| /* |
| * 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.druid.query.topn; |
| |
| import com.fasterxml.jackson.annotation.JsonCreator; |
| import com.fasterxml.jackson.annotation.JsonProperty; |
| import org.apache.druid.java.util.common.StringUtils; |
| import org.apache.druid.query.aggregation.AggregatorFactory; |
| import org.apache.druid.query.aggregation.PostAggregator; |
| import org.apache.druid.query.dimension.DimensionSpec; |
| import org.apache.druid.query.ordering.StringComparators; |
| import org.joda.time.DateTime; |
| |
| import java.nio.ByteBuffer; |
| import java.util.Comparator; |
| import java.util.List; |
| |
| /** |
| */ |
| public class LexicographicTopNMetricSpec implements TopNMetricSpec |
| { |
| private static final byte CACHE_TYPE_ID = 0x1; |
| |
| private static Comparator<String> comparator = StringComparators.LEXICOGRAPHIC; |
| |
| private final String previousStop; |
| |
| @JsonCreator |
| public LexicographicTopNMetricSpec( |
| @JsonProperty("previousStop") String previousStop |
| ) |
| { |
| this.previousStop = previousStop; |
| } |
| |
| @Override |
| public void verifyPreconditions(List<AggregatorFactory> aggregatorSpecs, List<PostAggregator> postAggregatorSpecs) |
| { |
| } |
| |
| @JsonProperty |
| public String getPreviousStop() |
| { |
| return previousStop; |
| } |
| |
| |
| @Override |
| public Comparator getComparator(List<AggregatorFactory> aggregatorSpecs, List<PostAggregator> postAggregatorSpecs) |
| { |
| return comparator; |
| } |
| |
| @Override |
| public TopNResultBuilder getResultBuilder( |
| DateTime timestamp, |
| DimensionSpec dimSpec, |
| int threshold, |
| Comparator comparator, |
| List<AggregatorFactory> aggFactories, |
| List<PostAggregator> postAggs |
| ) |
| { |
| return new TopNLexicographicResultBuilder( |
| timestamp, |
| dimSpec, |
| threshold, |
| previousStop, |
| comparator, |
| aggFactories |
| ); |
| } |
| |
| @Override |
| public byte[] getCacheKey() |
| { |
| byte[] previousStopBytes = previousStop == null ? new byte[]{} : StringUtils.toUtf8(previousStop); |
| |
| return ByteBuffer.allocate(1 + previousStopBytes.length) |
| .put(CACHE_TYPE_ID) |
| .put(previousStopBytes) |
| .array(); |
| } |
| |
| @Override |
| public <T> TopNMetricSpecBuilder<T> configureOptimizer(TopNMetricSpecBuilder<T> builder) |
| { |
| builder.skipTo(previousStop); |
| builder.ignoreAfterThreshold(); |
| return builder; |
| } |
| |
| @Override |
| public void initTopNAlgorithmSelector(TopNAlgorithmSelector selector) |
| { |
| selector.setAggregateAllMetrics(true); |
| } |
| |
| @Override |
| public String getMetricName(DimensionSpec dimSpec) |
| { |
| return dimSpec.getOutputName(); |
| } |
| |
| @Override |
| public boolean canBeOptimizedUnordered() |
| { |
| return false; |
| } |
| |
| @Override |
| public String toString() |
| { |
| return "LexicographicTopNMetricSpec{" + |
| "previousStop='" + previousStop + '\'' + |
| '}'; |
| } |
| |
| @Override |
| public boolean equals(Object o) |
| { |
| if (this == o) { |
| return true; |
| } |
| if (o == null || getClass() != o.getClass()) { |
| return false; |
| } |
| |
| LexicographicTopNMetricSpec that = (LexicographicTopNMetricSpec) o; |
| |
| if (previousStop != null ? !previousStop.equals(that.previousStop) : that.previousStop != null) { |
| return false; |
| } |
| |
| return true; |
| } |
| |
| @Override |
| public int hashCode() |
| { |
| return previousStop != null ? previousStop.hashCode() : 0; |
| } |
| } |