Remove XPackFeatureSet interface (elastic#115679)

XPackFeatureSet hasn't been used for many years. But the inner "Usage" class
is still used. This commit moves the Usage class up to its own file as
XPackFeatureUsage, and removes the defunct XPackFeatureSet interface.

closes elastic#29736

x-pack/plugin/analytics/src/test/java/org/elasticsearch/xpack/analytics/action/AnalyticsInfoTransportActionTests.java

@@ -20,7 +20,7 @@
 import org.elasticsearch.test.MockUtils;
 import org.elasticsearch.threadpool.ThreadPool;
 import org.elasticsearch.transport.TransportService;
-import org.elasticsearch.xpack.core.XPackFeatureSet;
+import org.elasticsearch.xpack.core.XPackFeatureUsage;
 import org.elasticsearch.xpack.core.action.XPackUsageFeatureResponse;
 import org.elasticsearch.xpack.core.analytics.AnalyticsFeatureSetUsage;
 import org.elasticsearch.xpack.core.analytics.action.AnalyticsStatsAction;
@@ -75,12 +75,12 @@ public void testAvailable() throws Exception {
         );
         PlainActionFuture<XPackUsageFeatureResponse> future = new PlainActionFuture<>();
         usageAction.masterOperation(task, null, clusterState, future);
-        XPackFeatureSet.Usage usage = future.get().getUsage();
+        XPackFeatureUsage usage = future.get().getUsage();
         assertThat(usage.available(), is(true));
 
         BytesStreamOutput out = new BytesStreamOutput();
         usage.writeTo(out);
-        XPackFeatureSet.Usage serializedUsage = new AnalyticsFeatureSetUsage(out.bytes().streamInput());
+        XPackFeatureUsage serializedUsage = new AnalyticsFeatureSetUsage(out.bytes().streamInput());
         assertThat(serializedUsage.available(), is(true));
         verify(client, times(1)).execute(any(), any(), any());
         verifyNoMoreInteractions(client);
@@ -103,12 +103,12 @@ public void testEnabled() throws Exception {
         );
         PlainActionFuture<XPackUsageFeatureResponse> future = new PlainActionFuture<>();
         usageAction.masterOperation(task, null, clusterState, future);
-        XPackFeatureSet.Usage usage = future.get().getUsage();
+        XPackFeatureUsage usage = future.get().getUsage();
         assertTrue(usage.enabled());
 
         BytesStreamOutput out = new BytesStreamOutput();
         usage.writeTo(out);
-        XPackFeatureSet.Usage serializedUsage = new AnalyticsFeatureSetUsage(out.bytes().streamInput());
+        XPackFeatureUsage serializedUsage = new AnalyticsFeatureSetUsage(out.bytes().streamInput());
         assertTrue(serializedUsage.enabled());
         verify(client, times(1)).execute(any(), any(), any());
         verifyNoMoreInteractions(client);

x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/CCRInfoTransportAction.java

@@ -16,7 +16,7 @@
 import org.elasticsearch.license.XPackLicenseState;
 import org.elasticsearch.transport.TransportService;
 import org.elasticsearch.xcontent.XContentBuilder;
-import org.elasticsearch.xpack.core.XPackFeatureSet;
+import org.elasticsearch.xpack.core.XPackFeatureUsage;
 import org.elasticsearch.xpack.core.XPackField;
 import org.elasticsearch.xpack.core.XPackSettings;
 import org.elasticsearch.xpack.core.action.XPackInfoFeatureAction;
@@ -58,7 +58,7 @@ public boolean enabled() {
         return enabled;
     }
 
-    public static class Usage extends XPackFeatureSet.Usage {
+    public static class Usage extends XPackFeatureUsage {
 
         private final int numberOfFollowerIndices;
         private final int numberOfAutoFollowPatterns;

x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/Ccr.java

@@ -92,7 +92,7 @@
 import org.elasticsearch.xpack.ccr.rest.RestResumeAutoFollowPatternAction;
 import org.elasticsearch.xpack.ccr.rest.RestResumeFollowAction;
 import org.elasticsearch.xpack.ccr.rest.RestUnfollowAction;
-import org.elasticsearch.xpack.core.XPackFeatureSet;
+import org.elasticsearch.xpack.core.XPackFeatureUsage;
 import org.elasticsearch.xpack.core.XPackField;
 import org.elasticsearch.xpack.core.action.XPackInfoFeatureAction;
 import org.elasticsearch.xpack.core.action.XPackUsageFeatureAction;
@@ -306,7 +306,7 @@ public List<NamedWriteableRegistry.Entry> getNamedWriteables() {
             ),
 
             // usage api
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.CCR, CCRInfoTransportAction.Usage::new)
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.CCR, CCRInfoTransportAction.Usage::new)
         );
     }
 

x-pack/plugin/core/src/internalClusterTest/java/org/elasticsearch/xpack/core/rest/action/XPackUsageRestCancellationIT.java

@@ -34,7 +34,7 @@
 import org.elasticsearch.transport.TransportService;
 import org.elasticsearch.transport.netty4.Netty4Plugin;
 import org.elasticsearch.xpack.core.LocalStateCompositeXPackPlugin;
-import org.elasticsearch.xpack.core.XPackFeatureSet;
+import org.elasticsearch.xpack.core.XPackFeatureUsage;
 import org.elasticsearch.xpack.core.action.TransportXPackUsageAction;
 import org.elasticsearch.xpack.core.action.XPackUsageAction;
 import org.elasticsearch.xpack.core.action.XPackUsageFeatureResponse;
@@ -168,7 +168,7 @@ protected void masterOperation(
         ) throws Exception {
             blockingXPackUsageActionExecuting.countDown();
             blockActionLatch.await();
-            listener.onResponse(new XPackUsageFeatureResponse(new XPackFeatureSet.Usage("test", false, false) {
+            listener.onResponse(new XPackUsageFeatureResponse(new XPackFeatureUsage("test", false, false) {
                 @Override
                 public TransportVersion getMinimalSupportedVersion() {
                     return TransportVersion.current();

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/HealthApiFeatureSetUsage.java

@@ -71,7 +71,7 @@
  *   "enabled": true
  * }
  */
-public class HealthApiFeatureSetUsage extends XPackFeatureSet.Usage {
+public class HealthApiFeatureSetUsage extends XPackFeatureUsage {
 
     private final Map<String, Object> usageStats;
 

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/RemoteClusterFeatureSetUsage.java

@@ -17,7 +17,7 @@
 import java.io.IOException;
 import java.util.List;
 
-public class RemoteClusterFeatureSetUsage extends XPackFeatureSet.Usage {
+public class RemoteClusterFeatureSetUsage extends XPackFeatureUsage {
 
     private final List<RemoteConnectionInfo> remoteConnectionInfos;
 

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/XPackClientPlugin.java

@@ -136,19 +136,19 @@ public List<Setting<?>> getSettings() {
     public List<NamedWriteableRegistry.Entry> getNamedWriteables() {
         return Stream.of(
             // graph
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.GRAPH, GraphFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.GRAPH, GraphFeatureSetUsage::new),
             // logstash
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.LOGSTASH, LogstashFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.LOGSTASH, LogstashFeatureSetUsage::new),
             // ML
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.MACHINE_LEARNING, MachineLearningFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.MACHINE_LEARNING, MachineLearningFeatureSetUsage::new),
             // inference
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.INFERENCE, InferenceFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.INFERENCE, InferenceFeatureSetUsage::new),
             // monitoring
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.MONITORING, MonitoringFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.MONITORING, MonitoringFeatureSetUsage::new),
             // security
             new NamedWriteableRegistry.Entry(ClusterState.Custom.class, TokenMetadata.TYPE, TokenMetadata::new),
             new NamedWriteableRegistry.Entry(NamedDiff.class, TokenMetadata.TYPE, TokenMetadata::readDiffFrom),
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.SECURITY, SecurityFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.SECURITY, SecurityFeatureSetUsage::new),
             // security : configurable cluster privileges
             new NamedWriteableRegistry.Entry(
                 ConfigurableClusterPrivilege.class,
@@ -180,20 +180,20 @@ public List<NamedWriteableRegistry.Entry> getNamedWriteables() {
                 RemoteClusterPermissionGroup::new
             ),
             // eql
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.EQL, EqlFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.EQL, EqlFeatureSetUsage::new),
             // esql
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.ESQL, EsqlFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.ESQL, EsqlFeatureSetUsage::new),
             // sql
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.SQL, SqlFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.SQL, SqlFeatureSetUsage::new),
             // watcher
             new NamedWriteableRegistry.Entry(Metadata.Custom.class, WatcherMetadata.TYPE, WatcherMetadata::new),
             new NamedWriteableRegistry.Entry(NamedDiff.class, WatcherMetadata.TYPE, WatcherMetadata::readDiffFrom),
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.WATCHER, WatcherFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.WATCHER, WatcherFeatureSetUsage::new),
             // licensing
             new NamedWriteableRegistry.Entry(Metadata.Custom.class, LicensesMetadata.TYPE, LicensesMetadata::new),
             new NamedWriteableRegistry.Entry(NamedDiff.class, LicensesMetadata.TYPE, LicensesMetadata::readDiffFrom),
             // rollup
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.ROLLUP, RollupFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.ROLLUP, RollupFeatureSetUsage::new),
             new NamedWriteableRegistry.Entry(PersistentTaskParams.class, RollupJob.NAME, RollupJob::new),
             new NamedWriteableRegistry.Entry(Task.Status.class, RollupJobStatus.NAME, RollupJobStatus::new),
             new NamedWriteableRegistry.Entry(PersistentTaskState.class, RollupJobStatus.NAME, RollupJobStatus::new),
@@ -207,9 +207,9 @@ public List<NamedWriteableRegistry.Entry> getNamedWriteables() {
                 in -> AutoFollowMetadata.readDiffFrom(Metadata.Custom.class, AutoFollowMetadata.TYPE, in)
             ),
             // ILM
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.INDEX_LIFECYCLE, IndexLifecycleFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.INDEX_LIFECYCLE, IndexLifecycleFeatureSetUsage::new),
             // SLM
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.SNAPSHOT_LIFECYCLE, SLMFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.SNAPSHOT_LIFECYCLE, SLMFeatureSetUsage::new),
             // ILM - Custom Metadata
             new NamedWriteableRegistry.Entry(Metadata.Custom.class, IndexLifecycleMetadata.TYPE, IndexLifecycleMetadata::new),
             new NamedWriteableRegistry.Entry(
@@ -247,7 +247,7 @@ public List<NamedWriteableRegistry.Entry> getNamedWriteables() {
             // Transforms
             new NamedWriteableRegistry.Entry(Metadata.Custom.class, TransformMetadata.TYPE, TransformMetadata::new),
             new NamedWriteableRegistry.Entry(NamedDiff.class, TransformMetadata.TYPE, TransformMetadata.TransformMetadataDiff::new),
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.TRANSFORM, TransformFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.TRANSFORM, TransformFeatureSetUsage::new),
             new NamedWriteableRegistry.Entry(PersistentTaskParams.class, TransformField.TASK_NAME, TransformTaskParams::new),
             new NamedWriteableRegistry.Entry(Task.Status.class, TransformField.TASK_NAME, TransformState::new),
             new NamedWriteableRegistry.Entry(PersistentTaskState.class, TransformField.TASK_NAME, TransformState::new),
@@ -263,48 +263,44 @@ public List<NamedWriteableRegistry.Entry> getNamedWriteables() {
                 i -> NullRetentionPolicyConfig.INSTANCE
             ),
             // Voting Only Node
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.VOTING_ONLY, VotingOnlyNodeFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.VOTING_ONLY, VotingOnlyNodeFeatureSetUsage::new),
             // Frozen indices
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.FROZEN_INDICES, FrozenIndicesFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.FROZEN_INDICES, FrozenIndicesFeatureSetUsage::new),
             // Spatial
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.SPATIAL, SpatialFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.SPATIAL, SpatialFeatureSetUsage::new),
             // Analytics
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.ANALYTICS, AnalyticsFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.ANALYTICS, AnalyticsFeatureSetUsage::new),
             // Aggregate metric field type
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.AGGREGATE_METRIC, AggregateMetricFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.AGGREGATE_METRIC, AggregateMetricFeatureSetUsage::new),
             // Enrich
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.ENRICH, EnrichFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.ENRICH, EnrichFeatureSetUsage::new),
             new NamedWriteableRegistry.Entry(Task.Status.class, ExecuteEnrichPolicyStatus.NAME, ExecuteEnrichPolicyStatus::new),
             // Searchable snapshots
             new NamedWriteableRegistry.Entry(
-                XPackFeatureSet.Usage.class,
+                XPackFeatureUsage.class,
                 XPackField.SEARCHABLE_SNAPSHOTS,
                 SearchableSnapshotFeatureSetUsage::new
             ),
             // Data Streams
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.DATA_STREAMS, DataStreamFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.DATA_STREAMS, DataStreamFeatureSetUsage::new),
             new NamedWriteableRegistry.Entry(
-                XPackFeatureSet.Usage.class,
+                XPackFeatureUsage.class,
                 XPackField.DATA_STREAM_LIFECYCLE,
                 DataStreamLifecycleFeatureSetUsage::new
             ),
             // Data Tiers
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.DATA_TIERS, DataTiersFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.DATA_TIERS, DataTiersFeatureSetUsage::new),
             // Archive
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.ARCHIVE, ArchiveFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.ARCHIVE, ArchiveFeatureSetUsage::new),
             // TSDB Downsampling
             new NamedWriteableRegistry.Entry(LifecycleAction.class, DownsampleAction.NAME, DownsampleAction::new),
             // Health API usage
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.HEALTH_API, HealthApiFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.HEALTH_API, HealthApiFeatureSetUsage::new),
             // Remote cluster usage
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.REMOTE_CLUSTERS, RemoteClusterFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.REMOTE_CLUSTERS, RemoteClusterFeatureSetUsage::new),
             // Enterprise Search
-            new NamedWriteableRegistry.Entry(
-                XPackFeatureSet.Usage.class,
-                XPackField.ENTERPRISE_SEARCH,
-                EnterpriseSearchFeatureSetUsage::new
-            ),
-            new NamedWriteableRegistry.Entry(XPackFeatureSet.Usage.class, XPackField.UNIVERSAL_PROFILING, ProfilingUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.ENTERPRISE_SEARCH, EnterpriseSearchFeatureSetUsage::new),
+            new NamedWriteableRegistry.Entry(XPackFeatureUsage.class, XPackField.UNIVERSAL_PROFILING, ProfilingUsage::new),
             new NamedWriteableRegistry.Entry(
                 PersistentTaskParams.class,
                 SecurityMigrationTaskParams.TASK_NAME,