sfs3::entities::ByteBuffer Class Reference

A growable buffer of bytes, with a read cursor and a write cursor. More...

#include <ByteBuffer.h>

Public Member Functions
	ByteBuffer ()
	Builds an unbounded buffer, which grows as long as there is memory.
	ByteBuffer (size_t capacity)
	Builds a bounded buffer.
	ByteBuffer (std::vector< uint8_t > bytes)
	Builds an unbounded buffer around bytes that already exist.
size_t	readPosition () const
void	readPosition (size_t newPos)
size_t	writePosition () const
void	writePosition (size_t newPos)
size_t	capacity () const
size_t	remaining () const
bool	hasRemaining () const
void	rewind ()
	Puts the read cursor back to the start of the buffer.
void	clear ()
	Empties the buffer and puts both cursors back to the start.
BufferView	view () const
	Returns a view of the whole backing store.
BufferView	remainingView () const
	Returns a view of the region still to read, from the read cursor to the write cursor.
const std::vector< uint8_t > &	bytes () const
	Returns the backing store.
uint8_t	read ()
BufferView	readView (size_t size)
	Reads a run of bytes without copying them.
std::vector< uint8_t >	read (size_t size)
	Reads a run of bytes into a new vector.
void	prepend (BufferView header)
	Inserts bytes in front of the content that is already in the buffer.
void	prepend (const std::vector< uint8_t > &bytes)
void	prepend (const uint8_t *bytes, size_t len)
std::string	hexDump () const
std::string	status () const

Static Public Member Functions
static std::string	hexDump (BufferView data)

Detailed Description

A growable buffer of bytes, with a read cursor and a write cursor.

Every read and write moves its own cursor forward, so you can fill a buffer and then read it back from the start with ByteBuffer::rewind. All the multi-byte numbers are big-endian, which is the byte order of the SmartFoxServer protocol.

A buffer is either bounded, with a fixed capacity given at construction, or unbounded, in which case it grows as needed.

Constructor & Destructor Documentation

ByteBuffer() [1/2]

sfs3::entities::ByteBuffer::ByteBuffer

(

size_t

capacity

)

Builds a bounded buffer.

Parameters

capacity

the fixed size of the buffer, in bytes

ByteBuffer() [2/2]

sfs3::entities::ByteBuffer::ByteBuffer

(

std::vector< uint8_t >

bytes

)

Builds an unbounded buffer around bytes that already exist.

Parameters

bytes

the bytes the buffer takes over

Member Function Documentation

readPosition() [1/2]

size_t sfs3::entities::ByteBuffer::readPosition

(

)

const

Returns

the position of the read cursor

readPosition() [2/2]

void sfs3::entities::ByteBuffer::readPosition

(

size_t

newPos

)

Parameters

newPos

the new position of the read cursor

writePosition() [1/2]

size_t sfs3::entities::ByteBuffer::writePosition

(

)

const

Returns

the position of the write cursor, which is also the amount of data in the buffer

writePosition() [2/2]

void sfs3::entities::ByteBuffer::writePosition

(

size_t

newPos

)

Parameters

newPos

the new position of the write cursor

capacity()

size_t sfs3::entities::ByteBuffer::capacity

(

)

const

Returns

the size of the backing store, in bytes

remaining()

size_t sfs3::entities::ByteBuffer::remaining

(

)

const

Returns

the number of bytes still to read, that is, write position minus read position

hasRemaining()

bool sfs3::entities::ByteBuffer::hasRemaining

(

)

const

Returns

true if there is at least one byte still to read

view()

BufferView sfs3::entities::ByteBuffer::view

(

)

const

Returns a view of the whole backing store.

NOTE: this covers the full capacity, including the bytes past the write position that were never written. To read only the data that is really in the buffer, bound the view with ByteBuffer::writePosition, or use ByteBuffer::remainingView.

Returns

a view of the backing store

remainingView()

BufferView sfs3::entities::ByteBuffer::remainingView

(

)

const

Returns a view of the region still to read, from the read cursor to the write cursor.

Use this, and not ByteBuffer::view, on a buffer that is partly consumed: view() always starts at the first byte and would hand back the bytes the reader already walked past.

Returns

a view of the bytes still to read

bytes()

const std::vector< uint8_t > & sfs3::entities::ByteBuffer::bytes

(

)

const

Returns the backing store.

NOTE: as with ByteBuffer::view, this is the full capacity, including any bytes past the write position that were never written.

Returns

the bytes of the buffer

read() [1/2]

uint8_t sfs3::entities::ByteBuffer::read

(

)

Returns

the next byte, moving the read cursor forward by one

readView()

BufferView sfs3::entities::ByteBuffer::readView

(

size_t

size

)

Reads a run of bytes without copying them.

Parameters

size	how many bytes to read

Returns

a view of those bytes, valid as long as the buffer is not changed

read() [2/2]

std::vector< uint8_t > sfs3::entities::ByteBuffer::read

(

size_t

size

)

Reads a run of bytes into a new vector.

Parameters

size	how many bytes to read

Returns

a copy of those bytes

prepend() [1/3]

void sfs3::entities::ByteBuffer::prepend

(

BufferView

header

)

Inserts bytes in front of the content that is already in the buffer.

This is how the protocol wraps a payload in its headers. The cost grows with the size of the buffer, because the payload is moved forward. Both cursors move with it, so a read that is in progress stays on the same byte.

Parameters

header

the bytes to insert at the start

prepend() [2/3]

void sfs3::entities::ByteBuffer::prepend

(

const std::vector< uint8_t > &

bytes

)

See also

ByteBuffer::prepend(BufferView)

prepend() [3/3]

void sfs3::entities::ByteBuffer::prepend	(	const uint8_t *	bytes,
		size_t	len )

See also

ByteBuffer::prepend(BufferView)

hexDump() [1/2]

std::string sfs3::entities::ByteBuffer::hexDump

(

)

const

Returns

the content of the buffer as a pretty-printed hexadecimal dump

hexDump() [2/2]

std::string sfs3::entities::ByteBuffer::hexDump ( BufferView data )

static

Returns

the given bytes as a pretty-printed hexadecimal dump

status()

std::string sfs3::entities::ByteBuffer::status

(

)

const

Returns

the capacity and the two cursor positions as text, for logging and debugging

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

• entities/ByteBuffer.h
• entities/ByteBuffer.cpp