Mercurial > hg-stable
view tests/test-dispatch.t @ 22778:80f2b63dd83a
parsers: add a function to efficiently lowercase ASCII strings
We need a way to efficiently lowercase ASCII strings. For example, 'hg status'
needs to build up the fold map -- a map from a canonical case (for OS X,
lowercase) to the actual case of each file and directory in the dirstate.
The current way we do that is to try decoding to ASCII and then calling
lower() on the string, labeled 'orig' below:
str.decode('ascii')
return str.lower()
This is pretty inefficient, and it turns out we can do much better.
I also tested out a condition-based approach, labeled 'cond' below:
(c >= 'A' && c <= 'Z') ? (c + ('a' - 'A')) : c
'cond' turned out to be slower in all cases. A 256-byte lookup table with
invalid values for everything past 127 performed similarly, but this was less
verbose.
On OS X 10.9 with LLVM version 6.0 (clang-600.0.51), the asciilower function
was run against two corpuses.
Corpus 1 (list of files from real-world repo, > 100k files):
orig: wall 0.428567 comb 0.430000 user 0.430000 sys 0.000000 (best of 24)
cond: wall 0.077204 comb 0.070000 user 0.070000 sys 0.000000 (best of 100)
lookup: wall 0.060714 comb 0.060000 user 0.060000 sys 0.000000 (best of 100)
Corpus 2 (mozilla-central, 113k files):
orig: wall 0.238406 comb 0.240000 user 0.240000 sys 0.000000 (best of 42)
cond: wall 0.040779 comb 0.040000 user 0.040000 sys 0.000000 (best of 100)
lookup: wall 0.037623 comb 0.040000 user 0.040000 sys 0.000000 (best of 100)
On a Linux server-class machine with GCC 4.4.6 20120305 (Red Hat 4.4.6-4):
Corpus 1 (real-world repo, > 100k files):
orig: wall 0.260899 comb 0.260000 user 0.260000 sys 0.000000 (best of 38)
cond: wall 0.054818 comb 0.060000 user 0.060000 sys 0.000000 (best of 100)
lookup: wall 0.048489 comb 0.050000 user 0.050000 sys 0.000000 (best of 100)
Corpus 2 (mozilla-central, 113k files):
orig: wall 0.153082 comb 0.150000 user 0.150000 sys 0.000000 (best of 65)
cond: wall 0.031007 comb 0.040000 user 0.040000 sys 0.000000 (best of 100)
lookup: wall 0.028793 comb 0.030000 user 0.030000 sys 0.000000 (best of 100)
SSE instructions might help even more, but I didn't experiment with those.
author | Siddharth Agarwal <sid0@fb.com> |
---|---|
date | Fri, 03 Oct 2014 18:42:39 -0700 |
parents | c1d93edcf004 |
children | 7109d5ddeb0c |
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test command parsing and dispatch $ hg init a $ cd a Redundant options used to crash (issue436): $ hg -v log -v $ hg -v log -v x $ echo a > a $ hg ci -Ama adding a Missing arg: $ hg cat hg cat: invalid arguments hg cat [OPTION]... FILE... output the current or given revision of files options ([+] can be repeated): -o --output FORMAT print output to file with formatted name -r --rev REV print the given revision --decode apply any matching decode filter -I --include PATTERN [+] include names matching the given patterns -X --exclude PATTERN [+] exclude names matching the given patterns (use "hg cat -h" to show more help) [255] [defaults] $ hg cat a a $ cat >> $HGRCPATH <<EOF > [defaults] > cat = -r null > EOF $ hg cat a a: no such file in rev 000000000000 [1] $ cd "$TESTTMP" OSError "No such file or directory" / "The system cannot find the path specified" should include filename even when it is empty $ hg -R a archive '' abort: *: '' (glob) [255] #if no-outer-repo No repo: $ hg cat abort: no repository found in '$TESTTMP' (.hg not found)! [255] #endif