content: /*
   * 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.asterix.external.operators;
  
  import org.apache.asterix.common.external.IDataSourceAdapter;
  import org.apache.asterix.external.api.ITypedAdapterFactory;
  import org.apache.hyracks.api.context.IHyracksTaskContext;
  import org.apache.hyracks.api.dataflow.IOperatorNodePushable;
  import org.apache.hyracks.api.dataflow.value.IRecordDescriptorProvider;
  import org.apache.hyracks.api.dataflow.value.RecordDescriptor;
  import org.apache.hyracks.api.exceptions.HyracksDataException;
  import org.apache.hyracks.api.job.JobSpecification;
  import org.apache.hyracks.api.job.profiling.IOperatorStats;
  import org.apache.hyracks.api.job.profiling.NoOpOperatorStats;
  import org.apache.hyracks.dataflow.std.base.AbstractSingleActivityOperatorDescriptor;
  import org.apache.hyracks.dataflow.std.base.AbstractUnaryOutputSourceOperatorNodePushable;
  import org.apache.hyracks.storage.am.common.api.ITupleFilter;
  import org.apache.hyracks.storage.am.common.api.ITupleFilterFactory;
  
  /*
   * A single activity operator that provides the functionality of scanning data using an
   * instance of the configured adapter.
   */
  public class ExternalScanOperatorDescriptor extends AbstractSingleActivityOperatorDescriptor {
  
      private static final long serialVersionUID = 2L;
  
      private final ITypedAdapterFactory adapterFactory;
  
      private final ITupleFilterFactory tupleFilterFactory;
  
      private final long outputLimit;
  
      public ExternalScanOperatorDescriptor(JobSpecification spec, RecordDescriptor rDesc,
              ITypedAdapterFactory dataSourceAdapterFactory, ITupleFilterFactory tupleFilterFactory, long outputLimit) {
          super(spec, 0, 1);
          outRecDescs[0] = rDesc;
          this.adapterFactory = dataSourceAdapterFactory;
          this.tupleFilterFactory = tupleFilterFactory;
          this.outputLimit = outputLimit;
      }
  
      public ExternalScanOperatorDescriptor(JobSpecification spec, RecordDescriptor rDesc,
              ITypedAdapterFactory dataSourceAdapterFactory) {
          this(spec, rDesc, dataSourceAdapterFactory, null, -1);
      }
  
      @Override
      public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx,
              IRecordDescriptorProvider recordDescProvider, final int partition, final int nPartitions) {
  
          return new AbstractUnaryOutputSourceOperatorNodePushable() {
  
              private IOperatorStats stats = NoOpOperatorStats.INSTANCE;
  
              @Override
              public void initialize() throws HyracksDataException {
                  IDataSourceAdapter adapter;
                  try {
                      writer.open();
                      ITupleFilter tupleFilter =
                              tupleFilterFactory != null ? tupleFilterFactory.createTupleFilter(ctx) : null;
                      adapter = adapterFactory.createAdapter(ctx, partition);
                      adapter.start(partition, writer, tupleFilter, outputLimit);
                      stats.getInputTupleCounter().update(adapter.getProcessedTuples());
                  } catch (Exception e) {
                      writer.fail();
                      throw HyracksDataException.create(e);
                  } finally {
                      writer.close();
                  }
              }
  
              @Override
              public void setOperatorStats(IOperatorStats stats) {
                  this.stats = stats;
              }
          };
  
      }
  
  }
  