Declare equals/hashCode consistent with compareTo (CodeQL java/inconsistent-compareto-and-equals)

persistit/core/src/main/java/com/persistit/BufferPool.java

@@ -1338,6 +1338,22 @@ public int compareTo(final BufferHolder buffer) {
 
         }
 
+        /**
+         * Equality is defined by the same (volumeId, page) ordering key used by
+         * {@link #compareTo(BufferHolder)}, so that {@code equals} stays
+         * consistent with the natural ordering.
+         */
+        @Override
+        public boolean equals(final Object object) {
+            return this == object
+                    || (object instanceof BufferHolder && compareTo((BufferHolder) object) == 0);
+        }
+
+        @Override
+        public int hashCode() {
+            return Long.hashCode(_volumeId) * 31 + Long.hashCode(_page);
+        }
+
         @Override
         public String toString() {
             final Buffer buffer = _buffer;

persistit/core/src/main/java/com/persistit/JournalManager.java

@@ -13,6 +13,7 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
+ * Portions Copyrighted 2026 3A Systems, LLC
  */
 
 package com.persistit;
@@ -2158,6 +2159,22 @@ public int compareTo(final TransactionMapItem ts) {
             }
         }
 
+        /**
+         * Equality is kept consistent with {@link #compareTo(TransactionMapItem)}:
+         * two items are equal exactly when they order equally (same commit
+         * timestamp for committed items, otherwise same start timestamp).
+         */
+        @Override
+        public boolean equals(final Object object) {
+            return this == object
+                    || (object instanceof TransactionMapItem && compareTo((TransactionMapItem) object) == 0);
+        }
+
+        @Override
+        public int hashCode() {
+            return Long.hashCode(isCommitted() ? _commitTimestamp : _startTimestamp);
+        }
+
         final static Comparator<TransactionMapItem> TRANSACTION_MAP_ITEM_COMPARATOR = new Comparator<TransactionMapItem>() {
 
             @Override

persistit/core/src/main/java/com/persistit/TreeBuilder.java

@@ -247,6 +247,24 @@ public int compareTo(final Node node) {
                 return _key.compareTo(node._key);
         }
 
+        /**
+         * Equality is kept consistent with {@link #compareTo(Node)}: two nodes
+         * are equal exactly when they order equally (same tree and key, or both
+         * with no tree).
+         */
+        @Override
+        public boolean equals(final Object object) {
+            return this == object || (object instanceof Node && compareTo((Node) object) == 0);
+        }
+
+        @Override
+        public int hashCode() {
+            // Consistent with compareTo: equal nodes share the same tree
+            // instance (or both have none), so the tree's identity hash yields
+            // equal hash codes for equal nodes.
+            return _tree == null ? 0 : System.identityHashCode(_tree);
+        }
+
         @Override
         public String toString() {
             Node n = this;