profile/
trace_dump.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
4
5//! A module for writing time profiler traces out to a self contained HTML file.
6
7use std::io::{self, Write};
8use std::{fs, path};
9
10use base::cross_process_instant::CrossProcessInstant;
11use profile_traits::time::{ProfilerCategory, TimerMetadata};
12use serde::Serialize;
13
14/// An RAII class for writing the HTML trace dump.
15#[derive(Debug)]
16pub struct TraceDump {
17    file: fs::File,
18}
19
20#[derive(Debug, Serialize)]
21struct TraceEntry {
22    category: ProfilerCategory,
23    metadata: Option<TimerMetadata>,
24
25    #[serde(rename = "startTime")]
26    start_time: u64,
27
28    #[serde(rename = "endTime")]
29    end_time: u64,
30}
31
32impl TraceDump {
33    /// Create a new TraceDump and write the prologue of the HTML file out to
34    /// disk.
35    pub fn new<P>(trace_file_path: P) -> io::Result<TraceDump>
36    where
37        P: AsRef<path::Path>,
38    {
39        let mut file = fs::File::create(trace_file_path)?;
40        write_prologue(&mut file)?;
41        Ok(TraceDump { file })
42    }
43
44    /// Write one trace to the trace dump file.
45    pub fn write_one(
46        &mut self,
47        category: &(ProfilerCategory, Option<TimerMetadata>),
48        start_time: CrossProcessInstant,
49        end_time: CrossProcessInstant,
50    ) {
51        let entry = TraceEntry {
52            category: category.0,
53            metadata: category.1.clone(),
54            start_time: (start_time - CrossProcessInstant::epoch()).whole_nanoseconds() as u64,
55            end_time: (end_time - CrossProcessInstant::epoch()).whole_nanoseconds() as u64,
56        };
57        serde_json::to_writer(&mut self.file, &entry).unwrap();
58        writeln!(&mut self.file, ",").unwrap();
59    }
60}
61
62impl Drop for TraceDump {
63    /// Write the epilogue of the trace dump HTML file out to disk on
64    /// destruction.
65    fn drop(&mut self) {
66        write_epilogue(&mut self.file).unwrap();
67    }
68}
69
70fn write_prologue(file: &mut fs::File) -> io::Result<()> {
71    writeln!(file, "{}", include_str!("./trace-dump-prologue-1.html"))?;
72    writeln!(file, "{}", include_str!("./trace-dump.css"))?;
73    writeln!(file, "{}", include_str!("./trace-dump-prologue-2.html"))
74}
75
76fn write_epilogue(file: &mut fs::File) -> io::Result<()> {
77    writeln!(file, "{}", include_str!("./trace-dump-epilogue-1.html"))?;
78    writeln!(file, "{}", include_str!("./trace-dump.js"))?;
79    writeln!(file, "{}", include_str!("./trace-dump-epilogue-2.html"))
80}
profile/trace_dump.rs

profile/
trace_dump.rs
