abstract_option.h

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/*
   Copyright (c) 2014, 2023, Oracle and/or its affiliates.
 
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   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.
 
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   as designated in a particular file or component or in included license
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   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.
 
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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_OPTION_INCLUDED
#define ABSTRACT_OPTION_INCLUDED
 
#include <assert.h>
#include <functional>
#include <string>
#include <vector>
 
#include "client/base/i_option_changed_listener.h"
 
#include "my_getopt.h"
#include "mysql/service_mysql_alloc.h"
 
namespace Mysql {
namespace Tools {
namespace Base {
namespace Options {
 
class Abstract_options_provider;
 
/**
  Abstract base with common option functionalities.
 */
template <typename T_type>
class Abstract_option : public I_option {
 public:
  ~Abstract_option() override;
 
  /**
    Adds new callback for this option for option_parsed() event to callback
    chain.
    I_Callable can be replaced with std::Function<void(char*)> once we get
    one.
   */
  void add_callback(std::function<void(char *)> *callback);
 
  /**
    Sets optid to given character to make possible usage of short option
    alternative.
   */
  T_type *set_short_character(char code);
 
 protected:
  /**
    Constructs new option.
    @param value Pointer to object to receive option value.
    @param var_type my_getopt internal option type.
    @param name Name of option. It is used in command line option name as
      --name.
    @param description Description of option to be printed in --help.
    @param default_value default value to be supplied to internal option
      data structure.
   */
  Abstract_option(void *value, ulong var_type, std::string name,
                  std::string description, longlong default_value);
 
  /**
    Returns my_getopt internal option data structure representing this option.
    To be used by Abstract_options_provider when preparing options array to
    return.
   */
  my_option get_my_option() override;
 
  /**
    Method to set listener on option changed events.
    For use from Abstract_options_provider class only.
   */
  void set_option_changed_listener(
      I_option_changed_listener *listener) override;
 
  my_option m_option_structure;
 
 private:
  void call_callbacks(char *argument) override;
 
  std::vector<std::function<void(char *)> *> m_callbacks;
  I_option_changed_listener *m_option_changed_listener;
 
  friend class Abstract_options_provider;
};
 
template <typename T_type>
Abstract_option<T_type>::~Abstract_option() {
  my_free(const_cast<char *>(m_option_structure.name));
  my_free(const_cast<char *>(m_option_structure.comment));
 
  for (std::vector<std::function<void(char *)> *>::iterator it =
           this->m_callbacks.begin();
       it != this->m_callbacks.end(); it++) {
    delete *it;
  }
}
 
template <typename T_type>
void Abstract_option<T_type>::add_callback(
    std::function<void(char *)> *callback) {
  this->m_callbacks.push_back(callback);
}
 
template <typename T_type>
T_type *Abstract_option<T_type>::set_short_character(char code) {
  // Change optid to new one
  uint32 old_optid = this->m_option_structure.id;
  this->m_option_structure.id = (int)code;
 
  // Inform that it has changed
  if (this->m_option_changed_listener != nullptr) {
    this->m_option_changed_listener->notify_option_optid_changed(this,
                                                                 old_optid);
  }
 
  return (T_type *)this;
}
 
template <typename T_type>
Abstract_option<T_type>::Abstract_option(void *value, ulong var_type,
                                         std::string name,
                                         std::string description,
                                         longlong default_value)
    : m_option_changed_listener(nullptr) {
  this->m_option_structure.block_size = 0;
  this->m_option_structure.max_value = 0;
  this->m_option_structure.min_value = 0;
  this->m_option_structure.typelib = nullptr;
  this->m_option_structure.u_max_value = nullptr;
 
  this->m_option_structure.app_type = this;
  this->m_option_structure.arg_type = REQUIRED_ARG;
  this->m_option_structure.comment =
      my_strdup(PSI_NOT_INSTRUMENTED, description.c_str(), MYF(MY_FAE));
  // This in future can be changed to atomic operation (compare_and_exchange)
  this->m_option_structure.id = Abstract_option::last_optid;
  Abstract_option::last_optid++;
  ;
  this->m_option_structure.def_value = default_value;
 
  this->m_option_structure.name =
      my_strdup(PSI_NOT_INSTRUMENTED, name.c_str(), MYF(MY_FAE));
  /*
   TODO mbabij 15-04-2014: this is based on previous usages of my_option.
   Everyone sets this the same as my_option::value, explain why.
   */
  this->m_option_structure.u_max_value = value;
 
  this->m_option_structure.value = value;
  this->m_option_structure.var_type = var_type;
  this->m_option_structure.arg_source = nullptr;
}
 
template <typename T_type>
my_option Abstract_option<T_type>::get_my_option() {
  return this->m_option_structure;
}
 
template <typename T_type>
void Abstract_option<T_type>::set_option_changed_listener(
    I_option_changed_listener *listener) {
  assert(this->m_option_changed_listener == nullptr);
 
  this->m_option_changed_listener = listener;
}
 
template <typename T_type>
void Abstract_option<T_type>::call_callbacks(char *argument) {
  std::vector<std::function<void(char *)> *>::iterator callback_it;
  for (callback_it = this->m_callbacks.begin();
       callback_it != this->m_callbacks.end(); callback_it++) {
    (**callback_it)(argument);
  }
}
 
}  // namespace Options
}  // namespace Base
}  // namespace Tools
}  // namespace Mysql
 
#endif