WriteBackCache< K, T > Class Template Reference

An abstract LRU cache implementation that tracks modifications to the cached items and performs writes of modified items to the cache source on demand. More...

#include <WriteBackCache.h++>

Public Member Functions
virtual	~WriteBackCache ()
	Destructor. More...
void	insert (K key, T *value)
	Inserts a key/value pair into the cache. More...
T *	lookup (K key)
	Looks up the value for a given key in the cache. More...
bool	remove (K key)
	Removes the value for a given key from the cache. More...
bool	sync ()
	Synchronizes the cache contents with the cache source. More...
bool	flush ()
	Flushes the cache. More...
void	setDirty (K key, bool dirty)
	Sets the "dirty" flag for the value for a given key in the cache. More...
bool	isDirty (K key) const

Protected Member Functions
	WriteBackCache (int maxCapacity)
	Constructs a new WriteBackCache with the given maximum capacity. More...
virtual void	write (const T *value)=0
	Writes a cached value to the cache source. More...

Detailed Description

template<typename K, class T>
class quark::util::WriteBackCache< K, T >

An abstract LRU cache implementation that tracks modifications to the cached items and performs writes of modified items to the cache source on demand.

Subclasses must provide a suitable public constructor and implement the write() method. The cache takes ownership of its values.

Template Parameters

K	The type of the cache's keys.
V	The type of the cache's values.

Author

Mark Lindner

Constructor & Destructor Documentation

~WriteBackCache()

virtual ~WriteBackCache ( )

virtual

Destructor.

WriteBackCache()

WriteBackCache ( int  maxCapacity )

protected

Constructs a new WriteBackCache with the given maximum capacity.

Member Function Documentation

flush()

bool flush

(

)

Flushes the cache.

Any values that are marked "dirty" will be written to the cache source via a call to write(). Then the cache will be cleared and all of its values explicitly deleted.

Returns

true if any writes occurred, false otherwise.

insert()

void insert	(	K	key,
		T *	value
	)

Inserts a key/value pair into the cache.

Parameters

key	The key.
value	The value.

isDirty()

bool isDirty

(

K

key

)

const

Parameters

key

The key.

Returns

true if the value is dirty, false otherwise.

lookup()

T* lookup

(

K

key

)

Looks up the value for a given key in the cache.

Parameters

key

The key.

Returns

The value, if found, otherwise NULL.

remove()

bool remove

(

K

key

)

Removes the value for a given key from the cache.

Parameters

key

The key.

Returns

true if the value was removed, false if the cache does not contain a value with the specified key.

setDirty()

void setDirty	(	K	key,
		bool	dirty
	)

Sets the "dirty" flag for the value for a given key in the cache.

A "dirty" value is one that has been modified and needs to be written back to the cache source eventually.

Parameters

key	The key.
dirty	The dirty flag.

sync()

bool sync

(

)

Synchronizes the cache contents with the cache source.

Any values that are marked "dirty" will be written to the cache source via a call to write(), and will then have their "dirty" flag cleared.

Returns

true if any writes occurred, false otherwise.

write()

virtual void write ( const T *  value )

protectedpure virtual

Writes a cached value to the cache source.

Parameters

value

The value to write.

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

• WriteBackCache.h++