/**
 * 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.solr.handler.dataimport;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * This class enables caching of data obtained from the DB to avoid too many sql
 * queries
 * <p/>
 * <p>
 * Refer to <a
 * href="http://wiki.apache.org/solr/DataImportHandler">http://wiki.apache.org/solr/DataImportHandler</a>
 * for more details.
 * </p>
 * <p/>
 * <b>This API is experimental and subject to change</b>
 *
 * @version $Id: CachedSqlEntityProcessor.java 887875 2009-12-07 10:27:47Z noble $
 * @since solr 1.3
 */
public class CachedSqlEntityProcessor extends SqlEntityProcessor {
  private boolean isFirst;

  @SuppressWarnings("unchecked")
  public void init(Context context) {
    super.init(context);
    super.cacheInit();
    isFirst = true;
  }

  public Map<String, Object> nextRow() {
    if (dataSourceRowCache != null)
      return getFromRowCacheTransformed();
    if (!isFirst)
      return null;
    String query = context.replaceTokens(context.getEntityAttribute("query"));
    isFirst = false;
    if (simpleCache != null) {
      return getSimpleCacheData(query);
    } else {
      return getIdCacheData(query);
    }

  }

  protected List<Map<String, Object>> getAllNonCachedRows() {
    List<Map<String, Object>> rows = new ArrayList<Map<String, Object>>();
    String q = getQuery();
    initQuery(context.replaceTokens(q));
    if (rowIterator == null)
      return rows;
    while (rowIterator.hasNext()) {
      Map<String, Object> arow = rowIterator.next();
      if (arow == null) {
        break;
      } else {
        rows.add(arow);
      }
    }
    return rows;
  }
}