Commit e2953184 authored by Niels Möller's avatar Niels Möller

New files, implementing a bare-bones string

stream.

Rev: src/nettle/buffer.c:1.1
Rev: src/nettle/buffer.h:1.1
parent df4e07bd
/* buffer.c
*
* A bare-bones string stream.
*/
/* nettle, low-level cryptographics library
*
* Copyright (C) 2002 Niels Mller
*
* The nettle library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or (at your
* option) any later version.
*
* The nettle 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with the nettle library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
* MA 02111-1307, USA.
*/
#include "buffer.h"
#include <stdlib.h>
#include <string.h>
static int
grow_realloc(struct nettle_buffer *buffer,
unsigned length)
{
if (!length)
{
realloc(buffer->contents, 0);
buffer->contents = NULL;
buffer->alloc = 0;
buffer->size = 0;
return 1;
}
else
{
unsigned alloc = buffer->alloc * 2 + length + 100;
uint8_t *p = realloc(buffer->contents, alloc);
if (!p)
return 0;
buffer->contents = p;
buffer->alloc = alloc;
return 1;
}
}
void
nettle_buffer_init(struct nettle_buffer *buffer)
{
buffer->contents = NULL;
buffer->alloc = 0;
buffer->grow = grow_realloc;
buffer->size = 0;
}
void
nettle_buffer_init_size(struct nettle_buffer *buffer,
unsigned length, uint8_t *space)
{
buffer->contents = space;
buffer->alloc = length;
buffer->grow = NULL;
buffer->size = 0;
}
void
nettle_buffer_clear(struct nettle_buffer *buffer)
{
NETTLE_BUFFER_GROW(buffer, 0);
}
uint8_t *
nettle_buffer_space(struct nettle_buffer *buffer,
unsigned length)
{
uint8_t *p;
if (buffer->size + length > buffer->alloc)
if (!NETTLE_BUFFER_GROW(buffer, length))
return NULL;
p = buffer->contents + buffer->size;
buffer->size += length;
return p;
}
int
nettle_buffer_write(struct nettle_buffer *buffer,
unsigned length, const uint8_t *data)
{
uint8_t *p = nettle_buffer_space(buffer, length);
if (p)
{
memcpy(p, data, length);
return 1;
}
else
return 0;
}
/* buffer.h
*
* A bare-bones string stream.
*/
/* nettle, low-level cryptographics library
*
* Copyright (C) 2002 Niels Möller
*
* The nettle library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or (at your
* option) any later version.
*
* The nettle 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with the nettle library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
* MA 02111-1307, USA.
*/
#ifndef NETTLE_BUFFER_H_INCLUDED
#define NETTLE_BUFFER_H_INCLUDED
#include <inttypes.h>
struct nettle_buffer
{
uint8_t *contents;
/* Allocated size */
unsigned alloc;
/* If GROW is NULL, no reallocation is done. Otherwise, it should be
* a function that reallocates the contents to at least the size SIZE
* + LENGTH. It can return 0 if allocation fails. Furthermore, if
* GROW is called with LENGTH = 0, it should deallocate the buffer
* space. */
int (*grow)(struct nettle_buffer *buffer, unsigned length);
/* Current size */
unsigned size;
};
/* Initializes a buffer that uses plain realloc */
void
nettle_buffer_init(struct nettle_buffer *buffer);
/* Initializes a buffer of fix size */
void
nettle_buffer_init_size(struct nettle_buffer *buffer,
unsigned length, uint8_t *space);
void
nettle_buffer_clear(struct nettle_buffer *buffer);
#define NETTLE_BUFFER_GROW(o, l) ((o)->grow && (o)->grow((o), l))
#define NETTLE_BUFFER_PUTC(buffer, c) \
( (((buffer)->size < (buffer)->alloc) || NETTLE_BUFFER_GROW((buffer), 1)) \
&& ((buffer)->contents[(buffer)->size++] = (c), 1) )
int
nettle_buffer_write(struct nettle_buffer *buffer,
unsigned length, const uint8_t *data);
/* Like nettle_buffer_write, but instead of copying data to the
* buffer, it returns a pointer to the area where the caller can copy
* the data. The pointer is valid only until the next call that can
* reallocate the buffer. */
uint8_t *
nettle_buffer_space(struct nettle_buffer *buffer,
unsigned length);
#endif /* NETTLE_BUFFER_H_INCLUDED */
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