4.x: Remove unused code from io.helidon.metrics.providers.micrometer.MMeterRegistry

Author: Captain1653

metrics/providers/micrometer/src/main/java/io/helidon/metrics/providers/micrometer/MMeterRegistry.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023, 2024 Oracle and/or its affiliates.
+ * Copyright (c) 2023, 2025 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -46,9 +46,7 @@
 import io.micrometer.core.instrument.Meter;
 import io.micrometer.core.instrument.MeterRegistry;
 import io.micrometer.core.instrument.Timer;
-import io.micrometer.core.instrument.composite.CompositeMeterRegistry;
 import io.micrometer.core.instrument.search.Search;
-import io.micrometer.prometheus.PrometheusMeterRegistry;
 
 /**
  * Implementation of {@link io.helidon.metrics.api.MeterRegistry} for the Micrometer adapter.
@@ -127,88 +125,6 @@ static Builder builder(
         return new Builder(delegate, metricsFactory);
     }
 
-    /**
-     * Creates a new meter registry which wraps an newly-created Micrometer
-     * {@link io.micrometer.core.instrument.composite.CompositeMeterRegistry} with a Prometheus meter registry
-     * automatically added, using the specified clock.
-     *
-     * @param metricsFactory  metrics factory the new meter registry should use in creating and registering meters
-     * @param clock           default clock to associate with the new meter registry
-     * @param metersProviders providers of built-in meters to be registered upon creation of the meter registry
-     * @return new wrapper around a new Micrometer composite meter registry
-     */
-    static MMeterRegistry create(MicrometerMetricsFactory metricsFactory,
-                                 Clock clock,
-                                 Collection<MetersProvider> metersProviders) {
-        CompositeMeterRegistry delegate = new CompositeMeterRegistry(ClockWrapper.create(clock));
-        // The specified clock is already a Helidon one so pass it directly; no need to wrap it.
-        return create(delegate,
-                      metricsFactory,
-                      metricsFactory.metricsConfig(),
-                      clock,
-                      metersProviders);
-    }
-
-    static MMeterRegistry create(io.micrometer.core.instrument.MeterRegistry delegate,
-                                 MicrometerMetricsFactory metricsFactory,
-                                 MetricsConfig metricsConfig,
-                                 Collection<MetersProvider> metersProviders) {
-
-        return create(delegate, metricsFactory, metricsConfig, MClock.create(delegate.config().clock()), metersProviders);
-    }
-
-    static MMeterRegistry create(io.micrometer.core.instrument.MeterRegistry delegate,
-                                 MicrometerMetricsFactory metricsFactory,
-                                 MetricsConfig metricsConfig,
-                                 Collection<MetersProvider> metersProviders,
-                                 Consumer<io.helidon.metrics.api.Meter> onAddListener,
-                                 Consumer<io.helidon.metrics.api.Meter> onRemoveListener) {
-        MMeterRegistry result = create(delegate, metricsFactory, metricsConfig, MClock.create(delegate.config().clock()));
-        result.onMeterAdded(onAddListener)
-                .onMeterRemoved(onRemoveListener);
-        return applyMetersProvidersToRegistry(metricsFactory, result, metersProviders);
-    }
-
-    static MMeterRegistry create(io.micrometer.core.instrument.MeterRegistry delegate,
-                                 MicrometerMetricsFactory metricsFactory,
-                                 MetricsConfig metricsConfig,
-                                 Clock clock,
-                                 Collection<MetersProvider> metersProviders) {
-
-        return applyMetersProvidersToRegistry(metricsFactory,
-                                              create(delegate,
-                                                     metricsFactory,
-                                                     metricsConfig,
-                                                     clock),
-                                              metersProviders);
-    }
-
-    static MMeterRegistry create(io.micrometer.core.instrument.MeterRegistry delegate,
-                                 MicrometerMetricsFactory metricsFactory,
-                                 MetricsConfig metricsConfig,
-                                 Clock clock) {
-
-        io.micrometer.core.instrument.MeterRegistry preppedDelegate =
-                ensurePrometheusRegistryIsPresent(delegate,
-                                                  metricsFactory.metricsConfig());
-
-        return new MMeterRegistry(preppedDelegate,
-                                  metricsFactory,
-                                  metricsConfig,
-                                  clock);
-    }
-
-    static MMeterRegistry create(io.micrometer.core.instrument.MeterRegistry delegate,
-                                 MicrometerMetricsFactory metricsFactory,
-                                 Collection<MetersProvider> metersProviders) {
-
-        return create(delegate,
-                      metricsFactory,
-                      metricsFactory.metricsConfig(),
-                      MClock.create(delegate.config().clock()),
-                      metersProviders);
-    }
-
     static MMeterRegistry applyMetersProvidersToRegistry(MetricsFactory factory,
                                                          MMeterRegistry registry,
                                                          Collection<MetersProvider> metersProviders) {
@@ -589,21 +505,6 @@ HM extends MMeter<M>> MMeter<M> meterIfRegistered(MMeter.Builder<?, M, HB, HM> m
         return null;
     }
 
-    private static io.micrometer.core.instrument.MeterRegistry ensurePrometheusRegistryIsPresent(
-            io.micrometer.core.instrument.MeterRegistry meterRegistry,
-            MetricsConfig metricsConfig) {
-
-        if (meterRegistry instanceof CompositeMeterRegistry compositeMeterRegistry) {
-            if (compositeMeterRegistry.getRegistries()
-                    .stream()
-                    .noneMatch(r -> r instanceof PrometheusMeterRegistry)) {
-                compositeMeterRegistry.add(
-                        new PrometheusMeterRegistry(key -> metricsConfig.lookupConfig(key).orElse(null)));
-            }
-        }
-        return meterRegistry;
-    }
-
     private <M extends Meter,
             HB extends MMeter.Builder<?, M, HB, HM>,
             HM extends MMeter<M>> io.helidon.metrics.api.Meter getOrCreate(HB mBuilder,
@@ -895,29 +796,4 @@ public R build() {
         }
     }
 
-    /**
-     * Micrometer-friendly wrapper around a Helidon clock.
-     */
-    private static class ClockWrapper implements io.micrometer.core.instrument.Clock {
-
-        private final Clock neutralClock;
-
-        private ClockWrapper(Clock neutralClock) {
-            this.neutralClock = neutralClock;
-        }
-
-        static ClockWrapper create(Clock clock) {
-            return new ClockWrapper(clock);
-        }
-
-        @Override
-        public long wallTime() {
-            return neutralClock.wallTime();
-        }
-
-        @Override
-        public long monotonicTime() {
-            return neutralClock.monotonicTime();
-        }
-    }
 }