[PATCH 9 of 9] match: use util.re.escape instead of re.escape

[Siddharth Agarwal]

# HG changeset patch
# User Siddharth Agarwal <sid0 at fb.com>
# Date 1405463690 25200
#      Tue Jul 15 15:34:50 2014 -0700
# Node ID 2d645e993f8cb3d386ae520e7233089316e830f2
# Parent  8ec138de734383da9ab4fd60e4a61054906f50ed
match: use util.re.escape instead of re.escape

For a pathological .hgignore with over 2500 glob lines and over 200000 calls to
re.escape, and with re2 available, this speeds up parsing the .hgignore from
0.75 seconds to 0.20 seconds. This causes e.g. 'hg status' with hgwatchman
enabled to go from 1.02 seconds to 0.47 seconds.

diff --git a/mercurial/match.py b/mercurial/match.py
--- a/mercurial/match.py
+++ b/mercurial/match.py
@@ -247,7 +247,7 @@
     i, n = 0, len(pat)
     res = ''
     group = 0
-    escape = re.escape
+    escape = util.re.escape
     def peek():
         return i < n and pat[i]
     while i < n:
@@ -310,11 +310,11 @@
     if kind == 're':
         return pat
     if kind == 'path':
-        return '^' + re.escape(pat) + '(?:/|$)'
+        return '^' + util.re.escape(pat) + '(?:/|$)'
     if kind == 'relglob':
         return '(?:|.*/)' + _globre(pat) + globsuffix
     if kind == 'relpath':
-        return re.escape(pat) + '(?:/|$)'
+        return util.re.escape(pat) + '(?:/|$)'
     if kind == 'relre':
         if pat.startswith('^'):
             return pat