migrate existing attachments to album-compatible gallery schema

Signal.xcodeproj/project.pbxproj

@@ -444,6 +444,7 @@
 		4C4BC6C32102D697004040C9 /* ContactDiscoveryOperationTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C4BC6C22102D697004040C9 /* ContactDiscoveryOperationTest.swift */; };
 		4C63CC00210A620B003AE45C /* SignalTSan.supp in Resources */ = {isa = PBXBuildFile; fileRef = 4C63CBFF210A620B003AE45C /* SignalTSan.supp */; };
 		4C6F527C20FFE8400097DEEE /* SignalUBSan.supp in Resources */ = {isa = PBXBuildFile; fileRef = 4C6F527B20FFE8400097DEEE /* SignalUBSan.supp */; };
+		4C7537892193779700DF5E37 /* OWS113MultiAttachmentMediaMessages.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C7537882193779700DF5E37 /* OWS113MultiAttachmentMediaMessages.swift */; };
 		4C858A52212DC5E1001B45D3 /* UIImage+OWS.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C858A51212DC5E1001B45D3 /* UIImage+OWS.swift */; };
 		4C948FF72146EB4800349F0D /* BlockListCache.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C948FF62146EB4800349F0D /* BlockListCache.swift */; };
 		4C9CA25D217E676900607C63 /* ZXingObjC.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 4C9CA25C217E676900607C63 /* ZXingObjC.framework */; };
@@ -1142,6 +1143,7 @@
 		4C4BC6C22102D697004040C9 /* ContactDiscoveryOperationTest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; name = ContactDiscoveryOperationTest.swift; path = contact/ContactDiscoveryOperationTest.swift; sourceTree = "<group>"; };
 		4C63CBFF210A620B003AE45C /* SignalTSan.supp */ = {isa = PBXFileReference; lastKnownFileType = text; path = SignalTSan.supp; sourceTree = "<group>"; };
 		4C6F527B20FFE8400097DEEE /* SignalUBSan.supp */ = {isa = PBXFileReference; lastKnownFileType = text; path = SignalUBSan.supp; sourceTree = "<group>"; };
+		4C7537882193779700DF5E37 /* OWS113MultiAttachmentMediaMessages.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = OWS113MultiAttachmentMediaMessages.swift; sourceTree = "<group>"; };
 		4C858A51212DC5E1001B45D3 /* UIImage+OWS.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UIImage+OWS.swift"; sourceTree = "<group>"; };
 		4C948FF62146EB4800349F0D /* BlockListCache.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = BlockListCache.swift; sourceTree = "<group>"; };
 		4C9CA25C217E676900607C63 /* ZXingObjC.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = ZXingObjC.framework; path = ThirdParty/Carthage/Build/iOS/ZXingObjC.framework; sourceTree = "<group>"; };
@@ -1639,6 +1641,7 @@
 				34D5872D208E2C4100D2255A /* OWS109OutgoingMessageState.m */,
 				349EA07B2162AEA700F7B17F /* OWS111UDAttributesMigration.swift */,
 				34B6A908218B8824007C4606 /* OWS112TypingIndicatorsMigration.swift */,
+				4C7537882193779700DF5E37 /* OWS113MultiAttachmentMediaMessages.swift */,
 				346129931FD1E30000532771 /* OWSDatabaseMigration.h */,
 				346129941FD1E30000532771 /* OWSDatabaseMigration.m */,
 				346129E51FD5C0C600532771 /* OWSDatabaseMigrationRunner.h */,
@@ -3267,6 +3270,7 @@
 				34AC0A15211B39EA00997B47 /* ContactsViewHelper.m in Sources */,
 				346129FF1FD5F31400532771 /* OWS103EnableVideoCalling.m in Sources */,
 				346129E31FD5C0BE00532771 /* VersionMigrations.m in Sources */,
+				4C7537892193779700DF5E37 /* OWS113MultiAttachmentMediaMessages.swift in Sources */,
 				34AC0A16211B39EA00997B47 /* OWSNavigationBar.swift in Sources */,
 				34AC0A1A211B39EA00997B47 /* CommonStrings.swift in Sources */,
 				34AC0A19211B39EA00997B47 /* OWSAlerts.swift in Sources */,

Signal/src/ViewControllers/MediaGalleryViewController.swift

@@ -640,7 +640,7 @@ class MediaGallery: NSObject, MediaGalleryDataSource, MediaTileViewControllerDel
         }
 
         guard let message = attachmentStream.fetchAlbumMessage(with: transaction) else {
-            owsFailDebug("attachment was unexpectedly empty")
+            owsFailDebug("message was unexpectedly nil")
             return nil
         }
 

SignalMessaging/environment/migrations/OWS113MultiAttachmentMediaMessages.swift

@@ -0,0 +1,72 @@
+//
+//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
+//
+
+import Foundation
+import SignalServiceKit
+
+@objc
+public class OWS113MultiAttachmentMediaMessages: OWSDatabaseMigration {
+
+    // MARK: - Dependencies
+
+    // MARK: -
+
+    // Increment a similar constant for each migration.
+    @objc
+    class func migrationId() -> String {
+        return "113"
+    }
+
+    override public func runUp(completion: @escaping OWSDatabaseMigrationCompletion) {
+        Logger.debug("")
+        BenchAsync(title: "\(self.logTag)") { (benchCompletion) in
+            self.doMigrationAsync(completion: {
+                benchCompletion()
+                completion()
+            })
+        }
+    }
+
+    private func doMigrationAsync(completion : @escaping OWSDatabaseMigrationCompletion) {
+        DispatchQueue.global().async {
+            var legacyAttachments: [(attachmentId: String, messageId: String)] = []
+
+            self.dbReadWriteConnection().read { transaction in
+                TSMessage.enumerateCollectionObjects(with: transaction) { object, _ in
+                    autoreleasepool {
+                        guard let message: TSMessage = object as? TSMessage else {
+                            Logger.debug("ignoring message with type: \(object)")
+                            return
+                        }
+
+                        guard let messageId = message.uniqueId else {
+                            owsFailDebug("messageId was unexpectedly nil")
+                            return
+                        }
+
+                        for attachmentId in message.attachmentIds {
+                            legacyAttachments.append((attachmentId: attachmentId as! String, messageId: messageId))
+                        }
+                    }
+                }
+            }
+            self.dbReadWriteConnection().readWrite { transaction in
+                for (attachmentId, messageId) in legacyAttachments {
+                    autoreleasepool {
+                        guard let attachment = TSAttachment.fetch(uniqueId: attachmentId, transaction: transaction) else {
+                            Logger.warn("missing attachment for messageId: \(messageId)")
+                            return
+                        }
+
+                        attachment.migrateAlbumMessageId(messageId)
+                        attachment.save(with: transaction)
+                    }
+                }
+                self.save(with: transaction)
+            }
+
+            completion()
+        }
+    }
+}

SignalMessaging/environment/migrations/OWSDatabaseMigrationRunner.m

@@ -47,6 +47,7 @@ NS_ASSUME_NONNULL_BEGIN
         [[OWS109OutgoingMessageState alloc] initWithPrimaryStorage:primaryStorage],
         [[OWS111UDAttributesMigration alloc] initWithPrimaryStorage:primaryStorage],
         [[OWS112TypingIndicatorsMigration alloc] initWithPrimaryStorage:primaryStorage],
+        [[OWS113MultiAttachmentMediaMessages alloc] initWithPrimaryStorage:primaryStorage],
     ];
 }
 

SignalServiceKit/src/Messages/Attachments/TSAttachment.h

@@ -45,6 +45,11 @@ typedef NS_ENUM(NSUInteger, TSAttachmentType) {
 @property (nonatomic, readonly, nullable) NSString *albumMessageId;
 - (nullable TSMessage *)fetchAlbumMessageWithTransaction:(YapDatabaseReadTransaction *)transaction;
 
+// `migrateAlbumMessageId` is only used in the migration to the new multi-attachment message scheme,
+// and shouldn't be used as a general purpose setter. Instead, `albumMessageId` should be passed as
+// an initializer param.
+- (void)migrateAlbumMessageId:(NSString *)albumMesssageId;
+
 #pragma mark -
 
 // This constructor is used for new instances of TSAttachmentPointer,

SignalServiceKit/src/Messages/Attachments/TSAttachment.m

@@ -254,6 +254,11 @@ NSUInteger const TSAttachmentSchemaVersion = 4;
     return [TSMessage fetchObjectWithUniqueID:self.albumMessageId transaction:transaction];
 }
 
+- (void)migrateAlbumMessageId:(NSString *)albumMesssageId
+{
+    _albumMessageId = albumMesssageId;
+}
+
 @end
 
 NS_ASSUME_NONNULL_END