+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,
# (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:
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()