Introduce IndexDefinition.getName and Schema.getIndexByName, and Inde…

…xCreator.withName.

Also makes FTS procedures use standard Schema.awaitIndexOnline instead of a local copy of that method.

community/community-it/kernel-it/src/test/java/org/neo4j/graphdb/SchemaAcceptanceTest.java

@@ -214,7 +214,7 @@ public void droppingAnUnexistingIndexShouldGiveHelpfulExceptionInSameTransaction
             }
             catch ( ConstraintViolationException e )
             {
-                assertThat( e.getMessage(), containsString( "No index was found for :MY_LABEL(my_property_key)." ) );
+                assertThat( e.getMessage(), containsString( "No such INDEX ON :MY_LABEL(my_property_key)." ) );
             }
             tx.success();
         }
@@ -238,7 +238,7 @@ public void droppingAnUnexistingIndexShouldGiveHelpfulExceptionInSeparateTransac
         }
         catch ( ConstraintViolationException e )
         {
-            assertThat( e.getMessage(), containsString( "No index was found for :MY_LABEL(my_property_key)." ) );
+            assertThat( e.getMessage(), containsString( "No such INDEX ON :MY_LABEL(my_property_key)." ) );
         }
 
         // THEN

community/community-it/kernel-it/src/test/java/org/neo4j/kernel/impl/coreapi/schema/SchemaImplTest.java

@@ -33,12 +33,15 @@
 import org.neo4j.graphdb.schema.IndexDefinition;
 import org.neo4j.graphdb.schema.Schema;
 import org.neo4j.helpers.collection.Iterables;
+import org.neo4j.internal.kernel.api.IndexReference;
 import org.neo4j.test.TestGraphDatabaseFactory;
 import org.neo4j.test.extension.EphemeralFileSystemExtension;
 import org.neo4j.test.extension.Inject;
 import org.neo4j.test.extension.TestDirectoryExtension;
 import org.neo4j.test.rule.TestDirectory;
 
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertThat;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertSame;
@@ -47,6 +50,8 @@
 @ExtendWith( {EphemeralFileSystemExtension.class, TestDirectoryExtension.class} )
 public class SchemaImplTest
 {
+    private static final Label USER_LABEL = Label.label( "User" );
+
     @Inject
     private EphemeralFileSystemAbstraction fs;
     @Inject
@@ -69,7 +74,7 @@ void shutdownDb()
     @Test
     void testGetIndexPopulationProgress() throws Exception
     {
-        assertFalse( indexExists( Label.label( "User" ) ) );
+        assertFalse( indexExists( USER_LABEL ) );
 
         // Create some nodes
         try ( Transaction tx = db.beginTx() )
@@ -90,9 +95,7 @@ void testGetIndexPopulationProgress() throws Exception
         try ( Transaction tx = db.beginTx() )
         {
             Schema schema = db.schema();
-            indexDefinition = schema.indexFor( Label.label( "User" ) )
-                    .on( "username" )
-                    .create();
+            indexDefinition = schema.indexFor( USER_LABEL ).on( "username" ).create();
             tx.success();
         }
 
@@ -119,6 +122,35 @@ void testGetIndexPopulationProgress() throws Exception
         }
     }
 
+    @Test
+    void createdIndexDefinitionsMustBeUnnamed()
+    {
+        try ( Transaction tx = db.beginTx() )
+        {
+            IndexDefinition index = db.schema().indexFor( USER_LABEL ).on( "name" ).create();
+            assertThat( index.getName(), is( IndexReference.UNNAMED_INDEX ) );
+            tx.success();
+        }
+    }
+
+    @Test
+    void mustRememberNamesOfCreatedIndex()
+    {
+        String indexName = "Users index";
+        try ( Transaction tx = db.beginTx() )
+        {
+            IndexDefinition index = db.schema().indexFor( USER_LABEL ).on( "name" ).withName( indexName ).create();
+            assertThat( index.getName(), is( indexName ) );
+            tx.success();
+        }
+        try ( Transaction tx = db.beginTx() )
+        {
+            IndexDefinition index = db.schema().getIndexByName( indexName );
+            assertThat( index.getName(), is( indexName ) );
+            tx.success();
+        }
+    }
+
     private boolean indexExists( Label label )
     {
         try ( Transaction transaction = db.beginTx() )

community/graphdb-api/src/main/java/org/neo4j/graphdb/schema/IndexCreator.java

@@ -27,7 +27,7 @@
  * A builder for entering details about an index to create. After all details have been entered
  * {@link #create()} must be called for the index to actually be created. An index creator knows
  * which {@link Label label} it is to be created for.
- *
+ * <p>
  * All methods except {@link #create()} will return an {@link IndexCreator} which should be
  * used for further interaction.
  *
@@ -38,14 +38,23 @@ public interface IndexCreator
     /**
      * Includes the given {@code propertyKey} in this index, such that {@link Node nodes} with
      * the assigned {@link Label label} and this property key will have its values indexed.
-     *
+     * <p>
      * NOTE: currently only a single property key per index is supported.
      *
      * @param propertyKey the property key to include in this index to be created.
      * @return an {@link IndexCreator} instance to be used for further interaction.
      */
     IndexCreator on( String propertyKey );
 
+    /**
+     * Assign a name to the index, which will then be returned from {@link IndexDefinition#getName()}, and can be used for finding the index with
+     * {@link Schema#getIndexByName(String)}.
+     *
+     * @param indexName the name to give the index.
+     * @return an {@link IndexCreator} instance to be used for further interaction.
+     */
+    IndexCreator withName( String indexName );
+
     /**
      * Creates an index with the details specified by the other methods in this interface.
      *

community/graphdb-api/src/main/java/org/neo4j/graphdb/schema/IndexDefinition.java

@@ -19,6 +19,8 @@
  */
 package org.neo4j.graphdb.schema;
 
+import java.util.Optional;
+
 import org.neo4j.graphdb.Label;
 import org.neo4j.graphdb.RelationshipType;
 import org.neo4j.graphdb.index.IndexManager;
@@ -133,4 +135,10 @@ public interface IndexDefinition
      * @return {@code true} if this is a composite index.
      */
     boolean isCompositeIndex();
+
+    /**
+     * Get the name given to this index when it was created, if any.
+     * If the index was not given any name, then the string {@code "Unnamed index"} is returned instead.
+     */
+    String getName();
 }

community/graphdb-api/src/main/java/org/neo4j/graphdb/schema/Schema.java

@@ -162,4 +162,12 @@ enum IndexState
      *             FAILED state
      */
     void awaitIndexesOnline( long duration, TimeUnit unit );
+
+    /**
+     * Get an {@link IndexDefinition} by the given name of the index.
+     * @param indexName The given name of the index.
+     * @return The index with that given name.
+     * @throws IllegalArgumentException if there is no index with that given name.
+     */
+    IndexDefinition getIndexByName( String indexName );
 }

community/kernel-api/src/main/java/org/neo4j/internal/kernel/api/SchemaWrite.java

@@ -40,6 +40,15 @@ public interface SchemaWrite
      */
     IndexReference indexCreate( SchemaDescriptor descriptor ) throws SchemaKernelException;
 
+    /**
+     * Create index from schema descriptor
+     *
+     * @param descriptor description of the index
+     * @param name name of the index
+     * @return the newly created index
+     */
+    IndexReference indexCreate( SchemaDescriptor descriptor, Optional<String> name ) throws SchemaKernelException;
+
     /**
      * Create index from schema descriptor
      *

community/kernel-api/src/main/java/org/neo4j/storageengine/api/schema/IndexDescriptor.java

@@ -107,7 +107,7 @@ public String providerVersion()
     @Override
     public String name()
     {
-        return userSuppliedName.orElse( "Unnamed index" );
+        return userSuppliedName.orElse( UNNAMED_INDEX );
     }
 
     public IndexProviderDescriptor providerDescriptor()

community/kernel/src/main/java/org/neo4j/kernel/impl/api/KernelTransactions.java

@@ -38,18 +38,15 @@
 import org.neo4j.kernel.api.KernelTransactionHandle;
 import org.neo4j.kernel.api.exceptions.Status;
 import org.neo4j.kernel.api.explicitindex.AutoIndexing;
-import org.neo4j.kernel.api.txstate.ExplicitIndexTransactionState;
 import org.neo4j.kernel.api.txstate.aux.AuxiliaryTransactionStateManager;
 import org.neo4j.kernel.availability.AvailabilityGuard;
 import org.neo4j.kernel.configuration.Config;
 import org.neo4j.kernel.impl.api.index.IndexingProvidersService;
 import org.neo4j.kernel.impl.api.state.ConstraintIndexCreator;
-import org.neo4j.kernel.impl.api.state.ExplicitIndexTransactionStateImpl;
 import org.neo4j.kernel.impl.constraints.ConstraintSemantics;
 import org.neo4j.kernel.impl.core.TokenHolders;
 import org.neo4j.kernel.impl.factory.AccessCapability;
 import org.neo4j.kernel.impl.index.ExplicitIndexStore;
-import org.neo4j.kernel.impl.index.IndexConfigStore;
 import org.neo4j.kernel.impl.locking.StatementLocks;
 import org.neo4j.kernel.impl.locking.StatementLocksFactory;
 import org.neo4j.kernel.impl.proc.Procedures;

community/kernel/src/main/java/org/neo4j/kernel/impl/coreapi/schema/IndexCreatorImpl.java

@@ -21,6 +21,7 @@
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Optional;
 
 import org.neo4j.graphdb.ConstraintViolationException;
 import org.neo4j.graphdb.Label;
@@ -32,16 +33,18 @@ public class IndexCreatorImpl implements IndexCreator
     private final Collection<String> propertyKeys;
     private final Label label;
     private final InternalSchemaActions actions;
+    private final Optional<String> indexName;
 
     public IndexCreatorImpl( InternalSchemaActions actions, Label label )
     {
-        this( actions, label, new ArrayList<>() );
+        this( actions, label, Optional.empty(), new ArrayList<>() );
     }
 
-    private IndexCreatorImpl( InternalSchemaActions actions, Label label, Collection<String> propertyKeys )
+    private IndexCreatorImpl( InternalSchemaActions actions, Label label, Optional<String> indexName, Collection<String> propertyKeys )
     {
         this.actions = actions;
         this.label = label;
+        this.indexName = indexName;
         this.propertyKeys = propertyKeys;
 
         assertInUnterminatedTransaction();
@@ -51,7 +54,14 @@ private IndexCreatorImpl( InternalSchemaActions actions, Label label, Collection
     public IndexCreator on( String propertyKey )
     {
         assertInUnterminatedTransaction();
-        return new IndexCreatorImpl( actions, label, copyAndAdd( propertyKeys, propertyKey) );
+        return new IndexCreatorImpl( actions, label, indexName, copyAndAdd( propertyKeys, propertyKey) );
+    }
+
+    @Override
+    public IndexCreator withName( String indexName )
+    {
+        assertInUnterminatedTransaction();
+        return new IndexCreatorImpl( actions, label, Optional.ofNullable( indexName ), propertyKeys );
     }
 
     @Override
@@ -64,7 +74,7 @@ public IndexDefinition create() throws ConstraintViolationException
             throw new ConstraintViolationException( "An index needs at least one property key to index" );
         }
 
-        return actions.createIndexDefinition( label, propertyKeys.toArray( new String[0] ) );
+        return actions.createIndexDefinition( label, indexName, propertyKeys.toArray( new String[0] ) );
     }
 
     private void assertInUnterminatedTransaction()

community/kernel/src/main/java/org/neo4j/kernel/impl/coreapi/schema/IndexDefinitionImpl.java

@@ -27,9 +27,14 @@
 import org.neo4j.graphdb.schema.IndexDefinition;
 import org.neo4j.hashing.HashFunction;
 import org.neo4j.internal.kernel.api.IndexReference;
+import org.neo4j.internal.kernel.api.TokenRead;
+import org.neo4j.internal.kernel.api.exceptions.KernelException;
+import org.neo4j.internal.kernel.api.schema.SchemaDescriptor;
 
 import static java.util.Arrays.asList;
 import static java.util.stream.Collectors.joining;
+import static org.neo4j.graphdb.Label.label;
+import static org.neo4j.graphdb.RelationshipType.withName;
 import static org.neo4j.helpers.collection.Iterables.stream;
 
 public class IndexDefinitionImpl implements IndexDefinition
@@ -213,6 +218,12 @@ public boolean isCompositeIndex()
         return propertyKeys.length > 1;
     }
 
+    @Override
+    public String getName()
+    {
+        return indexReference == null ? IndexReference.UNNAMED_INDEX : indexReference.name();
+    }
+
     @Override
     public int hashCode()
     {

community/kernel/src/main/java/org/neo4j/kernel/impl/coreapi/schema/InternalSchemaActions.java

@@ -19,6 +19,8 @@
  */
 package org.neo4j.kernel.impl.coreapi.schema;
 
+import java.util.Optional;
+
 import org.neo4j.graphdb.Label;
 import org.neo4j.graphdb.RelationshipType;
 import org.neo4j.graphdb.schema.ConstraintDefinition;
@@ -31,7 +33,7 @@
  */
 public interface InternalSchemaActions
 {
-    IndexDefinition createIndexDefinition( Label label, String... propertyKey );
+    IndexDefinition createIndexDefinition( Label label, Optional<String> indexName, String... propertyKey );
 
     void dropIndexDefinitions( IndexDefinition indexDefinition );
 

community/kernel/src/main/java/org/neo4j/kernel/impl/coreapi/schema/SchemaImpl.java

@@ -24,6 +24,8 @@
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
 import java.util.concurrent.TimeUnit;
 import java.util.function.Function;
 import java.util.function.Supplier;
@@ -241,6 +243,32 @@ public void awaitIndexesOnline( long duration, TimeUnit unit )
         }
     }
 
+    @Override
+    public IndexDefinition getIndexByName( String indexName )
+    {
+        Objects.requireNonNull( indexName );
+        Iterator<IndexDefinition> indexes = getIndexes().iterator();
+        IndexDefinition index = null;
+        while ( indexes.hasNext() )
+        {
+            IndexDefinition candidate = indexes.next();
+            if ( candidate.getName().equals( indexName ) )
+            {
+                if ( index != null )
+                {
+                    throw new IllegalStateException( "Multiple indexes found by the name '" + indexName + "'. " +
+                            "Try iterating Schema#getIndexes() and filter by name instead." );
+                }
+                index = candidate;
+            }
+        }
+        if ( index == null )
+        {
+            throw new IllegalArgumentException( "No index found with the name '" + indexName + "'." );
+        }
+        return index;
+    }
+
     @Override
     public IndexState getIndexState( final IndexDefinition index )
     {
@@ -514,21 +542,20 @@ private static class GDBSchemaActions implements InternalSchemaActions
         }
 
         @Override
-        public IndexDefinition createIndexDefinition( Label label, String... propertyKeys )
+        public IndexDefinition createIndexDefinition( Label label, Optional<String> indexName, String... propertyKeys )
         {
             KernelTransaction transaction = safeAcquireTransaction( transactionSupplier );
 
             try ( Statement ignore = transaction.acquireStatement() )
             {
                 try
                 {
-                    IndexDefinition indexDefinition = new IndexDefinitionImpl( this, null, new Label[]{label}, propertyKeys, false );
                     TokenWrite tokenWrite = transaction.tokenWrite();
                     int labelId = tokenWrite.labelGetOrCreateForName( label.name() );
-                    int[] propertyKeyIds = getOrCreatePropertyKeyIds( tokenWrite, indexDefinition );
+                    int[] propertyKeyIds = getOrCreatePropertyKeyIds( tokenWrite, propertyKeys );
                     LabelSchemaDescriptor descriptor = forLabel( labelId, propertyKeyIds );
-                    transaction.schemaWrite().indexCreate( descriptor );
-                    return indexDefinition;
+                    IndexReference indexReference = transaction.schemaWrite().indexCreate( descriptor, indexName );
+                    return new IndexDefinitionImpl( this, indexReference, new Label[]{label}, propertyKeys, false );
                 }
 
                 catch ( IllegalTokenNameException e )

community/kernel/src/main/java/org/neo4j/kernel/impl/newapi/Operations.java

@@ -919,6 +919,12 @@ public IndexReference indexCreate( SchemaDescriptor descriptor ) throws SchemaKe
         return indexCreate( descriptor, config.get( GraphDatabaseSettings.default_schema_provider ), Optional.empty() );
     }
 
+    @Override
+    public IndexReference indexCreate( SchemaDescriptor descriptor, Optional<String> indexName ) throws SchemaKernelException
+    {
+        return indexCreate( descriptor, config.get( GraphDatabaseSettings.default_schema_provider ), indexName );
+    }
+
     @Override
     public IndexReference indexCreate( SchemaDescriptor descriptor,
             String provider,