xmlrpclib.Transport

 

 

class Transport:
    """Handles an HTTP transaction to an XML-RPC server."""

    # client identifier (may be overridden)
    user_agent = "xmlrpclib.py/%s (by www.pythonware.com)" % __version__

    #if true, we'll request gzip encoding
    accept_gzip_encoding = True

    # if positive, encode request using gzip if it exceeds this threshold
    # note that many server will get confused, so only use it if you know
    # that they can decode such a request
    encode_threshold = None #None = don't encode

    def __init__(self, use_datetime=0):
        self._use_datetime = use_datetime
        self._connection = (None, None)
        self._extra_headers = []
    ##
    # Send a complete request, and parse the response.
    # Retry request if a cached connection has disconnected.
    #
    # @param host Target host.
    # @param handler Target PRC handler.
    # @param request_body XML-RPC request body.
    # @param verbose Debugging flag.
    # @return Parsed response.

    def request(self, host, handler, request_body, verbose=0):
        #retry request once if cached connection has gone cold
        for i in (0, 1):
            try:
                return self.single_request(host, handler, request_body, verbose)
            except socket.error, e:
                if i or e.errno not in (errno.ECONNRESET, errno.ECONNABORTED, errno.EPIPE):
                    raise
            except httplib.BadStatusLine: #close after we sent request
                if i:
                    raise

    ##
    # Send a complete request, and parse the response.
    #
    # @param host Target host.
    # @param handler Target PRC handler.
    # @param request_body XML-RPC request body.
    # @param verbose Debugging flag.
    # @return Parsed response.

    def single_request(self, host, handler, request_body, verbose=0):
        # issue XML-RPC request

        h = self.make_connection(host)
        if verbose:
            h.set_debuglevel(1)

        try:
            self.send_request(h, handler, request_body)
            self.send_host(h, host)
            self.send_user_agent(h)
            self.send_content(h, request_body)

            response = h.getresponse(buffering=True)
            if response.status == 200:
                self.verbose = verbose
                return self.parse_response(response)
        except Fault:
            raise
        except Exception:
            # All unexpected errors leave connection in
            # a strange state, so we clear it.
            self.close()
            raise

        #discard any response data and raise exception
        if (response.getheader("content-length", 0)):
            response.read()
        raise ProtocolError(
            host + handler,
            response.status, response.reason,
            response.msg,
            )

    ##
    # Create parser.
    #
    # @return A 2-tuple containing a parser and a unmarshaller.

    def getparser(self):
        # get parser and unmarshaller
        return getparser(use_datetime=self._use_datetime)

    ##
    # Get authorization info from host parameter
    # Host may be a string, or a (host, x509-dict) tuple; if a string,
    # it is checked for a "user:pw@host" format, and a "Basic
    # Authentication" header is added if appropriate.
    #
    # @param host Host descriptor (URL or (URL, x509 info) tuple).
    # @return A 3-tuple containing (actual host, extra headers,
    #     x509 info).  The header and x509 fields may be None.

    def get_host_info(self, host):

        x509 = {}
        if isinstance(host, TupleType):
            host, x509 = host

        import urllib
        auth, host = urllib.splituser(host)

        if auth:
            import base64
            auth = base64.encodestring(urllib.unquote(auth))
            auth = string.join(string.split(auth), "") # get rid of whitespace
            extra_headers = [
                ("Authorization", "Basic " + auth)
                ]
        else:
            extra_headers = None

        return host, extra_headers, x509

    ##
    # Connect to server.
    #
    # @param host Target host.
    # @return A connection handle.

    def make_connection(self, host):
        #return an existing connection if possible.  This allows
        #HTTP/1.1 keep-alive.
        if self._connection and host == self._connection[0]:
            return self._connection[1]

        # create a HTTP connection object from a host descriptor
        chost, self._extra_headers, x509 = self.get_host_info(host)
        #store the host argument along with the connection object
        self._connection = host, httplib.HTTPConnection(chost)
        return self._connection[1]

    ##
    # Clear any cached connection object.
    # Used in the event of socket errors.
    #
    def close(self):
        if self._connection[1]:
            self._connection[1].close()
            self._connection = (None, None)

    ##
    # Send request header.
    #
    # @param connection Connection handle.
    # @param handler Target RPC handler.
    # @param request_body XML-RPC body.

    def send_request(self, connection, handler, request_body):
        if (self.accept_gzip_encoding and gzip):
            connection.putrequest("POST", handler, skip_accept_encoding=True)
            connection.putheader("Accept-Encoding", "gzip")
        else:
            connection.putrequest("POST", handler)

    ##
    # Send host name.
    #
    # @param connection Connection handle.
    # @param host Host name.
    #
    # Note: This function doesn't actually add the "Host"
    # header anymore, it is done as part of the connection.putrequest() in
    # send_request() above.

    def send_host(self, connection, host):
        extra_headers = self._extra_headers
        if extra_headers:
            if isinstance(extra_headers, DictType):
                extra_headers = extra_headers.items()
            for key, value in extra_headers:
                connection.putheader(key, value)

    ##
    # Send user-agent identifier.
    #
    # @param connection Connection handle.

    def send_user_agent(self, connection):
        connection.putheader("User-Agent", self.user_agent)

    ##
    # Send request body.
    #
    # @param connection Connection handle.
    # @param request_body XML-RPC request body.

    def send_content(self, connection, request_body):
        connection.putheader("Content-Type", "text/xml")

        #optionally encode the request
        if (self.encode_threshold is not None and
            self.encode_threshold < len(request_body) and
            gzip):
            connection.putheader("Content-Encoding", "gzip")
            request_body = gzip_encode(request_body)

        connection.putheader("Content-Length", str(len(request_body)))
        connection.endheaders(request_body)

    ##
    # Parse response.
    #
    # @param file Stream.
    # @return Response tuple and target method.

    def parse_response(self, response):
        # read response data from httpresponse, and parse it

        # Check for new http response object, else it is a file object
        if hasattr(response,'getheader'):
            if response.getheader("Content-Encoding", "") == "gzip":
                stream = GzipDecodedResponse(response)
            else:
                stream = response
        else:
            stream = response

        p, u = self.getparser()

        while 1:
            data = stream.read(1024)
            if not data:
                break
            if self.verbose:
                print "body:", repr(data)
            p.feed(data)

        if stream is not response:
            stream.close()
        p.close()

        return u.close()

##
# Standard transport class for XML-RPC over HTTPS.