Add new time_duration method to Timed trait

Add a new method for recording timings using std::time::Duration
instead of a u64 of milliseconds. The duration is converted to the
number of milliseconds before being send to the sink. Any integer
overflow will cause an error to be returned.

Fixes #48

CHANGES.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## [v0.12.0](https://github.com/tshlabs/cadence/tree/0.12.0) - ????-??-??
+* Add new `time_duration` method to `Timed` trait per
+  [#48](https://github.com/tshlabs/cadence/issues/48). This allows users to record
+  timings using the `Duration` struct from the standard library.
+
 ## [v0.11.0](https://github.com/tshlabs/cadence/tree/0.11.0) - 2017-01-18
 * **Breaking change** - Remove deprecated `AsyncMetricSink` per
   [#47](https://github.com/tshlabs/cadence/issues/47). Users are encouraged to
@@ -11,7 +16,7 @@
   of the client to care about the `MetricSink` implementation, put it behind an `Arc`
   pointer in the client and remove the type `T` from the signature. This makes the
   client easier to use and share between threads.
-* Remove use of `Arc` inside various sinks per [#35](https://github.com/tshlabs/cadence/issues/45).
+* Remove use of `Arc` inside various sinks per [#35](https://github.com/tshlabs/cadence/issues/35).
 
 ## [v0.10.0](https://github.com/tshlabs/cadence/tree/0.10.0) - 2017-01-08
 * **Breaking change** - Remove deprecated `ConsoleMetricSink` and `LoggingMetricSink`

Cargo.toml

@@ -16,3 +16,6 @@ crossbeam = "0.2.10"
 [lib]
 name = "cadence"
 path = "src/lib.rs"
+
+[badges]
+travis-ci = { repository = "tshlabs/cadence" }

src/client.rs

@@ -12,10 +12,12 @@
 use std::fmt;
 use std::net::{ToSocketAddrs, UdpSocket};
 use std::sync::Arc;
+use std::time::Duration;
 
 use ::sinks::{MetricSink, UdpMetricSink};
 
-use ::types::{MetricResult, Counter, Timer, Gauge, Meter, Histogram, Metric};
+use ::types::{MetricResult, MetricError, ErrorKind, Counter, Timer, Gauge,
+              Meter, Histogram, Metric};
 
 
 /// Trait for incrementing and decrementing counters.
@@ -50,6 +52,12 @@ pub trait Counted {
 pub trait Timed {
     /// Record a timing in milliseconds with the given key
     fn time(&self, key: &str, time: u64) -> MetricResult<Timer>;
+
+    /// Record a timing in milliseocnds with the given key
+    ///
+    /// The duration will be truncated to millisecond precision. If the
+    /// duration cannot be represented as a `u64` an error will be returned.
+    fn time_duration(&self, key: &str, duration: Duration) -> MetricResult<Timer>;
 }
 
 
@@ -142,7 +150,6 @@ pub trait MetricClient: Counted + Timed + Gauged + Metered + Histogrammed {}
 /// For more information about the uses for each type of metric, see the
 /// documentation for each mentioned trait.
 ///
-///
 /// # Sinks
 ///
 /// The client uses some implementation of a `MetricSink` to emit the metrics.
@@ -381,6 +388,19 @@ impl Timed for StatsdClient {
         self.send_metric(&timer)?;
         Ok(timer)
     }
+
+    fn time_duration(&self, key: &str, duration: Duration) -> MetricResult<Timer> {
+        let secs_as_ms = duration.as_secs().checked_mul(1_000);
+        let nanos_as_ms = (duration.subsec_nanos() as u64).checked_div(1_000_000);
+
+        let millis = secs_as_ms
+            .and_then(|v1| nanos_as_ms.and_then(|v2| v1.checked_add(v2)))
+            .ok_or_else(|| MetricError::from((ErrorKind::InvalidInput, "u64 overflow")))?;
+
+        let timer = Timer::new(&self.prefix, key, millis);
+        self.send_metric(&timer)?;
+        Ok(timer)
+    }
 }
 
 
@@ -429,9 +449,12 @@ fn trim_key(val: &str) -> &str {
 
 #[cfg(test)]
 mod tests {
+    use std::time::Duration;
+    use std::u64;
     use super::{trim_key, Counted, Timed, Gauged, Metered, Histogrammed,
                 MetricClient, StatsdClient};
     use ::sinks::NopMetricSink;
+    use ::types::{ErrorKind, Timer};
 
     #[test]
     fn test_trim_key_with_trailing_dot() {
@@ -498,4 +521,22 @@ mod tests {
         client.meter("some.meter", 29).unwrap();
         client.histogram("some.histogram", 32).unwrap();
     }
+
+    #[test]
+    fn test_statsd_client_time_duration_no_overflow() {
+        let client = StatsdClient::from_sink("prefix", NopMetricSink);
+        let res = client.time_duration("key", Duration::from_millis(157));
+        let expected = Timer::new("prefix", "key", 157);
+
+        assert_eq!(expected, res.unwrap());
+    }
+
+    #[test]
+    fn test_statsd_client_time_duration_with_overflow() {
+        let client = StatsdClient::from_sink("prefix", NopMetricSink);
+        let res = client.time_duration("key", Duration::from_secs(u64::MAX));
+        let err = res.unwrap_err();
+
+        assert_eq!(ErrorKind::InvalidInput, err.kind())
+    }
 }

tests/lib.rs

@@ -70,6 +70,14 @@ fn test_statsd_client_time() {
 }
 
 
+#[test]
+fn test_statsd_client_time_duration() {
+    let client = new_nop_client("client.test");
+    let expected = Timer::new("client.test", "timer.key", 35);
+    assert_eq!(expected, client.time_duration("timer.key", Duration::from_millis(35)).unwrap());
+}
+
+
 #[test]
 fn test_statsd_client_gauge() {
     let client = new_nop_client("client.test");