Gio::InputStream Class Reference

Base class for implementing streaming input. More...

#include <giomm/inputstream.h>

Inheritance diagram for Gio::InputStream:

Public Member Functions
	InputStream (InputStream && src) noexcept
InputStream &	operator= (InputStream && src) noexcept
	~InputStream () noexcept override
GInputStream *	gobj ()
	Provides access to the underlying C GObject. More...
const GInputStream *	gobj () const
	Provides access to the underlying C GObject. More...
GInputStream *	gobj_copy ()
	Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. More...
gssize	read (void * buffer, gsize count, const Glib::RefPtr< Cancellable > & cancellable)
	Tries to read count bytes from the stream into the buffer starting at buffer. More...
gssize	read (void * buffer, gsize count)
	A read() convenience overload. More...
bool	read_all (void * buffer, gsize count, gsize & bytes_read, const Glib::RefPtr< Cancellable > & cancellable)
	Tries to read count bytes from the stream into the buffer starting at buffer. More...
bool	read_all (void * buffer, gsize count, gsize & bytes_read)
	A read_all() convenience overload. More...
Glib::RefPtr< Glib::Bytes >	read_bytes (gsize count, const Glib::RefPtr< Cancellable > & cancellable)
	Like g_input_stream_read(), this tries to read count bytes from the stream in a blocking fashion. More...
void	read_bytes_async (gsize count, const SlotAsyncReady & slot, const Glib::RefPtr< Cancellable > & cancellable, int io_priority=Glib::PRIORITY_DEFAULT)
	Request an asynchronous read of count bytes from the stream into a new Glib::Bytes. More...
void	read_bytes_async (gsize count, const SlotAsyncReady & slot, int io_priority=Glib::PRIORITY_DEFAULT)
	Request an asynchronous read of count bytes from the stream into a new Glib::Bytes. More...
Glib::RefPtr< Glib::Bytes >	read_bytes_finish (const Glib::RefPtr< AsyncResult > & result)
	Finishes an asynchronous stream read-into-Bytes operation. More...
gssize	skip (gsize count, const Glib::RefPtr< Cancellable > & cancellable)
	Tries to skip count bytes from the stream. More...
gssize	skip (gsize count)
	A skip() convenience overload. 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	read_async (void * buffer, gsize count, const SlotAsyncReady & slot, const Glib::RefPtr< Cancellable > & cancellable, int io_priority=Glib::PRIORITY_DEFAULT)
	Request an asynchronous read of count bytes from the stream into the buffer starting at buffer. More...
void	read_async (void * buffer, gsize count, const SlotAsyncReady & slot, int io_priority=Glib::PRIORITY_DEFAULT)
	Request an asynchronous read of count bytes from the stream into the buffer starting at buffer. More...
gssize	read_finish (const Glib::RefPtr< AsyncResult > & result)
	Finishes an asynchronous stream read operation. More...
void	read_all_async (void * buffer, gsize count, const SlotAsyncReady & slot, const Glib::RefPtr< Cancellable > & cancellable, int io_priority=Glib::PRIORITY_DEFAULT)
	Request an asynchronous read of count bytes from the stream into the buffer starting at buffer. More...
void	read_all_async (void * buffer, gsize count, const SlotAsyncReady & slot, int io_priority=Glib::PRIORITY_DEFAULT)
	Request an asynchronous read of count bytes from the stream into the buffer starting at buffer. More...
bool	read_all_finish (const Glib::RefPtr< AsyncResult > & result, gsize & bytes_read)
	Finishes an asynchronous stream read operation started with g_input_stream_read_all_async(). More...
void	skip_async (gsize count, const SlotAsyncReady & slot, const Glib::RefPtr< Cancellable > & cancellable, int io_priority=Glib::PRIORITY_DEFAULT)
	Request an asynchronous skip of count bytes from the stream into the buffer starting at buffer. More...
void	skip_async (gsize count, const SlotAsyncReady & slot, int io_priority=Glib::PRIORITY_DEFAULT)
	Request an asynchronous skip of count bytes from the stream into the buffer starting at buffer. More...
gssize	skip_finish (const Glib::RefPtr< AsyncResult > & result)
	Finishes a stream skip operation. More...
void	close_async (const SlotAsyncReady & slot, const Glib::RefPtr< Cancellable > & cancellable, int io_priority=Glib::PRIORITY_DEFAULT)
	Requests an asynchronous closes of the stream, releasing resources related to it. More...
void	close_async (const SlotAsyncReady & slot, int io_priority=Glib::PRIORITY_DEFAULT)
	Requests an asynchronous closes of the stream, releasing resources related to it. More...
gboolean	close_finish (const Glib::RefPtr< AsyncResult > & result)
	Finishes closing a stream asynchronously, started from g_input_stream_close_async(). More...
bool	is_closed () const
	Checks if an input stream is closed. More...
bool	has_pending () const
	Checks if an input stream has pending actions. More...
Public Member Functions inherited from Glib::Object
	Object (const Object &)=delete
Object &	operator= (const Object &)=delete
	Object (Object && src) noexcept
Object &	operator= (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
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. 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...
void	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...
void	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...
sigc::connection	connect_property_changed_with_return (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_with_return (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 GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system. More...

Protected Member Functions
	InputStream ()
bool	set_pending ()
	Sets stream to have actions pending. More...
void	clear_pending ()
	Clears the pending flag on stream. More...
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
ObjectBase &	operator= (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::InputStream >	wrap (GInputStream * object, bool take_copy=false)
	A Glib::wrap() method for this object. More...
Related Functions inherited from Glib::Object
Glib::RefPtr< Glib::Object >	wrap (GObject * object, bool take_copy=false)

Additional Inherited Members
Public Types inherited from Glib::Object
using	DestroyNotify = void(*)(gpointer data)

Detailed Description

Base class for implementing streaming input.

Since glibmm 2.16:

Constructor & Destructor Documentation

InputStream() [1/2]

Gio::InputStream::InputStream ( InputStream &&  src )

noexcept

~InputStream()

Gio::InputStream::~InputStream ( )

overridenoexcept

InputStream() [2/2]

Gio::InputStream::InputStream ( )

protected

Member Function Documentation

clear_pending()

void Gio::InputStream::clear_pending ( )

protected

Clears the pending flag on stream.

Since glibmm 2.50:

close() [1/2]

bool Gio::InputStream::close

(

)

A close() convenience overload.

close() [2/2]

bool Gio::InputStream::close

(

const Glib::RefPtr< Cancellable > &

cancellable

)

Closes the stream, releasing resources related to it.

Once the stream is closed, all other operations will throw a Gio::Error with CLOSED. Closing a stream multiple times will not return an error.

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 throw a Gio::Error with CLOSED for all operations. Still, it is important to check and report the error to the user.

The operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, a Gio::Error will be thrown with CANCELLED. 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.

Parameters

cancellable

Cancellable object.

Returns

true on success, false on failure.

Exceptions

Glib::Error

close_async() [1/2]

void Gio::InputStream::close_async	(	const SlotAsyncReady &	slot,
		const Glib::RefPtr< Cancellable > &	cancellable,
		int	io_priority = Glib::PRIORITY_DEFAULT
	)

Requests an asynchronous closes of the stream, releasing resources related to it.

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

For behaviour details see 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.

Parameters

slot	Callback to call when the request is satisfied.
cancellable	A Cancellable object.
io_priority	The I/O priority of the request.

close_async() [2/2]

void Gio::InputStream::close_async	(	const SlotAsyncReady &	slot,
		int	io_priority = Glib::PRIORITY_DEFAULT
	)

Requests an asynchronous closes of the stream, releasing resources related to it.

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

For behaviour details see 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.

Parameters

slot	Callback to call when the request is satisfied.
io_priority	The I/O priority of the request.

close_finish()

gboolean Gio::InputStream::close_finish

(

const Glib::RefPtr< AsyncResult > &

result

)

Finishes closing a stream asynchronously, started from g_input_stream_close_async().

Parameters

result

A AsyncResult.

Returns

true if the stream was closed successfully.

Exceptions

Glib::Error

get_type()

static GType Gio::InputStream::get_type ( )

static

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

gobj() [1/2]

GInputStream * Gio::InputStream::gobj ( )

inline

Provides access to the underlying C GObject.

gobj() [2/2]

const GInputStream * Gio::InputStream::gobj ( ) const

inline

Provides access to the underlying C GObject.

gobj_copy()

GInputStream * Gio::InputStream::gobj_copy

(

)

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

has_pending()

bool Gio::InputStream::has_pending

(

)

const

Checks if an input stream has pending actions.

Since glibmm 2.50:

Returns

true if stream has pending actions.

is_closed()

bool Gio::InputStream::is_closed

(

)

const

Checks if an input stream is closed.

Since glibmm 2.50:

Returns

true if the stream is closed.

operator=()

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

noexcept

read() [1/2]

gssize Gio::InputStream::read	(	void *	buffer,
		gsize	count
	)

A read() convenience overload.

read() [2/2]

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

Tries to read count bytes from the stream into the buffer starting at buffer.

Will block during this read.

If count is zero returns zero and does nothing. A value of count larger than G_MAXSSIZE will cause a Gio::Error with INVALID_ARGUMENT to be thrown.

On success, the number of bytes read into the buffer is returned. It is not an error if this is not the same as the requested size, as it can happen e.g. near the end of a file. Zero is returned on end of file (or if count is zero), but never otherwise.

The operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, a Gio::Error will be thrown with CANCELLED. If an operation was partially finished when the operation was cancelled the partial result will be returned, without an error.

Parameters

buffer	A buffer to read data into (which should be at least count bytes long).
count	The number of bytes that will be read from the stream.
cancellable	Cancellable object.

Returns

Number of bytes read, or -1 on error.

Exceptions

Glib::Error

read_all() [1/2]

bool Gio::InputStream::read_all	(	void *	buffer,
		gsize	count,
		gsize &	bytes_read
	)

A read_all() convenience overload.

read_all() [2/2]

bool Gio::InputStream::read_all	(	void *	buffer,
		gsize	count,
		gsize &	bytes_read,
		const Glib::RefPtr< Cancellable > &	cancellable
	)

Tries to read count bytes from the stream into the buffer starting at buffer.

Will block during this read.

This function is similar to g_input_stream_read(), except it tries to read as many bytes as requested, only stopping on an error or end of stream.

On a successful read of count bytes, or if we reached the end of the stream, true is returned, and bytes_read is set to the number of bytes read into buffer.

If there is an error during the operation false is returned and error is set to indicate the error status.

As a special exception to the normal conventions for functions that use Error, if this function returns false (and sets error) then bytes_read will be set to the number of bytes that were successfully read before the error was encountered. This functionality is only available from C. If you need it from another language then you must write your own loop around g_input_stream_read().

Parameters

buffer	A buffer to read data into (which should be at least count bytes long).
count	The number of bytes that will be read from the stream.
bytes_read	Location to store the number of bytes that was read from the stream.
cancellable	Optional Cancellable object, nullptr to ignore.

Returns

true on success, false if there was an error.

Exceptions

Glib::Error

read_all_async() [1/2]

void Gio::InputStream::read_all_async	(	void *	buffer,
		gsize	count,
		const SlotAsyncReady &	slot,
		const Glib::RefPtr< Cancellable > &	cancellable,
		int	io_priority = Glib::PRIORITY_DEFAULT
	)

Request an asynchronous read of count bytes from the stream into the buffer starting at buffer.

This is the asynchronous equivalent of read_all().

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

During an async request no other sync and async calls are allowed, and will result in Gio::Error with PENDING being thrown.

A value of count larger than MAXSSIZE will cause a Gio::Error with INVALID_ARGUMENT to be thrown.

On success, the number of bytes read into the buffer will be passed to the slot callback. It is not an error if this is not the same as the requested size, as it can happen e.g. near the end of a file, but generally we try to read as many bytes as requested. Zero is returned on end of file (or if count is zero), but never otherwise.

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

Parameters

buffer	A buffer to read data into (which should be at least count bytes long).
count	The number of bytes that will be read from the stream.
slot	Callback to call when the request is satisfied.
cancellable	A Cancellable object.
io_priority	The I/O priority of the request.

read_all_async() [2/2]

void Gio::InputStream::read_all_async	(	void *	buffer,
		gsize	count,
		const SlotAsyncReady &	slot,
		int	io_priority = Glib::PRIORITY_DEFAULT
	)

Request an asynchronous read of count bytes from the stream into the buffer starting at buffer.

This is the asynchronous equivalent of read_all().

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

During an async request no other sync and async calls are allowed, and will result in a Gio::Error with PENDING being thrown.

A value of count larger than MAXSSIZE will cause a Gio::Error with INVALID_ARGUMENT to be thrown.

On success, the number of bytes read into the buffer will be passed to the slot callback. It is not an error if this is not the same as the requested size, as it can happen e.g. near the end of a file, but generally we try to read as many bytes as requested. Zero is returned on end of file (or if count is zero), but never otherwise.

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

Parameters

buffer	A buffer to read data into (which should be at least count bytes long).
count	The number of bytes that will be read from the stream.
slot	Callback to call when the request is satisfied.
io_priority	The I/O priority of the request.

read_all_finish()

bool Gio::InputStream::read_all_finish	(	const Glib::RefPtr< AsyncResult > &	result,
		gsize &	bytes_read
	)

Finishes an asynchronous stream read operation started with g_input_stream_read_all_async().

As a special exception to the normal conventions for functions that use Error, if this function returns false (and sets error) then bytes_read will be set to the number of bytes that were successfully read before the error was encountered. This functionality is only available from C. If you need it from another language then you must write your own loop around g_input_stream_read_async().

Since glibmm 2.44:

Parameters

result	A AsyncResult.
bytes_read	Location to store the number of bytes that was read from the stream.

Returns

true on success, false if there was an error.

Exceptions

Glib::Error

read_async() [1/2]

void Gio::InputStream::read_async	(	void *	buffer,
		gsize	count,
		const SlotAsyncReady &	slot,
		const Glib::RefPtr< Cancellable > &	cancellable,
		int	io_priority = Glib::PRIORITY_DEFAULT
	)

Request an asynchronous read of count bytes from the stream into the buffer starting at buffer.

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

During an async request no other sync and async calls are allowed, and will result in Gio::Error with PENDING being thrown.

A value of count larger than MAXSSIZE will cause a Gio::Error with INVALID_ARGUMENT to be thrown.

On success, the number of bytes read into the buffer will be passed to the slot callback. It is not an error if this is not the same as the requested size, as it can happen e.g. near the end of a file, but generally we try to read as many bytes as requested. Zero is returned on end of file (or if count is zero), but never otherwise.

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

Parameters

buffer	A buffer to read data into (which should be at least count bytes long).
count	The number of bytes that will be read from the stream.
slot	Callback to call when the request is satisfied.
cancellable	A Cancellable object.
io_priority	The I/O priority of the request.

read_async() [2/2]

void Gio::InputStream::read_async	(	void *	buffer,
		gsize	count,
		const SlotAsyncReady &	slot,
		int	io_priority = Glib::PRIORITY_DEFAULT
	)

Request an asynchronous read of count bytes from the stream into the buffer starting at buffer.

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

During an async request no other sync and async calls are allowed, and will result in a Gio::Error with PENDING being thrown.

A value of count larger than MAXSSIZE will cause a Gio::Error with INVALID_ARGUMENT to be thrown.

On success, the number of bytes read into the buffer will be passed to the slot callback. It is not an error if this is not the same as the requested size, as it can happen e.g. near the end of a file, but generally we try to read as many bytes as requested. Zero is returned on end of file (or if count is zero), but never otherwise.

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

Parameters

buffer	A buffer to read data into (which should be at least count bytes long).
count	The number of bytes that will be read from the stream.
slot	Callback to call when the request is satisfied.
io_priority	The I/O priority of the request.

read_bytes()

Glib::RefPtr< Glib::Bytes > Gio::InputStream::read_bytes	(	gsize	count,
		const Glib::RefPtr< Cancellable > &	cancellable
	)

Like g_input_stream_read(), this tries to read count bytes from the stream in a blocking fashion.

However, rather than reading into a user-supplied buffer, this will create a new Bytes containing the data that was read. This may be easier to use from language bindings.

If count is zero, returns a zero-length Bytes and does nothing. A value of count larger than G_MAXSSIZE will cause a IO_ERROR_INVALID_ARGUMENT error.

On success, a new Bytes is returned. It is not an error if the size of this object is not the same as the requested size, as it can happen e.g. near the end of a file. A zero-length Bytes is returned on end of file (or if count is zero), but never otherwise.

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 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 nullptr is returned and error is set accordingly.

Since glibmm 2.34:

Parameters

count	Maximum number of bytes that will be read from the stream. Common values include 4096 and 8192.
cancellable	Optional Cancellable object, nullptr to ignore.

Returns

A new Bytes, or nullptr on error.

Exceptions

Glib::Error

read_bytes_async() [1/2]

void Gio::InputStream::read_bytes_async	(	gsize	count,
		const SlotAsyncReady &	slot,
		const Glib::RefPtr< Cancellable > &	cancellable,
		int	io_priority = Glib::PRIORITY_DEFAULT
	)

Request an asynchronous read of count bytes from the stream into a new Glib::Bytes.

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

During an async request no other sync and async calls are allowed, and will result in Gio::Error with PENDING being thrown.

A value of count larger than MAXSSIZE will cause a Gio::Error with INVALID_ARGUMENT to be thrown.

On success, the new Glib::Bytes will be passed to the callback. It is not an error if this is smaller than the requested size, as it can happen e.g. near the end of a file, but generally we try to read as many bytes as requested. Zero is returned on end of file (or if count is zero), but never otherwise.

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

Parameters

count	The number of bytes that will be read from the stream.
slot	Callback to call when the request is satisfied.
cancellable	A Cancellable object.
io_priority	The I/O priority of the request.

Since glibmm 2.34:

read_bytes_async() [2/2]

void Gio::InputStream::read_bytes_async	(	gsize	count,
		const SlotAsyncReady &	slot,
		int	io_priority = Glib::PRIORITY_DEFAULT
	)

Request an asynchronous read of count bytes from the stream into a new Glib::Bytes.

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

During an async request no other sync and async calls are allowed, and will result in Gio::Error with PENDING being thrown.

A value of count larger than MAXSSIZE will cause a Gio::Error with INVALID_ARGUMENT to be thrown.

On success, the new Glib::Bytes will be passed to the callback. It is not an error if this is smaller than the requested size, as it can happen e.g. near the end of a file, but generally we try to read as many bytes as requested. Zero is returned on end of file (or if count is zero), but never otherwise.

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

Parameters

count	The number of bytes that will be read from the stream.
slot	Callback to call when the request is satisfied.h
io_priority	The I/O priority of the request.

Since glibmm 2.34:

read_bytes_finish()

Glib::RefPtr< Glib::Bytes > Gio::InputStream::read_bytes_finish

(

const Glib::RefPtr< AsyncResult > &

result

)

Finishes an asynchronous stream read-into-Bytes operation.

Since glibmm 2.34:

Parameters

result

A AsyncResult.

Returns

The newly-allocated Bytes, or nullptr on error.

Exceptions

Glib::Error

read_finish()

gssize Gio::InputStream::read_finish

(

const Glib::RefPtr< AsyncResult > &

result

)

Finishes an asynchronous stream read operation.

Parameters

result

A AsyncResult.

Returns

Number of bytes read in, or -1 on error, or 0 on end of file.

Exceptions

Glib::Error

set_pending()

bool Gio::InputStream::set_pending ( )

protected

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 2.50:

Returns

true if pending was previously unset and is now set.

Exceptions

Glib::Error

skip() [1/2]

gssize Gio::InputStream::skip

(

gsize

count

)

A skip() convenience overload.

skip() [2/2]

gssize Gio::InputStream::skip	(	gsize	count,
		const Glib::RefPtr< Cancellable > &	cancellable
	)

Tries to skip count bytes from the stream.

Will block during the operation.

This is identical to g_input_stream_read(), from a behaviour standpoint, but the bytes that are skipped are not returned to the user. Some streams have an implementation that is more efficient than reading the data.

This function is optional for inherited classes, as the default implementation emulates it using read.

The operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, a Gio::Error will be thrown with CANCELLED. If an operation was partially finished when the operation was cancelled the partial result will be returned, without an error.

Parameters

count	The number of bytes that will be skipped from the stream.
cancellable	Cancellable object.

Returns

Number of bytes skipped, or -1 on error.

Exceptions

Glib::Error

skip_async() [1/2]

void Gio::InputStream::skip_async	(	gsize	count,
		const SlotAsyncReady &	slot,
		const Glib::RefPtr< Cancellable > &	cancellable,
		int	io_priority = Glib::PRIORITY_DEFAULT
	)

Request an asynchronous skip of count bytes from the stream into the buffer starting at buffer.

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

During an async request no other sync and async calls are allowed, and will result in Gio::Error with PENDING being thrown.

A value of count larger than MAXSSIZE will cause a Gio::Error with INVALID_ARGUMENT to be thrown.

On success, the number of bytes skipped 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. near the end of a file, but generally we try to skip as many bytes as requested. Zero is returned on end of file (or if count is zero), but never otherwise.

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

Parameters

count	The number of bytes that will be skipped from the stream.
slot	Callback to call when the request is satisfied.
cancellable	A Cancellable object.
io_priority	The I/O priority of the request.

skip_async() [2/2]

void Gio::InputStream::skip_async	(	gsize	count,
		const SlotAsyncReady &	slot,
		int	io_priority = Glib::PRIORITY_DEFAULT
	)

Request an asynchronous skip of count bytes from the stream into the buffer starting at buffer.

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

During an async request no other sync and async calls are allowed, and will result in Gio::Error with PENDING being thrown.

A value of count larger than MAXSSIZE will cause a Gio::Error with INVALID_ARGUMENT to be thrown.

On success, the number of bytes skipped 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. near the end of a file, but generally we try to skip as many bytes as requested. Zero is returned on end of file (or if count is zero), but never otherwise.

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

Parameters

count	The number of bytes that will be skipped from the stream.
slot	Callback to call when the request is satisfied.
io_priority	The I/O priority of the request.

skip_finish()

gssize Gio::InputStream::skip_finish

(

const Glib::RefPtr< AsyncResult > &

result

)

Finishes a stream skip operation.

Parameters

result

A AsyncResult.

Returns

The size of the bytes skipped, or -1 on error.

Exceptions

Glib::Error

Friends And Related Function Documentation

wrap()

Glib::RefPtr< Gio::InputStream > wrap ( GInputStream *  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.