From e2cb1724053e67a4bb14b0b2c9d848e771d53a7e Mon Sep 17 00:00:00 2001 From: Evan Broder Date: Fri, 24 Oct 2008 03:35:21 -0400 Subject: [PATCH] Now that we're using Python 2.5, we can actually write with statements svn path=/trunk/packages/sipb-xen-base/; revision=1197 --- debian/changelog | 6 +++ debian/control | 2 +- debian/pyversions | 1 + .../python-support/sipb-xen-base/invirt/common.py | 55 ++++++-------------- .../python-support/sipb-xen-base/invirt/config.py | 26 +++++---- 5 files changed, 38 insertions(+), 52 deletions(-) create mode 100644 debian/pyversions diff --git a/debian/changelog b/debian/changelog index 435e984..5391977 100644 --- a/debian/changelog +++ b/debian/changelog @@ -1,3 +1,9 @@ +sipb-xen-base (8.23) unstable; urgency=low + + * Now that we're using Python 2.5, we can actually write with statements + + -- Evan Broder Fri, 24 Oct 2008 03:32:00 -0400 + sipb-xen-base (8.22) unstable; urgency=low * Please - anything but etch. Anything! diff --git a/debian/control b/debian/control index 3ffb38a..5ded7ab 100644 --- a/debian/control +++ b/debian/control @@ -3,7 +3,7 @@ Section: base Priority: extra Maintainer: SIPB Xen Project Build-Depends: cdbs (>= 0.4.23-1.1), debhelper (>= 4.1.0), python-support -Standards-Version: 3.7.2 +Standards-Version: 3.8.0 Package: sipb-xen-base Architecture: all diff --git a/debian/pyversions b/debian/pyversions new file mode 100644 index 0000000..b3dc41e --- /dev/null +++ b/debian/pyversions @@ -0,0 +1 @@ +2.5- diff --git a/files/usr/share/python-support/sipb-xen-base/invirt/common.py b/files/usr/share/python-support/sipb-xen-base/invirt/common.py index d986196..77770a6 100644 --- a/files/usr/share/python-support/sipb-xen-base/invirt/common.py +++ b/files/usr/share/python-support/sipb-xen-base/invirt/common.py @@ -1,5 +1,8 @@ +from __future__ import with_statement + import unittest from fcntl import flock, LOCK_EX, LOCK_SH, LOCK_UN +import contextlib as clib class struct(object): 'A simple namespace object.' @@ -20,46 +23,18 @@ def dicts2struct(x): else: return x -# -# Hacks to work around lack of Python 2.5's `with` statement. -# - -def with_closing(rsrc): - """ - Utility to emulate Python 2.5's `with closing(rsrc)` context manager. - - E.g., - @with_closing(file('/tmp/foo')) - def contents(f): - return f.read() - # now 'contents' is the contents of /tmp/foo - """ - def wrapper(func): - try: return func(rsrc) - finally: rsrc.close() - return wrapper - -def with_lock_file(path, exclusive = True): - """ - Context manager for lock files. Example: - - @with_lock_file('/tmp/mylock') - def input(): - print 'locked' - return raw_input() - # prints 'locked' - print input # prints what raw_input() returned - """ - def wrapper(func): - @with_closing(file(path, 'w')) - def g(f): - if exclusive: locktype = LOCK_EX - else: locktype = LOCK_SH - flock(f, locktype) - try: return func() - finally: flock(f, LOCK_UN) - return g - return wrapper +@clib.contextmanager +def lock_file(path, exclusive = True): + with clib.closing(file(path, 'w')) as f: + if exclusive: + locktype = LOCK_EX + else: + locktype = LOCK_SH + flock(f, locktype) + try: + yield + finally: + flock(f, LOCK_UN) # # Tests. diff --git a/files/usr/share/python-support/sipb-xen-base/invirt/config.py b/files/usr/share/python-support/sipb-xen-base/invirt/config.py index 8648c70..69cb899 100644 --- a/files/usr/share/python-support/sipb-xen-base/invirt/config.py +++ b/files/usr/share/python-support/sipb-xen-base/invirt/config.py @@ -1,11 +1,14 @@ +from __future__ import with_statement + import json from invirt.common import * from os import rename from os.path import getmtime +from contextlib import closing default_src_path = '/etc/invirt/master.yaml' default_cache_path = '/var/lib/invirt/cache.json' -lock_file = '/var/lib/invirt/cache.lock' +lock_path = '/var/lib/invirt/cache.lock' def load(src_path = default_src_path, cache_path = default_cache_path, @@ -53,8 +56,9 @@ def load(src_path = default_src_path, # (changing) version of the data (but the transaction can share the # lock with other concurrent reads). This isolation is accomplished # using an atomic filesystem rename in the refreshing stage. - try: ns.cfg = with_closing(file(cache_path)) ( - lambda f: json.read(f.read())) + try: + with closing(file(cache_path)) as f: + ns.cfg = json.read(f.read()) except: do_refresh = True if do_refresh: @@ -68,17 +72,17 @@ def load(src_path = default_src_path, try: loader = yaml.CSafeLoader except: loader = yaml.SafeLoader try: - @with_lock_file(lock_file) - def refresh_cache(): - ns.cfg = with_closing(file(src_path)) ( - lambda f: yaml.load(f, loader)) - try: with_closing(file(cache_path + '.tmp', 'w')) ( - lambda f: f.write(json.write(ns.cfg))) + with lock_file(lock_path): + with closing(file(src_path)) as f: + ns.cfg = yaml.load(f, loader) + try: + with closing(file(cache_path + '.tmp', 'w')) as f: + f.write(json.write(ns.cfg)) except: pass # silent failure else: rename(cache_path + '.tmp', cache_path) except IOError: - ns.cfg = with_closing(file(src_path)) ( - lambda f: yaml.load(f, loader)) + with closing(file(src_path)) as f: + ns.cfg = yaml.load(f, loader) return ns.cfg dicts = load() -- 1.7.9.5