text: # Copyright (c) 2012 The Chromium Embedded Framework Authors. All rights
  # reserved. Use of this source code is governed by a BSD-style license that
  # can be found in the LICENSE file.
  
  import os
  import sys
  import urllib
  
  def check_url(url):
    """ Check the URL and raise an exception if invalid. """
    if ':' in url[:7]:
      parts = url.split(':', 1)
      if (parts[0] == 'http' or parts[0] == 'https' or parts[0] == 'svn') and \
          parts[1] == urllib.quote(parts[1]):
        return url
    sys.stderr.write('Invalid URL: '+url+"\n")
    raise Exception('Invalid URL: '+url)
  
  def get_svn_info(path):
    """ Retrieves the URL and revision from svn info. """
    url = 'None'
    rev = 'None'
    if path[0:4] == 'http' or os.path.exists(path):
      try:
        stream = os.popen('svn info '+path)
        for line in stream:
          if line[0:4] == "URL:":
            url = check_url(line[5:-1])
          elif line[0:9] == "Revision:":
            rev = str(int(line[10:-1]))
      except IOError, (errno, strerror):
        sys.stderr.write('Failed to read svn info: '+strerror+"\n")
        raise
    return {'url': url, 'revision': rev}
  
  def get_revision(path = '.'):
    """ Retrieves the revision from svn info. """
    info = get_svn_info(path)
    if info['revision'] == 'None':
      raise Exception('Unable to retrieve SVN revision for "'+path+'"')
    return info['revision']
  
  def get_changed_files(path = '.'):
    """ Retrieves the list of changed files from svn status. """
    files = []
    if os.path.exists(path):
      try:
        stream = os.popen('svn status '+path)
        for line in stream:
          status = line[0]
          # Return paths with add, modify and switch status.
          if status == 'A' or status == 'M' or status == 'S':
            files.append(line[8:].strip())
      except IOError, (errno, strerror):
        sys.stderr.write('Failed to read svn status: '+strerror+"\n")
        raise
    return files
  