Mercurial > hg
view tests/test-mactext.t @ 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 $REPO --config experimental.dirstate-tree.in-memory=1
then visualizing the recorded JSON file in https://www.speedscope.app/
Differential Revision: https://phab.mercurial-scm.org/D10554
author | Simon Sapin <simon.sapin@octobus.net> |
---|---|
date | Fri, 30 Apr 2021 14:22:14 +0200 |
parents | 768056549737 |
children |
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$ cat > unix2mac.py <<EOF > import sys > > for path in sys.argv[1:]: > data = open(path, 'rb').read() > data = data.replace(b'\n', b'\r') > open(path, 'wb').write(data) > EOF $ hg init $ echo '[hooks]' >> .hg/hgrc $ echo 'pretxncommit.cr = python:hgext.win32text.forbidcr' >> .hg/hgrc $ echo 'pretxnchangegroup.cr = python:hgext.win32text.forbidcr' >> .hg/hgrc $ cat .hg/hgrc [hooks] pretxncommit.cr = python:hgext.win32text.forbidcr pretxnchangegroup.cr = python:hgext.win32text.forbidcr $ echo hello > f $ hg add f $ hg ci -m 1 $ "$PYTHON" unix2mac.py f $ hg ci -m 2 attempt to commit or push text file(s) using CR line endings in dea860dc51ec: f transaction abort! rollback completed abort: pretxncommit.cr hook failed [40] $ hg cat f | f --hexdump 0000: 68 65 6c 6c 6f 0a |hello.| $ f --hexdump f f: 0000: 68 65 6c 6c 6f 0d |hello.|