abstract_chain_element.h

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/*
  Copyright (c) 2015, 2024, Oracle and/or its affiliates.
 
  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License, version 2.0,
  as published by the Free Software Foundation.
 
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  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License, version 2.0, for more details.
 
  You should have received a copy of the GNU General Public License
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  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
*/
 
#ifndef ABSTRACT_CHAIN_ELEMENT_INCLUDED
#define ABSTRACT_CHAIN_ELEMENT_INCLUDED
 
#include <stddef.h>
#include <atomic>
#include <functional>
 
#include "client/base/message_data.h"
#include "client/dump/abstract_progress_reporter.h"
#include "client/dump/i_chain_element.h"
#include "client/dump/item_processing_data.h"
#include "client/dump/simple_id_generator.h"
#include "my_inttypes.h"
 
namespace Mysql {
namespace Tools {
namespace Dump {
 
class Abstract_chain_element : public virtual I_chain_element,
                               public virtual Abstract_progress_reporter {
 public:
  /**
    Returns an application unique ID of this chain element object. This helps
    progress watching with multiple parts of chain during all objects
    processing.
   */
  uint64 get_id() const override;
 
  /** Disable move assignment to avoid Wvirtual-move-assign warning */
  Abstract_chain_element &operator=(Abstract_chain_element &&other) = delete;
 
  // Fix "inherits ... via dominance" warnings
  void register_progress_watcher(
      I_progress_watcher *new_progress_watcher) override {
    Abstract_progress_reporter::register_progress_watcher(new_progress_watcher);
  }
 
 protected:
  Abstract_chain_element(
      std::function<bool(const Mysql::Tools::Base::Message_data &)>
          *message_handler,
      Simple_id_generator *object_id_generator);
 
  /**
    Process task object with specified function if that task object can be
    casted to type TType. Returns true if object was processed.
   */
  template <typename TType, typename TClass>
  bool try_process_task(
      Item_processing_data *item_to_process,
      void (TClass::*processing_func)(TType *, Item_processing_data *)) {
    TType *casted_object =
        dynamic_cast<TType *>(item_to_process->get_process_task_object());
    if (casted_object != nullptr)
      (((TClass *)this)->*processing_func)(casted_object, item_to_process);
    return casted_object != nullptr;
  }
 
  /**
    Process task object with specified function if that task object can be
    casted to type TType. Returns true if object was processed.
   */
  template <typename TType, typename TClass>
  bool try_process_task(Item_processing_data *item_to_process,
                        void (TClass::*processing_func)(TType *)) {
    TType *casted_object =
        dynamic_cast<TType *>(item_to_process->get_process_task_object());
    if (casted_object != nullptr)
      (((TClass *)this)->*processing_func)(casted_object);
    return casted_object != nullptr;
  }
 
  void object_processing_starts(Item_processing_data *item_to_process);
 
  Item_processing_data *object_to_be_processed_in_child(
      Item_processing_data *current_item_data,
      I_chain_element *child_chain_element);
 
  Item_processing_data *new_task_created(I_dump_task *dump_task_created);
 
  Item_processing_data *new_chain_created(
      Chain_data *new_chain_data, Item_processing_data *parent_processing_data,
      I_chain_element *child_chain_element);
 
  Item_processing_data *new_chain_created(
      Item_processing_data *current_item_data, I_dump_task *dump_task_created);
 
  void object_processing_ends(Item_processing_data *processed_item);
 
  uint64 generate_new_object_id();
 
  Simple_id_generator *get_object_id_generator() const;
 
  /**
    Passes message to message callback.
   */
  void pass_message(const Mysql::Tools::Base::Message_data &message_data);
 
  std::function<bool(const Mysql::Tools::Base::Message_data &)>
      *get_message_handler() const;
 
 protected:
  virtual bool need_callbacks_in_child();
 
  // Must be protected to allow subclasses to call explicitly.
  void item_completion_in_child_callback(
      Item_processing_data *item_processed) override;
 
 private:
  /**
    Wrapper on item_completion_in_child_callback which allows creation of
    pointer to function which will then fetch correct virtual method pointer.
   */
  void item_completion_in_child_callback_wrapper(
      Item_processing_data *item_processed);
  /**
    Wrapper on item_completion_in_child_callback_wrapper which also sets
    precessed task to be fully completed.
   */
  void item_completion_in_child_completes_task_callback(
      Item_processing_data *item_processed);
 
  Item_processing_data *task_to_be_processed_in_child(
      Item_processing_data *current_item_data,
      I_chain_element *child_chain_element, I_dump_task *task_to_be_processed,
      std::function<void(Item_processing_data *)> *callback);
 
  uint64 m_id;
  std::function<bool(const Mysql::Tools::Base::Message_data &)>
      *m_message_handler;
  std::function<void(Item_processing_data *)> m_item_processed_callback;
  std::function<void(Item_processing_data *)>
      m_item_processed_complete_callback;
  Simple_id_generator *m_object_id_generator;
 
  /**
    Stores next chain element ID to be used. Used as ID generator.
   */
  static std::atomic<uint64_t> next_id;
};
 
}  // namespace Dump
}  // namespace Tools
}  // namespace Mysql
 
#endif