[Python-checkins] cpython: Issue #11258: Speed up ctypes.util.find_library() under Linux by a factor

Sat Apr 23 17:56:24 CEST 2011

http://hg.python.org/cpython/rev/19d9f0a177de
changeset: 69533:19d9f0a177de
user: Antoine Pitrou <solipsis at pitrou.net>
date: Sat Apr 23 17:51:04 2011 +0200
summary:
 Issue #11258: Speed up ctypes.util.find_library() under Linux by a factor
of 5 to 10. Initial patch by Jonas H.
files:
 Lib/ctypes/util.py | 22 ++++++++++++++--------
 Misc/ACKS | 1 +
 Misc/NEWS | 3 +++
 3 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/Lib/ctypes/util.py b/Lib/ctypes/util.py
--- a/Lib/ctypes/util.py
+++ b/Lib/ctypes/util.py
@@ -1,5 +1,6 @@
 import sys, os
 import contextlib
+import subprocess
 
 # find_library(name) returns the pathname of a library, or None.
 if os.name == "nt":
@@ -203,14 +204,19 @@
 abi_type = mach_map.get(machine, 'libc6')
 
 # XXX assuming GLIBC's ldconfig (with option -p)
- expr = r'(\S+)\s+\((%s(?:, OS ABI:[^\)]*)?)\)[^/]*(/[^\(\)\s]*lib%s\.[^\(\)\s]*)' \
- % (abi_type, re.escape(name))
- with contextlib.closing(os.popen('LC_ALL=C LANG=C /sbin/ldconfig -p 2>/dev/null')) as f:
- data = f.read()
- res = re.search(expr, data)
- if not res:
- return None
- return res.group(1)
+ regex = os.fsencode(
+ '\s+(lib%s\.[^\s]+)\s+\(%s' % (re.escape(name), abi_type))
+ try:
+ with subprocess.Popen(['/sbin/ldconfig', '-p'],
+ stdin=subprocess.DEVNULL,
+ stderr=subprocess.DEVNULL,
+ stdout=subprocess.PIPE,
+ env={'LC_ALL': 'C', 'LANG': 'C'}) as p:
+ res = re.search(regex, p.stdout.read())
+ if res:
+ return os.fsdecode(res.group(1))
+ except OSError:
+ pass
 
 def find_library(name):
 return _findSoname_ldconfig(name) or _get_soname(_findLib_gcc(name))
diff --git a/Misc/ACKS b/Misc/ACKS
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -338,6 +338,7 @@
 Michael Guravage
 Lars Gustäbel
 Thomas Güttler
+Jonas H.
 Barry Haddow
 Paul ten Hagen
 Rasmus Hahn
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -113,6 +113,9 @@
 Library
 -------
 
+- Issue #11258: Speed up ctypes.util.find_library() under Linux by a factor
+ of 5 to 10. Initial patch by Jonas H.
+
 - Issue #11382: Trivial system calls, such as dup() or pipe(), needn't
 release the GIL. Patch by Charles-François Natali.
 
-- 
Repository URL: http://hg.python.org/cpython
