mariadb/sql/sql_string.h
2011-05-12 14:30:34 +03:00

466 lines
14 KiB
C++

#ifndef MYSQL_SQL_STRING_H_INCLUDED
#define MYSQL_SQL_STRING_H_INCLUDED
/* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/* This file is originally from the mysql distribution. Coded by monty */
#ifdef USE_PRAGMA_INTERFACE
#pragma interface /* gcc class implementation */
#endif
#ifndef NOT_FIXED_DEC
#define NOT_FIXED_DEC 31
#endif
#ifdef MYSQL_CLIENT
#error Attempt to use server-side sql_string on client. Use client/sql_string.h
#endif
class String;
int sortcmp(const String *a,const String *b, CHARSET_INFO *cs);
String *copy_if_not_alloced(String *a,String *b,uint32 arg_length);
uint32 copy_and_convert(char *to, uint32 to_length, CHARSET_INFO *to_cs,
const char *from, uint32 from_length,
CHARSET_INFO *from_cs, uint *errors);
uint32 well_formed_copy_nchars(CHARSET_INFO *to_cs,
char *to, uint to_length,
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(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,
CHARSET_INFO *from_cs, size_t nbytes= 0);
class String
{
char *Ptr;
uint32 str_length,Alloced_length, extra_alloc;
bool alloced;
CHARSET_INFO *str_charset;
public:
String()
{
Ptr=0; str_length=Alloced_length=extra_alloc=0; alloced=0;
str_charset= &my_charset_bin;
}
String(uint32 length_arg)
{
alloced=0; Alloced_length= extra_alloc= 0; (void) real_alloc(length_arg);
str_charset= &my_charset_bin;
}
String(const char *str, CHARSET_INFO *cs)
{
Ptr=(char*) str; str_length= (uint32) strlen(str);
Alloced_length= extra_alloc= 0; alloced=0;
str_charset=cs;
}
/*
NOTE: If one intend to use the c_ptr() method, the following two
contructors need the size of memory for STR to be at least LEN+1 (to make
room for zero termination).
*/
String(const char *str,uint32 len, CHARSET_INFO *cs)
{
Ptr=(char*) str; str_length=len; Alloced_length= extra_alloc=0; alloced=0;
str_charset=cs;
}
String(char *str,uint32 len, CHARSET_INFO *cs)
{
Ptr=(char*) str; Alloced_length=str_length=len; extra_alloc= 0; alloced=0;
str_charset=cs;
}
String(const String &str)
{
Ptr=str.Ptr ; str_length=str.str_length ;
Alloced_length=str.Alloced_length; extra_alloc= 0; 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(CHARSET_INFO *charset_arg)
{ str_charset= charset_arg; }
inline CHARSET_INFO *charset() const { return str_charset; }
inline uint32 length() const { return str_length;}
inline uint32 alloced_length() const { return Alloced_length;}
inline uint32 extra_allocation() const { return extra_alloc;}
inline char& operator [] (uint32 i) const { return Ptr[i]; }
inline void length(uint32 len) { str_length=len ; }
inline void extra_allocation(uint32 len) { extra_alloc= 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;
}
void set(String &str,uint32 offset,uint32 arg_length)
{
DBUG_ASSERT(&str != this);
free();
Ptr=(char*) str.ptr()+offset; str_length=arg_length;
if (str.Alloced_length)
Alloced_length=str.Alloced_length-offset;
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, CHARSET_INFO *cs)
{
free();
Ptr=(char*) str; str_length=Alloced_length=arg_length;
str_charset=cs;
}
inline void set(const char *str,uint32 arg_length, CHARSET_INFO *cs)
{
free();
Ptr=(char*) str; str_length=arg_length;
str_charset=cs;
}
bool set_ascii(const char *str, uint32 arg_length);
inline void set_quick(char *str,uint32 arg_length, 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, CHARSET_INFO *cs);
bool set(longlong num, CHARSET_INFO *cs)
{ return set_int(num, false, cs); }
bool set(ulonglong num, CHARSET_INFO *cs)
{ return set_int((longlong)num, true, cs); }
bool set_real(double num,uint decimals, CHARSET_INFO *cs);
/* Move handling of buffer from some other object to String */
void reassociate(char *ptr, uint32 length, uint32 alloced_length,
CHARSET_INFO *cs)
{
free();
Ptr= ptr;
str_length= length;
Alloced_length= alloced_length;
str_charset= cs;
alloced= ptr != 0;
}
/*
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()
{
Ptr[str_length--]= '\0';
}
inline void free()
{
if (alloced)
{
alloced=0;
my_free(Ptr,MYF(0));
}
Alloced_length= extra_alloc= 0;
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 realloc_with_extra(uint32 arg_length)
{
if (extra_alloc < 4096)
extra_alloc= extra_alloc*2+128;
return realloc(arg_length + extra_alloc);
}
bool realloc_with_extra_if_needed(uint32 arg_length)
{
if (arg_length < Alloced_length)
return 0;
return realloc_with_extra(arg_length);
}
inline void shrink(uint32 arg_length) // Shrink buffer
{
if (ALIGN_SIZE(arg_length+1) < 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() { 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;
}
return *this;
}
bool copy(); // Alloc string if not alloced
bool copy(const String &s); // Allocate new string
bool copy(const char *s,uint32 arg_length, CHARSET_INFO *cs); // Allocate new string
static bool needs_conversion(uint32 arg_length,
CHARSET_INFO *cs_from, CHARSET_INFO *cs_to,
uint32 *offset);
bool copy_aligned(const char *s, uint32 arg_length, uint32 offset,
CHARSET_INFO *cs);
bool set_or_copy_aligned(const char *s, uint32 arg_length, CHARSET_INFO *cs);
bool copy(const char*s,uint32 arg_length, CHARSET_INFO *csfrom,
CHARSET_INFO *csto, uint *errors);
void move(String &s)
{
free();
Ptr=s.Ptr ; str_length=s.str_length ; Alloced_length=s.Alloced_length;
extra_alloc= s.extra_alloc;
alloced= s.alloced;
s.alloced= 0;
}
bool append(const String &s);
bool append(const char *s);
bool append(const char *s,uint32 arg_length);
bool append(const char *s,uint32 arg_length, CHARSET_INFO *cs);
bool append(IO_CACHE* file, uint32 arg_length);
bool append_with_prefill(const char *s, uint32 arg_length,
uint32 full_length, char fill_char);
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_with_extra(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, 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);
friend class Field;
uint32 numchars();
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)
{
qs_append(str, (uint32)strlen(str));
}
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)
{
qs_append((ulonglong)i);
}
void qs_append(ulong i)
{
qs_append((ulonglong)i);
}
void qs_append(ulonglong 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;
}
};
static inline bool check_if_only_end_space(CHARSET_INFO *cs, char *str,
char *end)
{
return str+ cs->cset->scan(cs, str, end, MY_SEQ_SPACES) == end;
}
#endif // MYSQL_SQL_STRING_H_INCLUDED