topology_settings.py

from enum import Enum
import json
import networkx as nx
from pprint import pformat

from distribution import Distribution
from json_endec import GraphDecoder


class TopologyType(Enum):
    """Types of miner topologies.
    """

    STATIC_UNIFORM_DELAY = 1  # Load the topology from a file.
    GEOMETRIC_UNIFORM_DELAY = 2
    LOBSTER_UNIFORM_DELAY = 3  # TODO: Toy example that should eventually be removed.
    # TODO: Add appropraite types


class TopologySettings:
    """Stores settings related to graph topologies.
    """

    def __init__(self, value):
        """Parses the settings in the value parameter.

        Arguments:
            value {str|dict} -- If a string, it is a pointer to a JSON-encoded file containing the settings. If a dict, then it is the settings.
        """

        if type(value) is str:
            # Treat the value as a file locator.
            with open(value, 'r') as settingsFile:
                data = json.load(settingsFile)
        else:
            data = value

        self.topology_type = TopologyType[data['type']]
        if self.topology_type == TopologyType.STATIC_UNIFORM_DELAY:
            self.network_delay = Distribution(data['networkDelay'])
            self.static_file = data['file']
            self.static_graph = None
        else:
            self.number_of_miners = data['numberOfMiners']

            if self.topology_type == TopologyType.GEOMETRIC_UNIFORM_DELAY or self.topology_type == TopologyType.LOBSTER_UNIFORM_DELAY:
                # Graphs with uniform delays for message transmission.
                self.network_delay = Distribution(data['networkDelay'])

                if self.topology_type == TopologyType.GEOMETRIC_UNIFORM_DELAY:
                    self.radius = data['radius']
                elif self.topology_type == TopologyType.LOBSTER_UNIFORM_DELAY:
                    self.p1 = data['p1']
                    self.p2 = data['p2']
            else:
                raise NotImplementedError("Selected topology type is not implemented.")

    def generateMinerGraph(self):
        """Generates a miner graph based on the settings in this object.
        Returns:
            networkx.Graph -- Graph of miners to be used in simulation.
        """

        graph = None
        if self.topology_type == TopologyType.STATIC_UNIFORM_DELAY:
            if not self.static_graph:
                with open(self.static_file, 'r') as infile:
                    raw_data = json.load(infile, cls=GraphDecoder)
                    self.static_graph = raw_data['graph']
            graph = self.static_graph
        else:
            while graph is None or not nx.is_connected(graph):
                if self.topology_type == TopologyType.GEOMETRIC_UNIFORM_DELAY or self.topology_type == TopologyType.LOBSTER_UNIFORM_DELAY:
                    # Graphs with uniform delays for message transmission.
                    if self.topology_type == TopologyType.GEOMETRIC_UNIFORM_DELAY:
                        graph = nx.random_geometric_graph(self.number_of_miners, self.radius)
                    elif self.topology_type == TopologyType.LOBSTER_UNIFORM_DELAY:
                        graph = nx.random_lobster(self.number_of_miners, self.p1, self.p2)
                else:
                    raise NotImplementedError("Selected topology type is not implemented.")

        for edge in graph.edges:
            graph.edges[edge]['network_delay'] = self.network_delay
        return graph

    def __str__(self):
        """        
        Returns:
            str -- String representation of object.
        """

        return pformat(self.__dict__, indent=8)

    def __repr__(self):
        """        
        Returns:
            str -- String representation of object.
        """

        return pformat(self.__dict__, indent=8)