structs.h

#ifndef STRUCTS_INCLUDED
#define STRUCTS_INCLUDED

/* Copyright (c) 2000, 2013, 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 */



/* The old structures from unireg */

#include "sql_plugin.h"                         /* plugin_ref */
#include "sql_const.h"                          /* MAX_REFLENGTH */
#include "my_time.h"                   /* enum_mysql_timestamp_type */
#include "thr_lock.h"                  /* thr_lock_type */
#include "my_base.h"                   /* ha_rows, ha_key_alg */

struct TABLE;
class Field;

class THD;

typedef struct st_date_time_format {
  uchar positions[8];
  char  time_separator;                 /* Separator between hour and minute */
  uint flag;                            /* For future */
  LEX_STRING format;
} DATE_TIME_FORMAT;


typedef struct st_keyfile_info {        /* used with ha_info() */
  uchar ref[MAX_REFLENGTH];             /* Pointer to current row */
  uchar dupp_ref[MAX_REFLENGTH];        /* Pointer to dupp row */
  uint ref_length;                      /* Length of ref (1-8) */
  uint block_size;                      /* index block size */
  File filenr;                          /* (uniq) filenr for table */
  ha_rows records;                      /* Records i datafilen */
  ha_rows deleted;                      /* Deleted records */
  ulonglong data_file_length;           /* Length off data file */
  ulonglong max_data_file_length;       /* Length off data file */
  ulonglong index_file_length;
  ulonglong max_index_file_length;
  ulonglong delete_length;              /* Free bytes */
  ulonglong auto_increment_value;
  int errkey,sortkey;                   /* Last errorkey and sorted by */
  time_t create_time;                   /* When table was created */
  time_t check_time;
  time_t update_time;
  ulong mean_rec_length;                /* physical reclength */
} KEYFILE_INFO;


class KEY_PART_INFO {   /* Info about a key part */
public:
  Field *field;
  uint  offset;                         /* offset in record (from 0) */
  uint  null_offset;                    /* Offset to null_bit in record */
  /* Length of key part in bytes, excluding NULL flag and length bytes */
  uint16 length;
  /*
    Number of bytes required to store the keypart value. This may be
    different from the "length" field as it also counts
     - possible NULL-flag byte (see HA_KEY_NULL_LENGTH)
     - possible HA_KEY_BLOB_LENGTH bytes needed to store actual value length.
  */
  uint16 store_length;
  uint16 key_type;
  uint16 fieldnr;                       /* Fieldnum in UNIREG */
  uint16 key_part_flag;                 /* 0 or HA_REVERSE_SORT */
  uint8 type;
  uint8 null_bit;                       /* Position to null_bit */
  void init_from_field(Field *fld);     
  void init_flags();                    
};


typedef struct st_key {
  uint  key_length;
  ulong flags;
  ulong actual_flags;
  uint  user_defined_key_parts;
  uint  actual_key_parts;
  uint  unused_key_parts;
  uint  usable_key_parts;
  uint  block_size;
  enum  ha_key_alg algorithm;
  union
  {
    plugin_ref parser;
    LEX_STRING *parser_name;
  };
  KEY_PART_INFO *key_part;
  char  *name;
  ulong *rec_per_key;
  union {
    int  bdb_return_if_eq;
  } handler;
  TABLE *table;
  LEX_STRING comment;
} KEY;


struct st_join_table;

typedef struct st_reginfo {             /* Extra info about reg */
  struct st_join_table *join_tab;       /* Used by SELECT() */
  enum thr_lock_type lock_type;         /* How database is used */
  bool not_exists_optimize;
  /*
    TRUE <=> range optimizer found that there is no rows satisfying
    table conditions.
  */
  bool impossible_range;
} REGINFO;


/*
  Originally MySQL used MYSQL_TIME structure inside server only, but since
  4.1 it's exported to user in the new client API. Define aliases for
  new names to keep existing code simple.
*/

typedef enum enum_mysql_timestamp_type timestamp_type;


typedef struct {
  ulong year,month,day,hour;
  ulonglong minute,second,second_part;
  bool neg;
} INTERVAL;


typedef struct st_known_date_time_format {
  const char *format_name;
  const char *date_format;
  const char *datetime_format;
  const char *time_format;
} KNOWN_DATE_TIME_FORMAT;

extern const char *show_comp_option_name[];

typedef int *(*update_var)(THD *, struct st_mysql_show_var *);

typedef struct  st_lex_user {
  LEX_STRING user, host, password, plugin, auth;
  bool uses_identified_by_clause;
  bool uses_identified_with_clause;
  bool uses_authentication_string_clause;
  bool uses_identified_by_password_clause;
} LEX_USER;

/*
  This structure specifies the maximum amount of resources which
  can be consumed by each account. Zero value of a member means
  there is no limit.
*/
typedef struct user_resources {
  /* Maximum number of queries/statements per hour. */
  uint questions;
  /*
     Maximum number of updating statements per hour (which statements are
     updating is defined by sql_command_flags array).
  */
  uint updates;
  /* Maximum number of connections established per hour. */
  uint conn_per_hour;
  /* Maximum number of concurrent connections. */
  uint user_conn;
  /*
     Values of this enum and specified_limits member are used by the
     parser to store which user limits were specified in GRANT statement.
  */
  enum {QUERIES_PER_HOUR= 1, UPDATES_PER_HOUR= 2, CONNECTIONS_PER_HOUR= 4,
        USER_CONNECTIONS= 8};
  uint specified_limits;
} USER_RESOURCES;


/*
  This structure is used for counting resources consumed and for checking
  them against specified user limits.
*/
typedef struct  user_conn {
  /*
     Pointer to user+host key (pair separated by '\0') defining the entity
     for which resources are counted (By default it is user account thus
     priv_user/priv_host pair is used. If --old-style-user-limits option
     is enabled, resources are counted for each user+host separately).
  */
  char *user;
  /* Pointer to host part of the key. */
  char *host;
  ulonglong reset_utime;
  /* Total length of the key. */
  uint len;
  /* Current amount of concurrent connections for this account. */
  uint connections;
  /*
     Current number of connections per hour, number of updating statements
     per hour and total number of statements per hour for this account.
  */
  uint conn_per_hour, updates, questions;
  /* Maximum amount of resources which account is allowed to consume. */
  USER_RESOURCES user_resources;
} USER_CONN;

        /* Bits in form->update */
#define REG_MAKE_DUPP           1       /* Make a copy of record when read */
#define REG_NEW_RECORD          2       /* Write a new record if not found */
#define REG_UPDATE              4       /* Uppdate record */
#define REG_DELETE              8       /* Delete found record */
#define REG_PROG                16      /* User is updating database */
#define REG_CLEAR_AFTER_WRITE   32
#define REG_MAY_BE_UPDATED      64
#define REG_AUTO_UPDATE         64      /* Used in D-forms for scroll-tables */
#define REG_OVERWRITE           128
#define REG_SKIP_DUP            256

#define STATUS_GARBAGE          1

#define STATUS_NOT_FOUND        2

#define STATUS_UPDATED          16

#define STATUS_NULL_ROW         32

#define STATUS_DELETED          64

/*
  Such interval is "discrete": it is the set of
  { auto_inc_interval_min + k * increment,
    0 <= k <= (auto_inc_interval_values-1) }
  Where "increment" is maintained separately by the user of this class (and is
  currently only thd->variables.auto_increment_increment).
  It mustn't derive from Sql_alloc, because SET INSERT_ID needs to
  allocate memory which must stay allocated for use by the next statement.
*/
class Discrete_interval {
private:
  ulonglong interval_min;
  ulonglong interval_values;
  ulonglong  interval_max;    // excluded bound. Redundant.
public:
  Discrete_interval *next;    // used when linked into Discrete_intervals_list

  bool in_range(const ulonglong value) const
  {
    return  ((value >= interval_min) && (value < interval_max));
  }

  void replace(ulonglong start, ulonglong val, ulonglong incr)
  {
    interval_min=    start;
    interval_values= val;
    interval_max=    (val == ULONGLONG_MAX) ? val : start + val * incr;
  }
  Discrete_interval(ulonglong start, ulonglong val, ulonglong incr) :
    next(NULL) { replace(start, val, incr); };
  Discrete_interval() : next(NULL) { replace(0, 0, 0); };
  ulonglong minimum() const { return interval_min;    };
  ulonglong values()  const { return interval_values; };
  ulonglong maximum() const { return interval_max;    };
  /*
    If appending [3,5] to [1,2], we merge both in [1,5] (they should have the
    same increment for that, user of the class has to ensure that). That is
    just a space optimization. Returns 0 if merge succeeded.
  */
  bool merge_if_contiguous(ulonglong start, ulonglong val, ulonglong incr)
  {
    if (interval_max == start)
    {
      if (val == ULONGLONG_MAX)
      {
        interval_values=   interval_max= val;
      }
      else
      {
        interval_values+=  val;
        interval_max=      start + val * incr;
      }
      return 0;
    }
    return 1;
  };
};

class Discrete_intervals_list {

#define DISCRETE_INTERVAL_LIST_HAS_MAX_ONE_ELEMENT 1

private:
  Discrete_interval        first_interval;
  Discrete_interval        *head;
  Discrete_interval        *tail;
  Discrete_interval        *current;
  uint                  elements;               
  void operator=(Discrete_intervals_list &);    // prevent use of this
  bool append(Discrete_interval *new_interval)
  {
    if (unlikely(new_interval == NULL))
      return true;
    DBUG_PRINT("info",("adding new auto_increment interval"));
    if (head == NULL)
      head= current= new_interval;
    else
      tail->next= new_interval;
    tail= new_interval;
    elements++;
    return false;
  }
  void copy_shallow(const Discrete_intervals_list *other)
  {
    const Discrete_interval *o_first_interval= &other->first_interval;
    first_interval= other->first_interval;
    head= other->head == o_first_interval ? &first_interval : other->head;
    tail= other->tail == o_first_interval ? &first_interval : other->tail;
    current=
      other->current == o_first_interval ? &first_interval : other->current;
    elements= other->elements;
  }
  Discrete_intervals_list(const Discrete_intervals_list &other)
  { copy_shallow(&other); }

public:
  Discrete_intervals_list()
    : head(NULL), tail(NULL), current(NULL), elements(0) {}
  void empty()
  {
    if (head)
    {
      // first element, not on heap, should not be delete-d; start with next:
      for (Discrete_interval *i= head->next; i;)
      {
#ifdef DISCRETE_INTERVAL_LIST_HAS_MAX_ONE_ELEMENT
        DBUG_ASSERT(0);
#endif
        Discrete_interval *next= i->next;
        delete i;
        i= next;
      }
    }
    head= tail= current= NULL;
    elements= 0;
  }
  void swap(Discrete_intervals_list *other)
  {
    const Discrete_intervals_list tmp(*other);
    other->copy_shallow(this);
    copy_shallow(&tmp);
  }
  const Discrete_interval *get_next()
  {
    const Discrete_interval *tmp= current;
    if (current != NULL)
      current= current->next;
    return tmp;
  }
  ~Discrete_intervals_list() { empty(); };
  bool append(ulonglong start, ulonglong val, ulonglong incr)
  {
    // If there are no intervals, add one.
    if (head == NULL)
    {
      first_interval.replace(start, val, incr);
      return append(&first_interval);
    }
    // If this interval can be merged with previous, do that.
    if (tail->merge_if_contiguous(start, val, incr) == 0)
      return false;
    // If this interval cannot be merged, append it.
#ifdef DISCRETE_INTERVAL_LIST_HAS_MAX_ONE_ELEMENT
    /*
      We cannot create yet another interval as we already contain one. This
      situation can happen. Assume innodb_autoinc_lock_mode>=1 and
       CREATE TABLE T(A INT AUTO_INCREMENT PRIMARY KEY) ENGINE=INNODB;
       INSERT INTO T VALUES (NULL),(NULL),(1025),(NULL);
      Then InnoDB will reserve [1,4] (because of 4 rows) then
      [1026,1026]. Only the first interval is important for
      statement-based binary logging as it tells the starting point. So we
      ignore the second interval:
    */
    return false;
#else
    return append(new Discrete_interval(start, val, incr));
#endif
  }
  ulonglong minimum()     const { return (head ? head->minimum() : 0); };
  ulonglong maximum()     const { return (head ? tail->maximum() : 0); };
  uint      nb_elements() const { return elements; }
};

#endif /* STRUCTS_INCLUDED */