Scheduler

backend/src/lib.rs

@@ -1,14 +1 @@
-pub fn add(left: u64, right: u64) -> u64 {
-    left + right
-}
 
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn it_works() {
-        let result = add(2, 2);
-        assert_eq!(result, 4);
-    }
-}

backend/src/scheduler.rs

@@ -0,0 +1,76 @@
+use std::{cmp::Ordering, collections::BinaryHeap};
+
+#[derive(Copy, Debug, Clone)]
+pub enum EventType {
+    Pause,
+    Stop,
+    Reset,
+    PIBusWriteComplete,
+    PIDMAComplete,
+    SIDMAComplete,
+}
+
+#[derive(Copy, Debug, Clone)]
+pub struct Event {
+    time: u64,
+    event_type: EventType,
+}
+
+impl Eq for Event {}
+
+impl PartialEq for Event {
+    fn eq(&self, other: &Self) -> bool {
+        self.time == other.time
+            && matches!(
+                (self.event_type, other.event_type),
+                (EventType::Pause, EventType::Pause)
+                    | (EventType::Stop, EventType::Stop)
+                    | (EventType::Reset, EventType::Reset)
+                    | (EventType::PIBusWriteComplete, EventType::PIBusWriteComplete)
+                    | (EventType::PIDMAComplete, EventType::PIDMAComplete)
+                    | (EventType::SIDMAComplete, EventType::SIDMAComplete)
+            )
+    }
+}
+
+impl Ord for Event {
+    fn cmp(&self, other: &Self) -> Ordering {
+        self.time.cmp(&other.time).reverse()
+    }
+}
+
+impl PartialOrd for Event {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+pub struct Scheduler {
+    events: BinaryHeap<Event>,
+    ticks: u64,
+}
+
+impl Scheduler {
+    pub fn new() -> Self {
+        Self {
+            events: BinaryHeap::new(),
+            ticks: 0,
+        }
+    }
+
+    pub fn enqueue_relative(&mut self, time: u64, event_type: EventType) {
+        self.enqueue_absolute(time + self.ticks, event_type)
+    }
+
+    pub fn enqueue_absolute(&mut self, time: u64, event_type: EventType) {
+        self.events.push(Event { time, event_type })
+    }
+
+    pub fn pop(&mut self) -> Option<Event> {
+        self.events.pop()
+    }
+
+    pub fn tick(&mut self, time: u64) {
+        self.ticks += time
+    }
+}

src/main.rs

@@ -1,7 +1 @@
-#![allow(unused_imports)]
+fn main() {}
-
-use backend::add;
-
-fn main() {
-    println!("Hello, world!");
-}