Allow experiments to exclude by ACI

service/src/main/java/org/whispersystems/textsecuregcm/configuration/dynamic/DynamicExperimentEnrollmentConfiguration.java

@@ -26,8 +26,8 @@ public class DynamicExperimentEnrollmentConfiguration {
     /**
      * What percentage of enrolled UUIDs should the experiment be enabled for.
      * <p>
-     * Unlike {@link this#enrollmentPercentage}, this is not stable by UUID. The same UUID may be
+     * Unlike {@link this#enrollmentPercentage}, this is not stable by UUID. The same UUID may be enrolled/unenrolled
-     * enrolled/unenrolled across calls.
+     * across calls.
      */
     @JsonProperty
     @Valid
@@ -49,6 +49,14 @@ public class DynamicExperimentEnrollmentConfiguration {
   @NotNull
   private final UuidSelector uuidSelector = new UuidSelector();
 
+
+  /**
+   * UUIDs that the experiment should always be disabled for. This takes precedence over uuidSelector.
+   */
+  @Valid
+  @NotNull
+  private final Set<UUID> excludedUuids = Collections.emptySet();
+
   /**
    * If the UUID is not enrolled via {@link UuidSelector#uuids}, what is the percentage chance it should be enrolled.
    * <p>
@@ -67,4 +75,9 @@ public class DynamicExperimentEnrollmentConfiguration {
   public UuidSelector getUuidSelector() {
     return uuidSelector;
   }
+
+  public Set<UUID> getExcludedUuids() {
+    return excludedUuids;
+  }
 }
+

service/src/main/java/org/whispersystems/textsecuregcm/experiment/ExperimentEnrollmentManager.java

@@ -5,11 +5,11 @@
 
 package org.whispersystems.textsecuregcm.experiment;
 
+import com.google.common.annotations.VisibleForTesting;
 import java.util.Optional;
 import java.util.Random;
 import java.util.UUID;
 import java.util.concurrent.ThreadLocalRandom;
-import com.google.common.annotations.VisibleForTesting;
 import org.whispersystems.textsecuregcm.configuration.dynamic.DynamicConfiguration;
 import org.whispersystems.textsecuregcm.configuration.dynamic.DynamicExperimentEnrollmentConfiguration;
 import org.whispersystems.textsecuregcm.configuration.dynamic.DynamicPreRegistrationExperimentEnrollmentConfiguration;
@@ -47,6 +47,9 @@ public class ExperimentEnrollmentManager {
   }
 
   Optional<Boolean> isAccountEnrolled(final UUID accountUuid, DynamicExperimentEnrollmentConfiguration config) {
+    if (config.getExcludedUuids().contains(accountUuid)) {
+      return Optional.of(false);
+    }
     if (config.getUuidSelector().getUuids().contains(accountUuid)) {
       final int r = random.nextInt(100);
       return Optional.of(r < config.getUuidSelector().getUuidEnrollmentPercentage());

service/src/test/java/org/whispersystems/textsecuregcm/experiment/ExperimentEnrollmentManagerTest.java

@@ -45,6 +45,7 @@ class ExperimentEnrollmentManagerTest {
   private Random random;
 
   private static final UUID ACCOUNT_UUID = UUID.randomUUID();
+  private static final UUID EXCLUDED_UUID = UUID.randomUUID();
   private static final String UUID_EXPERIMENT_NAME = "uuid_test";
   private static final String E164_AND_UUID_EXPERIMENT_NAME = "e164_uuid_test";
 
@@ -98,6 +99,12 @@ class ExperimentEnrollmentManagerTest {
 
     when(experimentEnrollmentConfiguration.getEnrollmentPercentage()).thenReturn(100);
     assertTrue(experimentEnrollmentManager.isEnrolled(account.getUuid(), UUID_EXPERIMENT_NAME));
+
+    when(experimentEnrollmentConfiguration.getExcludedUuids()).thenReturn(Set.of(EXCLUDED_UUID));
+    when(experimentEnrollmentConfiguration.getEnrollmentPercentage()).thenReturn(100);
+    when(uuidSelector.getUuidEnrollmentPercentage()).thenReturn(100);
+    when(uuidSelector.getUuids()).thenReturn(Set.of(EXCLUDED_UUID));
+    assertFalse(experimentEnrollmentManager.isEnrolled(EXCLUDED_UUID, UUID_EXPERIMENT_NAME));
   }
 
   @Test