Performance Timer

A high-resolution stopwatch timer for Swift projects, using DispatchTime to measure with nanosecond accuracy.

Precise time measurement supporting conversions to alternative time units (seconds, milliseconds, microseconds, and nanoseconds).

Features

• Basic stopwatch functions: start(), stop(), and reset()
• Lap times: Call lap() while timer is running to record a lap time
• Elapsed time: Call elasped to get the current timer value without recording a lap time
• Measure the execution time of an async function

Examples

// Initialize the timer, setting the reporting units to milliseconds
var timer = PerformanceTimer(reportingUnits: .milliseconds)

// Start the timer
timer.start()

// Simulate some work
usleep(500_000) // 500 milliseconds

// Record a lap time
let firstLap = timer.lap() // Returns lap duration in milliseconds
print("First lap: \(firstLap) \(timer.reportingUnits.label)")

// Simulate more work
usleep(250_000) // 250 milliseconds

// Record another lap
let secondLap = timer.lap()
print("Second lap: \(secondLap) \(timer.reportingUnits.label)")

// Stop the timer
let finalLap = timer.stop()
print("Final lap: \(finalLap) \(timer.reportingUnits.label)")

print("Total duration: \(timer.total) \(timer.reportingUnits.label)")

Detailed lap time available from the laps array, given in the reporting units ...

for (index, lap) in timer.laps.enumerated() {
  print("Lap \(index): \(lap) \(timer.reportingUnits.label)")
}
// "Lap 0: 1.005140667 s"
// ...

... or get raw times, given as an array of DispatchTime ...

for (index, time) in timer.times.enumerated() {
  print("Lap \(index) DispatchTime: \(time)")
}
// "Lap 0 DispatchTime: DispatchTime(rawValue: 5088168112547)"
// ...

To time how long to run a single async function, we can run the function in the measureAsync closure...

// Some function for which we need to time how long it takes to run
func someAsyncTask() async throws -> String {
  sleep(2)
  return "Slept for 2 seconds"
}

// Create an instance of the timer and execute the function in the `measureAsync` closure
var timer = PerformanceTimer(reportingUnits: .milliseconds)
do {
  let (result, time) = try await timer.measureAsync {
    try await someAsyncTask()
  }
  print("Task Result: \(result), Took: \(time) \(timer.reportingUnits.label)")    
} catch {
  print("Error: \(error)")
}

Contributing

Feel free to contribute by opening an issue or submitting a pull request. Suggestions, improvements, and additional features are welcome.

License

This project is licensed under the MIT License. See the LICENSE file for details.

Contact

For questions or support, contact me on BlueSky🦋 @kieran.firecresthorizon.uk.