Migrate to shared data NSUserDefaults.

Signal/src/AppDelegate.m

@@ -24,6 +24,7 @@
 #import "VersionMigrations.h"
 #import "ViewControllerUtils.h"
 #import <AxolotlKit/SessionCipher.h>
+#import <SignalServiceKit/NSUserDefaults+OWS.h>
 #import <SignalServiceKit/OWSBatchMessageProcessor.h>
 #import <SignalServiceKit/OWSDisappearingMessagesJob.h>
 #import <SignalServiceKit/OWSFailedAttachmentDownloadsJob.h>
@@ -103,6 +104,18 @@ static NSString *const kURLHostVerifyPrefix             = @"verify";
 
     DDLogWarn(@"%@ application: didFinishLaunchingWithOptions.", self.logTag);
 
+    // We need to this _after_ we set up logging but _before_ we do
+    // anything else.
+    [self ensureMigrationToSharedData];
+
+#if RELEASE
+    // ensureMigrationToSharedData may have changed the state of the logging
+    // preference, so honor that change if necessary.
+    if (loggingIsEnabled && !OWSPreferences.loggingIsEnabled) {
+        [DebugLogger.sharedLogger disableFileLogging];
+    }
+#endif
+
     [AppVersion instance];
 
     [self startupLogging];
@@ -176,6 +189,21 @@ static NSString *const kURLHostVerifyPrefix             = @"verify";
     return YES;
 }
 
+- (void)ensureMigrationToSharedData
+{
+    if ([OWSPreferences hasMigratedToSharedData]) {
+        return;
+    }
+
+    [NSUserDefaults migrateToSharedUserDefaults];
+
+    [TSStorageManager migrateToSharedData];
+    [OWSProfileManager migrateToSharedData];
+    [TSAttachmentStream migrateToSharedData];
+
+    [OWSPreferences setHasMigratedToSharedData:YES];
+}
+
 - (void)startupLogging
 {
     DDLogInfo(@"iOS Version: %@", [UIDevice currentDevice].systemVersion);

Signal/src/Profiles/OWSProfileManager.h

@@ -29,6 +29,8 @@ extern const NSUInteger kOWSProfileManager_MaxAvatarDiameter;
 
 - (void)resetProfileStorage;
 
++ (void)migrateToSharedData;
+
 #pragma mark - Local Profile
 
 // These two methods should only be called from the main thread.

Signal/src/Profiles/OWSProfileManager.m

@@ -1384,22 +1384,29 @@ const NSUInteger kOWSProfileManager_MaxAvatarDiameter = 640;
     return image;
 }
 
++ (NSString *)oldProfileAvatarsDirPath
+{
+    return [[OWSFileSystem appDocumentDirectoryPath] stringByAppendingPathComponent:@"ProfileAvatars"];
+}
+
++ (NSString *)newProfileAvatarsDirPath
+{
+    return [[OWSFileSystem appSharedDataDirectoryPath] stringByAppendingPathComponent:@"ProfileAvatars"];
+}
+
++ (void)migrateToSharedData
+{
+    [OWSFileSystem moveAppFilePath:self.oldProfileAvatarsDirPath
+                sharedDataFilePath:self.newProfileAvatarsDirPath
+                     exceptionName:@"ProfileManagerCouldNotMigrateProfileDirectory"];
+}
+
 - (NSString *)profileAvatarsDirPath
 {
     static NSString *profileAvatarsDirPath = nil;
     static dispatch_once_t onceToken;
     dispatch_once(&onceToken, ^{
-        NSString *documentDirPath = [OWSFileSystem appDocumentDirectoryPath];
-        NSString *sharedDataDirPath = [OWSFileSystem appSharedDataDirectoryPath];
-
-        NSString *oldProfileAvatarsDirPath = [documentDirPath stringByAppendingPathComponent:@"ProfileAvatars"];
-        NSString *newProfileAvatarsDirPath = [sharedDataDirPath stringByAppendingPathComponent:@"ProfileAvatars"];
-
-        [OWSFileSystem moveAppFilePath:oldProfileAvatarsDirPath
-                    sharedDataFilePath:newProfileAvatarsDirPath
-                         exceptionName:@"ProfileManagerCouldNotMigrateProfileDirectory"];
-
-        profileAvatarsDirPath = newProfileAvatarsDirPath;
+        profileAvatarsDirPath = OWSProfileManager.newProfileAvatarsDirPath;
 
         BOOL isDirectory;
         BOOL exists = [[NSFileManager defaultManager] fileExistsAtPath:profileAvatarsDirPath isDirectory:&isDirectory];

Signal/src/environment/OWSPreferences.h

@@ -27,6 +27,9 @@ extern NSString *const OWSPreferencesKeyEnableDebugLog;
 
 #pragma mark - Specific Preferences
 
++ (BOOL)hasMigratedToSharedData;
++ (void)setHasMigratedToSharedData:(BOOL)value;
+
 - (BOOL)getHasSentAMessage;
 - (void)setHasSentAMessage:(BOOL)enabled;
 

Signal/src/environment/OWSPreferences.m

@@ -4,6 +4,7 @@
 
 #import "OWSPreferences.h"
 #import "TSStorageHeaders.h"
+#import <SignalServiceKit/NSUserDefaults+OWS.h>
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -22,6 +23,7 @@ NSString *const OWSPreferencesKeyCallKitPrivacyEnabled = @"CallKitPrivacyEnabled
 NSString *const OWSPreferencesKeyCallsHideIPAddress = @"CallsHideIPAddress";
 NSString *const OWSPreferencesKeyHasDeclinedNoContactsView = @"hasDeclinedNoContactsView";
 NSString *const OWSPreferencesKeyIOSUpgradeNagVersion = @"iOSUpgradeNagVersion";
+NSString *const OWSPreferencesKey_HasMigratedToSharedData = @"hasMigratedToSharedData";
 
 @implementation OWSPreferences
 
@@ -40,10 +42,7 @@ NSString *const OWSPreferencesKeyIOSUpgradeNagVersion = @"iOSUpgradeNagVersion";
 #pragma mark - Helpers
 
 - (void)clear {
-    @synchronized(self) {
-        NSString *appDomain = NSBundle.mainBundle.bundleIdentifier;
-        [NSUserDefaults.standardUserDefaults removePersistentDomainForName:appDomain];
-    }
+    [NSUserDefaults removeAll];
 }
 
 - (nullable id)tryGetValueForKey:(NSString *)key
@@ -61,6 +60,23 @@ NSString *const OWSPreferencesKeyIOSUpgradeNagVersion = @"iOSUpgradeNagVersion";
 
 #pragma mark - Specific Preferences
 
++ (BOOL)hasMigratedToSharedData
+{
+    NSNumber *preference = [NSUserDefaults.appUserDefaults objectForKey:OWSPreferencesKey_HasMigratedToSharedData];
+
+    if (preference) {
+        return [preference boolValue];
+    } else {
+        return NO;
+    }
+}
+
++ (void)setHasMigratedToSharedData:(BOOL)value
+{
+    [NSUserDefaults.appUserDefaults setObject:@(value) forKey:OWSPreferencesKey_HasMigratedToSharedData];
+    [NSUserDefaults.appUserDefaults synchronize];
+}
+
 - (BOOL)screenSecurityIsEnabled
 {
     NSNumber *preference = [self tryGetValueForKey:OWSPreferencesKeyScreenSecurity];
@@ -94,7 +110,7 @@ NSString *const OWSPreferencesKeyIOSUpgradeNagVersion = @"iOSUpgradeNagVersion";
 
 + (BOOL)loggingIsEnabled
 {
-    NSNumber *preference = [NSUserDefaults.standardUserDefaults objectForKey:OWSPreferencesKeyEnableDebugLog];
+    NSNumber *preference = [NSUserDefaults.appUserDefaults objectForKey:OWSPreferencesKeyEnableDebugLog];
 
     if (preference) {
         return [preference boolValue];
@@ -108,8 +124,8 @@ NSString *const OWSPreferencesKeyIOSUpgradeNagVersion = @"iOSUpgradeNagVersion";
     // Logging preferences are stored in UserDefaults instead of the database, so that we can (optionally) start
     // logging before the database is initialized. This is important because sometimes there are problems *with* the
     // database initialization, and without logging it would be hard to track down.
-    [NSUserDefaults.standardUserDefaults setObject:@(flag) forKey:OWSPreferencesKeyEnableDebugLog];
-    [NSUserDefaults.standardUserDefaults synchronize];
+    [NSUserDefaults.appUserDefaults setObject:@(flag) forKey:OWSPreferencesKeyEnableDebugLog];
+    [NSUserDefaults.appUserDefaults synchronize];
 }
 
 - (void)setHasSentAMessage:(BOOL)enabled

Signal/src/environment/VersionMigrations.m

@@ -8,9 +8,10 @@
 #import "OWSDatabaseMigrationRunner.h"
 #import "PushManager.h"
 #import "SignalKeyingStorage.h"
-#import "TSAccountManager.h"
-#import "TSNetworkManager.h"
 #import <SignalServiceKit/AppVersion.h>
+#import <SignalServiceKit/NSUserDefaults+OWS.h>
+#import <SignalServiceKit/TSAccountManager.h>
+#import <SignalServiceKit/TSNetworkManager.h>
 
 #define NEEDS_TO_REGISTER_PUSH_KEY @"Register For Push"
 #define NEEDS_TO_REGISTER_ATTRIBUTES @"Register Attributes"
@@ -125,39 +126,39 @@
 
 + (void)blockingAttributesUpdate {
     LIControllerBlockingOperation blockingOperation = ^BOOL(void) {
-      [[NSUserDefaults standardUserDefaults] setObject:@YES forKey:NEEDS_TO_REGISTER_ATTRIBUTES];
+        [[NSUserDefaults appUserDefaults] setObject:@YES forKey:NEEDS_TO_REGISTER_ATTRIBUTES];
 
-      __block dispatch_semaphore_t sema = dispatch_semaphore_create(0);
+        __block dispatch_semaphore_t sema = dispatch_semaphore_create(0);
 
-      __block BOOL success;
+        __block BOOL success;
 
-      TSUpdateAttributesRequest *request = [[TSUpdateAttributesRequest alloc] initWithManualMessageFetching:NO];
-      [[TSNetworkManager sharedManager] makeRequest:request
-          success:^(NSURLSessionDataTask *task, id responseObject) {
-              success = YES;
-              dispatch_semaphore_signal(sema);
-          }
-          failure:^(NSURLSessionDataTask *task, NSError *error) {
-              if (!IsNSErrorNetworkFailure(error)) {
-                  OWSProdError([OWSAnalyticsEvents errorUpdateAttributesRequestFailed]);
-              }
-              success = NO;
-              DDLogError(@"Updating attributess failed with error: %@", error.description);
-              dispatch_semaphore_signal(sema);
-          }];
+        TSUpdateAttributesRequest *request = [[TSUpdateAttributesRequest alloc] initWithManualMessageFetching:NO];
+        [[TSNetworkManager sharedManager] makeRequest:request
+            success:^(NSURLSessionDataTask *task, id responseObject) {
+                success = YES;
+                dispatch_semaphore_signal(sema);
+            }
+            failure:^(NSURLSessionDataTask *task, NSError *error) {
+                if (!IsNSErrorNetworkFailure(error)) {
+                    OWSProdError([OWSAnalyticsEvents errorUpdateAttributesRequestFailed]);
+                }
+                success = NO;
+                DDLogError(@"Updating attributess failed with error: %@", error.description);
+                dispatch_semaphore_signal(sema);
+            }];
 
 
-      dispatch_semaphore_wait(sema, DISPATCH_TIME_FOREVER);
+        dispatch_semaphore_wait(sema, DISPATCH_TIME_FOREVER);
 
-      return success;
+        return success;
     };
 
     LIControllerRetryBlock retryBlock = [LockInteractionController defaultNetworkRetry];
 
     [LockInteractionController performBlock:blockingOperation
                             completionBlock:^{
-                              [[NSUserDefaults standardUserDefaults] removeObjectForKey:NEEDS_TO_REGISTER_ATTRIBUTES];
-                              DDLogWarn(@"Successfully updated attributes.");
+                                [[NSUserDefaults appUserDefaults] removeObjectForKey:NEEDS_TO_REGISTER_ATTRIBUTES];
+                                DDLogWarn(@"Successfully updated attributes.");
                             }
                                  retryBlock:retryBlock
                                 usesNetwork:YES];

SignalServiceKit/src/Messages/Attachments/TSAttachmentStream.h

@@ -57,6 +57,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (CGFloat)audioDurationSeconds;
 
++ (void)migrateToSharedData;
+
 @end
 
 NS_ASSUME_NONNULL_END

SignalServiceKit/src/Messages/Attachments/TSAttachmentStream.m

@@ -180,22 +180,29 @@ NS_ASSUME_NONNULL_BEGIN
     return [dataSource writeToPath:filePath];
 }
 
++ (NSString *)oldAttachmentsDirPath
+{
+    return [[OWSFileSystem appDocumentDirectoryPath] stringByAppendingPathComponent:@"Attachments"];
+}
+
++ (NSString *)newAttachmentsDirPath
+{
+    return [[OWSFileSystem appSharedDataDirectoryPath] stringByAppendingPathComponent:@"Attachments"];
+}
+
++ (void)migrateToSharedData
+{
+    [OWSFileSystem moveAppFilePath:self.oldAttachmentsDirPath
+                sharedDataFilePath:self.newAttachmentsDirPath
+                     exceptionName:@"CouldNotMigrateAttachmentsDirectory"];
+}
+
 + (NSString *)attachmentsFolder
 {
     static NSString *attachmentsFolder = nil;
     static dispatch_once_t onceToken;
     dispatch_once(&onceToken, ^{
-        NSString *documentDirPath = [OWSFileSystem appDocumentDirectoryPath];
-        NSString *sharedDataDirPath = [OWSFileSystem appSharedDataDirectoryPath];
-
-        NSString *oldAttachmentsDirPath = [documentDirPath stringByAppendingPathComponent:@"Attachments"];
-        NSString *newAttachmentsDirPath = [sharedDataDirPath stringByAppendingPathComponent:@"Attachments"];
-
-        [OWSFileSystem moveAppFilePath:oldAttachmentsDirPath
-                    sharedDataFilePath:newAttachmentsDirPath
-                         exceptionName:@"CouldNotMigrateAttachmentsDirectory"];
-
-        attachmentsFolder = newAttachmentsDirPath;
+        attachmentsFolder = TSAttachmentStream.newAttachmentsDirPath;
 
         BOOL isDirectory;
         BOOL exists = [[NSFileManager defaultManager] fileExistsAtPath:attachmentsFolder isDirectory:&isDirectory];

SignalServiceKit/src/Storage/TSStorageManager.h

@@ -63,6 +63,8 @@ NS_ASSUME_NONNULL_BEGIN
 @property (nullable, nonatomic, readonly) YapDatabaseConnection *dbReadConnection;
 @property (nullable, nonatomic, readonly) YapDatabaseConnection *dbReadWriteConnection;
 
++ (void)migrateToSharedData;
+
 @end
 
 NS_ASSUME_NONNULL_END

SignalServiceKit/src/Storage/TSStorageManager.m

@@ -207,10 +207,11 @@ void setDatabaseInitialized()
     static TSStorageManager *sharedManager = nil;
     static dispatch_once_t onceToken;
     dispatch_once(&onceToken, ^{
-        sharedManager = [[self alloc] initDefault];
 #if TARGET_OS_IPHONE
-        [sharedManager protectSignalFiles];
+        [TSStorageManager protectSignalFiles];
 #endif
+
+        sharedManager = [[self alloc] initDefault];
     });
     return sharedManager;
 }
@@ -355,7 +356,8 @@ void setDatabaseInitialized()
     [TSDatabaseView asyncRegistrationCompletion];
 }
 
-- (void)protectSignalFiles {
++ (void)protectSignalFiles
+{
     // The old database location was in the Document directory,
     // so protect the database files individually.
     [OWSFileSystem protectFolderAtPath:[self oldDatabaseFilePath]];
@@ -375,12 +377,12 @@ void setDatabaseInitialized()
     return FALSE;
 }
 
-- (NSString *)oldDatabaseDirPath
++ (NSString *)oldDatabaseDirPath
 {
     return [OWSFileSystem appDocumentDirectoryPath];
 }
 
-- (NSString *)newDatabaseDirPath
++ (NSString *)newDatabaseDirPath
 {
     NSString *databaseDirPath = [[OWSFileSystem appSharedDataDirectoryPath] stringByAppendingPathComponent:@"database"];
 
@@ -405,52 +407,52 @@ void setDatabaseInitialized()
     return databaseDirPath;
 }
 
-- (NSString *)databaseFilename
++ (NSString *)databaseFilename
 {
     return @"Signal.sqlite";
 }
 
-- (NSString *)databaseFilename_SHM
++ (NSString *)databaseFilename_SHM
 {
     return [self.databaseFilename stringByAppendingString:@"-shm"];
 }
 
-- (NSString *)databaseFilename_WAL
++ (NSString *)databaseFilename_WAL
 {
     return [self.databaseFilename stringByAppendingString:@"-wal"];
 }
 
-- (NSString *)oldDatabaseFilePath
++ (NSString *)oldDatabaseFilePath
 {
     return [self.oldDatabaseDirPath stringByAppendingPathComponent:self.databaseFilename];
 }
 
-- (NSString *)oldDatabaseFilePath_SHM
++ (NSString *)oldDatabaseFilePath_SHM
 {
     return [self.oldDatabaseDirPath stringByAppendingPathComponent:self.databaseFilename_SHM];
 }
 
-- (NSString *)oldDatabaseFilePath_WAL
++ (NSString *)oldDatabaseFilePath_WAL
 {
     return [self.oldDatabaseDirPath stringByAppendingPathComponent:self.databaseFilename_WAL];
 }
 
-- (NSString *)newDatabaseFilePath
++ (NSString *)newDatabaseFilePath
 {
     return [self.newDatabaseDirPath stringByAppendingPathComponent:self.databaseFilename];
 }
 
-- (NSString *)newDatabaseFilePath_SHM
++ (NSString *)newDatabaseFilePath_SHM
 {
     return [self.newDatabaseDirPath stringByAppendingPathComponent:self.databaseFilename_SHM];
 }
 
-- (NSString *)newDatabaseFilePath_WAL
++ (NSString *)newDatabaseFilePath_WAL
 {
     return [self.newDatabaseDirPath stringByAppendingPathComponent:self.databaseFilename_WAL];
 }
 
-- (NSString *)dbPath
++ (void)migrateToSharedData
 {
     [OWSFileSystem moveAppFilePath:self.oldDatabaseFilePath
                 sharedDataFilePath:self.newDatabaseFilePath
@@ -461,32 +463,13 @@ void setDatabaseInitialized()
     [OWSFileSystem moveAppFilePath:self.oldDatabaseFilePath_WAL
                 sharedDataFilePath:self.newDatabaseFilePath_WAL
                      exceptionName:TSStorageManagerExceptionName_CouldNotMoveDatabaseFile];
+}
 
-    NSFileManager *fileManager = [NSFileManager defaultManager];
-    BOOL hasAllNewFiles = ([fileManager fileExistsAtPath:self.newDatabaseFilePath] &&
-        [fileManager fileExistsAtPath:self.newDatabaseFilePath_SHM] &&
-        [fileManager fileExistsAtPath:self.newDatabaseFilePath_WAL]);
-    BOOL hasAnyNewFiles = ([fileManager fileExistsAtPath:self.newDatabaseFilePath] ||
-        [fileManager fileExistsAtPath:self.newDatabaseFilePath_SHM] ||
-        [fileManager fileExistsAtPath:self.newDatabaseFilePath_WAL]);
-    if (!hasAllNewFiles && !hasAnyNewFiles) {
-        for (NSString *filePath in @[
-                 self.newDatabaseFilePath,
-                 self.newDatabaseFilePath_SHM,
-                 self.newDatabaseFilePath_WAL,
-                 self.newDatabaseFilePath,
-                 self.newDatabaseFilePath_SHM,
-                 self.newDatabaseFilePath_WAL,
-             ]) {
-            DDLogInfo(@"%@ Database file %@ exists %d", self.logTag, filePath, [fileManager fileExistsAtPath:filePath]);
-        }
-        OWSFail(@"%@ Incomplete set of database files.", self.logTag);
-    }
-
-    DDLogError(@"databasePath: %@", self.newDatabaseFilePath);
-    [DDLog flushLog];
+- (NSString *)dbPath
+{
+    DDLogVerbose(@"databasePath: %@", TSStorageManager.newDatabaseFilePath);
 
-    return self.newDatabaseFilePath;
+    return TSStorageManager.newDatabaseFilePath;
 }
 
 + (BOOL)isDatabasePasswordAccessible

SignalServiceKit/src/Util/AppVersion.m

@@ -3,6 +3,7 @@
 //
 
 #import "AppVersion.h"
+#import <SignalServiceKit/NSUserDefaults+OWS.h>
 
 NSString *const kNSUserDefaults_FirstAppVersion = @"kNSUserDefaults_FirstAppVersion";
 NSString *const kNSUserDefaults_LastAppVersion = @"kNSUserDefaults_LastVersion";
@@ -36,24 +37,22 @@ NSString *const kNSUserDefaults_LastCompletedLaunchAppVersion = @"kNSUserDefault
     
     // The version of the app when it was first launched.
     // nil if the app has never been launched before.
-    self.firstAppVersion = [[NSUserDefaults standardUserDefaults] objectForKey:kNSUserDefaults_FirstAppVersion];
+    self.firstAppVersion = [[NSUserDefaults appUserDefaults] objectForKey:kNSUserDefaults_FirstAppVersion];
     // The version of the app the last time it was launched.
     // nil if the app has never been launched before.
-    self.lastAppVersion = [[NSUserDefaults standardUserDefaults] objectForKey:kNSUserDefaults_LastAppVersion];
+    self.lastAppVersion = [[NSUserDefaults appUserDefaults] objectForKey:kNSUserDefaults_LastAppVersion];
     self.lastCompletedLaunchAppVersion =
-        [[NSUserDefaults standardUserDefaults] objectForKey:kNSUserDefaults_LastCompletedLaunchAppVersion];
+        [[NSUserDefaults appUserDefaults] objectForKey:kNSUserDefaults_LastCompletedLaunchAppVersion];
 
     // Ensure the value for the "first launched version".
     if (!self.firstAppVersion) {
         self.firstAppVersion = self.currentAppVersion;
-        [[NSUserDefaults standardUserDefaults] setObject:self.currentAppVersion
-                                                  forKey:kNSUserDefaults_FirstAppVersion];
+        [[NSUserDefaults appUserDefaults] setObject:self.currentAppVersion forKey:kNSUserDefaults_FirstAppVersion];
     }
     
     // Update the value for the "most recently launched version".
-    [[NSUserDefaults standardUserDefaults] setObject:self.currentAppVersion
-                                              forKey:kNSUserDefaults_LastAppVersion];
-    [[NSUserDefaults standardUserDefaults] synchronize];
+    [[NSUserDefaults appUserDefaults] setObject:self.currentAppVersion forKey:kNSUserDefaults_LastAppVersion];
+    [[NSUserDefaults appUserDefaults] synchronize];
 
     DDLogInfo(@"%@ firstAppVersion: %@", self.logTag, self.firstAppVersion);
     DDLogInfo(@"%@ lastAppVersion: %@", self.logTag, self.lastAppVersion);
@@ -68,9 +67,9 @@ NSString *const kNSUserDefaults_LastCompletedLaunchAppVersion = @"kNSUserDefault
     self.lastCompletedLaunchAppVersion = self.currentAppVersion;
 
     // Update the value for the "most recently launch-completed version".
-    [[NSUserDefaults standardUserDefaults] setObject:self.currentAppVersion
-                                              forKey:kNSUserDefaults_LastCompletedLaunchAppVersion];
-    [[NSUserDefaults standardUserDefaults] synchronize];
+    [[NSUserDefaults appUserDefaults] setObject:self.currentAppVersion
+                                         forKey:kNSUserDefaults_LastCompletedLaunchAppVersion];
+    [[NSUserDefaults appUserDefaults] synchronize];
 }
 
 - (BOOL)isFirstLaunch

SignalServiceKit/src/Util/NSUserDefaults+OWS.h

@@ -0,0 +1,17 @@
+//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface NSUserDefaults (OWS)
+
++ (NSUserDefaults *)appUserDefaults;
+
++ (void)migrateToSharedUserDefaults;
+
++ (void)removeAll;
+
+@end
+
+NS_ASSUME_NONNULL_END

SignalServiceKit/src/Util/NSUserDefaults+OWS.m

@@ -0,0 +1,37 @@
+//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//
+
+#import "NSUserDefaults+OWS.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@implementation NSUserDefaults (OWS)
+
++ (NSUserDefaults *)appUserDefaults
+{
+    return [[NSUserDefaults alloc] initWithSuiteName:@"group.org.whispersystems.signal.group"];
+}
+
++ (void)migrateToSharedUserDefaults
+{
+    NSUserDefaults *appUserDefaults = self.appUserDefaults;
+
+    NSDictionary<NSString *, id> *dictionary = [NSUserDefaults standardUserDefaults].dictionaryRepresentation;
+    for (NSString *key in dictionary) {
+        id value = dictionary[key];
+        OWSAssert(value);
+        [appUserDefaults setObject:value forKey:key];
+    }
+}
+
++ (void)removeAll
+{
+    NSString *appDomain = NSBundle.mainBundle.bundleIdentifier;
+    [NSUserDefaults.standardUserDefaults removePersistentDomainForName:appDomain];
+    // TODO: How to clear the shared user defaults?
+}
+
+@end
+
+NS_ASSUME_NONNULL_END