SP/web2py/gluon/cfs.py
Saturneic 064f602b1a Add.
2018-10-25 23:33:13 +08:00

55 lines
1.4 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
| This file is part of the web2py Web Framework
| Copyrighted by Massimo Di Pierro <mdipierro@cs.depaul.edu>
| License: LGPLv3 (http://www.gnu.org/licenses/lgpl.html)
Functions required to execute app components
--------------------------------------------
Note:
FOR INTERNAL USE ONLY
"""
from os import stat
from gluon.fileutils import read_file
from gluon._compat import thread
cfs = {} # for speed-up
cfs_lock = thread.allocate_lock() # and thread safety
def getcfs(key, filename, filter=None):
"""
Caches the *filtered* file `filename` with `key` until the file is
modified.
Args:
key(str): the cache key
filename: the file to cache
filter: is the function used for filtering. Normally `filename` is a
.py file and `filter` is a function that bytecode compiles the file.
In this way the bytecode compiled file is cached. (Default = None)
This is used on Google App Engine since pyc files cannot be saved.
"""
try:
t = stat(filename).st_mtime
except OSError:
return filter() if callable(filter) else ''
cfs_lock.acquire()
item = cfs.get(key, None)
cfs_lock.release()
if item and item[0] == t:
return item[1]
if not callable(filter):
data = read_file(filename)
else:
data = filter()
cfs_lock.acquire()
cfs[key] = (t, data)
cfs_lock.release()
return data