Mercurial > hg
view tests/test-remotefilelog-bundle2.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 | 0800d9e6e216 |
children | 68b7faeb6ef3 |
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#require no-windows $ . "$TESTDIR/remotefilelog-library.sh" $ hg init master $ grep generaldelta master/.hg/requires generaldelta $ cd master preferuncompressed = False so that we can make both generaldelta and non-generaldelta clones $ cat >> .hg/hgrc <<EOF > [remotefilelog] > server=True > [experimental] > bundle2-exp = True > [server] > preferuncompressed = False > EOF $ echo x > x $ hg commit -qAm x $ cd .. $ hgcloneshallow ssh://user@dummy/master shallow-generaldelta -q --pull --config experimental.bundle2-exp=True 1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob) $ grep generaldelta shallow-generaldelta/.hg/requires generaldelta $ hgcloneshallow ssh://user@dummy/master shallow-plain -q --pull --config format.usegeneraldelta=False --config format.generaldelta=False --config experimental.bundle2-exp=True $ grep generaldelta shallow-plain/.hg/requires [1] $ cd master $ echo a > a $ hg commit -qAm a pull from generaldelta to generaldelta $ cd ../shallow-generaldelta $ hg pull -u pulling from ssh://user@dummy/master searching for changes adding changesets adding manifests adding file changes added 1 changesets with 0 changes to 0 files new changesets 2fbb8bb2b903 1 files updated, 0 files merged, 0 files removed, 0 files unresolved 1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob) push from generaldelta to generaldelta $ echo b > b $ hg commit -qAm b $ hg push pushing to ssh://user@dummy/master searching for changes remote: adding changesets remote: adding manifests remote: adding file changes remote: added 1 changesets with 1 changes to 1 files pull from generaldelta to non-generaldelta $ cd ../shallow-plain $ hg pull -u pulling from ssh://user@dummy/master searching for changes adding changesets adding manifests adding file changes added 2 changesets with 0 changes to 0 files new changesets 2fbb8bb2b903:d6788bd632ca 2 files updated, 0 files merged, 0 files removed, 0 files unresolved 1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob) push from non-generaldelta to generaldelta $ echo c > c $ hg commit -qAm c $ hg push pushing to ssh://user@dummy/master searching for changes remote: adding changesets remote: adding manifests remote: adding file changes remote: added 1 changesets with 1 changes to 1 files