Mercurial > hg
view tests/test-share.t @ 17616:9535a0dc41f2
store: implement fncache basic path encoding in C
(This is not yet enabled; it will be turned on in a followup patch.)
The path encoding performed by fncache is complex and (perhaps
surprisingly) slow enough to negatively affect the overall performance
of Mercurial.
For a short path (< 120 bytes), the Python code can be reduced to a fairly
tractable state machine that either determines that nothing needs to be
done in a single pass, or performs the encoding in a second pass.
For longer paths, we avoid the more complicated hashed encoding scheme
for now, and fall back to Python.
Raw performance: I measured in a repo containing 150,000 files in its tip
manifest, with a median path name length of 57 bytes, and 95th percentile
of 96 bytes.
In this repo, the Python code takes 3.1 seconds to encode all path
names, while the hybrid C-and-Python code (called from Python) takes
0.21 seconds, for a speedup of about 14.
Across several other large repositories, I've measured the speedup from
the C code at between 26x and 40x.
For path names above 120 bytes where we must fall back to Python for
hashed encoding, the speedup is about 1.7x. Thus absolute performance
will depend strongly on the characteristics of a particular repository.
author | Bryan O'Sullivan <bryano@fb.com> |
---|---|
date | Tue, 18 Sep 2012 15:42:19 -0700 |
parents | bc7377160fa7 |
children | 7a9cbb315d84 |
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$ "$TESTDIR/hghave" killdaemons || exit 80 $ echo "[extensions]" >> $HGRCPATH $ echo "share = " >> $HGRCPATH prepare repo1 $ hg init repo1 $ cd repo1 $ echo a > a $ hg commit -A -m'init' adding a share it $ cd .. $ hg share repo1 repo2 updating working directory 1 files updated, 0 files merged, 0 files removed, 0 files unresolved share shouldn't have a store dir $ cd repo2 $ test -d .hg/store [1] Some sed versions appends newline, some don't, and some just fails $ cat .hg/sharedpath; echo $TESTTMP/repo1/.hg (glob) trailing newline on .hg/sharedpath is ok $ hg tip -q 0:d3873e73d99e $ echo '' >> .hg/sharedpath $ cat .hg/sharedpath $TESTTMP/repo1/.hg (glob) $ hg tip -q 0:d3873e73d99e commit in shared clone $ echo a >> a $ hg commit -m'change in shared clone' check original $ cd ../repo1 $ hg log changeset: 1:8af4dc49db9e tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: change in shared clone changeset: 0:d3873e73d99e user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: init $ hg update 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cat a # should be two lines of "a" a a commit in original $ echo b > b $ hg commit -A -m'another file' adding b check in shared clone $ cd ../repo2 $ hg log changeset: 2:c2e0ac586386 tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: another file changeset: 1:8af4dc49db9e user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: change in shared clone changeset: 0:d3873e73d99e user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: init $ hg update 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cat b # should exist with one "b" b hg serve shared clone $ hg serve -n test -p $HGPORT -d --pid-file=hg.pid $ cat hg.pid >> $DAEMON_PIDS $ "$TESTDIR/get-with-headers.py" localhost:$HGPORT 'raw-file/' 200 Script output follows -rw-r--r-- 4 a -rw-r--r-- 2 b test unshare command $ hg unshare $ test -d .hg/store $ test -f .hg/sharedpath [1] $ hg unshare abort: this is not a shared repo [255] check that a change does not propagate $ echo b >> b $ hg commit -m'change in unshared' $ cd ../repo1 $ hg id -r tip c2e0ac586386 tip $ cd .. Explicitly kill daemons to let the test exit on Windows $ "$TESTDIR/killdaemons.py" $DAEMON_PIDS