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view contrib/hg-ssh @ 44363:f7459da77f23
nodemap: introduce an option to use mmap to read the nodemap mapping
The performance and memory benefit is much greater if we don't have to copy all
the data in memory for each information. So we introduce an option (on by
default) to read the data using mmap.
This changeset is the last one definition the API for index support nodemap
data. (they have to be able to use the mmaping).
Below are some benchmark comparing the best we currently have in 5.3 with the
final step of this series (using the persistent nodemap implementation in
Rust). The benchmark run `hg perfindex` with various revset and the following
variants:
Before:
* do not use the persistent nodemap
* use the CPython implementation of the index for nodemap
* use mmapping of the changelog index
After:
* use the MixedIndex Rust code, with the NodeTree object for nodemap access
(still in review)
* use the persistent nodemap data from disk
* access the persistent nodemap data through mmap
* use mmapping of the changelog index
The persistent nodemap greatly speed up most operation on very large
repositories. Some of the previously very fast lookup end up a bit slower because
the persistent nodemap has to be setup. However the absolute slowdown is very
small and won't matters in the big picture.
Here are some numbers (in seconds) for the reference copy of mozilla-try:
Revset Before After abs-change speedup
-10000: 0.004622 0.005532 0.000910 × 0.83
-10: 0.000050 0.000132 0.000082 × 0.37
tip 0.000052 0.000085 0.000033 × 0.61
0 + (-10000:) 0.028222 0.005337 -0.022885 × 5.29
0 0.023521 0.000084 -0.023437 × 280.01
(-10000:) + 0 0.235539 0.005308 -0.230231 × 44.37
(-10:) + :9 0.232883 0.000180 -0.232703 ×1293.79
(-10000:) + (:99) 0.238735 0.005358 -0.233377 × 44.55
:99 + (-10000:) 0.317942 0.005593 -0.312349 × 56.84
:9 + (-10:) 0.313372 0.000179 -0.313193 ×1750.68
:9 0.316450 0.000143 -0.316307 ×2212.93
On smaller repositories, the cost of nodemap related operation is not as big, so
the win is much more modest. Yet it helps shaving a handful of millisecond here
and there.
Here are some numbers (in seconds) for the reference copy of mercurial:
Revset Before After abs-change speedup
-10: 0.000065 0.000097 0.000032 × 0.67
tip 0.000063 0.000078 0.000015 × 0.80
0 0.000561 0.000079 -0.000482 × 7.10
-10000: 0.004609 0.003648 -0.000961 × 1.26
0 + (-10000:) 0.005023 0.003715 -0.001307 × 1.35
(-10:) + :9 0.002187 0.000108 -0.002079 ×20.25
(-10000:) + 0 0.006252 0.003716 -0.002536 × 1.68
(-10000:) + (:99) 0.006367 0.003707 -0.002660 × 1.71
:9 + (-10:) 0.003846 0.000110 -0.003736 ×34.96
:9 0.003854 0.000099 -0.003755 ×38.92
:99 + (-10000:) 0.007644 0.003778 -0.003866 × 2.02
Differential Revision: https://phab.mercurial-scm.org/D7894
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
---|---|
date | Tue, 11 Feb 2020 11:18:52 +0100 |
parents | 99e231afc29c |
children | c102b704edb5 |
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#!/usr/bin/env python # # Copyright 2005-2007 by Intevation GmbH <intevation@intevation.de> # # Author(s): # Thomas Arendsen Hein <thomas@intevation.de> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. """ hg-ssh - a wrapper for ssh access to a limited set of mercurial repos To be used in ~/.ssh/authorized_keys with the "command" option, see sshd(8): command="hg-ssh path/to/repo1 /path/to/repo2 ~/repo3 ~user/repo4" ssh-dss ... (probably together with these other useful options: no-port-forwarding,no-X11-forwarding,no-agent-forwarding) This allows pull/push over ssh from/to the repositories given as arguments. If all your repositories are subdirectories of a common directory, you can allow shorter paths with: command="cd path/to/my/repositories && hg-ssh repo1 subdir/repo2" You can use pattern matching of your normal shell, e.g.: command="cd repos && hg-ssh user/thomas/* projects/{mercurial,foo}" You can also add a --read-only flag to allow read-only access to a key, e.g.: command="hg-ssh --read-only repos/*" """ from __future__ import absolute_import import os import shlex import sys # enable importing on demand to reduce startup time import hgdemandimport hgdemandimport.enable() from mercurial import ( dispatch, pycompat, ui as uimod, ) def main(): # Prevent insertion/deletion of CRs dispatch.initstdio() cwd = os.getcwd() readonly = False args = sys.argv[1:] while len(args): if args[0] == '--read-only': readonly = True args.pop(0) else: break allowed_paths = [ os.path.normpath(os.path.join(cwd, os.path.expanduser(path))) for path in args ] orig_cmd = os.getenv('SSH_ORIGINAL_COMMAND', '?') try: cmdargv = shlex.split(orig_cmd) except ValueError as e: sys.stderr.write('Illegal command "%s": %s\n' % (orig_cmd, e)) sys.exit(255) if cmdargv[:2] == ['hg', '-R'] and cmdargv[3:] == ['serve', '--stdio']: path = cmdargv[2] repo = os.path.normpath(os.path.join(cwd, os.path.expanduser(path))) if repo in allowed_paths: cmd = [b'-R', pycompat.fsencode(repo), b'serve', b'--stdio'] req = dispatch.request(cmd) if readonly: if not req.ui: req.ui = uimod.ui.load() req.ui.setconfig( b'hooks', b'pretxnopen.hg-ssh', b'python:__main__.rejectpush', b'hg-ssh', ) req.ui.setconfig( b'hooks', b'prepushkey.hg-ssh', b'python:__main__.rejectpush', b'hg-ssh', ) dispatch.dispatch(req) else: sys.stderr.write('Illegal repository "%s"\n' % repo) sys.exit(255) else: sys.stderr.write('Illegal command "%s"\n' % orig_cmd) sys.exit(255) def rejectpush(ui, **kwargs): ui.warn((b"Permission denied\n")) # mercurial hooks use unix process conventions for hook return values # so a truthy return means failure return True if __name__ == '__main__': main()