mutter/src/core/meta-anonymous-file.h
Jonas Dreßler 551a57ed7f Add read-only anonymous file abstraction MetaAnonymousFile
Add MetaAnonymousFile, an abstraction around anonymous read-only files.
Files can be created by calling meta_anonymous_file_new(), passing the
data of the file. Subsequent calls to meta_anonymous_file_open_fd()
return a fd that's ready to be sent over the socket.

When mapmode is META_ANONYMOUS_FILE_MAPMODE_PRIVATE the fd is only
guaranteed to be mmap-able readonly with MAP_PRIVATE but does not
require duplicating the file for each resource when memfd_create is
available. META_ANONYMOUS_FILE_MAPMODE_SHARED may be used when the
client must be able to map the file with MAP_SHARED but it also means
that the file has to be duplicated even when memfd_create is available.

Pretty much all of this code was written for weston by Sebastian Wick,
see https://gitlab.freedesktop.org/wayland/weston/merge_requests/240.

Co-authored-by: Sebastian Wick <sebastian@sebastianwick.net>

https://gitlab.gnome.org/GNOME/mutter/merge_requests/1012
2020-04-21 17:52:08 +02:00

54 lines
1.7 KiB
C

/*
* Copyright (C) 2020 Sebastian Wick
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*
* Author: Sebastian Wick <sebastian@sebastianwick.net>
*/
#ifndef META_ANONYMOUS_FILE_H
#define META_ANONYMOUS_FILE_H
#include "meta/common.h"
#include "core/util-private.h"
typedef struct _MetaAnonymousFile MetaAnonymousFile;
typedef enum _MetaAnonymousFileMapmode
{
META_ANONYMOUS_FILE_MAPMODE_PRIVATE,
META_ANONYMOUS_FILE_MAPMODE_SHARED,
} MetaAnonymousFileMapmode;
META_EXPORT_TEST
MetaAnonymousFile * meta_anonymous_file_new (size_t size,
const uint8_t *data);
META_EXPORT_TEST
void meta_anonymous_file_free (MetaAnonymousFile *file);
META_EXPORT_TEST
size_t meta_anonymous_file_size (MetaAnonymousFile *file);
META_EXPORT_TEST
int meta_anonymous_file_open_fd (MetaAnonymousFile *file,
MetaAnonymousFileMapmode mapmode);
META_EXPORT_TEST
void meta_anonymous_file_close_fd (int fd);
#endif /* META_ANONYMOUS_FILE_H */