qemu/include/io/channel-file.h
Fabiano Rosas 4760cedc61 io: Introduce qio_channel_file_new_dupfd
Add a new helper function for creating a QIOChannelFile channel with a
duplicated file descriptor. This saves the calling code from having to
do error checking on the dup() call.

Suggested-by: "Daniel P. Berrangé" <berrange@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: "Daniel P. Berrangé" <berrange@redhat.com>
Link: https://lore.kernel.org/r/20240311233335.17299-2-farosas@suse.de
Signed-off-by: Peter Xu <peterx@redhat.com>
2024-03-12 15:22:23 -04:00

111 lines
3.3 KiB
C

/*
* QEMU I/O channels files driver
*
* Copyright (c) 2015 Red Hat, Inc.
*
* This 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.
*
* This 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 this library; if not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef QIO_CHANNEL_FILE_H
#define QIO_CHANNEL_FILE_H
#include "io/channel.h"
#include "qom/object.h"
#define TYPE_QIO_CHANNEL_FILE "qio-channel-file"
OBJECT_DECLARE_SIMPLE_TYPE(QIOChannelFile, QIO_CHANNEL_FILE)
/**
* QIOChannelFile:
*
* The QIOChannelFile object provides a channel implementation
* that is able to perform I/O on block devices, character
* devices, FIFOs, pipes and plain files. While it is technically
* able to work on sockets too on the UNIX platform, this is not
* portable to Windows and lacks some extra sockets specific
* functionality. So the QIOChannelSocket object is recommended
* for that use case.
*
*/
struct QIOChannelFile {
QIOChannel parent;
int fd;
};
/**
* qio_channel_file_new_fd:
* @fd: the file descriptor
*
* Create a new IO channel object for a file represented
* by the @fd parameter. @fd can be associated with a
* block device, character device, fifo, pipe, or a
* regular file. For sockets, the QIOChannelSocket class
* should be used instead, as this provides greater
* functionality and cross platform portability.
*
* The channel will own the passed in file descriptor
* and will take responsibility for closing it, so the
* caller must not close it. If appropriate the caller
* should dup() its FD before opening the channel.
*
* Returns: the new channel object
*/
QIOChannelFile *
qio_channel_file_new_fd(int fd);
/**
* qio_channel_file_new_dupfd:
* @fd: the file descriptor
* @errp: pointer to initialized error object
*
* Create a new IO channel object for a file represented by the @fd
* parameter. Like qio_channel_file_new_fd(), but the @fd is first
* duplicated with dup().
*
* The channel will own the duplicated file descriptor and will take
* responsibility for closing it, the original FD is owned by the
* caller.
*
* Returns: the new channel object
*/
QIOChannelFile *
qio_channel_file_new_dupfd(int fd, Error **errp);
/**
* qio_channel_file_new_path:
* @path: the file path
* @flags: the open flags (O_RDONLY|O_WRONLY|O_RDWR, etc)
* @mode: the file creation mode if O_CREAT is set in @flags
* @errp: pointer to initialized error object
*
* Create a new IO channel object for a file represented
* by the @path parameter. @path can point to any
* type of file on which sequential I/O can be
* performed, whether it be a plain file, character
* device or block device.
*
* Returns: the new channel object
*/
QIOChannelFile *
qio_channel_file_new_path(const char *path,
int flags,
mode_t mode,
Error **errp);
#endif /* QIO_CHANNEL_FILE_H */