Mercurial > hg
view tests/test-remotefilelog-log.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 | cc3ad5c3af3b |
children | 40b51c28b242 |
line wrap: on
line source
#require no-windows $ . "$TESTDIR/remotefilelog-library.sh" $ hg init master $ cd master $ cat >> .hg/hgrc <<EOF > [remotefilelog] > server=True > EOF $ echo x > x $ hg commit -qAm x $ mkdir dir $ echo y > dir/y $ hg commit -qAm y $ cd .. Shallow clone from full $ hgcloneshallow ssh://user@dummy/master shallow --noupdate streaming all changes 2 files to transfer, 473 bytes of data transferred 473 bytes in * seconds (*/sec) (glob) searching for changes no changes found $ cd shallow $ cat .hg/requires dotencode exp-remotefilelog-repo-req-1 fncache generaldelta persistent-nodemap (rust !) revlog-compression-zstd (zstd !) revlogv1 sparserevlog store $ hg update 2 files updated, 0 files merged, 0 files removed, 0 files unresolved 2 files fetched over 1 fetches - (2 misses, 0.00% hit ratio) over *s (glob) Log on a file without -f $ hg log dir/y warning: file log can be slow on large repos - use -f to speed it up changeset: 1:2e73264fab97 tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: y Log on a file with -f $ hg log -f dir/y changeset: 1:2e73264fab97 tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: y Log on a file with kind in path $ hg log -r "filelog('path:dir/y')" changeset: 1:2e73264fab97 tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: y Log on multiple files with -f $ hg log -f dir/y x changeset: 1:2e73264fab97 tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: y changeset: 0:b292c1e3311f user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: x Log on a directory $ hg log dir changeset: 1:2e73264fab97 tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: y Log on a file from inside a directory $ cd dir $ hg log y warning: file log can be slow on large repos - use -f to speed it up changeset: 1:2e73264fab97 tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: y Log on a file via -fr $ cd .. $ hg log -fr tip dir/ --template '{rev}\n' 1 Trace renames $ hg mv x z $ hg commit -m move $ hg log -f z -T '{desc} {file_copies}\n' -G @ move z (x) : o x Verify remotefilelog handles rename metadata stripping when comparing file sizes $ hg debugrebuilddirstate $ hg status