org.springframework.core.metrics.jfr.FlightRecorderStartupStep Maven / Gradle / Ivy
/*
* Copyright 2012-2020 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.jfr;
import java.util.Iterator;
import java.util.function.Consumer;
import java.util.function.Supplier;
import org.jetbrains.annotations.NotNull;
import org.springframework.core.metrics.StartupStep;
/**
* {@link StartupStep} implementation for the Java Flight Recorder.
* This variant delegates to a {@link FlightRecorderStartupEvent JFR event extension}
* to collect and record data in Java Flight Recorder.
*
* @author Brian Clozel
*/
class FlightRecorderStartupStep implements StartupStep {
private final FlightRecorderStartupEvent event;
private final FlightRecorderTags tags = new FlightRecorderTags();
private final Consumer recordingCallback;
public FlightRecorderStartupStep(long id, String name, long parentId,
Consumer recordingCallback) {
this.event = new FlightRecorderStartupEvent(id, name, parentId);
this.event.begin();
this.recordingCallback = recordingCallback;
}
@Override
public String getName() {
return this.event.name;
}
@Override
public long getId() {
return this.event.eventId;
}
@Override
public Long getParentId() {
return this.event.parentId;
}
@Override
public StartupStep tag(String key, String value) {
this.tags.add(key, value);
return this;
}
@Override
public StartupStep tag(String key, Supplier value) {
this.tags.add(key, value.get());
return this;
}
@Override
public Tags getTags() {
return this.tags;
}
@Override
public void end() {
this.event.end();
if (this.event.shouldCommit()) {
StringBuilder builder = new StringBuilder();
this.tags.forEach(tag ->
builder.append(tag.getKey()).append('=').append(tag.getValue()).append(',')
);
this.event.setTags(builder.toString());
}
this.event.commit();
this.recordingCallback.accept(this);
}
protected FlightRecorderStartupEvent getEvent() {
return this.event;
}
static class FlightRecorderTags implements Tags {
private Tag[] tags = new Tag[0];
public void add(String key, String value) {
Tag[] newTags = new Tag[this.tags.length + 1];
System.arraycopy(this.tags, 0, newTags, 0, this.tags.length);
newTags[newTags.length - 1] = new FlightRecorderTag(key, value);
this.tags = newTags;
}
public void add(String key, Supplier value) {
add(key, value.get());
}
@NotNull
@Override
public Iterator iterator() {
return new TagsIterator();
}
private class TagsIterator implements Iterator {
private int idx = 0;
@Override
public boolean hasNext() {
return this.idx < tags.length;
}
@Override
public Tag next() {
return tags[this.idx++];
}
@Override
public void remove() {
throw new UnsupportedOperationException("tags are append only");
}
}
}
static class FlightRecorderTag implements Tag {
private final String key;
private final String value;
public FlightRecorderTag(String key, String value) {
this.key = key;
this.value = value;
}
@Override
public String getKey() {
return this.key;
}
@Override
public String getValue() {
return this.value;
}
}
}