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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 super::{
CommonMetricData, ErrorType, LabeledBooleanMetric, LabeledCounterMetric, LabeledStringMetric,
MetricId,
};
use crate::ipc::need_ipc;
use std::borrow::Cow;
use std::marker::PhantomData;
/// Sealed traits protect against downstream implementations.
///
/// We wrap it in a private module that is inaccessible outside of this module.
mod private {
use super::{
need_ipc, LabeledBooleanMetric, LabeledCounterMetric, LabeledStringMetric, MetricId,
};
use crate::private::CounterMetric;
use std::sync::Arc;
/// The sealed trait.
///
/// This allows us to define which FOG metrics can be used
/// as labeled types.
pub trait Sealed {
type GleanMetric: glean::private::AllowLabeled + Clone;
fn from_glean_metric(id: MetricId, metric: Arc<Self::GleanMetric>, label: &str) -> Self;
}
// `LabeledMetric<LabeledBooleanMetric>` is possible.
//
impl Sealed for LabeledBooleanMetric {
type GleanMetric = glean::private::BooleanMetric;
fn from_glean_metric(_id: MetricId, metric: Arc<Self::GleanMetric>, _label: &str) -> Self {
if need_ipc() {
// TODO: Instrument this error.
LabeledBooleanMetric::Child(crate::private::boolean::BooleanMetricIpc)
} else {
LabeledBooleanMetric::Parent(metric)
}
}
}
// `LabeledMetric<LabeledStringMetric>` is possible.
//
impl Sealed for LabeledStringMetric {
type GleanMetric = glean::private::StringMetric;
fn from_glean_metric(_id: MetricId, metric: Arc<Self::GleanMetric>, _label: &str) -> Self {
if need_ipc() {
// TODO: Instrument this error.
LabeledStringMetric::Child(crate::private::string::StringMetricIpc)
} else {
LabeledStringMetric::Parent(metric)
}
}
}
// `LabeledMetric<LabeledCounterMetric>` is possible.
//
impl Sealed for LabeledCounterMetric {
type GleanMetric = glean::private::CounterMetric;
fn from_glean_metric(id: MetricId, metric: Arc<Self::GleanMetric>, label: &str) -> Self {
if need_ipc() {
LabeledCounterMetric::Child {
id,
label: label.to_string(),
}
} else {
LabeledCounterMetric::Parent(CounterMetric::Parent { id, inner: metric })
}
}
}
}
/// Marker trait for metrics that can be nested inside a labeled metric.
///
/// This trait is sealed and cannot be implemented for types outside this crate.
pub trait AllowLabeled: private::Sealed {}
// Implement the trait for everything we marked as allowed.
impl<T> AllowLabeled for T where T: private::Sealed {}
/// A labeled metric.
///
/// Labeled metrics allow to record multiple sub-metrics of the same type under different string labels.
///
/// ## Example
///
/// The following piece of code will be generated by `glean_parser`:
///
/// ```rust,ignore
/// use glean::metrics::{LabeledMetric, BooleanMetric, CommonMetricData, Lifetime};
/// use once_cell::sync::Lazy;
///
/// mod error {
/// pub static seen_one: Lazy<LabeledMetric<BooleanMetric, DynamicLabel>> = Lazy::new(|| LabeledMetric::new(CommonMetricData {
/// name: "seen_one".into(),
/// category: "error".into(),
/// send_in_pings: vec!["ping".into()],
/// disabled: false,
/// lifetime: Lifetime::Ping,
/// ..Default::default()
/// }, None));
/// }
/// ```
///
/// It can then be used with:
///
/// ```rust,ignore
/// errro::seen_one.get("upload").set(true);
/// ```
pub struct LabeledMetric<T: AllowLabeled, E> {
/// The metric ID of the underlying metric.
id: MetricId,
/// Wrapping the underlying core metric.
///
/// We delegate all functionality to this and wrap it up again in our own metric type.
core: glean::private::LabeledMetric<T::GleanMetric>,
label_enum: PhantomData<E>,
}
impl<T, E> LabeledMetric<T, E>
where
T: AllowLabeled,
{
/// Create a new labeled metric from the given metric instance and optional list of labels.
///
/// See [`get`](#method.get) for information on how static or dynamic labels are handled.
pub fn new(
id: MetricId,
meta: CommonMetricData,
labels: Option<Vec<Cow<'static, str>>>,
) -> LabeledMetric<T, E> {
let core = glean::private::LabeledMetric::new(meta, labels);
LabeledMetric {
id,
core,
label_enum: PhantomData,
}
}
}
#[inherent]
impl<U, E> glean::traits::Labeled<U> for LabeledMetric<U, E>
where
U: AllowLabeled + Clone,
{
/// Gets a specific metric for a given label.
///
/// If a set of acceptable labels were specified in the `metrics.yaml` file,
/// and the given label is not in the set, it will be recorded under the special `OTHER_LABEL` label.
///
/// If a set of acceptable labels was not specified in the `metrics.yaml` file,
/// only the first 16 unique labels will be used.
/// After that, any additional labels will be recorded under the special `OTHER_LABEL` label.
///
/// Labels must be `snake_case` and less than 30 characters.
/// If an invalid label is used, the metric will be recorded in the special `OTHER_LABEL` label.
pub fn get(&self, label: &str) -> U {
let metric = self.core.get(label);
U::from_glean_metric(self.id, metric, label)
}
/// **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 {
if need_ipc() {
panic!("Use of labeled metrics in IPC land not yet implemented!");
} else {
self.core.test_get_num_recorded_errors(error)
}
}
}
#[cfg(test)]
mod test {
use once_cell::sync::Lazy;
use super::*;
use crate::common_test::*;
use crate::metrics::DynamicLabel;
// Smoke test for what should be the generated code.
static GLOBAL_METRIC: Lazy<LabeledMetric<LabeledBooleanMetric, DynamicLabel>> =
Lazy::new(|| {
LabeledMetric::new(
0.into(),
CommonMetricData {
name: "global".into(),
category: "metric".into(),
send_in_pings: vec!["ping".into()],
disabled: false,
..Default::default()
},
None,
)
});
#[test]
fn smoke_test_global_metric() {
let _lock = lock_test();
GLOBAL_METRIC.get("a_value").set(true);
assert_eq!(
true,
GLOBAL_METRIC.get("a_value").test_get_value("ping").unwrap()
);
}
#[test]
fn sets_labeled_bool_metrics() {
let _lock = lock_test();
let store_names: Vec<String> = vec!["store1".into()];
let metric: LabeledMetric<LabeledBooleanMetric, DynamicLabel> = LabeledMetric::new(
0.into(),
CommonMetricData {
name: "bool".into(),
category: "labeled".into(),
send_in_pings: store_names,
disabled: false,
..Default::default()
},
None,
);
metric.get("upload").set(true);
assert!(metric.get("upload").test_get_value("store1").unwrap());
assert_eq!(None, metric.get("download").test_get_value("store1"));
}
#[test]
fn sets_labeled_string_metrics() {
let _lock = lock_test();
let store_names: Vec<String> = vec!["store1".into()];
let metric: LabeledMetric<LabeledStringMetric, DynamicLabel> = LabeledMetric::new(
0.into(),
CommonMetricData {
name: "string".into(),
category: "labeled".into(),
send_in_pings: store_names,
disabled: false,
..Default::default()
},
None,
);
metric.get("upload").set("Glean");
assert_eq!(
"Glean",
metric.get("upload").test_get_value("store1").unwrap()
);
assert_eq!(None, metric.get("download").test_get_value("store1"));
}
#[test]
fn sets_labeled_counter_metrics() {
let _lock = lock_test();
let store_names: Vec<String> = vec!["store1".into()];
let metric: LabeledMetric<LabeledCounterMetric, DynamicLabel> = LabeledMetric::new(
0.into(),
CommonMetricData {
name: "counter".into(),
category: "labeled".into(),
send_in_pings: store_names,
disabled: false,
..Default::default()
},
None,
);
metric.get("upload").add(10);
assert_eq!(10, metric.get("upload").test_get_value("store1").unwrap());
assert_eq!(None, metric.get("download").test_get_value("store1"));
}
#[test]
fn records_errors() {
let _lock = lock_test();
let store_names: Vec<String> = vec!["store1".into()];
let metric: LabeledMetric<LabeledBooleanMetric, DynamicLabel> = LabeledMetric::new(
0.into(),
CommonMetricData {
name: "bool".into(),
category: "labeled".into(),
send_in_pings: store_names,
disabled: false,
..Default::default()
},
None,
);
metric.get(&"1".repeat(72)).set(true);
assert_eq!(
1,
metric.test_get_num_recorded_errors(ErrorType::InvalidLabel)
);
}
#[test]
fn predefined_labels() {
let _lock = lock_test();
let store_names: Vec<String> = vec!["store1".into()];
#[allow(dead_code)]
enum MetricLabels {
Label1 = 0,
Label2 = 1,
}
let metric: LabeledMetric<LabeledBooleanMetric, MetricLabels> = LabeledMetric::new(
0.into(),
CommonMetricData {
name: "bool".into(),
category: "labeled".into(),
send_in_pings: store_names,
disabled: false,
..Default::default()
},
Some(vec!["label1".into(), "label2".into()]),
);
metric.get("label1").set(true);
metric.get("label2").set(false);
metric.get("not_a_label").set(true);
assert_eq!(true, metric.get("label1").test_get_value("store1").unwrap());
assert_eq!(
false,
metric.get("label2").test_get_value("store1").unwrap()
);
// The label not in the predefined set is recorded to the `other` bucket.
assert_eq!(
true,
metric.get("__other__").test_get_value("store1").unwrap()
);
assert_eq!(
0,
metric.test_get_num_recorded_errors(ErrorType::InvalidLabel)
);
}
}