├── .gitignore
├── README.md
├── src
    └── main
    │   └── java
    │       └── com
    │           └── wilb0t
    │               └── flamegraph
    │                   ├── JfrStackTraceWriter.java
    │                   ├── JfrToFolded.java
    │                   └── JfrStackTraceReader.java
└── pom.xml


/.gitignore:
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 1 | target/
 2 | ## IntelliJ
 3 | .idea
 4 | *.iml
 5 | 
 6 | ## Temp
 7 | dependency-reduced-pom.xml
 8 | 
 9 | .DS_Store
10 | 


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/README.md:
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 1 | # flame-graph-jfr
 2 | 
 3 | Convert java 11 JFR to folded format for https://github.com/brendangregg/FlameGraph
 4 | 
 5 | ## Usage
 6 | 
 7 | Requires java 11 jdk or higher.
 8 | 
 9 | `mvn clean package`
10 | 
11 | `java -jar target/flame-graph-1.0-SNAPSHOT-shaded.jar -i some-j11-flight-recorder.flr -o output.fld`
12 | 
13 | Clone https://github.com/brendangregg/FlameGraph
14 | 
15 | In FlameGraph dir
16 | 
17 | `./flamegraph.pl <some path>/output.fld > flamegraph.svg`
18 | 
19 | Open flamegraph.svg in your browser to explore!
20 | 
21 | Should see something like
22 | [![Example](http://www.brendangregg.com/FlameGraphs/cpu-bash-flamegraph.svg)](http://www.brendangregg.com/FlameGraphs/cpu-bash-flamegraph.svg)
23 | 


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/src/main/java/com/wilb0t/flamegraph/JfrStackTraceWriter.java:
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 1 | package com.wilb0t.flamegraph;
 2 | 
 3 | import java.io.BufferedWriter;
 4 | import java.io.File;
 5 | import java.io.FileWriter;
 6 | import java.io.IOException;
 7 | import java.io.Writer;
 8 | import java.nio.charset.StandardCharsets;
 9 | import java.util.Map;
10 | 
11 | public class JfrStackTraceWriter {
12 | 
13 |   public void write(File outputFile, Map<String, Long> traceCounts) throws IOException {
14 |     try (Writer writer = new FileWriter(outputFile, StandardCharsets.UTF_8);
15 |          BufferedWriter bufferedWriter = new BufferedWriter(writer)
16 |     ) {
17 |       traceCounts.forEach(
18 |           (trace, count) ->
19 |           {
20 |             try {
21 |               bufferedWriter.write(String.format("%s %d%n", trace, count));
22 |             } catch (IOException e) {
23 |               throw new RuntimeException(e);
24 |             }
25 |           }
26 |       );
27 |     }
28 |   }
29 | }
30 | 


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/src/main/java/com/wilb0t/flamegraph/JfrToFolded.java:
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 1 | package com.wilb0t.flamegraph;
 2 | 
 3 | import java.io.File;
 4 | import java.io.IOException;
 5 | import java.util.HashMap;
 6 | import java.util.List;
 7 | import java.util.Map;
 8 | 
 9 | public class JfrToFolded {
10 | 
11 |   public static void main(String[] args) {
12 |     try {
13 |       var processedArgs = processArgs(args);
14 |       if (!processedArgs.keySet().containsAll(List.of("-o", "-i"))) {
15 |         throw new IllegalArgumentException("Must pass -i <input file> -o <output file>");
16 |       }
17 | 
18 |       var jfr = new File(processedArgs.get("-i"));
19 |       var folded = new File(processedArgs.get("-o"));
20 | 
21 |       jfrToFolded(jfr, folded);
22 |     } catch (IOException e) {
23 |       System.err.println(e.getMessage());
24 |       throw new RuntimeException(e);
25 |     }
26 |   }
27 | 
28 |   private static void jfrToFolded(File jfr, File folded) throws IOException {
29 |     var reader = new JfrStackTraceReader();
30 |     var writer = new JfrStackTraceWriter();
31 | 
32 |     var traceCounts = reader.getStackTraces(jfr.toPath());
33 |     writer.write(folded, traceCounts);
34 |   }
35 | 
36 |   static Map<String, String> processArgs(String[] args) {
37 |     var processed = new HashMap<String, String>();
38 |     for (int i = 0; i <= args.length - 2; i += 2) {
39 |       processed.put(args[i], args[i+1]);
40 |     }
41 |     return processed;
42 |   }
43 | }
44 | 


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/pom.xml:
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 1 | <?xml version="1.0" encoding="UTF-8"?>
 2 | <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 3 |   <modelVersion>4.0.0</modelVersion>
 4 | 
 5 |   <groupId>com.wilb0t</groupId>
 6 |   <name>flame-graph-jfr</name>
 7 |   <artifactId>flame-graph-jfr</artifactId>
 8 |   <version>1.0-SNAPSHOT</version>
 9 |   <packaging>jar</packaging>
10 | 
11 |   <properties>
12 |     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
13 |   </properties>
14 | 
15 |   <dependencies>
16 |     <!-- compile scope -->
17 | 
18 |     <!-- test scope -->
19 |     <dependency>
20 |       <groupId>org.junit.jupiter</groupId>
21 |       <artifactId>junit-jupiter-api</artifactId>
22 |       <version>5.4.0</version>
23 |       <scope>test</scope>
24 |     </dependency>
25 |     <dependency>
26 |       <groupId>org.junit.jupiter</groupId>
27 |       <artifactId>junit-jupiter-engine</artifactId>
28 |       <version>5.4.0</version>
29 |       <scope>test</scope>
30 |     </dependency>
31 |     <dependency>
32 |       <groupId>org.hamcrest</groupId>
33 |       <artifactId>java-hamcrest</artifactId>
34 |       <version>2.0.0.0</version>
35 |       <scope>test</scope>
36 |     </dependency>
37 |   </dependencies>
38 | 
39 |   <build>
40 |     <plugins>
41 |       <plugin>
42 |         <groupId>org.apache.maven.plugins</groupId>
43 |         <artifactId>maven-compiler-plugin</artifactId>
44 |         <version>3.8.1</version>
45 |         <configuration>
46 |           <release>11</release>
47 |         </configuration>
48 |       </plugin>
49 |       <plugin>
50 |         <groupId>org.apache.maven.plugins</groupId>
51 |         <artifactId>maven-shade-plugin</artifactId>
52 |         <version>3.2.1</version>
53 |         <executions>
54 |           <execution>
55 |             <goals>
56 |               <goal>shade</goal>
57 |             </goals>
58 |             <configuration>
59 |               <shadedArtifactAttached>true</shadedArtifactAttached>
60 |               <transformers>
61 |                 <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
62 |                   <mainClass>com.wilb0t.flamegraph.JfrToFolded</mainClass>
63 |                 </transformer>
64 |               </transformers>
65 |             </configuration>
66 |           </execution>
67 |         </executions>
68 |       </plugin>
69 |     </plugins>
70 |   </build>
71 | </project>
72 | 


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/src/main/java/com/wilb0t/flamegraph/JfrStackTraceReader.java:
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 1 | package com.wilb0t.flamegraph;
 2 | 
 3 | import static java.util.stream.Collectors.summingLong;
 4 | 
 5 | import java.io.IOException;
 6 | import java.nio.file.Path;
 7 | import java.util.Collections;
 8 | import java.util.Map;
 9 | import java.util.function.Function;
10 | import java.util.stream.Collectors;
11 | import java.util.stream.Stream;
12 | import jdk.jfr.consumer.RecordedEvent;
13 | import jdk.jfr.consumer.RecordedFrame;
14 | import jdk.jfr.consumer.RecordedMethod;
15 | import jdk.jfr.consumer.RecordedStackTrace;
16 | import jdk.jfr.consumer.RecordingFile;
17 | 
18 | public class JfrStackTraceReader {
19 | 
20 |   private static final String EVENT_TYPE = "jdk.ExecutionSample";
21 | 
22 |   public Map<String, Long> getStackTraces(Path input) throws IOException {
23 |     try (var recording = new RecordingFile(input)) {
24 |       return asStream(recording)
25 |           .filter(event -> event.getEventType().getName().equalsIgnoreCase(EVENT_TYPE))
26 |           .map(JfrStackTraceReader::getTrace)
27 |           .collect(Collectors.groupingBy(Function.identity(), summingLong(s -> 1)));
28 |     }
29 |   }
30 | 
31 |   private static Stream<RecordedEvent> asStream(RecordingFile recording) throws IOException {
32 |     if (recording.hasMoreEvents()) {
33 |       RecordedEvent event = recording.readEvent();
34 |       return Stream.iterate(
35 |           event,
36 |           e -> recording.hasMoreEvents(),
37 |           e -> {
38 |             try {
39 |               return recording.readEvent();
40 |             } catch (IOException ex) {
41 |               throw new RuntimeException(ex);
42 |             }
43 |           });
44 |     }
45 |     return Stream.empty();
46 |   }
47 | 
48 |   private static String getTrace(RecordedEvent event) {
49 |     RecordedStackTrace trace = event.getStackTrace();
50 |     if (trace == null) {
51 |       return "";
52 |     }
53 |     var frames = trace.getFrames().stream()
54 |         .filter(RecordedFrame::isJavaFrame)
55 |         .flatMap(JfrStackTraceReader::getFrameName)
56 |         .collect(Collectors.toList());
57 |     Collections.reverse(frames);
58 | 
59 |     return String.join(";", frames);
60 |   }
61 | 
62 |   private static Stream<String> getFrameName(RecordedFrame frame) {
63 |     StringBuilder methodBuilder = new StringBuilder();
64 |     RecordedMethod method = frame.getMethod();
65 |     if (method == null) {
66 |       return Stream.empty();
67 |     }
68 | 
69 |     methodBuilder
70 |         .append(method.getType().getName())
71 |         .append("::")
72 |         .append(method.getName());
73 | 
74 |     return Stream.of(methodBuilder.toString());
75 |   }
76 | 
77 | }
78 | 


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