Mercurial > hg
view mercurial/filelog.py @ 42743:8c9a6adec67a
rust-discovery: using the children cache in add_missing
The DAG range computation often needs to get back to very old
revisions, and turns out to be disproportionately long, given
that the end goal is to remove the descendents of the given
missing revisons from the undecided set.
The fast iteration capabilities available in the Rust case make
it possible to avoid the DAG range entirely, at the cost of
precomputing the children cache, and to simply iterate on
children of the given missing revisions.
This is a case where staying on the same side of the interface
between the two languages has clear benefits.
On discoveries with initial undecided sets
small enough to bypass sampling entirely, the total cost of
computing the children cache and the subsequent iteration
becomes better than the Python + C counterpart, which relies on
reachableroots2.
For example, on a repo with more than one million revisions with
an initial undecided set of 11 elements, we get these figures:
Rust version with simple iteration
addcommons: 57.287us
first undecided computation: 184.278334ms
first children cache computation: 131.056us
addmissings iteration: 42.766us
first addinfo total: 185.24 ms
Python + C version
first addcommons: 0.29 ms
addcommons 0.21 ms
first undecided computation 191.35 ms
addmissings 45.75 ms
first addinfo total: 237.77 ms
On discoveries with large undecided sets, the initial price paid
makes the first addinfo slower than the Python + C version,
but that's more than compensated by the gain in sampling and
subsequent iterations.
Here's an extreme example with an undecided set of a million revisions:
Rust version:
first undecided computation: 293.842629ms
first children cache computation: 407.911297ms
addmissings iteration: 34.312869ms
first addinfo total: 776.02 ms
taking initial sample
query 2: sampling time: 1318.38 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings: 143.062us
Python + C version:
first undecided computation 298.13 ms
addmissings 80.13 ms
first addinfo total: 399.62 ms
taking initial sample
query 2: sampling time: 3957.23 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings 52.88 ms
Differential Revision: https://phab.mercurial-scm.org/D6428
author | Georges Racinet <georges.racinet@octobus.net> |
---|---|
date | Tue, 16 Apr 2019 01:16:39 +0200 |
parents | bf1e8d2ab900 |
children | 268662aac075 |
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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 .i18n import _ from .node import ( nullid, nullrev, ) from . import ( error, repository, revlog, ) from .utils import ( interfaceutil, storageutil, ) @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. # Used by LFS. self._revlog.filename = path def __len__(self): return len(self._revlog) def __iter__(self): return self._revlog.__iter__() def hasnode(self, node): if node in (nullid, nullrev): return False try: self._revlog.rev(node) return True except (TypeError, ValueError, IndexError, error.LookupError): return False 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 storageutil.fileidlookup(self._revlog, node, self._revlog.indexfile) def linkrev(self, rev): return self._revlog.linkrev(rev) def commonancestorsheads(self, node1, node2): return self._revlog.commonancestorsheads(node1, node2) # Used by dagop.blockdescendants(). def descendants(self, revs): return self._revlog.descendants(revs) def heads(self, start=None, stop=None): return self._revlog.heads(start, stop) # Used by hgweb, children extension. def children(self, node): return self._revlog.children(node) def iscensored(self, rev): return self._revlog.iscensored(rev) def revision(self, node, _df=None, raw=False): return self._revlog.revision(node, _df=_df, raw=raw) def rawdata(self, node, _df=None): return self._revlog.rawdata(node, _df=_df) def emitrevisions(self, nodes, nodesorder=None, revisiondata=False, assumehaveparentrevisions=False, deltamode=repository.CG_DELTAMODE_STD): return self._revlog.emitrevisions( nodes, nodesorder=nodesorder, revisiondata=revisiondata, assumehaveparentrevisions=assumehaveparentrevisions, deltamode=deltamode) 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, maybemissingparents=False): if maybemissingparents: raise error.Abort(_('revlog storage does not support missing ' 'parents write mode')) 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 censorrevision(self, tr, node, tombstone=b''): return self._revlog.censorrevision(tr, node, tombstone=tombstone) def files(self): return self._revlog.files() def read(self, node): return storageutil.filtermetadata(self.revision(node)) def add(self, text, meta, transaction, link, p1=None, p2=None): if meta or text.startswith('\1\n'): text = storageutil.packmeta(meta, text) return self.addrevision(text, transaction, link, p1, p2) def renamed(self, node): return storageutil.filerevisioncopied(self, node) 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. """ return not storageutil.filedataequivalent(self, node, text) def verifyintegrity(self, state): return self._revlog.verifyintegrity(state) def storageinfo(self, exclusivefiles=False, sharedfiles=False, revisionscount=False, trackedsize=False, storedsize=False): return self._revlog.storageinfo( exclusivefiles=exclusivefiles, sharedfiles=sharedfiles, revisionscount=revisionscount, trackedsize=trackedsize, storedsize=storedsize) # TODO these aren't part of the interface and aren't internal methods. # Callers should be fixed to not use them. # Used by bundlefilelog, unionfilelog. @property def indexfile(self): return self._revlog.indexfile @indexfile.setter def indexfile(self, value): self._revlog.indexfile = value # Used by repo upgrade. 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) class narrowfilelog(filelog): """Filelog variation to be used with narrow stores.""" def __init__(self, opener, path, narrowmatch): super(narrowfilelog, self).__init__(opener, path) self._narrowmatch = narrowmatch def renamed(self, node): res = super(narrowfilelog, self).renamed(node) # Renames that come from outside the narrowspec are problematic # because we may lack the base text for the rename. This can result # in code attempting to walk the ancestry or compute a diff # encountering a missing revision. We address this by silently # removing rename metadata if the source file is outside the # narrow spec. # # A better solution would be to see if the base revision is available, # rather than assuming it isn't. # # An even better solution would be to teach all consumers of rename # metadata that the base revision may not be available. # # TODO consider better ways of doing this. if res and not self._narrowmatch(res[0]): return None return res def size(self, rev): # Because we have a custom renamed() that may lie, we need to call # the base renamed() to report accurate results. node = self.node(rev) if super(narrowfilelog, self).renamed(node): return len(self.read(node)) else: return super(narrowfilelog, self).size(rev) def cmp(self, node, text): different = super(narrowfilelog, self).cmp(node, text) # Because renamed() may lie, we may get false positives for # different content. Check for this by comparing against the original # renamed() implementation. if different: if super(narrowfilelog, self).renamed(node): t2 = self.read(node) return t2 != text return different