Github user ppadma commented on a diff in the pull request:
https://github.com/apache/drill/pull/1112#discussion_r168295700
--- Diff:
exec/java-exec/src/main/java/org/apache/drill/exec/record/metadata/RepeatedListColumnMetadata.java
---
@@ -0,0 +1,94 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * 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.
+ */
+package org.apache.drill.exec.record.metadata;
+
+import org.apache.drill.common.types.TypeProtos.DataMode;
+import org.apache.drill.common.types.TypeProtos.MinorType;
+import org.apache.drill.exec.record.MaterializedField;
+
+import com.google.common.base.Preconditions;
+
+public class RepeatedListColumnMetadata extends AbstractColumnMetadata {
+
+ private AbstractColumnMetadata childSchema;
+
+ public RepeatedListColumnMetadata(MaterializedField field) {
+ super(field);
+ Preconditions.checkArgument(field.getType().getMinorType() ==
MinorType.LIST);
+ Preconditions.checkArgument(field.getType().getMode() ==
DataMode.REPEATED);
+ Preconditions.checkArgument(field.getChildren().size() <= 1);
+ if (! field.getChildren().isEmpty()) {
+ childSchema =
MetadataUtils.fromField(field.getChildren().iterator().next());
+ Preconditions.checkArgument(childSchema.isArray());
+ }
+ }
+
+ public RepeatedListColumnMetadata(String name, AbstractColumnMetadata
childSchema) {
+ super(name, MinorType.LIST, DataMode.REPEATED);
+ if (childSchema != null) {
+ Preconditions.checkArgument(childSchema.isArray());
+ }
+ this.childSchema = childSchema;
+ }
+
+ public void childSchema(ColumnMetadata childMetadata) {
+ Preconditions.checkState(childSchema == null);
+ Preconditions.checkArgument(childMetadata.mode() == DataMode.REPEATED);
+ childSchema = (AbstractColumnMetadata) childMetadata;
+ }
+
+ @Override
+ public StructureType structureType() { return StructureType.MULTI_ARRAY;
}
+
+ @Override
+ public MaterializedField schema() {
+ MaterializedField field = emptySchema();
+ if (childSchema != null) {
+ field.addChild(childSchema.schema());
+ }
+ return field;
+ }
+
+ @Override
+ public MaterializedField emptySchema() {
+ return MaterializedField.create(name(), majorType());
+ }
+
+ @Override
+ public ColumnMetadata cloneEmpty() {
+ return new RepeatedListColumnMetadata(name, null);
+ }
+
+ @Override
+ public AbstractColumnMetadata copy() {
+ return new RepeatedListColumnMetadata(name, childSchema);
+ }
+
+ @Override
+ public ColumnMetadata childSchema() { return childSchema; }
+
+ @Override
+ public int dimensions() {
+
+ // If there is no child, then we don't know the
+ // dimensionality.
+
+ return childSchema == null ? -1
--- End diff --
can we use a static final instead of -1 ?
---
