third_party/waf/waflib/Tools/md5_tstamp.py

   1 #! /usr/bin/env python
   2 # encoding: utf-8
   3
   4 """
   5 Re-calculate md5 hashes of files only when the file time have changed::
   6
   7         def options(opt):
   8                 opt.load('md5_tstamp')
   9
  10 The hashes can also reflect either the file contents (STRONGEST=True) or the
  11 file time and file size.
  12
  13 The performance benefits of this module are usually insignificant.
  14 """
  15
  16 import os, stat
  17 from waflib import Utils, Build, Node
  18
  19 STRONGEST = True
  20
  21 Build.SAVED_ATTRS.append('hashes_md5_tstamp')
  22 def h_file(self):
  23         filename = self.abspath()
  24         st = os.stat(filename)
  25
  26         cache = self.ctx.hashes_md5_tstamp
  27         if filename in cache and cache[filename][0] == st.st_mtime:
  28                 return cache[filename][1]
  29
  30         if STRONGEST:
  31                 ret = Utils.h_file(filename)
  32         else:
  33                 if stat.S_ISDIR(st[stat.ST_MODE]):
  34                         raise IOError('Not a file')
  35                 ret = Utils.md5(str((st.st_mtime, st.st_size)).encode()).digest()
  36
  37         cache[filename] = (st.st_mtime, ret)
  38         return ret
  39 h_file.__doc__ = Node.Node.h_file.__doc__
  40 Node.Node.h_file = h_file
  41