fix: added a persistence layer over keys stored in standard defaults by rudderstack

Podfile.lock

@@ -33,10 +33,10 @@ EXTERNAL SOURCES:
 SPEC CHECKSUMS:
   MetricsReporter: 99596ee5003c69949ed2f50acc34aee83c42f843
   RSCrashReporter: 6b8376ac729b0289ebe0908553e5f56d8171f313
-  Rudder: 8091e861028a12add1107b03d224d4abf08c597f
+  Rudder: c3fd4dca549852fd14153a928979fbced4b901a3
   RudderKit: d9d6997696e1642b753d8bdf94e57af643a68f03
   SQLCipher: 905b145f65f349f26da9e60a19901ad24adcd381
 
 PODFILE CHECKSUM: b6937cee06e0633464427ff0d975d40e17419e9f
 
-COCOAPODS: 1.14.3
+COCOAPODS: 1.14.2

Rudder.xcodeproj/xcshareddata/xcschemes/RudderTests-iOS.xcscheme

@@ -18,7 +18,7 @@
             parallelizable = "YES">
             <BuildableReference
                BuildableIdentifier = "primary"
-               BlueprintIdentifier = "ED04A23B29839DCC0080A88D"
+               BlueprintIdentifier = "ED99903A2A69103A00031B06"
                BuildableName = "RudderTests-iOS.xctest"
                BlueprintName = "RudderTests-iOS"
                ReferencedContainer = "container:Rudder.xcodeproj">

Sources/Classes/Headers/Public/RSDefaultsPersistence.h

@@ -0,0 +1,22 @@
+//
+//  RSDefaultsPersistence.h
+//  Rudder
+//
+//  Created by Desu Sai Venkat on 30/01/24.
+//
+
+@interface RSDefaultsPersistence : NSObject {
+    NSMutableDictionary *data;
+    NSURL *fileURL;
+    dispatch_queue_t dataAccessQueue;
+}
+
+- (instancetype)init NS_UNAVAILABLE NS_SWIFT_UNAVAILABLE("Use `RSDefaultsPersistence.sharedInstance()` instead.");
++ (instancetype)sharedInstance;
+- (void) copyStandardDefaultsToPersistenceIfNeeded;
+- (void) clearState;
+- (void)writeObject:(id)object forKey:(NSString *)key;
+- (id)readObjectForKey:(NSString *)key;
+- (void)removeObjectForKey:(NSString *)key;
+
+@end

Sources/Classes/Headers/Public/RSEventRepository.h

@@ -17,6 +17,7 @@
 #import "RSElementCache.h"
 #import "RSCloudModeManager.h"
 #import "RSDeviceModeManager.h"
+#import "RSDefaultsPersistence.h"
 #import "RSPreferenceManager.h"
 #import "RSDBPersistentManager.h"
 #import "RSDataResidencyManager.h"
@@ -37,6 +38,7 @@ NS_ASSUME_NONNULL_BEGIN
     RSDataResidencyManager* dataResidencyManager;
     RSServerConfigManager* configManager;
     RSNetworkManager* networkManager;
+    RSDefaultsPersistence* defaultsPersistence;
     RSPreferenceManager *preferenceManager;
     RSCloudModeManager *cloudModeManager;
     RSDeviceModeManager *deviceModeManager;

Sources/Classes/Headers/Public/RSPreferenceManager.h

@@ -1,11 +1,12 @@
 //
 //  RSPreferenceManager.h
-//  Pods-DummyTestProject
+//  Rudder
 //
 //  Created by Arnab Pal on 27/01/20.
 //
 
 #import <Foundation/Foundation.h>
+#import "RSDefaultsPersistence.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -25,6 +26,7 @@ extern NSString *const RSLastActiveTimestamp;
 extern NSString *const RSSessionAutoTrackStatus;
 
 + (instancetype) getInstance;
++ (NSArray *) getPreferenceKeys;
 
 - (void) updateLastUpdatedTime: (long) updatedTime;
 - (long) getLastUpdatedTime;
@@ -41,6 +43,7 @@ extern NSString *const RSSessionAutoTrackStatus;
 - (void) deleteBuildVersionCode;
 
 - (void) performMigration;
+- (void) restoreMissingKeysFromPersistence;
 
 - (NSString* __nullable) getBuildNumber;
 - (void) saveBuildNumber: (NSString* __nonnull) buildNumber;

Sources/Classes/Headers/Public/RSUtils.h

@@ -21,6 +21,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 + (NSString*) getTimestamp;
 + (NSString *)getFilePath:(NSString *)fileName;
++ (NSURL *)getFileURL:(NSString *) fileName;
 + (long) getTimeStampLong;
 + (NSString*) getUniqueId;
 + (NSString*) getLocale;
@@ -43,6 +44,7 @@ NS_ASSUME_NONNULL_BEGIN
 + (BOOL) isApplicationUpdated;
 + (NSString* _Nullable) getDeviceId;
 + (BOOL)isFileExists:(NSString *)fileName;
++ (BOOL)doesFileExistsAtURL:(NSURL *)fileURL;
 + (BOOL)removeFile:(NSString *)fileName;
 + (BOOL) isDBMessageEmpty:(RSDBMessage*)dbMessage;
 + (BOOL) isEmptyString:(NSString *)value;

Sources/Classes/RSDefaultsPersistence.m

@@ -0,0 +1,115 @@
+//
+//  RSDefaultsPersistence.m
+//  Rudder
+//
+//  Created by Desu Sai Venkat on 30/01/24.
+//
+
+#import <Foundation/Foundation.h>
+#import "RSUtils.h"
+#import "RSLogger.h"
+#import "RSDefaultsPersistence.h"
+
+static RSDefaultsPersistence *instance;
+static NSString * const standardDefaultsCopied = @"standardDefaultsCopied";
+
+@implementation RSDefaultsPersistence
+
++ (instancetype)sharedInstance {
+    if(instance == nil) {
+        static dispatch_once_t onceToken;
+        dispatch_once(&onceToken, ^{
+            instance = [[self alloc] init];
+        });
+    }
+    return instance;
+}
+
+- (instancetype)init {
+    self = [super init];
+    if (self) {
+        data = [NSMutableDictionary dictionary];
+        fileURL = [RSUtils getFileURL:@"rsDefaultsPersistence.plist"];
+        dataAccessQueue = dispatch_queue_create("com.rudderstack.defaultspersistence", DISPATCH_QUEUE_SERIAL);
+        [self loadFromFile];
+    }
+    return self;
+}
+
+- (void)loadFromFile {
+    if ([RSUtils doesFileExistsAtURL:fileURL]) {
+        NSError *error = nil;
+        NSDictionary* dictFromFile = [NSMutableDictionary dictionaryWithContentsOfURL:fileURL error:&error];
+        if (error == nil && dictFromFile != nil) {
+            [data addEntriesFromDictionary:dictFromFile];
+        }
+    }
+}
+
+// this would be executed only once after the SDK has been updated from a version without DefaultsPersistence
+// to a version with DefaultsPersistence to ensure that the persistence layer and standard defaults are in same state.
+- (void)copyStandardDefaultsToPersistenceIfNeeded {
+    BOOL userDefaultsCopiedAlready = [self readObjectForKey:standardDefaultsCopied];
+    if(!userDefaultsCopiedAlready) {
+        [RSLogger logDebug:@"RSDefaultsPersistence: copyStandardDefaultsToPersistenceIfNeeded: Copying Standard Defaults to Persistence layer"];
+        NSArray* preferenceKeys = [RSPreferenceManager getPreferenceKeys];
+        for(NSString* key in preferenceKeys) {
+            id value = [[NSUserDefaults standardUserDefaults] objectForKey:key];
+            if(value != nil) {
+                [self writeObject:value forKey:key];
+            }
+        }
+        // Set the flag to indicate that standard defaults have been copied to the persistence layer
+        [self writeObject:@YES forKey:standardDefaultsCopied];
+    }
+}
+
+// the caller of this method should ensure that this is dispatched to the dataAccessQueue synchronously
+- (void)writeToFile {
+    NSError* error = nil;
+    [data writeToURL:fileURL error:&error];
+    if (error != nil) {
+        [RSLogger logError: [NSString stringWithFormat:@"RSDefaultsPersistence: writeToFile: Error writing to file: %@", error]];
+    }
+}
+
+- (void) writeToFileSync {
+    dispatch_sync(dataAccessQueue, ^{
+        [self writeToFile];
+    });
+}
+
+- (void)writeObject:(id)object forKey:(NSString *)key {
+    dispatch_sync(dataAccessQueue, ^{
+        if (object && key) {
+            data[key] = object;
+            [self writeToFile];
+        }
+    });
+}
+
+- (id)readObjectForKey:(NSString *)key {
+    __block id result;
+    dispatch_sync(dataAccessQueue, ^{
+        result = data[key];
+    });
+    return result;
+
+}
+
+- (void)removeObjectForKey:(NSString *)key {
+    dispatch_sync(dataAccessQueue, ^{
+        [data removeObjectForKey:key];
+        [self writeToFile];
+    });
+}
+
+// for testing purpose only
+- (void) clearState {
+    dispatch_sync(dataAccessQueue, ^{
+        [data removeAllObjects];
+        [self writeToFile];
+    });
+}
+
+@end

Sources/Classes/RSEventRepository.m

@@ -57,9 +57,14 @@ - (instancetype)init:(NSString*)_writeKey config:(RSConfig*)_config client:(RSCl
 
         self->authToken = [RSUtils getBase64EncodedString: [[NSString alloc] initWithFormat:@"%@:", self->writeKey]];
 
+        [RSLogger logDebug:@"EventRepository: Initiating DefaultsPersistence"];
+        self->defaultsPersistence = [RSDefaultsPersistence sharedInstance];
+        [self->defaultsPersistence copyStandardDefaultsToPersistenceIfNeeded];
+
         [RSLogger logDebug:@"EventRepository: Initiating RSPreferenceManager"];
         self->preferenceManager = [RSPreferenceManager getInstance];
         [self->preferenceManager performMigration];
+        [self->preferenceManager restoreMissingKeysFromPersistence];
 
         [self clearAnonymousIdIfRequired];