avoid ByteBuffer allocation for clustering key too

Author: netudima

src/java/org/apache/cassandra/cql3/selection/ResultSetBuilder.java

@@ -107,6 +107,11 @@ public void add(ByteBuffer v)
         inputRow.add(v);
     }
 
+    public void add(byte[] v)
+    {
+        inputRow.add(v);
+    }
+
     public void add(Cell<?> c, long nowInSec)
     {
         inputRow.add(c, nowInSec);

src/java/org/apache/cassandra/cql3/selection/Selector.java

@@ -369,12 +369,24 @@ public void add(ByteBuffer v)
             index++;
         }
 
+        public void add(byte[] v)
+        {
+            values[index] = v;
+
+            if (v != null)
+            {
+                writetimes.addNoTimestamp(index);
+                ttls.addNoTimestamp(index);
+            }
+            index++;
+        }
+
         public void add(ColumnData columnData, long nowInSec)
         {
             ColumnMetadata column = columns.get(index);
             if (columnData == null)
             {
-                add(null);
+                add((byte[]) null);
             }
             else
             {

src/java/org/apache/cassandra/cql3/statements/SelectStatement.java

@@ -1228,7 +1228,7 @@ public void processPartition(RowIterator partition, QueryOptions options, Result
                         result.add(keyComponents[def.position()]);
                         break;
                     case CLUSTERING:
-                        result.add(row.clustering().bufferAt(def.position()));
+                        result.add(row.clustering().arrayAt(def.position()));
                         break;
                     case REGULAR:
                         result.add(row.getColumnData(def), nowInSec);

src/java/org/apache/cassandra/db/ClusteringPrefix.java

@@ -313,6 +313,11 @@ default ByteBuffer bufferAt(int i)
         return accessor().toBuffer(get(i));
     }
 
+    default byte[] arrayAt(int i)
+    {
+        return accessor().toArray(get(i));
+    }
+
     default String stringAt(int i, ClusteringComparator comparator)
     {
         return comparator.subtype(i).getString(get(i), accessor());