wu-sheng commented on a change in pull request #4308: provide thread stack analyzes URL: https://github.com/apache/skywalking/pull/4308#discussion_r373939512
########## File path: oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/profile/analyze/ProfileStackNode.java ########## @@ -0,0 +1,244 @@ +/* + * 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.profile.analyze; + +import com.google.common.base.Objects; +import org.apache.skywalking.oap.server.core.query.entity.ProfileStackElement; + +import java.util.*; +import java.util.function.Consumer; +import java.util.stream.Collectors; + +/** + * Work for profiling stacks, intermediate state of the {@link ProfileStackElement} and {@link ProfileStack} + */ +public class ProfileStackNode { + + private String codeSignature; + private List<ProfileStack> detectedStacks; + private List<ProfileStackNode> children; + private int duration; + + /** + * create new empty, un-init node + * @return + */ + public static ProfileStackNode newNode() { + ProfileStackNode emptyNode = new ProfileStackNode(); + emptyNode.detectedStacks = new LinkedList<>(); + emptyNode.children = new ArrayList<>(); + return emptyNode; + } + + /** + * accumulate {@link ProfileStack} to this tree, it will invoke on the tree root node + * @param stack + */ + public void accumulateFrom(ProfileStack stack) { + List<String> stackList = stack.getStack(); + if (codeSignature == null) { + codeSignature = stackList.get(0); + } + // add detected stack + this.detectedBy(stack); + + // handle stack children + ProfileStackNode parent = this; + for (int depth = 1; depth < stackList.size(); depth++) { + String elementCodeSignature = stackList.get(depth); + + // find same code signature children + ProfileStackNode childElement = null; + for (ProfileStackNode child : parent.children) { + if (Objects.equal(child.codeSignature, elementCodeSignature)) { + childElement = child; + break; + } + } + + if (childElement != null) { + // add detected stack + childElement.detectedBy(stack); + parent = childElement; + } else { + // add children + ProfileStackNode childNode = newNode(); + childNode.codeSignature = elementCodeSignature; + childNode.detectedBy(stack); + + parent.children.add(childNode); + parent = childNode; + } + } + } + + /** + * combine from other {@link ProfileStackNode} + * @param node + * @return + */ + public ProfileStackNode combine(ProfileStackNode node) { + // combine this node + this.combineDetectedStacks(node); + + // merge tree using LDR to traversal tree node + // using stack to avoid recursion + // merge key.children <- value.children + LinkedList<Pair<ProfileStackNode, ProfileStackNode>> stack = new LinkedList<>(); + stack.add(new Pair<>(this, node)); + while (!stack.isEmpty()) { + Pair<ProfileStackNode, ProfileStackNode> needCombineNode = stack.pop(); + + // merge value children to key + // add to stack if need to keep traversal + combineChildrenNodes(needCombineNode.key, needCombineNode.value, stack::add); + } + + return this; + } + + /** + * merge all children nodes to appoint node + * @param mergeTo + * @param combineNode + * @param needKeepEach if keep traversal, need report + */ + private void combineChildrenNodes(ProfileStackNode mergeTo, ProfileStackNode combineNode, Consumer<Pair<ProfileStackNode, ProfileStackNode>> needKeepEach) { + for (ProfileStackNode childrenNode : combineNode.children) { + // find node from mergeTo children + ProfileStackNode combinedNode = mergeTo.children.stream().filter(n -> childrenNode.matches(n)).findFirst().orElse(null); + + if (combinedNode == null) { + mergeTo.children.add(childrenNode); + } else { + combinedNode.combineDetectedStacks(childrenNode); + needKeepEach.accept(new Pair<>(combinedNode, childrenNode)); + } Review comment: You are iterating `combineNode` and process found or not, but 1. Once it is found, it has not been removed from `mergeTo`, then all elements all been process multiple times. 1. You seem missing node left in `mergeTo#children`, if some of them are not included in `combineNode` ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
