| /* |
| * 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.drill.exec.store.hive; |
| |
| import com.fasterxml.jackson.annotation.JsonCreator; |
| import com.fasterxml.jackson.annotation.JsonProperty; |
| import org.apache.hadoop.fs.Path; |
| |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.List; |
| import java.util.Map; |
| |
| /** |
| * Helper class that stores partition values per key. |
| * Key to index mapper contains key and index corresponding to partition values position in partition values list. |
| * Since several keys may have that same partition values, such structure is optimized to save memory usage. |
| * Partition values are stored in list of consecutive values. |
| */ |
| public class HivePartitionHolder { |
| |
| private final Map<Path, Integer> keyToIndexMapper; |
| private final List<List<String>> partitionValues; |
| |
| @JsonCreator |
| public HivePartitionHolder(@JsonProperty("keyToIndexMapper") Map<Path, Integer> keyToIndexMapper, |
| @JsonProperty("partitionValues") List<List<String>> partitionValues) { |
| this.keyToIndexMapper = keyToIndexMapper; |
| this.partitionValues = partitionValues; |
| } |
| |
| public HivePartitionHolder() { |
| this.keyToIndexMapper = new HashMap<>(); |
| this.partitionValues = new ArrayList<>(); |
| } |
| |
| @JsonProperty |
| public Map<Path, Integer> getKeyToIndexMapper() { |
| return keyToIndexMapper; |
| } |
| |
| @JsonProperty |
| public List<List<String>> getPartitionValues() { |
| return partitionValues; |
| } |
| |
| /** |
| * Checks if partition values already exist in holder. |
| * If not, adds them to holder and adds key and index corresponding to partition values to mapper. |
| * If partition values exist, adds key and existing partition values index to mapper. |
| * |
| * @param key mapper key |
| * @param values partition values |
| */ |
| public void add(Path key, List<String> values) { |
| int index = partitionValues.indexOf(values); |
| if (index == -1) { |
| index = partitionValues.size(); |
| partitionValues.add(values); |
| |
| } |
| keyToIndexMapper.put(key, index); |
| } |
| |
| /** |
| * Returns list of partition values stored in holder for the given key. |
| * If there are no corresponding partition values, return empty list. |
| * |
| * @param key mapper key |
| * @return list of partition values |
| */ |
| public List<String> get(Path key) { |
| Integer index = keyToIndexMapper.get(key); |
| if (index == null) { |
| return Collections.emptyList(); |
| } |
| return partitionValues.get(index); |
| } |
| |
| } |