~drizzle-trunk/drizzle/development

1336.3.3 by Djellel E. Difallah
add file ./drizzled/optimizer/cost_vector.h
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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
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 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
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 *
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 *  Copyright (C) 2008 Sun Microsystems
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 *
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 *  This program is free software; you can redistribute it and/or modify
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 *  it under the terms of the GNU General Public License as published by
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 *  the Free Software Foundation; version 2 of the License.
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 *
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 *  This program is distributed in the hope that it will be useful,
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 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 *  GNU General Public License for more details.
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 *
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 *  You should have received a copy of the GNU General Public License
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 *  along with this program; if not, write to the Free Software
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 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
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 */
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#ifndef DRIZZLED_OPTIMIZER_COST_VECTOR_H
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#define DRIZZLED_OPTIMIZER_COST_VECTOR_H
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namespace drizzled
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{
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namespace optimizer
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{
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class CostVector
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{
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public:
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  CostVector() :
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    io_count(0.0),
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    avg_io_cost(1.0),
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    cpu_cost(0.0),
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    mem_cost(0.0),
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    import_cost(0.0)
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  {}
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  double total_cost()
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  {
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    return IO_COEFF*io_count*avg_io_cost + CPU_COEFF * cpu_cost +
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      MEM_COEFF*mem_cost + IMPORT_COEFF*import_cost;
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  }
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  void zero()
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  {
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    avg_io_cost= 1.0;
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    io_count= cpu_cost= mem_cost= import_cost= 0.0;
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  }
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  void multiply(double m)
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  {
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    io_count *= m;
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    cpu_cost *= m;
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    import_cost *= m;
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    /* Don't multiply mem_cost */
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  }
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  void add(const CostVector* cost)
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  {
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    double io_count_sum= io_count + cost->io_count;
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    add_io(cost->io_count, cost->avg_io_cost);
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    io_count= io_count_sum;
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    cpu_cost += cost->cpu_cost;
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  }
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  void add_io(double add_io_cnt, double add_avg_cost)
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  {
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    double io_count_sum= io_count + add_io_cnt;
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    avg_io_cost= (io_count * avg_io_cost +
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                  add_io_cnt * add_avg_cost) / io_count_sum;
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    io_count= io_count_sum;
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  }
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  /* accessor methods*/
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  void setIOCount(double m)
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  {
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     io_count= m;
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  }
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  double getIOCount() const 
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  {
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     return io_count;
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  }
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  void setAvgIOCost(double m)
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  {
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     avg_io_cost= m;
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  }
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  double getAvgIOCost() const 
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  {
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     return avg_io_cost;
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  }
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  void setCpuCost(double m)
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  { 
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     cpu_cost= m;
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  }
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  double getCpuCost() const
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  {
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     return cpu_cost;
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  }
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  void setMemCost(double m)
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  { 
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     mem_cost= m;
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  }
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  double getMemCost() const
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  {
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     return mem_cost;
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  }
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  void setImportCost(double m)
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  {
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     import_cost= m;
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  }
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  double getImportCost() const
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  {
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     return import_cost;
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  }
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private:
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  double io_count;     /* number of I/O                 */
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  double avg_io_cost;  /* cost of an average I/O oper.  */
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  double cpu_cost;     /* cost of operations in CPU     */
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  double mem_cost;     /* cost of used memory           */
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  double import_cost;  /* cost of remote operations     */
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  static const uint32_t IO_COEFF=1;
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  static const uint32_t CPU_COEFF=1;
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  static const uint32_t MEM_COEFF=1;
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  static const uint32_t IMPORT_COEFF=1;
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};
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} /* namespace optimizer */
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} /* namespace drizzled */
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#endif /* DRIZZLED_OPTIMIZER_COST_VECTOR_H */