BasePlugin.h

// (c) Copyright 2022 CERN for the benefit of the LHCb Collaboration.
//
// This software is distributed under the terms of the GNU General Public
// Licence version 3 (GPL Version 3), copied verbatim in the file "LICENCE".
//
// In applying this licence, CERN does not waive the privileges and immunities
// granted to it by virtue of its status as an Intergovernmental Organization
// or submit itself to any jurisdiction.
 
 
#pragma once
 
// Standard C
#include <dlfcn.h>
 
// STL
#include <vector>
#include <string>
 
// SQLamarr
#include "SQLamarr/db_functions.h"
#include "SQLamarr/BaseSqlInterface.h"
#include "SQLamarr/Transformer.h"
 
namespace SQLamarr
{
  class BasePlugin: public BaseSqlInterface, public Transformer
  {
    public:
      BasePlugin (
          SQLite3DB& db,
          const std::string& library,
          const std::string& function_name,
          const std::string& select_query,
          const std::string& output_table,
          const std::vector<std::string> outputs,
          const std::vector<std::string> reference_keys = {"ref_id"}
          );
 
      BasePlugin (BasePlugin&) = delete;
 
      virtual ~BasePlugin() {dlclose(m_handle);}
 
      void execute () override;
 
    protected:
      virtual void eval_parametrization (float* output, const float* input) = 0;
 
    private: // Properties
      const std::string m_library;
      const std::string m_function_name;
      const std::string m_select_query;
      const std::string m_output_table;
      const std::vector<std::string> m_outputs;
      const std::vector<std::string> m_refkeys;
 
      void *m_handle;
 
    private: // Methods
      std::vector<std::string>  get_column_names() const;
      std::string  compose_delete_query();
      std::string  compose_create_query();
      std::string  compose_insert_query();
 
    protected:
      template <typename Func_t> Func_t load_func (const std::string& fname);
  };
 
 
  // Templated implementation
  template <typename Func_t> 
  Func_t BasePlugin::load_func (const std::string& fname)
  {
    Func_t ret = Func_t(dlsym(m_handle, fname.c_str()));
 
    if (!ret)
    {
      std::cerr << "Failure while loading " << fname << std::endl;
      throw std::runtime_error("Failed loading function");
    }
 
    return ret;
  }
}