view README @ 33927:853574db5b12

encoding: add fast path of from/tolocal() for ASCII strings

This is micro optimization, but seems not bad since to/fromlocal() is called
lots of times and isasciistr() is cheap and simple.

We boldly assume that any non-ASCII characters have at least one 8-bit byte.
This isn't true for some email character sets (e.g. ISO-2022-JP and UTF-7),
but I believe no such encodings are used as a platform default. Shift_JIS,
a major crap, is okay as it should have a leading byte in 0x80-0xff range.

  (with mercurial repo)
  $ export HGRCPATH=/dev/null HGPLAIN=
  $ hg log --time --config experimental.stabilization=all > /dev/null

  (original)
  time: real 7.460 secs (user 7.420+0.000 sys 0.030+0.000)
  time: real 7.670 secs (user 7.590+0.000 sys 0.080+0.000)
  time: real 7.560 secs (user 7.510+0.000 sys 0.040+0.000)

  (this patch)
  time: real 7.340 secs (user 7.260+0.000 sys 0.060+0.000)
  time: real 7.260 secs (user 7.210+0.000 sys 0.030+0.000)
  time: real 7.310 secs (user 7.260+0.000 sys 0.060+0.000)

Mercurial
=========

Mercurial is a fast, easy to use, distributed revision control tool
for software developers.

Basic install::

 $ make            # see install targets
 $ make install    # do a system-wide install
 $ hg debuginstall # sanity-check setup
 $ hg              # see help

Running without installing::

 $ make local      # build for inplace usage
 $ ./hg --version  # should show the latest version

See https://mercurial-scm.org/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.