Critical to the functioning of CacheLayer--makes decisions which pieces of data to keep and which to throw out. More...

#include <CachePolicy.hpp>

Inheritance diagram for Sirikata::Transfer::CachePolicy:

Collaboration diagram for Sirikata::Transfer::CachePolicy:

Classes
struct	Data
Public Member Functions
	CachePolicy (cache_usize_type allocatedSpace, float maxSizePct)
virtual	~CachePolicy ()
	Virtual destructor since children will allocate class members.
virtual void	use (const Fingerprint &id, Data *data, cache_usize_type size)=0
	Marks the entry as used.
virtual void	useAndUpdate (const Fingerprint &id, Data *data, cache_usize_type oldsize, cache_usize_type newsize)=0
	Marks the entry as used, and update the space usage.
virtual void	destroy (const Fingerprint &id, Data *data, cache_usize_type size)=0
	Deletes the opaque data (and anything other corresponding info)
virtual Data *	create (const Fingerprint &id, cache_usize_type size)=0
	Allocates opaque data (and anything other corresponding info) At this point, the allocation must not fail.
virtual bool	cachable (cache_usize_type requiredSpace)
	Allocates a certain number of bytes for use in a new cache entry.
virtual bool	nextItem (cache_usize_type requiredSpace, Fingerprint &myprint)=0
Protected Member Functions
void	updateSpace (cache_usize_type oldsize, cache_usize_type newsize)
Protected Attributes
cache_usize_type	mTotalSize
float	mMaxSizePct
cache_ssize_type	mFreeSpace

Detailed Description

Critical to the functioning of CacheLayer--makes decisions which pieces of data to keep and which to throw out.

Constructor & Destructor Documentation

Sirikata::Transfer::CachePolicy::CachePolicy	(	cache_usize_type	allocatedSpace,
		float	maxSizePct
	)		`[inline]`

virtual Sirikata::Transfer::CachePolicy::~CachePolicy ( ) [inline, virtual]

Virtual destructor since children will allocate class members.

Member Function Documentation

virtual bool Sirikata::Transfer::CachePolicy::cachable ( cache_usize_type requiredSpace ) [inline, virtual]

Allocates a certain number of bytes for use in a new cache entry.

Parameters:

requiredSpace the amount of space this single entry needs

Returns:: whether the space could be allocated

References Sirikata::Logging::insane, mFreeSpace, mMaxSizePct, mTotalSize, and SILOG.

Referenced by Sirikata::Transfer::CacheMap::alloc().

virtual Data* Sirikata::Transfer::CachePolicy::create	(	const Fingerprint &	id,
		cache_usize_type	size
	)		`[pure virtual]`

Allocates opaque data (and anything other corresponding info) At this point, the allocation must not fail.

It is up to the CacheLayer to respect the decision from allocateSpace().

Parameters:

id	The FileId corresponding to the data.
size	The amount of space allocated (should be the same as was earlier passed to allocateSpace).

Returns:: The corresponding opaque data.

Implemented in Sirikata::Transfer::LRUPolicy.

Referenced by Sirikata::Transfer::CacheMap::write_iterator::insert().

virtual void Sirikata::Transfer::CachePolicy::destroy	(	const Fingerprint &	id,
		Data *	data,
		cache_usize_type	size
	)		`[pure virtual]`

Deletes the opaque data (and anything other corresponding info)

Parameters:

id	The FileId corresponding to the data.
data	The opaque data corresponding to this policy.
size	The size of the file data.

Implemented in Sirikata::Transfer::LRUPolicy.

Referenced by Sirikata::Transfer::CacheMap::write_iterator::erase(), and Sirikata::Transfer::CacheMap::write_iterator::eraseAll().

virtual bool Sirikata::Transfer::CachePolicy::nextItem	(	cache_usize_type	requiredSpace,
		Fingerprint &	myprint
	)		`[pure virtual]`

Implemented in Sirikata::Transfer::LRUPolicy.

Referenced by Sirikata::Transfer::CacheMap::alloc().

void Sirikata::Transfer::CachePolicy::updateSpace	(	cache_usize_type	oldsize,
		cache_usize_type	newsize
	)		`[inline, protected]`

References Sirikata::Logging::insane, mFreeSpace, and SILOG.

Referenced by Sirikata::Transfer::LRUPolicy::create(), Sirikata::Transfer::LRUPolicy::destroy(), and Sirikata::Transfer::LRUPolicy::useAndUpdate().

virtual void Sirikata::Transfer::CachePolicy::use	(	const Fingerprint &	id,
		Data *	data,
		cache_usize_type	size
	)		`[pure virtual]`

Marks the entry as used.

Parameters:

id	The FileId corresponding to the data.
data	The opaque data corresponding to this policy.
size	The size of the file data.

Implemented in Sirikata::Transfer::LRUPolicy.

Referenced by Sirikata::Transfer::CacheMap::write_iterator::use(), and Sirikata::Transfer::CacheMap::read_iterator::use().

virtual void Sirikata::Transfer::CachePolicy::useAndUpdate	(	const Fingerprint &	id,
		Data *	data,
		cache_usize_type	oldsize,
		cache_usize_type	newsize
	)		`[pure virtual]`

Marks the entry as used, and update the space usage.

Parameters:

id	The FileId corresponding to the data.
data	The opaque data corresponding to this policy.
oldsize	The previous size of the data.
newsize	The new size of the data.

Implemented in Sirikata::Transfer::LRUPolicy.

Referenced by Sirikata::Transfer::CacheMap::write_iterator::update().