~drizzle-trunk/drizzle/development

/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-

 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:

 *

 *  Copyright (C) 2008 Sun Microsystems

 *

 *  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

 */

/* This file defines all string functions */

class Item_str_func :public Item_func

{

public:

  Item_str_func() :Item_func() { decimals=NOT_FIXED_DEC; }

  Item_str_func(Item *a) :Item_func(a) {decimals=NOT_FIXED_DEC; }

  Item_str_func(Item *a,Item *b) :Item_func(a,b) { decimals=NOT_FIXED_DEC; }

  Item_str_func(Item *a,Item *b,Item *c) :Item_func(a,b,c) { decimals=NOT_FIXED_DEC; }

  Item_str_func(Item *a,Item *b,Item *c,Item *d) :Item_func(a,b,c,d) {decimals=NOT_FIXED_DEC; }

  Item_str_func(Item *a,Item *b,Item *c,Item *d, Item* e) :Item_func(a,b,c,d,e) {decimals=NOT_FIXED_DEC; }

  Item_str_func(List<Item> &list) :Item_func(list) {decimals=NOT_FIXED_DEC; }

  int64_t val_int();

  double val_real();

  my_decimal *val_decimal(my_decimal *);

  enum Item_result result_type () const { return STRING_RESULT; }

  void left_right_max_length();

  bool fix_fields(Session *session, Item **ref);

};

class Item_func_concat :public Item_str_func

{

  String tmp_value;

public:

  Item_func_concat(List<Item> &list) :Item_str_func(list) {}

  Item_func_concat(Item *a,Item *b) :Item_str_func(a,b) {}

  String *val_str(String *);

  void fix_length_and_dec();

  const char *func_name() const { return "concat"; }

};

class Item_func_concat_ws :public Item_str_func

{

  String tmp_value;

public:

  Item_func_concat_ws(List<Item> &list) :Item_str_func(list) {}

  String *val_str(String *);

  void fix_length_and_dec();

  const char *func_name() const { return "concat_ws"; }

  table_map not_null_tables() const { return 0; }

};

class Item_func_reverse :public Item_str_func

{

  String tmp_value;

public:

  Item_func_reverse(Item *a) :Item_str_func(a) {}

  String *val_str(String *);

  void fix_length_and_dec();

  const char *func_name() const { return "reverse"; }

};

class Item_func_replace :public Item_str_func

{

  String tmp_value,tmp_value2;

public:

  Item_func_replace(Item *org,Item *find,Item *replace)

    :Item_str_func(org,find,replace) {}

  String *val_str(String *);

  void fix_length_and_dec();

  const char *func_name() const { return "replace"; }

};

class Item_func_insert :public Item_str_func

{

  String tmp_value;

public:

  Item_func_insert(Item *org,Item *start,Item *length,Item *new_str)

    :Item_str_func(org,start,length,new_str) {}

  String *val_str(String *);

  void fix_length_and_dec();

  const char *func_name() const { return "insert"; }

};

class Item_str_conv :public Item_str_func

{

protected:

  uint32_t multiply;

  my_charset_conv_case converter;

  String tmp_value;

public:

  Item_str_conv(Item *item) :Item_str_func(item) {}

  String *val_str(String *);

};

class Item_func_lcase :public Item_str_conv

{

public:

  Item_func_lcase(Item *item) :Item_str_conv(item) {}

  const char *func_name() const { return "lcase"; }

  void fix_length_and_dec();

};

class Item_func_ucase :public Item_str_conv

{

public:

  Item_func_ucase(Item *item) :Item_str_conv(item) {}

  const char *func_name() const { return "ucase"; }

  void fix_length_and_dec();

};

class Item_func_left :public Item_str_func

{

  String tmp_value;

public:

  Item_func_left(Item *a,Item *b) :Item_str_func(a,b) {}

  String *val_str(String *);

  void fix_length_and_dec();

  const char *func_name() const { return "left"; }

};

class Item_func_right :public Item_str_func

{

  String tmp_value;

public:

  Item_func_right(Item *a,Item *b) :Item_str_func(a,b) {}

  String *val_str(String *);

  void fix_length_and_dec();

  const char *func_name() const { return "right"; }

};

class Item_func_substr :public Item_str_func

{

  String tmp_value;

public:

  Item_func_substr(Item *a,Item *b) :Item_str_func(a,b) {}

  Item_func_substr(Item *a,Item *b,Item *c) :Item_str_func(a,b,c) {}

  String *val_str(String *);

  void fix_length_and_dec();

  const char *func_name() const { return "substr"; }

};

class Item_func_substr_index :public Item_str_func

{

  String tmp_value;

public:

  Item_func_substr_index(Item *a,Item *b,Item *c) :Item_str_func(a,b,c) {}

  String *val_str(String *);

  void fix_length_and_dec();

  const char *func_name() const { return "substring_index"; }

};

class Item_func_trim :public Item_str_func

{

protected:

  String tmp_value;

  String remove;

public:

  Item_func_trim(Item *a,Item *b) :Item_str_func(a,b) {}

  Item_func_trim(Item *a) :Item_str_func(a) {}

  String *val_str(String *);

  void fix_length_and_dec();

  const char *func_name() const { return "trim"; }

  virtual void print(String *str, enum_query_type query_type);

  virtual const char *mode_name() const { return "both"; }

};

class Item_func_ltrim :public Item_func_trim

{

public:

  Item_func_ltrim(Item *a,Item *b) :Item_func_trim(a,b) {}

  Item_func_ltrim(Item *a) :Item_func_trim(a) {}

  String *val_str(String *);

  const char *func_name() const { return "ltrim"; }

  const char *mode_name() const { return "leading"; }

};

class Item_func_rtrim :public Item_func_trim

{

public:

  Item_func_rtrim(Item *a,Item *b) :Item_func_trim(a,b) {}

  Item_func_rtrim(Item *a) :Item_func_trim(a) {}

  String *val_str(String *);

  const char *func_name() const { return "rtrim"; }

  const char *mode_name() const { return "trailing"; }

};

class Item_func_sysconst :public Item_str_func

{

public:

  Item_func_sysconst()

  { collation.set(system_charset_info,DERIVATION_SYSCONST); }

  Item *safe_charset_converter(const CHARSET_INFO * const tocs);

  /*

    Used to create correct Item name in new converted item in

    safe_charset_converter, return string representation of this function

    call

  */

  virtual const char *fully_qualified_func_name() const = 0;

  bool check_vcol_func_processor(unsigned char *int_arg __attribute__((unused)))

  { return true; }

};

class Item_func_database :public Item_func_sysconst

{

public:

  Item_func_database() :Item_func_sysconst() {}

  String *val_str(String *);

  void fix_length_and_dec()

  {

    max_length= MAX_FIELD_NAME * system_charset_info->mbmaxlen;

    maybe_null=1;

  }

  const char *func_name() const { return "database"; }

  const char *fully_qualified_func_name() const { return "database()"; }

};

class Item_func_user :public Item_func_sysconst

{

protected:

  bool init (const char *user, const char *host);

public:

  Item_func_user()

  {

    str_value.set("", 0, system_charset_info);

  }

  String *val_str(String *)

  {

    assert(fixed == 1);

    return (null_value ? 0 : &str_value);

  }

  bool fix_fields(Session *session, Item **ref);

  void fix_length_and_dec()

  {

    max_length= (USERNAME_CHAR_LENGTH + HOSTNAME_LENGTH + 1) *

                system_charset_info->mbmaxlen;

  }

  const char *func_name() const { return "user"; }

  const char *fully_qualified_func_name() const { return "user()"; }

  int save_in_field(Field *field,

                    bool no_conversions __attribute__((unused)))

  {

    return save_str_value_in_field(field, &str_value);

  }

};

class Item_func_current_user :public Item_func_user

{

  Name_resolution_context *context;

public:

  Item_func_current_user(Name_resolution_context *context_arg)

    : context(context_arg) {}

  bool fix_fields(Session *session, Item **ref);

  const char *func_name() const { return "current_user"; }

  const char *fully_qualified_func_name() const { return "current_user()"; }

};

class Item_func_soundex :public Item_str_func

{

  String tmp_value;

public:

  Item_func_soundex(Item *a) :Item_str_func(a) {}

  String *val_str(String *);

  void fix_length_and_dec();

  const char *func_name() const { return "soundex"; }

};

class Item_func_elt :public Item_str_func

{

public:

  Item_func_elt(List<Item> &list) :Item_str_func(list) {}

  double val_real();

  int64_t val_int();

  String *val_str(String *str);

  void fix_length_and_dec();

  const char *func_name() const { return "elt"; }

};

class Item_func_make_set :public Item_str_func

{

  Item *item;

  String tmp_str;

public:

  Item_func_make_set(Item *a,List<Item> &list) :Item_str_func(list),item(a) {}

  String *val_str(String *str);

  bool fix_fields(Session *session, Item **ref)

  {

    assert(fixed == 0);

    return ((!item->fixed && item->fix_fields(session, &item)) ||

	    item->check_cols(1) ||

	    Item_func::fix_fields(session, ref));

  }

  void split_sum_func(Session *session, Item **ref_pointer_array, List<Item> &fields);

  void fix_length_and_dec();

  void update_used_tables();

  const char *func_name() const { return "make_set"; }

  bool walk(Item_processor processor, bool walk_subquery, unsigned char *arg)

  {

    return item->walk(processor, walk_subquery, arg) ||

      Item_str_func::walk(processor, walk_subquery, arg);

  }

  Item *transform(Item_transformer transformer, unsigned char *arg);

  virtual void print(String *str, enum_query_type query_type);

};

class Item_func_format :public Item_str_func

{

  String tmp_str;

public:

  Item_func_format(Item *org, Item *dec);

  String *val_str(String *);

  void fix_length_and_dec();

  const char *func_name() const { return "format"; }

  virtual void print(String *str, enum_query_type query_type);

};

class Item_func_char :public Item_str_func

{

public:

  Item_func_char(List<Item> &list) :Item_str_func(list)

  { collation.set(&my_charset_bin); }

  Item_func_char(List<Item> &list, const CHARSET_INFO * const cs) :Item_str_func(list)

  { collation.set(cs); }  

  String *val_str(String *);

  void fix_length_and_dec() 

  {

    max_length= arg_count * 4;

  }

  const char *func_name() const { return "char"; }

};

class Item_func_repeat :public Item_str_func

{

  String tmp_value;

public:

  Item_func_repeat(Item *arg1,Item *arg2) :Item_str_func(arg1,arg2) {}

  String *val_str(String *);

  void fix_length_and_dec();

  const char *func_name() const { return "repeat"; }

};

class Item_func_rpad :public Item_str_func

{

  String tmp_value, rpad_str;

public:

  Item_func_rpad(Item *arg1,Item *arg2,Item *arg3)

    :Item_str_func(arg1,arg2,arg3) {}

  String *val_str(String *);

  void fix_length_and_dec();

  const char *func_name() const { return "rpad"; }

};

class Item_func_lpad :public Item_str_func

{

  String tmp_value, lpad_str;

public:

  Item_func_lpad(Item *arg1,Item *arg2,Item *arg3)

    :Item_str_func(arg1,arg2,arg3) {}

  String *val_str(String *);

  void fix_length_and_dec();

  const char *func_name() const { return "lpad"; }

};

class Item_func_conv :public Item_str_func

{

public:

  Item_func_conv(Item *a,Item *b,Item *c) :Item_str_func(a,b,c) {}

  const char *func_name() const { return "conv"; }

  String *val_str(String *);

  void fix_length_and_dec()

  {

    collation.set(default_charset());

    max_length=64;

    maybe_null= 1;

  }

};

class Item_func_hex :public Item_str_func

{

  String tmp_value;

public:

  Item_func_hex(Item *a) :Item_str_func(a) {}

  const char *func_name() const { return "hex"; }

  String *val_str(String *);

  void fix_length_and_dec()

  {

    collation.set(default_charset());

    decimals=0;

    max_length=args[0]->max_length*2*collation.collation->mbmaxlen;

  }

};

class Item_func_unhex :public Item_str_func

{

  String tmp_value;

public:

  Item_func_unhex(Item *a) :Item_str_func(a) 

  { 

    /* there can be bad hex strings */

    maybe_null= 1; 

  }

  const char *func_name() const { return "unhex"; }

  String *val_str(String *);

  void fix_length_and_dec()

  {

    collation.set(&my_charset_bin);

    decimals=0;

    max_length=(1+args[0]->max_length)/2;

  }

};

class Item_func_binary :public Item_str_func

{

public:

  Item_func_binary(Item *a) :Item_str_func(a) {}

  String *val_str(String *a)

  {

    assert(fixed == 1);

    String *tmp=args[0]->val_str(a);

    null_value=args[0]->null_value;

    if (tmp)

      tmp->set_charset(&my_charset_bin);

    return tmp;

  }

  void fix_length_and_dec()

  {

    collation.set(&my_charset_bin);

    max_length=args[0]->max_length;

  }

  virtual void print(String *str, enum_query_type query_type);

  const char *func_name() const { return "cast_as_binary"; }

};

class Item_load_file :public Item_str_func

{

  String tmp_value;

public:

  Item_load_file(Item *a) :Item_str_func(a) {}

  String *val_str(String *);

  const char *func_name() const { return "load_file"; }

  void fix_length_and_dec()

  {

    collation.set(&my_charset_bin, DERIVATION_COERCIBLE);

    maybe_null=1;

    max_length=MAX_BLOB_WIDTH;

  }

  bool check_vcol_func_processor(unsigned char *int_arg __attribute__((unused)))

  { return true; }

};

class Item_func_export_set: public Item_str_func

{

 public:

  Item_func_export_set(Item *a,Item *b,Item* c) :Item_str_func(a,b,c) {}

  Item_func_export_set(Item *a,Item *b,Item* c,Item* d) :Item_str_func(a,b,c,d) {}

  Item_func_export_set(Item *a,Item *b,Item* c,Item* d,Item* e) :Item_str_func(a,b,c,d,e) {}

  String  *val_str(String *str);

  void fix_length_and_dec();

  const char *func_name() const { return "export_set"; }

};

class Item_func_quote :public Item_str_func

{

  String tmp_value;

public:

  Item_func_quote(Item *a) :Item_str_func(a) {}

  const char *func_name() const { return "quote"; }

  String *val_str(String *);

  void fix_length_and_dec()

  {

    collation.set(args[0]->collation);

    max_length= args[0]->max_length * 2 + 2;

  }

};

class Item_func_conv_charset :public Item_str_func

{

  bool use_cached_value;

public:

  bool safe;

  const CHARSET_INFO *conv_charset; // keep it public

  Item_func_conv_charset(Item *a, const CHARSET_INFO * const cs) :Item_str_func(a) 

  { conv_charset= cs; use_cached_value= 0; safe= 0; }

  Item_func_conv_charset(Item *a, const CHARSET_INFO * const cs, bool cache_if_const) 

    :Item_str_func(a) 

  {

    assert(args[0]->fixed);

    conv_charset= cs;

    if (cache_if_const && args[0]->const_item())

    {

      uint32_t errors= 0;

      String tmp, *str= args[0]->val_str(&tmp);

      if (!str || str_value.copy(str->ptr(), str->length(),

                                 str->charset(), conv_charset, &errors))

        null_value= 1;

      use_cached_value= 1;

      str_value.mark_as_const();

      safe= (errors == 0);

    }

    else

    {

      use_cached_value= 0;

      /*

        Conversion from and to "binary" is safe.

        Conversion to Unicode is safe.

        Other kind of conversions are potentially lossy.

      */

      safe= (args[0]->collation.collation == &my_charset_bin ||

             cs == &my_charset_bin ||

             (cs->state & MY_CS_UNICODE));

    }

  }

  String *val_str(String *);

  void fix_length_and_dec();

  const char *func_name() const { return "convert"; }

  virtual void print(String *str, enum_query_type query_type);

};

class Item_func_set_collation :public Item_str_func

{

public:

  Item_func_set_collation(Item *a, Item *b) :Item_str_func(a,b) {};

  String *val_str(String *);

  void fix_length_and_dec();

  bool eq(const Item *item, bool binary_cmp) const;

  const char *func_name() const { return "collate"; }

  enum Functype functype() const { return COLLATE_FUNC; }

  virtual void print(String *str, enum_query_type query_type);

  Item_field *filed_for_view_update()

  {

    /* this function is transparent for view updating */

    return args[0]->filed_for_view_update();

  }

};

class Item_func_charset :public Item_str_func

{

public:

  Item_func_charset(Item *a) :Item_str_func(a) {}

  String *val_str(String *);

  const char *func_name() const { return "charset"; }

  void fix_length_and_dec()

  {

     collation.set(system_charset_info);

     max_length= 64 * collation.collation->mbmaxlen; // should be enough

     maybe_null= 0;

  };

  table_map not_null_tables() const { return 0; }

};

class Item_func_collation :public Item_str_func

{

public:

  Item_func_collation(Item *a) :Item_str_func(a) {}

  String *val_str(String *);

  const char *func_name() const { return "collation"; }

  void fix_length_and_dec()

  {

     collation.set(system_charset_info);

     max_length= 64 * collation.collation->mbmaxlen; // should be enough

     maybe_null= 0;

  };

  table_map not_null_tables() const { return 0; }

};

class Item_func_weight_string :public Item_str_func

{

  String tmp_value;

  uint32_t flags;

  uint32_t nweights;

public:

  Item_func_weight_string(Item *a, uint32_t nweights_arg, uint32_t flags_arg)

  :Item_str_func(a) { nweights= nweights_arg; flags= flags_arg; }

  const char *func_name() const { return "weight_string"; }

  String *val_str(String *);

  void fix_length_and_dec();

  /*

    TODO: Currently this Item is not allowed for virtual columns

    only due to a bug in generating virtual column value.

  */

  bool check_vcol_func_processor(unsigned char *int_arg __attribute__((unused)))

  { return true; }

};

#define UUID_LENGTH (8+1+4+1+4+1+4+1+12)

class Item_func_uuid: public Item_str_func

{

public:

  Item_func_uuid(): Item_str_func() {}

  void fix_length_and_dec() {

    collation.set(system_charset_info);

    /*

       NOTE! uuid() should be changed to use 'ascii'

       charset when hex(), format(), md5(), etc, and implicit

       number-to-string conversion will use 'ascii'

    */

    max_length= UUID_LENGTH * system_charset_info->mbmaxlen;

  }

  const char *func_name() const{ return "uuid"; }

  String *val_str(String *);

  bool check_vcol_func_processor(unsigned char *int_arg __attribute__((unused)))

  { return true; }

};