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  Note: 
13      FOR INTERNAL USE ONLY 
14  """ 
15   
16  from os import stat 
17  import thread 
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      Args: 
30          key(str): the cache key 
31          filename: the file to cache 
32          filter: is the function used for filtering. Normally `filename` is a 
33              .py file and `filter` is a function that bytecode compiles the file. 
34              In this way the bytecode compiled file is cached. (Default = None) 
35   
36      This is used on Google App Engine since pyc files cannot be saved. 
37      """ 
38      try: 
39          t = stat(filename).st_mtime 
40      except OSError: 
41          return filter() if callable(filter) else '' 
42      cfs_lock.acquire() 
43      item = cfs.get(key, None) 
44      cfs_lock.release() 
45      if item and item[0] == t: 
46          return item[1] 
47      if not callable(filter): 
48          data = read_file(filename) 
49      else: 
50          data = filter() 
51      cfs_lock.acquire() 
52      cfs[key] = (t, data) 
53      cfs_lock.release() 
54      return data 
55