Mercurial > hg
view hgext/narrow/narrowdirstate.py @ 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 | 687b865b95ad |
children | f927ad5a4e2c |
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# narrowdirstate.py - extensions to mercurial dirstate to support narrow clones # # Copyright 2017 Google, Inc. # # 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 mercurial.i18n import _ from mercurial import error def wrapdirstate(repo, dirstate): """Add narrow spec dirstate ignore, block changes outside narrow spec.""" def _editfunc(fn): def _wrapper(self, *args, **kwargs): narrowmatch = repo.narrowmatch() for f in args: if f is not None and not narrowmatch(f) and f not in self: raise error.Abort( _( b"cannot track '%s' - it is outside " + b"the narrow clone" ) % f ) return fn(self, *args, **kwargs) return _wrapper class narrowdirstate(dirstate.__class__): # Prevent adding/editing/copying/deleting files that are outside the # sparse checkout @_editfunc def normal(self, *args, **kwargs): return super(narrowdirstate, self).normal(*args, **kwargs) @_editfunc def add(self, *args): return super(narrowdirstate, self).add(*args) @_editfunc def normallookup(self, *args): return super(narrowdirstate, self).normallookup(*args) @_editfunc def copy(self, *args): return super(narrowdirstate, self).copy(*args) @_editfunc def remove(self, *args): return super(narrowdirstate, self).remove(*args) @_editfunc def merge(self, *args): return super(narrowdirstate, self).merge(*args) def rebuild(self, parent, allfiles, changedfiles=None): if changedfiles is None: # Rebuilding entire dirstate, let's filter allfiles to match the # narrowspec. allfiles = [f for f in allfiles if repo.narrowmatch()(f)] super(narrowdirstate, self).rebuild(parent, allfiles, changedfiles) dirstate.__class__ = narrowdirstate return dirstate