Modul struktur angelegt und request klasse eingefügt

5 files changed, 807 insertions, 0 deletions

diff --git a/module/__init__.py b/module/__init__.py
new file mode 100644
index 000000000..8d1c8b69c
--- /dev/null
+++ b/module/__init__.py
@@ -0,0 +1 @@
+ 
diff --git a/module/network/Keepalive.py b/module/network/Keepalive.py
new file mode 100644
index 000000000..68abe087d
--- /dev/null
+++ b/module/network/Keepalive.py
@@ -0,0 +1,617 @@
+#   This library is free software; you can redistribute it and/or
+#   modify it under the terms of the GNU Lesser General Public
+#   License as published by the Free Software Foundation; either
+#   version 2.1 of the License, or (at your option) any later version.
+#
+#   This library is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+#   Lesser General Public License for more details.
+#
+#   You should have received a copy of the GNU Lesser General Public
+#   License along with this library; if not, write to the 
+#      Free Software Foundation, Inc., 
+#      59 Temple Place, Suite 330, 
+#      Boston, MA  02111-1307  USA
+
+# This file is part of urlgrabber, a high-level cross-protocol url-grabber
+# Copyright 2002-2004 Michael D. Stenner, Ryan Tomayko
+
+"""An HTTP handler for urllib2 that supports HTTP 1.1 and keepalive.
+
+>>> import urllib2
+>>> from keepalive import HTTPHandler
+>>> keepalive_handler = HTTPHandler()
+>>> opener = urllib2.build_opener(keepalive_handler)
+>>> urllib2.install_opener(opener)
+>>> 
+>>> fo = urllib2.urlopen('http://www.python.org')
+
+If a connection to a given host is requested, and all of the existing
+connections are still in use, another connection will be opened.  If
+the handler tries to use an existing connection but it fails in some
+way, it will be closed and removed from the pool.
+
+To remove the handler, simply re-run build_opener with no arguments, and
+install that opener.
+
+You can explicitly close connections by using the close_connection()
+method of the returned file-like object (described below) or you can
+use the handler methods:
+
+  close_connection(host)
+  close_all()
+  open_connections()
+
+NOTE: using the close_connection and close_all methods of the handler
+should be done with care when using multiple threads.
+  * there is nothing that prevents another thread from creating new
+    connections immediately after connections are closed
+  * no checks are done to prevent in-use connections from being closed
+
+>>> keepalive_handler.close_all()
+
+EXTRA ATTRIBUTES AND METHODS
+
+  Upon a status of 200, the object returned has a few additional
+  attributes and methods, which should not be used if you want to
+  remain consistent with the normal urllib2-returned objects:
+
+    close_connection()  -  close the connection to the host
+    readlines()         -  you know, readlines()
+    status              -  the return status (ie 404)
+    reason              -  english translation of status (ie 'File not found')
+
+  If you want the best of both worlds, use this inside an
+  AttributeError-catching try:
+
+  >>> try: status = fo.status
+  >>> except AttributeError: status = None
+
+  Unfortunately, these are ONLY there if status == 200, so it's not
+  easy to distinguish between non-200 responses.  The reason is that
+  urllib2 tries to do clever things with error codes 301, 302, 401,
+  and 407, and it wraps the object upon return.
+
+  For python versions earlier than 2.4, you can avoid this fancy error
+  handling by setting the module-level global HANDLE_ERRORS to zero.
+  You see, prior to 2.4, it's the HTTP Handler's job to determine what
+  to handle specially, and what to just pass up.  HANDLE_ERRORS == 0
+  means "pass everything up".  In python 2.4, however, this job no
+  longer belongs to the HTTP Handler and is now done by a NEW handler,
+  HTTPErrorProcessor.  Here's the bottom line:
+
+    python version < 2.4
+        HANDLE_ERRORS == 1  (default) pass up 200, treat the rest as
+                            errors
+        HANDLE_ERRORS == 0  pass everything up, error processing is
+                            left to the calling code
+    python version >= 2.4
+        HANDLE_ERRORS == 1  pass up 200, treat the rest as errors
+        HANDLE_ERRORS == 0  (default) pass everything up, let the
+                            other handlers (specifically,
+                            HTTPErrorProcessor) decide what to do
+
+  In practice, setting the variable either way makes little difference
+  in python 2.4, so for the most consistent behavior across versions,
+  you probably just want to use the defaults, which will give you
+  exceptions on errors.
+
+"""
+
+# $Id: keepalive.py,v 1.16 2006/09/22 00:58:05 mstenner Exp $
+
+import urllib2
+import httplib
+import socket
+import thread
+
+DEBUG = None
+
+import sslfactory
+
+import sys
+if sys.version_info < (2, 4): HANDLE_ERRORS = 1
+else: HANDLE_ERRORS = 0
+    
+class ConnectionManager:
+    """
+    The connection manager must be able to:
+      * keep track of all existing
+      """
+    def __init__(self):
+        self._lock = thread.allocate_lock()
+        self._hostmap = {} # map hosts to a list of connections
+        self._connmap = {} # map connections to host
+        self._readymap = {} # map connection to ready state
+
+    def add(self, host, connection, ready):
+        self._lock.acquire()
+        try:
+            if not self._hostmap.has_key(host): self._hostmap[host] = []
+            self._hostmap[host].append(connection)
+            self._connmap[connection] = host
+            self._readymap[connection] = ready
+        finally:
+            self._lock.release()
+
+    def remove(self, connection):
+        self._lock.acquire()
+        try:
+            try:
+                host = self._connmap[connection]
+            except KeyError:
+                pass
+            else:
+                del self._connmap[connection]
+                del self._readymap[connection]
+                self._hostmap[host].remove(connection)
+                if not self._hostmap[host]: del self._hostmap[host]
+        finally:
+            self._lock.release()
+
+    def set_ready(self, connection, ready):
+        try: self._readymap[connection] = ready
+        except KeyError: pass
+        
+    def get_ready_conn(self, host):
+        conn = None
+        self._lock.acquire()
+        try:
+            if self._hostmap.has_key(host):
+                for c in self._hostmap[host]:
+                    if self._readymap[c]:
+                        self._readymap[c] = 0
+                        conn = c
+                        break
+        finally:
+            self._lock.release()
+        return conn
+
+    def get_all(self, host=None):
+        if host:
+            return list(self._hostmap.get(host, []))
+        else:
+            return dict(self._hostmap)
+
+class KeepAliveHandler:
+    def __init__(self):
+        self._cm = ConnectionManager()
+        
+    #### Connection Management
+    def open_connections(self):
+        """return a list of connected hosts and the number of connections
+        to each.  [('foo.com:80', 2), ('bar.org', 1)]"""
+        return [(host, len(li)) for (host, li) in self._cm.get_all().items()]
+
+    def close_connection(self, host):
+        """close connection(s) to <host>
+        host is the host:port spec, as in 'www.cnn.com:8080' as passed in.
+        no error occurs if there is no connection to that host."""
+        for h in self._cm.get_all(host):
+            self._cm.remove(h)
+            h.close()
+        
+    def close_all(self):
+        """close all open connections"""
+        for host, conns in self._cm.get_all().items():
+            for h in conns:
+                self._cm.remove(h)
+                h.close()
+        
+    def _request_closed(self, request, host, connection):
+        """tells us that this request is now closed and the the
+        connection is ready for another request"""
+        self._cm.set_ready(connection, 1)
+
+    def _remove_connection(self, host, connection, close=0):
+        if close: connection.close()
+        self._cm.remove(connection)
+        
+    #### Transaction Execution
+    def do_open(self, req):
+        host = req.get_host()
+        if not host:
+            raise urllib2.URLError('no host given')
+
+        try:
+            h = self._cm.get_ready_conn(host)
+            while h:
+                r = self._reuse_connection(h, req, host)
+
+                # if this response is non-None, then it worked and we're
+                # done.  Break out, skipping the else block.
+                if r: break
+
+                # connection is bad - possibly closed by server
+                # discard it and ask for the next free connection
+                h.close()
+                self._cm.remove(h)
+                h = self._cm.get_ready_conn(host)
+            else:
+                # no (working) free connections were found.  Create a new one.
+                h = self._get_connection(host)
+                if DEBUG: DEBUG.info("creating new connection to %s (%d)",
+                                     host, id(h))
+                self._cm.add(host, h, 0)
+                self._start_transaction(h, req)
+                r = h.getresponse()
+        except (socket.error, httplib.HTTPException), err:
+            raise urllib2.URLError(err)
+            
+        # if not a persistent connection, don't try to reuse it
+        if r.will_close: self._cm.remove(h)
+
+        if DEBUG: DEBUG.info("STATUS: %s, %s", r.status, r.reason)
+        r._handler = self
+        r._host = host
+        r._url = req.get_full_url()
+        r._connection = h
+        r.code = r.status
+        r.headers = r.msg
+        r.msg = r.reason
+        
+        if r.status == 200 or not HANDLE_ERRORS:
+            return r
+        else:
+            return self.parent.error('http', req, r,
+                                     r.status, r.msg, r.headers)
+
+    def _reuse_connection(self, h, req, host):
+        """start the transaction with a re-used connection
+        return a response object (r) upon success or None on failure.
+        This DOES not close or remove bad connections in cases where
+        it returns.  However, if an unexpected exception occurs, it
+        will close and remove the connection before re-raising.
+        """
+        try:
+            self._start_transaction(h, req)
+            r = h.getresponse()
+            # note: just because we got something back doesn't mean it
+            # worked.  We'll check the version below, too.
+        except (socket.error, httplib.HTTPException):
+            r = None
+        except:
+            # adding this block just in case we've missed
+            # something we will still raise the exception, but
+            # lets try and close the connection and remove it
+            # first.  We previously got into a nasty loop
+            # where an exception was uncaught, and so the
+            # connection stayed open.  On the next try, the
+            # same exception was raised, etc.  The tradeoff is
+            # that it's now possible this call will raise
+            # a DIFFERENT exception
+            if DEBUG: DEBUG.error("unexpected exception - closing " + \
+                                  "connection to %s (%d)", host, id(h))
+            self._cm.remove(h)
+            h.close()
+            raise
+                    
+        if r is None or r.version == 9:
+            # httplib falls back to assuming HTTP 0.9 if it gets a
+            # bad header back.  This is most likely to happen if
+            # the socket has been closed by the server since we
+            # last used the connection.
+            if DEBUG: DEBUG.info("failed to re-use connection to %s (%d)",
+                                 host, id(h))
+            r = None
+        else:
+            if DEBUG: DEBUG.info("re-using connection to %s (%d)", host, id(h))
+
+        return r
+
+    def _start_transaction(self, h, req):
+        try:
+            if req.has_data():
+                data = req.get_data()
+                h.putrequest('POST', req.get_selector(), skip_accept_encoding=1)
+                if not req.headers.has_key('Content-type'):
+                    h.putheader('Content-type',
+                                'application/x-www-form-urlencoded')
+                if not req.headers.has_key('Content-length'):
+                    h.putheader('Content-length', '%d' % len(data))
+            else:
+                h.putrequest('GET', req.get_selector(), skip_accept_encoding=1)
+        except (socket.error, httplib.HTTPException), err:
+            raise urllib2.URLError(err)
+
+        for args in self.parent.addheaders:
+            h.putheader(*args)
+        for k, v in req.headers.items():
+            h.putheader(k, v)
+        h.endheaders()
+        if req.has_data():
+            h.send(data)
+
+    def _get_connection(self, host):
+        return NotImplementedError
+
+class HTTPHandler(KeepAliveHandler, urllib2.HTTPHandler):
+    def __init__(self):
+        KeepAliveHandler.__init__(self)
+
+    def http_open(self, req):
+        return self.do_open(req)
+
+    def _get_connection(self, host):
+        return HTTPConnection(host)
+
+class HTTPSHandler(KeepAliveHandler, urllib2.HTTPSHandler):
+    def __init__(self, ssl_factory=None):
+        KeepAliveHandler.__init__(self)
+        if not ssl_factory:
+            ssl_factory = sslfactory.get_factory()
+        self._ssl_factory = ssl_factory
+    
+    def https_open(self, req):
+        return self.do_open(req)
+
+    def _get_connection(self, host):
+        return self._ssl_factory.get_https_connection(host)
+
+class HTTPResponse(httplib.HTTPResponse):
+    # we need to subclass HTTPResponse in order to
+    # 1) add readline() and readlines() methods
+    # 2) add close_connection() methods
+    # 3) add info() and geturl() methods
+
+    # in order to add readline(), read must be modified to deal with a
+    # buffer.  example: readline must read a buffer and then spit back
+    # one line at a time.  The only real alternative is to read one
+    # BYTE at a time (ick).  Once something has been read, it can't be
+    # put back (ok, maybe it can, but that's even uglier than this),
+    # so if you THEN do a normal read, you must first take stuff from
+    # the buffer.
+
+    # the read method wraps the original to accomodate buffering,
+    # although read() never adds to the buffer.
+    # Both readline and readlines have been stolen with almost no
+    # modification from socket.py
+    
+
+    def __init__(self, sock, debuglevel=0, strict=0, method=None):
+        if method: # the httplib in python 2.3 uses the method arg
+            httplib.HTTPResponse.__init__(self, sock, debuglevel, method)
+        else: # 2.2 doesn't
+            httplib.HTTPResponse.__init__(self, sock, debuglevel)
+        self.fileno = sock.fileno
+        self.code = None
+        self._rbuf = ''
+        self._rbufsize = 8096
+        self._handler = None # inserted by the handler later
+        self._host = None    # (same)
+        self._url = None     # (same)
+        self._connection = None # (same)
+
+    _raw_read = httplib.HTTPResponse.read
+
+    def close(self):
+        if self.fp:
+            self.fp.close()
+            self.fp = None
+            if self._handler:
+                self._handler._request_closed(self, self._host,
+                                              self._connection)
+
+    def close_connection(self):
+        self._handler._remove_connection(self._host, self._connection, close=1)
+        self.close()
+        
+    def info(self):
+        return self.headers
+
+    def geturl(self):
+        return self._url
+
+    def read(self, amt=None):
+        # the _rbuf test is only in this first if for speed.  It's not
+        # logically necessary
+        if self._rbuf and not amt is None:
+            L = len(self._rbuf)
+            if amt > L:
+                amt -= L
+            else:
+                s = self._rbuf[:amt]
+                self._rbuf = self._rbuf[amt:]
+                return s
+
+        s = self._rbuf + self._raw_read(amt)
+        self._rbuf = ''
+        return s
+
+    def readline(self, limit=-1):
+        data = ""
+        i = self._rbuf.find('\n')
+        while i < 0 and not (0 < limit <= len(self._rbuf)):
+            new = self._raw_read(self._rbufsize)
+            if not new: break
+            i = new.find('\n')
+            if i >= 0: i = i + len(self._rbuf)
+            self._rbuf = self._rbuf + new
+        if i < 0: i = len(self._rbuf)
+        else: i = i+1
+        if 0 <= limit < len(self._rbuf): i = limit
+        data, self._rbuf = self._rbuf[:i], self._rbuf[i:]
+        return data
+
+    def readlines(self, sizehint = 0):
+        total = 0
+        list = []
+        while 1:
+            line = self.readline()
+            if not line: break
+            list.append(line)
+            total += len(line)
+            if sizehint and total >= sizehint:
+                break
+        return list
+
+
+class HTTPConnection(httplib.HTTPConnection):
+    # use the modified response class
+    response_class = HTTPResponse
+
+class HTTPSConnection(httplib.HTTPSConnection):
+    response_class = HTTPResponse
+    
+#########################################################################
+#####   TEST FUNCTIONS
+#########################################################################
+
+def error_handler(url):
+    global HANDLE_ERRORS
+    orig = HANDLE_ERRORS
+    keepalive_handler = HTTPHandler()
+    opener = urllib2.build_opener(keepalive_handler)
+    urllib2.install_opener(opener)
+    pos = {0: 'off', 1: 'on'}
+    for i in (0, 1):
+        print "  fancy error handling %s (HANDLE_ERRORS = %i)" % (pos[i], i)
+        HANDLE_ERRORS = i
+        try:
+            fo = urllib2.urlopen(url)
+            foo = fo.read()
+            fo.close()
+            try: status, reason = fo.status, fo.reason
+            except AttributeError: status, reason = None, None
+        except IOError, e:
+            print "  EXCEPTION: %s" % e
+            raise
+        else:
+            print "  status = %s, reason = %s" % (status, reason)
+    HANDLE_ERRORS = orig
+    hosts = keepalive_handler.open_connections()
+    print "open connections:", hosts
+    keepalive_handler.close_all()
+
+def continuity(url):
+    import md5
+    format = '%25s: %s'
+    
+    # first fetch the file with the normal http handler
+    opener = urllib2.build_opener()
+    urllib2.install_opener(opener)
+    fo = urllib2.urlopen(url)
+    foo = fo.read()
+    fo.close()
+    m = md5.new(foo)
+    print format % ('normal urllib', m.hexdigest())
+
+    # now install the keepalive handler and try again
+    opener = urllib2.build_opener(HTTPHandler())
+    urllib2.install_opener(opener)
+
+    fo = urllib2.urlopen(url)
+    foo = fo.read()
+    fo.close()
+    m = md5.new(foo)
+    print format % ('keepalive read', m.hexdigest())
+
+    fo = urllib2.urlopen(url)
+    foo = ''
+    while 1:
+        f = fo.readline()
+        if f: foo = foo + f
+        else: break
+    fo.close()
+    m = md5.new(foo)
+    print format % ('keepalive readline', m.hexdigest())
+
+def comp(N, url):
+    print '  making %i connections to:\n  %s' % (N, url)
+
+    sys.stdout.write('  first using the normal urllib handlers')
+    # first use normal opener
+    opener = urllib2.build_opener()
+    urllib2.install_opener(opener)
+    t1 = fetch(N, url)
+    print '  TIME: %.3f s' % t1
+
+    sys.stdout.write('  now using the keepalive handler       ')
+    # now install the keepalive handler and try again
+    opener = urllib2.build_opener(HTTPHandler())
+    urllib2.install_opener(opener)
+    t2 = fetch(N, url)
+    print '  TIME: %.3f s' % t2
+    print '  improvement factor: %.2f' % (t1/t2, )
+    
+def fetch(N, url, delay=0):
+    import time
+    lens = []
+    starttime = time.time()
+    for i in range(N):
+        if delay and i > 0: time.sleep(delay)
+        fo = urllib2.urlopen(url)
+        foo = fo.read()
+        fo.close()
+        lens.append(len(foo))
+    diff = time.time() - starttime
+
+    j = 0
+    for i in lens[1:]:
+        j = j + 1
+        if not i == lens[0]:
+            print "WARNING: inconsistent length on read %i: %i" % (j, i)
+
+    return diff
+
+def test_timeout(url):
+    global DEBUG
+    dbbackup = DEBUG
+    class FakeLogger:
+        def debug(self, msg, *args): print msg % args
+        info = warning = error = debug
+    DEBUG = FakeLogger()
+    print "  fetching the file to establish a connection"
+    fo = urllib2.urlopen(url)
+    data1 = fo.read()
+    fo.close()
+ 
+    i = 20
+    print "  waiting %i seconds for the server to close the connection" % i
+    while i > 0:
+        sys.stdout.write('\r  %2i' % i)
+        sys.stdout.flush()
+        time.sleep(1)
+        i -= 1
+    sys.stderr.write('\r')
+
+    print "  fetching the file a second time"
+    fo = urllib2.urlopen(url)
+    data2 = fo.read()
+    fo.close()
+
+    if data1 == data2:
+        print '  data are identical'
+    else:
+        print '  ERROR: DATA DIFFER'
+
+    DEBUG = dbbackup
+
+    
+def test(url, N=10):
+    print "checking error hander (do this on a non-200)"
+    try: error_handler(url)
+    except IOError, e:
+        print "exiting - exception will prevent further tests"
+        sys.exit()
+    print
+    print "performing continuity test (making sure stuff isn't corrupted)"
+    continuity(url)
+    print
+    print "performing speed comparison"
+    comp(N, url)
+    print
+    print "performing dropped-connection check"
+    test_timeout(url)
+    
+if __name__ == '__main__':
+    import time
+    import sys
+    try:
+        N = int(sys.argv[1])
+        url = sys.argv[2]
+    except:
+        print "%s <integer> <url>" % sys.argv[0]
+    else:
+        test(url, N)
diff --git a/module/network/Request.py b/module/network/Request.py
new file mode 100755
index 000000000..3325d085d
--- /dev/null
+++ b/module/network/Request.py
@@ -0,0 +1,99 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+"""
+authored by: RaNaN
+"""
+import urllib
+import urllib2
+import cookielib
+import Keepalive
+
+from Keepalive import HTTPHandler
+from cStringIO import StringIO
+from gzip import GzipFile
+
+"""
+    handles all outgoing HTTP-Requests of the Server
+    Usage: create Request Instance
+    use retrieveURL and call it with a url at least
+    additionaly you can firstly pass the get and secondly the post data in form of a dictonary
+    when the last argument is true the handler simulate a http referer with the last called url.
+    retrieveUrl returns response as string
+    
+"""
+class Downloader(urllib.FancyURLopener):
+    version = "Mozilla/5.0 (Windows; U; Windows NT 5.1; de; rv:1.9.0.8) Gecko/2009032609 Firefox/3.0.8"
+
+
+
+class Request:
+    def __init__(self):
+	
+	self.lastURL = None
+	#self.cookiefile = 'cookies.lwp'
+	self.cj = cookielib.CookieJar()
+
+#	if os.path.isfile(self.cookiefile):
+ #           self.cj.load(self.cookiefile)
+
+        self.handler = HTTPHandler()
+	self.opener = urllib2.build_opener(self.handler, urllib2.HTTPCookieProcessor(self.cj))
+	#self.opener.add_handler()
+	
+	self.opener.addheaders = [
+        ("User-Agent","Mozilla/5.0 (Windows; U; Windows NT 5.1; de; rv:1.9.0.8) Gecko/2009032609 Firefox/3.0.8"),
+        ("Accept-Encoding","gzip,deflate"),
+        ("Accept","text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"),
+        ("Accept-Charset","ISO-8859-1,utf-8;q=0.7,*;q=0.7"),
+	("Connection","keep-alive"),
+        ("Keep-Alive","300")]
+	
+	self.downloader = Downloader()
+	
+    
+    def retrieveURL(self,url, get = {}, post = {}, ref = True):
+	
+	if post:
+	    post = urllib.urlencode(post)
+	else:
+	   post = None
+	
+	if get:
+	    get = urllib.urlencode(get)
+	else:
+	   get = ""
+	
+	url = url + get
+        req = urllib2.Request(url, data = post)
+		
+	if ref and self.lastURL is not None:
+	    req.add_header("Referer",self.lastURL)
+	
+	rep = self.opener.open(req)
+	
+	output = rep.read()
+	
+	print rep.headers
+		
+	self.cj.extract_cookies(rep, req)
+	
+	if rep.headers.has_key("content-encoding") :
+	    if rep.headers["content-encoding"] == "gzip" :
+		output = GzipFile('','r',0,StringIO(output)).read()
+	
+	self.lastURL = url
+		
+	return output
+
+    def addAuth(self, user, pw):
+        auth_handler = urllib2.HTTPBasicAuthHandler()
+	auth_handler.add_password(user, passwd= pw)
+	self.opener.add_handler(auth_handler)
+
+    def download(url, filename, reporthook = None, data = None): #default von urlretrieve auch None?
+       return self.downloader.urlretrieve(url, filename, reporthook, data)
+
+
+if __name__ == "__main__" :
+    import doctest
+    doctest.testmod()
diff --git a/module/network/__init__.py b/module/network/__init__.py
new file mode 100644
index 000000000..8d1c8b69c
--- /dev/null
+++ b/module/network/__init__.py
@@ -0,0 +1 @@
+ 
diff --git a/module/network/sslfactory.py b/module/network/sslfactory.py
new file mode 100644
index 000000000..f7e6d3d7e
--- /dev/null
+++ b/module/network/sslfactory.py
@@ -0,0 +1,89 @@
+#   This library is free software; you can redistribute it and/or
+#   modify it under the terms of the GNU Lesser General Public
+#   License as published by the Free Software Foundation; either
+#   version 2.1 of the License, or (at your option) any later version.
+#
+#   This library is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+#   Lesser General Public License for more details.
+#
+#   You should have received a copy of the GNU Lesser General Public
+#   License along with this library; if not, write to the 
+#      Free Software Foundation, Inc., 
+#      59 Temple Place, Suite 330, 
+#      Boston, MA  02111-1307  USA
+
+# This file is part of urlgrabber, a high-level cross-protocol url-grabber
+
+import httplib
+import urllib2
+
+try:
+    from M2Crypto import SSL
+    from M2Crypto import httpslib
+    from M2Crypto import m2urllib2
+
+    have_m2crypto = True
+except ImportError:
+    have_m2crypto = False
+
+DEBUG = None
+
+if have_m2crypto:
+    
+    class M2SSLFactory:
+
+        def __init__(self, ssl_ca_cert, ssl_context):
+            self.ssl_context = self._get_ssl_context(ssl_ca_cert, ssl_context)
+
+        def _get_ssl_context(self, ssl_ca_cert, ssl_context):
+            """
+            Create an ssl context using the CA cert file or ssl context.
+
+            The CA cert is used first if it was passed as an option. If not,
+            then the supplied ssl context is used. If no ssl context was supplied,
+            None is returned.
+            """
+            if ssl_ca_cert:
+                context = SSL.Context()
+                context.load_verify_locations(ssl_ca_cert)
+                context.set_verify(SSL.verify_peer, -1)
+                return context
+            else:
+                return ssl_context
+
+        def create_https_connection(self, host, response_class = None):
+            connection = httplib.HTTPSConnection(host, self.ssl_context)
+            if response_class:
+                connection.response_class = response_class
+            return connection
+
+        def create_opener(self, *handlers):
+            return m2urllib2.build_opener(self.ssl_context, *handlers)
+
+
+class SSLFactory:
+
+    def create_https_connection(self, host, response_class = None):
+        connection = httplib.HTTPSConnection(host)
+        if response_class:
+            connection.response_class = response_class
+        return connection
+
+    def create_opener(self, *handlers):
+        return urllib2.build_opener(*handlers)
+
+   
+
+def get_factory(ssl_ca_cert = None, ssl_context = None):
+    """ Return an SSLFactory, based on if M2Crypto is available. """
+    if have_m2crypto:
+        return M2SSLFactory(ssl_ca_cert, ssl_context)
+    else:
+        # Log here if someone provides the args but we don't use them.
+        if ssl_ca_cert or ssl_context:
+            if DEBUG:
+                DEBUG.warning("SSL arguments supplied, but M2Crypto is not available. "
+                        "Using Python SSL.")
+        return SSLFactory()