org.gridkit.jvmtool.jfr_jdk.parser.JsonEventAdapter Maven / Gradle / Ivy

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Java Flight Recorder Integration for SJK (Mission Control 6)
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package org.gridkit.jvmtool.jfr_jdk.parser;

import java.io.IOException;
import java.time.Instant;
import java.util.Collection;
import java.util.HashSet;
import java.util.Set;
import java.util.concurrent.TimeUnit;

import org.gridkit.jvmtool.util.json.JsonStreamWriter;

import jdk.jfr.ValueDescriptor;
import jdk.jfr.consumer.RecordedClass;
import jdk.jfr.consumer.RecordedEvent;
import jdk.jfr.consumer.RecordedMethod;
import jdk.jfr.consumer.RecordedObject;

public class JsonEventAdapter {

	private final int depthThreshold;
	private Set whiteList;
	private Set blackList;
	
	public JsonEventAdapter() {
		this(Integer.MAX_VALUE);
	}
	
	public JsonEventAdapter(int jsonMaxDepth) {
		this.depthThreshold = jsonMaxDepth;
	}
	
	public void setWhiteList(Collection events) {
		whiteList = new HashSet(events);
	}

	public void setBlackList(Collection events) {
		blackList = new HashSet(events);
	}

	public void encodeEvent(RecordedEvent event, JsonStreamWriter writer) throws IOException {
		writer.writeStartObject();
		try {
			String eventType = event.getEventType().getName();
			if (shouldOutput(eventType)) {
				writer.writeStringField("eventType", event.getEventType().getName());
				encodeObject(event, writer, 0);
			}
		}
		finally {
			writer.writeEndObject();
		}
	}

	private boolean shouldOutput(String eventType) {
		if (whiteList != null && !whiteList.contains(eventType)) {
			return false;
		}
		if (blackList != null && blackList.contains(eventType)) {
			return false;
		}
		return true;
	}

	private void encodeObject(RecordedObject obj, JsonStreamWriter writer, int depth) throws IOException {
		if (obj instanceof RecordedMethod) {
			// actual method representation is too verbose
			RecordedMethod rm = (RecordedMethod) obj;
			String mclass = rm.getType().getName();
			String mmethod = rm.getName();
			writer.writeStringField("class", mclass);
			writer.writeStringField("method", mmethod);
			writer.writeBooleanField("hidden", rm.isHidden());
		}
		else {
			
			if (obj instanceof RecordedClass) {
				RecordedClass rc = (RecordedClass) obj;
				
				writer.writeStringField("className", rc.getName());
				return; // skip class details so far
			}
			
			for(ValueDescriptor vd: obj.getFields()) {
				String name = vd.getName();
				Object val = obj.getValue(name);
				if (obj instanceof RecordedEvent) {
					// use Instant for timestamps
					if ("startTime".equals(name)) {
						val = ((RecordedEvent) obj).getStartTime();
					}
					else if ("endTime".equals(name)) {
						val = ((RecordedEvent) obj).getEndTime();
					}
				}
				if (val instanceof Object[]) {
					writer.writeFieldName(name);
					writer.writeStartArray();
					try {
						for(Object e: (Object[])val) {
							if (e instanceof RecordedObject) {
								if (depth < depthThreshold) {									
									writer.writeStartObject();
									try {
										encodeObject((RecordedObject) e, writer, depth + 1);
									}
									finally {
										writer.writeEndObject();
									}
								}
								else {
									writer.writeString("(JSON depth exceeded!)");
								}
							}
							else {
								encodeValue(e, writer);
							}
						}					
					}
					finally {
						writer.writeEndArray();
					}
				}
				else if (val instanceof RecordedObject) {
					writer.writeFieldName(name);
					if (depth < depthThreshold) {
						writer.writeStartObject();
						try {
							encodeObject((RecordedObject)val, writer, depth + 1);
						}
						finally {
							writer.writeEndObject();
						}
					}
					else {
						writer.writeString("(JSON depth exceeded!)");
					}
				}
				else {
					writer.writeFieldName(name);
					encodeValue(val, writer);
				}
			}
		}
	}
	
	private void encodeValue(Object val, JsonStreamWriter writer) throws IOException {
		if (val == null) {
			writer.writeNull();
		}
		else if (val instanceof Float || val instanceof Double) {
			writer.writeNumber(((Number)val).doubleValue());
		}
		else if (val instanceof Character) {
			writer.writeString(val.toString());
		}
		else if (val instanceof Number) {
			writer.writeNumber(((Number) val).longValue());
		}
		else if (val instanceof Boolean) {
			writer.writeBoolean(Boolean.TRUE.equals(val));
		}
		else if (val instanceof Instant) {
			long epochNs = TimeUnit.SECONDS.toNanos(((Instant) val).getEpochSecond());
			epochNs += ((Instant) val).getNano();
			writer.writeNumber(epochNs);
		}
		else {
			writer.writeString(val.toString());
		}
	}
}