mrproliu commented on a change in pull request #4555: Correlation protocol implement URL: https://github.com/apache/skywalking/pull/4555#discussion_r397135217
########## File path: apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/CorrelationContext.java ########## @@ -0,0 +1,150 @@ +/* + * 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.apm.agent.core.context; + +import org.apache.skywalking.apm.agent.core.base64.Base64; +import org.apache.skywalking.apm.agent.core.conf.Config; +import org.apache.skywalking.apm.util.StringUtil; + +import java.util.HashMap; +import java.util.Map; +import java.util.Objects; +import java.util.Optional; +import java.util.stream.Collectors; + +/** + * Correlation context, use to propagation user custom data. + * Working on the protocol and delegate set/get method. + */ +public class CorrelationContext { + + private final Map<String, String> data; + + public CorrelationContext() { + this.data = new HashMap<>(Config.Correlation.ELEMENT_MAX_NUMBER); + } + + public Optional<String> set(String key, String value) { + // key must not null + if (key == null) { + return Optional.empty(); + } + if (value == null) { + value = ""; + } + + // check value length + if (value.length() > Config.Correlation.VALUE_MAX_LENGTH) { + return Optional.empty(); + } + + // already contain key + if (data.containsKey(key)) { + final String previousValue = data.put(key, value); + return Optional.of(previousValue); + } + + // check keys count + if (data.size() >= Config.Correlation.ELEMENT_MAX_NUMBER) { + return Optional.empty(); + } + + // setting + data.put(key, value); + return Optional.empty(); + } + + public Optional<String> get(String key) { + if (key == null) { + return Optional.empty(); + } + + return Optional.ofNullable(data.get(key)); + } + + /** + * Serialize this {@link CorrelationContext} to a {@link String} + * + * @return the serialization string. + */ + String serialize() { + if (data.isEmpty()) { + return ""; + } + + return data.entrySet().stream() + .map(entry -> Base64.encode(entry.getKey()) + ":" + Base64.encode(entry.getValue())) + .collect(Collectors.joining(",")); + } + + /** + * Deserialize data from {@link String} + */ + void deserialize(String value) { + if (StringUtil.isEmpty(value)) { + return; + } + + for (String perData : value.split(",")) { + final String[] parts = perData.split(":"); + String perDataKey = parts[0]; + String perDataValue = parts.length > 1 ? parts[1] : ""; + data.put(Base64.decode2UTFString(perDataKey), Base64.decode2UTFString(perDataValue)); + } + } + + /** + * Prepare for the cross-process propagation. Inject the {@link #data} into {@link ContextCarrier#getCorrelationContext()} + */ + void inject(ContextCarrier carrier) { + carrier.getCorrelationContext().data.putAll(this.data); Review comment: fixed. ---------------------------------------------------------------- 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: us...@infra.apache.org With regards, Apache Git Services
