Add FabricScheduler and FabricTask for task scheduling

Author: renvins

fabric/src/main/java/it/renvins/serverpulse/fabric/task/FabricScheduler.java

@@ -0,0 +1,49 @@
+package it.renvins.serverpulse.fabric.task;
+
+import java.util.Queue;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ConcurrentLinkedDeque;
+import java.util.concurrent.ForkJoinPool;
+
+import it.renvins.serverpulse.common.scheduler.Task;
+import it.renvins.serverpulse.common.scheduler.TaskScheduler;
+import net.fabricmc.fabric.api.event.lifecycle.v1.ServerTickEvents;
+import net.minecraft.server.MinecraftServer;
+
+public class FabricScheduler implements TaskScheduler {
+
+    private final Queue<FabricTask> tasks = new ConcurrentLinkedDeque<>();
+
+    public FabricScheduler() {
+        ServerTickEvents.END_SERVER_TICK.register(this::onServerTick);
+    }
+
+    @Override
+    public void runSync(Runnable task) {
+        FabricTask taskWrapper = new FabricTask(task, false, 0, 0);
+        tasks.add(taskWrapper);
+    }
+
+    @Override
+    public void runAsync(Runnable task) {
+        CompletableFuture.runAsync(task);
+    }
+
+    @Override
+    public Task runTaskTimerAsync(Runnable task, long delayTicks, long periodTicks) {
+        FabricTask fabricTask = new FabricTask(() -> CompletableFuture.runAsync(task),
+                true, delayTicks, periodTicks);
+        tasks.add(fabricTask);
+        return fabricTask;
+    }
+
+    private void onServerTick(MinecraftServer server) {
+        tasks.removeIf(task -> {
+            if (task.isCancelled()) {
+                return true;
+            }
+            task.tick();
+            return task.isCancelled();
+        });
+    }
+}

fabric/src/main/java/it/renvins/serverpulse/fabric/task/FabricTask.java

@@ -0,0 +1,54 @@
+package it.renvins.serverpulse.fabric.task;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.logging.Level;
+
+import it.renvins.serverpulse.common.scheduler.Task;
+import it.renvins.serverpulse.fabric.ServerPulseFabric;
+
+public class FabricTask implements Task {
+
+    private final AtomicBoolean cancelled = new AtomicBoolean(false);
+
+    private final Runnable runnable;
+    private final boolean isPeriodic;
+    private final long period;
+
+    private long ticksUntilRun;
+
+    public FabricTask(Runnable runnable, boolean isPeriodic, long delay, long period) {
+        this.runnable = runnable;
+        this.isPeriodic = isPeriodic;
+        this.period = period;
+        this.ticksUntilRun = delay;
+    }
+
+    @Override
+    public void cancel() {
+        cancelled.set(true);
+    }
+
+    @Override
+    public boolean isCancelled() {
+        return cancelled.get();
+    }
+
+    public void tick() {
+        if (cancelled.get()) {
+            return;
+        }
+
+        if (--ticksUntilRun <= 0) {
+            try {
+                runnable.run();
+            } catch (Exception e) {
+                ServerPulseFabric.LOGGER.log(Level.SEVERE, "An error occurred while executing task!", e);
+            }
+            if (isPeriodic && !cancelled.get()) {
+                ticksUntilRun = period;
+            } else {
+                cancel();
+            }
+        }
+    }
+}