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Diffstat (limited to 'third_party/rust/glean-core/src/metrics/timespan.rs')
| -rw-r--r-- | third_party/rust/glean-core/src/metrics/timespan.rs | 308 |
1 files changed, 308 insertions, 0 deletions
diff --git a/third_party/rust/glean-core/src/metrics/timespan.rs b/third_party/rust/glean-core/src/metrics/timespan.rs new file mode 100644 index 0000000000..b4d3bd5902 --- /dev/null +++ b/third_party/rust/glean-core/src/metrics/timespan.rs @@ -0,0 +1,308 @@ +// 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 std::convert::TryInto; +use std::sync::{Arc, RwLock}; +use std::time::Duration; + +use crate::common_metric_data::CommonMetricDataInternal; +use crate::error_recording::{record_error, test_get_num_recorded_errors, ErrorType}; +use crate::metrics::time_unit::TimeUnit; +use crate::metrics::Metric; +use crate::metrics::MetricType; +use crate::storage::StorageManager; +use crate::CommonMetricData; +use crate::Glean; + +/// A timespan metric. +/// +/// Timespans are used to make a measurement of how much time is spent in a particular task. +/// +// Implementation note: +// Because we dispatch this, we handle this with interior mutability. +// The whole struct is clonable, but that's comparable cheap, as it does not clone the data. +// Cloning `CommonMetricData` is not free, as it contains strings, so we also wrap that in an Arc. +#[derive(Clone, Debug)] +pub struct TimespanMetric { + meta: Arc<CommonMetricDataInternal>, + time_unit: TimeUnit, + start_time: Arc<RwLock<Option<u64>>>, +} + +impl MetricType for TimespanMetric { + fn meta(&self) -> &CommonMetricDataInternal { + &self.meta + } +} + +// IMPORTANT: +// +// When changing this implementation, make sure all the operations are +// also declared in the related trait in `../traits/`. +impl TimespanMetric { + /// Creates a new timespan metric. + pub fn new(meta: CommonMetricData, time_unit: TimeUnit) -> Self { + Self { + meta: Arc::new(meta.into()), + time_unit, + start_time: Arc::new(RwLock::new(None)), + } + } + + /// Starts tracking time for the provided metric. + /// + /// This records an error if it's already tracking time (i.e. start was + /// already called with no corresponding + /// [`set_stop`](TimespanMetric::set_stop)): in that case the original start + /// time will be preserved. + pub fn start(&self) { + let start_time = time::precise_time_ns(); + + let metric = self.clone(); + crate::launch_with_glean(move |glean| metric.set_start(glean, start_time)); + } + + /// Set start time synchronously. + #[doc(hidden)] + pub fn set_start(&self, glean: &Glean, start_time: u64) { + if !self.should_record(glean) { + return; + } + + let mut lock = self + .start_time + .write() + .expect("Lock poisoned for timespan metric on start."); + + if lock.is_some() { + record_error( + glean, + &self.meta, + ErrorType::InvalidState, + "Timespan already started", + None, + ); + return; + } + + *lock = Some(start_time); + } + + /// Stops tracking time for the provided metric. Sets the metric to the elapsed time. + /// + /// This will record an error if no [`set_start`](TimespanMetric::set_start) was called. + pub fn stop(&self) { + let stop_time = time::precise_time_ns(); + + let metric = self.clone(); + crate::launch_with_glean(move |glean| metric.set_stop(glean, stop_time)); + } + + /// Set stop time synchronously. + #[doc(hidden)] + pub fn set_stop(&self, glean: &Glean, stop_time: u64) { + // Need to write in either case, so get the lock first. + let mut lock = self + .start_time + .write() + .expect("Lock poisoned for timespan metric on stop."); + + if !self.should_record(glean) { + // Reset timer when disabled, so that we don't record timespans across + // disabled/enabled toggling. + *lock = None; + return; + } + + if lock.is_none() { + record_error( + glean, + &self.meta, + ErrorType::InvalidState, + "Timespan not running", + None, + ); + return; + } + + let start_time = lock.take().unwrap(); + let duration = match stop_time.checked_sub(start_time) { + Some(duration) => duration, + None => { + record_error( + glean, + &self.meta, + ErrorType::InvalidValue, + "Timespan was negative", + None, + ); + return; + } + }; + let duration = Duration::from_nanos(duration); + self.set_raw_inner(glean, duration); + } + + /// Aborts a previous [`set_start`](TimespanMetric::set_start) call. No + /// error is recorded if no [`set_start`](TimespanMetric::set_start) was + /// called. + pub fn cancel(&self) { + let metric = self.clone(); + crate::dispatcher::launch(move || { + let mut lock = metric + .start_time + .write() + .expect("Lock poisoned for timespan metric on cancel."); + *lock = None; + }); + } + + /// Explicitly sets the timespan value. + /// + /// This API should only be used if your library or application requires + /// recording times in a way that can not make use of + /// [`set_start`](TimespanMetric::set_start)/[`set_stop`](TimespanMetric::set_stop)/[`cancel`](TimespanMetric::cancel). + /// + /// Care should be taken using this if the ping lifetime might contain more + /// than one timespan measurement. To be safe, + /// [`set_raw`](TimespanMetric::set_raw) should generally be followed by + /// sending a custom ping containing the timespan. + /// + /// # Arguments + /// + /// * `elapsed` - The elapsed time to record. + pub fn set_raw(&self, elapsed: Duration) { + let metric = self.clone(); + crate::launch_with_glean(move |glean| metric.set_raw_sync(glean, elapsed)); + } + + /// Explicitly sets the timespan value in nanoseconds. + /// + /// This API should only be used if your library or application requires + /// recording times in a way that can not make use of + /// [`set_start`](TimespanMetric::set_start)/[`set_stop`](TimespanMetric::set_stop)/[`cancel`](TimespanMetric::cancel). + /// + /// Care should be taken using this if the ping lifetime might contain more + /// than one timespan measurement. To be safe, + /// [`set_raw`](TimespanMetric::set_raw) should generally be followed by + /// sending a custom ping containing the timespan. + /// + /// # Arguments + /// + /// * `elapsed_nanos` - The elapsed time to record, in nanoseconds. + pub fn set_raw_nanos(&self, elapsed_nanos: i64) { + let elapsed = Duration::from_nanos(elapsed_nanos.try_into().unwrap_or(0)); + self.set_raw(elapsed) + } + + /// Explicitly sets the timespan value synchronously. + #[doc(hidden)] + pub fn set_raw_sync(&self, glean: &Glean, elapsed: Duration) { + if !self.should_record(glean) { + return; + } + + let lock = self + .start_time + .read() + .expect("Lock poisoned for timespan metric on set_raw."); + + if lock.is_some() { + record_error( + glean, + &self.meta, + ErrorType::InvalidState, + "Timespan already running. Raw value not recorded.", + None, + ); + return; + } + + self.set_raw_inner(glean, elapsed); + } + + fn set_raw_inner(&self, glean: &Glean, elapsed: Duration) { + let mut report_value_exists: bool = false; + glean.storage().record_with(glean, &self.meta, |old_value| { + match old_value { + Some(old @ Metric::Timespan(..)) => { + // If some value already exists, report an error. + // We do this out of the storage since recording an + // error accesses the storage as well. + report_value_exists = true; + old + } + _ => Metric::Timespan(elapsed, self.time_unit), + } + }); + + if report_value_exists { + record_error( + glean, + &self.meta, + ErrorType::InvalidState, + "Timespan value already recorded. New value discarded.", + None, + ); + }; + } + + /// **Test-only API (exported for FFI purposes).** + /// + /// Gets the currently stored value as an integer. + /// + /// This doesn't clear the stored value. + pub fn test_get_value(&self, ping_name: Option<String>) -> Option<i64> { + crate::block_on_dispatcher(); + crate::core::with_glean(|glean| { + self.get_value(glean, ping_name.as_deref()).map(|val| { + val.try_into() + .expect("Timespan can't be represented as i64") + }) + }) + } + + /// Get the current value + #[doc(hidden)] + pub fn get_value<'a, S: Into<Option<&'a str>>>( + &self, + glean: &Glean, + ping_name: S, + ) -> Option<u64> { + let queried_ping_name = ping_name + .into() + .unwrap_or_else(|| &self.meta().inner.send_in_pings[0]); + + match StorageManager.snapshot_metric_for_test( + glean.storage(), + queried_ping_name, + &self.meta.identifier(glean), + self.meta.inner.lifetime, + ) { + Some(Metric::Timespan(time, time_unit)) => Some(time_unit.duration_convert(time)), + _ => None, + } + } + + /// **Exported for test purposes.** + /// + /// Gets the number of recorded errors for the given metric and error type. + /// + /// # Arguments + /// + /// * `error` - The type of error + /// * `ping_name` - represents the optional name of the ping to retrieve the + /// metric for. Defaults to the first value in `send_in_pings`. + /// + /// # Returns + /// + /// The number of errors reported. + pub fn test_get_num_recorded_errors(&self, error: ErrorType) -> i32 { + crate::block_on_dispatcher(); + + crate::core::with_glean(|glean| { + test_get_num_recorded_errors(glean, self.meta(), error).unwrap_or(0) + }) + } +} |