simon
/
SCCD


			
				
					
						
						
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							<class name="NetworkClient">
    <constructor>
        <body>
            self.socket = None
            self.host = None
            self.received_data = ""
            self.send_data = ""
            self.parsing_data = ""
            self.queue = []
        </body>
    </constructor>

    <scxml>
        <parallel id="parallel">
        <state id="client" initial="wait_for_destination">
            <transition event="connect" cond="self.socket is not None" target="close">
                <parameter name="hostname"/>
                <parameter name="port"/>
                <script>
                    self.host = (hostname, port)
                </script>
            </transition>
            <transition event="connect" cond="self.socket is None" target="init">
                <parameter name="hostname"/>
                <parameter name="port"/>
                <script>
                    self.host = (hostname, port)
                </script>
            </transition>

            <state id="wait_for_destination"/>

            <state id="init">
                <onentry>
                    <raise scope="output" event="create_socket" output="socket_out"/>
                </onentry>
                <transition port="socket_in" event="created_socket" target="../connecting">
                    <parameter name="socket"/>
                    <script>
                        self.socket = socket
                    </script>
                </transition>
            </state>

            <state id="connecting">
                <onentry>
                    <raise scope="output" event="connect_socket" output="socket_out">
                        <parameter expr="self.socket"/>
                        <parameter expr="self.host"/>
                    </raise>
                </onentry>
                <transition event="connected_socket" port="socket_in" target="../connected">
                    <raise scope="broad" event="connected"/>
                </transition>
            </state>

            <parallel id="connected">
                <!-- We explicitly use the fact that there is no threading -->
                <state id="processing" initial="processing">
                    <state id="processing">
                        <transition cond="'\0' in self.received_data" target="../parse">
                            <script>
                                self.parsing_data, self.received_data = self.received_data.split('\0', 1)
                            </script>
                        </transition>
                    </state>
                    <state id="parse">
                        <transition cond="self.parsing_data.startswith('MSG ')" target="../processing">
                            <raise scope="broad" event="receive_message">
                                <parameter expr="self.parsing_data[4:]"/>
                            </raise>
                        </transition>
                        <transition cond="self.parsing_data.startswith('ACK MSG')" target="../processing"/>
                        <transition cond="self.parsing_data.startswith('ACK JOIN')" target="../processing">
                            <raise scope="broad" event="joined">
                                <parameter expr="self.parsing_data.split(' ')[2]"/>
                            </raise>
                        </transition>
                        <transition cond="self.parsing_data.startswith('ALIVE')" target="../processing">
                            <raise scope="broad" event="alive"/>
                        </transition>
                        <transition cond="self.parsing_data.startswith('ACK LEAVE')" target="../processing">
                            <raise scope="broad" event="left"/>
                        </transition>
                    </state>
                </state>

                <state id="receiving">
                    <state id="receive">
                        <onentry>
                            <raise scope="output" event="recv_socket" output="socket_out">
                                <parameter expr="self.socket"/>
                            </raise>
                        </onentry>
                        <transition port="socket_in" event="received_socket" cond="(self.socket == socket) and (data != '')" target=".">
                            <parameter name="socket"/>
                            <parameter name="data"/>
                            <script>
                                print("Got data " + repr(data))
                                print("Total data: " + repr(self.received_data))
                                self.received_data += data
                            </script>
                        </transition>
                        <!-- For the sake of this exercise, wait for timeout instead of directly signaling this close -->
                        <transition port="socket_in" event="received_socket" cond="(self.socket == socket) and (data == '')" target=".">
                            <parameter name="socket"/>
                            <parameter name="data"/>
                            <raise event="close"/>
                        </transition>
                    </state>
                </state>

                <state id="sending" initial="waiting_for_inputdata">
                    <state id="waiting_for_inputdata">
                        <transition cond="len(self.queue) > 0" target="../transmitting">
                            <script>
                                self.send_data = self.queue.pop(0) + "\0"
                            </script>
                        </transition>
                    </state>

                    <state id="transmitting">
                        <onentry>
                            <raise scope="output" event="send_socket" output="socket_out">
                                <parameter expr="self.socket"/>
                                <parameter expr="self.send_data"/>
                            </raise>
                        </onentry>
                        <transition port="socket_in" cond="self.socket == socket and (sent == len(self.send_data))" event="sent_socket" target="../waiting_for_inputdata">
                            <parameter name="socket"/>
                            <parameter name="sent"/>
                            <script>
                                self.send_data = ""
                            </script>
                        </transition>
                        <transition port="socket_in" cond="self.socket == socket and (sent != len(self.send_data))" event="sent_socket" target=".">
                            <parameter name="socket"/>
                            <parameter name="sent"/>
                            <script>
                                self.send_data = self.send_data[sent:]
                            </script>
                        </transition>
                    </state>
                </state>
            </parallel>
            <transition event="close" target="error_close"/>

            <state id="error_close">
                <onentry>
                    <raise scope="output" event="close_socket" output="socket_out">
                        <parameter expr="self.socket"/>
                    </raise>
                </onentry>
                <transition event="closed_socket" cond="self.socket == socket" target="../wait_for_destination">
                    <parameter name="socket"/>
                    <script>
                        self.socket = None
                        self.host = None
                    </script>
                </transition>
            </state>

            <state id="close">
                <onentry>
                    <raise scope="output" event="close_socket" output="socket_out">
                        <parameter expr="self.socket"/>
                    </raise>
                </onentry>
                <transition event="closed_socket" cond="self.socket == socket" target="../init">
                    <parameter name="socket"/>
                    <raise scope="broad" event="disconnected"/>
                </transition>
            </state>

            <transition event="disconnect" cond="self.socket is not None" target="close">
                <script>
                    print("Closing socket")
                </script>
            </transition>
            <transition event="disconnect" cond="self.socket is None" target="wait_for_destination">
                <script>
                    print("Signaling disconnectedness")
                </script>
                <raise scope="broad" event="disconnected"/>
            </transition>
        </state>

        <state id="queue">
            <state id="queue">
                <transition event="send_message" target=".">
                    <parameter name="data"/>
                    <script>
                        self.queue.append("MSG %s: %s" % (socket.gethostname(), data))
                    </script>
                </transition>
                <transition event="join" target=".">
                    <parameter name="data"/>
                    <script>
                        self.queue.append("JOIN %s" % data)
                    </script>
                </transition>
                <transition event="leave" target=".">
                    <script>
                        self.queue.append("LEAVE")
                    </script>
                </transition>
                <transition event="poll" target=".">
                    <script>
                        self.queue.append("POLL")
                    </script>
                </transition>
            </state>
        </state>
        </parallel>
    </scxml>
</class>