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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
/// This implements the developer facing API for recording timespan metrics.
///
/// Instances of this class type are automatically generated by the parsers at build time,
/// allowing developers to record values that were previously registered in the metrics.yaml file.
///
/// The timespan API only exposes the `TimespanMetricType.start()`, `TimespanMetricType.stop()`
/// and `TimespanMetricType.cancel()` methods.
public typealias TimespanMetricType = TimespanMetric
extension TimespanMetricType {
/// Convenience method to simplify measuring a function or block of code
///
/// - parameters:
/// * funcToMeasure: Accepts a function or closure to measure that can return a value
public func measure<U>(funcToMeasure: () -> U) -> U {
start()
// Putting `stop` in a `defer` block guarantees it will execute at the end
// of the scope, after the return value is pushed onto the stack.
// under the "Specifying Cleanup Actions" section.
defer {
stop()
}
return funcToMeasure()
}
/// Convenience method to simplify measuring a function or block of code
///
/// If the measured function throws, the measurement is canceled and the exception rethrown.
///
/// - parameters:
/// * funcToMeasure: Accepts a function or closure to measure that can return a value
public func measure<U>(funcToMeasure: () throws -> U) throws -> U {
start()
do {
let returnValue = try funcToMeasure()
stop()
return returnValue
} catch {
cancel()
throw error
}
}
}