| /* |
| * 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.expr.fn.impl; |
| |
| import org.apache.drill.exec.expr.DrillAggFunc; |
| import org.apache.drill.exec.expr.annotations.FunctionTemplate; |
| import org.apache.drill.exec.expr.annotations.Output; |
| import org.apache.drill.exec.expr.annotations.Param; |
| import org.apache.drill.exec.expr.annotations.Workspace; |
| import org.apache.drill.exec.expr.holders.NullableVarCharHolder; |
| import org.apache.drill.exec.expr.holders.ObjectHolder; |
| import org.apache.drill.exec.vector.complex.writer.BaseWriter; |
| |
| /** |
| * Aggregate function which collects incoming VarChar column values into the list. |
| */ |
| @FunctionTemplate(name = "collect_to_list_varchar", |
| scope = FunctionTemplate.FunctionScope.POINT_AGGREGATE, |
| isInternal = true) |
| public class CollectToListVarcharAggFunction implements DrillAggFunc { |
| |
| @Param NullableVarCharHolder input; |
| @Output BaseWriter.ComplexWriter writer; |
| @Workspace ObjectHolder writerHolder; |
| |
| @Override |
| public void setup() { |
| writerHolder = new ObjectHolder(); |
| } |
| |
| @Override |
| public void add() { |
| org.apache.drill.exec.vector.complex.writer.BaseWriter.ListWriter listWriter; |
| if (writerHolder.obj == null) { |
| writerHolder.obj = writer.rootAsList(); |
| } |
| |
| listWriter = (org.apache.drill.exec.vector.complex.writer.BaseWriter.ListWriter) writerHolder.obj; |
| |
| if (input.isSet > 0) { |
| listWriter.varChar().writeVarChar(input.start, input.end, input.buffer); |
| } |
| } |
| |
| @Override |
| public void output() { |
| } |
| |
| @Override |
| public void reset() { |
| writerHolder.obj = null; |
| } |
| } |