Mercurial > hg
view .hgignore @ 47116:04bcba539c96
dirstate-tree: Avoid BTreeMap double-lookup when inserting a dirstate entry
The child nodes of a given node in the tree-shaped dirstate are kept in a
`BTreeMap` where keys are file names as strings. Finding or inserting a value
in the map takes `O(log(n))` string comparisons, which adds up when constructing
the tree.
The `entry` API allows finding a "spot" in the map that may or may not be
occupied and then access that value or insert a new one without doing map
lookup again. However the current API is limited in that calling `entry`
requires an owned key (and so a memory allocation), even if it ends up not
being used in the case where the map already has a value with an equal key.
This is still a win, with 4% better end-to-end time for `hg status` measured
here with hyperfine:
```
Benchmark #1: ../hg2/hg status -R $REPO --config=experimental.dirstate-tree.in-memory=1
Time (mean ± σ): 1.337 s ± 0.018 s [User: 892.9 ms, System: 437.5 ms]
Range (min … max): 1.316 s … 1.373 s 10 runs
Benchmark #2: ./hg status -R $REPO --config=experimental.dirstate-tree.in-memory=1
Time (mean ± σ): 1.291 s ± 0.008 s [User: 853.4 ms, System: 431.1 ms]
Range (min … max): 1.283 s … 1.309 s 10 runs
Summary
'./hg status -R $REPO --config=experimental.dirstate-tree.in-memory=1' ran
1.04 ± 0.02 times faster than '../hg2/hg status -R $REPO --config=experimental.dirstate-tree.in-memory=1'
```
* ./hg is this revision
* ../hg2/hg is its parent
* $REPO is an old snapshot of mozilla-central
Differential Revision: https://phab.mercurial-scm.org/D10550
author | Simon Sapin <simon.sapin@octobus.net> |
---|---|
date | Tue, 27 Apr 2021 12:42:21 +0200 |
parents | 3e23794b9e1c |
children | e8138eba17ee |
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syntax: glob *.elc *.tmp *.orig *.rej *~ *.mergebackup *.o *.so *.dll *.exe *.pyd *.pyc *.pyo *$py.class *.swp *.prof *.zip \#*\# .\#* tests/artifacts/cache/big-file-churn.hg tests/.coverage* tests/.testtimes* tests/.hypothesis tests/hypothesis-generated tests/annotated tests/exceptions tests/python3 tests/*.err tests/htmlcov build contrib/chg/chg contrib/hgsh/hgsh contrib/vagrant/.vagrant dist packages doc/common.txt doc/*.[0-9] doc/*.[0-9].txt doc/*.[0-9].gendoc.txt doc/*.[0-9].{x,ht}ml MANIFEST MANIFEST.in patches mercurial/__modulepolicy__.py mercurial/__version__.py mercurial/hgpythonlib.h mercurial.egg-info .DS_Store tags cscope.* .vscode/* .idea/* .asv/* .pytype/* .mypy_cache i18n/hg.pot locale/*/LC_MESSAGES/hg.mo hgext/__index__.py rust/target/ rust/*/target/ # Generated wheels wheelhouse/ syntax: rootglob # See Profiling in rust/README.rst .cargo/config syntax: regexp ^\.pc/ ^\.(pydev)?project # hackable windows distribution additions ^hg-python ^hg.py$