gossip.communication package¶

Submodules¶

gossip.communication.client_receiver module¶

class gossip.communication.client_receiver.GossipClientReceiver(client_receiver_label, client_socket, ipv4_address, tcp_port, to_controller_queue, connection_pool)[source]¶

Bases: multiprocessing.process.Process

A client receiver is a process which receives data from a specified socket.

Constructor.

Parameters:

client_receiver_label – A label to derive the concrete functionality of this client receiver client_socket – The socket from/to the affected the affected client ipv4_address – The IPv4 address of the client tcp_port – The TCP port of the client to_controller_queue – The queue which connects this client receiver with the responsible controller connection_pool – If the socket crashes, the connection will be removed in this connection pool

handle_client()[source]¶

Receives new messages until the client dies. It also kills connections to clients which send malformed messages. Therefor it informs the responsible controller as well.

run()[source]¶

This typical run method of the client receiver process is responsible for handling a connection for the Gossip instance. It handles incoming messages and forwards them to the controller. If a connection crashes, this method pushes a specified command to the responsible controller.

gossip.communication.client_sender module¶

class gossip.communication.client_sender.GossipSender(sender_label, from_controller_queue, to_controller_queue, connection_pool)[source]¶

Bases: multiprocessing.process.Process

The Gossip sender receives new commands from the responsible controller. The sender is responsible for sending new messages to specified receivers. It is able to establish new connections as well if the controller sends the appropriate command to do so.

Constructor.

Parameters:	sender_label – A label to derive the concrete functionality of this client sender from_controller_queue – The client sender gets new commands via this queue from the responsible controller to_controller_queue – This instance forwards the controller queue to new receiver instances connection_pool – The connection pool which contains all connections/sockets

run()[source]¶

This is a typical run method for the sender process. It waits for commands from the controller to establish new connections or to send messages to established connections. The sender gets the appropriate connection/socket from the connection pool.

gossip.communication.connection module¶

class gossip.communication.connection.GossipConnectionPool(connection_pool_label, cache_size=30)[source]¶

Bases: object

Thread-safe implementation of a pool for Gossip connections.

Constructor.

Parameters:	connection_pool_label – A label to derive the concrete functionality of this connection pool cache_size – (optional): The max. amount of connections in this connection pool.

CONNECTION = 'Connection'¶

SERVER_IDENTIFIER = 'ServerIdentifier'¶

add_connection(identifier, connection, server_identifier=None)[source]¶

Adds new identifier with its connection.

Parameters:	identifier – An object which identifies an unique connection connection – A connection object server_identifier – (optional) The server identifier of the peer

filter_new_server_identifiers(server_identifiers, identifier_to_exclude=None)[source]¶

Provides all given identifiers which are not known until now.

Parameters:	server_identifiers – Server identifiers to check against known ones identifier_to_exclude – (optional) Server identifiers to exclude
Returns:	Identifiers which are not known as server identifiers in the connection pool until now

get_capacity()[source]¶

Provides the left capacity of the current connection pool.

Returns:	The left capacity

get_connection(identifier)[source]¶

Gets a connection from the pool.

Parameters:	identifier – Unique identifier to find the affected connection

get_identifiers()[source]¶

Gets a list of all identifiers.

Returns:	List of all identifier strings

get_random_identifier(identifier_to_exclude)[source]¶

Provides a random identifier which represents an active connection in the pool at the moment.

Parameters:	identifier_to_exclude – Identifier to exclude
Returns:	Random identifier

get_server_identifier(identifier)[source]¶

Gets the server identifier for one connection.

Parameters:	identifier – Unique identifier to find the affected server identifier

get_server_identifiers(identifier_to_exclude=None)[source]¶

Collects server identifiers

Parameters:	identifier_to_exclude – (optional) Server identifiers to exclude

remove_connection(identifier)[source]¶

Removes an existing connection from the pool.

Parameters:	identifier – Unique identifier to find the affected connection

update_connection(identifier, server_identifier)[source]¶

Updates an existing identifier with its connection.

Parameters:	identifier – An object which identifies an unique connection server_identifier – The server identifier of the peer

gossip.communication.server module¶

class gossip.communication.server.GossipServer(server_label, client_receiver_label, bind_address, tcp_port, to_controller_queue, connection_pool)[source]¶

Bases: multiprocessing.process.Process

The Gossip server waits for new connections established by other clients. It also instantiates new receivers for incoming connections.

Parameters:

server_label – A label to derive the concrete functionality of this gossip server client_receiver_label – This label is used for newly instantiated receivers bind_address – IPv4 address which is used to listen for new connections tcp_port – TCP port which is used to listen for new connections to_controller_queue – Newly instantiated receivers need to know a queue to communicate with the controller connection_pool – New connections will be added to the appropriate connection pool

run()[source]¶

Typical run method for the sender process. It waits for new connections, refers to newly instantiated receiver instances, and finally starts the new receivers.