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.
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  package org.apache.beam.sdk.extensions.sql.meta.provider.bigquery;
  
  import java.util.List;
  import org.apache.beam.sdk.extensions.sql.meta.BeamSqlTableFilter;
  import org.apache.beam.sdk.extensions.sql.meta.Table;
  import org.apache.beam.sdk.io.gcp.bigquery.BigQueryUtils.ConversionOptions;
  import org.apache.beam.sdk.metrics.Counter;
  import org.apache.beam.sdk.metrics.Metrics;
  import org.apache.beam.sdk.transforms.DoFn;
  import org.apache.beam.sdk.transforms.ParDo;
  import org.apache.beam.sdk.values.PBegin;
  import org.apache.beam.sdk.values.PCollection;
  import org.apache.beam.sdk.values.Row;
  
  public class BigQueryPerfTable extends BigQueryTable {
    private final String namespace;
    private final String metric;
  
    BigQueryPerfTable(Table table, ConversionOptions options, String namespace, String metric) {
      super(table, options);
      this.namespace = namespace;
      this.metric = metric;
    }
  
    @Override
    public PCollection<Row> buildIOReader(PBegin begin) {
      return super.buildIOReader(begin)
          .apply(ParDo.of(new RowMonitor(namespace, metric)))
          .setRowSchema(this.schema);
    }
  
    @Override
    public PCollection<Row> buildIOReader(
        PBegin begin, BeamSqlTableFilter filters, List<String> fieldNames) {
      return super.buildIOReader(begin, filters, fieldNames)
          .apply(ParDo.of(new RowMonitor(namespace, metric)))
          .setRowSchema(this.schema);
    }
  
    /** Monitor that records the number of Fields in each Row read from an IO. */
    private static class RowMonitor extends DoFn<Row, Row> {
  
      private Counter totalRows;
  
      RowMonitor(String namespace, String name) {
        this.totalRows = Metrics.counter(namespace, name);
      }
  
      @ProcessElement
      public void processElement(ProcessContext c) {
        totalRows.inc(c.element().getFieldCount());
        c.output(c.element());
      }
    }
  }
  