narrowbundle2: mark most constants as module-private

This became obvious when preparing the previous change, so there's no
reason to not just do it now while it's easy.

Differential Revision: https://phab.mercurial-scm.org/D2005

hgext/narrow/narrowbundle2.py

@@ -1,496 +1,496 b''
 # narrowbundle2.py - bundle2 extensions for narrow repository support
 #
 # Copyright 2017 Google, 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 collections
 import errno
 import struct
 
 from mercurial.i18n import _
 from mercurial.node import (
     bin,
     nullid,
     nullrev,
 )
 from mercurial import (
     bundle2,
     changegroup,
     dagutil,
     error,
     exchange,
     extensions,
     repair,
     util,
     wireproto,
 )
 
 from . import (
     narrowrepo,
     narrowspec,
 )
 
 NARROWCAP = 'narrow'
-NARROWACL_SECTION = 'narrowhgacl'
-CHANGESPECPART = NARROWCAP + ':changespec'
-SPECPART = NARROWCAP + ':spec'
-SPECPART_INCLUDE = 'include'
-SPECPART_EXCLUDE = 'exclude'
-KILLNODESIGNAL = 'KILL'
-DONESIGNAL = 'DONE'
-ELIDEDCSHEADER = '>20s20s20sl' # cset id, p1, p2, len(text)
-ELIDEDMFHEADER = '>20s20s20s20sl' # manifest id, p1, p2, link id, len(text)
-CSHEADERSIZE = struct.calcsize(ELIDEDCSHEADER)
-MFHEADERSIZE = struct.calcsize(ELIDEDMFHEADER)
+_NARROWACL_SECTION = 'narrowhgacl'
+_CHANGESPECPART = NARROWCAP + ':changespec'
+_SPECPART = NARROWCAP + ':spec'
+_SPECPART_INCLUDE = 'include'
+_SPECPART_EXCLUDE = 'exclude'
+_KILLNODESIGNAL = 'KILL'
+_DONESIGNAL = 'DONE'
+_ELIDEDCSHEADER = '>20s20s20sl' # cset id, p1, p2, len(text)
+_ELIDEDMFHEADER = '>20s20s20s20sl' # manifest id, p1, p2, link id, len(text)
+_CSHEADERSIZE = struct.calcsize(_ELIDEDCSHEADER)
+_MFHEADERSIZE = struct.calcsize(_ELIDEDMFHEADER)
 
 # When advertising capabilities, always include narrow clone support.
 def getrepocaps_narrow(orig, repo, **kwargs):
     caps = orig(repo, **kwargs)
     caps[NARROWCAP] = ['v0']
     return caps
 
 def _computeellipsis(repo, common, heads, known, match, depth=None):
     """Compute the shape of a narrowed DAG.
 
     Args:
       repo: The repository we're transferring.
       common: The roots of the DAG range we're transferring.
               May be just [nullid], which means all ancestors of heads.
       heads: The heads of the DAG range we're transferring.
       match: The narrowmatcher that allows us to identify relevant changes.
       depth: If not None, only consider nodes to be full nodes if they are at
              most depth changesets away from one of heads.
 
     Returns:
       A tuple of (visitnodes, relevant_nodes, ellipsisroots) where:
 
         visitnodes: The list of nodes (either full or ellipsis) which
                     need to be sent to the client.
         relevant_nodes: The set of changelog nodes which change a file inside
                  the narrowspec. The client needs these as non-ellipsis nodes.
         ellipsisroots: A dict of {rev: parents} that is used in
                        narrowchangegroup to produce ellipsis nodes with the
                        correct parents.
     """
     cl = repo.changelog
     mfl = repo.manifestlog
 
     cldag = dagutil.revlogdag(cl)
     # dagutil does not like nullid/nullrev
     commonrevs = cldag.internalizeall(common - set([nullid])) | set([nullrev])
     headsrevs = cldag.internalizeall(heads)
     if depth:
         revdepth = {h: 0 for h in headsrevs}
 
     ellipsisheads = collections.defaultdict(set)
     ellipsisroots = collections.defaultdict(set)
 
     def addroot(head, curchange):
         """Add a root to an ellipsis head, splitting heads with 3 roots."""
         ellipsisroots[head].add(curchange)
         # Recursively split ellipsis heads with 3 roots by finding the
         # roots' youngest common descendant which is an elided merge commit.
         # That descendant takes 2 of the 3 roots as its own, and becomes a
         # root of the head.
         while len(ellipsisroots[head]) > 2:
             child, roots = splithead(head)
             splitroots(head, child, roots)
             head = child  # Recurse in case we just added a 3rd root
 
     def splitroots(head, child, roots):
         ellipsisroots[head].difference_update(roots)
         ellipsisroots[head].add(child)
         ellipsisroots[child].update(roots)
         ellipsisroots[child].discard(child)
 
     def splithead(head):
         r1, r2, r3 = sorted(ellipsisroots[head])
         for nr1, nr2 in ((r2, r3), (r1, r3), (r1, r2)):
             mid = repo.revs('sort(merge() & %d::%d & %d::%d, -rev)',
                             nr1, head, nr2, head)
             for j in mid:
                 if j == nr2:
                     return nr2, (nr1, nr2)
                 if j not in ellipsisroots or len(ellipsisroots[j]) < 2:
                     return j, (nr1, nr2)
         raise error.Abort('Failed to split up ellipsis node! head: %d, '
                           'roots: %d %d %d' % (head, r1, r2, r3))
 
     missing = list(cl.findmissingrevs(common=commonrevs, heads=headsrevs))
     visit = reversed(missing)
     relevant_nodes = set()
     visitnodes = map(cl.node, missing)
     required = set(headsrevs) | known
     for rev in visit:
         clrev = cl.changelogrevision(rev)
         ps = cldag.parents(rev)
         if depth is not None:
             curdepth = revdepth[rev]
             for p in ps:
                 revdepth[p] = min(curdepth + 1, revdepth.get(p, depth + 1))
         needed = False
         shallow_enough = depth is None or revdepth[rev] <= depth
         if shallow_enough:
             curmf = mfl[clrev.manifest].read()
             if ps:
                 # We choose to not trust the changed files list in
                 # changesets because it's not always correct. TODO: could
                 # we trust it for the non-merge case?
                 p1mf = mfl[cl.changelogrevision(ps[0]).manifest].read()
                 needed = any(match(f) for f in curmf.diff(p1mf).iterkeys())
                 if not needed and len(ps) > 1:
                     # For merge changes, the list of changed files is not
                     # helpful, since we need to emit the merge if a file
                     # in the narrow spec has changed on either side of the
                     # merge. As a result, we do a manifest diff to check.
                     p2mf = mfl[cl.changelogrevision(ps[1]).manifest].read()
                     needed = any(match(f) for f in curmf.diff(p2mf).iterkeys())
             else:
                 # For a root node, we need to include the node if any
                 # files in the node match the narrowspec.
                 needed = any(match(f) for f in curmf)
 
         if needed:
             for head in ellipsisheads[rev]:
                 addroot(head, rev)
             for p in ps:
                 required.add(p)
             relevant_nodes.add(cl.node(rev))
         else:
             if not ps:
                 ps = [nullrev]
             if rev in required:
                 for head in ellipsisheads[rev]:
                     addroot(head, rev)
                 for p in ps:
                     ellipsisheads[p].add(rev)
             else:
                 for p in ps:
                     ellipsisheads[p] |= ellipsisheads[rev]
 
     # add common changesets as roots of their reachable ellipsis heads
     for c in commonrevs:
         for head in ellipsisheads[c]:
             addroot(head, c)
     return visitnodes, relevant_nodes, ellipsisroots
 
 def _packellipsischangegroup(repo, common, match, relevant_nodes,
                              ellipsisroots, visitnodes, depth, source, version):
     if version in ('01', '02'):
         raise error.Abort(
             'ellipsis nodes require at least cg3 on client and server, '
             'but negotiated version %s' % version)
     # We wrap cg1packer.revchunk, using a side channel to pass
     # relevant_nodes into that area. Then if linknode isn't in the
     # set, we know we have an ellipsis node and we should defer
     # sending that node's data. We override close() to detect
     # pending ellipsis nodes and flush them.
     packer = changegroup.getbundler(version, repo)
     # Let the packer have access to the narrow matcher so it can
     # omit filelogs and dirlogs as needed
     packer._narrow_matcher = lambda : match
     # Give the packer the list of nodes which should not be
     # ellipsis nodes. We store this rather than the set of nodes
     # that should be an ellipsis because for very large histories
     # we expect this to be significantly smaller.
     packer.full_nodes = relevant_nodes
     # Maps ellipsis revs to their roots at the changelog level.
     packer.precomputed_ellipsis = ellipsisroots
     # Maps CL revs to per-revlog revisions. Cleared in close() at
     # the end of each group.
     packer.clrev_to_localrev = {}
     packer.next_clrev_to_localrev = {}
     # Maps changelog nodes to changelog revs. Filled in once
     # during changelog stage and then left unmodified.
     packer.clnode_to_rev = {}
     packer.changelog_done = False
     # If true, informs the packer that it is serving shallow content and might
     # need to pack file contents not introduced by the changes being packed.
     packer.is_shallow = depth is not None
 
     return packer.generate(common, visitnodes, False, source)
 
 # Serve a changegroup for a client with a narrow clone.
 def getbundlechangegrouppart_narrow(bundler, repo, source,
                                     bundlecaps=None, b2caps=None, heads=None,
                                     common=None, **kwargs):
     cgversions = b2caps.get('changegroup')
     getcgkwargs = {}
     if cgversions:  # 3.1 and 3.2 ship with an empty value
         cgversions = [v for v in cgversions
                       if v in changegroup.supportedoutgoingversions(repo)]
         if not cgversions:
             raise ValueError(_('no common changegroup version'))
         version = getcgkwargs['version'] = max(cgversions)
     else:
         raise ValueError(_("server does not advertise changegroup version,"
                            " can't negotiate support for ellipsis nodes"))
 
     include = sorted(filter(bool, kwargs.get('includepats', [])))
     exclude = sorted(filter(bool, kwargs.get('excludepats', [])))
     newmatch = narrowspec.match(repo.root, include=include, exclude=exclude)
     if not repo.ui.configbool("experimental", "narrowservebrokenellipses"):
         outgoing = exchange._computeoutgoing(repo, heads, common)
         if not outgoing.missing:
             return
         def wrappedgetbundler(orig, *args, **kwargs):
             bundler = orig(*args, **kwargs)
             bundler._narrow_matcher = lambda : newmatch
             return bundler
         with extensions.wrappedfunction(changegroup, 'getbundler',
                                         wrappedgetbundler):
             cg = changegroup.makestream(repo, outgoing, version, source)
         part = bundler.newpart('changegroup', data=cg)
         part.addparam('version', version)
         if 'treemanifest' in repo.requirements:
             part.addparam('treemanifest', '1')
 
         if include or exclude:
-            narrowspecpart = bundler.newpart(SPECPART)
+            narrowspecpart = bundler.newpart(_SPECPART)
             if include:
                 narrowspecpart.addparam(
-                    SPECPART_INCLUDE, '\n'.join(include), mandatory=True)
+                    _SPECPART_INCLUDE, '\n'.join(include), mandatory=True)
             if exclude:
                 narrowspecpart.addparam(
-                    SPECPART_EXCLUDE, '\n'.join(exclude), mandatory=True)
+                    _SPECPART_EXCLUDE, '\n'.join(exclude), mandatory=True)
 
         return
 
     depth = kwargs.get('depth', None)
     if depth is not None:
         depth = int(depth)
         if depth < 1:
             raise error.Abort(_('depth must be positive, got %d') % depth)
 
     heads = set(heads or repo.heads())
     common = set(common or [nullid])
     oldinclude = sorted(filter(bool, kwargs.get('oldincludepats', [])))
     oldexclude = sorted(filter(bool, kwargs.get('oldexcludepats', [])))
     known = {bin(n) for n in kwargs.get('known', [])}
     if known and (oldinclude != include or oldexclude != exclude):
         # Steps:
         # 1. Send kill for "$known & ::common"
         #
         # 2. Send changegroup for ::common
         #
         # 3. Proceed.
         #
         # In the future, we can send kills for only the specific
         # nodes we know should go away or change shape, and then
         # send a data stream that tells the client something like this:
         #
         # a) apply this changegroup
         # b) apply nodes XXX, YYY, ZZZ that you already have
         # c) goto a
         #
         # until they've built up the full new state.
         # Convert to revnums and intersect with "common". The client should
         # have made it a subset of "common" already, but let's be safe.
         known = set(repo.revs("%ln & ::%ln", known, common))
         # TODO: we could send only roots() of this set, and the
         # list of nodes in common, and the client could work out
         # what to strip, instead of us explicitly sending every
         # single node.
         deadrevs = known
         def genkills():
             for r in deadrevs:
-                yield KILLNODESIGNAL
+                yield _KILLNODESIGNAL
                 yield repo.changelog.node(r)
-            yield DONESIGNAL
-        bundler.newpart(CHANGESPECPART, data=genkills())
+            yield _DONESIGNAL
+        bundler.newpart(_CHANGESPECPART, data=genkills())
         newvisit, newfull, newellipsis = _computeellipsis(
             repo, set(), common, known, newmatch)
         if newvisit:
             cg = _packellipsischangegroup(
                 repo, common, newmatch, newfull, newellipsis,
                 newvisit, depth, source, version)
             part = bundler.newpart('changegroup', data=cg)
             part.addparam('version', version)
             if 'treemanifest' in repo.requirements:
                 part.addparam('treemanifest', '1')
 
     visitnodes, relevant_nodes, ellipsisroots = _computeellipsis(
         repo, common, heads, set(), newmatch, depth=depth)
 
     repo.ui.debug('Found %d relevant revs\n' % len(relevant_nodes))
     if visitnodes:
         cg = _packellipsischangegroup(
             repo, common, newmatch, relevant_nodes, ellipsisroots,
             visitnodes, depth, source, version)
         part = bundler.newpart('changegroup', data=cg)
         part.addparam('version', version)
         if 'treemanifest' in repo.requirements:
             part.addparam('treemanifest', '1')
 
 def applyacl_narrow(repo, kwargs):
     username = repo.ui.shortuser(repo.ui.username())
     user_includes = repo.ui.configlist(
-        NARROWACL_SECTION, username + '.includes',
-        repo.ui.configlist(NARROWACL_SECTION, 'default.includes'))
+        _NARROWACL_SECTION, username + '.includes',
+        repo.ui.configlist(_NARROWACL_SECTION, 'default.includes'))
     user_excludes = repo.ui.configlist(
-        NARROWACL_SECTION, username + '.excludes',
-        repo.ui.configlist(NARROWACL_SECTION, 'default.excludes'))
+        _NARROWACL_SECTION, username + '.excludes',
+        repo.ui.configlist(_NARROWACL_SECTION, 'default.excludes'))
     if not user_includes:
         raise error.Abort(_("{} configuration for user {} is empty")
-                          .format(NARROWACL_SECTION, username))
+                          .format(_NARROWACL_SECTION, username))
 
     user_includes = [
         'path:.' if p == '*' else 'path:' + p for p in user_includes]
     user_excludes = [
         'path:.' if p == '*' else 'path:' + p for p in user_excludes]
 
     req_includes = set(kwargs.get('includepats', []))
     req_excludes = set(kwargs.get('excludepats', []))
 
     invalid_includes = []
     req_includes, req_excludes = narrowspec.restrictpatterns(
         req_includes, req_excludes,
         user_includes, user_excludes, invalid_includes)
 
     if invalid_includes:
         raise error.Abort(
             _("The following includes are not accessible for {}: {}")
             .format(username, invalid_includes))
 
     new_args = {}
     new_args.update(kwargs)
     new_args['includepats'] = req_includes
     if req_excludes:
         new_args['excludepats'] = req_excludes
     return new_args
 
[e-mail](SPECPART, (SPECPART_INCLUDE, SPECPART_EXCLUDE))
[e-mail](_SPECPART, (_SPECPART_INCLUDE, _SPECPART_EXCLUDE))
 def _handlechangespec_2(op, inpart):
-    includepats = set(inpart.params.get(SPECPART_INCLUDE, '').splitlines())
-    excludepats = set(inpart.params.get(SPECPART_EXCLUDE, '').splitlines())
+    includepats = set(inpart.params.get(_SPECPART_INCLUDE, '').splitlines())
+    excludepats = set(inpart.params.get(_SPECPART_EXCLUDE, '').splitlines())
     narrowspec.save(op.repo, includepats, excludepats)
     if not narrowrepo.requirement in op.repo.requirements:
         op.repo.requirements.add(narrowrepo.requirement)
         op.repo._writerequirements()
     op.repo.invalidate(clearfilecache=True)
 
[e-mail](CHANGESPECPART)
[e-mail](_CHANGESPECPART)
 def _handlechangespec(op, inpart):
     repo = op.repo
     cl = repo.changelog
 
     # changesets which need to be stripped entirely. either they're no longer
     # needed in the new narrow spec, or the server is sending a replacement
     # in the changegroup part.
     clkills = set()
 
     # A changespec part contains all the updates to ellipsis nodes
     # that will happen as a result of widening or narrowing a
     # repo. All the changes that this block encounters are ellipsis
     # nodes or flags to kill an existing ellipsis.
     chunksignal = changegroup.readexactly(inpart, 4)
-    while chunksignal != DONESIGNAL:
-        if chunksignal == KILLNODESIGNAL:
+    while chunksignal != _DONESIGNAL:
+        if chunksignal == _KILLNODESIGNAL:
             # a node used to be an ellipsis but isn't anymore
             ck = changegroup.readexactly(inpart, 20)
             if cl.hasnode(ck):
                 clkills.add(ck)
         else:
             raise error.Abort(
                 _('unexpected changespec node chunk type: %s') % chunksignal)
         chunksignal = changegroup.readexactly(inpart, 4)
 
     if clkills:
         # preserve bookmarks that repair.strip() would otherwise strip
         bmstore = repo._bookmarks
         class dummybmstore(dict):
             def applychanges(self, repo, tr, changes):
                 pass
             def recordchange(self, tr): # legacy version
                 pass
         repo._bookmarks = dummybmstore()
         chgrpfile = repair.strip(op.ui, repo, list(clkills), backup=True,
                                  topic='widen')
         repo._bookmarks = bmstore
         if chgrpfile:
             # presence of _widen_bundle attribute activates widen handler later
             op._widen_bundle = chgrpfile
     # Set the new narrowspec if we're widening. The setnewnarrowpats() method
     # will currently always be there when using the core+narrowhg server, but
     # other servers may include a changespec part even when not widening (e.g.
     # because we're deepening a shallow repo).
     if util.safehasattr(repo, 'setnewnarrowpats'):
         repo.setnewnarrowpats()
 
 def handlechangegroup_widen(op, inpart):
     """Changegroup exchange handler which restores temporarily-stripped nodes"""
     # We saved a bundle with stripped node data we must now restore.
     # This approach is based on mercurial/repair.py@6ee26a53c111.
     repo = op.repo
     ui = op.ui
 
     chgrpfile = op._widen_bundle
     del op._widen_bundle
     vfs = repo.vfs
 
     ui.note(_("adding branch\n"))
     f = vfs.open(chgrpfile, "rb")
     try:
         gen = exchange.readbundle(ui, f, chgrpfile, vfs)
         if not ui.verbose:
             # silence internal shuffling chatter
             ui.pushbuffer()
         if isinstance(gen, bundle2.unbundle20):
             with repo.transaction('strip') as tr:
                 bundle2.processbundle(repo, gen, lambda: tr)
         else:
             gen.apply(repo, 'strip', 'bundle:' + vfs.join(chgrpfile), True)
         if not ui.verbose:
             ui.popbuffer()
     finally:
         f.close()
 
     # remove undo files
     for undovfs, undofile in repo.undofiles():
         try:
             undovfs.unlink(undofile)
         except OSError as e:
             if e.errno != errno.ENOENT:
                 ui.warn(_('error removing %s: %s\n') %
                         (undovfs.join(undofile), str(e)))
 
     # Remove partial backup only if there were no exceptions
     vfs.unlink(chgrpfile)
 
 def setup():
     """Enable narrow repo support in bundle2-related extension points."""
     extensions.wrapfunction(bundle2, 'getrepocaps', getrepocaps_narrow)
 
     wireproto.gboptsmap['narrow'] = 'boolean'
     wireproto.gboptsmap['depth'] = 'plain'
     wireproto.gboptsmap['oldincludepats'] = 'csv'
     wireproto.gboptsmap['oldexcludepats'] = 'csv'
     wireproto.gboptsmap['includepats'] = 'csv'
     wireproto.gboptsmap['excludepats'] = 'csv'
     wireproto.gboptsmap['known'] = 'csv'
 
     # Extend changegroup serving to handle requests from narrow clients.
     origcgfn = exchange.getbundle2partsmapping['changegroup']
     def wrappedcgfn(*args, **kwargs):
         repo = args[1]
-        if repo.ui.has_section(NARROWACL_SECTION):
+        if repo.ui.has_section(_NARROWACL_SECTION):
             getbundlechangegrouppart_narrow(
                 *args, **applyacl_narrow(repo, kwargs))
         elif kwargs.get('narrow', False):
             getbundlechangegrouppart_narrow(*args, **kwargs)
         else:
             origcgfn(*args, **kwargs)
     exchange.getbundle2partsmapping['changegroup'] = wrappedcgfn
 
     # Extend changegroup receiver so client can fixup after widen requests.
     origcghandler = bundle2.parthandlermapping['changegroup']
     def wrappedcghandler(op, inpart):
         origcghandler(op, inpart)
         if util.safehasattr(op, '_widen_bundle'):
             handlechangegroup_widen(op, inpart)
     wrappedcghandler.params = origcghandler.params
     bundle2.parthandlermapping['changegroup'] = wrappedcghandler