From patchwork Sat Aug 18 09:27:24 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [09,of,12] revlogdeltas: extract _getcandidaterevs in a function From: Boris Feld X-Patchwork-Id: 33874 Message-Id: <8e08a733133d84db3587.1534584444@FB-lair> To: mercurial-devel@mercurial-scm.org Cc: gregory.szorc@gmail.com Date: Sat, 18 Aug 2018 11:27:24 +0200 # HG changeset patch # User Boris Feld # Date 1534570054 -7200 # Sat Aug 18 07:27:34 2018 +0200 # Node ID 8e08a733133d84db3587e2d780acbb654ade7371 # Parent 23aa0ae26db3a1f912e4f32ffb1f72758d4462f0 # EXP-Topic sparse-snapshot # Available At https://bitbucket.org/octobus/mercurial-devel/ # hg pull https://bitbucket.org/octobus/mercurial-devel/ -r 8e08a733133d revlogdeltas: extract _getcandidaterevs in a function The logic barely uses the object it is attached to. This is an important function that we will clean up in the coming changesets. Moving it at the top level helps us with that cleanup. diff --git a/mercurial/revlogutils/deltas.py b/mercurial/revlogutils/deltas.py --- a/mercurial/revlogutils/deltas.py +++ b/mercurial/revlogutils/deltas.py @@ -568,57 +568,57 @@ def isgooddeltainfo(revlog, deltainfo, r return True +def _candidate_groups(revlog, p1, p2, cachedelta): + """ + Provides revisions that present an interest to be diffed against, + grouped by level of easiness. + """ + gdelta = revlog._generaldelta + curr = len(revlog) + prev = curr - 1 + p1r, p2r = revlog.rev(p1), revlog.rev(p2) + + # should we try to build a delta? + if prev != nullrev and revlog.storedeltachains: + tested = set() + # This condition is true most of the time when processing + # changegroup data into a generaldelta repo. The only time it + # isn't true is if this is the first revision in a delta chain + # or if ``format.generaldelta=true`` disabled ``lazydeltabase``. + if cachedelta and gdelta and revlog._lazydeltabase: + # Assume what we received from the server is a good choice + # build delta will reuse the cache + yield (cachedelta[0],) + tested.add(cachedelta[0]) + + if gdelta: + # exclude already lazy tested base if any + parents = [p for p in (p1r, p2r) + if p != nullrev and p not in tested] + + if not revlog._deltabothparents and len(parents) == 2: + parents.sort() + # To minimize the chance of having to build a fulltext, + # pick first whichever parent is closest to us (max rev) + yield (parents[1],) + # then the other one (min rev) if the first did not fit + yield (parents[0],) + tested.update(parents) + elif len(parents) > 0: + # Test all parents (1 or 2), and keep the best candidate + yield parents + tested.update(parents) + + if prev not in tested: + # other approach failed try against prev to hopefully save us a + # fulltext. + yield (prev,) + tested.add(prev) + class deltacomputer(object): def __init__(self, revlog): self.revlog = revlog - def _getcandidaterevs(self, p1, p2, cachedelta): - """ - Provides revisions that present an interest to be diffed against, - grouped by level of easiness. - """ - revlog = self.revlog - gdelta = revlog._generaldelta - curr = len(revlog) - prev = curr - 1 - p1r, p2r = revlog.rev(p1), revlog.rev(p2) - - # should we try to build a delta? - if prev != nullrev and revlog.storedeltachains: - tested = set() - # This condition is true most of the time when processing - # changegroup data into a generaldelta repo. The only time it - # isn't true is if this is the first revision in a delta chain - # or if ``format.generaldelta=true`` disabled ``lazydeltabase``. - if cachedelta and gdelta and revlog._lazydeltabase: - # Assume what we received from the server is a good choice - # build delta will reuse the cache - yield (cachedelta[0],) - tested.add(cachedelta[0]) - - if gdelta: - # exclude already lazy tested base if any - parents = [p for p in (p1r, p2r) - if p != nullrev and p not in tested] - - if not revlog._deltabothparents and len(parents) == 2: - parents.sort() - # To minimize the chance of having to build a fulltext, - # pick first whichever parent is closest to us (max rev) - yield (parents[1],) - # then the other one (min rev) if the first did not fit - yield (parents[0],) - tested.update(parents) - elif len(parents) > 0: - # Test all parents (1 or 2), and keep the best candidate - yield parents - tested.update(parents) - - if prev not in tested: - # other approach failed try against prev to hopefully save us a - # fulltext. - yield (prev,) - tested.add(prev) def buildtext(self, revinfo, fh): """Builds a fulltext version of a revision @@ -712,7 +712,7 @@ class deltacomputer(object): depending on whether it is inlined or not Returns the first acceptable candidate revision, as ordered by - _getcandidaterevs + _candidate_groups If no suitable deltabase is found, we return delta info for a full snapshot. @@ -736,7 +736,8 @@ class deltacomputer(object): deltainfo = None deltas_limit = revinfo.textlen * LIMIT_DELTA2TEXT - for candidaterevs in self._getcandidaterevs(p1, p2, cachedelta): + candidate_groups = _candidate_groups(self.revlog, p1, p2, cachedelta) + for candidaterevs in candidate_groups: # filter out delta base that will never produce good delta candidaterevs = [r for r in candidaterevs if self.revlog.length(r) <= deltas_limit]