text: /**
   * Copyright 2013 Netflix, Inc.
   *
   * Licensed 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 com.netflix.astyanax.cql.reads.model;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  
  import com.datastax.driver.core.ResultSet;
  import com.google.common.base.Function;
  import com.google.common.collect.Lists;
  import com.netflix.astyanax.Serializer;
  import com.netflix.astyanax.cql.schema.CqlColumnFamilyDefinitionImpl;
  import com.netflix.astyanax.cql.util.CqlTypeMapping;
  import com.netflix.astyanax.model.ColumnFamily;
  import com.netflix.astyanax.model.Row;
  import com.netflix.astyanax.model.Rows;
  
  /**
   * Impl for {@link Rows} that parses the {@link ResultSet} from java driver and translates back to Astyanax Rows. 
   * Note that if your schema has a clustering key, then each individual row from the result set is a unique column, 
   * and all result set rows with the same partition key map to a unique Astyanax row. 
   * 
   * @author poberai
   *
   * @param <K>
   * @param <C>
   */
  public class CqlRowListImpl<K, C> implements Rows<K, C> {
  
  	private final List<Row<K,C>>   rows;
  	private final Map<K, Row<K,C>> lookup;
  
  	private final ColumnFamily<K,C> cf;
  	private final CqlColumnFamilyDefinitionImpl cfDef; 
  	
  	public CqlRowListImpl() {
  		this.rows = new ArrayList<Row<K, C>>();
  		this.lookup = new HashMap<K, Row<K,C>>();
  		
  		this.cf = null;
  		this.cfDef = null;
  	}
  	
  	public CqlRowListImpl(List<Row<K,C>> newRows) {
  		this.rows = new ArrayList<Row<K, C>>();
  		this.rows.addAll(newRows);
  		this.lookup = new HashMap<K, Row<K,C>>();
  		for (Row<K,C> row : this.rows) {
  			this.lookup.put(row.getKey(), row);
  		}
  		this.cf = null;
  		this.cfDef = null;
  	}
  
  	public CqlRowListImpl(List<com.datastax.driver.core.Row> resultRows, ColumnFamily<K,C> cf) {
  		
  		this.rows = new ArrayList<Row<K, C>>();
  		this.lookup = new HashMap<K, Row<K,C>>();
  		
  		this.cf = cf;
  		this.cfDef = (CqlColumnFamilyDefinitionImpl) cf.getColumnFamilyDefinition();
  		
  		Serializer<?> keySerializer = cf.getKeySerializer();
  		K prevKey = null; 
  		List<com.datastax.driver.core.Row> tempList = new ArrayList<com.datastax.driver.core.Row>();
  		
  		for (com.datastax.driver.core.Row row : resultRows) {
  			
  			K rowKey = (K) CqlTypeMapping.getDynamicColumn(row, keySerializer, 0, cf);
  			
  			if (prevKey == null || prevKey.equals(rowKey)) {
  				tempList.add(row);
  			} else {
  			
  				// we found a set of contiguous rows that match with the same row key
  				addToResultRows(tempList);
  				tempList = new ArrayList<com.datastax.driver.core.Row>();
  				tempList.add(row);
  			}
  			prevKey = rowKey;
  		}
  		// flush the final list
  		if (tempList.size() > 0) {
  			addToResultRows(tempList);
  		}
  		
  		for (Row<K,C> row : rows) {
  			this.lookup.put(row.getKey(),  row);
  		}
  	}
  
  	private void addToResultRows(List<com.datastax.driver.core.Row> rowList) {
  
  		if (cfDef.getClusteringKeyColumnDefinitionList().size() == 0 || cfDef.getRegularColumnDefinitionList().size() > 1) {
  			for (com.datastax.driver.core.Row row : rowList) {
  				this.rows.add(new CqlRowImpl<K, C>(row, cf));
  			}
  		} else {
  			this.rows.add(new CqlRowImpl<K, C>(rowList, cf));
  		}
  	}
  	
  	@Override
  	public Iterator<Row<K, C>> iterator() {
  		return rows.iterator();
  	}
  
  	@Override
  	public Row<K, C> getRow(K key) {
  		return lookup.get(key);
  	}
  
  	@Override
  	public int size() {
  		return rows.size();
  	}
  
  	@Override
  	public boolean isEmpty() {
  		return rows.isEmpty();
  	}
  
  	@Override
  	public Row<K, C> getRowByIndex(int index) {
  		return rows.get(index);
  	}
  
  	@Override
  	public Collection<K> getKeys() {
  		return Lists.transform(rows, new Function<Row<K,C>, K>() {
  			@Override
  			public K apply(Row<K, C> row) {
  				return row.getKey();
  			}
  		});
  	}
  }
  