use std::sync::Arc;
use proto;
use metrics::{Opts, Collector, Metric};
use value::{Value, ValueType};
use desc::Desc;
use errors::{Result, Error};
use vec::{MetricVec, MetricVecBuilder};
#[derive(Clone)]
pub struct Counter {
v: Arc<Value>,
}
impl Counter {
pub fn new<S: Into<String>>(name: S, help: S) -> Result<Counter> {
let opts = Opts::new(name, help);
Counter::with_opts(opts)
}
pub fn with_opts(opts: Opts) -> Result<Counter> {
let desc = try!(Desc::new(opts.fq_name(), opts.help, vec![], opts.const_labels));
Counter::with_desc(desc, &[])
}
fn with_desc(desc: Desc, label_values: &[&str]) -> Result<Counter> {
let v = try!(Value::new(desc, ValueType::Counter, 0.0, label_values));
Ok(Counter { v: Arc::new(v) })
}
#[inline]
pub fn inc_by(&self, v: f64) -> Result<()> {
if v < 0.0 {
return Err(Error::DecreaseCounter(v));
}
Ok(self.v.inc_by(v))
}
#[inline]
pub fn inc(&self) {
self.inc_by(1.0).unwrap()
}
#[inline]
pub fn get(&self) -> f64 {
self.v.get()
}
}
impl Collector for Counter {
fn desc(&self) -> &Desc {
&self.v.desc
}
fn collect(&self) -> proto::MetricFamily {
self.v.collect()
}
}
impl Metric for Counter {
fn metric(&self) -> proto::Metric {
self.v.metric()
}
}
#[derive(Clone)]
pub struct CounterVecBuilder {}
impl MetricVecBuilder for CounterVecBuilder {
type Output = Counter;
fn build(&self, desc: &Desc, vals: &[&str]) -> Result<Counter> {
Counter::with_desc(desc.clone(), vals)
}
}
pub type CounterVec = MetricVec<CounterVecBuilder>;
impl CounterVec {
pub fn new(opts: Opts, label_names: &[&str]) -> Result<CounterVec> {
let variable_names = label_names.iter().map(|s| (*s).to_owned()).collect();
let desc = try!(Desc::new(opts.fq_name(), opts.help, variable_names, opts.const_labels));
let metric_vec = MetricVec::create(desc, proto::MetricType::COUNTER, CounterVecBuilder {});
Ok(metric_vec as CounterVec)
}
}
#[cfg(test)]
mod tests {
use metrics::{Opts, Collector};
use super::*;
#[test]
fn test_counter() {
let opts = Opts::new("test", "test help").const_label("a", "1").const_label("b", "2");
let counter = Counter::with_opts(opts).unwrap();
counter.inc();
assert_eq!(counter.get() as u64, 1);
counter.inc_by(42.0).unwrap();
assert_eq!(counter.get() as u64, 43);
let mf = counter.collect();
let m = mf.get_metric().as_ref().get(0).unwrap();
assert_eq!(m.get_label().len(), 2);
assert_eq!(m.get_counter().get_value() as u64, 43);
}
}