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Description
GFileIOStream provides io streams that both read and write to the same file handle.
GFileIOStream implements GSeekable, which allows the io stream to jump to arbitrary positions in the file and to truncate the file, provided the filesystem of the file supports these operations.
To find the position of a file io stream, use
g_seekable_tell().
To find out if a file io stream supports seeking, use g_seekable_can_seek().
To position a file io stream, use g_seekable_seek().
To find out if a file io stream supports truncating, use
g_seekable_can_truncate(). To truncate a file io
stream, use g_seekable_truncate().
The default implementation of all the GFileIOStream operations and the implementation of GSeekable just call into the same operations on the output stream.
Functions
g_file_io_stream_get_etag ()
char *
g_file_io_stream_get_etag (GFileIOStream *stream);
Gets the entity tag for the file when it has been written. This must be called after the stream has been written and closed, as the etag can change while writing.
Since 2.22
g_file_io_stream_query_info ()
GFileInfo * g_file_io_stream_query_info (GFileIOStream *stream,const char *attributes,GCancellable *cancellable,GError **error);
Queries a file io stream for the given attributes
.
This function blocks while querying the stream. For the asynchronous
version of this function, see g_file_io_stream_query_info_async().
While the stream is blocked, the stream will set the pending flag
internally, and any other operations on the stream will fail with
G_IO_ERROR_PENDING.
Can fail if the stream was already closed (with error
being set to
G_IO_ERROR_CLOSED), the stream has pending operations (with error
being
set to G_IO_ERROR_PENDING), or if querying info is not supported for
the stream's interface (with error
being set to G_IO_ERROR_NOT_SUPPORTED). I
all cases of failure, NULL will be returned.
If cancellable
is not NULL, then the operation can be cancelled by
triggering the cancellable object from another thread. If the operation
was cancelled, the error G_IO_ERROR_CANCELLED will be set, and NULL will
be returned.
Parameters
stream |
||
attributes |
a file attribute query string. |
|
cancellable |
optional GCancellable object, |
[allow-none] |
error |
Since 2.22
g_file_io_stream_query_info_async ()
void g_file_io_stream_query_info_async (GFileIOStream *stream,const char *attributes,int io_priority,GCancellable *cancellable,GAsyncReadyCallback callback,gpointer user_data);
Asynchronously queries the stream
for a GFileInfo. When completed,
callback
will be called with a GAsyncResult which can be used to
finish the operation with g_file_io_stream_query_info_finish().
For the synchronous version of this function, see
g_file_io_stream_query_info().
Parameters
stream |
||
attributes |
a file attribute query string. |
|
io_priority |
the I/O priority of the request |
|
cancellable |
optional GCancellable object, |
[allow-none] |
callback |
callback to call when the request is satisfied. |
[scope async] |
user_data |
the data to pass to callback function. |
[closure] |
Since 2.22
g_file_io_stream_query_info_finish ()
GFileInfo * g_file_io_stream_query_info_finish (GFileIOStream *stream,GAsyncResult *result,GError **error);
Finalizes the asynchronous query started
by g_file_io_stream_query_info_async().
Since 2.22
Types and Values
GFileIOStream
typedef struct _GFileIOStream GFileIOStream;
A subclass of GIOStream for opened files. This adds a few file-specific operations and seeking and truncating.
GFileIOStream implements GSeekable.