Feature flags performance improvements

bugsnag · Dec 17, 2024 · 2f44b7b · 2f44b7b
1 parent 615a965
commit 2f44b7b
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Showing 27 changed files with 897 additions and 184 deletions.
diff --git a/Bugsnag.xcodeproj/project.pbxproj b/Bugsnag.xcodeproj/project.pbxproj
diff --git a/Bugsnag/BugsnagInternals.h b/Bugsnag/BugsnagInternals.h
@@ -21,8 +21,18 @@
 
 #import "BugsnagHandledState.h"
 #import "BugsnagNotifier.h"
+#import "FeatureFlags/BSGFeatureFlagStore.h"
 
-@interface BSGFeatureFlagStore : NSObject <NSCopying>
+@interface BSGMemoryFeatureFlagStore : NSObject <BSGFeatureFlagStore>
+@end
+
+@interface BSGPersistentFeatureFlagStore : NSObject <BSGFeatureFlagStore>
+@end
+
+@interface BSGAtomicFeatureFlagStore : NSObject <BSGFeatureFlagStore>
+@end
+
+@interface BSGCompositeFeatureFlagStore : NSObject <BSGFeatureFlagStore>
 @end
 
 NS_ASSUME_NONNULL_BEGIN
@@ -79,7 +89,7 @@ typedef void (^ BSGClientObserver)(BSGClientObserverEvent event, _Nullable id va
 
 @property (retain, nonatomic) BugsnagConfiguration *configuration;
 
-@property (readonly, nonatomic) BSGFeatureFlagStore *featureFlagStore;
+@property (readonly, nonatomic) BSGCompositeFeatureFlagStore *featureFlagStore;
 
 @property (strong, nonatomic) BugsnagMetadata *metadata;
 
@@ -161,7 +171,7 @@ typedef void (^ BSGClientObserver)(BSGClientObserverEvent event, _Nullable id va
 
 - (NSDictionary *)toJsonWithRedactedKeys:(nullable NSSet *)redactedKeys;
 
-@property (readwrite, strong, nonnull, nonatomic) BSGFeatureFlagStore *featureFlagStore;
+@property (readwrite, strong, nonnull, nonatomic) id<BSGFeatureFlagStore> featureFlagStore;
 
 @end
 

diff --git a/Bugsnag/Client/BugsnagClient+Private.h b/Bugsnag/Client/BugsnagClient+Private.h
@@ -19,6 +19,7 @@
 @class BugsnagNotifier;
 @class BugsnagSessionTracker;
 @class BugsnagSystemState;
+@class BSGPersistentFeatureFlagStore;
 
 NS_ASSUME_NONNULL_BEGIN
 

diff --git a/Bugsnag/Client/BugsnagClient.m b/Bugsnag/Client/BugsnagClient.m
@@ -72,6 +72,9 @@
 #import "BugsnagUser+Private.h"
 #import "BSGPersistentDeviceID.h"
 #import "BugsnagCocoaPerformanceFromBugsnagCocoa.h"
+#import "BSGPersistentFeatureFlagStore.h"
+#import "BSGAtomicFeatureFlagStore.h"
+#import "BSGCompositeFeatureFlagStore.h"
 
 static struct {
     // Contains the user-specified metadata, including the user tab from config.
@@ -141,6 +144,7 @@ static void BSSerializeDataCrashHandler(const BSG_KSCrashReportWriter *writer, b
         writer->addIntegerElement(writer, "thermalState", bsg_runContext->thermalState);
 
         BugsnagBreadcrumbsWriteCrashReport(writer, requiresAsyncSafety);
+        BugsnagFeatureFlagsWriteCrashReport(writer, requiresAsyncSafety);
 
         // Create a file to indicate that the crash has been handled by
         // the library. This exists in case the subsequent `onCrash` handler
@@ -211,13 +215,10 @@ - (instancetype)initWithConfiguration:(BugsnagConfiguration *)configuration {
                           withEmail:_configuration.user.email
                             andName:_configuration.user.name];
         }
-
-        _featureFlagStore = [configuration.featureFlagStore copy];
 
         _state = [[BugsnagMetadata alloc] initWithDictionary:@{
             BSGKeyClient: @{
                 BSGKeyContext: _configuration.context ?: [NSNull null],
-                BSGKeyFeatureFlags: BSGFeatureFlagStoreToJSON(_featureFlagStore),
             },
             BSGKeyUser: [_configuration.user toJson] ?: @{}
         }];
@@ -236,6 +237,11 @@ - (instancetype)initWithConfiguration:(BugsnagConfiguration *)configuration {
         bsg_g_bugsnag_data.onCrash = (void (*)(const BSG_KSCrashReportWriter *))self.configuration.onCrashHandler;
 
         _breadcrumbStore = [[BugsnagBreadcrumbs alloc] initWithConfiguration:self.configuration];
+
+        id<BSGFeatureFlagStore> persistentFeatureFlagsStore = [[BSGPersistentFeatureFlagStore alloc] initWithStorageDirectory:fileLocations.featureFlags];
+        _featureFlagStore = [BSGCompositeFeatureFlagStore storeWithMemoryStore:[configuration.featureFlagStore copy]
+                                                               persistentStore:persistentFeatureFlagsStore
+                                                                   atomicStore:[BSGAtomicFeatureFlagStore store]];
 
         // Start with a copy of the configuration metadata
         self.metadata = [[_configuration metadata] copy];
@@ -285,6 +291,7 @@ - (void)start {
     [self.metadata setStorageBuffer:&bsg_g_bugsnag_data.metadataJSON file:BSGFileLocations.current.metadata];
     [self.state setStorageBuffer:&bsg_g_bugsnag_data.stateJSON file:BSGFileLocations.current.state];
     [self.breadcrumbStore removeAllBreadcrumbs];
+    [self.featureFlagStore synchronizeFlagsWithMemoryStore];
 
 #if BSG_HAVE_REACHABILITY
     [self setupConnectivityListener];
@@ -796,9 +803,9 @@ - (void)notifyInternal:(BugsnagEvent *_Nonnull)event
     [event.metadata addMetadata:BSGDeviceMetadataFromRunContext(bsg_runContext) toSection:BSGKeyDevice];
 
     // App hang events will already contain feature flags
-    if (!event.featureFlagStore.count) {
+    if (event.featureFlagStore.isEmpty) {
         @synchronized (self.featureFlagStore) {
-            event.featureFlagStore = [self.featureFlagStore copy];
+            event.featureFlagStore = [self.featureFlagStore copyMemoryStore];
         }
     }
 
@@ -882,8 +889,7 @@ - (void)dealloc {
 
 - (void)addFeatureFlagWithName:(NSString *)name variant:(nullable NSString *)variant {
     @synchronized (self.featureFlagStore) {
-        BSGFeatureFlagStoreAddFeatureFlag(self.featureFlagStore, name, variant);
-        [self.state addMetadata:BSGFeatureFlagStoreToJSON(self.featureFlagStore) withKey:BSGKeyFeatureFlags toSection:BSGKeyClient];
+        [self.featureFlagStore addFeatureFlag:name withVariant:variant];
     }
     if (self.observer) {
         self.observer(BSGClientObserverAddFeatureFlag, [BugsnagFeatureFlag flagWithName:name variant:variant]);
@@ -892,8 +898,7 @@ - (void)addFeatureFlagWithName:(NSString *)name variant:(nullable NSString *)var
 
 - (void)addFeatureFlagWithName:(NSString *)name {
     @synchronized (self.featureFlagStore) {
-        BSGFeatureFlagStoreAddFeatureFlag(self.featureFlagStore, name, nil);
-        [self.state addMetadata:BSGFeatureFlagStoreToJSON(self.featureFlagStore) withKey:BSGKeyFeatureFlags toSection:BSGKeyClient];
+        [self.featureFlagStore addFeatureFlag:name withVariant:nil];
     }
     if (self.observer) {
         self.observer(BSGClientObserverAddFeatureFlag, [BugsnagFeatureFlag flagWithName:name]);
@@ -902,8 +907,7 @@ - (void)addFeatureFlagWithName:(NSString *)name {
 
 - (void)addFeatureFlags:(NSArray<BugsnagFeatureFlag *> *)featureFlags {
     @synchronized (self.featureFlagStore) {
-        BSGFeatureFlagStoreAddFeatureFlags(self.featureFlagStore, featureFlags);
-        [self.state addMetadata:BSGFeatureFlagStoreToJSON(self.featureFlagStore) withKey:BSGKeyFeatureFlags toSection:BSGKeyClient];
+        [self.featureFlagStore addFeatureFlags:featureFlags];
     }
     if (self.observer) {
         for (BugsnagFeatureFlag *featureFlag in featureFlags) {
@@ -914,8 +918,7 @@ - (void)addFeatureFlags:(NSArray<BugsnagFeatureFlag *> *)featureFlags {
 
 - (void)clearFeatureFlagWithName:(NSString *)name {
     @synchronized (self.featureFlagStore) {
-        BSGFeatureFlagStoreClear(self.featureFlagStore, name);
-        [self.state addMetadata:BSGFeatureFlagStoreToJSON(self.featureFlagStore) withKey:BSGKeyFeatureFlags toSection:BSGKeyClient];
+        [self.featureFlagStore clear:name];
     }
     if (self.observer) {
         self.observer(BSGClientObserverClearFeatureFlag, name);
@@ -924,8 +927,7 @@ - (void)clearFeatureFlagWithName:(NSString *)name {
 
 - (void)clearFeatureFlags {
     @synchronized (self.featureFlagStore) {
-        BSGFeatureFlagStoreClear(self.featureFlagStore, nil);
-        [self.state addMetadata:BSGFeatureFlagStoreToJSON(self.featureFlagStore) withKey:BSGKeyFeatureFlags toSection:BSGKeyClient];
+        [self.featureFlagStore clear];
     }
     if (self.observer) {
         self.observer(BSGClientObserverClearFeatureFlag, nil);
@@ -1076,7 +1078,7 @@ - (void)appHangDetectedAtDate:(NSDate *)date withThreads:(NSArray<BugsnagThread
     self.appHangEvent.context = self.context;
 
     @synchronized (self.featureFlagStore) {
-        self.appHangEvent.featureFlagStore = [self.featureFlagStore copy];
+        self.appHangEvent.featureFlagStore = [self.featureFlagStore copyMemoryStore];
     }
 
     [self.appHangEvent symbolicateIfNeeded];
@@ -1225,9 +1227,7 @@ - (nullable BugsnagEvent *)generateEventForLastLaunchWithError:(BugsnagError *)e
                               session:session];
 
     event.context = stateDict[BSGKeyClient][BSGKeyContext];
-
-    id featureFlags = stateDict[BSGKeyClient][BSGKeyFeatureFlags];
-    event.featureFlagStore = BSGFeatureFlagStoreFromJSON(featureFlags);
+    event.featureFlagStore = BSGFeatureFlagStoreWithFlags([self.featureFlagStore persistedFlags]);
 
     return event;
 }

diff --git a/Bugsnag/Configuration/BugsnagConfiguration+Private.h b/Bugsnag/Configuration/BugsnagConfiguration+Private.h
@@ -24,7 +24,7 @@ BSG_OBJC_DIRECT_MEMBERS
 
 @property (readonly, nonatomic) NSDictionary<NSString *, id> *dictionaryRepresentation;
 
-@property (nonatomic) BSGFeatureFlagStore *featureFlagStore;
+@property (nonatomic) BSGMemoryFeatureFlagStore *featureFlagStore;
 
 @property (copy, nonatomic) BugsnagMetadata *metadata;
 

diff --git a/Bugsnag/Configuration/BugsnagConfiguration.m b/Bugsnag/Configuration/BugsnagConfiguration.m
@@ -28,7 +28,7 @@
 
 #import "BSGConfigurationBuilder.h"
 #import "BSGDefines.h"
-#import "BSGFeatureFlagStore.h"
+#import "BSGMemoryFeatureFlagStore.h"
 #import "BSGKeys.h"
 #import "BugsnagApiClient.h"
 #import "BugsnagEndpointConfiguration.h"
@@ -166,7 +166,7 @@ - (instancetype)initWithApiKey:(NSString *)apiKey {
     if (apiKey) {
         [self setApiKey:apiKey];
     }
-    _featureFlagStore = [[BSGFeatureFlagStore alloc] init];
+    _featureFlagStore = [[BSGMemoryFeatureFlagStore alloc] init];
     _metadata = [[BugsnagMetadata alloc] init];
     _endpoints = [BugsnagEndpointConfiguration new];
     _autoDetectErrors = YES;
@@ -241,7 +241,7 @@ - (instancetype)initWithDictionaryRepresentation:(NSDictionary<NSString *, id> *
     _bundleVersion = dictionaryRepresentation[BSGKeyBundleVersion];
     _context = dictionaryRepresentation[BSGKeyContext];
     _enabledReleaseStages = dictionaryRepresentation[BSGKeyEnabledReleaseStages];
-    _featureFlagStore = [[BSGFeatureFlagStore alloc] init];
+    _featureFlagStore = [[BSGMemoryFeatureFlagStore alloc] init];
     _releaseStage = dictionaryRepresentation[BSGKeyReleaseStage];
     return self;
 }
@@ -508,23 +508,23 @@ - (void)addPlugin:(id<BugsnagPlugin> _Nonnull)plugin {
 // MARK: - <BugsnagFeatureFlagStore>
 
 - (void)addFeatureFlagWithName:(NSString *)name variant:(nullable NSString *)variant {
-    BSGFeatureFlagStoreAddFeatureFlag(self.featureFlagStore, name, variant);
+    [self.featureFlagStore addFeatureFlag:name withVariant:variant];
 }
 
 - (void)addFeatureFlagWithName:(NSString *)name {
-    BSGFeatureFlagStoreAddFeatureFlag(self.featureFlagStore, name, nil);
+    [self.featureFlagStore addFeatureFlag:name withVariant:nil];
 }
 
 - (void)addFeatureFlags:(NSArray<BugsnagFeatureFlag *> *)featureFlags {
-    BSGFeatureFlagStoreAddFeatureFlags(self.featureFlagStore, featureFlags);
+    [self.featureFlagStore addFeatureFlags:featureFlags];
 }
 
 - (void)clearFeatureFlagWithName:(NSString *)name {
-    BSGFeatureFlagStoreClear(self.featureFlagStore, name);
+    [self.featureFlagStore clear:name];
 }
 
 - (void)clearFeatureFlags {
-    BSGFeatureFlagStoreClear(self.featureFlagStore, nil);
+    [self.featureFlagStore clear];
 }
 
 // MARK: - <MetadataStore>

diff --git a/Bugsnag/Delivery/BSGEventUploadKSCrashReportOperation.m b/Bugsnag/Delivery/BSGEventUploadKSCrashReportOperation.m
@@ -37,7 +37,7 @@
                 return nil;
             }
             NSMutableArray *keys = [NSMutableArray array];
-            NSString *pattern = @"\"(report|process|system|system_atcrash|binary_images|crash|threads|error|user_atcrash|config|metaData|state|breadcrumbs)\":";
+            NSString *pattern = @"\"(report|process|system|system_atcrash|binary_images|crash|threads|error|user_atcrash|config|metaData|state|breadcrumbs|featureFlags)\":";
             NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:pattern options:0 error:nil];
             for (NSTextCheckingResult *result in [regex matchesInString:string options:0 range:NSMakeRange(0, string.length)]) {
                 if ([result numberOfRanges] == 2) {

diff --git a/Bugsnag/FeatureFlags/BSGAtomicFeatureFlagStore.h b/Bugsnag/FeatureFlags/BSGAtomicFeatureFlagStore.h
@@ -0,0 +1,31 @@
+//
+//  BSGAtomicFeatureFlagStore.h
+//  Bugsnag
+//
+//  Created by Robert B on 16/12/2024.
+//  Copyright © 2024 Bugsnag Inc. All rights reserved.
+//
+
+#import "BugsnagInternals.h"
+#import "BSGDefines.h"
+#import "BSGFeatureFlagStore.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+
+BSG_OBJC_DIRECT_MEMBERS
+@interface BSGAtomicFeatureFlagStore ()
+
++ (instancetype)store;
+
+@end
+
+#pragma mark - Crash reporting
+
+/**
+ * Inserts the current feature flags into a crash report.
+ *
+ */
+void BugsnagFeatureFlagsWriteCrashReport(const BSG_KSCrashReportWriter * _Nonnull writer,
+                                         bool requiresAsyncSafety);
+NS_ASSUME_NONNULL_END