Glib::Bytes Class Reference

A simple refcounted data type representing an immutable byte sequence from an unspecified origin. More...

#include <glibmm/bytes.h>

Public Member Functions
void	reference () const
	Increment the reference count for this object.
void	unreference () const
	Decrement the reference count for this object.
GBytes *	gobj ()
	Provides access to the underlying C instance.
const GBytes *	gobj () const
	Provides access to the underlying C instance.
GBytes *	gobj_copy () const
	Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.
	Bytes ()=delete
	Bytes (const Bytes &)=delete
Bytes &	operator= (const Bytes &)=delete
gconstpointer	get_data (gsize &size) const
	Get the byte data in the Bytes.
gsize	get_size () const
	Get the size of the byte data in the Bytes.

Static Public Member Functions
static Glib::RefPtr< Glib::Bytes >	create (gconstpointer data, gsize size)
static guint	hash (gconstpointer bytes)
	Creates an integer hash code for the byte data in the Bytes.
static bool	equal (gconstpointer bytes1, gconstpointer bytes2)
	Compares the two Bytes values being pointed to and returns true if they are equal.
static gint	compare (gconstpointer bytes1, gconstpointer bytes2)
	Compares the two Bytes values.

Protected Member Functions
void	operator delete (void *, std::size_t)

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

Detailed Description

A simple refcounted data type representing an immutable byte sequence from an unspecified origin.

The purpose of the Bytes class is to keep the memory region that it holds alive for as long as anyone holds a reference to the bytes. When the last reference count is dropped, the memory is released. Multiple unrelated callers can use byte data in the Bytes object without coordinating their activities, resting assured that the byte data will not change or move while they hold a reference.

A Bytes object can come from many different origins that may have different procedures for freeing the memory region. Examples are memory from g_malloc(), from memory slices, from a GMappedFile or memory from other allocators.

Since glibmm 2.34

Constructor & Destructor Documentation

Bytes() [1/2]

Glib::Bytes::Bytes ( )

delete

Bytes() [2/2]

Glib::Bytes::Bytes ( const Bytes & )

delete

Member Function Documentation

compare()

static gint Glib::Bytes::compare ( gconstpointer bytes1, gconstpointer bytes2 )

static

Compares the two Bytes values.

This function can be used to sort GBytes instances in lexicographical order.

If bytes1 and bytes2 have different length but the shorter one is a prefix of the longer one then the shorter one is considered to be less than the longer one. Otherwise the first byte where both differ is used for comparison. If bytes1 has a smaller value at that position it is considered less, otherwise greater than bytes2.

Since glibmm 2.32

Parameters

bytes1	A pointer to a Bytes.
bytes2	A pointer to a Bytes to compare with bytes1.

Returns

A negative value if bytes1 is less than bytes2, a positive value if bytes1 is greater than bytes2, and zero if bytes1 is equal to bytes2.

create()

static Glib::RefPtr< Glib::Bytes > Glib::Bytes::create ( gconstpointer data, gsize size )

static

equal()

static bool Glib::Bytes::equal ( gconstpointer bytes1, gconstpointer bytes2 )

static

Compares the two Bytes values being pointed to and returns true if they are equal.

This function can be passed to g_hash_table_new() as the key_equal_func parameter, when using non-nullptr Bytes pointers as keys in a HashTable.

Since glibmm 2.32

Parameters

bytes1	A pointer to a Bytes.
bytes2	A pointer to a Bytes to compare with bytes1.

Returns

true if the two keys match.

get_data()

gconstpointer Glib::Bytes::get_data

(

gsize &

size

)

const

Get the byte data in the Bytes.

This data should not be modified.

This function will always return the same pointer for a given Bytes.

nullptr may be returned if size is 0. This is not guaranteed, as the Bytes may represent an empty string with data non-nullptr and size as 0. nullptr will not be returned if size is non-zero.

Since glibmm 2.32

Parameters

size	Location to return size of byte data.

Returns

A pointer to the byte data, or nullptr.

get_size()

gsize Glib::Bytes::get_size

(

)

const

Get the size of the byte data in the Bytes.

This function will always return the same value for a given Bytes.

Since glibmm 2.32

Returns

The size.

gobj() [1/2]

GBytes * Glib::Bytes::gobj

(

)

Provides access to the underlying C instance.

gobj() [2/2]

const GBytes * Glib::Bytes::gobj

(

)

const

Provides access to the underlying C instance.

gobj_copy()

GBytes * Glib::Bytes::gobj_copy

(

)

const

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

hash()

static guint Glib::Bytes::hash ( gconstpointer bytes )

static

Creates an integer hash code for the byte data in the Bytes.

This function can be passed to g_hash_table_new() as the key_hash_func parameter, when using non-nullptr Bytes pointers as keys in a HashTable.

Since glibmm 2.32

Parameters

bytes

A pointer to a Bytes key.

Returns

A hash value corresponding to the key.

operator delete()

void Glib::Bytes::operator delete ( void * , std::size_t  )

protected

operator=()

Bytes & Glib::Bytes::operator= ( const Bytes & )

delete

reference()

void Glib::Bytes::reference

(

)

const

Increment the reference count for this object.

You should never need to do this manually - use the object via a RefPtr instead.

unreference()

void Glib::Bytes::unreference

(

)

const

Decrement the reference count for this object.

You should never need to do this manually - use the object via a RefPtr instead.

Friends And Related Symbol Documentation

wrap()

Glib::RefPtr< Glib::Bytes > wrap ( GBytes * 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.