1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182

use std::any::Any;
use std::f64::INFINITY;

use serde::{Deserialize, Serialize};

use super::model::Model;
use super::ModelMessage;
use crate::input_modeling::random_variable::IndexRandomVariable;
use crate::input_modeling::uniform_rng::UniformRNG;
use crate::utils::error::SimulationError;

/// The exclusive gateway splits a process flow into a set of possible paths.
/// The process will only follow one of the possible paths. Path selection is
/// determined by Weighted Index distribution random variates, so this atomic
/// model exhibits stochastic behavior. The exclusive gateway is a BPMN
/// concept.
#[derive(Debug, Clone, Deserialize, Serialize)]
#[serde(rename_all = "camelCase")]
pub struct ExclusiveGateway {
    id: String,
    ports_in: PortsIn,
    ports_out: PortsOut,
    port_weights: IndexRandomVariable,
    #[serde(default)]
    state: State,
    #[serde(default)]
    snapshot: Metrics,
    #[serde(default)]
    history: Vec<Metrics>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
struct PortsIn {
    flow_paths: Vec<String>,
    snapshot: Option<String>,
    history: Option<String>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
struct PortsOut {
    flow_paths: Vec<String>,
    snapshot: Option<String>,
    history: Option<String>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
struct State {
    event_list: Vec<ScheduledEvent>,
    #[serde(default)]
    global_time: f64,
}

impl Default for State {
    fn default() -> Self {
        let initalization_event = ScheduledEvent {
            time: 0.0,
            event: Event::Run,
        };
        State {
            event_list: vec![initalization_event],
            global_time: 0.0,
        }
    }
}

#[derive(Debug, Clone, Serialize, Deserialize)]
enum Event {
    Run,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
struct ScheduledEvent {
    time: f64,
    event: Event,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
struct Metrics {
    last_job: Option<(String, String, f64)>, // port, message, time
}

impl Default for Metrics {
    fn default() -> Self {
        Metrics { last_job: None }
    }
}

impl ExclusiveGateway {
    fn need_snapshot_metrics(&self) -> bool {
        self.ports_in.snapshot.is_some() && self.ports_out.snapshot.is_some()
    }

    fn need_historical_metrics(&self) -> bool {
        self.need_snapshot_metrics()
            && self.ports_in.history.is_some()
            && self.ports_out.history.is_some()
    }
}

impl Model for ExclusiveGateway {
    fn as_any(&self) -> &dyn Any {
        self
    }

    fn id(&self) -> String {
        self.id.clone()
    }

    fn status(&self) -> String {
        String::from("Active")
    }

    fn events_ext(
        &mut self,
        uniform_rng: &mut UniformRNG,
        incoming_message: ModelMessage,
    ) -> Result<Vec<ModelMessage>, SimulationError> {
        let mut outgoing_messages: Vec<ModelMessage> = Vec::new();
        let port_number = self.port_weights.random_variate(uniform_rng)?;
        // Possible metrics updates
        if self.need_snapshot_metrics() {
            self.snapshot.last_job = Some((
                self.ports_out.flow_paths[port_number].clone(),
                incoming_message.message.clone(),
                self.state.global_time,
            ));
        }
        if self.need_historical_metrics() {
            self.history.push(self.snapshot.clone());
        }
        // State changes
        outgoing_messages.push(ModelMessage {
            port_name: self.ports_out.flow_paths[port_number].clone(),
            message: incoming_message.message,
        });
        Ok(outgoing_messages)
    }

    fn events_int(
        &mut self,
        _uniform_rng: &mut UniformRNG,
    ) -> Result<Vec<ModelMessage>, SimulationError> {
        let events = self.state.event_list.clone();
        self.state.event_list = self
            .state
            .event_list
            .iter()
            .filter(|scheduled_event| scheduled_event.time != 0.0)
            .cloned()
            .collect();
        events
            .iter()
            .filter(|scheduled_event| scheduled_event.time == 0.0)
            .for_each(|scheduled_event| match scheduled_event.event {
                Event::Run => {}
            });
        Ok(Vec::new())
    }

    fn time_advance(&mut self, time_delta: f64) {
        self.state
            .event_list
            .iter_mut()
            .for_each(|scheduled_event| {
                scheduled_event.time -= time_delta;
            });
        self.state.global_time += time_delta;
    }

    fn until_next_event(&self) -> f64 {
        self.state
            .event_list
            .iter()
            .fold(INFINITY, |until_next_event, event| {
                f64::min(until_next_event, event.time)
            })
    }
}