Github user ppadma commented on a diff in the pull request:
https://github.com/apache/drill/pull/1121#discussion_r169162527
--- Diff:
exec/java-exec/src/main/java/org/apache/drill/exec/physical/impl/protocol/VectorContainerAccessor.java
---
@@ -0,0 +1,132 @@
+/*
+ * 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.physical.impl.protocol;
+
+import java.util.Collections;
+import java.util.Iterator;
+
+import org.apache.drill.common.expression.SchemaPath;
+import org.apache.drill.exec.record.BatchSchema;
+import org.apache.drill.exec.record.TypedFieldId;
+import org.apache.drill.exec.record.VectorContainer;
+import org.apache.drill.exec.record.VectorWrapper;
+import org.apache.drill.exec.record.WritableBatch;
+import org.apache.drill.exec.record.selection.SelectionVector2;
+import org.apache.drill.exec.record.selection.SelectionVector4;
+
+public class VectorContainerAccessor implements BatchAccessor {
+
+ public static class ContainerAndSv2Accessor extends
VectorContainerAccessor {
+
+ private SelectionVector2 sv2;
+
+ public void setSelectionVector(SelectionVector2 sv2) {
+ this.sv2 = sv2;
+ }
+
+ @Override
+ public SelectionVector2 getSelectionVector2() {
+ return sv2;
+ }
+ }
+
+ public static class ContainerAndSv4Accessor extends
VectorContainerAccessor {
+
+ private SelectionVector4 sv4;
+
+ @Override
+ public SelectionVector4 getSelectionVector4() {
+ return sv4;
+ }
+ }
+
+ private VectorContainer container;
+ private SchemaTracker schemaTracker = new SchemaTracker();
+
+ /**
+ * Set the vector container. Done initially, and any time the schema of
+ * the container may have changed. May be called with the same container
+ * as the previous call, or a different one. A schema change occurs
+ * unless the vectors are identical across the two containers.
+ *
+ * @param container the container that holds vectors to be sent
+ * downstream
+ */
+
+ public void setContainer(VectorContainer container) {
+ this.container = container;
+ if (container != null) {
+ schemaTracker.trackSchema(container);
+ }
+ }
+
+ @Override
+ public BatchSchema getSchema() {
+ return container == null ? null : container.getSchema();
+ }
+
+ @Override
+ public int schemaVersion() { return schemaTracker.schemaVersion(); }
+
+ @Override
+ public int getRowCount() {
+ return container == null ? 0 : container.getRecordCount();
+ }
+
+ @Override
+ public VectorContainer getOutgoingContainer() { return container; }
+
+ @Override
+ public TypedFieldId getValueVectorId(SchemaPath path) {
+ return container.getValueVectorId(path);
+ }
+
+ @Override
+ public VectorWrapper<?> getValueAccessorById(Class<?> clazz, int... ids)
{
+ return container.getValueAccessorById(clazz, ids);
+ }
+
+ @Override
+ public WritableBatch getWritableBatch() {
+ return WritableBatch.get(container);
+ }
+
+ @Override
+ public SelectionVector2 getSelectionVector2() {
+ // Throws an exception by default
--- End diff --
should we make that explicit by indicating what exceptions it might throw.
---
