Mercurial > hg
view mercurial/filelog.py @ 39017:ef3d3a2f9aa5
changegroup: refactor delta parent code
We had recently abstracted the delta parent functions to
facilitate extracting code from cgpacker. Now that we're in
a better place, it is time to revisit the design.
Changegroup version 1 requires that the previous node be used as the
delta parent. Later versions allow any available node to be used
as the base.
In the case where an arbitrary parent can be used, the choice of
a delta parent is best left in the hands of the storage backend.
So it makes sense for the delta parent selection to be hidden
away in the storage layer. This means deferring the choice of the
delta parent selection function to as close to delta generation
time as possible.
This commit moves the delta selection logic to essentially just
before delta generation. However, because changegroup version 1
limits what we can do, we have retained the ability to force a
delta against the previous revision.
As part of this, I realized that the ellipsis parent function was
unused! That's because ellipsis mode always sends full revisions
and not deltas.
Differential Revision: https://phab.mercurial-scm.org/D4214
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Wed, 08 Aug 2018 20:17:48 -0700 |
parents | 93777d16a25d |
children | b41d023a412a |
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# filelog.py - file history class for mercurial # # Copyright 2005-2007 Matt Mackall <mpm@selenic.com> # # 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 from . import ( error, repository, revlog, ) from .utils import ( interfaceutil, ) @interfaceutil.implementer(repository.ifilestorage) class filelog(object): def __init__(self, opener, path): self._revlog = revlog.revlog(opener, '/'.join(('data', path + '.i')), censorable=True) # full name of the user visible file, relative to the repository root self.filename = path self.index = self._revlog.index self.version = self._revlog.version self.storedeltachains = self._revlog.storedeltachains self._generaldelta = self._revlog._generaldelta def __len__(self): return len(self._revlog) def __iter__(self): return self._revlog.__iter__() def revs(self, start=0, stop=None): return self._revlog.revs(start=start, stop=stop) def parents(self, node): return self._revlog.parents(node) def parentrevs(self, rev): return self._revlog.parentrevs(rev) def rev(self, node): return self._revlog.rev(node) def node(self, rev): return self._revlog.node(rev) def lookup(self, node): return self._revlog.lookup(node) def linkrev(self, rev): return self._revlog.linkrev(rev) def flags(self, rev): return self._revlog.flags(rev) def commonancestorsheads(self, node1, node2): return self._revlog.commonancestorsheads(node1, node2) def descendants(self, revs): return self._revlog.descendants(revs) def headrevs(self): return self._revlog.headrevs() def heads(self, start=None, stop=None): return self._revlog.heads(start, stop) def children(self, node): return self._revlog.children(node) def deltaparent(self, rev): return self._revlog.deltaparent(rev) def candelta(self, baserev, rev): return self._revlog.candelta(baserev, rev) def iscensored(self, rev): return self._revlog.iscensored(rev) def rawsize(self, rev): return self._revlog.rawsize(rev) def checkhash(self, text, node, p1=None, p2=None, rev=None): return self._revlog.checkhash(text, node, p1=p1, p2=p2, rev=rev) def revision(self, node, _df=None, raw=False): return self._revlog.revision(node, _df=_df, raw=raw) def revdiff(self, rev1, rev2): return self._revlog.revdiff(rev1, rev2) def addrevision(self, revisiondata, transaction, linkrev, p1, p2, node=None, flags=revlog.REVIDX_DEFAULT_FLAGS, cachedelta=None): return self._revlog.addrevision(revisiondata, transaction, linkrev, p1, p2, node=node, flags=flags, cachedelta=cachedelta) def addgroup(self, deltas, linkmapper, transaction, addrevisioncb=None): return self._revlog.addgroup(deltas, linkmapper, transaction, addrevisioncb=addrevisioncb) def getstrippoint(self, minlink): return self._revlog.getstrippoint(minlink) def strip(self, minlink, transaction): return self._revlog.strip(minlink, transaction) def files(self): return self._revlog.files() def checksize(self): return self._revlog.checksize() def read(self, node): t = self.revision(node) if not t.startswith('\1\n'): return t s = t.index('\1\n', 2) return t[s + 2:] def add(self, text, meta, transaction, link, p1=None, p2=None): if meta or text.startswith('\1\n'): text = revlog.packmeta(meta, text) return self.addrevision(text, transaction, link, p1, p2) def renamed(self, node): if self.parents(node)[0] != revlog.nullid: return False t = self.revision(node) m = revlog.parsemeta(t)[0] # copy and copyrev occur in pairs. In rare cases due to bugs, # one can occur without the other. if m and "copy" in m and "copyrev" in m: return (m["copy"], revlog.bin(m["copyrev"])) return False def size(self, rev): """return the size of a given revision""" # for revisions with renames, we have to go the slow way node = self.node(rev) if self.renamed(node): return len(self.read(node)) if self.iscensored(rev): return 0 # XXX if self.read(node).startswith("\1\n"), this returns (size+4) return self._revlog.size(rev) def cmp(self, node, text): """compare text with a given file revision returns True if text is different than what is stored. """ t = text if text.startswith('\1\n'): t = '\1\n\1\n' + text samehashes = not self._revlog.cmp(node, t) if samehashes: return False # censored files compare against the empty file if self.iscensored(self.rev(node)): return text != '' # renaming a file produces a different hash, even if the data # remains unchanged. Check if it's the case (slow): if self.renamed(node): t2 = self.read(node) return t2 != text return True @property def filename(self): return self._revlog.filename @filename.setter def filename(self, value): self._revlog.filename = value # TODO these aren't part of the interface and aren't internal methods. # Callers should be fixed to not use them. @property def indexfile(self): return self._revlog.indexfile @indexfile.setter def indexfile(self, value): self._revlog.indexfile = value @property def datafile(self): return self._revlog.datafile @property def opener(self): return self._revlog.opener @property def _lazydeltabase(self): return self._revlog._lazydeltabase @_lazydeltabase.setter def _lazydeltabase(self, value): self._revlog._lazydeltabase = value @property def _deltabothparents(self): return self._revlog._deltabothparents @_deltabothparents.setter def _deltabothparents(self, value): self._revlog._deltabothparents = value @property def _inline(self): return self._revlog._inline @property def _withsparseread(self): return getattr(self._revlog, '_withsparseread', False) @property def _srmingapsize(self): return self._revlog._srmingapsize @property def _srdensitythreshold(self): return self._revlog._srdensitythreshold def _deltachain(self, rev, stoprev=None): return self._revlog._deltachain(rev, stoprev) def chainbase(self, rev): return self._revlog.chainbase(rev) def chainlen(self, rev): return self._revlog.chainlen(rev) def clone(self, tr, destrevlog, **kwargs): if not isinstance(destrevlog, filelog): raise error.ProgrammingError('expected filelog to clone()') return self._revlog.clone(tr, destrevlog._revlog, **kwargs) def start(self, rev): return self._revlog.start(rev) def end(self, rev): return self._revlog.end(rev) def length(self, rev): return self._revlog.length(rev) def compress(self, data): return self._revlog.compress(data) def _addrevision(self, *args, **kwargs): return self._revlog._addrevision(*args, **kwargs)