1# Copyright (C) 2011 Google Inc. All rights reserved. 2# 3# Redistribution and use in source and binary forms, with or without 4# modification, are permitted provided that the following conditions are 5# met: 6# 7# * Redistributions of source code must retain the above copyright 8# notice, this list of conditions and the following disclaimer. 9# * Redistributions in binary form must reproduce the above 10# copyright notice, this list of conditions and the following disclaimer 11# in the documentation and/or other materials provided with the 12# distribution. 13# * Neither the name of Google Inc. nor the names of its 14# contributors may be used to endorse or promote products derived from 15# this software without specific prior written permission. 16# 17# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 18# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 20# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 21# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 22# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 23# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 27# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 29"""Wrapper module for fetching URLs.""" 30 31import urllib 32 33 34class UrlFetcher(object): 35 """Class with restricted interface to fetch URLs (makes testing easier)""" 36 def __init__(self, filesystem): 37 self._filesystem = filesystem 38 39 def fetch(self, url): 40 """Fetches the contents of the URL as a string.""" 41 file_object = urllib.urlopen(url) 42 content = file_object.read() 43 file_object.close() 44 return content 45 46 def fetch_into_file(self, url): 47 """Fetches the contents of the URL into a temporary file and return the filename. 48 49 This is the equivalent of urllib.retrieve() except that we don't return any headers. 50 """ 51 file_object, filename = self._filesystem.open_binary_tempfile('-fetched') 52 contents = self.fetch(url) 53 file_object.write(contents) 54 file_object.close() 55 return filename 56