1 files changed, 53 insertions, 0 deletions
diff --git a/src/counters/timer.rs b/src/counters/timer.rs
new file mode 100644
index 0000000..fd25063
--- /dev/null
+++ b/src/counters/timer.rs
@@ -0,0 +1,53 @@
+use std::fmt::{Display, Error, Formatter};
+
+/// A timer.
+#[derive(Copy, Clone, Debug, Default)]
+pub struct Timer {
+    time: f64,
+    start: Option<f64>,
+}
+
+impl Timer {
+    /// Creates a new timer initialized to zero and not started.
+    pub fn new() -> Self {
+        Timer {
+            time: 0.0,
+            start: None,
+        }
+    }
+
+    /// Resets the timer to 0.
+    pub fn reset(&mut self) {
+        self.time = 0.0
+    }
+
+    /// Start the timer.
+    pub fn start(&mut self) {
+        self.time = 0.0;
+        self.start = Some(instant::now());
+    }
+
+    /// Pause the timer.
+    pub fn pause(&mut self) {
+        if let Some(start) = self.start {
+            self.time += instant::now() - start;
+        }
+        self.start = None;
+    }
+
+    /// Resume the timer.
+    pub fn resume(&mut self) {
+        self.start = Some(instant::now());
+    }
+
+    /// The measured time between the last `.start()` and `.pause()` calls.
+    pub fn time(&self) -> f64 {
+        self.time
+    }
+}
+
+impl Display for Timer {
+    fn fmt(&self, f: &mut Formatter) -> Result<(), Error> {
+        write!(f, "{}s", self.time)
+    }
+}