view tests/test-check-pyflakes.t @ 16943:8d08a28aa63e

matcher: use re2 bindings if available

There are two sets of Python re2 bindings available on the internet;
this code works with both.

Using re2 can greatly improve "hg status" performance when a .hgignore
file becomes even modestly complex.

Example: "hg status" on a clean tree with 134K files, where "hg
debugignore" reports a regexp 4256 bytes in size.

  no .hgignore: 1.76 sec
  Python re:    2.79
  re2:          1.82

The overhead of regexp matching drops from 1.03 seconds with stock
re to 0.06 with re2.

(For comparison, a git repo with the same contents and .gitignore
file runs "git status -s" in 1.71 seconds, i.e. only slightly faster
than hg with re2.)

  $ "$TESTDIR/hghave" pyflakes || exit 80
  $ cd "`dirname "$TESTDIR"`"
  $ pyflakes mercurial hgext 2>&1 | "$TESTDIR/filterpyflakes.py"
  hgext/inotify/linux/__init__.py:*: 'from _inotify import *' used; unable to detect undefined names (glob)