detect/
delay_tracker.rs

1// Copyright 2020 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5/// DelayTracker keeps track of how recently we sent a crash report of each type, and whether we
6/// should mute too-frequent requests.
7use {
8    crate::{Mode, MINIMUM_SIGNATURE_INTERVAL_NANOS},
9    fuchsia_triage::SnapshotTrigger,
10    injectable_time::TimeSource,
11    log::warn,
12    std::collections::HashMap,
13    std::sync::Arc,
14};
15
16pub struct DelayTracker {
17    last_sent: HashMap<String, i64>,
18    time_source: Arc<dyn TimeSource + Send + Sync>,
19    program_mode: Mode,
20}
21
22impl DelayTracker {
23    pub(crate) fn new(
24        time_source: Arc<dyn TimeSource + Send + Sync>,
25        program_mode: Mode,
26    ) -> DelayTracker {
27        DelayTracker { last_sent: HashMap::new(), time_source, program_mode }
28    }
29
30    fn appropriate_report_interval(&self, desired_interval: i64) -> i64 {
31        if self.program_mode == Mode::IntegrationTest
32            || desired_interval >= MINIMUM_SIGNATURE_INTERVAL_NANOS
33        {
34            desired_interval
35        } else {
36            MINIMUM_SIGNATURE_INTERVAL_NANOS
37        }
38    }
39
40    // If it's OK to send, remember the time and return true.
41    pub(crate) fn ok_to_send(&mut self, snapshot: &SnapshotTrigger) -> bool {
42        let now = self.time_source.now();
43        let interval = self.appropriate_report_interval(snapshot.interval);
44        let should_send = match self.last_sent.get(&snapshot.signature) {
45            None => true,
46            Some(time) => time <= &(now - interval),
47        };
48        if should_send {
49            self.last_sent.insert(snapshot.signature.to_string(), now);
50            if snapshot.interval < MINIMUM_SIGNATURE_INTERVAL_NANOS {
51                // To reduce logspam, put this warning here rather than above where the
52                // calculation is. The calculation may happen every time we check diagnostics; this
53                // will happen at most every MINIMUM_SIGNATURE_INTERVAL (except in tests).
54                warn!(
55                    "Signature {} has interval {} nanos, less than minimum {}",
56                    snapshot.signature, snapshot.interval, MINIMUM_SIGNATURE_INTERVAL_NANOS
57                );
58            }
59        }
60        should_send
61    }
62}
63
64#[cfg(test)]
65mod test {
66    use super::*;
67    use injectable_time::FakeTime;
68    use static_assertions::const_assert;
69
70    #[fuchsia::test]
71    fn verify_test_mode() {
72        let time = Arc::new(FakeTime::new());
73        let mut tracker = DelayTracker::new(time.clone(), Mode::IntegrationTest);
74        time.set_ticks(1);
75        let trigger_slow = SnapshotTrigger { signature: "slow".to_string(), interval: 10 };
76        let trigger_fast = SnapshotTrigger { signature: "fast".to_string(), interval: 1 };
77        let ok_slow_1 = tracker.ok_to_send(&trigger_slow);
78        let ok_fast_1 = tracker.ok_to_send(&trigger_fast);
79        time.set_ticks(3);
80        let ok_slow_2 = tracker.ok_to_send(&trigger_slow);
81        let ok_fast_2 = tracker.ok_to_send(&trigger_fast);
82        // This one should obviously succeed.
83        assert!(ok_slow_1);
84        // It should allow a different snapshot signature too.
85        assert!(ok_fast_1);
86        // It should reject the first (slow) signature the second time.
87        assert!(!ok_slow_2);
88        // The second (fast) signature should be accepted repeatedly.
89        assert!(ok_fast_2);
90    }
91
92    #[fuchsia::test]
93    fn verify_appropriate_report_interval() {
94        const_assert!(MINIMUM_SIGNATURE_INTERVAL_NANOS > 1);
95        let time = Arc::new(FakeTime::new());
96        let test_tracker = DelayTracker::new(time.clone(), Mode::IntegrationTest);
97        let production_tracker = DelayTracker::new(time, Mode::Production);
98
99        assert_eq!(test_tracker.appropriate_report_interval(1), 1);
100        assert_eq!(
101            production_tracker.appropriate_report_interval(1),
102            MINIMUM_SIGNATURE_INTERVAL_NANOS
103        );
104    }
105}
detect/delay_tracker.rs

detect/
delay_tracker.rs
