glibmm: Gio::IOStream Class Reference

IOStream - Base class for implementing read/write streams. More...

#include </home/kjell/checkout/gnome/glibmm/gio/giomm/iostream.h>

Inheritance diagram for Gio::IOStream:

Public Types

- Public Types inherited from Glib::Object
using DestroyNotify = void(*)(gpointer data)
 
- Public Types inherited from sigc::trackable
typedef internal::func_destroy_notify func_destroy_notify
 
- Public Types inherited from sigc::notifiable
typedef internal::func_destroy_notify func_destroy_notify
 

Public Member Functions

 IOStream (IOStream&& src) noexcept
 
IOStreamoperator= (IOStream&& src) noexcept
 
 ~IOStream () noexcept override
 
GIOStream* gobj ()
 Provides access to the underlying C GObject. More...

 
const GIOStream* gobj () const
 Provides access to the underlying C GObject. More...

 
GIOStream* gobj_copy ()
 Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. More...

 
void splice_async (const Glib::RefPtr< IOStream >& stream2, const SlotAsyncReady& slot, const Glib::RefPtr< Cancellable >& cancellable, SpliceFlags flags=SpliceFlags::NONE, int io_priority=Glib::PRIORITY_DEFAULT)
 Asyncronously splice the output stream to the input stream of stream2, and splice the output stream of stream2 to the input stream of this stream. More...

 
void splice_async (const Glib::RefPtr< IOStream >& stream2, const SlotAsyncReady& slot, SpliceFlags flags=SpliceFlags::NONE, int io_priority=Glib::PRIORITY_DEFAULT)
 A non-cancellable version of splice_async(). More...

 
Glib::RefPtr< InputStreamget_input_stream ()
 Gets the input stream for this object. More...

 
Glib::RefPtr< OutputStreamget_output_stream ()
 Gets the output stream for this object. More...

 
bool close (const Glib::RefPtr< Cancellable >& cancellable)
 Closes the stream, releasing resources related to it. More...

 
bool close ()
 A close() convenience overload. More...

 
void close_async (const SlotAsyncReady& slot, const Glib::RefPtr< Cancellable >& cancellable, int io_priority=Glib::PRIORITY_DEFAULT)
 
void close_async (const SlotAsyncReady& slot, int io_priority=Glib::PRIORITY_DEFAULT)
 
bool close_finish (const Glib::RefPtr< AsyncResult >& result)
 Closes a stream. More...

 
bool is_closed () const
 Checks if a stream is closed. More...

 
bool has_pending () const
 Checks if a stream has pending actions. More...

 
bool set_pending ()
 Sets stream to have actions pending. More...

 
void clear_pending ()
 Clears the pending flag on stream. More...

 
- Public Member Functions inherited from Glib::Object
 Object (const Object&)=delete
 
Objectoperator= (const Object&)=delete
 
 Object (Object&& src) noexcept
 
Objectoperator= (Object&& src) noexcept
 
void* get_data (const QueryQuark& key)
 
void set_data (const Quark& key, void* data)
 
void set_data (const Quark& key, void* data, DestroyNotify notify)
 
void remove_data (const QueryQuark& quark)
 
void* steal_data (const QueryQuark& quark)
 
- Public Member Functions inherited from Glib::ObjectBase
 ObjectBase (const ObjectBase&)=delete
 
ObjectBaseoperator= (const ObjectBase&)=delete
 
void set_property_value (const Glib::ustring& property_name, const Glib::ValueBase& value)
 You probably want to use a specific property_*() accessor method instead. More...

 
void get_property_value (const Glib::ustring& property_name, Glib::ValueBase& value) const
 You probably want to use a specific property_*() accessor method instead. More...

 
template<class PropertyType >
void set_property (const Glib::ustring& property_name, const PropertyType& value)
 You probably want to use a specific property_*() accessor method instead. More...

 
template<class PropertyType >
void get_property (const Glib::ustring& property_name, PropertyType& value) const
 You probably want to use a specific property_*() accessor method instead. More...

 
template<class PropertyType >
PropertyType get_property (const Glib::ustring& property_name) const
 You probably want to use a specific property_*() accessor method instead. More...

 
sigc::connection connect_property_changed (const Glib::ustring& property_name, const sigc::slot< void()>& slot)
 You can use the signal_changed() signal of the property proxy instead. More...

 
sigc::connection connect_property_changed (const Glib::ustring& property_name, sigc::slot< void()>&& slot)
 You can use the signal_changed() signal of the property proxy instead. More...

 
void freeze_notify ()
 Increases the freeze count on object. More...

 
void thaw_notify ()
 Reverts the effect of a previous call to freeze_notify(). More...

 
virtual void reference () const
 Increment the reference count for this object. More...

 
virtual void unreference () const
 Decrement the reference count for this object. More...

 
GObject* gobj ()
 Provides access to the underlying C GObject. More...

 
const GObject* gobj () const
 Provides access to the underlying C GObject. More...

 
GObject* gobj_copy () const
 Give a ref-ed copy to someone. Use for direct struct access. More...

 
- Public Member Functions inherited from sigc::trackable
 trackable () noexcept
 
 trackable (const trackable &src) noexcept
 
 trackable (trackable &&src) noexcept
 
 ~trackable ()
 
void add_destroy_notify_callback (notifiable *data, func_destroy_notify func) const
 
void notify_callbacks ()
 
trackableoperator= (const trackable &src)
 
trackableoperator= (trackable &&src) noexcept
 
void remove_destroy_notify_callback (notifiable *data) const
 

Static Public Member Functions

static GType get_type ()
 Get the GType for this class, for use with the underlying GObject type system. More...

 
static bool splice_finish (const Glib::RefPtr< AsyncResult >& result)
 Finishes an asynchronous io stream splice operation. More...

 

Related Functions

(Note that these are not member functions.)

Glib::RefPtr< Gio::IOStreamwrap (GIOStream* object, bool take_copy=false)
 A Glib::wrap() method for this object. More...

 

Additional Inherited Members

- Protected Member Functions inherited from Glib::Object
 Object ()
 
 Object (const Glib::ConstructParams& construct_params)
 
 Object (GObject* castitem)
 
 ~Object () noexcept override
 
- Protected Member Functions inherited from Glib::ObjectBase
 ObjectBase ()
 This default constructor is called implicitly from the constructor of user-derived classes, even if, for instance, Gtk::Button calls a different ObjectBase constructor. More...

 
 ObjectBase (const char* custom_type_name)
 A derived constructor always overrides this choice. More...

 
 ObjectBase (const std::type_info& custom_type_info)
 This constructor is a special feature to allow creation of derived types on the fly, without having to use g_object_new() manually. More...

 
 ObjectBase (ObjectBase&& src) noexcept
 
ObjectBaseoperator= (ObjectBase&& src) noexcept
 
virtual ~ObjectBase () noexcept=0
 
void initialize (GObject* castitem)
 
void initialize_move (GObject* castitem, Glib::ObjectBase* previous_wrapper)
 

Detailed Description

IOStream - Base class for implementing read/write streams.

IOStream represents an object that has both read and write streams. Generally the two streams acts as separate input and output streams, but they share some common resources and state. For instance, for seekable streams they may use the same position in both streams.

Examples of IOStream objects are SocketConnection which represents a two-way network connection, and FileIOStream which represent a file handle opened in read-write mode.

To do the actual reading and writing you need to get the substreams with get_input_stream() and get_output_stream().

The IOStream object owns the input and the output streams, not the other way around, so keeping the substreams alive will not keep the IOStream object alive. If the IOStream object is freed it will be closed, thus closing the substream, so even if the substreams stay alive they will always just return a Gio::IO_ERROR_CLOSED for all operations.

To close a stream use close() which will close the common stream object and also the individual substreams. You can also close the substreams themselves. In most cases this only marks the substream as closed, so further I/O on it fails. However, some streams may support "half-closed" states where one direction of the stream is actually shut down.

Since glibmm 2.22:

Constructor & Destructor Documentation

Gio::IOStream::IOStream ( IOStream&&  src)
noexcept
Gio::IOStream::~IOStream ( )
overridenoexcept

Member Function Documentation

void Gio::IOStream::clear_pending ( )

Clears the pending flag on stream.

Since glibmm 2.22:
bool Gio::IOStream::close ( const Glib::RefPtr< Cancellable >&  cancellable)

Closes the stream, releasing resources related to it.

This will also close the individual input and output streams, if they are not already closed.

Once the stream is closed, all other operations will return Gio::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 Gio::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 nullptr, then the operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, the error Gio::Error::CANCELLED will be returned. Cancelling a close will still leave the stream closed, but some streams can use a faster close that doesn't block to e.g. check errors.

The default implementation of this method just calls close on the individual input/output streams.

Since glibmm 2.22:
Parameters
cancellableOptional Cancellable object, nullptr to ignore.
Returns
true on success, false on failure.
Exceptions
Glib::Error
bool Gio::IOStream::close ( )

A close() convenience overload.

void Gio::IOStream::close_async ( const SlotAsyncReady slot,
const Glib::RefPtr< Cancellable >&  cancellable,
int  io_priority = Glib::PRIORITY_DEFAULT 
)
void Gio::IOStream::close_async ( const SlotAsyncReady slot,
int  io_priority = Glib::PRIORITY_DEFAULT 
)
bool Gio::IOStream::close_finish ( const Glib::RefPtr< AsyncResult >&  result)

Closes a stream.

Since glibmm 2.22:
Parameters
resultA AsyncResult.
Returns
true if stream was successfully closed, false otherwise.
Exceptions
Glib::Error
Glib::RefPtr<InputStream> Gio::IOStream::get_input_stream ( )

Gets the input stream for this object.

This is used for reading.

Since glibmm 2.22:
Returns
A InputStream, owned by the IOStream. Do not free.
Glib::RefPtr<OutputStream> Gio::IOStream::get_output_stream ( )

Gets the output stream for this object.

This is used for writing.

Since glibmm 2.22:
Returns
A OutputStream, owned by the IOStream. Do not free.
static GType Gio::IOStream::get_type ( )
static

Get the GType for this class, for use with the underlying GObject type system.

GIOStream* Gio::IOStream::gobj ( )
inline

Provides access to the underlying C GObject.

const GIOStream* Gio::IOStream::gobj ( ) const
inline

Provides access to the underlying C GObject.

GIOStream* Gio::IOStream::gobj_copy ( )

Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

bool Gio::IOStream::has_pending ( ) const

Checks if a stream has pending actions.

Since glibmm 2.22:
Returns
true if stream has pending actions.
bool Gio::IOStream::is_closed ( ) const

Checks if a stream is closed.

Since glibmm 2.22:
Returns
true if the stream is closed.
IOStream& Gio::IOStream::operator= ( IOStream&&  src)
noexcept
bool Gio::IOStream::set_pending ( )

Sets stream to have actions pending.

If the pending flag is already set or stream is closed, it will return false and set error.

Since glibmm 2.22:
Returns
true if pending was previously unset and is now set.
Exceptions
Glib::Error
void Gio::IOStream::splice_async ( const Glib::RefPtr< IOStream >&  stream2,
const SlotAsyncReady slot,
const Glib::RefPtr< Cancellable >&  cancellable,
SpliceFlags  flags = SpliceFlags::NONE,
int  io_priority = Glib::PRIORITY_DEFAULT 
)

Asyncronously splice the output stream to the input stream of stream2, and splice the output stream of stream2 to the input stream of this stream.

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

Parameters
stream2The second IOStream.
slotA SlotAsyncReady slot.
cancellableA Cancellable object.
flagsA set of SpliceFlags.
io_priorityThe io priority of the request.
Since glibmm 2.34:
void Gio::IOStream::splice_async ( const Glib::RefPtr< IOStream >&  stream2,
const SlotAsyncReady slot,
SpliceFlags  flags = SpliceFlags::NONE,
int  io_priority = Glib::PRIORITY_DEFAULT 
)

A non-cancellable version of splice_async().

static bool Gio::IOStream::splice_finish ( const Glib::RefPtr< AsyncResult >&  result)
static

Finishes an asynchronous io stream splice operation.

Since glibmm 2.28:
Parameters
resultA AsyncResult.
Returns
true on success, false otherwise.
Exceptions
Glib::Error

Friends And Related Function Documentation

Glib::RefPtr< Gio::IOStream > wrap ( GIOStream *  object,
bool  take_copy = false 
)
related

A Glib::wrap() method for this object.

Parameters
objectThe C instance.
take_copyFalse if the result should take ownership of the C instance. True if it should take a new copy or ref.
Returns
A C++ instance that wraps this C instance.