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.
match: remove unnecessary setting of self._always
The 'always' class calls its parent constructor with an empty list of
patterns, which will result in a matcher that always matches. The
parent constructor will set self._always to True in such cases, so
there is no need to set it again.
bookmarks: split ui.write() so that it can be easily ported to formatter api
Test output changes because color labels are applied separately.
bookmarks: iterate bookmarks list even if it is known to be empty
This clarifies that "no bookmarks set" is displayed in addition to the list
of bookmarks. In JSON output, for example, [] should be written if empty,
and "no bookmarks set" message should be skipped.
repoview: remove hiddencache verification
We have been running hiddencache verification since 3.1.1 and so
far not received a bug report concerning it. Therefore we remove
the verification code and make the hiddencache authoritive. That
way we get the intended speedup.
color: reorganise and sectionify the help text
The color docstring was getting long. This splits it up into
bite-sized sections and rearranges the order of the paragraphs a
little to match these sections.