Source Code for Module web2py.gluon.cfs

 1  #!/usr/bin/env python 
 2  # -*- coding: utf-8 -*- 
 3   
 4  """ 
 5  This file is part of the web2py Web Framework 
 6  Copyrighted by Massimo Di Pierro <mdipierro@cs.depaul.edu> 
 7  License: LGPLv3 (http://www.gnu.org/licenses/lgpl.html) 
 8   
 9  Functions required to execute app components 
10  ============================================ 
11   
12  FOR INTERNAL USE ONLY 
13  """ 
14   
15  import os 
16  import stat 
17  import thread 
18  from fileutils import read_file 
19   
20  cfs = {}  # for speed-up 
21  cfs_lock = thread.allocate_lock()  # and thread safety 
22   
23   
24 -def getcfs(key, filename, filter=None): 
25      """ 
26      Caches the *filtered* file `filename` with `key` until the file is 
27      modified. 
28   
29      :param key: the cache key 
30      :param filename: the file to cache 
31      :param filter: is the function used for filtering. Normally `filename` is a 
32          .py file and `filter` is a function that bytecode compiles the file. 
33          In this way the bytecode compiled file is cached. (Default = None) 
34   
35      This is used on Google App Engine since pyc files cannot be saved. 
36      """ 
37      t = os.stat(filename)[stat.ST_MTIME] 
38      cfs_lock.acquire() 
39      item = cfs.get(key, None) 
40      cfs_lock.release() 
41      if item and item[0] == t: 
42          return item[1] 
43      if not filter: 
44          data = read_file(filename) 
45      else: 
46          data = filter() 
47      cfs_lock.acquire() 
48      cfs[key] = (t, data) 
49      cfs_lock.release() 
50      return data 
51