logger: restore Logger and logging callback on integ. test teardown

include/cassandra.h

@@ -11298,6 +11298,15 @@ CASS_EXPORT void
 cass_log_set_callback(CassLogCallback callback,
                       void* data);
 
+/**
+ * Analogous getter - useful for restoring logger to previous values.
+ * 
+ * @param[out] callback_out Current logging callback. Must point to a valid memory area.
+ * @param[out] data_out Current Logger instance. Must point to a valid memory area.
+ */
+CASS_EXPORT void
+cass_log_get_callback_and_data(CassLogCallback* callback_out, void** data_out);
+
 /**
  * Sets the log queue size.
  *

src/logger.cpp

@@ -30,6 +30,10 @@ void cass_log_set_callback(CassLogCallback callback, void* data) {
   Logger::set_callback(callback, data);
 }
 
+void cass_log_get_callback_and_data(CassLogCallback* callback_out, void** data_out) {
+  Logger::get_callback_and_data(callback_out, data_out);
+}
+
 void cass_log_set_queue_size(size_t queue_size) {
   // Deprecated
 }
@@ -66,3 +70,8 @@ void Logger::set_callback(CassLogCallback cb, void* data) {
   cb_ = cb == NULL ? noop_log_callback : cb;
   data_ = data;
 }
+
+void Logger::get_callback_and_data(CassLogCallback* cb_out, void** data_out) {
+  *cb_out = cb_;
+  *data_out = data_;
+}

src/logger.hpp

@@ -31,6 +31,7 @@ class Logger {
 public:
   static void set_log_level(CassLogLevel level);
   static void set_callback(CassLogCallback cb, void* data);
+  static void get_callback_and_data(CassLogCallback* cb_out, void** data_out);
 
 #if defined(__GNUC__) || defined(__clang__)
 #define ATTR_FORMAT(string, first) __attribute__((__format__(__printf__, string, first)))

tests/src/integration/logger.cpp

@@ -44,6 +44,10 @@ Logger::~Logger() {
   if (output_.is_open()) {
     output_.close();
   }
+  if (restore_old_logger_) {
+    // `initialize` has beed called, so let's restore global logger
+    cass_log_set_callback(old_log_callback_, old_data_);
+  }
 }
 
 void Logger::initialize(const std::string& test_case, const std::string& test_name) {
@@ -72,6 +76,10 @@ void Logger::initialize(const std::string& test_case, const std::string& test_na
 
   // Set the maximum driver log level to capture all logs messages
   cass_log_set_level(CASS_LOG_TRACE);
+
+  // Remember the old logger before setting it (to be restored in dtor)
+  cass_log_get_callback_and_data(&old_log_callback_, &old_data_);
+  restore_old_logger_ = true;
   cass_log_set_callback(Logger::log, this);
 }
 

tests/src/integration/logger.hpp

@@ -97,6 +97,11 @@ class Logger {
    * Number of log messages that match the search criteria
    */
   size_t count_;
+
+  /** We need these to restore the globals on teardown. */
+  bool restore_old_logger_ = false;
+  CassLogCallback old_log_callback_;
+  void* old_data_;
 
   /**
    * Log the message from the driver (callback)