Mercurial > hg
view tests/test-convert-tagsbranch-topology.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 | 86fe3c404c1e |
children |
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#require git $ echo "[core]" >> $HOME/.gitconfig $ echo "autocrlf = false" >> $HOME/.gitconfig $ echo "[core]" >> $HOME/.gitconfig $ echo "autocrlf = false" >> $HOME/.gitconfig $ cat <<EOF >> $HGRCPATH > [extensions] > convert = > [convert] > hg.usebranchnames = True > hg.tagsbranch = tags-update > EOF $ GIT_AUTHOR_NAME='test'; export GIT_AUTHOR_NAME $ GIT_AUTHOR_EMAIL='test@example.org'; export GIT_AUTHOR_EMAIL $ GIT_AUTHOR_DATE="2007-01-01 00:00:00 +0000"; export GIT_AUTHOR_DATE $ GIT_COMMITTER_NAME="$GIT_AUTHOR_NAME"; export GIT_COMMITTER_NAME $ GIT_COMMITTER_EMAIL="$GIT_AUTHOR_EMAIL"; export GIT_COMMITTER_EMAIL $ GIT_COMMITTER_DATE="$GIT_AUTHOR_DATE"; export GIT_COMMITTER_DATE $ count=10 $ action() > { > GIT_AUTHOR_DATE="2007-01-01 00:00:$count +0000" > GIT_COMMITTER_DATE="$GIT_AUTHOR_DATE" > git "$@" >/dev/null 2>/dev/null || echo "git command error" > count=`expr $count + 1` > } $ glog() > { > hg log -G --template '{rev} "{desc|firstline}" files: {files}\n' "$@" > } $ convertrepo() > { > hg convert --datesort git-repo hg-repo > } Build a GIT repo with at least 1 tag $ mkdir git-repo $ cd git-repo $ git init >/dev/null 2>&1 $ echo a > a $ git add a $ action commit -m "rev1" $ action tag -m "tag1" tag1 $ cd .. Convert without tags $ hg convert git-repo hg-repo --config convert.skiptags=True initializing destination hg-repo repository scanning source... sorting... converting... 0 rev1 updating bookmarks $ hg -R hg-repo tags tip 0:d98c8ad3a4cf $ rm -rf hg-repo Do a first conversion $ convertrepo initializing destination hg-repo repository scanning source... sorting... converting... 0 rev1 updating tags updating bookmarks Simulate upstream updates after first conversion $ cd git-repo $ echo b > a $ git add a $ action commit -m "rev2" $ action tag -m "tag2" tag2 $ cd .. Perform an incremental conversion $ convertrepo scanning source... sorting... converting... 0 rev2 updating tags updating bookmarks Print the log $ cd hg-repo $ glog o 3 "update tags" files: .hgtags | | o 2 "rev2" files: a | | o | 1 "update tags" files: .hgtags / o 0 "rev1" files: a $ cd ..