Merge branch 'relay-cache-instance'

6 files changed, 90 insertions, 115 deletions

diff --git a/ios/MullvadVPN.xcodeproj/project.pbxproj b/ios/MullvadVPN.xcodeproj/project.pbxproj
index 5d8832ca44..bf46a635ec 100644
--- a/ios/MullvadVPN.xcodeproj/project.pbxproj
+++ b/ios/MullvadVPN.xcodeproj/project.pbxproj
@@ -287,7 +287,7 @@
 		58F7CA882692E34000FC59FD /* WireguardKeysContentView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 58F7CA872692E34000FC59FD /* WireguardKeysContentView.swift */; };
 		58F8AC0E25D3F8CE002BE0ED /* ProblemReportReviewViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 58F8AC0D25D3F8CE002BE0ED /* ProblemReportReviewViewController.swift */; };
 		58FB865526E8BF3100F188BC /* AppStorePaymentManagerError.swift in Sources */ = {isa = PBXBuildFile; fileRef = 58FB865426E8BF3100F188BC /* AppStorePaymentManagerError.swift */; };
-		58FB865A26EA214400F188BC /* RelayCacheObserver.swift in Sources */ = {isa = PBXBuildFile; fileRef = 58FB865926EA214400F188BC /* RelayCacheObserver.swift */; };
+		58FB865A26EA214400F188BC /* RelayCacheTrackerObserver.swift in Sources */ = {isa = PBXBuildFile; fileRef = 58FB865926EA214400F188BC /* RelayCacheTrackerObserver.swift */; };
 		58FC040A27B3EE03001C21F0 /* TunnelMonitor.swift in Sources */ = {isa = PBXBuildFile; fileRef = 58FC040927B3EE03001C21F0 /* TunnelMonitor.swift */; };
 		58FD5BE724192A2C00112C88 /* AppStoreReceipt.swift in Sources */ = {isa = PBXBuildFile; fileRef = 58FD5BE624192A2B00112C88 /* AppStoreReceipt.swift */; };
 		58FD5BF024238EB300112C88 /* SKProduct+Formatting.swift in Sources */ = {isa = PBXBuildFile; fileRef = 58FD5BEF24238EB300112C88 /* SKProduct+Formatting.swift */; };
@@ -753,7 +753,7 @@
 		58F7D26427EB50A300E4D821 /* ResultOperation.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ResultOperation.swift; sourceTree = "<group>"; };
 		58F8AC0D25D3F8CE002BE0ED /* ProblemReportReviewViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ProblemReportReviewViewController.swift; sourceTree = "<group>"; };
 		58FB865426E8BF3100F188BC /* AppStorePaymentManagerError.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppStorePaymentManagerError.swift; sourceTree = "<group>"; };
-		58FB865926EA214400F188BC /* RelayCacheObserver.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RelayCacheObserver.swift; sourceTree = "<group>"; };
+		58FB865926EA214400F188BC /* RelayCacheTrackerObserver.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RelayCacheTrackerObserver.swift; sourceTree = "<group>"; };
 		58FC040927B3EE03001C21F0 /* TunnelMonitor.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TunnelMonitor.swift; sourceTree = "<group>"; };
 		58FD5BE624192A2B00112C88 /* AppStoreReceipt.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppStoreReceipt.swift; sourceTree = "<group>"; };
 		58FD5BEF24238EB300112C88 /* SKProduct+Formatting.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "SKProduct+Formatting.swift"; sourceTree = "<group>"; };
@@ -1059,7 +1059,7 @@
 		585DA87526B0249A00B8C587 /* RelayCache */ = {
 			isa = PBXGroup;
 			children = (
-				58FB865926EA214400F188BC /* RelayCacheObserver.swift */,
+				58FB865926EA214400F188BC /* RelayCacheTrackerObserver.swift */,
 				58BFA5C522A7C97F00A6173D /* RelayCacheTracker.swift */,
 			);
 			path = RelayCache;
@@ -2060,7 +2060,7 @@
 				584D26C2270C8542004EA533 /* SettingsStaticTextFooterView.swift in Sources */,
 				587B7536266528A200DEF7E9 /* NotificationManager.swift in Sources */,
 				5820EDA9288FE064006BF4E4 /* DeviceManagementInteractor.swift in Sources */,
-				58FB865A26EA214400F188BC /* RelayCacheObserver.swift in Sources */,
+				58FB865A26EA214400F188BC /* RelayCacheTrackerObserver.swift in Sources */,
 				58ACF64D26567A5000ACE4B7 /* CustomSwitch.swift in Sources */,
 				58F2E14C276A61C000A79513 /* RotateKeyOperation.swift in Sources */,
 				5871FB96254ADE4E0051A0A4 /* ConsolidatedApplicationLog.swift in Sources */,
diff --git a/ios/MullvadVPN/RelayCache/RelayCacheTracker.swift b/ios/MullvadVPN/RelayCache/RelayCacheTracker.swift
index b003ae6868..c6d0b64ef0 100644
--- a/ios/MullvadVPN/RelayCache/RelayCacheTracker.swift
+++ b/ios/MullvadVPN/RelayCache/RelayCacheTracker.swift
@@ -21,11 +21,10 @@ class RelayCacheTracker {
     /// Tracker log.
     private let logger = Logger(label: "RelayCacheTracker")
 
-    /// The cache location used by the class instance.
-    private let cacheFileURL: URL
-
-    /// The location of prebundled `relays.json`.
-    private let prebundledRelaysFileURL: URL
+    /// Relay cache.
+    private let cache = RelayCache(
+        securityGroupIdentifier: ApplicationConfiguration.securityGroupIdentifier
+    )!
 
     /// Lock used for synchronization.
     private let nslock = NSLock()
@@ -47,35 +46,17 @@ class RelayCacheTracker {
     private let apiProxy = REST.ProxyFactory.shared.createAPIProxy()
 
     /// Observers.
-    private let observerList = ObserverList<RelayCacheObserver>()
+    private let observerList = ObserverList<RelayCacheTrackerObserver>()
 
     /// Memory cache.
     private var cachedRelays: CachedRelays?
 
-    /// A shared instance of `RelayCache`
-    static let shared: RelayCacheTracker = {
-        let cacheFileURL = RelayCache
-            .defaultCacheFileURL(
-                forSecurityApplicationGroupIdentifier: ApplicationConfiguration
-                    .securityGroupIdentifier
-            )!
-        let prebundledRelaysFileURL = RelayCache.preBundledRelaysFileURL!
-
-        return RelayCacheTracker(
-            cacheFileURL: cacheFileURL,
-            prebundledRelaysFileURL: prebundledRelaysFileURL
-        )
-    }()
-
-    private init(cacheFileURL: URL, prebundledRelaysFileURL: URL) {
-        self.cacheFileURL = cacheFileURL
-        self.prebundledRelaysFileURL = prebundledRelaysFileURL
+    /// A shared instance of `RelayCacheTracker`.
+    static let shared = RelayCacheTracker()
 
+    private init() {
         do {
-            cachedRelays = try RelayCache.readWithFallback(
-                cacheFileURL: cacheFileURL,
-                preBundledRelaysFileURL: prebundledRelaysFileURL
-            )
+            cachedRelays = try cache.read()
         } catch {
             logger.error(
                 error: error,
@@ -180,11 +161,11 @@ class RelayCacheTracker {
 
     // MARK: - Observation
 
-    func addObserver(_ observer: RelayCacheObserver) {
+    func addObserver(_ observer: RelayCacheTrackerObserver) {
         observerList.append(observer)
     }
 
-    func removeObserver(_ observer: RelayCacheObserver) {
+    func removeObserver(_ observer: RelayCacheTrackerObserver) {
         observerList.remove(observer)
     }
 
@@ -242,14 +223,11 @@ class RelayCacheTracker {
         cachedRelays = newCachedRelays
         nslock.unlock()
 
-        try RelayCache.write(
-            cacheFileURL: cacheFileURL,
-            record: newCachedRelays
-        )
+        try cache.write(record: newCachedRelays)
 
         DispatchQueue.main.async {
             self.observerList.forEach { observer in
-                observer.relayCache(self, didUpdateCachedRelays: newCachedRelays)
+                observer.relayCacheTracker(self, didUpdateCachedRelays: newCachedRelays)
             }
         }
     }
diff --git a/ios/MullvadVPN/RelayCache/RelayCacheObserver.swift b/ios/MullvadVPN/RelayCache/RelayCacheTrackerObserver.swift
index 4b109340f0..fcb38b55d6 100644
--- a/ios/MullvadVPN/RelayCache/RelayCacheObserver.swift
+++ b/ios/MullvadVPN/RelayCache/RelayCacheTrackerObserver.swift
@@ -1,6 +1,6 @@
 //
-//  RelayCacheObserver.swift
-//  RelayCacheObserver
+//  RelayCacheTrackerObserver.swift
+//  RelayCacheTrackerObserver
 //
 //  Created by pronebird on 09/09/2021.
 //  Copyright © 2021 Mullvad VPN AB. All rights reserved.
@@ -9,9 +9,9 @@
 import Foundation
 import RelayCache
 
-protocol RelayCacheObserver: AnyObject {
-    func relayCache(
-        _ relayCache: RelayCacheTracker,
+protocol RelayCacheTrackerObserver: AnyObject {
+    func relayCacheTracker(
+        _ tracker: RelayCacheTracker,
         didUpdateCachedRelays cachedRelays: CachedRelays
     )
 }
diff --git a/ios/MullvadVPN/SceneDelegate.swift b/ios/MullvadVPN/SceneDelegate.swift
index 6a8a136f4a..df8b629b92 100644
--- a/ios/MullvadVPN/SceneDelegate.swift
+++ b/ios/MullvadVPN/SceneDelegate.swift
@@ -931,11 +931,11 @@ extension SceneDelegate: TunnelObserver {
     }
 }
 
-// MARK: - RelayCacheObserver
+// MARK: - RelayCacheTrackerObserver
 
-extension SceneDelegate: RelayCacheObserver {
-    func relayCache(
-        _ relayCache: RelayCacheTracker,
+extension SceneDelegate: RelayCacheTrackerObserver {
+    func relayCacheTracker(
+        _ tracker: RelayCacheTracker,
         didUpdateCachedRelays cachedRelays: CachedRelays
     ) {
         selectLocationViewController?.setCachedRelays(cachedRelays)
diff --git a/ios/PacketTunnel/PacketTunnelProvider.swift b/ios/PacketTunnel/PacketTunnelProvider.swift
index 00b8c47b97..1ec04c0afe 100644
--- a/ios/PacketTunnel/PacketTunnelProvider.swift
+++ b/ios/PacketTunnel/PacketTunnelProvider.swift
@@ -40,6 +40,11 @@ class PacketTunnelProvider: NEPacketTunnelProvider, TunnelMonitorDelegate {
     /// Last runtime error.
     private var lastError: Error?
 
+    /// Relay cache.
+    private let relayCache = RelayCache(
+        securityGroupIdentifier: ApplicationConfiguration.securityGroupIdentifier
+    )!
+
     /// Current selector result.
     private var selectorResult: RelaySelectorResult?
 
@@ -363,7 +368,7 @@ class PacketTunnelProvider: NEPacketTunnelProvider, TunnelMonitorDelegate {
 
         switch nextRelay {
         case .automatic:
-            selectorResult = try Self.selectRelayEndpoint(
+            selectorResult = try selectRelayEndpoint(
                 relayConstraints: tunnelSettings.relayConstraints
             )
         case let .set(aSelectorResult):
@@ -436,17 +441,10 @@ class PacketTunnelProvider: NEPacketTunnelProvider, TunnelMonitorDelegate {
 
     /// Load relay cache with potential networking to refresh the cache and pick the relay for the
     /// given relay constraints.
-    private class func selectRelayEndpoint(relayConstraints: RelayConstraints) throws
+    private func selectRelayEndpoint(relayConstraints: RelayConstraints) throws
         -> RelaySelectorResult
     {
-        let cacheFileURL = RelayCache.defaultCacheFileURL(
-            forSecurityApplicationGroupIdentifier: ApplicationConfiguration.securityGroupIdentifier
-        )!
-        let prebundledRelaysURL = RelayCache.preBundledRelaysFileURL!
-        let cachedRelayList = try RelayCache.readWithFallback(
-            cacheFileURL: cacheFileURL,
-            preBundledRelaysFileURL: prebundledRelaysURL
-        )
+        let cachedRelayList = try relayCache.read()
 
         return try RelaySelector.evaluate(
             relays: cachedRelayList.relays,
diff --git a/ios/RelayCache/RelayCache.swift b/ios/RelayCache/RelayCache.swift
index 64ce748128..0952f05438 100644
--- a/ios/RelayCache/RelayCache.swift
+++ b/ios/RelayCache/RelayCache.swift
@@ -9,80 +9,40 @@
 import Foundation
 import MullvadREST
 
-public class RelayCache {
-    /// The default cache file location bound by app group container.
-    public static func defaultCacheFileURL(
-        forSecurityApplicationGroupIdentifier appGroupIdentifier: String
-    ) -> URL? {
-        let containerURL = FileManager.default.containerURL(
-            forSecurityApplicationGroupIdentifier: appGroupIdentifier
-        )
+public final class RelayCache {
+    /// Cache file location.
+    let cacheFileURL: URL
 
-        return containerURL?.appendingPathComponent("relays.json")
-    }
+    /// Location of pre-bundled relays file.
+    let prebundledRelaysFileURL: URL
 
-    /// The path to pre-bundled `relays.json` file.
-    public static var preBundledRelaysFileURL: URL? {
-        return Bundle(for: Self.self).url(forResource: "relays", withExtension: "json")
-    }
-
-    /// Safely read the cache file from disk using file coordinator.
-    public static func read(cacheFileURL: URL) throws -> CachedRelays {
-        var result: Result<CachedRelays, Error>?
-        let fileCoordinator = NSFileCoordinator(filePresenter: nil)
+    /// Initialize cache with default cache file location in app group container.
+    public init?(securityGroupIdentifier: String) {
+        guard let containerURL = FileManager.default.containerURL(
+            forSecurityApplicationGroupIdentifier: securityGroupIdentifier
+        ), let prebundledRelaysFileURL = Bundle(for: Self.self)
+            .url(forResource: "relays", withExtension: "json") else { return nil }
 
-        let accessor = { (fileURLForReading: URL) in
-            result = Result {
-                let data = try Data(contentsOf: fileURLForReading)
-                return try JSONDecoder().decode(CachedRelays.self, from: data)
-            }
-        }
-
-        var error: NSError?
-        fileCoordinator.coordinate(
-            readingItemAt: cacheFileURL,
-            options: [.withoutChanges],
-            error: &error,
-            byAccessor: accessor
-        )
-
-        if let error = error {
-            result = .failure(error)
-        }
-
-        return try result!.get()
+        cacheFileURL = containerURL.appendingPathComponent("relays.json", isDirectory: false)
+        self.prebundledRelaysFileURL = prebundledRelaysFileURL
     }
 
     /// Safely read the cache file from disk using file coordinator and fallback to prebundled
     /// relays in case if the relay cache file is missing.
-    public static func readWithFallback(cacheFileURL: URL, preBundledRelaysFileURL: URL)
-        throws -> CachedRelays
-    {
+    public func read() throws -> CachedRelays {
         do {
-            return try Self.read(cacheFileURL: cacheFileURL)
+            return try readDiskCache()
         } catch {
             if error is DecodingError || (error as? CocoaError)?.code == .fileReadNoSuchFile {
-                return try Self.readPrebundledRelays(fileURL: preBundledRelaysFileURL)
+                return try readPrebundledRelays()
             } else {
                 throw error
             }
         }
     }
 
-    /// Read pre-bundled relays file from disk.
-    public static func readPrebundledRelays(fileURL: URL) throws -> CachedRelays {
-        let data = try Data(contentsOf: fileURL)
-        let relays = try REST.Coding.makeJSONDecoder()
-            .decode(REST.ServerRelaysResponse.self, from: data)
-
-        return CachedRelays(
-            relays: relays,
-            updatedAt: Date(timeIntervalSince1970: 0)
-        )
-    }
-
     /// Safely write the cache file on disk using file coordinator.
-    public static func write(cacheFileURL: URL, record: CachedRelays) throws {
+    public func write(record: CachedRelays) throws {
         var result: Result<Void, Error>?
         let fileCoordinator = NSFileCoordinator(filePresenter: nil)
 
@@ -107,4 +67,43 @@ public class RelayCache {
 
         try result?.get()
     }
+
+    /// Safely read the cache file from disk using file coordinator.
+    private func readDiskCache() throws -> CachedRelays {
+        var result: Result<CachedRelays, Error>?
+        let fileCoordinator = NSFileCoordinator(filePresenter: nil)
+
+        let accessor = { (fileURLForReading: URL) in
+            result = Result {
+                let data = try Data(contentsOf: fileURLForReading)
+                return try JSONDecoder().decode(CachedRelays.self, from: data)
+            }
+        }
+
+        var error: NSError?
+        fileCoordinator.coordinate(
+            readingItemAt: cacheFileURL,
+            options: [.withoutChanges],
+            error: &error,
+            byAccessor: accessor
+        )
+
+        if let error = error {
+            result = .failure(error)
+        }
+
+        return try result!.get()
+    }
+
+    /// Read pre-bundled relays file from disk.
+    private func readPrebundledRelays() throws -> CachedRelays {
+        let data = try Data(contentsOf: prebundledRelaysFileURL)
+        let relays = try REST.Coding.makeJSONDecoder()
+            .decode(REST.ServerRelaysResponse.self, from: data)
+
+        return CachedRelays(
+            relays: relays,
+            updatedAt: Date(timeIntervalSince1970: 0)
+        )
+    }
 }