Added ActionTerminatedException to BackoffPerformer

Author: Alexander Damian

include/cppkafka/exceptions.h

@@ -134,6 +134,14 @@ class CPPKAFKA_API QueueException : public Exception {
     Error error_;
 };
 
+/**
+ * Backoff performer has no more retries left for a specific action.
+ */
+class CPPKAFKA_API ActionTerminatedException : public Exception {
+public:
+    ActionTerminatedException(const std::string& error);
+};
+
 } // cppkafka
 
 #endif // CPPKAFKA_EXCEPTIONS_H

include/cppkafka/utils/backoff_performer.h

@@ -136,7 +136,7 @@ class CPPKAFKA_API BackoffPerformer {
             backoff = increase_backoff(backoff);
         }
         // No more retries left or we have a terminal error.
-        throw Exception("Commit failed: no more retries.");
+        throw ActionTerminatedException("Commit failed: no more retries.");
     }
 private:
     TimeUnit increase_backoff(TimeUnit backoff);