Add TPS and MSPT metrics

src/main/java/ru/ruscalworld/fabricexporter/FabricExporter.java

@@ -8,6 +8,8 @@ import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import ru.ruscalworld.fabricexporter.config.MainConfig;
 import ru.ruscalworld.fabricexporter.metrics.OnlinePlayers;
+import ru.ruscalworld.fabricexporter.metrics.TicksPerSecond;
+import ru.ruscalworld.fabricexporter.metrics.MillisPerTick;
 
 import java.io.IOException;
 import java.util.Timer;
@@ -29,6 +31,8 @@ public class FabricExporter implements ModInitializer {
 
         MetricUpdater metricUpdater = new MetricUpdater(this);
         metricUpdater.registerMetric(new OnlinePlayers());
+        metricUpdater.registerMetric(new TicksPerSecond());
+        metricUpdater.registerMetric(new MillisPerTick());
 
         ServerLifecycleEvents.SERVER_STARTING.register(this::setServer);
         ServerLifecycleEvents.SERVER_STARTED.register(server -> {

src/main/java/ru/ruscalworld/fabricexporter/MetricUpdater.java

@@ -1,5 +1,7 @@
 package ru.ruscalworld.fabricexporter;
 
+import ru.ruscalworld.fabricexporter.metrics.Metric;
+
 import java.util.ArrayList;
 import java.util.List;
 import java.util.TimerTask;

src/main/java/ru/ruscalworld/fabricexporter/metrics/Metric.java

@@ -1,6 +1,7 @@
-package ru.ruscalworld.fabricexporter;
+package ru.ruscalworld.fabricexporter.metrics;
 
 import io.prometheus.client.Gauge;
+import ru.ruscalworld.fabricexporter.FabricExporter;
 
 public abstract class Metric {
     private final Gauge gauge;

src/main/java/ru/ruscalworld/fabricexporter/metrics/MillisPerTick.java

@@ -0,0 +1,19 @@
+package ru.ruscalworld.fabricexporter.metrics;
+
+import me.lucko.spark.api.statistic.StatisticWindow;
+import me.lucko.spark.api.statistic.misc.DoubleAverageInfo;
+import me.lucko.spark.api.statistic.types.GenericStatistic;
+import ru.ruscalworld.fabricexporter.FabricExporter;
+
+public class MillisPerTick extends SparkMetric {
+    public MillisPerTick() {
+        super("mspt", "Milliseconds per tick (MSPT)");
+    }
+
+    @Override
+    public double getCurrentValue(FabricExporter exporter) {
+        GenericStatistic<DoubleAverageInfo, StatisticWindow.MillisPerTick> mspt = this.getSpark().mspt();
+        if (mspt == null) return 0;
+        return mspt.poll(StatisticWindow.MillisPerTick.MINUTES_1).mean();
+    }
+}

src/main/java/ru/ruscalworld/fabricexporter/metrics/OnlinePlayers.java

@@ -1,7 +1,6 @@
 package ru.ruscalworld.fabricexporter.metrics;
 
 import ru.ruscalworld.fabricexporter.FabricExporter;
-import ru.ruscalworld.fabricexporter.Metric;
 
 public class OnlinePlayers extends Metric {
     public OnlinePlayers() {

src/main/java/ru/ruscalworld/fabricexporter/metrics/SparkMetric.java

@@ -0,0 +1,14 @@
+package ru.ruscalworld.fabricexporter.metrics;
+
+import me.lucko.spark.api.Spark;
+import me.lucko.spark.api.SparkProvider;
+
+public abstract class SparkMetric extends Metric {
+    public SparkMetric(String name, String help) {
+        super(name, help);
+    }
+
+    public Spark getSpark() {
+        return SparkProvider.get();
+    }
+}

src/main/java/ru/ruscalworld/fabricexporter/metrics/TicksPerSecond.java

@@ -0,0 +1,18 @@
+package ru.ruscalworld.fabricexporter.metrics;
+
+import me.lucko.spark.api.statistic.StatisticWindow;
+import me.lucko.spark.api.statistic.types.DoubleStatistic;
+import ru.ruscalworld.fabricexporter.FabricExporter;
+
+public class TicksPerSecond extends SparkMetric {
+    public TicksPerSecond() {
+        super("tps", "Current TPS on server");
+    }
+
+    @Override
+    public double getCurrentValue(FabricExporter exporter) {
+        DoubleStatistic<StatisticWindow.TicksPerSecond> tps = this.getSpark().tps();
+        if (tps == null) return 20;
+        return tps.poll(StatisticWindow.TicksPerSecond.MINUTES_1);
+    }
+}