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Differential D4076

changegroup: define functions for creating changegroup packers
ClosedPublic

Authored by indygreg on Aug 3 2018, 5:04 PM.

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rHG19344024a8e1: changegroup: define functions for creating changegroup packers
Summary

Currently, we have 3 classes for changegroup generation. Each class
handles a specific changegroup format. And each subsequent version's
class inherits from the previous one.

The interface for the classes is not very well defined and a lot of
version-specific behavior is behind overloaded functions. This
approach adds complexity and makes changegroup generation difficult
to reason about.

Upcoming commits will be consolidating these 3 classes so differences
between changegroup versions and changegroup generation are controlled
by parameters to a single constructor / type rather than by
overriding class attributes via inheritance.

We begin this process by building dedicated functions for creating
each changegroup packer instance. Currently they just call the
constructor on the appropriate class. This will soon change.

Diff Detail

Repository
rHG Mercurial
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Unit
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Event Timeline

indygreg created this revision.Aug 3 2018, 5:04 PM
Closed by commit rHG19344024a8e1: changegroup: define functions for creating changegroup packers (authored by indygreg). · Explain WhyAug 6 2018, 2:56 AM
This revision was automatically updated to reflect the committed changes.

Revision Contents
Changeset List

PathPackages
Mmercurial/changegroup.py (19 lines)

Diff 9952

mercurial/changegroup.py

def _manifestsdone(self): def _manifestsdone(self):
return self.close() return self.close()
def builddeltaheader(self, node, p1n, p2n, basenode, linknode, flags): def builddeltaheader(self, node, p1n, p2n, basenode, linknode, flags):
return struct.pack( return struct.pack(
self.deltaheader, node, p1n, p2n, basenode, linknode, flags) self.deltaheader, node, p1n, p2n, basenode, linknode, flags)
_packermap = {'01': (cg1packer, cg1unpacker), def _makecg1packer(repo, filematcher, bundlecaps):
return cg1packer(repo, filematcher, bundlecaps=bundlecaps)
def _makecg2packer(repo, filematcher, bundlecaps):
return cg2packer(repo, filematcher, bundlecaps=bundlecaps)
def _makecg3packer(repo, filematcher, bundlecaps):
return cg3packer(repo, filematcher, bundlecaps=bundlecaps)
_packermap = {'01': (_makecg1packer, cg1unpacker),
# cg2 adds support for exchanging generaldelta # cg2 adds support for exchanging generaldelta
'02': (cg2packer, cg2unpacker), '02': (_makecg2packer, cg2unpacker),
# cg3 adds support for exchanging revlog flags and treemanifests # cg3 adds support for exchanging revlog flags and treemanifests
'03': (cg3packer, cg3unpacker), '03': (_makecg3packer, cg3unpacker),
} }
def allsupportedversions(repo): def allsupportedversions(repo):
versions = set(_packermap.keys()) versions = set(_packermap.keys())
if not (repo.ui.configbool('experimental', 'changegroup3') or if not (repo.ui.configbool('experimental', 'changegroup3') or
repo.ui.configbool('experimental', 'treemanifest') or repo.ui.configbool('experimental', 'treemanifest') or
'treemanifest' in repo.requirements): 'treemanifest' in repo.requirements):
versions.discard('03') versions.discard('03')
raise error.ProgrammingError('version 01 changegroups do not support ' raise error.ProgrammingError('version 01 changegroups do not support '
'sparse file matchers') 'sparse file matchers')
# Requested files could include files not in the local store. So # Requested files could include files not in the local store. So
# filter those out. # filter those out.
filematcher = matchmod.intersectmatchers(repo.narrowmatch(), filematcher = matchmod.intersectmatchers(repo.narrowmatch(),
filematcher) filematcher)
return _packermap[version][0](repo, filematcher=filematcher, fn = _packermap[version][0]
bundlecaps=bundlecaps) return fn(repo, filematcher, bundlecaps)
def getunbundler(version, fh, alg, extras=None): def getunbundler(version, fh, alg, extras=None):
return _packermap[version][1](fh, alg, extras=extras) return _packermap[version][1](fh, alg, extras=extras)
def _changegroupinfo(repo, nodes, source): def _changegroupinfo(repo, nodes, source):
if repo.ui.verbose or source == 'bundle': if repo.ui.verbose or source == 'bundle':
repo.ui.status(_("%d changesets found\n") % len(nodes)) repo.ui.status(_("%d changesets found\n") % len(nodes))
if repo.ui.debugflag: if repo.ui.debugflag: