Do not persist ReversedType in system_schema.columns

patch by Aleksey Yeschenko; reviewed by Sam Tunnicliffe for
CASSANDRA-6717

src/java/org/apache/cassandra/config/ColumnDefinition.java

@@ -37,6 +37,11 @@ public class ColumnDefinition extends ColumnSpecification implements Comparable<
 
     public static final int NO_POSITION = -1;
 
+    public enum ClusteringOrder
+    {
+        ASC, DESC, NONE
+    }
+
     /*
      * The type of CQL3 column this definition represents.
      * There is 4 main type of CQL3 columns: those parts of the partition key,
@@ -222,6 +227,14 @@ public class ColumnDefinition extends ColumnSpecification implements Comparable<
         return kind == Kind.REGULAR;
     }
 
+    public ClusteringOrder clusteringOrder()
+    {
+        if (!isClusteringColumn())
+            return ClusteringOrder.NONE;
+
+        return type.isReversed() ? ClusteringOrder.DESC : ClusteringOrder.ASC;
+    }
+
     /**
      * For convenience sake, if position == NO_POSITION, this method will return 0. The callers should first check
      * isOnAllComponents() to distinguish between proper 0 position and NO_POSITION.

src/java/org/apache/cassandra/schema/SchemaKeyspace.java

@@ -34,6 +34,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import org.apache.cassandra.config.*;
+import org.apache.cassandra.config.ColumnDefinition.ClusteringOrder;
 import org.apache.cassandra.cql3.ColumnIdentifier;
 import org.apache.cassandra.cql3.QueryProcessor;
 import org.apache.cassandra.cql3.UntypedResultSet;
@@ -117,6 +118,7 @@ public final class SchemaKeyspace
                 + "keyspace_name text,"
                 + "table_name text,"
                 + "column_name text,"
+                + "clustering_order text,"
                 + "column_name_bytes blob,"
                 + "kind text,"
                 + "position int,"
@@ -1163,10 +1165,15 @@ public final class SchemaKeyspace
     {
         RowUpdateBuilder adder = new RowUpdateBuilder(Columns, timestamp, mutation).clustering(table.cfName, column.name.toString());
 
+        AbstractType<?> type = column.type;
+        if (type instanceof ReversedType)
+            type = ((ReversedType) type).baseType;
+
         adder.add("column_name_bytes", column.name.bytes)
              .add("kind", column.kind.toString().toLowerCase())
              .add("position", column.isOnAllComponents() ? ColumnDefinition.NO_POSITION : column.position())
-             .add("type", column.type.toString())
+             .add("clustering_order", column.clusteringOrder().toString().toLowerCase())
+             .add("type", type.toString())
              .build();
     }
 
@@ -1193,8 +1200,11 @@ public final class SchemaKeyspace
         ColumnDefinition.Kind kind = ColumnDefinition.Kind.valueOf(row.getString("kind").toUpperCase());
 
         int position = row.getInt("position");
+        ClusteringOrder order = ClusteringOrder.valueOf(row.getString("clustering_order").toUpperCase());
 
         AbstractType<?> type = parseType(row.getString("type"));
+        if (order == ClusteringOrder.DESC)
+            type = ReversedType.getInstance(type);
 
         return new ColumnDefinition(keyspace, table, name, type, position, kind);
     }