Mercurial > hg
view contrib/hg-ssh @ 47120:7109a38830c9
dirstate-tree: Fold "tracked descendants" counter update in main walk
For the purpose of implementing `has_tracked_dir` (which means "has tracked
descendants) without an expensive sub-tree traversal, we maintaing a counter
of tracked descendants on each "directory" node of the tree-shaped dirstate.
Before this changeset, mutating or inserting a node at a given path would
involve:
* Walking the tree from root through ancestors to find the node or the spot
where to insert it
* Looking at the previous node if any to decide what counter update is needed
* Performing any node mutation
* Walking the tree *again* to update counters in ancestor nodes
When profiling `hg status` on a large repo, this second walk takes times
while loading a the dirstate from disk.
It turns out we have enough information to decide before he first tree walk
what counter update is needed. This changeset merges the two walks, gaining
~10% of the total time for `hg update` (in the same hyperfine benchmark as
the previous changeset).
---
Profiling was done by compiling with this `.cargo/config`:
[profile.release]
debug = true
then running with:
py-spy record -r 500 -n -o /tmp/hg.json --format speedscope -- \
./hg status -R $REPO --config experimental.dirstate-tree.in-memory=1
then visualizing the recorded JSON file in https://www.speedscope.app/
Differential Revision: https://phab.mercurial-scm.org/D10554
author | Simon Sapin <simon.sapin@octobus.net> |
---|---|
date | Fri, 30 Apr 2021 14:22:14 +0200 |
parents | c102b704edb5 |
children | 724066f23e2d |
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#!/usr/bin/env python3 # # 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()