MBufferCircular Class Reference

Byte buffer with variable capacity that allows efficient buffering by having one reader/getter and one writer/putter. More...

Public Types
enum	{ DEFAULT_INITIAL_CAPACITY = 1024 }

Public Member Functions
	MBufferCircular (unsigned initialCapacity=DEFAULT_INITIAL_CAPACITY)
	Create buffer of a given initial capacity. More...
	~MBufferCircular ()
	Circular buffer destructor.
unsigned	GetSize () const
	Number of bytes buffered, available for getting.
unsigned	CanPutWithoutResize () const
	How many bytes can be put into circular buffer without necessity to reallocate buffer. More...
void	Clear ()
	Clear the contents of the buffer so the size becomes zero.
void	Resize (unsigned newCapacity)
	Resize the buffer to given capacity. More...
void	Put (const char *buff, unsigned size)
	Put the whole given buffer, grow object capacity if necessary. More...
unsigned	Get (char *buff, unsigned size)
	Get the data given chunk from the circular buffer. More...

Detailed Description

Byte buffer with variable capacity that allows efficient buffering by having one reader/getter and one writer/putter.

This is a slightly more efficient std::deque, which lacks methods to pop chunks of bytes. Grows as necessary to accommodate putting of any number of bytes. However, of course, one cannot get more bytes than available in the buffer. The class is low level and it does not throw exceptions as any would be a program error. Synchronization has to be provided outside.

Member Enumeration Documentation

anonymous enum

Enumerator
DEFAULT_INITIAL_CAPACITY	Default initial capacity of the buffer.

Constructor & Destructor Documentation

MBufferCircular::MBufferCircular

(

unsigned

initialCapacity = DEFAULT_INITIAL_CAPACITY

)

Create buffer of a given initial capacity.

Parameters

initialCapacity

Byte size of the initial buffer, will grow if necessary. Should be more than 2, typical is a power of 2 like 512. The default initial capacity is 1024.

Member Function Documentation

unsigned MBufferCircular::CanPutWithoutResize ( ) const

inline

How many bytes can be put into circular buffer without necessity to reallocate buffer.

This method is rarely needed as the buffer is reallocated at necessity.

unsigned MBufferCircular::Get	(	char *	buff,
		unsigned	size
	)

Get the data given chunk from the circular buffer.

Parameters

buff	Buffer where to get the data.
size	Size of the chunk. Size and offset should fit within the buffer length.

Returns

Actual number of bytes got, could be zero if the buffer is empty.

void MBufferCircular::Put	(	const char *	buff,
		unsigned	size
	)

Put the whole given buffer, grow object capacity if necessary.

Parameters

buff	Buffer where the chunk is located.
size	Size of the chunk.

void MBufferCircular::Resize

(

unsigned

newCapacity

)

Resize the buffer to given capacity.

Note that the real amount of bytes that can be put into the buffer is one less than its capacity. In most cases there is no need for this method to be called as the growth happens transparently when necessary.

Parameters

newCapacity

New capacity of the buffer.