feat: add in the Setlogcallback function for desktop analytics

Author: AustinBenoit

analytics/integration_test/src/integration_test.cc

@@ -242,6 +242,25 @@ TEST_F(FirebaseAnalyticsTest, TestSetProperties) {
       InitiateOnDeviceConversionMeasurementWithHashedPhoneNumber(hashed_phone);
 }
 
+#if defined(_WIN32)
+TEST_F(FirebaseAnalyticsTest, TestSetLogCallback) {
+  bool log_callback_called = false;
+  firebase::analytics::SetLogCallback(
+      [&](firebase::analytics::LogLevel log_level, const char* message) {
+        log_callback_called = true;
+      });
+  // Log an event with an invalid parameter to trigger a log message.
+  const firebase::analytics::Parameter kInvalidParameters[] = {
+      firebase::analytics::Parameter("invalid_character_!", 5),
+  };
+  firebase::analytics::LogEvent(
+      "invalid_event", kInvalidParameters,
+      sizeof(kInvalidParameters) / sizeof(kInvalidParameters[0]));
+  EXPECT_TRUE(log_callback_called);
+  firebase::analytics::SetLogCallback(nullptr);
+}
+#endif  // defined(_WIN32)
+
 TEST_F(FirebaseAnalyticsTest, TestLogEvents) {
   // Log an event with no parameters.
   firebase::analytics::LogEvent(firebase::analytics::kEventLogin);

analytics/src/analytics_android.cc

@@ -609,6 +609,9 @@ void ResetAnalyticsData() {
   util::CheckAndClearJniExceptions(env);
 }
 
+// NO-OP in Android and iOS. Only used in Windows.
+void SetLogCallback(const LogCallback&) {}
+
 // NO-OP in Android and iOS. Only used in Windows.
 void NotifyAppLifecycleChange(AppLifecycleState) {}
 

analytics/src/analytics_desktop.cc

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 #include <map>
+#include <mutex>
 #include <sstream>
 #include <string>
 #include <vector>
@@ -44,6 +45,8 @@ static HMODULE g_analytics_module = 0;
 // Future data for analytics.
 // This is initialized in `Initialize()` and cleaned up in `Terminate()`.
 static bool g_initialized = false;
+static LogCallback g_log_callback;
+static std::mutex g_log_callback_mutex;
 static int g_fake_instance_id = 0;
 static bool g_analytics_collection_enabled = true;
 static std::string g_app_id;
@@ -385,6 +388,41 @@ void ResetAnalyticsData() {
   g_fake_instance_id++;
 }
 
+// C-style callback that will be passed to the Google Analytics C API.
+static void GoogleAnalyticsWraperLogCallback(GoogleAnalytics_LogLevel log_level,
+                            const char* message) {
+  if (g_log_callback) {
+    LogLevel sdk_log_level;
+    switch (log_level) {
+      case kDebug:
+        sdk_log_level = kLogLevelDebug;
+        break;
+      case kInfo:
+        sdk_log_level = kLogLevelInfo;
+        break;
+      case kWarning:
+        sdk_log_level = kLogLevelWarning;
+        break;
+      case kError:
+        sdk_log_level = kLogLevelError;
+        break;
+      default:
+        sdk_log_level = kLogLevelInfo;
+    }
+    g_log_callback(sdk_log_level, message);
+  }
+}
+
+// Allows the passing of a callback to be used when the SDK logs any
+// messages regarding its behavior. The callback must be thread-safe.
+void SetLogCallback(const LogCallback& callback) {
+  FIREBASE_ASSERT_RETURN_VOID(internal::IsInitialized());
+  // The C API does not support user data, so we must use a global variable.
+  std::lock_guard<std::mutex> lock(g_log_callback_mutex);
+  g_log_callback = callback;
+  GoogleAnalytics_SetLogCallback(GoogleAnalyticsWraperLogCallback);
+}
+
 // Notify the Analytics SDK about the current state of the app's lifecycle.
 void NotifyAppLifecycleChange(AppLifecycleState state) {
   FIREBASE_ASSERT_RETURN_VOID(internal::IsInitialized());

analytics/src/analytics_ios.mm

@@ -379,6 +379,9 @@ void ResetAnalyticsData() {
   g_resetter->Reset();
 }
 
+// No-Op on iOS and Android. Only used in Windows desktop apps.
+void SetLogCallback(const LogCallback&) {}
+
 // No-Op on iOS and Android. Only used in Windows desktop apps.
 void NotifyAppLifecycleChange(AppLifecycleState) {}
 

analytics/src/include/firebase/analytics.h

@@ -19,6 +19,7 @@
 
 #include <cstddef>
 #include <cstdint>
+#include <functional>
 #include <map>
 #include <string>
 #include <vector>
@@ -558,6 +559,28 @@ void SetSessionTimeoutDuration(int64_t milliseconds);
 /// instance id.
 void ResetAnalyticsData();
 
+/// @brief The log level of the message logged by the SDK.
+enum LogLevel {
+  kLogLevelDebug,
+  kLogLevelInfo,
+  kLogLevelWarning,
+  kLogLevelError,
+};
+
+/// @brief The callback type for logging messages from the SDK.
+///
+/// The callback is invoked whenever the SDK logs a message.
+///
+/// @param[in] log_level The log level of the message.
+/// @param[in] message The message logged by the SDK.
+using LogCallback =  std::function<void(LogLevel, const char*)>;
+
+/// @brief Allows the passing of a callback to be used when the SDK logs any
+/// messages regarding its behavior. The callback must be thread-safe.
+///
+/// @param[in] callback The callback to use. Must be thread-safe.
+void SetLogCallback(const LogCallback& callback);
+
 /// @brief The state of an app in its lifecycle.
 ///
 /// kUnknown is an invalid state that is used to capture uninitialized values.