code: /*
   * 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.skywalking.oap.server.core.profiling.trace.analyze;
  
  import java.util.Collections;
  import java.util.EnumSet;
  import java.util.Set;
  import java.util.function.BiConsumer;
  import java.util.function.BinaryOperator;
  import java.util.function.Function;
  import java.util.function.Supplier;
  import java.util.stream.Collector;
  import org.apache.skywalking.oap.server.core.query.type.ProfileStackTree;
  
  /**
   * Work for {@link ProfileAnalyzer} to analyze.
   */
  public class ProfileAnalyzeCollector implements Collector<ProfileStack, ProfileStackNode, ProfileStackTree> {
      @Override
      public Supplier<ProfileStackNode> supplier() {
          return ProfileStackNode::newNode;
      }
  
      @Override
      public BiConsumer<ProfileStackNode, ProfileStack> accumulator() {
          return ProfileStackNode::accumulateFrom;
      }
  
      @Override
      public BinaryOperator<ProfileStackNode> combiner() {
          return ProfileStackNode::combine;
      }
  
      @Override
      public Function<ProfileStackNode, ProfileStackTree> finisher() {
          return ProfileStackNode::buildAnalyzeResult;
      }
  
      @Override
      public Set<Characteristics> characteristics() {
          return Collections.unmodifiableSet(EnumSet.of(Characteristics.CONCURRENT, Characteristics.UNORDERED));
      }
  }
  