| /* |
| * 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.store.mongo; |
| |
| import java.util.LinkedList; |
| import java.util.List; |
| |
| import org.apache.drill.common.exceptions.ExecutionSetupException; |
| import org.apache.drill.common.expression.SchemaPath; |
| import org.apache.drill.exec.ops.ExecutorFragmentContext; |
| import org.apache.drill.exec.physical.base.GroupScan; |
| import org.apache.drill.exec.physical.impl.BatchCreator; |
| import org.apache.drill.exec.physical.impl.ScanBatch; |
| import org.apache.drill.exec.record.RecordBatch; |
| import org.apache.drill.exec.store.RecordReader; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import com.google.common.base.Preconditions; |
| |
| public class MongoScanBatchCreator implements BatchCreator<MongoSubScan> { |
| static final Logger logger = LoggerFactory |
| .getLogger(MongoScanBatchCreator.class); |
| |
| @Override |
| public ScanBatch getBatch(ExecutorFragmentContext context, MongoSubScan subScan, |
| List<RecordBatch> children) throws ExecutionSetupException { |
| Preconditions.checkArgument(children.isEmpty()); |
| List<RecordReader> readers = new LinkedList<>(); |
| for (BaseMongoSubScanSpec scanSpec : subScan.getChunkScanSpecList()) { |
| try { |
| List<SchemaPath> columns = subScan.getColumns(); |
| if (columns == null) { |
| columns = GroupScan.ALL_COLUMNS; |
| } |
| readers.add(new MongoRecordReader(scanSpec, columns, context, subScan.getMongoStoragePlugin())); |
| } catch (Exception e) { |
| logger.error("MongoRecordReader creation failed for subScan: {}.", subScan); |
| logger.error(e.getMessage(), e); |
| throw new ExecutionSetupException(e); |
| } |
| } |
| logger.info("Number of record readers initialized : {}", readers.size()); |
| return new ScanBatch(subScan, context, readers); |
| } |
| |
| } |