Implementation of powermanager functions

code/cli/munki/shared/munkistatus.swift

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+//
+//  munkistatus.swift
+//  munki
+//
+//  Created by Greg Neagle on 8/6/24.
+//
+
+import Foundation

code/cli/munki/shared/powermanager.swift

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+//
+//  powermanager.swift
+//  munki
+//
+//  Created by Greg Neagle on 8/6/24.
+//
+//  Copyright 2024 Greg Neagle.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//       https://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+
+import Foundation
+import IOKit.ps
+import IOKit.pwr_mgt
+
+// The IOKit Power Source and Power Management APIs are not very Swift-friendly.
+// This post https://forums.developer.apple.com/forums/thread/712711 helped with
+// getting these relatively safe
+
+func getPowerSource() -> String? {
+    guard
+        let powerSourcesInfo = IOPSCopyPowerSourcesInfo()?.takeRetainedValue(),
+        let powerSource = IOPSGetProvidingPowerSourceType(powerSourcesInfo)?.takeRetainedValue()
+    else {
+        return nil
+    }
+    return powerSource as String
+}
+
+func onACPower() -> Bool {
+    // Returns a boolean to indicate if the machine is on AC power
+    return getPowerSource() == kIOPMACPowerKey
+}
+
+func onBatteryPower() -> Bool {
+    // Returns a boolean to indicate if the machine is on battery power
+    return getPowerSource() == kIOPMBatteryPowerKey
+}
+
+func getBatteryPercentage() -> Int {
+    // Returns battery charge percentage
+    guard
+        let psi = IOPSCopyPowerSourcesInfo()?.takeRetainedValue(),
+        let cf = IOPSCopyPowerSourcesList(psi)?.takeRetainedValue()
+    else {
+        return 0
+    }
+    let psl = cf as [CFTypeRef]
+    for ps in psl {
+        guard
+            let cfd = IOPSGetPowerSourceDescription(psi, ps)?.takeUnretainedValue()
+        else {
+            return 0
+        }
+        let d = cfd as! [String: Any]
+        guard
+            let psTypeStr = d[kIOPSTypeKey] as? String
+        else {
+            return 0
+        }
+        if psTypeStr == "InternalBattery" {
+            guard
+                let psCapacity = d[kIOPSCurrentCapacityKey] as? Int
+            else {
+                return 0
+            }
+            return psCapacity
+        }
+    }
+    return 0
+}
+
+func hasInternalBattery() -> Bool {
+    // Determine if this Mac has a power source of 'InternalBattery'
+    guard
+        let psi = IOPSCopyPowerSourcesInfo()?.takeRetainedValue(),
+        let cf = IOPSCopyPowerSourcesList(psi)?.takeRetainedValue()
+    else {
+        return false
+    }
+    let psl = cf as [CFTypeRef]
+    for ps in psl {
+        guard
+            let cfd = IOPSGetPowerSourceDescription(psi, ps)?.takeUnretainedValue()
+        else {
+            return false
+        }
+        let d = cfd as! [String: Any]
+        guard
+            let psTypeStr = d[kIOPSTypeKey] as? String
+        else {
+            return false
+        }
+        if psTypeStr == "InternalBattery" {
+            return true
+        }
+    }
+    return false
+}
+
+// MARK: no sleep assertions
+
+func assertIOPM(name: CFString, reason: CFString) -> IOPMAssertionID? {
+    // Uses IOKit functions to prevent sleep.
+    var assertionID = IOPMAssertionID(0)
+    let success = IOPMAssertionCreateWithName(
+        name,
+        IOPMAssertionLevel(kIOPMAssertionLevelOn),
+        reason,
+        &assertionID
+    )
+    if success == kIOReturnSuccess {
+        return assertionID
+    }
+    return nil
+}
+
+func assertNoIdleSleep(reason: String) -> IOPMAssertionID? {
+    // Uses IOKit functions to prevent idle sleep.
+    displayInfo("Preventing idle sleep")
+    let kIOPMAssertPreventUserIdleSystemSleep = "PreventUserIdleSystemSleep" as CFString
+    return assertIOPM(name: kIOPMAssertPreventUserIdleSystemSleep, reason: reason as CFString)
+}
+
+func assertNoDisplaySleep(reason: String) -> IOPMAssertionID? {
+    // Uses IOKit functions to prevent idle sleep.
+    displayInfo("Preventing display sleep")
+    let kIOPMAssertPreventUserDisplaySystemSleep = "PreventUserDisplaySystemSleep" as CFString
+    return assertIOPM(name: kIOPMAssertPreventUserDisplaySystemSleep, reason: reason as CFString)
+}
+
+func removeNoSleepAssertion(_ id: IOPMAssertionID?) {
+    if let id {
+        displayInfo("Allowing idle/display sleep")
+        IOPMAssertionRelease(id)
+    }
+}
+
+class Caffeinator {
+    // A simple object that prevents idle sleep and automagically
+    // removes the assertion when the object goes out of scope or is deleted
+
+    var assertionID: IOPMAssertionID?
+
+    init(reason: String = "Munki is installing software") {
+        assertionID = assertNoIdleSleep(reason: reason)
+    }
+
+    deinit {
+        removeNoSleepAssertion(assertionID)
+    }
+}