site_scons/http_download.py

   1 #!/usr/bin/python2.4
   2 # Copyright 2009, Google Inc.
   3 # All rights reserved.
   4 #
   5 # Redistribution and use in source and binary forms, with or without
   6 # modification, are permitted provided that the following conditions are
   7 # met:
   8 #
   9 #     * Redistributions of source code must retain the above copyright
  10 # notice, this list of conditions and the following disclaimer.
  11 #     * Redistributions in binary form must reproduce the above
  12 # copyright notice, this list of conditions and the following disclaimer
  13 # in the documentation and/or other materials provided with the
  14 # distribution.
  15 #     * Neither the name of Google Inc. nor the names of its
  16 # contributors may be used to endorse or promote products derived from
  17 # this software without specific prior written permission.
  18 #
  19 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  22 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  23 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30
  31 """Download a file from a URL to a file on disk.
  32
  33 This module supports username and password with basic authentication.
  34 """
  35
  36 import base64
  37 import os
  38 import urllib2
  39
  40
  41 def _CreateDirectory(path):
  42   """Create a directory tree, ignore if it's already there."""
  43   try:
  44     os.makedirs(path)
  45     return True
  46   except os.error:
  47     return False
  48
  49
  50 def HttpDownload(url, target, username=None, password=None):
  51   """Download a file from a remote server.
  52
  53   Args:
  54     url: A URL to download from.
  55     target: Filename to write download to.
  56     username: Optional username for download.
  57     password: Optional password for download (ignored if no username).
  58   """
  59
  60   headers = [('Accept', '*/*')]
  61   if username:
  62     if password:
  63       auth_code = base64.b64encode(username + ':' + password)
  64     else:
  65       auth_code = base64.b64encode(username)
  66     headers.append(('Authorization', 'Basic ' + auth_code))
  67   opener = urllib2.build_opener()
  68   opener.addheaders = headers
  69   urllib2.install_opener(opener)
  70   src = urllib2.urlopen(url)
  71   data = src.read()
  72   src.close()
  73
  74   _CreateDirectory(os.path.split(target)[0])
  75   fh = open(target, 'wb')
  76   fh.write(data)
  77   fh.close()