make world size calculate async

Author: radiant-ai

src/main/java/de/sldk/mc/metrics/WorldSize.java

@@ -2,6 +2,8 @@
 
 import de.sldk.mc.utils.PathFileSize;
 import io.prometheus.client.Gauge;
+
+import java.util.concurrent.CompletableFuture;
 import java.util.logging.Logger;
 import org.bukkit.World;
 import org.bukkit.plugin.Plugin;
@@ -27,13 +29,17 @@ protected void clear() {
 
     @Override
     public void collect(World world) {
-        try {
-            PathFileSize pathUtils = new PathFileSize(world.getWorldFolder().toPath());
-            long size = pathUtils.getSize();
+        CompletableFuture.supplyAsync(() -> {
+            try {
+                PathFileSize pathUtils = new PathFileSize(world.getWorldFolder().toPath());
+                return pathUtils.getSize();
+            } catch (Throwable t) {
+                log.throwing(this.getClass().getSimpleName(), "collect", t);
+            }
+            return 0L;
+        }).thenAccept(size -> {
             String worldName = world.getName();
             WORLD_SIZE.labels(worldName).set(size);
-        } catch (Throwable t) {
-            log.throwing(this.getClass().getSimpleName(), "collect", t);
-        }
+        });
     }
 }

src/test/java/de/sldk/mc/metrics/WorldSizeTest.java

@@ -50,19 +50,21 @@ public void doesNotPopulateMetricIfFileDoesNotExist() {
     }
 
     @Test
-    public void setsMetricWithCorrectNameAndLabel() {
+    public void setsMetricWithCorrectNameAndLabel() throws InterruptedException {
         String worldName = new RandomString(10).nextString();
         givenWorldFileExists(worldName);
         worldSizeMetric.collect(world);
+        Thread.sleep(500);
         assertNotNull(getMetricValue(worldName));
     }
 
     @Test
-    public void setsCorrectWorldSizeValue() throws IOException {
+    public void setsCorrectWorldSizeValue() throws IOException, InterruptedException {
         String worldName = new RandomString(10).nextString();
         int worldSize = new Random().ints(128, 1024).findFirst().getAsInt();
         givenWorldFileExists(worldName, worldSize);
         worldSizeMetric.collect(world);
+        Thread.sleep(500);
         Double value = getMetricValue(worldName);
         assertEquals(worldSize, value.longValue());
     }