added retry logic for producers

include/cppkafka/message_internal.h

@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2017, Matias Fontanini
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following disclaimer
+ *   in the documentation and/or other materials provided with the
+ *   distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef CPPKAFKA_MESSAGE_INTERNAL_H
+#define CPPKAFKA_MESSAGE_INTERNAL_H
+
+#include <memory>
+#include "message.h"
+
+namespace cppkafka {
+
+struct Internal {
+    virtual ~Internal() = default;
+};
+using InternalPtr = std::shared_ptr<Internal>;
+
+/**
+ * \brief Private message data structure
+ */
+class MessageInternal {
+    friend class Producer;
+    
+public:
+    static std::unique_ptr<MessageInternal> load(Message& message) {
+        if (message.get_user_data()) {
+            // Unpack internal data
+            std::unique_ptr<MessageInternal> internal_data(static_cast<MessageInternal*>(message.get_user_data()));
+            message.load_internal(internal_data->user_data_, internal_data->internal_);
+            return internal_data;
+        }
+        return nullptr;
+    }
+    
+private:
+    MessageInternal(void* user_data, std::shared_ptr<Internal> internal)
+    : user_data_(user_data),
+      internal_(internal) {
+    }
+    
+    void*          user_data_;
+    InternalPtr    internal_;
+};
+
+}
+
+#endif //CPPKAFKA_MESSAGE_INTERNAL_H