Mercurial > hg
view hg @ 42237:9f45d3d526f9
hgtagsfnodescache: inherit fnode from parent when possible
If a changeset does not update the content of `.hgtags`, it means it will use
the same file-node (for `.hgtags`) as its parents. In this case we can
directly reuse the parent's file-node.
We use this property when updating the `hgtagsfnodescache` taking a faster path
if we already have a cached value for the parents of the node we are looking
at.
Doing so provides a large performance boost when looking at a lot of fnodes,
especially on repository with very large manifest:
timing for `tagsmod.fnoderevs(ui, repo, repo.changelog.revs())`
mercurial: (41907 revisions, 1923 files)
before: 6.9 seconds
after: 2.7 seconds (-54%)
pypy: (96266 revisions, 5198 files)
before: 80 seconds
after: 20 seconds (-75%)
mozilla-central: (463411 revisions, 272080 files)
before: 7166.4 seconds
after: 47.8 seconds (-99%, x150 speedup)
On a copy of mozilla-try with about 35K heads ans 1.7M changesets, this moves
the computation from many hours to a couple of minutes, making it more
interesting to do a full warm up of this cache before computing tags (from a
cold cache).
There seems to be other performance low hanging fruits, like avoiding the use of
changectx or a more revision centric logic. However, the new code is fast enough
for my needs right now.
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
---|---|
date | Mon, 11 Mar 2019 01:10:20 +0100 |
parents | 5e78c100a215 |
children | 5c9c71cde1c9 |
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#!/usr/bin/env python # # mercurial - scalable distributed SCM # # 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 import os import sys if os.environ.get('HGUNICODEPEDANTRY', False): try: reload(sys) sys.setdefaultencoding("undefined") except NameError: pass libdir = '@LIBDIR@' if libdir != '@' 'LIBDIR' '@': if not os.path.isabs(libdir): libdir = os.path.join(os.path.dirname(os.path.realpath(__file__)), libdir) libdir = os.path.abspath(libdir) sys.path.insert(0, libdir) from hgdemandimport import tracing with tracing.log('hg script'): # enable importing on demand to reduce startup time try: if sys.version_info[0] < 3 or sys.version_info >= (3, 6): import hgdemandimport; hgdemandimport.enable() except ImportError: sys.stderr.write("abort: couldn't find mercurial libraries in [%s]\n" % ' '.join(sys.path)) sys.stderr.write("(check your install and PYTHONPATH)\n") sys.exit(-1) from mercurial import dispatch dispatch.run()