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// 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
use inherent::inherent;
use std::convert::TryInto;
use super::{CommonMetricData, DistributionData, MemoryUnit, MetricId};
use glean::traits::MemoryDistribution;
use crate::ipc::{need_ipc, with_ipc_payload};
/// A memory distribution metric.
///
/// Memory distributions are used to accumulate and store memory measurements for analyzing distributions of the memory data.
#[derive(Clone)]
pub enum MemoryDistributionMetric {
Parent {
/// The metric's ID.
///
/// **TEST-ONLY** - Do not use unless gated with `#[cfg(test)]`.
id: MetricId,
inner: glean::private::MemoryDistributionMetric,
},
Child(MemoryDistributionMetricIpc),
}
#[derive(Clone, Debug)]
pub struct MemoryDistributionMetricIpc(MetricId);
impl MemoryDistributionMetric {
/// Create a new memory distribution metric.
pub fn new(id: MetricId, meta: CommonMetricData, memory_unit: MemoryUnit) -> Self {
if need_ipc() {
MemoryDistributionMetric::Child(MemoryDistributionMetricIpc(id))
} else {
let inner = glean::private::MemoryDistributionMetric::new(meta, memory_unit);
MemoryDistributionMetric::Parent { id, inner }
}
}
#[cfg(test)]
pub(crate) fn child_metric(&self) -> Self {
match self {
MemoryDistributionMetric::Parent { id, .. } => {
MemoryDistributionMetric::Child(MemoryDistributionMetricIpc(*id))
}
MemoryDistributionMetric::Child(_) => {
panic!("Can't get a child metric from a child metric")
}
}
}
}
#[inherent]
impl MemoryDistribution for MemoryDistributionMetric {
/// Accumulates the provided sample in the metric.
///
/// ## Arguments
///
/// * `sample` - The sample to be recorded by the metric. The sample is assumed to be in the
/// configured memory unit of the metric.
///
/// ## Notes
///
/// Values bigger than 1 Terabyte (2<sup>40</sup> bytes) are truncated
/// and an `ErrorType::InvalidValue` error is recorded.
pub fn accumulate(&self, sample: u64) {
match self {
MemoryDistributionMetric::Parent { inner, .. } => {
// values are capped at 2**40.
// If the value doesn't fit into `i64` it's definitely to large
// and cause an error.
// glean-core handles that.
let sample = sample.try_into().unwrap_or_else(|_| {
log::warn!(
"Memory size too large to fit into into 64-bytes. Saturating at i64::MAX."
);
i64::MAX
});
inner.accumulate(sample);
}
MemoryDistributionMetric::Child(c) => {
with_ipc_payload(move |payload| {
if let Some(v) = payload.memory_samples.get_mut(&c.0) {
v.push(sample);
} else {
payload.memory_samples.insert(c.0, vec![sample]);
}
});
}
}
}
/// **Test-only API.**
///
/// Get the currently-stored histogram as a DistributionData of the serialized value.
/// This doesn't clear the stored value.
///
/// ## Arguments
///
/// * `ping_name` - the storage name to look into.
///
/// ## Return value
///
/// Returns the stored value or `None` if nothing stored.
pub fn test_get_value<'a, S: Into<Option<&'a str>>>(
&self,
ping_name: S,
) -> Option<DistributionData> {
let ping_name = ping_name.into().map(|s| s.to_string());
match self {
MemoryDistributionMetric::Parent { inner, .. } => inner.test_get_value(ping_name),
MemoryDistributionMetric::Child(c) => {
panic!("Cannot get test value for {:?} in non-parent process!", c.0)
}
}
}
/// **Exported for test purposes.**
///
/// Gets the number of recorded errors for the given 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 recorded.
pub fn test_get_num_recorded_errors(&self, error: glean::ErrorType) -> i32 {
match self {
MemoryDistributionMetric::Parent { inner, .. } => {
inner.test_get_num_recorded_errors(error)
}
MemoryDistributionMetric::Child(c) => panic!(
"Cannot get the number of recorded errors for {:?} in non-parent process!",
c.0
),
}
}
}
#[cfg(test)]
mod test {
use super::*;
use crate::{common_test::*, ipc, metrics};
#[test]
fn smoke_test_memory_distribution() {
let _lock = lock_test();
let metric = MemoryDistributionMetric::new(
0.into(),
CommonMetricData {
name: "memory_distribution_metric".into(),
category: "telemetry".into(),
send_in_pings: vec!["store1".into()],
disabled: false,
..Default::default()
},
MemoryUnit::Kilobyte,
);
metric.accumulate(42);
let metric_data = metric.test_get_value("store1").unwrap();
assert_eq!(1, metric_data.values[&42494]);
assert_eq!(0, metric_data.values[&44376]);
assert_eq!(43008, metric_data.sum);
}
#[test]
fn memory_distribution_child() {
let _lock = lock_test();
let parent_metric = &metrics::test_only_ipc::a_memory_dist;
parent_metric.accumulate(42);
{
let child_metric = parent_metric.child_metric();
// scope for need_ipc RAII
let _raii = ipc::test_set_need_ipc(true);
child_metric.accumulate(13 * 9);
}
let metric_data = parent_metric.test_get_value("store1").unwrap();
assert_eq!(1, metric_data.values[&42494]);
assert_eq!(0, metric_data.values[&44376]);
assert_eq!(43008, metric_data.sum);
// Single-process IPC machine goes brrrrr...
let buf = ipc::take_buf().unwrap();
assert!(buf.len() > 0);
assert!(ipc::replay_from_buf(&buf).is_ok());
let data = parent_metric.test_get_value(None).expect("must have data");
assert_eq!(2, data.values.values().fold(0, |acc, count| acc + count));
assert_eq!(1, data.values[&42494]);
assert_eq!(1, data.values[&115097]);
assert_eq!(162816, data.sum);
}
}