[vlc-devel] [PATCH 1/3] Add an Open Subtitles hash function

[Rémi Denis-Courmont]

Le lundi 20 avril 2015, 18:59:55 Hugo Beauzée-Luyssen a écrit :
> ---
>  include/vlc_hash.h | 31 +++++++++++++++++++++
>  src/Makefile.am    |  2 ++
>  src/libvlccore.sym |  1 +
>  src/misc/hash.c    | 79
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 113
> insertions(+)
>  create mode 100644 include/vlc_hash.h
>  create mode 100644 src/misc/hash.c
> 
> diff --git a/include/vlc_hash.h b/include/vlc_hash.h
> new file mode 100644
> index 0000000..5cf8b13
> --- /dev/null
> +++ b/include/vlc_hash.h
> @@ -0,0 +1,31 @@
> +/**************************************************************************
> *** + * vlc_hash.h: Various hash generation functions
> +
> ***************************************************************************
> ** + * Copyright (C) 2003-2015 VLC authors and VideoLAN
> + *
> + * Authors: Hugo Beauzée-Luyssen <hugo at beauzee.fr>
> + *
> + * This program 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.
> + *
> + * 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 Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser 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 VLC_HASH_H
> +#define VLC_HASH_H
> +
> +#include <vlc_common.h>
> +
> +VLC_API uint64_t hash_OpenSubtitles( vlc_object_t* p_obj, const char*
> psz_uri, int64_t *p_size );
> +
> +#endif // VLC_HASH_H
> +

In my world, hash functions take data as input, not a URL.

> diff --git a/src/Makefile.am b/src/Makefile.am
> index 1f02494..f374f4f 100644
> --- a/src/Makefile.am
> +++ b/src/Makefile.am
> @@ -50,6 +50,7 @@ pluginsinclude_HEADERS = \
>  	../include/vlc_fs.h \
>  	../include/vlc_gcrypt.h \
>  	../include/vlc_opengl.h \
> +	../include/vlc_hash.h \
>  	../include/vlc_http.h \
>  	../include/vlc_httpd.h \
>  	../include/vlc_image.h \
> @@ -458,6 +459,7 @@ SOURCES_libvlc_common = \
>  	misc/cpu.c \
>  	misc/epg.c \
>  	misc/exit.c \
> +	misc/hash.c \
>  	config/configuration.h \
>  	config/core.c \
>  	config/chain.c \
> diff --git a/src/libvlccore.sym b/src/libvlccore.sym
> index e89cf4e..eeb66f3 100644
> --- a/src/libvlccore.sym
> +++ b/src/libvlccore.sym
> @@ -663,3 +663,4 @@ addons_manager_Remove
>  addon_entry_New
>  addon_entry_Hold
>  addon_entry_Release
> +hash_OpenSubtitles
> diff --git a/src/misc/hash.c b/src/misc/hash.c
> new file mode 100644
> index 0000000..cc5370a
> --- /dev/null
> +++ b/src/misc/hash.c
> @@ -0,0 +1,79 @@
> +/**************************************************************************
> *** + * hash.c: Various hash generation functions
> +
> ***************************************************************************
> ** + * Copyright (C) 2003-2015 VLC authors and VideoLAN
> + *
> + * Authors: Hugo Beauzée-Luyssen <hugo at beauzee.fr>
> + *
> + * This program 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.
> + *
> + * 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 Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser 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. +
> ***************************************************************************
> **/ +
> +#ifdef HAVE_CONFIG_H
> +# include "config.h"
> +#endif
> +
> +#include <vlc_hash.h>
> +#include <vlc_fs.h>
> +#include <vlc_stream.h>
> +#include <vlc_input_item.h>
> +
> +#include <fcntl.h>
> +#include <unistd.h>
> +#include <sys/stat.h>
> +
> +uint64_t hash_OpenSubtitles( vlc_object_t* p_obj, const char* psz_uri,
> int64_t* p_size ) +{
> +    uint64_t hash = 0;
> +    int64_t size = 0;
> +
> +    stream_t* p_stream = stream_UrlNew( p_obj, psz_uri );
> +    if ( p_stream == NULL )
> +        return 0;
> +
> +    bool b_can_seek;
> +    stream_Control( p_stream, STREAM_CAN_SEEK, &b_can_seek );
> +    if ( b_can_seek == false )
> +        goto bailout;
> +
> +    size = stream_Size( p_stream );
> +    uint64_t tmp = 0;
> +    hash = size;
> +
> +    for( size_t i = 0; i < 65536 / sizeof(tmp); i++)
> +    {
> +        if ( stream_Read( p_stream, &tmp, sizeof(tmp) ) <= 0 )
> +        {
> +            goto bailout;
> +        }
> +        hash += tmp;

A new libvlccore function to implement the 64-bits sum.  Also architecture-
dependant and potentially undefined value...

Is this some elaborate joke?

> +    }
> +
> +    if ( stream_Seek( p_stream, size - 65536 ) != VLC_SUCCESS )
> +        goto bailout;
> +
> +    for( size_t i = 0; i < 65536 / sizeof(tmp); i++)
> +    {
> +        if ( stream_Read( p_stream, &tmp, sizeof(tmp) ) <= 0 )
> +        {
> +            goto bailout;
> +        }
> +        hash += tmp;
> +    }
> +
> +bailout:
> +    stream_Delete( p_stream );
> +    *p_size = size;
> +    return hash;
> +}

-- 
Rémi Denis-Courmont
http://www.remlab.net/