Use singleton instance for default project-id

server/src/main/java/org/elasticsearch/cluster/block/ClusterBlocks.java

@@ -438,7 +438,7 @@ private static void writeBlockSet(Set<ClusterBlock> blocks, StreamOutput out) th
     public static ClusterBlocks readFrom(StreamInput in) throws IOException {
         if (in.getTransportVersion().onOrAfter(TransportVersions.MULTI_PROJECT)) {
             final Set<ClusterBlock> global = readBlockSet(in);
-            final Map<ProjectId, ProjectBlocks> projectBlocksMap = in.readImmutableMap(ProjectId::new, ProjectBlocks::readFrom);
+            final Map<ProjectId, ProjectBlocks> projectBlocksMap = in.readImmutableMap(ProjectId::readFrom, ProjectBlocks::readFrom);
             if (global.isEmpty()
                 && noProjectOrDefaultProjectOnly(projectBlocksMap)
                 && projectBlocksMap.getOrDefault(Metadata.DEFAULT_PROJECT_ID, ProjectBlocks.EMPTY).indices().isEmpty()) {

server/src/main/java/org/elasticsearch/cluster/metadata/Metadata.java

@@ -88,7 +88,7 @@ public class Metadata implements Diffable<Metadata>, ChunkedToXContent {
     public static final String UNKNOWN_CLUSTER_UUID = "_na_";
     // TODO multi-project: verify that usages are really expected to work on the default project only,
     // and that they are not a stop-gap solution to make the tests pass
-    public static final ProjectId DEFAULT_PROJECT_ID = new ProjectId("default");
+    public static final ProjectId DEFAULT_PROJECT_ID = ProjectId.DEFAULT;
 
     public enum XContentContext {
         /* Custom metadata should be returned as part of API call */
@@ -1154,7 +1154,7 @@ public static Metadata readFrom(StreamInput in) throws IOException {
                 builder.put(ReservedStateMetadata.readFrom(in));
             }
 
-            builder.projectMetadata(in.readMap(ProjectId::new, ProjectMetadata::readFrom));
+            builder.projectMetadata(in.readMap(ProjectId::readFrom, ProjectMetadata::readFrom));
         }
         return builder.build();
     }

server/src/main/java/org/elasticsearch/cluster/metadata/ProjectId.java

@@ -19,17 +19,39 @@
 import org.elasticsearch.xcontent.XContentParser;
 
 import java.io.IOException;
+import java.util.Objects;
 
-public record ProjectId(String id) implements Writeable, ToXContent {
+public class ProjectId implements Writeable, ToXContent {
 
-    public static final Reader<ProjectId> READER = ProjectId::new;
+    private static final String DEFAULT_STRING = "default";
+    public static final ProjectId DEFAULT = new ProjectId(DEFAULT_STRING);
+    public static final Reader<ProjectId> READER = ProjectId::readFrom;
     private static final int MAX_LENGTH = 128;
 
-    public ProjectId {
+    private final String id;
+
+    private ProjectId(String id) {
         if (Strings.isNullOrBlank(id)) {
             throw new IllegalArgumentException("project-id cannot be empty");
         }
-        assert isValidFormatId(id) : "project-id [" + id + "] must be alphanumeric ASCII with up to " + MAX_LENGTH + " chars";
+        if (isValidFormatId(id) == false) {
+            final var message = "project-id [" + id + "] must be alphanumeric ASCII with up to " + MAX_LENGTH + " chars";
+            assert false : message;
+            throw new IllegalArgumentException(message);
+        }
+        this.id = id;
+    }
+
+    public String id() {
+        return id;
+    }
+
+    public static ProjectId fromId(String id) {
+        if (DEFAULT_STRING.equals(id)) {
+            return DEFAULT;
+        } else {
+            return new ProjectId(id);
+        }
     }
 
     static boolean isValidFormatId(String id) {
@@ -53,8 +75,8 @@ private static boolean isValidIdChar(char c) {
         return (c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_' || c == '-';
     }
 
-    public ProjectId(StreamInput in) throws IOException {
-        this(in.readString());
+    public static ProjectId readFrom(StreamInput in) throws IOException {
+        return fromId(in.readString());
     }
 
     @Override
@@ -79,4 +101,16 @@ public static ProjectId ofNullable(@Nullable String id, @Nullable ProjectId fall
     public String toString() {
         return this.id;
     }
+
+    @Override
+    public boolean equals(Object o) {
+        if (o == null || getClass() != o.getClass()) return false;
+        ProjectId projectId = (ProjectId) o;
+        return Objects.equals(id, projectId.id);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hashCode(id);
+    }
 }

server/src/main/java/org/elasticsearch/cluster/metadata/ProjectMetadata.java

@@ -2136,7 +2136,7 @@ public Iterator<? extends ToXContent> toXContentChunked(ToXContent.Params p) {
     }
 
     public static ProjectMetadata readFrom(StreamInput in) throws IOException {
-        ProjectId id = new ProjectId(in);
+        ProjectId id = ProjectId.readFrom(in);
         Builder builder = builder(id);
         Function<String, MappingMetadata> mappingLookup;
         Map<String, MappingMetadata> mappingMetadataMap = in.readMapValues(MappingMetadata::new, MappingMetadata::getSha256);

server/src/main/java/org/elasticsearch/cluster/project/AbstractProjectResolver.java

@@ -50,7 +50,7 @@ public ProjectId getProjectId() {
         if (headerValue == null) {
             return getFallbackProjectId();
         }
-        return new ProjectId(headerValue);
+        return ProjectId.fromId(headerValue);
     }
 
     @Override
@@ -89,7 +89,7 @@ public boolean supportsMultipleProjects() {
     }
 
     protected static ProjectMetadata findProject(Metadata metadata, String headerValue) {
-        var project = metadata.projects().get(new ProjectId(headerValue));
+        var project = metadata.projects().get(ProjectId.fromId(headerValue));
         if (project == null) {
             throw new IllegalArgumentException("Could not find project with id [" + headerValue + "]");
         }

server/src/main/java/org/elasticsearch/cluster/routing/GlobalRoutingTable.java

@@ -179,7 +179,7 @@ public static Diff<GlobalRoutingTable> readDiffFrom(StreamInput in) throws IOExc
     }
 
     public static GlobalRoutingTable readFrom(StreamInput in) throws IOException {
-        final var table = in.readImmutableOpenMap(ProjectId::new, RoutingTable::readFrom);
+        final var table = in.readImmutableOpenMap(ProjectId::readFrom, RoutingTable::readFrom);
         return new GlobalRoutingTable(table);
     }
 

server/src/main/java/org/elasticsearch/cluster/routing/allocation/command/AbstractAllocateAllocationCommand.java

@@ -109,7 +109,7 @@ protected AbstractAllocateAllocationCommand(StreamInput in) throws IOException {
         shardId = in.readVInt();
         node = in.readString();
         if (in.getTransportVersion().onOrAfter(TransportVersions.MULTI_PROJECT)) {
-            projectId = new ProjectId(in);
+            projectId = ProjectId.readFrom(in);
         } else {
             projectId = Metadata.DEFAULT_PROJECT_ID;
         }

server/src/main/java/org/elasticsearch/cluster/routing/allocation/command/CancelAllocationCommand.java

@@ -84,7 +84,7 @@ public CancelAllocationCommand(StreamInput in) throws IOException {
         node = in.readString();
         allowPrimary = in.readBoolean();
         if (in.getTransportVersion().onOrAfter(TransportVersions.MULTI_PROJECT)) {
-            projectId = new ProjectId(in);
+            projectId = ProjectId.readFrom(in);
         } else {
             projectId = Metadata.DEFAULT_PROJECT_ID;
         }

server/src/main/java/org/elasticsearch/cluster/routing/allocation/command/MoveAllocationCommand.java

@@ -69,7 +69,7 @@ public MoveAllocationCommand(StreamInput in) throws IOException {
         fromNode = in.readString();
         toNode = in.readString();
         if (in.getTransportVersion().onOrAfter(TransportVersions.MULTI_PROJECT)) {
-            projectId = new ProjectId(in);
+            projectId = ProjectId.readFrom(in);
         } else {
             projectId = Metadata.DEFAULT_PROJECT_ID;
         }

server/src/test/java/org/elasticsearch/action/admin/cluster/health/TransportClusterHealthActionTests.java

@@ -41,21 +41,21 @@ public void testWaitForInitializingShards() throws Exception {
         final String[] indices = { "test" };
         final ClusterHealthRequest request = new ClusterHealthRequest(TEST_REQUEST_TIMEOUT);
         request.waitForNoInitializingShards(true);
-        var projectId = new ProjectId(randomUUID());
+        var projectId = randomUniqueProjectId();
         ClusterState clusterState = randomClusterStateWithInitializingShards("test", 0, projectId);
         var project = clusterState.metadata().getProject(projectId);
         ClusterHealthResponse response = createResponse(indices, clusterState, project);
         assertThat(TransportClusterHealthAction.prepareResponse(request, response, project, null), equalTo(1));
 
         request.waitForNoInitializingShards(true);
-        projectId = new ProjectId(randomUUID());
+        projectId = randomUniqueProjectId();
         clusterState = randomClusterStateWithInitializingShards("test", between(1, 10), projectId);
         project = clusterState.metadata().getProject(projectId);
         response = createResponse(indices, clusterState, project);
         assertThat(TransportClusterHealthAction.prepareResponse(request, response, project, null), equalTo(0));
 
         request.waitForNoInitializingShards(false);
-        projectId = new ProjectId(randomUUID());
+        projectId = randomUniqueProjectId();
         clusterState = randomClusterStateWithInitializingShards("test", randomInt(20), projectId);
         project = clusterState.metadata().getProject(projectId);
         response = createResponse(indices, clusterState, project);
@@ -67,7 +67,7 @@ public void testWaitForAllShards() {
         final ClusterHealthRequest request = new ClusterHealthRequest(TEST_REQUEST_TIMEOUT);
         request.waitForActiveShards(ActiveShardCount.ALL);
 
-        var projectId = new ProjectId(randomUUID());
+        var projectId = randomUniqueProjectId();
         ClusterState clusterState = randomClusterStateWithInitializingShards("test", 1, projectId);
         var project = clusterState.metadata().getProject(projectId);
         ClusterHealthResponse response = createResponse(indices, clusterState, project);
@@ -125,7 +125,7 @@ ClusterState randomClusterStateWithInitializingShards(String index, final int in
         }
 
         var projects = randomMap(0, 5, () -> {
-            var id = new ProjectId(randomUUID());
+            var id = randomUniqueProjectId();
             return Tuple.tuple(id, ProjectMetadata.builder(id).build());
         });
         return ClusterState.builder(ClusterName.DEFAULT)

server/src/test/java/org/elasticsearch/action/admin/cluster/state/TransportClusterStateActionTests.java

@@ -107,7 +107,7 @@ public void testGetClusterStateWithDefaultProjectOnly() throws Exception {
 
     public void testGetClusterStateForOneProjectOfMany() throws Exception {
         final Set<String> indexNames = randomSet(1, 8, () -> randomAlphaOfLengthBetween(4, 12));
-        final ProjectId projectId = new ProjectId(randomUUID());
+        final ProjectId projectId = randomUniqueProjectId();
 
         final ProjectResolver projectResolver = TestProjectResolvers.singleProject(projectId);
         final ClusterStateRequest request = buildRandomRequest(indexNames);
@@ -117,7 +117,7 @@ public void testGetClusterStateForOneProjectOfMany() throws Exception {
         final ProjectMetadata.Builder[] projects = new ProjectMetadata.Builder[numberOfProjects];
         projects[0] = projectBuilder(projectId, indexNames);
         for (int i = 1; i < numberOfProjects; i++) {
-            projects[i] = projectBuilder(new ProjectId(randomUUID()), randomSet(0, 12, () -> randomAlphaOfLengthBetween(4, 12)));
+            projects[i] = projectBuilder(randomUniqueProjectId(), randomSet(0, 12, () -> randomAlphaOfLengthBetween(4, 12)));
         }
         final ClusterState state = buildClusterState(projects);
 
@@ -133,7 +133,7 @@ public void testGetClusterStateForManyProjects() throws Exception {
         final ProjectId[] projectIds = new ProjectId[numberOfProjects];
         final Set<String> indexNames = randomSet(5, 20, () -> randomAlphaOfLengthBetween(4, 12));
         for (int i = 0; i < numberOfProjects; i++) {
-            projectIds[i] = new ProjectId(randomUUID());
+            projectIds[i] = randomUniqueProjectId();
             projects[i] = projectBuilder(projectIds[i], randomSubsetOf(indexNames));
         }
         final ClusterState state = buildClusterState(projects);

server/src/test/java/org/elasticsearch/action/admin/indices/create/TransportCreateIndexActionTests.java

@@ -61,7 +61,7 @@ public class TransportCreateIndexActionTests extends ESTestCase {
     private static final String UNMANAGED_SYSTEM_INDEX_NAME = ".my-system";
     private static final String MANAGED_SYSTEM_INDEX_NAME = ".my-managed";
     private static final String SYSTEM_ALIAS_NAME = ".my-alias";
-    private static final ProjectId PROJECT_ID = new ProjectId("test_project_id");
+    private static final ProjectId PROJECT_ID = ProjectId.fromId("test_project_id");
     private static final ClusterState CLUSTER_STATE = ClusterState.builder(new ClusterName("test"))
         .metadata(Metadata.builder().build())
         .putProjectMetadata(ProjectMetadata.builder(PROJECT_ID).build())

server/src/test/java/org/elasticsearch/action/bulk/TransportBulkActionTests.java

@@ -632,7 +632,7 @@ public void testFailuresDuringPrerequisiteActions() throws InterruptedException
         // Construct a cluster state that contains the required data streams.
         // using a single, non-default project
         final ClusterState oldState = clusterService.state();
-        final ProjectId projectId = new ProjectId(randomUUID());
+        final ProjectId projectId = randomUniqueProjectId();
         final Metadata metadata = Metadata.builder(oldState.metadata())
             .removeProject(Metadata.DEFAULT_PROJECT_ID)
             .put(

server/src/test/java/org/elasticsearch/action/datastreams/DataStreamsActionUtilTests.java

@@ -19,7 +19,6 @@
 import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver.ResolvedExpression;
-import org.elasticsearch.cluster.metadata.ProjectId;
 import org.elasticsearch.cluster.metadata.ProjectMetadata;
 import org.elasticsearch.common.collect.ImmutableOpenMap;
 import org.elasticsearch.common.settings.Settings;
@@ -52,7 +51,7 @@ public void testDataStreamsResolveConcreteIndexNames() {
         var dataStreamFailureIndex1 = new Index(".fs-foo1", IndexMetadata.INDEX_UUID_NA_VALUE);
         var dataStreamFailureIndex2 = new Index(".fs-bar2", IndexMetadata.INDEX_UUID_NA_VALUE);
 
-        var projectId = new ProjectId(randomUUID());
+        var projectId = randomUniqueProjectId();
         ClusterState clusterState = ClusterState.builder(new ClusterName("test-cluster"))
             .putProjectMetadata(
                 ProjectMetadata.builder(projectId)

server/src/test/java/org/elasticsearch/action/support/ActiveShardCountTests.java

@@ -14,7 +14,6 @@
 import org.elasticsearch.cluster.TestShardRoutingRoleStrategies;
 import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.cluster.metadata.Metadata;
-import org.elasticsearch.cluster.metadata.ProjectId;
 import org.elasticsearch.cluster.metadata.ProjectMetadata;
 import org.elasticsearch.cluster.routing.IndexRoutingTable;
 import org.elasticsearch.cluster.routing.IndexShardRoutingTable;
@@ -63,7 +62,7 @@ public void testEnoughShardsWhenProjectIsGone() {
             .numberOfShards(randomIntBetween(1, 3))
             .numberOfReplicas(randomIntBetween(1, 3))
             .build();
-        ProjectMetadata projectMetadata = ProjectMetadata.builder(new ProjectId(randomUUID())).put(indexMetadata, randomBoolean()).build();
+        ProjectMetadata projectMetadata = ProjectMetadata.builder(randomUniqueProjectId()).put(indexMetadata, randomBoolean()).build();
         Index index = new Index(indexName, "_uuid");
         ShardId shardId = new ShardId(index, 0);
         ShardRouting shardRouting = ShardRouting.newUnassigned(

server/src/test/java/org/elasticsearch/action/support/replication/BroadcastReplicationTests.java

@@ -116,7 +116,7 @@ public void setUp() throws Exception {
         );
         transportService.start();
         transportService.acceptIncomingRequests();
-        projectId = new ProjectId(randomUUID());
+        projectId = randomUniqueProjectId();
         broadcastReplicationAction = new TestBroadcastReplicationAction(
             clusterService,
             transportService,

server/src/test/java/org/elasticsearch/action/termvectors/TransportMultiTermVectorsActionTests.java

@@ -91,7 +91,7 @@ public static void beforeClass() throws Exception {
             emptySet()
         );
 
-        ProjectId projectId = new ProjectId(randomBase64UUID());
+        ProjectId projectId = randomUniqueProjectId();
         projectResolver = TestProjectResolvers.singleProject(projectId);
         final Index index1 = new Index("index1", randomBase64UUID());
         final Index index2 = new Index("index2", randomBase64UUID());

server/src/test/java/org/elasticsearch/cluster/ClusterChangedEventTests.java

@@ -14,7 +14,6 @@
 import org.elasticsearch.cluster.metadata.IndexGraveyard;
 import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.cluster.metadata.Metadata;
-import org.elasticsearch.cluster.metadata.ProjectId;
 import org.elasticsearch.cluster.metadata.ProjectMetadata;
 import org.elasticsearch.cluster.node.DiscoveryNode;
 import org.elasticsearch.cluster.node.DiscoveryNodeRole;
@@ -485,8 +484,8 @@ public void testChangedCustomMetadataSet() {
     public void testChangedCustomMetadataSetMultiProject() {
         final CustomProjectMetadata project1Custom = new CustomProjectMetadata("project1");
         final CustomProjectMetadata project2Custom = new CustomProjectMetadata("project2");
-        final ProjectMetadata project1 = ProjectMetadata.builder(new ProjectId(randomUUID())).build();
-        final ProjectMetadata project2 = ProjectMetadata.builder(new ProjectId(randomUUID())).build();
+        final ProjectMetadata project1 = ProjectMetadata.builder(randomUniqueProjectId()).build();
+        final ProjectMetadata project2 = ProjectMetadata.builder(randomUniqueProjectId()).build();
         final ClusterState originalState = ClusterState.builder(TEST_CLUSTER_NAME)
             .metadata(Metadata.builder().put(project1).put(project2).build())
             .build();
@@ -514,7 +513,7 @@ public void testChangedCustomMetadataSetMultiProject() {
         // Add custom in completely new project
         newState = ClusterState.builder(originalState)
             .putProjectMetadata(
-                ProjectMetadata.builder(new ProjectId(randomUUID())).putCustom(project2Custom.getWriteableName(), project2Custom).build()
+                ProjectMetadata.builder(randomUniqueProjectId()).putCustom(project2Custom.getWriteableName(), project2Custom).build()
             )
             .build();
         event = new ClusterChangedEvent("_na_", originalState, newState);
@@ -727,7 +726,7 @@ private static DiscoveryNode newNode(final String nodeId, Set<DiscoveryNodeRole>
 
     // Create the metadata for a cluster state.
     private static ProjectMetadata createProject(final List<Index> indices) {
-        final ProjectMetadata.Builder builder = ProjectMetadata.builder(new ProjectId(randomUUID()));
+        final ProjectMetadata.Builder builder = ProjectMetadata.builder(randomUniqueProjectId());
         for (Index index : indices) {
             builder.put(createIndexMetadata(index), true);
         }