Add callback to pre-process breadcrumbs before adding (#814)

* Add beforeBreadcrumb callback stubs

* Add hook implementation for Apple

* Fix threading issues on Android

* Fix potential recursive onBeforeBreadcrumb handler invocation when printing to logs

* Update changelog

* Update package snapshot

* Remove unimplemented api

* Replace game thread check with static init check

* Updated GC checks

* Update package snapshots

* Fix beforeBreadcrumb for native

* Fix minor error/warnings

* Remove static init check

* Update readme

* Add beforeBreadcrumbHandler to sample

* Fix build error on Mac

Author: tustanivsky

CHANGELOG.md

@@ -10,6 +10,7 @@
 
 - Allow Sentry CLI to authenticate via environment variables during debug symbols upload ([#836](https://github.com/getsentry/sentry-unreal/pull/836))
 - Added the ability to specify a separate DSN for crashes while in editor vs cooked title ([#853](https://github.com/getsentry/sentry-unreal/pull/853))
+- Add callback to pre-process breadcrumbs before adding ([#814](https://github.com/getsentry/sentry-unreal/pull/814))
 
 ### Fixes
 

README.md

@@ -53,7 +53,7 @@ Blog posts:
 
 - Only crash events captured on Android contain the full callstack. Events that were captured manually won't have the native C++ part there.
 
-- If an event was captured during the garbage collection, the `BeforeSendHandler` will not be invoked.
+- `BeforeSendHandler` and `BeforeBreadcrumbHandler` hooks will not be invoked during garbage collection.
 
 - It may be required to upgrade the C++ standard library (`libstdc++`) on older Linux distributions (such as Ubuntu 18.04 and 20.04) to ensure crashpad handler proper functionality within the deployment environment. This can be achieved with something like this:
 ```

plugin-dev/Source/Sentry/Private/Android/AndroidSentrySubsystem.cpp

@@ -28,7 +28,7 @@
 #include "Dom/JsonObject.h"
 #include "Serialization/JsonSerializer.h"
 
-void FAndroidSentrySubsystem::InitWithSettings(const USentrySettings* settings, USentryBeforeSendHandler* beforeSendHandler, USentryTraceSampler* traceSampler)
+void FAndroidSentrySubsystem::InitWithSettings(const USentrySettings* settings, USentryBeforeSendHandler* beforeSendHandler, USentryBeforeBreadcrumbHandler* beforeBreadcrumbHandler, USentryTraceSampler* traceSampler)
 {
 	TSharedPtr<FJsonObject> SettingsJson = MakeShareable(new FJsonObject);
 	SettingsJson->SetStringField(TEXT("dsn"), settings->Dsn);
@@ -55,6 +55,10 @@ void FAndroidSentrySubsystem::InitWithSettings(const USentrySettings* settings,
 	{
 		SettingsJson->SetNumberField(TEXT("tracesSampler"), (jlong)traceSampler);
 	}
+	if(beforeBreadcrumbHandler != nullptr)
+	{
+		SettingsJson->SetNumberField(TEXT("beforeBreadcrumb"), (jlong)beforeBreadcrumbHandler);
+	}
 
 	FString SettingsJsonStr;
 	TSharedRef<TJsonWriter<>> JsonWriter = TJsonWriterFactory<>::Create(&SettingsJsonStr);

plugin-dev/Source/Sentry/Private/Android/AndroidSentrySubsystem.h

@@ -7,7 +7,7 @@
 class FAndroidSentrySubsystem : public ISentrySubsystem
 {
 public:
-	virtual void InitWithSettings(const USentrySettings* settings, USentryBeforeSendHandler* beforeSendHandler, USentryTraceSampler* traceSampler) override;
+	virtual void InitWithSettings(const USentrySettings* settings, USentryBeforeSendHandler* beforeSendHandler, USentryBeforeBreadcrumbHandler* beforeBreadcrumbHandler, USentryTraceSampler* traceSampler) override;
 	virtual void Close() override;
 	virtual bool IsEnabled() override;
 	virtual ESentryCrashedLastRun IsCrashedLastRun() override;

plugin-dev/Source/Sentry/Private/Android/Java/SentryBridgeJava.java

@@ -34,6 +34,7 @@
 public class SentryBridgeJava {
 	public static native void onConfigureScope(long callbackAddr, IScope scope);
 	public static native SentryEvent onBeforeSend(long handlerAddr, SentryEvent event, Hint hint);
+	public static native Breadcrumb onBeforeBreadcrumb(long handlerAddr, Breadcrumb breadcrumb, Hint hint);
 	public static native float onTracesSampler(long samplerAddr, SamplingContext samplingContext);
 
 	public static void init(Activity activity, final String settingsJsonStr, final long beforeSendHandler) {
@@ -85,6 +86,15 @@ public Double sample(SamplingContext samplingContext) {
 							}
 						});
 					}
+					if(settingJson.has("beforeBreadcrumb")) {
+						final long beforeBreadcrumbAddr = settingJson.getLong("beforeBreadcrumb");
+						options.setBeforeBreadcrumb(new SentryOptions.BeforeBreadcrumbCallback() {
+							@Override
+							public Breadcrumb execute(Breadcrumb breadcrumb, Hint hint) {
+								return onBeforeBreadcrumb(beforeBreadcrumbAddr, breadcrumb, hint);
+							}
+						});
+					}
 				} catch (JSONException e) {
 					throw new RuntimeException(e);
 				}

plugin-dev/Source/Sentry/Private/Android/Jni/SentryJniAndroid.cpp

@@ -5,16 +5,19 @@
 #include "Android/Infrastructure/SentryJavaClasses.h"
 #include "Android/AndroidSentrySubsystem.h"
 #include "Android/SentryScopeAndroid.h"
+#include "Android/SentryBreadcrumbAndroid.h"
 #include "Android/SentryEventAndroid.h"
 #include "Android/SentryHintAndroid.h"
 #include "Android/SentrySamplingContextAndroid.h"
 
 #include "Android/AndroidJNI.h"
 
 #include "SentryDefines.h"
+#include "SentryBreadcrumb.h"
 #include "SentryEvent.h"
 #include "SentryHint.h"
 #include "SentryBeforeSendHandler.h"
+#include "SentryBeforeBreadcrumbHandler.h"
 #include "SentryTraceSampler.h"
 #include "SentrySamplingContext.h"
 #include "UObject/GarbageCollection.h"
@@ -66,6 +69,32 @@ JNI_METHOD jobject Java_io_sentry_unreal_SentryBridgeJava_onBeforeSend(JNIEnv* e
 	return ProcessedEvent ? event : nullptr;
 }
 
+JNI_METHOD jobject Java_io_sentry_unreal_SentryBridgeJava_onBeforeBreadcrumb(JNIEnv* env, jclass clazz, jlong objAddr, jobject breadcrumb, jobject hint)
+{
+	if (FUObjectThreadContext::Get().IsRoutingPostLoad)
+	{
+		// Don't print to logs within `onBeforeBreadcrumb` handler as this can lead to creating new breadcrumb
+		return breadcrumb;
+	}
+
+	if (IsGarbageCollecting())
+	{
+		// If breadcrumb is added during garbage collection we can't instantiate UObjects safely or obtain a GC lock
+		// since there is no guarantee it will be ever freed.
+		// In this case breadcrumb will be added without calling a `beforeBreadcrumb` handler.
+		return breadcrumb;
+	}
+
+	USentryBeforeBreadcrumbHandler* handler = reinterpret_cast<USentryBeforeBreadcrumbHandler*>(objAddr);
+
+	USentryBreadcrumb* BreadcrumbToProcess = USentryBreadcrumb::Create(MakeShareable(new SentryBreadcrumbAndroid(breadcrumb)));
+	USentryHint* HintToProcess = USentryHint::Create(MakeShareable(new SentryHintAndroid(hint)));
+
+	USentryBreadcrumb* ProcessedBreadcrumb = handler->HandleBeforeBreadcrumb(BreadcrumbToProcess, HintToProcess);
+
+	return ProcessedBreadcrumb ? breadcrumb : nullptr;
+}
+
 JNI_METHOD jfloat Java_io_sentry_unreal_SentryBridgeJava_onTracesSampler(JNIEnv* env, jclass clazz, jlong objAddr, jobject samplingContext)
 {
 	FGCScopeGuard GCScopeGuard;

plugin-dev/Source/Sentry/Private/Apple/AppleSentrySubsystem.cpp

@@ -12,9 +12,11 @@
 #include "SentrySamplingContextApple.h"
 #include "SentryIdApple.h"
 
+#include "SentryBreadcrumb.h"
 #include "SentryEvent.h"
 #include "SentrySettings.h"
 #include "SentryBeforeSendHandler.h"
+#include "SentryBeforeBreadcrumbHandler.h"
 #include "SentryDefines.h"
 #include "SentrySamplingContext.h"
 #include "SentryTraceSampler.h"
@@ -30,7 +32,7 @@
 #include "UObject/UObjectThreadContext.h"
 #include "Utils/SentryLogUtils.h"
 
-void FAppleSentrySubsystem::InitWithSettings(const USentrySettings* settings, USentryBeforeSendHandler* beforeSendHandler, USentryTraceSampler* traceSampler)
+void FAppleSentrySubsystem::InitWithSettings(const USentrySettings* settings, USentryBeforeSendHandler* beforeSendHandler, USentryBeforeBreadcrumbHandler* beforeBreadcrumbHandler, USentryTraceSampler* traceSampler)
 {
 	[SENTRY_APPLE_CLASS(PrivateSentrySDKOnly) setSdkName:@"sentry.cocoa.unreal"];
 
@@ -110,6 +112,30 @@ void FAppleSentrySubsystem::InitWithSettings(const USentrySettings* settings, US
 					return traceSampler->Sample(Context, samplingValue) ? [NSNumber numberWithFloat:samplingValue] : nil;
 				};
 			}
+			if (beforeBreadcrumbHandler != nullptr)
+			{
+				options.beforeBreadcrumb = ^SentryBreadcrumb* (SentryBreadcrumb* breadcrumb) {
+					if (FUObjectThreadContext::Get().IsRoutingPostLoad)
+					{
+						// Don't print to logs within `onBeforeBreadcrumb` handler as this can lead to creating new breadcrumb
+						return breadcrumb;
+					}
+
+					if (IsGarbageCollecting())
+					{
+						// If breadcrumb is added during garbage collection we can't instantiate UObjects safely or obtain a GC lock
+						// since there is no guarantee it will be ever freed.
+						// In this case breadcrumb will be added without calling a `beforeBreadcrumb` handler.
+						return breadcrumb;
+					}
+
+					USentryBreadcrumb* BreadcrumbToProcess = USentryBreadcrumb::Create(MakeShareable(new SentryBreadcrumbApple(breadcrumb)));
+
+					USentryBreadcrumb* ProcessedBreadcrumb = beforeBreadcrumbHandler->HandleBeforeBreadcrumb(BreadcrumbToProcess, nullptr);
+
+					return ProcessedBreadcrumb ? breadcrumb : nullptr;
+				};
+			}
 		}];
 
 		dispatch_group_leave(sentryDispatchGroup);

plugin-dev/Source/Sentry/Private/Apple/AppleSentrySubsystem.h

@@ -7,7 +7,7 @@
 class FAppleSentrySubsystem : public ISentrySubsystem
 {
 public:
-	virtual void InitWithSettings(const USentrySettings* settings, USentryBeforeSendHandler* beforeSendHandler, USentryTraceSampler* traceSampler) override;
+	virtual void InitWithSettings(const USentrySettings* settings, USentryBeforeSendHandler* beforeSendHandler, USentryBeforeBreadcrumbHandler* beforeBreadcrumbHandler, USentryTraceSampler* traceSampler) override;
 	virtual void Close() override;
 	virtual bool IsEnabled() override;
 	virtual ESentryCrashedLastRun IsCrashedLastRun() override;

plugin-dev/Source/Sentry/Private/GenericPlatform/GenericPlatformSentrySubsystem.cpp

@@ -15,6 +15,8 @@
 #include "SentryEvent.h"
 #include "SentryModule.h"
 #include "SentryBeforeSendHandler.h"
+#include "SentryBeforeBreadcrumbHandler.h"
+#include "SentryBreadcrumb.h"
 
 #include "SentryTraceSampler.h"
 
@@ -69,6 +71,18 @@ void PrintVerboseLog(sentry_level_t level, const char* message, va_list args, vo
 	}
 }
 
+/* static */ sentry_value_t FGenericPlatformSentrySubsystem::HandleBeforeBreadcrumb(sentry_value_t breadcrumb, void* hint, void* closure)
+{
+	if (closure)
+	{
+		return StaticCast<FGenericPlatformSentrySubsystem*>(closure)->OnBeforeBreadcrumb(breadcrumb, hint, closure);
+	}
+	else
+	{
+		return breadcrumb;
+	}
+}
+
 /* static */ sentry_value_t FGenericPlatformSentrySubsystem::HandleOnCrash(const sentry_ucontext_t* uctx, sentry_value_t event, void* closure)
 {
 	if (closure)
@@ -114,6 +128,39 @@ sentry_value_t FGenericPlatformSentrySubsystem::OnBeforeSend(sentry_value_t even
 	return ProcessedEvent ? event : sentry_value_new_null();
 }
 
+// Currently this handler is not set anywhere since the Unreal SDK doesn't use `sentry_add_breadcrumb` directly and relies on
+// custom scope implementation to store breadcrumbs instead.
+// The support for it will be enabled with https://github.com/getsentry/sentry-native/pull/1166 
+sentry_value_t FGenericPlatformSentrySubsystem::OnBeforeBreadcrumb(sentry_value_t breadcrumb, void* hint, void* closure)
+{
+	if (!closure || this != closure)
+	{
+		return breadcrumb;
+	}
+
+	if (FUObjectThreadContext::Get().IsRoutingPostLoad)
+	{
+		// Don't print to logs within `onBeforeBreadcrumb` handler as this can lead to creating new breadcrumb
+		return breadcrumb;
+	}
+
+	if (IsGarbageCollecting())
+	{
+		// If breadcrumb is added during garbage collection we can't instantiate UObjects safely or obtain a GC lock
+		// since there is no guarantee it will be ever freed.
+		// In this case breadcrumb will be added without calling a `beforeBreadcrumb` handler.
+		return breadcrumb;
+	}
+
+	TSharedPtr<FGenericPlatformSentryBreadcrumb> Breadcrumb = MakeShareable(new FGenericPlatformSentryBreadcrumb(breadcrumb));
+
+	USentryBreadcrumb* BreadcrumbToProcess = USentryBreadcrumb::Create(Breadcrumb);
+
+	USentryBreadcrumb* ProcessedBreadcrumb = GetBeforeBreadcrumbHandler()->HandleBeforeBreadcrumb(BreadcrumbToProcess, nullptr);
+
+	return ProcessedBreadcrumb ? breadcrumb : sentry_value_new_null();
+}
+
 sentry_value_t FGenericPlatformSentrySubsystem::OnCrash(const sentry_ucontext_t* uctx, sentry_value_t event, void* closure)
 {
 	if (!closure || this != closure)
@@ -159,16 +206,19 @@ sentry_value_t FGenericPlatformSentrySubsystem::OnCrash(const sentry_ucontext_t*
 
 FGenericPlatformSentrySubsystem::FGenericPlatformSentrySubsystem()
 	: beforeSend(nullptr)
+	, beforeBreadcrumb(nullptr)
 	, crashReporter(MakeShareable(new FGenericPlatformSentryCrashReporter))
 	, isEnabled(false)
 	, isStackTraceEnabled(true)
+	, isPiiAttachmentEnabled(false)
 	, isScreenshotAttachmentEnabled(false)
 {
 }
 
-void FGenericPlatformSentrySubsystem::InitWithSettings(const USentrySettings* settings, USentryBeforeSendHandler* beforeSendHandler, USentryTraceSampler* traceSampler)
+void FGenericPlatformSentrySubsystem::InitWithSettings(const USentrySettings* settings, USentryBeforeSendHandler* beforeSendHandler, USentryBeforeBreadcrumbHandler* beforeBreadcrumbHandler, USentryTraceSampler* traceSampler)
 {
 	beforeSend = beforeSendHandler;
+	beforeBreadcrumb = beforeBreadcrumbHandler;
 
 	scopeStack.Push(MakeShareable(new FGenericPlatformSentryScope()));
 
@@ -298,6 +348,15 @@ ESentryCrashedLastRun FGenericPlatformSentrySubsystem::IsCrashedLastRun()
 
 void FGenericPlatformSentrySubsystem::AddBreadcrumb(TSharedPtr<ISentryBreadcrumb> breadcrumb)
 {
+	if (beforeBreadcrumb != nullptr)
+	{
+		sentry_value_t processdBreadcrumb = HandleBeforeBreadcrumb(StaticCastSharedPtr<FGenericPlatformSentryBreadcrumb>(breadcrumb)->GetNativeObject(), nullptr, this);
+		if (sentry_value_is_null(processdBreadcrumb))
+		{
+			return;
+		}
+	}
+
 	GetCurrentScope()->AddBreadcrumb(breadcrumb);
 }
 
@@ -310,6 +369,15 @@ void FGenericPlatformSentrySubsystem::AddBreadcrumbWithParams(const FString& Mes
 	Breadcrumb->SetData(Data);
 	Breadcrumb->SetLevel(Level);
 
+	if (beforeBreadcrumb != nullptr)
+	{
+		sentry_value_t processdBreadcrumb = HandleBeforeBreadcrumb(Breadcrumb->GetNativeObject(), nullptr, this);
+		if (sentry_value_is_null(processdBreadcrumb))
+		{
+			return;
+		}
+	}
+
 	GetCurrentScope()->AddBreadcrumb(Breadcrumb);
 }
 
@@ -514,6 +582,11 @@ USentryBeforeSendHandler* FGenericPlatformSentrySubsystem::GetBeforeSendHandler(
 	return beforeSend;
 }
 
+USentryBeforeBreadcrumbHandler* FGenericPlatformSentrySubsystem::GetBeforeBreadcrumbHandler()
+{
+	return beforeBreadcrumb;
+}
+
 void FGenericPlatformSentrySubsystem::TryCaptureScreenshot() const
 {
 	if (!isScreenshotAttachmentEnabled)

plugin-dev/Source/Sentry/Private/GenericPlatform/GenericPlatformSentrySubsystem.h

@@ -18,7 +18,7 @@ class FGenericPlatformSentrySubsystem : public ISentrySubsystem
 public:
 	FGenericPlatformSentrySubsystem();
 
-	virtual void InitWithSettings(const USentrySettings* settings, USentryBeforeSendHandler* beforeSendHandler, USentryTraceSampler* traceSampler) override;
+	virtual void InitWithSettings(const USentrySettings* settings, USentryBeforeSendHandler* beforeSendHandler, USentryBeforeBreadcrumbHandler* beforeBreadcrumbHandler, USentryTraceSampler* traceSampler) override;
 	virtual void Close() override;
 	virtual bool IsEnabled() override;
 	virtual ESentryCrashedLastRun IsCrashedLastRun() override;
@@ -47,6 +47,7 @@ class FGenericPlatformSentrySubsystem : public ISentrySubsystem
 	virtual TSharedPtr<ISentryTransactionContext> ContinueTrace(const FString& sentryTrace, const TArray<FString>& baggageHeaders) override;
 
 	USentryBeforeSendHandler* GetBeforeSendHandler();
+	USentryBeforeBreadcrumbHandler* GetBeforeBreadcrumbHandler();
 
 	void TryCaptureScreenshot() const;
 
@@ -67,16 +68,19 @@ class FGenericPlatformSentrySubsystem : public ISentrySubsystem
 	virtual FString GetHandlerExecutableName() const { return TEXT("invalid"); }
 
 	virtual sentry_value_t OnBeforeSend(sentry_value_t event, void* hint, void* closure);
+	virtual sentry_value_t OnBeforeBreadcrumb(sentry_value_t breadcrumb, void* hint, void* closure);
 	virtual sentry_value_t OnCrash(const sentry_ucontext_t* uctx, sentry_value_t event, void* closure);
 
 private:
 	/**
 	 * Static wrappers that are passed to the Sentry library.
 	 */
 	static sentry_value_t HandleBeforeSend(sentry_value_t event, void* hint, void* closure);
+	static sentry_value_t HandleBeforeBreadcrumb(sentry_value_t breadcrumb, void* hint, void* closure);
 	static sentry_value_t HandleOnCrash(const sentry_ucontext_t* uctx, sentry_value_t event, void* closure);
 
 	USentryBeforeSendHandler* beforeSend;
+	USentryBeforeBreadcrumbHandler* beforeBreadcrumb;
 
 	TSharedPtr<FGenericPlatformSentryCrashReporter> crashReporter;