HHH-16884 Improve efficiency of UpdateCoordinatorStandard in tracking tables to be updated

Author: Sanne

hibernate-core/src/main/java/org/hibernate/persister/entity/mutation/TableSet.java

@@ -0,0 +1,84 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or http://www.gnu.org/licenses/lgpl-2.1.html.
+ */
+package org.hibernate.persister.entity.mutation;
+
+import java.util.Arrays;
+import java.util.BitSet;
+
+import org.hibernate.sql.model.MutationTarget;
+import org.hibernate.sql.model.TableMapping;
+
+/**
+ * Represents a Set of TableMapping(s); table mappings are
+ * identified by an ordered unique id: the order in which
+ * they are updated within the scope of a particular persister.
+ * This makes it possible to store a set of them as a bitset,
+ * which is typically more efficient than using a {@link java.util.Set}.
+ * These table ids come from {@link org.hibernate.sql.model.TableMapping#getRelativePosition}.
+ * <p>N.B. Make sure to not store TableMappings from different
+ * persisters, as their unique identifiers will overlap:
+ * we'll only verify a mismatch if assertions are enabled.</p>
+ */
+public final class TableSet {
+
+	private BitSet bits;
+	private Object[] checks; //Meant for assertions only
+
+	public void add(final TableMapping tableMapping) {
+		if ( bits == null ) {
+			bits = new BitSet();
+		}
+		assert addForChecks( tableMapping );
+		bits.set( tableMapping.getRelativePosition() );
+	}
+
+	public boolean isEmpty() {
+		return bits == null;
+	}
+
+	public boolean contains(final TableMapping tableMapping) {
+		assert matchRead( tableMapping );
+		return bits != null && bits.get( tableMapping.getRelativePosition() );
+	}
+
+	//Meant for assertions only
+	private boolean matchRead(final TableMapping tableMapping) {
+		if ( bits != null ) {
+			final int index = tableMapping.getRelativePosition();
+			if ( bits.get( index ) ) {
+				return checks[index] == tableMapping;
+			}
+		}
+		return true; //to make the assertion happy
+	}
+
+	//Meant for assertions only
+	private boolean addForChecks(final TableMapping tableMapping) {
+		final int position = tableMapping.getRelativePosition();
+		ensureCapacity( position );
+		if ( checks[position] != null ) {
+			//pre-existing in the set: verify it's the same one.
+			if ( checks[position] != tableMapping ) {
+				return false;//fail the assertion
+			}
+		}
+		checks[position] = tableMapping;
+		return true; //to make the assertion happy
+	}
+
+	//Meant for assertions only
+	private void ensureCapacity(final int position) {
+		final int increments = 3; //Needs to be at least 1.
+		if ( checks == null ) {
+			checks = new Object[position + increments];
+		}
+		else if ( checks.length <= position ) {
+			checks = Arrays.copyOf( checks, position + increments );
+		}
+	}
+
+}

hibernate-core/src/main/java/org/hibernate/persister/entity/mutation/UpdateCoordinatorStandard.java

@@ -1242,10 +1242,10 @@ protected class UpdateValuesAnalysisImpl implements UpdateValuesAnalysis {
 		private final int[] dirtyAttributeIndexes;
 		private final InclusionChecker dirtinessChecker;
 
-		private final Set<EntityTableMapping> tablesNeedingUpdate = new HashSet<>();
-		private final Set<EntityTableMapping> tablesNeedingDynamicUpdate = new HashSet<>();
-		private final Set<EntityTableMapping> tablesWithNonNullValues = new HashSet<>();
-		private final Set<EntityTableMapping> tablesWithPreviousNonNullValues = new HashSet<>();
+		private final TableSet tablesNeedingUpdate = new TableSet();
+		private final TableSet tablesNeedingDynamicUpdate = new TableSet();
+		private final TableSet tablesWithNonNullValues = new TableSet();
+		private final TableSet tablesWithPreviousNonNullValues = new TableSet();
 
 		private final List<AttributeAnalysis> attributeAnalyses = new ArrayList<>();
 
@@ -1316,17 +1316,17 @@ public Object[] getValues() {
 		}
 
 		@Override
-		public Set<EntityTableMapping> getTablesNeedingUpdate() {
+		public TableSet getTablesNeedingUpdate() {
 			return tablesNeedingUpdate;
 		}
 
 		@Override
-		public Set<EntityTableMapping> getTablesWithNonNullValues() {
+		public TableSet getTablesWithNonNullValues() {
 			return tablesWithNonNullValues;
 		}
 
 		@Override
-		public Set<EntityTableMapping> getTablesWithPreviousNonNullValues() {
+		public TableSet getTablesWithPreviousNonNullValues() {
 			return tablesWithPreviousNonNullValues;
 		}
 

hibernate-core/src/main/java/org/hibernate/persister/entity/mutation/UpdateValuesAnalysis.java

@@ -7,7 +7,6 @@
 package org.hibernate.persister.entity.mutation;
 
 import java.util.List;
-import java.util.Set;
 
 import org.hibernate.Incubating;
 import org.hibernate.sql.model.TableMapping;
@@ -29,17 +28,17 @@ public interface UpdateValuesAnalysis extends ValuesAnalysis {
 	 *
 	 * @apiNote {@linkplain TableMapping#isInverse() Inverse tables} are not included in the result
 	 */
-	Set<EntityTableMapping> getTablesNeedingUpdate();
+	TableSet getTablesNeedingUpdate();
 
 	/**
 	 * Descriptor of the tables which had any non-null value bindings
 	 */
-	Set<EntityTableMapping> getTablesWithNonNullValues();
+	TableSet getTablesWithNonNullValues();
 
 	/**
 	 * Descriptor of the tables which had any non-null value bindings
 	 */
-	Set<EntityTableMapping> getTablesWithPreviousNonNullValues();
+	TableSet getTablesWithPreviousNonNullValues();
 
 	/**
 	 * Descriptors for the analysis of each attribute