comp_hook.h

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// Search Node computation hook implementation -*- C++ -*-

// $Id: comp_hook.h 601 2008-04-29 23:18:57Z herman $
// Copyright (C) 2003 Hermann Schichl
//
// This file is part of the COCONUT API.  This library
// is free software; you can redistribute it and/or modify it under the
// terms of the Library GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// Library GNU General Public License for more details.

// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the Library GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the Library GNU General Public License.

#ifndef _COMP_HOOK_H
#define _COMP_HOOK_H

#include <dbtools.h>
#include <search_node.h>
#include <delta.h>

namespace coco {

class wnc_hook_base;


class work_node_comp_hook
{
private:
  wnc_hook_base* __wh;

private:
  work_node_comp_hook(wnc_hook_base* w) : __wh(w) {}

public:
  work_node_comp_hook(const wnc_hook_base& w);
  work_node_comp_hook(const work_node_comp_hook& wh);

  ~work_node_comp_hook();

  work_node_comp_hook& operator=(const work_node_comp_hook& w);

  void operator()(const work_node& wn, dbt_row& dbr,
                  std::list<delta>* add_ds = NULL,
                  std::list<certificate>* add_cs = NULL);

  bool init_columns(vdbl::standard_table& stable);

  bool drop_columns(vdbl::standard_table& stable);

  const std::string& name() const;
};


class wnc_hook_base
{
private:
  std::string __name;
  std::list<std::string> __managed_cols;

protected:
  template <class _CI>
  bool _init_column(vdbl::standard_table& stable, const std::string& colname,
                    const _CI& c);

  template <class _CI>
  bool _init_column(vdbl::standard_table& stable, const char* colname,
                    const _CI& c)
        { return _init_column(stable, std::string(colname), c); }

  bool _drop_columns(vdbl::standard_table& stable);

  search_node_relation parent_relation(const work_node& wn) const;

  search_node_id node_id(const work_node& wn) const;

public:
  wnc_hook_base() : __name(), __managed_cols() {}
  wnc_hook_base(const std::string& name) : __name(name), __managed_cols() {}
  wnc_hook_base(const char* name) : __name(name), __managed_cols() {}
  wnc_hook_base(const wnc_hook_base& w) : __name(w.__name),
                                          __managed_cols(w.__managed_cols) {}

  virtual ~wnc_hook_base() {}

  virtual wnc_hook_base* new_copy() const = 0;

  virtual void operator()(const work_node& wn, dbt_row& dbr,
                          std::list<delta>* add_ds,
                          std::list<certificate>* add_cs) const = 0;

  virtual bool init_columns(vdbl::standard_table& stable) { return false; }

  virtual bool drop_columns(vdbl::standard_table& stable) { return false; }

  const std::string& name() const { return __name; }
};

inline work_node_comp_hook::work_node_comp_hook(const wnc_hook_base& w)
{
  __wh = w.new_copy();
}

inline work_node_comp_hook::work_node_comp_hook(const work_node_comp_hook& wh)
{
  __wh = wh.__wh->new_copy();
}

inline work_node_comp_hook::~work_node_comp_hook()
{
  if(__wh) delete __wh;
}

inline work_node_comp_hook&
        work_node_comp_hook::operator=(const work_node_comp_hook& w)
{
  if(__wh) delete __wh;
  __wh = w.__wh->new_copy();
  return *this;
}

inline void work_node_comp_hook::operator()(const work_node& wn, dbt_row& dbr,
                   std::list<delta>* add_ds, std::list<certificate>* add_cs)
{
  (*__wh)(wn, dbr, add_ds, add_cs);
}

inline bool work_node_comp_hook::init_columns(vdbl::standard_table& stable)
{
  return __wh->init_columns(stable);
}

inline bool work_node_comp_hook::drop_columns(vdbl::standard_table& stable)
{
  return __wh->drop_columns(stable);
}

inline const std::string& work_node_comp_hook::name() const
{
  return __wh->name();
}

template <class _CI>
bool wnc_hook_base::_init_column(vdbl::standard_table& stable,
                                 const std::string& colname, const _CI& c)
{
  bool ret = stable.add_col(colname, vdbl::typed_col<_CI>(c),
                             vdbl::colflags(true));
  if(ret)
    __managed_cols.push_back(colname);
  return ret;
}

} // namespace coco

#endif // _COMP_HOOK_H

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