refactor(feature-flagging): separate agent runtime and telemetry

Author: leoromanovsky

dd-smoke-tests/openfeature/build.gradle

@@ -21,7 +21,7 @@ smokeTestApp {
 
 dependencies {
   testImplementation project(':dd-smoke-tests')
-  testImplementation project(':products:feature-flagging:feature-flagging-lib')
+  testImplementation project(':products:feature-flagging:feature-flagging-agent-runtime')
 }
 
 spotless {

…ng/feature-flagging-lib/build.gradle.kts …-flagging-agent-runtime/build.gradle.ktsproducts/feature-flagging/feature-flagging-lib/build.gradle.kts renamed to products/feature-flagging/feature-flagging-agent-runtime/build.gradle.kts products/feature-flagging/feature-flagging-lib/build.gradle.kts renamed to products/feature-flagging/feature-flagging-agent-runtime/build.gradle.kts

@@ -5,13 +5,7 @@ plugins {
 
 apply(from = "$rootDir/gradle/java.gradle")
 
-description = "Feature flagging remote config and exposure handling"
-
-extra["excludedClassesCoverage"] = listOf(
-  // POJOs
-  "com.datadog.featureflag.ExposureCache.Key",
-  "com.datadog.featureflag.ExposureCache.Value"
-)
+description = "Java agent runtime for Feature Flagging configuration and telemetry"
 
 dependencies {
   api(libs.slf4j)
@@ -20,13 +14,10 @@ dependencies {
   api(project(":communication"))
   implementation(project(":internal-api"))
   api(project(":products:feature-flagging:feature-flagging-bootstrap"))
+  implementation(project(":products:feature-flagging:feature-flagging-telemetry"))
   implementation(project(":utils:logging-utils"))
   api(project(":utils:queue-utils"))
 
-  compileOnly(project(":dd-trace-core")) // shading does not work with this one
-  // Platform JSON writer for the ffe_* tag values.
-  compileOnly(project(":components:json"))
-
   testImplementation(libs.bundles.junit5)
   testImplementation(libs.bundles.mockito)
   testImplementation(project(":utils:test-utils"))

…ing/feature-flagging-lib/gradle.lockfile …e-flagging-agent-runtime/gradle.lockfileproducts/feature-flagging/feature-flagging-lib/gradle.lockfile renamed to products/feature-flagging/feature-flagging-agent-runtime/gradle.lockfile products/feature-flagging/feature-flagging-lib/gradle.lockfile renamed to products/feature-flagging/feature-flagging-agent-runtime/gradle.lockfile

@@ -1,7 +1,7 @@
 # This is a Gradle generated file for dependency locking.
 # Manual edits can break the build and are not advised.
 # This file is expected to be part of source control.
-# To regenerate this file, run: ./gradlew :products:feature-flagging:feature-flagging-lib:dependencies --write-locks
+# To regenerate this file, run: ./gradlew :products:feature-flagging:feature-flagging-agent-runtime:dependencies --write-locks
 cafe.cryptography:curve25519-elisabeth:0.1.0=runtimeClasspath,testRuntimeClasspath
 cafe.cryptography:ed25519-elisabeth:0.1.0=runtimeClasspath,testRuntimeClasspath
 ch.qos.logback:logback-classic:1.2.13=testCompileClasspath,testRuntimeClasspath
@@ -92,7 +92,6 @@ org.junit.platform:junit-platform-launcher:1.14.1=testRuntimeClasspath
 org.junit.platform:junit-platform-runner:1.14.1=testRuntimeClasspath
 org.junit.platform:junit-platform-suite-api:1.14.1=testRuntimeClasspath
 org.junit.platform:junit-platform-suite-commons:1.14.1=testRuntimeClasspath
-org.junit:junit-bom:5.14.0=spotbugs
 org.junit:junit-bom:5.14.1=testCompileClasspath,testRuntimeClasspath
 org.mockito:mockito-core:4.4.0=testCompileClasspath,testRuntimeClasspath
 org.mockito:mockito-junit-jupiter:4.4.0=testCompileClasspath,testRuntimeClasspath

…tureflag/ConfigurationSourceService.java …tureflag/ConfigurationSourceService.javaproducts/feature-flagging/feature-flagging-lib/src/main/java/com/datadog/featureflag/ConfigurationSourceService.java renamed to products/feature-flagging/feature-flagging-agent-runtime/src/main/java/com/datadog/featureflag/ConfigurationSourceService.java products/feature-flagging/feature-flagging-lib/src/main/java/com/datadog/featureflag/ConfigurationSourceService.java renamed to products/feature-flagging/feature-flagging-agent-runtime/src/main/java/com/datadog/featureflag/ConfigurationSourceService.java

@@ -11,6 +11,7 @@
 import datadog.communication.BackendApi;
 import datadog.communication.BackendApiFactory;
 import datadog.communication.ddagent.SharedCommunicationObjects;
+import datadog.openfeature.internal.telemetry.ExposureDeduplicationCache;
 import datadog.trace.api.Config;
 import datadog.trace.api.featureflag.FeatureFlaggingGateway;
 import datadog.trace.api.featureflag.exposure.ExposureEvent;
@@ -105,7 +106,7 @@ private static class ExposureSerializingHandler implements Runnable {
     private BackendApi evp;
 
     private final Map<String, String> context;
-    private final ExposureCache cache;
+    private final ExposureDeduplicationCache cache;
 
     private final List<ExposureEvent> buffer = new ArrayList<>();
     private final Runnable errorCallback;
@@ -118,7 +119,7 @@ public ExposureSerializingHandler(
         final Map<String, String> context,
         final Runnable errorCallback) {
       this.queue = queue;
-      this.cache = new LRUExposureCache(queue.capacity());
+      this.cache = new ExposureDeduplicationCache(queue.capacity());
       this.jsonAdapter = new Moshi.Builder().build().adapter(ExposuresRequest.class);
       this.backendApiFactory = backendApiFactory;
       this.context = context;
@@ -166,7 +167,8 @@ private void consumeBatch() {
 
     /** Adds an element to the buffer taking care of duplicated exposures thanks to the LRU cache */
     private boolean addToBuffer(final ExposureEvent event) {
-      if (cache.add(event)) {
+      if (cache.shouldEmit(
+          event.flag.key, event.subject.id, event.variant.key, event.allocation.key)) {
         buffer.add(event);
         return true;
       }

…/datadog/featureflag/ExposureWriter.java …/datadog/featureflag/ExposureWriter.javaproducts/feature-flagging/feature-flagging-lib/src/main/java/com/datadog/featureflag/ExposureWriter.java renamed to products/feature-flagging/feature-flagging-agent-runtime/src/main/java/com/datadog/featureflag/ExposureWriter.java products/feature-flagging/feature-flagging-lib/src/main/java/com/datadog/featureflag/ExposureWriter.java renamed to products/feature-flagging/feature-flagging-agent-runtime/src/main/java/com/datadog/featureflag/ExposureWriter.java

@@ -1,5 +1,6 @@
 package com.datadog.featureflag;
 
+import datadog.openfeature.internal.telemetry.SpanEnrichmentAccumulator;
 import datadog.trace.api.interceptor.MutableSpan;
 import datadog.trace.api.interceptor.TraceInterceptor;
 import datadog.trace.bootstrap.instrumentation.api.AgentSpan;

…adog/featureflag/ExposureWriterImpl.java …adog/featureflag/ExposureWriterImpl.javaproducts/feature-flagging/feature-flagging-lib/src/main/java/com/datadog/featureflag/ExposureWriterImpl.java renamed to products/feature-flagging/feature-flagging-agent-runtime/src/main/java/com/datadog/featureflag/ExposureWriterImpl.java products/feature-flagging/feature-flagging-lib/src/main/java/com/datadog/featureflag/ExposureWriterImpl.java renamed to products/feature-flagging/feature-flagging-agent-runtime/src/main/java/com/datadog/featureflag/ExposureWriterImpl.java

@@ -1,5 +1,6 @@
 package com.datadog.featureflag;
 
+import datadog.openfeature.internal.telemetry.SpanEnrichmentAccumulator;
 import datadog.trace.bootstrap.instrumentation.api.AgentSpan;
 import java.util.Map;
 import java.util.WeakHashMap;

…featureflag/RemoteConfigServiceImpl.java …featureflag/RemoteConfigServiceImpl.javaproducts/feature-flagging/feature-flagging-lib/src/main/java/com/datadog/featureflag/RemoteConfigServiceImpl.java renamed to products/feature-flagging/feature-flagging-agent-runtime/src/main/java/com/datadog/featureflag/RemoteConfigServiceImpl.java products/feature-flagging/feature-flagging-lib/src/main/java/com/datadog/featureflag/RemoteConfigServiceImpl.java renamed to products/feature-flagging/feature-flagging-agent-runtime/src/main/java/com/datadog/featureflag/RemoteConfigServiceImpl.java

@@ -1,5 +1,6 @@
 package com.datadog.featureflag;
 
+import datadog.openfeature.internal.telemetry.SpanEnrichmentAccumulator;
 import datadog.trace.api.GlobalTracer;
 import datadog.trace.api.featureflag.FeatureFlaggingGateway;
 import datadog.trace.api.featureflag.SpanEnrichmentEvent;