Extend metric utils

src/main/java/io/netty5/buffer/api/pool/MetricUtils.java

@@ -1,8 +1,5 @@
 package io.netty5.buffer.api.pool;
 
-import io.netty5.buffer.api.pool.PoolArenaMetric;
-import io.netty5.buffer.api.pool.PooledBufferAllocator;
-import io.netty5.util.internal.ReflectionUtil;
 import java.lang.invoke.MethodHandle;
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.MethodType;
@@ -22,7 +19,7 @@ public class MetricUtils {
 		MethodHandle handle = null;
 		try {
 			// Find the class
-			var pooledBufferClass = Class.forName("io.netty5.buffer.api.pool.PooledBufferAllocatorMetric");
+			var pooledBufferClass = Class.forName("io.netty5.buffer.api.pool.PooledBufferAllocatorMetricUtils");
 			// Find the handle of the method
 			handle = lookup.findVirtual(pooledBufferClass, "arenaMetrics", MethodType.methodType(List.class));
 		} catch (NoSuchMethodException | IllegalAccessException | ClassNotFoundException ignored) {

src/main/java/io/netty5/buffer/api/pool/PooledBufferAllocatorMetricUtils.java

@@ -0,0 +1,60 @@
+package io.netty5.buffer.api.pool;
+
+import java.util.List;
+
+public class PooledBufferAllocatorMetricUtils implements BufferAllocatorMetric {
+
+	private final PooledBufferAllocator allocator;
+
+	@SuppressWarnings("RedundantThrows")
+	public PooledBufferAllocatorMetricUtils(PooledBufferAllocator allocator) throws Throwable {
+		this.allocator = allocator;
+	}
+
+	/**
+	 * Return the number of arenas.
+	 */
+	public int numArenas() {
+		return allocator.numArenas();
+	}
+
+	/**
+	 * Return a {@link List} of all {@link PoolArenaMetric}s that are provided by this pool.
+	 */
+	public List<PoolArenaMetric> arenaMetrics() {
+		return allocator.arenaMetrics();
+	}
+
+	/**
+	 * Return the number of thread local caches used by this {@link PooledBufferAllocator}.
+	 */
+	public int numThreadLocalCaches() {
+		return allocator.numThreadLocalCaches();
+	}
+
+	/**
+	 * Return the size of the small cache.
+	 */
+	public int smallCacheSize() {
+		return allocator.smallCacheSize();
+	}
+
+	/**
+	 * Return the size of the normal cache.
+	 */
+	public int normalCacheSize() {
+		return allocator.normalCacheSize();
+	}
+
+	/**
+	 * Return the chunk size for an arena.
+	 */
+	public int chunkSize() {
+		return allocator.chunkSize();
+	}
+
+	@Override
+	public long usedMemory() {
+		return allocator.usedMemory();
+	}
+}

src/main/java/it/cavallium/dbengine/netty/JMXPooledNettyMonitoring.java

@@ -2,40 +2,23 @@ package it.cavallium.dbengine.netty;
 
 import io.netty5.buffer.api.pool.BufferAllocatorMetric;
 import io.netty5.buffer.api.pool.PooledBufferAllocator;
+import io.netty5.buffer.api.pool.PooledBufferAllocatorMetricUtils;
 import java.lang.reflect.Field;
 
 public class JMXPooledNettyMonitoring extends JMXNettyMonitoring implements JMXNettyMonitoringMBean {
 
 	private final PooledBufferAllocator alloc;
 	private final BufferAllocatorMetric metric;
-	private Field smallCacheSize;
+	private PooledBufferAllocatorMetricUtils metricUtils;
-	private Field numThreadLocalCaches;
-	private Field normalCacheSize;
-	private Field chunkSize;
 
 	public JMXPooledNettyMonitoring(String name, PooledBufferAllocator alloc) {
 		super(name, alloc.isDirectBufferPooled(), alloc.metric());
 		this.alloc = alloc;
 		this.metric = alloc.metric();
 		try {
-			//noinspection JavaReflectionMemberAccess
+			this.metricUtils = new PooledBufferAllocatorMetricUtils(alloc);
-			numThreadLocalCaches = metric.getClass().getDeclaredField("numThreadLocalCaches");
+		} catch (Throwable e) {
-		} catch (NoSuchFieldException e) {
+			this.metricUtils = null;
-		}
-		try {
-			//noinspection JavaReflectionMemberAccess
-			smallCacheSize = metric.getClass().getDeclaredField("smallCacheSize");
-		} catch (NoSuchFieldException e) {
-		}
-		try {
-			//noinspection JavaReflectionMemberAccess
-			normalCacheSize = metric.getClass().getDeclaredField("normalCacheSize");
-		} catch (NoSuchFieldException e) {
-		}
-		try {
-			//noinspection JavaReflectionMemberAccess
-			chunkSize = metric.getClass().getDeclaredField("chunkSize");
-		} catch (NoSuchFieldException e) {
 		}
 	}
 
@@ -51,11 +34,7 @@ public class JMXPooledNettyMonitoring extends JMXNettyMonitoring implements JMXN
 
 	@Override
 	public Integer getNumThreadLocalCachesArenas() {
-		try {
+		return metricUtils != null ? metricUtils.numThreadLocalCaches() : 0;
-			return numThreadLocalCaches.getInt(metric);
-		} catch (IllegalAccessException e) {
-			return 0;
-		}
 	}
 
 	@Deprecated
@@ -66,28 +45,16 @@ public class JMXPooledNettyMonitoring extends JMXNettyMonitoring implements JMXN
 
 	@Override
 	public Integer getSmallCacheSize() {
-		try {
+		return metricUtils != null ? metricUtils.smallCacheSize() : 0;
-			return smallCacheSize.getInt(metric);
-		} catch (IllegalAccessException e) {
-			return 0;
-		}
 	}
 
 	@Override
 	public Integer getNormalCacheSize() {
-		try {
+		return metricUtils != null ? metricUtils.normalCacheSize() : 0;
-			return normalCacheSize.getInt(metric);
-		} catch (IllegalAccessException e) {
-			return 0;
-		}
 	}
 
 	@Override
 	public Integer getChunkSize() {
-		try {
+		return metricUtils != null ? metricUtils.chunkSize() : 0;
-			return chunkSize.getInt(metric);
-		} catch (IllegalAccessException e) {
-			return 0;
-		}
 	}
 }