Removed dependency on Producer and dr_callback_proxy

Author: accelerated

Diff for: include/cppkafka/message.h

@@ -180,7 +180,7 @@ class CPPKAFKA_API Message {
 
     Message(rd_kafka_message_t* handle, NonOwningTag);
     Message(HandlePtr handle);
-    void load_internal(void* user_data, InternalPtr internal);
+    Message& load_internal();
 
     HandlePtr handle_;
     Buffer payload_;

Diff for: include/cppkafka/message_internal.h

@@ -31,11 +31,10 @@
 #define CPPKAFKA_MESSAGE_INTERNAL_H
 
 #include <memory>
-#include "message.h"
 
 namespace cppkafka {
 
-class Producer;
+class Message;
 
 struct Internal {
     virtual ~Internal() = default;
@@ -45,16 +44,37 @@ using InternalPtr = std::shared_ptr<Internal>;
 /**
  * \brief Private message data structure
  */
-class MessageInternal {
-    friend Producer;
-public:
-    static std::unique_ptr<MessageInternal> load(const Producer& producer, Message& message);
-private:
+struct MessageInternal {
     MessageInternal(void* user_data, std::shared_ptr<Internal> internal);
+    static std::unique_ptr<MessageInternal> load(Message& message);
     void*          user_data_;
     InternalPtr    internal_;
 };
 
+template <typename BuilderType>
+struct MessageInternalGuard {
+    MessageInternalGuard(BuilderType& builder)
+    : builder_(builder),
+      user_data_(builder.user_data()) {
+        if (builder_.internal()) {
+            // Swap contents with user_data
+            ptr_.reset(new MessageInternal(user_data_, builder_.internal()));
+            builder_.user_data(ptr_.get()); //overwrite user data
+        }
+    }
+    ~MessageInternalGuard() {
+        //Restore user data
+        builder_.user_data(user_data_);
+    }
+    void release() {
+        ptr_.release();
+    }
+private:
+    BuilderType& builder_;
+    std::unique_ptr<MessageInternal> ptr_;
+    void* user_data_;
+};
+
 }
 
 #endif //CPPKAFKA_MESSAGE_INTERNAL_H

Diff for: include/cppkafka/producer.h

@@ -31,14 +31,12 @@
 #define CPPKAFKA_PRODUCER_H
 
 #include <memory>
-#include <tuple>
 #include "kafka_handle_base.h"
 #include "configuration.h"
 #include "buffer.h"
 #include "topic.h"
 #include "macros.h"
 #include "message_builder.h"
-#include "message_internal.h"
 
 namespace cppkafka {
 
@@ -80,7 +78,6 @@ class Message;
  */
 class CPPKAFKA_API Producer : public KafkaHandleBase {
 public:
-    friend MessageInternal;
     /**
      * The policy to use for the payload. The default policy is COPY_PAYLOAD
      */
@@ -159,11 +156,7 @@ class CPPKAFKA_API Producer : public KafkaHandleBase {
      */
     void flush(std::chrono::milliseconds timeout);
 private:
-    using LoadResult = std::tuple<void*, std::unique_ptr<MessageInternal>>;
-    LoadResult load_internal(void* user_data, InternalPtr internal);
-    
     PayloadPolicy message_payload_policy_;
-    bool has_internal_data_;
 };
 
 } // cppkafka

Diff for: include/cppkafka/utils/buffered_producer.h

@@ -104,7 +104,7 @@ class CPPKAFKA_API BufferedProducer {
     /**
      * Callback to indicate a message failed to be flushed
      */
-    using FlushFailureCallback = std::function<bool(const Builder&, Error error)>;
+    using FlushFailureCallback = std::function<bool(const MessageBuilder&, Error error)>;
 
     /**
      * \brief Constructs a buffered producer using the provided configuration
@@ -369,24 +369,22 @@ class CPPKAFKA_API BufferedProducer {
         if (!has_internal_data_ && (max_number_retries_ > 0)) {
             has_internal_data_ = true; //enable once
         }
-        if (has_internal_data_) {
-            // Add message tracker
+        if (has_internal_data_ && !builder.internal()) {
+            // Add message tracker only if it hasn't been added before
             TrackerPtr tracker = std::make_shared<Tracker>(SenderType::Async, max_number_retries_);
             builder.internal(tracker);
             return tracker;
         }
         return nullptr;
     }
-
     template <typename BuilderType>
     void do_add_message(BuilderType&& builder, MessagePriority priority, bool do_flush);
-    void do_add_message(const Message& message, MessagePriority priority, bool do_flush);
-    template <typename MessageType>
-    void produce_message(MessageType&& message);
+    template <typename BuilderType>
+    void produce_message(BuilderType&& builder);
     Configuration prepare_configuration(Configuration config);
     void on_delivery_report(const Message& message);
-    template <typename MessageType>
-    void async_produce(MessageType&& message, bool throw_on_error);
+    template <typename BuilderType>
+    void async_produce(BuilderType&& message, bool throw_on_error);
 
     // Members
     Producer producer_;
@@ -466,7 +464,7 @@ void BufferedProducer<BufferType>::sync_produce(const MessageBuilder& builder) {
 
 template <typename BufferType>
 void BufferedProducer<BufferType>::produce(const Message& message) {
-    async_produce(message, true);
+    async_produce(MessageBuilder(message), true);
 }
 
 template <typename BufferType>
@@ -546,13 +544,6 @@ void BufferedProducer<BufferType>::do_add_message(BuilderType&& builder,
     }
 }
 
-template <typename BufferType>
-void BufferedProducer<BufferType>::do_add_message(const Message& message,
-                                                  MessagePriority priority,
-                                                  bool do_flush) {
-    do_add_messsage(MessageBuilder(message), priority, do_flush);
-}
-
 template <typename BufferType>
 Producer& BufferedProducer<BufferType>::get_producer() {
     return producer_;
@@ -615,11 +606,14 @@ void BufferedProducer<BufferType>::set_flush_failure_callback(FlushFailureCallba
 }
 
 template <typename BufferType>
-template <typename MessageType>
-void BufferedProducer<BufferType>::produce_message(MessageType&& message) {
+template <typename BuilderType>
+void BufferedProducer<BufferType>::produce_message(BuilderType&& builder) {
+    using builder_type = typename std::decay<BuilderType>::type;
     while (true) {
         try {
-            producer_.produce(std::forward<MessageType>(message));
+            MessageInternalGuard<builder_type> internal_guard(const_cast<builder_type&>(builder));
+            producer_.produce(builder);
+            internal_guard.release();
             // Sent successfully
             ++pending_acks_;
             break;
@@ -637,23 +631,23 @@ void BufferedProducer<BufferType>::produce_message(MessageType&& message) {
 }
 
 template <typename BufferType>
-template <typename MessageType>
-void BufferedProducer<BufferType>::async_produce(MessageType&& message, bool throw_on_error) {
+template <typename BuilderType>
+void BufferedProducer<BufferType>::async_produce(BuilderType&& builder, bool throw_on_error) {
     try {
         TestParameters* test_params = get_test_parameters();
         if (test_params && test_params->force_produce_error_) {
             throw HandleException(Error(RD_KAFKA_RESP_ERR_UNKNOWN));
         }
-        produce_message(std::forward<MessageType>(message));
+        produce_message(std::forward<BuilderType>(builder));
     }
     catch (const HandleException& ex) {
         // If we have a flush failure callback and it returns true, we retry producing this message later
         CallbackInvoker<FlushFailureCallback> callback("flush failure", flush_failure_callback_, &producer_);
-        if (!callback || callback(std::forward<MessageType>(message), ex.get_error())) {
-            TrackerPtr tracker = std::static_pointer_cast<Tracker>(message.internal());
+        if (!callback || callback(std::forward<BuilderType>(builder), ex.get_error())) {
+            TrackerPtr tracker = std::static_pointer_cast<Tracker>(builder.internal());
             if (tracker && tracker->num_retries_ > 0) {
                 --tracker->num_retries_;
-                do_add_message(std::forward<MessageType>(message), MessagePriority::High, false);
+                do_add_message(std::forward<BuilderType>(builder), MessagePriority::High, false);
                 return;
             }
         }
@@ -676,7 +670,8 @@ template <typename BufferType>
 void BufferedProducer<BufferType>::on_delivery_report(const Message& message) {
     //Get tracker data
     TestParameters* test_params = get_test_parameters();
-    TrackerPtr tracker = std::static_pointer_cast<Tracker>(message.internal());
+    TrackerPtr tracker = has_internal_data_ ?
+        std::static_pointer_cast<Tracker>(MessageInternal::load(const_cast<Message&>(message))->internal_) : nullptr;
     bool should_retry = false;
     if (message.get_error() || (test_params && test_params->force_delivery_error_)) {
         // We should produce this message again if we don't have a produce failure callback

Diff for: src/configuration.cpp

@@ -31,7 +31,7 @@
 #include <vector>
 #include <librdkafka/rdkafka.h>
 #include "exceptions.h"
-#include "message_internal.h"
+#include "message.h"
 #include "producer.h"
 #include "consumer.h"
 
@@ -40,10 +40,8 @@ using std::map;
 using std::move;
 using std::vector;
 using std::initializer_list;
-using std::unique_ptr;
-using boost::optional;
-
 using std::chrono::milliseconds;
+using boost::optional;
 
 namespace cppkafka {
 
@@ -52,7 +50,6 @@ namespace cppkafka {
 void delivery_report_callback_proxy(rd_kafka_t*, const rd_kafka_message_t* msg, void *opaque) {
     Producer* handle = static_cast<Producer*>(opaque);
     Message message = Message::make_non_owning((rd_kafka_message_t*)msg);
-    unique_ptr<MessageInternal> internal_data(MessageInternal::load(*handle, message));
     CallbackInvoker<Configuration::DeliveryReportCallback>
         ("delivery report", handle->get_configuration().get_delivery_report_callback(), handle)
         (*handle, message);

Diff for: src/message.cpp

@@ -28,6 +28,7 @@
  */
 
 #include "message.h"
+#include "message_internal.h"
 
 using std::chrono::milliseconds;
 
@@ -64,9 +65,13 @@ Message::Message(HandlePtr handle)
   user_data_(handle_ ? handle_->_private : nullptr) {
 }
 
-void Message::load_internal(void* user_data, InternalPtr internal) {
-    user_data_ = user_data;
-    internal_ = internal;
+Message& Message::load_internal() {
+    if (user_data_) {
+        MessageInternal* mi = static_cast<MessageInternal*>(user_data_);
+        user_data_ = mi->user_data_;
+        internal_ = mi->internal_;
+    }
+    return *this;
 }
 
 // MessageTimestamp

Diff for: src/message_internal.cpp

@@ -27,23 +27,22 @@
  *
  */
 #include "message_internal.h"
-#include "producer.h"
+#include "message.h"
+#include "message_builder.h"
 
 namespace cppkafka {
 
-MessageInternal::MessageInternal(void* user_data, std::shared_ptr<Internal> internal)
+// MessageInternal
+
+MessageInternal::MessageInternal(void* user_data,
+                                 std::shared_ptr<Internal> internal)
 : user_data_(user_data),
   internal_(internal) {
 }
 
-std::unique_ptr<MessageInternal> MessageInternal::load(const Producer& producer, Message& message) {
-    if (producer.has_internal_data_ && 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;
+std::unique_ptr<MessageInternal> MessageInternal::load(Message& message) {
+    return std::unique_ptr<MessageInternal>(message.load_internal().get_handle() ?
+                                            static_cast<MessageInternal*>(message.get_handle()->_private) : nullptr);
 }
 
 }

Diff for: src/producer.cpp

@@ -42,8 +42,7 @@ using std::get;
 namespace cppkafka {
 
 Producer::Producer(Configuration config)
-: KafkaHandleBase(move(config)), message_payload_policy_(PayloadPolicy::COPY_PAYLOAD),
-  has_internal_data_(false) {
+: KafkaHandleBase(move(config)), message_payload_policy_(PayloadPolicy::COPY_PAYLOAD) {
     char error_buffer[512];
     auto config_handle = get_configuration().get_handle();
     rd_kafka_conf_set_opaque(config_handle, this);
@@ -69,37 +68,33 @@ void Producer::produce(const MessageBuilder& builder) {
     const Buffer& payload = builder.payload();
     const Buffer& key = builder.key();
     const int policy = static_cast<int>(message_payload_policy_);
-    LoadResult load_result = load_internal(builder.user_data(), builder.internal());
     auto result = rd_kafka_producev(get_handle(),
                                     RD_KAFKA_V_TOPIC(builder.topic().data()),
                                     RD_KAFKA_V_PARTITION(builder.partition()),
                                     RD_KAFKA_V_MSGFLAGS(policy),
                                     RD_KAFKA_V_TIMESTAMP(builder.timestamp().count()),
                                     RD_KAFKA_V_KEY((void*)key.get_data(), key.get_size()),
                                     RD_KAFKA_V_VALUE((void*)payload.get_data(), payload.get_size()),
-                                    RD_KAFKA_V_OPAQUE(get<0>(load_result)),
+                                    RD_KAFKA_V_OPAQUE(builder.user_data()),
                                     RD_KAFKA_V_END);
     check_error(result);
-    get<1>(load_result).release(); //data has been passed-on to rdkafka so we release ownership
 }
 
 void Producer::produce(const Message& message) {
     const Buffer& payload = message.get_payload();
     const Buffer& key = message.get_key();
     const int policy = static_cast<int>(message_payload_policy_);
     int64_t duration = message.get_timestamp() ? message.get_timestamp().get().get_timestamp().count() : 0;
-    LoadResult load_result = load_internal(message.get_user_data(), message.internal());
     auto result = rd_kafka_producev(get_handle(),
                                     RD_KAFKA_V_TOPIC(message.get_topic().data()),
                                     RD_KAFKA_V_PARTITION(message.get_partition()),
                                     RD_KAFKA_V_MSGFLAGS(policy),
                                     RD_KAFKA_V_TIMESTAMP(duration),
                                     RD_KAFKA_V_KEY((void*)key.get_data(), key.get_size()),
                                     RD_KAFKA_V_VALUE((void*)payload.get_data(), payload.get_size()),
-                                    RD_KAFKA_V_OPAQUE(get<0>(load_result)),
+                                    RD_KAFKA_V_OPAQUE(message.get_user_data()),
                                     RD_KAFKA_V_END);
     check_error(result);
-    get<1>(load_result).release(); //data has been passed-on to rdkafka so we release ownership
 }
 
 int Producer::poll() {
@@ -119,16 +114,4 @@ void Producer::flush(milliseconds timeout) {
     check_error(result);
 }
 
-Producer::LoadResult Producer::load_internal(void* user_data, InternalPtr internal) {
-    unique_ptr<MessageInternal> internal_data;
-    if (!has_internal_data_ && internal) {
-        has_internal_data_ = true; //enable once for this producer
-    }
-    if (has_internal_data_ && get_configuration().get_delivery_report_callback()) {
-        internal_data.reset(new MessageInternal(user_data, internal));
-        user_data = internal_data.get(); //point to the internal data
-    }
-    return LoadResult(user_data, move(internal_data));
-}
-
 } // cppkafka