sql_analyse.h

#ifndef SQL_ANALYSE_INCLUDED
#define SQL_ANALYSE_INCLUDED

/* Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program 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
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA */


/* Analyse database */

#include "procedure.h"                          /* Procedure */

#define my_thd_charset  default_charset_info

#define DEC_IN_AVG 4

typedef struct st_number_info
{
  // if zerofill is true, the number must be zerofill, or string
  bool      negative, is_float, zerofill, maybe_zerofill;
  int8      integers;
  int8      decimals;
  double    dval;
  ulonglong ullval;
} NUM_INFO;

typedef struct st_extreme_value_number_info
{
  ulonglong ullval;
  longlong  llval;
  double    max_dval, min_dval;
} EV_NUM_INFO;

typedef struct st_tree_info
{
  bool   found;
  String *str;
  Item   *item;
} TREE_INFO;

uint check_ulonglong(const char *str, uint length);
bool get_ev_num_info(EV_NUM_INFO *ev_info, NUM_INFO *info, const char *num);
bool test_if_number(NUM_INFO *info, const char *str, uint str_len);
int compare_double(const double *s, const double *t);
int compare_double2(void* cmp_arg __attribute__((unused)),
                    const double *s, const double *t);
int compare_longlong(const longlong *s, const longlong *t);
int compare_longlong2(void* cmp_arg __attribute__((unused)),
                      const longlong *s, const longlong *t);
int compare_ulonglong(const ulonglong *s, const ulonglong *t);
int compare_ulonglong2(void* cmp_arg __attribute__((unused)),
                       const ulonglong *s, const ulonglong *t);
int compare_decimal2(int* len, const char *s, const char *t);
void free_string(String*);
class select_analyse;

class field_info :public Sql_alloc
{
protected:
  ulong   treemem, tree_elements, empty, nulls, min_length, max_length;
  uint    room_in_tree;
  my_bool found;
  TREE    tree;
  Item    *item;
  select_analyse *pc;

public:
  field_info(Item* a, select_analyse* b)
  : treemem(0), tree_elements(0), empty(0),
    nulls(0), min_length(0), max_length(0), room_in_tree(1),
    found(0),item(a), pc(b) {};

  virtual ~field_info() { delete_tree(&tree); }
  virtual void   add() = 0;
  virtual void   get_opt_type(String*, ha_rows) = 0;
  virtual String *get_min_arg(String *) = 0;
  virtual String *get_max_arg(String *) = 0;
  virtual String *avg(String*, ha_rows) = 0;
  virtual String *std(String*, ha_rows) = 0;
  virtual tree_walk_action collect_enum() = 0;
  virtual uint decimals() { return 0; }
  friend  class select_analyse;
};


int collect_string(String *element, element_count count,
                   TREE_INFO *info);

int sortcmp2(void* cmp_arg __attribute__((unused)),
             const String *a,const String *b);

class field_str :public field_info
{
  String      min_arg, max_arg;
  ulonglong   sum;
  bool        must_be_blob, was_zero_fill, was_maybe_zerofill,
              can_be_still_num;
  NUM_INFO    num_info;
  EV_NUM_INFO ev_num_info;

public:
  field_str(Item* a, select_analyse* b) :field_info(a,b), 
    min_arg("",default_charset_info),
    max_arg("",default_charset_info), sum(0),
    must_be_blob(0), was_zero_fill(0),
    was_maybe_zerofill(0), can_be_still_num(1)
    { init_tree(&tree, 0, 0, sizeof(String), (qsort_cmp2) sortcmp2,
                0, (tree_element_free) free_string, NULL); };

  void   add();
  void   get_opt_type(String*, ha_rows);
  String *get_min_arg(String *not_used __attribute__((unused)))
  { return &min_arg; }
  String *get_max_arg(String *not_used __attribute__((unused)))
  { return &max_arg; }
  String *avg(String *s, ha_rows rows)
  {
    if (!(rows - nulls))
      s->set_real((double) 0.0, 1,my_thd_charset);
    else
      s->set_real((ulonglong2double(sum) / ulonglong2double(rows - nulls)),
             DEC_IN_AVG,my_thd_charset);
    return s;
  }
  friend int collect_string(String *element, element_count count,
                            TREE_INFO *info);
  tree_walk_action collect_enum()
  { return (tree_walk_action) collect_string; }
  String *std(String *s __attribute__((unused)),
              ha_rows rows __attribute__((unused)))
  { return (String*) 0; }
};


int collect_decimal(uchar *element, element_count count,
                    TREE_INFO *info);

class field_decimal :public field_info
{
  my_decimal min_arg, max_arg;
  my_decimal sum[2], sum_sqr[2];
  int cur_sum;
  int bin_size;
public:
  field_decimal(Item* a, select_analyse* b) :field_info(a,b)
  {
    bin_size= my_decimal_get_binary_size(a->max_length, a->decimals);
    init_tree(&tree, 0, 0, bin_size, (qsort_cmp2)compare_decimal2,
              0, 0, (void *)&bin_size);
  };

  void   add();
  void   get_opt_type(String*, ha_rows);
  String *get_min_arg(String *);
  String *get_max_arg(String *);
  String *avg(String *s, ha_rows rows);
  friend int collect_decimal(uchar *element, element_count count,
                             TREE_INFO *info);
  tree_walk_action collect_enum()
  { return (tree_walk_action) collect_decimal; }
  String *std(String *s, ha_rows rows);
};


int collect_real(double *element, element_count count, TREE_INFO *info);

class field_real: public field_info
{
  double min_arg, max_arg;
  double sum, sum_sqr;
  uint   max_notzero_dec_len;

public:
  field_real(Item* a, select_analyse* b) :field_info(a,b),
    min_arg(0), max_arg(0),  sum(0), sum_sqr(0), max_notzero_dec_len(0)
    { init_tree(&tree, 0, 0, sizeof(double),
                (qsort_cmp2) compare_double2, 0, NULL, NULL); }

  void   add();
  void   get_opt_type(String*, ha_rows);
  String *get_min_arg(String *s)
  {
    s->set_real(min_arg, item->decimals, my_thd_charset);
    return s;
  }
  String *get_max_arg(String *s)
  {
    s->set_real(max_arg, item->decimals, my_thd_charset);
    return s;
  }
  String *avg(String *s, ha_rows rows)
  {
    if (!(rows - nulls))
      s->set_real((double) 0.0, 1,my_thd_charset);
    else
      s->set_real(((double)sum / (double) (rows - nulls)), item->decimals,my_thd_charset);
    return s;
  }
  String *std(String *s, ha_rows rows)
  {
    double tmp = ulonglong2double(rows);
    if (!(tmp - nulls))
      s->set_real((double) 0.0, 1,my_thd_charset);
    else
    {
      double tmp2 = ((sum_sqr - sum * sum / (tmp - nulls)) /
                     (tmp - nulls));
      s->set_real(((double) tmp2 <= 0.0 ? 0.0 : sqrt(tmp2)), item->decimals,my_thd_charset);
    }
    return s;
  }
  uint   decimals() { return item->decimals; }
  friend int collect_real(double *element, element_count count,
                          TREE_INFO *info);
  tree_walk_action collect_enum()
  { return (tree_walk_action) collect_real;}
};

int collect_longlong(longlong *element, element_count count,
                     TREE_INFO *info);

class field_longlong: public field_info
{
  longlong min_arg, max_arg;
  longlong sum, sum_sqr;

public:
  field_longlong(Item* a, select_analyse* b) :field_info(a,b), 
    min_arg(0), max_arg(0), sum(0), sum_sqr(0)
    { init_tree(&tree, 0, 0, sizeof(longlong),
                (qsort_cmp2) compare_longlong2, 0, NULL, NULL); }

  void   add();
  void   get_opt_type(String*, ha_rows);
  String *get_min_arg(String *s) { s->set(min_arg,my_thd_charset); return s; }
  String *get_max_arg(String *s) { s->set(max_arg,my_thd_charset); return s; }
  String *avg(String *s, ha_rows rows)
  {
    if (!(rows - nulls))
      s->set_real((double) 0.0, 1,my_thd_charset);
    else
      s->set_real(((double) sum / (double) (rows - nulls)), DEC_IN_AVG,my_thd_charset);
    return s;
  }
  String *std(String *s, ha_rows rows)
  {
    double tmp = ulonglong2double(rows);
    if (!(tmp - nulls))
      s->set_real((double) 0.0, 1,my_thd_charset);
    else
    {
      double tmp2 = ((sum_sqr - sum * sum / (tmp - nulls)) /
                    (tmp - nulls));
      s->set_real(((double) tmp2 <= 0.0 ? 0.0 : sqrt(tmp2)), DEC_IN_AVG,my_thd_charset);
    }
    return s;
  }
  friend int collect_longlong(longlong *element, element_count count,
                              TREE_INFO *info);
  tree_walk_action collect_enum()
  { return (tree_walk_action) collect_longlong;}
};

int collect_ulonglong(ulonglong *element, element_count count,
                      TREE_INFO *info);

class field_ulonglong: public field_info
{
  ulonglong min_arg, max_arg;
  ulonglong sum, sum_sqr;

public:
  field_ulonglong(Item* a, select_analyse * b) :field_info(a,b),
    min_arg(0), max_arg(0), sum(0),sum_sqr(0)
    { init_tree(&tree, 0, 0, sizeof(ulonglong),
                (qsort_cmp2) compare_ulonglong2, 0, NULL, NULL); }
  void   add();
  void   get_opt_type(String*, ha_rows);
  String *get_min_arg(String *s) { s->set(min_arg,my_thd_charset); return s; }
  String *get_max_arg(String *s) { s->set(max_arg,my_thd_charset); return s; }
  String *avg(String *s, ha_rows rows)
  {
    if (!(rows - nulls))
      s->set_real((double) 0.0, 1,my_thd_charset);
    else
      s->set_real((ulonglong2double(sum) / ulonglong2double(rows - nulls)),
             DEC_IN_AVG,my_thd_charset);
    return s;
  }
  String *std(String *s, ha_rows rows)
  {
    double tmp = ulonglong2double(rows);
    if (!(tmp - nulls))
      s->set_real((double) 0.0, 1,my_thd_charset);
    else
    {
      double tmp2 = ((ulonglong2double(sum_sqr) - 
                     ulonglong2double(sum * sum) / (tmp - nulls)) /
                     (tmp - nulls));
      s->set_real(((double) tmp2 <= 0.0 ? 0.0 : sqrt(tmp2)), DEC_IN_AVG,my_thd_charset);
    }
    return s;
  }
  friend int collect_ulonglong(ulonglong *element, element_count count,
                               TREE_INFO *info);
  tree_walk_action collect_enum()
  { return (tree_walk_action) collect_ulonglong; }
};


class select_analyse : public select_send
{
  select_result *result; //< real output stream
  
  Item_proc    *func_items[10]; //< items for output metadata and column data
  List<Item>   result_fields; //< same as func_items but capable for send_data()
  field_info   **f_info, **f_end; //< bounds for column data accumulator array
  
  ha_rows      rows; //< counter of original SELECT query output rows
  uint         output_str_length; //< max.width for the Optimal_fieldtype column

public:
  const uint max_tree_elements; //< maximum number of distinct values per column
  const uint max_treemem; //< maximum amount of memory to allocate per column

public:
  select_analyse(select_result *result, const Proc_analyse_params *params)
  : result(result), f_info(NULL), f_end(NULL), rows(0), output_str_length(0),
    max_tree_elements(params->max_tree_elements),
    max_treemem(params->max_treemem)
  {}

  ~select_analyse() { cleanup(); }

  virtual void cleanup();
  virtual uint field_count(List<Item> &) const
  { return array_elements(func_items); }
  virtual int prepare(List<Item> &list, SELECT_LEX_UNIT *u)
  { return result->prepare(list, u); }
  virtual bool send_result_set_metadata(List<Item> &fields, uint flag);
  virtual bool send_data(List<Item> &items);
  virtual bool send_eof();
  virtual void abort_result_set();

private:
  bool init(List<Item> &field_list);
  bool change_columns();
};

bool append_escaped(String *to_str, String *from_str);

#endif /* SQL_ANALYSE_INCLUDED */