Glib::Checksum Class Reference

Computes the checksum for data. More...

#include <glibmm/checksum.h>

Public Types
enum	ChecksumType {   CHECKSUM_MD5,   CHECKSUM_SHA1,   CHECKSUM_SHA256,   CHECKSUM_SHA512 }
	The hashing algorithm to be used by Checksum when performing the digest of some data. More...

Public Member Functions
	Checksum ()
	Constructs an invalid object. More...
	Checksum (GChecksum* castitem, bool make_a_copy=false)
	Checksum (const Checksum& src)
Checksum&	operator= (const Checksum& src)
	Checksum (Checksum&& other) noexcept
Checksum&	operator= (Checksum&& other) noexcept
	~Checksum () noexcept
void	swap (Checksum& other) noexcept
GChecksum*	gobj ()
const GChecksum*	gobj () const
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. More...
	Checksum (ChecksumType checksum_type)
	Creates a new Checksum, using the checksum algorithm checksum_type. More...
	operator bool () const
	Returns true if the Checksum object is valid. More...
void	reset ()
	Resets the state of the checksum back to its initial state. More...
void	update (const guchar* data, gsize length)
	Feeds data into an existing Checksum. More...
void	update (const std::string& data)
	Feeds data into an existing Checksum. More...
void	get_digest (guint8* buffer, gsize* digest_len) const
	Gets the digest from checksum as a raw binary vector and places it into buffer. More...
std::string	get_string () const
	Gets the digest as an hexadecimal string. More...

Static Public Member Functions
static std::string	compute_checksum (ChecksumType checksum_type, const guchar* data, gsize length)
	Computes the checksum for a binary data of length. More...
static std::string	compute_checksum (ChecksumType checksum_type, const std::string& str)
	Computes the checksum of a string. More...
static gssize	get_length (ChecksumType checksum_type)
	Gets the length in bytes of digests of type checksum_type. More...

Protected Attributes
GChecksum*	gobject_

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

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:

Constructor & Destructor Documentation

Checksum() [1/5]

Glib::Checksum::Checksum

(

)

Constructs an invalid object.

E.g. for output arguments to methods. There is not much you can do with the object before it has been assigned a valid value.

Checksum() [2/5]

Glib::Checksum::Checksum ( GChecksum *  castitem, bool  make_a_copy = false  )

explicit

Checksum() [3/5]

Glib::Checksum::Checksum

(

const Checksum&

src

)

Checksum() [4/5]

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

noexcept

~Checksum()

Glib::Checksum::~Checksum ( )

noexcept

Checksum() [5/5]

Glib::Checksum::Checksum ( ChecksumType  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 ( ChecksumType  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 ChecksumType.
data	Binary blob to compute the digest of.
length	Length of data.

Returns

The digest of the binary data as a string in hexadecimal.

compute_checksum() [2/2]

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

static

Computes the checksum of a string.

Parameters

checksum_type	A ChecksumType
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 ( ChecksumType  checksum_type )

static

Gets the length in bytes of digests of type checksum_type.

Parameters

checksum_type

A ChecksumType.

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 an 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.

gobj() [1/2]

GChecksum* Glib::Checksum::gobj ( )

inline

gobj() [2/2]

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

inline

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=

(

const Checksum&

src

)

operator=() [2/2]

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

noexcept

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,
		gsize	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 Function 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