enum GOutputStreamSpliceFlags

typedef enum {
  G_OUTPUT_STREAM_SPLICE_NONE         = 0,
  G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE = (1 << 0),
  G_OUTPUT_STREAM_SPLICE_CLOSE_TARGET = (1 << 1)
} GOutputStreamSpliceFlags;

GOutputStreamSpliceFlags determine how streams should be spliced.

GOutputStream

typedef struct _GOutputStream GOutputStream;

Base class for writing output.

All classes derived from GOutputStream should implement synchronous writing, splicing, flushing and closing streams, but may implement asynchronous versions.

g_output_stream_write ()

gssize              g_output_stream_write               (GOutputStream *stream,
                                                         const void *buffer,
                                                         gsize count,
                                                         GCancellable *cancellable,
                                                         GError **error);

Tries to write count bytes from buffer into the stream. Will block during the operation.

If count is 0, returns 0 and does nothing. A value of count larger than G_MAXSSIZE will cause a G_IO_ERROR_INVALID_ARGUMENT error.

On success, the number of bytes written to the stream is returned. It is not an error if this is not the same as the requested size, as it can happen e.g. on a partial I/O error, or if there is not enough storage in the stream. All writes block until at least one byte is written or an error occurs; 0 is never returned (unless count is 0).

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 returned. If an operation was partially finished when the operation was cancelled the partial result will be returned, without an error.

On error -1 is returned and error is set accordingly.

g_output_stream_write_all ()

gboolean            g_output_stream_write_all           (GOutputStream *stream,
                                                         const void *buffer,
                                                         gsize count,
                                                         gsize *bytes_written,
                                                         GCancellable *cancellable,
                                                         GError **error);

Tries to write count bytes from buffer into the stream. Will block during the operation.

This function is similar to g_output_stream_write(), except it tries to write as many bytes as requested, only stopping on an error.

On a successful write of count bytes, TRUE is returned, and bytes_written is set to count.

If there is an error during the operation FALSE is returned and error is set to indicate the error status, bytes_written is updated to contain the number of bytes written into the stream before the error occurred.

g_output_stream_splice ()

gssize              g_output_stream_splice              (GOutputStream *stream,
                                                         GInputStream *source,
                                                         GOutputStreamSpliceFlags flags,
                                                         GCancellable *cancellable,
                                                         GError **error);

Splices an input stream into an output stream.

g_output_stream_flush ()

gboolean            g_output_stream_flush               (GOutputStream *stream,
                                                         GCancellable *cancellable,
                                                         GError **error);

Flushed any outstanding buffers in the stream. Will block during the operation. Closing the stream will implicitly cause a flush.

This function is optional for inherited classes.

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 returned.

g_output_stream_close ()

gboolean            g_output_stream_close               (GOutputStream *stream,
                                                         GCancellable *cancellable,
                                                         GError **error);

Closes the stream, releasing resources related to it.

Once the stream is closed, all other operations will return G_IO_ERROR_CLOSED. Closing a stream multiple times will not return an error.

Closing a stream will automatically flush any outstanding buffers in the stream.

Streams will be automatically closed when the last reference is dropped, but you might want to call this function to make sure resources are released as early as possible.

Some streams might keep the backing store of the stream (e.g. a file descriptor) open after the stream is closed. See the documentation for the individual stream for details.

On failure the first error that happened will be reported, but the close operation will finish as much as possible. A stream that failed to close will still return G_IO_ERROR_CLOSED for all operations. Still, it is important to check and report the error to the user, otherwise there might be a loss of data as all data might not be written.

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 returned. Cancelling a close will still leave the stream closed, but there some streams can use a faster close that doesn't block to e.g. check errors. On cancellation (as with any error) there is no guarantee that all written data will reach the target.

g_output_stream_write_async ()

void                g_output_stream_write_async         (GOutputStream *stream,
                                                         const void *buffer,
                                                         gsize count,
                                                         int io_priority,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);

Request an asynchronous write of count bytes from buffer into the stream. When the operation is finished callback will be called. You can then call g_output_stream_write_finish() to get the result of the operation.

During an async request no other sync and async calls are allowed, and will result in G_IO_ERROR_PENDING errors.

A value of count larger than G_MAXSSIZE will cause a G_IO_ERROR_INVALID_ARGUMENT error.

On success, the number of bytes written will be passed to the callback. It is not an error if this is not the same as the requested size, as it can happen e.g. on a partial I/O error, but generally we try to write as many bytes as requested.

You are guaranteed that this method will never fail with G_IO_ERROR_WOULD_BLOCK - if stream can't accept more data, the method will just wait until this changes.

Any outstanding I/O request with higher priority (lower numerical value) will be executed before an outstanding request with lower priority. Default priority is G_PRIORITY_DEFAULT.

The asyncronous methods have a default fallback that uses threads to implement asynchronicity, so they are optional for inheriting classes. However, if you override one you must override all.

For the synchronous, blocking version of this function, see g_output_stream_write().

g_output_stream_write_finish ()

gssize              g_output_stream_write_finish        (GOutputStream *stream,
                                                         GAsyncResult *result,
                                                         GError **error);

Finishes a stream write operation.

g_output_stream_splice_async ()

void                g_output_stream_splice_async        (GOutputStream *stream,
                                                         GInputStream *source,
                                                         GOutputStreamSpliceFlags flags,
                                                         int io_priority,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);

Splices a stream asynchronously. When the operation is finished callback will be called. You can then call g_output_stream_splice_finish() to get the result of the operation.

For the synchronous, blocking version of this function, see g_output_stream_splice().

g_output_stream_splice_finish ()

gssize              g_output_stream_splice_finish       (GOutputStream *stream,
                                                         GAsyncResult *result,
                                                         GError **error);

Finishes an asynchronous stream splice operation.

g_output_stream_flush_async ()

void                g_output_stream_flush_async         (GOutputStream *stream,
                                                         int io_priority,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);

Flushes a stream asynchronously. For behaviour details see g_output_stream_flush().

When the operation is finished callback will be called. You can then call g_output_stream_flush_finish() to get the result of the operation.

g_output_stream_flush_finish ()

gboolean            g_output_stream_flush_finish        (GOutputStream *stream,
                                                         GAsyncResult *result,
                                                         GError **error);

Finishes flushing an output stream.

g_output_stream_close_async ()

void                g_output_stream_close_async         (GOutputStream *stream,
                                                         int io_priority,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);

Requests an asynchronous close of the stream, releasing resources related to it. When the operation is finished callback will be called. You can then call g_output_stream_close_finish() to get the result of the operation.

For behaviour details see g_output_stream_close().

The asyncronous methods have a default fallback that uses threads to implement asynchronicity, so they are optional for inheriting classes. However, if you override one you must override all.

g_output_stream_close_finish ()

gboolean            g_output_stream_close_finish        (GOutputStream *stream,
                                                         GAsyncResult *result,
                                                         GError **error);

Closes an output stream.

g_output_stream_is_closing ()

gboolean            g_output_stream_is_closing          (GOutputStream *stream);

Checks if an output stream is being closed. This can be used inside e.g. a flush implementation to see if the flush (or other i/o operation) is called from within the closing operation.

Since 2.24

g_output_stream_is_closed ()

gboolean            g_output_stream_is_closed           (GOutputStream *stream);

Checks if an output stream has already been closed.

g_output_stream_has_pending ()

gboolean            g_output_stream_has_pending         (GOutputStream *stream);

Checks if an ouput stream has pending actions.

g_output_stream_set_pending ()

gboolean            g_output_stream_set_pending         (GOutputStream *stream,
                                                         GError **error);

Sets stream to have actions pending. If the pending flag is already set or stream is closed, it will return FALSE and set error.

g_output_stream_clear_pending ()

void                g_output_stream_clear_pending       (GOutputStream *stream);

Clears the pending flag on stream.