kwargs):
         super(bundlephasecache, self).__init__(*args, **kwargs)
         if hasattr(self, 'opener'):
             self.opener = vfsmod.readonlyvfs(self.opener)
 
     def write(self):
         raise NotImplementedError
 
     def _write(self, fp):
         raise NotImplementedError
 
     def _updateroots(self, repo, phase, newroots, tr, invalidate=True):
         self._phaseroots[phase] = newroots
         if invalidate:
             self.invalidate()
         self.dirty = True
 
 
 def _getfilestarts(cgunpacker):
     filespos = {}
     for chunkdata in iter(cgunpacker.filelogheader, {}):
         fname = chunkdata[b'filename']
         filespos[fname] = cgunpacker.tell()
         for chunk in iter(lambda: cgunpacker.deltachunk(None), {}):
             pass
     return filespos
 
 
-class bundlerepository:
+_bundle_repo_baseclass = object
+
+if typing.TYPE_CHECKING:
+    _bundle_repo_baseclass = localrepo.localrepository
+
+
+class bundlerepository(_bundle_repo_baseclass):
     """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, bundlepath, url, tempparent):
         self._tempparent = tempparent
         self._url = url
 
         self.ui.setconfig(b'phases', b'publish', False, b'bundlerepo')
 
         # dict with the mapping 'filename' -> position in the changegroup.
         self._cgfilespos = {}
         self._bundlefile = None
         self._cgunpacker = None
         self.tempfile = None
         f = util.posixfile(bundlepath, b"rb")
         bundle = exchange.readbundle(self.ui, f, bundlepath)
 
         if isinstance(bundle, bundle2.unbundle20):
             self._bundlefile = bundle
 
             cgpart = None
             for part in bundle.iterparts(seekable=True):
                 if part.type == b'phase-heads':
                     self._handle_bundle2_phase_part(bundle, part)
                 elif part.type == b'changegroup':
                     if cgpart:
                         raise NotImplementedError(
                             b"can't process multiple changegroups"
                         )
                     cgpart = part
                     self._handle_bundle2_cg_part(bundle, part)
 
             if not cgpart:
                 raise error.Abort(_(b"No changegroups found"))
 
             # This is required to placate a later consumer, which expects
             # the payload offset to be at the beginning of the changegroup.
             # We need to do this after the iterparts() generator advances
             # because iterparts() will seek to end of payload after the
             # generator returns control to iterparts().
             cgpart.seek(0, os.SEEK_SET)
 
         elif isinstance(bundle, changegroup.cg1unpacker):
             self._handle_bundle1(bundle, bundlepath)
         else:
             raise error.Abort(
                 _(b'bundle type %r cannot be read') % type(bundle)
             )
 
     def _handle_bundle1(self, bundle, bundlepath):
         if bundle.compressed():
             f = self._writetempbundle(bundle.read, b'.hg10un', header=b'HG10UN')
             bundle = exchange.readbundle(self.ui, f, bundlepath, self.vfs)
 
         self._bundlefile = bundle
         self._cgunpacker = bundle
 
         self.firstnewrev = self.changelog.repotiprev + 1
         phases.retractboundary(
             self,
             None,
             phases.draft,
             [ctx.node() for ctx in self[self.firstnewrev :]],
         )
 
     def _handle_bundle2_cg_part(self, bundle, part):
         assert part.type == b'changegroup'
         cgstream = part
         targetphase = part.params.get(b'targetphase')
         try:
             targetphase = int(targetphase)
         except TypeError:
             pass
         if targetphase is None:
             targetphase = phases.draft
         if targetphase not in phases.allphases:
             m = _(b'unsupported targetphase: %d')
             m %= targetphase
             raise error.Abort(m)
         version = part.params.get(b'version', b'01')
         legalcgvers = changegroup.supportedincomingversions(self)
         if version not in legalcgvers:
             msg = _(b'Unsupported changegroup version: %s')
             raise error.Abort(msg % version)
         if bundle.compressed():
             cgstream = self._writetempbundle(part.read, b'.cg%sun' % version)
 
         self._cgunpacker = changegroup.getunbundler(version, cgstream, b'UN')
 
         self.firstnewrev = self.changelog.repotiprev + 1
         phases.retractboundary(
             self,
             None,
             targetphase,
             [ctx.node() for ctx in self[self.firstnewrev :]],
         )
 
     def _handle_bundle2_phase_part(self, bundle, part):
         assert part.type == b'phase-heads'
 
         unfi = self.unfiltered()
         headsbyphase = phases.binarydecode(part)
         phases.updatephases(unfi, lambda: None, headsbyphase)
 
     def _writetempbundle(self, readfn, suffix, header=b''):
         """Write a temporary file to disk"""
         fdtemp, temp = self.vfs.mkstemp(prefix=b"hg-bundle-", suffix=suffix)
         self.tempfile = temp
 
         with os.fdopen(fdtemp, 'wb') as fptemp:
             fptemp.write(header)
             while True:
                 chunk = readfn(2**18)
                 if not chunk:
                     break
                 fptemp.write(chunk)
 
         return self.vfs.open(self.tempfile, mode=b"rb")
 
     @localrepo.unfilteredpropertycache
     def _phasecache(self):
         return bundlephasecache(self, self._phasedefaults)
 
     @localrepo.unfilteredpropertycache
     def changelog(self):
         # consume the header if it exists
         self._cgunpacker.changelogheader()
         c = bundlechangelog(self.svfs, self._cgunpacker)
         self.manstart = self._cgunpacker.tell()
         return c
 
     def _refreshchangelog(self):
         # changelog for bundle repo are not filecache, this method is not
         # applicable.
         pass
 
     @localrepo.unfilteredpropertycache
     def manifestlog(self):
         self._cgunpacker.seek(self.manstart)
         # consume the header if it exists
         self._cgunpacker.manifestheader()
         linkmapper = self.unfiltered().changelog.rev
         rootstore = bundlemanifest(
             self.nodeconstants, self.svfs, self._cgunpacker, linkmapper
         )
         self.filestart = self._cgunpacker.tell()
 
         return manifest.manifestlog(
             self.svfs, self, rootstore, self.narrowmatch()
         )
 
     def _consumemanifest(self):
         """Consumes the manifest portion of the bundle, setting filestart so the
         file portion can be read."""
         self._cgunpacker.seek(self.manstart)
         self._cgunpacker.manifestheader()
         for delta in self._cgunpacker.deltaiter():
             pass
         self.filestart = self._cgunpacker.tell()
 
     @localrepo.unfilteredpropertycache
     def manstart(self):
         self.changelog
         return self.manstart
 
     @localrepo.unfilteredpropertycache
     def filestart(self):
         self.manifestlog
 
         # If filestart was not set by self.manifestlog, that means the
         # manifestlog implementation did not consume the manifests from the
         # changegroup (ex: it might be consuming trees from a separate bundle2
         # part instead). So we need to manually consume it.
         if 'filestart' not in self.__dict__:
             self._consumemanifest()
 
         return self.filestart
 
     def url(self):
         return self._url
 
     def file(self, f):
         if not self._cgfilespos:
             self._cgunpacker.seek(self.filestart)
             self._cgfilespos = _getfilestarts(self._cgunpacker)
 
         if f in self._cgfilespos:
             self._cgunpacker.seek(self._cgfilespos[f])
             linkmapper = self.unfiltered().changelog.rev
             return bundlefilelog(self.svfs, f, self._cgunpacker, linkmapper)
         else:
             return super(bundlerepository, self).file(f)
 
     def close(self):
         """Close assigned bundle file immediately."""
         self._bundlefile.close()
         if self.tempfile is not None:
             self.vfs.unlink(self.tempfile)
         if self._tempparent:
             shutil.rmtree(self._tempparent, True)
 
     def cancopy(self):
         return False
 
     def peer(self, path=None, remotehidden=False):
         return bundlepeer(self, path=path, remotehidden=remotehidden)
 
     def getcwd(self):
         return encoding.getcwd()  # always outside the repo
 
     # Check if parents exist in localrepo before setting
     def setparents(self, p1, p2=None):
         if p2 is None:
             p2 = self.nullid
         p1rev = self.changelog.rev(p1)
         p2rev = self.changelog.rev(p2)
         msg = _(b"setting parent to node %s that only exists in the bundle\n")
         if self.changelog.repotiprev < p1rev:
             self.ui.warn(msg % hex(p1))
         if self.changelog.repotiprev < p2rev:
             self.ui.warn(msg % hex(p2))
         return super(bundlerepository, self).setparents(p1, p2)
 
 
 def instance(ui, path, create, intents=None, createopts=None):
     if create:
         raise error.Abort(_(b'cannot create new bundle repository'))
     # internal config: bundle.mainreporoot
     parentpath = ui.config(b"bundle", b"mainreporoot")
     if not parentpath:
         # try to find the correct path to the working directory repo
         parentpath = cmdutil.findrepo(encoding.getcwd())
         if parentpath is None:
             parentpath = b''
     if parentpath:
         # Try to make the full path relative so we get a nice, short URL.
         # In particular, we don't want temp dir names in test outputs.
         cwd = encoding.getcwd()
         if parentpath == cwd:
             parentpath = b''
         else:
             cwd = pathutil.normasprefix(cwd)
             if parentpath.startswith(cwd):
                 parentpath = parentpath[len(cwd) :]
     u = urlutil.url(path)
     path = u.localpath()
     if u.scheme == b'bundle':
         s = path.split(b"+", 1)
         if len(s) == 1:
             repopath, bundlename = parentpath, s[0]
         else:
             repopath, bundlename = s
     else:
         repopath, bundlename = parentpath, path
 
     return makebundlerepository(ui, repopath, bundlename)
 
 
 def makebundlerepository(ui, repopath, bundlepath):
     """Make a bundle repository object based on repo and bundle paths."""
     if repopath:
         url = b'bundle:%s+%s' % (util.expandpath(repopath), bundlepath)
     else:
         url = b'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:
         repo = localrepo.instance(ui, repopath, create=False)
         tempparent = None
     except error.RequirementError:
         raise  # no fallback if the backing repo is unsupported
     except error.RepoError:
         tempparent = pycompat.mkdtemp()
         try:
             repo = localrepo.instance(ui, tempparent, create=True)
         except Exception:
             shutil.rmtree(tempparent)
             raise
 
     class derivedbundlerepository(bundlerepository, repo.__class__):
         pass
 
     repo.__class__ = derivedbundlerepository
     bundlerepository.__init__(repo, bundlepath, url, tempparent)
 
     return repo
 
 
 class bundletransactionmanager:
     def transaction(self):
         return None
 
     def close(self):
         raise NotImplementedError
 
     def release(self):
         raise NotImplementedError
 
 
 def getremotechanges(
     ui, repo, peer, onlyheads=None, bundlename=None, force=False
 ):
     """obtains a bundle of changes incoming from peer
 
     "onlyheads" restricts the returned changes to those reachable from the
       specified heads.
     "bundlename", if given, stores the bundle to this file path permanently;
       otherwise it's stored to a temp file and gets deleted again when you call
       the returned "cleanupfn".
     "force" indicates whether to proceed on unrelated repos.
 
     Returns a tuple (local, csets, cleanupfn):
 
     "local" is a local repo from which to obtain the actual incoming
       changesets; it is a bundlerepo for the obtained bundle when the
       original "peer" is remote.
     "csets" lists the incoming changeset node ids.
     "cleanupfn" must be called without arguments when you're done processing
       the changes; it closes both the original "peer" and the one returned
       here.
     """
     tmp = discovery.findcommonincoming(repo, peer, heads=onlyheads, force=force)
     common, incoming, rheads = tmp
     if not incoming:
         try:
             if bundlename:
                 os.unlink(bundlename)
         except OSError:
             pass
         return repo, [], peer.close
 
     commonset = set(common)
     rheads = [x for x in rheads if x not in commonset]
 
     bundle = None
     bundlerepo = None
     localrepo = peer.local()
     if bundlename or not localrepo:
         # create a bundle (uncompressed if peer repo is not local)
 
         # developer config: devel.legacy.exchange
         legexc = ui.configlist(b'devel', b'legacy.exchange')
         forcebundle1 = b'bundle2' not in legexc and b'bundle1' in legexc
         canbundle2 = (
             not forcebundle1
             and peer.capable(b'getbundle')
             and peer.capable(b'bundle2')
         )
         if canbundle2:
             with peer.commandexecutor() as e:
                 b2 = e.callcommand(
                     b'getbundle',
                     {
                         b'source': b'incoming',
                         b'common': common,
                         b'heads': rheads,
                         b'bundlecaps': exchange.caps20to10(
                             repo, role=b'client'
                         ),
                         b'cg': True,
                     },
                 ).result()
 
                 fname = bundle = changegroup.writechunks(
                     ui, b2._forwardchunks(), bundlename
                 )
         else:
             if peer.capable(b'getbundle'):
                 with peer.commandexecutor() as e:
                     cg = e.callcommand(
                         b'getbundle',
                         {
                             b'source': b'incoming',
                             b'common': common,
                             b'heads': rheads,
                         },
                     ).result()
             elif onlyheads is None and not peer.capable(b'changegroupsubset'):
                 # compat with older servers when pulling all remote heads
 
                 with peer.commandexecutor() as e:
                     cg = e.callcommand(
                         b'changegroup',
                         {
                             b'nodes': incoming,
                             b'source': b'incoming',
                         },
                     ).result()
 
                 rheads = None
             else:
                 with peer.commandexecutor() as e:
                     cg = e.callcommand(
                         b'changegroupsubset',
                         {
                             b'bases': incoming,
                             b'heads': rheads,
                             b'source': b'incoming',
                         },
                     ).result()
 
             if localrepo:
                 bundletype = b"HG10BZ"
             else:
                 bundletype = b"HG10UN"
             fname = bundle = bundle2.writebundle(ui, cg, bundlename, bundletype)
         # keep written bundle?
         if bundlename:
             bundle = None
         if not localrepo:
             # use the created uncompressed bundlerepo
             localrepo = bundlerepo = makebundlerepository(
                 repo.baseui, repo.root, fname
             )
 
             # this repo contains local and peer now, so filter out local again
             common = repo.heads()
     if localrepo:
         # Part of common may be remotely filtered
         # So use an unfiltered version
         # The discovery process probably need cleanup to avoid that
         localrepo = localrepo.unfiltered()
 
     csets = localrepo.changelog.findmissing(common, rheads)
 
     if bundlerepo:
         reponodes = [ctx.node() for ctx in bundlerepo[bundlerepo.firstnewrev :]]
 
         with peer.commandexecutor() as e:
             remotephases = e.callcommand(
                 b'listkeys',
                 {
                     b'namespace': b'phases',
                 },
             ).result()
 
         pullop = exchange.pulloperation(
             bundlerepo, peer, path=None, heads=reponodes
         )
         pullop.trmanager = bundletransactionmanager()
         exchange._pullapplyphases(pullop, remotephases)
 
     def cleanup():
         if bundlerepo:
             bundlerepo.close()
         if bundle:
             os.unlink(bundle)
         peer.close()
 
     return (localrepo, csets, cleanup)