add memory metric

src/main/java/xyz/mcutils/backend/service/MetricService.java

@@ -9,8 +9,11 @@ import org.springframework.stereotype.Service;
 import xyz.mcutils.backend.common.Timer;
 import xyz.mcutils.backend.repository.MetricsRepository;
 import xyz.mcutils.backend.service.metric.Metric;
+import xyz.mcutils.backend.service.metric.impl.IntegerMetric;
+import xyz.mcutils.backend.service.metric.impl.MapMetric;
 import xyz.mcutils.backend.service.metric.metrics.RequestsPerRouteMetric;
 import xyz.mcutils.backend.service.metric.metrics.TotalRequestsMetric;
+import xyz.mcutils.backend.service.metric.metrics.process.MemoryMetric;
 
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -41,6 +44,7 @@ public class MetricService {
         // Register the metrics
         registerMetric(new TotalRequestsMetric());
         registerMetric(new RequestsPerRouteMetric());
+        registerMetric(new MemoryMetric());
 
         // Load the metrics from Redis
         loadMetrics();
@@ -82,8 +86,8 @@ public class MetricService {
      */
     public void loadMetrics() {
         log.info("Loading metrics");
-        for (Metric<?> metric : metricsRepository.findAll()) {
+        for (Metric<?> metricToLoad : metricsRepository.findAll()) {
-            metrics.put(metric.getClass(), metric);
+
         }
         log.info("Loaded {} metrics", metrics.size());
     }
@@ -113,7 +117,13 @@ public class MetricService {
     private void writeToInflux() {
         List<Point> points = new ArrayList<>();
         for (Metric<?> metric : metrics.values()) {
-            points.add(metric.toPoint());
+            if (metric.isCollector()) {
+                metric.collect();
+            }
+            Point point = metric.toPoint();
+            if (point != null) {
+                points.add(point);
+            }
         }
         influxWriteApi.writePoints(points);
         log.info("Wrote {} metrics to Influx", metrics.size());

src/main/java/xyz/mcutils/backend/service/metric/Metric.java

@@ -1,15 +1,17 @@
 package xyz.mcutils.backend.service.metric;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.influxdb.annotations.Measurement;
 import com.influxdb.client.write.Point;
 import lombok.AllArgsConstructor;
 import lombok.Getter;
 import lombok.Setter;
+import lombok.ToString;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.redis.core.RedisHash;
 
 @AllArgsConstructor
-@Getter @Setter
+@Getter @Setter @ToString
 @RedisHash(value = "metric")
 public abstract class Metric<T> {
     /**
@@ -22,6 +24,18 @@ public abstract class Metric<T> {
      */
     private T value;
 
+    /**
+     * Should this metric be collected
+     * before pushing to Influx?
+     */
+    @JsonIgnore
+    private transient boolean collector;
+
+    /**
+     * Collects the metric.
+     */
+    public void collect() {}
+
     /**
      * Gets this point as a {@link Point}.
      *

src/main/java/xyz/mcutils/backend/service/metric/impl/IntegerMetric.java

@@ -6,7 +6,7 @@ import xyz.mcutils.backend.service.metric.Metric;
 public class IntegerMetric extends Metric<Integer> {
 
     public IntegerMetric(String id) {
-        super(id, 0);
+        super(id, 0, false);
     }
 
     /**

src/main/java/xyz/mcutils/backend/service/metric/impl/MapMetric.java

@@ -9,11 +9,14 @@ import java.util.Map;
 public class MapMetric <A, B> extends Metric<Map<A, B>> {
 
     public MapMetric(String id) {
-        super(id, new HashMap<>());
+        super(id, new HashMap<>(), false);
     }
 
     @Override
     public Point toPoint() {
+        if (getValue().isEmpty()) { // The map is empty
+            return null;
+        }
         Point point = Point.measurement(getId());
         for (Map.Entry<A, B> entry : getValue().entrySet()) {
             switch (entry.getValue().getClass().getSimpleName()) {
@@ -23,6 +26,9 @@ public class MapMetric <A, B> extends Metric<Map<A, B>> {
                 case "Double":
                     point.addField(entry.getKey().toString(), (double) entry.getValue());
                     break;
+                case "Long":
+                    point.addField(entry.getKey().toString(), (long) entry.getValue());
+                    break;
                 default:
                     point.addField(entry.getKey().toString(), entry.getValue().toString());
                     break;

src/main/java/xyz/mcutils/backend/service/metric/metrics/process/MemoryMetric.java

@@ -0,0 +1,24 @@
+package xyz.mcutils.backend.service.metric.metrics.process;
+
+import xyz.mcutils.backend.service.metric.impl.IntegerMetric;
+import xyz.mcutils.backend.service.metric.impl.MapMetric;
+
+public class MemoryMetric extends MapMetric<String, Long> {
+
+    public MemoryMetric() {
+        super("memory");
+    }
+
+    @Override
+    public boolean isCollector() {
+        return true;
+    }
+
+    @Override
+    public void collect() {
+        Runtime runtime = Runtime.getRuntime();
+
+        this.getValue().put("total", runtime.totalMemory());
+        this.getValue().put("used", runtime.totalMemory() - runtime.freeMemory());
+    }
+}