Source Code for Module 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  from os import stat 
16  import thread 
17  import logging 
18  from gluon.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      try: 
38          t = stat(filename).st_mtime 
39      except OSError: 
40          return filter() if callable(filter) else '' 
41      cfs_lock.acquire() 
42      item = cfs.get(key, None) 
43      cfs_lock.release() 
44      if item and item[0] == t: 
45          return item[1] 
46      if not callable(filter): 
47          data = read_file(filename) 
48      else: 
49          data = filter() 
50      cfs_lock.acquire() 
51      cfs[key] = (t, data) 
52      cfs_lock.release() 
53      return data 
54