Blob Class Reference

#include <Blob.h>

Public Member Functions
	Blob ()
	Blob (const Blob &)=delete
	Blob (Blob &&other)
	~Blob ()=default
Blob &	operator= (const Blob &)=delete
Blob &	operator= (Blob &&other)
Blob	subBlob (size_t offset, size_t size=-1) const
size_t	size () const
bool	empty () const
const void *	data () const
bool	operator! () const
	operator bool () const
std::string_view	string_view () const
const std::string &	displayPath () const
Blob	withDisplayPath (std::string_view displayPath)

Static Public Member Functions
static Blob	fromMalloc (const void *data, size_t size)
static Blob	fromMalloc (std::unique_ptr< void, FreeDeleter > data, size_t size)
static Blob	fromFile (std::string_view path)
static Blob	fromString (std::string string)
static Blob	copy (const void *data, size_t size)
static Blob	copy (const Blob &other)
static Blob	view (const void *data, size_t size)
static Blob	view (std::string_view data)
static Blob	read (FILE *file, size_t size)
static Blob	read (InputStream *stream, size_t size)
static Blob	concat (const Blob &l, const Blob &r)
static Blob	share (const Blob &other)

Private Attributes
const void *	_data = nullptr
size_t	_size = 0
std::shared_ptr< void >	_state
std::string	_displayPath

Friends
void	swap (Blob &l, Blob &r)

Detailed Description

Blob is an abstraction that couples a contiguous memory region with the knowledge of how to deallocate it.

Deallocation is type-erased (like it's done in std::shared_ptr), so you don't have to pass in deleter as a template parameter.

For debug and error reporting purposes, Blob also stores a string describing the data source.

Constructor & Destructor Documentation

Blob() [1/3]

Blob::Blob ( )

inline

Blob() [2/3]

Blob::Blob ( const Blob &  )

delete

Blob() [3/3]

Blob::Blob ( Blob &&  other )

inline

~Blob()

Blob::~Blob ( )

default

Member Function Documentation

concat()

Blob Blob::concat ( const Blob &  l, const Blob &  r  )

static

Parameters

l	First blob.
r	Second blob.

Returns

Newly allocated blob that contains a concatenation of the data of the two provided blobs.

copy() [1/2]

Blob Blob::copy ( const Blob &  other )

static

Parameters

other

Blob to copy.

Returns

Copy of the provided Blob in malloc-allocated memory.

copy() [2/2]

Blob Blob::copy ( const void *  data, size_t  size  )

static

Parameters

data	Memory region pointer.
size	Memory region size.

Returns

Blob that owns a copy of the provided memory region.

data()

const void * Blob::data ( ) const

inline

displayPath()

const std::string & Blob::displayPath ( ) const

inline

empty()

bool Blob::empty ( ) const

inline

fromFile()

Blob Blob::fromFile ( std::string_view  path )

static

Parameters

path	Path to a file.

Returns

Blob that wraps the memory mapping of the provided file, with display path set to path.

Exceptions

std::runtime_error

If file doesn't exist or on some other OS error.

fromMalloc() [1/2]

Blob Blob::fromMalloc ( const void *  data, size_t  size  )

static

Parameters

data	Pointer to a malloc-allocated memory region.
size	Size of the memory region.

Returns

Blob that takes ownership of the provided memory region.

fromMalloc() [2/2]

Blob Blob::fromMalloc ( std::unique_ptr< void, FreeDeleter >  data, size_t  size  )

static

fromString()

Blob Blob::fromString ( std::string  string )

static

Parameters

string

String to create a blob from.

Returns

Blob that wraps the provided string.

operator bool()

Blob::operator bool ( ) const

inlineexplicit

operator!()

bool Blob::operator! ( ) const

inline

operator=() [1/2]

Blob & Blob::operator= ( Blob &&  other )

inline

operator=() [2/2]

Blob & Blob::operator= ( const Blob &  )

delete

read() [1/2]

Blob Blob::read ( FILE *  file, size_t  size  )

static

Parameters

file	File to read from.
size	Number of bytes to read.

Returns

Blob that owns the data that was read from the provided file.

Exceptions

Exception

If the provided number of bytes couldn't be read.

read() [2/2]

Blob Blob::read ( InputStream *  stream, size_t  size  )

static

Parameters

stream	Stream to read from.
size	Number of bytes to read.

Returns

Blob that owns the data that was read from the provided file, with display path set to the display path of the passed stream.

Exceptions

Exception

If the provided number of bytes couldn't be read.

share()

Blob Blob::share ( const Blob &  other )

static

Parameters

other

Blob to share.

Returns

Blob that shares the memory ownership with other.

size()

size_t Blob::size ( ) const

inline

string_view()

std::string_view Blob::string_view ( ) const

inline

subBlob()

Blob Blob::subBlob	(	size_t	offset,
		size_t	size = -1
	)		const

Pretty much like substr, but for Blobs.

Important difference from substr is that the underlying memory is not copied and is instead shared between the two blobs. It will be freed when both are destroyed, so cases where a small subblob holds a 100Mb chunk of memory are possible, be careful.

Also, this function doesn't throw std::out_of_range if offset is larger than the blob's size, returning an empty blob in this case instead.

Parameters

offset	Offset in the blob.
size	Size of the subblob.

Returns

Subblob that shares the ownership of the underlying memory with this blob.

view() [1/2]

Blob Blob::view ( const void *  data, size_t  size  )

static

Parameters

data	Memory region pointer.
size	Memory region size.

Returns

Non-owning blob view into the provided memory region.

view() [2/2]

Blob Blob::view ( std::string_view  data )

static

Parameters

data	Memory region

Returns

Non-owning blob view into the provided memory region.

withDisplayPath()

Blob Blob::withDisplayPath ( std::string_view  displayPath )

inline

Friends And Related Function Documentation

swap

void swap ( Blob &  l, Blob &  r  )

friend

Member Data Documentation

_data

const void* Blob::_data = nullptr

private

_displayPath

std::string Blob::_displayPath

private

_size

size_t Blob::_size = 0

private

_state

std::shared_ptr<void> Blob::_state

private

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The documentation for this class was generated from the following files:

• src/Utility/Memory/Blob.h
• src/Utility/Memory/Blob.cpp