XrdOucBuffPool Class Reference

#include <XrdOucBuffer.hh>

Collaboration diagram for XrdOucBuffPool:

Classes
struct	BuffSlot

Public Member Functions
XrdOucBuffer *	Alloc (int sz)
int	MaxSize () const
	XrdOucBuffPool (int minsz=4096, int maxsz=65536, int minh=1, int maxh=16, int rate=1)
	~XrdOucBuffPool ()

Private Attributes
BuffSlot *	bSlot
int	incBsz
int	shfBsz
int	rndBsz
int	maxBsz
int	slots

Static Private Attributes
static int	alignit

Friends
class	XrdOucBuffer

Detailed Description

These classes allow for buffer management to minimize data copying. They are typically used in conjunction with the XrdOucErrInfo class. The XrdOucBuffPool class defines a pool of buffers and one such object must exist for each buffer pool (there can be many such pools). This object manufactures XrdOucBuffer objects. You can also create XrdOucBuffers without using a buffer pool (i.e. one time buffers). See the XrdOucBuffer constructor for details on how to do this and the associated caveats.

Constructor & Destructor Documentation

XrdOucBuffPool()

XrdOucBuffPool::XrdOucBuffPool	(	int	minsz = 4096,
		int	maxsz = 65536,
		int	minh = 1,
		int	maxh = 16,
		int	rate = 1
	)

Constructor

Parameters

minsz	- the minimum size a buffer can have. If it is smaller than 1024 it is set to 1024. The minsz is also adjusted to be equal to the closest smaller value of 1024*(2**n) (i.e. 1K, 2k, 4K, etc). If it's greater than 16MB, it is set to 16MB.
maxsz	- the maximum size a buffer can have and must be >= minsz. If it's >minsz it is rounded up to the next minsz increment. Buffer sizes are always allocated in minsz increments.
minh	- the minimum number of buffers that should be held in reserve when a buffer is recycled.
maxh	- the maximum number of buffers that should be held in reserve when a buffer is recycled. The value applies to the smallest buffer size and is progessively reduced as the buffer size increases. If maxh < minh it is set to minh.
rate	- specifies how quickly the hold vale is to be reduced as buffer sizes increase. A rate of 0 specifies a purely linear decrease. Higher values logrithmically decrease the hold.

~XrdOucBuffPool()

XrdOucBuffPool::~XrdOucBuffPool ( )

inline

Destructor - You must not destroy this object prior to recycling all oustanding buffers allocated out of this pool.

References bSlot.

Member Function Documentation

Alloc()

XrdOucBuffer * XrdOucBuffPool::Alloc

(

int

sz

)

Allocate a buffer object.

Parameters

sz	- the desired size. It os rounded up to be a multiple of incBsz but cannot exceed maxBsz.

Returns

!0 - pointer to usable buffer object of suitable size.

=0 - insufficient memort ro allocate a buffer.

MaxSize()

int XrdOucBuffPool::MaxSize ( ) const

inline

Obtain the maximum size a buffer can have.

Returns

The maximum size a buffer can be.

References maxBsz.

Friends And Related Symbol Documentation

XrdOucBuffer

friend class XrdOucBuffer

friend

Member Data Documentation

alignit

int XrdOucBuffPool::alignit

staticprivate

bSlot

BuffSlot* XrdOucBuffPool::bSlot

private

Referenced by XrdOucBuffer::Recycle(), and ~XrdOucBuffPool().

incBsz

int XrdOucBuffPool::incBsz

private

maxBsz

int XrdOucBuffPool::maxBsz

private

Referenced by MaxSize().

rndBsz

int XrdOucBuffPool::rndBsz

private

shfBsz

int XrdOucBuffPool::shfBsz

private

slots

int XrdOucBuffPool::slots

private

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

• XrdOucBuffer.hh