122 lines
2.9 KiB
C
122 lines
2.9 KiB
C
/* ****************************************************************************
|
|
* stream/builtin/csum32.c -- built-in stream for making a 32-bit checksum.
|
|
* Copyright (C) 2017 Thomas "Cakeisalie5" Touhey <thomas@touhey.fr>
|
|
*
|
|
* This file is part of libcasio.
|
|
* libcasio 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 3.0 of the License,
|
|
* or (at your option) any later version.
|
|
*
|
|
* libcasio 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 libcasio; if not, see <http://www.gnu.org/licenses/>.
|
|
* ************************************************************************* */
|
|
#include "builtin.h"
|
|
|
|
/* ---
|
|
* Cookie structure.
|
|
* --- */
|
|
|
|
struct thecookie {
|
|
casio_stream_t *_stream;
|
|
casio_uint32_t *_checksum;
|
|
};
|
|
|
|
/* ---
|
|
* Callbacks.
|
|
* --- */
|
|
|
|
/**
|
|
* csum32_read:
|
|
* Read from this stream.
|
|
*
|
|
* @arg cookie the cookie.
|
|
* @arg data the data pointer.
|
|
* @arg size the data size.
|
|
* @arg timeout the timeout.
|
|
* @return the error code (0 if ok).
|
|
*/
|
|
|
|
CASIO_LOCAL int csum32_read(struct thecookie *cookie,
|
|
unsigned char *dest, size_t size, unsigned int timeout)
|
|
{
|
|
int err;
|
|
|
|
/* Make the call. */
|
|
|
|
err = casio_read(cookie->_stream, dest, size, timeout);
|
|
if (err) return (err);
|
|
|
|
/* Make the checksum. */
|
|
|
|
*cookie->_checksum = casio_checksum32(dest, size, *cookie->_checksum);
|
|
return (0);
|
|
}
|
|
|
|
/**
|
|
* csum32_close:
|
|
* Close the stream.
|
|
*
|
|
* @arg cookie the cookie.
|
|
* @return the error code (0 if ok).
|
|
*/
|
|
|
|
CASIO_LOCAL int csum32_close(struct thecookie *cookie)
|
|
{
|
|
casio_free(cookie);
|
|
return (0);
|
|
}
|
|
|
|
/* Callbacks. */
|
|
|
|
CASIO_LOCAL casio_streamfuncs_t const csum32_callbacks = {
|
|
(casio_stream_close_t *)csum32_close,
|
|
(casio_stream_read_t *)csum32_read,
|
|
NULL, NULL,
|
|
NULL, NULL, NULL, NULL
|
|
};
|
|
|
|
/* ---
|
|
* Main functions.
|
|
* --- */
|
|
|
|
/**
|
|
* casio_open_csum32:
|
|
* Open a 32-bit checksum stream.
|
|
*
|
|
* @arg stream the stream to make.
|
|
* @arg original the original stream.
|
|
* @arg csum the checksum pointer.
|
|
* @return the error code (0 if ok).
|
|
*/
|
|
|
|
int CASIO_EXPORT casio_open_csum32(casio_stream_t **stream,
|
|
casio_stream_t *original, casio_uint32_t *csum)
|
|
{
|
|
struct thecookie *cookie = NULL;
|
|
casio_openmode_t openmode;
|
|
|
|
if (!casio_isreadable(original))
|
|
return (casio_error_op);
|
|
|
|
/* Allocate the cookie. */
|
|
|
|
cookie = casio_alloc(1, sizeof(struct thecookie));
|
|
if (!cookie) return (casio_error_alloc);
|
|
|
|
/* Fill the cookie. */
|
|
|
|
cookie->_stream = original;
|
|
cookie->_checksum = csum;
|
|
|
|
/* Initialize and return da stream. */
|
|
|
|
openmode = casio_get_openmode(original) & CASIO_OPENMODE_READ;
|
|
return (casio_open_stream(stream, openmode, cookie, &csum32_callbacks, 0));
|
|
}
|