diff --git a/src/main/java/org/warp/commonutils/metrics/AtomicDetailedTimeAbsoluteSamples.java b/src/main/java/org/warp/commonutils/metrics/AtomicDetailedTimeAbsoluteSamples.java
index 7b8ac9a..e9ba97f 100644
--- a/src/main/java/org/warp/commonutils/metrics/AtomicDetailedTimeAbsoluteSamples.java
+++ b/src/main/java/org/warp/commonutils/metrics/AtomicDetailedTimeAbsoluteSamples.java
@@ -1,13 +1,18 @@
 package org.warp.commonutils.metrics;
 
+import it.unimi.dsi.fastutil.objects.Object2ObjectMap;
+import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap;
+import it.unimi.dsi.fastutil.objects.ObjectOpenHashSet;
+import java.util.Collections;
 import java.util.HashMap;
+import java.util.Set;
 
 public class AtomicDetailedTimeAbsoluteSamples<T> implements AtomicDetailedTimeAbsoluteSamplesSnapshot<T> {
 
 	private final boolean isSnapshot;
 	private final int sampleTime;
 	private final int samplesCount;
-	private HashMap<T, AtomicTimeAbsoluteSamples> detailedAtomicTimeSamples = new HashMap<>();
+	private Object2ObjectMap<T, AtomicTimeAbsoluteSamples> detailedAtomicTimeSamples = new Object2ObjectOpenHashMap<>();
 
 	/**
 	 * @param sampleTime   in milliseconds
@@ -22,7 +27,7 @@ public class AtomicDetailedTimeAbsoluteSamples<T> implements AtomicDetailedTimeA
 	public AtomicDetailedTimeAbsoluteSamples(int sampleTime, int samplesCount, HashMap<T, AtomicTimeAbsoluteSamplesSnapshot> detailedAtomicTimeSamples, boolean isSnapshot) {
 		this.sampleTime = sampleTime;
 		this.samplesCount = samplesCount;
-		this.detailedAtomicTimeSamples = new HashMap<>();
+		this.detailedAtomicTimeSamples = new Object2ObjectOpenHashMap<>();
 		detailedAtomicTimeSamples.forEach((detail, sample) -> this.detailedAtomicTimeSamples.put(detail, (AtomicTimeAbsoluteSamples) sample));
 		this.isSnapshot = isSnapshot;
 	}
@@ -45,6 +50,11 @@ public class AtomicDetailedTimeAbsoluteSamples<T> implements AtomicDetailedTimeA
 		getDetailed(detail).set(count);
 	}
 
+	@Override
+	public synchronized Set<T> getDetails() {
+		return Collections.unmodifiableSet(new ObjectOpenHashSet<>(detailedAtomicTimeSamples.keySet()));
+	}
+
 	@Override
 	public synchronized double getAveragePerSecond(T detail, long timeRange) {
 		updateSamples();
@@ -86,6 +96,9 @@ public class AtomicDetailedTimeAbsoluteSamples<T> implements AtomicDetailedTimeA
 	}
 
 	public synchronized AtomicDetailedTimeAbsoluteSamples<T> snapshot() {
+		if (isSnapshot) {
+			return this;
+		}
 		var clonedDetailedAtomicTimeSamples = new HashMap<T, AtomicTimeAbsoluteSamplesSnapshot>(detailedAtomicTimeSamples);
 		clonedDetailedAtomicTimeSamples.replaceAll((key, value) -> ((AtomicTimeAbsoluteSamples) value).snapshot());
 		return new AtomicDetailedTimeAbsoluteSamples<>(sampleTime,
diff --git a/src/main/java/org/warp/commonutils/metrics/AtomicDetailedTimeAbsoluteSamplesSnapshot.java b/src/main/java/org/warp/commonutils/metrics/AtomicDetailedTimeAbsoluteSamplesSnapshot.java
index 9040111..4776a34 100644
--- a/src/main/java/org/warp/commonutils/metrics/AtomicDetailedTimeAbsoluteSamplesSnapshot.java
+++ b/src/main/java/org/warp/commonutils/metrics/AtomicDetailedTimeAbsoluteSamplesSnapshot.java
@@ -1,7 +1,11 @@
 package org.warp.commonutils.metrics;
 
+import java.util.Set;
+
 public interface AtomicDetailedTimeAbsoluteSamplesSnapshot<T> extends AtomicTimeAbsoluteSamplesSnapshot {
 
+	Set<T> getDetails();
+
 	double getAveragePerSecond(T detail, long timeRange);
 
 	long getCurrentCount(T detail);
diff --git a/src/main/java/org/warp/commonutils/metrics/AtomicDetailedTimeIncrementalSamples.java b/src/main/java/org/warp/commonutils/metrics/AtomicDetailedTimeIncrementalSamples.java
index 71e2a70..1e0eca1 100644
--- a/src/main/java/org/warp/commonutils/metrics/AtomicDetailedTimeIncrementalSamples.java
+++ b/src/main/java/org/warp/commonutils/metrics/AtomicDetailedTimeIncrementalSamples.java
@@ -1,12 +1,17 @@
 package org.warp.commonutils.metrics;
 
+import it.unimi.dsi.fastutil.objects.Object2ObjectMap;
+import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap;
+import it.unimi.dsi.fastutil.objects.ObjectOpenHashSet;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
+import java.util.Set;
 
 public class AtomicDetailedTimeIncrementalSamples<T> extends AtomicTimeIncrementalSamples implements
 		AtomicDetailedTimeIncrementalSamplesSnapshot<T> {
 
-	private HashMap<T, AtomicTimeIncrementalSamples> detailedAtomicTimeSamples = new HashMap<>();
+	private Object2ObjectMap<T, AtomicTimeIncrementalSamples> detailedAtomicTimeSamples = new Object2ObjectOpenHashMap<>();
 
 	/**
 	 * @param sampleTime   in milliseconds
@@ -19,7 +24,7 @@ public class AtomicDetailedTimeIncrementalSamples<T> extends AtomicTimeIncrement
 	public AtomicDetailedTimeIncrementalSamples(long startTime, long[] samples, int sampleTime, long currentSampleStartTime, long totalEvents,
 			HashMap<T, AtomicTimeIncrementalSamplesSnapshot> detailedAtomicTimeSamples, boolean isSnapshot) {
 		super(startTime, samples, sampleTime, currentSampleStartTime, totalEvents, isSnapshot);
-		this.detailedAtomicTimeSamples = new HashMap<>();
+		this.detailedAtomicTimeSamples = new Object2ObjectOpenHashMap<>();
 		detailedAtomicTimeSamples.forEach((detail, sample) -> this.detailedAtomicTimeSamples.put(detail, (AtomicTimeIncrementalSamples) sample));
 	}
 
@@ -38,6 +43,11 @@ public class AtomicDetailedTimeIncrementalSamples<T> extends AtomicTimeIncrement
 		increment(count);
 	}
 
+	@Override
+	public synchronized Set<T> getDetails() {
+		return Collections.unmodifiableSet(new ObjectOpenHashSet<>(detailedAtomicTimeSamples.keySet()));
+	}
+
 	@Override
 	public synchronized double getAveragePerSecond(T detail, long timeRange) {
 		updateSamples();
@@ -73,6 +83,9 @@ public class AtomicDetailedTimeIncrementalSamples<T> extends AtomicTimeIncrement
 	}
 
 	public synchronized AtomicDetailedTimeIncrementalSamples<T> snapshot() {
+		if (isSnapshot) {
+			return this;
+		}
 		var clonedDetailedAtomicTimeSamples = new HashMap<T, AtomicTimeIncrementalSamplesSnapshot>(detailedAtomicTimeSamples);
 		clonedDetailedAtomicTimeSamples.replaceAll((key, value) -> ((AtomicTimeIncrementalSamples) value).snapshot());
 		return new AtomicDetailedTimeIncrementalSamples<>(startTime, Arrays.copyOf(this.samples, this.samples.length), sampleTime,
diff --git a/src/main/java/org/warp/commonutils/metrics/AtomicDetailedTimeIncrementalSamplesSnapshot.java b/src/main/java/org/warp/commonutils/metrics/AtomicDetailedTimeIncrementalSamplesSnapshot.java
index 2b3bca4..84b981f 100644
--- a/src/main/java/org/warp/commonutils/metrics/AtomicDetailedTimeIncrementalSamplesSnapshot.java
+++ b/src/main/java/org/warp/commonutils/metrics/AtomicDetailedTimeIncrementalSamplesSnapshot.java
@@ -1,7 +1,11 @@
 package org.warp.commonutils.metrics;
 
+import java.util.Set;
+
 public interface AtomicDetailedTimeIncrementalSamplesSnapshot<T> extends AtomicTimeIncrementalSamplesSnapshot {
 
+	Set<T> getDetails();
+
 	double getAveragePerSecond(T detail, long timeRange);
 
 	long getApproximateCount(T detail, long timeRange);
diff --git a/src/main/java/org/warp/commonutils/metrics/AtomicTimeIncrementalSamples.java b/src/main/java/org/warp/commonutils/metrics/AtomicTimeIncrementalSamples.java
index 0ad63e2..fd2de8b 100644
--- a/src/main/java/org/warp/commonutils/metrics/AtomicTimeIncrementalSamples.java
+++ b/src/main/java/org/warp/commonutils/metrics/AtomicTimeIncrementalSamples.java
@@ -124,6 +124,9 @@ public class AtomicTimeIncrementalSamples implements AtomicTimeIncrementalSample
 	}
 
 	public synchronized AtomicTimeIncrementalSamplesSnapshot snapshot() {
+		if (isSnapshot) {
+			return this;
+		}
 		return new AtomicTimeIncrementalSamples(startTime, Arrays.copyOf(this.samples, this.samples.length), sampleTime, currentSampleStartTime, totalEvents, true);
 	}
 }