glibmm 2.78.1
Public Member Functions | Static Public Member Functions | Protected Member Functions | Related Functions | List of all members
Gio::PollableInputStream Class Reference

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

#include <giomm/pollableinputstream.h>

Inheritance diagram for Gio::PollableInputStream:
Inheritance graph
[legend]

Public Member Functions

 PollableInputStream (PollableInputStream && src) noexcept
 
PollableInputStreamoperator= (PollableInputStream && src) noexcept
 
 ~PollableInputStream () noexcept override
 
GPollableInputStream * gobj ()
 Provides access to the underlying C GObject. More...
 
const GPollableInputStream * gobj () const
 Provides access to the underlying C GObject. More...
 
bool can_poll () const
 Checks if stream is actually pollable. More...
 
bool is_readable () const
 Checks if stream can be read. More...
 
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(). More...
 
gssize read_nonblocking (void * buffer, gsize count)
 A read_nonblocking() convenience overload. More...
 
- Public Member Functions inherited from Glib::Interface
 Interface ()
 A Default constructor. More...
 
 Interface (Interface && src) noexcept
 
Interfaceoperator= (Interface && src) noexcept
 
 Interface (const Glib::Interface_Class & interface_class)
 Called by constructors of derived classes. More...
 
 Interface (GObject * castitem)
 Called by constructors of derived classes. More...
 
 ~Interface () noexcept override
 
 Interface (const Interface &)=delete
 
Interfaceoperator= (const Interface &)=delete
 
GObject * gobj ()
 
const GObject * gobj () const
 
- 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...
 

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. More...
 

Protected Member Functions

 PollableInputStream ()
 You should derive from this class to use it. More...
 
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. 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)
 

Related Functions

(Note that these are not member functions.)

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

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.

Virtual: read_nonblocking

Parameters
bufferA buffer to read data into (which should be at least count bytes long).
countThe number of bytes you want to read.
cancellableA 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 Function Documentation

◆ wrap()

Glib::RefPtr< Gio::PollableInputStream > wrap ( GPollableInputStream *  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.