roundup/install_util.py

   1 #
   2 # Copyright (c) 2001 Bizar Software Pty Ltd (http://www.bizarsoftware.com.au/)
   3 # This module is free software, and you may redistribute it and/or modify
   4 # under the same terms as Python, so long as this copyright message and
   5 # disclaimer are retained in their original form.
   6 #
   7 # IN NO EVENT SHALL BIZAR SOFTWARE PTY LTD BE LIABLE TO ANY PARTY FOR
   8 # DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING
   9 # OUT OF THE USE OF THIS CODE, EVEN IF THE AUTHOR HAS BEEN ADVISED OF THE
  10 # POSSIBILITY OF SUCH DAMAGE.
  11 #
  12 # BIZAR SOFTWARE PTY LTD SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  13 # BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  14 # FOR A PARTICULAR PURPOSE.  THE CODE PROVIDED HEREUNDER IS ON AN "AS IS"
  15 # BASIS, AND THERE IS NO OBLIGATION WHATSOEVER TO PROVIDE MAINTENANCE,
  16 # SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  17 #
  18 # $Id: install_util.py,v 1.11 2006-01-25 03:11:43 richard Exp $
  19
  20 """Support module to generate and check fingerprints of installed files.
  21 """
  22 __docformat__ = 'restructuredtext'
  23
  24 import os, shutil
  25 from roundup.anypy.hashlib_ import sha1
  26
  27 sgml_file_types = [".xml", ".ent", ".html"]
  28 hash_file_types = [".py", ".sh", ".conf", ".cgi"]
  29 slast_file_types = [".css"]
  30
  31 digested_file_types = sgml_file_types + hash_file_types + slast_file_types
  32
  33 def extractFingerprint(lines):
  34     # get fingerprint from last line
  35     if lines[-1].startswith("#SHA: "):
  36         # handle .py/.sh comment
  37         return lines[-1][6:].strip()
  38     elif lines[-1].startswith("<!-- SHA: "):
  39         # handle xml/html files
  40         fingerprint = lines[-1][10:]
  41         fingerprint = fingerprint.replace('-->', '')
  42         return fingerprint.strip()
  43     elif lines[-1].startswith("/* SHA: "):
  44         # handle css files
  45         fingerprint = lines[-1][8:]
  46         fingerprint = fingerprint.replace('*/', '')
  47         return fingerprint.strip()
  48     return None
  49
  50 def checkDigest(filename):
  51     """Read file, check for valid fingerprint, return TRUE if ok"""
  52     # open and read file
  53     inp = open(filename, "r")
  54     lines = inp.readlines()
  55     inp.close()
  56
  57     fingerprint = extractFingerprint(lines)
  58     if fingerprint is None:
  59         return 0
  60     del lines[-1]
  61
  62     # calculate current digest
  63     digest = sha1()
  64     for line in lines:
  65         digest.update(line)
  66
  67     # compare current to stored digest
  68     return fingerprint == digest.hexdigest()
  69
  70
  71 class DigestFile:
  72     """ A class that you can use like open() and that calculates
  73         and writes a SHA digest to the target file.
  74     """
  75
  76     def __init__(self, filename):
  77         self.filename = filename
  78         self.digest = sha1()
  79         self.file = open(self.filename, "w")
  80
  81     def write(self, data):
  82         lines = data.splitlines()
  83         # if the file is coming from an installed tracker being used as a
  84         # template, then we will want to re-calculate the SHA
  85         fingerprint = extractFingerprint(lines)
  86         if fingerprint is not None:
  87             data = '\n'.join(lines[:-1]) + '\n'
  88         self.file.write(data)
  89         self.digest.update(data)
  90
  91     def close(self):
  92         file, ext = os.path.splitext(self.filename)
  93
  94         if ext in sgml_file_types:
  95             self.file.write("<!-- SHA: %s -->\n" % (self.digest.hexdigest(),))
  96         elif ext in hash_file_types:
  97             self.file.write("#SHA: %s\n" % (self.digest.hexdigest(),))
  98         elif ext in slast_file_types:
  99             self.file.write("/* SHA: %s */\n" % (self.digest.hexdigest(),))
 100
 101         self.file.close()
 102
 103
 104 def copyDigestedFile(src, dst, copystat=1):
 105     """ Copy data from `src` to `dst`, adding a fingerprint to `dst`.
 106         If `copystat` is true, the file status is copied, too
 107         (like shutil.copy2).
 108     """
 109     if os.path.isdir(dst):
 110         dst = os.path.join(dst, os.path.basename(src))
 111
 112     dummy, ext = os.path.splitext(src)
 113     if ext not in digested_file_types:
 114         if copystat:
 115             return shutil.copy2(src, dst)
 116         else:
 117             return shutil.copyfile(src, dst)
 118
 119     fsrc = None
 120     fdst = None
 121     try:
 122         fsrc = open(src, 'r')
 123         fdst = DigestFile(dst)
 124         shutil.copyfileobj(fsrc, fdst)
 125     finally:
 126         if fdst: fdst.close()
 127         if fsrc: fsrc.close()
 128
 129     if copystat: shutil.copystat(src, dst)
 130
 131
 132 def test():
 133     import sys
 134
 135     testdata = open(sys.argv[0], 'r').read()
 136
 137     for ext in digested_file_types:
 138         testfile = "__digest_test" + ext
 139
 140         out = DigestFile(testfile)
 141         out.write(testdata)
 142         out.close()
 143
 144         assert checkDigest(testfile), "digest ok w/o modification"
 145
 146         mod = open(testfile, 'r+')
 147         mod.seek(0)
 148         mod.write('# changed!')
 149         mod.close()
 150
 151         assert not checkDigest(testfile), "digest fails after modification"
 152
 153         os.remove(testfile)
 154
 155
 156 if __name__ == '__main__':
 157     test()
 158
 159 # vim: set filetype=python ts=4 sw=4 et si