Mercurial > hg
view tests/test-revlog.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 $REPO --config experimental.dirstate-tree.in-memory=1
then visualizing the recorded JSON file in https://www.speedscope.app/
Differential Revision: https://phab.mercurial-scm.org/D10554
author | Simon Sapin <simon.sapin@octobus.net> |
---|---|
date | Fri, 30 Apr 2021 14:22:14 +0200 |
parents | 4c041c71ec01 |
children | 8d3c2f9d4af7 |
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$ hg init empty-repo $ cd empty-repo Flags on revlog version 0 are rejected >>> with open('.hg/store/00changelog.i', 'wb') as fh: ... fh.write(b'\x00\x01\x00\x00') and None $ hg log abort: unknown flags (0x01) in version 0 revlog 00changelog.i [50] Unknown flags on revlog version 1 are rejected >>> with open('.hg/store/00changelog.i', 'wb') as fh: ... fh.write(b'\x00\x04\x00\x01') and None $ hg log abort: unknown flags (0x04) in version 1 revlog 00changelog.i [50] Unknown version is rejected >>> with open('.hg/store/00changelog.i', 'wb') as fh: ... fh.write(b'\x00\x00\xbe\xef') and None $ hg log abort: unknown version (48879) in revlog 00changelog.i [50] $ cd .. Test for CVE-2016-3630 $ hg init >>> import codecs >>> open("a.i", "wb").write(codecs.decode(codecs.decode( ... b"""eJxjYGZgZIAAYQYGxhgom+k/FMx8YKx9ZUaKSOyqo4cnuKb8mbqHV5cBCVTMWb1Cwqkhe4Gsg9AD ... Joa3dYtcYYYBAQ8Qr4OqZAYRICPTSr5WKd/42rV36d+8/VmrNpv7NP1jQAXrQE4BqQUARngwVA==""", ... "base64"), "zlib")) and None $ hg debugrevlogindex a.i rev linkrev nodeid p1 p2 0 2 99e0332bd498 000000000000 000000000000 1 3 6674f57a23d8 99e0332bd498 000000000000 >>> from mercurial.revlogutils.constants import KIND_OTHER >>> from mercurial import revlog, vfs >>> tvfs = vfs.vfs(b'.') >>> tvfs.options = {b'revlogv1': True} >>> rl = revlog.revlog(tvfs, target=(KIND_OTHER, b'test'), indexfile=b'a.i') >>> rl.revision(1) mpatchError(*'patch cannot be decoded'*) (glob)