Cache device links in memory rather than on disk

SignalServiceKit/src/Loki/API/LokiFileServerAPI.swift

@@ -24,8 +24,8 @@ public final class LokiFileServerAPI : LokiDotNetAPI {
 
     /// Gets the device links associated with the given hex encoded public key from the
     /// server and stores and returns the valid ones.
-    public static func getDeviceLinks(associatedWith hexEncodedPublicKey: String, usingCache: Bool = false) -> Promise<Set<DeviceLink>> {
-        return getDeviceLinks(associatedWith: [ hexEncodedPublicKey ], usingCache: usingCache)
+    public static func getDeviceLinks(associatedWith hexEncodedPublicKey: String) -> Promise<Set<DeviceLink>> {
+        return getDeviceLinks(associatedWith: [ hexEncodedPublicKey ])
     }
 
     @objc(getDeviceLinksAssociatedWithHexEncodedPublicKeys:)
@@ -35,7 +35,7 @@ public final class LokiFileServerAPI : LokiDotNetAPI {
     
     /// Gets the device links associated with the given hex encoded public keys from the
     /// server and stores and returns the valid ones.
-    public static func getDeviceLinks(associatedWith hexEncodedPublicKeys: Set<String>, usingCache: Bool = false) -> Promise<Set<DeviceLink>> {
+    public static func getDeviceLinks(associatedWith hexEncodedPublicKeys: Set<String>) -> Promise<Set<DeviceLink>> {
         let hexEncodedPublicKeysDescription = "[ \(hexEncodedPublicKeys.joined(separator: ", ")) ]"
         print("[Loki] Getting device links for: \(hexEncodedPublicKeysDescription).")
         return getAuthToken(for: server).then(on: DispatchQueue.global()) { token -> Promise<Set<DeviceLink>> in
@@ -84,23 +84,17 @@ public final class LokiFileServerAPI : LokiDotNetAPI {
                         return deviceLink
                     }
                 })
-            }.then(on: DispatchQueue.global()) { deviceLinks -> Promise<Set<DeviceLink>> in
-                let (promise, seal) = Promise<Set<DeviceLink>>.pending()
-                if usingCache {
-                    storage.setDeviceLinksInCache(deviceLinks)
-                    seal.fulfill(deviceLinks)
-                } else {
-                    // Dispatch async on the main queue to avoid nested write transactions
-                    DispatchQueue.main.async {
-                        storage.dbReadWriteConnection.readWrite{ transaction in
-                            storage.setDeviceLinks(deviceLinks, in: transaction)
-                        }
-                        // We have to wait for the device links to be stored because a lot of our logic relies
-                        // on them being in the database
-                        seal.fulfill(deviceLinks)
+            }.map(on: DispatchQueue.global()) { deviceLinks in
+                storage.cacheDeviceLinks(deviceLinks)
+                /*
+                // Dispatch async on the main queue to avoid nested write transactions
+                DispatchQueue.main.async {
+                    storage.dbReadWriteConnection.readWrite { transaction in
+                        storage.setDeviceLinks(deviceLinks, in: transaction)
                     }
                 }
-                return promise
+                 */
+                return deviceLinks
             }
         }
     }

SignalServiceKit/src/Loki/Database/OWSPrimaryStorage+Loki.swift

@@ -1,19 +1,14 @@
 
 public extension OWSPrimaryStorage {
-    
+
+    private static var deviceLinkCache: Set<DeviceLink> = []
+
     private func getDeviceLinkCollection(for masterHexEncodedPublicKey: String) -> String {
         return "LokiDeviceLinkCollection-\(masterHexEncodedPublicKey)"
     }
     
-    public func setDeviceLinksInCache(_ deviceLinks: Set<DeviceLink>) {
-        self.deviceLinkCache = deviceLinks
-    }
-    
-    public func syncDeviceLinkCacheToDatabase(in transaction: YapDatabaseReadWriteTransaction) {
-        if !self.deviceLinkCache.isEmpty {
-            self.setDeviceLinks(self.deviceLinkCache, in: transaction)
-            self.deviceLinkCache.removeAll()
-        }
+    public func cacheDeviceLinks(_ deviceLinks: Set<DeviceLink>) {
+        OWSPrimaryStorage.deviceLinkCache.formUnion(deviceLinks)
     }
 
     public func setDeviceLinks(_ deviceLinks: Set<DeviceLink>, in transaction: YapDatabaseReadWriteTransaction) {
@@ -22,19 +17,24 @@ public extension OWSPrimaryStorage {
     }
 
     public func addDeviceLink(_ deviceLink: DeviceLink, in transaction: YapDatabaseReadWriteTransaction) {
+        OWSPrimaryStorage.deviceLinkCache.insert(deviceLink)
+        /*
         let collection = getDeviceLinkCollection(for: deviceLink.master.hexEncodedPublicKey)
         transaction.setObject(deviceLink, forKey: deviceLink.slave.hexEncodedPublicKey, inCollection: collection)
+         */
     }
 
     public func removeDeviceLink(_ deviceLink: DeviceLink, in transaction: YapDatabaseReadWriteTransaction) {
+        OWSPrimaryStorage.deviceLinkCache.remove(deviceLink)
+        /*
         let collection = getDeviceLinkCollection(for: deviceLink.master.hexEncodedPublicKey)
         transaction.removeObject(forKey: deviceLink.slave.hexEncodedPublicKey, inCollection: collection)
+         */
     }
     
     public func getDeviceLinks(for masterHexEncodedPublicKey: String, in transaction: YapDatabaseReadTransaction) -> Set<DeviceLink> {
-        if !self.deviceLinkCache.isEmpty {
-            return self.deviceLinkCache
-        }
+        return OWSPrimaryStorage.deviceLinkCache.filter { $0.master.hexEncodedPublicKey == masterHexEncodedPublicKey }
+        /*
         let collection = getDeviceLinkCollection(for: masterHexEncodedPublicKey)
         guard !transaction.allKeys(inCollection: collection).isEmpty else { return [] } // Fixes a crash that used to occur on Josh's device
         var result: Set<DeviceLink> = []
@@ -43,9 +43,12 @@ public extension OWSPrimaryStorage {
             result.insert(deviceLink)
         }
         return result
+         */
     }
     
     public func getDeviceLink(for slaveHexEncodedPublicKey: String, in transaction: YapDatabaseReadTransaction) -> DeviceLink? {
+        return OWSPrimaryStorage.deviceLinkCache.filter { $0.slave.hexEncodedPublicKey == slaveHexEncodedPublicKey }.first
+        /*
         let query = YapDatabaseQuery(string: "WHERE \(DeviceLinkIndex.slaveHexEncodedPublicKey) = ?", parameters: [ slaveHexEncodedPublicKey ])
         let deviceLinks = DeviceLinkIndex.getDeviceLinks(for: query, in: transaction)
         guard deviceLinks.count <= 1 else {
@@ -53,6 +56,7 @@ public extension OWSPrimaryStorage {
             return nil
         }
         return deviceLinks.first
+         */
     }
     
     public func getMasterHexEncodedPublicKey(for slaveHexEncodedPublicKey: String, in transaction: YapDatabaseReadTransaction) -> String? {

SignalServiceKit/src/Loki/Protocol/Multi Device/MultiDeviceProtocol.swift

@@ -24,7 +24,7 @@ public final class MultiDeviceProtocol : NSObject {
     internal static var storage: OWSPrimaryStorage { OWSPrimaryStorage.shared() }
 
     // MARK: - Settings
-    public static let deviceLinkUpdateInterval: TimeInterval = 20
+    public static let deviceLinkUpdateInterval: TimeInterval = 60
     
     // MARK: - Multi Device Destination
     public struct MultiDeviceDestination : Hashable {
@@ -144,16 +144,11 @@ public final class MultiDeviceProtocol : NSObject {
         }
     }
 
-    @objc(updateDeviceLinksIfNeededForHexEncodedPublicKey:in:usingCache:)
-    public static func updateDeviceLinksIfNeeded(for hexEncodedPublicKey: String, in transaction: YapDatabaseReadTransaction, usingCache: Bool = false) -> AnyPromise {
-        let promise = getMultiDeviceDestinations(for: hexEncodedPublicKey, in: transaction, usingCache: usingCache)
+    @objc(updateDeviceLinksIfNeededForHexEncodedPublicKey:in:)
+    public static func updateDeviceLinksIfNeeded(for hexEncodedPublicKey: String, in transaction: YapDatabaseReadTransaction) -> AnyPromise {
+        let promise = getMultiDeviceDestinations(for: hexEncodedPublicKey, in: transaction)
         return AnyPromise.from(promise)
     }
-    
-    @objc(syncDeviceLinkCacheToDatabaseInTransaction:)
-    public static func syncDeviceLinkCacheToDatabase(in transaction: YapDatabaseReadWriteTransaction) {
-        storage.syncDeviceLinkCacheToDatabase(in: transaction)
-    }
 
     /// See [Auto-Generated Friend Requests](https://github.com/loki-project/session-protocol-docs/wiki/Auto-Generated-Friend-Requests) for more information.
     @objc(getAutoGeneratedMultiDeviceFRMessageForHexEncodedPublicKey:in:)
@@ -289,7 +284,7 @@ public final class MultiDeviceProtocol : NSObject {
 // Here (in a non-@objc extension) because it doesn't interoperate well with Obj-C
 public extension MultiDeviceProtocol {
 
-    fileprivate static func getMultiDeviceDestinations(for hexEncodedPublicKey: String, in transaction: YapDatabaseReadTransaction, usingCache: Bool = false) -> Promise<Set<MultiDeviceDestination>> {
+    fileprivate static func getMultiDeviceDestinations(for hexEncodedPublicKey: String, in transaction: YapDatabaseReadTransaction) -> Promise<Set<MultiDeviceDestination>> {
         let (promise, seal) = Promise<Set<MultiDeviceDestination>>.pending()
         func getDestinations(in transaction: YapDatabaseReadTransaction? = nil) {
             storage.dbReadConnection.read { transaction in
@@ -311,7 +306,7 @@ public extension MultiDeviceProtocol {
         }
         if timeSinceLastUpdate > deviceLinkUpdateInterval {
             let masterHexEncodedPublicKey = storage.getMasterHexEncodedPublicKey(for: hexEncodedPublicKey, in: transaction) ?? hexEncodedPublicKey
-            LokiFileServerAPI.getDeviceLinks(associatedWith: masterHexEncodedPublicKey, usingCache: usingCache).done(on: DispatchQueue.global()) { _ in
+            LokiFileServerAPI.getDeviceLinks(associatedWith: masterHexEncodedPublicKey).done(on: DispatchQueue.global()) { _ in
                 getDestinations()
                 lastDeviceLinkUpdate[hexEncodedPublicKey] = Date()
             }.catch(on: DispatchQueue.global()) { error in

SignalServiceKit/src/Messages/OWSMessageManager.m

@@ -1266,18 +1266,16 @@ NS_ASSUME_NONNULL_BEGIN
     // Loki: Update device links in a blocking way
     // FIXME: This is horrible for performance
     // FIXME: ========
-    // FIX: Using the cache for write to avoid deadlock
     // The envelope source is set during UD decryption
     if ([ECKeyPair isValidHexEncodedPublicKeyWithCandidate:envelope.source] && dataMessage.publicChatInfo == nil) { // Handled in LokiPublicChatPoller for open group messages
         dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
         dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
-        [[LKMultiDeviceProtocol updateDeviceLinksIfNeededForHexEncodedPublicKey:envelope.source in:transaction usingCache: true].ensureOn(queue, ^() {
+        [[LKMultiDeviceProtocol updateDeviceLinksIfNeededForHexEncodedPublicKey:envelope.source in:transaction].ensureOn(queue, ^() {
             dispatch_semaphore_signal(semaphore);
         }).catchOn(queue, ^(NSError *error) {
             dispatch_semaphore_signal(semaphore);
         }) retainUntilComplete];
         dispatch_semaphore_wait(semaphore, dispatch_time(DISPATCH_TIME_NOW, 10 * NSEC_PER_SEC));
-        [LKMultiDeviceProtocol syncDeviceLinkCacheToDatabaseInTransaction:transaction];
     }
     // FIXME: ========
 

SignalServiceKit/src/Storage/OWSPrimaryStorage.h

@@ -25,7 +25,6 @@ extern NSString *const OWSUIDatabaseConnectionNotificationsKey;
 @property (nonatomic, readonly) YapDatabaseConnection *uiDatabaseConnection;
 @property (nonatomic, readonly) YapDatabaseConnection *dbReadConnection;
 @property (nonatomic, readonly) YapDatabaseConnection *dbReadWriteConnection;
-@property (nonatomic) NSSet<LKDeviceLink*> *deviceLinkCache;
 
 - (void)updateUIDatabaseConnectionToLatest;
 

SignalServiceKit/src/Storage/OWSPrimaryStorage.m

@@ -76,8 +76,6 @@ void VerifyRegistrationsForPrimaryStorage(OWSStorage *storage)
     if (self) {
         [self loadDatabase];
         
-        _deviceLinkCache = [NSSet set];
-
         _dbReadPool = [[YapDatabaseConnectionPool alloc] initWithDatabase:self.database];
         _dbReadWriteConnection = [self newDatabaseConnection];
         _uiDatabaseConnection = [self newDatabaseConnection];