-def load( path = default_path ):
- with file( path ) as f:
- return yaml.load( f, default_loader )
+ if not do_refresh:
+ # try reading from the cache first
+ try: cfg = with_closing(file(cache_path))(lambda f: json.read(f.read()))
+ except: do_refresh = True
+
+ if do_refresh:
+ # Atomically reload the source and regenerate the cache. The read and
+ # write must be a single transaction, or a stale version may be
+ # written.
+ @with_lock_file('/var/lib/invirt/cache.lock')
+ def cfg():
+ import yaml
+ try: default_loader = yaml.CSafeLoader
+ except: default_loader = yaml.SafeLoader
+ cfg = with_closing(file(src_path))(lambda f: yaml.load(f, default_loader))
+ try: with_closing(file(cache_path, 'w'))(lambda f: f.write(json.write(cfg)))
+ except: pass # silent failure
+ return cfg
+ return cfg
+
+dicts = load()
+structs = dicts2struct(dicts)