| /** |
| * 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.pulsar.structuredeventlog; |
| |
| import org.apache.pulsar.structuredeventlog.slf4j.Slf4jStructuredEventLog; |
| |
| /** |
| * Structured event logging interface |
| * |
| * Allows resources and attribute key value pairs to be attached to a logged event. |
| * |
| * Basic usage: |
| * <pre> |
| * StructuredEventLog logger = StructuredEventLog.newLogger(); |
| * logger.newRootEvent() |
| * .resource("remote", remoteAddr) |
| * .resource("local", localAddr) |
| * .attr("path", request.getPath()) |
| * .log(Events.READ_REQUEST); |
| * </pre> |
| */ |
| public interface StructuredEventLog { |
| /** |
| * Create a new root event. Root events occur in response to some external stimulus, such as |
| * a user request, a timer being triggered or a threshold being crossed. |
| * |
| * The level of the event is INFO by default. |
| * |
| * The root event will generate a new traceId, and will have a empty parent Id. If this |
| * information is provided, as can be the case with a user request, they can be set |
| * with Event#traceId(String) and Event#parentId(String). |
| */ |
| Event newRootEvent(); |
| |
| /** |
| * Create an new event resources object, which can be used across multiple |
| * root events. |
| */ |
| EventResources newEventResources(); |
| |
| /** |
| * Retrieves an event from the call stack. This can be used, along with Event#stash(), |
| * to bridge an event across an API without having to modify the API to pass the event |
| * object. |
| * |
| * For example, the child event, METHOD2, in the following example, will share the traceId |
| * with METHOD1, and METHOD1's id will be match the parentId of METHOD2. |
| * |
| * <pre> |
| * void method1() { |
| * Event e = logger.newRootEvent() |
| * .timed() |
| * .resource("foo", bar); |
| * |
| * e.stash(); |
| * unmodifiableMethod(); |
| * e.log(Events.METHOD1); |
| * } |
| * |
| * void unmodifiableMethod() { |
| * logger.unstash().newChildEvent().log(Events.METHOD2); |
| * } |
| * </pre> |
| * |
| * This should be used sparingly. |
| */ |
| Event unstash(); |
| |
| /** |
| * Create a new logger object, from which root events can be created. |
| */ |
| public static StructuredEventLog newLogger() { |
| return Slf4jStructuredEventLog.INSTANCE; |
| } |
| } |