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.calcite.test;
  
  import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
  import com.fasterxml.jackson.core.JsonParser;
  import com.fasterxml.jackson.databind.ObjectMapper;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.lang.ref.SoftReference;
  import java.util.ArrayList;
  import java.util.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  
  /** Set of queries against the FoodMart database. */
  public class FoodMartQuerySet {
    private static SoftReference<FoodMartQuerySet> ref;
  
    public final Map<Integer, FoodmartQuery> queries = new LinkedHashMap<>();
  
    private FoodMartQuerySet() throws IOException {
      final ObjectMapper mapper = new ObjectMapper();
      mapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);
      mapper.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);
  
      final InputStream inputStream =
          new net.hydromatic.foodmart.queries.FoodmartQuerySet().getQueries();
      FoodmartRoot root = mapper.readValue(inputStream, FoodmartRoot.class);
      for (FoodmartQuery query : root.queries) {
        queries.put(query.id, query);
      }
    }
  
    /** Returns the singleton instance of the query set. It is backed by a
     * soft reference, so it may be freed if memory is short and no one is
     * using it. */
    public static synchronized FoodMartQuerySet instance() throws IOException {
      final SoftReference<FoodMartQuerySet> refLocal = ref;
      if (refLocal != null) {
        final FoodMartQuerySet set = refLocal.get();
        if (set != null) {
          return set;
        }
      }
      final FoodMartQuerySet set = new FoodMartQuerySet();
      ref = new SoftReference<>(set);
      return set;
    }
  
    /** JSON root element. */
    public static class FoodmartRoot {
      public final List<FoodmartQuery> queries = new ArrayList<>();
    }
  
    /** JSON query element. */
    @JsonIgnoreProperties(value = {"columns", "rows"})
    public static class FoodmartQuery {
      public int id;
      public String sql;
  
      @Override public String toString() {
        return "id=" + id;
      }
    }
  }
  