Allow specifying the used HighCardinalityTagsDetector instance

micrometer-core/src/main/java/io/micrometer/core/instrument/MeterRegistry.java

@@ -964,21 +964,19 @@ public Config withHighCardinalityTagsDetector(long threshold, Duration delay) {
         }
 
         /**
-         * Creates and starts a new {@link HighCardinalityTagsDetector} for this registry.
-         * @param threshold The threshold to use to detect high cardinality tags (if the
-         * number of Meters with the same name is higher than this value, that's a high
-         * cardinality tag).
-         * @param delay The delay between the termination of one check and the
-         * commencement of the next.
-         * @param meterNameConsumer A consumer that will be called for each high
-         * cardinality tag detected.
+         * Uses the supplied {@code Function<MeterRegistry, HighCardinalityTagsDetector>}
+         * to create a new {@link HighCardinalityTagsDetector} for this registry. After
+         * the {@link HighCardinalityTagsDetector} is created, it also starts it. The
+         * implementation of the factory {@code Function} must pass the registry instance
+         * to one of the constructors of {@link HighCardinalityTagsDetector}.
+         * @param highCardinalityTagsDetectorFactory The {@code Function} that creates the
+         * {@link HighCardinalityTagsDetector} instance
          * @return This configuration instance.
-         * @since 1.12.0
+         * @since 1.14.0
          */
-        public Config withHighCardinalityTagsDetector(long threshold, Duration delay,
-                Consumer<String> meterNameConsumer) {
-            return withHighCardinalityTagsDetector(
-                    new HighCardinalityTagsDetector(MeterRegistry.this, threshold, delay, meterNameConsumer));
+        public Config withHighCardinalityTagsDetector(
+                Function<MeterRegistry, HighCardinalityTagsDetector> highCardinalityTagsDetectorFactory) {
+            return withHighCardinalityTagsDetector(highCardinalityTagsDetectorFactory.apply(MeterRegistry.this));
         }
 
         private Config withHighCardinalityTagsDetector(HighCardinalityTagsDetector newHighCardinalityTagsDetector) {

micrometer-core/src/test/java/io/micrometer/core/instrument/HighCardinalityTagsDetectorTests.java

@@ -15,15 +15,15 @@
  */
 package io.micrometer.core.instrument;
 
-import java.time.Duration;
-import java.util.function.Consumer;
-
 import io.micrometer.common.lang.Nullable;
 import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
+import java.time.Duration;
+import java.util.function.Consumer;
+
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.awaitility.Awaitility.await;
 
@@ -91,24 +91,22 @@ void shouldNotDetectNoTags() {
     }
 
     @Test
-    void addsCustomMeterNameConsumer() {
-        TestCustomMeterNameConsumer customMeterNameConsumer = new TestCustomMeterNameConsumer();
-        this.highCardinalityTagsDetector = new HighCardinalityTagsDetector(registry, 3, Duration.ofMinutes(1),
-                customMeterNameConsumer);
-
+    void shouldBeManagedThroughMeterRegistry() {
         for (int i = 0; i < 4; i++) {
             Counter.builder("test.counter").tag("index", String.valueOf(i)).register(registry).increment();
         }
-        highCardinalityTagsDetector.start();
 
-        await().atMost(Duration.ofSeconds(1))
-            .until(() -> "test.counter_customized".equals(customMeterNameConsumer.getName()));
+        registry.config()
+            .withHighCardinalityTagsDetector(
+                    r -> new HighCardinalityTagsDetector(r, 3, Duration.ofMinutes(1), testMeterNameConsumer));
+
+        await().atMost(Duration.ofSeconds(1)).until(() -> "test.counter".equals(testMeterNameConsumer.getName()));
     }
 
     private static class TestMeterNameConsumer implements Consumer<String> {
 
         @Nullable
-        private String name;
+        private volatile String name;
 
         @Override
         public void accept(String name) {
@@ -122,21 +120,4 @@ public String getName() {
 
     }
 
-    private static class TestCustomMeterNameConsumer implements Consumer<String> {
-
-        @Nullable
-        private String name;
-
-        @Override
-        public void accept(String name) {
-            this.name = name + "_customized";
-        }
-
-        @Nullable
-        public String getName() {
-            return this.name;
-        }
-
-    }
-
 }