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use crate::attributes::{Attributes, OnFlush, Prefixed, WithAttributes};
use crate::input::{Input, InputDyn, InputKind, InputMetric, InputScope};
use crate::lru_cache as lru;
use crate::name::MetricName;
use crate::Flush;
use std::sync::Arc;
#[cfg(not(feature = "parking_lot"))]
use std::sync::RwLock;
#[cfg(feature = "parking_lot")]
use parking_lot::RwLock;
use std::io;
pub trait CachedInput: Input + Send + Sync + 'static + Sized {
fn cached(self, max_size: usize) -> InputCache {
InputCache::wrap(self, max_size)
}
}
#[derive(Clone)]
pub struct InputCache {
attributes: Attributes,
target: Arc<dyn InputDyn + Send + Sync + 'static>,
cache: Arc<RwLock<lru::LRUCache<MetricName, InputMetric>>>,
}
impl InputCache {
fn wrap<OUT: Input + Send + Sync + 'static>(target: OUT, max_size: usize) -> InputCache {
InputCache {
attributes: Attributes::default(),
target: Arc::new(target),
cache: Arc::new(RwLock::new(lru::LRUCache::with_capacity(max_size))),
}
}
}
impl WithAttributes for InputCache {
fn get_attributes(&self) -> &Attributes {
&self.attributes
}
fn mut_attributes(&mut self) -> &mut Attributes {
&mut self.attributes
}
}
impl Input for InputCache {
type SCOPE = InputScopeCache;
fn metrics(&self) -> Self::SCOPE {
let target = self.target.input_dyn();
InputScopeCache {
attributes: self.attributes.clone(),
target,
cache: self.cache.clone(),
}
}
}
#[derive(Clone)]
pub struct InputScopeCache {
attributes: Attributes,
target: Arc<dyn InputScope + Send + Sync + 'static>,
cache: Arc<RwLock<lru::LRUCache<MetricName, InputMetric>>>,
}
impl WithAttributes for InputScopeCache {
fn get_attributes(&self) -> &Attributes {
&self.attributes
}
fn mut_attributes(&mut self) -> &mut Attributes {
&mut self.attributes
}
}
impl InputScope for InputScopeCache {
fn new_metric(&self, name: MetricName, kind: InputKind) -> InputMetric {
let name = self.prefix_append(name);
let lookup = { write_lock!(self.cache).get(&name).cloned() };
lookup.unwrap_or_else(|| {
let new_metric = self.target.new_metric(name.clone(), kind);
write_lock!(self.cache).insert(name, new_metric.clone());
new_metric
})
}
}
impl Flush for InputScopeCache {
fn flush(&self) -> io::Result<()> {
self.notify_flush_listeners();
self.target.flush()
}
}