/// <summary>
/// Here we have a mock program that might be used as part of a simulation that is
/// used to generate data to help choose the optimal location for a new grocery store
/// co-op in a neighborhood of people who travel by foot and bicycle.
/// The flyweight pattern is used to save RAM when creating the very large number
/// of objects used to represent individual NeighborhoodMembers by separating out
/// intrinsic state from extrinsic state and sharing state where it makes sense.
/// </summary>
/// <param name="args"></param>
private static void Main(string[] args)
{
Console.OutputEncoding = System.Text.Encoding.UTF8;
Console.WriteLine("🚴 Starting City Planning Simulation for new Grocery Store Location");
Console.WriteLine("--------------------------------------------------------------------");
var rng = new Random();
const int simulationPopulationSize = 100_000;
const int simulationHeightWidth = 100;
const int flyweightBankSize = 5;
var transportModes = new[] {
new TransportationMethod("walk", 1),
new TransportationMethod("bicycle", 2)
};
var subdivisions = new[] {
new Subdivision("north_side", 120),
new Subdivision("east_side", 210),
new Subdivision("downtown", 300),
new Subdivision("lakeside", 310)
};
var neighborhoodMembers = new NeighborhoodMember[flyweightBankSize];
for (var i = 0; i < flyweightBankSize; i++)
{
var member = new NeighborhoodMember();
var(x, y) = GetRandomCoordinates(rng, simulationHeightWidth);
var modeOfTransport = GetRandomTransportation(rng, transportModes);
var subdivision = GetRandomSubdivision(rng, subdivisions);
member.PositionX = x;
member.PositionY = y;
member.TransportationMethod = modeOfTransport;
member.Subdivision = subdivision;
neighborhoodMembers[i] = member;
}
var factory = new SharedStateFactory(neighborhoodMembers);
factory.DisplayCache();
for (var i = 0; i < simulationPopulationSize; i++)
{
var member = new NeighborhoodMember();
var(item1, item2) = GetRandomCoordinates(rng, simulationHeightWidth);
var modeOfTransport = GetRandomTransportation(rng, transportModes);
var subdivision = GetRandomSubdivision(rng, subdivisions);
member.PositionX = item1;
member.PositionY = item2;
member.TransportationMethod = modeOfTransport;
member.Subdivision = subdivision;
AddMemberToSimulation(factory, member, i);
}
Console.WriteLine("Simulation Complete.");
Console.WriteLine("--------------------------------------------------------------------");
}
private static void AddMemberToSimulation(
SharedStateFactory factory,
NeighborhoodMember member,
int i)
{
var flyweight = factory.GetFlyweight(new NeighborhoodMember {
TransportationMethod = member.TransportationMethod,
Subdivision = member.Subdivision
});
// Here, our simulation client calculates extrinsic state and passes
// it to the flyweight's methods
if (i % 10_000 != 0)
{
return;
}
Console.WriteLine($"Iteration # {i}");
flyweight.RenderPosition(member);
}