epee::byte_slice Class Reference

#include <byte_slice.h>

Collaboration diagram for epee::byte_slice:

Classes
struct	adapt_buffer

Public Types
using	value_type = std::uint8_t
using	size_type = std::size_t
using	difference_type = std::ptrdiff_t
using	pointer = const std::uint8_t*
using	const_pointer = const std::uint8_t*
using	reference = std::uint8_t
using	const_reference = std::uint8_t
using	iterator = pointer
using	const_iterator = const_pointer

Public Member Functions
	byte_slice () noexcept
	Construct empty slice.
	byte_slice (std::nullptr_t) noexcept
	Construct empty slice.
	byte_slice (std::initializer_list< span< const std::uint8_t > > sources)
	Scatter-gather (copy) multiple sources into a single allocated slice.
	byte_slice (std::vector< std::uint8_t > &&buffer)
	Convert buffer into a slice using one allocation for shared count.
	byte_slice (std::string &&buffer)
	Convert buffer into a slice using one allocation for shared count.
	byte_slice (byte_stream &&stream, bool shrink=true)
	Convert stream into a slice with zero allocations.
	byte_slice (byte_slice &&source) noexcept
	~byte_slice () noexcept=default
byte_slice &	operator= (byte_slice &&) noexcept
byte_slice	clone () const noexcept
iterator	begin () const noexcept
const_iterator	cbegin () const noexcept
iterator	end () const noexcept
const_iterator	cend () const noexcept
bool	empty () const noexcept
const std::uint8_t *	data () const noexcept
std::size_t	size () const noexcept
std::size_t	remove_prefix (std::size_t max_bytes) noexcept
byte_slice	take_slice (std::size_t max_bytes) noexcept
byte_slice	get_slice (std::size_t begin, std::size_t end) const
std::unique_ptr< byte_slice_data, release_byte_slice >	take_buffer () noexcept

Private Member Functions
	byte_slice (byte_slice_data *storage, span< const std::uint8_t > portion) noexcept
	Internal use only; use to increase storage reference count.
template<typename T>
	byte_slice (const adapt_buffer, T &&buffer)

Private Attributes
std::unique_ptr< byte_slice_data, release_byte_slice >	storage_
span< const std::uint8_t >	portion_

Detailed Description

Inspired by slices in golang. Storage is thread-safe reference counted, allowing for cheap copies or range selection on the bytes. The bytes owned by this class are always immutable.

The functions operator=, take_slice and remove_prefix may alter the reference count for the backing store, which will invalidate pointers previously returned if the reference count is zero. Be careful about "caching" pointers in these circumstances.

Member Typedef Documentation

const_iterator

using epee::byte_slice::const_iterator = const_pointer

const_pointer

using epee::byte_slice::const_pointer = const std::uint8_t*

const_reference

using epee::byte_slice::const_reference = std::uint8_t

difference_type

using epee::byte_slice::difference_type = std::ptrdiff_t

iterator

using epee::byte_slice::iterator = pointer

pointer

using epee::byte_slice::pointer = const std::uint8_t*

reference

using epee::byte_slice::reference = std::uint8_t

size_type

using epee::byte_slice::size_type = std::size_t

value_type

using epee::byte_slice::value_type = std::uint8_t

Constructor & Destructor Documentation

byte_slice() [1/9]

epee::byte_slice::byte_slice ( byte_slice_data * storage, span< const std::uint8_t > portion )

privatenoexcept

Internal use only; use to increase storage reference count.

byte_slice() [2/9]

template<typename T>

epee::byte_slice::byte_slice ( const adapt_buffer , T && buffer )

explicitprivate

byte_slice() [3/9]

epee::byte_slice::byte_slice ( )

inlinenoexcept

Construct empty slice.

byte_slice() [4/9]

epee::byte_slice::byte_slice ( std::nullptr_t )

inlinenoexcept

Construct empty slice.

byte_slice() [5/9]

epee::byte_slice::byte_slice ( std::initializer_list< span< const std::uint8_t > > sources )

explicit

Scatter-gather (copy) multiple sources into a single allocated slice.

byte_slice() [6/9]

epee::byte_slice::byte_slice ( std::vector< std::uint8_t > && buffer )

explicit

Convert buffer into a slice using one allocation for shared count.

byte_slice() [7/9]

epee::byte_slice::byte_slice ( std::string && buffer )

explicit

Convert buffer into a slice using one allocation for shared count.

byte_slice() [8/9]

epee::byte_slice::byte_slice ( byte_stream && stream, bool shrink = true )

explicit

Convert stream into a slice with zero allocations.

byte_slice() [9/9]

epee::byte_slice::byte_slice ( byte_slice && source )

noexcept

~byte_slice()

epee::byte_slice::~byte_slice ( )

defaultnoexcept

Member Function Documentation

begin()

iterator epee::byte_slice::begin ( ) const

inlinenoexcept

cbegin()

const_iterator epee::byte_slice::cbegin ( ) const

inlinenoexcept

cend()

const_iterator epee::byte_slice::cend ( ) const

inlinenoexcept

clone()

byte_slice epee::byte_slice::clone ( ) const

inlinenoexcept

Returns

A shallow (cheap) copy of the data from this slice.

data()

const std::uint8_t * epee::byte_slice::data ( ) const

inlinenoexcept

empty()

bool epee::byte_slice::empty ( ) const

inlinenoexcept

end()

iterator epee::byte_slice::end ( ) const

inlinenoexcept

get_slice()

byte_slice epee::byte_slice::get_slice	(	std::size_t	begin,
		std::size_t	end ) const

Return a shallow (cheap) copy of a slice from begin and end offsets.

Exceptions

std::out_of_range	If end < begin.
std::out_of_range	If size() < end.

Returns

Slice starting at data() + begin of size end - begin.

operator=()

byte_slice & epee::byte_slice::operator= ( byte_slice && source )

noexcept

Note

May invalidate previously retrieved pointers.

remove_prefix()

std::size_t epee::byte_slice::remove_prefix ( std::size_t max_bytes )

noexcept

Drop bytes from the beginning of this slice.

Note

May invalidate previously retrieved pointers.

Postcondition

this->size() = this->size() - std::min(this->size(), max_bytes)

if (this->size() <= max_bytes) this->data() = nullptr

Returns

Number of bytes removed.

size()

std::size_t epee::byte_slice::size ( ) const

inlinenoexcept

take_buffer()

std::unique_ptr< byte_slice_data, release_byte_slice > epee::byte_slice::take_buffer ( )

noexcept

Postcondition

empty()

Returns

Ownership of ref-counted buffer.

take_slice()

byte_slice epee::byte_slice::take_slice ( std::size_t max_bytes )

noexcept

"Take" bytes from the beginning of this slice.

Note

May invalidate previously retrieved pointers.

Postcondition

this->size() = this->size() - std::min(this->size(), max_bytes)

if (this->size() <= max_bytes) this->data() = nullptr

Returns

Slice containing the bytes removed from this slice.

Member Data Documentation

portion_

span<const std::uint8_t> epee::byte_slice::portion_

private

storage_

std::unique_ptr<byte_slice_data, release_byte_slice> epee::byte_slice::storage_

private

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

• contrib/epee/include/byte_slice.h
• contrib/epee/src/byte_slice.cpp