Operations: simplify AsyncOperation, remove advanced features

14 files changed, 27 insertions, 734 deletions

diff --git a/ios/MullvadVPN/Operations/AnyOperationObserver.swift b/ios/MullvadVPN/Operations/AnyOperationObserver.swift
deleted file mode 100644
index 9c394f8b5a..0000000000
--- a/ios/MullvadVPN/Operations/AnyOperationObserver.swift
+++ /dev/null
@@ -1,19 +0,0 @@
-//
-//  AnyOperationObserver.swift
-//  MullvadVPN
-//
-//  Created by pronebird on 06/07/2020.
-//  Copyright © 2020 Mullvad VPN AB. All rights reserved.
-//
-
-import Foundation
-
-class AnyOperationObserver<OperationType: OperationProtocol>: OperationBlockObserver<OperationType> {
-    init<T: OperationObserver>(_ observer: T) where T.OperationType == OperationType {
-        super.init(
-            willExecute: observer.operationWillExecute,
-            willFinish: observer.operationWillFinish,
-            didFinish: observer.operationDidFinish
-        )
-    }
-}
diff --git a/ios/MullvadVPN/Operations/AssociatedValue.swift b/ios/MullvadVPN/Operations/AssociatedValue.swift
deleted file mode 100644
index 6fc860dbf3..0000000000
--- a/ios/MullvadVPN/Operations/AssociatedValue.swift
+++ /dev/null
@@ -1,31 +0,0 @@
-//
-//  AssociatedValue.swift
-//  MullvadVPN
-//
-//  Created by pronebird on 06/07/2020.
-//  Copyright © 2020 Mullvad VPN AB. All rights reserved.
-//
-
-import Foundation
-
-/// A container type for storing associated values
-final class AssociatedValue<T>: NSObject {
-    let value: T
-    init(_ value: T) {
-        self.value = value
-    }
-
-    class func get(object: Any, key: UnsafeRawPointer) -> T? {
-        let container = objc_getAssociatedObject(object, key) as? AssociatedValue<T>
-        return container?.value
-    }
-
-    class func set(object: Any, key: UnsafeRawPointer, value: T?) {
-        objc_setAssociatedObject(
-            object,
-            key,
-            value.flatMap { AssociatedValue($0) },
-            .OBJC_ASSOCIATION_RETAIN_NONATOMIC
-        )
-    }
-}
diff --git a/ios/MullvadVPN/Operations/AsyncBlockOperation.swift b/ios/MullvadVPN/Operations/AsyncBlockOperation.swift
index c8f4287b32..a7f0ffdd29 100644
--- a/ios/MullvadVPN/Operations/AsyncBlockOperation.swift
+++ b/ios/MullvadVPN/Operations/AsyncBlockOperation.swift
@@ -10,7 +10,7 @@ import Foundation
 
 /// Asynchronous block operation
 class AsyncBlockOperation: AsyncOperation {
-    private let block: (@escaping () -> Void) -> Void
+    private let block: ((@escaping () -> Void) -> Void)
 
     init(_ block: @escaping (@escaping () -> Void) -> Void) {
         self.block = block
@@ -18,9 +18,8 @@ class AsyncBlockOperation: AsyncOperation {
     }
 
     override func main() {
-        self.block { [weak self] in
+        block { [weak self] in
             self?.finish()
         }
     }
 }
-
diff --git a/ios/MullvadVPN/Operations/AsyncOperation.swift b/ios/MullvadVPN/Operations/AsyncOperation.swift
index 44e8e791f3..2d1819ee30 100644
--- a/ios/MullvadVPN/Operations/AsyncOperation.swift
+++ b/ios/MullvadVPN/Operations/AsyncOperation.swift
@@ -9,17 +9,10 @@
 import Foundation
 
 /// A base implementation of an asynchronous operation
-class AsyncOperation: Operation, OperationProtocol {
-
-    /// A state transaction lock used to perform critical sections of code within `start`, `cancel`
-    /// and `finish` calls.
-    fileprivate let transactionLock = NSRecursiveLock()
+class AsyncOperation: Operation {
 
     /// A state lock used for manipulating the operation state flags in a thread safe fashion.
-    fileprivate let stateLock = NSRecursiveLock()
-
-    /// The operation observers.
-    fileprivate var observers: [AnyOperationObserver<AsyncOperation>] = []
+    private let stateLock = NSRecursiveLock()
 
     /// Operation state flags.
     private var _isExecuting = false
@@ -43,14 +36,14 @@ class AsyncOperation: Operation, OperationProtocol {
     }
 
     final override func start() {
-        transactionLock.withCriticalBlock {
-            if self.isCancelled {
-                self.finish()
-            } else {
-                self.observers.forEach { $0.operationWillExecute(self) }
-                self.setExecuting(true)
-                self.main()
-            }
+        stateLock.lock()
+        if _isCancelled {
+            finish()
+            stateLock.unlock()
+        } else {
+            setExecuting(true)
+            stateLock.unlock()
+            main()
         }
     }
 
@@ -58,99 +51,34 @@ class AsyncOperation: Operation, OperationProtocol {
         // Override in subclasses
     }
 
-    /// Cancel operation
-    /// Subclasses should override `operationDidCancel` instead
-    final override func cancel() {
-        transactionLock.withCriticalBlock {
-            if self.isCancelled {
-                super.cancel()
-            } else {
-                self.setCancelled(true)
-
-                super.cancel()
-
-                // Only notify the operation about cancellation when it is already running,
-                // otherwise the call to `start` should automatically `finish()` the operation.
-                if self.isExecuting {
-                    self.operationDidCancel()
-                }
+    override func cancel() {
+        stateLock.withCriticalBlock {
+            if !_isCancelled {
+                willChangeValue(for: \.isCancelled)
+                _isCancelled = true
+                didChangeValue(for: \.isCancelled)
             }
         }
-    }
-
-    /// Override in subclasses to support task cancellation.
-    /// Subclasses should call `finish()` to complete the operation
-    func operationDidCancel() {
-        // no-op
+        super.cancel()
     }
 
     final func finish() {
-        transactionLock.withCriticalBlock {
-            guard !self.isFinished else { return }
-
-            self.stateLock.withCriticalBlock {
-                self.observers.forEach { $0.operationWillFinish(self) }
-            }
-
-            if self.isExecuting {
-                self.setExecuting(false)
+        stateLock.withCriticalBlock {
+            if _isExecuting {
+               setExecuting(false)
             }
 
-            self.setFinished(true)
-
-            self.stateLock.withCriticalBlock {
-                self.observers.forEach { $0.operationDidFinish(self) }
+            if !_isFinished {
+                willChangeValue(for: \.isFinished)
+                _isFinished = true
+                didChangeValue(for: \.isFinished)
             }
         }
     }
 
     private func setExecuting(_ value: Bool) {
         willChangeValue(for: \.isExecuting)
-        stateLock.withCriticalBlock { _isExecuting = value }
+        _isExecuting = value
         didChangeValue(for: \.isExecuting)
     }
-
-    private func setFinished(_ value: Bool) {
-        willChangeValue(for: \.isFinished)
-        stateLock.withCriticalBlock { _isFinished = value }
-        didChangeValue(for: \.isFinished)
-    }
-
-    private func setCancelled(_ value: Bool) {
-        willChangeValue(for: \.isCancelled)
-        stateLock.withCriticalBlock { _isCancelled = value }
-        didChangeValue(for: \.isCancelled)
-    }
-
-    // MARK: - Observation
-
-    /// Add type-erased operation observer
-    fileprivate func addAnyObserver(_ observer: AnyOperationObserver<AsyncOperation>) {
-        stateLock.withCriticalBlock {
-            self.observers.append(observer)
-        }
-    }
-}
-
-/// This extension exists because Swift has some issues with infering the associated type in `OperationObserver`
-extension OperationProtocol where Self: AsyncOperation {
-    func addObserver<T: OperationObserver>(_ observer: T) where T.OperationType == Self {
-        let transform = TransformOperationObserver<AsyncOperation>(observer)
-        let wrapped = AnyOperationObserver(transform)
-        addAnyObserver(wrapped)
-    }
-}
-
-
-protocol OperationSubclassing {
-    /// Use this method in subclasses or extensions where you would like to synchronize
-    /// the class members access using the same lock used for guarding from race conditions
-    /// when managing operation state.
-    func synchronized<T>(_ body: () -> T) -> T
-}
-
-extension AsyncOperation: OperationSubclassing {
-    func synchronized<T>(_ body: () -> T) -> T {
-        return stateLock.withCriticalBlock(body)
-    }
 }
diff --git a/ios/MullvadVPN/Operations/DelayOperation.swift b/ios/MullvadVPN/Operations/DelayOperation.swift
deleted file mode 100644
index 80719b573d..0000000000
--- a/ios/MullvadVPN/Operations/DelayOperation.swift
+++ /dev/null
@@ -1,48 +0,0 @@
-//
-//  DelayOperation.swift
-//  MullvadVPN
-//
-//  Created by pronebird on 06/07/2020.
-//  Copyright © 2020 Mullvad VPN AB. All rights reserved.
-//
-
-import Foundation
-
-enum DelayTimerType {
-    case deadline
-    case walltime
-}
-
-class DelayOperation: AsyncOperation {
-    private let delay: TimeInterval
-    private let timerType: DelayTimerType
-    private var timer: DispatchSourceTimer?
-
-    init(delay: TimeInterval, timerType: DelayTimerType) {
-        self.delay = delay
-        self.timerType = timerType
-    }
-
-    override func main() {
-        let timer = DispatchSource.makeTimerSource()
-        timer.setEventHandler { [weak self] in
-            self?.finish()
-        }
-
-        switch timerType {
-        case .deadline:
-            timer.schedule(deadline: DispatchTime.now() + delay)
-        case .walltime:
-            timer.schedule(wallDeadline: DispatchWallTime.now() + delay)
-        }
-
-        self.timer = timer
-        timer.activate()
-    }
-
-    override func operationDidCancel() {
-        timer?.cancel()
-        timer = nil
-        finish()
-    }
-}
diff --git a/ios/MullvadVPN/Operations/InputOperation.swift b/ios/MullvadVPN/Operations/InputOperation.swift
deleted file mode 100644
index a1c9d6931d..0000000000
--- a/ios/MullvadVPN/Operations/InputOperation.swift
+++ /dev/null
@@ -1,103 +0,0 @@
-//
-//  InputOperation.swift
-//  MullvadVPN
-//
-//  Created by pronebird on 06/07/2020.
-//  Copyright © 2020 Mullvad VPN AB. All rights reserved.
-//
-
-import Foundation
-
-protocol InputOperation: OperationProtocol {
-    associatedtype Input
-
-    /// When overriding `input` in Subclasses, make sure to call `operationDidSetInput`
-    var input: Input? { get set }
-
-    func operationDidSetInput(_ input: Input?)
-}
-
-private var kInputOperationAssociatedValue = 0
-extension InputOperation where Self: OperationSubclassing {
-    var input: Input? {
-        get {
-            return synchronized {
-                return AssociatedValue.get(object: self, key: &kInputOperationAssociatedValue)
-            }
-        }
-        set {
-            synchronized {
-                AssociatedValue.set(object: self, key: &kInputOperationAssociatedValue, value: newValue)
-
-                operationDidSetInput(newValue)
-            }
-        }
-    }
-
-    func operationDidSetInput(_ input: Input?) {
-        // Override in subclasses
-    }
-}
-
-extension InputOperation {
-
-    @discardableResult func inject<Dependency>(from dependency: Dependency, via block: @escaping (Dependency.Output) -> Input?) -> Self
-        where Dependency: OutputOperation
-    {
-        let observer = OperationBlockObserver<Dependency>(willFinish: { [weak self] (operation) in
-            guard let self = self else { return }
-
-            if let output = operation.output {
-                self.input = block(output)
-            }
-        })
-        dependency.addObserver(observer)
-        addDependency(dependency)
-
-        return self
-    }
-
-    @discardableResult func injectResult<Dependency>(from dependency: Dependency) -> Self
-        where Dependency: OutputOperation, Dependency.Output == Input?
-    {
-        return self.inject(from: dependency, via: { $0 })
-    }
-
-    /// Inject input from operation that outputs `Result<Input, Failure>`
-    @discardableResult func injectResult<Dependency, Failure>(from dependency: Dependency) -> Self
-        where Dependency: OutputOperation, Failure: Error, Dependency.Output == Result<Input, Failure>
-    {
-        return self.inject(from: dependency) { (output) -> Input? in
-            switch output {
-            case .success(let value):
-                return value
-            case .failure:
-                return nil
-            }
-        }
-    }
-
-    /// Inject input from operation that outputs `Result<Input, Never>`
-    @discardableResult func injectResult<Dependency>(from dependency: Dependency) -> Self
-        where Dependency: OutputOperation, Dependency.Output == Result<Input, Never>
-    {
-        return self.inject(from: dependency) { (output) -> Input? in
-            switch output {
-            case .success(let value):
-                return value
-            }
-        }
-    }
-
-    /// Inject input from operation that outputs `Result<Input?, Never>`
-    @discardableResult func injectResult<Dependency>(from dependency: Dependency) -> Self
-        where Dependency: OutputOperation, Dependency.Output == Result<Input?, Never>
-    {
-        return self.inject(from: dependency) { (output) -> Input? in
-            switch output {
-            case .success(let value):
-                return value
-            }
-        }
-    }
-}
diff --git a/ios/MullvadVPN/Operations/OperationBlockObserver.swift b/ios/MullvadVPN/Operations/OperationBlockObserver.swift
deleted file mode 100644
index 1ba2f1ae50..0000000000
--- a/ios/MullvadVPN/Operations/OperationBlockObserver.swift
+++ /dev/null
@@ -1,67 +0,0 @@
-//
-//  OperationBlockObserver.swift
-//  MullvadVPN
-//
-//  Created by pronebird on 06/07/2020.
-//  Copyright © 2020 Mullvad VPN AB. All rights reserved.
-//
-
-import Foundation
-
-class OperationBlockObserver<OperationType: OperationProtocol>: OperationObserver {
-    private var willExecute: ((OperationType) -> Void)?
-    private var willFinish: ((OperationType) -> Void)?
-    private var didFinish: ((OperationType) -> Void)?
-
-    let queue: DispatchQueue?
-
-    init(
-        queue: DispatchQueue? = nil,
-        willExecute: ((OperationType) -> Void)? = nil,
-        willFinish: ((OperationType) -> Void)? = nil,
-        didFinish: ((OperationType) -> Void)? = nil
-    ) {
-        self.queue = queue
-        self.willExecute = willExecute
-        self.willFinish = willFinish
-        self.didFinish = didFinish
-    }
-
-    func operationWillExecute(_ operation: OperationType) {
-        if let willExecute = willExecute {
-            scheduleEvent {
-                willExecute(operation)
-            }
-        }
-    }
-
-    func operationWillFinish(_ operation: OperationType) {
-        if let willFinish = self.willFinish {
-            scheduleEvent {
-                willFinish(operation)
-            }
-        }
-    }
-
-    func operationDidFinish(_ operation: OperationType) {
-        if let didFinish = self.didFinish {
-            scheduleEvent {
-                didFinish(operation)
-            }
-        }
-    }
-
-    private func scheduleEvent(_ body: @escaping () -> Void) {
-        if let queue = queue {
-            queue.async(execute: body)
-        } else {
-            body()
-        }
-    }
-}
-
-extension OperationProtocol {
-    func addDidFinishBlockObserver(queue: DispatchQueue? = nil, _ block: @escaping (Self) -> Void) {
-        addObserver(OperationBlockObserver(queue: queue, didFinish: block))
-    }
-}
diff --git a/ios/MullvadVPN/Operations/OperationObserver.swift b/ios/MullvadVPN/Operations/OperationObserver.swift
deleted file mode 100644
index a7d3ea3aa3..0000000000
--- a/ios/MullvadVPN/Operations/OperationObserver.swift
+++ /dev/null
@@ -1,18 +0,0 @@
-//
-//  OperationObserver.swift
-//  MullvadVPN
-//
-//  Created by pronebird on 06/07/2020.
-//  Copyright © 2020 Mullvad VPN AB. All rights reserved.
-//
-
-import Foundation
-
-protocol OperationObserver {
-    associatedtype OperationType: OperationProtocol
-
-    func operationWillExecute(_ operation: OperationType)
-    func operationWillFinish(_ operation: OperationType)
-    func operationDidFinish(_ operation: OperationType)
-}
-
diff --git a/ios/MullvadVPN/Operations/OperationProtocol.swift b/ios/MullvadVPN/Operations/OperationProtocol.swift
deleted file mode 100644
index a41102c265..0000000000
--- a/ios/MullvadVPN/Operations/OperationProtocol.swift
+++ /dev/null
@@ -1,20 +0,0 @@
-//
-//  OperationProtocol.swift
-//  MullvadVPN
-//
-//  Created by pronebird on 06/07/2020.
-//  Copyright © 2020 Mullvad VPN AB. All rights reserved.
-//
-
-import Foundation
-
-protocol OperationProtocol: Operation {
-    /// Add operation observer
-    func addObserver<T: OperationObserver>(_ observer: T) where T.OperationType == Self
-
-    /// Finish operation
-    func finish()
-
-    /// Cancel operation
-    func cancel()
-}
diff --git a/ios/MullvadVPN/Operations/OutputOperation.swift b/ios/MullvadVPN/Operations/OutputOperation.swift
deleted file mode 100644
index 064d54a2e9..0000000000
--- a/ios/MullvadVPN/Operations/OutputOperation.swift
+++ /dev/null
@@ -1,50 +0,0 @@
-//
-//  OutputOperation.swift
-//  MullvadVPN
-//
-//  Created by pronebird on 06/07/2020.
-//  Copyright © 2020 Mullvad VPN AB. All rights reserved.
-//
-
-import Foundation
-
-protocol OutputOperation: OperationProtocol {
-    associatedtype Output
-
-    var output: Output? { get set }
-
-    func finish(with output: Output)
-}
-
-extension OutputOperation {
-    func finish(with output: Output) {
-        self.output = output
-        self.finish()
-    }
-}
-
-private var kOutputOperationAssociatedValue = 0
-extension OutputOperation where Self: OperationSubclassing {
-    var output: Output? {
-        get {
-            return synchronized {
-                return AssociatedValue.get(object: self, key: &kOutputOperationAssociatedValue)
-            }
-        }
-        set {
-            synchronized {
-                AssociatedValue.set(object: self, key: &kOutputOperationAssociatedValue, value: newValue)
-            }
-        }
-    }
-}
-
-extension OperationProtocol where Self: OutputOperation {
-    func addDidFinishBlockObserver(queue: DispatchQueue? = nil, _ block: @escaping (Self, Output) -> Void) {
-        addDidFinishBlockObserver(queue: queue) { (operation) in
-            if let output = operation.output {
-                block(operation, output)
-            }
-        }
-    }
-}
diff --git a/ios/MullvadVPN/Operations/ResultOperation.swift b/ios/MullvadVPN/Operations/ResultOperation.swift
deleted file mode 100644
index 7ce9c20358..0000000000
--- a/ios/MullvadVPN/Operations/ResultOperation.swift
+++ /dev/null
@@ -1,63 +0,0 @@
-//
-//  ResultOperation.swift
-//  MullvadVPN
-//
-//  Created by pronebird on 06/07/2020.
-//  Copyright © 2020 Mullvad VPN AB. All rights reserved.
-//
-
-import Foundation
-
-class ResultOperation<Success, Failure: Error>: AsyncOperation, OutputOperation {
-    typealias Output = Result<Success, Failure>
-
-    private enum Executor {
-        case callback((@escaping (Result<Success, Failure>) -> Void) -> Void)
-        case transform(() -> Result<Success, Failure>)
-    }
-
-    private let executor: Executor
-
-    private init(_ executor: Executor) {
-        self.executor = executor
-    }
-
-    convenience init(_ block: @escaping (@escaping (Output) -> Void) -> Void) {
-        self.init(.callback(block))
-    }
-
-    convenience init(_ block: @escaping () -> Output) {
-        self.init(.transform(block))
-    }
-
-    override func main() {
-        switch executor {
-        case .callback(let block):
-            block { [weak self] (result) in
-                self?.finish(with: result)
-            }
-
-        case .transform(let block):
-            self.finish(with: block())
-        }
-    }
-
-}
-
-extension ResultOperation where Failure == Never {
-    /// A convenience initializer for infallible `ResultOperation` that automatically wraps the
-    /// return value of the given closure into `Result<Success, Never>`
-    convenience init(_ block: @escaping () -> Success) {
-        self.init(.transform({ .success(block()) }))
-    }
-
-    /// A convenience initializer for infallible `ResultOperation` that automatically wraps the
-    /// value, passed to the given closure, into `Result<Success, Never>`
-    convenience init(_ block: @escaping (@escaping (Success) -> Void) -> Void) {
-        self.init(.callback({ (finish) in
-            block {
-                finish(.success($0))
-            }
-        }))
-    }
-}
diff --git a/ios/MullvadVPN/Operations/RetryOperation.swift b/ios/MullvadVPN/Operations/RetryOperation.swift
deleted file mode 100644
index 1e73e81d79..0000000000
--- a/ios/MullvadVPN/Operations/RetryOperation.swift
+++ /dev/null
@@ -1,120 +0,0 @@
-//
-//  RetryOperation.swift
-//  MullvadVPN
-//
-//  Created by pronebird on 06/07/2020.
-//  Copyright © 2020 Mullvad VPN AB. All rights reserved.
-//
-
-import Foundation
-
-enum WaitStrategy {
-    case immediate
-    case constant(TimeInterval)
-
-    var iterator: AnyIterator<TimeInterval> {
-        switch self {
-        case .immediate:
-            return AnyIterator { .zero }
-        case .constant(let constant):
-            return AnyIterator { constant }
-        }
-    }
-}
-
-struct RetryStrategy {
-    var maxRetries: Int
-    var waitStrategy: WaitStrategy
-    var waitTimerType: DelayTimerType
-}
-
-class RetryOperation<OperationType, Success, Failure: Error>: AsyncOperation, OutputOperation
-    where OperationType: OutputOperation, OperationType.Output == Result<Success, Failure>
-{
-    typealias Output = OperationType.Output
-
-    private let operationQueue = OperationQueue()
-
-    private let producer: () -> OperationType
-    private let delayIterator: AnyIterator<TimeInterval>
-
-    private var retryCount: Int = 0
-    private let retryStrategy: RetryStrategy
-
-    private var childConfigurator: ((OperationType) -> Void)?
-
-    init(underlyingQueue: DispatchQueue? = nil, strategy: RetryStrategy, producer: @escaping () -> OperationType) {
-        operationQueue.underlyingQueue = underlyingQueue
-        delayIterator = strategy.waitStrategy.iterator
-        retryStrategy = strategy
-        self.producer = producer
-    }
-
-    override func main() {
-        retry()
-    }
-
-    override func operationDidCancel() {
-        operationQueue.cancelAllOperations()
-    }
-
-    private func retry(delay: TimeInterval? = nil) {
-        let child = producer()
-
-        child.addDidFinishBlockObserver { [weak self] (operation) in
-            guard let self = self else { return }
-
-            // Operation finished without output set?
-            guard let result = operation.output else {
-                self.finish()
-                return
-            }
-
-            self.synchronized {
-                guard case .failure(let error) = result,
-                    let delay = self.delayIterator.next(),
-                    self.shouldRetry(error: error) else {
-                    self.finish(with: result)
-                    return
-                }
-
-                self.retryCount += 1
-                self.retry(delay: delay)
-            }
-        }
-
-        synchronized {
-            childConfigurator?(child)
-        }
-
-        if let delay = delay {
-            let delayOperation = DelayOperation(delay: delay, timerType: retryStrategy.waitTimerType)
-
-            child.addDependency(delayOperation)
-            operationQueue.addOperation(delayOperation)
-        }
-
-        operationQueue.addOperation(child)
-    }
-
-    private func setChildConfigurator(_ body: @escaping (OperationType) -> Void) {
-        synchronized {
-            self.childConfigurator = body
-        }
-    }
-
-    private func shouldRetry(error: Failure) -> Bool {
-        return retryCount < retryStrategy.maxRetries && !self.isCancelled
-    }
-
-}
-
-extension RetryOperation: InputOperation where OperationType: InputOperation {
-    typealias Input = OperationType.Input
-
-    func operationDidSetInput(_ input: OperationType.Input?) {
-        setChildConfigurator { (child) in
-            child.input = input
-        }
-    }
-}
diff --git a/ios/MullvadVPN/Operations/TransformOperation.swift b/ios/MullvadVPN/Operations/TransformOperation.swift
deleted file mode 100644
index ce2a1617ea..0000000000
--- a/ios/MullvadVPN/Operations/TransformOperation.swift
+++ /dev/null
@@ -1,50 +0,0 @@
-//
-//  TransformOperation.swift
-//  MullvadVPN
-//
-//  Created by pronebird on 06/07/2020.
-//  Copyright © 2020 Mullvad VPN AB. All rights reserved.
-//
-
-import Foundation
-
-class TransformOperation<Input, Output>: AsyncOperation, InputOperation, OutputOperation {
-    private enum Executor {
-        case callback((Input, @escaping (Output) -> Void) -> Void)
-        case transform((Input) -> Output)
-    }
-
-    private let executor: Executor
-
-    private init(input: Input? = nil, executor: Executor) {
-        self.executor = executor
-
-        super.init()
-        self.input = input
-    }
-
-    convenience init(input: Input? = nil, _ block: @escaping (Input, @escaping (Output) -> Void) -> Void) {
-        self.init(input: input, executor: .callback(block))
-    }
-
-    convenience init(input: Input? = nil, _ block: @escaping (Input) -> Output) {
-        self.init(input: input, executor: .transform(block))
-    }
-
-    override func main() {
-        guard let input = input else {
-            self.finish()
-            return
-        }
-
-        switch executor {
-        case .callback(let block):
-            block(input) { [weak self] (result) in
-                self?.finish(with: result)
-            }
-
-        case .transform(let block):
-            self.finish(with: block(input))
-        }
-    }
-}
diff --git a/ios/MullvadVPN/Operations/TransformOperationObserver.swift b/ios/MullvadVPN/Operations/TransformOperationObserver.swift
deleted file mode 100644
index e6ed695e0b..0000000000
--- a/ios/MullvadVPN/Operations/TransformOperationObserver.swift
+++ /dev/null
@@ -1,45 +0,0 @@
-//
-//  TransformOperationObserver.swift
-//  MullvadVPN
-//
-//  Created by pronebird on 06/07/2020.
-//  Copyright © 2020 Mullvad VPN AB. All rights reserved.
-//
-
-import Foundation
-
-/// A private type erasing observer that type casts the input operation type to the expected
-/// operation type before calling the wrapped observer
-class TransformOperationObserver<S: OperationProtocol>: OperationObserver {
-    private let willExecute: (S) -> Void
-    private let willFinish: (S) -> Void
-    private let didFinish: (S) -> Void
-
-    init<T: OperationObserver>(_ observer: T) {
-        willExecute = Self.wrap(observer.operationWillExecute)
-        willFinish = Self.wrap(observer.operationWillFinish)
-        didFinish = Self.wrap(observer.operationDidFinish)
-    }
-
-    func operationWillExecute(_ operation: S) {
-        willExecute(operation)
-    }
-
-    func operationWillFinish(_ operation: S) {
-        willFinish(operation)
-    }
-
-    func operationDidFinish(_ operation: S) {
-        didFinish(operation)
-    }
-
-    private class func wrap<U>(_ body: @escaping (U) -> Void) -> (S) -> Void {
-        return { (operation: S) in
-            if let transformed = operation as? U {
-                body(transformed)
-            } else {
-                fatalError("\(Self.self) failed to cast \(S.self) to \(U.self)")
-            }
-        }
-    }
-}