Streamline SignalRecipient.

SignalServiceKit/src/Contacts/ContactsUpdater.m

@@ -38,6 +38,16 @@ NS_ASSUME_NONNULL_BEGIN
     return self;
 }
 
+- (SignalRecipient *)signalRecipientForRegisteredRecipientId:(NSString *)recipientId
+{
+    __block SignalRecipient *recipient;
+    [OWSPrimaryStorage.dbReadWriteConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
+        recipient =
+            [SignalRecipient ensureRecipientExistsWithRegisteredRecipientId:recipientId transaction:transaction];
+    }];
+    return recipient;
+}
+
 - (void)lookupIdentifier:(NSString *)identifier
                  success:(void (^)(SignalRecipient *recipient))success
                  failure:(void (^)(NSError *error))failure
@@ -52,7 +62,7 @@ NS_ASSUME_NONNULL_BEGIN
     [self contactIntersectionWithSet:[NSSet setWithObject:identifier]
                              success:^(NSSet<NSString *> *_Nonnull matchedIds) {
                                  if (matchedIds.count == 1) {
-                                     success([SignalRecipient recipientWithTextSecureIdentifier:identifier]);
+                                     success([self signalRecipientForRegisteredRecipientId:identifier]);
                                  } else {
                                      failure(OWSErrorMakeNoSuchSignalRecipientError());
                                  }
@@ -75,7 +85,8 @@ NS_ASSUME_NONNULL_BEGIN
                                  if (matchedIds.count > 0) {
                                      NSMutableArray<SignalRecipient *> *recipients = [NSMutableArray new];
                                      for (NSString *identifier in matchedIds) {
-                                         [recipients addObject:[SignalRecipient recipientWithTextSecureIdentifier:identifier]];
+                                         [recipients
+                                             addObject:[self signalRecipientForRegisteredRecipientId:identifier]];
                                      }
                                      success([recipients copy]);
                                  } else {
@@ -109,18 +120,9 @@ NS_ASSUME_NONNULL_BEGIN
                              success:^(NSSet<NSString *> *matchedIds) {
                                  [recipientIds minusSet:matchedIds];
 
-                                 // Cleaning up unregistered identifiers
-                                 [OWSPrimaryStorage.dbReadWriteConnection
-                                     readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
-                                         for (NSString *identifier in recipientIds) {
-                                             SignalRecipient *recipient =
-                                                 [SignalRecipient fetchObjectWithUniqueID:identifier
-                                                                              transaction:transaction];
-
-                                             [recipient removeWithTransaction:transaction];
-                                         }
-                                     }];
-
+                                 // TODO:
+                                 //
+                                 // Update cache of registered identifiers.
                                  DDLogInfo(@"%@ successfully intersected contacts.", self.logTag);
                                  success();
                              }
@@ -165,7 +167,8 @@ NS_ASSUME_NONNULL_BEGIN
               [OWSPrimaryStorage.dbReadWriteConnection
                   readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
                       for (NSString *identifier in identifiers) {
-                          [SignalRecipient ensureRecipientExistsWithRecipientId:identifier transaction:transaction];
+                          [SignalRecipient ensureRecipientExistsWithRegisteredRecipientId:identifier
+                                                                              transaction:transaction];
                       }
                   }];
 

SignalServiceKit/src/Contacts/SignalAccount.h

@@ -41,11 +41,6 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (instancetype)initWithRecipientId:(NSString *)recipientId;
 
-// In most cases this should be non-null. This should only
-// be null in the case where the SignalRecipient was
-// deleted before this property was accessed.
-- (nullable SignalRecipient *)signalRecipientWithTransaction:(YapDatabaseReadTransaction *)transaction;
-
 @end
 
 NS_ASSUME_NONNULL_END

SignalServiceKit/src/Contacts/SignalAccount.m

@@ -36,15 +36,6 @@ NS_ASSUME_NONNULL_BEGIN
     return self;
 }
 
-- (nullable SignalRecipient *)signalRecipientWithTransaction:(YapDatabaseReadTransaction *)transaction
-{
-    OWSAssertIsOnMainThread();
-    OWSAssert(transaction);
-
-    OWSAssert(self.recipientId.length > 0);
-    return [SignalRecipient recipientWithTextSecureIdentifier:self.recipientId withTransaction:transaction];
-}
-
 - (nullable NSString *)uniqueId
 {
     return _recipientId;

SignalServiceKit/src/Contacts/SignalRecipient.h

@@ -6,22 +6,20 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
-// This class serves two purposes:
-//
-// * We only _persist_ SignalRecipient instances when we know
-//   that it corresponds to an account on the Signal service.
-//   So SignalRecipient serves as a defacto cache of "known
-//   Signal users."
-// * We hang the "known device list" for signal accounts on
-//   this entity.
+// We hang the "known device list" for signal accounts on this entity.
 @interface SignalRecipient : TSYapDatabaseObject
 
 @property (readonly) NSOrderedSet *devices;
 
+@property (nonatomic) BOOL mayBeUnregistered;
+
 - (instancetype)init NS_UNAVAILABLE;
 
 + (instancetype)selfRecipient;
 
++ (SignalRecipient *)ensureRecipientExistsWithRegisteredRecipientId:(NSString *)recipientId
+                                                        transaction:(YapDatabaseReadWriteTransaction *)transaction;
+
 + (SignalRecipient *)ensureRecipientExistsWithRecipientId:(NSString *)recipientId
                                               transaction:(YapDatabaseReadWriteTransaction *)transaction;
 
@@ -29,6 +27,7 @@ NS_ASSUME_NONNULL_BEGIN
                                     deviceId:(UInt32)deviceId
                                  transaction:(YapDatabaseReadWriteTransaction *)transaction;
 
+// TODO: Replace with cache of known signal account ids.
 + (nullable instancetype)recipientWithTextSecureIdentifier:(NSString *)textSecureIdentifier;
 + (nullable instancetype)recipientWithTextSecureIdentifier:(NSString *)textSecureIdentifier
                                            withTransaction:(YapDatabaseReadTransaction *)transaction;

SignalServiceKit/src/Contacts/SignalRecipient.m

@@ -22,6 +22,25 @@ NS_ASSUME_NONNULL_BEGIN
     return @"SignalRecipient";
 }
 
+- (void)removeWithTransaction:(YapDatabaseReadWriteTransaction *)transaction
+{
+    OWSFail(@"%@ We should no longer remove SignalRecipients.", self.logTag);
+
+    [super removeWithTransaction:transaction];
+}
+
++ (SignalRecipient *)ensureRecipientExistsWithRegisteredRecipientId:(NSString *)recipientId
+                                                        transaction:(YapDatabaseReadWriteTransaction *)transaction
+{
+    SignalRecipient *recipient =
+        [self ensureRecipientExistsWithRegisteredRecipientId:recipient transaction:transaction];
+    if (recipient.mayBeUnregistered) {
+        recipient.mayBeUnregistered = NO;
+        [recipient saveWithTransaction:transaction];
+    }
+    return recipient;
+}
+
 + (SignalRecipient *)ensureRecipientExistsWithRecipientId:(NSString *)recipientId
                                               transaction:(YapDatabaseReadWriteTransaction *)transaction
 {

SignalServiceKit/src/Messages/OWSMessageSender.m

@@ -712,7 +712,12 @@ NSString *const OWSMessageSenderRateLimitedException = @"RateLimitedException";
             [message updateWithSkippedRecipient:recipient.recipientId transaction:transaction];
         }
 
-        [recipient removeWithTransaction:transaction];
+        if (recipient.mayBeUnregistered) {
+            return;
+        }
+        recipient.mayBeUnregistered = YES;
+        [recipient saveWithTransaction:transaction];
+
         [[TSInfoMessage userNotRegisteredMessageInThread:thread recipientId:recipient.recipientId]
             saveWithTransaction:transaction];
     }];
@@ -1010,6 +1015,11 @@ NSString *const OWSMessageSenderRateLimitedException = @"RateLimitedException";
         [self.dbConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
             [recipient saveWithTransaction:transaction];
             [message updateWithSentRecipient:recipient.uniqueId transaction:transaction];
+
+            if (recipient.mayBeUnregistered) {
+                recipient.mayBeUnregistered = NO;
+                [recipient saveWithTransaction:transaction];
+            }
         }];
 
         [self handleMessageSentLocally:message];
@@ -1075,6 +1085,7 @@ NSString *const OWSMessageSenderRateLimitedException = @"RateLimitedException";
             DDLogWarn(@"%@ Unregistered recipient: %@", self.logTag, recipient.uniqueId);
 
             OWSAssert(thread);
+
             [self unregisteredRecipient:recipient message:message thread:thread];
             NSError *error = OWSErrorMakeNoSuchSignalRecipientError();
             // No need to retry if the recipient is not registered.