percona-server-5.6.51-91.0/sql/sql_string.h

#ifndef SQL_STRING_INCLUDED
#define SQL_STRING_INCLUDED

/* Copyright (c) 2000, 2015, 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, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   Without limiting anything contained in the foregoing, this file,
   which is part of C Driver for MySQL (Connector/C), is also subject to the
   Universal FOSS Exception, version 1.0, a copy of which can be found at
   http://oss.oracle.com/licenses/universal-foss-exception.

   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, version 2.0, 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 "m_ctype.h"                            /* my_charset_bin */
#include "my_sys.h"              /* alloc_root, my_free, my_realloc */
#include "m_string.h"                           /* TRASH */


/**
  A wrapper class for null-terminated constant strings.
  Constructors make sure that the position of the '\0' terminating byte
  in m_str is always in sync with m_length.

  This class must stay as small as possible as we often
  pass it and its descendants (such as Name_string) into functions
  using call-by-value evaluation.

  Don't add new members or virual methods into this class!
*/
class Simple_cstring
{
private:
  const char *m_str;
  size_t m_length;
protected:
  /**
    Initialize from a C string whose length is already known.
  */
  void set(const char *str_arg, size_t length_arg)
  {
    // NULL is allowed only with length==0
    DBUG_ASSERT(str_arg || length_arg == 0);
    // For non-NULL, make sure length_arg is in sync with '\0' terminator.
    DBUG_ASSERT(!str_arg || str_arg[length_arg] == '\0');
    m_str= str_arg;
    m_length= length_arg;
  }
public:
  Simple_cstring()
  {
    set(NULL, 0);
  }
  Simple_cstring(const char *str_arg, size_t length_arg)
  {
    set(str_arg, length_arg);
  }
  Simple_cstring(const LEX_STRING arg)
  {
    set(arg.str, arg.length);
  }
  void reset()
  {
    set(NULL, 0);
  }
  /**
    Set to a null-terminated string.
  */
  void set(const char *str)
  {
    set(str, str ? strlen(str) : 0);
  }
  /**
    Return string buffer.
  */
  const char *ptr() const { return m_str; }
  /**
    Check if m_ptr is set.
  */
  bool is_set() const { return m_str != NULL; }
  /**
    Return name length.
  */
  size_t length() const { return m_length; }
  /**
    Compare to another Simple_cstring.
  */
  bool eq_bin(const Simple_cstring other) const
  {
    return m_length == other.m_length &&
           memcmp(m_str, other.m_str, m_length) == 0;
  }
  /**
    Copy to the given buffer
  */
  void strcpy(char *buff) const
  {
    memcpy(buff, m_str, m_length);
    buff[m_length]= '\0';
  }
};


class String;
typedef struct charset_info_st CHARSET_INFO;
typedef struct st_io_cache IO_CACHE;
typedef struct st_mem_root MEM_ROOT;

int sortcmp(const String *a,const String *b, const CHARSET_INFO *cs);
String *copy_if_not_alloced(String *a,String *b,uint32 arg_length);
inline uint32 copy_and_convert(char *to, uint32 to_length,
                               const CHARSET_INFO *to_cs,
                               const char *from, uint32 from_length,
                               const CHARSET_INFO *from_cs, uint *errors)
{
  return my_convert(to, to_length, to_cs, from, from_length, from_cs, errors);
}
uint32 well_formed_copy_nchars(const CHARSET_INFO *to_cs,
                               char *to, uint to_length,
                               const CHARSET_INFO *from_cs,
                               const char *from, uint from_length,
                               uint nchars,
                               const char **well_formed_error_pos,
                               const char **cannot_convert_error_pos,
                               const char **from_end_pos);
size_t my_copy_with_hex_escaping(const CHARSET_INFO *cs,
                                 char *dst, size_t dstlen,
                                 const char *src, size_t srclen);
uint convert_to_printable(char *to, size_t to_len,
                          const char *from, size_t from_len,
                          const CHARSET_INFO *from_cs, size_t nbytes= 0);

class String
{
  char *Ptr;
  uint32 str_length,Alloced_length;
  bool alloced;
  const CHARSET_INFO *str_charset;
public:
  String()
  {
    Ptr=0; str_length=Alloced_length=0; alloced=0;
    str_charset= &my_charset_bin;
  }
  String(uint32 length_arg)
  {
    alloced=0; Alloced_length=0; (void) real_alloc(length_arg);
    str_charset= &my_charset_bin;
  }
  String(const char *str, const CHARSET_INFO *cs)
  {
    Ptr=(char*) str; str_length=(uint) strlen(str); Alloced_length=0; alloced=0;
    str_charset=cs;
  }
  String(const char *str,uint32 len, const CHARSET_INFO *cs)
  {
    Ptr=(char*) str; str_length=len; Alloced_length=0; alloced=0;
    str_charset=cs;
  }
  String(char *str,uint32 len, const CHARSET_INFO *cs)
  {
    Ptr=(char*) str; Alloced_length=str_length=len; alloced=0;
    str_charset=cs;
  }
  String(const String &str)
  {
    Ptr=str.Ptr ; str_length=str.str_length ;
    Alloced_length=str.Alloced_length; alloced=0;
    str_charset=str.str_charset;
  }
  static void *operator new(size_t size, MEM_ROOT *mem_root) throw ()
  { return (void*) alloc_root(mem_root, (uint) size); }
  static void operator delete(void *ptr_arg, size_t size)
  {
    (void) ptr_arg;
    (void) size;
    TRASH(ptr_arg, size);
  }
  static void operator delete(void *, MEM_ROOT *)
  { /* never called */ }
  ~String() { free(); }

  inline void set_charset(const CHARSET_INFO *charset_arg)
  { str_charset= charset_arg; }
  inline const CHARSET_INFO *charset() const { return str_charset; }
  inline uint32 length() const { return str_length;}
  inline uint32 alloced_length() const { return Alloced_length;}
  inline char& operator [] (uint32 i) const { return Ptr[i]; }
  inline void length(uint32 len) { str_length=len ; }
  inline bool is_empty() const { return (str_length == 0); }
  inline void mark_as_const() { Alloced_length= 0;}
  inline const char *ptr() const { return Ptr; }
  inline char *c_ptr()
  {
    DBUG_ASSERT(!alloced || !Ptr || !Alloced_length ||
                (Alloced_length >= (str_length + 1)));

    if (!Ptr || Ptr[str_length])		/* Should be safe */
      (void) realloc(str_length);
    return Ptr;
  }
  inline char *c_ptr_quick()
  {
    if (Ptr && str_length < Alloced_length)
      Ptr[str_length]=0;
    return Ptr;
  }
  inline char *c_ptr_safe()
  {
    if (Ptr && str_length < Alloced_length)
      Ptr[str_length]=0;
    else
      (void) realloc(str_length);
    return Ptr;
  }
  LEX_STRING lex_string() const
  {
    LEX_STRING lex_string = { (char*) ptr(), length() };
    return lex_string;
  }

  void set(String &str,uint32 offset,uint32 arg_length)
  {
    DBUG_ASSERT(&str != this);
    free();
    Ptr=(char*) str.ptr()+offset; str_length=arg_length; alloced=0;
    if (str.Alloced_length)
      Alloced_length=str.Alloced_length-offset;
    else
      Alloced_length=0;
    str_charset=str.str_charset;
  }


  /**
     Points the internal buffer to the supplied one. The old buffer is freed.
     @param str Pointer to the new buffer.
     @param arg_length Length of the new buffer in characters, excluding any
            null character.
     @param cs Character set to use for interpreting string data.
     @note The new buffer will not be null terminated.
  */
  inline void set(char *str,uint32 arg_length, const CHARSET_INFO *cs)
  {
    free();
    Ptr=(char*) str; str_length=Alloced_length=arg_length ; alloced=0;
    str_charset=cs;
  }
  inline void set(const char *str,uint32 arg_length, const CHARSET_INFO *cs)
  {
    free();
    Ptr=(char*) str; str_length=arg_length; Alloced_length=0 ; alloced=0;
    str_charset=cs;
  }
  bool set_ascii(const char *str, uint32 arg_length);
  inline void set_quick(char *str,uint32 arg_length, const CHARSET_INFO *cs)
  {
    if (!alloced)
    {
      Ptr=(char*) str; str_length=Alloced_length=arg_length;
    }
    str_charset=cs;
  }
  bool set_int(longlong num, bool unsigned_flag, const CHARSET_INFO *cs);
  bool set(longlong num, const CHARSET_INFO *cs)
  { return set_int(num, false, cs); }
  bool set(ulonglong num, const CHARSET_INFO *cs)
  { return set_int((longlong)num, true, cs); }
  bool set_real(double num,uint decimals, const CHARSET_INFO *cs);

  /*
    PMG 2004.11.12
    This is a method that works the same as perl's "chop". It simply
    drops the last character of a string. This is useful in the case
    of the federated storage handler where I'm building a unknown
    number, list of values and fields to be used in a sql insert
    statement to be run on the remote server, and have a comma after each.
    When the list is complete, I "chop" off the trailing comma

    ex.
      String stringobj;
      stringobj.append("VALUES ('foo', 'fi', 'fo',");
      stringobj.chop();
      stringobj.append(")");

    In this case, the value of string was:

    VALUES ('foo', 'fi', 'fo',
    VALUES ('foo', 'fi', 'fo'
    VALUES ('foo', 'fi', 'fo')

  */
  inline void chop()
  {
    str_length--;
    Ptr[str_length]= '\0';
    DBUG_ASSERT(strlen(Ptr) == str_length);
  }

  inline void free()
  {
    if (alloced)
    {
      alloced=0;
      Alloced_length=0;
      my_free(Ptr);
      Ptr=0;
      str_length=0;				/* Safety */
    }
  }
  inline bool alloc(uint32 arg_length)
  {
    if (arg_length < Alloced_length)
      return 0;
    return real_alloc(arg_length);
  }
  bool real_alloc(uint32 arg_length);			// Empties old string
  bool realloc(uint32 arg_length, bool force_on_heap= false);

  // Shrink the buffer, but only if it is allocated on the heap.
  inline void shrink(uint32 arg_length)
  {
    if (!is_alloced())
      return;
    if (arg_length < Alloced_length)
    {
      char *new_ptr;
      if (!(new_ptr=(char*) my_realloc(Ptr,arg_length,MYF(0))))
      {
	Alloced_length = 0;
	real_alloc(arg_length);
      }
      else
      {
	Ptr=new_ptr;
	Alloced_length=arg_length;
      }
    }
  }
  bool is_alloced() const { return alloced; }
  inline String& operator = (const String &s)
  {
    if (&s != this)
    {
      /*
        It is forbidden to do assignments like
        some_string = substring_of_that_string
       */
      DBUG_ASSERT(!s.uses_buffer_owned_by(this));
      free();
      Ptr=s.Ptr ; str_length=s.str_length ; Alloced_length=s.Alloced_length;
      str_charset=s.str_charset;
      alloced=0;
    }
    return *this;
  }
  /**
    Takeover the buffer owned by another string.
    "this" becames the owner of the buffer and
    is further responsible to free it.
    The string "s" is detouched from the buffer (cleared).

    @param s - a String object to steal buffer from.
  */
  inline void takeover(String &s)
  {
    DBUG_ASSERT(this != &s);
    // Make sure buffers of the two Strings do not overlap
    DBUG_ASSERT(!s.uses_buffer_owned_by(this));
    free();
    Ptr= s.Ptr;
    str_length= s.str_length;
    Alloced_length= s.Alloced_length;
    alloced= s.alloced;
    str_charset= s.str_charset;
    s.Ptr= NULL;
    s.Alloced_length= 0;
    s.str_length= 0;
    s.alloced= 0;
  }

  bool copy();					// Alloc string if not alloced
  bool copy(const String &s);			// Allocate new string
  // Allocate new string
  bool copy(const char *s,uint32 arg_length, const CHARSET_INFO *cs);
  static bool needs_conversion(uint32 arg_length,
  			       const CHARSET_INFO *cs_from, const CHARSET_INFO *cs_to,
			       uint32 *offset);
  static bool needs_conversion_on_storage(uint32 arg_length,
                                          const CHARSET_INFO *cs_from,
                                          const CHARSET_INFO *cs_to);
  bool copy_aligned(const char *s, uint32 arg_length, uint32 offset,
		    const CHARSET_INFO *cs);
  bool set_or_copy_aligned(const char *s, uint32 arg_length,
                           const CHARSET_INFO *cs);
  bool copy(const char*s,uint32 arg_length, const CHARSET_INFO *csfrom,
	    const CHARSET_INFO *csto, uint *errors);
  bool append(const String &s);
  bool append(const char *s);
  bool append(LEX_STRING *ls)
  {
    return append(ls->str, (uint32) ls->length);
  }
  bool append(Simple_cstring str)
  {
    return append(str.ptr(), static_cast<uint>(str.length()));
  }
  bool append(const char *s, uint32 arg_length);
  bool append(const char *s, uint32 arg_length, const CHARSET_INFO *cs);
  bool append_ulonglong(ulonglong val);
  bool append(IO_CACHE* file, uint32 arg_length);
  bool append_with_prefill(const char *s, uint32 arg_length,
			   uint32 full_length, char fill_char);
  bool append_parenthesized(long nr, int radix= 10);
  int strstr(const String &search,uint32 offset=0); // Returns offset to substring or -1
  int strrstr(const String &search,uint32 offset=0); // Returns offset to substring or -1
  bool replace(uint32 offset,uint32 arg_length,const char *to,uint32 length);
  bool replace(uint32 offset,uint32 arg_length,const String &to);
  inline bool append(char chr)
  {
    if (str_length < Alloced_length)
    {
      Ptr[str_length++]=chr;
    }
    else
    {
      if (realloc(str_length+1))
	return 1;
      Ptr[str_length++]=chr;
    }
    return 0;
  }
  bool fill(uint32 max_length,char fill);
  void strip_sp();
  friend int sortcmp(const String *a,const String *b, const CHARSET_INFO *cs);
  friend int stringcmp(const String *a,const String *b);
  friend String *copy_if_not_alloced(String *a,String *b,uint32 arg_length);
  uint32 numchars() const;
  int charpos(int i,uint32 offset=0);

  int reserve(uint32 space_needed)
  {
    return realloc(str_length + space_needed);
  }
  int reserve(uint32 space_needed, uint32 grow_by);
  /*
    The following append operations do NOT check alloced memory
    q_*** methods writes values of parameters itself
    qs_*** methods writes string representation of value
  */
  void q_append(const char c)
  {
    Ptr[str_length++] = c;
  }
  void q_append(const uint32 n)
  {
    int4store(Ptr + str_length, n);
    str_length += 4;
  }
  void q_append(double d)
  {
    float8store(Ptr + str_length, d);
    str_length += 8;
  }
  void q_append(double *d)
  {
    float8store(Ptr + str_length, *d);
    str_length += 8;
  }
  void q_append(const char *data, uint32 data_len)
  {
    memcpy(Ptr + str_length, data, data_len);
    str_length += data_len;
  }

  void write_at_position(int position, uint32 value)
  {
    int4store(Ptr + position,value);
  }

  void qs_append(const char *str, uint32 len);
  void qs_append(double d);
  void qs_append(double *d);
  inline void qs_append(const char c)
  {
     Ptr[str_length]= c;
     str_length++;
  }
  void qs_append(int i);
  void qs_append(uint i);

  /* Inline (general) functions used by the protocol functions */

  inline char *prep_append(uint32 arg_length, uint32 step_alloc)
  {
    uint32 new_length= arg_length + str_length;
    if (new_length > Alloced_length)
    {
      if (realloc(new_length + step_alloc))
        return 0;
    }
    uint32 old_length= str_length;
    str_length+= arg_length;
    return Ptr+ old_length;			/* Area to use */
  }

  inline bool append(const char *s, uint32 arg_length, uint32 step_alloc)
  {
    uint32 new_length= arg_length + str_length;
    if (new_length > Alloced_length && realloc(new_length + step_alloc))
      return TRUE;
    memcpy(Ptr+str_length, s, arg_length);
    str_length+= arg_length;
    return FALSE;
  }
  void print(String *print);

  /* Swap two string objects. Efficient way to exchange data without memcpy. */
  void swap(String &s);

  inline bool uses_buffer_owned_by(const String *s) const
  {
    return (s->alloced && Ptr >= s->Ptr && Ptr < s->Ptr + s->str_length);
  }
  bool is_ascii() const
  {
    if (length() == 0)
      return TRUE;
    if (charset()->mbminlen > 1)
      return FALSE;
    for (const char *c= ptr(), *end= c + length(); c < end; c++)
    {
      if (!my_isascii(*c))
        return FALSE;
    }
    return TRUE;
  }
  /**
    Make a zero-terminated copy of our value,allocated in the specified MEM_ROOT

    @param root         MEM_ROOT to allocate the result

    @return allocated string or NULL
  */
  char *dup(MEM_ROOT *root) const
  {
    if (str_length > 0 && Ptr[str_length - 1] == 0)
      return static_cast<char *>(memdup_root(root, Ptr, str_length));

    char *ret= static_cast<char*>(alloc_root(root, str_length + 1));
    if (ret != NULL)
    {
      memcpy(ret, Ptr, str_length);
      ret[str_length]= 0;
    }
    return ret;
  }
};


/**
  String class wrapper with a preallocated buffer of size buff_sz

  This class allows to replace sequences of:
     char buff[12345];
     String str(buff, sizeof(buff));
     str.length(0);
  with a simple equivalent declaration:
     StringBuffer<12345> str;
*/

template<size_t buff_sz>
class StringBuffer : public String
{
  char buff[buff_sz];

public:
  StringBuffer() : String(buff, buff_sz, &my_charset_bin) { length(0); }
  explicit StringBuffer(const CHARSET_INFO *cs) : String(buff, buff_sz, cs)
  {
    length(0);
  }
  StringBuffer(const char *str, size_t length, const CHARSET_INFO *cs)
    : String(buff, buff_sz, cs)
  {
    set(str, length, cs);
  }
};


static inline bool check_if_only_end_space(const CHARSET_INFO *cs, char *str,
                                           char *end)
{
  return str+ cs->cset->scan(cs, str, end, MY_SEQ_SPACES) == end;
}

bool
validate_string(const CHARSET_INFO *cs, const char *str, uint32 length,
                size_t *valid_length, bool *length_error);
#endif /* SQL_STRING_INCLUDED */