Mercurial > hg-stable
view contrib/hgperf @ 47346:f27f2afb15da
dirstate-tree: Skip readdir() in `hg status -mard`
When running the status algorithm in a mode where we don’t list unknown
or ignored files, all we care about are files that are listed in the dirstate.
We can there for skip making expensive calls to readdir() to list the contents
of filesystem directories, and instead only run stat() to get the filesystem
state of files listed in the dirstate. (This state may be an error for files
that don’t exist anymore on the filesystem.)
On 16 CPU threads, this reduces the time spent in the `status()` function for
`hg status -mard` on an old snapshot of mozilla-central from ~70ms to ~50ms.
Differential Revision: https://phab.mercurial-scm.org/D10752
author | Simon Sapin <simon.sapin@octobus.net> |
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date | Wed, 19 May 2021 16:18:16 +0200 |
parents | d4ba4d51f85f |
children |
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#!/usr/bin/env python3 # # hgperf - measure performance of Mercurial commands # # Copyright 2014 Olivia Mackall <olivia@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. '''measure performance of Mercurial commands Using ``hgperf`` instead of ``hg`` measures performance of the target Mercurial command. For example, the execution below measures performance of :hg:`heads --topo`:: $ hgperf heads --topo All command output via ``ui`` is suppressed, and just measurement result is displayed: see also "perf" extension in "contrib". Costs of processing before dispatching to the command function like below are not measured:: - parsing command line (e.g. option validity check) - reading configuration files in But ``pre-`` and ``post-`` hook invocation for the target command is measured, even though these are invoked before or after dispatching to the command function, because these may be required to repeat execution of the target command correctly. ''' import os import sys 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) # enable importing on demand to reduce startup time try: from mercurial import demandimport demandimport.enable() except ImportError: import sys 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, util, ) def timer(func, title=None): results = [] begin = util.timer() count = 0 while True: ostart = os.times() cstart = util.timer() r = func() cstop = util.timer() ostop = os.times() count += 1 a, b = ostart, ostop results.append((cstop - cstart, b[0] - a[0], b[1] - a[1])) if cstop - begin > 3 and count >= 100: break if cstop - begin > 10 and count >= 3: break if title: sys.stderr.write("! %s\n" % title) if r: sys.stderr.write("! result: %s\n" % r) m = min(results) sys.stderr.write( "! wall %f comb %f user %f sys %f (best of %d)\n" % (m[0], m[1] + m[2], m[1], m[2], count) ) orgruncommand = dispatch.runcommand def runcommand(lui, repo, cmd, fullargs, ui, options, d, cmdpats, cmdoptions): ui.pushbuffer() lui.pushbuffer() timer( lambda: orgruncommand( lui, repo, cmd, fullargs, ui, options, d, cmdpats, cmdoptions ) ) ui.popbuffer() lui.popbuffer() dispatch.runcommand = runcommand dispatch.run()