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/*
* $Id: pi-buffer.c,v 1.10 2006/10/12 14:21:22 desrod Exp $
*
* pi-buffer.c: simple data block management for variable data storage
*
* Copyright (c) 2004-2005, Florent Pillet.
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Library General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This library 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 Library
* General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "pi-buffer.h"
pi_buffer_t*
pi_buffer_new (size_t capacity)
{
pi_buffer_t* buf;
buf = (struct pi_buffer_t *) malloc (sizeof (struct pi_buffer_t));
if (buf == NULL)
return NULL;
if (capacity <= 0)
capacity = 16; /* allocating 0 byte is illegal - use a small value instead */
buf->data = (unsigned char *) malloc (capacity);
if (buf->data == NULL) {
free (buf);
return NULL;
}
buf->allocated = capacity;
buf->used = 0;
return buf;
}
pi_buffer_t*
pi_buffer_expect (pi_buffer_t *buf, size_t expect)
{
if ((buf->allocated - buf->used) >= expect)
return buf;
if (buf->data)
buf->data = (unsigned char *) realloc (buf->data, buf->used + expect);
else
buf->data = (unsigned char *) malloc (expect);
if (buf->data == NULL) {
buf->allocated = 0;
buf->used = 0;
return NULL;
}
buf->allocated = buf->used + expect;
return buf;
}
pi_buffer_t*
pi_buffer_append (pi_buffer_t *buf, const void *data, size_t len)
{
if (pi_buffer_expect (buf, len) == NULL)
return NULL;
memcpy (buf->data + buf->used, data, len);
buf->used += len;
return buf;
}
pi_buffer_t *
pi_buffer_append_buffer (pi_buffer_t *dest, const pi_buffer_t *src)
{
return pi_buffer_append (dest, src->data, src->used);
}
void
pi_buffer_clear (pi_buffer_t *buf)
{
buf->used = 0;
if (buf->allocated > (size_t)65535)
{
buf->data = (unsigned char *) realloc (buf->data, 65535);
buf->allocated = (buf->data == NULL) ? 0 : 65535;
}
}
void
pi_buffer_free (pi_buffer_t* buf)
{
if (buf) {
if (buf->data)
free (buf->data);
free (buf);
}
}
/* vi: set ts=8 sw=4 sts=4 noexpandtab: cin */
/* ex: set tabstop=4 expandtab: */
/* Local Variables: */
/* indent-tabs-mode: t */
/* c-basic-offset: 8 */
/* End: */