field.h

/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
 *
 *  Copyright (C) 2008 Sun Microsystems, Inc.
 *
 *  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, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

/*
  Because of the function new_field() all field classes that have static
  variables must declare the size_of() member function.
*/



#pragma once

#include <drizzled/common_fwd.h>
#include <drizzled/sql_error.h>
#include <drizzled/type/decimal.h>
#include <drizzled/key_map.h>
#include <drizzled/sql_list.h>
#include <drizzled/structs.h>
#include <drizzled/charset.h>
#include <drizzled/item_result.h>

#include <string>
#include <vector>

#include <drizzled/visibility.h>

namespace drizzled {

#define DATETIME_DEC                     6
#define DOUBLE_TO_STRING_CONVERSION_BUFFER_SIZE FLOATING_POINT_BUFFER

#define ASSERT_COLUMN_MARKED_FOR_READ assert(getTable() && (not getTable()->read_set || isReadSet()))
#define ASSERT_COLUMN_MARKED_FOR_WRITE assert(getTable() && (not getTable()->write_set || isWriteSet()))

const uint32_t max_field_size= (uint32_t) 4294967295U;

int field_conv(Field *to,Field *from);

class DRIZZLED_API Field : boost::noncopyable
{
public:
  unsigned char *ptr; 
  unsigned char *null_ptr; 
private:
  Table *table;

public:
  Table *getTable()
  {
    assert(table);
    return table;
  }

  Table *getTable() const
  {
    assert(table);
    return table;
  }

  void setTable(Table *table_arg)
  {
    table= table_arg;
  }

  Table *orig_table; 
  const char *field_name; 
  str_ref comment; 
  key_map key_start;
  key_map part_of_key;
  key_map part_of_key_not_clustered;
  key_map part_of_sortkey;

  /*
    We use three additional unireg types for TIMESTAMP for hysterical
    raisins and limitations in the MySQL FRM file format.

    A good TODO is to clean this up as we can support just about
    anything in the table proto message now.
  */
  enum utype
  {
    NONE,
    NEXT_NUMBER,
    TIMESTAMP_OLD_FIELD,
    TIMESTAMP_DN_FIELD,
    TIMESTAMP_UN_FIELD,
    TIMESTAMP_DNUN_FIELD
  };

  utype unireg_check;
  uint32_t field_length; 
  uint32_t flags;

  bool isUnsigned() const
  {
    return flags & UNSIGNED_FLAG;
  }

private:
  uint16_t field_index; 
public:

  uint16_t position() const
  {
    return field_index;
  }

  void setPosition(uint32_t arg)
  {
    field_index= arg;
  }

  unsigned char null_bit; 
  bool is_created_from_null_item;

  static void *operator new(size_t size);
  static void *operator new(size_t size, memory::Root *mem_root);
  static void operator delete(void *, size_t)
  { }
  static void operator delete(void *, memory::Root *)
  { }

  Field(unsigned char *ptr_arg,
        uint32_t length_arg,
        unsigned char *null_ptr_arg,
        unsigned char null_bit_arg,
        utype unireg_check_arg,
        const char *field_name_arg);
  virtual ~Field() {}

  bool hasDefault() const
  {
    return not (flags & NO_DEFAULT_VALUE_FLAG);
  }

  /* Store functions returns 1 on overflow and -1 on fatal error */
  virtual int store(const char *to,
                    uint32_t length,
                    const charset_info_st * const cs)=0;
  virtual int store(double nr)=0;
  virtual int store(int64_t nr, bool unsigned_val)=0;
  virtual int store_decimal(const type::Decimal *d)=0;
  int store_and_check(enum_check_fields check_level,
                      const char *to,
                      uint32_t length,
                      const charset_info_st * const cs);
  virtual int store_time(type::Time &ltime, type::timestamp_t t_type);
  virtual double val_real() const=0;
  virtual int64_t val_int() const =0;
  virtual type::Decimal *val_decimal(type::Decimal *) const;
  String *val_str_internal(String *str) const
  {
    return val_str(str, str);
  }

  /*
     val_str(buf1, buf2) gets two buffers and should use them as follows:
     if it needs a temp buffer to convert result to string - use buf1
       example Field_tiny::val_str()
     if the value exists as a string already - use buf2
       example Field_varstring::val_str() (???)
     consequently, buf2 may be created as 'String buf;' - no memory
     will be allocated for it. buf1 will be allocated to hold a
     value if it's too small. Using allocated buffer for buf2 may result in
     an unnecessary free (and later, may be an alloc).
     This trickery is used to decrease a number of malloc calls.
  */
  virtual String *val_str(String*, String *) const =0;

  /*
   str_needs_quotes() returns true if the value returned by val_str() needs
   to be quoted when used in constructing an SQL query.
  */
  virtual bool str_needs_quotes() { return false; }
  virtual Item_result result_type () const=0;
  virtual Item_result cmp_type () const { return result_type(); }
  virtual Item_result cast_to_int_type () const { return result_type(); }

  static bool type_can_have_key_part(enum_field_types);
  static enum_field_types field_type_merge(enum_field_types, enum_field_types);

  static Item_result result_merge_type(enum_field_types);

  virtual bool eq(Field *field);
  virtual bool eq_def(Field *field);

  virtual bool is_timestamp() const
  {
    return false;
  }

  virtual uint32_t pack_length() const;

  virtual uint32_t pack_length_in_rec() const;

  virtual uint32_t data_length();
  virtual uint32_t used_length();
  virtual uint32_t sort_length() const;

  virtual uint32_t max_data_length() const;
  virtual int reset(void);
  virtual void reset_fields();
  virtual void set_default();
  virtual bool binary() const;
  virtual bool zero_pack() const;
  virtual enum ha_base_keytype key_type() const;
  virtual uint32_t key_length() const;
  virtual enum_field_types type() const =0;
  virtual enum_field_types real_type() const;
  virtual int cmp_max(const unsigned char *a, const unsigned char *b, uint32_t max_len);
  virtual int cmp(const unsigned char *,const unsigned char *)=0;
  int cmp_internal(const unsigned char *str) { return cmp(ptr,str); }
  virtual int cmp_binary(const unsigned char *a,const unsigned char *b,
                         uint32_t max_length=UINT32_MAX);
  virtual int cmp_offset(uint32_t row_offset);
  virtual int cmp_binary_offset(uint32_t row_offset);
  virtual int key_cmp(const unsigned char *a,const unsigned char *b);
  virtual int key_cmp(const unsigned char *str, uint32_t length);
  virtual uint32_t decimals() const;

  // For new field
  virtual uint32_t size_of() const =0;

  bool is_null(ptrdiff_t row_offset= 0) const;
  bool is_real_null(ptrdiff_t row_offset= 0) const;
  bool is_null_in_record(const unsigned char *record) const;
  bool is_null_in_record_with_offset(ptrdiff_t offset) const;
  void set_null(ptrdiff_t row_offset= 0);
  void set_notnull(ptrdiff_t row_offset= 0);
  bool maybe_null(void) const;
  bool real_maybe_null(void) const;

  virtual void make_field(SendField *);
  virtual void sort_string(unsigned char *buff,uint32_t length)=0;
  virtual bool optimize_range(uint32_t idx, uint32_t part);
  virtual bool can_be_compared_as_int64_t() const
  {
    return false;
  }
  virtual void free() {}
  virtual Field *new_field(memory::Root*, Table*, bool keep_type);
  virtual Field *new_key_field(memory::Root *root, Table *new_table,
                               unsigned char *new_ptr,
                               unsigned char *new_null_ptr,
                               uint32_t new_null_bit);
  Field* clone(memory::Root*, Table*);
  void move_field(unsigned char *ptr_arg,unsigned char *null_ptr_arg,unsigned char null_bit_arg)
  {
    ptr= ptr_arg;
    null_ptr= null_ptr_arg;
    null_bit= null_bit_arg;
  }
  void move_field(unsigned char *ptr_arg) { ptr=ptr_arg; }
  virtual void move_field_offset(ptrdiff_t ptr_diff)
  {
    ptr= ADD_TO_PTR(ptr,ptr_diff, unsigned char*);
    if (null_ptr)
      null_ptr= ADD_TO_PTR(null_ptr,ptr_diff,unsigned char*);
  }
  virtual void get_image(unsigned char *buff, uint32_t length, const charset_info_st * const)
  {
    memcpy(buff,ptr,length);
  }
  virtual void get_image(std::basic_string<unsigned char> &buff, uint32_t length, const charset_info_st * const)
  {
    buff.append(ptr,length);
  }
  virtual void set_image(const unsigned char *buff,uint32_t length, const charset_info_st * const)
  {
    memcpy(ptr,buff,length);
  }

  virtual uint32_t get_key_image(unsigned char *buff, uint32_t length)
  {
    get_image(buff, length, &my_charset_bin);
    return length;
  }
  virtual uint32_t get_key_image(std::basic_string<unsigned char> &buff, uint32_t length)
  {
    get_image(buff, length, &my_charset_bin);
    return length;
  }
  virtual void set_key_image(const unsigned char *buff,uint32_t length)
  {
    set_image(buff,length, &my_charset_bin);
  }
  int64_t val_int_offset(uint32_t row_offset)
  {
    ptr+=row_offset;
    int64_t tmp=val_int();
    ptr-=row_offset;
    return tmp;
  }

  int64_t val_int_internal(const unsigned char *new_ptr)
  {
    unsigned char *old_ptr= ptr;
    ptr= const_cast<unsigned char*>(new_ptr);
    int64_t return_value= val_int();
    ptr= old_ptr;
    return return_value;
  }

  String *val_str_internal(String *str, const unsigned char *new_ptr)
  {
    unsigned char *old_ptr= ptr;
    ptr= const_cast<unsigned char*>(new_ptr);
    val_str_internal(str);
    ptr= old_ptr;
    return str;
  }

  virtual unsigned char *pack(unsigned char *to,
                              const unsigned char *from,
                              uint32_t max_length,
                              bool low_byte_first);

  unsigned char *pack(unsigned char *to, const unsigned char *from);

  virtual const unsigned char *unpack(unsigned char* to,
                                      const unsigned char *from,
                                      uint32_t param_data,
                                      bool low_byte_first);
  const unsigned char *unpack(unsigned char* to,
                              const unsigned char *from);

  virtual unsigned char *pack_key(unsigned char* to,
                                  const unsigned char *from,
                                  uint32_t max_length,
                                  bool low_byte_first)
  {
    return pack(to, from, max_length, low_byte_first);
  }
  virtual const unsigned char *unpack_key(unsigned char* to,
                                          const unsigned char *from,
                                          uint32_t max_length,
                                          bool low_byte_first)
  {
    return unpack(to, from, max_length, low_byte_first);
  }
  virtual uint32_t max_packed_col_length(uint32_t max_length)
  {
    return max_length;
  }

  uint32_t offset(const unsigned char *record)
  {
    return (uint32_t) (ptr - record);
  }
  void copy_from_tmp(int offset);
  uint32_t fill_cache_field(CacheField *copy);
  virtual bool get_date(type::Time &ltime,uint32_t fuzzydate) const;
  virtual bool get_time(type::Time &ltime) const;
  virtual const charset_info_st *charset(void) const { return &my_charset_bin; }
  virtual const charset_info_st *sort_charset(void) const { return charset(); }
  virtual bool has_charset(void) const { return false; }
  virtual void set_charset(const charset_info_st * const)
  {}
  virtual enum Derivation derivation(void) const
  {
    return DERIVATION_IMPLICIT;
  }
  virtual void set_derivation(enum Derivation)
  {}
  bool set_warning(DRIZZLE_ERROR::enum_warning_level,
                   drizzled::error_t code,
                   int cuted_increment);
  void set_datetime_warning(DRIZZLE_ERROR::enum_warning_level,
                            drizzled::error_t code,
                            const char *str,
                            uint32_t str_len,
                            type::timestamp_t ts_type,
                            int cuted_increment);
  void set_datetime_warning(DRIZZLE_ERROR::enum_warning_level,
                            drizzled::error_t code,
                            int64_t nr,
                            type::timestamp_t ts_type,
                            int cuted_increment);
  void set_datetime_warning(DRIZZLE_ERROR::enum_warning_level,
                            const drizzled::error_t code,
                            double nr,
                            type::timestamp_t ts_type);
  bool check_overflow(int op_result)
  {
    return (op_result == E_DEC_OVERFLOW);
  }
  int warn_if_overflow(int op_result);
  void init(Table *table_arg);

  /* maximum possible display length */
  virtual uint32_t max_display_length()= 0;

  virtual uint32_t is_equal(CreateField *new_field);
  int64_t convert_decimal2int64_t(const type::Decimal *val,
                                  bool unsigned_flag,
                                  int *err);
  /* The max. number of characters */
  uint32_t char_length() const
  {
    return field_length / charset()->mbmaxlen;
  }

  enum column_format_type column_format() const
  {
    return (enum column_format_type)
      ((flags >> COLUMN_FORMAT_FLAGS) & COLUMN_FORMAT_MASK);
  }

  /* Hash value */
  virtual void hash(uint32_t *nr, uint32_t *nr2) const;
  friend bool reopen_table(Session *,Table *,bool);

  friend class CopyField;
  friend class Item_avg_field;
  friend class Item_std_field;
  friend class Item_sum_num;
  friend class Item_sum_sum;
  friend class Item_sum_str;
  friend class Item_sum_count;
  friend class Item_sum_avg;
  friend class Item_sum_std;
  friend class Item_sum_min;
  friend class Item_sum_max;
  friend class Item_func_group_concat;

  bool isReadSet() const;
  bool isWriteSet();
  void setReadSet(bool arg= true);
  void setWriteSet(bool arg= true);

protected:

  void pack_num(uint64_t arg, unsigned char *destination= NULL);
  void pack_num(uint32_t arg, unsigned char *destination= NULL);
  uint64_t unpack_num(uint64_t &destination, const unsigned char *arg= NULL) const;
  uint32_t unpack_num(uint32_t &destination, const unsigned char *arg= NULL) const;
};

namespace field {

inline bool isDateTime(const enum_field_types &arg)
{
  switch (arg)
  {
  case DRIZZLE_TYPE_DATE:
  case DRIZZLE_TYPE_DATETIME:
  case DRIZZLE_TYPE_MICROTIME:
  case DRIZZLE_TYPE_TIME:
  case DRIZZLE_TYPE_TIMESTAMP:
    return true;

  case DRIZZLE_TYPE_BLOB:
  case DRIZZLE_TYPE_BOOLEAN:
  case DRIZZLE_TYPE_DECIMAL:
  case DRIZZLE_TYPE_DOUBLE:
  case DRIZZLE_TYPE_ENUM:
  case DRIZZLE_TYPE_LONG:
  case DRIZZLE_TYPE_LONGLONG:
  case DRIZZLE_TYPE_NULL:
  case DRIZZLE_TYPE_UUID:
  case DRIZZLE_TYPE_IPV6:
  case DRIZZLE_TYPE_VARCHAR:
    return false;
  }

  assert(0);
  abort();
}

} // namespace field

std::ostream& operator<<(std::ostream& output, const Field &field);

class SendField
{
public:
  const char *db_name;
  const char *table_name;
  const char *org_table_name;
  const char *col_name;
  const char *org_col_name;
  uint32_t length;
  uint32_t charsetnr;
  uint32_t flags;
  uint32_t decimals;
  enum_field_types type;
};

uint32_t pack_length_to_packflag(uint32_t type);
uint32_t calc_pack_length(enum_field_types type,uint32_t length);
int set_field_to_null(Field *field);
int set_field_to_null_with_conversions(Field *field, bool no_conversions);

bool test_if_important_data(const charset_info_st * const cs,
                            const char *str,
                            const char *strend);

} /* namespace drizzled */