jfrs

Java Flight Recorder reader for Rust

Features

Read events (low-level API)

```rust fn main() { let mut reader = JfrReader::new(File::open("/path/to/recording.jfr").unwrap());

for (reader, chunk) in reader.chunks().flatten() {
    for event in reader.events(&chunk).filter(|e| e.class.name() == "jdk.ExecutionSample") {
        let thread_name = event.value
            .get_field("sampledThread", &chunk)
            .and_then(|f| f.get_field("osName", &chunk))
            .and_then(|v| match v {
                ValueDescriptor::Primitive(Primitive::String(s)) => Some(s),
                _ => None,
            })
            .unwrap();
        println!("sampled thread: {}", thread_name);
    }
}

} ```

[Experimental] Deserialize events as Rust struct

NOTE As of now, deserialization performance is very poor. See tuning_notes.md for the details.

Though low-level API provides full functionality to interpret the events as you need, usually we want to map known JFR events to the Rust structure.

jfrs also provides serde-rs based deserialization feature.

```rust fn main() { let mut reader = JfrReader::new(File::open("/path/to/recording.jfr").unwrap());

for (reader, chunk) in reader.chunks().flatten() {
    for event in reader.events(&chunk).filter(|e| e.class.name() == "jdk.ExecutionSample") {
        let sample: ExecutionSample = from_event(&chunk, &event).unwrap();
        println!("sampled thread: {}", sample.sampled_thread.and_then(|t| t.os_name).unwrap());
    }
}

} ```