1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131

//! Export [flame] data to [speedscope]'s profile format.
//!
//! Base profile's are derived from top-level spans, so it's recommended to ensure that you have
//! an appropriately named span that encompasses the entire run of the program.
//!
//! [flame]: https://github.com/TyOverby/flame
//! [speedscope]: https://www.speedscope.app/

#[macro_use]
extern crate serde;

pub mod model;

use flame::Span;
use indexmap::IndexSet;
use model::*;
use std::io::Write;

/// Convert flame spans to the speedscope profile format.
pub fn spans_to_speedscope(spans: Vec<Span>) -> SpeedscopeFile {
    let mut frames = IndexSet::new();
    let profiles = spans
        .into_iter()
        .map(|span| Profile::Evented {
            name: span.name.clone(),
            unit: ValueUnit::Nanoseconds,
            start_value: span.start_ns,
            end_value: span.end_ns,
            events: {
                let mut events = Vec::new();
                span_extend_events(&mut frames, &mut events, span);
                events
            },
        })
        .collect();
    SpeedscopeFile {
        // always the same
        schema: "https://www.speedscope.app/file-format-schema.json",
        active_profile_index: None,
        exporter: None,
        name: None,
        profiles,
        shared: Shared {
            frames: frames.into_iter().collect(),
        },
    }
}

fn span_extend_events(frames: &mut IndexSet<Frame>, events: &mut Vec<Event>, span: Span) {
    let (frame, _) = frames.insert_full(Frame::new(span.name));
    events.push(Event {
        event_type: EventType::OpenFrame,
        at: span.start_ns,
        frame,
    });
    for child in span.children {
        span_extend_events(frames, events, child);
    }
    events.push(Event {
        event_type: EventType::CloseFrame,
        at: span.end_ns,
        frame,
    });
}

#[inline]
/// Dump flame spans to a writer, e.g. a file.
/// ```no_run
/// # use std::fs::File;
/// flamescope::dump(&mut File::create("flamescope.json").unwrap()).unwrap();
/// ```
pub fn dump(writer: impl Write) -> serde_json::Result<()> {
    write_spans(writer, flame::spans())
}

#[inline]
/// Dump flame spans to a writer, e.g. a file, specifying the spans you want to write.
/// ```no_run
/// # use std::fs::File;
/// flamescope::write_spans(
///     &mut File::create("flamescope.json").unwrap(),
///     // if you wanted only every other span, for some reason.
///     flame::spans()
///         .into_iter()
///         .enumerate()
///         .filter(|(i, _)| i % 2 == 0)
///         .map(|(_, span)| span)
///         .collect(),
/// ).unwrap();
/// ```
pub fn write_spans(writer: impl Write, spans: Vec<Span>) -> serde_json::Result<()> {
    let speedscope = spans_to_speedscope(spans);
    serde_json::to_writer(writer, &speedscope)
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test() {
        {
            let _guard = flame::start_guard("the main");
            {
                let _guard_two = flame::start_guard("foobar");
            }
        }
        let actual = spans_to_speedscope(flame::spans());
        match &actual.profiles[0] {
            Profile::Evented { name, events, .. } => {
                assert_eq!(name, "the main");
                assert_eq!(events[0].frame, 0);
                assert_eq!(events[0].event_type, EventType::OpenFrame);
                assert_eq!(events[1].frame, 0);
                assert_eq!(events[1].event_type, EventType::CloseFrame);
            }
            _ => unreachable!(),
        }
        assert_eq!(
            actual.shared,
            Shared {
                frames: vec![Frame {
                    name: "foobar".into(),
                    file: None,
                    line: None,
                    col: None,
                }]
            }
        );
    }
}