build/android/gyp/util/md5_check.py

   1 # Copyright 2013 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4
   5 import hashlib
   6 import os
   7
   8
   9 def UpdateMd5ForFile(md5, path, block_size=2**16):
  10   with open(path, 'rb') as infile:
  11     while True:
  12       data = infile.read(block_size)
  13       if not data:
  14         break
  15       md5.update(data)
  16
  17
  18 def UpdateMd5ForDirectory(md5, dir_path):
  19   for root, _, files in os.walk(dir_path):
  20     for f in files:
  21       UpdateMd5ForFile(md5, os.path.join(root, f))
  22
  23
  24 def UpdateMd5ForPath(md5, path):
  25   if os.path.isdir(path):
  26     UpdateMd5ForDirectory(md5, path)
  27   else:
  28     UpdateMd5ForFile(md5, path)
  29
  30
  31 class Md5Checker(object):
  32   def __init__(self, stamp=None, inputs=[], command=[]):
  33     self.stamp = stamp
  34
  35     md5 = hashlib.md5()
  36     for i in inputs:
  37       UpdateMd5ForPath(md5, i)
  38     for s in command:
  39       md5.update(s)
  40     self.new_digest = md5.hexdigest()
  41
  42     self.old_digest = ''
  43     if os.path.exists(stamp):
  44       with open(stamp, 'r') as old_stamp:
  45         self.old_digest = old_stamp.read()
  46
  47   def IsStale(self):
  48     return self.old_digest != self.new_digest
  49
  50   def Write(self):
  51     with open(self.stamp, 'w') as new_stamp:
  52       new_stamp.write(self.new_digest)