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c1be59f40a
John J. Lee writes: "the patch makes it possible to implement functionality like HTTP cookie handling, Refresh handling, etc. etc. using handler objects. At the moment urllib2's handler objects aren't quite up to the job, which results in a lot of cut-n-paste and subclassing. I believe the changes are backwards-compatible, with the exception of people who've reimplemented build_opener()'s functionality -- those people would need to call opener.add_handler(HTTPErrorProcessor). The main change is allowing handlers to implement methods like: http_request(request) http_response(request, response) In addition to the usual http_open(request) http_error{_*}(...) " Note that the change isn't well documented at least in part because handlers aren't well documented at all. Need to fix this. Add a bunch of new tests. It appears that none of these tests actually use the network, so they don't need to be guarded by a resource flag.
1303 lines
43 KiB
Python
1303 lines
43 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
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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__ = "2.1"
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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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def __del__(self):
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# XXX is this safe? what if user catches exception, then
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# extracts fp and discards exception?
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if self.fp:
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self.fp.close()
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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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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 __del__(self):
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self.close()
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def close(self):
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for handler in self.handlers:
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handler.close()
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self.handlers = []
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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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self.parent = None
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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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|
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class HTTPErrorProcessor(BaseHandler):
|
|
"""Process HTTP error responses."""
|
|
handler_order = 1000 # after all other processing
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|
|
def http_response(self, request, response):
|
|
code, msg, hdrs = response.code, response.msg, response.info()
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|
|
|
if code != 200:
|
|
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):
|
|
def http_error_default(self, req, fp, code, msg, hdrs):
|
|
raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)
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|
|
class HTTPRedirectHandler(BaseHandler):
|
|
# maximum number of redirections before assuming we're in a loop
|
|
max_redirections = 10
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|
|
|
def redirect_request(self, req, fp, code, msg, headers, newurl):
|
|
"""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
|
|
redirection response is received. If a redirection should
|
|
take place, return a new Request to allow http_error_30x to
|
|
perform the redirect. Otherwise, raise HTTPError if no-one
|
|
else should try to handle this url. Return None if you can't
|
|
but another Handler might.
|
|
"""
|
|
m = req.get_method()
|
|
if (code in (301, 302, 303, 307) and m in ("GET", "HEAD")
|
|
or code in (301, 302, 303) and m == "POST"):
|
|
# Strictly (according to RFC 2616), 301 or 302 in response
|
|
# to a POST MUST NOT cause a redirection without confirmation
|
|
# from the user (of urllib2, in this case). In practice,
|
|
# essentially all clients do redirect in this case, so we
|
|
# do the same.
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|
return Request(newurl, headers=req.headers)
|
|
else:
|
|
raise HTTPError(req.get_full_url(), code, msg, headers, fp)
|
|
|
|
# Implementation note: To avoid the server sending us into an
|
|
# infinite loop, the request object needs to track what URLs we
|
|
# have already seen. Do this by adding a handler-specific
|
|
# attribute to the Request object.
|
|
def http_error_302(self, req, fp, code, msg, headers):
|
|
if 'location' in headers:
|
|
newurl = headers['location']
|
|
elif 'uri' in headers:
|
|
newurl = headers['uri']
|
|
else:
|
|
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
|
|
# request, although that might interact poorly with other
|
|
# handlers that also use handler-specific request attributes
|
|
new = self.redirect_request(req, fp, code, msg, headers, newurl)
|
|
if new is None:
|
|
return
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|
|
|
# loop detection
|
|
# .redirect_dict has a key (url, code) if url was previously
|
|
# visited as a result of a redirection with that code. The
|
|
# code is needed in addition to the URL because visiting a URL
|
|
# twice isn't necessarily a loop: there is more than one way
|
|
# to redirect (301, 302, 303, 307, refresh).
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|
key = (newurl, code)
|
|
if hasattr(req, 'redirect_dict'):
|
|
visited = new.redirect_dict = req.redirect_dict
|
|
if key in visited or len(visited) >= self.max_redirections:
|
|
raise HTTPError(req.get_full_url(), code,
|
|
self.inf_msg + msg, headers, fp)
|
|
else:
|
|
visited = new.redirect_dict = req.redirect_dict = {}
|
|
visited[key] = None
|
|
|
|
# Don't close the fp until we are sure that we won't use it
|
|
# with HTTPError.
|
|
fp.read()
|
|
fp.close()
|
|
|
|
return self.parent.open(new)
|
|
|
|
http_error_301 = http_error_303 = http_error_307 = http_error_302
|
|
|
|
inf_msg = "The HTTP server returned a redirect error that would " \
|
|
"lead to an infinite loop.\n" \
|
|
"The last 30x error message was:\n"
|
|
|
|
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:
|
|
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
|
|
|
|
# XXX Should rewrite do_open() to use the new httplib interface,
|
|
# would be a little simpler.
|
|
|
|
def do_open(self, http_class, req):
|
|
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)
|
|
|
|
h.putrequest(req.get_method(), req.get_selector())
|
|
for k, v in req.headers.items():
|
|
h.putheader(k, v)
|
|
for k, v in req.unredirected_hdrs.items():
|
|
h.putheader(k, v)
|
|
# httplib will attempt to connect() here. be prepared
|
|
# to convert a socket error to a URLError.
|
|
try:
|
|
h.endheaders()
|
|
except socket.error, err:
|
|
raise URLError(err)
|
|
if req.has_data():
|
|
h.send(req.get_data())
|
|
|
|
code, msg, hdrs = h.getreply()
|
|
fp = h.getfile()
|
|
response = addinfourl(fp, hdrs, req.get_full_url())
|
|
# XXXX should these be methods, for uniformity with rest of interface?
|
|
response.code = code
|
|
response.msg = msg
|
|
return response
|
|
|
|
|
|
class HTTPHandler(AbstractHTTPHandler):
|
|
|
|
def http_open(self, req):
|
|
return self.do_open(httplib.HTTP, req)
|
|
|
|
http_request = AbstractHTTPHandler.do_request
|
|
|
|
if hasattr(httplib, 'HTTPS'):
|
|
class HTTPSHandler(AbstractHTTPHandler):
|
|
|
|
def https_open(self, req):
|
|
return self.do_open(httplib.HTTPS, 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 comman-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')
|
|
# XXX handle custom username & password
|
|
try:
|
|
host = socket.gethostbyname(host)
|
|
except socket.error, msg:
|
|
raise URLError(msg)
|
|
host, port = splitport(host)
|
|
if port is None:
|
|
port = ftplib.FTP_PORT
|
|
path, attrs = splitattr(req.get_selector())
|
|
path = unquote(path)
|
|
dirs = path.split('/')
|
|
dirs, file = dirs[:-1], dirs[-1]
|
|
if dirs and not dirs[0]:
|
|
dirs = dirs[1:]
|
|
user = passwd = '' # XXX
|
|
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, passwd, host, port
|
|
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)
|