A circular buffer that can be used to efficiently transfer data between buffers and/or streams. More...

#include <CircularBuffer.h++>

Inheritance diagram for CircularBuffer< T >:

Collaboration diagram for CircularBuffer< T >:

Public Member Functions
	CircularBuffer (uint_t size)
	Construct a new CircularBuffer with the given size. More...

	~CircularBuffer ()
	Destructor. More...

void	clear ()
	Clear the buffer. More...

void	setSize (uint_t newSize)
	Resize the buffer. More...

uint_t	write (const T *buf, uint_t count)
	Write data from an array into the buffer. More...

uint_t	write (Buffer< T > &buffer, uint_t count=0)
	Write data from a Buffer into the buffer. More...

uint_t	write (Stream &stream, uint_t count=0)
	Read data from a stream and write it into the buffer. More...

uint_t	read (T *buf, uint_t count)
	Read data from the buffer into an array. More...

uint_t	read (Buffer< T > &buffer, uint_t count=0)
	Read data from the buffer into a Buffer. More...

uint_t	read (Stream &stream, uint_t count=0)
	Read data from the buffer and write it to a stream. More...

uint_t	peek (const T &value, uint_t maxlen, bool &found, bool resetPeek=true)
	Scan forward from the current peek position for an element equal to the given value. More...

uint_t	fill (const T &value, uint_t count)
	Fill the buffer with the given value. More...

uint_t	getReadExtent () const
	Get the read extent. More...

uint_t	getWriteExtent () const
	Get the write extent. More...

uint_t	getRemaining () const
	Get the number of elements available to be read from the buffer. More...

uint_t	getPeekRemaining () const
	Get the number of elements available to be peeked, that is, the number of elements between the peek position and the write position. More...

bool	isEmpty () const
	Determine if the buffer is empty. More...

bool	isFull () const
	Determine if the buffer is full. More...

uint_t	getFree () const
	Get the number of elements available to be written to the buffer. More...

T *	getReadPos ()
	Get the current read position. More...

T *	getWritePos ()
	Get the current write position. More...

T *	getPeekPos ()
	Get the current peek position. More...

T *	advanceReadPos (uint_t count)
	Advance the read position by the given number of elements. More...

T *	advanceWritePos (uint_t count)
	Advance the write position by the given number of elements. More...

T *	advanceReadPos ()
	Advance the read position by the number of elements in the read extent, wrapping to the beginning of the buffer if necessary. More...

T *	advanceWritePos ()
	Advance the write position by the number of elements in the write extent, wrapping to the beginning of the buffer if necessary. More...

T *	advancePeekPos (uint_t count)
	Advance the peek position by the given number of elements, wrapping to the beginning of the buffer if necessary. More...

void	resetPeekPos ()
	Reset the peek position to the read position. More...

bool	isPartialWrite () const
	Determine if a partially-written element is in the buffer. More...

bool	isPartialRead () const
	Determine if a partially-read element is in the buffer. More...

void	markReadPos ()
	Marks the current read position. More...

void	rewindReadPos ()
	Rewinds the read position to the read mark, and clears the read mark. More...

void	markWritePos ()
	Marks the current write position. More...

void	rewindWritePos ()
	Rewinds the write position to the write mark, and clears the write mark. More...

bool	setReadPosFromMark (uint_t count)
	Moves the read position relative to the read mark. More...

bool	setWritePosFromMark (uint_t count)
	Moves the write position relative to the write mark. More...

uint_t	getSize () const
	Get the size of the buffer. More...

virtual bool	hasRemaining () const
	Test if the buffer has elements available to be read or written. More...

T *	getBase ()
	Get a pointer to the base of the buffer. More...

const T *	getBase () const
	Get a pointer to the base of the buffer. More...

Protected Attributes
T *	_data
	A pointer to the raw buffer. More...

uint_t	_size
	The size of the buffer. More...

bool	_owner
	Whether this object owns the raw buffer. More...

Detailed Description

template<typename T>
class ccxx::CircularBuffer< T >

A circular buffer that can be used to efficiently transfer data between buffers and/or streams.

The buffer has a read position and a write position, as well as a peek position. When either the read position or the write position reaches the end of the buffer, it wraps around to the beginning, but the read position can never overtake the write position. The peek position is always between the read position and the write position, and is used to "look ahead" for a specific value.

Author: Mark Lindner

Constructor & Destructor Documentation

◆ CircularBuffer()

CircularBuffer ( uint_t size )

Construct a new CircularBuffer with the given size.

Parameters

size	The capacity of the buffer, in elements.

◆ ~CircularBuffer()

~CircularBuffer ( )

Destructor.

Member Function Documentation

◆ advancePeekPos()

T* advancePeekPos ( uint_t count )

Advance the peek position by the given number of elements, wrapping to the beginning of the buffer if necessary.

If there are not enough elements between the current peek position and the write position, the peek position is not moved.

Parameters

count The number of elements to advance.

Returns: The new peek position.

◆ advanceReadPos() [1/2]

T* advanceReadPos ( uint_t count )

Advance the read position by the given number of elements.

Parameters

count The number of elements to advance. If the value is greater than the number of bytes available to be read, the read position is left unchanged.

Returns: The new read position.

◆ advanceReadPos() [2/2]

T* advanceReadPos ( )

inline

Advance the read position by the number of elements in the read extent, wrapping to the beginning of the buffer if necessary.

Returns: The new read position.

◆ advanceWritePos() [1/2]

T* advanceWritePos ( uint_t count )

Advance the write position by the given number of elements.

Parameters

count The number of elements to advance. If the value is greater than the number of elements available to be written, the write position is left unchanged.

Returns: The new write position.

◆ advanceWritePos() [2/2]

T* advanceWritePos ( )

inline

Advance the write position by the number of elements in the write extent, wrapping to the beginning of the buffer if necessary.

Returns: The new write position.

◆ clear()

void clear ( )

virtual

Clear the buffer.

Resets the buffer to an "empty" state.

Reimplemented from AbstractBuffer< T >.

◆ fill()

uint_t fill	(	const T &	value,
		uint_t	count
	)

Fill the buffer with the given value.

Fills the requested number of items. If the requested count exceeds the number of items available to be written, only the available (free) items are filled.

Parameters

value	The value to fill with.
count	The number of items to fill.

Returns: The number of items actually filled.

◆ getBase() [1/2]

T* getBase ( )

inlineinherited

Get a pointer to the base of the buffer.

◆ getBase() [2/2]

const T* getBase ( ) const

inlineinherited

Get a pointer to the base of the buffer.

◆ getFree()

uint_t getFree ( ) const

inline

Get the number of elements available to be written to the buffer.

◆ getPeekPos()

T* getPeekPos ( )

inline

Get the current peek position.

◆ getPeekRemaining()

uint_t getPeekRemaining ( ) const

inline

Get the number of elements available to be peeked, that is, the number of elements between the peek position and the write position.

◆ getReadExtent()

uint_t getReadExtent ( ) const

Get the read extent.

Returns: The number of contiguous elements that can be read beginning at the current read position, without wrapping to the beginning of the buffer.

◆ getReadPos()

T* getReadPos ( )

inline

Get the current read position.

◆ getRemaining()

uint_t getRemaining ( ) const

inlinevirtual

Get the number of elements available to be read from the buffer.

Implements AbstractBuffer< T >.

◆ getSize()

uint_t getSize ( ) const

inlineinherited

Get the size of the buffer.

Returns: The size, in elements.

◆ getWriteExtent()

uint_t getWriteExtent ( ) const

Get the write extent.

Returns: The number of contiguous elements that can be written beginning at the current write position, without wrapping to the beginning of the buffer.

◆ getWritePos()

T* getWritePos ( )

inline

Get the current write position.

◆ hasRemaining()

virtual bool hasRemaining ( ) const

inlinevirtualinherited

Test if the buffer has elements available to be read or written.

Reimplemented in Buffer< T >, and Buffer< char >.

◆ isEmpty()

bool isEmpty ( ) const

inline

Determine if the buffer is empty.

◆ isFull()

bool isFull ( ) const

inline

Determine if the buffer is full.

◆ isPartialRead()

bool isPartialRead ( ) const

inline

Determine if a partially-read element is in the buffer.

This will always be false when the template parameter is an object of size 1.

◆ isPartialWrite()

bool isPartialWrite ( ) const

inline

Determine if a partially-written element is in the buffer.

This will always be false when the template parameter is an object of size 1.

◆ markReadPos()

void markReadPos ( )

Marks the current read position.

As long as no writes are performed on the buffer, the read position can be rewound to the mark by calling rewindReadPos().

◆ markWritePos()

void markWritePos ( )

Marks the current write position.

As long as no reads are performed on the buffer, the write position can be rewound to the mark by calling rewindWritePos().

◆ peek()

uint_t peek	(	const T &	value,
		uint_t	maxlen,
		bool &	found,
		bool	resetPeek = `true`
	)

Scan forward from the current peek position for an element equal to the given value.

Parameters

value	The value to scan for.
maxlen	The maximum number of elements to scan.
found	A flag that is set to true if the item was found, and false otherwise.
resetPeek	If true, reset the peek position to the read position before scanning.

Returns: The number of elements between the current read position and the peeked value, inclusive, if found; otherwise, the number of elements scanned (up to maxlen).

◆ read() [1/3]

uint_t read	(	T *	buf,
		uint_t	count
	)

Read data from the buffer into an array.

Parameters

buf	The base of the array.
count	The number of elements to write to the array.

Returns: The number of elements actually written.

◆ read() [2/3]

uint_t read	(	Buffer< T > &	buffer,
		uint_t	count = `0`
	)

Read data from the buffer into a Buffer.

Parameters

buffer	The buffer to read into.
count	The number of elements to copy to the buffer, or 0 to write as much as possible.

Returns: The number of elements actually written.

◆ read() [3/3]

uint_t read	(	Stream &	stream,
		uint_t	count = `0`
	)

Read data from the buffer and write it to a stream.

Parameters

stream	The stream to write to.
count	The number of bytes to write to the stream.

Returns: The number of bytes actually written.

Exceptions

IOException If an I/O error occurs.

◆ resetPeekPos()

void resetPeekPos ( )

Reset the peek position to the read position.

◆ rewindReadPos()

void rewindReadPos ( )

Rewinds the read position to the read mark, and clears the read mark.

If no read mark is set, the method does nothing.

◆ rewindWritePos()

void rewindWritePos ( )

Rewinds the write position to the write mark, and clears the write mark.

If no write mark is set, the method does nothing.

◆ setReadPosFromMark()

bool setReadPosFromMark ( uint_t count )

Moves the read position relative to the read mark.

Parameters

count The offset to set the read position to, relative to the read mark.

Returns: true on success, or false if the count is invalid or if no read mark is currently set.

◆ setSize()

void setSize ( uint_t newSize )

virtual

Resize the buffer.

Parameters

newSize The new size, in elements.

Reimplemented from AbstractBuffer< T >.

◆ setWritePosFromMark()

bool setWritePosFromMark ( uint_t count )

Moves the write position relative to the write mark.

Parameters

count The offset to set the write position to, relative to the write mark.

Returns: true on success, or false if the count is invalid or if no write mark is currently set.

◆ write() [1/3]

uint_t write	(	const T *	buf,
		uint_t	count
	)

Write data from an array into the buffer.

Parameters

buf	The base of the array.
count	The number of elements to read from the array.

Returns: The number of elements actually read.

◆ write() [2/3]

uint_t write	(	Buffer< T > &	buffer,
		uint_t	count = `0`
	)

Write data from a Buffer into the buffer.

Parameters

buffer	The buffer of data to write.
count	The number of elements to write from the buffer, or 0 to write as much as possible.

Returns: The number of elements actually read.

◆ write() [3/3]

uint_t write	(	Stream &	stream,
		uint_t	count = `0`
	)

Read data from a stream and write it into the buffer.

Parameters

stream	The stream to read from.
count	The number of elements to write from the stream.

Returns: The number of elements actually written to the buffer.

Exceptions

IOException If an I/O error occurs.

Member Data Documentation

◆ _data

T* _data

protectedinherited

A pointer to the raw buffer.

◆ _owner

bool _owner

protectedinherited

Whether this object owns the raw buffer.

◆ _size

uint_t _size

protectedinherited

The size of the buffer.

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

CircularBuffer.h++

Public Member Functions

Protected Attributes

Detailed Description

template<typename T> class ccxx::CircularBuffer< T >

Constructor & Destructor Documentation

◆ CircularBuffer()

◆ ~CircularBuffer()

Member Function Documentation

◆ advancePeekPos()

◆ advanceReadPos() [1/2]

◆ advanceReadPos() [2/2]

◆ advanceWritePos() [1/2]

◆ advanceWritePos() [2/2]

◆ clear()

◆ fill()

◆ getBase() [1/2]

◆ getBase() [2/2]

◆ getFree()

◆ getPeekPos()

◆ getPeekRemaining()

◆ getReadExtent()

◆ getReadPos()

◆ getRemaining()

◆ getSize()

◆ getWriteExtent()

◆ getWritePos()

◆ hasRemaining()

◆ isEmpty()

◆ isFull()

◆ isPartialRead()

◆ isPartialWrite()

◆ markReadPos()

◆ markWritePos()

◆ peek()

◆ read() [1/3]

◆ read() [2/3]

◆ read() [3/3]

◆ resetPeekPos()

◆ rewindReadPos()

◆ rewindWritePos()

◆ setReadPosFromMark()

◆ setSize()

◆ setWritePosFromMark()

◆ write() [1/3]

◆ write() [2/3]

◆ write() [3/3]

Member Data Documentation

◆ _data

◆ _owner

◆ _size

template<typename T>
class ccxx::CircularBuffer< T >