org.springframework.core.metrics.StartupStep Maven / Gradle / Ivy
/*
* Copyright 2002-2020 the original author or authors.
*
* Licensed 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
*
* https://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.springframework.core.metrics;
import java.util.function.Supplier;
import org.springframework.lang.Nullable;
/**
* Step recording metrics about a particular phase or action happening during the {@link ApplicationStartup}.
*
* The lifecycle of a {@code StartupStep} goes as follows:
*
* - the step is created and starts by calling {@link ApplicationStartup#start(String) the application startup}
* and is assigned a unique {@link StartupStep#getId() id}.
*
- we can then attach information with {@link Tags} during processing
*
- we then need to mark the {@link #end()} of the step
*
*
* Implementations can track the "execution time" or other metrics for steps.
*
* @author Brian Clozel
* @since 5.3
*/
public interface StartupStep {
/**
* Return the name of the startup step.
*
A step name describes the current action or phase. This technical
* name should be "." namespaced and can be reused to describe other instances of
* similar steps during application startup.
*/
String getName();
/**
* Return the unique id for this step within the application startup.
*/
long getId();
/**
* Return, if available, the id of the parent step.
*
The parent step is the step that was started the most recently
* when the current step was created.
*/
@Nullable
Long getParentId();
/**
* Add a {@link Tag} to the step.
* @param key tag key
* @param value tag value
*/
StartupStep tag(String key, String value);
/**
* Add a {@link Tag} to the step.
* @param key tag key
* @param value {@link Supplier} for the tag value
*/
StartupStep tag(String key, Supplier value);
/**
* Return the {@link Tag} collection for this step.
*/
Tags getTags();
/**
* Record the state of the step and possibly other metrics like execution time.
* Once ended, changes on the step state are not allowed.
*/
void end();
/**
* Immutable collection of {@link Tag}.
*/
interface Tags extends Iterable {
}
/**
* Simple key/value association for storing step metadata.
*/
interface Tag {
/**
* Return the {@code Tag} name.
*/
String getKey();
/**
* Return the {@code Tag} value.
*/
String getValue();
}
}