mirror of https://github.com/python/cpython
1315 lines
44 KiB
Python
1315 lines
44 KiB
Python
"""An extensible library for opening URLs using a variety of protocols
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The simplest way to use this module is to call the urlopen function,
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which accepts a string containing a URL or a Request object (described
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below). It opens the URL and returns the results as file-like
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object; the returned object has some extra methods described below.
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The OpenerDirector manages a collection of Handler objects that do
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all the actual work. Each Handler implements a particular protocol or
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option. The OpenerDirector is a composite object that invokes the
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Handlers needed to open the requested URL. For example, the
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HTTPHandler performs HTTP GET and POST requests and deals with
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non-error returns. The HTTPRedirectHandler automatically deals with
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HTTP 301, 302, 303 and 307 redirect errors, and the HTTPDigestAuthHandler
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deals with digest authentication.
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urlopen(url, data=None) -- basic usage is that same as original
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urllib. pass the url and optionally data to post to an HTTP URL, and
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get a file-like object back. One difference is that you can also pass
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a Request instance instead of URL. Raises a URLError (subclass of
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IOError); for HTTP errors, raises an HTTPError, which can also be
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treated as a valid response.
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build_opener -- function that creates a new OpenerDirector instance.
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will install the default handlers. accepts one or more Handlers as
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arguments, either instances or Handler classes that it will
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instantiate. if one of the argument is a subclass of the default
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handler, the argument will be installed instead of the default.
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install_opener -- installs a new opener as the default opener.
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objects of interest:
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OpenerDirector --
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Request -- an object that encapsulates the state of a request. the
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state can be a simple as the URL. it can also include extra HTTP
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headers, e.g. a User-Agent.
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BaseHandler --
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exceptions:
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URLError-- a subclass of IOError, individual protocols have their own
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specific subclass
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HTTPError-- also a valid HTTP response, so you can treat an HTTP error
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as an exceptional event or valid response
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internals:
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BaseHandler and parent
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_call_chain conventions
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Example usage:
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import urllib2
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# set up authentication info
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authinfo = urllib2.HTTPBasicAuthHandler()
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authinfo.add_password('realm', 'host', 'username', 'password')
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proxy_support = urllib2.ProxyHandler({"http" : "http://ahad-haam:3128"})
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# build a new opener that adds authentication and caching FTP handlers
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opener = urllib2.build_opener(proxy_support, authinfo, urllib2.CacheFTPHandler)
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# install it
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urllib2.install_opener(opener)
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f = urllib2.urlopen('http://www.python.org/')
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"""
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# XXX issues:
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# If an authentication error handler that tries to perform
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# authentication for some reason but fails, how should the error be
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# signalled? The client needs to know the HTTP error code. But if
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# the handler knows that the problem was, e.g., that it didn't know
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# that hash algo that requested in the challenge, it would be good to
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# pass that information along to the client, too.
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# XXX to do:
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# name!
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# documentation (getting there)
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# complex proxies
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# abstract factory for opener
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# ftp errors aren't handled cleanly
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# gopher can return a socket.error
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# check digest against correct (i.e. non-apache) implementation
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import base64
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import ftplib
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import gopherlib
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import httplib
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import inspect
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import md5
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import mimetypes
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import mimetools
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import os
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import posixpath
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import random
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import re
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import rfc822
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import sha
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import socket
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import sys
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import time
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import urlparse
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import bisect
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try:
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from cStringIO import StringIO
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except ImportError:
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from StringIO import StringIO
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# not sure how many of these need to be gotten rid of
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from urllib import unwrap, unquote, splittype, splithost, \
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addinfourl, splitport, splitgophertype, splitquery, \
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splitattr, ftpwrapper, noheaders, splituser, splitpasswd
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# support for FileHandler, proxies via environment variables
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from urllib import localhost, url2pathname, getproxies
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__version__ = "2.4"
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_opener = None
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def urlopen(url, data=None):
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global _opener
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if _opener is None:
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_opener = build_opener()
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return _opener.open(url, data)
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def install_opener(opener):
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global _opener
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_opener = opener
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# do these error classes make sense?
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# make sure all of the IOError stuff is overridden. we just want to be
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# subtypes.
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class URLError(IOError):
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# URLError is a sub-type of IOError, but it doesn't share any of
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# the implementation. need to override __init__ and __str__.
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# It sets self.args for compatibility with other EnvironmentError
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# subclasses, but args doesn't have the typical format with errno in
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# slot 0 and strerror in slot 1. This may be better than nothing.
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def __init__(self, reason):
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self.args = reason,
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self.reason = reason
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def __str__(self):
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return '<urlopen error %s>' % self.reason
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class HTTPError(URLError, addinfourl):
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"""Raised when HTTP error occurs, but also acts like non-error return"""
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__super_init = addinfourl.__init__
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def __init__(self, url, code, msg, hdrs, fp):
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self.code = code
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self.msg = msg
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self.hdrs = hdrs
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self.fp = fp
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self.filename = url
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# The addinfourl classes depend on fp being a valid file
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# object. In some cases, the HTTPError may not have a valid
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# file object. If this happens, the simplest workaround is to
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# not initialize the base classes.
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if fp is not None:
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self.__super_init(fp, hdrs, url)
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def __str__(self):
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return 'HTTP Error %s: %s' % (self.code, self.msg)
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class GopherError(URLError):
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pass
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class Request:
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def __init__(self, url, data=None, headers={}):
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# unwrap('<URL:type://host/path>') --> 'type://host/path'
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self.__original = unwrap(url)
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self.type = None
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# self.__r_type is what's left after doing the splittype
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self.host = None
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self.port = None
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self.data = data
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self.headers = {}
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for key, value in headers.items():
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self.add_header(key, value)
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self.unredirected_hdrs = {}
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def __getattr__(self, attr):
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# XXX this is a fallback mechanism to guard against these
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# methods getting called in a non-standard order. this may be
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# too complicated and/or unnecessary.
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# XXX should the __r_XXX attributes be public?
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if attr[:12] == '_Request__r_':
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name = attr[12:]
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if hasattr(Request, 'get_' + name):
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getattr(self, 'get_' + name)()
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return getattr(self, attr)
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raise AttributeError, attr
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def get_method(self):
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if self.has_data():
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return "POST"
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else:
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return "GET"
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# XXX these helper methods are lame
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def add_data(self, data):
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self.data = data
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def has_data(self):
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return self.data is not None
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def get_data(self):
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return self.data
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def get_full_url(self):
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return self.__original
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def get_type(self):
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if self.type is None:
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self.type, self.__r_type = splittype(self.__original)
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if self.type is None:
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raise ValueError, "unknown url type: %s" % self.__original
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return self.type
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def get_host(self):
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if self.host is None:
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self.host, self.__r_host = splithost(self.__r_type)
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if self.host:
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self.host = unquote(self.host)
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return self.host
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def get_selector(self):
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return self.__r_host
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def set_proxy(self, host, type):
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self.host, self.type = host, type
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self.__r_host = self.__original
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def add_header(self, key, val):
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# useful for something like authentication
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self.headers[key.capitalize()] = val
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def add_unredirected_header(self, key, val):
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# will not be added to a redirected request
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self.unredirected_hdrs[key.capitalize()] = val
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def has_header(self, header_name):
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return bool(header_name in self.headers or
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header_name in self.unredirected_hdrs)
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class OpenerDirector:
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def __init__(self):
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server_version = "Python-urllib/%s" % __version__
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self.addheaders = [('User-agent', server_version)]
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# manage the individual handlers
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self.handlers = []
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self.handle_open = {}
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self.handle_error = {}
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self.process_response = {}
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self.process_request = {}
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def add_handler(self, handler):
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added = False
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for meth in dir(handler):
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i = meth.find("_")
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protocol = meth[:i]
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condition = meth[i+1:]
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if condition.startswith("error"):
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j = meth[i+1:].find("_") + i + 1
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kind = meth[j+1:]
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try:
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kind = int(kind)
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except ValueError:
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pass
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lookup = self.handle_error.get(protocol, {})
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self.handle_error[protocol] = lookup
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elif condition == "open":
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kind = protocol
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lookup = getattr(self, "handle_"+condition)
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elif condition in ["response", "request"]:
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kind = protocol
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lookup = getattr(self, "process_"+condition)
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else:
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continue
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handlers = lookup.setdefault(kind, [])
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if handlers:
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bisect.insort(handlers, handler)
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else:
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handlers.append(handler)
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added = True
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if added:
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# XXX why does self.handlers need to be sorted?
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bisect.insort(self.handlers, handler)
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handler.add_parent(self)
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def close(self):
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# Only exists for backwards compatibility.
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pass
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def _call_chain(self, chain, kind, meth_name, *args):
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# XXX raise an exception if no one else should try to handle
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# this url. return None if you can't but someone else could.
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handlers = chain.get(kind, ())
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for handler in handlers:
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func = getattr(handler, meth_name)
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result = func(*args)
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if result is not None:
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return result
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def open(self, fullurl, data=None):
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# accept a URL or a Request object
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if isinstance(fullurl, basestring):
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req = Request(fullurl, data)
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else:
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req = fullurl
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if data is not None:
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req.add_data(data)
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protocol = req.get_type()
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# pre-process request
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meth_name = protocol+"_request"
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for processor in self.process_request.get(protocol, []):
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meth = getattr(processor, meth_name)
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req = meth(req)
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response = self._open(req, data)
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# post-process response
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meth_name = protocol+"_response"
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for processor in self.process_response.get(protocol, []):
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meth = getattr(processor, meth_name)
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response = meth(req, response)
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return response
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def _open(self, req, data=None):
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result = self._call_chain(self.handle_open, 'default',
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'default_open', req)
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if result:
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return result
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protocol = req.get_type()
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result = self._call_chain(self.handle_open, protocol, protocol +
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'_open', req)
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if result:
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return result
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return self._call_chain(self.handle_open, 'unknown',
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'unknown_open', req)
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def error(self, proto, *args):
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if proto in ['http', 'https']:
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# XXX http[s] protocols are special-cased
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dict = self.handle_error['http'] # https is not different than http
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proto = args[2] # YUCK!
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meth_name = 'http_error_%s' % proto
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http_err = 1
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orig_args = args
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else:
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dict = self.handle_error
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meth_name = proto + '_error'
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http_err = 0
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args = (dict, proto, meth_name) + args
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result = self._call_chain(*args)
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if result:
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return result
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if http_err:
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args = (dict, 'default', 'http_error_default') + orig_args
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return self._call_chain(*args)
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# XXX probably also want an abstract factory that knows when it makes
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# sense to skip a superclass in favor of a subclass and when it might
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# make sense to include both
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def build_opener(*handlers):
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"""Create an opener object from a list of handlers.
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The opener will use several default handlers, including support
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for HTTP and FTP.
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If any of the handlers passed as arguments are subclasses of the
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default handlers, the default handlers will not be used.
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"""
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opener = OpenerDirector()
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default_classes = [ProxyHandler, UnknownHandler, HTTPHandler,
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HTTPDefaultErrorHandler, HTTPRedirectHandler,
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FTPHandler, FileHandler, HTTPErrorProcessor]
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if hasattr(httplib, 'HTTPS'):
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default_classes.append(HTTPSHandler)
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skip = []
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for klass in default_classes:
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for check in handlers:
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if inspect.isclass(check):
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if issubclass(check, klass):
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skip.append(klass)
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elif isinstance(check, klass):
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skip.append(klass)
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for klass in skip:
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default_classes.remove(klass)
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for klass in default_classes:
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opener.add_handler(klass())
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for h in handlers:
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if inspect.isclass(h):
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h = h()
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opener.add_handler(h)
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return opener
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class BaseHandler:
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handler_order = 500
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def add_parent(self, parent):
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self.parent = parent
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def close(self):
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# Only exists for backwards compatibility
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pass
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def __lt__(self, other):
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if not hasattr(other, "handler_order"):
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# Try to preserve the old behavior of having custom classes
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# inserted after default ones (works only for custom user
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# classes which are not aware of handler_order).
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return True
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return self.handler_order < other.handler_order
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class HTTPErrorProcessor(BaseHandler):
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"""Process HTTP error responses."""
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handler_order = 1000 # after all other processing
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def http_response(self, request, response):
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code, msg, hdrs = response.code, response.msg, response.info()
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if code != 200:
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response = self.parent.error(
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'http', request, response, code, msg, hdrs)
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return response
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https_response = http_response
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class HTTPDefaultErrorHandler(BaseHandler):
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def http_error_default(self, req, fp, code, msg, hdrs):
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raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)
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class HTTPRedirectHandler(BaseHandler):
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# maximum number of redirections before assuming we're in a loop
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max_redirections = 10
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def redirect_request(self, req, fp, code, msg, headers, newurl):
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"""Return a Request or None in response to a redirect.
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This is called by the http_error_30x methods when a
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redirection response is received. If a redirection should
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take place, return a new Request to allow http_error_30x to
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perform the redirect. Otherwise, raise HTTPError if no-one
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else should try to handle this url. Return None if you can't
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but another Handler might.
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"""
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m = req.get_method()
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if (code in (301, 302, 303, 307) and m in ("GET", "HEAD")
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or code in (301, 302, 303) and m == "POST"):
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# Strictly (according to RFC 2616), 301 or 302 in response
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# to a POST MUST NOT cause a redirection without confirmation
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# from the user (of urllib2, in this case). In practice,
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# essentially all clients do redirect in this case, so we
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# do the same.
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return Request(newurl, headers=req.headers)
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else:
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raise HTTPError(req.get_full_url(), code, msg, headers, fp)
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|
|
# Implementation note: To avoid the server sending us into an
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# infinite loop, the request object needs to track what URLs we
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# have already seen. Do this by adding a handler-specific
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# attribute to the Request object.
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def http_error_302(self, req, fp, code, msg, headers):
|
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if 'location' in headers:
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newurl = headers['location']
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elif 'uri' in headers:
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newurl = headers['uri']
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else:
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return
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newurl = urlparse.urljoin(req.get_full_url(), newurl)
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|
|
# XXX Probably want to forget about the state of the current
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# request, although that might interact poorly with other
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# handlers that also use handler-specific request attributes
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new = self.redirect_request(req, fp, code, msg, headers, newurl)
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if new is None:
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return
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|
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# loop detection
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|
# .redirect_dict has a key (url, code) if url was previously
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# visited as a result of a redirection with that code. The
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# code is needed in addition to the URL because visiting a URL
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|
# twice isn't necessarily a loop: there is more than one way
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# to redirect (301, 302, 303, 307, refresh).
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key = (newurl, code)
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if hasattr(req, 'redirect_dict'):
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visited = new.redirect_dict = req.redirect_dict
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if key in visited or len(visited) >= self.max_redirections:
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raise HTTPError(req.get_full_url(), code,
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self.inf_msg + msg, headers, fp)
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else:
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visited = new.redirect_dict = req.redirect_dict = {}
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visited[key] = None
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|
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# Don't close the fp until we are sure that we won't use it
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# with HTTPError.
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fp.read()
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fp.close()
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return self.parent.open(new)
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|
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http_error_301 = http_error_303 = http_error_307 = http_error_302
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|
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inf_msg = "The HTTP server returned a redirect error that would " \
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"lead to an infinite loop.\n" \
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"The last 30x error message was:\n"
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|
|
class ProxyHandler(BaseHandler):
|
|
# Proxies must be in front
|
|
handler_order = 100
|
|
|
|
def __init__(self, proxies=None):
|
|
if proxies is None:
|
|
proxies = getproxies()
|
|
assert hasattr(proxies, 'has_key'), "proxies must be a mapping"
|
|
self.proxies = proxies
|
|
for type, url in proxies.items():
|
|
setattr(self, '%s_open' % type,
|
|
lambda r, proxy=url, type=type, meth=self.proxy_open: \
|
|
meth(r, proxy, type))
|
|
|
|
def proxy_open(self, req, proxy, type):
|
|
orig_type = req.get_type()
|
|
type, r_type = splittype(proxy)
|
|
host, XXX = splithost(r_type)
|
|
if '@' in host:
|
|
user_pass, host = host.split('@', 1)
|
|
if ':' in user_pass:
|
|
user, password = user_pass.split(':', 1)
|
|
user_pass = base64.encodestring('%s:%s' % (unquote(user),
|
|
unquote(password)))
|
|
req.add_header('Proxy-authorization', 'Basic ' + user_pass)
|
|
host = unquote(host)
|
|
req.set_proxy(host, type)
|
|
if orig_type == type:
|
|
# let other handlers take care of it
|
|
# XXX this only makes sense if the proxy is before the
|
|
# other handlers
|
|
return None
|
|
else:
|
|
# need to start over, because the other handlers don't
|
|
# grok the proxy's URL type
|
|
return self.parent.open(req)
|
|
|
|
# feature suggested by Duncan Booth
|
|
# XXX custom is not a good name
|
|
class CustomProxy:
|
|
# either pass a function to the constructor or override handle
|
|
def __init__(self, proto, func=None, proxy_addr=None):
|
|
self.proto = proto
|
|
self.func = func
|
|
self.addr = proxy_addr
|
|
|
|
def handle(self, req):
|
|
if self.func and self.func(req):
|
|
return 1
|
|
|
|
def get_proxy(self):
|
|
return self.addr
|
|
|
|
class CustomProxyHandler(BaseHandler):
|
|
# Proxies must be in front
|
|
handler_order = 100
|
|
|
|
def __init__(self, *proxies):
|
|
self.proxies = {}
|
|
|
|
def proxy_open(self, req):
|
|
proto = req.get_type()
|
|
try:
|
|
proxies = self.proxies[proto]
|
|
except KeyError:
|
|
return None
|
|
for p in proxies:
|
|
if p.handle(req):
|
|
req.set_proxy(p.get_proxy())
|
|
return self.parent.open(req)
|
|
return None
|
|
|
|
def do_proxy(self, p, req):
|
|
return self.parent.open(req)
|
|
|
|
def add_proxy(self, cpo):
|
|
if cpo.proto in self.proxies:
|
|
self.proxies[cpo.proto].append(cpo)
|
|
else:
|
|
self.proxies[cpo.proto] = [cpo]
|
|
|
|
class HTTPPasswordMgr:
|
|
def __init__(self):
|
|
self.passwd = {}
|
|
|
|
def add_password(self, realm, uri, user, passwd):
|
|
# uri could be a single URI or a sequence
|
|
if isinstance(uri, basestring):
|
|
uri = [uri]
|
|
uri = tuple(map(self.reduce_uri, uri))
|
|
if not realm in self.passwd:
|
|
self.passwd[realm] = {}
|
|
self.passwd[realm][uri] = (user, passwd)
|
|
|
|
def find_user_password(self, realm, authuri):
|
|
domains = self.passwd.get(realm, {})
|
|
authuri = self.reduce_uri(authuri)
|
|
for uris, authinfo in domains.iteritems():
|
|
for uri in uris:
|
|
if self.is_suburi(uri, authuri):
|
|
return authinfo
|
|
return None, None
|
|
|
|
def reduce_uri(self, uri):
|
|
"""Accept netloc or URI and extract only the netloc and path"""
|
|
parts = urlparse.urlparse(uri)
|
|
if parts[1]:
|
|
return parts[1], parts[2] or '/'
|
|
else:
|
|
return parts[2], '/'
|
|
|
|
def is_suburi(self, base, test):
|
|
"""Check if test is below base in a URI tree
|
|
|
|
Both args must be URIs in reduced form.
|
|
"""
|
|
if base == test:
|
|
return True
|
|
if base[0] != test[0]:
|
|
return False
|
|
common = posixpath.commonprefix((base[1], test[1]))
|
|
if len(common) == len(base[1]):
|
|
return True
|
|
return False
|
|
|
|
|
|
class HTTPPasswordMgrWithDefaultRealm(HTTPPasswordMgr):
|
|
|
|
def find_user_password(self, realm, authuri):
|
|
user, password = HTTPPasswordMgr.find_user_password(self, realm,
|
|
authuri)
|
|
if user is not None:
|
|
return user, password
|
|
return HTTPPasswordMgr.find_user_password(self, None, authuri)
|
|
|
|
|
|
class AbstractBasicAuthHandler:
|
|
|
|
rx = re.compile('[ \t]*([^ \t]+)[ \t]+realm="([^"]*)"', re.I)
|
|
|
|
# XXX there can actually be multiple auth-schemes in a
|
|
# www-authenticate header. should probably be a lot more careful
|
|
# in parsing them to extract multiple alternatives
|
|
|
|
def __init__(self, password_mgr=None):
|
|
if password_mgr is None:
|
|
password_mgr = HTTPPasswordMgr()
|
|
self.passwd = password_mgr
|
|
self.add_password = self.passwd.add_password
|
|
|
|
def http_error_auth_reqed(self, authreq, host, req, headers):
|
|
# XXX could be multiple headers
|
|
authreq = headers.get(authreq, None)
|
|
if authreq:
|
|
mo = AbstractBasicAuthHandler.rx.match(authreq)
|
|
if mo:
|
|
scheme, realm = mo.groups()
|
|
if scheme.lower() == 'basic':
|
|
return self.retry_http_basic_auth(host, req, realm)
|
|
|
|
def retry_http_basic_auth(self, host, req, realm):
|
|
user,pw = self.passwd.find_user_password(realm, host)
|
|
if pw is not None:
|
|
raw = "%s:%s" % (user, pw)
|
|
auth = 'Basic %s' % base64.encodestring(raw).strip()
|
|
if req.headers.get(self.auth_header, None) == auth:
|
|
return None
|
|
req.add_header(self.auth_header, auth)
|
|
return self.parent.open(req)
|
|
else:
|
|
return None
|
|
|
|
class HTTPBasicAuthHandler(AbstractBasicAuthHandler, BaseHandler):
|
|
|
|
auth_header = 'Authorization'
|
|
|
|
def http_error_401(self, req, fp, code, msg, headers):
|
|
host = urlparse.urlparse(req.get_full_url())[1]
|
|
return self.http_error_auth_reqed('www-authenticate',
|
|
host, req, headers)
|
|
|
|
|
|
class ProxyBasicAuthHandler(AbstractBasicAuthHandler, BaseHandler):
|
|
|
|
auth_header = 'Proxy-authorization'
|
|
|
|
def http_error_407(self, req, fp, code, msg, headers):
|
|
host = req.get_host()
|
|
return self.http_error_auth_reqed('proxy-authenticate',
|
|
host, req, headers)
|
|
|
|
|
|
def randombytes(n):
|
|
"""Return n random bytes."""
|
|
# Use /dev/urandom if it is available. Fall back to random module
|
|
# if not. It might be worthwhile to extend this function to use
|
|
# other platform-specific mechanisms for getting random bytes.
|
|
if os.path.exists("/dev/urandom"):
|
|
f = open("/dev/urandom")
|
|
s = f.read(n)
|
|
f.close()
|
|
return s
|
|
else:
|
|
L = [chr(random.randrange(0, 256)) for i in range(n)]
|
|
return "".join(L)
|
|
|
|
class AbstractDigestAuthHandler:
|
|
# Digest authentication is specified in RFC 2617.
|
|
|
|
# XXX The client does not inspect the Authentication-Info header
|
|
# in a successful response.
|
|
|
|
# XXX It should be possible to test this implementation against
|
|
# a mock server that just generates a static set of challenges.
|
|
|
|
# XXX qop="auth-int" supports is shaky
|
|
|
|
def __init__(self, passwd=None):
|
|
if passwd is None:
|
|
passwd = HTTPPasswordMgr()
|
|
self.passwd = passwd
|
|
self.add_password = self.passwd.add_password
|
|
self.retried = 0
|
|
self.nonce_count = 0
|
|
|
|
def reset_retry_count(self):
|
|
self.retried = 0
|
|
|
|
def http_error_auth_reqed(self, auth_header, host, req, headers):
|
|
authreq = headers.get(auth_header, None)
|
|
if self.retried > 5:
|
|
# Don't fail endlessly - if we failed once, we'll probably
|
|
# fail a second time. Hm. Unless the Password Manager is
|
|
# prompting for the information. Crap. This isn't great
|
|
# but it's better than the current 'repeat until recursion
|
|
# depth exceeded' approach <wink>
|
|
raise HTTPError(req.get_full_url(), 401, "digest auth failed",
|
|
headers, None)
|
|
else:
|
|
self.retried += 1
|
|
if authreq:
|
|
scheme = authreq.split()[0]
|
|
if scheme.lower() == 'digest':
|
|
return self.retry_http_digest_auth(req, authreq)
|
|
else:
|
|
raise ValueError("AbstractDigestAuthHandler doesn't know "
|
|
"about %s"%(scheme))
|
|
|
|
def retry_http_digest_auth(self, req, auth):
|
|
token, challenge = auth.split(' ', 1)
|
|
chal = parse_keqv_list(parse_http_list(challenge))
|
|
auth = self.get_authorization(req, chal)
|
|
if auth:
|
|
auth_val = 'Digest %s' % auth
|
|
if req.headers.get(self.auth_header, None) == auth_val:
|
|
return None
|
|
req.add_header(self.auth_header, auth_val)
|
|
resp = self.parent.open(req)
|
|
return resp
|
|
|
|
def get_cnonce(self, nonce):
|
|
# The cnonce-value is an opaque
|
|
# quoted string value provided by the client and used by both client
|
|
# and server to avoid chosen plaintext attacks, to provide mutual
|
|
# authentication, and to provide some message integrity protection.
|
|
# This isn't a fabulous effort, but it's probably Good Enough.
|
|
dig = sha.new("%s:%s:%s:%s" % (self.nonce_count, nonce, time.ctime(),
|
|
randombytes(8))).hexdigest()
|
|
return dig[:16]
|
|
|
|
def get_authorization(self, req, chal):
|
|
try:
|
|
realm = chal['realm']
|
|
nonce = chal['nonce']
|
|
qop = chal.get('qop')
|
|
algorithm = chal.get('algorithm', 'MD5')
|
|
# mod_digest doesn't send an opaque, even though it isn't
|
|
# supposed to be optional
|
|
opaque = chal.get('opaque', None)
|
|
except KeyError:
|
|
return None
|
|
|
|
H, KD = self.get_algorithm_impls(algorithm)
|
|
if H is None:
|
|
return None
|
|
|
|
user, pw = self.passwd.find_user_password(realm, req.get_full_url())
|
|
if user is None:
|
|
return None
|
|
|
|
# XXX not implemented yet
|
|
if req.has_data():
|
|
entdig = self.get_entity_digest(req.get_data(), chal)
|
|
else:
|
|
entdig = None
|
|
|
|
A1 = "%s:%s:%s" % (user, realm, pw)
|
|
A2 = "%s:%s" % (req.has_data() and 'POST' or 'GET',
|
|
# XXX selector: what about proxies and full urls
|
|
req.get_selector())
|
|
if qop == 'auth':
|
|
self.nonce_count += 1
|
|
ncvalue = '%08x' % self.nonce_count
|
|
cnonce = self.get_cnonce(nonce)
|
|
noncebit = "%s:%s:%s:%s:%s" % (nonce, ncvalue, cnonce, qop, H(A2))
|
|
respdig = KD(H(A1), noncebit)
|
|
elif qop is None:
|
|
respdig = KD(H(A1), "%s:%s" % (nonce, H(A2)))
|
|
else:
|
|
# XXX handle auth-int.
|
|
pass
|
|
|
|
# XXX should the partial digests be encoded too?
|
|
|
|
base = 'username="%s", realm="%s", nonce="%s", uri="%s", ' \
|
|
'response="%s"' % (user, realm, nonce, req.get_selector(),
|
|
respdig)
|
|
if opaque:
|
|
base = base + ', opaque="%s"' % opaque
|
|
if entdig:
|
|
base = base + ', digest="%s"' % entdig
|
|
if algorithm != 'MD5':
|
|
base = base + ', algorithm="%s"' % algorithm
|
|
if qop:
|
|
base = base + ', qop=auth, nc=%s, cnonce="%s"' % (ncvalue, cnonce)
|
|
return base
|
|
|
|
def get_algorithm_impls(self, algorithm):
|
|
# lambdas assume digest modules are imported at the top level
|
|
if algorithm == 'MD5':
|
|
H = lambda x: md5.new(x).hexdigest()
|
|
elif algorithm == 'SHA':
|
|
H = lambda x: sha.new(x).hexdigest()
|
|
# XXX MD5-sess
|
|
KD = lambda s, d: H("%s:%s" % (s, d))
|
|
return H, KD
|
|
|
|
def get_entity_digest(self, data, chal):
|
|
# XXX not implemented yet
|
|
return None
|
|
|
|
|
|
class HTTPDigestAuthHandler(BaseHandler, AbstractDigestAuthHandler):
|
|
"""An authentication protocol defined by RFC 2069
|
|
|
|
Digest authentication improves on basic authentication because it
|
|
does not transmit passwords in the clear.
|
|
"""
|
|
|
|
auth_header = 'Authorization'
|
|
|
|
def http_error_401(self, req, fp, code, msg, headers):
|
|
host = urlparse.urlparse(req.get_full_url())[1]
|
|
retry = self.http_error_auth_reqed('www-authenticate',
|
|
host, req, headers)
|
|
self.reset_retry_count()
|
|
return retry
|
|
|
|
|
|
class ProxyDigestAuthHandler(BaseHandler, AbstractDigestAuthHandler):
|
|
|
|
auth_header = 'Proxy-Authorization'
|
|
|
|
def http_error_407(self, req, fp, code, msg, headers):
|
|
host = req.get_host()
|
|
retry = self.http_error_auth_reqed('proxy-authenticate',
|
|
host, req, headers)
|
|
self.reset_retry_count()
|
|
return retry
|
|
|
|
class AbstractHTTPHandler(BaseHandler):
|
|
|
|
def __init__(self, debuglevel=0):
|
|
self._debuglevel = debuglevel
|
|
|
|
def set_http_debuglevel(self, level):
|
|
self._debuglevel = level
|
|
|
|
def do_request(self, request):
|
|
host = request.get_host()
|
|
if not host:
|
|
raise URLError('no host given')
|
|
|
|
if request.has_data(): # POST
|
|
data = request.get_data()
|
|
if not request.has_header('Content-type'):
|
|
request.add_unredirected_header(
|
|
'Content-type',
|
|
'application/x-www-form-urlencoded')
|
|
if not request.has_header('Content-length'):
|
|
request.add_unredirected_header(
|
|
'Content-length', '%d' % len(data))
|
|
|
|
scheme, sel = splittype(request.get_selector())
|
|
sel_host, sel_path = splithost(sel)
|
|
if not request.has_header('Host'):
|
|
request.add_unredirected_header('Host', sel_host or host)
|
|
for name, value in self.parent.addheaders:
|
|
name = name.capitalize()
|
|
if not request.has_header(name):
|
|
request.add_unredirected_header(name, value)
|
|
|
|
return request
|
|
|
|
def do_open(self, http_class, req):
|
|
"""Return an addinfourl object for the request, using http_class.
|
|
|
|
http_class must implement the HTTPConnection API from httplib.
|
|
The addinfourl return value is a file-like object. It also
|
|
has methods and attributes including:
|
|
- info(): return a mimetools.Message object for the headers
|
|
- geturl(): return the original request URL
|
|
- code: HTTP status code
|
|
"""
|
|
host = req.get_host()
|
|
if not host:
|
|
raise URLError('no host given')
|
|
|
|
h = http_class(host) # will parse host:port
|
|
h.set_debuglevel(self._debuglevel)
|
|
|
|
headers = dict(req.headers)
|
|
headers.update(req.unredirected_hdrs)
|
|
# We want to make an HTTP/1.1 request, but the addinfourl
|
|
# class isn't prepared to deal with a persistent connection.
|
|
# It will try to read all remaining data from the socket,
|
|
# which will block while the server waits for the next request.
|
|
# So make sure the connection gets closed after the (only)
|
|
# request.
|
|
headers["Connection"] = "close"
|
|
try:
|
|
h.request(req.get_method(), req.get_selector(), req.data, headers)
|
|
r = h.getresponse()
|
|
except socket.error, err: # XXX what error?
|
|
raise URLError(err)
|
|
|
|
if r.status == 200:
|
|
# Pick apart the HTTPResponse object to get the addinfourl
|
|
# object initialized properly
|
|
resp = addinfourl(r.fp, r.msg, req.get_full_url())
|
|
resp.code = r.status
|
|
resp.msg = r.reason
|
|
return resp
|
|
else:
|
|
return self.parent.error("http", req, r.fp, r.status, r.msg,
|
|
r.msg.dict)
|
|
|
|
|
|
class HTTPHandler(AbstractHTTPHandler):
|
|
|
|
def http_open(self, req):
|
|
return self.do_open(httplib.HTTPConnection, req)
|
|
|
|
http_request = AbstractHTTPHandler.do_request
|
|
|
|
if hasattr(httplib, 'HTTPS'):
|
|
class HTTPSHandler(AbstractHTTPHandler):
|
|
|
|
def https_open(self, req):
|
|
return self.do_open(httplib.HTTPSConnection, req)
|
|
|
|
https_request = AbstractHTTPHandler.do_request
|
|
|
|
class UnknownHandler(BaseHandler):
|
|
def unknown_open(self, req):
|
|
type = req.get_type()
|
|
raise URLError('unknown url type: %s' % type)
|
|
|
|
def parse_keqv_list(l):
|
|
"""Parse list of key=value strings where keys are not duplicated."""
|
|
parsed = {}
|
|
for elt in l:
|
|
k, v = elt.split('=', 1)
|
|
if v[0] == '"' and v[-1] == '"':
|
|
v = v[1:-1]
|
|
parsed[k] = v
|
|
return parsed
|
|
|
|
def parse_http_list(s):
|
|
"""Parse lists as described by RFC 2068 Section 2.
|
|
|
|
In particular, parse comma-separated lists where the elements of
|
|
the list may include quoted-strings. A quoted-string could
|
|
contain a comma.
|
|
"""
|
|
# XXX this function could probably use more testing
|
|
|
|
list = []
|
|
end = len(s)
|
|
i = 0
|
|
inquote = 0
|
|
start = 0
|
|
while i < end:
|
|
cur = s[i:]
|
|
c = cur.find(',')
|
|
q = cur.find('"')
|
|
if c == -1:
|
|
list.append(s[start:])
|
|
break
|
|
if q == -1:
|
|
if inquote:
|
|
raise ValueError, "unbalanced quotes"
|
|
else:
|
|
list.append(s[start:i+c])
|
|
i = i + c + 1
|
|
continue
|
|
if inquote:
|
|
if q < c:
|
|
list.append(s[start:i+c])
|
|
i = i + c + 1
|
|
start = i
|
|
inquote = 0
|
|
else:
|
|
i = i + q
|
|
else:
|
|
if c < q:
|
|
list.append(s[start:i+c])
|
|
i = i + c + 1
|
|
start = i
|
|
else:
|
|
inquote = 1
|
|
i = i + q + 1
|
|
return map(lambda x: x.strip(), list)
|
|
|
|
class FileHandler(BaseHandler):
|
|
# Use local file or FTP depending on form of URL
|
|
def file_open(self, req):
|
|
url = req.get_selector()
|
|
if url[:2] == '//' and url[2:3] != '/':
|
|
req.type = 'ftp'
|
|
return self.parent.open(req)
|
|
else:
|
|
return self.open_local_file(req)
|
|
|
|
# names for the localhost
|
|
names = None
|
|
def get_names(self):
|
|
if FileHandler.names is None:
|
|
FileHandler.names = (socket.gethostbyname('localhost'),
|
|
socket.gethostbyname(socket.gethostname()))
|
|
return FileHandler.names
|
|
|
|
# not entirely sure what the rules are here
|
|
def open_local_file(self, req):
|
|
host = req.get_host()
|
|
file = req.get_selector()
|
|
localfile = url2pathname(file)
|
|
stats = os.stat(localfile)
|
|
size = stats.st_size
|
|
modified = rfc822.formatdate(stats.st_mtime)
|
|
mtype = mimetypes.guess_type(file)[0]
|
|
headers = mimetools.Message(StringIO(
|
|
'Content-type: %s\nContent-length: %d\nLast-modified: %s\n' %
|
|
(mtype or 'text/plain', size, modified)))
|
|
if host:
|
|
host, port = splitport(host)
|
|
if not host or \
|
|
(not port and socket.gethostbyname(host) in self.get_names()):
|
|
return addinfourl(open(localfile, 'rb'),
|
|
headers, 'file:'+file)
|
|
raise URLError('file not on local host')
|
|
|
|
class FTPHandler(BaseHandler):
|
|
def ftp_open(self, req):
|
|
host = req.get_host()
|
|
if not host:
|
|
raise IOError, ('ftp error', 'no host given')
|
|
host, port = splitport(host)
|
|
if port is None:
|
|
port = ftplib.FTP_PORT
|
|
|
|
# username/password handling
|
|
user, host = splituser(host)
|
|
if user:
|
|
user, passwd = splitpasswd(user)
|
|
else:
|
|
passwd = None
|
|
host = unquote(host)
|
|
user = unquote(user or '')
|
|
passwd = unquote(passwd or '')
|
|
|
|
try:
|
|
host = socket.gethostbyname(host)
|
|
except socket.error, msg:
|
|
raise URLError(msg)
|
|
path, attrs = splitattr(req.get_selector())
|
|
dirs = path.split('/')
|
|
dirs = map(unquote, dirs)
|
|
dirs, file = dirs[:-1], dirs[-1]
|
|
if dirs and not dirs[0]:
|
|
dirs = dirs[1:]
|
|
try:
|
|
fw = self.connect_ftp(user, passwd, host, port, dirs)
|
|
type = file and 'I' or 'D'
|
|
for attr in attrs:
|
|
attr, value = splitattr(attr)
|
|
if attr.lower() == 'type' and \
|
|
value in ('a', 'A', 'i', 'I', 'd', 'D'):
|
|
type = value.upper()
|
|
fp, retrlen = fw.retrfile(file, type)
|
|
headers = ""
|
|
mtype = mimetypes.guess_type(req.get_full_url())[0]
|
|
if mtype:
|
|
headers += "Content-type: %s\n" % mtype
|
|
if retrlen is not None and retrlen >= 0:
|
|
headers += "Content-length: %d\n" % retrlen
|
|
sf = StringIO(headers)
|
|
headers = mimetools.Message(sf)
|
|
return addinfourl(fp, headers, req.get_full_url())
|
|
except ftplib.all_errors, msg:
|
|
raise IOError, ('ftp error', msg), sys.exc_info()[2]
|
|
|
|
def connect_ftp(self, user, passwd, host, port, dirs):
|
|
fw = ftpwrapper(user, passwd, host, port, dirs)
|
|
## fw.ftp.set_debuglevel(1)
|
|
return fw
|
|
|
|
class CacheFTPHandler(FTPHandler):
|
|
# XXX would be nice to have pluggable cache strategies
|
|
# XXX this stuff is definitely not thread safe
|
|
def __init__(self):
|
|
self.cache = {}
|
|
self.timeout = {}
|
|
self.soonest = 0
|
|
self.delay = 60
|
|
self.max_conns = 16
|
|
|
|
def setTimeout(self, t):
|
|
self.delay = t
|
|
|
|
def setMaxConns(self, m):
|
|
self.max_conns = m
|
|
|
|
def connect_ftp(self, user, passwd, host, port, dirs):
|
|
key = user, host, port, '/'.join(dirs)
|
|
if key in self.cache:
|
|
self.timeout[key] = time.time() + self.delay
|
|
else:
|
|
self.cache[key] = ftpwrapper(user, passwd, host, port, dirs)
|
|
self.timeout[key] = time.time() + self.delay
|
|
self.check_cache()
|
|
return self.cache[key]
|
|
|
|
def check_cache(self):
|
|
# first check for old ones
|
|
t = time.time()
|
|
if self.soonest <= t:
|
|
for k, v in self.timeout.items():
|
|
if v < t:
|
|
self.cache[k].close()
|
|
del self.cache[k]
|
|
del self.timeout[k]
|
|
self.soonest = min(self.timeout.values())
|
|
|
|
# then check the size
|
|
if len(self.cache) == self.max_conns:
|
|
for k, v in self.timeout.items():
|
|
if v == self.soonest:
|
|
del self.cache[k]
|
|
del self.timeout[k]
|
|
break
|
|
self.soonest = min(self.timeout.values())
|
|
|
|
class GopherHandler(BaseHandler):
|
|
def gopher_open(self, req):
|
|
host = req.get_host()
|
|
if not host:
|
|
raise GopherError('no host given')
|
|
host = unquote(host)
|
|
selector = req.get_selector()
|
|
type, selector = splitgophertype(selector)
|
|
selector, query = splitquery(selector)
|
|
selector = unquote(selector)
|
|
if query:
|
|
query = unquote(query)
|
|
fp = gopherlib.send_query(selector, query, host)
|
|
else:
|
|
fp = gopherlib.send_selector(selector, host)
|
|
return addinfourl(fp, noheaders(), req.get_full_url())
|
|
|
|
#bleck! don't use this yet
|
|
class OpenerFactory:
|
|
|
|
default_handlers = [UnknownHandler, HTTPHandler,
|
|
HTTPDefaultErrorHandler, HTTPRedirectHandler,
|
|
FTPHandler, FileHandler]
|
|
handlers = []
|
|
replacement_handlers = []
|
|
|
|
def add_handler(self, h):
|
|
self.handlers = self.handlers + [h]
|
|
|
|
def replace_handler(self, h):
|
|
pass
|
|
|
|
def build_opener(self):
|
|
opener = OpenerDirector()
|
|
for ph in self.default_handlers:
|
|
if inspect.isclass(ph):
|
|
ph = ph()
|
|
opener.add_handler(ph)
|
|
|
|
if __name__ == "__main__":
|
|
# XXX some of the test code depends on machine configurations that
|
|
# are internal to CNRI. Need to set up a public server with the
|
|
# right authentication configuration for test purposes.
|
|
if socket.gethostname() == 'bitdiddle':
|
|
localhost = 'bitdiddle.cnri.reston.va.us'
|
|
elif socket.gethostname() == 'bitdiddle.concentric.net':
|
|
localhost = 'localhost'
|
|
else:
|
|
localhost = None
|
|
urls = [
|
|
# Thanks to Fred for finding these!
|
|
'gopher://gopher.lib.ncsu.edu/11/library/stacks/Alex',
|
|
'gopher://gopher.vt.edu:10010/10/33',
|
|
|
|
'file:/etc/passwd',
|
|
'file://nonsensename/etc/passwd',
|
|
'ftp://www.python.org/pub/python/misc/sousa.au',
|
|
'ftp://www.python.org/pub/tmp/blat',
|
|
'http://www.espn.com/', # redirect
|
|
'http://www.python.org/Spanish/Inquistion/',
|
|
('http://www.python.org/cgi-bin/faqw.py',
|
|
'query=pythonistas&querytype=simple&casefold=yes&req=search'),
|
|
'http://www.python.org/',
|
|
'ftp://gatekeeper.research.compaq.com/pub/DEC/SRC/research-reports/00README-Legal-Rules-Regs',
|
|
]
|
|
|
|
## if localhost is not None:
|
|
## urls = urls + [
|
|
## 'file://%s/etc/passwd' % localhost,
|
|
## 'http://%s/simple/' % localhost,
|
|
## 'http://%s/digest/' % localhost,
|
|
## 'http://%s/not/found.h' % localhost,
|
|
## ]
|
|
|
|
## bauth = HTTPBasicAuthHandler()
|
|
## bauth.add_password('basic_test_realm', localhost, 'jhylton',
|
|
## 'password')
|
|
## dauth = HTTPDigestAuthHandler()
|
|
## dauth.add_password('digest_test_realm', localhost, 'jhylton',
|
|
## 'password')
|
|
|
|
|
|
cfh = CacheFTPHandler()
|
|
cfh.setTimeout(1)
|
|
|
|
## # XXX try out some custom proxy objects too!
|
|
## def at_cnri(req):
|
|
## host = req.get_host()
|
|
## print host
|
|
## if host[-18:] == '.cnri.reston.va.us':
|
|
## return 1
|
|
## p = CustomProxy('http', at_cnri, 'proxy.cnri.reston.va.us')
|
|
## ph = CustomProxyHandler(p)
|
|
|
|
## install_opener(build_opener(dauth, bauth, cfh, GopherHandler, ph))
|
|
install_opener(build_opener(cfh, GopherHandler))
|
|
|
|
for url in urls:
|
|
if isinstance(url, tuple):
|
|
url, req = url
|
|
else:
|
|
req = None
|
|
print url
|
|
try:
|
|
f = urlopen(url, req)
|
|
except IOError, err:
|
|
print "IOError:", err
|
|
except socket.error, err:
|
|
print "socket.error:", err
|
|
else:
|
|
buf = f.read()
|
|
f.close()
|
|
print "read %d bytes" % len(buf)
|
|
print
|
|
time.sleep(0.1)
|