swift-metrics/Sources/Metrics/Metrics.swift

//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift Metrics API open source project
//
// Copyright (c) 2018-2019 Apple Inc. and the Swift Metrics API project authors
// Licensed under Apache License v2.0
//
// See LICENSE.txt for license information
// See CONTRIBUTORS.txt for the list of Swift Metrics API project authors
//
// SPDX-License-Identifier: Apache-2.0
//
//===----------------------------------------------------------------------===//
// swift-format-ignore-file
// Note: Whitespace changes are used to workaround compiler bug
// https://github.com/swiftlang/swift/issues/79285

@_exported import CoreMetrics
import Foundation

@_exported import class CoreMetrics.Timer

extension Timer {
    /// Convenience for measuring duration of a closure.
    ///
    /// - parameters:
    ///     - label: The label for the Timer.
    ///     - dimensions: The dimensions for the Timer.
    ///     - body: Closure to run & record.
    @inlinable
    public static func measure<T>(
        label: String,
        dimensions: [(String, String)] = [],
        body: @escaping () throws -> T
    ) rethrows -> T {
        let timer = Timer(label: label, dimensions: dimensions)
        let start = DispatchTime.now().uptimeNanoseconds
        defer {
            let delta = DispatchTime.now().uptimeNanoseconds - start
            timer.recordNanoseconds(delta)
        }
        return try body()
    }

    /// Record the time interval (with nanosecond precision) between the passed `since` dispatch time and `end` dispatch time.
    ///
    /// - parameters:
    ///   - since: Start of the interval as `DispatchTime`.
    ///   - end: End of the interval, defaulting to `.now()`.
    public func recordInterval(since: DispatchTime, end: DispatchTime = .now()) {
        self.recordNanoseconds(end.uptimeNanoseconds - since.uptimeNanoseconds)
    }
}

extension Timer {
    /// Convenience for recording a duration based on TimeInterval.
    ///
    /// - parameters:
    ///     - duration: The duration to record.
    @inlinable
    public func record(_ duration: TimeInterval) {
        self.recordSeconds(duration)
    }

    /// Convenience for recording a duration based on DispatchTimeInterval.
    ///
    /// - parameters:
    ///     - duration: The duration to record.
    @inlinable
    public func record(_ duration: DispatchTimeInterval) {
        // This wrapping in a optional is a workaround because DispatchTimeInterval
        // is a non-frozen public enum and Dispatch is built with library evolution
        // mode turned on.
        // This means we should have an `@unknown default` case, but this breaks
        // on non-Darwin platforms.
        // Switching over an optional means that the `.none` case will map to
        // `default` (which means we'll always have a valid case to go into
        // the default case), but in reality this case will never exist as this
        // optional will never be nil.
        let duration = Optional(duration)
        switch duration {
        case .nanoseconds(let value):
            self.recordNanoseconds(value)
        case .microseconds(let value):
            self.recordMicroseconds(value)
        case .milliseconds(let value):
            self.recordMilliseconds(value)
        case .seconds(let value):
            self.recordSeconds(value)
        case .never:
            self.record(0)
        default:
            self.record(0)
        }
    }
}

extension Timer {
    /// Convenience for recording a duration based on `Duration`.
    ///
    /// `Duration` will be converted to an `Int64` number of nanoseconds, and then recorded with nanosecond precision.
    ///
    /// - Parameters:
    ///     - duration: The `Duration` to record.
    @available(macOS 13, iOS 16, tvOS 16, watchOS 9, *)
    @inlinable
    public func record(duration: Duration) {
        // `Duration` doesn't have a nice way to convert it nanoseconds or seconds,
        // and manual conversion can overflow.
        let seconds = duration.components.seconds.multipliedReportingOverflow(by: 1_000_000_000)
        guard !seconds.overflow else { return self.recordNanoseconds(Int64.max) }

        let nanoseconds = seconds.partialValue.addingReportingOverflow(duration.components.attoseconds / 1_000_000_000)
        guard !nanoseconds.overflow else { return self.recordNanoseconds(Int64.max) }

        self.recordNanoseconds(nanoseconds.partialValue)
    }

    #if compiler(>=6.0)
    /// Convenience for measuring duration of a closure.
    ///
    /// - Parameters:
    ///    - clock: The clock used for measuring the duration. Defaults to the continuous clock.
    ///    - body: The closure to record the duration of.
    @inlinable
    @available(macOS 13, iOS 16, tvOS 16, watchOS 9, *)
    public func measure<Result, Failure: Error, Clock: _Concurrency.Clock>(
        clock: Clock = .continuous,
        // DO NOT FIX THE WHITESPACE IN THE NEXT LINE UNTIL 5.10 IS UNSUPPORTED
        // https://github.com/swiftlang/swift/issues/79285
        body: () throws(Failure) -> Result) throws(Failure) -> Result where Clock.Duration == Duration {
        let start = clock.now
        defer {
            self.record(duration: start.duration(to: clock.now))
        }
        return try body()
    }

    /// Convenience for measuring duration of a closure.
    ///
    /// - Parameters:
    ///    - clock: The clock used for measuring the duration. Defaults to the continuous clock.
    ///    - isolation: The isolation of the method. Defaults to the isolation of the caller.
    ///    - body: The closure to record the duration of.
    @inlinable
    @available(macOS 13, iOS 16, tvOS 16, watchOS 9, *)
    public func measure<Result, Failure: Error, Clock: _Concurrency.Clock>(
        clock: Clock = .continuous,
        isolation: isolated (any Actor)? = #isolation,
        // DO NOT FIX THE WHITESPACE IN THE NEXT LINE UNTIL 5.10 IS UNSUPPORTED
        // https://github.com/swiftlang/swift/issues/79285
        body: () async throws(Failure) -> sending Result) async throws(Failure) -> sending Result where Clock.Duration == Duration {
        let start = clock.now
        defer {
            self.record(duration: start.duration(to: clock.now))
        }
        return try await body()
    }
    #endif
}