Avoid crashing on startup due to database view creation.

* Substitute unread view for unseen view until unseen view is ready.
* Register as many views as possible async.
* Perform blocking, safe migrations before async registration of views.

// FREEBIE

src/Contacts/TSThread.m

@@ -193,7 +193,7 @@ NS_ASSUME_NONNULL_BEGIN
 - (NSArray<id<OWSReadTracking>> *)unseenMessagesWithTransaction:(YapDatabaseReadTransaction *)transaction
 {
     NSMutableArray<id<OWSReadTracking>> *messages = [NSMutableArray new];
-    [[transaction ext:TSUnseenDatabaseViewExtensionName]
+    [[TSDatabaseView unseenDatabaseViewExtension:transaction]
         enumerateRowsInGroup:self.uniqueId
                   usingBlock:^(
                       NSString *collection, NSString *key, id object, id metadata, NSUInteger index, BOOL *stop) {

src/Devices/OWSReadReceiptsProcessor.m

@@ -95,7 +95,7 @@ NSString *const OWSReadReceiptsProcessorMarkedMessageAsReadNotification =
             [interactionsToMarkAsRead addObject:message];
 
             [self.storageManager.dbConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
-                [[transaction ext:TSUnseenDatabaseViewExtensionName]
+                [[TSDatabaseView unseenDatabaseViewExtension:transaction]
                     enumerateRowsInGroup:message.uniqueThreadId
                               usingBlock:^(NSString *collection,
                                   NSString *key,

src/Messages/OWSBlockingManager.m

@@ -11,6 +11,7 @@
 NS_ASSUME_NONNULL_BEGIN
 
 NSString *const kNSNotificationName_BlockedPhoneNumbersDidChange = @"kNSNotificationName_BlockedPhoneNumbersDidChange";
+
 NSString *const kOWSBlockingManager_BlockedPhoneNumbersCollection = @"kOWSBlockingManager_BlockedPhoneNumbersCollection";
 // This key is used to persist the current "blocked phone numbers" state.
 NSString *const kOWSBlockingManager_BlockedPhoneNumbersKey = @"kOWSBlockingManager_BlockedPhoneNumbersKey";

src/Storage/TSDatabaseSecondaryIndexes.m

@@ -1,9 +1,5 @@
 //
-//  TSDatabaseSecondaryIndexes.m
-//  Signal
-//
-//  Created by Frederic Jacobs on 26/01/15.
-//  Copyright (c) 2015 Open Whisper Systems. All rights reserved.
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
 //
 
 #import "TSDatabaseSecondaryIndexes.h"
@@ -43,4 +39,5 @@
     YapDatabaseQuery *query   = [YapDatabaseQuery queryWithFormat:formattedString];
     [[transaction ext:@"idx"] enumerateKeysMatchingQuery:query usingBlock:block];
 }
+
 @end

src/Storage/TSDatabaseView.h

@@ -5,36 +5,53 @@
 #import <Foundation/Foundation.h>
 #import <YapDatabase/YapDatabaseViewTransaction.h>
 
+extern NSString *const kNSNotificationName_DatabaseViewRegistrationComplete;
+
+extern NSString *const TSInboxGroup;
+extern NSString *const TSArchiveGroup;
+extern NSString *const TSUnreadIncomingMessagesGroup;
+extern NSString *const TSSecondaryDevicesGroup;
+
+extern NSString *const TSThreadDatabaseViewExtensionName;
+
+extern NSString *const TSMessageDatabaseViewExtensionName;
+extern NSString *const TSUnreadDatabaseViewExtensionName;
+
+extern NSString *const TSSecondaryDevicesDatabaseViewExtensionName;
+
 @interface TSDatabaseView : NSObject
 
-extern NSString *TSInboxGroup;
-extern NSString *TSArchiveGroup;
-extern NSString *TSUnreadIncomingMessagesGroup;
-extern NSString *TSSecondaryDevicesGroup;
+- (instancetype)init NS_UNAVAILABLE;
 
-extern NSString *TSThreadDatabaseViewExtensionName;
-extern NSString *TSMessageDatabaseViewExtensionName;
-extern NSString *TSThreadOutgoingMessageDatabaseViewExtensionName;
-extern NSString *TSUnreadDatabaseViewExtensionName;
-extern NSString *TSUnseenDatabaseViewExtensionName;
-extern NSString *TSThreadSpecialMessagesDatabaseViewExtensionName;
-extern NSString *TSSecondaryDevicesDatabaseViewExtensionName;
++ (BOOL)hasPendingViewRegistrations;
 
-+ (BOOL)registerThreadDatabaseView;
-+ (BOOL)registerThreadInteractionsDatabaseView;
-+ (BOOL)registerThreadOutgoingMessagesDatabaseView;
++ (void)registerThreadDatabaseView;
+
++ (void)registerThreadInteractionsDatabaseView;
++ (void)asyncRegisterThreadOutgoingMessagesDatabaseView;
 
 // Instances of OWSReadTracking for wasRead is NO and shouldAffectUnreadCounts is YES.
 //
 // Should be used for "unread message counts".
-+ (BOOL)registerUnreadDatabaseView;
++ (void)registerUnreadDatabaseView;
 
 // Should be used for "unread indicator".
 //
 // Instances of OWSReadTracking for wasRead is NO.
-+ (BOOL)registerUnseenDatabaseView;
++ (void)asyncRegisterUnseenDatabaseView;
+
++ (void)asyncRegisterThreadSpecialMessagesDatabaseView;
 
-+ (BOOL)registerThreadSpecialMessagesDatabaseView;
 + (void)asyncRegisterSecondaryDevicesDatabaseView;
 
+// Returns the "unseen" database view if it is ready;
+// otherwise it returns the "unread" database view.
++ (id)unseenDatabaseViewExtension:(YapDatabaseReadTransaction *)transaction;
+
+// NOTE: It is not safe to call this method until hasPendingViewRegistrations is YES.
++ (id)threadOutgoingMessageDatabaseView:(YapDatabaseReadTransaction *)transaction;
+
+// NOTE: It is not safe to call this method until hasPendingViewRegistrations is YES.
++ (id)threadSpecialMessagesDatabaseView:(YapDatabaseReadTransaction *)transaction;
+
 @end

src/Storage/TSDatabaseView.m

@@ -12,32 +12,88 @@
 #import "TSThread.h"
 #import <YapDatabase/YapDatabaseView.h>
 
-NSString *TSInboxGroup   = @"TSInboxGroup";
-NSString *TSArchiveGroup = @"TSArchiveGroup";
+NSString *const kNSNotificationName_DatabaseViewRegistrationComplete =
+    @"kNSNotificationName_DatabaseViewRegistrationComplete";
 
-NSString *TSUnreadIncomingMessagesGroup = @"TSUnreadIncomingMessagesGroup";
-NSString *TSSecondaryDevicesGroup = @"TSSecondaryDevicesGroup";
+NSString *const TSInboxGroup = @"TSInboxGroup";
+NSString *const TSArchiveGroup = @"TSArchiveGroup";
 
-NSString *TSThreadDatabaseViewExtensionName  = @"TSThreadDatabaseViewExtensionName";
-NSString *TSMessageDatabaseViewExtensionName = @"TSMessageDatabaseViewExtensionName";
-NSString *TSThreadOutgoingMessageDatabaseViewExtensionName = @"TSThreadOutgoingMessageDatabaseViewExtensionName";
-NSString *TSUnreadDatabaseViewExtensionName  = @"TSUnreadDatabaseViewExtensionName";
-NSString *TSUnseenDatabaseViewExtensionName = @"TSUnseenDatabaseViewExtensionName";
-NSString *TSThreadSpecialMessagesDatabaseViewExtensionName = @"TSThreadSpecialMessagesDatabaseViewExtensionName";
-NSString *TSSecondaryDevicesDatabaseViewExtensionName = @"TSSecondaryDevicesDatabaseViewExtensionName";
+NSString *const TSUnreadIncomingMessagesGroup = @"TSUnreadIncomingMessagesGroup";
+NSString *const TSSecondaryDevicesGroup = @"TSSecondaryDevicesGroup";
+
+NSString *const TSThreadDatabaseViewExtensionName = @"TSThreadDatabaseViewExtensionName";
+NSString *const TSMessageDatabaseViewExtensionName = @"TSMessageDatabaseViewExtensionName";
+NSString *const TSThreadOutgoingMessageDatabaseViewExtensionName = @"TSThreadOutgoingMessageDatabaseViewExtensionName";
+NSString *const TSUnreadDatabaseViewExtensionName = @"TSUnreadDatabaseViewExtensionName";
+NSString *const TSUnseenDatabaseViewExtensionName = @"TSUnseenDatabaseViewExtensionName";
+NSString *const TSThreadSpecialMessagesDatabaseViewExtensionName = @"TSThreadSpecialMessagesDatabaseViewExtensionName";
+NSString *const TSSecondaryDevicesDatabaseViewExtensionName = @"TSSecondaryDevicesDatabaseViewExtensionName";
+
+@interface TSDatabaseView ()
+
+@property (nonatomic) int pendingViewRegistrations;
+
+@end
+
+#pragma mark -
 
 @implementation TSDatabaseView
 
-+ (BOOL)registerMessageDatabaseViewWithName:(NSString *)viewName
++ (instancetype)sharedInstance
+{
+    static TSDatabaseView *sharedInstance = nil;
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+        sharedInstance = [[self alloc] initDefault];
+    });
+    return sharedInstance;
+}
+
+- (instancetype)initDefault
+{
+    self = [super init];
+
+    if (!self) {
+        return self;
+    }
+
+    OWSSingletonAssert();
+
+    return self;
+}
+
+- (void)setPendingViewRegistrations:(int)pendingViewRegistrations
+{
+    OWSAssert([NSThread isMainThread]);
+
+    _pendingViewRegistrations = pendingViewRegistrations;
+
+    if (pendingViewRegistrations == 0) {
+        [[NSNotificationCenter defaultCenter] postNotificationName:kNSNotificationName_DatabaseViewRegistrationComplete
+                                                            object:nil
+                                                          userInfo:nil];
+    }
+}
+
++ (BOOL)hasPendingViewRegistrations
+{
+    OWSAssert([NSThread isMainThread]);
+
+    return [TSDatabaseView sharedInstance].pendingViewRegistrations > 0;
+}
+
++ (void)registerMessageDatabaseViewWithName:(NSString *)viewName
                                viewGrouping:(YapDatabaseViewGrouping *)viewGrouping
                                     version:(NSString *)version
+                                      async:(BOOL)async
 {
+    OWSAssert([NSThread isMainThread]);
     OWSAssert(viewName.length > 0);
     OWSAssert((viewGrouping));
 
     YapDatabaseView *existingView = [[TSStorageManager sharedManager].database registeredExtension:viewName];
     if (existingView) {
-        return YES;
+        return;
     }
 
     YapDatabaseViewSorting *viewSorting = [self messagesSorting];
@@ -50,10 +106,27 @@ NSString *TSSecondaryDevicesDatabaseViewExtensionName = @"TSSecondaryDevicesData
     YapDatabaseView *view =
         [[YapDatabaseView alloc] initWithGrouping:viewGrouping sorting:viewSorting versionTag:version options:options];
 
-    return [[TSStorageManager sharedManager].database registerExtension:view withName:viewName];
+    if (async) {
+        TSDatabaseView.sharedInstance.pendingViewRegistrations++;
+
+        [[TSStorageManager sharedManager].database
+            asyncRegisterExtension:view
+                          withName:viewName
+                   completionBlock:^(BOOL ready) {
+                       OWSCAssert(ready);
+
+                       DDLogInfo(@"%@ asyncRegisterExtension: %@ -> %d", self.tag, viewName, ready);
+
+                       dispatch_async(dispatch_get_main_queue(), ^{
+                           TSDatabaseView.sharedInstance.pendingViewRegistrations--;
+                       });
+                   }];
+    } else {
+        [[TSStorageManager sharedManager].database registerExtension:view withName:viewName];
+    }
 }
 
-+ (BOOL)registerUnreadDatabaseView
++ (void)registerUnreadDatabaseView
 {
     YapDatabaseViewGrouping *viewGrouping = [YapDatabaseViewGrouping withObjectBlock:^NSString *(
         YapDatabaseReadTransaction *transaction, NSString *collection, NSString *key, id object) {
@@ -66,12 +139,13 @@ NSString *TSSecondaryDevicesDatabaseViewExtensionName = @"TSSecondaryDevicesData
         return nil;
     }];
 
-    return [self registerMessageDatabaseViewWithName:TSUnreadDatabaseViewExtensionName
+    [self registerMessageDatabaseViewWithName:TSUnreadDatabaseViewExtensionName
                                  viewGrouping:viewGrouping
-                                             version:@"1"];
+                                      version:@"1"
+                                        async:NO];
 }
 
-+ (BOOL)registerUnseenDatabaseView
++ (void)asyncRegisterUnseenDatabaseView
 {
     YapDatabaseViewGrouping *viewGrouping = [YapDatabaseViewGrouping withObjectBlock:^NSString *(
         YapDatabaseReadTransaction *transaction, NSString *collection, NSString *key, id object) {
@@ -84,12 +158,13 @@ NSString *TSSecondaryDevicesDatabaseViewExtensionName = @"TSSecondaryDevicesData
         return nil;
     }];
 
-    return [self registerMessageDatabaseViewWithName:TSUnseenDatabaseViewExtensionName
+    [self registerMessageDatabaseViewWithName:TSUnseenDatabaseViewExtensionName
                                  viewGrouping:viewGrouping
-                                             version:@"1"];
+                                      version:@"1"
+                                        async:YES];
 }
 
-+ (BOOL)registerThreadSpecialMessagesDatabaseView
++ (void)asyncRegisterThreadSpecialMessagesDatabaseView
 {
     YapDatabaseViewGrouping *viewGrouping = [YapDatabaseViewGrouping withObjectBlock:^NSString *(
         YapDatabaseReadTransaction *transaction, NSString *collection, NSString *key, id object) {
@@ -110,12 +185,13 @@ NSString *TSSecondaryDevicesDatabaseViewExtensionName = @"TSSecondaryDevicesData
         return nil;
     }];
 
-    return [self registerMessageDatabaseViewWithName:TSThreadSpecialMessagesDatabaseViewExtensionName
+    [self registerMessageDatabaseViewWithName:TSThreadSpecialMessagesDatabaseViewExtensionName
                                  viewGrouping:viewGrouping
-                                             version:@"1"];
+                                      version:@"1"
+                                        async:YES];
 }
 
-+ (BOOL)registerThreadInteractionsDatabaseView
++ (void)registerThreadInteractionsDatabaseView
 {
     YapDatabaseViewGrouping *viewGrouping = [YapDatabaseViewGrouping withObjectBlock:^NSString *(
         YapDatabaseReadTransaction *transaction, NSString *collection, NSString *key, id object) {
@@ -125,12 +201,13 @@ NSString *TSSecondaryDevicesDatabaseViewExtensionName = @"TSSecondaryDevicesData
         return interaction.uniqueThreadId;
     }];
 
-    return [self registerMessageDatabaseViewWithName:TSMessageDatabaseViewExtensionName
+    [self registerMessageDatabaseViewWithName:TSMessageDatabaseViewExtensionName
                                  viewGrouping:viewGrouping
-                                             version:@"1"];
+                                      version:@"1"
+                                        async:NO];
 }
 
-+ (BOOL)registerThreadOutgoingMessagesDatabaseView
++ (void)asyncRegisterThreadOutgoingMessagesDatabaseView
 {
     YapDatabaseViewGrouping *viewGrouping = [YapDatabaseViewGrouping withObjectBlock:^NSString *(
         YapDatabaseReadTransaction *transaction, NSString *collection, NSString *key, id object) {
@@ -140,16 +217,18 @@ NSString *TSSecondaryDevicesDatabaseViewExtensionName = @"TSSecondaryDevicesData
         return nil;
     }];
 
-    return [self registerMessageDatabaseViewWithName:TSThreadOutgoingMessageDatabaseViewExtensionName
+    [self registerMessageDatabaseViewWithName:TSThreadOutgoingMessageDatabaseViewExtensionName
                                  viewGrouping:viewGrouping
-                                             version:@"2"];
+                                      version:@"2"
+                                        async:YES];
 }
 
-+ (BOOL)registerThreadDatabaseView {
++ (void)registerThreadDatabaseView
+{
     YapDatabaseView *threadView =
         [[TSStorageManager sharedManager].database registeredExtension:TSThreadDatabaseViewExtensionName];
     if (threadView) {
-        return YES;
+        return;
     }
 
     YapDatabaseViewGrouping *viewGrouping = [YapDatabaseViewGrouping
@@ -178,8 +257,7 @@ NSString *TSSecondaryDevicesDatabaseViewExtensionName = @"TSSecondaryDevicesData
     YapDatabaseView *databaseView =
         [[YapDatabaseView alloc] initWithGrouping:viewGrouping sorting:viewSorting versionTag:@"1" options:options];
 
-    return [[TSStorageManager sharedManager]
-                .database registerExtension:databaseView
+    [[TSStorageManager sharedManager].database registerExtension:databaseView
                                                         withName:TSThreadDatabaseViewExtensionName];
 }
 
@@ -305,6 +383,40 @@ NSString *TSSecondaryDevicesDatabaseViewExtensionName = @"TSSecondaryDevicesData
                }];
 }
 
++ (id)unseenDatabaseViewExtension:(YapDatabaseReadTransaction *)transaction
+{
+    OWSAssert(transaction);
+
+    id result = [transaction ext:TSUnseenDatabaseViewExtensionName];
+
+    if (!result) {
+        result = [transaction ext:TSUnreadDatabaseViewExtensionName];
+        OWSAssert(result);
+    }
+
+    return result;
+}
+
++ (id)threadOutgoingMessageDatabaseView:(YapDatabaseReadTransaction *)transaction
+{
+    OWSAssert(transaction);
+
+    id result = [transaction ext:TSThreadOutgoingMessageDatabaseViewExtensionName];
+    OWSAssert(result);
+
+    return result;
+}
+
++ (id)threadSpecialMessagesDatabaseView:(YapDatabaseReadTransaction *)transaction
+{
+    OWSAssert(transaction);
+
+    id result = [transaction ext:TSThreadSpecialMessagesDatabaseViewExtensionName];
+    OWSAssert(result);
+
+    return result;
+}
+
 #pragma mark - Logging
 
 + (NSString *)tag

src/Storage/TSStorageManager.h

@@ -27,7 +27,16 @@ NS_ASSUME_NONNULL_BEGIN
  */
 + (BOOL)isDatabasePasswordAccessible;
 
-- (void)setupDatabase;
+/**
+ * The safeBlockingMigrationsBlock block will
+ * run any outstanding version migrations that are a) blocking and b) safe
+ * to be run before the environment and storage is completely configured.
+ *
+ * Specifically, these migration should not depend on or affect the data
+ * of any database view.
+ */
+- (void)setupDatabaseWithSafeBlockingMigrations:(void (^_Nonnull)())safeBlockingMigrationsBlock;
+
 - (void)deleteThreadsAndMessages;
 - (void)resetSignalStorage;
 

src/Storage/TSStorageManager.m

@@ -191,17 +191,30 @@ static NSString *keychainDBPassAccount    = @"TSDatabasePass";
     };
 }
 
-- (void)setupDatabase
+- (void)setupDatabaseWithSafeBlockingMigrations:(void (^_Nonnull)())safeBlockingMigrationsBlock
 {
     // Synchronously register extensions which are essential for views.
     [TSDatabaseView registerThreadDatabaseView];
     [TSDatabaseView registerThreadInteractionsDatabaseView];
-    [TSDatabaseView registerThreadOutgoingMessagesDatabaseView];
     [TSDatabaseView registerUnreadDatabaseView];
-    [TSDatabaseView registerUnseenDatabaseView];
-    [TSDatabaseView registerThreadSpecialMessagesDatabaseView];
     [self.database registerExtension:[TSDatabaseSecondaryIndexes registerTimeStampIndex] withName:@"idx"];
 
+    // Run the blocking migrations.
+    //
+    // These need to run _before_ the async registered database views or
+    // they will block on them, which (in the upgrade case) can block
+    // return of appDidFinishLaunching... which in term can cause the
+    // app to crash on launch.
+    safeBlockingMigrationsBlock();
+
+    // Asynchronously register other extensions.
+    //
+    // All sync registrations must be done before all async registrations,
+    // or the sync registrations will block on the async registrations.
+    [TSDatabaseView asyncRegisterUnseenDatabaseView];
+    [TSDatabaseView asyncRegisterThreadOutgoingMessagesDatabaseView];
+    [TSDatabaseView asyncRegisterThreadSpecialMessagesDatabaseView];
+
     // Register extensions which aren't essential for rendering threads async
     [[OWSIncomingMessageFinder new] asyncRegisterExtension];
     [TSDatabaseView asyncRegisterSecondaryDevicesDatabaseView];