Streamline SignalRecipient.

SignalServiceKit/src/Contacts/SignalRecipient.h

@@ -6,7 +6,14 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
-// We hang the "known device list" for signal accounts on this entity.
+// SignalRecipient serves two purposes:
+//
+// a) It serves as a cache of "known" Signal accounts.  When the service indicates
+//    that an account exists, we make sure that an instance of SignalRecipient exists
+//    for that recipient id (using mark as registered).
+//    When the service indicates that an account does not exist, we remove any
+//    SignalRecipient.
+// b) We hang the "known device list" for known signal accounts on this entity.
 @interface SignalRecipient : TSYapDatabaseObject
 
 @property (nonatomic, readonly) NSOrderedSet *devices;
@@ -20,14 +27,15 @@ NS_ASSUME_NONNULL_BEGIN
 + (instancetype)getOrCreatedUnsavedRecipientForRecipientId:(NSString *)recipientId
                                                transaction:(YapDatabaseReadTransaction *)transaction;
 
-- (void)addDevices:(NSSet *)set;
+- (void)addDevicesToRegisteredRecipient:(NSSet *)devices
-- (void)removeDevices:(NSSet *)set;
+                            transaction:(YapDatabaseReadWriteTransaction *)transaction;
+- (void)removeDevicesFromRegisteredRecipient:(NSSet *)devices
+                                 transaction:(YapDatabaseReadWriteTransaction *)transaction;
 
 - (NSString *)recipientId;
 
 - (NSComparisonResult)compare:(SignalRecipient *)other;
 
-// TODO: Replace with cache of known signal account ids.
 + (BOOL)isRegisteredSignalAccount:(NSString *)recipientId transaction:(YapDatabaseReadTransaction *)transaction;
 
 + (SignalRecipient *)markAccountAsRegistered:(NSString *)recipientId transaction:(YapDatabaseReadWriteTransaction *)transaction;

SignalServiceKit/src/Contacts/SignalRecipient.m

@@ -10,8 +10,6 @@ NS_ASSUME_NONNULL_BEGIN
 
 @interface SignalRecipient ()
 
-@property (nonatomic) BOOL mayBeUnregistered;
-
 @property (nonatomic) NSOrderedSet *devices;
 
 @end
@@ -96,12 +94,7 @@ NS_ASSUME_NONNULL_BEGIN
     OWSAssert(transaction);
     OWSAssert(recipientId.length > 0);
 
-    SignalRecipient *_Nullable instance = [self recipientForRecipientId:recipientId transaction:transaction];
+    return [self recipientForRecipientId:recipientId transaction:transaction];
-    if (instance && !instance.mayBeUnregistered) {
-        return instance;
-    } else {
-        return nil;
-    }
 }
 
 + (nullable instancetype)recipientForRecipientId:(NSString *)recipientId
@@ -134,9 +127,11 @@ NS_ASSUME_NONNULL_BEGIN
     return myself;
 }
 
-- (void)addDevices:(NSSet *)set
+- (void)addDevices:(NSSet *)devices
 {
-    if ([self.uniqueId isEqual:[TSAccountManager localNumber]] && [set containsObject:@(1)]) {
+    OWSAssert(devices.count > 0);
+    
+    if ([self.uniqueId isEqual:[TSAccountManager localNumber]] && [devices containsObject:@(1)]) {
         OWSFail(@"%@ in %s adding self as recipient device", self.logTag, __PRETTY_FUNCTION__);
         return;
     }
@@ -144,19 +139,45 @@ NS_ASSUME_NONNULL_BEGIN
     NSMutableOrderedSet *updatedDevices = (self.devices
                                            ? [self.devices mutableCopy]
                                            : [NSMutableOrderedSet new]);
-    [updatedDevices unionSet:set];
+    [updatedDevices unionSet:devices];
     self.devices = [updatedDevices copy];
 }
 
-- (void)removeDevices:(NSSet *)set
+- (void)removeDevices:(NSSet *)devices
 {
+    OWSAssert(devices.count > 0);
+    
     NSMutableOrderedSet *updatedDevices = (self.devices
                                            ? [self.devices mutableCopy]
                                            : [NSMutableOrderedSet new]);
-    [updatedDevices minusSet:set];
+    [updatedDevices minusSet:devices];
     self.devices = [updatedDevices copy];
 }
 
+- (void)addDevicesToRegisteredRecipient:(NSSet *)devices transaction:(YapDatabaseReadWriteTransaction *)transaction
+{
+    OWSAssert(transaction);
+    OWSAssert(devices.count > 0);
+    
+    [self addDevices:devices];
+
+    SignalRecipient *latest = [SignalRecipient markAccountAsRegistered:self.recipientId transaction:transaction];
+    [latest addDevices:devices];
+    [latest saveWithTransaction:transaction];
+}
+
+- (void)removeDevicesFromRegisteredRecipient:(NSSet *)devices transaction:(YapDatabaseReadWriteTransaction *)transaction
+{
+    OWSAssert(transaction);
+    OWSAssert(devices.count > 0);
+
+    [self removeDevices:devices];
+
+    SignalRecipient *latest = [SignalRecipient markAccountAsRegistered:self.recipientId transaction:transaction];
+    [latest removeDevices:devices];
+    [latest saveWithTransaction:transaction];
+}
+
 - (NSString *)recipientId
 {
     return self.uniqueId;
@@ -174,19 +195,10 @@ NS_ASSUME_NONNULL_BEGIN
     DDLogVerbose(@"%@ saved signal recipient: %@", self.logTag, self.recipientId);
 }
 
-+ (BOOL)isRegisteredSignalAccount:(NSString *)recipientId
-{
-    __block BOOL result;
-    [self.dbReadConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
-        result = [self isRegisteredSignalAccount:recipientId transaction:transaction];
-    }];
-    return result;
-}
-
 + (BOOL)isRegisteredSignalAccount:(NSString *)recipientId transaction:(YapDatabaseReadTransaction *)transaction
 {
     SignalRecipient *_Nullable instance = [self recipientForRecipientId:recipientId transaction:transaction];
-    return (instance && !instance.mayBeUnregistered);
+    return instance != nil;
 }
 
 + (SignalRecipient *)markAccountAsRegistered:(NSString *)recipientId transaction:(YapDatabaseReadWriteTransaction *)transaction
@@ -201,9 +213,6 @@ NS_ASSUME_NONNULL_BEGIN
 
         instance = [[self alloc] initWithTextSecureIdentifier:recipientId];
         [instance saveWithTransaction:transaction];
-    } else if (instance.mayBeUnregistered) {
-        instance.mayBeUnregistered = NO;
-        [instance saveWithTransaction:transaction];
     }
     return instance;
 }
@@ -236,11 +245,7 @@ NS_ASSUME_NONNULL_BEGIN
     if (!instance) {
         return;
     }
-    if (instance.mayBeUnregistered) {
+    [instance removeWithTransaction:transaction];
-        return;
-    }
-    instance.mayBeUnregistered = YES;
-    [instance saveWithTransaction:transaction];
 }
 
 @end

SignalServiceKit/src/Messages/OWSMessageSender.m

@@ -77,7 +77,7 @@ void AssertIsOnSendingQueue()
                   messageSender:(OWSMessageSender *)messageSender
                    dbConnection:(YapDatabaseConnection *)dbConnection
                         success:(void (^)(void))aSuccessHandler
-                        failure:(void (^)(NSError *_Nonnull error))aFailureHandler NS_DESIGNATED_INITIALIZER;
+                        failure:(void (^)(NSError * error))aFailureHandler NS_DESIGNATED_INITIALIZER;
 
 @end
 
@@ -99,7 +99,7 @@ void AssertIsOnSendingQueue()
 @property (nonatomic, readonly) OWSMessageSender *messageSender;
 @property (nonatomic, readonly) YapDatabaseConnection *dbConnection;
 @property (nonatomic, readonly) void (^successHandler)(void);
-@property (nonatomic, readonly) void (^failureHandler)(NSError *_Nonnull error);
+@property (nonatomic, readonly) void (^failureHandler)(NSError * error);
 
 @end
 
@@ -111,7 +111,7 @@ void AssertIsOnSendingQueue()
                   messageSender:(OWSMessageSender *)messageSender
                    dbConnection:(YapDatabaseConnection *)dbConnection
                         success:(void (^)(void))successHandler
-                        failure:(void (^)(NSError *_Nonnull error))failureHandler
+                        failure:(void (^)(NSError * error))failureHandler
 {
     self = [super init];
     if (!self) {
@@ -151,7 +151,7 @@ void AssertIsOnSendingQueue()
 
     // Sanity check preconditions
     if (self.message.hasAttachments) {
-        [self.dbConnection readWithBlock:^(YapDatabaseReadTransaction *_Nonnull transaction) {
+        [self.dbConnection readWithBlock:^(YapDatabaseReadTransaction * transaction) {
             TSAttachmentStream *attachmentStream
                 = (TSAttachmentStream *)[self.message attachmentWithTransaction:transaction];
             OWSAssert(attachmentStream);
@@ -1157,7 +1157,7 @@ NSString *const OWSMessageSenderRateLimitedException = @"RateLimitedException";
     }
 
     [self.dbConnection
-        asyncReadWriteWithBlock:^(YapDatabaseReadWriteTransaction *_Nonnull transaction) {
+        asyncReadWriteWithBlock:^(YapDatabaseReadWriteTransaction * transaction) {
             if (extraDevices.count < 1 && missingDevices.count < 1) {
                 OWSProdFail([OWSAnalyticsEvents messageSenderErrorNoMissingOrExtraDevices]);
             }
@@ -1170,16 +1170,16 @@ NSString *const OWSMessageSenderRateLimitedException = @"RateLimitedException";
                                                  protocolContext:transaction];
                 }
 
-                [recipient removeDevices:[NSSet setWithArray:extraDevices]];
+                [recipient removeDevicesFromRegisteredRecipient:[NSSet setWithArray:extraDevices]
+                             transaction:transaction];
             }
 
             if (missingDevices && missingDevices.count > 0) {
                 DDLogInfo(@"%@ Adding missing devices: %@", self.logTag, missingDevices);
-                [recipient addDevices:[NSSet setWithArray:missingDevices]];
+                [recipient addDevicesToRegisteredRecipient:[NSSet setWithArray:missingDevices]
+                                              transaction:transaction];
             }
 
-            [recipient saveWithTransaction:transaction];
-
             dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
                 completionHandler();
             });
@@ -1271,7 +1271,11 @@ NSString *const OWSMessageSenderRateLimitedException = @"RateLimitedException";
             }
         } @catch (NSException *exception) {
             if ([exception.name isEqualToString:OWSMessageSenderInvalidDeviceException]) {
-                [recipient removeDevices:[NSSet setWithObject:deviceNumber]];
+                [self.dbConnection
+                 asyncReadWriteWithBlock:^(YapDatabaseReadWriteTransaction * transaction) {
+                     [recipient removeDevicesFromRegisteredRecipient:[NSSet setWithObject:deviceNumber]
+                                  transaction:transaction];
+                 }];
             } else {
                 @throw exception;
             }