Glib::Checksum Class Reference

Computes the checksum for data. More...

#include <glibmm/checksum.h>

Public Types
enum class	Type {   MD5 ,   SHA1 ,   SHA256 ,   SHA512 ,   SHA384 }

Public Member Functions
	Checksum ()
	Checksum (GChecksum *gobject, bool make_a_copy=true)
	Checksum (const Checksum &other)
Checksum &	operator= (const Checksum &other)
	Checksum (Checksum &&other) noexcept
Checksum &	operator= (Checksum &&other) noexcept
	~Checksum () noexcept
void	swap (Checksum &other) noexcept
GChecksum *	gobj ()
	Provides access to the underlying C instance.
const GChecksum *	gobj () const
	Provides access to the underlying C instance.
GChecksum *	gobj_copy () const
	Provides access to the underlying C instance. The caller is responsible for freeing it. Use when directly setting fields in structs.
	Checksum (Type checksum_type)
	Creates a new Checksum, using the checksum algorithm checksum_type.
	operator bool () const
	Returns true if the Checksum object is valid.
void	reset ()
	Resets the state of the checksum back to its initial state.
void	update (const guchar *data, gssize length)
	Feeds data into an existing Checksum.
void	update (const std::string &data)
	Feeds data into an existing Checksum.
void	get_digest (guint8 *buffer, gsize *digest_len) const
	Gets the digest from checksum as a raw binary vector and places it into buffer.
std::string	get_string () const
	Gets the digest as a hexadecimal string.

Static Public Member Functions
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system.
static std::string	compute_checksum (Type checksum_type, const guchar *data, gsize length)
	Computes the checksum for a binary data of length.
static std::string	compute_checksum (Type checksum_type, const std::string & str)
	Computes the checksum of a string.
static gssize	get_length (Type checksum_type)
	Gets the length in bytes of digests of type checksum_type.

Protected Attributes
GChecksum *	gobject_

Related Symbols
(Note that these are not member symbols.)
void	swap (Checksum &lhs, Checksum &rhs) noexcept
Glib::Checksum	wrap (GChecksum *object, bool take_copy=false)
	A Glib::wrap() method for this object.

Detailed Description

Computes the checksum for data.

This is a generic API for computing checksums (or "digests") for a sequence of arbitrary bytes, using various hashing algorithms like MD5, SHA-1 and SHA-256. Checksums are commonly used in various environments and specifications.

glibmm supports incremental checksums by calling update() as long as there's data available and then using get_string() or get_digest() to compute the checksum and return it either as a string in hexadecimal form, or as a raw sequence of bytes. To compute the checksum for binary blobs and NULL-terminated strings in one go, use the static compute_checksum() convenience functions().

Since glibmm 2.16:

Member Enumeration Documentation

Type

enum class Glib::Checksum::Type

strong

Enumerator
MD5	Use the MD5 hashing algorithm.
SHA1	Use the SHA-1 hashing algorithm.
SHA256	Use the SHA-256 hashing algorithm.
SHA512	Use the SHA-512 hashing algorithm (Since: 2.36).
SHA384	Use the SHA-384 hashing algorithm (Since: 2.51).

Constructor & Destructor Documentation

Checksum() [1/5]

Glib::Checksum::Checksum

(

)

Checksum() [2/5]

Glib::Checksum::Checksum ( GChecksum *  gobject, bool  make_a_copy = true  )

explicit

Checksum() [3/5]

Glib::Checksum::Checksum

(

const Checksum &

other

)

Checksum() [4/5]

Glib::Checksum::Checksum ( Checksum &&  other )

noexcept

~Checksum()

Glib::Checksum::~Checksum ( )

noexcept

Checksum() [5/5]

Glib::Checksum::Checksum ( Type  checksum_type )

explicit

Creates a new Checksum, using the checksum algorithm checksum_type.

If the checksum_type is not known, then operator bool() will return false.

Parameters

checksum_type

Checksum type, one of defined above.

Member Function Documentation

compute_checksum() [1/2]

static std::string Glib::Checksum::compute_checksum ( Type  checksum_type, const guchar *  data, gsize  length  )

static

Computes the checksum for a binary data of length.

This is a convenience wrapper for g_checksum_new(), g_checksum_get_string() and g_checksum_free().

The hexadecimal string returned will be in lower case.

Since glibmm 2.16:

Parameters

checksum_type	A Glib::Checksum::Type.
data	Binary blob to compute the digest of.
length	Length of data.

Returns

The digest of the binary data as a string in hexadecimal, or nullptr if g_checksum_new() fails for checksum_type.

compute_checksum() [2/2]

static std::string Glib::Checksum::compute_checksum ( Type  checksum_type, const std::string &  str  )

static

Computes the checksum of a string.

Parameters

checksum_type	A Type
str	The string to compute the checksum of.

Returns

The checksum as a hexadecimal string.

get_digest()

void Glib::Checksum::get_digest	(	guint8 *	buffer,
		gsize *	digest_len
	)		const

Gets the digest from checksum as a raw binary vector and places it into buffer.

The size of the digest depends on the type of checksum.

Once this function has been called, the Checksum is closed and can no longer be updated with g_checksum_update().

Since glibmm 2.16:

Parameters

buffer	Output buffer.
digest_len	An inout parameter. The caller initializes it to the size of buffer. After the call it contains the length of the digest.

get_length()

static gssize Glib::Checksum::get_length ( Type  checksum_type )

static

Gets the length in bytes of digests of type checksum_type.

Parameters

checksum_type

A Type.

Returns

The checksum length, or -1 if checksum_type is not supported.

get_string()

std::string Glib::Checksum::get_string

(

)

const

Gets the digest as a hexadecimal string.

Once this function has been called the Checksum can no longer be updated with g_checksum_update().

The hexadecimal characters will be lower case.

Since glibmm 2.16:

Returns

The hexadecimal representation of the checksum. The returned string is owned by the checksum and should not be modified or freed.

get_type()

static GType Glib::Checksum::get_type ( )

static

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

gobj() [1/2]

GChecksum * Glib::Checksum::gobj ( )

inline

Provides access to the underlying C instance.

gobj() [2/2]

const GChecksum * Glib::Checksum::gobj ( ) const

inline

Provides access to the underlying C instance.

gobj_copy()

GChecksum * Glib::Checksum::gobj_copy

(

)

const

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

operator bool()

Glib::Checksum::operator bool ( ) const

explicit

Returns true if the Checksum object is valid.

This will return false, for instance, if an unsupported checksum type was provided to the constructor.

operator=() [1/2]

Checksum & Glib::Checksum::operator= ( Checksum &&  other )

noexcept

operator=() [2/2]

Checksum & Glib::Checksum::operator=

(

const Checksum &

other

)

reset()

void Glib::Checksum::reset

(

)

Resets the state of the checksum back to its initial state.

Since glibmm 2.18:

swap()

void Glib::Checksum::swap ( Checksum &  other )

noexcept

update() [1/2]

void Glib::Checksum::update	(	const guchar *	data,
		gssize	length
	)

Feeds data into an existing Checksum.

The checksum must still be open, that is g_checksum_get_string() or g_checksum_get_digest() must not have been called on checksum.

Since glibmm 2.16:

Parameters

data	Buffer used to compute the checksum.
length	Size of the buffer, or -1 if it is a null-terminated string.

update() [2/2]

void Glib::Checksum::update

(

const std::string &

data

)

Feeds data into an existing Checksum.

The checksum must still be open, that is get_string() or get_digest() must not have been called on the checksum.

Parameters

data	Buffer used to compute the checksum

Friends And Related Symbol Documentation

swap()

void swap ( Checksum &  lhs, Checksum &  rhs  )

related

Parameters

lhs	The left-hand side
rhs	The right-hand side

wrap()

Glib::Checksum wrap ( GChecksum *  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.

Member Data Documentation

gobject_

GChecksum* Glib::Checksum::gobject_

protected