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
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */

use crate::dom::bindings::cell::DomRefCell;
use crate::dom::bindings::codegen::Bindings::PerformanceBinding::PerformanceEntryList as DOMPerformanceEntryList;
use crate::dom::bindings::codegen::Bindings::PerformanceBinding::{
    DOMHighResTimeStamp, PerformanceMethods,
};
use crate::dom::bindings::error::{Error, Fallible};
use crate::dom::bindings::inheritance::Castable;
use crate::dom::bindings::num::Finite;
use crate::dom::bindings::reflector::{reflect_dom_object, DomObject};
use crate::dom::bindings::root::DomRoot;
use crate::dom::bindings::str::DOMString;
use crate::dom::eventtarget::EventTarget;
use crate::dom::globalscope::GlobalScope;
use crate::dom::performanceentry::PerformanceEntry;
use crate::dom::performancemark::PerformanceMark;
use crate::dom::performancemeasure::PerformanceMeasure;
use crate::dom::performancenavigation::PerformanceNavigation;
use crate::dom::performancenavigationtiming::PerformanceNavigationTiming;
use crate::dom::performanceobserver::PerformanceObserver as DOMPerformanceObserver;
use crate::dom::window::Window;
use dom_struct::dom_struct;
use metrics::ToMs;
use std::cell::Cell;
use std::cmp::Ordering;
use std::collections::VecDeque;

const INVALID_ENTRY_NAMES: &'static [&'static str] = &[
    "navigationStart",
    "unloadEventStart",
    "unloadEventEnd",
    "redirectStart",
    "redirectEnd",
    "fetchStart",
    "domainLookupStart",
    "domainLookupEnd",
    "connectStart",
    "connectEnd",
    "secureConnectionStart",
    "requestStart",
    "responseStart",
    "responseEnd",
    "domLoading",
    "domInteractive",
    "domContentLoadedEventStart",
    "domContentLoadedEventEnd",
    "domComplete",
    "loadEventStart",
    "loadEventEnd",
];

/// Implementation of a list of PerformanceEntry items shared by the
/// Performance and PerformanceObserverEntryList interfaces implementations.
#[derive(JSTraceable, MallocSizeOf)]
pub struct PerformanceEntryList {
    /// https://w3c.github.io/performance-timeline/#dfn-performance-entry-buffer
    entries: DOMPerformanceEntryList,
}

impl PerformanceEntryList {
    pub fn new(entries: DOMPerformanceEntryList) -> Self {
        PerformanceEntryList { entries }
    }

    pub fn get_entries_by_name_and_type(
        &self,
        name: Option<DOMString>,
        entry_type: Option<DOMString>,
    ) -> Vec<DomRoot<PerformanceEntry>> {
        let mut res = self
            .entries
            .iter()
            .filter(|e| {
                name.as_ref().map_or(true, |name_| *e.name() == *name_) &&
                    entry_type
                        .as_ref()
                        .map_or(true, |type_| *e.entry_type() == *type_)
            })
            .map(|e| e.clone())
            .collect::<Vec<DomRoot<PerformanceEntry>>>();
        res.sort_by(|a, b| {
            a.start_time()
                .partial_cmp(&b.start_time())
                .unwrap_or(Ordering::Equal)
        });
        res
    }

    pub fn clear_entries_by_name_and_type(
        &mut self,
        name: Option<DOMString>,
        entry_type: Option<DOMString>,
    ) {
        self.entries.retain(|e| {
            name.as_ref().map_or(true, |name_| *e.name() != *name_) &&
                entry_type
                    .as_ref()
                    .map_or(true, |type_| *e.entry_type() != *type_)
        });
    }

    fn get_last_entry_start_time_with_name_and_type(
        &self,
        name: DOMString,
        entry_type: DOMString,
    ) -> f64 {
        match self
            .entries
            .iter()
            .rev()
            .find(|e| *e.entry_type() == *entry_type && *e.name() == *name)
        {
            Some(entry) => entry.start_time(),
            None => 0.,
        }
    }
}

impl IntoIterator for PerformanceEntryList {
    type Item = DomRoot<PerformanceEntry>;
    type IntoIter = ::std::vec::IntoIter<DomRoot<PerformanceEntry>>;

    fn into_iter(self) -> Self::IntoIter {
        self.entries.into_iter()
    }
}

#[derive(JSTraceable, MallocSizeOf)]
struct PerformanceObserver {
    observer: DomRoot<DOMPerformanceObserver>,
    entry_types: Vec<DOMString>,
}

#[dom_struct]
pub struct Performance {
    eventtarget: EventTarget,
    buffer: DomRefCell<PerformanceEntryList>,
    observers: DomRefCell<Vec<PerformanceObserver>>,
    pending_notification_observers_task: Cell<bool>,
    navigation_start_precise: u64,
    /// https://w3c.github.io/performance-timeline/#dfn-maxbuffersize
    /// The max-size of the buffer, set to 0 once the pipeline exits.
    /// TODO: have one max-size per entry type.
    resource_timing_buffer_size_limit: Cell<usize>,
    resource_timing_buffer_current_size: Cell<usize>,
    resource_timing_buffer_pending_full_event: Cell<bool>,
    resource_timing_secondary_entries: DomRefCell<VecDeque<DomRoot<PerformanceEntry>>>,
}

impl Performance {
    fn new_inherited(navigation_start_precise: u64) -> Performance {
        Performance {
            eventtarget: EventTarget::new_inherited(),
            buffer: DomRefCell::new(PerformanceEntryList::new(Vec::new())),
            observers: DomRefCell::new(Vec::new()),
            pending_notification_observers_task: Cell::new(false),
            navigation_start_precise,
            resource_timing_buffer_size_limit: Cell::new(250),
            resource_timing_buffer_current_size: Cell::new(0),
            resource_timing_buffer_pending_full_event: Cell::new(false),
            resource_timing_secondary_entries: DomRefCell::new(VecDeque::new()),
        }
    }

    pub fn new(global: &GlobalScope, navigation_start_precise: u64) -> DomRoot<Performance> {
        reflect_dom_object(
            Box::new(Performance::new_inherited(navigation_start_precise)),
            global,
        )
    }

    /// Clear all buffered performance entries, and disable the buffer.
    /// Called as part of the window's "clear_js_runtime" workflow,
    /// performed when exiting a pipeline.
    pub fn clear_and_disable_performance_entry_buffer(&self) {
        let mut buffer = self.buffer.borrow_mut();
        buffer.entries.clear();
        self.resource_timing_buffer_size_limit.set(0);
    }

    /// Add a PerformanceObserver to the list of observers with a set of
    /// observed entry types.

    pub fn add_multiple_type_observer(
        &self,
        observer: &DOMPerformanceObserver,
        entry_types: Vec<DOMString>,
    ) {
        let mut observers = self.observers.borrow_mut();
        match observers.iter().position(|o| *o.observer == *observer) {
            // If the observer is already in the list, we only update the observed
            // entry types.
            Some(p) => observers[p].entry_types = entry_types,
            // Otherwise, we create and insert the new PerformanceObserver.
            None => observers.push(PerformanceObserver {
                observer: DomRoot::from_ref(observer),
                entry_types,
            }),
        };
    }

    pub fn add_single_type_observer(
        &self,
        observer: &DOMPerformanceObserver,
        entry_type: &DOMString,
        buffered: bool,
    ) {
        if buffered {
            let buffer = self.buffer.borrow();
            let mut new_entries =
                buffer.get_entries_by_name_and_type(None, Some(entry_type.clone()));
            if new_entries.len() > 0 {
                let mut obs_entries = observer.entries();
                obs_entries.append(&mut new_entries);
                observer.set_entries(obs_entries);
            }

            if !self.pending_notification_observers_task.get() {
                self.pending_notification_observers_task.set(true);
                let task_source = self.global().performance_timeline_task_source();
                task_source.queue_notification(&self.global());
            }
        }
        let mut observers = self.observers.borrow_mut();
        match observers.iter().position(|o| *o.observer == *observer) {
            // If the observer is already in the list, we only update
            // the observed entry types.
            Some(p) => {
                // Append the type if not already present, otherwise do nothing
                if !observers[p].entry_types.contains(entry_type) {
                    observers[p].entry_types.push(entry_type.clone())
                }
            },
            // Otherwise, we create and insert the new PerformanceObserver.
            None => observers.push(PerformanceObserver {
                observer: DomRoot::from_ref(observer),
                entry_types: vec![entry_type.clone()],
            }),
        };
    }

    /// Remove a PerformanceObserver from the list of observers.
    pub fn remove_observer(&self, observer: &DOMPerformanceObserver) {
        let mut observers = self.observers.borrow_mut();
        let index = match observers.iter().position(|o| &(*o.observer) == observer) {
            Some(p) => p,
            None => return,
        };

        observers.remove(index);
    }

    /// Queue a notification for each performance observer interested in
    /// this type of performance entry and queue a low priority task to
    /// notify the observers if no other notification task is already queued.
    ///
    /// Algorithm spec:
    /// <https://w3c.github.io/performance-timeline/#queue-a-performanceentry>
    /// Also this algorithm has been extented according to :
    /// <https://w3c.github.io/resource-timing/#sec-extensions-performance-interface>
    pub fn queue_entry(&self, entry: &PerformanceEntry) -> Option<usize> {
        // https://w3c.github.io/performance-timeline/#dfn-determine-eligibility-for-adding-a-performance-entry
        if entry.entry_type() == "resource" && !self.should_queue_resource_entry(entry) {
            return None;
        }

        // Steps 1-3.
        // Add the performance entry to the list of performance entries that have not
        // been notified to each performance observer owner, filtering the ones it's
        // interested in.
        for o in self
            .observers
            .borrow()
            .iter()
            .filter(|o| o.entry_types.contains(entry.entry_type()))
        {
            o.observer.queue_entry(entry);
        }

        // Step 4.
        //add the new entry to the buffer.
        self.buffer
            .borrow_mut()
            .entries
            .push(DomRoot::from_ref(entry));

        let entry_last_index = self.buffer.borrow_mut().entries.len() - 1;

        // Step 5.
        // If there is already a queued notification task, we just bail out.
        if self.pending_notification_observers_task.get() {
            return None;
        }

        // Step 6.
        // Queue a new notification task.
        self.pending_notification_observers_task.set(true);
        let task_source = self.global().performance_timeline_task_source();
        task_source.queue_notification(&self.global());

        Some(entry_last_index)
    }

    /// Observers notifications task.
    ///
    /// Algorithm spec (step 7):
    /// <https://w3c.github.io/performance-timeline/#queue-a-performanceentry>
    pub fn notify_observers(&self) {
        // Step 7.1.
        self.pending_notification_observers_task.set(false);

        // Step 7.2.
        // We have to operate over a copy of the performance observers to avoid
        // the risk of an observer's callback modifying the list of registered
        // observers. This is a shallow copy, so observers can
        // disconnect themselves by using the argument of their own callback.
        let observers: Vec<DomRoot<DOMPerformanceObserver>> = self
            .observers
            .borrow()
            .iter()
            .map(|o| DomRoot::from_ref(&*o.observer))
            .collect();

        // Step 7.3.
        for o in observers.iter() {
            o.notify();
        }
    }

    fn now(&self) -> f64 {
        (time::precise_time_ns() - self.navigation_start_precise).to_ms()
    }

    fn can_add_resource_timing_entry(&self) -> bool {
        self.resource_timing_buffer_current_size.get() <=
            self.resource_timing_buffer_size_limit.get()
    }
    fn copy_secondary_resource_timing_buffer(&self) {
        while self.can_add_resource_timing_entry() {
            let entry = self
                .resource_timing_secondary_entries
                .borrow_mut()
                .pop_front();
            if let Some(ref entry) = entry {
                self.queue_entry(entry);
            } else {
                break;
            }
        }
    }
    // `fire a buffer full event` paragraph of
    // https://w3c.github.io/resource-timing/#sec-extensions-performance-interface
    fn fire_buffer_full_event(&self) {
        while !self.resource_timing_secondary_entries.borrow().is_empty() {
            let no_of_excess_entries_before = self.resource_timing_secondary_entries.borrow().len();

            if !self.can_add_resource_timing_entry() {
                self.upcast::<EventTarget>()
                    .fire_event(atom!("resourcetimingbufferfull"));
            }
            self.copy_secondary_resource_timing_buffer();
            let no_of_excess_entries_after = self.resource_timing_secondary_entries.borrow().len();
            if no_of_excess_entries_before <= no_of_excess_entries_after {
                self.resource_timing_secondary_entries.borrow_mut().clear();
                break;
            }
        }
        self.resource_timing_buffer_pending_full_event.set(false);
    }
    /// `add a PerformanceResourceTiming entry` paragraph of
    /// https://w3c.github.io/resource-timing/#sec-extensions-performance-interface
    fn should_queue_resource_entry(&self, entry: &PerformanceEntry) -> bool {
        // Step 1 is done in the args list.
        if !self.resource_timing_buffer_pending_full_event.get() {
            // Step 2.
            if self.can_add_resource_timing_entry() {
                // Step 2.a is done in `queue_entry`
                // Step 2.b.
                self.resource_timing_buffer_current_size
                    .set(self.resource_timing_buffer_current_size.get() + 1);
                // Step 2.c.
                return true;
            }
            // Step 3.
            self.resource_timing_buffer_pending_full_event.set(true);
            self.fire_buffer_full_event();
        }
        // Steps 4 and 5.
        self.resource_timing_secondary_entries
            .borrow_mut()
            .push_back(DomRoot::from_ref(entry));
        false
    }

    pub fn update_entry(&self, index: usize, entry: &PerformanceEntry) {
        if let Some(e) = self.buffer.borrow_mut().entries.get_mut(index) {
            *e = DomRoot::from_ref(entry);
        }
    }
}

impl PerformanceMethods for Performance {
    // FIXME(avada): this should be deprecated in the future, but some sites still use it
    // https://dvcs.w3.org/hg/webperf/raw-file/tip/specs/NavigationTiming/Overview.html#performance-timing-attribute
    fn Timing(&self) -> DomRoot<PerformanceNavigationTiming> {
        let entries = self.GetEntriesByType(DOMString::from("navigation"));
        if entries.len() > 0 {
            return DomRoot::from_ref(
                entries[0]
                    .downcast::<PerformanceNavigationTiming>()
                    .unwrap(),
            );
        }
        unreachable!("Are we trying to expose Performance.timing in workers?");
    }

    // https://w3c.github.io/navigation-timing/#dom-performance-navigation
    fn Navigation(&self) -> DomRoot<PerformanceNavigation> {
        PerformanceNavigation::new(&self.global())
    }

    // https://dvcs.w3.org/hg/webperf/raw-file/tip/specs/HighResolutionTime/Overview.html#dom-performance-now
    fn Now(&self) -> DOMHighResTimeStamp {
        reduce_timing_resolution(self.now())
    }

    // https://www.w3.org/TR/hr-time-2/#dom-performance-timeorigin
    fn TimeOrigin(&self) -> DOMHighResTimeStamp {
        reduce_timing_resolution(self.navigation_start_precise as f64)
    }

    // https://www.w3.org/TR/performance-timeline-2/#dom-performance-getentries
    fn GetEntries(&self) -> Vec<DomRoot<PerformanceEntry>> {
        self.buffer
            .borrow()
            .get_entries_by_name_and_type(None, None)
    }

    // https://www.w3.org/TR/performance-timeline-2/#dom-performance-getentriesbytype
    fn GetEntriesByType(&self, entry_type: DOMString) -> Vec<DomRoot<PerformanceEntry>> {
        self.buffer
            .borrow()
            .get_entries_by_name_and_type(None, Some(entry_type))
    }

    // https://www.w3.org/TR/performance-timeline-2/#dom-performance-getentriesbyname
    fn GetEntriesByName(
        &self,
        name: DOMString,
        entry_type: Option<DOMString>,
    ) -> Vec<DomRoot<PerformanceEntry>> {
        self.buffer
            .borrow()
            .get_entries_by_name_and_type(Some(name), entry_type)
    }

    // https://w3c.github.io/user-timing/#dom-performance-mark
    fn Mark(&self, mark_name: DOMString) -> Fallible<()> {
        let global = self.global();
        // Step 1.
        if global.is::<Window>() && INVALID_ENTRY_NAMES.contains(&mark_name.as_ref()) {
            return Err(Error::Syntax);
        }

        // Steps 2 to 6.
        let entry = PerformanceMark::new(&global, mark_name, self.now(), 0.);
        // Steps 7 and 8.
        self.queue_entry(&entry.upcast::<PerformanceEntry>());

        // Step 9.
        Ok(())
    }

    // https://w3c.github.io/user-timing/#dom-performance-clearmarks
    fn ClearMarks(&self, mark_name: Option<DOMString>) {
        self.buffer
            .borrow_mut()
            .clear_entries_by_name_and_type(mark_name, Some(DOMString::from("mark")));
    }

    // https://w3c.github.io/user-timing/#dom-performance-measure
    fn Measure(
        &self,
        measure_name: DOMString,
        start_mark: Option<DOMString>,
        end_mark: Option<DOMString>,
    ) -> Fallible<()> {
        // Steps 1 and 2.
        let end_time = match end_mark {
            Some(name) => self
                .buffer
                .borrow()
                .get_last_entry_start_time_with_name_and_type(DOMString::from("mark"), name),
            None => self.now(),
        };

        // Step 3.
        let start_time = match start_mark {
            Some(name) => self
                .buffer
                .borrow()
                .get_last_entry_start_time_with_name_and_type(DOMString::from("mark"), name),
            None => 0.,
        };

        // Steps 4 to 8.
        let entry = PerformanceMeasure::new(
            &self.global(),
            measure_name,
            start_time,
            end_time - start_time,
        );

        // Step 9 and 10.
        self.queue_entry(&entry.upcast::<PerformanceEntry>());

        // Step 11.
        Ok(())
    }

    // https://w3c.github.io/user-timing/#dom-performance-clearmeasures
    fn ClearMeasures(&self, measure_name: Option<DOMString>) {
        self.buffer
            .borrow_mut()
            .clear_entries_by_name_and_type(measure_name, Some(DOMString::from("measure")));
    }
    // https://w3c.github.io/resource-timing/#dom-performance-clearresourcetimings
    fn ClearResourceTimings(&self) {
        self.buffer
            .borrow_mut()
            .clear_entries_by_name_and_type(None, Some(DOMString::from("resource")));
        self.resource_timing_buffer_current_size.set(0);
    }

    // https://w3c.github.io/resource-timing/#dom-performance-setresourcetimingbuffersize
    fn SetResourceTimingBufferSize(&self, max_size: u32) {
        self.resource_timing_buffer_size_limit
            .set(max_size as usize);
    }

    // https://w3c.github.io/resource-timing/#dom-performance-onresourcetimingbufferfull
    event_handler!(
        resourcetimingbufferfull,
        GetOnresourcetimingbufferfull,
        SetOnresourcetimingbufferfull
    );
}

// https://www.w3.org/TR/hr-time-2/#clock-resolution
pub fn reduce_timing_resolution(exact: f64) -> DOMHighResTimeStamp {
    // We need a granularity no finer than 5 microseconds.
    // 5 microseconds isn't an exactly representable f64 so WPT tests
    // might occasionally corner-case on rounding.
    // web-platform-tests/wpt#21526 wants us to use an integer number of
    // microseconds; the next divisor of milliseconds up from 5 microseconds
    // is 10, which is 1/100th of a millisecond.
    Finite::wrap((exact * 100.0).floor() / 100.0)
}