NOTE
This change does not affect the current gnulib-tool.py, just `python`
branch.
Still this change is going to be integrated later into the gnulib-tool.py.
I've been testing a new command-line parsing along with parsing cached
configuration (configure.ac, gnulib-cache.m4 and gnulib-comp.m4 processing).
I've noticed that we spend a lot of time whilst processing the contents of
AC_PREREQ and AC_CONFIG_AUX_DIR macros. These regular expressions have the
following form (I've removed some junk):
".*AC_PREREQ\\(\\[(.*?)\\]\\)"
".*AC_CONFIG_AUX_DIR\\(\\[(.*?)\\]\\)"
In Python, however, it seems to be enough to just use the following form:
"AC_PREREQ\\(\\[(.*?)\\]\\)"
"AC_CONFIG_AUX_DIR\\(\\[(.*?)\\]\\)"
Once I started using the latest form, the time required to process each of
these regular expressions decreased for about half a second. The regex works
even on the following cases:
"hello([AC_PREREQ([2.67])])"
" AC_PREREQ([2.67])"
"helloAC_PREREQ([2.67])world"
I suspect that the original form just was a copy-paste from the original
gnulib-tool, where it could have been used due to the usage of sed to parse
the contents of the configure.ac file. So the questions are:
1. Is the new behavior correct?
2. Shall I push this small optimization?
I'd like to do it, because right now everything else I've rewritten works
almost instantly, but I still have some doubts. What do you think?
BTW, the version from the pygnulib differs a bit already from the
gnulib-tool
shell script; I've attached the patch. I've also decided to use raw string
literals just to make regex less verbose.
--
With best regards,
Dmitry Selyutin
From 71a8d4a82caf17350cd3fad4ba6feb7b7fdb3e94 Mon Sep 17 00:00:00 2001
From: Dmitry Selyutin <ghostma...@gmail.com>
Date: Tue, 12 Sep 2017 18:47:55 +0300
Subject: [PATCH] config: simplify cache regular expressions
---
pygnulib/config.py | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/pygnulib/config.py b/pygnulib/config.py
index d08181db6..b174b166a 100644
--- a/pygnulib/config.py
+++ b/pygnulib/config.py
@@ -430,9 +430,9 @@ class Base:
class Cache(Base):
"""gnulib cached configuration"""
_AUTOCONF_ = {
- "autoconf" : _re_.compile(".*AC_PREREQ\\(\\[(.*?)\\]\\)", _re_.S | _re_.M),
- "auxdir" : _re_.compile("^AC_CONFIG_AUX_DIR\\(\\[(.*?)\\]\\)$", _re_.S | _re_.M),
- "libtool" : _re_.compile("A[CM]_PROG_LIBTOOL", _re_.S | _re_.M)
+ "autoconf" : _re_.compile(r"AC_PREREQ\(\[(.*?)\]\)", _re_.S | _re_.M),
+ "auxdir" : _re_.compile(r"AC_CONFIG_AUX_DIR\(\[(.*?)\]\)$", _re_.S | _re_.M),
+ "libtool" : _re_.compile(r"A[CM]_PROG_LIBTOOL", _re_.S | _re_.M)
}
_GNULIB_CACHE_ = {
"local" : (str, "gl_LOCAL_DIR"),
@@ -470,7 +470,7 @@ class Cache(Base):
_GNULIB_CACHE_STR_ += [_key_]
else:
_GNULIB_CACHE_LIST_ += [_key_]
- _GNULIB_CACHE_PATTERN_ = _re_.compile("^(gl_.*?)\\(\\[(.*?)\\]\\)$", _re_.S | _re_.M)
+ _GNULIB_CACHE_PATTERN_ = _re_.compile(r"^(gl_.*?)\(\[(.*?)\]\)$", _re_.S | _re_.M)
def __init__(self, root, m4_base, autoconf=None, **kwargs):
--
2.13.4
