Gio::PollableInputStream Class Reference

PollableInputStream - Interface for pollable input streams. More...

#include <giomm/pollableinputstream.h>

Inheritance diagram for Gio::PollableInputStream:

Public Member Functions
	PollableInputStream (PollableInputStream &&src) noexcept
PollableInputStream &	operator= (PollableInputStream &&src) noexcept
	~PollableInputStream () noexcept override
GPollableInputStream *	gobj ()
	Provides access to the underlying C GObject.
const GPollableInputStream *	gobj () const
	Provides access to the underlying C GObject.
bool	can_poll () const
	Checks if stream is actually pollable.
bool	is_readable () const
	Checks if stream can be read.
gssize	read_nonblocking (void *buffer, gsize count, const Glib::RefPtr< Cancellable > &cancellable)
	Attempts to read up to count bytes from stream into buffer, as with g_input_stream_read().
gssize	read_nonblocking (void *buffer, gsize count)
	A read_nonblocking() convenience overload.
Public Member Functions inherited from Glib::Interface
	Interface ()
	A Default constructor.
	Interface (Interface &&src) noexcept
Interface &	operator= (Interface &&src) noexcept
	Interface (const Glib::Interface_Class &interface_class)
	Called by constructors of derived classes.
	Interface (GObject *castitem)
	Called by constructors of derived classes.
	~Interface () noexcept override
	Interface (const Interface &)=delete
Interface &	operator= (const Interface &)=delete
GObject *	gobj ()
const GObject *	gobj () const
Public Member Functions inherited from Glib::ObjectBase
	ObjectBase (const ObjectBase &)=delete
ObjectBase &	operator= (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.
void	get_property_value (const Glib::ustring & property_name, Glib::ValueBase & value) const
	You probably want to use a specific property_*() accessor method instead.
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.
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.
template<class PropertyType >
PropertyType	get_property (const Glib::ustring & property_name) const
	You probably want to use a specific property_*() accessor method instead.
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.
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.
void	freeze_notify ()
	Increases the freeze count on object.
void	thaw_notify ()
	Reverts the effect of a previous call to freeze_notify().
virtual void	reference () const
	Increment the reference count for this object.
virtual void	unreference () const
	Decrement the reference count for this object.
GObject *	gobj ()
	Provides access to the underlying C GObject.
const GObject *	gobj () const
	Provides access to the underlying C GObject.
GObject *	gobj_copy () const
	Give a ref-ed copy to someone. Use for direct struct access.

Static Public Member Functions
static void	add_interface (GType gtype_implementer)
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system.

Protected Member Functions
	PollableInputStream ()
	You should derive from this class to use it.
virtual bool	can_poll_vfunc () const
virtual bool	is_readable_vfunc () const
virtual gssize	read_nonblocking_vfunc (void *buffer, gsize count)
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.
	ObjectBase (const char *custom_type_name)
	A derived constructor always overrides this choice.
	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.
	ObjectBase (ObjectBase &&src) noexcept
ObjectBase &	operator= (ObjectBase &&src) noexcept
virtual	~ObjectBase () noexcept=0
void	initialize (GObject *castitem)
void	initialize_move (GObject *castitem, Glib::ObjectBase *previous_wrapper)

Related Symbols
(Note that these are not member symbols.)
Glib::RefPtr< Gio::PollableInputStream >	wrap (GPollableInputStream *object, bool take_copy=false)
	A Glib::wrap() method for this object.

Detailed Description

PollableInputStream - Interface for pollable input streams.

PollableInputStream is implemented by InputStreams that can be polled for readiness to read. This can be used when interfacing with a non-GIO API that expects UNIX-file-descriptor-style asynchronous I/O rather than GIO-style.

Since glibmm 2.34:

Constructor & Destructor Documentation

PollableInputStream() [1/2]

Gio::PollableInputStream::PollableInputStream ( )

protected

You should derive from this class to use it.

PollableInputStream() [2/2]

Gio::PollableInputStream::PollableInputStream ( PollableInputStream &&  src )

noexcept

~PollableInputStream()

Gio::PollableInputStream::~PollableInputStream ( )

overridenoexcept

Member Function Documentation

add_interface()

static void Gio::PollableInputStream::add_interface ( GType  gtype_implementer )

static

can_poll()

bool Gio::PollableInputStream::can_poll

(

)

const

Checks if stream is actually pollable.

Some classes may implement PollableInputStream but have only certain instances of that class be pollable. If this method returns false, then the behavior of other PollableInputStream methods is undefined.

For any given stream, the value returned by this method is constant; a stream cannot switch from pollable to non-pollable or vice versa.

Since glibmm 2.28:

Returns

true if stream is pollable, false if not.

can_poll_vfunc()

virtual bool Gio::PollableInputStream::can_poll_vfunc ( ) const

protectedvirtual

get_type()

static GType Gio::PollableInputStream::get_type ( )

static

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

gobj() [1/2]

GPollableInputStream * Gio::PollableInputStream::gobj ( )

inline

Provides access to the underlying C GObject.

gobj() [2/2]

const GPollableInputStream * Gio::PollableInputStream::gobj ( ) const

inline

Provides access to the underlying C GObject.

is_readable()

bool Gio::PollableInputStream::is_readable

(

)

const

Checks if stream can be read.

Note that some stream types may not be able to implement this 100% reliably, and it is possible that a call to g_input_stream_read() after this returns true would still block. To guarantee non-blocking behavior, you should always use g_pollable_input_stream_read_nonblocking(), which will return a Gio::Error::WOULD_BLOCK error rather than blocking.

The behaviour of this method is undefined if g_pollable_input_stream_can_poll() returns false for stream.

Since glibmm 2.28:

Returns

true if stream is readable, false if not. If an error has occurred on stream, this will result in g_pollable_input_stream_is_readable() returning true, and the next attempt to read will return the error.

is_readable_vfunc()

virtual bool Gio::PollableInputStream::is_readable_vfunc ( ) const

protectedvirtual

operator=()

PollableInputStream & Gio::PollableInputStream::operator= ( PollableInputStream &&  src )

noexcept

read_nonblocking() [1/2]

gssize Gio::PollableInputStream::read_nonblocking	(	void *	buffer,
		gsize	count
	)

A read_nonblocking() convenience overload.

read_nonblocking() [2/2]

gssize Gio::PollableInputStream::read_nonblocking	(	void *	buffer,
		gsize	count,
		const Glib::RefPtr< Cancellable > &	cancellable
	)

Attempts to read up to count bytes from stream into buffer, as with g_input_stream_read().

If stream is not currently readable, this will immediately return Gio::Error::WOULD_BLOCK, and you can use g_pollable_input_stream_create_source() to create a Source that will be triggered when stream is readable.

Note that since this method never blocks, you cannot actually use cancellable to cancel it. However, it will return an error if cancellable has already been cancelled when you call, which may happen if you call this method after a source triggers due to having been cancelled.

The behaviour of this method is undefined if g_pollable_input_stream_can_poll() returns false for stream.

Parameters

buffer	A buffer to read data into (which should be at least count bytes long).
count	The number of bytes you want to read.
cancellable	A Cancellable, or nullptr.

Returns

The number of bytes read, or -1 on error (including Gio::Error::WOULD_BLOCK).

Exceptions

Glib::Error

read_nonblocking_vfunc()

virtual gssize Gio::PollableInputStream::read_nonblocking_vfunc ( void *  buffer, gsize  count  )

protectedvirtual

Exceptions

Glib::Error.

Friends And Related Symbol Documentation

wrap()

Glib::RefPtr< Gio::PollableInputStream > wrap ( GPollableInputStream *  object, bool  take_copy = false  )

related

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

Parameters

object	The C instance.
take_copy	False 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.