Instances of this class provide a simple cache between an application or filesystem (or other) driver. More...

#include <core/DspStorageCache.h>

Inheritance diagram for MityDSP::tcDspStorageCache:

Classes
struct	buf_list
	cache-list header structure More...

Public Member Functions
	tcDspStorageCache (tcDspStorageBase *apDevice, unsigned int anNumSectors)
	This constructor is used to create a read/write cache of the specified number of sectors for a tcDspStorageBase-derived class instance.
	~tcDspStorageCache ()
	Default destructor.
virtual void	reset (void)
	This routine resets all cache entries, without flushing any dirty entries.
virtual int	write (void apAddr, void apData, int anBytes)
	This routine writes an arbitrary amount of data to an MMC device at a specified offset from the start of the device.
virtual int	write (unsigned int anSector, unsigned int anOffset, void *apData, int anBytes)
	Sector-based version of the write method.
virtual int	read (void apStartAddr, void apBuffer, int anBytes)
	This routine reads an arbitrary amount of data from an MMC device from the specified offset position.
virtual int	read (unsigned int anSector, unsigned int anOffset, void *apBuffer, int anBytes)
	Sector-based version of the read method.
Public Member Functions inherited from MityDSP::tcDspStorageBase
	tcDspStorageBase ()
	This constructor is used to initialize storage base class.
virtual	~tcDspStorageBase ()
	Default Destructor.
virtual bool	erase (unsigned int anSector)
	This routine provides a default erase method.
virtual void	registerISRCallback (tfIsrCallback afCallback, void *apUserArg)
	This method is used to register a callback that is activated whenever the device changes state.
virtual void *	getAddress (unsigned int anSector, unsigned int anOffset)
	This routine uses the device's sector map to compute an offset address from a supplied sector and offset.
virtual unsigned int	getSize (unsigned int anSector)
	This routine uses the device's sector map to determine the size of the specified sector.
virtual unsigned int	getSector (void *apAddr)
	This routine uses the device's sector map to compute a sector from a from a supplied offset address.
virtual double	getDeviceSizeKB (void)
	This routine returns the size of the device in kilobytes.
const tsSectorMap *	getMap (int &anNumSectors)
	This routine returns a pointer to access the device's sector map.
virtual bool	getMediaPresent ()

Protected Types
typedef struct MityDSP::tcDspStorageCache::buf_list	tsBufferList
	cache-list header structure

Protected Member Functions
void	resetDeviceInfo (void)
	This routine reads sector map information from the underlying device and creates copies of the map and the required cache buffers to match.
tsBufferList *	getCacheSector (unsigned int anSector, unsigned int anExpectedSize, bool abLoad)
	This method checks the current cache for the sector in question.
tsBufferList *	flushCacheSector (tsBufferList *anEntry)
	This method checks the specified cache entry to see if it's "dirty".

Protected Attributes
LCK_Handle	mhMutex
	Lock to serialize access.
BUF_Handle	mhSectorPool
	Pool of sector buffers.
BUF_Handle	mhSectorListPool
	Pool of cache list entries.
tcDspStorageBase *	mpDevice
	Access to the storage device to cache.
unsigned int	mnCacheSectors
	Maximum sectors in cache.
unsigned int	mnMaxSectorSize
	Largest sector size (bytes)
tsBufferList *	mpCacheHead
	Head of cache linked list.
bool	mbAnyDirty
	Set whenever any cache entries need to be flushed.
Protected Attributes inherited from MityDSP::tcDspStorageBase
unsigned int	mnNumSectors
	Number of sectors in this device.
double	mnDeviceSize
	Overall device size (in bytes)
tsSectorMap *	mpSectorInfo
	Map of sectors and sizes.
bool	mbMediaPresent
	True if device is loaded.
tfIsrCallback	mfIsrCallback
void *	mpUserArg
	User-supplied argument for ISR callback.

Additional Inherited Members
Public Types inherited from MityDSP::tcDspStorageBase
typedef void(*	tfIsrCallback )(bool, void *)
	prototype for the ISR callback
Static Public Member Functions inherited from MityDSP::tcDspStorageBase
static int	readDispatch (unsigned int anSector, unsigned int anOffset, char apBuffer, unsigned int anLength, void apInstance)
	Static dispatch routine to allow the read method to be registered as a callback.
static int	writeDispatch (unsigned int anSector, unsigned int anOffset, char apData, unsigned int anBytes, void apInstance)
	Static dispatch routine to allow the write method to be registered as a callback.
Public Attributes inherited from MityDSP::tcDspStorageBase
unsigned int	mnTxBytes
	Count of bytes written (debug)
unsigned int	mnRxBytes
	Count of bytes read (debug)

Detailed Description

Instances of this class provide a simple cache between an application or filesystem (or other) driver.

See also:: tcDspStorageCache Page

Member Typedef Documentation

typedef struct MityDSP::tcDspStorageCache::buf_list MityDSP::tcDspStorageCache::tsBufferList

protected

cache-list header structure

Constructor & Destructor Documentation

tcDspStorageCache::tcDspStorageCache	(	tcDspStorageBase *	apDevice,
		unsigned int	anNumSectors
	)

This constructor is used to create a read/write cache of the specified number of sectors for a tcDspStorageBase-derived class instance.

Parameters:

[in]	apDevice	Pointer to the underlying tcDspStorageBase device.
[in]	anNumSectors	Maximum number of sectors to cache.

Returns:: None.

See also:: DspStorageCache.h

tcDspStorageCache::~tcDspStorageCache ( )

Default destructor.

Returns:: None.

See also:: DspStorageCache.h

Member Function Documentation

void tcDspStorageCache::reset ( void )

virtual

This routine resets all cache entries, without flushing any dirty entries.

This is necessary when a removable device is removed, and subsequently reinserted (with unknown changes made in the mean time).

Writing out dirty cache entries in this case would be bad... a flush should have been done prior to removal by the application.

Returns:: None.

See also:: DspStorageCache.h

int tcDspStorageCache::write	(	void *	apAddr,
		void *	apData,
		int	anBytes
	)

virtual

This routine writes an arbitrary amount of data to an MMC device at a specified offset from the start of the device.

The routine handles preservation of data when only a partial sector is written. The data does not have to be sector aligned, although writing aligned, full sectors is most efficient.

Parameters:

[in]	apAddr	Pointer to the offset position on the MMC device.
[in]	apData	A buffer containing the data to be written.
[in]	anBytes	Size of the data to be written in bytes.

Returns:: The number of bytes successfully written.

See also:: DspStorageCache.h

Implements MityDSP::tcDspStorageBase.

int tcDspStorageCache::write	(	unsigned int	anSector,
		unsigned int	anOffset,
		void *	apData,
		int	anBytes
	)

virtual

Sector-based version of the write method.

Note:: A request to write sector 0xFFFFFFFF is taken to be a request to flush all dirty cache entries.

Parameters:

[in]	anSector	The sector to write to.
[in]	anOffset	The offset from the start of the sector.
[in]	apData	A buffer containing the data to be written.
[in]	anBytes	Size of the data to be written in bytes.

Returns:: The number of bytes successfully written.

See also:: DspStorageCache.h

Implements MityDSP::tcDspStorageBase.

int tcDspStorageCache::read	(	void *	apStartAddr,
		void *	apBuffer,
		int	anBytes
	)

virtual

This routine reads an arbitrary amount of data from an MMC device from the specified offset position.

Results of the read are stored in apBuffer.

Parameters:

[in]	apStartAddr	Pointer to the data offset on the MMC device.
[out]	apBuffer	A buffer to hold the data that is read.
[in]	anBytes	Size of the data to be read in bytes.

Returns:: The number of bytes successfully read.

See also:: DspStorageCache.h

Implements MityDSP::tcDspStorageBase.

int tcDspStorageCache::read	(	unsigned int	anSector,
		unsigned int	anOffset,
		void *	apBuffer,
		int	anBytes
	)

virtual

Sector-based version of the read method.

Parameters:

[in]	anSector	The sector to copy from.
[in]	anOffset	The offset from the start of the sector.
[out]	apBuffer	A buffer to hold the data that is read.
[in]	anBytes	Size of the data to be read in bytes.

Returns:: The number of bytes successfully read.

See also:: DspStorageCache.h

Implements MityDSP::tcDspStorageBase.

void tcDspStorageCache::resetDeviceInfo ( void )

protected

This routine reads sector map information from the underlying device and creates copies of the map and the required cache buffers to match.

Any outstanding cache buffer should be freed prior to this call.

Returns:: None

See also:: DspStorageCache.h

tcDspStorageCache::tsBufferList * tcDspStorageCache::getCacheSector	(	unsigned int	anSector,
		unsigned int	anExpectedSize,
		bool	abLoad
	)

protected

This method checks the current cache for the sector in question.

If not found, the sector is loaded (flushing the oldest entry, if necessary). A pointer to the cache entry is returned.

In either case, the sector is moved to the front of the cache list.

Parameters:

[in]	anSector	The sector to load or retrieve from cache
[in]	anExpectedSize	The expected sector size
[in]	abLoad	If false, the entire sector is about to be written, so don't load it from the underlying device.

Returns:: Pointer to the cache entry.

See also:: DspStorageCache.h

tcDspStorageCache::tsBufferList * tcDspStorageCache::flushCacheSector ( tsBufferList * anEntry )

protected

This method checks the specified cache entry to see if it's "dirty".

If so, it is written out to the underlying device and marked clean.

Parameters:

[in] anEntry The cache entry to write back to the underlying device.

Returns:: The next cache entry in the list.

See also:: DspStorageCache.h

Member Data Documentation

LCK_Handle MityDSP::tcDspStorageCache::mhMutex

protected

Lock to serialize access.

BUF_Handle MityDSP::tcDspStorageCache::mhSectorPool

protected

Pool of sector buffers.

BUF_Handle MityDSP::tcDspStorageCache::mhSectorListPool

protected

Pool of cache list entries.

tcDspStorageBase* MityDSP::tcDspStorageCache::mpDevice

protected

Access to the storage device to cache.

unsigned int MityDSP::tcDspStorageCache::mnCacheSectors

protected

Maximum sectors in cache.

unsigned int MityDSP::tcDspStorageCache::mnMaxSectorSize

protected

Largest sector size (bytes)

tsBufferList* MityDSP::tcDspStorageCache::mpCacheHead

protected

Head of cache linked list.

bool MityDSP::tcDspStorageCache::mbAnyDirty

protected

Set whenever any cache entries need to be flushed.

Classes

Public Member Functions

Protected Types

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation