/*
* 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.hive.hcatalog.streaming.mutate.worker;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
/**
* Tracks the (partition, bucket) combinations that have been encountered, checking that a group is not revisited.
* Potentially memory intensive.
*/
class GroupingValidator {
private final Map<String, Set<Integer>> visited;
private final StringBuffer partitionKeyBuilder;
private long groups;
private String lastPartitionKey;
private int lastBucketId = -1;
GroupingValidator() {
visited = new HashMap<String, Set<Integer>>();
partitionKeyBuilder = new StringBuffer(64);
}
/**
* Checks that this group is either the same as the last or is a new group.
*/
boolean isInSequence(List<String> partitionValues, int bucketId) {
String partitionKey = getPartitionKey(partitionValues);
if (Objects.equals(lastPartitionKey, partitionKey) && lastBucketId == bucketId) {
return true;
}
lastPartitionKey = partitionKey;
lastBucketId = bucketId;
Set<Integer> bucketIdSet = visited.get(partitionKey);
if (bucketIdSet == null) {
// If the bucket id set component of this data structure proves to be too large there is the
// option of moving it to Trove or HPPC in an effort to reduce size.
bucketIdSet = new HashSet<>();
visited.put(partitionKey, bucketIdSet);
}
boolean newGroup = bucketIdSet.add(bucketId);
if (newGroup) {
groups++;
}
return newGroup;
}
private String getPartitionKey(List<String> partitionValues) {
partitionKeyBuilder.setLength(0);
boolean first = true;
for (String element : partitionValues) {
if (first) {
first = false;
} else {
partitionKeyBuilder.append('/');
}
partitionKeyBuilder.append(element);
}
String partitionKey = partitionKeyBuilder.toString();
return partitionKey;
}
@Override
public String toString() {
return "GroupingValidator [groups=" + groups + ",lastPartitionKey=" + lastPartitionKey + ",lastBucketId="
+ lastBucketId + "]";
}
}