metrics/
lib.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
5use std::cell::Cell;
6use std::cmp::Ordering;
7use std::time::Duration;
8
9use base::cross_process_instant::CrossProcessInstant;
10use compositing_traits::largest_contentful_paint_candidate::LargestContentfulPaintType;
11use malloc_size_of_derive::MallocSizeOf;
12use profile_traits::time::{
13    ProfilerCategory, ProfilerChan, TimerMetadata, TimerMetadataFrameType, TimerMetadataReflowType,
14    send_profile_data,
15};
16use script_traits::ProgressiveWebMetricType;
17use servo_config::opts;
18use servo_url::ServoUrl;
19
20/// TODO make this configurable
21/// maximum task time is 50ms (in ns)
22pub const MAX_TASK_NS: u128 = 50000000;
23/// 10 second window
24const INTERACTIVE_WINDOW_SECONDS: Duration = Duration::from_secs(10);
25
26pub trait ToMs<T> {
27    fn to_ms(&self) -> T;
28}
29
30impl ToMs<f64> for u64 {
31    fn to_ms(&self) -> f64 {
32        *self as f64 / 1000000.
33    }
34}
35
36fn set_metric(
37    pwm: &ProgressiveWebMetrics,
38    metadata: Option<TimerMetadata>,
39    metric_type: ProgressiveWebMetricType,
40    category: ProfilerCategory,
41    attr: &Cell<Option<CrossProcessInstant>>,
42    metric_time: CrossProcessInstant,
43    url: &ServoUrl,
44) {
45    attr.set(Some(metric_time));
46
47    // Send the metric to the time profiler.
48    send_profile_data(
49        category,
50        metadata,
51        pwm.time_profiler_chan(),
52        metric_time,
53        metric_time,
54    );
55
56    // Print the metric to console if the print-pwm option was given.
57    if opts::get().print_pwm {
58        let navigation_start = pwm
59            .navigation_start()
60            .unwrap_or_else(CrossProcessInstant::epoch);
61        println!(
62            "{:?} {:?} {:?}",
63            url,
64            metric_type,
65            (metric_time - navigation_start).as_seconds_f64()
66        );
67    }
68}
69
70/// A data structure to track web metrics dfined in various specifications:
71///
72///  - <https://w3c.github.io/paint-timing/>
73///  - <https://github.com/WICG/time-to-interactive> / <https://github.com/GoogleChrome/lighthouse/issues/27>
74///
75///  We can look at three different metrics here:
76///    - navigation start -> visually ready (dom content loaded)
77///    - navigation start -> thread ready (main thread available)
78///    - visually ready -> thread ready
79#[derive(MallocSizeOf)]
80pub struct ProgressiveWebMetrics {
81    /// Whether or not this metric is for an `<iframe>` or a top level frame.
82    frame_type: TimerMetadataFrameType,
83    /// when we navigated to the page
84    navigation_start: Option<CrossProcessInstant>,
85    /// indicates if the page is visually ready
86    dom_content_loaded: Cell<Option<CrossProcessInstant>>,
87    /// main thread is available -- there's been a 10s window with no tasks longer than 50ms
88    main_thread_available: Cell<Option<CrossProcessInstant>>,
89    // max(main_thread_available, dom_content_loaded)
90    time_to_interactive: Cell<Option<CrossProcessInstant>>,
91    /// The first paint of a particular document.
92    /// TODO(mrobinson): It's unclear if this particular metric is reflected in the specification.
93    ///
94    /// See <https://w3c.github.io/paint-timing/#sec-reporting-paint-timing>.
95    first_paint: Cell<Option<CrossProcessInstant>>,
96    /// The first "contentful" paint of a particular document.
97    ///
98    /// See <https://w3c.github.io/paint-timing/#first-contentful-paint>
99    first_contentful_paint: Cell<Option<CrossProcessInstant>>,
100    /// The time at which the largest contentful paint was rendered.
101    ///
102    /// See <https://www.w3.org/TR/largest-contentful-paint/>
103    largest_contentful_paint: Cell<Option<CrossProcessInstant>>,
104    #[ignore_malloc_size_of = "can't measure channels"]
105    time_profiler_chan: ProfilerChan,
106    url: ServoUrl,
107}
108
109#[derive(Clone, Copy, Debug, MallocSizeOf)]
110pub struct InteractiveWindow {
111    start: CrossProcessInstant,
112}
113
114impl Default for InteractiveWindow {
115    fn default() -> Self {
116        Self {
117            start: CrossProcessInstant::now(),
118        }
119    }
120}
121
122impl InteractiveWindow {
123    // We need to either start or restart the 10s window
124    //   start: we've added a new document
125    //   restart: there was a task > 50ms
126    //   not all documents are interactive
127    pub fn start_window(&mut self) {
128        self.start = CrossProcessInstant::now();
129    }
130
131    /// check if 10s has elapsed since start
132    pub fn needs_check(&self) -> bool {
133        CrossProcessInstant::now() - self.start > INTERACTIVE_WINDOW_SECONDS
134    }
135
136    pub fn get_start(&self) -> CrossProcessInstant {
137        self.start
138    }
139}
140
141#[derive(Debug)]
142pub enum InteractiveFlag {
143    DOMContentLoaded,
144    TimeToInteractive(CrossProcessInstant),
145}
146
147impl ProgressiveWebMetrics {
148    pub fn new(
149        time_profiler_chan: ProfilerChan,
150        url: ServoUrl,
151        frame_type: TimerMetadataFrameType,
152    ) -> ProgressiveWebMetrics {
153        ProgressiveWebMetrics {
154            frame_type,
155            navigation_start: None,
156            dom_content_loaded: Cell::new(None),
157            main_thread_available: Cell::new(None),
158            time_to_interactive: Cell::new(None),
159            first_paint: Cell::new(None),
160            first_contentful_paint: Cell::new(None),
161            largest_contentful_paint: Cell::new(None),
162            time_profiler_chan,
163            url,
164        }
165    }
166
167    fn make_metadata(&self, first_reflow: bool) -> TimerMetadata {
168        TimerMetadata {
169            url: self.url.to_string(),
170            iframe: self.frame_type.clone(),
171            incremental: match first_reflow {
172                true => TimerMetadataReflowType::FirstReflow,
173                false => TimerMetadataReflowType::Incremental,
174            },
175        }
176    }
177
178    pub fn set_dom_content_loaded(&self) {
179        if self.dom_content_loaded.get().is_none() {
180            self.dom_content_loaded
181                .set(Some(CrossProcessInstant::now()));
182        }
183    }
184
185    pub fn set_main_thread_available(&self, time: CrossProcessInstant) {
186        if self.main_thread_available.get().is_none() {
187            self.main_thread_available.set(Some(time));
188        }
189    }
190
191    pub fn dom_content_loaded(&self) -> Option<CrossProcessInstant> {
192        self.dom_content_loaded.get()
193    }
194
195    pub fn first_paint(&self) -> Option<CrossProcessInstant> {
196        self.first_paint.get()
197    }
198
199    pub fn first_contentful_paint(&self) -> Option<CrossProcessInstant> {
200        self.first_contentful_paint.get()
201    }
202
203    pub fn largest_contentful_paint(&self) -> Option<CrossProcessInstant> {
204        self.largest_contentful_paint.get()
205    }
206
207    pub fn main_thread_available(&self) -> Option<CrossProcessInstant> {
208        self.main_thread_available.get()
209    }
210
211    pub fn set_first_paint(&self, paint_time: CrossProcessInstant, first_reflow: bool) {
212        set_metric(
213            self,
214            Some(self.make_metadata(first_reflow)),
215            ProgressiveWebMetricType::FirstPaint,
216            ProfilerCategory::TimeToFirstPaint,
217            &self.first_paint,
218            paint_time,
219            &self.url,
220        );
221    }
222
223    pub fn set_first_contentful_paint(&self, paint_time: CrossProcessInstant, first_reflow: bool) {
224        set_metric(
225            self,
226            Some(self.make_metadata(first_reflow)),
227            ProgressiveWebMetricType::FirstContentfulPaint,
228            ProfilerCategory::TimeToFirstContentfulPaint,
229            &self.first_contentful_paint,
230            paint_time,
231            &self.url,
232        );
233    }
234
235    pub fn set_largest_contentful_paint(
236        &self,
237        paint_time: CrossProcessInstant,
238        area: usize,
239        lcp_type: LargestContentfulPaintType,
240    ) {
241        set_metric(
242            self,
243            Some(self.make_metadata(false)),
244            ProgressiveWebMetricType::LargestContentfulPaint { area, lcp_type },
245            ProfilerCategory::TimeToLargestContentfulPaint,
246            &self.largest_contentful_paint,
247            paint_time,
248            &self.url,
249        );
250    }
251
252    // can set either dlc or tti first, but both must be set to actually calc metric
253    // when the second is set, set_tti is called with appropriate time
254    pub fn maybe_set_tti(&self, metric: InteractiveFlag) {
255        if self.get_tti().is_some() {
256            return;
257        }
258        match metric {
259            InteractiveFlag::DOMContentLoaded => self.set_dom_content_loaded(),
260            InteractiveFlag::TimeToInteractive(time) => self.set_main_thread_available(time),
261        }
262
263        let dcl = self.dom_content_loaded.get();
264        let mta = self.main_thread_available.get();
265        let (dcl, mta) = match (dcl, mta) {
266            (Some(dcl), Some(mta)) => (dcl, mta),
267            _ => return,
268        };
269        let metric_time = match dcl.partial_cmp(&mta) {
270            Some(Ordering::Less) => mta,
271            Some(_) => dcl,
272            None => panic!("no ordering possible. something bad happened"),
273        };
274        set_metric(
275            self,
276            Some(self.make_metadata(true)),
277            ProgressiveWebMetricType::TimeToInteractive,
278            ProfilerCategory::TimeToInteractive,
279            &self.time_to_interactive,
280            metric_time,
281            &self.url,
282        );
283    }
284
285    pub fn get_tti(&self) -> Option<CrossProcessInstant> {
286        self.time_to_interactive.get()
287    }
288
289    pub fn needs_tti(&self) -> bool {
290        self.get_tti().is_none()
291    }
292
293    pub fn navigation_start(&self) -> Option<CrossProcessInstant> {
294        self.navigation_start
295    }
296
297    pub fn set_navigation_start(&mut self, time: CrossProcessInstant) {
298        self.navigation_start = Some(time);
299    }
300
301    pub fn time_profiler_chan(&self) -> &ProfilerChan {
302        &self.time_profiler_chan
303    }
304}
305
306#[cfg(test)]
307mod test {
308    use super::*;
309
310    fn test_metrics() -> ProgressiveWebMetrics {
311        let (sender, _) = ipc_channel::ipc::channel().unwrap();
312        let profiler_chan = ProfilerChan(sender);
313        let mut metrics = ProgressiveWebMetrics::new(
314            profiler_chan,
315            ServoUrl::parse("about:blank").unwrap(),
316            TimerMetadataFrameType::RootWindow,
317        );
318
319        assert!((&metrics).navigation_start().is_none());
320        assert!(metrics.get_tti().is_none());
321        assert!(metrics.first_contentful_paint().is_none());
322        assert!(metrics.first_paint().is_none());
323
324        metrics.set_navigation_start(CrossProcessInstant::now());
325
326        metrics
327    }
328
329    #[test]
330    fn test_set_dcl() {
331        let metrics = test_metrics();
332        metrics.maybe_set_tti(InteractiveFlag::DOMContentLoaded);
333        let dcl = metrics.dom_content_loaded();
334        assert!(dcl.is_some());
335
336        // try to overwrite
337        metrics.maybe_set_tti(InteractiveFlag::DOMContentLoaded);
338        assert_eq!(metrics.dom_content_loaded(), dcl);
339        assert_eq!(metrics.get_tti(), None);
340    }
341
342    #[test]
343    fn test_set_mta() {
344        let metrics = test_metrics();
345        let now = CrossProcessInstant::now();
346        metrics.maybe_set_tti(InteractiveFlag::TimeToInteractive(now));
347        let main_thread_available_time = metrics.main_thread_available();
348        assert!(main_thread_available_time.is_some());
349        assert_eq!(main_thread_available_time, Some(now));
350
351        // try to overwrite
352        metrics.maybe_set_tti(InteractiveFlag::TimeToInteractive(
353            CrossProcessInstant::now(),
354        ));
355        assert_eq!(metrics.main_thread_available(), main_thread_available_time);
356        assert_eq!(metrics.get_tti(), None);
357    }
358
359    #[test]
360    fn test_set_tti_dcl() {
361        let metrics = test_metrics();
362        let now = CrossProcessInstant::now();
363        metrics.maybe_set_tti(InteractiveFlag::TimeToInteractive(now));
364        let main_thread_available_time = metrics.main_thread_available();
365        assert!(main_thread_available_time.is_some());
366
367        metrics.maybe_set_tti(InteractiveFlag::DOMContentLoaded);
368        let dom_content_loaded_time = metrics.dom_content_loaded();
369        assert!(dom_content_loaded_time.is_some());
370
371        assert_eq!(metrics.get_tti(), dom_content_loaded_time);
372    }
373
374    #[test]
375    fn test_set_tti_mta() {
376        let metrics = test_metrics();
377        metrics.maybe_set_tti(InteractiveFlag::DOMContentLoaded);
378        let dcl = metrics.dom_content_loaded();
379        assert!(dcl.is_some());
380
381        let time = CrossProcessInstant::now();
382        metrics.maybe_set_tti(InteractiveFlag::TimeToInteractive(time));
383        let mta = metrics.main_thread_available();
384        assert!(mta.is_some());
385
386        assert_eq!(metrics.get_tti(), mta);
387    }
388
389    #[test]
390    fn test_first_paint_setter() {
391        let metrics = test_metrics();
392        metrics.set_first_paint(CrossProcessInstant::now(), false);
393        assert!(metrics.first_paint().is_some());
394    }
395
396    #[test]
397    fn test_first_contentful_paint_setter() {
398        let metrics = test_metrics();
399        metrics.set_first_contentful_paint(CrossProcessInstant::now(), false);
400        assert!(metrics.first_contentful_paint().is_some());
401    }
402}
metrics/lib.rs

metrics/
lib.rs
