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use crate::export::metrics::aggregation::{Aggregation, AggregationKind, LastValue};
use crate::metrics::{
aggregators::Aggregator,
sdk_api::{Descriptor, Number},
};
use opentelemetry_api::metrics::{MetricsError, Result};
use opentelemetry_api::Context;
use std::any::Any;
use std::sync::{Arc, Mutex};
use std::time::SystemTime;
pub fn last_value() -> LastValueAggregator {
LastValueAggregator {
inner: Mutex::new(Inner::default()),
}
}
#[derive(Debug)]
pub struct LastValueAggregator {
inner: Mutex<Inner>,
}
impl Aggregation for LastValueAggregator {
fn kind(&self) -> &AggregationKind {
&AggregationKind::LAST_VALUE
}
}
impl Aggregator for LastValueAggregator {
fn aggregation(&self) -> &dyn Aggregation {
self
}
fn update(&self, _cx: &Context, number: &Number, _descriptor: &Descriptor) -> Result<()> {
self.inner.lock().map_err(Into::into).map(|mut inner| {
inner.state = Some(LastValueData {
value: number.clone(),
timestamp: opentelemetry_api::time::now(),
});
})
}
fn synchronized_move(
&self,
other: &Arc<dyn Aggregator + Send + Sync>,
_descriptor: &Descriptor,
) -> Result<()> {
if let Some(other) = other.as_any().downcast_ref::<Self>() {
self.inner.lock().map_err(From::from).and_then(|mut inner| {
other.inner.lock().map_err(From::from).map(|mut other| {
other.state = inner.state.take();
})
})
} else {
Err(MetricsError::InconsistentAggregator(format!(
"Expected {:?}, got: {:?}",
self, other
)))
}
}
fn merge(
&self,
other: &(dyn Aggregator + Send + Sync),
_descriptor: &Descriptor,
) -> Result<()> {
if let Some(other) = other.as_any().downcast_ref::<Self>() {
self.inner.lock().map_err(From::from).and_then(|mut inner| {
other.inner.lock().map_err(From::from).map(|mut other| {
match (&inner.state, &other.state) {
(Some(checkpoint), Some(other_checkpoint))
if other_checkpoint.timestamp > checkpoint.timestamp =>
{
inner.state = other.state.take()
}
(None, Some(_)) => inner.state = other.state.take(),
_ => (),
}
})
})
} else {
Err(MetricsError::InconsistentAggregator(format!(
"Expected {:?}, got: {:?}",
self, other
)))
}
}
fn as_any(&self) -> &dyn Any {
self
}
}
impl LastValue for LastValueAggregator {
fn last_value(&self) -> Result<(Number, SystemTime)> {
self.inner.lock().map_err(Into::into).and_then(|inner| {
if let Some(checkpoint) = &inner.state {
Ok((checkpoint.value.clone(), checkpoint.timestamp))
} else {
Err(MetricsError::NoDataCollected)
}
})
}
}
#[derive(Debug, Default)]
struct Inner {
state: Option<LastValueData>,
}
#[derive(Debug)]
struct LastValueData {
value: Number,
timestamp: SystemTime,
}