~drizzle-trunk/drizzle/development

/* Copyright (C) 2000 MySQL AB

   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 is originally from the mysql distribution. Coded by monty */

#include <config.h>

#include <drizzled/definitions.h>

#include <drizzled/internal/my_sys.h>

#include <drizzled/internal/m_string.h>

#include <drizzled/memory/root.h>

#include <drizzled/charset.h>

#include <algorithm>

#include <drizzled/sql_string.h>

using namespace std;

namespace drizzled {

/*****************************************************************************

** String functions

*****************************************************************************/

String::String()

  : Ptr(NULL),

    str_length(0),

    Alloced_length(0),

    alloced(false),

    str_charset(&my_charset_bin)

{ }

String::String(size_t length_arg)

  : Ptr(NULL),

    str_length(0),

    Alloced_length(0),

    alloced(false),

    str_charset(&my_charset_bin)

{

  (void) real_alloc(length_arg);

}

String::String(const char *str, const charset_info_st * const cs)

  : Ptr(const_cast<char *>(str)),

    str_length(static_cast<size_t>(strlen(str))),

    Alloced_length(0),

    alloced(false),

    str_charset(cs)

{ }

String::String(const char *str, size_t len, const charset_info_st * const cs)

  : Ptr(const_cast<char *>(str)),

    str_length(len),

    Alloced_length(0),

    alloced(false),

    str_charset(cs)

{ }

String::String(char *str, size_t len, const charset_info_st * const cs)

  : Ptr(str),

    str_length(len),

    Alloced_length(len),

    alloced(false),

    str_charset(cs)

{ }

String::String(const String &str)

  : Ptr(str.Ptr),

    str_length(str.str_length),

    Alloced_length(str.Alloced_length),

    alloced(false),

    str_charset(str.str_charset)

{ }

void *String::operator new(size_t size, memory::Root *mem_root)

{

  return mem_root->alloc(size);

}

String::~String() { free(); }

void String::real_alloc(size_t arg_length)

{

  arg_length=ALIGN_SIZE(arg_length+1);

  str_length=0;

  if (Alloced_length < arg_length)

  {

    if (Alloced_length > 0)

      free();

    Ptr=(char*) malloc(arg_length);

    Alloced_length=arg_length;

    alloced=1;

  }

  Ptr[0]=0;

}

/*

** Check that string is big enough. Set string[alloc_length] to 0

** (for C functions)

*/

void String::realloc(size_t alloc_length)

{

  size_t len=ALIGN_SIZE(alloc_length+1);

  if (Alloced_length < len)

  {

    char *new_ptr;

    if (alloced)

    {

      new_ptr= (char*) ::realloc(Ptr,len);

      Ptr=new_ptr;

      Alloced_length=len;

    }

    else 

    {

      new_ptr= (char*) malloc(len);

      if (str_length)				// Avoid bugs in memcpy on AIX

        memcpy(new_ptr,Ptr,str_length);

      new_ptr[str_length]=0;

      Ptr=new_ptr;

      Alloced_length=len;

      alloced=1;

    }

  }

  Ptr[alloc_length]=0;			// This make other funcs shorter

}

void String::set_int(int64_t num, bool unsigned_flag, const charset_info_st * const cs)

{

  size_t l= 20 * cs->mbmaxlen + 1;

  alloc(l);

  str_length=(size_t) (cs->cset->int64_t10_to_str)(cs, Ptr, l, unsigned_flag ? 10 : -10,num);

  str_charset=cs;

}

void String::set_real(double num,size_t decimals, const charset_info_st * const cs)

{

  char buff[FLOATING_POINT_BUFFER];

  size_t len;

  str_charset=cs;

  if (decimals >= NOT_FIXED_DEC)

  {

    len= internal::my_gcvt(num, internal::MY_GCVT_ARG_DOUBLE, sizeof(buff) - 1, buff, NULL);

    copy(buff, len, cs);

    return;

  }

  len= internal::my_fcvt(num, decimals, buff, NULL);

  copy(buff, len, cs);

}

void String::copy()

{

  if (!alloced)

  {

    Alloced_length=0;				// Force realloc

    realloc(str_length);

  }

}

void String::copy(const String &str)

{

  alloc(str.str_length);

  str_length=str.str_length;

  memmove(Ptr, str.Ptr, str_length);		// May be overlapping

  Ptr[str_length]=0;

  str_charset=str.str_charset;

}

void String::copy(const std::string& arg, const charset_info_st * const cs)	// Allocate new string

{

  alloc(arg.size());

  if ((str_length= arg.size()))

    memcpy(Ptr, arg.c_str(), arg.size());

  Ptr[arg.size()]= 0;

  str_charset= cs;

}

void String::copy(const char *str,size_t arg_length, const charset_info_st* cs)

{

  alloc(arg_length);

  if ((str_length=arg_length))

    memcpy(Ptr,str,arg_length);

  Ptr[arg_length]=0;

  str_charset=cs;

}

/*

  Checks that the source string can be just copied to the destination string

  without conversion.

  SYNPOSIS

  needs_conversion()

  arg_length		Length of string to copy.

  from_cs		Character set to copy from

  to_cs			Character set to copy to

  size_t *offset	Returns number of unaligned characters.

  RETURN

   0  No conversion needed

   1  Either character set conversion or adding leading  zeros

      (e.g. for UCS-2) must be done

  NOTE

  to_cs may be NULL for "no conversion" if the system variable

  character_set_results is NULL.

*/

bool String::needs_conversion(size_t arg_length, const charset_info_st* from_cs, const charset_info_st* to_cs)

{

  if (!to_cs ||

      to_cs == &my_charset_bin ||

      to_cs == from_cs ||

      my_charset_same(from_cs, to_cs) ||

      (from_cs == &my_charset_bin && not (arg_length % to_cs->mbminlen)))

    return false;

  return true;

}

/*

  Set a string to the value of a latin1-string, keeping the original charset

  SYNOPSIS

    copy_or_set()

    str			String of a simple charset (latin1)

    arg_length		Length of string

  IMPLEMENTATION

    If string object is of a simple character set, set it to point to the

    given string.

    If not, make a copy and convert it to the new character set.

  RETURN

    0	ok

    1	Could not allocate result buffer

*/

void String::set_ascii(const char *str, size_t arg_length)

{

  if (str_charset->mbminlen == 1)

  {

    set(str, arg_length, str_charset);

    return;

  }

  copy(str, arg_length, str_charset);

}

void String::append(const String &s)

{

  if (s.length())

  {

    realloc(str_length+s.length());

    memcpy(Ptr+str_length,s.ptr(),s.length());

    str_length+=s.length();

  }

}

/*

  Append an ASCII string to the a string of the current character set

*/

void String::append(const char *s,size_t arg_length)

{

  if (arg_length == 0)

    return;

  /*

    For an ASCII compatinble string we can just append.

  */

  realloc(str_length+arg_length);

  memcpy(Ptr +str_length, s, arg_length);

  str_length+=arg_length;

}

/*

  Append a 0-terminated ASCII string

*/

void String::append(const char *s)

{

  append(s, strlen(s));

}

void String::append_with_prefill(const char *s,size_t arg_length, size_t full_length, char fill_char)

{

  int t_length= arg_length > full_length ? arg_length : full_length;

  realloc(str_length + t_length);

  t_length= full_length - arg_length;

  if (t_length > 0)

  {

    memset(Ptr+str_length, fill_char, t_length);

    str_length=str_length + t_length;

  }

  append(s, arg_length);

}

size_t String::numchars()

{

  return str_charset->cset->numchars(str_charset, Ptr, Ptr+str_length);

}

int String::charpos(int i,size_t offset)

{

  if (i <= 0)

    return i;

  return str_charset->cset->charpos(str_charset,Ptr+offset,Ptr+str_length,i);

}

int String::strstr(const String &s,size_t offset)

{

  if (s.length() + offset <= str_length)

  {

    if (!s.length())

      return ((int) offset);	// Empty string is always found

    const char *str = Ptr+offset;

    const char *search=s.ptr();

    const char *last=Ptr+str_length-s.length()+1;

    const char *search_end=s.ptr()+s.length();

skip:

    while (str != last)

    {

      if (*str++ == *search)

      {

        const char* i= str; 

        const char* j= search + 1;

        while (j != search_end)

          if (*i++ != *j++) goto skip;

        return (int) (str - Ptr) - 1;

      }

    }

  }

  return -1;

}

/*

** Search string from end. Offset is offset to the end of string

*/

int String::strrstr(const String &s,size_t offset)

{

  if (s.length() <= offset && offset <= str_length)

  {

    if (!s.length())

      return offset;				// Empty string is always found

    const char *str = Ptr+offset-1;

    const char *search=s.ptr()+s.length()-1;

    const char *last=Ptr+s.length()-2;

    const char *search_end=s.ptr()-1;

skip:

    while (str != last)

    {

      if (*str-- == *search)

      {

        const char* i= str; 

        const char* j= search-1;

        while (j != search_end)

          if (*i-- != *j--) goto skip;

        return (int) (i-Ptr) + 1;

      }

    }

  }

  return -1;

}

/*

  Replace substring with string

  If wrong parameter or not enough memory, do nothing

*/

void String::replace(size_t offset,size_t arg_length,const String &to)

{

  replace(offset,arg_length,to.ptr(),to.length());

}

void String::replace(size_t offset,size_t arg_length,

                     const char *to, size_t to_length)

{

  long diff = (long) to_length-(long) arg_length;

  if (offset+arg_length <= str_length)

  {

    if (diff < 0)

    {

      if (to_length)

	memcpy(Ptr+offset,to,to_length);

      memmove(Ptr+offset+to_length, Ptr+offset+arg_length,

              str_length-offset-arg_length);

    }

    else

    {

      if (diff)

      {

	realloc(str_length+(size_t) diff);

	internal::bmove_upp((unsigned char*) Ptr+str_length+diff,

                            (unsigned char*) Ptr+str_length,

                            str_length-offset-arg_length);

      }

      if (to_length)

	memcpy(Ptr+offset,to,to_length);

    }

    str_length+=(size_t) diff;

  }

}

/*

  Compare strings according to collation, without end space.

  SYNOPSIS

    sortcmp()

    s		First string

    t		Second string

    cs		Collation

  NOTE:

    Normally this is case sensitive comparison

  RETURN

  < 0	s < t

  0	s == t

  > 0	s > t

*/

int sortcmp(const String *s,const String *t, const charset_info_st * const cs)

{

 return cs->coll->strnncollsp(cs,

                              (unsigned char *) s->ptr(),s->length(),

                              (unsigned char *) t->ptr(),t->length(), 0);

}

/*

  Compare strings byte by byte. End spaces are also compared.

  SYNOPSIS

    stringcmp()

    s		First string

    t		Second string

  NOTE:

    Strings are compared as a stream of unsigned chars

  RETURN

  < 0	s < t

  0	s == t

  > 0	s > t

*/

int stringcmp(const String *s,const String *t)

{

  size_t s_len= s->length(), t_len= t->length(), len= min(s_len,t_len);

  int cmp= memcmp(s->ptr(), t->ptr(), len);

  return (cmp) ? cmp : (int) (s_len - t_len);

}

String *copy_if_not_alloced(String *to,String *from,size_t from_length)

{

  if (from->Alloced_length >= from_length)

    return from;

  if (from->alloced || !to || from == to)

  {

    (void) from->realloc(from_length);

    return from;

  }

  to->realloc(from_length);

  if ((to->str_length= min(from->str_length,from_length)))

    memcpy(to->Ptr,from->Ptr,to->str_length);

  to->str_charset=from->str_charset;

  return to;

}

/****************************************************************************

  Help functions

****************************************************************************/

/*

  copy a string,

  with optional character set conversion,

  with optional left padding (for binary -> UCS2 conversion)

  SYNOPSIS

    well_formed_copy_nchars()

    to			     Store result here

    to_length                Maxinum length of "to" string

    to_cs		     Character set of "to" string

    from		     Copy from here

    from_length		     Length of from string

    from_cs		     From character set

    nchars                   Copy not more that nchars characters

    well_formed_error_pos    Return position when "from" is not well formed

                             or NULL otherwise.

    cannot_convert_error_pos Return position where a not convertable

                             character met, or NULL otherwise.

    from_end_pos             Return position where scanning of "from"

                             string stopped.

  NOTES

  RETURN

    length of bytes copied to 'to'

*/

size_t

well_formed_copy_nchars(const charset_info_st * const to_cs,

                        char *to, size_t to_length,

                        const charset_info_st * const from_cs,

                        const char *from, size_t from_length,

                        size_t nchars,

                        const char **well_formed_error_pos,

                        const char **cannot_convert_error_pos,

                        const char **from_end_pos)

{

  size_t res;

  assert((to_cs == &my_charset_bin) ||

         (from_cs == &my_charset_bin) ||

         (to_cs == from_cs) ||

         my_charset_same(from_cs, to_cs));

  if (to_length < to_cs->mbminlen || !nchars)

  {

    *from_end_pos= from;

    *cannot_convert_error_pos= NULL;

    *well_formed_error_pos= NULL;

    return 0;

  }

  if (to_cs == &my_charset_bin)

  {

    res= min(min(nchars, to_length), from_length);

    memmove(to, from, res);

    *from_end_pos= from + res;

    *well_formed_error_pos= NULL;

    *cannot_convert_error_pos= NULL;

  }

  else

  {

    int well_formed_error;

    size_t from_offset;

    if ((from_offset= (from_length % to_cs->mbminlen)) &&

        (from_cs == &my_charset_bin))

    {

      /*

        Copying from BINARY to UCS2 needs to prepend zeros sometimes:

        INSERT INTO t1 (ucs2_column) VALUES (0x01);

        0x01 -> 0x0001

      */

      size_t pad_length= to_cs->mbminlen - from_offset;

      memset(to, 0, pad_length);

      memmove(to + pad_length, from, from_offset);

      nchars--;

      from+= from_offset;

      from_length-= from_offset;

      to+= to_cs->mbminlen;

      to_length-= to_cs->mbminlen;

    }

    set_if_smaller(from_length, to_length);

    res= to_cs->cset->well_formed_len(to_cs, from, from + from_length,

                                      nchars, &well_formed_error);

    memmove(to, from, res);

    *from_end_pos= from + res;

    *well_formed_error_pos= well_formed_error ? from + res : NULL;

    *cannot_convert_error_pos= NULL;

    if (from_offset)

      res+= to_cs->mbminlen;

  }

  return res;

}

void String::print(String& str) const

{

  const char* last= Ptr + str_length;

  for (const char* st= Ptr; st < last; st++)

  {

    unsigned char c= *st;

    switch (c)

    {

    case '\\':

      str.append("\\\\", sizeof("\\\\")-1);

      break;

    case '\0':

      str.append("\\0", sizeof("\\0")-1);

      break;

    case '\'':

      str.append("\\'", sizeof("\\'")-1);

      break;

    case '\n':

      str.append("\\n", sizeof("\\n")-1);

      break;

    case '\r':

      str.append("\\r", sizeof("\\r")-1);

      break;

    case '\032': // Ctrl-Z

      str.append("\\Z", sizeof("\\Z")-1);

      break;

    default:

      str.append(c);

    }

  }

}

/*

  Quote the given identifier.

  If the given identifier is empty, it will be quoted.

  SYNOPSIS

  append_identifier()

  name                  the identifier to be appended

  name_length           length of the appending identifier

*/

/* Factor the extern out */

extern const charset_info_st *system_charset_info;

void String::append_identifier(const char *name, size_t in_length)

{

  // The identifier must be quoted as it includes a quote character or it's a keyword

  reserve(in_length * 2 + 2);

  const char quote_char= '`';

  append(&quote_char, 1);

  for (const char* name_end= name+in_length ; name < name_end ; name+= in_length)

  {

    unsigned char chr= (unsigned char) *name;

    in_length= my_mbcharlen(system_charset_info, chr);

    /*

      my_mbcharlen can return 0 on a wrong multibyte

      sequence. It is possible when upgrading from 4.0,

      and identifier contains some accented characters.

      The manual says it does not work. So we'll just

      change length to 1 not to hang in the endless loop.

    */

    if (!in_length)

      in_length= 1;

    if (in_length == 1 && chr == (unsigned char) quote_char)

      append(&quote_char, 1);

    append(name, in_length);

  }

  append(&quote_char, 1);

}

void String::append_identifier(str_ref v)

{

  append_identifier(v.data(), v.size());

}