Skip redundant tag deduplication

Both `KeyValues` and `Tags` unconditionally maintain the invariant that
they wrap distinct key-value pairs.

benchmarks/build.gradle

@@ -13,15 +13,18 @@ configurations {
 dependencies {
  // Use the baseline to avoid using new APIs in the benchmarks
  compileOnly libs.reactor.perfBaseline.core
+ compileOnly libs.reactor.perfBaseline.coreMicrometer
  compileOnly libs.jsr305
 
  implementation "org.openjdk.jmh:jmh-core:$jmhVersion"
  implementation libs.reactor.perfBaseline.extra, {
  exclude group: 'io.projectreactor', module: 'reactor-core'
  }
+ implementation platform(libs.micrometer.bom)
  annotationProcessor "org.openjdk.jmh:jmh-generator-annprocess:$jmhVersion"
 
  current project(':reactor-core')
+ current project(':reactor-core-micrometer')
  baseline libs.reactor.perfBaseline.core, {
  changing = true
  }

benchmarks/src/main/java/reactor/core/observability/micrometer/MicrometerMeterListenerConfigurationResolveTagsBenchmark.java

@@ -0,0 +1,53 @@
+package reactor.core.observability.micrometer;
+
+import io.micrometer.core.instrument.Tags;
+import java.util.concurrent.TimeUnit;
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Fork;
+import org.openjdk.jmh.annotations.Level;
+import org.openjdk.jmh.annotations.Measurement;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Param;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.Setup;
+import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.annotations.Warmup;
+import org.reactivestreams.Publisher;
+import reactor.core.publisher.Mono;
+
+@BenchmarkMode({Mode.AverageTime})
+@Warmup(iterations = 5, time = 5, timeUnit = TimeUnit.SECONDS)
+@Measurement(iterations = 5, time = 5, timeUnit = TimeUnit.SECONDS)
+@Fork(value = 1)
+@OutputTimeUnit(TimeUnit.NANOSECONDS)
+@State(Scope.Benchmark)
+public class MicrometerMeterListenerConfigurationResolveTagsBenchmark {
+ @Param({"1", "2", "5", "10"})
+ private int distinctTagCount;
+
+ @Param({"1", "2", "5", "10"})
+ private int totalTagCount;
+
+ private Publisher<Void> publisher;
+
+ @Setup(Level.Iteration)
+ public void setup() {
+ publisher = addTags(Mono.empty(), distinctTagCount, totalTagCount);
+ }
+
+ @SuppressWarnings("unused")
+ @Benchmark
+ public Tags measureThroughput() {
+ return MicrometerMeterListenerConfiguration.resolveTags(publisher, Tags.of("k", "v"));
+ }
+
+ private static <T> Mono<T> addTags(Mono<T> source, int distinct, int total) {
+ if (total == 0) {
+ return source;
+ }
+
+ return addTags(source.tag("k-" + total % distinct, "v-" + total), distinct, total - 1);
+ }
+}

gradle/libs.versions.toml

@@ -9,6 +9,7 @@
 # Baselines, should be updated on every release
 baseline-core-api = "3.6.10"
 baselinePerfCore = "3.6.10"
+baselinePerfCoreMicrometer = "1.1.9"
 baselinePerfExtra = "3.5.2"
 
 # Other shared versions
@@ -46,6 +47,7 @@ kotlin-stdlib = { module = "org.jetbrains.kotlin:kotlin-stdlib", version.ref = "
 reactiveStreams = { module = "org.reactivestreams:reactive-streams", version.ref = "reactiveStreams" }
 reactiveStreams-tck = { module = "org.reactivestreams:reactive-streams-tck", version.ref = "reactiveStreams" }
 reactor-perfBaseline-core = { module = "io.projectreactor:reactor-core", version.ref = "baselinePerfCore" }
+reactor-perfBaseline-coreMicrometer = { module = "io.projectreactor:reactor-core-micrometer", version.ref = "baselinePerfCoreMicrometer" }
 reactor-perfBaseline-extra = { module = "io.projectreactor.addons:reactor-extra", version.ref = "baselinePerfExtra" }
 
 [plugins]

reactor-core-micrometer/src/main/java/reactor/core/observability/micrometer/MicrometerMeterListenerConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022 VMware Inc. or its affiliates, All Rights Reserved.
+ * Copyright (c) 2022-2024 VMware Inc. or its affiliates, All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -93,9 +93,8 @@ static Tags resolveTags(Publisher<?> source, Tags tags) {
  Scannable scannable = Scannable.from(source);
 
  if (scannable.isScanAvailable()) {
- List<Tag> discoveredTags = scannable.tagsDeduplicated()
- .entrySet().stream()
- .map(e -> Tag.of(e.getKey(), e.getValue()))
+ List<Tag> discoveredTags = scannable.tags()
+ .map(t -> Tag.of(t.getT1(), t.getT2()))
  .collect(Collectors.toList());
  return tags.and(discoveredTags);
  }

reactor-core-micrometer/src/main/java/reactor/core/observability/micrometer/MicrometerObservationListenerConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022 VMware Inc. or its affiliates, All Rights Reserved.
+ * Copyright (c) 2022-2024 VMware Inc. or its affiliates, All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -70,9 +70,8 @@ static KeyValues resolveKeyValues(Publisher<?> source, KeyValues tags) {
  Scannable scannable = Scannable.from(source);
 
  if (scannable.isScanAvailable()) {
- List<KeyValue> discoveredTags = scannable.tagsDeduplicated()
- .entrySet().stream()
- .map(e -> KeyValue.of(e.getKey(), e.getValue()))
+ List<KeyValue> discoveredTags = scannable.tags()
+ .map(e -> KeyValue.of(e.getT1(), e.getT2()))
  .collect(Collectors.toList());
  return tags.and(discoveredTags);
  }

reactor-core/src/main/java/reactor/core/publisher/FluxMetrics.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2022 VMware Inc. or its affiliates, All Rights Reserved.
+ * Copyright (c) 2018-2024 VMware Inc. or its affiliates, All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -295,9 +295,8 @@ static Tags resolveTags(Publisher<?> source, Tags tags) {
  Scannable scannable = Scannable.from(source);
 
  if (scannable.isScanAvailable()) {
- List<Tag> discoveredTags = scannable.tagsDeduplicated()
- .entrySet().stream()
- .map(e -> Tag.of(e.getKey(), e.getValue()))
+ List<Tag> discoveredTags = scannable.tags()
+ .map(t -> Tag.of(t.getT1(), t.getT2()))
  .collect(Collectors.toList());
  return tags.and(discoveredTags);
  }