[FFmpeg-devel] [PATCH 1/7] avutil/uuid: add utility library for manipulating UUIDs as specified in RFC 4122

[Lynne]

22 Feb 2022, 14:01 by zane at zanevaniperen.com:

> Loosely based on libuuid
>
> Co-authored-by: Pierre-Anthony Lemieux <pal at palemieux.com>
> Signed-off-by: Pierre-Anthony Lemieux <pal at palemieux.com>
> Signed-off-by: Zane van Iperen <zane at zanevaniperen.com>
> --- 
> +int av_uuid_parse(const char *in, AVUUID uu)
> +{
> +    size_t len = strlen(in);
> +    if (len != 36)
> +        return -1;
> +
> +    return av_uuid_parse_range(in, in + len, uu);
> +}
> +
> +int av_uuid_parse_range(const char *in_start, const char *in_end, AVUUID uu)
> +{
> +    int i;
> +    const char *cp;
> +    char buf[3];
> +
> +    if ((in_end - in_start) != 36)
> +        return -1;
> +
> +    for (i = 0, cp = in_start; i < 36; i++, cp++) {
> +
> +        if (i == 8 || i == 13 || i == 18 || i == 23) {
> +            if (*cp == '-')
> +                continue;
> +            return AVERROR(EINVAL);
> +        }
> +
> +        if (!av_isxdigit(*cp))
> +            return AVERROR(EINVAL);
> +    }
> +
> +    buf[2] = '\0';
> +    for (i = 0, cp = in_start; i < 16; i++) {
> +
> +        if (i == 4 || i == 6 || i == 8 || i == 10)
> +            cp++;
> +
> +        buf[0] = *cp++;
>

What's up with all those whitespace newlines?


> +        buf[1] = *cp++;
> +
> +        errno = 0;
> +        uu[i] = strtoul(buf, NULL, 16);
> +        if (errno)
> +            return AVERROR(errno);
> +    }
> +
> +    return 0;
> +}
> +
> +void av_uuid_unparse(const AVUUID uuid, char *out)
> +{
> +    static char const hexdigits_lower[16] = "0123456789abcdef";
> +
> +    char *p = out;
> +
> +    for (int i = 0; i < 16; i++) {
> +        size_t tmp;
> +
> +        if (i == 4 || i == 6 || i == 8 || i == 10) {
> +            *p++ = '-';
> +        }
>

Code style


> +
> +        tmp = uuid[i];
> +        *p++ = hexdigits_lower[tmp >> 4];
> +        *p++ = hexdigits_lower[tmp & 15];
> +    }
> +
> +    *p = '\0';
> +}
> +
> +int av_uuid_urn_parse(const char *in, AVUUID uu)
> +{
> +    return av_uuid_parse(in + 9, uu);
> +}
> +
> +int av_uuid_equal(const AVUUID uu1, const AVUUID uu2)
> +{
> +    return memcmp(uu1, uu2, AV_UUID_LEN) == 0;
> +}
> +
> +void av_uuid_copy(AVUUID dest, const AVUUID src)
> +{
> +    memcpy(dest, src, AV_UUID_LEN);
> +}
> +
> +void av_uuid_nil_set(AVUUID uu)
> +{
> +    memset(uu, 0, AV_UUID_LEN);
> +}
> diff --git a/libavutil/uuid.h b/libavutil/uuid.h
> new file mode 100644
> index 0000000000..b5d8166898
> --- /dev/null
> +++ b/libavutil/uuid.h
> @@ -0,0 +1,167 @@
> +/*
> + * Copyright (c) 2022 Pierre-Anthony Lemieux <pal at palemieux.com>
> + *                    Zane van Iperen <zane at zanevaniperen.com>
> + *
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg 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.
> + *
> + * FFmpeg 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 FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +/*
> + * Copyright (C) 1996, 1997 Theodore Ts'o.
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, and the entire permission notice in its entirety,
> + *    including the disclaimer of warranties.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + *    notice, this list of conditions and the following disclaimer in the
> + *    documentation and/or other materials provided with the distribution.
> + * 3. The name of the author may not be used to endorse or promote
> + *    products derived from this software without specific prior
> + *    written permission.
> + *
> + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
> + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
> + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF
> + * WHICH ARE HEREBY DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE
> + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
> + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
> + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
> + * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
> + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
> + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
> + * USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH
> + * DAMAGE.
> + */
>

Why the double header in the header file? It doesn't contain
any libuuid code.