TSmartBuffer Class Reference

Holds a char buffer and manages its memory. More...

#include <TSmartBuffer.h>

Public Member Functions
	TSmartBuffer ()
	Constructs an empty TSmartBuffer.
	TSmartBuffer (char *buffer, size_t size)
	Constructs a TSmartBuffer from a C-style array.
	~TSmartBuffer ()
	Destructs the TSmartBuffer, free-ing the array, if necessary.
	TSmartBuffer (const TSmartBuffer &other)
	Copy constructor.
TSmartBuffer &	operator= (TSmartBuffer other)
	Assignment operator.
	TSmartBuffer (TSmartBuffer &&other)
	Move constructor.
void	Clear ()
	Clears the object.
void	SetBuffer (char *buffer, size_t size)
	Sets the current buffer.
const char *	GetData () const
	Returns the data pointer.
size_t	GetSize () const
	Returns the size of the array.
TSmartBuffer	BufferSubset (size_t pos, size_t length=-1) const
	Returns a subset of the current array.
void	Advance (size_t dist)
	Advances the pointer by the amount given.
void	Print (Option_t *opt="") const
	Prints a short description of the TSmartBuffer.

Private Member Functions
void	swap (TSmartBuffer &other)
	Swaps the contents of two TSmartBuffers.
	ClassDef (TSmartBuffer, 0)

Private Attributes
char *	fAllocatedLocation
	The pointer that was allocated by malloc().
char *	fData
	The pointer to the current data.
size_t	fSize
	The size of the current subset of the data.
std::atomic_int *	fReferenceCount
	The location of the reference count.

Detailed Description

Holds a char buffer and manages its memory.

TSmartBuffer holds a char buffer, and deletes it at the appropriate time. This is done in a threadsafe manner. Subsets of the buffer can be made without copying the underlying C-style array. The underlying C-style array will be free'd only when no references to the buffer, nor to subsets of the buffer, exist.

TSmartBuffer is intended to be lightweight, and cheap to pass by value.

Constructor & Destructor Documentation

TSmartBuffer::TSmartBuffer

(

)

Constructs an empty TSmartBuffer.

The data pointer will be set to NULL The size will be equal to zero.

TSmartBuffer::TSmartBuffer	(	char *	buffer,
		size_t	size
	)

Constructs a TSmartBuffer from a C-style array.

The buffer must have been allocated using malloc. The buffer must not be managed by another TSmartBuffer. Once constructed, the buffer belongs to the object, which will call free() on it accordingly.

TSmartBuffer::~TSmartBuffer

(

)

Destructs the TSmartBuffer, free-ing the array, if necessary.

The TSmartBuffer will call free() on the underlying C-style array if it is the last reference to that array.

TSmartBuffer::TSmartBuffer

(

const TSmartBuffer &

other

)

Copy constructor.

TSmartBuffer::TSmartBuffer

(

TSmartBuffer &&

other

)

Move constructor.

Member Function Documentation

void TSmartBuffer::Advance

(

size_t

dist

)

Advances the pointer by the amount given.

Parameters

dist	The distance by which the pointer should be advanced.

If the buffer cannot be advanced that far, the pointer will be advanced to the end of the buffer.

TSmartBuffer TSmartBuffer::BufferSubset	(	size_t	pos,
		size_t	length = -1
	)		const

Returns a subset of the current array.

Parameters

pos	The position of the start of the subset of the buffer. Should range from 0 to GetSize()-1.
length	The length of the subset of the buffer. If equal to -1, then the remainder of the buffer is used.

The object returned will point to a subset of the the existing buffer. The underlying array is not copied. free() will only be called on the underlying array once no references to the array or any of its subsets remain.

TSmartBuffer::ClassDef ( TSmartBuffer  , 0    )

private

void TSmartBuffer::Clear

(

)

Clears the object.

The object will be left in the same state as if it had just been constructed by TSmartBuffer(). This does not need to be called prior to the object begin destructed.

const char* TSmartBuffer::GetData ( ) const

inline

Returns the data pointer.

If the object does not currently hold a buffer, returns NULL. Otherwise, the result is the location of the data buffer. Reads from the location of GetData() to GetData()+GetSize()-1 are valid.

size_t TSmartBuffer::GetSize ( ) const

inline

Returns the size of the array.

The size returned is the size of the current buffer. This may not correspond to the size of the buffer passed in, depending on the use of BufferSubset.

TSmartBuffer & TSmartBuffer::operator=

(

TSmartBuffer

other

)

Assignment operator.

void TSmartBuffer::Print

(

Option_t *

opt = ""

)

const

Prints a short description of the TSmartBuffer.

void TSmartBuffer::SetBuffer	(	char *	buffer,
		size_t	size
	)

Sets the current buffer.

The object will be left in the same state as if it had just been constructed by TSmartBuffer(buffer, size).

void TSmartBuffer::swap ( TSmartBuffer &  other )

private

Swaps the contents of two TSmartBuffers.

For internal use only.

Member Data Documentation

char* TSmartBuffer::fAllocatedLocation

private

The pointer that was allocated by malloc().

free() will be called on this location only when the last reference to it is deleted. All buffer subsets share this value.

char* TSmartBuffer::fData

private

The pointer to the current data.

std::atomic_int* TSmartBuffer::fReferenceCount

private

The location of the reference count.

size_t TSmartBuffer::fSize

private

The size of the current subset of the data.

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

• include/TSmartBuffer.h
• libraries/TRawFormat/TSmartBuffer.cxx