Use cache for base time unit strings

Closes gh-4352
micrometer-metrics · Dec 10, 2023 · e81f3d7 · e81f3d7
1 parent 29e437b
commit e81f3d7
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/micrometer-core/src/main/java/io/micrometer/core/instrument/MeterRegistry.java b/micrometer-core/src/main/java/io/micrometer/core/instrument/MeterRegistry.java
@@ -279,8 +279,12 @@ protected String getConventionName(Meter.Id id) {
      */
     protected abstract DistributionStatisticConfig defaultHistogramConfig();
 
+    private final EnumMap<TimeUnit, String> baseTimeUnitStringCache = new EnumMap<>(TimeUnit.class);
+
     private String getBaseTimeUnitStr() {
-        return getBaseTimeUnit().toString().toLowerCase();
+        TimeUnit baseTimeUnit = getBaseTimeUnit();
+        return this.baseTimeUnitStringCache.computeIfAbsent(baseTimeUnit,
+                (timeUnit) -> timeUnit.toString().toLowerCase());
     }
 
     /**