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/* Copyright (C) 2004 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 */
#if defined(__GNUC__) && defined(USE_PRAGMA_IMPLEMENTATION)
#pragma implementation
#endif
#include "buffer.h"
#include <m_string.h>
const uint Buffer::BUFFER_INITIAL_SIZE= 4096;
const uint Buffer::MAX_BUFFER_SIZE= 16777216;
/*
Puts the given string to the buffer.
SYNOPSIS
append()
position start position in the buffer
string string to be put in the buffer
len_arg the length of the string. This way we can avoid some
strlens.
DESCRIPTION
The method puts a string into the buffer, starting from position .
In the case when the buffer is too small it reallocs the buffer. The
total size of the buffer is restricted with 16.
RETURN
0 - ok
1 - got an error in reserve()
*/
int Buffer::append(size_t position, const char *string, size_t len_arg)
{
if (reserve(position, len_arg))
return 1;
strnmov((char*) buffer + position, string, len_arg);
return 0;
}
/*
Checks whether the current buffer size is ok to put a string of the length
"len_arg" starting from "position" and reallocs it if no.
SYNOPSIS
reserve()
position the number starting byte on the buffer to store a buffer
len_arg the length of the string.
DESCRIPTION
The method checks whether it is possible to put a string of the "len_arg"
length into the buffer, starting from "position" byte. In the case when the
buffer is too small it reallocs the buffer. The total size of the buffer is
restricted with 16 Mb.
RETURN
0 - ok
1 - realloc error or we have come to the 16Mb barrier
*/
int Buffer::reserve(size_t position, size_t len_arg)
{
if (position + len_arg >= MAX_BUFFER_SIZE)
goto err;
if (position + len_arg >= buffer_size)
{
buffer= (uchar*) my_realloc(buffer,
min(MAX_BUFFER_SIZE,
max((uint) (buffer_size*1.5),
position + len_arg)), MYF(0));
if (!(buffer))
goto err;
buffer_size= (size_t) (buffer_size*1.5);
}
return 0;
err:
error= 1;
return 1;
}
int Buffer::get_size()
{
return (uint) buffer_size;
}
int Buffer::is_error()
{
return error;
}
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