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/* Copyright (C) 2003 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 Street, Fifth Floor, Boston, MA 02110-1301, USA */
#ifndef __BUFFER_HPP_INCLUDED__
#define __BUFFER_HPP_INCLUDED__
#include <ndb_global.h>
/* This class represents a buffer of binary data, where you can append
* data at the end, and later read the entire bunch.
* It will take care of the hairy details of realloc()ing the space
* for you
*/
class UtilBuffer {
public:
UtilBuffer() { data = NULL; len = 0; alloc_size = 0; };
~UtilBuffer() { if(data) free(data); data = NULL; len = 0; alloc_size = 0; };
int reallocate(size_t newsize) {
if(newsize < len) {
errno = EINVAL;
return -1;
}
void *newdata;
if((newdata = realloc(data, newsize)) == NULL) {
errno = ENOMEM;
return -1;
}
alloc_size = newsize;
data = newdata;
return 0;
};
int grow(size_t l) {
if(l > alloc_size)
return reallocate(l);
return 0;
};
int append(const void *d, size_t l) {
int ret;
ret = grow(len+l);
if(ret != 0)
return ret;
memcpy((char *)data+len, d, l);
len+=l;
return 0;
};
void * append(size_t l){
if(grow(len+l) != 0)
return 0;
void * ret = (char*)data+len;
len += l;
return ret;
}
int assign(const void * d, size_t l) {
/* Free the old data only after copying, in case d==data. */
void *old_data= data;
data = NULL;
len = 0;
alloc_size = 0;
int ret= append(d, l);
if (old_data)
free(old_data);
return ret;
}
void clear() {
len = 0;
}
int length() const { return len; }
void *get_data() const { return data; }
bool empty () const { return len == 0; }
private:
void *data; /* Pointer to data storage */
size_t len; /* Size of the stored data */
size_t alloc_size; /* Size of the allocated space,
* i.e. len can grow to this size */
};
#endif /* !__BUFFER_HPP_INCLUDED__ */
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